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Adamcik J, Berquand A and Mezzenga R (2011), "Single-step direct measurement of amyloid fibrils stiffness by peak force quantitative nanomechanical atomic force microscopy", Applied Physics Letters. Vol. 98(19), pp. 193701. AIP.
BibTeX:
@article{Adamcik2011,
  author = {Adamcik, Jozef and Berquand, Alexandre and Mezzenga, Raffaele},
  title = {Single-step direct measurement of amyloid fibrils stiffness by peak force quantitative nanomechanical atomic force microscopy},
  journal = {Applied Physics Letters},
  publisher = {AIP},
  year = {2011},
  volume = {98},
  number = {19},
  pages = {193701},
  url = {http://link.aip.org/link/?APL/98/193701/1},
  doi = {10.1063/1.3589369}
}
Adamcik J, Lara C, Usov I, Jeong JS, Ruggeri FS, Dietler G, Lashuel H, Hamley I and Mezzenga R (2012), "Measurement of intrinsic properties of amyloid fibrils by peak force QNM method", Nanoscale. Vol. 4(15), pp. 4426-9. The Royal Society of Chemistry.
Abstract: We report the investigation of the mechanical properties of different types of amyloid fibrils by the peak force quantitative nanomechanical (PF-QNM) technique. We demonstrate that this technique correctly measures the Youngs modulus independent of the polymorphic state and the cross-sectional structural details of the fibrils, and we show that values for amyloid fibrils assembled from heptapeptides, a-synuclein, Ab(142), insulin, b-lactoglobulin,lysozyme, ovalbumin, Tau protein and bovine serum albumin all fall in the range of 24 GPa.
BibTeX:
@article{Adamcik2012a,
  author = {Adamcik, Jozef and Lara, Cecile and Usov, Ivan and Jeong, Jae Sun and Ruggeri, Francesco Simone and Dietler, Giovanni and Lashuel, Hilal and Hamley, Ian and Mezzenga, Raffaele},
  title = {Measurement of intrinsic properties of amyloid fibrils by peak force QNM method},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2012},
  volume = {4},
  number = {15},
  pages = {4426--9},
  url = {http://pubs.rsc.org/en/content/articlehtml/2012/nr/c2nr30768e},
  doi = {10.1039/c2nr30768e}
}
Adamcik J and Mezzenga R (2012), "Study of amyloid fibrils via atomic force microscopy", Current Opinion in Colloid & Interface Science., August, 2012. , pp. 1-8. Elsevier Ltd.
Abstract: Protein fibrils are a crucial subject of study in various research fields and disciplines. Amyloid fibrils are highly ordered fibrillar structures assembled from either peptides or unfolded proteins, which have a great importance in biology, medicine and recently have started to find an important role in many nanotechnology applications. Understanding the mechanisms of fibrillation, the structural features, the physical and mechanical properties of these fibrils is an essential step to both unraveling their biological role and also their successful applications in nanotechnology and material science. Atomic force microscopy (AFM) is one of the most widely used single-molecule techniques to study the properties of amyloid fibrils. In this review we will discuss how the application of AFM during last few years has allowed moving considerably forward in the research of amyloid fibrils. We will review how AFM has rapidly evolved from a purely microscopic technique, providing important information about fibrils structure and fibrillation processes, to a tool capable to probe also intrinsic properties of amyloid fibrils such as their strength and Young's moduli.
BibTeX:
@article{Adamcik2012,
  author = {Adamcik, Jozef and Mezzenga, Raffaele},
  title = {Study of amyloid fibrils via atomic force microscopy},
  journal = {Current Opinion in Colloid & Interface Science},
  publisher = {Elsevier Ltd},
  year = {2012},
  pages = {1--8},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S1359029412000957 http://dx.doi.org/10.1016/j.cocis.2012.08.001},
  doi = {10.1016/j.cocis.2012.08.001}
}
Adams PG, Cadby AJ, Robinson B, Tsukatani Y, Tank M, Wen J, Blankenship RE, Bryant DA and Hunter CN (2013), "Comparison of the physical characteristics of chlorosomes from three different phyla of green phototrophic bacteria.", Biochimica et Biophysica Acta., July, 2013. Vol. 1827(10), pp. 1235-44. Elsevier B.V..
Abstract: Chlorosomes, the major antenna complexes in green sulphur bacteria, filamentous anoxygenic phototrophs, and phototrophic acidobacteria, are attached to the cytoplasmic side of the inner cell membrane and contain thousands of bacteriochlorophyll (BChl) molecules that harvest light and channel the energy to membrane-bound reaction centres. Chlorosomes from phototrophs representing three different phyla, Chloroflexus (Cfx.) aurantiacus, Chlorobaculum (Cba.) tepidum and the newly discovered "Candidatus (Ca.) Chloracidobacterium (Cab.) thermophilum" were analysed using PeakForce Tapping atomic force microscopy (PFT-AFM). Gentle PFT-AFM imaging in buffered solutions that maintained the chlorosomes in a near-native state revealed ellipsoids of variable size, with surface bumps and undulations that differ between individual chlorosomes. Cba. tepidum chlorosomes were the largest (133×57×36nm; 141,000nm(3) volume), compared with chlorosomes from Cfx. aurantiacus (120×44×30nm; 84,000nm(3)) and "Ca. Cab. thermophilum" (99×40×31nm; 65,000nm(3)). Reflecting the contributions of thousands of pigment-pigment stacking interactions to the stability of these supramolecular assemblies, analysis by nanomechanical mapping shows that chlorosomes are highly stable and that their integrity is disrupted only by very strong forces of 1000-2000pN. AFM topographs of "Ca. Cab. thermophilum" chlorosomes that had retained their attachment to the cytoplasmic membrane showed that this membrane dynamically changes shape and is composed of protrusions of up to 30nm wide and 6nm above the mica support, possibly representing different protein domains. Spectral imaging revealed significant heterogeneity in the fluorescence emission of individual chlorosomes, likely reflecting the variations in BChl c homolog composition and internal arrangements of the stacked BChls within each chlorosome.
BibTeX:
@article{Adams2013,
  author = {Adams, Peter G. and Cadby, Ashley J. and Robinson, Benjamin and Tsukatani, Yusuke and Tank, Marcus and Wen, Jianzhong and Blankenship, Robert E. and Bryant, Donald A. and Hunter, C. Neil},
  title = {Comparison of the physical characteristics of chlorosomes from three different phyla of green phototrophic bacteria.},
  journal = {Biochimica et Biophysica Acta},
  publisher = {Elsevier B.V.},
  year = {2013},
  volume = {1827},
  number = {10},
  pages = {1235--44},
  url = {http://dx.doi.org/10.1016/j.bbabio.2013.07.004},
  doi = {10.1016/j.bbabio.2013.07.004}
}
Agapov RL, Robbins J, Thomas R, Hardman DL and Foster MD (2013), "The effect of fluorosurfactant, copolymer latex, and cross-linker on the surface properties of floor polishes: An investigation using AFM with adhesion mapping", Progress in Organic Coatings., April, 2013. Vol. null(null)
BibTeX:
@article{Agapov2013,
  author = {Agapov, Rebecca L. and Robbins, James and Thomas, Richard and Hardman, Dave L. and Foster, Mark D.},
  title = {The effect of fluorosurfactant, copolymer latex, and cross-linker on the surface properties of floor polishes: An investigation using AFM with adhesion mapping},
  journal = {Progress in Organic Coatings},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.porgcoat.2013.03.020},
  doi = {10.1016/j.porgcoat.2013.03.020}
}
Allhusen JS and Conboy JC (2013), "Preparation and characterization of conductive and transparent ruthenium dioxide sol-gel films.", ACS applied materials & interfaces., November, 2013. Vol. 5(22), pp. 11683-91. American Chemical Society.
Abstract: RuO2 conductive thin films were synthesized using the sol-gel method and deposited onto transparent insulating substrates. The optical transmission, film thickness, surface morphology and composition, resistivity, and spectroelectrochemical performance have been characterized. The optical transmission values of these films ranged from 70 to 89% in the visible region and from 56 to 88% in the infrared region. Resistivity values of the RuO2 sol-gel films varied from 1.02 × 10(-3) to 1.13 $ cm and are highly dependent on the initial solution concentration of RuO2 in the sol-gel. The RuO2 sol-gel films were used as electrodes for the electrochemical oxidation and reduction of ferrocenemethanol. The electrochemical behavior of our novel RuO2 sol-gel films was compared to that of a standard platinum disk electrode and showed no appreciable differences in the half-wave potential (E1/2). The mechanical and chemical stability of the coatings was tested by physical abrasion and exposure to highly acidic, oxidizing Piranha solution. Repeated exposure to these extreme conditions did not result in any appreciable decline in electrochemical performance. Finally, the use of the novel RuO2 sol-gel conductive and transparent films was demonstrated in a spectroelectrochemistry experiment in which the oxidation and reduction of ferrocenemethanol was monitored via UV-vis spectroscopy as the applied potential was cycled.
BibTeX:
@article{Allhusen2013,
  author = {Allhusen, John S and Conboy, John C},
  title = {Preparation and characterization of conductive and transparent ruthenium dioxide sol-gel films.},
  journal = {ACS applied materials & interfaces},
  publisher = {American Chemical Society},
  year = {2013},
  volume = {5},
  number = {22},
  pages = {11683--91},
  url = {http://pubs.acs.org/doi/abs/10.1021/am403219p},
  doi = {10.1021/am403219p}
}
Alsteens D, Dupres V, Yunus S, Latgé J-P, Heinisch JJ and Dufrêne YF (2012), "High-resolution imaging of chemical and biological sites on living cells using peak force tapping atomic force microscopy", Langmuir : the ACS journal of surfaces and colloids., December, 2012. Vol. 28(49), pp. 16738-44. American Chemical Society.
Abstract: Currently, there is a growing need for methods that can quantify and map the molecular interactions of biological samples, both with high-force sensitivity and high spatial resolution. Force-volume imaging is a valuable atomic force microscopy (AFM) modality for probing specific sites on biosurfaces. However, the low speed and poor spatial resolution of this method have severely hampered its widespread use in life science research. We use a novel AFM mode (i.e., peak force tapping with chemically functionalized tips) to probe the localization and interactions of chemical and biological sites on living cells at high speed and high resolution (8 min for 1 $m × 1 $m images at 512 pixels × 512 pixels). First, we demonstrate the ability of the method to quantify and image hydrophobic forces on organic surfaces and on microbial pathogens. Next, we detect single sensor proteins on yeast cells, and we unravel their mechanical properties in relation to cellular function. Owing to its key capabilities (quantitative mapping, resolution of a few nanometers, and true correlation with topography), this novel biochemically sensitive imaging technique is a powerful complement to other advanced AFM modes for quantitative, high-resolution bioimaging.
BibTeX:
@article{Alsteens2012,
  author = {Alsteens, David and Dupres, Vincent and Yunus, Sami and Latgé, Jean-Paul and Heinisch, Jürgen J. and Dufrêne, Yves F.},
  title = {High-resolution imaging of chemical and biological sites on living cells using peak force tapping atomic force microscopy},
  journal = {Langmuir : the ACS journal of surfaces and colloids},
  publisher = {American Chemical Society},
  year = {2012},
  volume = {28},
  number = {49},
  pages = {16738--44},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23198968 http://dx.doi.org/10.1021/la303891j},
  doi = {10.1021/la303891j}
}
Alsteens D, Trabelsi H, Soumillion P and Dufrêne YF (2013), "Multiparametric atomic force microscopy imaging of single bacteriophages extruding from living bacteria", Nature Communications., December, 2013. Vol. 4 Nature Publishing Group.
BibTeX:
@article{Alsteens2013,
  author = {Alsteens, David and Trabelsi, Heykel and Soumillion, Patrice and Dufrêne, Yves F.},
  title = {Multiparametric atomic force microscopy imaging of single bacteriophages extruding from living bacteria},
  journal = {Nature Communications},
  publisher = {Nature Publishing Group},
  year = {2013},
  volume = {4},
  url = {http://www.nature.com/ncomms/2013/131213/ncomms3926/full/ncomms3926.html http://www.nature.com/doifinder/10.1038/ncomms3926},
  doi = {10.1038/ncomms3926}
}
Anderson KD, Young SL, Jiang H, Jakubiak R, Bunning TJ, Naik RR and Tsukruk VV (2012), "Plasma-Enhanced Copolymerization of Amino Acid and Synthetic Monomers", Langmuir., January, 2012. Vol. 28(3), pp. 1833-45.
Abstract: In this paper we report the use of plasma-enhanced chemical vapor deposition (PECVD) for the simultaneous deposition and copolymerization of an amino acid with other organic and inorganic monomers. We investigate the fundamental effects of plasma-enhanced copolymerization on different material chemistries in stable ultrathin coatings of mixed composition with an amino acid component. This study serves to determine the feasibility of a direct, facile method for integrating biocompatible/active materials into robust polymerized coatings with the ability to plasma copolymerize a biological molecule (l-tyrosine) with different synthetic materials in a dry, one-step process to form ultrathin coatings of mixed composition. This process may lead to a method of interfacing biologic systems with synthetic materials as a way to enhance the biomaterial?tissue interface and preserve biological activity within composite films. In this paper we report the use of plasma-enhanced chemical vapor deposition (PECVD) for the simultaneous deposition and copolymerization of an amino acid with other organic and inorganic monomers. We investigate the fundamental effects of plasma-enhanced copolymerization on different material chemistries in stable ultrathin coatings of mixed composition with an amino acid component. This study serves to determine the feasibility of a direct, facile method for integrating biocompatible/active materials into robust polymerized coatings with the ability to plasma copolymerize a biological molecule (l-tyrosine) with different synthetic materials in a dry, one-step process to form ultrathin coatings of mixed composition. This process may lead to a method of interfacing biologic systems with synthetic materials as a way to enhance the biomaterial?tissue interface and preserve biological activity within composite films.
BibTeX:
@article{Anderson2011,
  author = {Anderson, Kyle D. and Young, Seth L. and Jiang, Hao and Jakubiak, Rachel and Bunning, Timothy J. and Naik, Rajesh R. and Tsukruk, Vladimir V.},
  title = {Plasma-Enhanced Copolymerization of Amino Acid and Synthetic Monomers},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {3},
  pages = {1833--45},
  url = {http://pubs.acs.org/doi/abs/10.1021/la204416h},
  doi = {10.1021/la204416h}
}
Anokhin DV, Lejnieks J, Mourran A, Zhu X, Keul H, Möller M, Konovalov O, Erina N and Ivanov Da (2012), "Interplay between H-bonding and alkyl-chain ordering in self-assembly of monodendritic L-alanine derivatives", ChemPhysChem., April, 2012. Vol. 13(6), pp. 1470-8.
Abstract: This paper reports on the synthesis and self-organizing properties of monodendrons consisting of L-alanine at the focal point and alkyl chains with different length at the periphery. The structures of thin films and monolayers are studied by temperature-resolved grazing-incidence X-ray diffraction and scanning force microscopy. The interplay between H-bonding and ordering of the alkyl chains results in a rich temperature-dependent phase behavior. The monodendrons form H-bonded stabilized clusters with the number of molecules depending on the length of the aliphatic chains and temperature. The clusters play the role of constitutive units in the subsequent self-assembly. Short alkyl chains allow the material to form thermodynamically stable crystalline phases. The molecules with longer side groups exhibit additional transitions from the crystalline phase to thermotropic columnar hexagonal or columnar rectangular liquid-crystalline phases. In monolayers deposited on highly ordered pyrolytic graphite, the materials show ordering similar to thin films. However, for the compound bearing hexadecyl chains the affinity of the alkyl groups to graphite dominates the self-assembly and thereby allows epitaxial growth of a 2D lattice with flat-on oriented molecules.
BibTeX:
@article{Anokhin2012,
  author = {Anokhin, Denis V and Lejnieks, J?nis and Mourran, Ahmed and Zhu, Xiaomin and Keul, Helmut and Möller, Martin and Konovalov, Oleg and Erina, Natalia and Ivanov, Dimitri a},
  title = {Interplay between H-bonding and alkyl-chain ordering in self-assembly of monodendritic L-alanine derivatives},
  journal = {ChemPhysChem},
  year = {2012},
  volume = {13},
  number = {6},
  pages = {1470--8},
  url = {http://onlinelibrary.wiley.com/doi/10.1002/cphc.201100739/abstract},
  doi = {10.1002/cphc.201100739}
}
Böttger R, Keller A, Bischoff L and Facsko S (2013), "Mapping the local elastic properties of nanostructured germanium surfaces: from nanoporous sponges to self-organized nanodots", Nanotechnology., March, 2013. Vol. 24(11), pp. 115702.
Abstract: Due to their reduced dimensions, the mechanical properties of nanostructures may differ substantially from those of bulk materials. Quantifying and understanding the nanomechanical properties of individual nanostructures is thus of tremendous importance both from a fundamental and a technological point of view. Here we employ a recently introduced atomic force microscopy mode, i.e., peak-force quantitative nanomechanical imaging, to map the local elastic properties of nanostructured germanium surfaces. This imaging mode allows the quantitative determination of the Young's modulus with nanometer resolution. Heavy-ion irradiation was used to fabricate different self-organized nanostructures on germanium surfaces. Depending on the sample temperature during irradiation, nanoporous sponge-like structures and hexagonally ordered nanodots are obtained. The sponge-like germanium surface is found to exhibit a surprisingly low Young's modulus well below 10 GPa, which furthermore depends on the ion energy. For the nanodot patterns, local variations in the Young's modulus are observed: at moderate sample temperatures, the dot crests have a lower modulus than the dot valley whereas this situation is reversed at high temperatures. These observations are explained by vacancy dynamics in the amorphous germanium matrix during irradiation. Our results furthermore offer the possibility to tune the local elastic properties of nanostructured germanium surfaces by adjusting the ion energy and sample temperature
BibTeX:
@article{Bottger2013,
  author = {Böttger, Roman and Keller, Adrian and Bischoff, Lothar and Facsko, Stefan},
  title = {Mapping the local elastic properties of nanostructured germanium surfaces: from nanoporous sponges to self-organized nanodots},
  journal = {Nanotechnology},
  year = {2013},
  volume = {24},
  number = {11},
  pages = {115702},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23449092 http://iopscience.iop.org/0957-4484/24/11/115702},
  doi = {10.1088/0957-4484/24/11/115702}
}
Ball V, Apaydin K, Laachachi A, Toniazzo V and Ruch D (2012), "Changes in Permeability and in Mechanical Properties of Layer-by-Layer Films Made from Poly(allylamine) and Montmorillonite Postmodified upon Reaction with Dopamine.", Biointerphases., December, 2012. Vol. 7(1-4), pp. 59.
Abstract: Polyelectrolyte multilayer (PEM) films present a versatile surface functionalization method allowing to address many applications. These coatings suffer; however, from weak mechanical properties this problem can be addressed by the regular incorporation of clays in the layering process. To allow for an even better control of a whole set of film properties, among them their thermal stability, their stability in water, and their impermeability to anions, we postmodify (PAH-MMT)(n) films with polydopamine, by putting the pristine PEM films in contact with an oxygenated dopamine solution. This straightforward treatment allows to totally suppress the diffusion of hexacyanoferrate anions in the films and affects significantly its mechanical properties even, if the distribution of polydopamine through the film thickness is not yet known.
BibTeX:
@article{Ball2012,
  author = {Ball, Vincent and Apaydin, Kadir and Laachachi, Abdelghani and Toniazzo, Valérie and Ruch, David},
  title = {Changes in Permeability and in Mechanical Properties of Layer-by-Layer Films Made from Poly(allylamine) and Montmorillonite Postmodified upon Reaction with Dopamine.},
  journal = {Biointerphases},
  year = {2012},
  volume = {7},
  number = {1-4},
  pages = {59},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23065829},
  doi = {10.1007/s13758-012-0059-1}
}
Barthelmess M and Bajt Sa (2011), "Thermal and stress studies of normal incidence Mo/B4C multilayers for a 6.7 nm wavelength", Appllied Optics. Vol. 50(11), pp. 1610-1619. OSA.
Abstract: Wavelength, reflectance, and stress stability of Mo=B4C multilayers were studied as a function of post- deposition annealing up to 900°C. These multilayers are of interest as normal incidence coatings for wavelengths above the boron K-absorption edge. Mo=B4C multilayers deposited at low sputtering pres- sure have high compressive stress. Zero stress can be achieved at 360°C–370°C, but annealing at <200°C is sufficient to reduce stress by period expansion of ∼ period remains stable up to ∼ 40 This stress relaxation is accompanied with a multilayer 0:02nm∼and a <0:5% decrease in normal incidence reflectivity. The multilayer 600°C, while intrinsic stress changes from compressive to tensile. A four-layer model with amorphous molybdenum and boron carbide layers separated by amorphous layers of molybdenum borides (MoxBy) is presented. These interlayers are present already in the as-deposited state and continue to grow with increasing temperature. Their presence lowers the optical contrast and the achievable reflectivity. However, they also increase multilayer thermal stability. At temperatures >600°C, a noticeable decrease in reflectivity associated with the phase transition from amorphous to crystalline molybdenum boride is observed. This is accompanied with an increase in in- terface and surface roughness and a change in stress as a function of temperature.
BibTeX:
@article{Barthelmess2011,
  author = {Barthelmess, Miriam and Bajt, Sa a},
  title = {Thermal and stress studies of normal incidence Mo/B4C multilayers for a 6.7 nm wavelength},
  journal = {Appllied Optics},
  publisher = {OSA},
  year = {2011},
  volume = {50},
  number = {11},
  pages = {1610--1619},
  url = {http://ao.osa.org/abstract.cfm?URI=ao-50-11-1610}
}
Baytekin HT, Baytekin B, Incorvati JT and Grzybowski BA (2012), "Material Transfer and Polarity Reversal in Contact Charging", Angewandte Chemie International Edition., March, 2012. Vol. 51, pp. 1-6.
BibTeX:
@article{Baytekin2012,
  author = {Baytekin, H. Tarik and Baytekin, Bilge and Incorvati, Jared T. and Grzybowski, Bartosz A.},
  title = {Material Transfer and Polarity Reversal in Contact Charging},
  journal = {Angewandte Chemie International Edition},
  year = {2012},
  volume = {51},
  pages = {1--6},
  url = {http://doi.wiley.com/10.1002/anie.201200057},
  doi = {10.1002/anie.201200057}
}
Beckford S and Zou M (2013), "Wear resistant PTFE thin film enabled by a polydopamine adhesive layer", Applied Surface Science.
Abstract: The influence of a polydopamine (PDA) adhesive layer on the friction and wear resistance of polytetrafluoroethylene (PTFE) thin films coated on stainless steel was investigated. The friction and wear tests were carried out using a ball on flat configuration under a normal load of 50g, sliding speed of 2.5mm/s, and stroke length of 15mm. It is found that the PDA/PTFE film is able to withstand approximately 500 times more rubbing cycles than the PTFE film alone. X-ray photoelectron spectroscopy (XPS) results show that a tenacious layer of PTFE remains adhered to the PDA layer, which enables the durability of the PDA/PTFE film. Because of the relatively low thickness of the film, PDA/PTFE shows great potential for use in applications where durable, thin films are desirable.
BibTeX:
@article{Beckford2013,
  author = {Beckford, Samuel and Zou, Min},
  title = {Wear resistant PTFE thin film enabled by a polydopamine adhesive layer},
  journal = {Applied Surface Science},
  year = {2013},
  url = {http://www.sciencedirect.com/science/article/pii/S0169433213022320}
}
Berquand A, Roduit C, Kasas S, Holloschi A, Ponce L and Hafner M (2010), "Atomic Force Microscopy Imaging of Living Cells", Microscopy Today. Vol. 18(06), pp. 8-14.
Abstract: Over the last two decades, Atomic Force Microscopy (AFM) has emerged as the tool of choice to image living organisms in a near-physiological environment. Whereas fluorescence microscopy techniques allow labeling and tracking of components inside cells and the observation of dynamic processes, AFM is mainly a surface technique that can be operated on a wide range of substrates including biological samples. AFM enables extraction of topographical, mechanical and chemical information from these samples.
BibTeX:
@article{Berquand2010,
  author = {Berquand, Alexandre and Roduit, Charles and Kasas, Sandor and Holloschi, Andreas and Ponce, Leslie and Hafner, Mathias},
  title = {Atomic Force Microscopy Imaging of Living Cells},
  journal = {Microscopy Today},
  year = {2010},
  volume = {18},
  number = {06},
  pages = {8--14},
  url = {http://dx.doi.org/10.1017/S1551929510000957},
  doi = {10.1017/S1551929510000957}
}
Bhaskar A, Deepa M, Rao TN and Varadaraju UV (2012), "Enhanced nanoscale conduction capability of a MoO 2/Graphene composite for high performance anodes in lithium ion batteries", Journal of Power Sources., October, 2012. Vol. 216, pp. 169-178. Elsevier B.V.
Abstract: A MoO2/Graphene composite as a high performance anode for Li ion batteries is synthesized by a one pot in-situ low temperature solution phase reduction method. Electron microscopy and Raman spectroscopy results confirm that 2D graphene layers entrap MoO2 nanoparticles homogeneously in the composite. X-ray photoelectron spectroscopy shows the presence of oxygen functionalities on graphene, which allows intimate contact between MoO2 nanoparticles and the graphene. Conductive atomic force microscopy reveals an extraordinarily high nanoscale electronic conductivity for MoO2/Graphene, greater by 8 orders of magnitude in comparison to bulk MoO2. The layered nanostructure and the conductive matrix provide uninhibited conducting pathways for fast charge transfer and transport between the oxide nanoparticles and graphene which are responsible for the high rate capability, a large lithium ion capacity of 770 mAh g−1, and an excellent cycling stability (550 mAh g−1 reversible capacity retained even after 1000 cycles!) at a current density of 540 mA g−1, thereby rendering it to be superior to previously reported values for neat MoO2 or MoO2/Graphene composite. Impedance analyses demonstrate a lowered interfacial resistance for the composite in comparison to neat MoO2. Our results demonstrate the enormous promise that MoO2/Graphene holds for practical Li-ion batteries
BibTeX:
@article{Bhaskar2012,
  author = {Bhaskar, Akkisetty and Deepa, Melepurath and Rao, T. N. and Varadaraju, U. V.},
  title = {Enhanced nanoscale conduction capability of a MoO 2/Graphene composite for high performance anodes in lithium ion batteries},
  journal = {Journal of Power Sources},
  publisher = {Elsevier B.V},
  year = {2012},
  volume = {216},
  pages = {169--178},
  url = {http://www.sciencedirect.com/science/article/pii/S0378775312009196},
  doi = {10.1016/j.jpowsour.2012.05.050}
}
Bitler A, Dover R and Shai Y (2012), "Fractal properties of macrophage membrane studied by AFM", Micron., May, 2012. Vol. 43(12), pp. 1239-1245. Elsevier Ltd.
Abstract: Complexity of cell membrane poses difficulties to quantify corresponding morphology changes during cell proliferation and damage. We suggest using fractal dimension of the cell membrane to quantify its complexity and track changes produced by various treatments. Glutaraldehyde fixed mouse RAW 264.7 macrophage membranes were chosen as model system and imaged in PeakForce QNM (quantitative nanomechanics) mode of AFM (atomic force microscope). The morphology of the membranes was characterized by fractal dimension. The parameter was calculated for set of AFM images by three different methods. The same calculations were done for the AFM images of macrophages treated with colchicine, an inhibitor of the microtubule polymerization, and microtubule stabilizing agent taxol. We conclude that fractal dimension can be additional and useful parameter to characterize the cell membrane complexity and track the morphology changes produced by different treatments.
BibTeX:
@article{Bitler2012,
  author = {Bitler, Arkadi and Dover, R. and Shai, Y.},
  title = {Fractal properties of macrophage membrane studied by AFM},
  journal = {Micron},
  publisher = {Elsevier Ltd},
  year = {2012},
  volume = {43},
  number = {12},
  pages = {1239--1245},
  url = {http://dx.doi.org/10.1016/j.micron.2012.04.009},
  doi = {10.1016/j.micron.2012.04.009}
}
Bočkutė K, Laukaitis G, Virbukas D and Milčius D (2013), "The Investigation of E-beam Deposited Titanium Dioxide and Calcium Titanate Thin Films", Materials Science (MEDŽIAGOTYRA). Vol. 19(3), pp. 2-6.
Abstract: Thin titanium dioxide and calcium titanate films were deposited using electron beam evaporation technique. The substrate temperature during the deposition was changed from room temperature to 600 °C to test its influence on TiO2 film formation and optical properties. The properties of CaTiO3 were investigated also. For the evaluation of the structural properties the formed thin ceramic films were studied by X-ray diffraction (XRD), energy dispersive spectrometry (EDS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Optical properties of thin TiO2 ceramics were investigated using optical spectroscope and the experimental data were collected in the ultraviolet-visible and near-infrared ranges with a step width of 1 nm. Electrical properties were investigated by impedance spectroscopy.It was found that substrate temperature has influence on the formed thin films density. The density increased when the substrate temperature increased. Substrate temperature had influence on the crystallographic, structural and optical properties also.
BibTeX:
@article{Bockute2013,
  author = {Bočkutė, Kristina and Laukaitis, Giedrius and Virbukas, Darius and Milčius, Darius},
  title = {The Investigation of E-beam Deposited Titanium Dioxide and Calcium Titanate Thin Films},
  journal = {Materials Science (MEDŽIAGOTYRA)},
  year = {2013},
  volume = {19},
  number = {3},
  pages = {2--6}
}
Bodvik R, Thormann E, Karlson L and Claesson PM (2011), "Temperature responsive surface layers of modified celluloses", Physical Chemistry Chemical Physics. Vol. 13(10), pp. 4260-8. The Royal Society of Chemistry.
Abstract: The temperature-dependent properties of pre-adsorbed layers of methylcellulose (MC) and hydroxypropylmethylcellulose (HPMC) were investigated on silica and hydrophobized silica surfaces. Three different techniques, quartz crystal microbalance with dissipation monitoring, ellipsometry, and atomic force microscopy imaging, were used, providing complementary and concise information on the structure, mass and viscoelastic properties of the polymer layer. Adsorption was conducted at 25 [degree]C, followed by a rinsing step. The properties of such pre-adsorbed layers were determined as a function of temperature in the range 25 [degree]C to 50 [degree]C. It was found that the layers became more compact with increasing temperature and that this effect was reversible, when decreasing the temperature. The compaction was more prominent for MC, as shown in the AFM images and in the thickness data derived from the QCM analysis. This is consistent with the fact that the phase transition temperature is lower, in the vicinity of 50 [degree]C, for MC than for HPMC. The water content of the adsorbed layers was found to be high, even at the highest temperature, 50 [degree]C, explored in this investigation.
BibTeX:
@article{Bodvik2011,
  author = {Bodvik, Rasmus and Thormann, Esben and Karlson, Leif and Claesson, Per M.},
  title = {Temperature responsive surface layers of modified celluloses},
  journal = {Physical Chemistry Chemical Physics},
  publisher = {The Royal Society of Chemistry},
  year = {2011},
  volume = {13},
  number = {10},
  pages = {4260--8},
  url = {http://dx.doi.org/10.1039/C0CP02074E}
}
Bodvik R, Thormann E, Karlson L and Claesson PM (2011), "Temperature-dependent adsorption of cellulose ethers on silica and hydrophobized silica immersed in aqueous polymer solution", RSC Advances. Vol. 1(2), pp. 305-314. The Royal Society of Chemistry.
Abstract: The influence of temperature on adsorption and the adsorbed layer properties of methylcellulose (MC) and hydroxypropylmethylcellulose (HPMC) were investigated on silica and hydrophobized silica surfaces immersed in aqueous polymer solution. To achieve a concise understanding a quartz crystal microbalance with dissipation, ellipsometry, and atomic force microscopy imaging were employed. These techniques provide complimentary information on the structure, mass and viscoelastic properties of the polymer layers. Adsorption was first allowed at 25 [degree]C. Next, the temperature was increased step-wise up to 50 [degree]C and then decreased again. This procedure highlights the temperature dependence of the adsorbed material, as well as the hysteresis in the adsorption due to temperature cycling. A change in temperature not only affects the adsorbed amount, but also the properties of the layer as illustrated by measurements of its water content, thickness and viscoelasticity.
BibTeX:
@article{Bodvik2011a,
  author = {Bodvik, Rasmus and Thormann, Esben and Karlson, Leif and Claesson, Per M.},
  title = {Temperature-dependent adsorption of cellulose ethers on silica and hydrophobized silica immersed in aqueous polymer solution},
  journal = {RSC Advances},
  publisher = {The Royal Society of Chemistry},
  year = {2011},
  volume = {1},
  number = {2},
  pages = {305--314},
  url = {http://dx.doi.org/10.1039/C1RA00235J}
}
Boye S, Appelhans D, Boyko V, Zschoche S, Komber H, Friedel P, Formanek P, Janke A, Voit BI and Lederer A (2012), "pH-triggered aggregate shape of different generations lysine-dendronized maleimide copolymers with maltose shell", Biomacromolecules., December, 2012. Vol. 13(12), pp. 4222-35.
Abstract: Glycopolymers are promising materials in the field of biomedical applications and in the fabrication of supramolecular structures with specific functions. For tunable design of supramolecular structures, glycopolymer architectures with specific properties (e.g., controlled self-assembly) are needed. Using the concept of dendronized polymers, a series of H-bond active giant glycomacromolecules with maleimide backbone and lysine dendrons of different generations were synthesized. They possess different macromolecular size and functionality along the backbone. Their peripheral maltose units lead to solubility under physiological conditions and controlled aggregation behavior. The aggregation behavior was investigated depending on generation number, pH value, and concentration. A portfolio of complementary analytical tools give an insight into the influence of the different parameters in shaping a rod-, coil-, and worm-like molecular structure and their controlled aggregate formation. MD simulation helped us to understand the complex aggregation behavior of the linear polymer chain without dendritic units.
BibTeX:
@article{Boye2012,
  author = {Boye, S and Appelhans, D and Boyko, V and Zschoche, S and Komber, H and Friedel, P and Formanek, P and Janke, A and Voit, B I and Lederer, A},
  title = {pH-triggered aggregate shape of different generations lysine-dendronized maleimide copolymers with maltose shell},
  journal = {Biomacromolecules},
  year = {2012},
  volume = {13},
  number = {12},
  pages = {4222--35},
  url = {http://pubs.acs.org/doi/abs/10.1021/bm301489s http://www.ncbi.nlm.nih.gov/pubmed/23110476},
  doi = {10.1021/bm301489s}
}
Bozna BL, Duman M and Hinterdorfer P (2013), "Force Spectroscopy and Recognition Imaging of Cells from the Immune System", In Single-molecule Studies of Proteins. New York, NY , pp. 49-75. Springer New York.
Abstract: An important role in regulating the immunity to infection and tumors is played by Invariant Natural Killer T (iNKT). They represent a population of T lymphocytes that secrete large amounts of cytokines, interferon, and tumor-necrosis factor upon recognition of endogenous and exogenous agonists such as CD1d-bound lipid molecules. Single-molecule force spectroscopy has been applied for the investigation of affinity of the iNKT T cell Receptor (TCR) molecules to human CD1d molecules loaded with glycolipids with different length of phytosphingosine chain. This brings new insights into the energy landscape by determining the kinetic rate constants of the iNKT TCR/hCD1d–glycosphingolipid (GSL) interaction. Furthermore, the lipids distribution across the cell’s membrane was revealed by using Topography and RECognition (TREC) method.
BibTeX:
@incollection{Oberhauser2013,
  author = {Bozna, Bianca L. and Duman, Memed and Hinterdorfer, Peter},
  editor = {Oberhauser, Andres F.},
  title = {Force Spectroscopy and Recognition Imaging of Cells from the Immune System},
  booktitle = {Single-molecule Studies of Proteins},
  publisher = {Springer New York},
  year = {2013},
  pages = {49--75},
  url = {http://www.springerlink.com/content/p38036l73v432xm8/ http://link.springer.com/10.1007/978-1-4614-4921-8},
  doi = {10.1007/978-1-4614-4921-8\_2}
}
Breland M, Patel B and Bajwa H (2012), "Engineered nanoparticles for targeted drug delivery", Systems, Applications and ldots., May, 2012. , pp. 1-5. IEEE.
Abstract: DNA based nanostructures and advances in DNA origami techniques have shown great potential in fabrication and of nanostructures and devices. Though a large number of DNA origami structures have been reported [1-3], very few applications of DNA structures have been presented. Custom shapes formed by programmable DNA self assembly can be used to engineer nanoscale devices such as a biological antenna. The focus of our research is to design a nanoscale antenna using DNA biostructure as a scaffold. Conductivity of such a biological antenna can be achieved by using conductive nanoparticles coating on DNA [4] or by attaching conducting polymers to DNA structures[5]. In this paper, we will present design of engineered nano-antennas with well defined engineering characteristics. Engineered nano-antennas have a resonant frequency, that can be used for diagnostic and drug delivery. The ability of such antennas to resonate at a particular frequency will give researchers the ability to communicate and control the nanoparticles. Such nanoparticles are carriers that can be used as advanced detection systems to help identifying toxicity of nanoparticles in the body. Organic molecules, such as folic acid, can be easily bonded to the surface of antenna to detect cancerous cells. We will further discuss detailed DNA origami techniques that can be used to realize such nanostructures.
BibTeX:
@article{Breland2012,
  author = {Breland, Matthew and Patel, Badal and Bajwa, Hassan},
  title = {Engineered nanoparticles for targeted drug delivery},
  journal = {Systems, Applications and ldots},
  publisher = {IEEE},
  year = {2012},
  pages = {1--5},
  url = {http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6223198}
}
Buck MR, Biacchi AJ, Popczun EJ and Schaak RE (2013), "Polymer-Assisted Synthesis of Colloidal Germanium Telluride Nano-Octahedra, Nanospheres, and Nanosheets", Chemistry of Materials., May, 2013. Vol. 25(10), pp. 2163-71.
Abstract: Germanium telluride (GeTe) nanostructures are a demonstrated platform for studying the effects of scaling on reversible, amorphous-to-crystalline phase transitions that are important for data storage and computing applications, and for understanding ferroelectric behavior at the nanometer scale. Despite the interest in GeTe, and the apparent advantages of solution-phase processing, there is a dearth of information related to the synthesis of high-quality, morphology-controlled, colloidal GeTe. This paper describes the preparation of colloidal GeTe nanostructures in the presence of surface-stabilizing polymers, which mediate particle–particle interactions and prevent aggregation of GeTe crystallites more effectively than conventional molecular stabilizers. As a result, several novel GeTe nanostructures are formed, including faceted octahedral nanoparticles, amorphous GexTe1–x alloy nanospheres and single-crystal two-dimensional (2D) GeTe nanosheets. The colloidal stability conferred by the polymer may provide the key experimental degree of freedom necessary to achieve higher-order morphology control for GeTe and related materials.
BibTeX:
@article{Buck2013,
  author = {Buck, Matthew R and Biacchi, Adam J and Popczun, Eric J and Schaak, Raymond E},
  title = {Polymer-Assisted Synthesis of Colloidal Germanium Telluride Nano-Octahedra, Nanospheres, and Nanosheets},
  journal = {Chemistry of Materials},
  year = {2013},
  volume = {25},
  number = {10},
  pages = {2163--71},
  url = {http://pubs.acs.org/doi/abs/10.1021/cm4009656},
  doi = {10.1021/cm4009656}
}
Busscher HJ, Norde W, Sharma PK and van der Mei HC (2010), "Interfacial re-arrangement in initial microbial adhesion to surfaces", Current Opinion in Colloid & Interface Science., December, 2010. Vol. 15(6), pp. 510-517. Elsevier Ltd.
Abstract: Upon initial microbial adhesion to a surface, multiple events occur that include interfacial re-arrangements in the region between an adhering organism and a surface. Application of physico-chemical mechanisms to explain microbial adhesion to surfaces requires better knowledge of the interfacial re-arrangement occurring immediately after adhesion than hitherto available.
BibTeX:
@article{Busscher2010,
  author = {Busscher, Henk J. and Norde, Willem and Sharma, Prashant K. and van der Mei, Henny C.},
  title = {Interfacial re-arrangement in initial microbial adhesion to surfaces},
  journal = {Current Opinion in Colloid & Interface Science},
  publisher = {Elsevier Ltd},
  year = {2010},
  volume = {15},
  number = {6},
  pages = {510--517},
  url = {http://www.sciencedirect.com/science/article/pii/S1359029410000567 http://linkinghub.elsevier.com/retrieve/pii/S1359029410000567},
  doi = {10.1016/j.cocis.2010.05.014}
}
Ca nas Na, Hirose K, Pascucci B, Wagner N, Friedrich KA and Hiesgen R (2013), "Investigations of lithium–sulfur batteries using electrochemical impedance spectroscopy", Electrochimica Acta., May, 2013. Vol. 97, pp. 42-51.
Abstract: The electrochemical behavior of lithium–sulfur (Li–S) batteries was investigated by means of electro- chemical impedance spectroscopy (EIS). Measurements were performed in equidistant charge intervals at different depths of discharge and charge during the first cycle. Additionally, the degradation of the cells was analyzed for up to 50 cycles. An equivalent electrical circuit is proposed to simulate the electro- chemical processes and to quantify the impedance contributions of Li–S batteries. EIS as a function of the cycle number shows an increased capacity for fading correlated with a decrease in the charge transfer resistance of the cathode. Atomic force microscopy (AFM) was also used to provide information about changes in the electrical conductivity of the cathode surface as they are related to the building of isolating film
BibTeX:
@article{Canas2013,
  author = {Cañas, Natalia a. and Hirose, Kei and Pascucci, Brigitta and Wagner, Norbert and Friedrich, K. Andreas and Hiesgen, Renate},
  title = {Investigations of lithium–sulfur batteries using electrochemical impedance spectroscopy},
  journal = {Electrochimica Acta},
  year = {2013},
  volume = {97},
  pages = {42--51},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0013468613003460},
  doi = {10.1016/j.electacta.2013.02.101}
}
Cano A, Jiménez A, Cháfer M, Chiral A and González-martinez C (2010), "Rice Bran-filled biodegradable pea starch film", insidefood.eu. , pp. 23-28.
Abstract: In the present work the effectiveness of incorporating rice bran on the development of starch films was studied. To this aim, two different size rice bran were used to formulate the films and microstructural (by means of SEM and AFM techniques) and physical properties (water vapour and oxygen permeability, optical and mechanical properties) of pure pea starch and composite films, stored during one and five weeks (25ºC-52.8 were analyzed. The results showed that bran addition, bran particle size and storage time modified the films properties. Thus, the addition of bran to starch matrices provoked an increased the elastic modulus (EM), water vapour and oxygen permeability and a decrease of the elongation at break and internal transmittance (Ti) values. These changes were more pronounced when using the biggest bran particle size. SEM micrographs of composite films showed fibers unevenly distributed throughout the continuous matrix, leading to structural irregularities, which explained the lower transparency (lower Ti values) of these films. Fiber particles were also observed in AFM micrographs as a dispersed phase. Despite those showed greater EM values (more rigid), they did not contribute to improve the mechanical properties of the matrix (it became less stretchable) probably due to the lack of a good integration within the continuous matrix. After five weeks of storage, moisture content, deformation at break and oxygen permeability values decreased (p<0.05) probably due to the starch recrystallization process. To summarize, it is suitable to obtain rice bran based starch film with proper properties. In order to minimize the effects of rice bran incorporation to the pure starch film properties, the use of the finer rice bran size is recommended.
BibTeX:
@article{Cano2010,
  author = {Cano, Amalia and Jiménez, Alberto and Cháfer, Maite and Chiral, Amaparo and González-martinez, Chelo},
  title = {Rice Bran-filled biodegradable pea starch film},
  journal = {insidefood.eu},
  year = {2010},
  pages = {23--28},
  url = {http://www.insidefood.eu/INSIDEFOODWEB/UK/WORD/proceedings/009O.pdf}
}
Celano U, Goux L, Opsomer K, Belmonte A, Iapichino M, Detavernier C, Jurczak M and Vandervorst W (2013), "Switching mechanism and reverse engineering of low-power Cu-based resistive switching devices.", Nanoscale., November, 2013. Vol. 5(22), pp. 11187-92.
Abstract: In the recent past, filamentary-based resistive switching devices have emerged as predominant candidates for future non-volatile memory storage. Most of the striking characteristics of these devices are still limited by the high power consumption and poor understanding of the intimate resistive switching mechanism. In this study, we present an atomic scale study of the filament formation in CuTe-Al2O3 by using a conductive scanning probe tip to analyse the shape and dimensions of the filament. Filaments studied were either created within a normal device or locally formed while using the tip as the top electrode. We demonstrate that it is possible to create with C-AFM a filament with a signature identical to a device (i.e. two orders of magnitude resistance window, 10(4) s retention operating at 5 $A). This is obtained by a dedicated material and resistance selection for the conductive tip. The filamentary mechanism of fully processed devices is demonstrated and observed by C-AFM. Filaments created with C-AFM can be repeatedly cycled and the ON state presents a 20 nm highly conductive spot which can be repeatedly turned into a poorly conductive path in the OFF state.
BibTeX:
@article{Celano2013,
  author = {Celano, Umberto and Goux, Ludovic and Opsomer, Karl and Belmonte, Attilio and Iapichino, Martina and Detavernier, Christophe and Jurczak, Malgorzata and Vandervorst, Wilfried},
  title = {Switching mechanism and reverse engineering of low-power Cu-based resistive switching devices.},
  journal = {Nanoscale},
  year = {2013},
  volume = {5},
  number = {22},
  pages = {11187--92},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/24080868},
  doi = {10.1039/c3nr03579d}
}
Chafidz A, Ali I, Ali Mohsin ME, Elleithy R and Al-Zahrani S (2012), "Atomic Force Microscopy, thermal, viscoelastic and mechanical properties of HDPE/CaCO3 nanocomposites", Journal of Polymer Research., March, 2012. Vol. 19(4), pp. 1-17.
Abstract: High Density Polyethylene (HDPE) and calcium carbonate (CaCO 3 ) nanocomposites were prepared from masterbatch by melt blending in twin screw extruder (TSE). The physical properties of HDPE/CaCO 3 nanocomposites samples (0, 10 and 20 wt% CaCO 3 masterbatch) were investigated. The morphology, thermal, rheological/viscoelastic and mechanical properties of the nanocomposites were characterized by Atomic Force microscopy (AFM), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analyzer (DMA) as well as tensile test. The AFM images showed homogeneous dispersion and distribution of nano-CaCO 3 in the HDPE matrix. The DSC analysis showed a decrease in crystallinity of HDPE/CaCO 3 nanocomposites with the increase of CaCO 3 loading. This was due to the presence of nanofiller which could restrict the movement of the polymer chain segments and reduced the free volume/spaces available to be occupied by the macromolecules, thus, hindered the crystal growth. However, there was an increase in crystallization temperature about 1–2 °C with the addition of CaCO 3 . It was suggested that the CaCO 3 nanoparticles acted as nucleating agent. In melt rheology study, the complex viscosities of HDPE/CaCO 3 nanocomposites were higher than the HDPE matrix and increased with the increasing of CaCO 3 masterbatch loading. The DMA results showed that the storage modulus increased with the increasing of nano-CaCO 3 contents. The improvement was more than 40 as compared to that of neat HDPE. Additionally, the tensile test results showed that with the addition of CaCO 3 masterbatch, modulus elasticity of nanocomposites sample increased while yield stress decreased.
BibTeX:
@article{Chafidz2012,
  author = {Chafidz, Achmad and Ali, Ilias and Ali Mohsin, M. E. and Elleithy, Rabeh and Al-Zahrani, Saeed},
  title = {Atomic Force Microscopy, thermal, viscoelastic and mechanical properties of HDPE/CaCO3 nanocomposites},
  journal = {Journal of Polymer Research},
  year = {2012},
  volume = {19},
  number = {4},
  pages = {1--17},
  url = {http://www.springerlink.com/content/v45771757j56l427/},
  doi = {10.1007/s10965-012-9860-2}
}
Chappanda KN, Smith YR, Mohanty SK, Rieth LW, Tathireddy P and Misra M (2012), "Growth and characterization of TiO2 nanotubes from sputtered Ti film on Si substrate.", Nanoscale research letters., July, 2012. Vol. 7(1), pp. 388.
Abstract: ABSTRACT: In this paper we present the synthesis of self-organized TiO2 nanotube arrays formed by anodization of thin Ti film deposited on Si wafers by D.C. sputtering. Organic electrolyte was used to demonstrate the growth of stable nanotubes at room temperature with voltages varying from 10-60V (D.C.). The tubes were about 1.4 times longer than the thickness of the sputtered Ti film showing little undesired dissolution of the metal in the electrolyte during anodization. By varying the thickness of the deposited Ti film, the length of the nanotubes could be controlled precisely irrespective of longer anodization time and/or anodization voltage. Scanning electron microscopy, atomic force microscopy, diffuse-reflectance UV-Vis spectroscopy, and X-ray diffraction were used to characterize the thin film nanotubes. The tubes exhibited good adhesion to the wafer and did not peel off after annealing in air at 350oC to form anatase TiO2. With TiO2 nanotubes on planar/stable Si substrates, one can envision their integration with the current micro-fabrication technique large scale fabrication of TiO2 nanotube based devices.
BibTeX:
@article{Chappanda2012,
  author = {Chappanda, Karumbaiah N and Smith, York R and Mohanty, Swomitra K and Rieth, Loren W and Tathireddy, Prashant and Misra, Mano},
  title = {Growth and characterization of TiO2 nanotubes from sputtered Ti film on Si substrate.},
  journal = {Nanoscale research letters},
  year = {2012},
  volume = {7},
  number = {1},
  pages = {388},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/22788778},
  doi = {10.1186/1556-276X-7-388}
}
Che Man SH, Thickett SC, Whittaker MR and Zetterlund PB (2013), "Synthesis of polystyrene nanoparticles "armoured" with nanodimensional graphene oxide sheets by miniemulsion polymerization", Journal of Polymer Science Part A: Polymer Chemistry., January, 2013. Vol. 51(1), pp. 47-58.
Abstract: Polystyrene particles “armoured? with nanosized graphene oxide (GO) sheets have been prepared by aqueous miniemulsion polymerization of styrene, exploiting the amphiphilic properties of GO in the absence of conventional surfactants. The nanoscale GO sheets were prepared from graphite nanofibers of diameter approximately 100 nm based on a novel procedure, thus effectively ensuring the absence of larger sheets. Polymerization proceeded to high conversion with minor coagulation, with final number-average particle diameters of approximately 500 nm, but relatively broad particle size distributions. Scanning electron microscopy analysis revealed particles with a textured surface, consistent with the expected morphology. Interestingly, analysis of GO sheets recovered from the polymerization revealed that the GO sheets are partially reduced during the polymerization—approximately 50% of the initial carboxyl groups of the GO were lost, consistent with some loss in colloidal stability at high conversion. The overall approach offers a convenient and attractive synthetic route to novel graphene-based polymeric nanostructures.
BibTeX:
@article{che_man_synthesis_2013,
  author = {Che Man, S. H. and Thickett, Stuart C. and Whittaker, Michael R. and Zetterlund, Per B.},
  title = {Synthesis of polystyrene nanoparticles "armoured" with nanodimensional graphene oxide sheets by miniemulsion polymerization},
  journal = {Journal of Polymer Science Part A: Polymer Chemistry},
  year = {2013},
  volume = {51},
  number = {1},
  pages = {47--58},
  url = {http://doi.wiley.com/10.1002/pola.26341},
  doi = {10.1002/pola.26341}
}
Chen C-L, Bromley KM, Moradian-Oldak J and DeYoreo JJ (2011), "In situ AFM Study of Amelogenin Assembly and Disassembly Dynamics on Charged Surfaces Provides Insights on Matrix Protein Self-Assembly", Journal of the American Chemical Society. Vol. 133(43), pp. 17406-17413. American Chemical Society.
Abstract: Because self-assembly of matrix proteins is a key step in hard tissue mineralization, developing an understanding of the assembly pathways and underlying mechanisms is likely to be important for successful hard tissue engineering. While many studies of matrix protein assembly have been performed on bulk solutions, in vivo these proteins are likely to be in contact with charged biological surfaces composed of lipids, proteins, or minerals. Here we report the results of an in situ atomic force microscopy (AFM) study of self-assembly by amelogenin?the principal protein of the extracellular matrix in developing enamel?in contact with two different charged substrates: hydrophilic negatively charged bare mica and positively charged 3-aminopropyl triethoxysilane (APS) silanized mica. First we demonstrate an AFM-based protocol for determining the size of both amelogenin monomers and oligomers. Using this protocol, we find that, although amelogenin exists primarily as ?26 nm in diameter nanospheres in bulk solution at a pH of 8.0 studied by dynamic light scattering, it behaves dramatically differently upon interacting with charged substrates at the same pH and exhibits complex substrate-dependent assembly pathways and dynamics. On positively charged APS-treated mica surfaces, amelogenin forms a relatively uniform population of decameric oligomers, which then transform into two main populations: higher-order assemblies of oligomers and amelogenin monomers, while on negatively charged bare mica surfaces, it forms a film of monomers that exhibits tip-induced desorption and patterning. The present study represents a successful attempt to identify the size of amelogenin oligomers and to directly monitor assembly and disassembly dynamics on surfaces. The findings have implications for amelogenin-controlled calcium phosphate mineralization in vitro and may offer new insights into in vivo self-assembly of matrix proteins as well as their control over hard tissue formation.
BibTeX:
@article{Chen2011,
  author = {Chen, Chun-Long and Bromley, Keith M and Moradian-Oldak, Janet and DeYoreo, James J},
  title = {In situ AFM Study of Amelogenin Assembly and Disassembly Dynamics on Charged Surfaces Provides Insights on Matrix Protein Self-Assembly},
  journal = {Journal of the American Chemical Society},
  publisher = {American Chemical Society},
  year = {2011},
  volume = {133},
  number = {43},
  pages = {17406--17413},
  url = {http://dx.doi.org/10.1021/ja206849c},
  doi = {10.1021/ja206849c}
}
Chen H, Xi N, Song B, Yang R, Lai KWC, Chen L and Qu C (2012), "Nano-robot Enabled Characterizations of Local Electrical Properties for Nano-structures", In IEEE International Conference on Nanotechnology (IEEE-NANO). Birmingham, United Kingdom , pp. 4.
Abstract: Local electrical characterization has wide spectrum of applications in various areas. However, there are a number of difficulties that hinder the precise measurement of local electrical properties of samples, particularly those within nano-scale spatial resolution. Inspired by these challenges, we developed a nano? robot enabled electrical characterization system that can be utilized to pinpoint the local electrical properties of materials, devices, and bioentities with high spatial and electrical resolution. This system consists of an electrical characterization unit and a nano-robot with an augment reality system, which was developed from a traditional atomic force microscopy (AFM). The augment reality system provides real-time visual feedback. The real-time visual display integrated with the real-time force feedback from the nano-robot allows a precise control of the position and force of the AFM tips towards samples, which are significant for the sensitivity of local electrical measurement. The system design and implementation are presented in the paper. Experiments were carried out to study the local conductance of a multi-wall carbon nanotube (MWCNT), demonstrating the effectiveness of this system.
BibTeX:
@inproceedings{Chen2012,
  author = {Chen, Hongzhi and Xi, Ning and Song, Bo and Yang, Ruiguo and Lai, King W C and Chen, Liangliang and Qu, Chengeng},
  title = {Nano-robot Enabled Characterizations of Local Electrical Properties for Nano-structures},
  booktitle = {IEEE International Conference on Nanotechnology (IEEE-NANO)},
  year = {2012},
  pages = {4}
}
Chen J, Cui X, Wang Q, Wang H, Zheng X, Liu C, Xue T, Wang S and Zheng W (2012), "One-pot photochemical synthesis of ultrathin Au nanocrystals on co-reduced graphene oxide and its application", Journal of Colloid and Interface Science., October, 2012. Vol. 383(1), pp. 140-147. Elsevier Inc..
Abstract: In this study, we have developed a simple and green method for one-pot synthesis of ultrathin gold nanocrystals attached to graphene through photo irradiation. High-yield ultrathin Au nanocrystals are distributed on the reduced graphene oxide, immediately followed by the deoxygenation of graphene oxide in the absence of chemical reductants and surfactants. The procedure has been thoroughly completed and the products have been analyzed by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), etc. The results show that both graphene oxide and photo irradiation play essential roles in the formation of ultrathin Au nanocrystals. The nanohybrids also display excellent electro-catalytical performance to methanol oxidation. This study not only has potential in the applications of bio-sensing and fuel cells, but also provides new procedures for the preparation of metal/graphene nanomaterials
BibTeX:
@article{chen_one-pot_2012,
  author = {Chen, Jianli and Cui, Xiaoqiang and Wang, Qiyu and Wang, Haitao and Zheng, Xianliang and Liu, Chang and Xue, Tianyu and Wang, Shumin and Zheng, Weitao},
  title = {One-pot photochemical synthesis of ultrathin Au nanocrystals on co-reduced graphene oxide and its application},
  journal = {Journal of Colloid and Interface Science},
  publisher = {Elsevier Inc.},
  year = {2012},
  volume = {383},
  number = {1},
  pages = {140--147},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0021979712006194},
  doi = {10.1016/j.jcis.2012.06.007}
}
Chen J, Zhang X, Zheng X, Liu C, Cui X and Zheng W (2013), "Size distribution-controlled preparation of graphene oxide nanosheets with different C/O ratios", Materials Chemistry and Physics., April, 2013. Vol. 139(1), pp. 8-11.
BibTeX:
@article{chen_size_2013,
  author = {Chen, Jianli and Zhang, Xiaoming and Zheng, Xianliang and Liu, Chang and Cui, Xiaoqiang and Zheng, Weitao},
  title = {Size distribution-controlled preparation of graphene oxide nanosheets with different C/O ratios},
  journal = {Materials Chemistry and Physics},
  year = {2013},
  volume = {139},
  number = {1},
  pages = {8--11},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0254058412010589},
  doi = {10.1016/j.matchemphys.2012.12.025}
}
Chen S-wW, Odorico M, Meillan M, Vellutini L, Teulon J-M, Parot P, Bennetau B and Pellequer J-L (2013), "Nanoscale structural features determined by AFM for single virus particles", Nanoscale., August, 2013. The Royal Society of Chemistry.
Abstract: In this work, we propose “single-image analysis?, as opposed to multi-image averaging, for extracting valuable information from AFM images of single bio-particles. This approach allows us to study molecular systems imaged by AFM under general circumstances without restrictions on their structural forms. As feature exhibition is a resolution correlation, we have performed AFM imaging on surfaces of tobacco mosaic virus (TMV) to demonstrate variations of structural patterns with probing resolution. Two AFM images were acquired with the same tip at different probing resolutions in terms of pixel width, i.e., 1.95 and 0.49 nm per pixel. For assessment, we have constructed an in silico topograph based on the three-dimensional crystal structure of TMV as a reference. The prominent artifacts observed in the AFM-determined shape of TMV were attributed to tip convolutions. The width of TMV rod was systematically overestimated by ?10 nm at both probing resolutions of AFM. Nevertheless, the effects of tip convolution were less severe in vertical orientation so that the estimated height of TMV by AFM imaging was in close agreement with the in silico X-ray topograph. Using dedicated image processing algorithms, we found that at low resolution (i.e., 1.95 nm per pixel), the extracted surface features of TMV can be interpreted as a partial or full helical repeat (three complete turns with ?7.0 nm in length), while individual protein subunits (?2.5 nm) were perceivable only at high resolution. The present study shows that the scales of revealed structural features in AFM images are subject to both probing resolution and processing algorithms for image analysis.
BibTeX:
@article{Chen2013a,
  author = {Chen, Shu-wen W. and Odorico, Michael and Meillan, Matthieu and Vellutini, Luc and Teulon, Jean-Marie and Parot, Pierre and Bennetau, Bernard and Pellequer, Jean-Luc},
  title = {Nanoscale structural features determined by AFM for single virus particles},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/nr/c3nr02706f},
  doi = {10.1039/c3nr02706f}
}
Chen Y, Harapanahalli AK, Busscher HJ, Norde W and van der Mei HC (2014), "Nanoscale cell wall deformation impacts long-range bacterial adhesion forces on surfaces", Applied and Environmental Microbiology., January, 2014. Vol. 80(2), pp. 637-43.
Abstract: Adhesion of bacteria occurs on virtually all natural and synthetic surfaces and is crucial for their survival. Once they are adhering, bacteria start growing and form a biofilm, in which they are protected against environmental attacks. Bacterial adhesion to surfaces is mediated by a combination of different short- and long-range forces. Here we present a new atomic force microscopy (AFM)-based method to derive long-range bacterial adhesion forces from the dependence of bacterial adhesion forces on the loading force, as applied during the use of AFM. The long-range adhesion forces of wild-type Staphylococcus aureus parent strains (0.5 and 0.8 nN) amounted to only one-third of these forces measured for their more deformable isogenic $pbp4 mutants that were deficient in peptidoglycan cross-linking. The measured long-range Lifshitz-Van der Waals adhesion forces matched those calculated from published Hamaker constants, provided that a 40% ellipsoidal deformation of the bacterial cell wall was assumed for the $pbp4 mutants. Direct imaging of adhering staphylococci using the AFM peak force-quantitative nanomechanical property mapping imaging mode confirmed a height reduction due to deformation in the $pbp4 mutants of 100 to 200 nm. Across naturally occurring bacterial strains, long-range forces do not vary to the extent observed here for the $pbp4 mutants. Importantly, however, extrapolating from the results of this study, it can be concluded that long-range bacterial adhesion forces are determined not only by the composition and structure of the bacterial cell surface but also by a hitherto neglected, small deformation of the bacterial cell wall, facilitating an increase in contact area and, therewith, in adhesion force.
BibTeX:
@article{Chen2013,
  author = {Chen, Yun and Harapanahalli, Akshay K and Busscher, Henk J and Norde, Willem and van der Mei, Henny C},
  title = {Nanoscale cell wall deformation impacts long-range bacterial adhesion forces on surfaces},
  journal = {Applied and Environmental Microbiology},
  year = {2014},
  volume = {80},
  number = {2},
  pages = {637--43},
  url = {http://aem.asm.org/content/early/2013/11/04/AEM.02745-13.abstract http://www.ncbi.nlm.nih.gov/pubmed/24212582},
  doi = {10.1128/AEM.02745-13}
}
Chu J-Y, Hsu W-S, Liu W-R, Lin H-M, Cheng H-M and Lin L-J (2012), "A Novel Inspection for Deformation Phenomenon of Reduced-graphene Oxide via Quantitative Nano-mechanical Atomic Force Microscopy", Procedia Engineering., January, 2012. Vol. 36, pp. 571-577.
Abstract: The deformation and stacking of graphene significantly affect the overall electronic and mechanical properties. The graphene sheets are easily stacked each other due to van der Waals attraction. The folded characteristic may prevent graphene stacking and increase the d-spacing between graphenes. It can easily form dense graphene structures with high surface area and be applied on electrode materials of battery, nano-composites and so on. The traditional topographic mapping of atomic force microscope (AFM) is hard to measure the characters of surface deformation and distinguish the folding and stacking. In this study, we apply a novel quantitative nano-mechanical AFM to analyze the reduced-graphene oxide (r-GO). The results indicate that the novel AFM system could recognize the difference between folding and stacking of r-GO effectively. Nevertheless, the images including topography, deformation, adhesion, and elastic modulus show the different phenomena between measuring region, which appears that status on measuring region are folding and stacking, respectively.
BibTeX:
@article{Chu2012,
  author = {Chu, Jen-You and Hsu, Wei-Sheng and Liu, Wei-Ren and Lin, Hung-Min and Cheng, Hsin-Ming and Lin, Li-Jiaun},
  title = {A Novel Inspection for Deformation Phenomenon of Reduced-graphene Oxide via Quantitative Nano-mechanical Atomic Force Microscopy},
  journal = {Procedia Engineering},
  year = {2012},
  volume = {36},
  pages = {571--577},
  url = {http://dx.doi.org/10.1016/j.proeng.2012.03.083},
  doi = {10.1016/j.proeng.2012.03.083}
}
Clar JG, Silvera-Batista CA, Youn S, Bonzongo J-CJ and Ziegler KJ (2013), "Interactive Forces between SDS-Suspended Single-Wall Carbon Nanotubes and Agarose Gels.", Journal of the American Chemical Society., October, 2013. American Chemical Society.
Abstract: Selective adsorption onto agarose gels has become a powerful method to separate single-wall carbon nanotubes (SWCNTs). A better understanding of the nature of the interactive forces and the specific sites responsible for adsorption should lead to significant improvements in the selectivity and yield of these separations. A combination of non-equilibrium and equilibrium studies are conducted to explore the potential role that van der Waals, ionic, hydrophobic, pi-pi, and ion-dipole interactions have on the selective adsorption between agarose and SWCNTs suspended with sodium dodecyl sulfate (SDS). The results demonstrate that any modification to the agarose gel surface and, consequently, the permanent dipole moments of agarose drastically reduces the retention of SWCNTs. Because these permanent dipoles are critical to retention and the fact that SDS-SWCNTs function as macro-ions, it is proposed that ion-dipole forces are the primary interaction responsible for adsorption. The selectivity of adsorption may be attributed to variations in polarizability between nanotube types, which create differences in both the structure and mobility of surfactant. These differences affect the enthalpy and entropy of adsorption and both play an integral part in the selectivity of adsorption. The overall adsorption process shows a complex behavior that is not well represented by the Langmuir model; therefore, calorimetric data should be used to extract thermodynamic information.
BibTeX:
@article{Clar2013,
  author = {Clar, Justin G and Silvera-Batista, Carlos A and Youn, Sejin and Bonzongo, Jean-Claude J and Ziegler, Kirk J},
  title = {Interactive Forces between SDS-Suspended Single-Wall Carbon Nanotubes and Agarose Gels.},
  journal = {Journal of the American Chemical Society},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://pubs.acs.org/doi/abs/10.1021/ja4052526},
  doi = {10.1021/ja4052526}
}
Clark N, Oikonomou A and Vijayaraghavan A (2013), "Ultrafast quantitative nanomechanical mapping of suspended graphene", physica status solidi (b)., December, 2013. Vol. 250(12), pp. 2672-2677.
BibTeX:
@article{Clark2013,
  author = {Clark, Nick and Oikonomou, Antonios and Vijayaraghavan, Aravind},
  title = {Ultrafast quantitative nanomechanical mapping of suspended graphene},
  journal = {physica status solidi (b)},
  year = {2013},
  volume = {250},
  number = {12},
  pages = {2672--2677},
  url = {http://doi.wiley.com/10.1002/pssb.201300137},
  doi = {10.1002/pssb.201300137}
}
Clos AL, Lasagna-Reeves CA, Castillo-Carranza DL, Sengupta U, Jackson GR, Kelly B, Beachkofsky TM and Kayed R (2011), "Formation of immunoglobulin light chain amyloid oligomers in primary cutaneous nodular amyloidosis", British Journal of Dermatology. Vol. 165, pp. 1349-54. Blackwell Publishing Ltd.
Abstract: Background Primary cutaneous nodular amyloidosis (PCNA) is thought to be a plasma cell dyscrasia. The amyloid deposits are found in the dermis and subcutis, and they contain clonal immunoglobulin light chains, produced by a local proliferation of plasma cells. New insights into amyloid diseases have revealed that the pathology is due more to the presence of small, misfolded protein species termed oligomers than to the deposition of fibrillar material. Objectives To demonstrate the presence of amyloid oligomers in PCNA and to provide evidence that cutaneous amyloid diseases share a common pathogenic pathway similar to other amyloid diseases. Methods Immunohistochemical staining with conformation-specific and sequence-specific antibodies was used to localize different amyloid species of light chain immunoglobulins in a case of PCNA. Additionally, in vitro characterization of immunoglobulin oligomers and fibrils was performed to determine, through toxicity studies in a human keratinocyte cell line, which amyloidogenic form of the immunoglobulin is toxic in PCNA. Results Amyloid oligomers were identified in PCNA. Oligomers were mainly formed by lambda light chain immunoglobulins, and kappa light chain oligomers were detected in lesser amounts. Amyloid species were detected intra- and extracellularly. In addition, amyloid oligomers and fibrils, derived from unknown protein sources, were detected. This finding suggests that immunoglobulin amyloids can act as seeds capable of inducing the aggregation of heterogeneous proteins in the skin. Furthermore, cytotoxicity studies demonstrated that immunoglobulin oligomers, but not monomers or fibrils, are toxic to human keratinocytes. Conclusions These data indicate that PCNA has common pathways with other amyloid diseases with respect to protein misfolding and pathogenesis. Immunoglobulin oligomers may prove to be targets for the treatment of PCNA.
BibTeX:
@article{Clos2011,
  author = {Clos, A. L. and Lasagna-Reeves, C. A. and Castillo-Carranza, Diana L. and Sengupta, U. and Jackson, G. R. and Kelly, B. and Beachkofsky, T. M. and Kayed, R.},
  title = {Formation of immunoglobulin light chain amyloid oligomers in primary cutaneous nodular amyloidosis},
  journal = {British Journal of Dermatology},
  publisher = {Blackwell Publishing Ltd},
  year = {2011},
  volume = {165},
  pages = {1349--54},
  url = {http://dx.doi.org/10.1111/j.1365-2133.2011.10508.x},
  doi = {10.1111/j.1365-2133.2011.10508.x}
}
Cohen SR and Kalfon-Cohen E (2013), "Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review", Beilstein Journal of Nanotechnology., November, 2013. Vol. 4(1), pp. 815-833. Beilstein-Institut.
BibTeX:
@article{Cohen2013,
  author = {Cohen, Sidney R and Kalfon-Cohen, Estelle},
  title = {Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review},
  journal = {Beilstein Journal of Nanotechnology},
  publisher = {Beilstein-Institut},
  year = {2013},
  volume = {4},
  number = {1},
  pages = {815--833},
  url = {http://www.beilstein-journals.org/bjnano/content/4/1/93},
  doi = {10.3762/bjnano.4.93}
}
Cohen-Karni T, Jeong KJ, Tsui JH, Reznor G, Mustata M, Wanunu M, Graham A, Marks C, Bell DC, Langer RS and Kohane DS (2012), "Nanocomposite gold-silk nanofibers", Nano Letters., August, 2012. , pp. 120828104132005. American Chemical Society.
