Materials Literature
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We reconsider the possibility of periodic deformations in nematic liquid crystal samples, and present a simple method to analyze their stability near the threshold. Our method consists in finding the matrix characterizing the total energy in terms of the integration constants of the linearized solutions of the variati…
Thermoascus aurantiacus xylanase is a thermostable enzyme which hydrolyses xylan, a major hemicellulose component of the biosphere. The crystal structure of this F/10 family xylanase, which has a triosephosphate isomerase (TIM) barrel (beta/alpha)(8) fold, has been solved to small-molecule accuracy at atomic resolutio…
A new approach for the replacement of heart valves consists of obtaining an acellular matrix from animal aortic valves that performs mechanically, is nonantigenic, and is free from calcification and fibroblast proliferation. Novel biochemical treatments must be developed for this purpose. In this work, we focus on the…
Dicyanamide-bound mononuclear compounds Cp(dppe)FeN(CN)2 (3) and Cp(PPh3)2RuN(CN)2 (4) were isolated in high yields by the reactions of Cp(dppe)FeCl (1) and Cp(PPh3)2RuCl (2), respectively, with excess sodium dicyanamide. Compounds 3 and 4 are excellent precursors for the design of dicyanamide-bridged binuclear comple…
To investigate the effects of polymer chemistry and topology (linear or graft copolymer) on in vivo biocompatibility and biostability based on cage implant system, various hydrogels, composed of short hydrophilic [polyethylene oxide (PEO)] and hydrophobic block, were prepared by polycondensation reaction. Poly(tetrame…
The vibrational properties (phonons) of a one-dimensional periodic phase of atoms physisorbed in the external groove of the carbon nanotube bundle are studied. Analytical expressions for the phonon dispersion relations are derived. The derived expressions are applied to Xe, Kr, and Ar adsorbates. The specific heat per…
Giant platinum-acetylides dendrimers were precisely synthesized by a divergent method; the sixth generation dendrimer, the diameter of which is larger than 10 nm, has 189 Pt atoms per molecule, and its molecular weight is as high as 139750.
The feasibility of alignment control of low-molecular-weight guest species by controlling the orientation of mesochannels in a mesoporous silica host has been shown for the first time; spectroscopically anisotropic absorption behaviour of a cyanine dye was observed upon its incorporation into the mesochannels of a mes…
The diffusive behavior of ethane and ethylene in single-walled carbon nanotubes is investigated using classical molecular dynamics simulations and density functional theory calculations. At low molecular densities, these nonspherical molecules follow a spiral path inside nanotubes with diameters of 13-22 A, which maxi…
Abstract 2,6-Di-tert-butylphenol is selectively transformed to 3,3′,5,5′-tetra-tert-butyl-4,4′-diphenoquinone in the presence of molecular oxygen using alkali-promoted Cu–Mg–Al hydrotalcites as recyclable heterogeneous catalysts.
Seven gadolinium complexes are shown to be excellent compounds for the preparation of heavy-atom derivatives for macromolecular crystallography projects. De novo phasing has been carried out using single-wavelength anomalous diffraction (SAD) on a series of gadolinium-derivative crystals of two proteins: hen egg-white…
The copolymerization of tert -butyl methacrylate (1) was carried out with the N -alkyl methacrylamides, e.g., N -octyl methacrylamide (2), N -ethyl methacrylamide (3), N -cyclohexyl methacrylamide (4), N -benzyl methacrylamide (5), and methacrylamide (6) . Thermal treatment of these copolymers leads to thermal syn eli…
A bis(radical) derivative based on a triphenylphosphane core substituted by two nitronyl nitroxide units is reported. This compound was isolated in two forms. One consists of an H2O adduct where H2O is hydrogen-bonded to the radical units, whereas the second lacks this bridging unit. Magnetic studies revealed that the…
The self-assembled supramolecular nanostructures of a bolaamphiphilic diacid, 1,20-octadecanedicarboxylic acid (ODA), on the subphase containing various metal ions have been investigated. Different from the bolaamphiphilic acid on pure water surface, exotic nanostructures were observed for the spreading Langmuir film…
Improved data quality now makes it feasible to exploit the weak anomalous signal derived only from the sulfurs inherent to the protein or in particular from halide ions incorporated by soaking. The latter technique requires the location of a high number of partially occupied halide sites. This number appears to be rou…
A new method of protein crystallization, the floating-drop vapour-diffusion technique, has been developed. The method combines the traditional sitting-drop vapour-diffusion technique and a novel two-liquid system. A crystallization drop composed of a mixture of sample and reagent floats on an insoluble and very dense…
A three-way model catalyst has been prepared with 0.58 wt % Pt on Ce 0.68 Zr 0.32 O 2 mixed oxide washcoated on a ceramic monolith. Conditions of the washcoating procedure, i.e., powder size distribution and acidic nature of the slurry, have been optimized. The activity on simultaneous elimination of NO, C 3 H 6, and…
A series of perfluoroalkyl end-capped poly(ethylene oxide) (PEO) of molecular weight M n = 10 000 and 20 000, noted F-HEUR-10K and F-HEUR-20K, with a well-defined structure were synthesized in two reaction steps. The reaction of PEO with a large excess of isophorone diisocyanate (IPDI) leads to an isocyanate-terminate…
A novel liquid crystalline quaternary five-block molecule is reported which is composed of four incompatible molecular parts, a rigid biphenyl core, two polar 2,3-dihydroxypropoxy groups in the terminal 4- and 4'-positions, and a branched semiperfluorinated chain in the lateral 3-position, consisting of a perfluorinat…
Layer-by-layer (LBL) films of a semiconducting polymer (POMA) alternated with a polyelectrolyte (PVS), adsorbed onto silicon oxide, mica, ITO/glass, Au/Cr/glass, hydrophilic and hydrophobic glass were studied by atomic force microscopy (AFM). The samples were characterized LBL with the AFM operating in the contact, fr…