Comparison of tarsal attachment in two closely related leaf beetle species.

Green dock beetles Gastrophysa viridula and Colorado potato beetles Leptinotarsa decemlineata having distinctly different body mass and gait habits were compared with respect to their tarsal morphology and attachment ability. The focus laid on shapes and dimensions of tenent setae related to the peeling line, i.e.

Elastic to Plastic Deformation in Uniaxially Stressed Polylelectrolyte Multilayer Films.

Polyelectrolyte multilayer (PEM) are thin polymeric films produced by alternating adsorption of positively and negatively charged polyelectrolytes (PE) on a substrate. These films are considered drug delivery agents as well as coating material for implants, due to their antibiofouling and biologically benign properties. For these reasons the film mechanical properties as well as response to mechanical stress are important measurement parameters.

Structure and Oxidation Behavior of Nickel Nanoparticles Supported by YSZ(111).

Nickel nanoparticles supported by the yttria-stabilized zirconia (111) surface show several preferential epitaxial relationships, as revealed by in situ X-ray diffraction. The two main nanoparticle orientations are found to have their [111] direction parallel to the substrate surface normal and ∼41.3 degrees tilted from this direction.

Eutectic nano-droplet template injection into bulk silicon to construct porous frameworks with concomitant conformal coating as anodes for Li-ion batteries.

Building porosity in monolithic materials is highly desired to design 3D electrodes, however ex-situ introduction or in-situ generation of nano-scale sacrificial template is still a great challenge. Here Al-Si eutectic droplet templates are uniformly injected into bulk Si through Al-induced solid-solid convection to construct a highly porous Si framework. This process is concomitant with process-inherent conformal coating of ion-conductive oxide.

Atomic structure and composition of the yttria-stabilized zirconia (111) surface.

Anomalous and nonanomalous surface X-ray diffraction is used to investigate the atomic structure and composition of the yttria-stabilized zirconia (YSZ)(111) surface. By simulation it is shown that the method is sensitive to Y surface segregation, but that the data must contain high enough Fourier components in order to distinguish between different models describing Y/Zr disorder. Data were collected at room temperature after two different annealing procedures.

Concentration and strain fields inside a Ag/Au core-shell nanowire studied by coherent X-ray diffraction.

Three-dimensional coherent diffraction patterns of an isolated, single-crystalline Ag/Au core-shell nanowire were recorded at different X-ray beam energies close to the Au LIII absorption edge. Two-dimensional slices of the three-dimensional diffraction pattern, with the diffraction vector oriented perpendicular to the wire axis, were investigated in detail. In reciprocal space, facet streaks with thickness fringes were clearly observed in the two-dimensional diffraction patterns, from which the shape and size of the corresponding cross sections of the nanowire could be revealed.

Real-time visualization of convective transportation of solid materials at nanoscale.

Convective transportation of materials in the solid state occurring in a prototype solid bilayer system of Al and Si with negligible mutual solubility has been directly imaged in real time at nanoscale using a valence energy-filtered transmission electron microscope. Such solid-state convection is driven by the stress gradient developing in the bilayer system due to the amorphous to crystalline phase transformation of the Si sublayer. The process is characterized by compression experienced in the Si phase crystallizing within the Al sublayer, as well as by the development of mushroom-shaped "plumes" of Al nanocrystals in the Si sublayer as a result of compressive stress relaxation and discrete, new nucleation of crystalline Al.

Electromagnetic response of superconductors with pinned vortices.

Some features of the vortex lattice in type-II superconductors and of its pinning and thermally activated depinning are given. Manipulation of a pinned single vortex by the tip of a Magnetic Force Microscope is mentioned. Statics and dynamics of pinned vortices in thick and thin strips and disks, and in rectangular plates, can be computed from continuum theory.

Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: case study of water.

We present a direct comparison of phase sensitive sum-frequency generation experiments with phase reconstruction obtained by the maximum entropy method. We show that both methods lead to the same complex spectrum. Furthermore, we discuss the strengths and weaknesses of each of these methods, analyzing possible sources of experimental and analytical errors.

Electron theory of fast and ultrafast dissipative magnetization dynamics.

For metallic magnets we review the experimental and electron-theoretical investigations of fast magnetization dynamics (on a timescale of ns to 100 ps) and of laser-pulse-induced ultrafast dynamics (few hundred fs). It is argued that for both situations the dominant contributions to the dissipative part of the dynamics arise from the excitation of electron-hole pairs and from the subsequent relaxation of these pairs by spin-dependent scattering processes, which transfer angular momentum to the lattice. By effective field theories (generalized breathing and bubbling Fermi-surface models) it is shown that the Gilbert equation of motion, which is often used to describe the fast dissipative magnetization dynamics, must be extended in several aspects.

Microstructured platforms to study nanotube-mediated long-distance cell-to-cell connections.

Recently, numerous innovative approaches have attempted to overcome the shortcomings of standard tissue culturing by providing custom-tailored substrates with superior features. In particular, tunable surface chemistry and topographical micro- and nanostructuring have been highlighted as potent effectors to control cell behavior. Apart from tissue engineering and the development of biosensors and diagnostic assays, the need for custom-tailored platform systems is accentuated by a variety of complex and poorly characterized biological processes.

Nanopatterning by block copolymer micelle nanolithography and bioinspired applications.

This comprehensive overview of block copolymer micelle nanolithography (BCMN) will discuss the synthesis of inorganic nanoparticle arrays by means of micellar diblock copolymer approach and the resulting experimental control of individual structural parameters of the nanopattern, e.g., particle density and particle size.

Lateral shear forces applied to cells with single elastic micropillars to influence focal adhesion dynamics.