Abstract: Cell-biomaterial interactions can be controlled by modifying the surface chemistry or nanotopography of the material, to induce cell proliferation and differentiation if desired. Here we combine both approaches in forming silk nanofibers (SNFs) containing gold nanoparticles (AuNPs) and subsequently chemically modifying the fibers. Silk fibroin mixed with gold seed nanoparticles was electrospun to form SNFs doped with gold seed nanoparticles (SNFseed). Following gold reduction, there was a two-fold increase in particle diameter confirmed by the appearance of a strong absorption peak at 525 nm. AuNPs were dispersed throughout the AuNP-doped silk nanofibers (SNFsAu). The Young?s modulus of the SNFsAu was almost 70% higher than that of SNFs. SNFsAu were modified with the arginine-glycine-aspartic acid (RGD) peptide. Human mesenchymal stem cells that were cultured on RGD-modified SNFAu had a more than two-fold larger cell area compared to the cells cultured on bare SNFs; SNFAu also increase cell size. We suggest that this approach can be used to alter the cell-material interface in tissue engineering and other applications. Cell-biomaterial interactions can be controlled by modifying the surface chemistry or nanotopography of the material, to induce cell proliferation and differentiation if desired. Here we combine both approaches in forming silk nanofibers (SNFs) containing gold nanoparticles (AuNPs) and subsequently chemically modifying the fibers. Silk fibroin mixed with gold seed nanoparticles was electrospun to form SNFs doped with gold seed nanoparticles (SNFseed). Following gold reduction, there was a two-fold increase in particle diameter confirmed by the appearance of a strong absorption peak at 525 nm. AuNPs were dispersed throughout the AuNP-doped silk nanofibers (SNFsAu). The Young?s modulus of the SNFsAu was almost 70% higher than that of SNFs. SNFsAu were modified with the arginine-glycine-aspartic acid (RGD) peptide. Human mesenchymal stem cells that were cultured on RGD-modified SNFAu had a more than two-fold larger cell area compared to the cells cultured on bare SNFs; SNFAu also increase cell size. We suggest that this approach can be used to alter the cell-material interface in tissue engineering and other applications.
BibTeX:
@article{Cohen-Karni2012,
  author = {Cohen-Karni, Tzahi and Jeong, Kyung Jae and Tsui, Jonathan H. and Reznor, Gally and Mustata, Mirela and Wanunu, Meni and Graham, Adam and Marks, Carolyn and Bell, David C. and Langer, Robert S. and Kohane, Daniel S.},
  title = {Nanocomposite gold-silk nanofibers},
  journal = {Nano Letters},
  publisher = {American Chemical Society},
  year = {2012},
  pages = {120828104132005},
  url = {http://dx.doi.org/10.1021/nl302810c},
  doi = {10.1021/nl302810c}
}
Cortés M, Gómez E and Vallés E (2012), "Magnetic CoPt (60–70 wt% Pt) microstructures fabricated by the electrochemical method", Journal of Micromechanics and Microengineering., May, 2012. Vol. 22(5), pp. 055016.
Abstract: CoPt microstructures, in the form of both discontinuous layers and patterned arrays, of 60–70 wt% Pt and nanometric thickness have been grown by electrodeposition through a resist mask prepared directly onto a glass/ITO substrate. This substrate was selected because its conductive ITO layer permits the electrodeposition process but does not show magnetic response. The lack of magnetic response of the substrate enables the magnetic properties of the microstructures deposited over it to be measured directly. Test microstructures of the different aspect ratio were successfully prepared, which confirms the suitability of the used bath; a good definition of both has been attained in spite of the significant hydrogen co-evolution. The deposition conditions have been adjusted to obtain a highly distorted hcp crystalline structure. Differences in the magnetic behaviour of the microstructures were observed depending on the orientations of the magnetic field applied. This work demonstrates the capability of the electrodeposition method to grow well-defined nanometric thick microstructures of hcp magnetic CoPt alloy with modulable magnetic properties as a function of the orientation of the applied magnetic field, microstructures which could be directly incorporated in magnetic microelectromechanical systems.
BibTeX:
@article{cortes_magnetic_2012,
  author = {Cortés, M and Gómez, E and Vallés, E},
  title = {Magnetic CoPt (60–70 wt% Pt) microstructures fabricated by the electrochemical method},
  journal = {Journal of Micromechanics and Microengineering},
  year = {2012},
  volume = {22},
  number = {5},
  pages = {055016},
  url = {http://iopscience.iop.org/0960-1317/22/5/055016 http://stacks.iop.org/0960-1317/22/i=5/a=055016?key=crossref.8a0d7686a5e47148889396dea64bf80b},
  doi = {10.1088/0960-1317/22/5/055016}
}
Costas-Mora I, Romero V, Lavilla I and Bendicho C (2013), "Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid-liquid-liquid microextraction", Analytica Chimica Acta., June, 2013. Vol. null(null)
BibTeX:
@article{Costas-Mora2013,
  author = {Costas-Mora, Isabel and Romero, Vanesa and Lavilla, Isela and Bendicho, Carlos},
  title = {Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid-liquid-liquid microextraction},
  journal = {Analytica Chimica Acta},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.aca.2013.06.007},
  doi = {10.1016/j.aca.2013.06.007}
}
Cranston ED, Eita M, Johansson E, Netrval J, Salajkova? M, Arwin H and Wågberg L (2011), "Determination of Young’s Modulus for Nanofibrillated Cellulose Multilayer Thin Films Using Buckling Mechanics", Biomacromolecules. Vol. 12(4), pp. 961-969. ACS Publications.
Abstract: The Young?s modulus of multilayer films containing nanofibrillated cellulose (NFC) and polyethyleneimine (PEI) was determined using the strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) technique.(1) Multilayer films were built up on polydimethylsiloxane substrates using electrostatic layer-by-layer assembly. At 50% relative humidity, SIEBIMM gave a constant Young?s modulus of 1.5 ± 0.2 GPa for 35?75 nm thick films. Conversely, in vacuum, the Young?s modulus was 10 times larger, at 17.2 ± 1.2 GPa. A slight decrease in buckling wavelength with increasing strain was observed by scanning electron microscopy with in situ compression, and above 10% strain, extensive cracking parallel to the compressive direction occurred. We conclude that whereas PEI acts as a ?glue? to hold multiple layers of NFC together, it prevents full development of hydrogen bonding and specific fibril?fibril interactions, and at high humidity, its hygroscopic nature decreases the elastic modulus when compared with pure NFC films.
BibTeX:
@article{Cranston2011,
  author = {Cranston, Emily D. and Eita, Mohamed and Johansson, Erik and Netrval, Julia and Salajkova?, Michaela and Arwin, Hans and Wågberg, Lars},
  title = {Determination of Young’s Modulus for Nanofibrillated Cellulose Multilayer Thin Films Using Buckling Mechanics},
  journal = {Biomacromolecules},
  publisher = {ACS Publications},
  year = {2011},
  volume = {12},
  number = {4},
  pages = {961--969},
  url = {http://pubs.acs.org/doi/abs/10.1021/bm101330w},
  doi = {10.1021/bm101330w}
}
Creutz CE, Eaton JM and Harris TE (2013), "Assembly of High Molecular Weight Complexes of Lipin on a Supported Lipid Bilayer Observed by Atomic Force Microscopy", Biochemistry., July, 2013. American Chemical Society.
Abstract: Lipins are phosphatidic acid phosphatases involved in the biosynthesis of triacylglycerols and phospholipids. They are associated with the endoplasmic reticulum but can also travel into the nucleus and alter gene expression. Previous studies indicate lipins in solution form high molecular weight complexes, possibly tetramers. This study was undertaken to determine if lipins form complexes on membranes as well. Murine lipin 1b was applied to a supported bilayer of phosphatidylcholine, phosphatidylserine, and cholesterol and examined by atomic force microscopy (AFM) over time. Lipin on bare mica appeared as a symmetric particle with a volume consistent with the size of a monomer. On the bilayer, lipin initially bound as asymmetric, curved particles that sometimes assembled into circular structures with an open center. Subsequently, lipin assemblies grew into large, symmetric particles with an average volume 12 times that of the monomer. Over time, some of the lipin assemblies were removed from the bilayer by the AFM probe leaving behind ?footprints? composed of complex patterns that may reflect the substructure of the lipin assemblies. The lipin complexes appeared very flat, with a diameter 20 times their height. The footprints had a similar diameter, providing confirmation of the extensive deformation of the protein under the AFM probe. The ability of lipin to form large complexes on membranes may have significant implications for the local concentrations of the product, diacylglycerol, formed during hydrolysis of phosphatidic acid and for cooperative hormonal regulation of lipin activity through phosphorylation of one or more monomers in the complexes.
BibTeX:
@article{Creutz2013,
  author = {Creutz, Carl E and Eaton, James M and Harris, Thurl E},
  title = {Assembly of High Molecular Weight Complexes of Lipin on a Supported Lipid Bilayer Observed by Atomic Force Microscopy},
  journal = {Biochemistry},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://dx.doi.org/10.1021/bi4004765},
  doi = {10.1021/bi4004765}
}
Dai Q, Berman D, Virwani K, Frommer J, Jubert P-O, Lam M, Topuria T, Imaino W and Nelson A (2010), "Self-Assembled Ferrimagnet−Polymer Composites for Magnetic Recording Media", Nano Letters., August, 2010. Vol. 10(8), pp. 3216-3221. American Chemical Society.
Abstract: A self-assembled magnetic recording medium was created using colloidal ferrimagnetic building blocks. Monodisperse cobalt ferrite nanoparticles (CoFe2O4) were synthesized using solution-based methods and then stabilized in solution using the amphiphilic diblock copolymer, poly(acrylic acid)-b-poly(styrene) (PAA-PS). The acid groups of the acrylate block bound the polymer to the nanoparticle surface via multivalent interactions, while the styrene block afforded the magnetic nanoparticle?polymer complex solubility in organic solvents. Moreover, the diblock copolymer improved the colloidal stability of the ferrimagnetic CoFe2O4 nanoparticles by reducing the strong interparticle magnetic interactions, which typically caused the ferrimagnetic nanoparticles to irreversibly aggregate. The nanoparticle?polymer complex was spin-coated onto a silicon substrate to afford self-organized thin film arrays, with the interparticle spacing determined by the molecular weight of the diblock copolymer. The thin film composite was also exposed to an external magnetic field while simultaneously heated above the glass transition temperature of poly(styrene) to allow the nanoparticles to physically rotate to align their easy axes with the direction of the magnetic field. In order to demonstrate that this self-assembled ferrimagnet?polymer composite was suitable as a magnetic recording media, read/write cycles were demonstrated using a contact magnetic tester. This work provides a simple route to synthesizing stabilized ferrimagnetic nanocrystals that are suitable for developing magnetic recording media.
BibTeX:
@article{Dai2010,
  author = {Dai, Qiu and Berman, David and Virwani, Kumar and Frommer, Jane and Jubert, Pierre-Olivier and Lam, Michelle and Topuria, Teya and Imaino, Wayne and Nelson, Alshakim},
  title = {Self-Assembled Ferrimagnet−Polymer Composites for Magnetic Recording Media},
  journal = {Nano Letters},
  publisher = {American Chemical Society},
  year = {2010},
  volume = {10},
  number = {8},
  pages = {3216--3221},
  url = {http://dx.doi.org/10.1021/nl1022749},
  doi = {10.1021/nl1022749}
}
Das H, Sunkari S, Oldham T, Rodgers J and Casady J (2013), "Uniformity and Morphology of 10 x 100mm 4° Off-Axis 4H-SiC Epitaxial Layers and their Effect on Device Performance", Materials Science Forum., January, 2013. Vol. 740-742, pp. 221-224.
Abstract: Homoepitaxial layers with very good thickness and doping uniformity were grown on 4 inch 4˚ off-axis substrates in a 10x100mm planetary reactor. Process optimizations resulted in reduction of the size of the triangular defects. Aggressive pre-etching of the substrate prior to growth resulted in further suppression of the triangular defect concentration from 3-5cm-2 to 0.5cm-2 using the same growth processes. Even imperfect areas of the substrate with scratches show suppressed nucleation of triangular defects. JBS diodes with triangular defects show increased leakage depending on the size of the defects. This effect is more pronounced at higher voltages.
BibTeX:
@article{das_uniformity_2013,
  author = {Das, Hrishikesh and Sunkari, Swapna and Oldham, Timothy and Rodgers, Josh and Casady, Janna},
  title = {Uniformity and Morphology of 10 x 100mm 4° Off-Axis 4H-SiC Epitaxial Layers and their Effect on Device Performance},
  journal = {Materials Science Forum},
  year = {2013},
  volume = {740-742},
  pages = {221--224},
  url = {http://www.scientific.net/MSF.740-742.221},
  doi = {10.4028/www.scientific.net/MSF.740-742.221}
}
Das PK, Kringos N, Wallqvist V and Birgisson B (2013), "Micromechanical investigation of phase separation in bitumen by combining atomic force microscopy with differential scanning calorimetry results", Road Materials and Pavement Design., April, 2013. Vol. 14(sup1), pp. 25-37. Taylor & Francis.
Abstract: The thermo-rheological behaviour of bitumen depends largely on its chemical structure and intermolecular microstructures. Bitumen is a complex mixture of organic molecules of different sizes and polarities for which the micro-structural knowledge is still rather incomplete. Knowledge at that level can have great implications for behaviour at a larger scale and will help to optimise the bitumen in its production stage. The present study is focused on understanding the fundamental mechanisms behind the micro-structural phase appearance and the speed or mobility at which they change. To do so, atomic force microscopy was utilised at different temperatures to investigate the phase separation behaviour for four different types of bitumen and co-relate it with the differential scanning calorimetry measurements. Based on the experimental evidences, it was found that the observed phase separation is mainly due to the wax/paraffin fraction presence in bitumen and that the investigated bitumen behaves quite differently. Recommendations are made to continue this research into qualitative information to be used on the asphalt mix design level. The thermo-rheological behaviour of bitumen depends largely on its chemical structure and intermolecular microstructures. Bitumen is a complex mixture of organic molecules of different sizes and polarities for which the micro-structural knowledge is still rather incomplete. Knowledge at that level can have great implications for behaviour at a larger scale and will help to optimise the bitumen in its production stage. The present study is focused on understanding the fundamental mechanisms behind the micro-structural phase appearance and the speed or mobility at which they change. To do so, atomic force microscopy was utilised at different temperatures to investigate the phase separation behaviour for four different types of bitumen and co-relate it with the differential scanning calorimetry measurements. Based on the experimental evidences, it was found that the observed phase separation is mainly due to the wax/paraffin fraction presence in bitumen and that the investigated bitumen behaves quite differently. Recommendations are made to continue this research into qualitative information to be used on the asphalt mix design level.
BibTeX:
@article{Das2013,
  author = {Das, Prabir Kumar and Kringos, Niki and Wallqvist, Viveca and Birgisson, Björn},
  title = {Micromechanical investigation of phase separation in bitumen by combining atomic force microscopy with differential scanning calorimetry results},
  journal = {Road Materials and Pavement Design},
  publisher = {Taylor & Francis},
  year = {2013},
  volume = {14},
  number = {sup1},
  pages = {25--37},
  url = {http://dx.doi.org/10.1080/14680629.2013.774744},
  doi = {10.1080/14680629.2013.774744}
}
Dasgupta D, Shishmanova IK, Ruiz-Carretero A, Lu K, Verhoeven MWGM, van Kuringen HPC, Portale G, Leclere P, Bastiaansen CWM, Broer DJ and Schenning APHJ (2013), "Patterned Silver Nanoparticles embedded in a Nanoporous Smectic Liquid Crystalline Polymer Network", Journal of the American Chemical Society., July, 2013. American Chemical Society.
Abstract: A nanoporous smectic liquid crystalline polymer network has been exploited to fabricate photo patternable organic-inorganic hybrid materials, wherein, the nanoporous channels control the diameter and orientational order of the silver nanoparticles.
BibTeX:
@article{Dasgupta2013,
  author = {Dasgupta, Debarshi and Shishmanova, Ivelina K and Ruiz-Carretero, Amparo and Lu, Kangbo and Verhoeven, Martinus W G M and van Kuringen, Huub P C and Portale, Giuseppe and Leclere, Philippe and Bastiaansen, Cees W M and Broer, Dirk J and Schenning, Albertus P H J},
  title = {Patterned Silver Nanoparticles embedded in a Nanoporous Smectic Liquid Crystalline Polymer Network},
  journal = {Journal of the American Chemical Society},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://dx.doi.org/10.1021/ja404825y},
  doi = {10.1021/ja404825y}
}
Demuth PC, Irvine DJ and Samuel RE (2012), "MULTILAYER COATING COMPOSITIONS, COATED SUBSTRATES AND METHODS THEREOF".
Abstract: The present invention provides, among other things, multilayer film coating compositions, coated substrates and methods thereof In some embodiments, a structure, comprising a substrate and a multilayer film on the substrate, wherein the multilayer film comprises a first plurality of first units, each first unit comprising a protamine polypeptide. In some embodiments, a structure comprising a microneedle substrate and a multilayer film coated on at least portion of the microneedle substrate, wherein the multilayer film comprises an agent for release and a first plurality of first unit; each first unit comprising a first layer and a second layer, wherein the first layer and the second layer are associated with one another.
BibTeX:
@misc{Demuth2012,
  author = {Demuth, P. C. and Irvine, D. J. and Samuel, R. E.},
  title = {MULTILAYER COATING COMPOSITIONS, COATED SUBSTRATES AND METHODS THEREOF},
  booktitle = {US Patent},
  year = {2012},
  url = {http://www.freepatentsonline.com/y2012/0027837.html}
}
Desbief S, Hergué N, Douhéret O, Surin M, Dubois P, Geerts Y, Lazzaroni R and Leclère P (2012), "Nanoscale investigation of the electrical properties in semiconductor polymer-carbon nanotube hybrid materials", Nanoscale., April, 2012. Vol. 4(8), pp. 2705-12. The Royal Society of Chemistry.
Abstract: The morphology and electrical properties of hybrids of a semiconducting polymer (namely poly(3-hexylthiophene) P3HT) and carbon nanotubes are investigated at the nanoscale with a combination of Scanning Probe Microscopy techniques, i.e., Conductive Atomic Force Microscopy (C-AFM) and time-resolved Current Sensing Force Spectroscopy Atomic Force Microscopy (CSFS-AFM, or PeakForce TUNA™). This allows us to probe the electrical properties of the 15 nm wide P3HT nanofibers as well as the interface between the polymer and single carbon nanotubes. This is achieved by applying controlled, low forces on the tip during imaging, which allows a direct comparison between the morphology and the electrical properties at the nanometre scale.
BibTeX:
@article{Desbief2012,
  author = {Desbief, Simon and Hergué, Noémie and Douhéret, Olivier and Surin, Mathieu and Dubois, Philippe and Geerts, Yves and Lazzaroni, Roberto and Leclère, Philippe},
  title = {Nanoscale investigation of the electrical properties in semiconductor polymer-carbon nanotube hybrid materials},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2012},
  volume = {4},
  number = {8},
  pages = {2705--12},
  url = {http://pubs.rsc.org/en/content/articlelanding/2012/nr/c2nr11888b http://www.ncbi.nlm.nih.gov/pubmed/22437692},
  doi = {10.1039/c2nr11888b}
}
Dokukin ME and Sokolov I (2012), "Quantitative mapping of elastic modulus of soft materials with HarmoniX and PeakForce QNM AFM modes", Langmuir., October, 2012. Vol. 28(46), pp. 16060-71. American Chemical Society.
Abstract: The modulus of elasticity of soft materials at the nanoscale is of interest when studying thin films, nanocomposites, biomaterials, etc. Two novel modes of atomic force microscopy (AFM) have been introduced recently, HarmoniX and PeakForce QNM. Both modes produce maps of distribution of the elastic modulus over the sample surface. Here we investigate the question how quantitative these maps are when studying soft materials. Three different polymers of the macroscopic Young's modulus of 0.6-0.7GPa (polyurethanes) and 2.7GPa (polystyrene) are analyzed using these new modes. The moduli obtained are compared with the data measured with the other commonly used techniques, dynamic mechanical analyzer (DMA), regular AFM, and nanoindenter. We show that the elastic modulus is overestimated in both the HarmoniX and PeakForce QNM modes when using regular sharp probes, because of excessively overstressed material of the samples. We further demonstrate that both AFM modes can work in the linear stress-strain regime when using a relatively dull indentation probe (starting from 210nm). The analysis of the elasticity models to be used shows that JKR model should be used for the samples considered here instead of DMT model which is currently implemented in HarmoniX and PeakForce QNM modes. Using the JKR model and240nm AFM probe in the PeakForce QNM mode, we demonstrate that a quantitative mapping of the elastic modulus of polymeric materials is possible. The spatial resolution of 50nm and minimum 2-3 indentation depth are achieved.
BibTeX:
@article{Dokukin2012,
  author = {Dokukin, Maxim E and Sokolov, Igor},
  title = {Quantitative mapping of elastic modulus of soft materials with HarmoniX and PeakForce QNM AFM modes},
  journal = {Langmuir},
  publisher = {American Chemical Society},
  year = {2012},
  volume = {28},
  number = {46},
  pages = {16060--71},
  url = {http://pubs.acs.org/doi/pdf/10.1021/la302706b http://pubs.acs.org/doi/abs/10.1021/la302706b},
  doi = {10.1021/la302706b}
}
Donescu D, Somoghi R, Spataru CI, Manaila-Maximean D, Panaitescu DM, Vasile E and Nistor CL (2013), "Hybrid polymeric latexes containing magnetite", Colloid and Polymer Science., May, 2013.
BibTeX:
@article{Donescu2013,
  author = {Donescu, Dan and Somoghi, Raluca and Spataru, Catalin Ilie and Manaila-Maximean, Doina and Panaitescu, Denis Mihaela and Vasile, Eugeniu and Nistor, Cristina L.},
  title = {Hybrid polymeric latexes containing magnetite},
  journal = {Colloid and Polymer Science},
  year = {2013},
  url = {http://link.springer.com/10.1007/s00396-013-2976-z},
  doi = {10.1007/s00396-013-2976-z}
}
Dufrêne YF, Martnez-Martn D, Medalsy I, Alsteens D and Müller DJ (2013), "Multiparametric imaging of biological systems by force-distance curve–based AFM", Nature Methods., August, 2013. Vol. 10(9), pp. 847-854. Nature Publishing Group.
Abstract: A current challenge in the life sciences is to understand how biological systems change their structural, biophysical and chemical properties to adjust functionality. Addressing this issue has been severely hampered by the lack of methods capable of imaging biosystems at high resolution while simultaneously mapping their multiple properties. Recent developments in force-distance (FD) curve–based atomic force microscopy (AFM) now enable researchers to combine (sub)molecular imaging with quantitative mapping of physical, chemical and biological interactions. Here we discuss the principles and applications of advanced FD-based AFM tools for the quantitative multiparametric characterization of complex cellular and biomolecular systems under physiological conditions.
BibTeX:
@article{Dufrene2013,
  author = {Dufrêne, Yves F and Martnez-Martn, David and Medalsy, Izhar and Alsteens, David and Müller, Daniel J},
  title = {Multiparametric imaging of biological systems by force-distance curve–based AFM},
  journal = {Nature Methods},
  publisher = {Nature Publishing Group},
  year = {2013},
  volume = {10},
  number = {9},
  pages = {847--854},
  url = {http://www.nature.com/doifinder/10.1038/nmeth.2602},
  doi = {10.1038/nmeth.2602}
}
Dunér G (2012), "Grafted Molecular Layers for Control of Surface Properties". Thesis at: KTH Royal Institute of Technology.
Abstract: The goal of this thesis work was to develop responsive surface grafted brushlayers for control of surface properties and to gain insights in the molecular mechanisms that control these properties. Three types of grafted layers were investigated, as outlined below. In the first system studied, poly(AAc) was synthesized by a grafting from approach, utilizing a photopolymerization reaction from a macroinitiator cast onto QCM substrates. The responsiveness in terms of frequency change, $f, of the resulting brushes to changes in bulk pH was studied with QCM. Further, the friction properties of poly(AAc) was elucidated with colloidal probe AFM as a function of pH and counterion valency. High friction ($=0.27) was found in presence of CaCl2 at high pH (7.5), but not under any other condition explored. It was concluded that the high friction was due to intralayer COO--Ca2+--OOC bridges. QCM-D was utilized for studying viscoelastic properties of growing poly(AAc) films during in situ photopolymerization. By Voigt modeling, the thickness, shear elasticity and shear viscosity were extracted. These parameters were observed to undergo sudden transitions at a critical thickness, and from this thickness the grafting density of the growing poly(AAc) layers was determined. In addition, the sensitivity to changes in $f and $D with respect to the thickness of the poly(AAc) films was investigated, and the results showed that high sensitivity in $D is retained at higher film thicknesses than for $f, and that the sensitivity with respect to noise can significantly alter the thickness that is best suited forthe study of viscoelastic changes in sensor applications. The work with QCM-D also involved the detection of structural variations within a thick brush layer of poly(AAc). Since lower overtones have higher penetration depth, these frequencies sense polymer segments further out in the brush. It was found that the apparent pKa of the poly(AAc) was higher for lower overtones, indicating therelative ease of acid dissociation in segments further out in the polyelectrolytebrush. In the second system studied, phenylethylamine (PEA) was electrografted to flatsurfaces of glassy carbon (GC). The nanomechanical properties, such as topography, deformation, adhesion and dissipation, were investigated using PeakForce quantitative nanomechanical mapping (QNM). One main finding is that globular domains of 40 to 50 nm indiameter appear in the electrografted PEA layer. They are assigned to clusters of PEA formed due to less rapid reactions between radicals and the GC surface compared to reactions with already grafted PEA. The interactions between the PEA layer and a silica sphere were further investigated by surface force measurements. A main finding is that the PEA surfaces were heavily charge regulated due to the limited net charge of the PEA layer compared to that of silica. In the third system studied, the mechanical response of polyelectrolytes as a function of applied load, probing angle and pH was investigated with PeakForce QNM. The used polyelectrolyte was poly(2-dimethylaminoethyl methacrylate)(PDMAEMA) with pKa of 6.5 to 7.5 and grafted to silica nanoparticles. While most research on polyelectrolyte brushes is conducted by employing flat and smooth surfaces, with a roughness on the nanometer scale, real surfaces are rarely ever ideally flat but rather they possess topographic irregularities on nano- and micro-scales, which locally imparts high curvatures. The spherical geometry of the core-shell nanoparticles serves as a model for real surfaces with respect to topographical irregularities of real surfaces. The nanoscale brushes were probed with an ultrasharp AFM tip, providing nanoscale resolution of topography, deformation, adhesion and dissipation. It was found that the mechanical response of the polyelectrolyte corona is dependent on the applied load and the polar angle of the tip-brush interaction. All nanomechanical data show a non-monotonic variation with horizontal position, and the peak values are shifted in magnitude and position as a function of peak force. The effect of pH on deformation was further investigated. The results showed that the brush is more resistant against compression over the centre than it is to deflection at larger horizontal positions, and this effect is amplified by charging the brush. This work provided understanding of the direction dependence of the mechanical properties and is relevant for the design of brush boundary lubricating agents for rough surfaces, where the polymer chains are both being bent and compressed under the influence of load and shear.
BibTeX:
@phdthesis{Duner2012b,
  author = {Dunér, Gunnar},
  title = {Grafted Molecular Layers for Control of Surface Properties},
  school = {KTH Royal Institute of Technology},
  year = {2012},
  url = {http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103703}
}
Dunér G, Iruthayaraj J, Daasbjerg K, Pedersen SU, Thormann E and Dėdinaitė A (2012), "Attractive Double-layer Forces and Charge Regulation upon Interaction between Electrografted Amine Layers and Silica", Journal of Colloid and Interface Science., July, 2012. Vol. 385(1), pp. 225-34.
Abstract: Amine functionalities have been introduced on glassy carbon surfaces through electrografting of 4-(2-aminoethyl)benzenediazonium tetrafluoroborate. The grafted layers were characterized by ellipsometry and by nanomechanical mapping in air and aqueous solutions using the atomic force microscopy PeakForce QNM mode. The layer was found to be 2.5 nm thick with low roughness, comparable to that of the glassy carbon substrate. However, small semi-spherical features were observed in the topographical image, indicating a clustering of the grafted amine compound. The nanomechanical mapping also demonstrated some swelling of the layer in water, and pointed towards an important contribution of electrostatic interactions for the tip-surface adhesion. The forces between an aminated glassy carbon surface and a $m-sized silica particle in aqueous solutions were measured at different ionic strength and pH-values. The results demonstrate that an attractive double-layer force predominates at large separations, and that the surface charge densities increase as the separation between the surfaces decreases. The degree of charge regulation on the aminated glassy carbon is significant. The relatively low surface charge density of the aminated glassy carbon is attributed to significant incorporation of counterions in the water-rich grafted layer.
BibTeX:
@article{Duner2012a,
  author = {Dunér, Gunnar and Iruthayaraj, Joseph and Daasbjerg, Kim and Pedersen, Steen Uttrup and Thormann, Esben and Dėdinaitė, Andra},
  title = {Attractive Double-layer Forces and Charge Regulation upon Interaction between Electrografted Amine Layers and Silica},
  journal = {Journal of Colloid and Interface Science},
  year = {2012},
  volume = {385},
  number = {1},
  pages = {225--34},
  url = {http://dx.doi.org/10.1016/j.jcis.2012.06.071 http://www.sciencedirect.com/science/article/pii/S0021979712007175},
  doi = {10.1016/j.jcis.2012.06.071}
}
Dunér G, Thormann E, Dėdinaitė A, Claesson PM, Matyjaszewski K and Tilton RD (2012), "Nanomechanical mapping of a high curvature polymer brush grafted from a rigid nanoparticle", Soft Matter. Vol. 8(32), pp. 8312-8320. The Royal Society of Chemistry.
BibTeX:
@article{Duner2012,
  author = {Dunér, Gunnar and Thormann, Esben and Dėdinaitė, Andra and Claesson, Per M. and Matyjaszewski, Krzysztof and Tilton, Robert D.},
  title = {Nanomechanical mapping of a high curvature polymer brush grafted from a rigid nanoparticle},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2012},
  volume = {8},
  number = {32},
  pages = {8312--8320},
  url = {http://pubs.rsc.org/en/content/articlehtml/2012/sm/c2sm26086g},
  doi = {10.1039/c2sm26086g}
}
Du Plooy JN, Buys A, Duim W and Pretorius E (2013), "Comparison of platelet ultrastructure and elastic properties in thrombo-embolic ischemic stroke and smoking using atomic force and scanning electron microscopy", PloS one., January, 2013. Vol. 8(7), pp. e69774. Public Library of Science.
Abstract: Thrombo-embolic ischemic stroke is a serious and debilitating disease, and it remains the second most common cause of death worldwide. Tobacco smoke exposure continues to be responsible for preventable deaths around the world, and is a major risk factor for stroke. Platelets play a fundamental role in clotting, and their pathophysiological functioning is present in smokers and stroke patients, resulting in a pro-thrombotic state. In the current manuscript, atomic force and scanning electron microscopy were used to compare the platelets of smokers, stroke patients and healthy individuals. Results showed that the elastic modulus of stroke platelets is decreased by up to 40 whereas there is an elasticity decrease of up to 20% in smokers' platelets. This indicates a biophysical alteration of the platelets. Ultrastructurally, both the stroke patients and smokers' platelets are more activated than the healthy control group, with prominent cytoskeletal rearrangement involved; but to a more severe extent in the stroke group than in the smokers. Importantly, this is a confirmation of the extent of smoking as risk factor for stroke. We conclude by suggesting that the combined AFM and SEM analyses of platelets might give valuable information about the disease status of patients. Efficacy of treatment regimes on the integrity, cell shape, roughness and health status of platelets may be tracked, as this cell's health status is crucial in the over-activated coagulation system of conditions like stroke.
BibTeX:
@article{DuPlooy2013,
  author = {Du Plooy, Jeanette Noel and Buys, Antoinette and Duim, Wiebren and Pretorius, Etheresia},
  editor = {Arumugam, Thiruma V.},
  title = {Comparison of platelet ultrastructure and elastic properties in thrombo-embolic ischemic stroke and smoking using atomic force and scanning electron microscopy},
  journal = {PloS one},
  publisher = {Public Library of Science},
  year = {2013},
  volume = {8},
  number = {7},
  pages = {e69774},
  url = {http://dx.plos.org/10.1371/journal.pone.0069774},
  doi = {10.1371/journal.pone.0069774}
}
Durkovic J, Canová I, Lagana R, Kucerová V, Moravck M, Priwitzer T, Urban J, Dvorák M and Krajnáková J (2013), "Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease.", Annals of botany., February, 2013. Vol. 111(2), pp. 215-27.
Abstract: BACKGROUND AND AIMS: Previous studies have shown that Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), is able to colonize remote areas in infected plants of Ulmus such as the leaf midrib and secondary veins. The objective of this study was to compare the performances in leaf traits between two Dutch elm hybrids 'Groeneveld' and 'Dodoens' which possess a contrasting tolerance to DED. Trait linkages were also tested with leaf mass per area (LMA) and with the reduced Young's modulus of elasticity (MOE) as a result of structural, developmental or functional linkages.
METHODS: Measurements and comparisons were made of leaf growth traits, primary xylem density components, gas exchange variables and chlorophyll a fluorescence yields between mature plants of 'Groeneveld' and 'Dodoens' grown under field conditions. A recently developed atomic force microscopy technique, PeakForce quantitative nanomechanical mapping, was used to reveal nanomechanical properties of the cell walls of tracheary elements such as MOE, adhesion and dissipation.
KEY RESULTS: 'Dodoens' had significantly higher values for LMA, leaf tissue thickness variables, tracheary element lumen area (A), relative hydraulic conductivity (RC), gas exchange variables and chlorophyll a fluorescence yields. 'Groeneveld' had stiffer cell walls of tracheary elements, and higher values for water-use efficiency and leaf water potential. Leaves with a large carbon and nutrient investment in LMA tended to have a greater leaf thickness and a higher net photosynthetic rate, but LMA was independent of RC. Significant linkages were also found between the MOE and some vascular traits such as RC, A and the number of tracheary elements per unit area.
CONCLUSIONS: Strong dissimilarities in leaf trait performances were observed between the examined Dutch elm hybrids. Both hybrids were clearly separated from each other in the multivariate leaf trait space. Leaf growth, vascular and gas exchange traits in the infected plants of 'Dodoens' were unaffected by the DED fungus. 'Dodoens' proved to be a valuable elm germplasm for further breeding strategies.
BibTeX:
@article{Durkovic2012,
  author = {Durkovic, Jaroslav and Canová, Ingrid and Lagana, Rastislav and Kucerová, Veronika and Moravck, Michal and Priwitzer, Tibor and Urban, Josef and Dvorák, Milon and Krajnáková, Jana},
  title = {Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease.},
  journal = {Annals of botany},
  year = {2013},
  volume = {111},
  number = {2},
  pages = {215--27},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23264236 http://aob.oxfordjournals.org/content/early/2012/12/20/aob.mcs274.short},
  doi = {10.1093/aob/mcs274}
}
Dworak N, Wnuk M, Zebrowski J, Bartosz G and Lewinska A (2013), "Genotoxic and mutagenic activity of diamond nanoparticles in human peripheral lymphocytes in vitro", Carbon.
Abstract: Carbon nanomaterials have the numerous applications in biomedical sciences and nanotechnology-based industries. Nanodiamonds due to their unique physico-chemical properties compared to other carbon nanomaterials are suggested to be better drug carriers or implant coating. Nevertheless, little is known about their short- and long-term toxicological effects on humans, other biological systems and surrounding environment. In the present study, we evaluated genotoxic and mutagenic potential of nanodiamond (particle size <10nm) in human lymphocytes in vitro. Starting from concentration of 50$g/ml, diamond nanopowder was cytotoxic, inhibited cell proliferation and induced apoptotic cell death. Nanodiamond-associated oxidative stress was revealed, the effect was dose-dependent and statistically significant. Nanodiamond-mediated DNA oxidative damage (8-oxoG level) and changes in chromatin stability was observed even at as low as 1$g/ml concentration, which was especially seen for DNA single strand breaks estimated with alkaline comet assay. In contrast, no induction of DNA double strand breaks (neutral comet assay) was documented after nanodiamond treatment. Nanodiamond at concentration of 10$g/ml was able to stimulate micronuclei production. Centromeric signals found in nanodiamond-induced micronuclei may be due to aneugenic activity of diamond nanopowder. Taken together, we showed that nanodiamond-mediated oxidative stress may contribute to DNA damage limiting nanodiamond biocompatibility.
BibTeX:
@article{Dworak2013,
  author = {Dworak, Natalia and Wnuk, Maciej and Zebrowski, Jacek and Bartosz, Grzegorz and Lewinska, Anna},
  title = {Genotoxic and mutagenic activity of diamond nanoparticles in human peripheral lymphocytes in vitro},
  journal = {Carbon},
  year = {2013},
  url = {http://www.sciencedirect.com/science/article/pii/S0008622313011329}
}
Earl SK, James TD, Marvel RE, Gomez DE, Davis TJ, Valentine JG, McCallum JC, Haglund RF and Roberts A (2013), "Vanadium dioxide thickness effects on tunable optical antennas", In SPIE Micro+Nano Materials, Devices, and Applications., December, 2013. , pp. 89232S. International Society for Optics and Photonics.
BibTeX:
@inproceedings{Earl2013,
  author = {Earl, Stuart K. and James, Timothy D. and Marvel, Robert E. and Gomez, Daniel E. and Davis, Timothy J. and Valentine, Jason G. and McCallum, Jeffrey C. and Haglund, Richard F. and Roberts, Ann},
  editor = {Friend, James and Tan, H. Hoe},
  title = {Vanadium dioxide thickness effects on tunable optical antennas},
  booktitle = {SPIE Micro+Nano Materials, Devices, and Applications},
  publisher = {International Society for Optics and Photonics},
  year = {2013},
  pages = {89232S},
  url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1788919 http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2033739},
  doi = {10.1117/12.2033739}
}
El H, Utegulov ZN, Khafizov M, Zaeem MA, Mamivand M, El Kadiri H, Asle Zaeem M, Oppedal A, Enakoutsa K, Cherkaoui M, Graham R and Arockiasamy A (2013), "Transformations and cracks in zirconia films leading to breakaway oxidation of Zircaloy", Acta Materialia., April, 2013. Vol. 61(11), pp. 3923-35. Acta Materialia Inc..
Abstract: Using combined Raman spectroscopy, atomic force microscopy and optical microscopy, this paper suggests that breakaway oxidation of Zircaloy is caused by the change of circumferential stress sign from compressive to tensile, which triggers catastrophic cracks to propagate from the oxide free surface toward the oxide–metal interface. The stress sign changes at a critical oxide thickness, which depends on the circumferential stress at the interface. This biaxial interfacial stress is promoted by a lattice expansion stress that accompanies the tetragonal to monoclinic crystal phase transition. In contrast with current research in the literature, this allotropic transformation is suggested to be beneficial, not detrimental, because it contributes to retard the thresholds for the change of circumferential stress sign, and thus breakaway oxidation. The tetragonal phase was revealed to localize at the interface and adopt the shape of prismatic isosceles triangles detected at early stages of oxidation. These growth morphologies are consistent with a cationic oxidation mechanism. Upon phase transition, the monoclinic variant quickly dominates the oxide scale above the interfacial regions and forces the overall oxidation to proceed by an anionic diffusion mechanism. The results of Raman spectroscopy compared well with those of atomic force microscopy.
BibTeX:
@article{ElKadiri2013,
  author = {El, Haitham and Utegulov, Z.N. N and Khafizov, M. and Zaeem, M Asle and Mamivand, M. and El Kadiri, Haitham and Asle Zaeem, M. and Oppedal, A.L. and Enakoutsa, K. and Cherkaoui, M. and Graham, R.H. and Arockiasamy, A.},
  title = {Transformations and cracks in zirconia films leading to breakaway oxidation of Zircaloy},
  journal = {Acta Materialia},
  publisher = {Acta Materialia Inc.},
  year = {2013},
  volume = {61},
  number = {11},
  pages = {3923--35},
  url = {http://dx.doi.org/10.1016/j.actamat.2013.02.052},
  doi = {10.1016/j.actamat.2013.02.052}
}
Elsen AM, Li Y, Li Q, Sheiko SS and Matyjaszewski K (2013), "Exploring Quality in Gradient Copolymers.", Macromolecular Rapid Communications., October, 2013.
Abstract: Quality of gradient copolymers is evaluated by atomic force microscopy (AFM) and correlated with molecular weight distribution (MWD) values. ARGET ATRP is employed with decreasing levels of catalyst concentrations to generate copolymers with increasing M¯w/M¯n values. The copolymers are transformed into molecular bottlebrushes to enable imaging and analysis of individual molecules by AFM. The average height (cross-sectional) profile of all bottlebrushes agrees with the instantaneous composition (ICHEMA-TMS ) of the analogous copolymer backbone, as determined by (1) H NMR. The copolymer synthesized with 500 ppm of catalyst exhibits more narrow distributions of both brush height and backbone length when analyzed as a bottlebrush by AFM. Correspondingly, the copolymers synthesized with lower catalyst concentrations yield bottlebrushes with broader height and length distribution. These results establish MWD values as an excellent trait to assess quality within gradient copolymers.
BibTeX:
@article{Elsen2013,
  author = {Elsen, Andrea M and Li, Yuanchao and Li, Qiaoxi and Sheiko, Sergei S and Matyjaszewski, Krzysztof},
  title = {Exploring Quality in Gradient Copolymers.},
  journal = {Macromolecular Rapid Communications},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/24150838},
  doi = {10.1002/marc.201300654}
}
Erickson B, Fang M, Wallace JM, Orr BG, Les CM and Banaszak Holl MM (2013), "Nanoscale structure of type I collagen fibrils: Quantitative measurement of D-spacing", Biotechnology Journal., January, 2013. Vol. 8(1), pp. 117-126.
BibTeX:
@article{erickson_nanoscale_2013,
  author = {Erickson, Blake and Fang, Ming and Wallace, Joseph M and Orr, Bradford G and Les, Clifford M and Banaszak Holl, Mark M},
  title = {Nanoscale structure of type I collagen fibrils: Quantitative measurement of D-spacing},
  journal = {Biotechnology Journal},
  year = {2013},
  volume = {8},
  number = {1},
  pages = {117--126},
  url = {http://doi.wiley.com/10.1002/biot.201200174},
  doi = {10.1002/biot.201200174}
}
Eskelsen JR, Qi Y, Schneider-Pollack S, Schmitt S, Hipps KW and Mazur U (2013), "Correlating elastic properties and molecular organization of an ionic organic nanostructure.", Nanoscale., November, 2013. , pp. 316-327. The Royal Society of Chemistry.
Abstract: Mechanical and structural properties of ionically self-assembled nanostructures of meso-tetra(4-sulfonatophenyl)porphyrin (TSPP) and meso-tetra(4-pyridyl)porphyrin (TPyP) are presented. This is the first time that elastic modulus of an ionic porphyrin nanostructure has been reported. X-ray photoelectron spectroscopy (XPS), UV-visible spectra, and elemental analysis all support a stoichiometric 1 : 1 TSPP to TPyP composition. Atomic force microscopy (AFM) revealed that the porphyrin nanostructure is composed of stacked ribbons about 20 nm tall, 70 nm wide, and several microns in length. High resolution transmission electron microscopy (HRTEM) images showed clear lattice fringes 1.5 ± 0.2 nm in width aligned along the length of the nanorod. Selected area electron diffraction (SAED) and powder X-ray diffraction patterns of TSPP:TPyP are consistent with an orthorhombic system and space group Imm2 with lattice parameters a = 26.71 b = 20.16 and c = 8.61 Crystallographic data is consistent with an arrangement of alternating face-to-face TSPP and TPyP molecules forming ordered columns along the length of the nanorods. The structural integrity of the solid is attributed to combined noncovalent interactions that include ionic, hydrogen bonding, and $-$ interactions. The values of Young's modulus obtained for the crystalline TSPP:TPyP nanorods averaged 6.5 ± 1.3 GPa. This modulus is comparable to those reported for covalently bonded flexible polymeric systems. The robust bonding character of the TSPP:TPyP nanostructures combined with their mechanical properties makes them excellent candidates for flexible optoelectronic devices.
BibTeX:
@article{Eskelsen2013,
  author = {Eskelsen, Jeremy R and Qi, Yun and Schneider-Pollack, Samantha and Schmitt, Samantha and Hipps, K W and Mazur, Ursula},
  title = {Correlating elastic properties and molecular organization of an ionic organic nanostructure.},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  pages = {316--327},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/nr/c3nr05047e},
  doi = {10.1039/c3nr05047e}
}
Faingold A, Cohen SR, Shahar R, Weiner S, Rapoport L and Wagner HD (2013), "The effect of hydration on mechanical anisotropy, topography and fibril organization of the osteonal lamellae", Journal of Biomechanics. Vol. 47(2), pp. 367-372. Elsevier.
Abstract: The effect of hydration on the mechanical properties of osteonal bone, in directions parallel and perpendicular to the bone axis, was studied on three length scales: (i) the mineralized fibril level (100nm), (ii) the lamellar level (6µm); and (iii) the osteon level (up to 30µm).We used a number of techniques, namely atomic force microscopy (AFM), nanoindentation and microindentation. The mechanical properties (stiffness, modulus and/or hardness) have been studied under dry and wet conditions. On all three length scales the mechanical properties under dry conditions were found to be higher by 30–50% compared to wet conditions. Also the mechanical anisotropy, represented by the ratio between the properties in directions parallel and perpendicular to the osteon axis (anisotropy ratio, designated here by AnR), surprisingly decreased somewhat upon hydration. AFM imaging of osteonal lamellae revealed a disappearance of the distinctive lamellar structure under wet conditions. Altogether, these results suggest that a change in mineralized fibril orientation takes place upon hydration.
BibTeX:
@article{Faingold2013,
  author = {Faingold, A. and Cohen, S. R. and Shahar, R. and Weiner, S. and Rapoport, L. and Wagner, H. D.},
  title = {The effect of hydration on mechanical anisotropy, topography and fibril organization of the osteonal lamellae},
  journal = {Journal of Biomechanics},
  publisher = {Elsevier},
  year = {2013},
  volume = {47},
  number = {2},
  pages = {367--372},
  url = {http://www.sciencedirect.com/science/article/pii/S0021929013005745 http://dx.doi.org/10.1016/j.jbiomech.2013.11.022},
  doi = {10.1016/j.jbiomech.2013.11.022}
}
Falk M, Andoralov V, Blum Z, Sotres J, Suyatin DB, Ruzgas T, Arnebrant T and Shleev S (2012), "Biofuel cell as a power source for electronic contact lenses", Biosensors and Bioelectronics., August, 2012. Vol. 37(1), pp. 38-45. Elsevier.
Abstract: Here we present unequivocal experimental proof that microscale cofactor- and membrane-less, direct electron transfer based enzymatic fuel cells do produce significant amounts of electrical energy in human lachrymal liquid (tears). 100 $m diameter gold wires, covered with 17 nm gold nanoparticles, were used to fashion three-dimensional nanostructured microelectrodes, which were biomodified with Corynascus thermophilus cellobiose dehydrogenase and Myrothecium verrucaria bilirubin oxidase as anodic and cathodic bioelements, respectively. The following characteristics of miniature glucose/oxygen biodevices operating in human tears were registered: 0.57 V open-circuit voltage, about 1 $W cm−2 maximum power density at a cell voltage of 0.5 V, and more than 20 h operational half-life. Theoretical calculations regarding the maximum recoverable electrical energy can be extracted from the biofuel and the biooxidant, glucose and molecular oxygen, each readily available in human lachrymal liquid, fully support our belief that biofuel cells can be used as electrical power sources for so called smart contact lenses.
BibTeX:
@article{falk_biofuel_2012,
  author = {Falk, Magnus and Andoralov, Viktor and Blum, Zoltan and Sotres, Javier and Suyatin, Dmitry B and Ruzgas, Tautgirdas and Arnebrant, Thomas and Shleev, Sergey},
  title = {Biofuel cell as a power source for electronic contact lenses},
  journal = {Biosensors and Bioelectronics},
  publisher = {Elsevier},
  year = {2012},
  volume = {37},
  number = {1},
  pages = {38--45},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0956566312002461 http://www.ncbi.nlm.nih.gov/pubmed/22621980},
  doi = {10.1016/j.bios.2012.04.030}
}
Fejfar A, Hývl M, Ledinský M, Vetushka A, Stuchlk J, Kočka J, Misra S, O’Donnell B, Foldyna M, Yu L and Roca i Cabarrocas P (2013), "Microscopic measurements of variations in local (photo)electronic properties in nanostructured solar cells", Solar Energy Materials and Solar Cells., December, 2013. Vol. 119, pp. 228-234.
Abstract: Modern nanostructured designs of solar cells improve photovoltaic conversion by better light trapping and collection of photogenerated charges. Illustrative example may be cells composed of radial junctions on semiconductor nanowires. In other cells the structural elements can be nanowires, nanorods or random light trapping structures. The elements have sizes from nm to $m. Inevitably, they exhibit variations of shape, size and properties which influence local photovoltaic conversion. The cells operate as random arrays of microscopic photodiodes connected in parallel with overall performance limited by weak diodes. Microscopic measurements of photoresponse are needed to assess the distribution of the local photodiodes, their connections and influence of weak diodes. We demonstrate the use of atomic force microscopy (AFM) with conductive cantilever for study of local (photo)electronic properties of silicon nanostructures: p–i–n radial junctions of amorphous Si grown on Si nanowires or mixed phase microcrystalline films. We have used the conductive AFM to study the local photoresponse of the microcrystalline grains in mixed phase thin films to changes of external illumination. We have observed variations of the conductivity of the radial junction solar cells based on Si nanowires. Finally, we discuss possibilities of comparing the local photoresponse to local photovoltaic conversion efficiency.
BibTeX:
@article{Fejfar2013,
  author = {Fejfar, Antonn and Hývl, Matěj and Ledinský, Martin and Vetushka, Aliaksei and Stuchlk, Jiř and Kočka, Jan and Misra, Soumyadeep and O’Donnell, Benedict and Foldyna, Martin and Yu, Linwei and Roca i Cabarrocas, Pere},
  title = {Microscopic measurements of variations in local (photo)electronic properties in nanostructured solar cells},
  journal = {Solar Energy Materials and Solar Cells},
  year = {2013},
  volume = {119},
  pages = {228--234},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0927024813003887 http://www.sciencedirect.com/science/article/pii/S0927024813003887},
  doi = {10.1016/j.solmat.2013.07.042}
}
Fischer H, Stadler H and Erina N (2013), "Quantitative temperature-depending mapping of mechanical properties of bitumen at the nanoscale using the AFM operated with PeakForce Tapping(TM) mode.", Journal of Microscopy., April, 2013.
Abstract: The mechanical properties of bitumen, such as elasticity/Young's modulus, stickiness/adhesion, hardness and energy loss, and sample deformation were acquired quantitatively and simultaneously with the topology at the microscale, discriminating clearly two separate phases within the bitumen. Temperature-dependent measurements revealed detailed and specific data about the changes of these properties with temperature, enabling the development of predictive models for the performance and durability of asphalt.
BibTeX:
@article{Fischer2013,
  author = {Fischer, H and Stadler, H and Erina, N},
  title = {Quantitative temperature-depending mapping of mechanical properties of bitumen at the nanoscale using the AFM operated with PeakForce Tapping(TM) mode.},
  journal = {Journal of Microscopy},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23550689},
  doi = {10.1111/jmi.12036}
}
Fleming RA and Zou M (2013), "Silica nanoparticle-based films on titanium substrates with long-term superhydrophilic and superhydrophobic stability", Applied Surface Science., September, 2013. Vol. 280, pp. 820-827.
Abstract: We report the fabrication of stable superhydrophilic and superhydrophobic surfaces on titanium substrates using simple methods. Sandblasting the titanium surface to generate microscale roughness, followed by dip-coating in a colloidal silica nanoparticle solution to generate nanoscale roughness and a hydrophilic surface chemistry, produces a superhydrophilic surface. Further chemical modification with a several-nanometer-thick low surface energy fluorinated carbon film renders the surface superhydrophobic. The wettability of these superhydrophilic and superhydrophobic surfaces display a high degree of stability, as both surfaces retain their wetting properties for at least 54 days under multiple wetting/de-wetting cycles. Furthermore, the superhydrophilic surfaces retain their wetting properties in excess of 25 months after storage in ambient atmosphere. Due to their long-term wetting stability and ease of fabrication, these surfaces have potential applications in a variety of fields, including biomedical fields where titanium is widely used.
BibTeX:
@article{fleming_silica_2013,
  author = {Fleming, Robert A. and Zou, Min},
  title = {Silica nanoparticle-based films on titanium substrates with long-term superhydrophilic and superhydrophobic stability},
  journal = {Applied Surface Science},
  year = {2013},
  volume = {280},
  pages = {820--827},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0169433213009951},
  doi = {10.1016/j.apsusc.2013.05.068}
}
Florian M, Merle K, Joachim S, Ludwig J, Tobias M, Renate H, Dominik K and Roswitha Z (2014), "Morphology Studies on High-Temperature Polymer Electrolyte Membrane Fuel Cell Electrodes", Journal of Power Sources., January, 2014. Elsevier Ltd.
Abstract: The electrode morphology influences the properties and performance of polymer electrolyte membrane fuel cells (PEMFC). Here we report our studies of two different electrodes for high-temperature PEMFC prepared by spraying and coating and their impact on the fuel cell performance. Differences in 3D microstructure and adhesion between catalyst layer and gas diffusion layer (GDL) of the electrodes were studied with X-ray microtomography. Scanning electrode microscope investigations show hairline cracks between agglomerates on the surface of the sprayed electrode, whereas the coated electrode shows a network of shrinkage cracks in the catalyst layer. The distribution of the electrode binder polytetrafluoroethylene (PTFE) is related to the locally resolved conductivity, which was determined by scanning the electrode surfaces with a conductive atomic force microscopy (AFM) tip. The macrostructures of the sprayed and coated electrodes are different but contain similar pore structures. The coated electrode has a higher PTFE concentration on the top region, which tends to form a nonconductive and less wettable “skin? on the electrode surface and delays the start-up of the fuel cell. In contrast to low-temperature PEMFC, the electrode morphology has only a minor impact on the steady-state cell performance of high-temperature PEMFC.
BibTeX:
@article{Florian2014,
  author = {Florian, Mack and Merle, Klages and Joachim, Scholta and Ludwig, Jörissen and Tobias, Morawietz and Renate, Hiesgen and Dominik, Kramer and Roswitha, Zeis},
  title = {Morphology Studies on High-Temperature Polymer Electrolyte Membrane Fuel Cell Electrodes},
  journal = {Journal of Power Sources},
  publisher = {Elsevier Ltd},
  year = {2014},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0378775314000470 http://www.sciencedirect.com/science/article/pii/S0378775314000470},
  doi = {10.1016/j.jpowsour.2014.01.032}
}
Foncy J, Cau J-c, Bartual-murgui C, François JM, Trévisiol E, Sévérac C and Marie J (2013), "Comparison of polyurethane and epoxy resist master mold for nanoscale soft lithography", Microelectronic Engineering., March, 2013. Vol. 110, pp. 183-7. Elsevier B.V..
Abstract: Soft lithography at the nanoscale requires a nanostructured silicon master mold generated by ebeam lithography and reactive ion etching. Such a fabrication is both expensive and time consuming for an expected industrial use of polydimethylsiloxane (PDMS) stamps in soft lithography. Our work focuses on a easy – low cost – technology to duplicate silicon master molds with nanoscale structures. Hence, master silicon molds patterned with nanometer scale lines have been replicated into epoxy resist and polyurethane by a process that implicated the following steps. First, the PDMS stamp made from a silicon master mold was used as template to copy this original mold into epoxy resist or polyurethane layer by nanoimprint. After characterization by Atomic Force Microscopy (AFM), these replicated molds were used to generate a second generation of PDMS stamps, which were ultimately employed to transfer labeled DNA probes on epoxysilane slides by soft lithography. Fluorescent microscopy reveals that molecular nanoscale patterns produced by these second generation PDMS stamps were exquisitely identical to those from the original PDMS stamp. As a conclusion, the epoxy resist or polyurethane are very attractive and cost-effective substrate to reproduce at large scale PDMS stamps initially made on a nanostructured silicon master mold.
BibTeX:
@article{foncy_comparison_2013,
  author = {Foncy, Julie and Cau, Jean-christophe and Bartual-murgui, Carlos and François, Jean Marie and Trévisiol, Emmanuelle and Sévérac, Childérick and Marie, Jean},
  title = {Comparison of polyurethane and epoxy resist master mold for nanoscale soft lithography},
  journal = {Microelectronic Engineering},
  publisher = {Elsevier B.V.},
  year = {2013},
  volume = {110},
  pages = {183--7},
  url = {http://dx.doi.org/10.1016/j.mee.2013.03.102 http://linkinghub.elsevier.com/retrieve/pii/S0167931713003316},
  doi = {10.1016/j.mee.2013.03.102}
}
Fortier P, Suei S and Kreplak L (2012), "Nanoscale strain-hardening of keratin fibres", PloS one., January, 2012. Vol. 7(7), pp. e41814.
Abstract: Mammalian appendages such as hair, quill and wool have a unique structure composed of a cuticle, a cortex and a medulla. The cortex, responsible for the mechanical properties of the fibers, is an assemblage of spindle-shaped keratinized cells bound together by a lipid/protein sandwich called the cell membrane complex. Each cell is itself an assembly of macrofibrils around 300 nm in diameter that are paracrystalline arrays of keratin intermediate filaments embedded in a sulfur-rich protein matrix. Each macrofibril is also attached to its neighbors by a cell membrane complex. In this study, we combined atomic force microscopy based nano-indentation with peak-force imaging to study the nanomechanical properties of macrofibrils perpendicular to their axis. For indentation depths in the 200 to 500 nm range we observed a decrease of the dynamic elastic modulus at 1 Hz with increasing depth. This yielded an estimate of 1.6GPa for the lateral modulus at 1 Hz of porcupine quill's macrofibrils. Using the same data we also estimated the dynamic elastic modulus at 1 Hz of the cell membrane complex surrounding each macrofibril, i.e., 13GPa. A similar estimate was obtained independently through elastic maps of the macrofibrils surface obtained in peak-force mode at 1 kHz. Furthermore, the macrofibrillar texture of the cortical cells was clearly identified on the elasticity maps, with the boundaries between macrofibrils being 40-50% stiffer than the macrofibrils themselves. Elasticity maps after indentation also revealed a local increase in dynamic elastic modulus over time indicative of a relaxation induced strain hardening that could be explained in term of a $-helix to $-sheet transition within the macrofibrils.
BibTeX:
@article{Fortier2012,
  author = {Fortier, Patrick and Suei, Sandy and Kreplak, Laurent},
  title = {Nanoscale strain-hardening of keratin fibres},
  journal = {PloS one},
  year = {2012},
  volume = {7},
  number = {7},
  pages = {e41814},
  url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3404990&tool=pmcentrez&rendertype=abstract},
  doi = {10.1371/journal.pone.0041814}
}
Foster B (2012), "New Atomic Force Microscopy (AFM) Approaches Life Sciences Gently, Quantitatively, and Correlatively", American Laboratory. (April), pp. 24-27.
Abstract: As discussed in last November’s Editor’s Page, the life sciences are the key sector propelling growth in microscopy and imaging. A large part of biological research centers inside the cell. While those internal structures and processes are still important, the rise of molecular biology and biophysics is driving new interest in both the cell membrane and in measuring the cell’s nano-mechanical properties, both at the cellular and molecular level. This shift is opening new life science opportunities for atomic force microscopy (AFM).
BibTeX:
@article{Foster2012,
  author = {Foster, Barbara},
  title = {New Atomic Force Microscopy (AFM) Approaches Life Sciences Gently, Quantitatively, and Correlatively},
  journal = {American Laboratory},
  year = {2012},
  number = {April},
  pages = {24--27},
  url = {http://www.bruker-axs.com/fileadmin/userupload/PDF2012/misc/AmericanLaboratoryNewAFM-ApproachesApril2012.pdf}
}
Francois JM, Formosa C, Schiavone M, Pillet F, Martin-Yken H and Dague E (2013), "Use of atomic force microscopy (AFM) to explore cell wall properties and response to stress in the yeast Saccharomyces cerevisiae", Current Genetics., November, 2013. Vol. 59(4), pp. 187-96.
Abstract: Over the past 20 years, the yeast cell wall has been thoroughly investigated by genetic and biochemical methods, leading to remarkable advances in the understanding of its biogenesis and molecular architecture as well as to the mechanisms by which this organelle is remodeled in response to environmental stresses. Being a dynamic structure that constitutes the frontier between the cell interior and its immediate surroundings, imaging cell surface, measuring mechanical properties of cell wall or probing cell surface proteins for localization or interaction with external biomolecules are among the most burning questions that biologists wished to address in order to better understand the structure-function relationships of yeast cell wall in adhesion, flocculation, aggregation, biofilm formation, interaction with antifungal drugs or toxins, as well as response to environmental stresses, such as temperature changes, osmotic pressure, shearing stress, etc. The atomic force microscopy (AFM) is nowadays the most qualified and developed technique that offers the possibilities to address these questions since it allows working directly on living cells to explore and manipulate cell surface properties at nanometer resolution and to analyze cell wall proteins at the single molecule level. In this minireview, we will summarize the most recent contributions made by AFM in the analysis of the biomechanical and biochemical properties of the yeast cell wall and illustrate the power of this tool to unravel unexpected effects caused by environmental stresses and antifungal agents on the surface of living yeast cells.
BibTeX:
@article{Francois2013,
  author = {Francois, Jean Marie and Formosa, Cécile and Schiavone, Marion and Pillet, Flavien and Martin-Yken, Hélène and Dague, Etienne},
  title = {Use of atomic force microscopy (AFM) to explore cell wall properties and response to stress in the yeast Saccharomyces cerevisiae},
  journal = {Current Genetics},
  year = {2013},
  volume = {59},
  number = {4},
  pages = {187--96},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/24071902 http://link.springer.com/10.1007/s00294-013-0411-0},
  doi = {10.1007/s00294-013-0411-0}
}
Frechette MF, Preda O, Krivda A, Veillette R, Trudeau M, Vaughan AS, David E, Couderc H, Vanga C and Castellon J (2012), "Polymer composites having large content of nanofiller: a case study involving epoxy", IEEE Conference on Electrical Insulation and Dielectric Phenomena. Montreal, Canada , pp. 541-6.
Abstract: The situation where the polymer nanocomposite contains a large amount of organic filler was studied. An epoxy nanocomposite having a content of 20% wt of nanosilica was used. Emphasis was put on imaging at nanoscale and some dielectric responses were measured using dielectric spectroscopy. Using HAAD mode, an area of less than 4 nm surrounding an isolated particle was imaged and found to have a very low atomic number. Only with AFM in peak-force mode that agglomerates were clearly detected. Relative to the dielectric response, no interfacial relaxation peak was observed. In spite of some agglomeration, the real part of the permittivity was found to be increased by the adjunct of the nanofiller
BibTeX:
@article{frechette2012polymer,
  author = {Frechette, M. F. and Preda, O. and Krivda, A. and Veillette, R. and Trudeau, M. and Vaughan, A. S. and David, E. and Couderc, H. and Vanga, C. and Castellon, J.},
  title = {Polymer composites having large content of nanofiller: a case study involving epoxy},
  journal = {IEEE Conference on Electrical Insulation and Dielectric Phenomena},
  year = {2012},
  pages = {541--6},
  url = {http://eprints.soton.ac.uk/344319/}
}
Frone AN, Berlioz S, Chailan J-F and Panaitescu DM (2013), "Morphology and thermal properties of PLA - cellulose nanofibers composites", Carbohydrate Polymers., August, 2013. Vol. 91(1), pp. 377-84.
Abstract: Biodegradable nanocomposites were obtained from polylactic acid (PLA) and cellulose nanofibers with diameters ranging from 11 to 44 nm. The influence of treated (with 3-aminopropyltriethoxysilane) and untreated nanofibers on the thermal properties of PLA was investigated in detail using multiple session Differential Scanning Calorimetry (DSC) analysis. The nucleating effect of the cellulose nanofibers was confirmed by all the DSC runs (two melting and two crystallization steps). The morphology of both neat PLA and nanocomposites was explored for the first time using a new powerful AFM technique, Peak Force QNM (Quantitative Mechanical Property Mapping at the Nanoscale), which emphasized the nanolevel characteristics by elastic modulus mapping. QNM analyses showed a better dispersion of the silane treated nanofibers in the matrix as compared to the untreated ones. Moreover, a higher degree of crystallinity was detected in the PLA composites containing untreated nanofibers compared to the composites with treated ones.
BibTeX:
@article{Frone2012,
  author = {Frone, Adriana N. and Berlioz, Sophie and Chailan, Jean-François and Panaitescu, Denis M.},
  title = {Morphology and thermal properties of PLA - cellulose nanofibers composites},
  journal = {Carbohydrate Polymers},
  year = {2013},
  volume = {91},
  number = {1},
  pages = {377--84},
  url = {http://dx.doi.org/10.1016/j.carbpol.2012.08.054},
  doi = {10.1016/j.carbpol.2012.08.054}
}
Frone AN, Perrin FX, Radovici C and Panaitescu DM (2013), "Influence of branched or un-branched alkyl substitutes of POSS on morphology, thermal and mechanical properties of polyethylene", Composites Part B: Engineering., February, 2013. Vol. 50, pp. 98-106. Elsevier Ltd.
Abstract: Organic-inorganic hybrids comprising octakis(dimethylsiloxy)octasilsesquioxanes with linear (POSSl) and branched C5 substitutes (POSSb) and low density polyethylene (PE) were prepared by a melt mixing method. The influence of both structure and concentration of POSSs on the morphological, thermal and mechanical characteristics of PE/POSSs nanocomposites was investigated. QNM analysis showed a similar distribution of POSS fillers regardless their structure. XRD and DSC results indicated that the addition of POSS does not induce changes in the crystal structure of PE but influences the amorphous peak characteristics and crystallinity degree. TGA analysis revealed that the presence of POSS strongly improves the thermo-oxidative stability of PE, the thermal stabilization effect being nearly the same for both POSS types. Mechanical characterization showed significant improvement of tensile strength and elongation properties of PE/POSS nanocomposites as compared to neat PE, the enhancement of mechanical properties being more pronounced for nanocomposite containing POSSb.
BibTeX:
@article{Frone2013,
  author = {Frone, Adriana Nicoleta and Perrin, François Xavier and Radovici, Constantin and Panaitescu, Denis Mihaela},
  title = {Influence of branched or un-branched alkyl substitutes of POSS on morphology, thermal and mechanical properties of polyethylene},
  journal = {Composites Part B: Engineering},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {50},
  pages = {98--106},
  url = {http://dx.doi.org/10.1016/j.compositesb.2013.01.028},
  doi = {10.1016/j.compositesb.2013.01.028}
}
Fu W-E, He BC and Chang YQ (2013), "Surface Mechanical Property Assessment of Ultra-Thin HfO 2 Films", Thin Solid Films., April, 2013.
Abstract: As the devices scale down, HfO2 is an excellent gate dielectric material and can replace SiO2 in complementary metal-oxide semiconductor technology. However, the mechanical property-based reliability such as wear resistance and deformation mechanism are rarely understood. This paper describes the effect of annealing treatment on 20-nm-thick HfO2 films under varying applied normal forces (31.3–104.2 $N). According to grazing incident X-ray diffraction analysis, the HfO2 thin films changed from amorphous to polycrystalline structure after annealing treatment. The scratch depth relative to initial surface was proportional to normal force. In addition, plowing behavior dominated the deformation mechanism in the form of lumps along the edge of groove by atomic force microscopy images. The annealing-induced crystallization resulted in reduced penetration depth, coefficient of friction, and wear rate at all applied normal forces, indicating that the surface hardness and wear resistance of HfO2 thin films can be enhanced through appropriate annealing treatment. Furthermore, substrate effect caused negative correlation between wear resistance and normal force was not obvious to annealed samples. It could be attributed to the broadening of HfSixOy interfacial layer which enhanced the structure strength
BibTeX:
@article{fu_surface_2013,
  author = {Fu, Wei-En and He, B. C. and Chang, Y. Q.},
  title = {Surface Mechanical Property Assessment of Ultra-Thin HfO 2 Films},
  journal = {Thin Solid Films},
  year = {2013},
  url = {http://www.sciencedirect.com/science/article/pii/S0040609013005774},
  doi = {10.1016/j.tsf.2013.03.117}
}
Garca S, Cuscó C, Brissos RF, Torrents E, Caubet A and Gamez P (2012), "Dual role of Cu²? ions on the aggregation and degradation of soluble A$ oligomers and protofibrils investigated by fluorescence spectroscopy and AFM", Journal of Inorganic Biochemistry., November, 2012. Vol. 116, pp. 26-36. Elsevier Inc..
Abstract: The neuropathological character of copper(II) ions (Cu(2+)) upon interaction with soluble human amyloid-$(1-42) that subsequently generates senile plaques and/or reactive oxygen species (ROS) is considered as one of the very important features of Alzheimer's disease. The present study carried out by using fluorescence spectroscopy and atomic-force microscopy (AFM) indeed confirms the dual role played by Cu(2+), namely as mediator of protein aggregation and as generator of ROS leading to irreversible protein alteration, which most likely involve two distinct copper-binding sites. The AFM investigations clearly evidence the copper-induced aggregation of A$ oligomers and protofibrils, while comparative fluorescence measurements with copper and zinc reveals the crucial involvement of redox-active copper in the generation of A$-cross-linked structures.
