Materials Literature
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Thrombus formation and eventual intimal hyperplasia are the leading causes of small-diameter synthetic vascular graft failure. To combat these issues, we have incorporated a diazeniumdiolate-modified nitric oxide (NO)-producing peptide into a polyurethane to improve the thromboresistance of this biocompatible polymer.…
We have investigated the photonic properties of a free-standing cholesteric elastomer film under biaxial mechanical load. The sample, which was obtained by UV cross-linking of a cholesteric side-chain polymer, shows substantially improved optical properties compared to cholesteric elastomers obtained by the anisotropi…
We present a neutron diffraction study of the transition between low-density and high-density amorphous ice (LDA and HDA, respectively) under pressure at approximately 0.3 GPa, at 130 K. All the intermediate diffraction patterns can be accurately decomposed into a linear combination of the patterns of pure LDA and HDA…
Abstract Summary: We have developed the first direct, organocatalytic, bulk ring‐opening polymerization (ROP) of ε ‐caprolactone ( ε ‐CL) with solid cotton and paper cellulose as the initiators. The mild ROPs were performed without solvent, and are operationally simple, inexpensive and environmentally benign. Organic‐…
A theoretical approach for the intramolecular energy transfer process involving the ligand-to-metal charge transfer (LMCT) state in lanthanide compounds is developed. Considering a two-electron interaction, both the direct Coulomb and exchange interactions are taken into account, leading to expressions from which sele…
We demonstrate that fluorescence of single molecules in the nanometric vicinity of a thin gold film can be effectively excited and detected through the film with an epi-illumination scanning confocal microscope. A full theoretical treatment of the fluorescence signal indicates that both excitation and emission are sur…
Analysis of the methanolic extract of Calotropis procera root barks enabled the identification of a novel cardenolide (2''-oxovoruscharin) to be made. Of the 27 compounds that we hemisynthesized, one (23) exhibited a very interesting profile with respect to its hemisynthetic chemical yield, its in vitro antitumor acti…
The reaction mechanism for nitrous oxide decomposition has been studied on hydrated and dehydrated mononuclear iron sites in Fe-ZSM-5 using density functional theory. In total, 46 different surface species with different spin states (spin multiplicity M(S) = 4 or 6) and 63 elementary reactions were considered. Heats o…
Five independent effective elastic moduli of a transversely isotropic multiwalled carbon nanotube (MWNT) are studied by analyzing its deformations under four loading conditions, i.e., axial tension, torsional moment, in-plane biaxial tension, and in-plane tension-compression stress. Two distributions of the tension lo…
Rare earth (or yttrium) doped BaCeO 3 has been widely investigated as a proton conducting material. Usually, the trivalent dopants are assumed to occupy the Ce 4+ -site, which introduces oxygen vacancies into the perovskite structure and furthers the protonic conductivity. Recent studies indicate the possibility of do…
Preferred crystallographic orientation, i.e. texture in crystalline materials powder diffraction data, can cause serious systematic errors in phase composition analysis and also in crystal structure determination. The March model [Dollase (1986). J. Appl. Cryst. 19 , 267–272] has been used widely in Rietveld refinemen…
Among the archaea, Methanococcus maripaludis has the unusual ability to use L- or D-alanine as a nitrogen source. To understand how this occurs, we tested the roles of three adjacent genes encoding homologs of alanine dehydrogenase, alanine racemase, and alanine permease. To produce mutations in these genes, we devise…
A new ternary intermetallic compound, namely, YbMn2Sb2, has been synthesized and its magnetic and electrical transport properties have been studied in the temperature range of 2 to 300 K. This compound crystallizes in a trigonal, La2O2S type structure (space group P3bm1, No. 164) and is found to be ferromagnetically o…
Density-functional studies of the electronic structures and exchange interaction parameters have been performed for a series of ferromagnetic full Heusler alloys of general formula ${\mathrm{Co}}_{2}\mathrm{Mn}Z$ $(Z=\mathrm{Ga},\mathrm{Si},\mathrm{Ge},\mathrm{Sn})$, ${\mathrm{Rh}}_{2}\mathrm{Mn}Z$ $(Z=\mathrm{Ge},\ma…
Pseudotetrahedral iron(II) coordination complexes that contain bridged nitride and terminal imide linkages, and exhibit singlet ground-state electronic configurations, are described. Sodium amalgam reduction of the ferromagnetically coupled dimer, {[PhBP(3)]Fe(mu-1,3-N(3))}(2) (2) ([PhBP(3)] = [PhB(CH(2)PPh(2))(3)](-)…
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We perform molecular dynamics simulations to investigate the shear dynamics of hydration water nanoconfined between two mica surfaces at 1 bar pressure and 298 K. Newtonian plateaus of shear viscosity comparable to the bulk value for different hydration layers D=0.92-2.44 nm are obtained. The origin of this persistent…
During the past ten years nanostructures have been subject of active research. Fabrication of such systems follows well developed methods. The increase in the number of materials available for research and applications requires that the methods of their characterization be even more precise then before. Thin film stru…
Gold nanoclusters encapsulated with organic molecules are of great interest for its possible applications in the fields of molecular electronics, catalysis and medical science. Here we demonstrate that monolayer and bilayer films of thiol-capped gold nanoclusters can exhibit diode-like properties provided controlled s…
Molecular dynamics simulations are used to study the spreading of binary polymer nanodroplets in a cylindrical geometry. The polymers, described by the bead-spring model, spread on a flat surface with a surface-coupled Langevin thermostat to mimic the effects of a corrugated surface. Each droplet consists of chains of…