Focal adhesions (FAs) are important adhesion sites between eukaryotic cells and the extracellular matrix, their size depending on the locally applied force. To quantitatively study the mechanosensitivity of FAs, we induce their growth and disassembly by varying the distribution of intracellular stress. We present a novel method for micromanipulation of living cells to explore the dynamics of focal adhesion (FA) assembly under force.

Aberration-compensated large-angle rocking-beam electron diffraction.

The application of convergent beam electron diffraction (CBED) to determine symmetry, refine structure factors, and measure specimen thickness requires rather thick specimen and is very difficult or even impossible in the case of large unit cell materials. The large-angle rocking-beam electron diffraction (LARBED) technique introduced in this paper gives access to the kind of experimental data contained in CBED patterns but over a much larger angular range. In addition to symmetry determination and thickness measurement even for thin samples this technique also allows, in principle, very accurate measurements of structure factors.

BET specific surface area and pore structure of MOFs determined by hydrogen adsorption at 20 K.

Low-pressure high-resolution hydrogen adsorption for the metal-organic framework MIL-101 are measured at 19.5 K and pressures below 57 kPa. The BET specific surface area and micropore volume are determined and compared to results from nitrogen adsorption at 77 K.

Single cell force spectroscopy of T cells recognizing a myelin-derived peptide on antigen presenting cells.

T-cell recognition of peptide-MHC complexes on APCs requires cell-cell interactions. The molecular events leading to T-cell activation have been extensively investigated, but the underlying physical binding forces between T-cells and APCs are largely unknown. We used single cell force spectroscopy for quantitation of interaction forces between T-cells and APCs presenting a tolerogenic peptide derived from myelin basic protein.

Conjugation of peptides to the passivation shell of gold nanoparticles for targeting of cell-surface receptors.

We report the preparation of gold nanoparticles (AuNPs) functionalized with the peptide-toxin conantokin-G and their selective binding to N-methyl-d-aspartate (NMDA) receptors recombinantly expressed by transfected HEK 293 cells. The AuNPs are passivated with a mixed self-assembled monolayer of ω-carboxy- and ω-amino-polyethylene glycol (PEG) thiols. We compare two different passivation systems: the alkyl-PEG600 system is characterized by a C(11)-alkyl chain between the thiol group and the PEG segment, whereas the PEG3000 system lacks this alkyl-chain.

Force-induced destabilization of focal adhesions at defined integrin spacings on nanostructured surfaces.

Focal adhesions are the anchoring points of cells to surfaces and are responsible for a large number of surface sensing processes. Nanopatterning studies have shown physiological changes in fibroblasts as a result of decreasing density of external binding ligands. The most striking of these changes is a decreased ability to form mature focal adhesions when lateral ligand distances exceed 76 nm.

Desiccation resistance of adhesive secretion in the protocarnivorous plant Roridula gorgonias as an adaptation to periodically dry environment.

To analyse the change of mass in the resinous secretion of Roridula gorgonias, we carried out long-term measurements using a computerised ultra microbalance. In contrast to the aqueous mucilage of other carnivorous flypaper traps, this water-insoluble secretion does not desiccate even in dead and formalin-preserved plants. We found no significant desiccation of secretory drops within 10 h of continuous weighing.

Tailored antireflective biomimetic nanostructures for UV applications.

Antireflective surfaces composed of biomimetic sub-wavelength structures that employ the 'moth eye principle' for reflectance reduction are highly desirable in many optical applications such as solar cells, photodetectors and laser optics. We report an efficient approach for the fabrication of antireflective surfaces based on a two-step process consisting of gold nanoparticle mask generation by micellar block copolymer nanolithography and a multi-step reactive ion etching process. Depending on the RIE process parameters nanostructured surfaces with tailored antireflective properties can easily be fabricated that show optimum performance for specific applications.

Polymeric substrates with tunable elasticity and nanoscopically controlled biomolecule presentation.

Despite tremendous progress in recent years, nanopatterning of hydrated polymeric systems such as hydrogels still represents a major challenge. Here, we employ block copolymer nanolithography to arrange gold nanoparticles on a solid template, followed by the transfer of the pattern to a polymeric hydrogel. In the next step, these nanoparticles serve as specific anchor points for active biomolecules.

Expanding micelle nanolithography to the self-assembly of multicomponent core-shell nanoparticles.

Size, composition, and pattern formation are crucial elements in the fabrication of functional multicomponent nanoparticles (NPs). Self-assembly techniques provide relevant control over NP size distribution (down to a few nanometers in diameter), but more importantly, such techniques are amenable for practical applications since the resulting NPs (and arrays thereof) are programmed in the molecular structure of the precursors. Here, the diblock copolymer micelle nanolithography concept of achieving monodisperse NPs is extended to direct the synthesis of multicomponent core-shell NPs arranged in a triangular lattice.

Molecular heterojunction morphology on rough substrate surfaces: component separation by Fourier subtraction.

The study of molecular heterojunction morphology is often complicated by the presence of a topographically complex substrate. On such substrates, it is difficult to definitively assign a topographic feature to a specific component. We propose a technique, based on the separation of features in reciprocal space (Fourier subtraction), to deconvolute a heterojunction surface into two real space images.

Obtaining molecular orientation from second harmonic and sum frequency scattering experiments in water: angular distribution and polarization dependence.

We present a method for determining molecular orientation from second-order nonlinear light scattering experiments. Our modeling shows that there is an optimal angular region, for which the scattering pattern is most sensitive to molecular orientation. We show that molecular orientation can be retrieved from measuring intensities at different polarization combinations, measuring the relative amplitudes of different vibrational modes of the same moiety and by analyzing the shape of the angular scattering pattern.