BibTeX:
@article{garcia_dual_2012,
  author = {Garca, Silvia and Cuscó, Cristina and Brissos, Rosa F. and Torrents, Ester and Caubet, Amparo and Gamez, Patrick},
  title = {Dual role of Cu²? ions on the aggregation and degradation of soluble A$ oligomers and protofibrils investigated by fluorescence spectroscopy and AFM},
  journal = {Journal of Inorganic Biochemistry},
  publisher = {Elsevier Inc.},
  year = {2012},
  volume = {116},
  pages = {26--36},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0162013412002255 http://www.sciencedirect.com/science/article/pii/S0162013412002255 http://www.ncbi.nlm.nih.gov/pubmed/23010326},
  doi = {10.1016/j.jinorgbio.2012.07.007}
}
Geydt P (2013), "Kelvin Probe Force Microscopy (KPFM) characterization of lanthanum lutetium oxide high-k dielectric thin films". Thesis at: LAPPEENRANTA UNIVERSITY OF TECHNOLOGY.
Abstract: Lanthanum lutetium oxide (LaLuO3) thin films were investigated considering their perspective application for industrial microelectronics. Scanning probe microscopy (SPM) techniques permitted to visualize the surface topography and study the electric properties. This work compared both the material properties (charge behavior for samples of 6 nm and 25 nm width) and the applied SPM modes. Particularly, Kelvin probe force microscopy (KPFM) was applied to characterize local potential difference with high lateral resolution. Measurements showed the difference in morphology, chargeability and charge dissipation time for both samples. The polarity effect was detected for this material for the first time. Lateral spreading of the charged spots indicate the diffusive mechanism to be predominant in charge dissipation. This allowed to estimate the diffusion coefficient and mobility. Using simple electrostatic model it was found that charge is partly leaking into the interface oxide layer.
BibTeX:
@phdthesis{Geydt2013,
  author = {Geydt, Pavel},
  title = {Kelvin Probe Force Microscopy (KPFM) characterization of lanthanum lutetium oxide high-k dielectric thin films},
  school = {LAPPEENRANTA UNIVERSITY OF TECHNOLOGY},
  year = {2013},
  url = {https://doria17-kk.lib.helsinki.fi/handle/10024/90627}
}
Giray Oral H, Parlak Z and Levent Degertekin F (2012), "Analysis of time-resolved interaction force mode AFM imaging using active and passive probes", Ultramicroscopy., June, 2012. , pp. 1-8. Elsevier.
BibTeX:
@article{giray_oral_analysis_2012,
  author = {Giray Oral, Hasan and Parlak, Zehra and Levent Degertekin, F.},
  title = {Analysis of time-resolved interaction force mode AFM imaging using active and passive probes},
  journal = {Ultramicroscopy},
  publisher = {Elsevier},
  year = {2012},
  pages = {1--8},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0304399112001118},
  doi = {10.1016/j.ultramic.2012.05.009}
}
Gong X (2012), "Toward high performance inverted polymer solar cells", Polymer., November, 2012. Vol. 53(24), pp. 5437-5448.
BibTeX:
@article{gong_toward_2012,
  author = {Gong, Xiong},
  title = {Toward high performance inverted polymer solar cells},
  journal = {Polymer},
  year = {2012},
  volume = {53},
  number = {24},
  pages = {5437--5448},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0032386112007914},
  doi = {10.1016/j.polymer.2012.09.023}
}
Grases F, Zelenková M and Söhnel O (2013), "Structure and formation mechanism of calcium phosphate concretions formed in simulated body fluid.", Urolithiasis., October, 2013.
Abstract: Synthetic calcium phosphate (CaP) concretions in the form of hemispheres formed under carefully controlled conditions (pH 7.4, 37 °C, no evaporation) from stagnant simulated body fluid on anionic polymeric substrate (laminin) were observed by scanning and transmission electron microscopy and atomic force microscopy. The hemispheres with diameter between approximately 50 and 200 $m were composed of closely connected round spherical and elliptical objects of diameter varying from 70 to 120 nm with surface layer composed of tightly packed spherical objects of diameter 25-30 nm. The phase composition of concretions consisting of amorphous material was uniform. The concretions were formed by aggregation of CaP clusters (Posner's clusters Ca9(PO4)3 or [Ca3(PO4)2] n ) generated in the solution by perikinetic coagulation, their settling onto a substrate and subsequent accumulation through surface migration (surface nucleation) followed by accretion of nanoparticles arriving from surrounding solution. The similarity of ultrafine structures of these synthetic CaP concretions and the compact phosphatic phase appearing in some phosphate calculi indicates that analogous mechanisms could be active at the formation of the latter in the kidneys.
BibTeX:
@article{Grases2013,
  author = {Grases, Felix and Zelenková, Markéta and Söhnel, Otakar},
  title = {Structure and formation mechanism of calcium phosphate concretions formed in simulated body fluid.},
  journal = {Urolithiasis},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/24132583},
  doi = {10.1007/s00240-013-0611-6}
}
Grasley ZC, Jones CA and Benhalima M (2011), "Extracting Viscoelastic Properties of Nanometric Phases using Atomic Force Microscopy", In NICOM.
BibTeX:
@inproceedings{Grasley2011,
  author = {Grasley, Z. C. and Jones, C. A. and Benhalima, M.},
  title = {Extracting Viscoelastic Properties of Nanometric Phases using Atomic Force Microscopy},
  booktitle = {NICOM},
  year = {2011}
}
Green RA, Hassarati RT, Goding JA, Baek S, Lovell NH, Martens PJ and Poole-Warren LA (2012), "Conductive Hydrogels: Mechanically Robust Hybrids for Use as Biomaterials", Macromolecular Bioscience., April, 2012. Vol. 12(4), pp. 494-501.
BibTeX:
@article{Green2012,
  author = {Green, Rylie A. and Hassarati, Rachelle T. and Goding, Josef A. and Baek, Sungchul and Lovell, Nigel H. and Martens, Penny J. and Poole-Warren, Laura A.},
  title = {Conductive Hydrogels: Mechanically Robust Hybrids for Use as Biomaterials},
  journal = {Macromolecular Bioscience},
  year = {2012},
  volume = {12},
  number = {4},
  pages = {494--501},
  url = {http://onlinelibrary.wiley.com/doi/10.1002/mabi.201100490/abstract?userIsAuthenticated=false&deniedAccessCustomisedMessage=},
  doi = {10.1002/mabi.201100490, 10.1002/mabi.201100490}
}
Guskova O, Schünemann C, Eichhorn K-J, Walzer K, Levichkova M, Grundmann S and Sommer J-U (2013), "Light Absorption in Organic Thin Films: The Importance of Oriented Molecules", The Journal of Physical Chemistry C., August, 2013. Vol. 117(33), pp. 17285.
Abstract: In this work we apply a joint experimental and theoretical approach to investigate thin films of side chain substituted dicyanovinyl quaterthiophenes (DCV4T-Et2) and DCV4T-Et2:C60 blends, prototypic absorbers for small molecule organic solar cells. Structural characterization of the morphology of thin films thermally deposited at different substrate temperatures on a silica surface was performed by variable angle spectroscopic ellipsometry, grazing incidence X-ray diffraction, and atomic force microscopy measurements. These methods, combined with full-atomistic molecular dynamic (MD) simulation, provide detailed information about thin film morphology, namely about molecular orientation, absorption, phase separation, and crystallinity, i.e., factors that affect the efficiency of organic solar cells. Using molecular dynamics simulation, we can constitute why the DCV4T-Et2 molecules arrange strongly tilted in pristine (69° to 70° tilt angle to the substrate normal) and DCV4T-Et2:C60 blend films (tilt angle of 65° to 69°).
BibTeX:
@article{guskova_light_2013,
  author = {Guskova, Olga and Schünemann, Christoph and Eichhorn, Klaus-Jochen and Walzer, Karsten and Levichkova, Marieta and Grundmann, Steffen and Sommer, Jens-Uwe},
  title = {Light Absorption in Organic Thin Films: The Importance of Oriented Molecules},
  journal = {The Journal of Physical Chemistry C},
  year = {2013},
  volume = {117},
  number = {33},
  pages = {17285},
  url = {http://pubs.acs.org/doi/abs/10.1021/jp4048083},
  doi = {10.1021/jp4048083}
}
Gutierrez J, Mondragon In and Tercjak A (2014), "Quantitative Nanoelectrical and Nanomechanical Properties of Nanostructured Hybrid Composites by PeakForce Tunneling Atomic Force Microscopy", The Journal of Physical Chemistry C., January, 2014. Vol. 118(2), pp. 1206-1212. American Chemical Society.
Abstract: Hybrid nanocomposites based on poly(styrene- b-ethylene oxide) (PS-b-PEO) block copolymer modified with a mixture of both vanadium and titanium nanoparticles were synthesized via a sol−gel process. With the aim of studying the influence of the addition of V:Ti nanoparticles on the self- assembled PS-b-PEO block copolymer, two different V:Ti mixtures were prepared. Addition of even 60 vol % sol−gel to fabrication of hybrid nanocomposites allows us to reach well- dispersed, uniform in size V:Ti nanoparticles on the substrate surface due to hydrogen-bond formation between the sol−gel network and PEO block. Atomic force microscopy results indicate that increasing of the sol−gel content to 40 vol % leads to change the matrix from an organic (PS-block-rich phase) to inorganic (V:Ti nanoparticles/PEO-block-rich) one without losing high nanometric order due to confinement of the V:Ti nanoparticles in the PEO block. Quantitative nanoelectrical and nanomechanical properties were studied that employed novel powerful PeakForce tunneling atomic force microscopy (TUNA) technology confirming conductive properties of the nanoparticles in designed advanced materials.
BibTeX:
@article{Gutierrez2014,
  author = {Gutierrez, Junkal and Mondragon, Iñaki and Tercjak, Agnieszka},
  title = {Quantitative Nanoelectrical and Nanomechanical Properties of Nanostructured Hybrid Composites by PeakForce Tunneling Atomic Force Microscopy},
  journal = {The Journal of Physical Chemistry C},
  publisher = {American Chemical Society},
  year = {2014},
  volume = {118},
  number = {2},
  pages = {1206--1212},
  url = {http://pubs.acs.org/doi/abs/10.1021/jp407690s},
  doi = {10.1021/jp407690s}
}
Han D, Pal S, Nangreave J, Deng Z, Liu Y and Yan H (2011), "DNA Origami with Complex Curvatures in Three-Dimensional Space", Science., April, 2011. Vol. 332(6027), pp. 342-6.
Abstract: We present a strategy to design and construct self-assembling DNA nanostructures that define intricate curved surfaces in three-dimensional (3D) space using the DNA origami folding technique. Double-helical DNA is bent to follow the rounded contours of the target object, and potential strand crossovers are subsequently identified. Concentric rings of DNA are used to generate in-plane curvature, constrained to 2D by rationally designed geometries and crossover networks. Out-of-plane curvature is introduced by adjusting the particular position and pattern of crossovers between adjacent DNA double helices, whose conformation often deviates from the natural, B-form twist density. A series of DNA nanostructures with high curvature—such as 2D arrangements of concentric rings and 3D spherical shells, ellipsoidal shells, and a nanoflask—were assembled.
BibTeX:
@article{Han2011,
  author = {Han, Dongran and Pal, Suchetan and Nangreave, Jeanette and Deng, Zhengtao and Liu, Yan and Yan, Hao},
  title = {DNA Origami with Complex Curvatures in Three-Dimensional Space},
  journal = {Science},
  year = {2011},
  volume = {332},
  number = {6027},
  pages = {342--6},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/21493857 http://www.sciencemag.org/content/332/6027/342.abstract},
  doi = {10.1126/science.1202998}
}
Hansson PM, Hormozan Y, Brandner BD, Linnros J, Claesson PM, Swerin A, Schoelkopf J, Gane PAC and Thormann E (2012), "Effect of Surface Depressions on Wetting and Interactions between Hydrophobic Pore Array Surfaces", Langmuir., July, 2012. Vol. 28(30), pp. 11121-11130.
Abstract: The surface structure is known to significantly affect the long-range capillary forces between hydrophobic surfaces in aqueous solutions. It is, however, not clear how small depressions in the surface will affect the interaction. To clarify this, we have used the AFM colloidal probe technique to measure interactions between hydrophobic microstructured pore array surfaces and a hydrophobic colloidal probe. The pore array surfaces were designed to display two different pore spacings, 1.4 and 4.0 $m, each with four different pore depths ranging from 0.2 to 12.0 $m. Water contact angles measured on the pore array surfaces are lower than expected from the Cassie–Baxter and Wenzel models and not affected by the pore depth. This suggests that the position of the three-phase contact line, and not the interactions underneath the droplet, determines the contact angle. Confocal Raman microscopy was used to investigate whether water penetrates into the pores. This is of importance for capillary forces where both the movement of the three-phase contact line and the situation at the solid/liquid interface influence the stability of bridging cavities. By analyzing the shape of the force curves, we distinguish whether the cavity between the probe and the surfaces was formed on a flat part of the surface or in close proximity to a pore. The pore depth and pore spacing were both found to statistically influence the distance at which cavities form as surfaces approach each other and the distance at which cavities rupture during retraction.
BibTeX:
@article{hansson_effect_2012,
  author = {Hansson, Petra M and Hormozan, Yashar and Brandner, Birgit D and Linnros, Jan and Claesson, Per M and Swerin, Agne and Schoelkopf, Joachim and Gane, Patrick A C and Thormann, Esben},
  title = {Effect of Surface Depressions on Wetting and Interactions between Hydrophobic Pore Array Surfaces},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {30},
  pages = {11121--11130},
  url = {http://pubs.acs.org/doi/abs/10.1021/la302036d},
  doi = {10.1021/la302036d}
}
Hansson PM, Skedung L, Claesson PM, Swerin A, Schoelkopf J, Gane PAC, Rutland MW and Thormann E (2011), "Robust Hydrophobic Surfaces Displaying Different Surface Roughness Scales While Maintaining the Same Wettability", Langmuir. Vol. 27(13), pp. 8153-8159. American Chemical Society.
Abstract: A range of surfaces coated with spherical silica particles, covering the size range from nanometer to micrometer, have been produced using Langmuir?Blodgett (LB) deposition. The particles were characterized both in suspension and in the Langmuir trough to optimize the surface preparation procedure. By limiting the particle aggregation and surface layer failures during the preparation steps, well-defined monolayers with a close-packed structure have been obtained for all particle sizes. Thus, this procedure led to structured surfaces with a characteristic variation in the amplitude and spatial roughness parameters. In order to obtain robust surfaces, a sintering protocol and an AFM-based wear test to determine the stability of the deposited surface layer were employed. Hydrophobization of the LB films followed by water contact angle measurements showed, for all tested particle sizes, the same increase in contact angle compared to the contact angle of a flat hydrophobic surface. This indicates nearly hexagonal packing and gives evidence for nearly complete surface wetting of the surface features.
BibTeX:
@article{Hansson2011,
  author = {Hansson, Petra M. and Skedung, Lisa and Claesson, Per M. and Swerin, Agne and Schoelkopf, Joachim and Gane, Patrick A. C. and Rutland, Mark W. and Thormann, Esben},
  title = {Robust Hydrophobic Surfaces Displaying Different Surface Roughness Scales While Maintaining the Same Wettability},
  journal = {Langmuir},
  publisher = {American Chemical Society},
  year = {2011},
  volume = {27},
  number = {13},
  pages = {8153--8159},
  url = {http://pubs.acs.org/doi/abs/10.1021/la201121p},
  doi = {10.1021/la201121p}
}
Hansson PM, Swerin A, Schoelkopf J, Gane PaC and Thormann E (2012), "Influence of Surface Topography on the Interactions between Nanostructured Hydrophobic Surfaces", Langmuir., May, 2012. Vol. 28(21), pp. 8026-34.
Abstract: Nanostructured particle coated surfaces, with hydrophobized particles arranged in close to hexagonal order and of specific diameters ranging from 30 nm up to 800 nm, were prepared by Langmuir-Blodgett deposition followed by silanization. These surfaces have been used to study interactions between hydrophobic surfaces and a hydrophobic probe using the AFM colloidal probe technique. The different particle coated surfaces exhibit similar water contact angles, independent of particle size, which facilitates studies of how the roughness length scale affects capillary forces (previously often referred to as "hydrophobic interactions") in aqueous solutions. For surfaces with smaller particles (diameter < 200 nm), an increase in roughness length scale is accompanied by a decrease in adhesion force and bubble rupture distance. It is suggested that this is caused by energy barriers that prevent the motion of the three-phase (vapor/liquid/solid) line over the surface features, which counteracts capillary growth. Some of the measured force curves display extremely long-range interaction behavior with rupture distances of several micrometers and capillary growth with an increase in volume during retraction. This is thought to be a consequence of nanobubbles resting on top of the surface features and an influx of air from the crevices between the particles on the surface.
BibTeX:
@article{hansson_influence_2012,
  author = {Hansson, Petra M and Swerin, Agne and Schoelkopf, Joachim and Gane, Patrick a C and Thormann, Esben},
  title = {Influence of Surface Topography on the Interactions between Nanostructured Hydrophobic Surfaces},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {21},
  pages = {8026--34},
  url = {http://pubs.acs.org/doi/abs/10.1021/la300628m http://www.ncbi.nlm.nih.gov/pubmed/22554262},
  doi = {10.1021/la300628m}
}
Hardij J, Cecchet F, Berquand A, Gheldof D, Chatelain C, Mullier F, Chatelain B and Dogné J-M (2013), "Characterisation of tissue factor-bearing extracellular vesicles with AFM: comparison of air-tapping-mode AFM and liquid Peak Force AFM", Journal of Extracellular Vesicles. Vol. 2, pp. 21045.
Abstract: Introduction : Extracellular vesicles (EVs) are shed from cells and carry markers of the parent cells. Vesicles derived from cancer cells reach the bloodstream and locally influence important physiological processes. It has been previously shown that procoagulant vesicles are circulating in patients’ fluids. These EVs are therefore considered as promising biomarkers for the thrombotic risk. Because of their small size, classical methods such as flow cytometry suffer from limitation for their characterisation. Atomic force microscopy (AFM) has been proposed as a promising complementary method for the characterisation of EVs. Objectives : The objectives of this study are: (a) to develop and validate AFM with specific antibodies (anti-TF) and (b) to compare air and liquid modes for EVs’ size and number determination as potential biomarkers of the prothrombotic risk. Methods : AFM multimode nanoscope III was used for air tapping mode (TM). AFM catalyst was used for liquid Peak Force Tapping (PFT) mode. Vesicles are generated according to Davila et al.'s protocol. Substrates are coated with various concentrations of antibodies, thanks to ethanolamine and glutaraldehyde. Results : Vesicles were immobilised on antibody-coated surfaces to select tissue factor (TF)-positive vesicles. The size range of vesicles observed in liquid PFT mode is 6–10 times higher than in air mode. This corresponds to the data found in the literature. Conclusion : We recommend liquid PFT mode to analyse vesicles on 5 µg/ml antibody-coated substrates. Keywords: extracellular vesicles; tissue factor; atomic force microscopy; coagulation; biomarker (Published: 27 August 2013) Citation: Journal of Extracellular Vesicles 2013, 2 : 21045 - http://dx.doi.org/10.3402/jev.v2i0.21045 To access the supplementary material to this article, please see Supplementary files under Article Tools online.
BibTeX:
@article{Hardij2013,
  author = {Hardij, Julie and Cecchet, Francesca and Berquand, Alexandre and Gheldof, Damien and Chatelain, Christian and Mullier, François and Chatelain, Bernard and Dogné, Jean-Michel},
  title = {Characterisation of tissue factor-bearing extracellular vesicles with AFM: comparison of air-tapping-mode AFM and liquid Peak Force AFM},
  journal = {Journal of Extracellular Vesicles},
  year = {2013},
  volume = {2},
  pages = {21045},
  url = {http://www.journalofextracellularvesicles.net/index.php/jev/article/view/21045/29821},
  doi = {10.3402/jev.v2i0.21045}
}
He B-C, Fu W-E, Liou H-C, Chang Y-QE, Pan S-P, Lin HM and Chen Y-F (2012), "Deformation of polystyrene nanoparticles under different AFM tapping loads", In Proc. of SPIE Vol. 8378. Vol. 8378, pp. 83780G-1.
Abstract: Deformation induced by contact force from the tip is the major measurement uncertainty using atomic force microscope (AFM) for the apex height of nanoparticles. Additionally, the contact force by the AFM tip is difficult and not reliable in traditional tapping and contact modes. In this work, the contact forces applied by the AFM were varied using a peak-force tapping method, which is unique technique to perform force-controlled scanning, to characterize the deformation of nanoparticles. The obtained measurement results were compared with a theoretical model developed for predicting the deformation between PS nanoparticles and tip/substrate. It was found that the deformation occurred at low force as 0.5 nN for polystyrene nanoparticles on mica substrate. The deformation was fully plastic. In addition, the deformation has a linear relationship with contact force, which is consistent with contact mechanics model.
BibTeX:
@inproceedings{He2012,
  author = {He, Bo-Ching and Fu, Wei-En and Liou, Huay-Chung and Chang, Yong-Qing E. and Pan, Shan-Peng and Lin, Hung Min and Chen, Yen-Fu},
  title = {Deformation of polystyrene nanoparticles under different AFM tapping loads},
  booktitle = {Proc. of SPIE Vol. 8378},
  year = {2012},
  volume = {8378},
  pages = {83780G--1},
  url = {http://link.aip.org/link/PSISDG/v8378/i1/p83780G/s1&Agg=doi},
  doi = {10.1117/12.921451}
}
Helmly S, Hiesgen R, Morawietz T, Yuan X-Z, Wang H and Andreas Friedrich K (2013), "Microscopic Investigation of Platinum Deposition in PEMFC Cross-Sections Using AFM and SEM", Journal of the Electrochemical Society., April, 2013. Vol. 160(6), pp. F687-F697.
BibTeX:
@article{Helmly2013,
  author = {Helmly, S. and Hiesgen, R. and Morawietz, T. and Yuan, X.-Z. and Wang, H. and Andreas Friedrich, K.},
  title = {Microscopic Investigation of Platinum Deposition in PEMFC Cross-Sections Using AFM and SEM},
  journal = {Journal of the Electrochemical Society},
  year = {2013},
  volume = {160},
  number = {6},
  pages = {F687--F697},
  url = {http://jes.ecsdl.org/cgi/doi/10.1149/2.130306jes},
  doi = {10.1149/2.130306jes}
}
Heu C, Berquand A, Elie-Caille C and Nicod L (2012), "Glyphosate-induced stiffening of HaCaT keratinocytes, a Peak Force Tapping study on living cells", Journal of Structural Biology., April, 2012. Vol. 178(1), pp. 1-7.
BibTeX:
@article{Heu2012,
  author = {Heu, Celine and Berquand, Alexandre and Elie-Caille, Celine and Nicod, Laurence},
  title = {Glyphosate-induced stiffening of HaCaT keratinocytes, a Peak Force Tapping study on living cells},
  journal = {Journal of Structural Biology},
  year = {2012},
  volume = {178},
  number = {1},
  pages = {1--7},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S1047847712000597},
  doi = {10.1016/j.jsb.2012.02.007}
}
Hiesgen R, Helmly S, Galm I, Morawietz T, Handl M and Friedrich K (2012), "Microscopic Analysis of Current and Mechanical Properties of Nafion® Studied by Atomic Force Microscopy", Membranes., November, 2012. Vol. 2(4), pp. 783-803.
Abstract: The conductivity of fuel cell membranes as well as their mechanical properties at the nanometer scale were characterized using advanced tapping mode atomic force microscopy (AFM) techniques. AFM produces high-resolution images under continuous current flow of the conductive structure at the membrane surface and provides some insight into the bulk conducting network in Nafion membranes. The correlation of conductivity with other mechanical properties, such as adhesion force, deformation and stiffness, were simultaneously measured with the current and provided an indication of subsurface phase separations and phase distribution at the surface of the membrane. The distribution of conductive pores at the surface was identified by the formation of water droplets. A comparison of nanostructure models with high-resolution current images is discussed in detail.
BibTeX:
@article{Hiesgen2012,
  author = {Hiesgen, Renate and Helmly, Stefan and Galm, Ines and Morawietz, Tobias and Handl, Michael and Friedrich, K.},
  title = {Microscopic Analysis of Current and Mechanical Properties of Nafion® Studied by Atomic Force Microscopy},
  journal = {Membranes},
  year = {2012},
  volume = {2},
  number = {4},
  pages = {783--803},
  url = {http://www.mdpi.com/2077-0375/2/4/783},
  doi = {10.3390/membranes2040783}
}
Hiesgen R, Helmly S, Morawietz T, Yuan X-Z, Wang H and Friedrich KA (2013), "Atomic force microscopy studies of conductive nanostructures in solid polymer electrolytes", Electrochimica Acta., November, 2013. Vol. 110, pp. 292-305. Elsevier Ltd.
Abstract: The conductivity of three different sulfonated polymer electrolyte membranes (PEM), two perfluorinated membranes, Nafion® and Aquivion®, and JST, a non- perfluorinated aromatic block copolymer, were compared using advanced material- sensitive and conductive atomic force microscopy (AFM). All of the membranes required activation by a current flow to reach significant conductivity for the AFM analysis, indicating the existence of a highly resistive surface skin layer. The two perfluorinated sulfonic acid membranes, a membrane with long side-chains (Nafion®) and a membrane with short side-chains (Aquivion®), exhibited similar properties. A lamellar surface structure, with polymer bundles or micelles in a parallel orientation, was also found for the Aquivion® membrane. AFM high-resolution current images, performed under a continuous current flow, were used to distinguish between the conducting network and the subsurface phase distribution at the membrane surface. The connected subnets of the JST membrane were approximately 100 - 200 nm in size, whereas those for the perfluorinated membrane surfaces were 200 - 300 nm in size. The conductive areas of the Aquivion® and JST membranes exhibited larger homogeneous conducting areas, corresponding to the smaller correlation lengths of ionic phase separation. Membrane cross sections were analyzed to elucidate the structure of the bulk ionic network of the Nafion® membrane, before and after operation. The existence of extended water layers in the bulk, even before operation, was confirmed.
BibTeX:
@article{Hiesgen2013,
  author = {Hiesgen, Renate and Helmly, Stefan and Morawietz, Tobias and Yuan, Xiao-Zi and Wang, Haijiang and Friedrich, K. Andreas},
  title = {Atomic force microscopy studies of conductive nanostructures in solid polymer electrolytes},
  journal = {Electrochimica Acta},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {110},
  pages = {292--305},
  url = {http://www.sciencedirect.com/science/article/pii/S0013468613008542 http://dx.doi.org/10.1016/j.electacta.2013.04.147 http://linkinghub.elsevier.com/retrieve/pii/S0013468613008542},
  doi = {10.1016/j.electacta.2013.04.147}
}
Hiesgen R, Sörgel S, Costa R, Carlé L, Galm I, Ca nas N, Pascucci B and Friedrich KA (2013), "AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries", Beilstein Journal of Nanotechnology., October, 2013. Vol. 4, pp. 611-624.
Abstract: In this work, material-sensitive atomic force microscopy (AFM) techniques were used to analyse the cathodes of lithium–sulfur batteries. A comparison of their nanoscale electrical, electrochemical, and morphological properties was performed with samples prepared by either suspension-spraying or doctor-blade coating with different binders. Morphological studies of the cathodes before and after the electrochemical tests were performed by using AFM and scanning electron microscopy (SEM). The cathodes that contained polyvinylidene fluoride (PVDF) and were prepared by spray-coating exhibited a superior stability of the morphology and the electric network associated with the capacity and cycling stability of these batteries. A reduction of the conductive area determined by conductive AFM was found to correlate to the battery capacity loss for all cathodes. X-ray diffraction (XRD) measurements of Li2S exposed to ambient air showed that insulating Li2S hydrolyses to insulating LiOH. This validates the significance of electrical ex-situ AFM analysis after cycling. Conductive tapping mode AFM indicated the existence of large carbon-coated sulfur particles. Based on the analytical findings, the first results of an optimized cathode showed a much improved discharge capacity of 800 mA·g(sulfur)−1 after 43 cycles.
BibTeX:
@article{Hiesgen2013a,
  author = {Hiesgen, Renate and Sörgel, Seniz and Costa, Rémi and Carlé, Linus and Galm, Ines and Cañas, Natalia and Pascucci, Brigitta and Friedrich, K Andreas},
  title = {AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries},
  journal = {Beilstein Journal of Nanotechnology},
  year = {2013},
  volume = {4},
  pages = {611--624},
  url = {http://www.beilstein-journals.org/bjnano/content/4/1/68},
  doi = {10.3762/bjnano.4.68}
}
Hiesgen R, Wehl I, Friedrich KA, Schulze M, Haug A, Bauder A, Carreras A, Yuan X-Z and Wang H (2010), "AFM investigation of polymer fuel cell gas diffusion layers before and after operation".
BibTeX:
@misc{Hiesgen2010,
  author = {Hiesgen, R. and Wehl, Ines and Friedrich, K. Andreas and Schulze, Mathias and Haug, Andrea and Bauder, Alexander and Carreras, Alejo and Yuan, Xiao-Zi and Wang, Haijiang},
  title = {AFM investigation of polymer fuel cell gas diffusion layers before and after operation},
  year = {2010}
}
Hiesgen R, Wehl I, Helmly S, Friedrich KA, Schulze M, Haug A, Yuan X-Z and Wang H (2011), "Analysis of Aged Polymer Electrolyte Fuel Cell (PEFC) Components by Non Traditional Methods" , pp. 259-269.
BibTeX:
@inproceedings{hiesgen_analysis_2011,
  author = {Hiesgen, Renate and Wehl, Ines and Helmly, Stefan and Friedrich, K Andreas and Schulze, Mathias and Haug, Andrea and Yuan, Xiao-Zi and Wang, Haijang},
  title = {Analysis of Aged Polymer Electrolyte Fuel Cell (PEFC) Components by Non Traditional Methods},
  year = {2011},
  pages = {259--269},
  url = {http://link.aip.org/link/ECSTF8/v35/i34/p259/s1&Agg=doi},
  doi = {10.1149/1.3654224}
}
Hofer A, Benstetter G, Biberger R, Leirer C and Brüderl G (2013), "Analysis of crystal defects on GaN-based semiconductors with advanced scanning probe microscope techniques", Thin Solid Films., October, 2013. Vol. 544, pp. 139-143. Elsevier B.V..
BibTeX:
@article{Hofer2013,
  author = {Hofer, Alexander and Benstetter, Günther and Biberger, Roland and Leirer, Christian and Brüderl, Georg},
  title = {Analysis of crystal defects on GaN-based semiconductors with advanced scanning probe microscope techniques},
  journal = {Thin Solid Films},
  publisher = {Elsevier B.V.},
  year = {2013},
  volume = {544},
  pages = {139--143},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0040609013006834},
  doi = {10.1016/j.tsf.2013.04.049}
}
Hozic A, Rico F, Colom A, Buzhynskyy N and Scheuring S (2012), "Nanomechanical Characterization of the Stiffness of Eye Lens Cells: A Pilot Study", Investigative Ophthalmology & Visual Science., March, 2012. Vol. 33(0), pp. 1-29.
Abstract: Purpose: To probe the mechanical properties of individual eye lens cells isolated from nucleus and cortex of adult sheep eye lens, and to characterize the effect of cytoskeletal drugs. Methods: We have used atomic force microscopy (AFM) featuring a spherical tip at the end of a soft cantilever to indent single lens cells and measure the Young's modulus of isolated nuclear and cortical lens cells. Measurements were carried out under basal conditions and after addition of drugs that disrupt actin filaments and microtubules. Results: We found that single lens cells were able to maintain their shape and mechanical properties after being isolated from the lens tissue. The median Young's modulus value for nuclear lens cells (4.83 kPa) was ∼20 fold higher than for cortical lens cells (0.22 kPa). Surprisingly, disruption of actin filaments and microtubules did not affect the measured Young's moduli. Conclusions: We found that single cells from the lens nucleus and cortex can be unambiguously distinguished using the elastic modulus as criterion. This uncommon maintenance of shape and elastic properties after cell isolation together with the null effect of actin filaments and microtubules targeting drugs suggest that the mechanical stability of fiber cells is provided by cellular elements other than the usual cytoskeletal proteins.
BibTeX:
@article{Hozic2012,
  author = {Hozic, Amela and Rico, Felix and Colom, Adai and Buzhynskyy, Nikolay and Scheuring, Simon},
  title = {Nanomechanical Characterization of the Stiffness of Eye Lens Cells: A Pilot Study},
  journal = {Investigative Ophthalmology & Visual Science},
  year = {2012},
  volume = {33},
  number = {0},
  pages = {1--29},
  url = {http://www.iovs.org/content/early/2012/03/14/iovs.11-8676 http://www.iovs.org/content/early/2012/03/14/iovs.11-8676.short http://www.iovs.org/content/53/4/2151.short},
  doi = {10.1167/iovs.11-8676}
}
Hu S, Mininni L, Hu Y, Erina N, Kindt JH and Su C (2012), "High-speed atomic force microscopy and peak force tapping control", In Metrology, Inspection, and Process Control for Microlithography XXVI. San Jose, California, March, 2012. , pp. 83241O--83241O-10. SPIE.
Abstract: ITRS Roadmap requires defect size measurement below 10 nanometers and challenging classifications for both blank and patterned wafers and masks. Atomic force microscope (AFM) is capable of providing metrology measurement in 3D at sub-nanometer accuracy but has long suffered from drawbacks in throughput and limitation of slow topography imaging without chemical information. This presentation focus on two disruptive technology developments, namely high speed AFM and quantitative nanomechanical mapping, which enables high throughput measurement with capability of identifying components through concurrent physical property imaging. The high speed AFM technology has allowed the imaging speed increase by 10-100 times without loss of the data quality. Such improvement enables the speed of defect review on a wafer to increase from a few defects per hour to nearly 100 defects an hour, approaching the requirements of ITRS Roadmap. Another technology development, Peak Force Tapping, substantially simplified the close loop system response, leading to self-optimization of most challenging samples groups to generate expert quality data. More importantly, AFM also simultaneously provides a series of mechanical property maps with a nanometer spatial resolution during defect review. These nanomechanical maps (including elastic modulus, hardness, and surface adhesion) provide complementary information for elemental analysis, differentiate defect materials by their physical properties, and assist defect classification beyond topographic measurements. This paper will explain the key enabling technologies, namely high speed tip-scanning AFM using innovative flexure design and control algorithm. Another critical element is AFM control using Peak Force Tapping, in which the instantaneous tip-sample interaction force is measured and used to derive a full suite of physical properties at each imaging pixel. We will provide examples of defect review data on different wafers and media disks. The similar AFM-based defect review capacity was also applied to EUV masks.
BibTeX:
@inproceedings{hu_high-speed_2012,
  author = {Hu, Shuiqing and Mininni, Lars and Hu, Yan and Erina, Natalia and Kindt, Johannes Heinrich and Su, Chanmin},
  editor = {Starikov, Alexander},
  title = {High-speed atomic force microscopy and peak force tapping control},
  booktitle = {Metrology, Inspection, and Process Control for Microlithography XXVI},
  publisher = {SPIE},
  year = {2012},
  pages = {83241O----83241O--10},
  url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1311118},
  doi = {10.1117/12.928545}
}
Hu S, Su C and Arnold W (2011), "Imaging of subsurface structures using atomic force acoustic microscopy at GHz frequencies", Journal of Applied Physics. Vol. 109(8), pp. 84324.
Abstract: We describe a technique to image subsurface structures using atomic force acoustic microscopy operated at 1 GHz. The devices to be imaged are insonified with 1 GHz ultrasonic waves which are amplitude-modulated at a fraction or multiple frequency of cantilever contact resonance. The transmitted signals are demodulated by the nonlinear tip–surface interaction, enabling one to image defects in the device based on their ultrasonic scattering power which is determined by the ultrasonic frequency, the acoustic mismatch between the elastic properties of the host material and the defects, by their geometry, and by diffraction effects
BibTeX:
@article{hu_imaging_2011,
  author = {Hu, Shuiqing and Su, Chanmin and Arnold, Walter},
  title = {Imaging of subsurface structures using atomic force acoustic microscopy at GHz frequencies},
  journal = {Journal of Applied Physics},
  year = {2011},
  volume = {109},
  number = {8},
  pages = {84324},
  url = {http://link.aip.org/link/JAPIAU/v109/i8/p084324/s1&Agg=doi},
  doi = {10.1063/1.3573484}
}
Huang Y, Wang Q, Wang M, Fei Z and Li M (2012), "Characterization and analysis of DLC films with different thickness deposited by RF magnetron PECVD", Rare Metals., March, 2012. Vol. 31(2), pp. 198-203.
BibTeX:
@article{huang_characterization_2012,
  author = {Huang, Yujie and Wang, Qi and Wang, Mei and Fei, Zhenyi and Li, Musen},
  title = {Characterization and analysis of DLC films with different thickness deposited by RF magnetron PECVD},
  journal = {Rare Metals},
  year = {2012},
  volume = {31},
  number = {2},
  pages = {198--203},
  url = {http://www.springerlink.com/index/10.1007/s12598-012-0491-x},
  doi = {10.1007/s12598-012-0491-x}
}
Hwang I and Yang C (2012), "Evidence of Epitaxial Growth of Molecular Layers of Dissolved Gas at a Hydrophobic/Water Interface", Arxiv preprint arXiv:1203.6696.
Abstract: The non-wetting phenomena of water on certain solid surfaces have been under intensive study for decades, but the nature of hydrophobic/water interfaces remains controversial. Here a water/graphite interface is investigated with high-sensitivity atomic force microscopy. We show evidence of nucleation and growth of an epitaxial monolayer on the graphite surface, probably caused by adsorption of nitrogen molecules dissolved in water. The subsequent adsorption process resembles the layer-plus-island, or Stranski-Krastanov, growth mode in heteroepitaxy. This finding underlines the importance of gas segregation at various water interfaces and may unravel many puzzles, especially the nature and the high stability of so-called nanobubbles at solid/water interfaces and in bulk water. Based on the hydrophobic effect, we propose that gas molecules dissolved in water may aggregate into clusters in bulk water as well as at solid/water interfaces. As a cluster grows above a critical size, it undergoes a transition into a gas bubble, which can explain formation or nucleation of gas bubbles in water.
BibTeX:
@article{Hwang2012,
  author = {Hwang, IS and Yang, CW},
  title = {Evidence of Epitaxial Growth of Molecular Layers of Dissolved Gas at a Hydrophobic/Water Interface},
  journal = {Arxiv preprint arXiv:1203.6696},
  year = {2012},
  url = {http://arxiv.org/abs/1203.6696}
}
Hynes MJ and Maurer JA (2012), "Unmasking Photolithography: A Versatile Way to Site Selectively Pattern Gold Substrates", Angewandte Chemie International., February, 2012. Vol. 51(9), pp. 2151-4.
BibTeX:
@article{Hynes2012,
  author = {Hynes, Matthew J. and Maurer, Joshua A.},
  title = {Unmasking Photolithography: A Versatile Way to Site Selectively Pattern Gold Substrates},
  journal = {Angewandte Chemie International},
  year = {2012},
  volume = {51},
  number = {9},
  pages = {2151--4},
  url = {http://onlinelibrary.wiley.com/doi/10.1002/anie.201107671/abstract?userIsAuthenticated=false&deniedAccessCustomisedMessage=},
  doi = {10.1002/anie.201107671}
}
Hynes MJ and Maurer JA (2012), "Photoinduced Monolayer Patterning for the Creation of Complex Protein Patterns.", Langmuir : the ACS journal of surfaces and colloids., November, 2012. American Chemical Society.
Abstract: This work investigates self-assembled monolayers that were formed from a glycol-terminated thiol monomer and were patterned using photoinduced monolayer desorption. Utilizing direct-write photolithography provided a facile means to generate complex protein patterns containing gradients and punctate regions. The ablated glycol monolayers were characterized using scanning probe microscopy, which allowed us to observe differences in the nanomechanical properties between the patterned and nonpatterned regions of the substrate. The patterned regions on the surface adsorbed proteins, and this process was monitored quantitatively using surface plasmon resonance imaging (SPRi). Moreover, the concentration of the protein could be controlled accurately by simply setting the gray level in the 8-bit image. Adsorbed protein was probed using a commercially available antibody binding assay, which showed significant enhancement over the background. The ability to produce complex protein patterns will contribute greatly to creating in vitro models that more accurately mimic an in vivo environment.
BibTeX:
@article{Hynes2012a,
  author = {Hynes, Matthew J and Maurer, Joshua A},
  title = {Photoinduced Monolayer Patterning for the Creation of Complex Protein Patterns.},
  journal = {Langmuir : the ACS journal of surfaces and colloids},
  publisher = {American Chemical Society},
  year = {2012},
  url = {http://pubs.acs.org/doi/abs/10.1021/la303429a},
  doi = {10.1021/la303429a}
}
Imbesi PM, Raymond JE, Tucker BS and Wooley KL (2012), "Thiol-ene “click? networks from amphiphilic fluoropolymers: full synthesis and characterization of a benchmark anti-biofouling surface", Journal of Materials Chemistry. Vol. 22(37), pp. 19462.
Abstract: The synthesis of heterogeneous, amphiphilic crosslinked networks from photo-initiated thiol-ene chemistry and full characterization of the physicochemical, anti-biofouling, mechanical, and thermal properties of this system are reported. Although interest in coatings that present heterogeneous surface features is increasing, anti-biofouling performance is typically compared to homogeneous biocidal- or non-toxic polydimethylsiloxane-based paints, for the advancement of commercial and novel systems, which leaves a need for a benchmark to compare highly complex, heterogeneous composites with similar complexities. This system has been generated and rigorously analyzed to understand how microscopic and nanoscopic disorder, resistance to protein adsorption and surface mechanical properties can be fine-tuned and optimized through oligomer selection, blend ratios and process conditions. Solution-state studies of individual and blended constituents probed the relative fluorescence intensities based on concentration and neighboring species that were used to identify microscopic disorder on the surface. Incubation of a fluorescently labelled protein on the benchmark surface showed 42% and 72% less adsorption than on model surfaces that largely expressed a single component. The extent of reaction and the identification of unconsumed functionalities were found through infrared spectroscopy. The benchmark surface had a Young’s modulus of approximately 0.5 GPa, 7 to 35 times higher than model surfaces, with 50 times the variation in modulus. Nanoscale surface adhesion force variation and bulk wettability and bulk thermal stability are also reported. This study provides an extensive list of metrics to be used for the development of complex, heterogeneous, anti-biofouling coatings, appropriate to both surface optimization and mechanical tunability, for implementation in real-world applications
BibTeX:
@article{Imbesi2012,
  author = {Imbesi, Philip M. and Raymond, Jeffery E. and Tucker, Bryan S. and Wooley, Karen L.},
  title = {Thiol-ene “click? networks from amphiphilic fluoropolymers: full synthesis and characterization of a benchmark anti-biofouling surface},
  journal = {Journal of Materials Chemistry},
  year = {2012},
  volume = {22},
  number = {37},
  pages = {19462},
  url = {http://xlink.rsc.org/?DOI=c2jm32005c},
  doi = {10.1039/c2jm32005c}
}
Imre B, Bedő D, Domján A, Schön P, Vancso GJ and Pukánszky B (2013), "Structure, properties and interfacial interactions in poly(lactic acid)/polyurethane blends prepared by reactive processing", European Polymer Journal., October, 2013. Vol. 49(10), pp. 3104-3113.
Abstract: Polyurethane elastomers are promising candidates for the impact modification of PLA producing blends for example for biomedicine. Poly(lactic acid) (PLA)/polyurethane elastomer (PU) blends were prepared by reactive processing and physical blending as comparison. The blends were characterized by a number of techniques including microscopy (scanning electron microscopy, SEM, and atomic force microscopy, AFM), rotational viscometry, thermal (dynamic mechanical analysis), DMA, and mechanical (tensile) measurements. The analysis and comparison of the structure and properties of physical and reactor blends proved the successful coupling of the phases. Coupling resulted in more advantageous structure and superior mechanical properties compared to those of physical blends as confirmed by morphology, macroscopic properties and the quantitative estimation of interfacial interactions. Structural studies and the composition dependence of properties indicated the formation of a submicron, phase-in-phase structure which positively influenced properties at large PU contents. The results strongly support that reactive processing is a convenient, cost-effective and environmentally friendly technique to obtain blends with superior properties
BibTeX:
@article{Imre2013,
  author = {Imre, Balázs and Bedő, Dániel and Domján, Attila and Schön, Peter and Vancso, G. Julius and Pukánszky, Béla},
  title = {Structure, properties and interfacial interactions in poly(lactic acid)/polyurethane blends prepared by reactive processing},
  journal = {European Polymer Journal},
  year = {2013},
  volume = {49},
  number = {10},
  pages = {3104--3113},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0014305713003480 http://dx.doi.org/10.1016/j.eurpolymj.2013.07.007},
  doi = {10.1016/j.eurpolymj.2013.07.007}
}
Jafarzadeh S, Claesson PM, Pan J and Thormann E (2014), "Direct measurement of colloidal interactions between polyaniline surfaces in a UV-curable coating formulation: The effect of surface hydropholicity/hydrophobicity and resin composition.", Langmuir : the ACS journal of surfaces and colloids., January, 2014. American Chemical Society.
Abstract: The interactions between polyaniline particles and polyaniline surfaces in polyester acrylate resin mixed with 1,6-hexanediol diacrylate monomer have been investigated using contact angle measurements and the atomic force microscopy colloidal probe technique. Polyaniline with different characteristics (hydrophilic and hydrophobic) were synthesized directly on spherical polystyrene particles of 10 µm in diameter. Surface forces were measured between core/shell structured polystyrene/polyaniline particles (and a pure polystyrene particle as reference) mounted on an atomic force microscope cantilever and a pressed pellet of either hydrophilic or hydrophobic polyaniline powders, in resins of various polymer:monomer ratio. A short-range purely repulsive interaction was observed between hydrophilic polyaniline (doped with phosphoric acid) surfaces in polyester acrylate resin. In contrast, interactions between hydrophobic polyaniline (doped with n-decyl phosphonic acid) were dominated by attractive forces, suggesting less compatibility and higher tendency for aggregation of these particles in liquid polyester acrylate compared to hydrophilic polyaniline. Both observations are in agreement with the conclusions from the interfacial energy studies performed by contact angle measurements.
BibTeX:
@article{Jafarzadeh2014,
  author = {Jafarzadeh, Shadi and Claesson, Per Martin and Pan, Jinshan and Thormann, Esben},
  title = {Direct measurement of colloidal interactions between polyaniline surfaces in a UV-curable coating formulation: The effect of surface hydropholicity/hydrophobicity and resin composition.},
  journal = {Langmuir : the ACS journal of surfaces and colloids},
  publisher = {American Chemical Society},
  year = {2014},
  url = {http://pubs.acs.org/doi/abs/10.1021/la4035062 http://www.ncbi.nlm.nih.gov/pubmed/24400981},
  doi = {10.1021/la4035062}
}
Jurak M (2012), "Changes in stability of the DPPC monolayer during its contact with the liquid phase", Chemistry and Physics of Lipids., April, 2012. Vol. 165(3), pp. 302-310.
Abstract: The Langmuir–Blodgett (LB) method was applied and a few series of advancing and receding contact angles measurements as a function of time were performed to examine stability of model phospholipid monolayers during their contact with water, formamide and diiodomethane droplets. The studied monolayer was single-component saturated phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) transferred onto mica surface. When the time of the contact angle measurements is prolonged in these systems, some changes in the DPPC layer structure occur due to the contact with probing liquid, especially water, which is reflected in the changes of measured contact angle. Generally, with increasing time of the droplet contact with DPPC monolayer the contact angle decreases. Some correlation between the contact angle decrease and molecular rearrangements of initially hydrophobic DPPC monolayer is observed if it comes into contact with water. On the other hand, the contact angle completed within the first few seconds can faithfully reflect the original structure of the layer, and thus its energetic state, because during this time the structure changes are insignificant. Basing on the measured contact angles the monolayer's apparent surface free energy and its components, corresponding to different contact times of the droplets, were calculated. These results are helpful for better characterization of the processes taking place in the phospholipid layers being in contact with polar (water and formamide) and nonpolar (diiodomethane) liquids.
BibTeX:
@article{jurak_changes_2012,
  author = {Jurak, Małgorzata},
  title = {Changes in stability of the DPPC monolayer during its contact with the liquid phase},
  journal = {Chemistry and Physics of Lipids},
  year = {2012},
  volume = {165},
  number = {3},
  pages = {302--310},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0009308412000205},
  doi = {10.1016/j.chemphyslip.2012.02.003}
}
König M, Koberling F, Schulz O, Ros R, Fore S, Sackrow M, Trautmann S and Erdmann R (2012), "Time-resolved single molecule microscopy coupled with atomic force microscopy", In Proc. SPIE., February, 2012. Vol. 8227, pp. 822717-822719.
Abstract: Time-resolved confocal microscopy is well established to image spectral and spatial properties of samples in biology and material science. Atomic Force Microscopy (AFM) in addition enables to investigate properties which are not optically addressable or are hidden by the diffraction limited optical resolution. We present a straight forward combination of single molecule sensitive time-resolved confocal microscopy with different commercially available AFMs. Besides an extra of information about for example a cell surface, the AFM tip can also be used to manipulate the sample on a nanometer scale down to the single molecule level.
BibTeX:
@inproceedings{konig_time-resolved_2012,
  author = {König, M. and Koberling, F. and Schulz, O. and Ros, R. and Fore, S. and Sackrow, M. and Trautmann, S. and Erdmann, R.},
  editor = {Conchello, Jose-Angel and Cogswell, Carol J and Wilson, Tony and Brown, Thomas G},
  title = {Time-resolved single molecule microscopy coupled with atomic force microscopy},
  booktitle = {Proc. SPIE},
  year = {2012},
  volume = {8227},
  pages = {822717--822719},
  url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1276548 http://proceedings.spiedigitallibrary.org/data/Conferences/SPIEP/63513/8227191.pdf},
  doi = {10.1117/12.906177}
}
Kaemmer S, Ruiter T, Luszcz K, Pittenger B and Minne S (2013), "Chemical Identification through Combined Raman and Nano-Mechanical Mapping", pmmimeetings.com. , pp. 2-3.
BibTeX:
@article{Kaemmer2013,
  author = {Kaemmer, S and Ruiter, T and Luszcz, K and Pittenger, Bede and Minne, S},
  title = {Chemical Identification through Combined Raman and Nano-Mechanical Mapping},
  journal = {pmmimeetings.com},
  year = {2013},
  pages = {2--3},
  url = {ftp://pmmimeetings.com/NMCManuscripts2/0030.pdf}
}
Kaemmer SB, Ruiter T and Pittenger B (2012), "Atomic Force Microscopy with Raman and Tip-Enhanced Raman Spectroscopy", Microscopy Today., November, 2012. Vol. 20(06), pp. 22-27.
BibTeX:
@article{Kaemmer2012,
  author = {Kaemmer, Stefan B. and Ruiter, Ton and Pittenger, Bede},
  title = {Atomic Force Microscopy with Raman and Tip-Enhanced Raman Spectroscopy},
  journal = {Microscopy Today},
  year = {2012},
  volume = {20},
  number = {06},
  pages = {22--27},
  url = {http://www.journals.cambridge.org/abstractS1551929512000855},
  doi = {10.1017/S1551929512000855}
}
Kafle K, Xi X, Lee CM, Tittmann BR, Cosgrove DJ, Park YB and Kim SH (2013), "Cellulose microfibril orientation in onion (Allium cepa L.) epidermis studied by atomic force microscopy (AFM) and vibrational sum frequency generation (SFG) spectroscopy", Cellulose., December, 2013.
BibTeX:
@article{Kafle2013,
  author = {Kafle, Kabindra and Xi, Xiaoning and Lee, Christopher M. and Tittmann, Bernhard R. and Cosgrove, Daniel J. and Park, Yong Bum and Kim, Seong H.},
  title = {Cellulose microfibril orientation in onion (Allium cepa L.) epidermis studied by atomic force microscopy (AFM) and vibrational sum frequency generation (SFG) spectroscopy},
  journal = {Cellulose},
  year = {2013},
  url = {http://link.springer.com/10.1007/s10570-013-0121-2},
  doi = {10.1007/s10570-013-0121-2}
}
Kalfagiannis N and Gupta A (2013), "Single-Step Measurement of Elastic Modulus and Adhesion Mapping of Surface of Carbonate Reservoir Rocks", In Volume 6: Polar and Arctic Sciences and Technology; Offshore Geotechnics; Petroleum Technology Symposium., June, 2013. , pp. V006T11A018. ASME.
BibTeX:
@inproceedings{Kalfagiannis2013,
  author = {Kalfagiannis, Nikolaos and Gupta, Anuj},
  title = {Single-Step Measurement of Elastic Modulus and Adhesion Mapping of Surface of Carbonate Reservoir Rocks},
  booktitle = {Volume 6: Polar and Arctic Sciences and Technology; Offshore Geotechnics; Petroleum Technology Symposium},
  publisher = {ASME},
  year = {2013},
  pages = {V006T11A018},
  url = {http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1786586},
  doi = {10.1115/OMAE2013-11258}
}
Keller A, Bald I, Rotaru A, Cauët E, Gothelf KV and Besenbacher F (2012), "Probing Electron-Induced Bond Cleavage at the Single-Molecule Level Using DNA Origami Templates", ACS Nano., May, 2012. Vol. 6(5), pp. 4392-4399.
Abstract: Low-energy electrons (LEEs) play an important role in nanolithography, atmospheric chemistry, and DNA radiation damage. Previously, the cleavage of specific chemical bonds triggered by LEEs has been demonstrated in a variety of small organic molecules such as halogenated benzenes and DNA nucleobases. Here we present a strategy that allows for the first time to visualize the electron-induced dissociation of single chemical bonds within complex, but well-defined self-assembled DNA nanostructures. We employ atomic force microscopy to image and quantify LEE-induced bond dissociations within specifically designed oligonucleotide targets that are attached to DNA origami templates. In this way, we use a highly selective approach to compare the efficiency of the electron-induced dissociation of a single disulfide bond with the more complex cleavage of the DNA backbone within a TT dinucleotide sequence. This novel technique enables the fast and parallel determination of DNA strand break yields with unprecedented control over the DNA’s primary and secondary structure. Thus the detailed investigation of DNA radiation damage in its most natural environment, e.g., DNA nucleosomes constituting the chromatin, now becomes feasible.
BibTeX:
@article{keller_probing_2012,
  author = {Keller, Adrian and Bald, Ilko and Rotaru, Alexandru and Cauët, Emilie and Gothelf, Kurt V and Besenbacher, Flemming},
  title = {Probing Electron-Induced Bond Cleavage at the Single-Molecule Level Using DNA Origami Templates},
  journal = {ACS Nano},
  year = {2012},
  volume = {6},
  number = {5},
  pages = {4392--4399},
  url = {http://pubs.acs.org/doi/abs/10.1021/nn3010747},
  doi = {10.1021/nn3010747}
}
Kemp AD, Harding CC, Cabral WA, Marini JC and Wallace JM (2012), "Effects of tissue hydration on nanoscale structural morphology and mechanics of individual Type I collagen fibrils in the Brtl mouse model of Osteogenesis Imperfecta", Journal of Structural Biology., December, 2012. Vol. 180(3), pp. 428-438.
Abstract: Type I collagen is the most abundant protein in mammals, and is a vital part of the extracellular matrix for numerous tissues. Despite collagen’s importance, little is known about its nanoscale morphology in tissues and how morphology relates to mechanical function. This study probes nanoscale structure and mechanical properties of collagen as a function of disease in native hydrated tendons. Wild type tendon and tendon from the Brtl/+ mouse model of Osteogenesis Imperfecta were investigated. An atomic force microscope (AFM) was used to image and indent minimally-processed collagen fibrils in hydrated and dehydrated conditions. AFM was used because of the ability to keep biological tissues as close to their native in situ conditions as possible. The study demonstrated phenotypic difference in Brtl/+ fibril morphology and mechanics in hydrated tendon which became more compelling upon dehydration. Dried tendons had a significant downward shift in fibril D-periodic spacing versus a shift up in wet tendons. Nanoscale changes in morphology in dry samples were accompanied by significant increases in modulus and adhesion force and decreased indentation depth. A minimal mechanical phenotype existed in hydrated samples, possibly due to water masking structural defects within the diseased fibrils. This study demonstrates that collagen nanoscale morphology and mechanics are impacted in Brtl/+ tendons, and that the phenotype can be modulated by the presence or absence of water. Dehydration causes artifacts in biological samples which require water and this factor must be considered for studies at any length scale in collagen-based tissues, especially when characterizing disease-induced differences.
BibTeX:
@article{kemp_effects_2012,
  author = {Kemp, Arika D and Harding, Chad C and Cabral, Wayne A and Marini, Joan C and Wallace, Joseph M},
  title = {Effects of tissue hydration on nanoscale structural morphology and mechanics of individual Type I collagen fibrils in the Brtl mouse model of Osteogenesis Imperfecta},
  journal = {Journal of Structural Biology},
  year = {2012},
  volume = {180},
  number = {3},
  pages = {428--438},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S1047847712002687},
  doi = {10.1016/j.jsb.2012.09.012}
}
Kenny S (2012), "Mechanical Characterization of Patterned Columnar Silver Nanorods with the Atomic Force Microscope". Thesis at: Virginia Commonwealth University.
Abstract: Patterned silver (Ag) columnar nanorods were prepared by the glancing angle physical vapor deposition method. The Ag columnar nanorods were grown on a Si (100) substrate patterned with posts in a square “lattice? of length 1 µm. An electron beam source was used as the evaporation method, creating the deposition flux which was oriented 85˚ from the substrate normal. A Dimension Icon with NanoScope V controller atomic force microscope was used to measure the spring constant in 10 nm increments along the long axis of five 670 nm long Ag nanorod specimens. The simple beam bending model was used to analyze the data. Unexpected behavior of the spring constant data was observed which prevented a conclusive physically realistic value of the Young’s modulus to be calculated.
BibTeX:
@phdthesis{Kenny2012,
  author = {Kenny, Sean},
  title = {Mechanical Characterization of Patterned Columnar Silver Nanorods with the Atomic Force Microscope},
  school = {Virginia Commonwealth University},
  year = {2012}
}
Khelifa F, Druart M-E, Habibi Y, Bénard F, Leclère P, Olivier M and Dubois P (2013), "Sol–gel incorporation of silica nanofillers for tuning the anti-corrosion protection of acrylate-based coatings", Progress in Organic Coatings., March, 2013. Vol. 76(5), pp. 900-11. Elsevier B.V..
Abstract: The aim of the present work is to synthesize through sol–gel approach new hybrid polymeric nanocomposites to be used as coating materials. An acrylic-based polymer was prepared by free-radical copolymerization of two monomers widely used for coatings, namely 2-ethylhexylacrylate (EHA) and glycidyl methacrylate (GMA) bearing epoxy moieties, in which silica nanoparticles were incorporated by in situ acid hydrolysis and subsequent condensation of tetraethoxysilane (TEOS). Glycidoxypropyl trimethoxysilane (GPTS) was used as coupling agent to fine-tune the compatibility between organic and inorganic phases. The morphology, mechanical properties and corrosion resistance of thin films applied on aluminum alloys were optimized by varying the content of silica nanoparticles whose properties were strongly affected by the TEOS/GPTS ratios. Performances of the obtained hybrid materials were scrutinized by atomic force microscopy (AFM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and electrochemical impedance spectroscopy (EIS). Thus it was evidenced that an optimum amount of silica nanoparticles with a precise morphology and composition in term of TEOS/GPTS ratio is needed to maintain good coating barrier properties. Outstanding anti-corrosion protection was reached by using optimized hybrid films.
BibTeX:
@article{Khelifa2013a,
  author = {Khelifa, Farid and Druart, Marie-Eve and Habibi, Youssef and Bénard, Freddy and Leclère, Philippe and Olivier, Marjorie and Dubois, Philippe},
  title = {Sol–gel incorporation of silica nanofillers for tuning the anti-corrosion protection of acrylate-based coatings},
  journal = {Progress in Organic Coatings},
  publisher = {Elsevier B.V.},
  year = {2013},
  volume = {76},
  number = {5},
  pages = {900--11},
  url = {http://dx.doi.org/10.1016/j.porgcoat.2013.02.005},
  doi = {10.1016/j.porgcoat.2013.02.005}
}
Khelifa F, Druart M-E, Habibi Y, Rioboo R, Olivier M, De Coninck J and Dubois P (2013), "Effect of photo-crosslinking on the performance of silica nanoparticle-filled epoxidized acrylic copolymer coatings", Journal of Materials Chemistry A. Vol. 1(35), pp. 10334.
Abstract: The effect of UV-crosslinking on the morphological, mechanical and barrier properties of a hybrid coating based on an epoxidized acrylic polymer filled with silica nanoparticles, incorporated in situ through the sol–gel method, was studied. A systematic comparison of coatings loaded with various amounts of silica nanoparticles subjected or not to UV-curing was reported. The morphological and mechanical properties were investigated by atomic force microscopy (AFM) and tribology tests, while the corrosion resistance of thin films applied on aluminum alloys was measured by electrochemical impedance spectroscopy (EIS). Our findings indicate that a synergic effect is brought about by the combination of silica nanoparticles and UV-curing, significantly enhancing the mechanical properties of the coating, although the corrosion protection was compromised. The resulting coating may be used in applications requiring high mechanical performance.
BibTeX:
@article{khelifa_effect_2013,
  author = {Khelifa, Farid and Druart, Marie-Eve and Habibi, Youssef and Rioboo, Romain and Olivier, Marjorie and De Coninck, Joël and Dubois, Philippe},
  title = {Effect of photo-crosslinking on the performance of silica nanoparticle-filled epoxidized acrylic copolymer coatings},
  journal = {Journal of Materials Chemistry A},
  year = {2013},
  volume = {1},
  number = {35},
  pages = {10334},
  url = {http://xlink.rsc.org/?DOI=c3ta11668a},
  doi = {10.1039/c3ta11668a}
}
Khelifa F, Ershov S, Habibi Y, Snyders R and Dubois P (2013), "Use of Free Radicals on the Surface of Plasma Polymer for the Initiation of a Polymerization Reaction.", ACS applied materials & interfaces., November, 2013. American Chemical Society.
Abstract: A novel approach to functionalize plasma polymer films (PPFs) through the grafting polymerization initiated from free radicals trapped in the film was developed in this work. 2-Ethylhexyl acrylate (EHA) was chosen as radically polymerizable monomer given the wide use of its corresponding polymer in coating and adhesive applications. The occurrence of the grafting was first confirmed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). Then grafted chains were studied in more detail. The thickness of grafted chains was quantitatively estimated by angle-resolved XPS (ARXPS), while their morphology and interfacial behavior were qualitatively investigated by atomic force microscopy (AFM), contact angle measurements, and quartz crystal microbalance (QCM). The latter technique provided additional insights regarding the swelling behavior of the grafted layer and its stability upon exposure to challenging environments. Reported scientific findings suggest to use this approach for the covalent binding of a very thin layer on the top surface of a PPF without affecting its bulk properties.
BibTeX:
@article{Khelifa2013,
  author = {Khelifa, Farid and Ershov, Sergey and Habibi, Youssef and Snyders, Rony and Dubois, Philippe},
  title = {Use of Free Radicals on the Surface of Plasma Polymer for the Initiation of a Polymerization Reaction.},
  journal = {ACS applied materials & interfaces},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://pubs.acs.org/doi/abs/10.1021/am402364j},
  doi = {10.1021/am402364j}
}
Khelifa F, Habibi Y, Benard F and Dubois P (2012), "Effect of cellulosic nanowhiskers on the performances of epoxidized acrylic copolymers", Journal of Materials Chemistry. Vol. 22(38), pp. 20520.
Abstract: The aim of the present work is to synthesize new nanocomposites based on an acrylic polymeric matrix loaded with cellulose nanowhiskers (CNWs). The acrylic copolymer was prepared by free-radical copolymerization of two monomers widely used for coating applications, namely 2-ethylhexylacrylate (EHA) and glycidyl methacrylate (GMA) bearing epoxy moieties, while CNWs were extracted from ramie fibers by the means of acid hydrolysis. A series of nanocomposites with various CNW loadings were obtained by solvent casting and were further crosslinked by an UV-induced curing. The extent of the crosslinking was substantiated by Fourier transform infrared spectroscopy (FTIR) whereas morphological, thermo-mechanical as well as optical properties were evaluated before and after the crosslinking by Scanning Electronic Microscopy (SEM), Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Dynamical Mechanical Analysis (DMA) and Polarized Optical Microscopy (POM). Thus it was demonstrated that strong interactions occur between the polymeric matrix and CNW, contributing to a significant improvement of the thermal stability and mechanical properties of the nanocomposites. More importantly, nanocomposites exhibit at certain CNW loading interesting optical properties.
BibTeX:
@article{khelifa_effect_2012,
  author = {Khelifa, Farid and Habibi, Youssef and Benard, Freddy and Dubois, Philippe},
  title = {Effect of cellulosic nanowhiskers on the performances of epoxidized acrylic copolymers},
  journal = {Journal of Materials Chemistry},
  year = {2012},
  volume = {22},
  number = {38},
  pages = {20520},
  url = {http://xlink.rsc.org/?DOI=c2jm33917j},
  doi = {10.1039/c2jm33917j}
}
Khelifa F, Habibi Y, Leclère P and Dubois P (2013), "Convection-assisted assembly of cellulose nanowhiskers embedded in an acrylic copolymer", Nanoscale., February, 2013. Vol. 5(3), pp. 1082-90. The Royal Society of Chemistry.
Abstract: Ultrathin films containing a high fraction of cellulose nanowhiskers embedded in an acrylic-based polymer matrix were successfully prepared by a shear-convective assembly method. Their morphological, chemical and physical properties were examined by AFM Peak Force Tapping, Ellipsometry, contact angle and X-ray photoelectronic spectroscopy (XPS). Smooth, stable, robust and hydrophobic ultrathin films were obtained. The processing conditions influence, to different extents, the organization and morphology of the resulting ultrathin films. Under the given experimental conditions, films with highly packed and oriented cellulose nanowhiskers were obtained. A post-treatment based on UV-curing allows a further enhancement of the stability of the films without impacting any other property.
BibTeX:
@article{Khelifa2012,
  author = {Khelifa, Farid and Habibi, Youssef and Leclère, Philippe and Dubois, Philippe},
  title = {Convection-assisted assembly of cellulose nanowhiskers embedded in an acrylic copolymer},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {5},
  number = {3},
  pages = {1082--90},
  url = {http://pubs.rsc.org/en/content/articlehtml/2012/nr/c2nr33194b http://www.ncbi.nlm.nih.gov/pubmed/23254336},
  doi = {10.1039/c2nr33194b}
}
Khripin CY, Tu X, Heddleston JM, Silvera-Batista C, Hight Walker AR, Fagan J and Zheng M (2013), "High-Resolution Length Fractionation of Surfactant-Dispersed Carbon Nanotubes", Analytical Chemistry., February, 2013. Vol. 85(3), pp. 1382-1388.
Abstract: Length fractionation of colloidal single-wall carbon nanotube (SWCNT) dispersions is required for many studies. Size-exclusion chromatography (SEC) has been developed as a reliable method for high-resolution length fractionation of DNA-dispersed SWCNTs but has not been applied to surfactant-dispersed SWCNTs due to their lower dispersion stability and tendency to adsorb onto SEC stationary phases. Here, we report that SEC length fractionation can be achieved for bile salt dispersed SWCNTs by using porous silica-based beads as the stationary phase and bile salt solution as the mobile phase. We demonstrate that the SEC length sorting method can be combined with existing ultracentrifugation SWCNT sorting methods to produce “orthogonally sorted? samples, including length sorted semiconducting SWCNTs, which are important for electronics applications as well as length sorted empty-core SWCNTs. Importantly, we show that unlike simple length fractionation by SEC or any other method, orthogonal sorting produces samples of consistent quality for different length fractions, with similar UV–vis-nearIR absorption and Raman spectral features
BibTeX:
@article{khripin_high-resolution_2013,
  author = {Khripin, Constantine Y and Tu, Xiaomin and Heddleston, John M and Silvera-Batista, Carlos and Hight Walker, Angela R and Fagan, Jeffrey and Zheng, Ming},
  title = {High-Resolution Length Fractionation of Surfactant-Dispersed Carbon Nanotubes},
  journal = {Analytical Chemistry},
  year = {2013},
  volume = {85},
  number = {3},
  pages = {1382--1388},
  url = {http://pubs.acs.org/doi/abs/10.1021/ac303349q},
  doi = {10.1021/ac303349q}
}
Khripin CY, Tu X, Howarter J, Fagan J and Zheng M (2012), "Concentration Measurement of Length-Fractionated Colloidal Single-Wall Carbon Nanotubes", Analytical Chemistry., October, 2012. Vol. 84(20), pp. 8733-8739.
BibTeX:
@article{khripin_concentration_2012,
  author = {Khripin, Constantine Y and Tu, Xiaomin and Howarter, John and Fagan, Jeffrey and Zheng, Ming},
  title = {Concentration Measurement of Length-Fractionated Colloidal Single-Wall Carbon Nanotubes},
  journal = {Analytical Chemistry},
  year = {2012},
  volume = {84},
  number = {20},
  pages = {8733--8739},
  url = {http://pubs.acs.org/doi/abs/10.1021/ac302023n},
  doi = {10.1021/ac302023n}
}
Khudaish EA, Al-Hinaai MM and Al-Harthi SH (2013), "A solid-state sensor based on tris(2,2′-bipyridyl)ruthenium(II) /poly(4-aminodiphenylamine) modified electrode: Characterization and applications", Sensors and Actuators B: Chemical., May, 2013. Vol. 185, pp. 478-87. Elsevier B.V..
Abstract: A solid-state sensor based on Poly(4-aminodiphenylamine) film deposited at glassy carbon electrode doped with tris(2,2′-bipyridyl)Ru(II) complex (Padpa/Ru/GCE) was constructed electrochemically. The surface morphology of the film modified electrode was characterized using electrochemical and surface scanning techniques. A redox property represented by [Ru(bpy)3]3+/2+ couple immobilized at the Padpa moiety was characterized using typical voltammetric techniques. The XPS data demonstrated the existence of (=N − ) bonding responsible for polymer formation while the degree of polymerization is reduced by the presence of components containing chloride ions, specifically (−NH3+Cl−) which is expected to rule the linkage of Padpa with Ru-complexes. The AFM image reveals a broken and fused Padpa/Ru fiber structure compared to a relatively uniform Padpa film. Parameters such as electron transfer coefficient, surface concentration, roughness and energy dissipation were estimated. Primarily, the modified electrode was applied as an environmental sensor for the simultaneous determination of Zn2+, Cd2+, Pb2+ and Cu2+ ions in water samples. The detection limits for these metal ions were dropped to 122.5, 21.7, 9.8 and 28.0 ppb, respectively.
BibTeX:
@article{Khudaish2013,
  author = {Khudaish, Emad A. and Al-Hinaai, Mohammed M. and Al-Harthi, Salim H.},
  title = {A solid-state sensor based on tris(2,2′-bipyridyl)ruthenium(II) /poly(4-aminodiphenylamine) modified electrode: Characterization and applications},
  journal = {Sensors and Actuators B: Chemical},
  publisher = {Elsevier B.V.},
  year = {2013},
  volume = {185},
  pages = {478--87},
  url = {http://dx.doi.org/10.1016/j.snb.2013.05.017},
  doi = {10.1016/j.snb.2013.05.017}
}
Korolkov VV, Allen S, Roberts CJ and Tendler SJB (2012), "Green Chemistry Approach to Surface Decoration: Trimesic Acid Self-Assembly on HOPG", The Journal of Physical Chemistry C., May, 2012. Vol. 116, pp. 11519-25. American Chemical Society.
Abstract: We have investigated trimesic acid (1,3,5-benzenetricarboxylic acid, TMA) adsorption on highly oriented pyrolytic graphite (HOPG) surface from aqueous medium at room temperature. Both atomic force and scanning tunnelling microscopy were utilized to follow the adsorption dynamics and molecular arrangements. We have proposed an optimised green chemistry approach for fabricating trimesic acid monolayer structures on HOPG. A chicken-wire arrangement for adsorbed molecules with an average pore size of 11±1Å was established and observed using both scanning techniques. This structure was found to be stable in the ambient for at least two days. We have investigated trimesic acid (1,3,5-benzenetricarboxylic acid, TMA) adsorption on highly oriented pyrolytic graphite (HOPG) surface from aqueous medium at room temperature. Both atomic force and scanning tunnelling microscopy were utilized to follow the adsorption dynamics and molecular arrangements. We have proposed an optimised green chemistry approach for fabricating trimesic acid monolayer structures on HOPG. A chicken-wire arrangement for adsorbed molecules with an average pore size of 11±1Å was established and observed using both scanning techniques. This structure was found to be stable in the ambient for at least two days.
BibTeX:
@article{Korolkov2012,
  author = {Korolkov, Vladimir V. and Allen, Stephanie and Roberts, Clive J. and Tendler, Saul J. B.},
  title = {Green Chemistry Approach to Surface Decoration: Trimesic Acid Self-Assembly on HOPG},
  journal = {The Journal of Physical Chemistry C},
  publisher = {American Chemical Society},
  year = {2012},
  volume = {116},
  pages = {11519--25},
  url = {http://dx.doi.org/10.1021/jp212388c},
  doi = {10.1021/jp212388c}
}
Kosaka PM, González S, Domnguez CM, Cebollada A, San Paulo A, Calleja M and Tamayo J (2013), "Atomic force microscopy reveals two phases in single stranded DNA self-assembled monolayers", Nanoscale., August, 2013. Vol. 5(16), pp. 7425-32. The Royal Society of Chemistry.
Abstract: We have investigated the structure of single-stranded (ss) DNA self-assembled monolayers (SAMs) on gold by combining peak force tapping, Kelvin probe and phase contrast atomic force microscopy (AFM) techniques. The adhesion, surface potential and phase shift signals show heterogeneities in the DNA film structure at two levels: microscale and nanoscale; which cannot be clearly discerned in the topography. Firstly, there is multilayer aggregation covering less than 5% of the surface. The DNA multilayers seem to be ordered phases and their existence suggests that DNA end-to-end interaction can play a role in the self-assembly process. Secondly, we find the formation of two phases in the DNA monolayer, which differ both in surface energy and surface potential. We relate the two domains to differences in the packing density and in the ssDNA conformation. The discovered heterogeneities in ssDNA SAMs provide a new scenario in our vision of these relevant films that have direct consequences on their biological, chemical and physical properties.
BibTeX:
@article{kosaka_atomic_2013,
  author = {Kosaka, Priscila M and González, Sheila and Domnguez, Carmen M and Cebollada, Alfonso and San Paulo, Alvaro and Calleja, Montserrat and Tamayo, Javier},
  title = {Atomic force microscopy reveals two phases in single stranded DNA self-assembled monolayers},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {5},
  number = {16},
  pages = {7425--32},
  url = {http://xlink.rsc.org/?DOI=c3nr01186k http://pubs.rsc.org/en/content/articlehtml/2013/nr/c3nr01186k http://www.ncbi.nlm.nih.gov/pubmed/23832284},
  doi = {10.1039/c3nr01186k}
}
Koscielska B, Yuzephovich OI, Bengus SV, Winiarski A, Sadowski W and Apiski M (2012), "Superconducting Properties of VN SiO2 Sol Gel Derived Thin Films", Acta Physica Polonica Series A. Vol. 121(4), pp. 832-5.
Abstract: In this work studies of structure and superconducting properties of VN SiO2 lms are reported. The lmswere obtained through thermal nitridation (ammonolysis) of sol gel derived V2O3 SiO2 coatings (in a properV2O3/SiO2 ratio) at 1200◦C. This process leads to the formation of disordered structure with VN metallic grainsdispersed in the insulating SiO2 matrix. The structural transformations occurring in the lms as a result ofammonolysis were studied using X-ray photoelectron spectroscopy (XPS). The critical superconducting parametersare obtained. The magnetoresistance at high magnetic elds has been investigated.
BibTeX:
@article{Koscielska2012,
  author = {Koscielska, B. and Yuzephovich, O. I. and Bengus, S. V. and Winiarski, A. and Sadowski, W. and Apiski, M.},
  title = {Superconducting Properties of VN SiO2 Sol Gel Derived Thin Films},
  journal = {Acta Physica Polonica Series A},
  year = {2012},
  volume = {121},
  number = {4},
  pages = {832--5},
  url = {http://przyrbwn.icm.edu.pl/APP/PDF/121/a121z4p122.pdf}
}
Krivosheeva O (2013), "Interfacial Properties of Film Forming Proteins and their Layer-by-Layer Assembly with Nanoparticles". Thesis at: KTH Royal Institute of Technology.
Abstract: The aim of this thesis work was to investigate the interfacial properties of film forming proteins, stability of the layers created by them, and their interactions with nanoparticles. Mussel adhesive protein (Mefp-1) and hydrophobins (HFBI and HFBII) were the three main proteins used. HFBI and HFBII are relatively small globular proteins produced by filamentous fungi. They display unusual surface activity, by spontaneously forming films at many interfaces. Mefp-1 is extracted from mussel byssus and posses high ability to strongly attach to different kinds of surfaces. Fundamental understanding of their interfacial properties is of general interest because of the variety of possible applications, for example in food, biomedicine, coatings, etc. The adsorption and layer stability studies of HFBI, HFBII, and Mefp-1 at the solid/water interface were studied by means of dual polarization interferometery (DPI). It was observed that the adsorbed amount of HFBII was higher than that of HFBI and the film formed by the former protein was more compact. The adsorption kinetics of the two hydrophobins displayed some unusual features. Further, it was found that layers formed by these proteins partially desorbed when the flow was stopped, and the desorption rate for HFBII was enhanced in the presence of hydrophobins in solution. Adsorption of Mefp-1 as a function of solution pH or degree of aggregation in the bulk was investigated. Adsorbed amount of non-aggregated Mefp-1 on silicon oxynitride increased with increasing buffer pH, but the resulting film was not more compact. Adsorption of slightly aggregated Mefp-1 resulted in higher adsorbed amount and formation of denser layer. Initial adsorption kinetics studies revealed almost no pH dependence of the non-aggregated mussel adhesive protein, but the kinetics was slowed down by presence of aggregates in the bulk solution. Moreover, the effect of ionic strength and low pH on preadsorbed Mefp-1 layer was investigated, and it was found that the protein layer exhibits higher resistance towards desorption than a synthetic polyelectrolyte with similar charge density. Finally, physical and nanomechanical properties of composite films consisting of Mefp-1 and ceria nanoparticles were examined. For fabrication of these films the layer-by-layer approach was used. Quartz crystal microbalance with dissipation (QCM-D) was utilized to measure sensed mass and visco-elastic properties of adsorbed layers. Atomic force microscopy (AFM) techniques, including peak force quantitative nanomechanical mapping (Peak Force QNM) and contact mode AFM, were used for measuring physical, mechanical and robustness properties of nanocomposite films in air. Independently on the number of layers an almost linear growth of sensed mass was observed while the total dissipation values increases after six steps. Moreover, increase in Mefp-1 concentration during deposition resulted in formation of a more rigid layer, by comparison with lower concentration. The robustness of the nanocomposite layer showed that at low pressures (about 16 MPa) plastic deformation occurs and increase in load result in abrasion of the layers at about 80 MPa
BibTeX:
@phdthesis{Krivosheeva2013a,
  author = {Krivosheeva, Olga},
  title = {Interfacial Properties of Film Forming Proteins and their Layer-by-Layer Assembly with Nanoparticles},
  school = {KTH Royal Institute of Technology},
  year = {2013},
  url = {http://kth.diva-portal.org/smash/record.jsf?pid=diva2:621225}
}
Krivosheeva O, Sababi M, Dedinaite A and Claesson PM (2013), "Nanostructured Composite Layers of Mussel Adhesive Protein and Ceria Nanoparticles.", Langmuir., July, 2013.
Abstract: Mussel adhesive proteins are known for their high affinity to a range of different surfaces, and they therefore appear as ideal candidates for producing thin inorganic-organic composite films with high robustness. In this work we explore the possibility of making cohesive films utilizing layer-by-layer deposition of the highly positively charged mussel adhesive protein, Mefp-1, and negatively charged ceria nanoparticles. This particular material combination was chosen due to recent findings that such films provide good corrosion protection. Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) was used for following the film formation process in situ on silica surfaces. A close to linear growth of the film with number of deposited layers were found for up to 18 deposition steps, the highest number of depositions investigated in this work. The Mefp-1 concentration during film deposition affected the film properties, where a higher protein concentration resulted in a stiffer film. It was also found that the added mass could be amplified by using a Mefp-1 solution containing small aggregates. The surface nanomechanical properties of dried multilayer films were investigated using Peak Force QNM (Quantitative Nanomechanical Mapping) in air. Homogeneous surface coverage was found under all conditions explored, and the Young's modulus of the outer region of the coating increased when a higher Mefp-1 concentration was used during film deposition. The nature of the outermost surface layer was found to significantly affect the surface nanomechanical properties. The abrasion resistance of the coating was measured by using controlled-force contact mode AFM.
BibTeX:
@article{Krivosheeva2013,
  author = {Krivosheeva, Olga and Sababi, Majid and Dedinaite, Andra and Claesson, Per Martin},
  title = {Nanostructured Composite Layers of Mussel Adhesive Protein and Ceria Nanoparticles.},
  journal = {Langmuir},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23815752},
  doi = {10.1021/la401693x}
}
Kulshreshtha PK, Maruyama K, Kiani S, Ziegler D, Blackwell J, Olynick D and Ashby PD (2013), "Nanoscale modulus and surface chemistry characterization for collapse free resists", In SPIE Advanced Lithography., April, 2013. Vol. 8681, pp. 86810O-86810O-11. International Society for Optics and Photonics.
BibTeX:
@inproceedings{Kulshreshtha2013,
  author = {Kulshreshtha, Prashant K. and Maruyama, Ken and Kiani, Sara and Ziegler, Dominik and Blackwell, James and Olynick, Deidre and Ashby, Paul D.},
  editor = {Starikov, Alexander and Cain, Jason P.},
  title = {Nanoscale modulus and surface chemistry characterization for collapse free resists},
  booktitle = {SPIE Advanced Lithography},
  publisher = {International Society for Optics and Photonics},
  year = {2013},
  volume = {8681},
  pages = {86810O--86810O--11},
  url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2011657 http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1679593},
  doi = {10.1117/12.2011657}
}
Kurganskaya I, Arvidson RS, Fischer C and Luttge A (2012), "Does the stepwave model predict mica dissolution kinetics?", Geochimica et Cosmochimica Acta., November, 2012. Vol. 97, pp. 120-130.
Abstract: The micas are a unique class of minerals because of their layered structure. A frequent question arising in mica dissolution studies is whether this layered structure radically changes the dissolution mechanism. We address this question here, using data from VSI and AFM experiments involving muscovite to evaluate crystallographic controls on mica dissolution. These data provide insight into the dissolution process, and reveal important links to patterns of dissolution observed in framework minerals. Under our experimental conditions (pH 9.4, 155 °C), the minimal global rate of normal surface retreat observed in VSI data was 1.42 × 10−10 mol/m2/s ($ = 27 while the local rate observed at deep etch pits reached 416 × 10−10 mol/m2/s ($ = 49. Complementary AFM data clearly show crystallographic control of mica dissolution, both in terms of step advance and the geometric influence of interlayer rotation (stacking periodicity). These observations indicate that basal/edge surface area ratios are highly variable and change continuously over the course of reaction, thus obviating their utility as characteristic parameters defining mica reactivity. Instead, these observations of overall dissolution rate and the influence of screw dislocations illustrate the link between atomic step movement and overall dissolution rate defined by surface retreat normal to the mica surface. Considered in light of similar observations available elsewhere in the literature, these relationships provide support for application of the stepwave model to mica dissolution kinetics. This approach provides a basic mechanistic link between the dissolution kinetics of phyllosilicates, framework silicates, and related minerals, and suggests a resolution to the general problem of mica reactivity.
BibTeX:
@article{kurganskaya_does_2012,
  author = {Kurganskaya, Inna and Arvidson, Rolf S and Fischer, Cornelius and Luttge, Andreas},
  title = {Does the stepwave model predict mica dissolution kinetics?},
  journal = {Geochimica et Cosmochimica Acta},
  year = {2012},
  volume = {97},
  pages = {120--130},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0016703712004917},
  doi = {10.1016/j.gca.2012.08.033}
}
Kurland NE, Drira Z and Yadavalli VK (2012), "Measurement of nanomechanical properties of biomolecules using atomic force microscopy", Micron., February, 2012. Vol. 43(2-3), pp. 116-28. Elsevier Ltd.
Abstract: The capabilities of atomic force microscopy (AFM) have been rapidly expanding beyond topographical imaging to now allow for the analysis of a wide range of properties of diverse materials. The technique of nanoindentation, traditionally performed via dedicated indenters can now be reliably achieved using AFM instrumentation, enabling mechanical property determination at the nanoscale using the high spatial and force resolutions of the AFM. In the study of biological systems, from biomolecules to complexes, this technique provides insight into how mesoscale properties and functions may arise from a myriad of single biomolecules. In vivo and in situ analyses of native structures under physiological conditions as well as the rapid analysis of molecular species under a variety of experimental treatments are made possible with this technique. As a result, AFM nanoindentation has emerged as a critical tool for the study of biological systems in their natural state, further contributing to both biomaterial design and pharmacological research. In this review, we detail the theory and progression of AFM-based nanoindentation, and present several applications of this technique as it has been used to probe biomolecules and biological nanostructures from single proteins to complex assemblies. We further detail the many challenges associated with mechanical models and required assumptions for model validity. AFM nanoindentation capabilities have provided an excellent improvement over conventional nanomechanical tools and by integration of topographical data from imaging, enabled the rapid extraction and presentation of mechanical data for biological samples.
BibTeX:
@article{Kurland,
  author = {Kurland, Nicholas E. and Drira, Zouheir and Yadavalli, Vamsi K.},
  title = {Measurement of nanomechanical properties of biomolecules using atomic force microscopy},
  journal = {Micron},
  publisher = {Elsevier Ltd},
  year = {2012},
  volume = {43},
  number = {2-3},
  pages = {116--28},
  url = {http://www.sciencedirect.com/science/article/pii/S0968432811001375},
  doi = {10.1016/j.micron.2011.07.017}
}
Lamic-Humblot A-F, Casale S, Léger C, Alpérine S and Louis C (2013), "An easy way to obtain thin gold film on silica glass substrate by chemical method", Thin Solid Films., May, 2013. Vol. null(null)
BibTeX:
@article{Lamic-Humblot2013,
  author = {Lamic-Humblot, Anne-Félicie and Casale, Sandra and Léger, Cédric and Alpérine, Serge and Louis, Catherine},
  title = {An easy way to obtain thin gold film on silica glass substrate by chemical method},
  journal = {Thin Solid Films},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.tsf.2013.05.085},
  doi = {10.1016/j.tsf.2013.05.085}
}
Lamprou DA, Venkatpurwar V and Kumar MNVR (2013), "Atomic Force Microscopy Images Label-Free, Drug Encapsulated Nanoparticles In Vivo and Detects Difference in Tissue Mechanical Properties of Treated and Untreated: A Tip for Nanotoxicology", PLoS ONE., May, 2013. Vol. 8(5), pp. e64490. Public Library of Science.
Abstract: Overcoming the intractable challenge of imaging of label-free, drug encapsulated nanoparticles in tissues in vivo would directly address associated regulatory concerns over 'nanotoxicology'. Here we demonstrate the utility of Atomic Force Microscopy (AFM) for visualising label-free, drug encapsulated polyester particles of ∼280 nm distributed within tissues following their intravenous or peroral administration to rodents. A surprising phenomenon, in which the tissues' mechanical stiffness was directly measured (also by AFM) and related to the number of embedded nanoparticles, was utilised to generate quantitative data sets for nanoparticles localisation. By coupling the normal determination of a drug's pharmacokinetics/pharmacodynamics with post-sacrifice measurement of nanoparticle localisation and number, we present for the first time an experimental design in which a single in vivo study relates the PK/PD of a nanomedicine to its toxicokinetics.
BibTeX:
@article{Lamprou2013,
  author = {Lamprou, Dimitrios A. and Venkatpurwar, Vinod and Kumar, M. N. V. Ravi},
  editor = {Kreplak, Laurent},
  title = {Atomic Force Microscopy Images Label-Free, Drug Encapsulated Nanoparticles In Vivo and Detects Difference in Tissue Mechanical Properties of Treated and Untreated: A Tip for Nanotoxicology},
  journal = {PLoS ONE},
  publisher = {Public Library of Science},
  year = {2013},
  volume = {8},
  number = {5},
  pages = {e64490},
  url = {http://dx.plos.org/10.1371/journal.pone.0064490},
  doi = {10.1371/journal.pone.0064490}
}
Landoulsi J and Dupres V (2013), "Direct AFM force mapping of surface nanoscale organization and protein adsorption on aluminum substrate", Physical Chemistry Chemical Physics., June, 2013. Vol. 15(21), pp. 8429-40.
Abstract: We investigate the nanoscale organization of a superficially hydroxylated Al substrate and its effect on subsequent protein adsorption using atomic force microscopy (AFM). For this purpose we used a mode which allows a direct mapping of a variety of surface properties (adhesion, elasticity, dissipation, etc.) to be probed simultaneously with topographical images. The hydroxylation treatment leads to a drastic modification of the surface morphology, owing to the formation of AlOOH compounds. In air, AFM images revealed the formation of regular nanorod-like structures randomly distributed, inducing the appearance of nanoporous domains on the surface. In buffer solution, prior to the adsorption of proteins, the surface nanoscale organization is preserved, mainly due to the chemical stability of AlOOH compounds under these conditions. The adsorption of proteins on the obtained nanostructured surface was performed using either a globular ($-lactoglobulin) or a fibrillar (collagen) protein and by modulating the adsorbed amount through the incubation time or the concentration of proteins in solution. At low amounts, collagen adsorbs on the whole surface without preferential localization. The surface topography remains similar to the bare surface, while significant changes were evidenced on adhesion and elasticity maps. This is due to the fact that the surface became adhesive and less stiff, owing to the presence of a soft and hydrated protein layer. By contrast, $-lactoglobulin tends to diffuse into the nanoporous domains, leading to their filling up, and the surface is blurred with a thick and dense protein layer upon increasing the amount of adsorbed molecules. Our findings demonstrate the interest in using AFM for surface mapping to investigate the mechanism of protein adsorption at the nanoscale on materials with high surface roughness.
BibTeX:
@article{landoulsi_direct_2013,
  author = {Landoulsi, Jessem and Dupres, Vincent},
  title = {Direct AFM force mapping of surface nanoscale organization and protein adsorption on aluminum substrate},
  journal = {Physical Chemistry Chemical Physics},
  year = {2013},
  volume = {15},
  number = {21},
  pages = {8429--40},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23628858 http://pubs.rsc.org/en/Content/ArticleLanding/2013/CP/c3cp00137g},
  doi = {10.1039/c3cp00137g}
}
Lanså ker PC, Gunnarsson K, Roos A, Niklasson GA and Granqvist CG (2011), "Au thin films deposited on SnO2:In and glass: Substrate effects on the optical and electrical properties", Thin Solid Films., January, 2011. Vol. 519(6), pp. 1930-1933.
Abstract: We report on a detailed study on the optical and electrical properties of Au films made by sputter deposition onto glass substrates with and without transparent and electrically conducting layers of SnO2:In. The Au films had thicknesses up to 10.7 nm and hence spanned the range for thin film growth from discrete islands, via large scale coalescence and formation of a meandering conducting network, to the formation of a more or less “holey? film. Scanning electron microscopy and atomic force microscopy demonstrated that the SnO2:In films were considerably rougher than the glass itself, and this roughness influenced the Au film formation so that large scale coalescence set in at a somewhat larger thickness for films on SnO2:In than on glass. Measurements of spectral optical transmittance and reflectance and of electrical resistance gave a fully consistent picture that could be reconciled with impeded Au film formation on the SnO2:In layer; this led to pronounced “plateaus? in the near infrared optical spectra for Au films on SnO2:In and a concomitant change from such two-layer films having a lower resistance than the single gold film at thicknesses below large scale coalescence to the opposite behavior for larger film thicknesses. Our work highlights the importance of the substrate roughness for transparent conductors comprising coinage metal films backed by wide band gap transparent conducting oxides.
BibTeX:
@article{lansaker_au_2011,
  author = {Lanså ker, PC C and Gunnarsson, K. and Roos, A. and Niklasson, G. A. and Granqvist, C. G.},
  title = {Au thin films deposited on SnO2:In and glass: Substrate effects on the optical and electrical properties},
  journal = {Thin Solid Films},
  year = {2011},
  volume = {519},
  number = {6},
  pages = {1930--1933},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0040609010013829 http://www.sciencedirect.com/science/article/pii/S0040609010013829},
  doi = {10.1016/j.tsf.2010.09.048}
}
Lara C, Gourdin-Bertin S, Adamcik J, Bolisetty S and Mezzenga R (2012), "Self-assembly of Ovalbumin into Amyloid and Non-Amyloid Fibrils.", Biomacromolecules., October, 2012. American Chemical Society.
Abstract: We study the fibrillation pathway of ovalbumin protein and report the simultaneous formation of several types of fibrils, with clear structural and physical differences. We compare the fibrillation mechanisms at low ionic strength with and without salt, and follow the kinetics of fibrils growth by atomic force microscopy (AFM), static and dynamic light scattering (SLS, DLS) and small angle X-ray scattering (SAXS). We show that, among the morphologies identified, long semi-flexible amyloid fibrils (Type I), with persistence length Lp 3 $m, Young modulus E 2.8 GPa and cross-$ structure are formed. We also observe much more flexible fibrils (Type III, Lp 63 nm), that can assemble into multi-stranded ribbons with time. They show significantly lower intrinsic stiffness (1.1 GPa) and a secondary structure, which is not characteristic of the well-ordered amyloids, as determined by circular dichroism (CD), wide angle X-ray scattering (WAXS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). In between these two main classes of fibrils, a third family, with intermediate flexibility (Type II, Lp 300 nm), is also resolved.
BibTeX:
@article{Lara2012,
  author = {Lara, Cecile and Gourdin-Bertin, Simon and Adamcik, Jozef and Bolisetty, Sreenath and Mezzenga, Raffaele},
  title = {Self-assembly of Ovalbumin into Amyloid and Non-Amyloid Fibrils.},
  journal = {Biomacromolecules},
  publisher = {American Chemical Society},
  year = {2012},
  url = {http://pubs.acs.org/doi/abs/10.1021/bm301481v},
  doi = {10.1021/bm301481v}
}
Lasagna-Reeves C, Castillo-Carranza DL, Sengupta U, Clos A, Jackson G and Kayed R (2011), "Tau oligomers impair memory and induce synaptic and mitochondrial dysfunction in wild-type mice", Molecular Neurodegeneration. Vol. 6(1), pp. 1-14. BioMed Central.
Abstract: Background The correlation between neurofibrillary tangles of tau and disease progression in the brains of Alzheimer's disease (AD) patients remains an area of contention. Innovative data are emerging from biochemical, cell-based and transgenic mouse studies that suggest that tau oligomers, a pre-filament form of tau, may be the most toxic and pathologically significant tau aggregate. Results Here we report that oligomers of recombinant full-length human tau protein are neurotoxic in vivo after subcortical stereotaxic injection into mice. Tau oligomers impaired memory consolidation, whereas tau fibrils and monomers did not. Additionally, tau oligomers induced synaptic dysfunction by reducing the levels of synaptic vesicle-associated proteins synaptophysin and septin-11. Tau oligomers produced mitochondrial dysfunction by decreasing the levels of NADH-ubiquinone oxidoreductase (electron transport chain complex I), and activated caspase-9, which is related to the apoptotic mitochondrial pathway. Conclusions This study identifies tau oligomers as an acutely toxic tau species in vivo, and suggests that tau oligomers induce neurodegeneration by affecting mitochondrial and synaptic function, both of which are early hallmarks in AD and other tauopathies. These results open new avenues for neuroprotective intervention strategies of tauopathies by targeting tau oligomers.
BibTeX:
@article{Lasagna-Reeves2011,
  author = {Lasagna-Reeves, Cristian and Castillo-Carranza, Diana L. and Sengupta, Urmi and Clos, Audra and Jackson, George and Kayed, Rakez},
  title = {Tau oligomers impair memory and induce synaptic and mitochondrial dysfunction in wild-type mice},
  journal = {Molecular Neurodegeneration},
  publisher = {BioMed Central},
  year = {2011},
  volume = {6},
  number = {1},
  pages = {1--14},
  url = {http://dx.doi.org/10.1186/1750-1326-6-39},
  doi = {10.1186/1750-1326-6-39}
}
Lazar P, Zhang S, Safářová K, Li Q, Froning JP, Granatier J, Hobza P, Zbořil R, Besenbacher F, Dong M and Otyepka M (2013), "Quantification of the interaction forces between metals and graphene by quantum chemical calculations and dynamic force measurements under ambient conditions.", ACS nano., February, 2013. Vol. 7(2), pp. 1646-51.
Abstract: The two-dimensional material graphene has numerous potential applications in nano(opto)electronics, which inevitably involve metal graphene interfaces.Theoretical approaches have been employed to examine metal graphene interfaces, but experimental evidence is currently lacking. Here, we combine atomic force microscopy (AFM) based dynamic force measurements and density functional theory calculations to quantify the interaction between metal-coated AFM tips and graphene under ambient conditions. The results show that copper has the strongest affinity to graphene among the studied metals (Cu, Ag, Au, Pt, Si), which has important implications for the construction of a new generation of electronic devices. Observed differences in the nature of the metal-graphene bonding are well reproduced by the calculations, which included nonlocal Hartree-Fock exchange and van der Waals effects.
BibTeX:
@article{Lazar2013,
  author = {Lazar, Petr and Zhang, Shuai and Safářová, Klára and Li, Qiang and Froning, Jens Peter and Granatier, Jaroslav and Hobza, Pavel and Zbořil, Radek and Besenbacher, Flemming and Dong, Mingdong and Otyepka, Michal},
  title = {Quantification of the interaction forces between metals and graphene by quantum chemical calculations and dynamic force measurements under ambient conditions.},
  journal = {ACS nano},
  year = {2013},
  volume = {7},
  number = {2},
  pages = {1646--51},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23346897},
  doi = {10.1021/nn305608a}
}
Lee G, Lee H, Nam K, Han J-H, Yang J, Lee SW, Yoon DS, Eom K and Kwon T (2012), "Nanomechanical characterization of chemical interaction between gold nanoparticles and chemical functional groups", Nanoscale research letters. Vol. 7(1), pp. 1-11.
BibTeX:
@article{lee_nanomechanical_2012,
  author = {Lee, Gyudo and Lee, Hyungbeen and Nam, Kihwan and Han, Jae-Hee and Yang, Jaemoon and Lee, Sang Woo and Yoon, Dae Sung and Eom, Kilho and Kwon, Taeyun},
  title = {Nanomechanical characterization of chemical interaction between gold nanoparticles and chemical functional groups},
  journal = {Nanoscale research letters},
  year = {2012},
  volume = {7},
  number = {1},
  pages = {1--11},
  url = {http://link.springer.com/article/10.1186/1556-276X-7-608}
}
Lee M, Urata SM, Aguilera JA, Perry CC and Milligan JR (2012), "Modeling the influence of histone proteins on the sensitivity of DNA to ionizing radiation", Radiation Research. Vol. 177(2), pp. 152-63.
Abstract: The DNA-binding proteins that are present in chromatin significantly affect the sensitivity of cells to ionizing radiation and to the radiation chemistry of DNA damage. The interaction between protein and DNA modifies the radiation chemistry of the latter. To model these processes, we have examined the effects of ionizing radiation on the minichromosome form of SV40 (which contains histone proteins arranged in nucleosomes) and also on plasmid DNA in the presence of lysozyme. Although high concentrations of lysozyme can bring about an extensive radioprotection by condensation of the plasmid, at lower levels it still produces significant radioprotective effects under conditions where this associative phase separation does not take place. The presence of histones or of lysozyme decreases the yield of modified guanines produced by ionizing radiation. Comparison with previous observations made with oligopeptides suggests that the mechanism responsible is electron donation to guanyl radicals in the DNA by tryptophan and tyrosine residues in the proteins. However, there was no evidence for DNA-protein crosslink formation.
BibTeX:
@article{Lee2012,
  author = {Lee, Melissa and Urata, Sarah M. and Aguilera, J. A. and Perry, C. C. and Milligan, J. R.},
  title = {Modeling the influence of histone proteins on the sensitivity of DNA to ionizing radiation},
  journal = {Radiation Research},
  year = {2012},
  volume = {177},
  number = {2},
  pages = {152--63},
  edition = {2011/11/23},
  url = {http://www.rrjournal.org/doi/pdf/10.1667/RR2812.1},
  doi = {10.1667/RR2812.1}
}
Li A, Lim TS, Shi H, Yin J, Tan SJ, Li Z, Low BC, Tan KSW and Lim CT (2011), "Molecular mechanistic insights into the endothelial receptor mediated cytoadherence of Plasmodium falciparum-infected erythrocytes.", PloS one., January, 2011. Vol. 6(3), pp. e16929.
Abstract: Cytoadherence or sequestration is essential for the pathogenesis of the most virulent human malaria species, Plasmodium falciparum (P. falciparum). Similar to leukocyte-endothelium interaction in response to inflammation, cytoadherence of P. falciparum infected red blood cells (IRBCs) to endothelium occurs under physiological shear stresses in blood vessels and involves an array of molecule complexes which cooperate to form stable binding. Here, we applied single-molecule force spectroscopy technique to quantify the dynamic force spectra and characterize the intrinsic kinetic parameters for specific ligand-receptor interactions involving two endothelial receptor proteins: thrombospondin (TSP) and CD36. It was shown that CD36 mediated interaction was much more stable than that mediated by TSP at single molecule level, although TSP-IRBC interaction appeared stronger than CD36-IRBC interaction in the high pulling rate regime. This suggests that TSP-mediated interaction may initiate cell adhesion by capturing the fast flowing IRBCs whereas CD36 functions as the 'holder' for providing stable binding.
BibTeX:
@article{Li2011a,
  author = {Li, Ang and Lim, Tong Seng and Shi, Hui and Yin, Jing and Tan, Swee Jin and Li, Zhengjun and Low, Boon Chuan and Tan, Kevin Shyong Wei and Lim, Chwee Teck},
  title = {Molecular mechanistic insights into the endothelial receptor mediated cytoadherence of Plasmodium falciparum-infected erythrocytes.},
  journal = {PloS one},
  year = {2011},
  volume = {6},
  number = {3},
  pages = {e16929},
  url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3060092&tool=pmcentrez&rendertype=abstract},
  doi = {10.1371/journal.pone.0016929}
}
Li A, Rénia L, Lim CT and Russell B (2013), "Atomic force microscopy of Plasmodium-infected red blood cells: detecting and localizing single molecular recognition events.", In Malaria: Methods in molecular biology. Clifton, NJ, January, 2013. Vol. 923(4), pp. 299-305. Springer.
Abstract: Atomic Force Microscopy (AFM) is a powerful tool for exploring the interaction between ligands and receptors, as well as their exact locations on the red cell surface. Here we discuss current and future applications for AFM based single-molecule force spectroscopy to study adhesion of Plasmodium-infected red blood cells. A protocol is provided for simultaneous topography and recognition imaging of the surface of Plasmodium falciparum-infected cells using CD36 functionalized tips.
BibTeX:
@incollection{Li2013,
  author = {Li, Ang and Rénia, Laurent and Lim, Chwee Teck and Russell, Bruce},
  editor = {Menard, Robert},
  title = {Atomic force microscopy of Plasmodium-infected red blood cells: detecting and localizing single molecular recognition events.},
  booktitle = {Malaria: Methods in molecular biology},
  publisher = {Springer},
  year = {2013},
  volume = {923},
  number = {4},
  pages = {299--305},
  url = {http://www.springerlink.com/content/m4071h7604t72285/},
  doi = {10.1007/978-1-62703-026-7\_21}
}
Li A, Sun W, Tan KSW and Lim CT (2010), "Molecular mechanistic insights into cytoadherence of human malaria infection", In Proceedings of the World Congress of Biomechanics.
Abstract: Malaria has remained as one of the most life threatening parasitic diseases on earth. The infections caused by Plasmodium falciparum, which is the most virulent and deadly species of human malarial parasite, are closely corre- lated to the structural and mechanistic changes on the infected red blood cells. Upon infection, the host cells not only gradual- ly lose their deformability during parasite maturation, but also develop surface parasite-coded structures termed ‘knobs’ which concentrate parasite-origin adhesive molecules and stick the parasitized cells to the blood vessel wall (a process known as cytoadherence) to escape from splenetic clearance. Knobs- mediated cytoadherence is believed to play a central role in the virulence associated with the disease. However, up to date, the detailed binding kinetics and surface distributions of the cy- toadherent ligands involved are not explicitly revealed. In this study, we utilize atomic force microscopy (AFM) based imag- ing and force spectroscopy techniques to investigate molecular binding mechanics of cytoadherent molecules, as well as co- localization mapping of molecular binding sites with surface structural changes. From the force spectra collected over a wide range of loading rates, we are able to characterize the intrinsic kinetic parameters of different cytoadherent mole- cules and establish a correlation to their rheological functions. Moreover, high resolution simultaneous topography imaging and adhesion mapping enable us to visualize the spatial distri- bution of the cytoadherent molecular binding sites and their co-localization with surface knobs structures. Our results will provide valuable and quantitative insights into the molecular mechanisms behind cytoadherence and thus of the disease and will be helpful in the development of new therapeutic strate- gies
BibTeX:
@inproceedings{li_molecular_2011,
  author = {Li, Ang and Sun, W and Tan, K S W and Lim, C T},
  title = {Molecular mechanistic insights into cytoadherence of human malaria infection},
  booktitle = {Proceedings of the World Congress of Biomechanics},
  year = {2010}
}
Li AG, Xing Y and Burggraf LW (2013), "Thermal Effects on Surface Structures and Properties of Bacillus Anthracis Spores at Nanometer Scales.", Langmuir., June, 2013. American Chemical Society.
Abstract: Bacteria spores, one of the hardiest forms of life known, can survive severe environmental stresses such as high temperature. Using thermal atomic force microscopy (AFM), we show that surface structures and properties of Bacillus anthracis spores when exposed to elevated temperatures undergo substantial changes at nanometer scales. Thermal blister-like nanostructures, which grow in size with increasing temperature, are formed on the spore surface when it is heated by a thermal tip. While thermal damage to the spore surface is persistent upon cooling of heat-treated spores to room temperature, thermal effects on surface properties of the spores are complex. The thermally induced nanostructures show a lower surface-tip adhesion and higher modulus than the surrounding spore surface. The overall trend is for the adhesion to decrease with increasing temperature. However, the adhesion of heat-treated spores may be smaller, equal, or larger than that of untreated spores, depending upon the degree of surface damage by heat. While the overall spore dimensions show little changes during and after the heat treatment, the size of spore sub-structures decreases significantly. In addition, we demonstrate a nanoscratch AFM method for imaging the subsurface structures of spores.
BibTeX:
@article{Li2013e,
  author = {Li, Alex G. and Xing, Yun and Burggraf, Larry Wilson},
  title = {Thermal Effects on Surface Structures and Properties of Bacillus Anthracis Spores at Nanometer Scales.},
  journal = {Langmuir},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://dx.doi.org/10.1021/la400992q},
  doi = {10.1021/la400992q}
}
Li C, Adamcik J and Mezzenga R (2012), "Biodegradable nanocomposites of amyloid fibrils and graphene with shape-memory and enzyme-sensing properties", Nature nanotechnology., May, 2012. Vol. 7(May), pp. 1-7. Nature Publishing Group.
Abstract: Graphene has exceptional mechanical and electronic properties, but its hydrophobic nature is a disadvantage in biologically related applications. Amyloid fibrils are naturally occurring protein aggregates that are stable in solution or under highly hydrated conditions, have well-organized supramolecular structures and outstanding strength. Here, we show that graphene and amyloid fibrils can be combined to create a new class of biodegradable composite materials with adaptable properties. This new composite material is inexpensive, highly conductive and can be degraded by enzymes. Furthermore, it can reversibly change shape in response to variations in humidity, and can be used in the design of biosensors for quantifying the activity of enzymes. The properties of the composite can be fine-tuned by changing the graphene-to-amyloid ratio.
BibTeX:
@article{Li2012,
  author = {Li, Chaoxu and Adamcik, Jozef and Mezzenga, Raffaele},
  title = {Biodegradable nanocomposites of amyloid fibrils and graphene with shape-memory and enzyme-sensing properties},
  journal = {Nature nanotechnology},
  publisher = {Nature Publishing Group},
  year = {2012},
  volume = {7},
  number = {May},
  pages = {1--7},
  url = {http://www.nature.com/nnano/journal/v7/n7/abs/nnano.2012.62.html http://www.ncbi.nlm.nih.gov/pubmed/22562038},
  doi = {10.1038/nnano.2012.62}
}
Li C, Minne SC, Pittenger B and Mednick A (2011), "Simultaneous Electrical and Mechanical Property Mapping at the Nanoscale with PeakForce TUNA".
BibTeX:
@misc{Li2011,
  author = {Li, Chunzeng and Minne, Steve C. and Pittenger, Bede and Mednick, Adam},
  title = {Simultaneous Electrical and Mechanical Property Mapping at the Nanoscale with PeakForce TUNA},
  booktitle = {Bruker Application Note AN132},
  publisher = {Bruker Corporation},
  year = {2011},
  volume = {AN132}
}
Li J, He Y, Han Y, Liu K, Wang J, Li Q, Fan S and Jiang K (2012), "Direct identification of metallic and semiconducting single-walled carbon nanotubes in scanning electron microscopy.", Nano Letters., August, 2012. Vol. 12(8), pp. 4095-101.
Abstract: Because of their excellent electrical and optical properties, carbon nanotubes have been regarded as extremely promising candidates for high-performance electronic and optoelectronic applications. However, effective and efficient distinction and separation of metallic and semiconducting single-walled carbon nanotubes are always challenges for their practical applications. Here we show that metallic and semiconducting single-walled carbon nanotubes on SiO(2) can have obviously different contrast in scanning electron microscopy due to their conductivity difference and thus can be effectively and efficiently identified. The correlation between conductivity and contrast difference has been confirmed by using voltage-contrast scanning electron microcopy, peak force tunneling atom force microscopy, and field effect transistor testing. This phenomenon can be understood via a proposed mechanism involving the e-beam-induced surface potential of insulators and the conductivity difference between metallic and semiconducting SWCNTs. This method demonstrates great promise to achieve rapid and large-scale distinguishing between metallic and semiconducting single-walled carbon nanotubes, adding a new function to conventional SEM.
BibTeX:
@article{Li2012a,
  author = {Li, Jie and He, Yujun and Han, Yimo and Liu, Kai and Wang, Jiaping and Li, Qunqing and Fan, Shoushan and Jiang, Kaili},
  title = {Direct identification of metallic and semiconducting single-walled carbon nanotubes in scanning electron microscopy.},
  journal = {Nano Letters},
  year = {2012},
  volume = {12},
  number = {8},
  pages = {4095--101},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/22730928},
  doi = {10.1021/nl301561f}
}
Li J, Pan M and Tang H (2014), "Understanding the short-side-chain Perfluorinated sulfonic acid and its application for high temperature polymer electrolyte membrane fuel cells", RSC Advances., October, 2014. Vol. 4(8), pp. 3944-65. The Royal Society of Chemistry.
Abstract: The great demand for high-temperature operation of polymer electrolyte membrane fuel cells (PEMFCs) has been well answered by short-side-chain perfluorinated sulfonic acid (SSC-PFSA) membranes through a good balance between transport properties and stability. It has been evidenced that fuel cells assembled with SSC-PFSA possess higher and more stable performance at elevated temperature up to 130 ?C compared to that of fuel cells based on conventional long-side-chain (LSC) PFSA (Nafion®) membranes. Moreover, the shorter side-pendent chains and the absence of the ether group and of the tertiary carbon also endow SSC-PFSAs with better durability, making them more suitable for working at harsh conditions in fuel cell systems. This critical review is dedicated to summarizing the properties of SSC-PFSA and providing insight into an understanding of their micro-morphologies, mass diffusion, enhanced proton transportation and their mutual correlation. Diversified measurement techniques applied to investigate the evolution of micro-morphologies, unique diffusion and transportation properties of SSC-PFSAs are reviewed. Despite the higher crystalline and higher water absorption of SSC-PFSAs than those of LSC-PFSAs, the notably less developed and less interconnected ionic clusters in SSC-PFSAs lead to lower mass permeability, and hence the high water uptake is not as well translated into transportation performance as expected. The factors and reasons for the enhanced electrochemical performance of SSC-PFSAs such as higher proton conductivity at elevated temperatures and low humidity conditions are also discussed and understood. Highlights of recent advances in SSC-PFSA- based membranes for fuel cell applications at wider temperature ranges are summarized as general references for researchers to further prompt the development of SSC-PFSAs. The SSC-PFSAs based membranes give a bright future for the next generation of high-temperature PEMFCs.
BibTeX:
@article{Li2013c,
  author = {Li, Junrui and Pan, Mu and Tang, Haolin},
  title = {Understanding the short-side-chain Perfluorinated sulfonic acid and its application for high temperature polymer electrolyte membrane fuel cells},
  journal = {RSC Advances},
  publisher = {The Royal Society of Chemistry},
  year = {2014},
  volume = {4},
  number = {8},
  pages = {3944--65},
  url = {http://xlink.rsc.org/?DOI=c3ra43735c http://pubs.rsc.org/en/content/articlehtml/2013/ra/c3ra43735c},
  doi = {10.1039/c3ra43735c}
}
Li M, Xiao X, Liu L, Xi N, Wang Y, Dong Z and Zhang W (2013), "Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients", Experimental Cell Research., July, 2013.
Abstract: CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500×500 nm2) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells.
BibTeX:
@article{li_nanoscale_2013,
  author = {Li, Mi and Xiao, Xiubin and Liu, Lianqing and Xi, Ning and Wang, Yuechao and Dong, Zaili and Zhang, Weijing},
  title = {Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients},
  journal = {Experimental Cell Research},
  year = {2013},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0014482713003194},
  doi = {10.1016/j.yexcr.2013.07.020}
}
Li W, Sepunaru L, Amdursky N, Cohen SR, Pecht I, Sheves M and Cahen D (2012), "Temperature and force dependence of nanoscale electron transport via the Cu protein azurin.", ACS nano., December, 2012. Vol. 6(12), pp. 10816-24.
Abstract: Solid-state electron transport (ETp) via a monolayer of immobilized azurin (Az) was examined by conducting probe atomic force microscopy (CP-AFM), as a function of both temperature (248-373K) and applied tip force (6-15 nN). At low forces, ETp via holo-Az (with Cu(2+)) is temperature-independent, but thermally activated via the Cu-depleted form of Az, apo-Az. While this observation agrees with those of macroscopic-scale measurements, we find that for holo-Az the mechanism of ETp at high temperatures changes upon an increase in the force applied by the tip to the proteins; namely, above 310 K and forces >6 nN ETp becomes thermally activated. This is in contrast to apo-Az, where increasing applied force causes only small monotonic increases in currents due to decreased electrode separation. The distinct ETp temperature dependence of holo- and apo-Az is assigned to a difference in structural response to pressure between the two protein forms. An important implication of these CP-AFM results (of measurements over a significant temperature range) is that for reliable ETp measurements on flexible macromolecules, such as proteins, the pressure applied during the measurements should be controlled or at least monitored.
BibTeX:
@article{li_temperature_2012,
  author = {Li, Wenjie and Sepunaru, Lior and Amdursky, Nadav and Cohen, Sidney R and Pecht, Israel and Sheves, Mordechai and Cahen, David},
  title = {Temperature and force dependence of nanoscale electron transport via the Cu protein azurin.},
  journal = {ACS nano},
  year = {2012},
  volume = {6},
  number = {12},
  pages = {10816--24},
  url = {http://pubs.acs.org/doi/abs/10.1021/nn3041705 http://www.ncbi.nlm.nih.gov/pubmed/23136937},
  doi = {10.1021/nn3041705}
}
Li W, Zhang X, Zhao X, Zhang X and Zhang A (2013), "Doubly dendronized chiral polymers showing thermoresponsive properties", Journal of Polymer Science Part A: Polymer Chemistry., September, 2013. , pp. n/a-n/a.
BibTeX:
@article{Li2013b,
  author = {Li, Wen and Zhang, Xiacong and Zhao, Xin and Zhang, Xiuqiang and Zhang, Afang},
  title = {Doubly dendronized chiral polymers showing thermoresponsive properties},
  journal = {Journal of Polymer Science Part A: Polymer Chemistry},
  year = {2013},
  pages = {n/a--n/a},
  url = {http://doi.wiley.com/10.1002/pola.26946},
  doi = {10.1002/pola.26946}
}
Li Y, Nese A, Matyjaszewski K and Sheiko SS (2013), "Molecular Tensile Machines: Anti-Arrhenius Cleavage of Disulfide Bonds", Macromolecules., September, 2013. Vol. 46, pp. 7196-201. American Chemical Society.
Abstract: Molecular tensile machines are bottlebrush molecules where tension along the backbone is self-generated due to steric repulsion between the densely grafted side chains. Upon adsorption onto a substrate, this intrinsic tension is amplified to the nanonewton range depending on the side chain length, grafting density, and interaction with the substrate. In this paper, bottlebrushes with a disulfide linker in the middle of the backbone were designed to study the effect of force and temperature on the scission of an individual disulfide bond. The scission process was monitored on molecular length scales by atomic force microscopy. The scission rate constant has been shown to increase exponentially with bond tension but decrease with temperature. This anti-Arrhenius behavior is ascribed to the decrease of substrate surface energy upon heating, which overpowers the corresponding effects of thermal energy and temperature dependent pre-exponential factor. Quantitative analysis using the force-modified Arrhenius and transition state theory (TST) equations, respectively, was conducted to determine the dissociation energy, maximum rupture force, and activation barrier of a disulfide bond under tension. Molecular tensile machines are bottlebrush molecules where tension along the backbone is self-generated due to steric repulsion between the densely grafted side chains. Upon adsorption onto a substrate, this intrinsic tension is amplified to the nanonewton range depending on the side chain length, grafting density, and interaction with the substrate. In this paper, bottlebrushes with a disulfide linker in the middle of the backbone were designed to study the effect of force and temperature on the scission of an individual disulfide bond. The scission process was monitored on molecular length scales by atomic force microscopy. The scission rate constant has been shown to increase exponentially with bond tension but decrease with temperature. This anti-Arrhenius behavior is ascribed to the decrease of substrate surface energy upon heating, which overpowers the corresponding effects of thermal energy and temperature dependent pre-exponential factor. Quantitative analysis using the force-modified Arrhenius and transition state theory (TST) equations, respectively, was conducted to determine the dissociation energy, maximum rupture force, and activation barrier of a disulfide bond under tension.
BibTeX:
@article{Li2013d,
  author = {Li, Yuanchao and Nese, Alper and Matyjaszewski, Krzysztof and Sheiko, Sergei S.},
  title = {Molecular Tensile Machines: Anti-Arrhenius Cleavage of Disulfide Bonds},
  journal = {Macromolecules},
  publisher = {American Chemical Society},
  year = {2013},
  volume = {46},
  pages = {7196--201},
  url = {http://dx.doi.org/10.1021/ma401178w},
  doi = {10.1021/ma401178w}
}
Li Y, Rubert M, Aslan H, Howard K, Yu Y, Dong M, Besenbacher F, Chen M and Manuscript A (2013), "Ultraporous Interweaving Electrospun Microfibers from PCL-PEO Binary Blends and their Inflammatory Responses", Nanoscale., January, 2013. The Royal Society of Chemistry.
BibTeX:
@article{Li2013a,
  author = {Li, Yanfang and Rubert, Marina and Aslan, Husnu and Howard, Ken and Yu, Ying and Dong, Mingdong and Besenbacher, Flemming and Chen, Menglin and Manuscript, Accepted},
  title = {Ultraporous Interweaving Electrospun Microfibers from PCL-PEO Binary Blends and their Inflammatory Responses},
  journal = {Nanoscale},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/nr/c3nr06197c},
  doi = {10.1039/c3nr06197c}
}
Liascukiene I, Aissaoui N, Asadauskas SJ, Landoulsi J and Lambert JF (2012), "Ordered nanostructures on hydroxylated aluminum surface through the self-assembly of fatty acids", Langmuir. Vol. 28(11), pp. 5116-5124.
Abstract: We investigate the mechanism of self-assembly of fatty acids (FA) and methyl oleate on an Al oxy-hydroxide surface with a view to deciphering the role and nature of interfacial processes (adsorption, chemical binding, molecular organization, etc.). For this purpose, we focus on parameters related to intrinsic properties of molecules, namely the level of unsaturation and the nature of the head group (carboxylic acid or ester). After the FA adsorption, the presence of coordinative bonded carboxylate species on the Al oxy-hydroxide surface is demonstrated by means of PM-IRRAS analysis. We observe that contact of methyl oleate with the surface leads to its chemical transformation through a saponification reaction. As a consequence, it binds to the surface in a manner similar to that for fatty acids. Through an innovative mode of atomic force microscopy (AFM), the organization of the adsorbed molecules is demonstrated. Our results reveal the existence of highly ordered nanostructures guided by the FA self-assembly. The size of these nanostructures was determined with accuracy, suggesting that it exceeds one FA monolayer. By contrast, no organization was observed with methyl oleate.
BibTeX:
@article{Liascukiene2012,
  author = {Liascukiene, I. and Aissaoui, N. and Asadauskas, S. J. and Landoulsi, J. and Lambert, J. F.},
  title = {Ordered nanostructures on hydroxylated aluminum surface through the self-assembly of fatty acids},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {11},
  pages = {5116--5124},
  url = {http://pubs.acs.org/doi/abs/10.1021/la2051542},
  doi = {10.1021/la2051542}
}
Liebscher M, Tzounis L, Pötschke P and Heinrich G (2013), "Influence of the viscosity ratio in PC/SAN blends filled with MWCNTs on the morphological, electrical, and melt rheological properties", Polymer., November, 2013. Vol. 54(25), pp. 6801-6808. Elsevier Ltd.
BibTeX:
@article{Liebscher2013,
  author = {Liebscher, Marco and Tzounis, Lazaros and Pötschke, Petra and Heinrich, Gert},
  title = {Influence of the viscosity ratio in PC/SAN blends filled with MWCNTs on the morphological, electrical, and melt rheological properties},
  journal = {Polymer},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {54},
  number = {25},
  pages = {6801--6808},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0032386113009944},
  doi = {10.1016/j.polymer.2013.10.040}
}
Lind TK, Zielińska P, Wacklin HP, Urbańczyk-Lipkowska Z and Cárdenas M (2013), "Continuous Flow Atomic Force Microscopy Imaging Reveals Fluidity and Time Dependent Interactions of Antimicrobial Dendrimer with Model Lipid Membranes.", ACS nano., December, 2013. American Chemical Society.
Abstract: In this paper an amphiphilic peptide dendrimer with potential applications against multi-resistant bacteria such as Staphylococcus aureus was synthesized and studied on model cell membranes. The combination of quartz crystal microbalance (QCM-D) and atomic force microscopy (AFM) imaging during continuous flow allowed for in situ monitoring of the very initial interaction processes and membrane transformations on longer time scales. We used three different membrane compositions of low and high melting temperature phospholipids to vary the membrane properties from a single fluid phase to a pure gel phase, while crossing the phase coexistence boundaries at room temperature. The interaction mechanism of the dendrimer was found to be time dependent and to vary remarkably with the fluidity and coexistence of liquid-solid phases in the membrane. Spherical micelle-like dendrimer-lipid aggregates were formed in the fluid phase bilayer and led to partial solubilisation of the membrane, while in gel-phase membranes the dendrimers caused areas of local depressions followed by re-deposition of flexible lipid patches. Domain coexistence led to a sequence of events initiated by the formation of a ribbon-like network followed by membrane solubilisation via spherical aggregates from the edges of bilayer patches. Our results show that the dendrimer molecules were able to destroy the membrane integrity through different mechanisms depending on the lipid phase and morphology and shed light to their antimicrobial activity. These findings could have an impact on the efficacy of the dendrimers since lipid membranes in certain bacteria have transition temperatures very close to the host body temperature.
BibTeX:
@article{Lind2013,
  author = {Lind, Tania Kjellerup and Zielińska, Paulina and Wacklin, Hanna Pauliina and Urbańczyk-Lipkowska, Zofia and Cárdenas, Marité},
  title = {Continuous Flow Atomic Force Microscopy Imaging Reveals Fluidity and Time Dependent Interactions of Antimicrobial Dendrimer with Model Lipid Membranes.},
  journal = {ACS nano},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/24303991 http://pubs.acs.org/doi/abs/10.1021/nn404530z},
  doi = {10.1021/nn404530z}
}
Ling S, Li C, Adamcik J, Wang S, Shao Z, Chen X and Mezzenga R (2014), "Directed Growth of Silk Nanofibrils on Graphene and Their Hybrid Nanocomposites", ACS Macro Letters., January, 2014. , pp. 146-152. American Chemical Society.
Abstract: Combination of proteins with other nanomaterials offers a promising strategy to fabricate novel hybrids with original functions in biology, medicine, nanotechnology, and materials science. Under carefully selected experimental conditions, we show that graphene nanosheets are able to direct one-dimensional self-assembly of silk fibroin, forming an unprecedented type of nanohybrids. These silk/graphene hybrids combine physical properties of both constituents and form functional composites with well-ordered hierarchical structures. Due to the facile fabrication process and their tunable nanostructures, the resultant hybrids show promise in applications as diverse as tissue engineering, drug delivery, nanoelectronics, nanomedicine, biosensors, and functional composites. Combination of proteins with other nanomaterials offers a promising strategy to fabricate novel hybrids with original functions in biology, medicine, nanotechnology, and materials science. Under carefully selected experimental conditions, we show that graphene nanosheets are able to direct one-dimensional self-assembly of silk fibroin, forming an unprecedented type of nanohybrids. These silk/graphene hybrids combine physical properties of both constituents and form functional composites with well-ordered hierarchical structures. Due to the facile fabrication process and their tunable nanostructures, the resultant hybrids show promise in applications as diverse as tissue engineering, drug delivery, nanoelectronics, nanomedicine, biosensors, and functional composites.
BibTeX:
@article{Ling2014,
  author = {Ling, Shengjie and Li, Chaoxu and Adamcik, Jozef and Wang, Suhang and Shao, Zhengzhong and Chen, Xin and Mezzenga, Raffaele},
  title = {Directed Growth of Silk Nanofibrils on Graphene and Their Hybrid Nanocomposites},
  journal = {ACS Macro Letters},
  publisher = {American Chemical Society},
  year = {2014},
  pages = {146--152},
  url = {http://dx.doi.org/10.1021/mz400639y},
  doi = {10.1021/mz400639y}
}
Liu D, Huang X, Wang Z, Jin A, Sun X, Zhu L, Wang F, Ma Y, Niu G, Hight Walker AR and Chen X (2013), "Gold Nanoparticle-Based Activatable Probe for Sensing Ultralow Levels of Prostate-Specific Antigen", ACS nano., May, 2013. (6), pp. 5568-5576. American Chemical Society.
Abstract: It is still in high demand to develop extremely sensitive and accurate clinical tools for biomarkers of interest for early diagnosis and monitoring of diseases. In this report, we present a highly sensitive and compatible gold nanoparticle (AuNP)-based fluorescence-activatable probe for sensing ultralow levels of prostate-specific antigen (PSA) in patient serum samples. The limit of detection of the newly developed probe for PSA was pushed down to 0.032 pg/mL, which is more than 2 orders of magnitude lower than that of the conventional fluorescence probe. The ultrahigh sensitivity of this probe was attributed to the high loading efficiency of the dyes on AuNP surfaces and high fluorescence quenching-unquenching abilities of the dye-AuNP pairs. The efficiency and robustness of this probe were investigated in patient serum samples, demonstrating the great potential of this probe in real-world applications.
BibTeX:
@article{Liu2013,
  author = {Liu, Dingbin and Huang, Xinglu and Wang, Zhantong and Jin, Albert and Sun, Xiaolian and Zhu, Lei and Wang, Fu and Ma, Ying and Niu, Gang and Hight Walker, Angela R and Chen, Xiaoyuan},
  title = {Gold Nanoparticle-Based Activatable Probe for Sensing Ultralow Levels of Prostate-Specific Antigen},
  journal = {ACS nano},
  publisher = {American Chemical Society},
  year = {2013},
  number = {6},
  pages = {5568--5576},
  url = {http://dx.doi.org/10.1021/nn401837q},
  doi = {10.1021/nn401837q}
}
Liu X, Dedinaite A, Rutland MW, Thormann E, Visnevskij C, Makuska R and Claesson PM (2012), "Electrostatically Anchored Branched Brush Layers.", Langmuir : the ACS journal of surfaces and colloids., October, 2012. American Chemical Society.
Abstract: A novel type of block copolymer has been synthesized. It consists of a linear cationic block and an uncharged bottle-brush block. The non-ionic bottle-brush block contains 45 units long poly(ethylene oxide) side chains. This polymer was synthesized with the intention of creating branched brush layers firmly physisorbed to negatively charged surfaces via the cationic block, mimicking the architecture (but not the chemistry) of bottle-brush molecules suggested to be present on the cartilage surface, and where contribute to the efficient lubrication of synovial joints. The adsorption properties of the diblock copolymer as well as of the two blocks separately were studied on silica surfaces using QCM-D and optical reflectometry. The adsorption kinetics data highlight that the diblock copolymers initially adsorb preferentially parallel to the surface with both the cationic block and the uncharged bottle-brush block in contact with the surface. However, as the adsorption proceeds a structural change occurs within the layer and the PEO bottle-brush block extends towards solution, forming a surface anchored branched brush layer. As the adsorption plateau has been reached the diblock copolymer layer is 46-48 nm thick, and the water content in the layer is above 90wt The combination of strong electrostatic anchoring and highly hydrated branched brush structures provide strong steric repulsion, low friction forces and high load bearing capacity. The strong electrostatic anchoring also provides high stability of preadsorbed layers under different ionic strength conditions.
BibTeX:
@article{Liu2012a,
  author = {Liu, Xiaoyan and Dedinaite, Andra and Rutland, Mark W and Thormann, Esben and Visnevskij, Ceslav and Makuska, Ricardas and Claesson, Per Martin},
  title = {Electrostatically Anchored Branched Brush Layers.},
  journal = {Langmuir : the ACS journal of surfaces and colloids},
  publisher = {American Chemical Society},
  year = {2012},
  url = {http://pubs.acs.org/doi/abs/10.1021/la3028989},
  doi = {10.1021/la3028989}
}
Liu Y, Luo D, Kou X-X, Wang X-D, Tay FR, Sha Y-L, Gan Y-H and Zhou Y-H (2013), "Hierarchical Intrafibrillar Nanocarbonated Apatite Assembly Improves the Nanomechanics and Cytocompatibility of Mineralized Collagen", Advanced Functional Materials., March, 2013. Vol. 23(11), pp. 1404-1411.
BibTeX:
@article{Liu2013b,
  author = {Liu, Yan and Luo, Dan and Kou, Xiao-Xing and Wang, Xue-Dong and Tay, Franklin R. and Sha, Yin-Lin and Gan, Ye-Hua and Zhou, Yan-Heng},
  title = {Hierarchical Intrafibrillar Nanocarbonated Apatite Assembly Improves the Nanomechanics and Cytocompatibility of Mineralized Collagen},
  journal = {Advanced Functional Materials},
  year = {2013},
  volume = {23},
  number = {11},
  pages = {1404--1411},
  url = {http://doi.wiley.com/10.1002/adfm.201201611},
  doi = {10.1002/adfm.201201611}
}
Liu Y, Luo D, Liu S, Fu Y, Kou X, Wang X, Sha Y, Gan Y and Zhou Y (2014), "Effect of Nanostructure of Mineralized Collagen Scaffolds on Their Physical Properties and Osteogenic Potential", Journal of Biomedical Nanotechnology., June, 2014. Vol. 10(6), pp. 1049-1060. American Scientific Publishers.
Abstract: Tissue engineering has enabled development of nanostructured collagen scaffolds to meet current challenges in regeneration of lost bone. In this study, extrafibrillarly-mineralized and intrafibrillarly-mineralized collagen scaffolds were fabricated separately by a conventional crystallization method and a biomimetic, bottom-up crystallization method. Atomic force microscopy (AFM) was employed to examine the nanotopography and nanomechanics of the mineralized collagen scaffolds. The in vitro cell responses to the surface of the mineralized collagen scaffolds were analyzed by laser scanning microscope and field emission scanning electron microscopy. AFM imaging showed that these two mineralized collagen scaffolds exhibited different nanostructure, including the size, morphology and location of the apatites in collagen fibrils. The nanomechanical testing demonstrated that the intrafibrillarly-mineralized collagen scaffold, with bone-like hierarchy, featured a significantly increased Young's modulus compared with the extrafibrillarly-mineralized collagen scaffold in both dry and wet conditions. However, these two mineralized collagen scaffolds had a similar thermal behavior. From the cell culture experiments, the intrafibrillarly-mineralized collagen scaffold showed higher cell proliferation and alkaline phosphatase activity than the extrafibrillarly-mineralized collagen scaffold. The utmost significance of this study is that the nanostructure of the mineralized collagen scaffolds can affect the initial cell adhesion, morphology and further osteogenic potential. The present study will help us to fabricate novel biomaterials for bone grafting and tissue engineering applications.
BibTeX:
@article{Liu,
  author = {Liu, Yan and Luo, Dan and Liu, Shuai and Fu, Yu and Kou, Xiaoxing and Wang, Xuedong and Sha, Yinlin and Gan, Yehua and Zhou, Yanheng},
  title = {Effect of Nanostructure of Mineralized Collagen Scaffolds on Their Physical Properties and Osteogenic Potential},
  journal = {Journal of Biomedical Nanotechnology},
  publisher = {American Scientific Publishers},
  year = {2014},
  volume = {10},
  number = {6},
  pages = {1049--1060},
  url = {http://www.ingentaconnect.com/content/asp/jbn/2014/00000010/00000006/art00014 http://openurl.ingenta.com/content/xref?genre=article&issn=1550-7033&volume=10&issue=6&spage=1049},
  doi = {10.1166/jbn.2014.1794}
}
Lofaj F, Ferdinandy M, Cempura G and Dusza J (2012), "Nanoindentation, AFM and tribological properties of thin nc-WC/a-C Coatings", Journal of the European Ceramic Society., July, 2012. Vol. 32(9), pp. 2043-2051.
Abstract: Instrumented indentation, AFM (atomic force microscopy) and tribological studies were performed on PE CVD (Plasma Enhanced Chemical Vapor Deposition) nanocomposite WC–C coatings to investigate the effects of surface roughness on the reliability of nanoindentation data and the possibilities of different AFM modes in nanomechanical testing, which can be used as a feedback to optimize deposition technology from the viewpoint of their mechanical properties. It was confirmed that surface roughness below 30&xa0;nm is necessary to keep the scatter of indentation modulus, EIT, and hardness, HIT, below 15 PF QNM (Peak Force Quantitative NanoMechanical) mode was successfully applied for qualitative mapping of the elastic modulus of coatings with the stiffness above 300&xa0;GPa. LFM (lateral force microscopy) mode showed only weak contrast and quantitative measurements in both AFM modes require precise calibration. Coefficients of friction of the studied WC–C coatings were below 0.2 at RT, but increased to 0.7–0.8 at 450&xa0;°C due to the formation of a transfer film. Optimization of the deposition conditions based on nanoindentation resulted in the increase of EIT from ∼220&xa0;GPa to 350&xa0;GPa and HIT from ∼17&xa0;GPa to ∼29&xa0;GPa.
BibTeX:
@article{Lofaj2012,
  author = {Lofaj, František and Ferdinandy, Milan and Cempura, Gregorz and Dusza, Ján},
  title = {Nanoindentation, AFM and tribological properties of thin nc-WC/a-C Coatings},
  journal = {Journal of the European Ceramic Society},
  year = {2012},
  volume = {32},
  number = {9},
  pages = {2043--2051},
  url = {http://www.sciencedirect.com/science/article/pii/S0955221912000945},
  doi = {10.1016/j.jeurceramsoc.2012.01.037}
}
Lofaj F, Stadler H, Fuchsova G, Hvizdos P and Duszova A (2011), "Elastic Properties of thin WC/C coatings", Chemicke Listy. Vol. 105, pp. 684-7.
BibTeX:
@article{Lofaj2011,
  author = {Lofaj, F. and Stadler, Hartmut and Fuchsova, G. and Hvizdos, P. and Duszova, A.},
  title = {Elastic Properties of thin WC/C coatings},
  journal = {Chemicke Listy},
  year = {2011},
  volume = {105},
  pages = {684--7}
}
Lokanathan AR, Zhang S, Regina VR, Cole MA, Ogaki R, Dong M, Besenbacher F, Meyer RL and Kingshott P (2011), "Mixed poly (ethylene glycol) and oligo (ethylene glycol) layers on gold as nonfouling surfaces created by backfilling", Biointerphases. Vol. 6(4), pp. 180-188. AVS.
BibTeX:
@article{Lokanathan2011,
  author = {Lokanathan, Arcot R and Zhang, Shuai and Regina, Viduthalai R and Cole, Martin A and Ogaki, Ryosuke and Dong, Mingdong and Besenbacher, Flemming and Meyer, Rikke L and Kingshott, Peter},
  title = {Mixed poly (ethylene glycol) and oligo (ethylene glycol) layers on gold as nonfouling surfaces created by backfilling},
  journal = {Biointerphases},
  publisher = {AVS},
  year = {2011},
  volume = {6},
  number = {4},
  pages = {180--188},
  url = {http://link.aip.org/link/?BIP/6/180/1},
  doi = {10.1116/1.3647506}
}
Lu A-Y, Wei S-Y, Wu C-Y, Hernandez Y, Chen T-Y, Liu T-H, Pao C-W, Chen F-R, Li L-J and Juang Z-Y (2012), "Decoupling of CVD graphene by controlled oxidation of recrystallized Cu", RSC Advances. Vol. 2(7), pp. 3008.
BibTeX:
@article{lu_decoupling_2012,
  author = {Lu, Ang-Yu and Wei, Sung-Yen and Wu, Chih-Yu and Hernandez, Yenny and Chen, Tzu-Yin and Liu, Te-Huan and Pao, Chun-Wei and Chen, Fu-Rong and Li, Lain-Jong and Juang, Zhen-Yu},
  title = {Decoupling of CVD graphene by controlled oxidation of recrystallized Cu},
  journal = {RSC Advances},
  year = {2012},
  volume = {2},
  number = {7},
  pages = {3008},
  url = {http://xlink.rsc.org/?DOI=c2ra01281b},
  doi = {10.1039/c2ra01281b}
}
Lukasiewicz MI, Witkowski BS, Wachnicki L, Kopalko K, Gieratowska S, Wittlin A, Jaworski M, Guziewicz E and Godlewski M (2011), "(Zn,Cu)O films by atomic layer deposition - structural, optical and electric properties", Acta Physica Polonica A. Vol. 120(6), pp. 34-6.
Abstract: ZnCuO thin lms have been deposited on silicon, glass and quartz substrates by atomic layer deposition method, using reactive organic precursors of zinc and copper. As zinc and copper precursors we applied diethylzinc and copper(II) acetyloacetonate. Structural, electrical and optical properties of the obtained ZnCuO layers are discussed based on the results of scanning electron microscopy, energy dispersive spectroscopy, X-ray di raction, atomic force microscopy, the Hall e ect and photoluminescence investigations
BibTeX:
@article{Wittlina2011,
  author = {Lukasiewicz, M. I. and Witkowski, B. S. and Wachnicki, L. and Kopalko, K. and Gieratowska, S. and Wittlin, A. and Jaworski, M. and Guziewicz, E. and Godlewski, M.},
  title = {(Zn,Cu)O films by atomic layer deposition - structural, optical and electric properties},
  journal = {Acta Physica Polonica A},
  year = {2011},
  volume = {120},
  number = {6},
  pages = {34--6},
  url = {http://yadda.icm.edu.pl/przyrbwn/element/bwmeta1.element.bwnjournal-article-appv120n6ap09kz http://przyrbwn.icm.edu.pl/APP/PDF/120/a120z6ap09.pdf}
}
Lyne Wallqvist V, Rutland MW, Claesson P and Birgisson B (2013), "Surface wrinkling: the phenomenon causing bees in bitumen", Journal of Materials Science., June, 2013.
BibTeX:
@article{Lyne2013,
  author = {Lyne, Å sa Laurell and Wallqvist, Viveca and Rutland, Mark W. and Claesson, Per and Birgisson, Björn},
  title = {Surface wrinkling: the phenomenon causing bees in bitumen},
  journal = {Journal of Materials Science},
  year = {2013},
  url = {http://link.springer.com/10.1007/s10853-013-7505-4},
  doi = {10.1007/s10853-013-7505-4}
}
Ma L, Jia J, Yang T, Yin G, Liu Y, Sun X and Tao X (2012), "Light-controlled self-assembly and conductance: from nanoribbons to nanospheres", RSC Advances. Vol. 2(7), pp. 2902.
Abstract: Photoswitchable azobenzene (AZO) chromophores were introduced to the bay-position of the traditional n-type perylene diimide (PDI). Photocontrolled self-assembly behaviours and the influence of the azobenzene substitution on the assembly structure were investigated by UV/vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Controlled morphological evolution of the nanostructures from ribbons to spheres was facilely realized by driving the azobenzene switching unit with 365 nm light irradiation. The nanoribbons demonstrated highly ordered structures while the order of the molecular arrangement was destroyed in the nanospheres, as a result of the curved molecular conformation induced by photoisomerization. In addition, the conductivity of the single nanoribbon was investigated. Thanks to the one-dimensional long-range ordered [small pi]-[small pi] stacking of the PDI cores, the nanoribbon showed good semiconducting properties with a conductance in the range of 2 [times] 10-5 S m-1 in air. Furthermore, the conductivity decreased with UV light irradiation, mainly due to the increased randomness within the nanostructures, representing the light-induced switching of conductance in the supramolecular systems that is extremely interesting for molecular devices.
BibTeX:
@article{ma_light-controlled_2012,
  author = {Ma, Lulu and Jia, Jiong and Yang, Tieying and Yin, Guangzhi and Liu, Yang and Sun, Xuan and Tao, Xutang},
  title = {Light-controlled self-assembly and conductance: from nanoribbons to nanospheres},
  journal = {RSC Advances},
  year = {2012},
  volume = {2},
  number = {7},
  pages = {2902},
  url = {http://xlink.rsc.org/?DOI=c2ra00816e http://dx.doi.org/10.1039/C2RA00816E},
  doi = {10.1039/c2ra00816e}
}
Maghsoudy-Louyeh S, Kim J, Kropf M and Tittmann B (2013), "Subsurface Image Analysis of Plant Cell Wall with Atomic Force Microscopy", Journal of Advanced Microscopy Research., June, 2013. Vol. 8(2), pp. 100-104. American Scientific Publishers.
Abstract: The hypothesis of this paper is that atomic force microscopy (AFM) is not just limited to imaging topography, but, with appropriate image processing, it can give important and quantitative subsurface information. The technical approach was to use high-resolution imaging of cellulosic structures with AFM, then use image processing with specially developed software. The example chosen here was a hydrated plant cell wall. The novelty of this work was that with the new software, it was possible to image and analyze four layers of plant cell wall laminates below that of the surface layer. In particular, the structure of primary celery (Apium graveolens L.) epidermis cell walls was characterized at the nano-scale using AFM in the Peak Force Tapping Mode. The plant cell wall micro-fibrils were found to be well separated with spacings of up to almost 50 nm and it was possible to identify and evaluate five layers in terms of fiber thickness, angular orientation and spacing. We concluded that the micro-fibril structure is weakly anisotropic and shows evidence of both horizontal and vertical bundling of micro-fibrils. The results are significant in that they provide information about cell wall characteristics several layers below the surface.
BibTeX:
@article{Maghsoudy-Louyeh2013,
  author = {Maghsoudy-Louyeh, Sahar and Kim, Jeong and Kropf, Matthew and Tittmann, Bernhard},
  title = {Subsurface Image Analysis of Plant Cell Wall with Atomic Force Microscopy},
  journal = {Journal of Advanced Microscopy Research},
  publisher = {American Scientific Publishers},
  year = {2013},
  volume = {8},
  number = {2},
  pages = {100--104},
  url = {http://www.ingentaconnect.com/content/asp/jamr/2013/00000008/00000002/art00003},
  doi = {10.1166/jamr.2013.1144}
}
Makrocka-Rydzyk M, Wegner K, Szutkowski K, Kozak M, Jurga S, Gao H and Matyjaszewski K (2012), "Morphology and NMR Self-Diffusion in PBA/PEO Miktoarm Star Copolymers", Zeitschrift für Physikalische Chemie., September, 2012. , pp. 120910001029009. Oldenbourg Wissenschaftsverlag GmbH Louisiana, Germany.
Abstract: Abstract Morphology and NMR self-diffusion of two miktoarm star copolymers differing in fraction of poly(n-butyl acrylate) and poly(ethylene oxide) (PBA and PEO) arms were under investigation. Structural characteristics of copolymers was obtained on the basis of Small Angle X-Ray Scattering (SAXS) investigations. The phase separated nanoscale morphology of the miktoarm star copolymer with a high fraction of PEO arms was confirmed by Scanning Probe Microscopy (SPM) studies. The modified Avrami approach was used to obtain the information on the non-isothermal crystallization kinetics of the studied systems. It was observed that the crystallization in the system with a higher content of PBA, occurring at higher undercooling, was characterized by a higher crystallization rate. It was also found that increase in PBA arms fraction leads to the reduction in the size of PEO domains. The activation energy of the crystallization process, estimated with Kissinger's method, is lower for miktoarm star copolymer with h...
BibTeX:
@article{Makrocka-Rydzyk2012,
  author = {Makrocka-Rydzyk, Monika and Wegner, Katarzyna and Szutkowski, Kosma and Kozak, Maciej and Jurga, Stefan and Gao, Haifeng and Matyjaszewski, Krzysztof},
  title = {Morphology and NMR Self-Diffusion in PBA/PEO Miktoarm Star Copolymers},
  journal = {Zeitschrift für Physikalische Chemie},
  publisher = {Oldenbourg Wissenschaftsverlag GmbH Louisiana, Germany},
  year = {2012},
  pages = {120910001029009},
  url = {http://www.oldenbourg-link.com/doi/abs/10.1524/zpch.2012.0300},
  doi = {10.1524/zpch.2012.0300}
}
Mallia VA, Seo H-i and Weiss RG (2013), "Influence of anions and alkyl chain lengths of N-alkyl-n-(R)-12-hydroxyoctadecyl ammonium salts on their hydrogels and organogels", Langmuir., May, 2013. Vol. 29(21), pp. 6476-84.
Abstract: The self-assembly and gelating characteristics of a set of N-alkyl-(R)-12-hydroxyoctadecylammonium salts (n-HOA-X, where n = 0-6, 18 is the length of the alkyl chain on nitrogen, X = Cl, n = 3, and X = Br, NO3, and BF4) are described. Solid-solid phase transitions were observed for powders of n-HOA-Cl, and orthorhombic-type crystal packing arrangements and lattice spacings were calculated from X-ray diffractograms at 22 °C. The diffractogram of 3-HOA-Br indicates the presence of more than one morph at room temperature, and that of 3-HOA-I corresponds to a lamellar packing arrangement. Differences in the molecular packing arrangements of 3-HOA-X are reflected in their gelation abilities. The melting temperatures (T(gel)) of the hydrogels of 3-HOA-Br are higher than those of 3-HOA-Cl at the same concentrations, and 3-HOA-I failed to gelate any of the investigated liquids. 3-HOA-NO3 gelated only water and CCl4 and 3-HOA-BF4 formed only hydrogels. Plots of changes in conductivities of the 3-HOA-X salts (where X = Cl, Br, NO3 and BF4) as a function of temperature were used to calculate the critical aggregation concentrations (CGCs). Because the CGCs from the 'falling drop' method are nearly the same as those from the conductivity measurements, aggregation, nucleation, and gelation must occur within a very narrow 3-HOA-X concentration range. T(gel) values of 2 wt % 3-HOA-Cl hydrogels (prepared by fast cooling of the sol phase) increased upon adding KCl up to 0.1 M. The effects can be attributed principally to the chloride anion rather than its cation partners. The properties of the hydrogels of 3-HOA-X do not follow the Hofmeister ranking rule. The variations in the counterions afford detailed insight into the behavior of 3-HOA-X in their neat solids and assemblies in gels as well as the processes accompanying gel formation in water and organic liquids.
BibTeX:
@article{mallia_influence_2013,
  author = {Mallia, V Ajay and Seo, Hyae-in and Weiss, Richard G},
  title = {Influence of anions and alkyl chain lengths of N-alkyl-n-(R)-12-hydroxyoctadecyl ammonium salts on their hydrogels and organogels},
  journal = {Langmuir},
  year = {2013},
  volume = {29},
  number = {21},
  pages = {6476--84},
  url = {http://pubs.acs.org/doi/abs/10.1021/la400748q},
  doi = {10.1021/la400748q}
}
Matczak M, Szyman?ski B, Urbaniak M, Nowicki M, Głowin?ski H, Kus?wik P, Schmidt M, Aleksiejew J, Dubowik J and Stobiecki F (2013), "Antiferromagnetic magnetostatic coupling in Co/Au/Co films with perpendicular anisotropy", Journal of Applied Physics., September, 2013. Vol. 114(9), pp. 093911. AIP Publishing LLC.
Abstract: Magnetization reversal processes in Au/Co/Au-wedge/Co/Au pseudo-spin-valve structures characterized by perpendicular anisotropy of 0.6-nm-thick Co layers were investigated by magneto-optical Kerr effect. The samples were deposited on a Ti/Au buffer layer of differing Au-layer thickness (different surface roughness and crystallite size). The distinctive influence of the buffer layer thickness on the dependences of switching fields, and energy of the effective interlayer coupling, versus Au spacer thickness is presented. In particular, increasing the buffer-layer thickness results in a decrease in the oscillation amplitude of the Ruderman–Kittel–Kasuya–Yosida-type interaction and in the enhancement of the antiferromagnetic coupling related to magnetostatic (orange peel) interactions. © 2013 AIP Publishing LLC
BibTeX:
@article{Matczak2013,
  author = {Matczak, M. and Szyman?ski, B. and Urbaniak, M. and Nowicki, M. and Głowin?ski, H. and Kus?wik, P. and Schmidt, M. and Aleksiejew, J. and Dubowik, J. and Stobiecki, F.},
  title = {Antiferromagnetic magnetostatic coupling in Co/Au/Co films with perpendicular anisotropy},
  journal = {Journal of Applied Physics},
  publisher = {AIP Publishing LLC},
  year = {2013},
  volume = {114},
  number = {9},
  pages = {093911},
  url = {http://link.aip.org/link/?JAPIAU/114/093911/1 http://link.aip.org/link/JAPIAU/v114/i9/p093911/s1&Agg=doi},
  doi = {10.1063/1.4819380}
}
Mavi MF and Ji JY (2013), "Endothelial Wound Recovery is Influenced by Treatment with Shear Stress, Wound Direction, and Substrate", Cellular and Molecular Bioengineering., April, 2013. Vol. 6(3), pp. 310-325.
Abstract: Proper and timely wound healing in the endothelium is vital for maintaining vascular homeostasis and preventing pathological conditions. The hemodynamic forces of the vasculature include shear stress and cyclic stretch. Here, we investigate the effects of shear stress on recovery of vertical or horizontal wounds that are perpendicular or parallel to flow, respectively under static or shearing condition. We further examined the effects of substrate difference on wound closure for cells on glass or silicone membrane using a modified flow chamber. Using bovine aortic endothelial cells, we analyzed wound area in scratch tests. We found that migration of cells into wound area was significantly enhanced on membrane substrate compared to glass under static condition, regardless of direction. However, continuously sheared wounds recovered differently between horizontal and vertical directions on glass, but better recovery was demonstrated in horizontal rather than vertical wounds on membrane. Here, we began to analyze the effects of flow induced shear stress and substrate difference on the direction of wound recovery in endothelial cells. We continue to investigate the effects of shear stress and substrate properties on the direction of endothelial wound recovery, in order to better understand how hemodynamic forces would affect endothelial wound healing.
BibTeX:
@article{mavi_endothelial_2013,
  author = {Mavi, Mustafa F and Ji, Julie Y},
  title = {Endothelial Wound Recovery is Influenced by Treatment with Shear Stress, Wound Direction, and Substrate},
  journal = {Cellular and Molecular Bioengineering},
  year = {2013},
  volume = {6},
  number = {3},
  pages = {310--325},
  url = {http://link.springer.com/10.1007/s12195-013-0277-8},
  doi = {10.1007/s12195-013-0277-8}
}
Medalsy I, Hensen U and Muller DJ (2011), "Imaging and Quantifying Chemical and Physical Properties of Native Proteins at Molecular Resolution by Force-Volume AFM", Angewandte Chemie International Edition., December, 2011. Vol. 50(50), pp. 12103-12108.
Abstract: Use the force: Force–volume atomic force microscopy (AFM) can image native membrane proteins and quantify and map their chemical and physical properties at molecular resolution (see images). For the light-driven proton pump bacteriorhodopsin (BR), the data shows that lipids form a flexible framework embedding a mechanically anisotropic proton pump, and that the BR adopts different structurally stable conformations that are important for proton pumping.
BibTeX:
@article{medalsy_imaging_2011,
  author = {Medalsy, Izhar and Hensen, Ulf and Muller, Daniel J},
  title = {Imaging and Quantifying Chemical and Physical Properties of Native Proteins at Molecular Resolution by Force-Volume AFM},
  journal = {Angewandte Chemie International Edition},
  year = {2011},
  volume = {50},
  number = {50},
  pages = {12103--12108},
  url = {http://doi.wiley.com/10.1002/anie.201103991},
  doi = {10.1002/anie.201103991}
}
Mehranfar M, Gaikwad R, Das S, Mitra SK and Thundat T (2014), "Effect of Temperature on Morphologies of Evaporation-triggered Asphaltene Nano-aggregates", Langmuir., January, 2014. American Chemical Society.
Abstract: We use atomic force microscopy to observe the structural changes in petroleum asphaltene aggregates in air as a function of temperature. The aggregates are obtained by evaporating a toluene solution containing asphaltene. Increase in temperature leads to transition from self-assembled fractal structures to substantially larger mobile "liquid-like" domains that show distinct tendencies of substrate repulsion and self-coalescence. This new aggregation dynamics of asphaltene can be explained by temperature-induced transition of asphaltene from pure amorphous to liquid crystalline phase. Observation of this new phenomenon for asphaltene will have wide implications for apshaltene handling and separation.
BibTeX:
@article{Mehranfar2014,
  author = {Mehranfar, Mahsa and Gaikwad, Ravi and Das, Siddhartha and Mitra, Sushanta K. and Thundat, Thomas},
  title = {Effect of Temperature on Morphologies of Evaporation-triggered Asphaltene Nano-aggregates},
  journal = {Langmuir},
  publisher = {American Chemical Society},
  year = {2014},
  url = {http://pubs.acs.org/doi/abs/10.1021/la4045896},
  doi = {10.1021/la4045896}
}
Mercier D, Boujday S, Annabi C, Villanneau R, Pradier C-M and Proust A (2012), "Bifunctional Polyoxometalates for Planar Gold Surface Nanostructuration and Protein Immobilization", The Journal of Physical Chemistry C., June, 2012. Vol. 116(24), pp. 13217-13224.
BibTeX:
@article{mercier_bifunctional_2012,
  author = {Mercier, Dimitri and Boujday, Souhir and Annabi, Cyrine and Villanneau, Richard and Pradier, Claire-Marie and Proust, Anna},
  title = {Bifunctional Polyoxometalates for Planar Gold Surface Nanostructuration and Protein Immobilization},
  journal = {The Journal of Physical Chemistry C},
  year = {2012},
  volume = {116},
  number = {24},
  pages = {13217--13224},
  url = {http://pubs.acs.org/doi/abs/10.1021/jp3031623},
  doi = {10.1021/jp3031623}
}
Mertens J, Daudén MI, Carrascosa JL and Tamayo J (2012), "Interaction of viral ATPases with nucleotides measured with a microcantilever", Sensors and Actuators B: Chemical., June, 2012. Vol. 171-172, pp. 263-270. Elsevier B.V..
Abstract: We report label-free measurements of the interaction between nucleotides and proteins using a cantilever-based sensor functionalized with viral ATPases. In the present study, immobilization curves and AFM imaging revealed the existence of two immobilization regimes over the wide range of gp19 concentrations assayed. Proteins start forming a monolayer over the surface and subsequently reorganize in three-dimensional aggregates of piled gp19 at higher protein concentrations. We show that in this regime the response to the binding of ATP is completely distinct to the observed stepped behavior of the monolayer regime described before. ATP interaction modifies the conformation of the proteins that build the clusters and, due to the interaction with the nucleotide, the cohesion of the aggregates is affected. As both ATP and AMP-PNP (a non hydrolyzable analog) can bind the gp19 aggregates producing a genuine deflection of the microcantilever, the competitive binding between them can be also detected in real time. Our hybrid bionanomechanical device reveals exciting opportunities to adsorb chemical species for the understanding of enzymatic behavior.
BibTeX:
@article{Mertens2012,
  author = {Mertens, Johann and Daudén, Mara I. and Carrascosa, José L. and Tamayo, Javier},
  title = {Interaction of viral ATPases with nucleotides measured with a microcantilever},
  journal = {Sensors and Actuators B: Chemical},
  publisher = {Elsevier B.V.},
  year = {2012},
  volume = {171-172},
  pages = {263--270},
  url = {http://dx.doi.org/10.1016/j.snb.2012.03.062},
  doi = {10.1016/j.snb.2012.03.062}
}
Mertens J, Daudén MI, Carrascosa JL and Tamayo J (2012), "Stepwise motion of a microcantilever driven by the hydrolysis of viral ATPases", Nanotechnology. Vol. 23, pp. 015501.
BibTeX:
@article{Mertens2012a,
  author = {Mertens, J. and Daudén, M. I. and Carrascosa, José L. and Tamayo, J.},
  title = {Stepwise motion of a microcantilever driven by the hydrolysis of viral ATPases},
  journal = {Nanotechnology},
  year = {2012},
  volume = {23},
  pages = {015501},
  url = {http://iopscience.iop.org/0957-4484/23/1/015501 http://www.nanoscience.imdea.org/Portals/22/downloads/publications/2012Nano23015501.pdf}
}
Mertz G, Hassouna F, Leclère P, Dahoun A, Toniazzo V and Ruch D (2012), "Correlation between (nano)-mechanical and chemical changes occurring during photo-oxidation of filled vulcanised styrene butadiene rubber (SBR)", Polymer Degradation and Stability., August, 2012.
Abstract: Photo-oxidation at $ > 290 nm was performed on vulcanised styrene butadiene rubber (SBR) designed for flooring applications. The effect of the presence of coated titanium dioxide (TiO2), used as a pigment, was evaluated. The chemical and nano-mechanical changes occurring at the surface during irradiation were studied by micro-FTIR spectroscopy and atomic force microscopy (AFM). Both techniques were used to obtain the oxidation profiles in the depth of the composites (in the absence and presence of TiO2) to characterise the oxidative layer formation. The nano-mechanical and chemical profiles were superimposed for both composites (SBR and SBR/TiO2) suggesting a correlation between both properties. Indeed, the increase of the DMT modulus determined by AFM reflects the crosslinking reactions which occur simultaneously with the formation of oxidised photo-products. Moreover, during irradiation, the mechanical properties were followed at low and high degree of deformation by means of dynamic mechanical analysis (DMA) and tensile test until break, respectively. We demonstrate that the physico-chemical properties of the oxidised layer which represents 20 $m of the 600 $m of the material can explain the loss of mechanical properties for both composites based on vulcanised SBR and SBR/TiO2 during irradiation at $ > 290 nm. We also demonstrate a different mechanical behaviour in presence of TiO2 compared to neat SBR that could be due to a competition between formation of photo-products and the filler-rubber debonding during photo-oxidation.
BibTeX:
@article{Mertz2012,
  author = {Mertz, Grégory and Hassouna, Fatima and Leclère, Philippe and Dahoun, Abdesselam and Toniazzo, Valérie and Ruch, David},
  title = {Correlation between (nano)-mechanical and chemical changes occurring during photo-oxidation of filled vulcanised styrene butadiene rubber (SBR)},
  journal = {Polymer Degradation and Stability},
  year = {2012},
  url = {http://dx.doi.org/10.1016/j.polymdegradstab.2012.08.008},
  doi = {10.1016/j.polymdegradstab.2012.08.008}
}
Mihaela PD, Nicoleta FA and Spataru IC (2013), "Effect of nanosilica on the morphology of polyethylene investigated by AFM", Composites Science and Technology., November, 2013. Vol. 74, pp. 131-8.
Abstract: Nanocomposites from low density polyethylene (PE) and nanosilica (NS) with and without a compatibilizer were prepared via direct melt blending. Their morphology and mechanical properties were investigated in relation to that of neat PE using peak force QNM (quantitative nanomechanics) analysis. A suppression of spherulitic development as compared to neat PE was observed in PE/NS nanocomposites. NS induced no modification in the lamellar thickness of PE but a slight decrease of the crystallinity was detected. Changes in the thickness and distribution of the amorphous strips were emphasized in samples containing the compatibilizer. For the first time the nano-mecanical properties of PE - NS interface were quantitatively characterized. AFM investigation of fractured samples revealed different mechanisms involved in deformation and breaking of neat PE and composites.
BibTeX:
@article{panaitescu_effect_2013,
  author = {Mihaela, Panaitescu Denis and Nicoleta, Frone Adriana and Spataru, Ilie Catalin},
  title = {Effect of nanosilica on the morphology of polyethylene investigated by AFM},
  journal = {Composites Science and Technology},
  year = {2013},
  volume = {74},
  pages = {131--8},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0266353812003557 http://dx.doi.org/10.1016/j.compscitech.2012.10.001},
  doi = {10.1016/j.compscitech.2012.10.001}
}
Milani P, Gholamirad M, Traas J, Arnéodo A, Boudaoud A, Argoul F and Hamant O (2011), "In vivo analysis of local wall stiffness at the shoot apical meristem in Arabidopsis using atomic force microscopy", The Plant Journal. Vol. 67(6), pp. 1116-1123. Blackwell Publishing Ltd.
Abstract: Whereas the morphogenesis of developing organisms is relatively well understood at the molecular level, the contribution of the mechanical properties of the cells to shape changes remains largely unknown, mainly because of the lack of quantified biophysical parameters at cellular or subcellular resolution. Here we designed an atomic force microscopy approach to investigate the elastic modulus of the outer cell wall in living shoot apical meristems (SAMs). SAMs are highly organized structures that contain the plant stem cells, and generate all of the aerial organs of the plant. Building on modeling and experimental data, we designed a protocol that is able to measure very local properties, i.e. within 40–100 nm deep into the wall of living meristematic cells. We identified three levels of complexity at the meristem surface, with significant heterogeneity in stiffness at regional, cellular and even subcellular levels. Strikingly, we found that the outer cell wall was much stiffer at the tip of the meristem (5 ± 2 MPa on average), covering the stem cell pool, than on the flanks of the meristem (1.5 ± 0.7 MPa on average). Altogether, these results demonstrate the existence of a multiscale spatialization of the mechanical properties of the meristem surface, in addition to the previously established molecular and cytological zonation of the SAM, correlating with regional growth rate distribution.
BibTeX:
@article{Milani2011,
  author = {Milani, Pascale and Gholamirad, Maryam and Traas, Jan and Arnéodo, Alain and Boudaoud, Arezki and Argoul, Françoise and Hamant, Olivier},
  title = {In vivo analysis of local wall stiffness at the shoot apical meristem in Arabidopsis using atomic force microscopy},
  journal = {The Plant Journal},
  publisher = {Blackwell Publishing Ltd},
  year = {2011},
  volume = {67},
  number = {6},
  pages = {1116--1123},
  url = {http://dx.doi.org/10.1111/j.1365-313X.2011.04649.x},
  doi = {10.1111/j.1365-313X.2011.04649.x}
}
Minne SC, Hu Y, Hu S, Pittenger B and Su C (2010), "NanoScale Quantitative Mechanical Property Mapping Using Peak Force Tapping Atomic Force Microscopy", Microscopy and Microanalysis., August, 2010. Vol. 16(S2), pp. 464-465.
BibTeX:
@article{Minne2010,
  author = {Minne, Steve C. and Hu, Yan and Hu, Shuiqing and Pittenger, Bede and Su, Chanmin},
  title = {NanoScale Quantitative Mechanical Property Mapping Using Peak Force Tapping Atomic Force Microscopy},
  journal = {Microscopy and Microanalysis},
  year = {2010},
  volume = {16},
  number = {S2},
  pages = {464--465},
  url = {http://www.journals.cambridge.org/abstractS1431927610061829},
  doi = {10.1017/S1431927610061829}
}
Molloy JK, Ceroni P, Venturi M, Bauer T, Sakamoto J and Bergamini G (2013), "Self-assembly of nanocrystalline tetra-terpyridine complexes: from molecules to mesoscopic objects", Soft Matter., September, 2013. Vol. 9(45), pp. 10754. The Royal Society of Chemistry.
BibTeX:
@article{Molloy2013,
  author = {Molloy, Jennifer Kelly and Ceroni, Paola and Venturi, Margherita and Bauer, Thomas and Sakamoto, Junji and Bergamini, Giacomo},
  title = {Self-assembly of nanocrystalline tetra-terpyridine complexes: from molecules to mesoscopic objects},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {9},
  number = {45},
  pages = {10754},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/sm/c3sm52353e http://xlink.rsc.org/?DOI=c3sm52353e},
  doi = {10.1039/c3sm52353e}
}
Montrose A, Cargou S, Nepveu F, Manczak R, Gué A-M and Reybier K (2013), "Impedimetric immunosensor for the detection of circulating pro-inflammatory monocytes as infection markers", Biosensors & Bioelectronics., November, 2013. Vol. 49, pp. 305-11. Elsevier.
Abstract: Circulating blood monocytes belong to the first line of defense against pathogens and inflammation. Monocytes can be divided into three populations defined by the expression of the cell surface molecules, CD 14 and CD 16. The CD 14(++) CD 16(-) cells, called "classical" monocytes, represent 85% to 95% of the total monocytes in a healthy person whereas CD 14(-) CD 16(+), called "proinflammatory" monocytes, are found in greater numbers in the blood of patients with acute inflammation and infectious diseases. This increase in the concentration of proinflammatory monocytes can be a good indicator of an infectious state. This study presents an immunosensor based on impedance detection for specific cell trapping of classical and proinflammatory monocytes. The grafting of specific antibodies (CD 14 or CD 16) was based on the use of mixed SAM associated with protein G. Each step of the functionalization was characterized by electrochemical methods, quartz crystal microbalance and atomic force microscopy. Faradaic electrochemical impedance spectroscopy and voltametric analysis confirmed the success of the modification process with a surface coverage reaching 92% for the antibody layer. The increase in the deposited mass at each step of the modification process confirmed this results revealing that one protein G in two was bound to an antibody. The cell trapping capacity, evaluated by the variation in the film resistance using non-faradaic impedance spectroscopy revealed that the cell trapping is selective, depending on the specific antibody grafted and quantitative with the range of detection being 1000 to 30,000 infected cells. This range of detection is consistent with the application targeted.
BibTeX:
@article{Montrose2013,
  author = {Montrose, Armelle and Cargou, Sébastien and Nepveu, Françoise and Manczak, Rémi and Gué, Anne-Marie and Reybier, Karine},
  title = {Impedimetric immunosensor for the detection of circulating pro-inflammatory monocytes as infection markers},
  journal = {Biosensors & Bioelectronics},
  publisher = {Elsevier},
  year = {2013},
  volume = {49},
  pages = {305--11},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23792623 http://dx.doi.org/10.1016/j.bios.2013.05.025},
  doi = {10.1016/j.bios.2013.05.025}
}
Moosburger-Will J, Jäger J, Horn S and Wellhausen C (2012), "Investigation of phase morphology of polyetherimide-toughened epoxy resin by scanning probe microscopy", Polymer Testing., December, 2012. Vol. 31(8), pp. 1008-1018.
Abstract: High resolution nanomechanical analysis in combination with high resolution topography imaging was used to investigate the phase morphology of a polyetherimide-toughened tetra-functional epoxy resin. A two-phase structure close to co-continuous morphology is observed. Here, polyetherimide and epoxy-rich regions can be clearly identified due to their different nanomechanical properties. Within the PEI-rich regions, the high resolution testing allows identification of polyetherimide-rich globules with a size between 50 nm and 500 nm, in addition to the well-known epoxy-rich rounded substructures with a diameter of about one micrometer. Etching influences the surface elastic properties and results in an increase of the epoxy surface modulus. Surface ageing results in a slight increase of the surface modulus.
BibTeX:
@article{moosburger-will_investigation_2012,
  author = {Moosburger-Will, Judith and Jäger, Jan and Horn, Siegfried and Wellhausen, Christian},
  title = {Investigation of phase morphology of polyetherimide-toughened epoxy resin by scanning probe microscopy},
  journal = {Polymer Testing},
  year = {2012},
  volume = {31},
  number = {8},
  pages = {1008--1018},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0142941812001407},
  doi = {10.1016/j.polymertesting.2012.08.001}
}
Morsi SM, Pakzad A, Amin A, Yassar RS and Heiden PA (2011), "Chemical and nanomechanical analysis of rice husk modified by ATRP-grafted oligomer", Journal of Colloid and Interface Science., August, 2011. Vol. 360(2), pp. 377-85. Elsevier Inc..
Abstract: Rice husk (RH), an abundant agricultural residue, was reacted with 2-bromoisobutyryl bromide, to convert it to a heterogeneous polyfunctional macroinitiator for Atom Transfer Radical Polymerization (ATRP). The number of active sites placed on the RH surface was small, but they were ATRP active. Non-polar methyl methacrylate (MMA) and polar acrylonitrile (AN) were polymerized from the RH, and a sequential monomer addition was used to prepare an amphiphilic PMMA-b-PAN copolymer on RH surface. FTIR qualitatively confirmed the grafting. Gravimetric and XPS analysis of the different RH surface compositions indicated thin layers of oligomeric PMMA, PAN, and PMMA-b-PAN. The modified surfaces were mapped by nanomechanical AFM to measure surface roughness, and adhesion and moduli using the Derjaguin-Muller-Toropov model. RH grafted with MMA possessed a roughness value of 7.92, and a hard and weakly adhering surface (13.1 GPa and 16.7 nN respectively) while RH grafted with AN yielded a roughness value of 29 with hardness and adhesion values of 4.0 GPa and 23.5 nN. The PMMA-b-PAN modification afforded a surface with a roughness value of 51.5 nm, with hardness and adhesion values of 3.0 GPa and 75.3 nN.
BibTeX:
@article{Morsi2011,
  author = {Morsi, Samir M. and Pakzad, Anahita and Amin, Amal and Yassar, Reza S. and Heiden, Patricia A.},
  title = {Chemical and nanomechanical analysis of rice husk modified by ATRP-grafted oligomer},
  journal = {Journal of Colloid and Interface Science},
  publisher = {Elsevier Inc.},
  year = {2011},
  volume = {360},
  number = {2},
  pages = {377--85},
  url = {http://www.sciencedirect.com/science/article/pii/S0021979711005017},
  doi = {10.1016/j.jcis.2011.04.065}
}
Mortell H, Senderling B, Rust MJ and Gettens RT (2011), "Design of a nano-scaffold for tissue engineering", In Bioengineering Conference (NEBEC), 2011 IEEE 37th Annual Northeast. Troy, NY, April, 2011. , pp. 1-2. IEEE.
Abstract: The goal of this study is to design a scaffold, utilizing topographical features on the nanometer scale, to determine the relationship between those features and cellular orientation during in vitro cell culture. Ultimately the goal of this study is to control the structure of engineered tissue which can be accomplished by directing cellular orientation during growth. The control of tissue structure is important because tissue structure determines tissue function. The topographical nano-scale features in this design are created by using self-assembled monolayers (SAMs) of the plasma protein fibrinogen. The scaffold is made out of polydimethylsiloxane (PDMS) and is fabricated utilizing a multi-step manufacturing process. In the future, the scaffold will provide a means to culture cells and characterize cellular orientation in relation to the patterned SAMs.
BibTeX:
@inproceedings{mortell_design_2011,
  author = {Mortell, H and Senderling, B and Rust, M J and Gettens, R T},
  title = {Design of a nano-scaffold for tissue engineering},
  booktitle = {Bioengineering Conference (NEBEC), 2011 IEEE 37th Annual Northeast},
  publisher = {IEEE},
  year = {2011},
  pages = {1--2},
  url = {http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=5778540},
  doi = {10.1109/NEBC.2011.5778540}
}
Moyer JA, Eaton C and Engel-Herbert R (2013), "Highly Conductive SrVO3 as a Bottom Electrode for Functional Perovskite Oxides", Advanced materials., May, 2013. Vol. 25(26), pp. 3578-82.
Abstract: Stoichiometric SrVO3 thin films grown by hybrid molecular beam epitaxy are demonstrated, meeting the stringent requirements of an ideal bottom electrode material. They display an order of magnitude lower room temperature resistivity and superior chemical stability, compared to the commonly employed SrRuO3 , as well as atomically smooth surfaces. Excellent structural compatibility with perovskite and related structures renders SrVO3 a high performance electrode material with the potential to promote the creation of new functional oxide electronic devices.
BibTeX:
@article{Moyer2013,
  author = {Moyer, Jarrett A. and Eaton, Craig and Engel-Herbert, Roman},
  title = {Highly Conductive SrVO3 as a Bottom Electrode for Functional Perovskite Oxides},
  journal = {Advanced materials},
  year = {2013},
  volume = {25},
  number = {26},
  pages = {3578--82},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23703901},
  doi = {10.1002/adma.201300900}
}
Mukumoto K, Li Y, Nese A, Sheiko SS and Matyjaszewski K (2012), "Synthesis and Characterization of Molecular Bottlebrushes Prepared by Iron-Based ATRP", Macromolecules., November, 2012. , pp. 121119092447004. American Chemical Society.
Abstract: Molecular bottlebrushes with hydrophobic poly(n-butyl acrylate) or polystyrene and hydrophilic poly(di(ethylene glycol) ethyl ether acrylate)) side chains were successfully synthesized by grafting from a poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) macroinitiator using iron-based atom transfer radical polymerization (ATRP). Iron(II) bromide, iron(III) bromide, and tetrabutylammonium bromide catalyst was employed for an ATRP grafting-from reaction, resulting in brush macromolecules with a narrow molecular weight distribution (Mw/Mn = 1.18?1.28). Molecular weights measured by multiangle laser light scattering correlates well with the theoretical values for all bottlebrushes. Imaging of individual bottlebrushes by atomic force microscopy exhibited a wormlike conformation. Initiation efficiencies were calculated by cleaving the side chains by alcoholysis and then injecting to gel permeation chromatography. The initiation efficiencies were ca. 80?95 showing relatively high values for a grafting from polymerization with an iron catalyst. These results indicate that iron-catalyzed ATRP allows well-controlled polymerization even when targeting dense grafting from procedures. The 0.1% (w/w) of water-soluble molecular bottlebrushes with poly(di(ethylene glycol) ethyl ether acrylate)) side chains displayed a lower critical solution temperature behavior in distilled water, and the average particle size started to increase above 8 °C due to intermolecular aggregation of the bottlebrushes. The slight decrease of the size in highly diluted solution (0.005% w/w) of the bottlebrush was observed as the temperature was increased, suggesting that intramolecular collapse of the individual molecules. Molecular bottlebrushes with hydrophobic poly(n-butyl acrylate) or polystyrene and hydrophilic poly(di(ethylene glycol) ethyl ether acrylate)) side chains were successfully synthesized by grafting from a poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) macroinitiator using iron-based atom transfer radical polymerization (ATRP). Iron(II) bromide, iron(III) bromide, and tetrabutylammonium bromide catalyst was employed for an ATRP grafting-from reaction, resulting in brush macromolecules with a narrow molecular weight distribution (Mw/Mn = 1.18?1.28). Molecular weights measured by multiangle laser light scattering correlates well with the theoretical values for all bottlebrushes. Imaging of individual bottlebrushes by atomic force microscopy exhibited a wormlike conformation. Initiation efficiencies were calculated by cleaving the side chains by alcoholysis and then injecting to gel permeation chromatography. The initiation efficiencies were ca. 80?95 showing relatively high values for a grafting from polymerization with an iron catalyst. These results indicate that iron-catalyzed ATRP allows well-controlled polymerization even when targeting dense grafting from procedures. The 0.1% (w/w) of water-soluble molecular bottlebrushes with poly(di(ethylene glycol) ethyl ether acrylate)) side chains displayed a lower critical solution temperature behavior in distilled water, and the average particle size started to increase above 8 °C due to intermolecular aggregation of the bottlebrushes. The slight decrease of the size in highly diluted solution (0.005% w/w) of the bottlebrush was observed as the temperature was increased, suggesting that intramolecular collapse of the individual molecules.
BibTeX:
@article{Mukumoto2012,
  author = {Mukumoto, Kosuke and Li, Yuanchao and Nese, Alper and Sheiko, Sergei S. and Matyjaszewski, Krzysztof},
  title = {Synthesis and Characterization of Molecular Bottlebrushes Prepared by Iron-Based ATRP},
  journal = {Macromolecules},
  publisher = {American Chemical Society},
  year = {2012},
  pages = {121119092447004},
  url = {http://dx.doi.org/10.1021/ma3020867},
  doi = {10.1021/ma3020867}
}
Nikiforov MP and Darling SB (2013), "Improved conductive atomic force microscopy measurements on organic photovoltaic materials via mitigation of contact area uncertainty", Progress in Photovoltaics: Research and Applications., November, 2013. Vol. 21(7), pp. 1433-1443.
Abstract: Physical processes that lead to conversion of light into electrical energy inside photovoltaic devices happen at the nanoscale. Therefore, understanding of electrical properties of photovoltaic materials at this length scale is of paramount importance for improvement of device performance. In this paper, we describe and validate a new framework for high-resolution quantita- tive measurements of electrical and mechanical properties of compliant materials with sub-100-nm resolution. Previous approaches have generally suffered from uncertainty in the quantitative level of contact between the probe and the material being measured; the methodology presented here overcomes this obstacle. We use the broadly studied ITO/PEDOT:PSS/ P3HT:PC61BM system as an example to illustrate variability of chemical composition and electrical properties of the active layer at hundred-nanometers and micrometer length scales.
BibTeX:
@article{Nikiforov2012,
  author = {Nikiforov, Maxim P. and Darling, Seth B.},
  title = {Improved conductive atomic force microscopy measurements on organic photovoltaic materials via mitigation of contact area uncertainty},
  journal = {Progress in Photovoltaics: Research and Applications},
  year = {2013},
  volume = {21},
  number = {7},
  pages = {1433--1443},
  url = {http://doi.wiley.com/10.1002/pip.2217},
  doi = {10.1002/pip.2217}
}
Nugraha B, Hong X, Mo X, Tan L, Zhang W, Chan P-M, Kang CH, Wang Y, Beng LT, Sun W, Choudhury D, Robens JM, McMillian M, Silva J, Dallas S, Tan C-H, Yue Z and Yu H (2011), "Galactosylated cellulosic sponge for multi-well drug safety testing", Biomaterials. Vol. 32(29), pp. 6982-6994.
Abstract: Hepatocyte spheroids can maintain mature differentiated functions, but collide to form bulkier structures when in extended culture. When the spheroid diameter exceeds 200 $m, cells in the inner core experience hypoxia and limited access to nutrients and drugs. Here we report the development of a thin galactosylated cellulosic sponge to culture hepatocytes in multi-well plates as 3D spheroids, and constrain them within a macroporous scaffold network to maintain spheroid size and prevent detachment. The hydrogel-based soft sponge conjugated with galactose provided suitable mechanical and chemical cues to support rapid formation of hepatocyte spheroids with a mature hepatocyte phenotype. The spheroids tethered in the sponge showed excellent maintenance of 3D cell morphology, cell–cell interaction, polarity, metabolic and transporter function and/or expression. For example, cytochrome P450 (CYP1A2, CYP2B2 and CYP3A2) activities were significantly elevated in spheroids exposed to $-naphthoflavone, phenobarbital, or pregnenolone-16$-carbonitrile, respectively. The sponge also exhibits minimal drug absorption compared to other commercially available scaffolds. As the cell seeding and culture protocols are similar to various high-throughput 2D cell-based assays, this platform is readily scalable and provides an alternative to current hepatocyte platforms used in drug safety testing applications.
BibTeX:
@article{Nugraha2011,
  author = {Nugraha, Bramasta and Hong, Xin and Mo, Xuejun and Tan, Looling and Zhang, Wenxia and Chan, Po-Mak and Kang, Chiang Huen and Wang, Yan and Beng, Lu Thong and Sun, Wanxin and Choudhury, Deepak and Robens, Jeffrey M and McMillian, Michael and Silva, Jose and Dallas, Shannon and Tan, Choon-Hong and Yue, Zhilian and Yu, Hanry},
  title = {Galactosylated cellulosic sponge for multi-well drug safety testing},
  journal = {Biomaterials},
  year = {2011},
  volume = {32},
  number = {29},
  pages = {6982--6994},
  url = {http://www.sciencedirect.com/science/article/pii/S0142961211006582},
  doi = {10.1016/j.biomaterials.2011.05.087}
}
Odent J, Leclère P, Raquez J-M and Dubois P (2013), "Toughening of polylactide by tailoring phase-morphology with P[CL-co-LA] random copolyesters as biodegradable impact modifiers", European Polymer Journal., April, 2013. Vol. 49(4), pp. 914-922.
Abstract: The utilization of partially miscible impact modifiers was investigated in the design of impact polylactide (PLA)-based materials. Rubbery random aliphatic copolyesters namely poly($-caprolactone-co-D,L-lactide) (P[CL-co-LA]) containing different compositions in LA comonomers were employed as impact modifiers. The relative content in LA comonomer spread along the copolymer chain was varied and its effect on the toughness of the resulting PLA-based materials was investigated. Dependence between toughness improvement and morphology of the resulting blends was established in terms of domain shape, average size and related size-distribution of the dispersed rubbery microdomains within the PLA matrix as shown by SEM, TEM and AFM. However, using Peak Force Tapping techniques (PFT-AFM) revealed peculiar morphologies upon the affinity and the interfacial compatibilization between the blend components. The overall results indicated that the dispersion of a P[CL-co-LA] copolymer containing 28 mol% LA comonomer provided a fourfold increase in impact strength for the resulting PLA blend, which could be correlated to the presence of ribbon-like rubbery microdomains.
BibTeX:
@article{Odent2012,
  author = {Odent, Jérémy and Leclère, Philippe and Raquez, Jean-Marie and Dubois, Philippe},
  title = {Toughening of polylactide by tailoring phase-morphology with P[CL-co-LA] random copolyesters as biodegradable impact modifiers},
  journal = {European Polymer Journal},
  year = {2013},
  volume = {49},
  number = {4},
  pages = {914--922},
  url = {http://dx.doi.org/10.1016/j.eurpolymj.2012.12.006 http://linkinghub.elsevier.com/retrieve/pii/S0014305712004156},
  doi = {10.1016/j.eurpolymj.2012.12.006}
}
Olsson ALJ, Arun N, Kanger JS, Busscher HJ, Ivanov IE, Camesano TA, Chen Y, Johannsmann D, van der Mei HC and Sharma PK (2012), "The influence of ionic strength on the adhesive bond stiffness of oral streptococci possessing different surface appendages as probed using AFM and QCM-D", Soft Matter. The Royal Society of Chemistry.
Abstract: Bacterial adhesion to surfaces poses threats to human-health, not always associated with adhering organisms, but often with their detachment causing contamination elsewhere. Bacterial adhesion mechanisms may not be valid for their detachment, known to proceed according to a visco-elastic mechanism. Here we aimed to investigate influences of ionic strength on the adhesive bond stiffness of two spherically shaped Streptococcus salivarius strains with different lengths of fibrillar surface appendages. The response of a Quartz-Crystal-Microbalance-with-Dissipation (QCM-D) upon streptococcal adhesion and changes in the ionic strength of the surrounding fluid indicated that the bond stiffness of S. salivarius HB7, possessing a dense layer of 91 nm long fibrils, was unaffected by ionic strength. Atomic-force-microscopic (AFM) imaging in PeakForce-QNM mode showed a small decrease in bond stiffness from 1200 to 880 kPa upon decreasing ionic strength from 57 to 5.7 mM, while Total-Internal-Reflection-Microscopy suggested a complete collapse of fibrils. S. salivarius HBV51, possessing a less dense layer of shorter (63 nm) fibrils, demonstrated a strong decrease in bond stiffness both from QCM-D and AFM upon decreasing the ionic strength, and a partial collapse of fibrils. Probably, the more hydrophobic and less negatively charged long fibrils on S. salivarius HB7 collapse side-on to the cell surface, while the more hydrophilic and negatively charged fibrils of S. salivarius HBV51 remain partially stretched. In summary, we demonstrate how a combination of different methods can yield a description of the structural changes occurring in the interfacial region between adhering, fibrillated streptococci and a substratum surface upon changing the ionic strength.
BibTeX:
@article{Olsson2012,
  author = {Olsson, Adam L. J. and Arun, Narasimhan and Kanger, Johannes S. and Busscher, Henk J. and Ivanov, Ivan E. and Camesano, Terri A. and Chen, Yun and Johannsmann, Diethelm and van der Mei, Henny C. and Sharma, Prashant K.},
  title = {The influence of ionic strength on the adhesive bond stiffness of oral streptococci possessing different surface appendages as probed using AFM and QCM-D},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2012},
  url = {http://pubs.rsc.org/en/content/articlehtml/2012/sm/c2sm26025e}
}
Oncins G and Daz-Marcos J (2012), "Atomic Force Microscopy : probing the Nanoworld", In Handbook of instrumental techniques from CCiTUB. Barcelona. Spain
Abstract: Atomic Force Microscope and related techniques have played a key role in the development of the nanotechnology revolution that is taking place in science. This paper reviews the basic principles behind the technique and its different operation modes and applications, pointing out research works performed in the Nanometric Techniques Unit of the CCiTUB in order to exemplify the vast array of capabilities of these instruments.
BibTeX:
@incollection{Oncins2012,
  author = {Oncins, Gerard and Daz-Marcos, Jordi},
  title = {Atomic Force Microscopy : probing the Nanoworld},
  booktitle = {Handbook of instrumental techniques from CCiTUB},
  year = {2012},
  url = {http://diposit.ub.edu/dspace/bitstream/2445/32162/1/MT07 - Atomic Force Microscopyed2.pdf}
}
Online VA, Liu X, Thormann E, Dedinaite A, Rutland M, Visnevskij C, Makuska R and Claesson PM (2013), "Low friction and high load bearing capacity layers formed by cationic-block-non-ionic bottle-brush copolymers in aqueous media", Soft Matter., April, 2013. Vol. 9(22), pp. 5361. The Royal Society of Chemistry.
BibTeX:
@article{Liu2013a,
  author = {Online, View Article and Liu, Xiaoyan and Thormann, Esben and Dedinaite, Andra and Rutland, Mark and Visnevskij, Ceslav and Makuska, Ricardas and Claesson, Per M.},
  title = {Low friction and high load bearing capacity layers formed by cationic-block-non-ionic bottle-brush copolymers in aqueous media},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {9},
  number = {22},
  pages = {5361},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/sm/c3sm27862j},
  doi = {10.1039/c3sm27862j}
}
Onyesom I, Lamprou Da, Sygellou L, Owusu-Ware SK, Antonijevic M, Chowdhry BZ and Douroumis D (2013), "Sirolimus encapsulated liposomes for cancer therapy: physicochemical and mechanical characterization of sirolimus distribution within liposome bilayers", Molecular Pharmaceutics., October, 2013. Vol. 10, pp. 4281-93. American Chemical Society.
Abstract: Sirolimus has recently been introduced as a therapeutic agent for breast and prostate cancer. In the current study, conventional and Stealth® liposomes were used as carriers for the encapsulation of sirolimus. The physicochemical characteristics of the sirolimus liposome nanoparticles were investigated including the particle size, zeta potential, stability and membrane integrity. In addition atomic force microscopy was used to study the morphology, surface roughness and mechanical properties such as elastic modulus deformation and deformation. Sirolimus encapsulation in Stealth liposomes® showed a high degree of deformation and lower packing density especially for dipalmitoyl-phosphatidylcholine (DPPC) Stealth® liposomes compared to unloaded. Similar results were obtained by differential scanning calorimetry (DSC) studies; sirolimus loaded liposomes were found to result in a distorted state of the bilayer. X-ray photon electron (XPS) analysis revealed a uniform distribution of sirolimus in multilamellar DPPC Stealth® liposomes compared to a non-uniform, greater outer layer lamellar distribution in distearoylphosphatidylcholine (DSPC) Stealth® liposomes.
BibTeX:
@article{Onyesome2013,
  author = {Onyesom, Ichioma and Lamprou, Dimitrios a and Sygellou, Lamprini and Owusu-Ware, Samuel K and Antonijevic, Milan and Chowdhry, Babur Z and Douroumis, Dennis},
  title = {Sirolimus encapsulated liposomes for cancer therapy: physicochemical and mechanical characterization of sirolimus distribution within liposome bilayers},
  journal = {Molecular Pharmaceutics},
  publisher = {American Chemical Society},
  year = {2013},
  volume = {10},
  pages = {4281--93},
  url = {http://dx.doi.org/10.1021/mp400362v},
  doi = {10.1021/mp400362v}
}
Orski SV, Kundu S, Gross R and Beers KL (2013), "Design and Implementation of Two-Dimensional Polymer Adsorption Models: Evaluating the Stability of Candida antarctica Lipase B/Solid-Support Interfaces by QCM-D", Biomacromolecules., February, 2013. Vol. 14(2), pp. 377-386.
BibTeX:
@article{orski_design_2013,
  author = {Orski, Sara V and Kundu, Santanu and Gross, Richard and Beers, Kathryn L},
  title = {Design and Implementation of Two-Dimensional Polymer Adsorption Models: Evaluating the Stability of Candida antarctica Lipase B/Solid-Support Interfaces by QCM-D},
  journal = {Biomacromolecules},
  year = {2013},
  volume = {14},
  number = {2},
  pages = {377--386},
  url = {http://pubs.acs.org/doi/abs/10.1021/bm301557y},
  doi = {10.1021/bm301557y}
}
Osborne J, Hu S, Wang H, Hu Y, Shi J, Hand S and Su C (2013), "High-speed atomic force microscopy for patterned defect review", In SPIE Proceedings., April, 2013. (8681)
Abstract: This paper reports recent progress in using Atomic Force Microscopy as a defect review tool for patterned wafers. The key developments in the AFM technology are substantial scan speed improvements and the ability to reach feature bottom-CDs in a narrow trench. The latter is accomplished by controlling the tip-sample interaction via the short-range interaction force. Narrow trenches with vertical side wall angles comparable to current FinFET dimensions were imaged using the AFM, where imaging speeds for this sample reached about 0.2 frames per second, providing quantified topographic data for key features of the trenches. The sub-10 nm resolution data of high speed AFM demonstrates the technology as a viable solution for defect review. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
BibTeX:
@inproceedings{osborne_high-speed_2013,
  author = {Osborne, Jason and Hu, Shuiqing and Wang, Haiming and Hu, Yan and Shi, Jian and Hand, Sean and Su, Chanmin},
  editor = {Starikov, Alexander and Cain, Jason P},
  title = {High-speed atomic force microscopy for patterned defect review},
  booktitle = {SPIE Proceedings},
  year = {2013},
  number = {8681},
  url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2011665},
  doi = {10.1117/12.2011665}
}
Osbourne D, Wilson Aruni A, Dou Y, Perry C, Boskovic DS, Roy F and Fletcher HM (2012), "VimA-dependent modulation of the secretome in Porphyromonas gingivalis", Molecular Oral Microbiology., December, 2012. Vol. 27(6), pp. 420-435.
BibTeX:
@article{osbourne_vima-dependent_2012,
  author = {Osbourne, D and Wilson Aruni, A and Dou, Y and Perry, C and Boskovic, D S and Roy, F and Fletcher, H M},
  title = {VimA-dependent modulation of the secretome in Porphyromonas gingivalis},
  journal = {Molecular Oral Microbiology},
  year = {2012},
  volume = {27},
  number = {6},
  pages = {420--435},
  url = {http://doi.wiley.com/10.1111/j.2041-1014.2012.00661.x},
  doi = {10.1111/j.2041-1014.2012.00661.x}
}
Pérez Madrigal MM, Giannotti MI, Oncins G, Franco L, Armelin E, Puiggal J, Sanz F, del Valle LJ and Alemán C (2013), "Bioactive nanomembranes of semiconductor polythiophene and thermoplastic polyurethane: thermal, nanostructural and nanomechanical properties", Polymer Chemistry. Vol. 4(3), pp. 568.
Abstract: Free-standing and supported nanomembranes have been prepared by spin-coating mixtures of a semiconducting polythiophene (P3TMA) derivative and thermoplastic polyurethane (TPU). Thermal studies of TPU:P3TMA blends with 60 : 40, 50 : 50, 40 : 60 and 20 : 80 weight ratios indicate a partial miscibility of the two components. Analysis of the glass transition temperatures allowed us to identify the highest miscibility for the blend with a 40 : 60 weight ratio, this composition being used to prepare both self-standing and supported nanomembranes. The thickness of ultra-thin films made with the 40 : 60 blend ranged from 11 to 93 nm, while the average roughness was 16.3 ± 0.8 nm. In these films the P3TMA-rich phase forms granules, which are dispersed throughout the rest of the film. Quantitative nanomechanical mapping has been used to determine the Young's modulus value by applying the Derjanguin–Müller–Toporov (DMT) contact mechanics model and the adhesion force of ultra-thin films. The modulus depends on the thickness of the films, values determined for the thicker (80–140 nm)/thinner (10–40 nm) regions of TPU, P3TMA and blend samples being 25/35 MPa, 3.5/12 GPa and 0.9/1.7 GPa, respectively. In contrast the adhesion force is homogeneous through the whole surface of the TPU and P3TMA films (average values: 7.2 and 5.0 nN, respectively), whereas for the blend it depends on the phase distribution. Thus, the adhesion force is higher for the TPU-rich domains than for the P3TMA-rich domains. Finally, the utility of the nanomembranes for tissue engineering applications has been proved by cellular proliferation assays. Results show that the blend is more active as a cellular matrix than each of the two individual polymers.
BibTeX:
@article{perez_madrigal_bioactive_2013,
  author = {Pérez Madrigal, Maria M. and Giannotti, Marina I. and Oncins, Gerard and Franco, Lourdes and Armelin, Elaine and Puiggal, Jordi and Sanz, Fausto and del Valle, Luis J. and Alemán, Carlos},
  title = {Bioactive nanomembranes of semiconductor polythiophene and thermoplastic polyurethane: thermal, nanostructural and nanomechanical properties},
  journal = {Polymer Chemistry},
  year = {2013},
  volume = {4},
  number = {3},
  pages = {568},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/py/c2py20654d http://xlink.rsc.org/?DOI=c2py20654d},
  doi = {10.1039/c2py20654d}
}
Pakzad A, Simonsen J, Heiden PA and Yassar RS (2011), "Size effects on the nanomechanical properties of cellulose I nanocrystals", Journal of Materials Research., September, 2011. Vol. 27(03), pp. 528-536.
Abstract: The ultimate properties of a fibrous composite system depend highly on the transverse mechanical properties of the fibers. Here, we report the size dependency of transverse elastic modulus in cellulose nanocrystals (CNCs). In addition, the mechanical properties of CNCs prepared from wood and cotton resources were investigated. Nanoindentation in an atomic force microscope (AFM) was used in combination with analytical contact mechanics modeling (Hertz model) and finite element analysis (FEA) to estimate the transverse elastic moduli (Et) of CNCs. FEA modeling estimated the results more accurately than the Hertz model. Based on the AFM–FEA calculations, wood CNCs had higher transverse elastic moduli in comparison to the cotton CNCs. Additionally, Et was shown to increase with a reduction in the CNCs’ diameter. This size-scale effect was related to the Ia/Ib ratio and crystalline structure of CNCs.
BibTeX:
@article{Pakzad2011,
  author = {Pakzad, Anahita and Simonsen, John and Heiden, Patricia A. and Yassar, Reza S.},
  title = {Size effects on the nanomechanical properties of cellulose I nanocrystals},
  journal = {Journal of Materials Research},
  year = {2011},
  volume = {27},
  number = {03},
  pages = {528--536},
  url = {http://www.journals.cambridge.org/abstractS0884291411002883},
  doi = {10.1557/jmr.2011.288}
}
Pakzad A, Simonsen J and Yassar RS (2012), "Elastic properties of thin poly(vinyl alcohol)–cellulose nanocrystal membranes", Nanotechnology., March, 2012. Vol. 23(8), pp. 85706.
Abstract: In spite of extensive studies on the preparation and characterization of nanocomposite materials, the correlation of their properties at the nanoscale with those in bulk is a relatively unexplored area. This is of great importance, especially for materials with potential biomedical applications, where surface properties are as important in determining their applicability as bulk characteristics. In this study, the nanomechanical characteristics of thin poly(vinyl alcohol) (PVOH)–poly(acrylic acid) (PAA)–cellulose nanocrystal (CNC) membranes were studied using the nanoindentation module in an atomic force microscope (AFM) and the properties were compared with the macro-scale properties obtained by tensile tests. In general, the elastic properties measured by nanoindentation followed the same trend as macro-scale tensile tests except for the PVOH 85-PAA 0-CNC 15 sample. In comparison to the macro-scale elastic properties, the measured elastic moduli with AFM were higher. Macro-scale tensile test results indicated that, in the presence of PAA, incorporation of CNCs up to 20 wt% improved the elastic modulus of PVOH, but when no PAA was added, increasing the CNC content above 10 wt% resulted in their agglomeration and degradation in mechanical properties of PVOH. The discrepancy between macro-scale tensile tests and nanoindentation in the PVOH 85-PAA 0-CNC 15 sample was correlated to the high degree of inhomogeneity of CNC dispersion in the matrix. It was found that the composites reinforced with cellulose nanocrystals had smaller indentation imprints and the pile-up effect increased with the increase of cellulose nanocrystal content.
BibTeX:
@article{pakzad_elastic_2012,
  author = {Pakzad, A. and Simonsen, J. and Yassar, R. S.},
  title = {Elastic properties of thin poly(vinyl alcohol)–cellulose nanocrystal membranes},
  journal = {Nanotechnology},
  year = {2012},
  volume = {23},
  number = {8},
  pages = {85706},
  url = {http://stacks.iop.org/0957-4484/23/i=8/a=085706?key=crossref.4818b2df84e14538a84b08adfdda0496 http://www.ncbi.nlm.nih.gov/pubmed/22293708},
  doi = {10.1088/0957-4484/23/8/085706}
}
Pakzad A, Simonsen J and Yassar RS (2012), "Gradient of nanomechanical properties in the interphase of cellulose nanocrystal composites", Composites Science and Technology., January, 2012. Vol. 72(2), pp. 314-319.
BibTeX:
@article{Pakzad2012,
  author = {Pakzad, Anahita and Simonsen, John and Yassar, Reza S.},
  title = {Gradient of nanomechanical properties in the interphase of cellulose nanocrystal composites},
  journal = {Composites Science and Technology},
  year = {2012},
  volume = {72},
  number = {2},
  pages = {314--319},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S026635381100412X},
  doi = {10.1016/j.compscitech.2011.11.020}
}
Pan T and Wang Z (2012), "Investigation of coating delamination on steels by surface topography and Volta potential difference", Journal of Solid State Electrochemistry., December, 2012. Vol. 17(4), pp. 1109-1115.
Abstract: Corrosion-induced delamination of an epoxy coating on the AISI/SAE 1045 carbon steel was studied under a humid atmospheric condition (temperature of 25 °C, one standard atmospheric pressure, and relative humidity of 90 by the technique of scanning Kelvin probe force microscopy (SKPFM). Surface-polished 1045 samples were first cold coated with the epoxy and then subject to the atmospheric corrosion under the humid atmospheric condition. At specified time intervals, surface Volta potential of the samples was measured using the SKPFM over the dry surface of epoxy coating. The map of Volta potentials demonstrated high contrasts among three characteristic zones: intact steel-epoxy interface, delaminated interface, and interface with active corrosion, which based on a rigorous calibration procedure were then linked to the actual corrosion potential of the steel (measured using a potentiostat w.r.t. a saturated calomel electrode). The SKPFM was found to be able to provide a mean of direct and nondestructive detection of early active corrosion and coating delamination of steels at a submicroscopic resolution, which outperformed the conventional electrochemical techniques for such purposes.
BibTeX:
@article{pan_investigation_2012,
  author = {Pan, Tongyan and Wang, Zhaoyang},
  title = {Investigation of coating delamination on steels by surface topography and Volta potential difference},
  journal = {Journal of Solid State Electrochemistry},
  year = {2012},
  volume = {17},
  number = {4},
  pages = {1109--1115},
  url = {http://link.springer.com/10.1007/s10008-012-1972-4},
  doi = {10.1007/s10008-012-1972-4}
}
Panaitescu D, Ciuprina F, Iorga M, Frone A, Radovici C, Ghiurea M, Sever S and Plesa I (2011), "Effects of SiO2 and Al2O3 nanofillers on polyethylene properties", Journal of Applied Polymer Science. Vol. 122(3), pp. 1921-1935. Wiley Subscription Services, Inc., A Wiley Company.
Abstract: Polymers filled with inorganic nanoparticles have become interesting materials as dielectrics because of their improved mechanical and electrical properties compared with the unfilled polymers and with polymer microcomposites. These improvements are mainly due to the large surface area of nanoparticles and new polymer–nanofiller interface characteristics. In the present work, polyethylene nanocomposites with SiO2 and Al2O3 nanoparticles were prepared by melt mixing. Mechanical and electrical properties of these composites were determined and morphological aspects were revealed by scanning electron microscopy, wide-angle X-ray diffraction, and atomic force microscopy. The effect of nanostructure and the importance of nanofiller dispersion were analyzed in connection with mechanical and electrical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
BibTeX:
@article{Panaitescu2011,
  author = {Panaitescu, Denis and Ciuprina, Florin and Iorga, Michaela and Frone, Adriana and Radovici, Constantin and Ghiurea, Marius and Sever, Serban and Plesa, Ilona},
  title = {Effects of SiO2 and Al2O3 nanofillers on polyethylene properties},
  journal = {Journal of Applied Polymer Science},
  publisher = {Wiley Subscription Services, Inc., A Wiley Company},
  year = {2011},
  volume = {122},
  number = {3},
  pages = {1921--1935},
  url = {http://dx.doi.org/10.1002/app.34297},
  doi = {10.1002/app.34297}
}
Panaitescu DM, Frone AN and Nicolae C (2013), "Micro- and nano-mechanical characterization of polyamide 11 and its composites containing cellulose nanofibers", European Polymer Journal.
Abstract: Nanocomposites from polyamide 11 and dried cellulose nanofibers (CNs), 16 - 30 nm in thickness and 50 - 400 nm in length, were prepared via direct melt mixing and their micro- and nano-mechanical properties were studied. (PF) QNM (Quantitative Nanomechanical Mapping) method was used to map nanomechanical properties at the surface of polyamide 11 and nanocomposites. This new AFM method emphasized both the increased modulus in nanocomposites as compared to the matrix and the microstructure on different levels in polyamide 11 and its nanocomposites. PF QNM showed that their crystalline structure consists of bundles of lamellar stacks, 200 – 350 nm in width and 20 - 40 nm wide lamellar stacks. Moreover, PF QNM study emphasized higher structural order in nanocomposites with 3 and 5 wt% CNs and lower in the nanocomposite with 8 wt% CNs as compared to the reference. These observations were verified and are consistent with both crystallinity values determined by DSC and micro-mechanical test results. The oriented bundles of lamellar stacks, observed by PF QNM, could be considered as the main blocks determining high mechanical properties for the studied nanomaterials.
BibTeX:
@article{Panaitescu2013,
  author = {Panaitescu, Denis Mihaela and Frone, Adriana Nicoleta and Nicolae, Cristian},
  title = {Micro- and nano-mechanical characterization of polyamide 11 and its composites containing cellulose nanofibers},
  journal = {European Polymer Journal},
  year = {2013},
  url = {http://www.sciencedirect.com/science/article/pii/S0014305713004916}
}
Panaitescu DM, Vuluga Z, Notingher PV and Nicolae C (2013), "The effect of poly[styrene- b -(ethylene- co -butylene)- b -styrene] on dielectric, thermal, and morphological characteristics of polypropylene/silica nanocomposites", Polymer Engineering & Science.
Abstract: The effect of poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) copolymer on the thermal and dielectric properties of polypropylene (PP)—nanosilica (NS) composites in relation with morphological aspects revealed by atomic force microscopy (AFM) was investigated in this article. SEBS hindered the crystallization process of PP in PP/NS composites, leading to a smaller degree of crystallinity and lower perfection of crystalline structure. Broader lamellar thickness distribution was obtained in nanocomposites containing SEBS. Almost two times higher dielectric loss as compared to PP reference and two relaxation processes were detected in $math image(f) curves of nanocomposites. The first peak, in the same frequency domain as for the references, was assigned to $-relaxation of polymer components together with interfacial polarization. The relaxation time follows the Arrhenius law with an activation energy of 80–90 kJ/mol. For the second process, the temperature dependence of the relaxation times obeyed the VFT equation. The dielectric changes following the incorporation of SEBS support its tendency to hinder the motional processes in PP, in accordance with DSC results. A smooth transition from a phase rich in SEBS to one containing mainly PP was detected in the AFM image of the composite with the larger amount of SEBS, emphasizing the good compatibility at the PP/SEBS interface.
BibTeX:
@article{panaitescu_effect_2013-1,
  author = {Panaitescu, Denis Mihaela and Vuluga, Zina and Notingher, Petru V and Nicolae, Cristian},
  title = {The effect of poly[styrene- b -(ethylene- co -butylene)- b -styrene] on dielectric, thermal, and morphological characteristics of polypropylene/silica nanocomposites},
  journal = {Polymer Engineering & Science},
  year = {2013},
  url = {http://doi.wiley.com/10.1002/pen.23475},
  doi = {10.1002/pen.23475}
}
Panaitescu DM, Vuluga Z, Radovici C and Nicolae C (2012), "Morphological investigation of PP/nanosilica composites containing SEBS", Polymer Testing., April, 2012. Vol. 31(2), pp. 355-365.
Abstract: The effect of styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) on the mechanical, thermal and morphological properties of polypropylene (PP) composites filled with nanosilica particles is investigated. A simultaneous increase of all tensile characteristics is observed in PP/nanosilica composites without SEBS and containing 5%SEBS and a large plastic deformation in the nanocomposite with 10 Different amounts of $-PP are detected by X-ray diffraction analysis and the calculated K-values correlate well with differential scanning calorimetry results. Quantitative mechanical characterization of nanocomposites is performed at nanolevel, using peak force QNM. This AFM technique allows the detection of nanosilica particles and SEBS domains at the surface of samples and gives indications of local interactions between nanosilica and the matrix from the correlation of modulus and adhesion maps, and the increased local values of elastic modulus on extended areas around nanoparticles.
BibTeX:
@article{panaitescu_morphological_2012,
  author = {Panaitescu, Denis Mihaela and Vuluga, Zina and Radovici, Constantin and Nicolae, Cristian},
  title = {Morphological investigation of PP/nanosilica composites containing SEBS},
  journal = {Polymer Testing},
  year = {2012},
  volume = {31},
  number = {2},
  pages = {355--365},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0142941811002145},
  doi = {10.1016/j.polymertesting.2011.12.010}
}
Parinaz S, Richard A, Tam KC, Akhlaghi SP and Berry RC (2013), "Surface modification of cellulose nanocrystal with chitosan oligosaccharide for drug delivery applications", Cellulose., May, 2013. Vol. 20(4), pp. 1747-64.
Abstract: A novel drug delivery system based on two of the most abundant natural biopolymers was developed by modifying the surface of oxidized cellulose nanocrystal (CNC) with chitosan oligosac- charide (CSOS). First, the primary alcohol moieties of CNC were selectively oxidized to carboxyl groups using the 2,2,6,6-tetramethylpiperidine-1-oxyl radical catalyst. The amino groups of CSOS were then reacted with carboxylic acid groups on oxidized CNC (CNC- OX) via the carbodiimide reaction using N-hydroxy- succinimide and 1-ethyl-3-(3-dimethylaminopropyl)- carbodiimide as coupling agents. Successful grafting of CSOS to CNC-OX was confirmed by infrared spectroscopy, thermogravimetry, potentiometric titra- tion, and zeta potential measurements. The grafting resulted in a conversion of*90 %carboxyl groups on CNC-OX and the degree of substitution was 0.26. CNC–CSOS nanoparticles showed a binding efficiency of 21.5 % and a drug loading of 14 % w/w. A drug selective electrode was used to directly measure the concentration of procaine hydrochloride released from CNC–CSOS particles. The in vitro drug release was studied at pH 8 and the nanoparticles revealed a fast release of up to 1 h, which can be used as biocompat- ible and biodegradable drug carriers for transdermal delivery applications.
BibTeX:
@article{Akhlaghi2013,
  author = {Parinaz, Seyedeh and Richard, Akhlaghi and Tam, Kam C. and Akhlaghi, Seyedeh Parinaz and Berry, Richard C.},
  title = {Surface modification of cellulose nanocrystal with chitosan oligosaccharide for drug delivery applications},
  journal = {Cellulose},
  year = {2013},
  volume = {20},
  number = {4},
  pages = {1747--64},
  url = {http://link.springer.com/10.1007/s10570-013-9954-y},
  doi = {10.1007/s10570-013-9954-y}
}
Passeri D, Rossi M, Tamburri E and Terranova ML (2013), "Mechanical characterization of polymeric thin films by atomic force microscopy based techniques", Analytical and Bioanalytical Chemistry., February, 2013. Vol. 405(5), pp. 1463-78.
Abstract: Polymeric thin films have been awakening continuous and growing interest for application in nanotechnology. For such applications, the assessment of their (nano)mechanical properties is a key issue, since they may dramatically vary between the bulk and the thin film state, even for the same polymer. Therefore, techniques are required for the in situ characterization of mechanical properties of thin films that must be nondestructive or only minimally destructive. Also, they must also be able to probe nanometer-thick ultrathin films and layers and capable of imaging the mechanical properties of the sample with nanometer lateral resolution, since, for instance, at these scales blends or copolymers are not uniform, their phases being separated. Atomic force microscopy (AFM) has been proposed as a tool for the development of a number of techniques that match such requirements. In this review, we describe the state of the art of the main AFM-based methods for qualitative and quantitative single-point measurements and imaging of mechanical properties of polymeric thin films, illustrating their specific merits and limitations.
BibTeX:
@article{Passeri2013,
  author = {Passeri, Daniele and Rossi, Marco and Tamburri, Emanuela and Terranova, Maria Letizia},
  title = {Mechanical characterization of polymeric thin films by atomic force microscopy based techniques},
  journal = {Analytical and Bioanalytical Chemistry},
  year = {2013},
  volume = {405},
  number = {5},
  pages = {1463--78},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23052864 http://www.springerlink.com/content/k686q1r435766654/},
  doi = {10.1007/s00216-012-6419-3}
}
Peng F, Wang Y, Sun L, Liu Y, Hu T, Zhang G, Ma G and Su Z (2012), "PEGylation of Proteins in Organic Solution: A Case Study for Interferon beta-1b", Bioconjugate Chemistry., September, 2012. Vol. 23(9), pp. 1812-1820.
Abstract: Conventional protein PEGylation is carried out in aqueous solution. However, some hydrophobic proteins seem to be stable in organic solution. In this study, a novel approach of PEGylating IFN-$-1b in an organic solution of 2-butanol (2-BuOH) was investigated. Compared with protein PEGylation in aqueous solution, the overall modification yields increased more than 37 while the yield of mono-PEGylated products could be increased by 36 Furthermore, the PEGylated IFN-$-1b, which was obtained in organic solution, demonstrated 18% more antiviral potency than those derived from aqueous solution. The PEGylation step could be directly connected to the previous protein separation step for process integration. Dynamic light scattering (DLS) and atomic force microscope (AFM) analysis revealed that IFN-$-1b formed aggregates both in water and in 2-BuOH solutions. However, the aggregates were much smaller and more homogeneous in 2-BuOH than those in aqueous solution, thereby providing larger solvent accessible protein surfaces, which resulted in a more productive PEGylation process. In addition, the results of circular dichroism (CD), fluorescence spectra, and peptide mapping suggested that the increased bioactivity came from the difference in PEGylation site distribution due to solution environment that induced conformational discrepancy. The results of this study show that PEGylation of IFN-$-1b in organic solution is a facile and efficient process, which might find applications for other hydrophobic proteins.
BibTeX:
@article{peng_pegylation_2012,
  author = {Peng, Fei and Wang, Yinjue and Sun, Lijing and Liu, Yongdong and Hu, Tao and Zhang, Guifeng and Ma, Guanghui and Su, Zhiguo},
  title = {PEGylation of Proteins in Organic Solution: A Case Study for Interferon beta-1b},
  journal = {Bioconjugate Chemistry},
  year = {2012},
  volume = {23},
  number = {9},
  pages = {1812--1820},
  url = {http://pubs.acs.org/doi/abs/10.1021/bc300081f},
  doi = {10.1021/bc300081f}
}
Peng Z and Wang M (2013), "Three dimensional surface characterization of human cartilages at a micron and nanometre scale", Wear., April, 2013. Vol. 301(1-2), pp. 210-217. Elsevier.
BibTeX:
@article{Peng2013,
  author = {Peng, Zhongxiao and Wang, Meiling},
  title = {Three dimensional surface characterization of human cartilages at a micron and nanometre scale},
  journal = {Wear},
  publisher = {Elsevier},
  year = {2013},
  volume = {301},
  number = {1-2},
  pages = {210--217},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0043164812003997},
  doi = {10.1016/j.wear.2012.11.056}
}
Peng Z and Wang M (2012), "Three dimensional surface characterization of human cartilages at a micron and nanometre scale", Wear., December, 2012. Vol. null(null)
Abstract: As reported, the pathological changes of osteoarthritis (OA), caused by wear in knee joints, initiate at a nanometre scale. However, very limited study has been done using quantitative techniques to study comprehensive surface morphology information of worn cartilages in three dimensions (3D) and at a nanometre scale. The aim of the study was to develop a technique for numerically characterizing the surface topographies of human cartilages and their changes in the wear process. Clinically collected healthy and osteoarthritic cartilage samples were prepared and then imaged using atomic force microscopy. Both conventional numerical parameters and a group of recently advanced feature parameters were used to characterize and compare dominant topographical features of the healthy and worn cartilage surfaces. 3D measurements of the samples were also conducted at a micrometre scale to compare differences in the surface features revealed at the nano- and micro-metre scale. This study has revealed that early surface alterations can be detected at the nanometre scale, while the micrometre scale surface characterizations provide more comprehensive surface evolution information from the healthy to severe OA condition. The work has also demonstrated a new approach to reveal the surface functional information which cannot be characterized using the conventional surface parameters. The quantitative surface characterization results may be utilised to develop an objective OA assessment method for clinical application and assist in tissue generation process.
BibTeX:
@article{Peng2012,
  author = {Peng, Z. and Wang, M.},
  title = {Three dimensional surface characterization of human cartilages at a micron and nanometre scale},
  journal = {Wear},
  year = {2012},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.wear.2012.11.056},
  doi = {10.1016/j.wear.2012.11.056}
}
Perrin FX, Panaitescu DM, Frone AN, Radovici C, Nicolae C, Xavier F, Mihaela D and Nicoleta A (2013), "The influence of alkyl substituents of POSS in polyethylene nanocomposites", Polymer., April, 2013. Vol. 54(9), pp. 2347-2354. Elsevier Ltd.
Abstract: The influence of the alkyl substituent of POSS containing Q8 cage in polyethylene (PE) – POSS nanohybrids was investigated in this paper. Octakis(dimethylsiloxy)octasilsesquioxanes bearing linear and branched alkyl substituents, chain length varying between C3 and C8 for the straight-chain derivatives and between C5 and C7 for the branched-ones have been prepared for this purpose. XRD analysis showed that POSS coalesced in amorphous aggregates even if the pristine POSS was crystalline and the amount of these aggregates decreases with the increased length of the alkyl substituent. Peak force QNM mode of AFM revealed the presence of high modulus poor-POSS-domains and low modulus rich-POSS-domains whose size was around 140 nm for the octapropyl substituted POSS composite and vary in the range 50–90 nm for the composites with longer alkyl substituents on POSS. Although improved compatibility and dispersion was highlighted for POSS with long alkyl substituents, short length linear alkyl substituents (e.g. propyl) for POSS are preferred for improvements in tensile strength and thermal stability
BibTeX:
@article{perrin_influence_2013,
  author = {Perrin, Francois Xavier and Panaitescu, Denis Mihaela and Frone, Adriana Nicoleta and Radovici, Constantin and Nicolae, Cristian and Xavier, Francois and Mihaela, Denis and Nicoleta, Adriana},
  title = {The influence of alkyl substituents of POSS in polyethylene nanocomposites},
  journal = {Polymer},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {54},
  number = {9},
  pages = {2347--2354},
  url = {http://dx.doi.org/10.1016/j.polymer.2013.02.035 http://linkinghub.elsevier.com/retrieve/pii/S0032386113001699},
  doi = {10.1016/j.polymer.2013.02.035}
}
Perry CC, Tang VJ, Konigsfeld KM, Aguilera JA and Milligan JR (2011), "Use of a Coumarin Labeled Hexa-Arginine Peptide as a Fluorescent Hydroxyl Radical Probe in a Nanoparticulate Plasmid DNA Condensate", The Journal of Physical Chemistry B. Vol. 115(32), pp. 9889-9897.
Abstract: Coumarin derivatives have found application as probes for the hydroxyl radical because one of the products of the reaction between them is a highly fluorescent umbelliferone. We have examined the interaction in aqueous solution between a cationic coumarin-labeled hexa-arginine peptide ligand and plasmid DNA, and compared after gamma irradiation the yields of products derived from both of them. At low ionic strengths, the ligand binds very tightly to the plasmid. Compared with the structurally similar 4-methylumbelliferone (phenolic pK(a) = 7.8), the fluorescent product derived from gamma irradiation of the coumarin labeled cationic peptide is significantly more acidic (pK(a) = 6.1), making it a very convenient probe for solutions of pH in the physiological range. The yield of this product is generally in excellent agreement over a wide range of conditions with that of the single strand break product produced by the reaction of the hydroxyl radical with the plasmid. Thus coumarin-labeled peptide ligands offer promise as hydroxyl radical probes for locations in close proximity to DNA.
BibTeX:
@article{Perry2011,
  author = {Perry, C. C. and Tang, V. J. and Konigsfeld, K. M. and Aguilera, J. A. and Milligan, J. R.},
  title = {Use of a Coumarin Labeled Hexa-Arginine Peptide as a Fluorescent Hydroxyl Radical Probe in a Nanoparticulate Plasmid DNA Condensate},
  journal = {The Journal of Physical Chemistry B},
  year = {2011},
  volume = {115},
  number = {32},
  pages = {9889--9897},
  url = {http://pubs.acs.org/doi/abs/10.1021/jp205198b},
  doi = {10.1021/jp205198b}
}
Perry CC, Urata SM, Lee M, Aguilera JA and Milligan JR (2012), "Radioprotective effects produced by the condensation of plasmid DNA with avidin and biotinylated gold nanoparticles", Radiation and Environmental Biophysics., July, 2012. Vol. 51(4), pp. 457-468.
BibTeX:
@article{perry_radioprotective_2012,
  author = {Perry, Christopher C and Urata, Sarah M and Lee, Melissa and Aguilera, Joe A and Milligan, Jamie R},
  title = {Radioprotective effects produced by the condensation of plasmid DNA with avidin and biotinylated gold nanoparticles},
  journal = {Radiation and Environmental Biophysics},
  year = {2012},
  volume = {51},
  number = {4},
  pages = {457--468},
  url = {http://link.springer.com/10.1007/s00411-012-0429-6},
  doi = {10.1007/s00411-012-0429-6}
}
Petrović ZS, Hong D, Javni I, Erina N, Zhang F and Ilavský J (2013), "Phase structure in segmented polyurethanes having fatty acid-based soft segments", Polymer., January, 2013. Vol. 54(1), pp. 372-380.
Abstract: Structural studies on two segmented polyurethanes prepared from modified oleic acid soft segments and butane diol/diphenylmethane diisocyanate hard segments, were performed. Polyurethanes were thermoplastic elastomers with 50% and 70% soft segment concentration (SSC) for TPU-50 and TPU-70, respectively. DMA revealed the co-continuous morphology in TPU-50 and dispersed hard domains in the soft matrix in TPU-70. AFM showed micron size globules in TPU-70 ascribed to hard segment-rich superstructures. Alternating small soft and hard domains were present in TPU-50, with ∼15 nm lateral dimensions and local modulus deviations from 40 to 50 MPa, consistent with co-continuous morphology. The dispersed hard domains in the soft matrix of TPU-70, and co-continuous phases in TPU-50 morphology was confirmed. USAXS showed the domain spacing of TPU-50 was about 13.3 nm. TPU-70 demonstrated domain spacing of about 11.3 nm. USAXS revealed that the interface between phase-separated domains exhibited surface-fractal-like behavior.
BibTeX:
@article{Petrovic2012,
  author = {Petrović, Zoran S. and Hong, DooPyo and Javni, Ivan and Erina, Natalia and Zhang, Fan and Ilavský, Jan},
  title = {Phase structure in segmented polyurethanes having fatty acid-based soft segments},
  journal = {Polymer},
  year = {2013},
  volume = {54},
  number = {1},
  pages = {372--380},
  url = {http://dx.doi.org/10.1016/j.polymer.2012.10.019 http://linkinghub.elsevier.com/retrieve/pii/S0032386112008750},
  doi = {10.1016/j.polymer.2012.10.019}
}
Pettersen S (2013), "Cross-linking oxidized cellulose nanofibrils for the formation of stable hydrogel structures". Thesis at: Norwegian University of Science and Technology. (June)
Abstract: The main goal of this project was to investigate whether the elastic properties of microfibrillated cellulose (MFC) suspensions pre-treated by TEMPO-mediated oxidation could be controlled by inducing crosslinks between the nanofibrils with short diamines. Using conductometric titration, the total carboxylate and aldehyde content in the MFC was measured as 0.810 mmol/g MFC and 0.181 mmol/g MFC, respectively. The viscoelastic properties of the MFC were investigated by dynamic measurements. The MFC showed a viscoelastic response for strains approximately < 0.04, and gel-like behavior (G’ > G’’, $ constant and < 45°) for frequencies from 0.01 – 10 Hz. The storage modulus for 0.80% MFC was approximately 125 Pa, and the storage modulus showed a power law dependence on concentration with a power of approximately three. Viscosity measurements showed that the MFC exhibited pseudoplastic (shear-thinning) behavior. The viscosity did not follow the Cox- Merz rule, with the dynamic viscosity being approximately ten times higher than the stead state viscosit hen $ Upon addition of hexamethylenediamine (HMDA) without heating the sample, both viscosity and storage modulus decreased. When the temperature was increased to 80° C, the storage modulus increased rapidly to a plateau of approximately 1375 Pa in a sample with 0.80% MFC and 3.05 mmol HMDA/g MFC. Small, cylindrical gels were successfully cast at a concentration of 0.80% MFC with different concentrations of HMDA and ethylenediamine (EDA) at 80° C Young’s modulus as measured by longitudinal compression, and correlated well with increasing crosslinker concentrations before reaching plateau values at approximately thirty times more amine than aldehyde. The gels with HMDA were almost twice as strong as the gels with EDA Young’s modulus as largest (approximately 3220 Pa) at HMDA concentrations of 3.05 mmol/g MFC. There was a clear color change from the grey color of the regular MFC to a yellow-brown color, correlating with both crosslinker concentration and measured Young’s modulus. When the non-toxic reduction agent 2-picoline-borane was added to the gels prior to casting, no color change was visible, but the gels reached almost equal Young’s moduli Some of the cast gels were freeze-dried, and revealed a sheet-like pore structure under scanning electron microscope (SEM) imaging. The freeze dried gels showed water absorption values of approximately 8000% for pure MFC gels and 4000% for gels with HMDA. Films were also prepared with only MFC and with concentrations of crosslinkers equal to those in the cast gels. These were imaged with laser profilometry (LP) and atomic force microscopy (AFM), and the images were analyzed for a correlation between surface roughness and crosslinker concentration. No significant correlation was observed in the AFM images, but the LP images showed a higher surface roughness at the highest crosslinker concentrations.
BibTeX:
@phdthesis{Pettersen2013,
  author = {Pettersen, SR},
  title = {Cross-linking oxidized cellulose nanofibrils for the formation of stable hydrogel structures},
  school = {Norwegian University of Science and Technology},
  year = {2013},
  number = {June},
  url = {http://www.diva-portal.org/smash/record.jsf?pid=diva2:649692}
}
Picas L, Milhiet P-E and Hernández-Borrell J (2012), "Atomic Force Microscopy: a versatile tool to probe the physical and chemical properties of supported membranes at the nanoscale.", Chemistry and Physics of Lipids., November, 2012. Vol. null(null)
Abstract: Atomic force microscopy (AFM) was developed in the 1980's following the invention of its precursor, scanning tunneling microscopy (STM), earlier in the decade. Several modes of operation have evolved, demonstrating the extreme versatility of this method for measuring the physicochemical properties of samples at the nanoscopic scale. AFM has proved an invaluable technique for visualizing the topographic characteristics of phospholipid monolayers and bilayers, such as roughness, height or laterally segregated domains. Implemented modes such as phase imaging have also provided criteria for discriminating the viscoelastic properties of different supported lipid bilayer (SLB) regions. In this review, we focus on the AFM force spectroscopy (FS) mode, which enables determination of the nanomechanical properties of membrane models. The interpretation of force curves is presented, together with newly emerging techniques that provide complementary information on physicochemical properties that may contribute to our understanding of the structure and function of biomembranes. Since AFM is an imaging technique, some basic indications on how real-time AFM imaging is evolving are also presented at the end of this paper.
BibTeX:
@article{Picas2012,
  author = {Picas, Laura and Milhiet, Pierre-Emmanuel and Hernández-Borrell, J},
  title = {Atomic Force Microscopy: a versatile tool to probe the physical and chemical properties of supported membranes at the nanoscale.},
  journal = {Chemistry and Physics of Lipids},
  year = {2012},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.chemphyslip.2012.10.005},
  doi = {10.1016/j.chemphyslip.2012.10.005}
}
Picas L, Rico F and Scheuring S (2012), "Direct Measurement of the Mechanical Properties of Lipid Phases in Supported Bilayers", Biophysical Journal., January, 2012. Vol. 102(1), pp. L01-L03.
Abstract: Biological membranes define not only the cell boundaries but any compartment within the cell. To some extent, the functionality of membranes is related to the elastic properties of the lipid bilayer and the mechanical and hydrophobic matching with functional membrane proteins. Supported lipid bilayers (SLBs) are valid biomimetic systems for the study of membrane biophysical properties. Here, we acquired high-resolution topographic and quantitative mechanics data of phase-separated SLBs using a recent atomic force microscopy (AFM) imaging mode based on force measurements. This technique allows us to quantitatively map at high resolution the mechanical differences of lipid phases at different loading forces. We have applied this approach to evaluate the contribution of the underlying hard support in the determination of the elastic properties of SLBs and to determine the adequate indentation range for obtaining reliable elastic moduli values. At ∼200 pN, elastic forces dominated the force-indentation response and the sample deformation was <20% of the bilayer thickness, at which the contribution of the support was found to be negligible. The obtained Young's modulus (E) of 19.3 MPa and 28.1 MPa allowed us to estimate the area stretch modulus (kA) as 106 pN/nm and 199 pN/nm and the bending stiffness (kc) as 18 kBT and 57 kBT for the liquid and gel phases, respectively.
BibTeX:
@article{picas_direct_2012,
  author = {Picas, Laura and Rico, Felix and Scheuring, Simon},
  title = {Direct Measurement of the Mechanical Properties of Lipid Phases in Supported Bilayers},
  journal = {Biophysical Journal},
  year = {2012},
  volume = {102},
  number = {1},
  pages = {L01--L03},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0006349511053525},
  doi = {10.1016/j.bpj.2011.11.4001}
}
Picas L, Rico FF, Deforet M and Scheuring S (2013), "Structural and mechanical heterogeneity of the erythrocyte membrane reveals hallmarks of membrane stability", ACS nano., February, 2013. Vol. 7(2), pp. 1054-63. American Chemical Society.
Abstract: The erythrocyte membrane, a metabolically regulated active structure that comprises lipid molecules, junctional complexes, and the spectrin network, enables the cell to undergo large passive deformations when passing through the microvascular system. Here we use atomic force microscopy (AFM) imaging and quantitative mechanical mapping at nanometer resolution to correlate structure and mechanics of key components of the erythrocyte membrane, crucial for cell integrity and function. Our data reveal structural and mechanical heterogeneity modulated by the metabolic state at unprecedented nanometer resolution. ATP-depletion, reducing skeletal junction phosphorylation in RBC cells, leads to membrane stiffening. Analysis of ghosts and shear-force opened erythrocytes show that, in the absence of cytosolic kinases, spectrin phosphorylation results in membrane stiffening at the extracellular face and a reduced junction remodeling in response to loading forces. Topography and mechanical mapping of single components at the cytoplasmic face reveal that, surprisingly, spectrin phosphorylation by ATP softens individual filaments. Our findings suggest that, besides the mechanical signature of each component, the RBC membrane mechanics is regulated by the metabolic state and the assembly of its structural elements.
BibTeX:
@article{Picas2013,
  author = {Picas, Laura and Rico, Félix Felix and Deforet, Maxime and Scheuring, Simon},
  title = {Structural and mechanical heterogeneity of the erythrocyte membrane reveals hallmarks of membrane stability},
  journal = {ACS nano},
  publisher = {American Chemical Society},
  year = {2013},
  volume = {7},
  number = {2},
  pages = {1054--63},
  url = {http://dx.doi.org/10.1021/nn303824j http://www.ncbi.nlm.nih.gov/pubmed/23347043},
  doi = {10.1021/nn303824j}
}
Ping J, Wang Y, Ying Y and Wu J (2012), "Application of Electrochemically Reduced Graphene Oxide on Screen-Printed Ion-Selective Electrode", Analytical Chemistry., April, 2012. Vol. 84(7), pp. 3473-3479.
Abstract: In this study, a novel disposable all-solid-state ion-selective electrode using graphene as the ion-to-electron transducer was developed. The graphene film was prepared on screen-printed electrode directly from the graphene oxide dispersion by a one-step electrodeposition technique. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to demonstrate the large double layer capacitance and fast charge transfer of the graphene film modified electrode. On the basis of these excellent properties, an all-solid-state calcium ion-selective electrode as the model was constructed using the calcium ion-selective membrane and graphene film modified electrode. The mechanism about the graphene promoting the ion-to-electron transformation was investigated in detail. The disposable electrode exhibited a Nernstian slope (29.1 mV/decade), low detection limit (10–5.8 M), and fast response time (less than 10 s). With the high hydrophobic character of graphene materials, no water film was formed between the ion-selective membrane and the underlying graphene layer. Further studies revealed that the developed electrode was insensitive to light, oxygen, and redox species. The use of the disposable electrode for real sample analysis obtained satisfactory results, which made it a promising alternative in routine sensing applications.
BibTeX:
@article{ping_application_2012,
  author = {Ping, Jianfeng and Wang, Yixian and Ying, Yibin and Wu, Jian},
  title = {Application of Electrochemically Reduced Graphene Oxide on Screen-Printed Ion-Selective Electrode},
  journal = {Analytical Chemistry},
  year = {2012},
  volume = {84},
  number = {7},
  pages = {3473--3479},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/22380625 http://dx.doi.org/10.1021/ac203480z},
  doi = {10.1021/ac203480z}
}
Pitliya P, Singh G, Chapa J, Karim A and Raghavan D (2013), "Dispersion–orientation effects of fulleropyrrolidine in zone annealed block-copolymer films toward optimizing OPV interfaces", Polymer., February, 2013. Vol. 54(4), pp. 1415-1424. Elsevier Ltd.
BibTeX:
@article{Pitliya2013a,
  author = {Pitliya, Praveen and Singh, Gurpreet and Chapa, Jose and Karim, Alamgir and Raghavan, Dharmaraj},
  title = {Dispersion–orientation effects of fulleropyrrolidine in zone annealed block-copolymer films toward optimizing OPV interfaces},
  journal = {Polymer},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {54},
  number = {4},
  pages = {1415--1424},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0032386112011305},
  doi = {10.1016/j.polymer.2012.12.068}
}
Pitliya P, Singh G, Garza J, Karim A and Raghavan D (2013), "Dispersion-Orientation Effects of Fulleropyrrolidine in Zone Annealed Block-Copolymer Filmstowards optimizing OPV interfaces", Polymer., January, 2013. Vol. null(null)
Abstract: Introduction of an insulating polystyrene block (BCP) poly methylmethacrylatecopolymer (PS-b-PMMA) layer between the poly 3,4-poly(ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) and thephotoactive layer (fullerene or functionalized fullerene/ poly-3-hexylthiophene) has been reported to improve solar cell performance. We explore how the morphological structure of this ordered interfacial BCP layer may be modified with novel synthesized electron accepting fulleropyrrolidine nanoparticles (f-NP), processed via a novel dynamic zone-annealing (ZA) method. N-methyl-2-(4-nitro phenyl) fulleropyrrolidine and N-methyl-2-(4-cyano phenyl) fulleropyrrolidine were synthesized by 1,3-dipolar cycloaddition of azomethineylides to fullerene and characterized by 1H NMR, 13C NMR, MALDI-TOFMS, cyclic voltammetry, and thermogravimetry. The newly synthesized f-NP’s exhibited higher thermal stability and equivalent electronic properties compared to conventionally used [6,6]-phenyl-C 61 -butyric acid methyl ester(PCBM) for photoactive layer. f-NP filled PS-b-PMMA thin films processed using uniform oven annealing promoted phase segregation driven aggregation of f-NP located at the defect junction points of the block copolymer films. In contrast, ZA of f-NP filled BCP films led to the homogeneous dispersion of f-NPs within the films, however the f-NP had a synergistic orientation effect on BCP films, switching PMMA cylinders from vertical to parallel orientation in the ZA films. This effect is presumably due to a lowering of thermal conductivity of the BCP film by nanoparticles that scatter the phonons thereby decreasing the mean free path length of phonon propagation. These results may be important for the self-assembly of thermally stable and interfacially insulating BCP films for improved solar cell devices.
BibTeX:
@article{Pitliya2013,
  author = {Pitliya, P. and Singh, G. and Garza, J.C. and Karim, A. and Raghavan, D.},
  title = {Dispersion-Orientation Effects of Fulleropyrrolidine in Zone Annealed Block-Copolymer Filmstowards optimizing OPV interfaces},
  journal = {Polymer},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.polymer.2012.12.068},
  doi = {10.1016/j.polymer.2012.12.068}
}
Pittenger B, Erina N and Su C (2014), "Mechanical Property Mapping at the Nanoscale Using PeakForce QNM Scanning Probe Technique", In Nanomechanical Analysis of High Performance Materials. Dordrecht Vol. 203(203), pp. 31-51. Springer Netherlands.
Abstract: Development of PeakForce QNM® a new, powerful scanning probe microscopy (SPM) method for high resolution, nanoscale quantitative mapping of mechanical properties is described. Material properties such as elastic modulus, dissipation, adhesion, and deformation are mapped simultaneously with topography at real imaging speeds with nanoscale resolution. PeakForce QNM has several distinct advantages over other SPM based methods for nanomechanical characterization including ease of use, unambiguous and quantitative material information, non-destructive to both tip and sample, and fast acquisition times. This chapter discusses the theory and operating principles of PeakForce QNM and applications to measure mechanical properties of a variety of materials ranging from polymer blends and films to single crystals and even cement paste.
BibTeX:
@incollection{Pittenger2014,
  author = {Pittenger, Bede and Erina, Natalia and Su, Chanmin},
  editor = {Tiwari, Atul},
  title = {Mechanical Property Mapping at the Nanoscale Using PeakForce QNM Scanning Probe Technique},
  booktitle = {Nanomechanical Analysis of High Performance Materials},
  publisher = {Springer Netherlands},
  year = {2014},
  volume = {203},
  number = {203},
  pages = {31--51},
  edition = {203},
  url = {http://link.springer.com/10.1007/978-94-007-6919-9},
  doi = {10.1007/978-94-007-6919-9}
}
Pittenger B and Slade A (2013), "Performing Quantitative Nanomechanical AFM Measurements on Live Cells", Microscopy Today., November, 2013. Vol. 21(06), pp. 12-17.
BibTeX:
@article{Pittenger2013,
  author = {Pittenger, Bede and Slade, Andrea},
  title = {Performing Quantitative Nanomechanical AFM Measurements on Live Cells},
  journal = {Microscopy Today},
  year = {2013},
  volume = {21},
  number = {06},
  pages = {12--17},
  url = {http://www.journals.cambridge.org/abstractS1551929513001077},
  doi = {10.1017/S1551929513001077}
}
Pittenger B, Slade A and Berquand A (2013), "Toward Quantitative Nanomechanical Measurements on Live Cells with PeakForce QNM".
Abstract: Measuring and mapping mechanical properties of live cells is of high importance in today’s biological research. Atomic force microscopy1 has been recognized since the mid-eighties as an excellent technique to image a wide range of samples in their near-natural environment. Although the primary function of atomic force microscopy is to generate a three-dimensional (3D) profile of the scanned surface, much more information is available through the technique. TappingMode™, which was developed in 1993,2 prevents tip and sample damage from friction and shear forces, and allows qualitative mechanical property mapping through phase imaging. Around the same time, force spectroscopy,3 and force volume4 were developed to study tip-sample forces at a point, or over an area respectively. Traditionally, force spectroscopy and force volume are the most commonly used modes to quantitatively measure mechanical forces at the nanometer scale. Unfortunately, both techniques have suffered from slow acquisition speed and a lack of automated tools to analyze the hundreds to thousands of curves required for good statistics.
BibTeX:
@misc{Pittenger2013a,
  author = {Pittenger, Bede and Slade, Andrea and Berquand, Alexandre},
  title = {Toward Quantitative Nanomechanical Measurements on Live Cells with PeakForce QNM},
  booktitle = {Bruker Application Note AN141},
  publisher = {Bruker},
  year = {2013},
  volume = {i},
  pages = {1--10}
}
Pivodov V, Ru F, Franková J, Pivodová V, Růžička F, Tománková K, Safářová K, Vrbková J and Ulrichová J (2013), "Comparing biocompatibility of gingival fibroblasts and bacterial strains on a different modified titanium discs.", Journal of Biomedical Materials Research. Part A., March, 2013. Vol. 101(10), pp. 2915-24.
Abstract: The modification of implant surface situated in the area of peri-implant sulcus has important role in bacterial and cell adhesion. Six different chemically and physically modified titanium discs were prepared: glazed (Tis-MALP), unglazed (Tis-O), unglazed and alkali-etched (Tis-OA), unglazed and coated with ZrN (Tis-OZ), unglazed, sand blasted, and acid etched (Tis-OPAE), and unglazed, sand blasted, acid, and alkali etched (Tis-OPAAE). Analysis of surface topography was determined using scanning electron microscopy and atomic force microscopy (AFM). Biocompatibility of gingival fibroblasts was characterized by the production of tumor necrosis factor alpha, collagen I, matrix metalloproteinase 2 (MMP-2) after 24 and 72 h and expression of $3 $1 integrin and vinculin using enzyme-linked immunosorbent assay (ELISA) or modified ELISA after 6 and 24 h. Microorganism adhesion (five bacterial strains) and biofilm formation was also evaluated. The adhesion of bacteria and gingival fibroblasts was significantly higher on titanium disc Tis-OPAAE and biofilm formation on the same surface for Streptococcus mutans, Streptococcus gordonii, and Streptococcus intermedius. The gingival fibroblasts on Tis-OPAAE disc had also significantly lower production of MMP-2. The collagen production was significantly lower on all surfaces with roughness higher than 0.2 $m. This study confirmed that the titanium disc with the surface roughness 3.39 $m (Tis-OPAAE) supported the adhesion of bacterial strains as well as gingival fibroblasts. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2013.
BibTeX:
@article{Frankova2013,
  author = {Pivodov, Veronika and Ru, Filip and Franková, Jana and Pivodová, Veronika and Růžička, Filip and Tománková, Kateřina and Safářová, Klára and Vrbková, Jana and Ulrichová, Jitka},
  title = {Comparing biocompatibility of gingival fibroblasts and bacterial strains on a different modified titanium discs.},
  journal = {Journal of Biomedical Materials Research. Part A},
  year = {2013},
  volume = {101},
  number = {10},
  pages = {2915--24},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23529774},
  doi = {10.1002/jbm.a.34598}
}
Platzman I, Muth CA, Lee-Thedieck C, Pallarola D, Atanasova R, Louban I, Altrock E and Spatz JP (2013), "Surface properties of nanostructured bio-active interfaces: impacts of surface stiffness and topography on cell–surface interactions", RSC Advances., June, 2013. Vol. 3(32), pp. 13293-303. The Royal Society of Chemistry.
Abstract: Due to their ability to confer key functions of the native extracellular matrix (ECM), poly(ethylene glycol) (PEG)-based and PEG-modified materials have been extensively used as biocompatible and bio- functionalized substrate systems to study the influence of environmental parameters on cell adhesion in vitro. Given wide-ranging recent evidence that ECM compliance influences a variety of cell functions, detailed determination and characterization of the specific PEG surface characteristics including topography, stiffness and chemistry is required. Here, we studied two frequently used bio-active interfaces—PEG-based and PEG-modified surfaces—to elucidate the differences between the physical surface properties, which cells can sense and respond to. For this purpose, two sets of surfaces were synthesized: the first set consisted of nanopatterned glass surfaces containing cRGD-functionalized gold nanoparticles surrounded by a passivated PEG-silane layer and the second set consisted of PEG-diacrylate (PEG-DA) hydrogels decorated with cRGD-functionalized gold nanoparticles. Although the two sets of nanostructured materials compared here were highly similar in terms of density and geometrical distribution of the presented bio-ligands, as well as in terms of mechanical bulk properties, the topography and mechanical properties of the surfaces were found to be substantially different and are described in detail. In comparison to the very stiff and ultra-smooth surface properties of the PEG-passivated glasses, the mechanical properties of PEG-DA surfaces in the biologically relevant stiffness range, together with the increased surface roughness at micro- and nanoscale levels have the potential to affect cell behavior. This potential was verified by studying the adhesive behavior of hematopoietic KG-1a and rat embryonic fibroblast (REF52) cells on both surfaces.
BibTeX:
@article{Platzman2013,
  author = {Platzman, Ilia and Muth, Christine Anna and Lee-Thedieck, Cornelia and Pallarola, Diego and Atanasova, Ralitsa and Louban, Ilia and Altrock, Eva and Spatz, Joachim P.},
  title = {Surface properties of nanostructured bio-active interfaces: impacts of surface stiffness and topography on cell–surface interactions},
  journal = {RSC Advances},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {3},
  number = {32},
  pages = {13293--303},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/ra/c3ra41579a},
  doi = {10.1039/c3ra41579a}
}
Pletikapić G, Berquand A, Radić TM and Svetličić V (2012), "Quantitative Nanomechanical Mapping of Marine Diatom in Seawater Using Peak Force Tapping Atomic Force Microscopy", Journal of Phycology., February, 2012. Vol. 48(1), pp. 174-185. Blackwell Publishing Ltd.
Abstract: It is generally accepted that a diatom cell wall is characterized by a siliceous skeleton covered by an organic envelope essentially composed of polysaccharides and proteins. Understanding of how the organic component is associated with the silica structure provides an important insight into the biomineralization process and patterning on the cellular level. Using a novel atomic force microscopy (AFM) imaging technique (Peak Force Tapping), we characterized nanomechanical properties (elasticity and deformation) of a weakly silicified marine diatom Cylindrotheca closterium (Ehrenb.) Reimann et J. C. Lewin (strain CCNA1). The nanomechanical properties were measured over the entire cell surface in seawater at a resolution that was not achieved previously. The fibulae were the stiffest (200 MPa) and the least deformable (only 1 nm). Girdle band region appeared as a series of parallel stripes characterized by two sets of values of Young’s modulus and deformation: one for silica stripes (43.7 Mpa, 3.7 nm) and the other between the stripes (21.3 MPa, 13.4 nm). The valve region was complex with average values of Young’s modulus (29.8 MPa) and deformation (10.2 nm) with high standard deviations. After acid treatment, we identified 15 nm sized silica spheres in the valve region connecting raphe with the girdle bands. The silica spheres were neither fused together nor forming a nanopattern. A cell wall model is proposed with individual silica nanoparticles incorporated in an organic matrix. Such organization of girdle band and valve regions enables the high flexibility needed for movement and adaptation to different environments while maintaining the integrity of the cell.
BibTeX:
@article{Pletikapic2012,
  author = {Pletikapić, Galja and Berquand, Alexandre and Radić, Tea Mišić and Svetličić, Vesna},
  title = {Quantitative Nanomechanical Mapping of Marine Diatom in Seawater Using Peak Force Tapping Atomic Force Microscopy},
  journal = {Journal of Phycology},
  publisher = {Blackwell Publishing Ltd},
  year = {2012},
  volume = {48},
  number = {1},
  pages = {174--185},
  url = {http://doi.wiley.com/10.1111/j.1529-8817.2011.01093.x},
  doi = {10.1111/j.1529-8817.2011.01093.x}
}
Pu Y, Zhu G-L, Ge B-S, Yu D-Y, Wang Y-P and Qin S (2013), "Photocurrent generation by recombinant allophycocyanin trimer multilayer on TiO2 electrode", Chinese Chemical Letters., January, 2013. Vol. null(null)
Abstract: A recombinant allophycocyanin trimer was successfully immobilized on a mesoporous TiO2 electrode. The formation of the immobilized surface was confirmed by multilayer adsorption of protein complexes. The key biophotovoltaic parameters were obtained, which showed that the recombinant allophycocyanin trimer could be a candidate for photosensitizer materials. The values of short-circuit current, open-circuit voltage, fill factor, and conversion efficiency were up to 0.73 mA/cm2, 0.52 V, 0.69, and 0.26 respectively.
BibTeX:
@article{Pu2013,
  author = {Pu, Yang and Zhu, Guo-Liang and Ge, Bao-Sheng and Yu, Dao-Yong and Wang, Yi-Peng and Qin, Song},
  title = {Photocurrent generation by recombinant allophycocyanin trimer multilayer on TiO2 electrode},
  journal = {Chinese Chemical Letters},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.cclet.2012.12.011},
  doi = {10.1016/j.cclet.2012.12.011}
}
Qiu Y, Pruitt JD, Thekveli SJ, Tucker RC and Nelson J (2012), "SILICONE HYDROGEL LENSES WITH WATER-RICH SURFACES". May, 2012.
Abstract: The invention is related to a hydrated silicone hydrogel contact lens having a layered structural configuration: a low water content silicone hydrogel core (or bulk material) completely covered with a layer of a water-rich (e.g., a water content greater than 80, hydrogel totally or substantially free of silicone. A hydrated silicone hydrogel contact lens of the invention possesses high oxygen permeability for maintaining the corneal health and a soft, water-rich, lubricious surface for wearing comfort.
BibTeX:
@misc{Qiu2012a,
  author = {Qiu, Yongxing and Pruitt, John Dallas and Thekveli, Sibichen J. and Tucker, Robert Carey and Nelson, Jared},
  title = {SILICONE HYDROGEL LENSES WITH WATER-RICH SURFACES},
  booktitle = {WO Patent ldots},
  year = {2012},
  url = {http://www.freepatentsonline.com/y2013/0250234.html http://patentscope.wipo.int/search/en/WO2012016096}
}
Qiu Y, Pruitt JD, Thekveli SJ, Tucker RC and Nelson J (2011), "Silicone hydrogel lenses with water-rich surfaces". July, 2011.
Abstract: The invention is related to a hydrated silicone hydrogel contact lens having a layered structural configuration: a lower water content silicone hydrogel core (or bulk material) completely covered with a layer of a higher water content hydrogel totally or substantially free of silicone. A hydrated silicone hydrogel contact lens of the invention possesses high oxygen permeability for maintaining the corneal health and a soft, water-rich, lubricious surface for wearing comfort.
BibTeX:
@misc{Qiu2012,
  author = {Qiu, Yongxing and Pruitt, John Dallas and Thekveli, Sibichen J. and Tucker, Robert Carey and Nelson, Jared},
  title = {Silicone hydrogel lenses with water-rich surfaces},
  booktitle = {WO Patent WO/2012/016,096},
  year = {2011},
  url = {http://www.freepatentsonline.com/y2012/0026458.html http://www.freepatentsonline.com/8480227.html}
}
Raaijmakers MJT, Hempenius MA, Schön PM, Vancso GJ, Nijmeijer A, Wessling M and Benes NE (2014), "Sieving of Hot Gases by Hyper-Cross-Linked Nanoscale-Hybrid Membranes", Journal of the American Chemical Society., December, 2014. Vol. 136(1), pp. 330-5. American Chemical Society.
Abstract: Macromolecular networks consisting of homogeneously distributed covalently bonded inorganic and organic precursors are anticipated to show remarkable characteristics, distinct from those of the individual constituents. A novel hyper-cross-linked ultrathin membrane is presented, consisting of a giant molecular network of alternating polyhedral oligomeric silsesquioxanes and aromatic imide bridges. The hybrid characteristics of the membrane are manifested in excellent gas separation performance at elevated temperatures, providing a new and key enabling technology for many important industrial scale applications.
BibTeX:
@article{Raaijmakers2013,
  author = {Raaijmakers, Michiel J. T. and Hempenius, Mark A. and Schön, Peter M. and Vancso, G. Julius and Nijmeijer, Arian and Wessling, Matthias and Benes, Nieck E.},
  title = {Sieving of Hot Gases by Hyper-Cross-Linked Nanoscale-Hybrid Membranes},
  journal = {Journal of the American Chemical Society},
  publisher = {American Chemical Society},
  year = {2014},
  volume = {136},
  number = {1},
  pages = {330--5},
  url = {http://pubs.acs.org/doi/abs/10.1021/ja410047u},
  doi = {10.1021/ja410047u}
}
Rahman LN, McKay F, Giuliani M, Quirk A, Moffatt BA, Harauz G and Dutcher JR (2012), "Interactions of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes at cold and ambient temperatures—Surface morphology and single-molecule force measurements show phase separation, and reveal tertiary and quaternary associations", Biochimica et Biophysica Acta (BBA) - Biomembranes., December, 2012. Vol. null(null)
Abstract: Dehydrins (group 2 late embryogenesis abundant proteins) are intrinsically-disordered proteins that are expressed in plants experiencing extreme environmental conditions such as drought or low temperature. Their roles include stabilizing cellular proteins and membranes, and sequestering metal ions. Here, we investigate the membrane interactions of the acidic dehydrin TsDHN-1 and the basic dehydrin TsDHN-2 derived from the crucifer Thellungiella salsuginea that thrives in the Canadian sub-Arctic. We show using compression studies with a Langmuir–Blodgett trough that both dehydrins can stabilize lipid monolayers with a lipid composition mimicking the composition of the plant outer mitochondrial membrane, which had previously been shown to induce ordered secondary structures (disorder-to-order transitions) in the proteins. Ellipsometry of the monolayers during compression showed an increase in monolayer thickness upon introducing TsDHN-1 (acidic) at 4 °C and TsDHN-2 (basic) at room temperature. Atomic force microscopy of supported lipid bilayers showed temperature-dependent phase transitions and domain formation induced by the proteins. These results support the conjecture that acidic dehydrins interact with and potentially stabilize plant outer mitochondrial membranes in conditions of cold stress. Single-molecule force spectroscopy of both proteins pulled from supported lipid bilayers indicated the induced formation of tertiary conformations in both proteins, and potentially a dimeric association for TsDHN-2.
BibTeX:
@article{Rahman2012,
  author = {Rahman, Luna N. and McKay, Fraser and Giuliani, Maximiliano and Quirk, Amanda and Moffatt, Barbara A. and Harauz, George and Dutcher, John R.},
  title = {Interactions of Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes at cold and ambient temperatures—Surface morphology and single-molecule force measurements show phase separation, and reveal tertiary and quaternary associations},
  journal = {Biochimica et Biophysica Acta (BBA) - Biomembranes},
  year = {2012},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.bbamem.2012.11.031},
  doi = {10.1016/j.bbamem.2012.11.031}
}
Ray JG, Naik SS, Hoff EA, Johnson AJ, Ly JT, Easterling CP, Patton DL and Savin DA (2012), "Stimuli-Responsive Peptide-Based ABA-Triblock Copolymers: Unique Morphology Transitions With pH", Macromolecular Rapid Communications., May, 2012. Vol. 33(9), pp. 819-826.
Abstract: We report the synthesis and solution characterization of poly(L-lysine)-b-poly(propylene oxide)-b-poly(L-lysine) (KPK) triblock copolymers with high lysine weight fractions (>75 wt. In contrast to PK diblock copolymers in this composition range, KPK triblock copolymers exhibit morphology transitions as a function of pH. Using a combination of light-scattering and microscopy techniques, we demonstrate spherical micelle-vesicle and spherical micelle-disk micelle transitions for different K fractions. We interpret these morphology changes in terms of the energy penalty associated with folding the core P block to form a spherical micelle in relation to the interfacial curvature associated with different charged states of the K block.
BibTeX:
@article{ray_stimuli-responsive_2012,
  author = {Ray, Jacob G and Naik, Sandeep S and Hoff, Emily A and Johnson, Ashley J and Ly, Jack T and Easterling, Charles P and Patton, Derek L and Savin, Daniel A},
  title = {Stimuli-Responsive Peptide-Based ABA-Triblock Copolymers: Unique Morphology Transitions With pH},
  journal = {Macromolecular Rapid Communications},
  year = {2012},
  volume = {33},
  number = {9},
  pages = {819--826},
  url = {http://doi.wiley.com/10.1002/marc.201100881},
  doi = {10.1002/marc.201100881}
}
Reedy, David E. J, Boyce BL, Foulk, James W. I, Field, Richard V. J, Ohlhausen JA, de Boer MP and Hazra SS (2010), "Predicting Fracture in Micron-Scale Polycrystalline Silicon MEMS Structures", In Sandia Report. Albuquerque, New Mexico 87185 and Livermore, California 94550 Vol. SAND2010-6(September) Institute of Electrical and Electronics Engineers.
Abstract: Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. Furthermore, it is not clear how to use a measured tensile strength distribution to predict the strength of a complex MEMS structure. To address such issues, two recently developed high throughput MEMS tensile test techniques have been used to measure strength distribution tails. The measured tensile strength distributions enable the definition of a threshold strength as well as an inferred maximum flaw size. The nature of strength-controlling flaws has been identified and sources of the observed variation in strength investigated. A double edge-notched specimen geometry was also tested to study the effect of a severe, micron-scale stress concentration on the measured strength distribution. Strength-based, Weibull-based, and fracture mechanics-based failure analyses were performed and compared with the experimental results.
BibTeX:
@techreport{ReedyDavidE.2010,
  author = {Reedy, David E., Jr. and Boyce, Brad L. and Foulk, James W., III and Field, Richard V., Jr. and Ohlhausen, J. A. and de Boer, Maarten P. and Hazra, Siddharth S.},
  title = {Predicting Fracture in Micron-Scale Polycrystalline Silicon MEMS Structures},
  booktitle = {Sandia Report},
  publisher = {Institute of Electrical and Electronics Engineers},
  year = {2010},
  volume = {SAND2010-6},
  number = {September},
  url = {http://prod.sandia.gov/techlib/access-control.cgi/2010/106701.pdf}
}
Remes Z, Kozak H, Rezek B, Ukraintsev E, Babchenko O, Kromka A, Girard H, Arnault J-C and Bergonzo P (2013), "Diamond-coated ATR prism for infrared absorption spectroscopy of surface-modified diamond nanoparticles", Applied Surface Science., January, 2013. Vol. null(null)
Abstract: Linear antenna microwave chemical vapor deposition process was used to homogeneously coat a 7 cm long silicon prism by 85 nm thin nanocrystalline diamond (NCD) layer. To show the advantages of the NCD-coated prism for attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) of nanoparticles, we apply diamond nanoparticles (DNPs) of 5 nm nominal size with various surface modifications by a drop-casting of their methanol dispersions. ATR-FTIR spectra of as-received, air-annealed, plasma-oxidized, and plasma-hydrogenated DNPs were measured in the 4000-1500 cm−1 spectral range. The spectra show high spectral resolution, high sensitivity to specific DNP surface moieties, and repeatability. The NCD coating provides mechanical protection against scratching and chemical stability of the surface. Moreover, unlike on bare Si surface, NCD hydrophilic properties enable optically homogeneous coverage by DNPs with some aggregation on submicron scale as evidenced by scanning electron microscopy and atomic force microscopy. Compared to transmission FTIR regime with KBr pellets, direct and uniform deposition of DNPs on NCD-ATR prism significantly simplifies and speeds up the analysis (from days to minutes). We discuss prospects for in-situ monitoring of surface modifications and molecular grafting.
BibTeX:
@article{Remes2013,
  author = {Remes, Z. and Kozak, H. and Rezek, B. and Ukraintsev, E. and Babchenko, O. and Kromka, A. and Girard, H.A. and Arnault, J.-C. and Bergonzo, P.},
  title = {Diamond-coated ATR prism for infrared absorption spectroscopy of surface-modified diamond nanoparticles},
  journal = {Applied Surface Science},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.apsusc.2013.01.039},
  doi = {10.1016/j.apsusc.2013.01.039}
}
Rico F, Su C and Scheuring S (2011), "Mechanical Mapping of Single Membrane Proteins at Submolecular Resolution", Nano Letters., August, 2011. Vol. 11(9), pp. 3983-3986. American Chemical Society.
Abstract: The capacity of proteins to carry out different functions is related to their ability to undergo conformation changes, which depends on the flexibility of protein structures. In this work, we applied a novel imaging mode based on indentation force spectroscopy to map quantitatively the flexibility of individual membrane proteins in their native, folded state at unprecedented submolecular resolution. Our results enabled us to correlate protein flexibility with crystal structure and showed that $-helices are stiff structures that may contribute importantly to the mechanical stability of membrane proteins, while interhelical loops appeared more flexible, allowing conformational changes related to function.
BibTeX:
@article{Rico2011,
  author = {Rico, Felix and Su, Chanmin and Scheuring, Simon},
  title = {Mechanical Mapping of Single Membrane Proteins at Submolecular Resolution},
  journal = {Nano Letters},
  publisher = {American Chemical Society},
  year = {2011},
  volume = {11},
  number = {9},
  pages = {3983--3986},
  url = {http://pubs.acs.org/doi/abs/10.1021/nl202351t http://www.ncbi.nlm.nih.gov/pubmed/21800925},
  doi = {10.1021/nl202351t}
}
Robinson MA, Graham DJ and Castner DG (2012), "ToF-SIMS Depth Profiling of Cells: z -Correction, 3D Imaging, and Sputter Rate of Individual NIH/3T3 Fibroblasts", Analytical Chemistry., June, 2012. Vol. 84(11), pp. 4880-4885.
Abstract: Proper display of three-dimensional time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging data of complex, nonflat samples requires a correction of the data in the z-direction. Inaccuracies in displaying three-dimensional ToF-SIMS data arise from projecting data from a nonflat surface onto a 2D image plane, as well as possible variations in the sputter rate of the sample being probed. The current study builds on previous studies by creating software written in Matlab, the ZCorrectorGUI (available at http://mvsa.nb.uw.edu/), to apply the z-correction to entire 3D data sets. Three-dimensional image data sets were acquired from NIH/3T3 fibroblasts by collecting ToF-SIMS images, using a dual beam approach (25 keV Bi3+ for analysis cycles and 20 keV C602+ for sputter cycles). The entire data cube was then corrected by using the new ZCorrectorGUI software, producing accurate chemical information from single cells in 3D. For the first time, a three-dimensional corrected view of a lipid-rich subcellular region, possibly the nuclear membrane, is presented. Additionally, the key assumption of a constant sputter rate throughout the data acquisition was tested by using ToF-SIMS and atomic force microscopy (AFM) analysis of the same cells. For the dried NIH/3T3 fibroblasts examined in this study, the sputter rate was found to not change appreciably in x, y, or z, and the cellular material was sputtered at a rate of approximately 10 nm per 1.25 × 1013 ions C602+/cm2.
BibTeX:
@article{robinson_tof-sims_2012,
  author = {Robinson, Michael A and Graham, Daniel J and Castner, David G},
  title = {ToF-SIMS Depth Profiling of Cells: z -Correction, 3D Imaging, and Sputter Rate of Individual NIH/3T3 Fibroblasts},
  journal = {Analytical Chemistry},
  year = {2012},
  volume = {84},
  number = {11},
  pages = {4880--4885},
  url = {http://pubs.acs.org/doi/abs/10.1021/ac300480g},
  doi = {10.1021/ac300480g}
}
Romasco-Tremper A, Mohney S, Andre K, Lin J and Muhlstein C (2012), "Softening under Membrane Contact Stress due to Ultra-thin Ru Coatings on Au Films", Materials Science and Engineering: A., December, 2012. Vol. null(null)
Abstract: This study reveals that ultra-thin, single-layer metal coatings can be used to tailor the deformation resistance of metal thin film surfaces, even when the penetration depths of the indents extend well beyond the coating layer. Nanoindentation of ultra-thin (≤20 nm) Ru and Pt coatings on thick Au films (350 nm) was used to illustrate how ultra-thin layers affect both the elastic and plastic deformation behavior. In spite of their (generally) higher hardness compared to Au, the Ru and Pt coating systems reduced the deformation resistance of the underlying Au, even though the maximum depth was on the order of the coating thickness. The effects of coating thickness, mechanical properties, and residual stress on the transitions between membrane- and substrate-dominated behavior were established by controlling the deposition conditions of the layers. The results show that the transition from ultra-thin coating- to underlying film-dominated response occurs when the indent penetration depth to coating thickness ratio is less than ∼0.5.
BibTeX:
@article{Romasco-Tremper2012,
  author = {Romasco-Tremper, A.L. and Mohney, S.E. and Andre, K.L. and Lin, J. and Muhlstein, C.L.},
  title = {Softening under Membrane Contact Stress due to Ultra-thin Ru Coatings on Au Films},
  journal = {Materials Science and Engineering: A},
  year = {2012},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.msea.2012.12.021},
  doi = {10.1016/j.msea.2012.12.021}
}
Rooj S, Das A, Morozov IA, Stöckelhuber KW, Stocek R and Heinrich G (2013), "Influence of “expanded clay? on the microstructure and fatigue crack growth behavior of carbon black filled NR composites", Composites Science and Technology., January, 2013. Vol. null(null)
Abstract: In this study, organo-montmorillonite (OMt) was treated with long alkyl chain containing docosanoic acid in order to obtain expanded organo-montmorillonite (EOMt) with increased interlayer distance. The X-ray diffraction (XRD) patterns confirmed the widening of the interlayer space of clay after intercalation of long alkyl chain docosanoic acid. The role of EOMt nanoparticles on the microstructure and fracture mechanical behavior of carbon black (CB) filled natural rubber (NR) composites was investigated. The microstructure of these clay filled NR/CB composites were revealed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Tear fatigue analysis (TFA) tests were carried out using pure-shear test specimen under cyclic conditions to explicate the crack growth behavior of CB filled NR in the presence of EOMt. A significant reduction in crack growth rate was noticed in the presence of only 5 phr of EOMt. The viscoelastic properties obtained from the dynamic mechanical analysis (DMA) for different CB filled NR-clay composites were utilized to estimate the tearing energy qualitatively using the ‘Persson-Brener’ equation. The reinforcement of rubber matrix was investigated by both the static and dynamic mechanical properties. A synergy in reinforcement between clay nanoparticles and CB was attested by the marked enhancement in both mechanical properties.
BibTeX:
@article{Rooj2013,
  author = {Rooj, Sandip and Das, Amit and Morozov, Ilya A. and Stöckelhuber, Klaus W. and Stocek, Radek and Heinrich, Gert},
  title = {Influence of “expanded clay? on the microstructure and fatigue crack growth behavior of carbon black filled NR composites},
  journal = {Composites Science and Technology},
  year = {2013},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.compscitech.2012.12.020},
  doi = {10.1016/j.compscitech.2012.12.020}
}
Saar-Dover R, Bitler A, Nezer R, Shmuel-Galia L, Firon A, Shimoni E, Trieu-Cuot P and Shai Y (2012), "D-Alanylation of Lipoteichoic Acids Confers Resistance to Cationic Peptides in Group B Streptococcus by Increasing the Cell Wall Density", PLoS Pathogens., September, 2012. Vol. 8(9), pp. e1002891. Public Library of Science.
Abstract: Cationic antimicrobial peptides (CAMPs) serve as the first line of defense of the innate immune system against invading microbial pathogens. Gram-positive bacteria can resist CAMPs by modifying their anionic teichoic acids (TAs) with D-alanine, but the exact mechanism of resistance is not fully understood. Here, we utilized various functional and biophysical approaches to investigate the interactions of the human pathogen Group B Streptococcus (GBS) with a series of CAMPs having different properties. The data reveal that: (i) D-alanylation of lipoteichoic acids (LTAs) enhance GBS resistance only to a subset of CAMPs and there is a direct correlation between resistance and CAMPs length and charge density; (ii) resistance due to reduced anionic charge of LTAs is not attributed to decreased amounts of bound peptides to the bacteria; and (iii) D-alanylation most probably alters the conformation of LTAs which results in increasing the cell wall density, as seen by Transmission Electron Microscopy, and reduces the penetration of CAMPs through the cell wall. Furthermore, Atomic Force Microscopy reveals increased surface rigidity of the cell wall of the wild-type GBS strain to more than 20-fold that of the dltA mutant. We propose that D-alanylation of LTAs confers protection against linear CAMPs mainly by decreasing the flexibility and permeability of the cell wall, rather than by reducing the electrostatic interactions of the peptide with the cell surface. Overall, our findings uncover an important protective role of the cell wall against CAMPs and extend our understanding of mechanisms of bacterial resistance.
BibTeX:
@article{Saar-Dover2012,
  author = {Saar-Dover, Ron and Bitler, Arkadi and Nezer, Ravit and Shmuel-Galia, Liraz and Firon, Arnaud and Shimoni, Eyal and Trieu-Cuot, Patrick and Shai, Yechiel},
  editor = {Peschel, Andreas},
  title = {D-Alanylation of Lipoteichoic Acids Confers Resistance to Cationic Peptides in Group B Streptococcus by Increasing the Cell Wall Density},
  journal = {PLoS Pathogens},
  publisher = {Public Library of Science},
  year = {2012},
  volume = {8},
  number = {9},
  pages = {e1002891},
  url = {http://dx.plos.org/10.1371/journal.ppat.1002891},
  doi = {10.1371/journal.ppat.1002891}
}
Sababi M (2013), "Nanocomposite Coatings for Corrosion Protection". Thesis at: KTH Royal Institute of Technology School. (November)
Abstract: This thesis describes technical and scientific aspects of new types of composite films/coatings for corrosion protection of carbon steel, composite films with nanometer thickness consisting of mussel adhesive protein (Mefp?1) and ceria nanoparticles, and polymeric composite coatings with micrometre thickness consisting of conducting polymer and ceria nanoparticles in a UV?curing polyester acrylate (PEA) resin. The influence of microstructure on corrosion behaviour was studied for a Fe?Cr?V?N alloy containing micro?sized nitrides with different chemical composition spread in martensitic alloy matrix. The Volta potential mapping suggested higher relative nobility for the nitride particles than the alloy matrix, and the nitrides with higher amounts of nitrogen and vanadium exhibited higher nobility. Potentiodynamic polarization measurements in a 0.1 M NaCl solution at neutral pH and ambient temperature showed passivity breakdown with initiation of localized corrosion which started in the boundary region surrounding the nitride particles, especially the ones enriched in Cr and Mo. Mefp?1/ceria nanocomposite films were formed on silica and metal substrates by layer?by?layer immersion deposition. The film formation process was studied in situ using a Quartz Crystal Microbalance with Dissipation (QCM?D). The film grows linearly with increasing number of immersions. Increasing Mefp?1 concentration or using Mefp?1 with larger size leads to more Mefp?1 being deposited. Peak Force Quantitative Nanomechanical Mapping (Peak Force QNM) of the composite films in air indicated that the elastic modulus of the film increased when the film deposited had a higher Mefp?1 concentration. It was also noted that the nature of the outermost layer can affect bulk morphology and surface mechanical properties of the film. The QCM?D study of Mefp?1 on an iron substrate showed that Mefp?1 adsorbs at a high rate and changes its conformation with increasing adsorption time. The QCM?D and in situ Peak Force QNM measurements showed that the addition of Fe3+ ions causes a transition in the single Mefp?1 layer from an extended and soft layer to a denser and stiffer layer. In situ ATR?FTIR and Confocal Raman Microscopy (CRM) analyses revealed complex formation between Fe3+ and catechol groups in Mefp?1. Moreover, optical microscopy, SEM and AFM characterization of the Mefp?1/ceria composite film formed on carbon steel showed micron?size aggregates rich in Mefp?1 and ceria, and a nanostructure of well dispersed ceria particles in the film. The CRM analysis confirmed the presence of Mefp?1/Fe complexes in the film. Electrochemical impedance microscopy and potentiodynamic polarization measurements showed that the Mefp? 1/ceria composite film can provide corrosion protection for carbon steel, and that the protection efficiency increases with exposure time. Composite coatings of 10 $m thickness composed of a UV?curing PEA resin and a small amount of conductive polymer and ceria nanoparticles were coated on carbon steel. The conductive polymer (PAni) was synthesized with phosphoric acid (PA) as the dopant by chemical oxidative polymerization. The ATR?FTIR and SEM analyses confirmed that the added particles were well dispersed in the coatings. Electrochemical measurements during long exposure in 0.1 M NaCl solution, including open circuit potential (OCP) and EIS, were performed to investigate the protective performance of the coatings. The results showed that adding ceria nanoparticles can improve the barrier properties of the coating, and adding PAni?PA can lead to active protection of the coating. Adding PAni? PA and ceria nanoparticles simultaneously in the coating can improve the protection and stability of the composite coating, providing excellent corrosion protection for carbon steel.
BibTeX:
@phdthesis{Sababi2013,
  author = {Sababi, Majid},
  title = {Nanocomposite Coatings for Corrosion Protection},
  school = {KTH Royal Institute of Technology School},
  year = {2013},
  number = {November}
}
Sababi M, Kettle J, Rautkoski H, Claesson PM and Thormann E (2012), "Structural and Nanomechanical Properties of Paperboard Coatings Studied by Peak Force Tapping Atomic Force Microscopy.", ACS applied materials & interfaces., September, 2012. American Chemical Society.
Abstract: Paper coating formulations containing starch, latex, and clay were applied to paperboard and have been investigated by scanning electron microscopy and Peak Force tapping atomic force microscopy. A special focus has been on the measurement of the variation of the surface topography and surface material properties with a nanometer scaled spatial resolution. The effects of coating composition and drying conditions were investigated. It is concluded that the air-coating interface of the coating is dominated by close-packed latex particles embedded in a starch matrix and that the spatial distribution of the different components in the coating can be identified due to their variation in material properties. Drying the coating at an elevated temperature compared to room temperature changes the surface morphology and the surface material properties due to partial film formation of latex. However, it is evident that the chosen elevated drying temperature and exposure time is insufficient to ensure complete film formation of the latex which in an end application will be needed.
BibTeX:
@article{Sababi2012,
  author = {Sababi, Majid and Kettle, John and Rautkoski, Hille and Claesson, Per M and Thormann, Esben},
  title = {Structural and Nanomechanical Properties of Paperboard Coatings Studied by Peak Force Tapping Atomic Force Microscopy.},
  journal = {ACS applied materials & interfaces},
  publisher = {American Chemical Society},
  year = {2012},
  url = {http://pubs.acs.org/doi/abs/10.1021/am301439k},
  doi = {10.1021/am301439k}
}
Sabir TS, Rowland LK, Milligan JR, Yan D, Aruni AW, Chen Q, Boskovic DS, Kurti RS and Perry CC (2013), "Mechanistic Investigation of Seeded Growth in Triblock Copolymer Stabilized Gold Nanoparticles", Langmuir., March, 2013. Vol. 29(12), pp. 3903-3911.
Abstract: We report the seeded synthesis of gold nanoparticles (GNPs) via the reduction of HAuCl4 by (L31 and F68) triblock copolymer (TBP) mixtures. In the present study, we focused on [TBP]/[Au(III)] ratios of 1–5 (≈1 mM HAuCl4) and seed sizes 20 nm. Under these conditions, the GNP growth rate is dominated by both the TBP and seed concentrations. With seeding, the final GNP size distributions are bimodal. Increasing the seed concentration (up to 0.1 nM) decreases the mean particle sizes 10-fold, from 1000 to 100 nm. The particles in the bimodal distribution are formed by the competitive direct growth in solution and the aggregative growth on the seeds. By monitoring kinetics of GNP growth, we propose that (1) the surface of the GNP seeds embedded in the TBP cavities form catalytic centers for GNP growth and (2) large GNPs are formed by the aggregation of GNP seeds in an autocatalytic growth process.
BibTeX:
@article{sabir_mechanistic_2013,
  author = {Sabir, Theodore S and Rowland, Leah K and Milligan, Jamie R and Yan, Dong and Aruni, A Wilson and Chen, Qiao and Boskovic, Danilo S and Kurti, R Steven and Perry, Christopher C},
  title = {Mechanistic Investigation of Seeded Growth in Triblock Copolymer Stabilized Gold Nanoparticles},
  journal = {Langmuir},
  year = {2013},
  volume = {29},
  number = {12},
  pages = {3903--3911},
  url = {http://pubs.acs.org/doi/abs/10.1021/la400387h},
  doi = {10.1021/la400387h}
}
Sabir TS, Yan D, Milligan JR, Aruni AW, Nick KE, Ramon RH, Hughes JA, Chen Q, Kurti RS and Perry CC (2012), "Kinetics of Gold Nanoparticle Formation Facilitated by Triblock Copolymers", The Journal of Physical Chemistry C. Vol. 116(7), pp. 4431-4441.
BibTeX:
@article{Sabir2012,
  author = {Sabir, Theodore S and Yan, Dong and Milligan, Jamie R and Aruni, A Wilson and Nick, Kevin E and Ramon, Ruth H and Hughes, Joseph A and Chen, Qiao and Kurti, R Steven and Perry, Christopher C},
  title = {Kinetics of Gold Nanoparticle Formation Facilitated by Triblock Copolymers},
  journal = {The Journal of Physical Chemistry C},
  year = {2012},
  volume = {116},
  number = {7},
  pages = {4431--4441},
  doi = {10.1021/jp210591h}
}
Sadeghian H, Koster NB and van den Dool TC (2013), "Introduction of a high throughput SPM for defect inspection and process control", In Proc. SPIE 8681, Metrology, Inspection, and Process Control for Microlithography XXVII., April, 2013. , pp. 868127-8. SPIE.
Abstract: The main driver for Semiconductor and Bio-MEMS industries is decreasing the feature size, moving from the current state-of-the-art at 22 nm towards 10 nm node. Consequently smaller defects and particles become problematic due to size and number, thus inspecting and characterizing them are very challenging. Existing industrial metrology and inspection methods cannot fulfil the requirements for these smaller features. Scanning probe Microscopy (SPM) has the distinct advantage of being able to discern the atomic structure of the substrate. It can image the 3D topography, but also a variety of material, mechanical and chemical properties. Therefore SPM has been suggested as one of the technologies that can fulfil the future requirements in terms of resolution and accuracy, while being capable of resolving 3D futures. However, the throughput of the current state-of-the-art SPMs are extremely low, as compared to the high-volume manufacturing requirements. This paper presents the development of an architecture[1] for a fully automated high throughput SPM, which can meet the requirements of future process metrology and inspection for 450 mm wafers. The targeted specifications of the concept are 1) inspecting more than 20 sites per wafer, 2) each site with dimension of about 10 × 10 $m2 (scalable to 100 × 100 $m2) and 3) with a throughput of more than 7 wafers per hour, or 70 wafers per hour with a coarse/fine scanning approach. The progress of the high throughput SPM development is discussed and the baseline design of the critical sub-modules and the research issues are presented. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
BibTeX:
@inproceedings{sadeghian_introduction_2013,
  author = {Sadeghian, H and Koster, N B and van den Dool, T C},
  editor = {Starikov, Alexander and Cain, Jason P},
  title = {Introduction of a high throughput SPM for defect inspection and process control},
  booktitle = {Proc. SPIE 8681, Metrology, Inspection, and Process Control for Microlithography XXVII},
  publisher = {SPIE},
  year = {2013},
  pages = {868127--8},
  url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2019389},
  doi = {10.1117/12.2019389}
}
Sagara Y, Komatsu T, Ueno T, Hanaoka K, Kato T and Nagano T (2013), "A Water-Soluble Mechanochromic Luminescent Pyrene Derivative Exhibiting Recovery of the Initial Photoluminescence Color in a High-Humidity Environment", Advanced Functional Materials., May, 2013. , pp. 5277-5284.
Abstract: Switching of the luminescence properties of molecular materials in response to mechanical stimulation is of fundamental interest and also has a range of potential applications. Herein, a water-soluble mechanochromic luminescent pyrene derivative having two hydrophilic dendrons is reported. This pyrene derivative is the first example of a mechanochromic luminescent organic compound that responds to relative humidity. Mechanical stimulation (grinding) of this pyrene derivative in the solid state results in a change of the photoluminescence from yellow to green. Subsequent exposure to water vapor induces recovery of the initial yellow photoluminescence. The color change is reversible through at least ten cycles. It is also demonstrated that this compound can be applied as a mechano-sensing material in frictional wear testing for grease, owing to its immiscibility in non-polar solvents and its non-crystalline behavior. Transmission electron microscope and atomic force microscope observations of samples prepared from dilute aqueous solutions of the pyrene derivative on suitable substrates, together with dynamic light scattering measurements for the compound in aqueous solution, indicate that this amphiphilic dumbbell-shaped molecule forms micelles in water.
BibTeX:
@article{sagara_water-soluble_2013,
  author = {Sagara, Yoshimitsu and Komatsu, Toru and Ueno, Tasuku and Hanaoka, Kenjiro and Kato, Takashi and Nagano, Tetsuo},
  title = {A Water-Soluble Mechanochromic Luminescent Pyrene Derivative Exhibiting Recovery of the Initial Photoluminescence Color in a High-Humidity Environment},
  journal = {Advanced Functional Materials},
  year = {2013},
  pages = {5277--5284},
  url = {http://doi.wiley.com/10.1002/adfm.201300180},
  doi = {10.1002/adfm.201300180}
}
Salvia-Trujillo L, Rojas-Graü MA, Soliva-Fortuny R and Martn-Belloso O (2013), "Effect of processing parameters on physicochemical characteristics of microfluidized lemongrass essential oil-alginate nanoemulsions", Food Hydrocolloids., January, 2013. Vol. 30(1), pp. 401-407. Elsevier Ltd.
Abstract: The purpose of this work was to study the effect of processing parameters (pressure and cycles) on the formation of microfluidized lemongrass oil-alginate nanoemulsions considering their average droplet size and size distribution, $-potential, viscosity and whiteness index. To confirm that nanoemulsions were in the nano-range, samples were also observed through transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques. Average droplet size, viscosity and whiteness index of nanoemulsions decreased by increasing the processing pressure and the cycles through the interaction chamber of the microfluidizer device. Nanoemulsions obtained at 150 MPa for 10 cycles exhibited a minimum average droplet size of 6 nm. Moreover, the droplet electrical charge of nanoemulsions ranged between −36.66 and −51.95 mV while it was −17.61 mV in the coarse emulsion. Furthermore, nanoemulsions obtained at 150 MPa for 3 times or more through the microfluidization system were almost transparent. Results obtained in the present study reveal that microfluidization is a potential technology to be used to produce nanoemulsions of essential oils. However, more information is needed about the influence of microfluidization conditions on the antimicrobial properties of essential oils dispersed in nano-sized emulsions.
BibTeX:
@article{salvia-trujillo_effect_2013,
  author = {Salvia-Trujillo, Laura and Rojas-Graü, M. Alejandra and Soliva-Fortuny, Robert and Martn-Belloso, Olga},
  title = {Effect of processing parameters on physicochemical characteristics of microfluidized lemongrass essential oil-alginate nanoemulsions},
  journal = {Food Hydrocolloids},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {30},
  number = {1},
  pages = {401--407},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0268005X12001579},
  doi = {10.1016/j.foodhyd.2012.07.004}
}
Samuel RE, Shukla A, Paik DH, Wang MX, Fang JC, Schmidt DJ and Hammond PT (2011), "Osteoconductive protamine-based polyelectrolyte multilayer functionalized surfaces", Biomaterials. Vol. 32(30), pp. 7491-7502.
Abstract: The integration of orthopedic implants with host bone presents a major challenge in joint arthroplasty, spinal fusion and tumor reconstruction. The cellular microenvironment can be programmed via implant surface functionalization allowing direct modulation of osteoblast adhesion, proliferation, and differentiation at the implant–bone interface. The development of layer-by-layer assembled polyelectrolyte multilayer (PEM) architectures has greatly expanded our ability to fabricate intricate nanometer to micron scale thin film coatings that conform to complex implant geometries. The in vivo therapeutic efficacy of thin PEM implant coatings for numerous biomedical applications has previously been reported. We have fabricated protamine-based PEM thin films that support the long-term proliferation and differentiation of pre-osteoblast cells on non-cross-linked film-coated surfaces. These hydrophilic PEM functionalized surfaces with nanometer-scale roughness facilitated increased deposition of calcified matrix by osteoblasts in vitro, and thus offer the potential to enhance implant integration with host bone. The coatings can make an immediate impact in the osteogenic culture of stem cells and assessment of the osteogenic potential of new therapeutic factors.
BibTeX:
@article{Samuel2011,
  author = {Samuel, Raymond E and Shukla, Anita and Paik, Daniel H and Wang, Mary X and Fang, Jean C and Schmidt, Daniel J and Hammond, Paula T},
  title = {Osteoconductive protamine-based polyelectrolyte multilayer functionalized surfaces},
  journal = {Biomaterials},
  year = {2011},
  volume = {32},
  number = {30},
  pages = {7491--7502},
  url = {http://www.sciencedirect.com/science/article/pii/S0142961211006971},
  doi = {10.1016/j.biomaterials.2011.06.032}
}
Sanchez DG, Hiesgen R, Wehl I and Friedrich KA (2011), "Correlation of Oscillation of Polymer Electrolyte Membrane Fuel Cells at Low Cathode Humidification with Nanoscale Membrane Properties" , pp. 41-54.
BibTeX:
@inproceedings{sanchez_correlation_2011,
  author = {Sanchez, Daniel G and Hiesgen, Renate and Wehl, Ines and Friedrich, K Andreas},
  title = {Correlation of Oscillation of Polymer Electrolyte Membrane Fuel Cells at Low Cathode Humidification with Nanoscale Membrane Properties},
  year = {2011},
  pages = {41--54},
  url = {http://ecst.ecsdl.org/cgi/doi/10.1149/1.3655686},
  doi = {10.1149/1.3655686}
}
Santonicola MG, Memesa M, Meszyńska A, Ma Y and Vancso GJ (2012), "Surface-grafted zwitterionic polymers as platforms for functional supported phospholipid membranes", Soft Matter. Vol. 8(5), pp. 1556.
Abstract: Polymer brushes grafted from surfaces using controlled polymerization techniques, most notably surface-initiated atom-transfer radical polymerization (SI-ATRP), provide robust and reproducible platforms with precise control of surface properties. These platforms are especially useful in biologically oriented applications involving the confinement of membrane proteins onto solid supports, including screening of pharmaceuticals and biosensing. Here we investigate a tunable zwitterion-based polymeric interface that can guide the assembly of neutral lipid membranes with high mechanical stability and reproducibility on various synthetic materials. By controlling the polymer architecture using ATRP, we show that phospholipid membranes can be made to self-assemble on thin layers of charge-balanced poly(sulfobetaine methacrylate) from fusion of DOPC vesicles under physiological conditions. The self-assembly kinetics and functionality of the polymer-supported lipid membranes are investigated using various surface sensitive techniques, including surface plasmon resonance, fluorescence microscopy, and atomic force microscopy. The growth of zwitterionic polymer layers with controlled length and grafting density allows for modulation of the adhesion of the lipid bilayers to surfaces, thus offering unique advantages for the design and synthesis of bioactive surfaces
BibTeX:
@article{santonicola_surface-grafted_2012,
  author = {Santonicola, M Gabriella and Memesa, Mine and Meszyńska, Anna and Ma, Yujie and Vancso, G. Julius},
  title = {Surface-grafted zwitterionic polymers as platforms for functional supported phospholipid membranes},
  journal = {Soft Matter},
  year = {2012},
  volume = {8},
  number = {5},
  pages = {1556},
  url = {http://xlink.rsc.org/?DOI=c1sm06709e},
  doi = {10.1039/c1sm06709e}
}
Schön P, Bagdi K, Molnár K, Markus P, Dutta S, Shirazi M, Noordermeer J, Pukánszky B and Vancso GJ (2011), "Atomic force microscopy based quantitative mapping of elastic moduli in phase separated polyurethanes and silica reinforced rubbers across the length scales", Materials Research Society Symposium Proceedings., January, 2011. Vol. 1318, pp. 191-196.
BibTeX:
@article{Schon2011b,
  author = {Schön, Peter and Bagdi, Kristóf and Molnár, Kinga and Markus, Patrick and Dutta, Saurabh and Shirazi, Morteza and Noordermeer, Jacques and Pukánszky, Béla and Vancso, G. Julius},
  title = {Atomic force microscopy based quantitative mapping of elastic moduli in phase separated polyurethanes and silica reinforced rubbers across the length scales},
  journal = {Materials Research Society Symposium Proceedings},
  year = {2011},
  volume = {1318},
  pages = {191--196},
  url = {http://journals.cambridge.org/abstractS1946427411001400},
  doi = {10.1557/opl.2011.140}
}
Schön P, Bagdi K, Molnár K, Markus P, Pukánszky B and Vancso GJ (2011), "Quantitative mapping of elastic moduli at the nanoscale in phase separated polyurethanes by AFM", European Polymer Journal., April, 2011. Vol. 47(4), pp. 692-698.
Abstract: The micro phase separated nanoscale morphology of phase separated polyurethanes (PUs) was visualized by atomic force microscopy (AFM) height and phase imaging of smooth surfaces obtained by ultramicrotonomy. PUs were obtained from 4,4′-methylenbis (phenyl isocyanate) (MDI), 1,4-butanediol (BD) and poly(tetrahydrofurane) polyether polyol (PTHF). The segmented polyether PUs with varying stoichiometric ratio of the isocyanate and hydroxyl groups were prepared to investigate the effect of molar mass, as well as the type and number of end-groups on their morphology and mechanical performance. The PU samples studied show characteristic “fingerprint? AFM phase images. Novel dynamic imaging modes of AFM, including HarmoniX material mapping and Peak Force Tapping were used to assess the mechanical performance of phase separated polyurethanes quantitatively as a function of their molecular structure. The values of surface elastic moduli were determined with nanoscale resolution and were in excellent agreement for both AFM modes. While tensile testing provides a bulk average value for the elastic modulus of the elastomers, the novel AFM based elastic moduli mappings introduced enable the study of surface stiffness with nanoscale resolution in a quantitative way.
BibTeX:
@article{Schon2011a,
  author = {Schön, Peter and Bagdi, Kristóf and Molnár, Kinga and Markus, Patrick and Pukánszky, Béla and Vancso, G. Julius},
  title = {Quantitative mapping of elastic moduli at the nanoscale in phase separated polyurethanes by AFM},
  journal = {European Polymer Journal},
  year = {2011},
  volume = {47},
  number = {4},
  pages = {692--698},
  url = {http://www.sciencedirect.com/science/article/pii/S001430571000340X},
  doi = {10.1016/j.eurpolymj.2010.09.029}
}
Schön P, Dutta S, Shirazi M, Noordermeer J and Vancso GJ (2011), "Quantitative mapping of surface elastic moduli in silica-reinforced rubbers and rubber blends across the length scales by AFM", Journal of Materials Science., January, 2011. Vol. 46(10), pp. 3507-16. Springer Netherlands.
Abstract: The surface elastic moduli of silica-reinforced rubbers and rubber blends were investigated by atomic force microscopy (AFM)-based HarmoniX material mapping. Styrene–butadiene rubbers (SBR) and ethylene–propylene–diene rubbers (EPDM) and SBR/EPDM rubber blends with varying concentrations of silica nanoparticles (0, 5, 10, 20, 50 parts per hundred rubber, phr) were prepared to investigate the effect of different composition on the resulting morphology, filler distribution and elastic moduli of a specific rubber or rubber blend sample. For SBR, the elastic modulus values varied from 0.5 MPa for unfilled SBR to 5 MPa for 50 phr reinforced SBR with the increase in the concentration of filler. For EPDM, the corresponding values increased from 1.4 MPa for unfilled EPDM to 4.5 MPa for 50 phr reinforced EPDM. Local stiff and soft domains in silica-reinforced SBR and EPDM rubbers and rubber blends were identified by HarmoniX AFM imaging. While the stiff silica particles show modulus values as high as 2 GPa, the rubber matrix reveals modulus values in the range of ca. 30 MPa for the rubber blends to ca. 300 MPa for the unfilled rubbers. The lower value of elastic modulus of the EPDM phase in the blend, compared to the blank EPDM compound can be attributed to the presence of Sunpar oil in the compound which has a very good affinity with EPDM and decreases the rubber modulus. The elastic moduli maps revealed an increase of the areal fraction of silica particles showing an intrinsic surface modulus value with rising silica content in the compound preparation mixture. HarmoniX AFM measurements revealed the formation of larger silica aggregates in EPDM in contrast to SBR where isolated silica particles were observed. For silica-reinforced rubber blends a phase separation into a soft (ca. 40 MPa) and a significantly harder phase could be observed (ca. 500 MPa–1.5 GPa) indicating the incorporation of silica particles in the SBR phase. Using HarmoniX AFM imaging significantly higher surface elastic moduli were observed compared to those obtained by bulk tensile testing. Possible reasons for the observed differences between bulk modulus values and those measured by AFM are discussed in detail, including the aspect of different averaging procedures like inherent to surface probing by AFM versus bulk tensile testing, different filler distributions in SBR and EPDM and the AFM modulus calibration procedures.
BibTeX:
@article{Schon2011,
  author = {Schön, Peter and Dutta, Saurabh and Shirazi, Morteza and Noordermeer, Jacques and Vancso, G. Julius},
  title = {Quantitative mapping of surface elastic moduli in silica-reinforced rubbers and rubber blends across the length scales by AFM},
  journal = {Journal of Materials Science},
  publisher = {Springer Netherlands},
  year = {2011},
  volume = {46},
  number = {10},
  pages = {3507--16},
  url = {http://www.springerlink.com/index/10.1007/s10853-011-5259-4},
  doi = {10.1007/s10853-011-5259-4}
}
Sharma S, Das K, Woo J and Gimzewski JK (2014), "Nanofilaments on glioblastoma exosomes revealed by peak force microscopy.", Journal of the Royal Society, Interface / the Royal Society., January, 2014. Vol. 11(92), pp. 20131150. The Royal Society.
Abstract: Exosomes are sub-100 nm extracellular vesicles secreted by normal and cancer cells. We present a high-resolution structure of previously unidentified nanofilaments on glioblastoma-derived exosomes, using nanoscale peak force imaging. These stiff, adhesive, trypsin- and RNAse-resistant surface nanofilaments add a new dimension to the current structural knowledge of exosome-mediated intercellular communication.
BibTeX:
@article{Sharma2014,
  author = {Sharma, Shivani and Das, Kingshuk and Woo, Jungreem and Gimzewski, James K},
  title = {Nanofilaments on glioblastoma exosomes revealed by peak force microscopy.},
  journal = {Journal of the Royal Society, Interface / the Royal Society},
  publisher = {The Royal Society},
  year = {2014},
  volume = {11},
  number = {92},
  pages = {20131150},
  url = {http://rsif.royalsocietypublishing.org/content/11/92/20131150.full},
  doi = {10.1098/rsif.2013.1150}
}
Shchepelina O, Drachuk I, Gupta MK, Lin J and Tsukruk VV (2011), "Silk-on-Silk Layer-by-Layer Microcapsules", Advanced Materials. Vol. 23(40), pp. 4655-4660. WILEY-VCH Verlag.
BibTeX:
@article{Shchepelina2011,
  author = {Shchepelina, Olga and Drachuk, Irina and Gupta, Maneesh K. and Lin, Jeffrey and Tsukruk, Vladimir V.},
  title = {Silk-on-Silk Layer-by-Layer Microcapsules},
  journal = {Advanced Materials},
  publisher = {WILEY-VCH Verlag},
  year = {2011},
  volume = {23},
  number = {40},
  pages = {4655--4660},
  url = {http://dx.doi.org/10.1002/adma.201102234},
  doi = {10.1002/adma.201102234}
}
Shi X, Zhang X, Xia T and Fang X (2012), "Living cell study at the single-molecule and single-cell levels by atomic force microscopy.", Nanomedicine (London, England)., October, 2012. Vol. 7(10), pp. 1625-37. Future Medicine Ltd London, UK.
Abstract: Atomic force microscopy (AFM) has been emerging as a multifunctional molecular tool in nanobiology and nanomedicine. This review summarizes the recent advances in AFM study of living mammalian cells at the single-molecule and single-cell levels. Besides nanoscale imaging of cell membrane structure, AFM-based force measurements on living cells are mainly discussed. These include the development and application of single-molecule force spectroscopy to investigate ligand-receptor binding strength and dissociation dynamics, and the characterization of cell mechanical properties in a physiological environment. Molecular manipulation of cells by AFM to change the cellular process is also described. Living-cell AFM study offers a new approach to understand the molecular mechanisms of cell function, disease development and drug effect, as well as to develop new strategies to achieve single-cell-based diagnosis.
BibTeX:
@article{Shi2012,
  author = {Shi, Xiaoli and Zhang, Xuejie and Xia, Tie and Fang, Xiaohong},
  title = {Living cell study at the single-molecule and single-cell levels by atomic force microscopy.},
  journal = {Nanomedicine (London, England)},
  publisher = {Future Medicine Ltd London, UK},
  year = {2012},
  volume = {7},
  number = {10},
  pages = {1625--37},
  url = {http://www.futuremedicine.com/doi/abs/10.2217/nnm.12.130},
  doi = {10.2217/nnm.12.130}
}
Shiu P-J, Chen H-M and Lee C-K (2014), "One-Step Purification of Delipidated Bacteriorhodopsin by Aqueous-Three-phase system from Purple membrane of Halobacterium", Food and Bioproducts Processing.
Abstract: Bacteriorhodopsin (BR), the only protein in the purple membrane (PM) of certain extreme halophilic microorganisms, functions as a light-driven proton pump using light energy to generate transmembrane proton gradient for ATP synthesis. BR naturally aggregates in a highly ordered two-dimensional hexagonal array of trimers in the PM of Halobacterium. The BR in the isolated PM can be employed to generate a photocurrent in a photocell. However, delipidated BR (deBR) has been reported be more efficient than BR for photocurrent generation. In the present work, detergent CHAPS was included in anaqueous three-phase system (A3PS) to remove the lipids in the out layer of the BR trimer during the preparation of deBR. A3PS that consisted of polypropyleneglycol (PPG), polyethyleneglycol (PEG), and phosphate buffer purified deBR directly from the cell lysate of H. salinarum with a recovery yield of 89.7 CHAPS along with the contaminant bacterioruberinpigment were partitioned into the top PPG-rich phase while deBR was mainly located at the interface between PEG-rich phase and the lower phosphate phase. After further purification by using ultrafiltrationto remove PEG, the purified deBR when immobilized on indium tin oxide (ITO) glass was able to generate 60% higher photocurrent density.
BibTeX:
@article{Shiu2014,
  author = {Shiu, Pei-Jing and Chen, Hsiu-Mei and Lee, Cheng-Kang},
  title = {One-Step Purification of Delipidated Bacteriorhodopsin by Aqueous-Three-phase system from Purple membrane of Halobacterium},
  journal = {Food and Bioproducts Processing},
  year = {2014},
  url = {http://www.sciencedirect.com/science/article/pii/S0960308514000157}
}
Shokuhfar T, Gao Q, Ashtana A, Walzack K, Heiden P and Friedrich C (2010), "Structural instabilities in TiO[sub 2] nanotubes", Journal of Applied Physics. Vol. 108(10), pp. 104310-104315. AIP.
BibTeX:
@article{Shokuhfar2010,
  author = {Shokuhfar, T. and Gao, Q. and Ashtana, A. and Walzack, K. and Heiden, P. and Friedrich, C.},
  title = {Structural instabilities in TiO[sub 2] nanotubes},
  journal = {Journal of Applied Physics},
  publisher = {AIP},
  year = {2010},
  volume = {108},
  number = {10},
  pages = {104310--104315},
  url = {http://link.aip.org/link/JAPIAU/v108/i10/p104310/s1&Agg=doi},
  doi = {10.1063/1.3500385}
}
Sikora A and Bednarz (2013), "Mapping of the Surface’s Mechanical Properties Through Analysis of Torsional Cantilever Bending in Dynamic Force Microscopy", In Acoustic Scanning Probe Microscopy. Berlin, Heidelberg , pp. 315-50. Springer Berlin Heidelberg.
Abstract: In atomic force microscopy, the cantilever probes provide sensing of the tip-sample forces, therefore are used for the surface’s topography imaging as well as the mechanical properties mapping at nanoscale. As in most techniques developed for local stiffness imaging based on so-called contact mode, the force applied to the surface exceeds acceptable level often causing damage to the sample. On the other hand, the most popular measurement technique based on the intermittent contact mode, where dynamic tip-sample interaction is measured and processed in order to provide surface’s shape tracking as well as imaging of energy dissipation, allows to perform the measurements with much less force and can be applied to a wide range of samples. This method, however, is insufficient in many cases, as it cannot provide detailed information about certain mechanical properties of the sample. Therefore, a new approach has been lately developed and successfully utilized in a number of applications. By the analysis of higher harmonics of the cantilever’s oscillation, one can obtain more specific information about the tip-sample interaction than in the case of phase imaging. Moreover, the time-resolved tapping mode, where advanced high-bandwidth signal processing is implemented, allows performing fast imaging of the stiffness, adhesion, peak force, and energy dissipation. As this technique provides gentle interaction with the surface, it can be used in imaging of fragile objects, such as biological samples. Due to the mechanical properties of the cantilever causing significant deformations of the detection bandwidth, the torsional bending of the cantilever is utilized in order to obtain the desired signal. In this chapter we discuss the principles of the implementation of this method and its application issues.
BibTeX:
@incollection{springerlink:10.1007/978-3-642-27494-7_11,
  author = {Sikora, Andrzej and Bednarz, ?ukasz},
  editor = {Marinello, Francesco and Passeri, Daniele and Savio, Enrico and Avouris, Phaedon and Bhushan, Bharat and Bimberg, Dieter and von Klitzing, Klaus and Sakaki, Hiroyuki and Wiesendanger, Roland},
  title = {Mapping of the Surface’s Mechanical Properties Through Analysis of Torsional Cantilever Bending in Dynamic Force Microscopy},
  booktitle = {Acoustic Scanning Probe Microscopy},
  publisher = {Springer Berlin Heidelberg},
  year = {2013},
  pages = {315--50},
  url = {http://dx.doi.org/10.1007/978-3-642-27494-711}
}
Sines IT, Vaughn II DD, Misra R, Popczun EJ and Schaak RE (2012), "Synthesis of tetragonal mackinawite-type FeS nanosheets by solvothermal crystallization", Journal of Solid State Chemistry., December, 2012. Vol. 196, pp. 17-20.
BibTeX:
@article{sines_synthesis_2012,
  author = {Sines, Ian T and Vaughn II, Dimitri D and Misra, Rajiv and Popczun, Eric J and Schaak, Raymond E},
  title = {Synthesis of tetragonal mackinawite-type FeS nanosheets by solvothermal crystallization},
  journal = {Journal of Solid State Chemistry},
  year = {2012},
  volume = {196},
  pages = {17--20},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0022459612004902},
  doi = {10.1016/j.jssc.2012.07.056}
}
Song J, Chen M, Regina VR, Wang C, Meyer RL, Xie E, Wang C, Besenbacher F and Dong M (2012), "Safe and Effective Ag Nanoparticles Immobilized Antimicrobial NanoNonwovens", Advanced Engineering Materials., May, 2012. Vol. 14(5), pp. B240--B246.
BibTeX:
@article{song_safe_2012,
  author = {Song, Jie and Chen, Menglin and Regina, Viduthalai R and Wang, Chenxuan and Meyer, Rikke L and Xie, Erqing and Wang, Chen and Besenbacher, Flemming and Dong, Mingdong},
  title = {Safe and Effective Ag Nanoparticles Immobilized Antimicrobial NanoNonwovens},
  journal = {Advanced Engineering Materials},
  year = {2012},
  volume = {14},
  number = {5},
  pages = {B240----B246},
  url = {http://doi.wiley.com/10.1002/adem.201180085},
  doi = {10.1002/adem.201180085}
}
Song J, Kahveci D, Chen M, Guo Z, Xie E, Xu X, Besenbacher F and Dong M (2012), "Enhanced Catalytic Activity of Lipase Encapsulated in PCL Nanofibers", Langmuir., April, 2012. Vol. 28(14), pp. 6157-6162.
Abstract: Use of biocatalysis for industrial synthetic chemistry is on the verge of significant growth. Enzyme immobilization as an effective strategy for improving the enzyme activity has emerged from developments especially in nanoscience and nanotechnology. Here, lipase from Burkholderia cepacia (LBC), as an example of the luxuriant enzymes, was successfully encapsulated in polycaprolactone (PCL) nanofibers, proven by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Evaluated in both organic and aqueous medium, the activation factor of the encapsulated enzymes in the hydrolysis reaction was generally higher than that in the transesterification reaction. Enhanced catalytic activities were found when 5–20 w/w % of LBC was loaded. The effect of different solvents pretreatment on the activity of immobilized LBC was also investigated. The highest activation factor was found up to 14 for the sample containing acetone-treated LBC/PCL (10 w/w . The encapsulated lipase reserved 50% of its original activity after the 10th run in the transesterification reaction in hexane medium. The mechanism of activation of lipase catalytic ability based on active PCL nanofiberous matrix is proposed.
BibTeX:
@article{song_enhanced_2012,
  author = {Song, Jie and Kahveci, Derya and Chen, Menglin and Guo, Zheng and Xie, Erqing and Xu, Xuebing and Besenbacher, Flemming and Dong, Mingdong},
  title = {Enhanced Catalytic Activity of Lipase Encapsulated in PCL Nanofibers},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {14},
  pages = {6157--6162},
  url = {http://pubs.acs.org/doi/abs/10.1021/la300469s},
  doi = {10.1021/la300469s}
}
Song J, Zhang Z, Zhang S, Liu L, Li Q, Xie E, Gothelf KV, Besenbacher F and Dong M (2013), "Isothermal Hybridization Kinetics of DNA Assembly of Two-Dimensional DNA Origami", Small., February, 2013. Vol. 9(17), pp. 2954-9.
BibTeX:
@article{Song2013,
  author = {Song, Jie and Zhang, Zhao and Zhang, Shuai and Liu, Lei and Li, Qiang and Xie, Erqing and Gothelf, Kurt Vesterager and Besenbacher, Flemming and Dong, Mingdong},
  title = {Isothermal Hybridization Kinetics of DNA Assembly of Two-Dimensional DNA Origami},
  journal = {Small},
  year = {2013},
  volume = {9},
  number = {17},
  pages = {2954--9},
  url = {http://doi.wiley.com/10.1002/smll.201202861},
  doi = {10.1002/smll.201202861}
}
Spadavecchia J, Boujday S, Landoulsi J and Pradier C-M (2011), "nPEG-TiO2 nanoparticles - a facile route to elaborate nanostructured surfaces for biological applications", Applied Materials & Interfaces. Vol. 3(2011), pp. 2637-2642.
BibTeX:
@article{Spadavecchia2011,
  author = {Spadavecchia, J. and Boujday, S. and Landoulsi, J. and Pradier, C.-M.},
  title = {nPEG-TiO2 nanoparticles - a facile route to elaborate nanostructured surfaces for biological applications},
  journal = {Applied Materials & Interfaces},
  year = {2011},
  volume = {3},
  number = {2011},
  pages = {2637--2642}
}
Steude A, Schmidt S, Robitzki AA and Panke O (2011), "An electrode array for electrochemical immuno-sensing using the example of impedimetric tenascin C detection", Lab on a Chip. Vol. 11(17), pp. 2884-2892. The Royal Society of Chemistry.
Abstract: Electrochemical biosensors allow simple, fast and sensitive analyte detection for various analytical problems. Especially immunosensors are favourable due to specificity and affinity of antigen recognition by the associated antibody. We present a novel electrode array qualified for parallel analysis and increased sample throughput. The chip has nine independent sample chambers. Each chamber contains a circular gold working electrode with a diameter of 1.9 mm that is surrounded by a ring-shaped auxiliary electrode with a platinum surface. The corresponding silver/silver chloride reference electrodes are embedded in a sealing lid. The chip is open to the full range of electrochemical real-time detection methods. Among these techniques, impedance spectroscopy is an attractive tool to detect fast and label-free interfacial changes originating from the biorecognition event at the electrode surface. The capabilities of the novel electrode array are demonstrated using the example of tumour marker tenascin C detection. This glycoprotein of the extracellular matrix is expressed in cancerous tissues, especially in solid tumours such as glioma or breast carcinoma. Electrodes covered with specific antibodies were exposed to tenascin C containing samples. Non-occupied binding sites were identified using a secondary peroxidase-conjugated antibody that generated an insoluble precipitate on the electrode in a subsequent amplification procedure. The charge transfer resistance obtained from impedimetric analysis of ferri-/ferrocyanide conversion at the electrode served as analytic parameter. This assay detected 14 ng (48 fmol) tenascin C that is sufficient for clinical diagnostics. The electrode surface could be regenerated at least 20-fold without loss of its analytical performance.
BibTeX:
@article{Steude2011,
  author = {Steude, Anja and Schmidt, Sabine and Robitzki, Andrea A and Panke, Oliver},
  title = {An electrode array for electrochemical immuno-sensing using the example of impedimetric tenascin C detection},
  journal = {Lab on a Chip},
  publisher = {The Royal Society of Chemistry},
  year = {2011},
  volume = {11},
  number = {17},
  pages = {2884--2892},
  url = {http://dx.doi.org/10.1039/C1LC20267G}
}
Strawhecker KE, Hsieh AJ, Chantawansri TL, Kalcioglu ZI and Van Vliet KJ (2012), "Influence of microstructure on micro-/nano-mechanical measurements of select model transparent poly(urethane urea) elastomers", Polymer., December, 2012. Vol. null(null)
Abstract: Morphology of 4,4′-dicyclohexylmethane diisocyanate–poly(tetramethylene oxide) (PTMO)–diethyltoluenediamine based poly(urethane urea) (PUU) elastomers is investigated by atomic force microscopy (AFM) and compared with elastic modulus data measured from AFM-enabled indentation, dynamic nanoindentation (nanoDMA), and dynamic mechanical analysis (DMA). These measurements highlight the effect of altering the molecular weight (Mw) of PTMO, which is used as a soft segment (SS), on the microstructure. In particular, at SS Mw 2000 g/mol, a strong microphase-separated morphology is observed, whereas a phase-mixed dominated microstructure is noted in PUU with SS Mw of 1000 and 650 g/mol. These observations are also consistent with DMA tan $ results. Furthermore, instrumented impact indentation is also utilized for elucidation of dynamic damping characteristics in these PUUs.
BibTeX:
@article{Strawhecker2012,
  author = {Strawhecker, Kenneth E. and Hsieh, Alex J. and Chantawansri, Tanya L. and Kalcioglu, Z. Ilke and Van Vliet, Krystyn J.},
  title = {Influence of microstructure on micro-/nano-mechanical measurements of select model transparent poly(urethane urea) elastomers},
  journal = {Polymer},
  year = {2012},
  volume = {null},
  number = {null},
  url = {http://dx.doi.org/10.1016/j.polymer.2012.12.018},
  doi = {10.1016/j.polymer.2012.12.018}
}
Strulson MK, Johnson DM and Maurer JA (2012), "Increased Stability of Glycol-Terminated Self-Assembled Monolayers for Long-Term Patterned Cell Culture", Langmuir. Vol. 28(9), pp. 4318-4324.
Abstract: Self-assembled monolayers (SAMs) are widely used to confine proteins and cells to a pattern to study cellular processes and behavior. To fully explore some of these phenomena, it is necessary to control cell growth and confinement for several weeks. Here, we present a simple method by which protein and cellular confinement to a pattern can be maintained for more than 35 days. This represents a significant increase in pattern stability compared to previous monolayer systems and is achieved using an amide-linked glycol monomer on 50 Å titanium/100 Å gold-coated glass coverslips. In addition, this study provides insight into the method of SAM degradation and excludes interfacial mixing of the monomers and blooming of the adlayer as major mechanisms for SAM degradation. Self-assembled monolayers (SAMs) are widely used to confine proteins and cells to a pattern to study cellular processes and behavior. To fully explore some of these phenomena, it is necessary to control cell growth and confinement for several weeks. Here, we present a simple method by which protein and cellular confinement to a pattern can be maintained for more than 35 days. This represents a significant increase in pattern stability compared to previous monolayer systems and is achieved using an amide-linked glycol monomer on 50 Å titanium/100 Å gold-coated glass coverslips. In addition, this study provides insight into the method of SAM degradation and excludes interfacial mixing of the monomers and blooming of the adlayer as major mechanisms for SAM degradation.
BibTeX:
@article{Strulson2012,
  author = {Strulson, Matthew K. and Johnson, Dawn M. and Maurer, Joshua A.},
  title = {Increased Stability of Glycol-Terminated Self-Assembled Monolayers for Long-Term Patterned Cell Culture},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {9},
  pages = {4318--4324},
  url = {http://dx.doi.org/10.1021/la2035533 http://pubs.acs.org/doi/abs/10.1021/la2035533 http://pubs.acs.org/doi/full/10.1021/la2035533},
  doi = {10.1021/la2035533}
}
Strulson MK and Maurer JA (2011), "Microcontact Printing for Creation of Patterned Lipid Bilayers on Tetraethylene Glycol Self-Assembled Monolayers", Langmuir. Vol. 27(19), pp. 12052-12057. American Chemical Society.
Abstract: Supported lipid bilayers (SLBs) formed on many different substrates have been widely used in the study of lipid bilayers. However, most SLBs suffer from inhomogeneities due to interactions between the lipid bilayer and the substrate. In order to avoid this problem, we have used microcontact printing to create patterned SLBs on top of ethylene-glycol-terminated self-assembled monolayers (SAMs). Glycol-terminated SAMs have previously been shown to resist absorbance of biomolecules including lipid vesicles. In our system, patterned lipid bilayer regions are separated by lipid monolayers, which form over the patterned hexadecanethiol portions of the surface. Furthermore, we demonstrate that $-hemolysin, a large transmembrane protein, inserts preferentially into the lipid bilayer regions of the substrate.
BibTeX:
@article{Strulson2011,
  author = {Strulson, Matthew K and Maurer, Joshua A},
  title = {Microcontact Printing for Creation of Patterned Lipid Bilayers on Tetraethylene Glycol Self-Assembled Monolayers},
  journal = {Langmuir},
  publisher = {American Chemical Society},
  year = {2011},
  volume = {27},
  number = {19},
  pages = {12052--12057},
  url = {http://dx.doi.org/10.1021/la201839w},
  doi = {10.1021/la201839w}
}
Su C (2010), "Mapping Quantitative Mechanical Properties at Molecular Scale Using Peak Force Tapping AFM", Microscopy and Microanalysis. Vol. 16(SupplementS2), pp. 364-365.
Abstract: Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.
BibTeX:
@article{Su2010a,
  author = {Su, C},
  title = {Mapping Quantitative Mechanical Properties at Molecular Scale Using Peak Force Tapping AFM},
  journal = {Microscopy and Microanalysis},
  year = {2010},
  volume = {16},
  number = {SupplementS2},
  pages = {364--365},
  url = {http://dx.doi.org/10.1017/S1431927610057132},
  doi = {10.1017/S1431927610057132}
}
Su C, Hu S, Hu Y, Erina N and Slade A (2010), "Quantitative Mechanical Mapping of Biomolecules and Cells in Fluid", In Materials Research Society Symposium Proceedings. Vol. 1261 Materials Research Society, 9800 McKnight Rd., Suite 327 Pittsburgh PA 15237 USA.
Abstract: Though atomic force microscopy (AFM) interrogates biological materials through mechanical interactions, achieving quantitative mechanical information such as modulus and adhesion at high resolution has been a challenging task. A technology for nanometer scale mechanical property mapping, peak force tapping (PFT), was developed to achieve high resolution imaging and quantitative mechanical measurements simultaneously. PFT controls instantaneous interaction force and record force spectroscopy at each pixel to calculate mechanical properties. A feedback loop maintains a constant peak force, a local maximum point in the force spectroscopy, at the level of Pico Newtons throughout the imaging process. Such high precision force controls enable application of ultra-sharp probe to image biological samples in vitro and accomplish molecular resolution in protein membranes. More importantly a full suite of mechanical properties, modulus, adhesion, energy dissipation and deformation are mapped concurrent with topographic imaging. To calculate nanomechanical properties reliably cantilever spring constant and tip shape were calibrated systematically. A method to accurately determine cantilever spring constant, capable of wafer scale cantilever calibration, was developed and tested against traceable force methods. With the knowledge of tip shape, derived from morphological dilation method using a reference sample, mechanical properties measured at the nanometer scale was compared with bench mark materials ranging from 0.7 MPa to 70 GPa. The same method was also applied to OmpG membranes, Lambda DNA strings, as well as live cells. Adhesion force mapping was also applied to detection of biotin/avidin un-bonding events using functionalized probes. The limitation of the measurement accuracy in biology samples will be discussed.
BibTeX:
@inproceedings{Su2010,
  author = {Su, Chanmin and Hu, Shuiqing and Hu, Yan and Erina, Natalia and Slade, Andrea},
  title = {Quantitative Mechanical Mapping of Biomolecules and Cells in Fluid},
  booktitle = {Materials Research Society Symposium Proceedings},
  publisher = {Materials Research Society, 9800 McKnight Rd., Suite 327 Pittsburgh PA 15237 USA},
  year = {2010},
  volume = {1261},
  url = {http://www.csa.com/partners/viewrecord.php?requester=gs&amp;collection=TRD&amp;recid=13847527EP}
}
Su H-N, Chen Z-H, Liu S-B, Qiao L-P, Chen X-L, He H-L, Zhao X, Zhou B-C and Zhang Y-Z (2012), "Characterization of Bacterial Polysaccharide Capsules and Detection in the Presence of Deliquescent Water by Atomic Force Microscopy", Applied and Environmental Microbiology., February, 2012. Vol. 78(9), pp. 3476-3479.
BibTeX:
@article{su_characterization_2012,
  author = {Su, H.-N. and Chen, Z.-H. and Liu, S.-B. and Qiao, L.-P. and Chen, X.-L. and He, H.-L. and Zhao, X and Zhou, B.-C. and Zhang, Y.-Z.},
  title = {Characterization of Bacterial Polysaccharide Capsules and Detection in the Presence of Deliquescent Water by Atomic Force Microscopy},
  journal = {Applied and Environmental Microbiology},
  year = {2012},
  volume = {78},
  number = {9},
  pages = {3476--3479},
  url = {http://aem.asm.org/cgi/doi/10.1128/AEM.00207-12},
  doi = {10.1128/AEM.00207-12}
}
Subramaniam V (2013), "Amyloid at the nanoscale: AFM and single-molecule investigations of early steps of aggregation and mature fibril growth, structure, and mechanics", Bulletin of the American Physical Society., March, 2013. Vol. Volume 58,
BibTeX:
@article{Subramaniam2013,
  author = {Subramaniam, Vinod},
  title = {Amyloid at the nanoscale: AFM and single-molecule investigations of early steps of aggregation and mature fibril growth, structure, and mechanics},
  journal = {Bulletin of the American Physical Society},
  year = {2013},
  volume = {Volume 58,},
  url = {http://meetings.aps.org/Meeting/MAR13/Event/188063}
}
Sun Y-X, Ren K-f, Wang J-l, Chang G-x and Ji J (2013), "Electrochemically Controlled Stiffness of Multilayers for Manipulation of Cell Adhesion", ACS applied materials & interfaces., May, 2013. Vol. 5, pp. 4597-602. American Chemical Society.
Abstract: Stimuli-responsive thin films attract considerable attention in different fields. Herein, an electrochemical redox multilayers with tunable stiffness is constructed through the layer-by-layer self-assembly method. The redox ferrocene modified poly(ethylenimine) play an essential role to induce multilayers' swelling/shrinking under an electrochemical stimulus, resulting reversible change of elastic modulus of the multilayers. The adhesion of fibroblast cells can be thus controlled from well spreading to round shape. Such soft multilayers with electrochemically controlled stiffness could have potentials for cell-based applications.
BibTeX:
@article{Sun2013,
  author = {Sun, Yi-Xin and Ren, Ke-feng and Wang, Jin-lei and Chang, Guo-xun and Ji, Jian},
  title = {Electrochemically Controlled Stiffness of Multilayers for Manipulation of Cell Adhesion},
  journal = {ACS applied materials & interfaces},
  publisher = {American Chemical Society},
  year = {2013},
  volume = {5},
  pages = {4597--602},
  url = {http://dx.doi.org/10.1021/am401088w},
  doi = {10.1021/am401088w}
}
Sweers KKM, Bennink ML and Subramaniam V (2012), "Nanomechanical properties of single amyloid fibrils", J. Phys. Condens. Matter., May, 2012. Vol. 24(24), pp. 243101.
Abstract: Amyloid fibrils are traditionally associated with neurodegenerative diseases like Alzheimer's disease, Parkinson's disease or Creutzfeldt-Jakob disease. However, the ability to form amyloid fibrils appears to be a more generic property of proteins. While disease-related, or pathological, amyloid fibrils are relevant for understanding the pathology and course of the disease, functional amyloids are involved, for example, in the exceptionally strong adhesive properties of natural adhesives. Amyloid fibrils are thus becoming increasingly interesting as versatile nanobiomaterials for applications in biotechnology. In the last decade a number of studies have reported on the intriguing mechanical characteristics of amyloid fibrils. In most of these studies atomic force microscopy (AFM) and atomic force spectroscopy play a central role. AFM techniques make it possible to probe, at nanometer length scales, and with exquisite control over the applied forces, biological samples in different environmental conditions. In this review we describe the different AFM techniques used for probing mechanical properties of single amyloid fibrils on the nanoscale. An overview is given of the existing mechanical studies on amyloid. We discuss the difficulties encountered with respect to the small fibril sizes and polymorphic behavior of amyloid fibrils. In particular, the different conformational packing of monomers within the fibrils leads to a heterogeneity in mechanical properties. We conclude with a brief outlook on how our knowledge of these mechanical properties of the amyloid fibrils can be exploited in the construction of nanomaterials from amyloid fibrils.
BibTeX:
@article{Sweers2012b,
  author = {Sweers, Kim K. M. and Bennink, Martin L. and Subramaniam, Vinod},
  title = {Nanomechanical properties of single amyloid fibrils},
  journal = {J. Phys. Condens. Matter},
  year = {2012},
  volume = {24},
  number = {24},
  pages = {243101},
  url = {http://stacks.iop.org/0953-8984/24/i=24/a=243101},
  doi = {10.1088/0953-8984/24/24/243101}
}
Sweers KKM, Segers-Nolten IMJ, Bennink ML and Subramaniam V (2012), "Structural model for $-synuclein fibrils derived from high resolution imaging and nanomechanical studies using atomic force microscopy", Soft Matter. Vol. 8(27), pp. 3215.
BibTeX:
@article{Sweers2012,
  author = {Sweers, Kim K. M. and Segers-Nolten, Ine M. J. and Bennink, Martin L. and Subramaniam, Vinod},
  title = {Structural model for $-synuclein fibrils derived from high resolution imaging and nanomechanical studies using atomic force microscopy},
  journal = {Soft Matter},
  year = {2012},
  volume = {8},
  number = {27},
  pages = {3215},
  url = {http://xlink.rsc.org/?DOI=c2sm25426c},
  doi = {10.1039/c2sm25426c}
}
Sweers KKM, Van Der Werf K, Bennink ML and Subramaniam V (2011), "Nanomechanical properties of $-synuclein amyloid fibrils: a comparative study by nanoindentation, harmonic force microscopy, and Peakforce QNM", Nanoscale Research Letters., January, 2011. Vol. 6(1), pp. 270. Springer Open Ltd.
Abstract: ABSTRACT: We report on the use of three different atomic force spectroscopy modalities to determine the nanomechanical properties of amyloid fibrils of the human $-synuclein protein. $-Synuclein forms fibrillar nanostructures of approximately 10 nm diameter and lengths ranging from 100 nm to several microns, which have been associated with Parkinson's disease. Atomic force microscopy (AFM) has been used to image the morphology of these protein fibrils deposited on a flat surface. For nanomechanical measurements, we used single-point nanoindentation, in which the AFM tip as the indenter is moved vertically to the fibril surface and back while the force is being recorded. We also used two recently developed AFM surface property mapping techniques: Harmonic force microscopy (HarmoniX) and Peakforce QNM. These modalities allow extraction of mechanical parameters of the surface with a lateral resolution and speed comparable to tapping-mode AFM imaging. Based on this phenomenological study, the elastic moduli of the $-synuclein fibrils determined using these three different modalities are within the range 1.3-2.1 GPa. We discuss the relative merits of these three methods for the determination of the elastic properties of protein fibrils, particularly considering the differences and difficulties of each method.
BibTeX:
@article{Sweers2011,
  author = {Sweers, Kim K. M. and Van Der Werf, Kees and Bennink, Martin L. and Subramaniam, Vinod},
  title = {Nanomechanical properties of $-synuclein amyloid fibrils: a comparative study by nanoindentation, harmonic force microscopy, and Peakforce QNM},
  journal = {Nanoscale Research Letters},
  publisher = {Springer Open Ltd},
  year = {2011},
  volume = {6},
  number = {1},
  pages = {270},
  url = {http://www.nanoscalereslett.com/content/6/1/270},
  doi = {10.1186/1556-276X-6-270}
}
Sweers KKM, van der Werf KO, Bennink ML and Subramaniam V (2012), "Spatially resolved frequency-dependent elasticity measured with pulsed force microscopy and nanoindentation", Nanoscale., March, 2012. Vol. 4(6), pp. 2072. American Chemical Society.
Abstract: Atomic force microscopy (AFM) is widely used to measure morphological and mechanical properties of biological materials at the nanoscale. AFM is able to visualize and measure these properties in different environmental conditions. However, these conditions can influence the results considerably, rendering their interpretation a matter of some subtlety. We demonstrate this by imaging ∼10 nm diameter $-synuclein amyloid fibrils, focusing specifically on the structure of the C-terminal part of the protein monomers incorporated into fibrils. Despite these influences leading to variations in fibril heights, we have shown that by maintaining careful control of AFM settings we can quantitatively compare the morphological parameters of fibrils imaged in air or in buffer conditions. From this comparison we were able to deduce the semiflexible character of this C-terminal region. Fibril height differences measured in air and liquid indicate that the C-terminal region collapses onto the fibril core upon drying. The fibril heights decrease upon increasing ion concentration in solution, suggesting that the C-terminal tails collapse into more compact structures as a result of charge screening. Finally, PeakForce QNM measurements show an apparent heterogeneity of C-terminal packing along the fibril length.
BibTeX:
@article{Sweers2012a,
  author = {Sweers, Kim K. M. and van der Werf, Kees O. and Bennink, Martin L. and Subramaniam, Vinod},
  title = {Spatially resolved frequency-dependent elasticity measured with pulsed force microscopy and nanoindentation},
  journal = {Nanoscale},
  publisher = {American Chemical Society},
  year = {2012},
  volume = {4},
  number = {6},
  pages = {2072},
  url = {http://pubs.rsc.org/en/content/articlelanding/2012/nr/c2nr12066f http://xlink.rsc.org/?DOI=c2nr12066f},
  doi = {10.1039/c2nr12066f}
}
Sweers KKM, van der Werf KO, Bennink ML and Subramaniam V (2012), "Atomic Force Microscopy under Controlled Conditions Reveals Structure of C-Terminal Region of $-Synuclein in Amyloid Fibrils", ACS nano., June, 2012. American Chemical Society.
Abstract: Atomic force microscopy (AFM) is widely used to measure morphological and mechanical properties of biological materials at the nanoscale. AFM is able to visualize and measure these properties in different environmental conditions. However, these conditions can influence the results considerably, rendering their interpretation a matter of some subtlety. We demonstrate this by imaging ∼10 nm diameter $-synuclein amyloid fibrils, focusing specifically on the structure of the C-terminal part of the protein monomers incorporated into fibrils. Despite these influences leading to variations in fibril heights, we have shown that by maintaining careful control of AFM settings we can quantitatively compare the morphological parameters of fibrils imaged in air or in buffer conditions. From this comparison we were able to deduce the semiflexible character of this C-terminal region. Fibril height differences measured in air and liquid indicate that the C-terminal region collapses onto the fibril core upon drying. The fibril heights decrease upon increasing ion concentration in solution, suggesting that the C-terminal tails collapse into more compact structures as a result of charge screening. Finally, PeakForce QNM measurements show an apparent heterogeneity of C-terminal packing along the fibril length.
BibTeX:
@article{Sweers2012a,
  author = {Sweers, Kim K. M. and van der Werf, Kees O. and Bennink, Martin L. and Subramaniam, Vinod},
  title = {Atomic Force Microscopy under Controlled Conditions Reveals Structure of C-Terminal Region of $-Synuclein in Amyloid Fibrils},
  journal = {ACS nano},
  publisher = {American Chemical Society},
  year = {2012},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/22695112 http://dx.doi.org/10.1021/nn300863n},
  doi = {10.1021/nn300863n}
}
Sweers KKM, van der Werf KO, Bennink ML and Subramaniam V (2012), "Frequency dependent behavior HarmoniX training sample measured with Peakforce QNM" , pp. 1-5.
Abstract: Recently several atomic force microscopy (AFM)?based surface property mapping techniques like pulsed force microscopy (PFM), harmonic force microscopy or Peakforce QNM®, have been introduced to measure the nano? and micro?mechanical properties of materials. These modes all work at different operating frequencies. However, complex materials are known to display viscoelastic behavior, a combination of solid and fluid?like responses, depending on the frequency at which the sample is probed. In this report, we show that the frequency?dependent mechanical behavior of complex materials, such as polymer blends that are frequently used as calibration samples, is clearly measurable with AFM. Although this frequency?dependent mechanical behavior is an established observation, we demonstrate that the new high frequency mapping techniques enable AFM?based rheology with nanoscale spatial resolution over a much broader frequency range compared to previous AFM?based studies. We further highlight that it is essential to account for the frequency?dependent variation in mechanical properties when using these thin polymer samples as calibration materials for elasticity measurements by high?frequency surface property mapping techniques. These results have significant implications for the accurate interpretation of the nanomechanical properties of polymers or complex biological samples. The calibration sample is composed of a blend of soft and hard polymers, consisting of low?density polyethylene (LDPE) islands in a polystyrene (PS) surrounding, with a stiffness of 0.2 GPa and 2 GPa respectively. The spring constant of the AFM cantilever was selected to match the stiffness of LDPE. From 260 Hz to 1100 Hz the sample was imaged with the PFM method. At low frequencies (0.5 – 35 Hz), single?point nanoindentation was performed. In addition to the material’s stiffness, the relative heights of the LDPE islands (with respect to the PS) were determined as a function of the frequency. At the lower operation frequencies for PFM, the islands exhibited lower heights than when measured with tapping mode at 120 kHz. Both spring constants and heights at the different frequencies clearly show a frequency dependent behavior.
BibTeX:
@article{Sweers2012c,
  author = {Sweers, Kim K. M. and van der Werf, Kees O. and Bennink, Martin L. and Subramaniam, Vinod},
  title = {Frequency dependent behavior HarmoniX training sample measured with Peakforce QNM},
  year = {2012},
  pages = {1--5}
}
Tan J-c, Saines PJ, Bithell EG and Cheetham AK (2012), "Hybrid Nanosheets of an Inorganic–Organic Framework Material: Facile Synthesis, Structure, and Elastic Properties", ACS Nano. Vol. 6(1), pp. 615-21. American Chemical Society.
Abstract: We report a new 2-D inorganic?organic framework material, MnDMS [Mn 2,2-dimethylsuccinate], featuring weakly bound hybrid layers in its bulk crystals that can be readily exfoliated into nanosheets via ultrasonication. The fully exfoliated hybrid nanosheets correspond to a unilamellar thickness of about 1 nm, while the partially exfoliated nanosheets (multilayer films) exhibit a typical thickness on the order of 10 nm. We used atomic force microscopy to characterize their surface topography and to map the variation of nanomechanical properties across the surface of the delaminated nanosheets. The morphology and crystallographic orientation of the exfoliated layers were further studied by transmission electron microscopy. Additionally, we investigated the elastic anisotropy underlying the bulk host material by means of single-crystal nanoindentation, from which the critical resolved shear stress ($crit) needed for the micromechanical delamination of individual layers was determined to be relatively small (?0.4 GPa).
BibTeX:
@article{Tan2012,
  author = {Tan, Jin-chong and Saines, Paul J. and Bithell, Erica G. and Cheetham, Anthony K.},
  title = {Hybrid Nanosheets of an Inorganic–Organic Framework Material: Facile Synthesis, Structure, and Elastic Properties},
  journal = {ACS Nano},
  publisher = {American Chemical Society},
  year = {2012},
  volume = {6},
  number = {1},
  pages = {615--21},
  url = {http://pubs.acs.org/doi/full/10.1021/nn204054k},
  doi = {10.1021/nn204054k}
}
Tang Y and McNeill CR (2013), "All-polymer solar cells utilizing low band gap polymers as donor and acceptor", Journal of Polymer Science Part B: Polymer Physics., March, 2013. Vol. 51(6), pp. 403-409.
Abstract: All-polymer solar cells based on blends of the low band gap polymers poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl] (PTB7) and poly[N,N-9-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,59-(2,29-bithiophene) (P(NDI2OD-T2)) are demonstrated. The use of the donor polymer PTB7 instead of poly(3-hexylthiophene) results in a higher open-circuit voltage and an overall spectral response better matched to the solar spectrum. A power conversion efficiency of 1.1% is reported with a peak external quantum efficiency of 18% at a wavelength of 680 nm. The microstructure of PTB7:P(NDI2OD-T2) blends is also investigated using a combination of grazing-incidence wide-angle X-ray scattering (GIWAXS), near-edge X-ray fine-structure (NEXAFS) spectroscopy, atomic force microscopy (AFM), and scanning transmission X-ray microscopy (STXM). GIWAXS measurements show that PTB7:P(NDI2OD-T2) blends contain P(NDI2OD-T2) crystallites with a (100) thickness of 9.5 nm dispersed in an amorphous PTB7 matrix. STXM measurements indicate a lack of mesoscale phase separation, with AFM and NEXAFS measurements revealing a P(NDI2OD-T2)-rich top surface with fibrillar morphology. These results indicate that the pairing of low band gap polymers as both donor and acceptor polymers in all-polymer solar cells may be an effective strategy for realizing high-efficiency all-polymer solar cells.
BibTeX:
@article{tang_all-polymer_2013,
  author = {Tang, Yaqi and McNeill, Christopher R},
  title = {All-polymer solar cells utilizing low band gap polymers as donor and acceptor},
  journal = {Journal of Polymer Science Part B: Polymer Physics},
  year = {2013},
  volume = {51},
  number = {6},
  pages = {403--409},
  url = {http://doi.wiley.com/10.1002/polb.23233},
  doi = {10.1002/polb.23233}
}
Tercjak A, Bergareche A, Caballero C, Tu non T and Linazasoro G (2013), "Lewy Bodies under Atomic Force Microscope.", Ultrastructural Pathology., October, 2013. Informa Healthcare USA, Inc. New York.
Abstract: Abstract Lewy bodies are the hallmark of Parkinson disease and their sophisticated analysis will undoubtedly elucidate the pathogenic process. They have been studied by using different microscopic tools. The authors have used atomic force microscopy (AFM) to study the ultramicrotom cut postmortem brain tissue of Parkinson disease patients. Under the same preparation conditions, they have found aggregated fibrillary nanostructures in Lewy bodies, as well as a loss of connections between neurons located in other parts of the substantia nigra. Although these results are preliminary and descriptive in nature, this paper reports the application of a novel and intriguing technique. Further studies including the study of cortical LB and Lewy neurites will be needed to determine the full potential of AFM in the study of the pathogenesis of cell death in Parkinson disease and other synucleinopathies.
BibTeX:
@article{Tercjak2013,
  author = {Tercjak, Agnieszka and Bergareche, Alberto and Caballero, Cristina and Tuñon, Teresa and Linazasoro, Gurutz},
  title = {Lewy Bodies under Atomic Force Microscope.},
  journal = {Ultrastructural Pathology},
  publisher = {Informa Healthcare USA, Inc. New York},
  year = {2013},
  url = {http://informahealthcare.com/doi/abs/10.3109/01913123.2013.825689},
  doi = {10.3109/01913123.2013.825689}
}
Thong YX, Poon YF, Chen T, Li L and Chan?Park MB (2013), "Direct Intermolecular Force Measurements between Functional Groups and Individual Metallic or Semiconducting Single?Walled Carbon Nanotubes", Small., September, 2013.
BibTeX:
@article{Thong2013,
  author = {Thong, Ya Xuan and Poon, Yin Fun and Chen, Tzu?Yin and Li, Lain?Jong and Chan?Park, Mary B.},
  title = {Direct Intermolecular Force Measurements between Functional Groups and Individual Metallic or Semiconducting Single?Walled Carbon Nanotubes},
  journal = {Small},
  year = {2013},
  url = {http://onlinelibrary.wiley.com/doi/10.1002/smll.201302084/full},
  doi = {10.1002/smll.201302084}
}
Tielemans M, Roose P, Ngo C, Lazzaroni R and Leclère P (2012), "Multiphase coatings from complex radiation curable polyurethane dispersions", Progress in Organic Coatings., June, 2012.
Abstract: The waterborne nature of radiation curable polyurethane dispersions largely respond to the current environmental concerns and do not require any additional coalescent since the film formation (drying) and hardening (photo-curing) take place in distinct steps. It is possible to design aqueous dispersions with distinct polymer particle populations resulting in micro-structured coatings with optimized properties over a wide range of curing conditions. Mixed dispersions based on hard and soft acrylated polyurethane particles were used as model systems for the present study. The minimum film formation temperature has been investigated as a function of the hard:soft polymer ratio. The elastic modulus of the dry coatings shows a reinforcing effect consistent with the inclusion of hard domains in a soft continuous matrix. However, the level of reinforcement is not properly predicted by the usual mechanical models and it is qualitatively accounted for by assuming a composition gradient (interphase) between the hard domains and the matrix. The multiple-phase structure was clearly established by Atomic Force Microscopy in agreement with thermal analysis data. Furthermore the local nanoscale mechanical properties were mapped using a new imaging mode based on real-time force–distance curve analysis. Finally, the coatings prepared using this multiple-phase pattern present a clear benefit over conventional homogeneous coatings by offering an improved balance of chemical and mechanical resistance in pigmented systems applied on melamine-coated MDF panels.
BibTeX:
@article{Tielemans2012,
  author = {Tielemans, Michel and Roose, Patrice and Ngo, Chinh and Lazzaroni, Roberto and Leclère, Philippe},
  title = {Multiphase coatings from complex radiation curable polyurethane dispersions},
  journal = {Progress in Organic Coatings},
  year = {2012},
  url = {http://dx.doi.org/10.1016/j.porgcoat.2012.05.010},
  doi = {10.1016/j.porgcoat.2012.05.010}
}
Tong WY, Shen W, Yeung CWF, Zhao Y, Cheng SH, Chu PK, Chan D, Chan GCF, Cheung KMC, Yeung KWK and Lam YW (2012), "Functional replication of the tendon tissue microenvironment by a bioimprinted substrate and the support of tenocytic differentiation of mesenchymal stem cells", Biomaterials., July, 2012. Vol. 33(31), pp. 7686-98. Elsevier Ltd.
Abstract: Although many studies have demonstrated that cell phenotype is affected by the surface properties of biomaterials, these materials often fail to mimic the complexity of the native tissue microenvironment (TME). In this study, we have developed a new experimental model that allows the characterisation and functional reconstruction of natural TME. We discovered that mesenchymal stem cells (MSC) cultured on cryostat sections of bovine Achilles tendon adopted an elongated and aligned morphology, and expressed tenocyte marker tenomodulin (TNMD). This suggests that tendon sections contain the signalling cues that guide MSCs to commit to the tenogenic lineage. To reconstruct this instructive niche, we prepared PDMS replica by using tendon sections as template. The resulting bioimprint faithfully copied the physical topography and elasticity of the section. This replica, when coated with collagen 1, supported tenogenesis of MSC without requiring exogenous growth factors. This study illustrates how extracellular biophysical and biochemical features intertwines to form a niche that influences the cell fate and demonstrated that such complex information could be conveniently reconstructed with synthetic materials and purified extracellular matrix proteins.
BibTeX:
@article{Tong2012,
  author = {Tong, Wing Yin and Shen, Wei and Yeung, Connie W F and Zhao, Ying and Cheng, Shuk Han and Chu, Paul K and Chan, Danny and Chan, Godfrey C F and Cheung, Kenneth M C and Yeung, Kelvin W K and Lam, Yun Wah},
  title = {Functional replication of the tendon tissue microenvironment by a bioimprinted substrate and the support of tenocytic differentiation of mesenchymal stem cells},
  journal = {Biomaterials},
  publisher = {Elsevier Ltd},
  year = {2012},
  volume = {33},
  number = {31},
  pages = {7686--98},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/22818988},
  doi = {10.1016/j.biomaterials.2012.07.002}
}
Toth PS, Valota AT, Velický M, Kinloch IA, Novoselov KS, Hill EW and Dryfe RAW (2014), "Electrochemistry in a drop: a study of the electrochemical behaviour of mechanically exfoliated graphene on photoresist coated silicon substrate", Chemical Science., October, 2014. Vol. 5, pp. 582-9. The Royal Society of Chemistry.
Abstract: A micro apparatus for electrochemical studies on individual high quality graphene flakes is presented. A microinjection-micromanipulator system has been employed to deposit droplets of aqueous solutions containing redox-active species directly on selected micro-scale areas of mechanically exfoliated graphene layers on polymer coated silicon wafers. This approach allows the clear distinction between the electrochemical activity of pristine basal planes and the edges (defects) or steps to be measured. Voltammetric measurements were performed in a two-electrode configuration, and the standard heterogeneous electron transfer rate (k?) for reduction of hexachloroiridate (IrCl6 2?) was estimated. The kinetics of electron transfer were evaluated for several types of graphene: mono, bi, and few layer basal planes, and the k? was estimated for an edge/step between two few layer graphene flakes. As a comparison, the kinetic behaviour of graphite basal planes was measured for the deposited aqueous droplets. The appearance of ruptures on the graphene monolayer was observed after deposition of the aqueous solution for the case of graphene on a bare silicon/silicon oxide substrate.
BibTeX:
@article{Toth2013,
  author = {Toth, Peter S. and Valota, Anna T. and Velický, Matěj and Kinloch, Ian A. and Novoselov, Kostya S. and Hill, Ernie W. and Dryfe, Robert A. W.},
  title = {Electrochemistry in a drop: a study of the electrochemical behaviour of mechanically exfoliated graphene on photoresist coated silicon substrate},
  journal = {Chemical Science},
  publisher = {The Royal Society of Chemistry},
  year = {2014},
  volume = {5},
  pages = {582--9},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/sc/c3sc52026a http://xlink.rsc.org/?DOI=c3sc52026a},
  doi = {10.1039/c3sc52026a}
}
Trtik P, Kaufmann J and Volz U (2011), "On the use of peak-force tapping atomic force microscopy for quantification of the local elastic modulus in hardened cement paste", Cement and Concrete Research. Vol. 42(1), pp. 215-221.
Abstract: A surface of epoxy-impregnated hardened cement paste was investigated using a novel atomic force microscopy (AFM) imaging mode that allows for the quantitative mapping of the local elastic modulus. The analyzed surface was previously prepared using focussed ion beam milling. The same surface was also characterized by electron microscopy and energy-dispersive X-ray spectroscopy. We demonstrate the capability of this quantitative nanomechanical mapping to provide information on the local distribution of the elastic modulus (from about 1 to about 100 GPa) with a spatial resolution in the range of decananometres, that corresponds to that of low-keV back-scattered electron imaging. Despite some surface roughness which affects the measured nanomechanical properties it is shown that topography, adhesion and Young's modulus can be clearly distinguished. The quantitative mapping of the local elastic modulus is able to discriminate between phases in the cement paste microstructure that cannot be distinguished from the corresponding back-scattered electron images.
BibTeX:
@article{Trtik2011,
  author = {Trtik, Pavel and Kaufmann, Josef and Volz, Udo},
  title = {On the use of peak-force tapping atomic force microscopy for quantification of the local elastic modulus in hardened cement paste},
  journal = {Cement and Concrete Research},
  year = {2011},
  volume = {42},
  number = {1},
  pages = {215--221},
  url = {http://www.sciencedirect.com/science/article/pii/S0008884611002316},
  doi = {10.1016/j.cemconres.2011.08.009}
}
Tsou A and Yablon D (2013), "Atomic Force Microscopy of Polymers", Scanning Probe Microscopy for Industrial ldots.
BibTeX:
@article{Tsou2013,
  author = {Tsou, AH and Yablon, DG},
  title = {Atomic Force Microscopy of Polymers},
  journal = {Scanning Probe Microscopy for Industrial ldots},
  year = {2013},
  url = {http://books.google.com/books?hl=en&lr=&id=pcl8AQAAQBAJ&oi=fnd&pg=PA210&ots=mHoTHh5pKr&sig=3-xzCCQPf3nt3-z0lZyPVnwLUTQ}
}
Udeh CU, Rannou P, Brown BP, Thomas JO and Faul CFJ (2013), "Tuning structure and function in tetra(aniline)-based rod–coil–rod architectures", Journal of Materials Chemistry C. Vol. 1(39), pp. 6428.
BibTeX:
@article{Udeh2013,
  author = {Udeh, Chinwe U. and Rannou, Patrice and Brown, Benjamin P. and Thomas, James O. and Faul, Charl F. J.},
  title = {Tuning structure and function in tetra(aniline)-based rod–coil–rod architectures},
  journal = {Journal of Materials Chemistry C},
  year = {2013},
  volume = {1},
  number = {39},
  pages = {6428},
  url = {http://xlink.rsc.org/?DOI=c3tc31088d},
  doi = {10.1039/c3tc31088d}
}
Ujihara M, Ahmed MMM, Imae T and Yamauchi Y (2013), "Massive-Exfoliation of Magnetic Graphene from Acceptor–Type GIC by Long-Chain Alkyl Amine", Journal of Materials Chemistry A., December, 2013. (207890) The Royal Society of Chemistry.
Abstract: Graphene can be prepared from a graphite intercalation compound (GIC) with acceptor-type intercalator, FeCl3. When the FeCl3-GIC is treated with primary amines at 90 °C for 6 h, the GIC is expanded to a few layers. The expansion is further facilitated, as the alkyl chain of primary amines becomes longer, while tertiary amines cannot penetrate inside the GIC because of their structural steric hindrance. The primary amine adsorbed in the GIC is oriented to form a bilayer by an indirect reaction among FeCl3-graphene-amine, and this process plays an important role on the expansion of GIC, as contrasted to the reaction of primary amines with donor-type GICs. Then the expanded-GIC is sonicated to exfoliate the graphene sheets. The obtained material indicated a superparamagnetic property due to the remaining iron compounds. This approach using FeCl3-GIC and primary amine is preferable for the mass production of graphene because of the mild reaction condition and the short treatment time for exfoliation from the chemically stable FeCl3-GIC. Moreover, the magnetization of graphene nano-composites could be useful for the magnetic-recovery process, electromagnetic heating, and the other applications.
BibTeX:
@article{Ujihara2013,
  author = {Ujihara, Masaki and Ahmed, Mahmoud Mohamed Mahmoud and Imae, Toyoko and Yamauchi, Yusuke},
  title = {Massive-Exfoliation of Magnetic Graphene from Acceptor–Type GIC by Long-Chain Alkyl Amine},
  journal = {Journal of Materials Chemistry A},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  number = {207890},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/ta/c3ta14117a http://pubs.rsc.org/en/Content/ArticleLanding/2013/TA/c3ta14117a},
  doi = {10.1039/c3ta14117a}
}
Usov I, Adamcik J and Mezzenga R (2013), "Polymorphism in bovine serum albumin fibrils: morphology and statistical analysis", Faraday Discussions., October, 2013. Vol. 166, pp. 151. The Royal Society of Chemistry.
Abstract: We investigate the self-assembly process of the globular protein bovine serum albumin (BSA) into fibrillar structures upon incubating the protein solution at high temperature (90 °C) and in an acidic environment (pH 2) for several days. The investigation is performed by atomic force microscopy (AFM) on the self-assembled fibrillar structures, adsorbed on mica substrates from a solution at different fibrillation time snapshots. A rigorous study of structural morphology reveals a sophisticated hierarchy of the BSA fibrils, where two major classes can be identified: flexible and rigid fibrils, with an order of magnitude of difference in their stiffness. Furthermore, each main class can be divided into two subclasses of thin and thick fibrils according to their average height. It is also shown that all types of flexible ribbon-like fibrils at some stage can wrap and close into nanotubes, that is into a rigid class of fibril. A precise statistical analysis of all the subclasses identified is developed throughout the manuscript. The determination of height and contour length distributions, persistence lengths, and other topological characteristics is carried out by processing the coordinates of BSA fibrils acquired from AFM imaging using in-house developed software. The resulting statistical analysis allows better understanding the fibrillation process and the structural properties of the BSA fibrils.
BibTeX:
@article{Usov2013,
  author = {Usov, Ivan and Adamcik, Jozef and Mezzenga, Raffaele},
  title = {Polymorphism in bovine serum albumin fibrils: morphology and statistical analysis},
  journal = {Faraday Discussions},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {166},
  pages = {151},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/fd/c3fd00083d http://xlink.rsc.org/?DOI=c3fd00083d},
  doi = {10.1039/c3fd00083d}
}
Vasilev C, Brindley AA, Olsen JD, Saer RG, Beatty JT and Hunter CN (2013), "Nano-mechanical mapping of the interactions between surface-bound RC-LH1-PufX core complexes and cytochrome c 2 attached to an AFM probe.", Photosynthesis Research., March, 2013.
Abstract: Electron transfer pathways in photosynthesis involve interactions between membrane-bound complexes such as reaction centres with an extrinsic partner. In this study, the biological specificity of electron transfer between the reaction centre-light-harvesting 1-PufX complex and its extrinsic electron donor, cytochrome c 2, formed the basis for mapping the location of surface-attached RC-LH1-PufX complexes using atomic force microscopy (AFM). This nano-mechanical mapping method used an AFM probe functionalised with cyt c 2 molecules to quantify the interaction forces involved, at the single-molecule level under native conditions. With surface-bound RC-His12-LH1-PufX complexes in the photo-oxidised state, the mean interaction force with cyt c 2 is approximately 480 pN with an interaction frequency of around 66  The latter value lowered 5.5-fold when chemically reduced RC-His12-LH1-PufX complexes are imaged in the dark to abolish electron transfer from cyt c 2 to the RC. The correspondence between topographic and adhesion images recorded over the same area of the sample shows that affinity-based AFM methods are a useful tool when topology alone is insufficient for spatially locating proteins at the surface of photosynthetic membranes.
BibTeX:
@article{Vasilev2013,
  author = {Vasilev, Cvetelin and Brindley, Amanda A and Olsen, John D and Saer, Rafael G and Beatty, J T and Hunter, C N},
  title = {Nano-mechanical mapping of the interactions between surface-bound RC-LH1-PufX core complexes and cytochrome c 2 attached to an AFM probe.},
  journal = {Photosynthesis Research},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23539360},
  doi = {10.1007/s11120-013-9812-7}
}
Volpatti LR and Knowles TPJ (2014), "Polymer physics inspired approaches for the study of the mechanical properties of amyloid fibrils", Journal of Polymer Science Part B: Polymer Physics., February, 2014. Vol. 52(4), pp. 281-92.
BibTeX:
@article{Volpatti2013,
  author = {Volpatti, Lisa R. and Knowles, Tuomas P. J.},
  title = {Polymer physics inspired approaches for the study of the mechanical properties of amyloid fibrils},
  journal = {Journal of Polymer Science Part B: Polymer Physics},
  year = {2014},
  volume = {52},
  number = {4},
  pages = {281--92},
  url = {http://doi.wiley.com/10.1002/polb.23428},
  doi = {10.1002/polb.23428}
}
Vuluga Z, Panaitescu DM, Radovici C, Nicolae C and Iorga MD (2012), "Effect of SEBS on morphology, thermal, and mechanical properties of PP/organoclay nanocomposites", Polymer Bulletin., June, 2012. Vol. 69(9), pp. 1073-1091.
Abstract: A simultaneously increase in stiffness and toughness is needed for improving polypropylene (PP) competitiveness in automotive industry. The aim of this paper is to investigate the effects of styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) on mechanical and thermal properties of PP, in the presence and the absence of nanoclay. The amount of SEBS in PP was ranged to obtain the matrix with the most favorable stiffness–toughness balance. For this purpose, SEBS domain size and distribution in PP/SEBS blends was determined by means of atomic force microscopy and correlated with mechanical properties. The influence of SEBS on the crystalline structure of PP in PP/organoclay nanocomposites was investigated by X-ray diffraction and differential scanning calorimetry, a synergistic effect of SEBS and nanoclay being pointed out. Moreover large improvement in the impact strength (almost 22 times) was obtained in the case of SEBS-containing nanocomposite in comparison with the composite without SEBS.
BibTeX:
@article{vuluga_effect_2012,
  author = {Vuluga, Zina and Panaitescu, Denis Mihaela and Radovici, Constantin and Nicolae, Cristian and Iorga, Michaela Doina},
  title = {Effect of SEBS on morphology, thermal, and mechanical properties of PP/organoclay nanocomposites},
  journal = {Polymer Bulletin},
  year = {2012},
  volume = {69},
  number = {9},
  pages = {1073--1091},
  url = {http://link.springer.com/10.1007/s00289-012-0780-4},
  doi = {10.1007/s00289-012-0780-4}
}
Walczyk W, Schön PM and Schönherr H (2013), "The effect of PeakForce tapping mode AFM imaging on the apparent shape of surface nanobubbles.", Journal of physics. Condensed matter : an Institute of Physics journal., May, 2013. Vol. 25(18), pp. 184005.
Abstract: Until now, TM AFM (tapping mode or intermittent contact mode atomic force microscopy) has been the most often applied direct imaging technique to analyze surface nanobubbles at the solid-aqueous interface. While the presence and number density of nanobubbles can be unequivocally detected and estimated, it remains unclear how much the a priori invasive nature of AFM affects the apparent shapes and dimensions of the nanobubbles. To be able to successfully address the unsolved questions in this field, the accurate knowledge of the nanobubbles' dimensions, radii of curvature etc is necessary. In this contribution we present a comparative study of surface nanobubbles on HOPG (highly oriented pyrolytic graphite) in water acquired with (i) TM AFM and (ii) the recently introduced PFT (PeakForce tapping) mode, in which the force exerted on the nanobubbles rather than the amplitude of the resonating cantilever is used as the AFM feedback parameter during imaging. In particular, we analyzed how the apparent size and shape of nanobubbles depend on the maximum applied force in PFT AFM. Even for forces as small as 73 pN, the nanobubbles appeared smaller than their true size, which was estimated from an extrapolation of the bubble height to zero applied force. In addition, the size underestimation was found to be more pronounced for larger bubbles. The extrapolated true nanoscopic contact angles for nanobubbles on HOPG, measured in PFT AFM, ranged from 145° to 175° and were only slightly underestimated by scanning with non-zero forces. This result was comparable to the nanoscopic contact angles of 160°-175° measured using TM AFM in the same set of experiments. Both values disagree, in accordance with the literature, with the macroscopic contact angle of water on HOPG, measured here to be 63° ± 2°.
BibTeX:
@article{Walczyk2013,
  author = {Walczyk, Wiktoria and Schön, Peter M and Schönherr, Holger},
  title = {The effect of PeakForce tapping mode AFM imaging on the apparent shape of surface nanobubbles.},
  journal = {Journal of physics. Condensed matter : an Institute of Physics journal},
  year = {2013},
  volume = {25},
  number = {18},
  pages = {184005},
  url = {http://stacks.iop.org/0953-8984/25/i=18/a=184005},
  doi = {10.1088/0953-8984/25/18/184005}
}
Wallace JM (2012), "Applications of atomic force microscopy for the assessment of nanoscale morphological and mechanical properties of bone", Bone., January, 2012. Vol. 50(1), pp. 420-427.
Abstract: Scanning probe microscopy (SPM) has been in use for 30years, and the form of SPM known as atomic force microscopy (AFM) has been around for 25 of those years. AFM has been used to produce high resolution images of a variety of samples ranging from DNA to carbon nanotubes. Type I collagen and many collagen-based tissues (including dentin, tendon, cartilage, skin, fascia, vocal cords, and cornea) have been studied with AFM, but comparatively few studies of bone have been undertaken. The purpose of this review is to introduce the general principles of AFM operation, demonstrate what AFM has been used for in bone research, and discuss the new directions that this technique can take the study of bone at the nanoscale.
BibTeX:
@article{wallace_applications_2012,
  author = {Wallace, Joseph M},
  title = {Applications of atomic force microscopy for the assessment of nanoscale morphological and mechanical properties of bone},
  journal = {Bone},
  year = {2012},
  volume = {50},
  number = {1},
  pages = {420--427},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S8756328211013470},
  doi = {10.1016/j.bone.2011.11.008}
}
Wallace JM, Harding C and Kemp A (2012), "Effects of Hydration on Nanoscale Structural Morphology and Mechanics of Individual Type I Collagen Fibrils", MRS Proceedings volume 1465., May, 2012. Vol. 1465 MRS.
Abstract: Type I collagen is one of the most vital proteins in our bodies and serves a number of structural roles. Despite collagen’s importance, little is known about its nanoscale morphology in tissues and how morphology relates to mechanical function. This study directly probes nanoscale structure and mechanics in collagen as a function of hydration utilizing atomic force microscopy investigations of the mouse tail tendon. We demonstrate that collagen morphology and mechanical properties at the nanoscale change with dehydration, indicating that hydration is a factor which must be considered when performing studies at any length scale in collagen-based tissues. Studies are underway to further investigate this phenomenon and to determine how these properties change with disease in tendon and other Type I collagen-based tissues.
BibTeX:
@article{wallace_effects_2012,
  author = {Wallace, J. M. and Harding, Chad and Kemp, Arika},
  title = {Effects of Hydration on Nanoscale Structural Morphology and Mechanics of Individual Type I Collagen Fibrils},
  journal = {MRS Proceedings volume 1465},
  publisher = {MRS},
  year = {2012},
  volume = {1465},
  url = {http://journals.cambridge.org/abstractS1946427412009268},
  doi = {10.1557/opl.2012.926}
}
Wang D, Russell TP, Nishi T and Nakajima K (2013), "Atomic Force Microscopy Nanomechanics Visualizes Molecular Diffusion and Microstructure at an Interface", ACS Macro Letters., August, 2013. , pp. 757-760. American Chemical Society.
Abstract: Here we demonstrate a simple, yet powerful method, atomic force microscopy (AFM) nanomechanical mapping, to directly visualize the interdiffusion and microstructure at the interface between two polymers. Nanomechanical measurements on the interface between poly(vinyl chloride) (PVC) and poly(caprolactone) (PCL) allow quantification of diffusion kinetics, observation of microstructure, and evaluation of mechanical properties of the interdiffusion regions. These results suggest that nanomechanical mapping of interdiffusion enables the quantification of diffusion with high resolution over large distances without the need of labeling and the assessment of mechanical property changes resulting from the interdiffusion.
BibTeX:
@article{Wang2013b,
  author = {Wang, Dong and Russell, Thomas P and Nishi, Toshio and Nakajima, Ken},
  title = {Atomic Force Microscopy Nanomechanics Visualizes Molecular Diffusion and Microstructure at an Interface},
  journal = {ACS Macro Letters},
  publisher = {American Chemical Society},
  year = {2013},
  pages = {757--760},
  url = {http://dx.doi.org/10.1021/mz400281f},
  doi = {10.1021/mz400281f}
}
Wang K, Ren H, Yi C, Liu C, Wang H, Huang L, Zhang H, Karim A and Gong X (2013), "Solution-Processed Fe3O4 Magnetic Nanoparticle Thin Film Aligned by an External Magnetostatic Field as a Hole Extraction Layer for Polymer Solar Cells.", ACS applied materials & interfaces., October, 2013. American Chemical Society.
Abstract: We report, for the first time, the effect of a solution-processed Fe3O4 magnetic nanoparticle (MNP) thin film and a Fe3O4 MNP thin film aligned by an external magnetostatic field, used as a hole extraction layer (HEL), respectively, in polymer solar cells (PSCs). The thin film of a Fe3O4 MNP shows a smoother surface, better transparency, and higher electrical conductivity than that of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin layer. Moreover, the thin film of a Fe3O4 MNP aligned by an external magnetostatic field possesses an enhanced electrical conductivity and lower internal series resistance, thus leading to greater than 13% enhancement in the power conversion efficiency of PSCs than those using a PEDOT:PSS thin film. It was also found that PSCs incorporated with a Fe3O4 MNP shows better stability compared with those using PEDOT:PSS as an anode buffer layer. These results demonstrated that utilization of a Fe3O4 MNP as a HEL in PSCs blazes a trail to achieve highly efficient and long-time-stable devices.
BibTeX:
@article{Wang2013a,
  author = {Wang, Kai and Ren, He and Yi, Chao and Liu, Chang and Wang, Hangxing and Huang, Lin and Zhang, Haoli and Karim, Alamgir and Gong, Xiong},
  title = {Solution-Processed Fe3O4 Magnetic Nanoparticle Thin Film Aligned by an External Magnetostatic Field as a Hole Extraction Layer for Polymer Solar Cells.},
  journal = {ACS applied materials & interfaces},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://dx.doi.org/10.1021/am4033179},
  doi = {10.1021/am4033179}
}
Wang M, Liu C, Thormann E and Dedinaite A (2013), "Hyaluronan and Phospholipid Association in Biolubrication.", Biomacromolecules., October, 2013. American Chemical Society.
Abstract: It is becoming increasingly clear that the outstanding lubrication of synovial joints is achieved by a sophisticated hierarchical structure of cartilage combined with synergistic actions of surface-active components present in the synovial fluid. In this work we focus on the association of two components of the synovial fluid, hyaluronan and dipalmitoyl phosphatidyl choline (DPPC), in bulk solution and at interfaces. We demonstrate that hyaluronan associates with DPPC vesicles and adsorbs to supported DPPC bilayers. The association structures formed at the interface are sufficiently stable to allow sequential adsorption of DPPC and hyaluronan, whereby promoting formation of thick composite layers of these two components. The lubricating ability of such composite layers was probed by the AFM colloidal probe technique and found to be very favorable with low friction coefficients and high load bearing capacity. With DPPC as the last adsorbed component a friction coefficient of 0.01 was found up to pressures significantly above what is encountered in healthy synovial joints. Hyaluronan as the last added component increases the friction coefficient to 0.03 and decreases the load bearing capacity somewhat (but still above what is needed in the synovial joint). Our data demonstrate that self-assembly structures formed by hyaluronan and phospholipids at interfaces are efficient aqueous lubricants, and it seems plausible that such self-assembly structures contribute to the exceptional lubrication of synovial joints.
BibTeX:
@article{Wang2013,
  author = {Wang, Min and Liu, Chao and Thormann, Esben and Dedinaite, Andra},
  title = {Hyaluronan and Phospholipid Association in Biolubrication.},
  journal = {Biomacromolecules},
  publisher = {American Chemical Society},
  year = {2013},
  url = {http://pubs.acs.org/doi/abs/10.1021/bm400947v},
  doi = {10.1021/bm400947v}
}
Wang M, Peng Z, Vasilev K and Ketheesan N (2013), "Investigation of Wear Particles Generated in Human Knee Joints Using Atomic Force Microscopy", Tribology Letters., May, 2013. Vol. 51(1), pp. 161-170.
BibTeX:
@article{Wang2013c,
  author = {Wang, M. and Peng, Z. and Vasilev, K. and Ketheesan, N.},
  title = {Investigation of Wear Particles Generated in Human Knee Joints Using Atomic Force Microscopy},
  journal = {Tribology Letters},
  year = {2013},
  volume = {51},
  number = {1},
  pages = {161--170},
  url = {http://link.springer.com/10.1007/s11249-013-0160-8},
  doi = {10.1007/s11249-013-0160-8}
}
Wang Y, Subbiahdoss G, Swartjes J, van der Mei HC, Busscher HJ and Libera M (2011), "Length-Scale Mediated Differential Adhesion of Mammalian Cells and Microbes", Advanced Functional Materials., October, 2011. Vol. 21(20), pp. 3916-3923.
BibTeX:
@article{Wang2011,
  author = {Wang, Yi and Subbiahdoss, Guruprakash and Swartjes, Jan and van der Mei, Henny C. and Busscher, Henk J. and Libera, Matthew},
  title = {Length-Scale Mediated Differential Adhesion of Mammalian Cells and Microbes},
  journal = {Advanced Functional Materials},
  year = {2011},
  volume = {21},
  number = {20},
  pages = {3916--3923},
  url = {http://doi.wiley.com/10.1002/adfm.201100659},
  doi = {10.1002/adfm.201100659}
}
Warden SJ, Galley MR, Hurd AL, Wallace JM, Gallant MA, Richard JS and George LA (2013), "Elevated Mechanical Loading When Young Provides Lifelong Benefits to Cortical Bone Properties in Female Rats Independent of a Surgically-Induced Menopause.", Endocrinology., June, 2013. , pp. en.2013-1227-.
Abstract: Exercise that mechanically loads the skeleton is advocated when young to enhance lifelong bone health. Whether the skeletal benefits of elevated loading when young persist into adulthood and following menopause are important questions. This study investigated the influence of a surgically-induced menopause in female Sprague-Dawley rats on the lifelong maintenance of the cortical bone benefits of skeletal loading when young. Animals had their right forearm extrinsically loaded 3 days/week between 4 and 10 weeks of age using the forearm axial compression loading model. Left forearms were internal controls and not loaded. Animals were subsequently detrained (restricted to cage activities) for 94 weeks (until age=2 years), with ovariectomy (OVX) or sham-OVX surgery being performed at 24 weeks of age. Loading enhanced midshaft ulna cortical bone mass, structure and estimated strength. These benefits persisted lifelong and contributed to loaded ulnas having greater strength after detraining. Loading also had effects on cortical bone quality. The benefits of loading when young were not influenced by a surgically-induced menopause as there were no interactions between loading and surgery. However, OVX had independent effects on cortical bone mass, structure and estimated strength at early post-surgery time points (up to age=58 weeks) and bone quality measures. These data indicate skeletal loading when young had lifelong benefits on cortical bone properties that persisted independent of a surgically-induced menopause. This suggests that skeletal loading associated with exercise when young may provide lifelong anti-fracture benefits by priming the skeleton to offset the cortical bone changes associated with aging and menopause.
BibTeX:
@article{Warden2013,
  author = {Warden, Stuart J and Galley, Matthew R and Hurd, Andrea L and Wallace, Joseph M and Gallant, Maxime A and Richard, Jeffrey S and George, Lydia A},
  title = {Elevated Mechanical Loading When Young Provides Lifelong Benefits to Cortical Bone Properties in Female Rats Independent of a Surgically-Induced Menopause.},
  journal = {Endocrinology},
  year = {2013},
  pages = {en.2013--1227--},
  url = {http://endo.endojournals.org/content/early/2013/06/13/en.2013-1227.abstract},
  doi = {10.1210/en.2013-1227}
}
Warner JA, Polkinghorne JC, Sarafolean J, Meyer S, Luo B, Frethem C and Haugstad G (2013), "Strain-induced crack formations in PDMS/DXA drug collars.", Acta Biomaterialia., July, 2013. Vol. 9(7), pp. 7335-42. Acta Materialia Inc..
Abstract: Drug-eluting systems are currently used in cardiac leads in order to reduce inflammation and fibrosis at the lead-tissue interface. Drug release from these drug delivery systems can be modulated by the manufacturing processes used to create the drug systems and assemble them onto the cardiac lead. In this study, scanning electron microscopy, atomic force microscopy and Raman microscopy are employed to explore the material characteristics of a polydimethylsiloxane-dexamethasone acetate drug collar used on cardiac leads when varying the strain during collar assembly on the lead. A novel test fixture was created in order to investigate these drug collars under simulated stresses. Measurements of the collar while fitted to a rod revealed microcracks that are hypothesized to affect the drug release performance, resulting in increased drug elution. It was found that the strain that occurs during assembly of the collar onto the lead is a key factor in the formation of these microcracks. Results also suggest that cracks tend to form in areas of high drug particle density, and propagate between drug particles.
BibTeX:
@article{Warner2013,
  author = {Warner, J. A. and Polkinghorne, J. C. and Sarafolean, J. and Meyer, S. and Luo, B. and Frethem, C. and Haugstad, G.},
  title = {Strain-induced crack formations in PDMS/DXA drug collars.},
  journal = {Acta Biomaterialia},
  publisher = {Acta Materialia Inc.},
  year = {2013},
  volume = {9},
  number = {7},
  pages = {7335--42},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23541599 http://dx.doi.org/10.1016/j.actbio.2013.03.028},
  doi = {10.1016/j.actbio.2013.03.028}
}
Williams JC (2012), "SURFACE CHARACTERIZATION OF VISCOELASTIC MATERIALS THROUGH SPECTRAL INTERMITTENT CONTACT ATOMIC FORCE MICROSCOPY". Thesis at: University of Maryland, College Park.
Abstract: The ability to recover material properties at the atomic scale has been the ongoing objective of the Atomic Force Microscope (AFM). More specifically, the most popular operation of the probe with this microscope (Intermittent Contact AFM) has not yet been able to resolve material properties of viscoelastic samples. By using the force and position time signals of the AFM and the constitutive equations for linear viscoelasticity, a method is developed by which such material properties are extracted in real-time scanning. A parametric study is then performed by simulating surface and AFM system conditions to understand the limits under which the method can accurately be performed in experiment. Suggestions are made to help experimentalists optimize the method to cater to the range of viscoelastic materials being measured and the results are related to measured material properties in literature. The method is found to be accurate for a wide range of viscoelastic materials.
BibTeX:
@phdthesis{Williams2012,
  author = {Williams, Jeffrey Charles},
  title = {SURFACE CHARACTERIZATION OF VISCOELASTIC MATERIALS THROUGH SPECTRAL INTERMITTENT CONTACT ATOMIC FORCE MICROSCOPY},
  school = {University of Maryland, College Park},
  year = {2012},
  url = {http://drum.lib.umd.edu/handle/1903/13074}
}
Woods CR, Britnell L, Eckmann A, Yu GL, Gorbachev RV, Kretinin AV, Park J, Ponomarenko LA, Katsnelson MI, Gornostyrev YN, Watanabe K, Taniguchi T, Casiraghi C, Geim AK and Novoselov KS (2014), "Commensurate-incommensurate transition for graphene on hexagonal boron nitride", January, 2014.
Abstract: When a crystal is subjected to a periodic potential, under certain circumstances (such as when the period of the potential is close to the crystal periodicity; the potential is strong enough, etc.) it might adjust itself to follow the periodicity of the potential, resulting in a, so called, commensurate state. Such commensurate-incommensurate transitions are ubiquitous phenomena in many areas of condensed matter physics: from magnetism and dislocations in crystals, to vortices in superconductors, and atomic layers adsorbed on a crystalline surface. Of particular interest might be the properties of topological defects between the two commensurate phases: solitons, domain walls, and dislocation walls. Here we report a commensurate-incommensurate transition for graphene on top of hexagonal boron nitride (hBN). Depending on the rotational angle between the two hexagonal lattices, graphene can either stretch to adjust to a slightly different hBN periodicity (the commensurate state found for small rotational angles) or exhibit little adjustment (the incommensurate state). In the commensurate state, areas with matching lattice constants are separated by domain walls that accumulate the resulting strain. Such soliton-like objects present significant fundamental interest, and their presence might explain recent observations when the electronic, optical, Raman and other properties of graphene-hBN heterostructures have been notably altered.
BibTeX:
@article{Woods2014,
  author = {Woods, C R and Britnell, L and Eckmann, A and Yu, G L and Gorbachev, R V and Kretinin, A. V. and Park, J. and Ponomarenko, L. A. and Katsnelson, M. I. and Gornostyrev, Yu. N. and Watanabe, K. and Taniguchi, T. and Casiraghi, C. and Geim, A. K. and Novoselov, K. S.},
  title = {Commensurate-incommensurate transition for graphene on hexagonal boron nitride},
  year = {2014},
  url = {http://arxiv.org/ftp/arxiv/papers/1401/1401.2637.pdf http://arxiv.org/abs/1401.2637}
}
Wu G, Verwilst P, Xu J, Xu H, Wang R, Smet M, Dehaen W, Faul CFJ, Wang Z and Zhang X (2012), "Bolaamphiphiles Bearing Bipyridine as Mesogenic Core: Rational Exploitation of Molecular Architectures for Controlled Self-Assembly", Langmuir., March, 2012. Vol. 28(11), pp. 5023-5030.
BibTeX:
@article{wu_bolaamphiphiles_2012,
  author = {Wu, Guanglu and Verwilst, Peter and Xu, Jun and Xu, Huaping and Wang, Ruji and Smet, Mario and Dehaen, Wim and Faul, Charl F J and Wang, Zhiqiang and Zhang, Xi},
  title = {Bolaamphiphiles Bearing Bipyridine as Mesogenic Core: Rational Exploitation of Molecular Architectures for Controlled Self-Assembly},
  journal = {Langmuir},
  year = {2012},
  volume = {28},
  number = {11},
  pages = {5023--5030},
  url = {http://pubs.acs.org/doi/abs/10.1021/la300369w},
  doi = {10.1021/la300369w}
}
Wu H, Tian M, Ning N, Zhang L, Wu Y and Tian H (2014), "New Understanding of Microstructure Formation of the Rubber Phase in Thermoplastic Vulcanizates (TPV)", Soft Matter., January, 2014. The Royal Society of Chemistry.
BibTeX:
@article{Wu2014,
  author = {Wu, Hanguang and Tian, Ming and Ning, Nanying and Zhang, Liqun and Wu, Youping and Tian, Hongchi},
  title = {New Understanding of Microstructure Formation of the Rubber Phase in Thermoplastic Vulcanizates (TPV)},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2014},
  url = {http://pubs.rsc.org/en/content/articlehtml/2014/sm/c3sm52375f http://pubs.rsc.org/en/Content/ArticleLanding/2014/SM/c3sm52375f},
  doi = {10.1039/c3sm52375f}
}
Wu J, Peng Z and Tipper J (2013), "Mechanical Properties and Three-Dimensional Topological Characterisation of Micron, Submicron and Nanoparticles from Artificial Joints", Tribology Letters., October, 2013.
BibTeX:
@article{Wu2013,
  author = {Wu, Jingping and Peng, Zhongxiao and Tipper, Joanne},
  title = {Mechanical Properties and Three-Dimensional Topological Characterisation of Micron, Submicron and Nanoparticles from Artificial Joints},
  journal = {Tribology Letters},
  year = {2013},
  url = {http://link.springer.com/10.1007/s11249-013-0228-5},
  doi = {10.1007/s11249-013-0228-5}
}
Wu Q, Bhattacharya M and Morgan SE (2013), "POSS Enhanced Phase Separation in Air Processed P3HT:PCBM Bulk Heterojunction Photovoltaic Systems.", ACS applied materials & interfaces., June, 2013. Vol. 5, pp. 6136-46. American Chemical Society.
Abstract: Nanoparticles have been shown in some cases to improve phase separation and morphology in bulk heterojunction organic photovoltaic cells. In this study, the effect of incorporation of polyhedral oligomeric silsesquioxane (POSS) molecules of different structures in air processed poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) films and photovoltaic cells was evaluated. Morphology and composition of the nanoscale phase separated domains were determined via conductive atomic force microscopy in conjunction with nanomechanical mapping and Raman imaging. UV-vis and fluorescence spectroscopy analysis of the films was performed at different stages of the process and with different levels of solvent vapor and thermal annealing. It was found that POSS molecules of selected structures provided enhancement in morphology control in films, translating to improvements in fill factor and power conversion efficiency of laboratory-scale OPV cells. The findings indicate the potential for further improvements in solar cell performance with specifically tailored POSS/polymer phase separated systems.
BibTeX:
@article{Wu2013a,
  author = {Wu, Qi and Bhattacharya, Mithun and Morgan, Sarah E},
  title = {POSS Enhanced Phase Separation in Air Processed P3HT:PCBM Bulk Heterojunction Photovoltaic Systems.},
  journal = {ACS applied materials & interfaces},
  publisher = {American Chemical Society},
  year = {2013},
  volume = {5},
  pages = {6136--46},
  url = {http://dx.doi.org/10.1021/am4010489},
  doi = {10.1021/am4010489}
}
Wu S, Guo Q, Zhang T and Mai Y-W (2013), "Phase behavior and nanomechanical mapping of block ionomer complexes", Soft Matter. The Royal Society of Chemistry.
BibTeX:
@article{Wu2013b,
  author = {Wu, Shuying and Guo, Qipeng and Zhang, Taiye and Mai, Yiu-Wing},
  title = {Phase behavior and nanomechanical mapping of block ionomer complexes},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/sm/c2sm27512k},
  doi = {10.1039/c2sm27512k}
}
Xu WZ, Bar-Nir BB-A and Kadla JF (2014), "Honeycomb membranes prepared from 3-O-amino acid functionalized cellulose derivatives", Carbohydrate Polymers., January, 2014. Vol. 100, pp. 126-34. Elsevier Ltd..
Abstract: The development of value-added wood-derived polymer products is of significant importance. Of particular interest is the synthesis of advanced bioactive cellulosic materials. In the present research, novel cellulosic honeycomb films are reported. Cellulose was reacted with dimethylthexylsilyl chloride to form regioselective 2,6-di-O-thexyldimethylsilyl cellulose followed by substitution of the C3 with functionalized poly(ethylene glycol) (PEG). The free end of the PEG side chains of the regioselective 3-O-poly(ethylene glycol)-2,6-di-O-thexyldimethylsilyl cellulose served as an attachment point for bioactive molecules. As an example, Fmoc-Gly-OH was linked to the free end of PEG to produce 3-O-Fmoc-Gly-poly(ethylene glycol)-2,6-di-O-thexyldimethylsilyl cellulose. Honeycomb films were produced through film casting under a humid airflow. AFM analysis revealed the directed self-assembly of the 3-O-Fmoc-Gly-poly(ethylene glycol)-2,6-di-O-thexyldimethylsilyl cellulose wherein the pendent 3-O-Fmoc-Gly-poly(ethylene glycol) groups allocated preferentially around the edges of the honeycomb pores.
BibTeX:
@article{Xu2013,
  author = {Xu, William Z. and Bar-Nir, Batia Ben-Aroya and Kadla, John F.},
  title = {Honeycomb membranes prepared from 3-O-amino acid functionalized cellulose derivatives},
  journal = {Carbohydrate Polymers},
  publisher = {Elsevier Ltd.},
  year = {2014},
  volume = {100},
  pages = {126--34},
  url = {http://dx.doi.org/10.1016/j.carbpol.2012.12.076 http://www.ncbi.nlm.nih.gov/pubmed/24188846},
  doi = {10.1016/j.carbpol.2012.12.076}
}
Xue C, Wong DY and Kasko AM (2013), "Complex Dynamic Substrate Control: Dual-Tone Hydrogel Photoresists Allow Double-Dissociation of Topography and Modulus.", Advanced materials (Deerfield Beach, Fla.)., December, 2013.
Abstract: Complex substrate control is demonstrated with a dual-tone hydrogel photoresist. By exposing a photodegradable hydrogel to UV light through a photomask, both swollen and eroded micropatterns with a decreased modulus can be created on the surface under different exposure conditions. This provides an important tool for investigating the synergistic effects of spatially heterogenous mechanical and topological cues on cell behavior.
BibTeX:
@article{Xue2013,
  author = {Xue, Changying and Wong, Darice Y and Kasko, Andrea M},
  title = {Complex Dynamic Substrate Control: Dual-Tone Hydrogel Photoresists Allow Double-Dissociation of Topography and Modulus.},
  journal = {Advanced materials (Deerfield Beach, Fla.)},
  year = {2013},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/24339260},
  doi = {10.1002/adma.201304591}
}
Yablon D (2013), "Overview of Atomic Force Microscopy", Scanning Probe Microscopy for Industrial ldots.
BibTeX:
@article{Yablon2013,
  author = {Yablon, DG},
  title = {Overview of Atomic Force Microscopy},
  journal = {Scanning Probe Microscopy for Industrial ldots},
  year = {2013},
  url = {http://books.google.com/books?hl=en&lr=&id=pcl8AQAAQBAJ&oi=fnd&pg=PA1&ots=mHoTHh5qEw&sig=cK1sen7IeMIMfyIM47hId2bLz6Y}
}
Yablon DG (2013), "Scanning Probe Microscopy for Industrial Applications: Nanomechanical Characterization (Google eBook)" , pp. 368. John Wiley & Sons.
Abstract: Describes new state-of-the-science tools and their contribution to industrial R&DWith contributions from leading international experts in the field, this book explains how scanning probe microscopy is used in industry, resulting in improved product formulation, enhanced processes, better quality control and assurance, and new business opportunities. Readers will learn about the use of scanning probe microscopy to support R&D efforts in the semiconductor, chemical, personal care product, biomaterial, pharmaceutical, and food science industries, among others.Scanning Probe Microscopy for Industrial Applications emphasizes nanomechanical characterization using scanning probe microscopy. The first half of the book is dedicated to a general overview of nanomechanical characterization methods, offering a complete practical tutorial for readers who are new to the topic. Several chapters include worked examples of useful calculations such as using Hertz mechanics with and without adhesion to model a contact, step-by-step instructions for simulations to guide cantilever selection for an experiment, and data analysis procedures for dynamic contact experiments.The second half of the book describes applications of nanomechanical characterization in industry, including:New formulation development for pharmaceuticalsMeasurement of critical dimensions and thin dielectric films in the semiconductor industryEffect of humidity and temperature on biomaterialsCharacterization of polymer blends to guide product formulation in the chemicals sectorUnraveling links between food structure and function in the food industryContributions are based on the authors' thorough review of the current literature as well as their own firsthand experience applying scanning probe microscopy to solve industrial R&D problems.By explaining the fundamentals before advancing to applications, Scanning Probe Microscopy for Industrial Applications offers a complete treatise that is accessible to both novices and professionals. All readers will discover how to apply scanning probe microscopy to build and enhance their R&D efforts.
BibTeX:
@book{Yablon2013a,
  author = {Yablon, Dalia G.},
  title = {Scanning Probe Microscopy for Industrial Applications: Nanomechanical Characterization (Google eBook)},
  publisher = {John Wiley & Sons},
  year = {2013},
  pages = {368},
  url = {http://books.google.com/books?hl=en&lr=&id=pcl8AQAAQBAJ&pgis=1}
}
Yang C-W, Lu Y-H and Hwang I-S (2013), "Imaging surface nanobubbles at graphite-water interfaces with different atomic force microscopy modes.", Journal of physics. Condensed matter : an Institute of Physics journal., May, 2013. Vol. 25(18), pp. 184010.
Abstract: We have imaged nanobubbles on highly ordered pyrolytic graphite (HOPG) surfaces in pure water with different atomic force microscopy (AFM) modes, including the frequency-modulation, the tapping, and the PeakForce techniques. We have compared the performance of these modes in obtaining the surface profiles of nanobubbles. The frequency-modulation mode yields a larger height value than the other two modes and can provide more accurate measurement of the surface profiles of nanobubbles. Imaging with PeakForce mode shows that a nanobubble appears smaller and shorter with increasing peak force and disappears above a certain peak force, but the size returns to the original value when the peak force is reduced. This indicates that imaging with high peak forces does not cause gas removal from the nanobubbles. Based on the presented findings and previous AFM observations, the existing models for nanobubbles are reviewed and discussed. The model of gas aggregate inside nanobubbles provides a better explanation for the puzzles of the high stability and the contact angle of surface nanobubbles.
BibTeX:
@article{Yang2013a,
  author = {Yang, Chih-Wen and Lu, Yi-Hsien and Hwang, Ing-Shouh},
  title = {Imaging surface nanobubbles at graphite-water interfaces with different atomic force microscopy modes.},
  journal = {Journal of physics. Condensed matter : an Institute of Physics journal},
  year = {2013},
  volume = {25},
  number = {18},
  pages = {184010},
  url = {http://stacks.iop.org/0953-8984/25/i=18/a=184010},
  doi = {10.1088/0953-8984/25/18/184010}
}
Yang T, Wang M, Cao Y, Huang F, Huang L, Peng J, Gong X, Cheng SZD and Cao Y (2012), "Polymer Solar Cells with a Low-Temperature-Annealed Sol-Gel-Derived MoOx Film as a Hole Extraction Layer", Advanced Energy Materials., March, 2012. Vol. 2(5), pp. 523-7.
Abstract: High power-conversion efficiencies (PCEs) from polymer solar cells with a low-temperature-annealed sol–gel-derived molybdenum oxide (S-MoOx) thin film as a buffer layer demonstrate that the S-MoOx (i.e., solution-processed) thin film can serve as the hole extraction layer in polymer solar cells in the quest for high performance.
BibTeX:
@article{yang_polymer_2012,
  author = {Yang, Tingbin and Wang, Ming and Cao, Yan and Huang, Fei and Huang, Lin and Peng, Junbiao and Gong, Xiong and Cheng, Stephen Z D and Cao, Yong},
  title = {Polymer Solar Cells with a Low-Temperature-Annealed Sol-Gel-Derived MoOx Film as a Hole Extraction Layer},
  journal = {Advanced Energy Materials},
  year = {2012},
  volume = {2},
  number = {5},
  pages = {523--7},
  url = {http://doi.wiley.com/10.1002/aenm.201100598},
  doi = {10.1002/aenm.201100598}
}
Yang T, Wang M, Duan C, Hu X, Huang L, Peng J, Huang F and Gong X (2012), "Inverted polymer solar cells with 8.4% efficiency by conjugated polyelectrolyte", Energy & Environmental Science. Vol. 5(8), pp. 8208.
Abstract: Bulk heterojunction (BHJ) polymer solar cells (PSCs) that can be fabricated by solution processing techniques are under intense investigation in both academic institutions and industrial companies because of their potential to enable mass production of flexible and cost-effective alternative to silicon-based solar cells. A combination of novel polymer development, nanoscale morphology control and processing optimization has led to over 8% power conversion efficiencies (PCEs) for BHJ PSCs with a conventional device structure. Attempts to develop PSCs with an inverted device structure as required for achieving high PECs and good stability have, however, met with limited success. Here, we report that a high PCE of 8.4% under AM 1.5G irradiation was achieved for BHJ PSCs with an inverted device structure. This high efficiency was obtained through interfacial engineering of solution-processed electron extraction layer, leading to facilitate electron transport and suppress bimolecular recombination. These results provided an important progress for solution-processed PSCs, and demonstrated that PSCs with an inverted device structure are comparable with PSCs with the conventional device structure.
BibTeX:
@article{yang_inverted_2012,
  author = {Yang, Tingbin and Wang, Ming and Duan, Chunhui and Hu, Xiaowen and Huang, Lin and Peng, Junbiao and Huang, Fei and Gong, Xiong},
  title = {Inverted polymer solar cells with 8.4% efficiency by conjugated polyelectrolyte},
  journal = {Energy & Environmental Science},
  year = {2012},
  volume = {5},
  number = {8},
  pages = {8208},
  url = {http://xlink.rsc.org/?DOI=c2ee22296e},
  doi = {10.1039/c2ee22296e}
}
Yang X, Cui C, Tong Z, Sabanayagam CR and Jia X (2013), "Poly($-caprolactone)-based copolymers bearing pendant cyclic ketals and reactive acrylates for the fabrication of photocrosslinked elastomers", Acta Biomaterialia., September, 2013. Vol. 9(9), pp. 8232-44. Acta Materialia Inc..
Abstract: Block copolymers of poly(ethylene glycol) and poly($-caprolactone) (PCL) with chemically addressable functional groups were synthesized and characterized. Ring-opening polymerization of $-caprolactone (CL) and 1,4,8-trioxaspiro-[4,6]-9-undecanone (TSU) using $-methoxy, $-hydroxyl poly(ethylene glycol) as the initiator afforded a copolymer with cyclic ketals being randomly distributed in the hydrophobic PCL block. At an initiator/catalyst molar ratio of 10/1 and a TSU/CL weight ratio of 1/4, a ketal-carrying copolymer (ECT2-CK) with Mn of 52 kDa and a ketal content of 15 mol.% was obtained. Quantitative side-chain deacetalization revealed the reactive ketones without noticeable polymer degradation. In our study, 10 mol.% of cyclic ketals were deprotected and the ketone-containing copolymer was designated as ECT2-CO. Reaction of ECT2-CO with 2-(2-(aminooxy)acetoxy)-ethyl acrylate gave rise to an acrylated product (ECT2-AC) containing an estimated 3-5 acrylate groups per chain. UV-initiated radical polymerization of ECT2-AC in dichloromethane resulted in a crosslinked network (xECT2-AC). Thermal and morphological analyses employing differential scanning calorimetry and atomic force microscopy operated in PeakForce Tapping mode revealed the semicrystalline nature of the network, which contained stiff crystalline lamellae dispersed in a softer amorphous interstitial. Macroscopic and nanoscale mechanical characterizations showed that ECT2-CK exhibited a significantly lower modulus than PCL of a similar molecular weight. Whereas ECT2-CK undergoes a plastic deformation with a distinct yield point and a cold-drawing region, xECT2-AC exhibits a compliant, elastomeric deformation with a Young's modulus of 0.5±0.1 MPa at 37°C. When properly processed, the crosslinked network exhibited shape-memory behaviors, with shape fixity and shape recovery values close to 1 and a shape recovery time of less than 4s at 37°C. In vitro studies showed that xECT2-AC films did not induce any cytotoxic effects on the cultured mesenchymal stem cells. The crosslinkable polyester copolymers can be potentially used as tissue engineering scaffolds and minimally invasive medical devices.
BibTeX:
@article{Yang2013,
  author = {Yang, Xiaowei and Cui, Chengzhong and Tong, Zhixiang and Sabanayagam, Chandran R and Jia, Xinqiao},
  title = {Poly($-caprolactone)-based copolymers bearing pendant cyclic ketals and reactive acrylates for the fabrication of photocrosslinked elastomers},
  journal = {Acta Biomaterialia},
  publisher = {Acta Materialia Inc.},
  year = {2013},
  volume = {9},
  number = {9},
  pages = {8232--44},
  url = {http://www.ncbi.nlm.nih.gov/pubmed/23770222 http://dx.doi.org/10.1016/j.actbio.2013.06.005},
  doi = {10.1016/j.actbio.2013.06.005}
}
Yang Y, Han D, Nangreave J, Liu Y and Yan H (2012), "DNA origami with double-stranded DNA as a unified scaffold.", ACS nano., September, 2012. Vol. 6(9), pp. 8209-15.
Abstract: Scaffolded DNA origami is a widely used technology for self-assembling precisely structured nanoscale objects that contain a large number of addressable features. Typical scaffolds are long, single strands of DNA (ssDNA) that are folded into distinct shapes through the action of many, short ssDNA staples that are complementary to several different domains of the scaffold. However, sources of long single-stranded DNA are scarce, limiting the size and complexity of structures that can be assembled. Here we demonstrated that dsDNA (double-stranded DNA) scaffolds can be directly used to fabricate integrated DNA origami structures that incorporate both of the constituent ssDNA molecules. Two basic principles were employed in the design of scaffold folding paths: folding path asymmetry and periodic convergence of the two ssDNA scaffold strands. Asymmetry in the folding path minimizes unwanted complementarity between staples, and incorporating an offset between the folding paths of each ssDNA scaffold strand reduces the number of times that complementary portions of the strands are brought into close proximity with one another, both of which decrease the likelihood of dsDNA scaffold recovery. Meanwhile, the folding paths of the two ssDNA scaffold strands were designed to periodically converge to promote the assembly of a single, unified structure rather than two individual ones. Our results reveal that this basic strategy can be used to reliably assemble integrated DNA nanostructures from dsDNA scaffolds.
BibTeX:
@article{yang_dna_2012,
  author = {Yang, Yang and Han, Dongran and Nangreave, Jeanette and Liu, Yan and Yan, Hao},
  title = {DNA origami with double-stranded DNA as a unified scaffold.},
  journal = {ACS nano},
  year = {2012},
  volume = {6},
  number = {9},
  pages = {8209--15},
  url = {http://pubs.acs.org/doi/abs/10.1021/nn302896c http://www.ncbi.nlm.nih.gov/pubmed/22830653},
  doi = {10.1021/nn302896c}
}
Ye L, Jing Y, Guo X, Sun H, Zhang S, Zhang M, Huo L and Hou J (2013), "Remove the Residual Additives toward Enhanced Efficiency with Higher Reproducibility in Polymer Solar Cells", The Journal of Physical Chemistry C., July, 2013. Vol. 117(29), pp. 14920-14928.
Abstract: Undesirable efficiency reproducibility was sometimes observed in fabrication of high performance polymer solar cell devices incorporating high boiling point additives. The anomalous results originated from the slow drying of additives not only reduced the controllability of device performance but also impeded the studies of device physics and material design. How to remove the residual additives and achieve stable interface properties is crucial for both the academic and industrial community. Herein, we demonstrated that the morphological stability is enhanced and efficiency reproducibility is increased obviously from 7.07 ± 0.27% to 7.53 ± 0.12% after spin-coating inert solvents for the PBDTTT-C-T/PCBM system. The relationship between processing conditions and photovoltaic performance was well explored and demonstrated via multiple techniques including atomic force microscopy, Kelvin probe force microscopy, transmission electron microscopy, and X-ray photospectroscopy. Most importantly, this method was successfully employed in more than five representative donor polymers. Our study suggested that the slow drying process of the residual high boiling point additives could induce undesirable morphological variation as well as unfavorable interfacial contact, and by washing with low boiling point “inert? solvent, like methanol, the negative influence caused by the residual additive can be avoided and hence the additives would perform more efficiently in the optimization of device performance of highly efficient PSCs.
BibTeX:
@article{Ye2013,
  author = {Ye, Long and Jing, Yan and Guo, Xia and Sun, Hao and Zhang, Shaoqing and Zhang, Maojie and Huo, Lijun and Hou, Jianhui},
  title = {Remove the Residual Additives toward Enhanced Efficiency with Higher Reproducibility in Polymer Solar Cells},
  journal = {The Journal of Physical Chemistry C},
  year = {2013},
  volume = {117},
  number = {29},
  pages = {14920--14928},
  url = {http://pubs.acs.org/doi/abs/10.1021/jp404395q},
  doi = {10.1021/jp404395q}
}
Young SL, Gupta M, Hanske C, Fery A, Scheibel T and Tsukruk VV (2012), "Utilizing Conformational Changes for Patterning Thin Films of Recombinant Spider Silk Proteins", Biomacromolecules., October, 2012. Vol. 13(10), pp. 3189-3199.
BibTeX:
@article{young_utilizing_2012,
  author = {Young, Seth L and Gupta, Maneesh and Hanske, Christoph and Fery, Andreas and Scheibel, Thomas and Tsukruk, Vladimir V},
  title = {Utilizing Conformational Changes for Patterning Thin Films of Recombinant Spider Silk Proteins},
  journal = {Biomacromolecules},
  year = {2012},
  volume = {13},
  number = {10},
  pages = {3189--3199},
  url = {http://pubs.acs.org/doi/abs/10.1021/bm300964h},
  doi = {10.1021/bm300964h}
}
Young TJ, Monclus MA, Burnett TL, Broughton WR, Ogin SL and Smith PA (2011), "The use of the PeakForce quantitative nanomechanical mapping AFM-based method for high-resolution Young's modulus measurement of polymers", Measurement Science and Technology., December, 2011. Vol. 22(12), pp. 125703.
Abstract: PeakForceTM quantitative nanomechanical mapping (QNMTM) is a new atomic force microscopy technique for measuring Young’s modulus of materials with high spatial resolution and surface sensitivity by probing at the nanoscale. In this work, modulus results from PeakForceTM QNMTM using three different probes are presented for a number of different polymers with a range of Young’s moduli that were measured independently by instrumented (nano) indentation testing (IIT). The results from the diamond and silicon AFM probes were consistent and in reasonable agreement with IIT values for the majority of samples. It is concluded that the technique is complementary to IIT; calibration requirements and potential improvements to the technique are discussed.
BibTeX:
@article{Young2011,
  author = {Young, T. J. and Monclus, M. A. and Burnett, T. L. and Broughton, W. R. and Ogin, S. L. and Smith, P. A.},
  title = {The use of the PeakForce quantitative nanomechanical mapping AFM-based method for high-resolution Young's modulus measurement of polymers},
  journal = {Measurement Science and Technology},
  year = {2011},
  volume = {22},
  number = {12},
  pages = {125703},
  url = {http://stacks.iop.org/0957-0233/22/i=12/a=125703?key=crossref.ab67700f8690dac265c633b46baa38e0},
  doi = {10.1088/0957-0233/22/12/125703}
}
Yu H, Aida N and Rahim A (2013), "Imaging in Cellular and Tissue Engineering" , pp. 298. Taylor & Francis Group.
Abstract: Details on specific imaging modalities for different cellular and tissue engineering applications are scattered throughout articles and chapters in the literature. Gathering this information into a single reference, Imaging in Cellular and Tissue Engineering presents both the fundamentals and state of the art in imaging methods, approaches, and applications in regenerative medicine.The book underscores the broadening scope of imaging applications in cellular and tissue engineering. It covers a wide range of optical and biological applications, including the repair or replacement of whole tissues (such as bone, cartilage, blood vessels, and bladder) and more novel artificially created support systems (such as artificial pancreas and bioartificial liver). Each chapter describes a particular application, relevant optical instrumentation, physical principles governing the imaging method, and strengths and weaknesses of the technique. The book also presents current and emerging data processing procedures.As the field of tissue engineering moves from creating simpler outer body parts to more sophisticated internal organs, researchers need to evaluate and control how well the tissues are engineered and integrated into the living body. Suitable for both experts and newcomers in bioengineering and biomedical imaging, this book shows researchers how to apply imaging techniques to next-generation engineered cells and tissues. It helps them assess the suitability of specific imaging modalities for applications with various functional requirements.
BibTeX:
@book{Yu2013,
  author = {Yu, Hanry and Aida, Nur and Rahim, Abdul},
  editor = {Yu, Hanry and Aida, Nur and Rahim, Abdul},
  title = {Imaging in Cellular and Tissue Engineering},
  publisher = {Taylor & Francis Group},
  year = {2013},
  pages = {298},
  url = {http://books.google.com/books?hl=en&lr=langen&id=RKn-7T84q5cC&pgis=1}
}
Yu X, Burnham Na, Mallick RB and Tao M (2013), "A systematic AFM-based method to measure adhesion differences between micron-sized domains in asphalt binders", Fuel., November, 2013. Vol. 113, pp. 443-447. Elsevier Ltd.
Abstract: The adhesion strength of asphalt binders is one of the fundamental properties that affect asphalt pavement’s performance. Atomic force microscopy (AFM) is one of the few methods that are capable of measuring adhesion of asphalt binders at the micro scale. Due to the stickiness and viscoelastic nature of the binder, challenges such as tip contamination are present in the measurement of AFM-based adhesion and the effects of operational parameters (e.g., the maximum compressive force and scanner drive speed) on adhesion measurements are often ignored in published studies. In this paper, a systematic AFM-based adhesion testing procedure was developed to minimize the above limitations, and used to characterize the adhesive force of four different asphalt binders. Results indicated that topographic images of solution-cast binder films displayed two micron-sized domains, with a height difference of a few nanometers between them. The adhesion difference between the raised and recessed areas of the binder films was considered to be statistically significant from t-tests, which might be attributed to the different chemical compositions between these two different domains. Such a rigorous AFM-based testing procedure can benefit adhesion measurements of other sticky polymeric materials. The adhesion difference between different domains should be helpful for building the link between chemical and mechanical properties of asphalt binders.
BibTeX:
@article{yu_systematic_2013,
  author = {Yu, Xiaokong and Burnham, Nancy a. and Mallick, Rajib B. and Tao, Mingjiang},
  title = {A systematic AFM-based method to measure adhesion differences between micron-sized domains in asphalt binders},
  journal = {Fuel},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {113},
  pages = {443--447},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0016236113004961},
  doi = {10.1016/j.fuel.2013.05.084}
}
Zdybicka-Barabas A, Mak P, Klys A, Skrzypiec K, Mendyk E, Fiołka M and Cytryńska M (2012), "Synergistic action of Galleria mellonella anionic peptide 2 and lysozyme against Gram-negative bacteria.", Biochimica et Biophysica Acta., June, 2012. Vol. 1818(11), pp. 2623-2635.
Abstract: Lysozyme and antimicrobial peptides are key factors of the humoral immune response in insects. In the present work lysozyme and anionic defense peptide (GMAP2) were isolated from the hemolymph of the greater wax moth Galleria mellonella and their antibacterial activity was investigated. Adsorption of G. mellonella lysozyme on the cell surface of Gram-positive and Gram-negative bacteria was demonstrated using immunoblotting with anti-G. mellonella lysozyme antibodies. Lysozyme effectively inhibited the growth of selected Gram-positive bacteria, which was accompanied by serious alterations of the cell surface, as revealed by atomic force microscopy (AFM) imaging. G. mellonella lysozyme used in concentrations found in the hemolymph of naive and immunized larvae, perforated also the Escherichia coli cell membrane and the level of such perforation was considerably increased by GMAP2. GMAP2 used alone did not perforate E. coli cells nor influence lysozyme muramidase activity. However, the peptide induced a decrease in the turgor pressure of the bacterial cell. Moreover, in the samples of bacteria treated with a mixture of lysozyme and GMAP2 the sodium chloride crystals were found, suggesting disturbance of ion transport across the membrane leading to cell disruption. These results clearly indicated the synergistic action of G. mellonella lysozyme and anionic peptide 2 against Gram-negative bacteria. The reported results suggested that, thanks to immune factors constitutively present in hemolymph, G. mellonella larvae are to some extent protected against infection caused by Gram-negative bacteria.
BibTeX:
@article{Zdybicka-Barabas2012,
  author = {Zdybicka-Barabas, Agnieszka and Mak, Pawel and Klys, Anna and Skrzypiec, Krzysztof and Mendyk, Ewaryst and Fiołka, Marta and Cytryńska, Małgorzata},
  title = {Synergistic action of Galleria mellonella anionic peptide 2 and lysozyme against Gram-negative bacteria.},
  journal = {Biochimica et Biophysica Acta},
  year = {2012},
  volume = {1818},
  number = {11},
  pages = {2623--2635},
  url = {http://dx.doi.org/10.1016/j.bbamem.2012.06.008},
  doi = {10.1016/j.bbamem.2012.06.008}
}
Zelenková M, Sohnel O and Grases F (2012), "Ultrafine Structure of the Hydroxyapatite Amorphous Phase in Noninfectious Phosphate Renal Calculi", Urology., April, 2012. Vol. 79(4), pp. 968.e1-6. Elsevier Inc..
Abstract: We aimed to establish detailed morphology of the structureless amorphous hydroxyapatite (HAP) phase to improve our understanding of the formation mechanism of these concretions. Noninfectious phosphate renal calculi composed mainly of HAP consist of inorganic material in the form of spherules, in a seemingly structureless and amorphous phase and organic matter. Methods Several cross-sections of a fraction of phosphate renal stone composed solely of the amorphous HAP phase were examined with atomic force microscope. Both 2- and 3-dimensional images of their structure and nanoscale elastic modulus maps were obtained. Results The amorphous hap phase consists of 2 distinctly different morphologic forms of hydroxyapatite: separate and/or intergrown columnar crystals, and spherical agglomerates with diameters in the range 150-300 nm consisting of spherulites approximately 10 nm in diameter. The columnar crystals are irregularly disseminated in the stone interior, which is porous because of cavities with depths in excess of 100 nm. Organic matter is almost evenly distributed throughout the stone interior. Conclusion Based on the observed calculus structure, the following mechanism of formation of the noninfectious phosphate calculi is suggested: Spherulites formed via the perikinetic aggregation of Posner's clusters present in urine supersaturated with respect to hydroxyapatite aggregate into spherical agglomerates that, after reaching a certain size, are retained in cavities with poor urodynamics, gradually settle, and become incorporated into developing concretion. The columnar crystals are probably nucleated on the detritus of organic origin embedded in the hydroxyapatite structureless phase.
BibTeX:
@article{Zelenkova2012,
  author = {Zelenková, Markéta and Sohnel, Otakar and Grases, Felix},
  title = {Ultrafine Structure of the Hydroxyapatite Amorphous Phase in Noninfectious Phosphate Renal Calculi},
  journal = {Urology},
  publisher = {Elsevier Inc.},
  year = {2012},
  volume = {79},
  number = {4},
  pages = {968.e1--6},
  url = {http://www.sciencedirect.com/science/article/pii/S0090429511026550},
  doi = {10.1016/j.urology.2011.11.020}
}
Zenerino A, Amigoni S, Taffin de Givenchy E, Josse D and Guittard F (2013), "Homogeneous dispersion of SiO2 nanoparticles in an hydrosoluble polymeric network", Reactive and Functional Polymers., August, 2013. Vol. 73(8), pp. 1065-71. Elsevier Ltd.
Abstract: The main difficulty still encountered in the elaboration of polymer/silica nanocomposites is the control of the nanoparticles dispersion homogeneity and the stability of the nanoparticle dispersion in the surrounding substance. The innovative point of this work is the elaboration of hybrid networks in aqueous solution performed with ASE (alkali swellable emulsion) thickeners grafted with silica nanoparticles. The thickening ability of the polymer should favour silica nanoparticles dispersion in fluid matrices. Two ASE copolymers were realised by copolymerisation in emulsion of MA (methacrylic acid) and EA (ethyl acrylate) and/or TFEM (trifluoroethyl methacrylate). The substitution of a part of EA by TFEM gave fluorinated ASE copolymers. Their free acid functions were then coupled with different ratio of amine functionalized silica nanoparticles to afford nanocomposites. The amounts of silica nanoparticles in the copolymers were determined by thermogravimetric experiments. Depending on the silica nanoparticles/copolymer ratio in basic aqueous solutions we achieved stable translucent gel like aqueous suspensions of silica nanoparticles containing 1 wt.% of the polymer/SiO2 nanocomposite.
BibTeX:
@article{Zenerino2013,
  author = {Zenerino, Arnaud and Amigoni, Sonia and Taffin de Givenchy, Elisabeth and Josse, Denis and Guittard, Frédéric},
  title = {Homogeneous dispersion of SiO2 nanoparticles in an hydrosoluble polymeric network},
  journal = {Reactive and Functional Polymers},
  publisher = {Elsevier Ltd},
  year = {2013},
  volume = {73},
  number = {8},
  pages = {1065--71},
  url = {http://dx.doi.org/10.1016/j.reactfunctpolym.2013.04.004 http://linkinghub.elsevier.com/retrieve/pii/S1381514813000916},
  doi = {10.1016/j.reactfunctpolym.2013.04.004}
}
Zeng G, Duan Y, Besenbacher F and Dong M (2012), "Nanomechanics of Amyloid Materials Studied by Atomic Force Microscopy", In Atomic Force Microscopy Investigations into Biology.
BibTeX:
@incollection{Zeng2012,
  author = {Zeng, Guanghong and Duan, Yusheng and Besenbacher, Flemming and Dong, Mingdong},
  title = {Nanomechanics of Amyloid Materials Studied by Atomic Force Microscopy},
  booktitle = {Atomic Force Microscopy Investigations into Biology},
  year = {2012}
}
Zhang F, Sababi M, Brinck T, Persson D, Pan J and Claesson PM (2013), "In situ investigations of Fe3+ induced complexation of adsorbed Mefp-1 protein film on iron substrate", Journal of Colloid and Interface Science., August, 2013. Vol. 404, pp. 62-71. Elsevier Inc..
Abstract: A range of in situ analytical techniques and theoretical calculations were applied to gain insights into the formation and properties of the Mefp-1 film on iron substrate, as well as the protein complexation with Fe(3+) ions. Adsorption kinetics of Mefp-1 and the complexation were investigated using QCM-D. The results suggest an initially fast adsorption, with the molecules oriented preferentially parallel to the surface, followed by a structural change within the film leading to molecules extending toward solution. Exposure to a diluted FeCl3 solution results in enhanced complexation within the adsorbed protein film, leading to water removal and film compaction. In situ Peak Force Tapping AFM was employed for determining morphology and nano-mechanical properties of the surface layer. The results, in agreement with the QCM-D observations, demonstrate that addition of Fe(3+) induces a transition from an extended and soft protein layer to a denser and stiffer one. Further, in situ ATR-FTIR and Confocal Raman Micro-spectroscopy (CRM) techniques were utilized to monitor compositional/structural changes in the surface layer due to addition of Fe(3+) ions. The spectroscopic analyses assisted by DFT calculations provide evidence for formation of tri-Fe(3+)/catechol complexes in the surface film, which is enhanced by Fe(3+) addition.
BibTeX:
@article{Zhang2013a,
  author = {Zhang, Fan and Sababi, Majid and Brinck, Tore and Persson, Dan and Pan, Jinshan and Claesson, Per M.},
  title = {In situ investigations of Fe3+ induced complexation of adsorbed Mefp-1 protein film on iron substrate},
  journal = {Journal of Colloid and Interface Science},
  publisher = {Elsevier Inc.},
  year = {2013},
  volume = {404},
  pages = {62--71},
  url = {http://dx.doi.org/10.1016/j.jcis.2013.05.016 http://www.ncbi.nlm.nih.gov/pubmed/23743045},
  doi = {10.1016/j.jcis.2013.05.016}
}
Zhang K, Wen M, Meng QN, Hu CQ, Li X, Liu C and Zheng WT (2012), "Effects of substrate bias voltage on the microstructure, mechanical properties and tribological behavior of reactive sputtered niobium carbide films", Surface and Coatings Technology., November, 2012. Vol. 212, pp. 185-191.
Abstract: Niobium carbide films have been deposited on Si(100) substrates using direct current reactive magnetron sputtering in discharging a mixture of CH4 and Ar gas. The effects of substrate bias voltage (Vb) and methane flow rate (FCH4) on the phase structure, composition, morphology, mechanical properties and tribological behavior for NbC films have been explored. For the film grown at FCH4 = 6 sccm, a phase transition from a mixture of hexagonal-Nb2C and cubic-NbC phases to cubic-NbC phase occurs with increasing the absolute value of Vb and no Csingle bondC bonding appears. In contrast, for the film deposited at FCH4 = 16 sccm, only the cubic-NbC phase is observed with increasing the absolute value of Vb and the Csingle bondC bonding appears. If FCH4 is fixed at either 6 or 16 sccm, as the absolute value of Vb is increased, the growing film surface becomes smoother, and the compressive stress increases. This can be attributed to the increase in the carbon ion bombarding energy, which leads to promoting the diffusion of adsorbed atoms and more carbon species' occupying the interstitial positions. It is found that the hardness (H) increases first, and then decreases after reaching a maximum value with increasing the absolute value of Vb. The friction coefficient for the film obtained at FCH4 = 16 sccm is lower than that at FCH4 = 6 sccm, which may be ascribed to the presence of either graphite or amorphous carbon in the film grown at FCH4 = 16 sccm. Furthermore, a high stress results in a poor wear resistance.
BibTeX:
@article{zhang_effects_2012,
  author = {Zhang, Kan and Wen, M and Meng, Q N and Hu, C Q and Li, X and Liu, C and Zheng, W T},
  title = {Effects of substrate bias voltage on the microstructure, mechanical properties and tribological behavior of reactive sputtered niobium carbide films},
  journal = {Surface and Coatings Technology},
  year = {2012},
  volume = {212},
  pages = {185--191},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0257897212009243},
  doi = {10.1016/j.surfcoat.2012.09.046}
}
Zhang L and Gao F (2012), "Self-assembled gold nanochains hybrid based on insulin fibrils", Journal of Nanoparticle Research., April, 2012. Vol. 14(5)
Abstract: We reported a facile method for preparing self-assembly gold nanochains by using insulin fibrils as biotemplate in aqueous environment. The gold nanochains hybrid nanostructures, which are insulin fibrils coated by gold nanoparticles, can be fabricated by simply reducing the salt precursors using DMAB. By increasing the molar ratio between salt precursors and insulin, denser hybrid nanochains can be obtained, meanwhile the mean diameter of gold nanoparticles is changing from 8 to 10 nm and then to 12 nm. The fabricated gold nanochains hybrid had helix structure, which was confirmed by circular dichroism spectra. The hybrid nanostructures were also investigated by transmission electron microscope, atomic force microscope, Fourier transform infrared spectra, and UV–Visible spectroscopy. As the wire-like structure become denser, the suspensions show color-changing, corresponding to the surface plasmon resonance red shift, which is attributed to the increasing mean size of nanoparticles. Based on the characterizations, a hypothetic mechanism was suggested to describe the formation processing of hybrid gold nanochains.
BibTeX:
@article{zhang_self-assembled_2012,
  author = {Zhang, Longgai and Gao, Faming},
  title = {Self-assembled gold nanochains hybrid based on insulin fibrils},
  journal = {Journal of Nanoparticle Research},
  year = {2012},
  volume = {14},
  number = {5},
  url = {http://link.springer.com/10.1007/s11051-012-0855-z},
  doi = {10.1007/s11051-012-0855-z}
}
Zhang S, Yuan XZ, Hiesgen R, Friedrich KA, Wang H, Schulze M, Haug A and Li H (2012), "Effect of open circuit voltage on degradation of a short proton exchange membrane fuel cell stack with bilayer membrane configurations", Journal of Power Sources. Vol. 205, pp. 290-300.
BibTeX:
@article{Zhang2012,
  author = {Zhang, S. and Yuan, X. Z and Hiesgen, R. and Friedrich, K. A and Wang, H. and Schulze, M. and Haug, A. and Li, H.},
  title = {Effect of open circuit voltage on degradation of a short proton exchange membrane fuel cell stack with bilayer membrane configurations},
  journal = {Journal of Power Sources},
  year = {2012},
  volume = {205},
  pages = {290--300},
  url = {http://www.sciencedirect.com/science/article/pii/S0378775312000353}
}
Zhang T, Mahgsoudy-Louyeh S, Tittmann B and Cosgrove DJ (2013), "Visualization of the nanoscale pattern of recently-deposited cellulose microfibrils and matrix materials in never-dried primary walls of the onion epidermis", Cellulose., July, 2013.
BibTeX:
@article{Zhang2013,
  author = {Zhang, Tian and Mahgsoudy-Louyeh, Sahar and Tittmann, Bernhard and Cosgrove, Daniel J.},
  title = {Visualization of the nanoscale pattern of recently-deposited cellulose microfibrils and matrix materials in never-dried primary walls of the onion epidermis},
  journal = {Cellulose},
  year = {2013},
  url = {http://link.springer.com/10.1007/s10570-013-9996-1},
  doi = {10.1007/s10570-013-9996-1}
}
Zhao B, Song Y, Wang S, Dai B, Zhang L, Dong Y, Lü J and Hu J (2013), "Mechanical mapping of nanobubbles by PeakForce atomic force microscopy", Soft Matter., July, 2013. Vol. 9(37), pp. 8837. The Royal Society of Chemistry.
BibTeX:
@article{Zhao2013,
  author = {Zhao, Binyu and Song, Yang and Wang, Shuo and Dai, Bin and Zhang, Lijuan and Dong, Yaming and Lü, Junhong and Hu, Jun},
  title = {Mechanical mapping of nanobubbles by PeakForce atomic force microscopy},
  journal = {Soft Matter},
  publisher = {The Royal Society of Chemistry},
  year = {2013},
  volume = {9},
  number = {37},
  pages = {8837},
  url = {http://pubs.rsc.org/en/content/articlehtml/2013/sm/c3sm50942g http://xlink.rsc.org/?DOI=c3sm50942g},
  doi = {10.1039/c3sm50942g}
}
Zhu P and Fang M (2012), "Nano-Morphology of Cartilage in Hydrated and Dehydrated Conditions Revealed by Atomic Force Microscopy", Journal of Physical Chemistry $& Biophysics. Vol. 02(01)
BibTeX:
@article{zhu_nano-morphology_2012,
  author = {Zhu, Peizhi and Fang, Ming},
  title = {Nano-Morphology of Cartilage in Hydrated and Dehydrated Conditions Revealed by Atomic Force Microscopy},
  journal = {Journal of Physical Chemistry $& Biophysics},
  year = {2012},
  volume = {02},
  number = {01},
  url = {http://www.omicsonline.org/2161-0398/2161-0398-2-106.digital/2161-0398-2-106.html},
  doi = {10.4172/2161-0398.1000106}
}
Zhuiykov S and Kats E (2013), "Development of Quasi-Two-Dimensional Nb2O5 for Functional Electrodes of Advanced Electrochemical Systems", World Academy of Science, Engineering and Technology. Vol. 78, pp. 484-9.
Abstract: In recent times there has been a growing interest in the development of quasi-two-dimensional niobium pentoxide (Nb2O5) as a semiconductor for the potential electronic applications such as capacitors, filtration, dye-sensitised solar cells and gas sensing platforms. Therefore once the purpose is established, Nb2O5 can be prepared in a number of nano- and sub-micron-structural morphologies that include rods, wires, belts and tubes. In this study films of Nb2O5 were prepared on gold plated silicon substrate using spin-coating technique and subsequently by mechanical exfoliation. The reason this method was employed was to achieve layers of less than 15nm in thickness. The sintering temperature of the specimen was 800oC. The morphology and structural characteristics of the films were analyzed by Atomic Force Microscopy (AFM), Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS).
BibTeX:
@article{Zhuiykov2013a,
  author = {Zhuiykov, S and Kats, E},
  title = {Development of Quasi-Two-Dimensional Nb2O5 for Functional Electrodes of Advanced Electrochemical Systems},
  journal = {World Academy of Science, Engineering and Technology},
  year = {2013},
  volume = {78},
  pages = {484--9}
}
Zhuiykov S and Kats E (2012), "Atomically thin two-dimensional materials for functional electrodes of electrochemical devices", Ionics., December, 2012. Vol. 19(6), pp. 825-865.
BibTeX:
@article{Zhuiykov2012,
  author = {Zhuiykov, Serge and Kats, Eugene},
  title = {Atomically thin two-dimensional materials for functional electrodes of electrochemical devices},
  journal = {Ionics},
  year = {2012},
  volume = {19},
  number = {6},
  pages = {825--865},
  url = {http://link.springer.com/10.1007/s11581-012-0837-2},
  doi = {10.1007/s11581-012-0837-2}
}
Zhuiykov S, Kats E, Kalantar-Zadeh K and Li Y (2013), "Synthesis and Nanoscale Investigation of the Electrical Properties of Quasi-2D Semiconductor Nb2O5 Nanosheets", IEEE Transactions on Nanotechnology., July, 2013. Vol. 12(4), pp. 641-648.
Abstract: Quasi-two-dimensional (Q2D) Nb2O 5 nanosheets with thickness of approximately 15–25 nm were fabricated by combined sol–gel/exfoliation method. Obtained Nb 2O5 nanosheets were chemically intercalated with H+ in order to improve their electrical conductivity. Then, their morphology and electrical properties were investigated at the nanoscale level with a combination of conductive atomic force microscopy (C-AFM), current sensing force spectroscopy atomic force microscopy (CSFS-AFM, or PeakForce TUNA), scanning tunneling microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman techniques. This allows us to probe the electrical properties of 10–20-nm Nb2O5 nanosheets as well as the interfaces between the substrate and the fabricated Nb 2O5 nanocrystals providing direct comparison between the morphology and the electrical properties at the nanometer scale. It was also proven that chemical H+ intercalation can improve conductivity of Q2D Nb2O 5 nanostructures.
BibTeX:
@article{Zhuiykov2013,
  author = {Zhuiykov, S. and Kats, E. and Kalantar-Zadeh, K. and Li, Y.},
  title = {Synthesis and Nanoscale Investigation of the Electrical Properties of Quasi-2D Semiconductor Nb2O5 Nanosheets},
  journal = {IEEE Transactions on Nanotechnology},
  year = {2013},
  volume = {12},
  number = {4},
  pages = {641--648},
  url = {http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6522825},
  doi = {10.1109/TNANO.2013.2265893}
}
Zuber K, Downey E, Hall C, Murphy P and Evans D (2013), "Growth of Sputtered Nanocomposite Alloys on Polymeric Substrates: The Role of the Substrate's Mechanical Hardness", Advanced Engineering Materials., August, 2013. , pp. n/a-n/a.
BibTeX:
@article{Zuber2013,
  author = {Zuber, Kamil and Downey, Elisabeth and Hall, Colin and Murphy, Peter and Evans, Drew},
  title = {Growth of Sputtered Nanocomposite Alloys on Polymeric Substrates: The Role of the Substrate's Mechanical Hardness},
  journal = {Advanced Engineering Materials},
  year = {2013},
  pages = {n/a--n/a},
  url = {http://doi.wiley.com/10.1002/adem.201300179},
  doi = {10.1002/adem.201300179}
}