Materials Literature
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The high accuracy of X-ray analyses at atomic resolution is now able to display subtle deformations from standard geometry of building blocks in proteins. From the analysis of nine ultra-high resolution protein structures, we derived the first experimental evidence that a significant pyramidalization at the main-chain…
Abstract Thymidine and uridine, as well as calf thymus DNA (ctDNA), have been shown for the first time to function as chiral photosensitizers in aqueous solution, to effect the enantiodifferentiating photoisomerization of (Z)-cyclooctene, giving the chiral (E)-isomer in enantiomeric excesses of up to 15%.
Neutron powder diffraction experiments at high temperature (300-1600 K) were performed at BENSC (Berlin, D), on synthetic Zn 0.97 Fe 2.02 O 4 , to investigate the cation partitioning of Zn and Fe over the tetrahedral and octahedral sites as a function of T. The data analysis combined Rietveld structure refinements wit…
Abstract A single-phase LaMnO3+δ perovskite with high surface area could be synthesized after air-calcining the hydroxide precursor at 650 °C and above. The precursor was easily obtained by dropping a mixed aqueous solution of La and Mn nitrates into highly basic aq. NH3 with and without the presence of N(CH3)4Br. The…
Abstract A low molecular weight gelator containing β-diketonato ligands was prepared from a derivative based on trans-(1R,2R)-diaminocyclohexane. Gels were converted to mechanically-robust and thermally-stable gels by complexation between β-diketonato ligands and divalent metal ions.
Two commercial chemical blowing agents, azodicarbonamide (ADC) and oxybisenzenesulphonylhydrazide (OBSH), were used alone and in blends for expanded natural rubber vulcanisates. The expanded rubber vulcanisates were characterised with respect to the apparent foam density, degree of crosslinking, tensile properties and…
Molecular Scaffolds formed by the linking of bicyclo[2.2.1]heptane (norbornane) subunits by sharing a common C2-bridge have great appeal to the molecular architect since modelling studies have shown that the syn-facially fused members have a curved topology. Furthermore, this curvature can be modified by replacement o…
Abstract. We examined the effects of the transparent fibroin film (silk film) on full‐thickness skin wounds. Full‐thickness dermatotomies (15 mm × 9 mm) were prepared on the dorsal wall of CRJ:CD‐1 nu/nu (ICR nu/nu ) mice. The area of the wounds dressed with silk film was reduced to 10% of that made by the dermatotomy…
Abstract The bleaching of cottonseed oil by alumina-pillared (Al-pillared) acid-activated clays was investigated. Acid activation of a Ca-rich montmorillonite (CMS STx-1) following treatment with 1, 4, and 8 eq/L sulfuric-acid solutions, as well as subsequent pillaring with alumina, produces new materials. These mater…
Two different behaviors controlled by local lattice environment of crystallization are observed in the IR spectra of polycrystalline natural tourmalines from the elbaite-schorl series in the O-H stretching region (3800-3100 cm -1 ). The first case is characterized by the presence of three O-H stretching bands, and is…
In situ poly(hydroxyalkanoate) (PHA) levels and repeating-unit compositions were examined in stratified photosynthetic microbial mats from Great Sippewissett Salt Marsh, Mass., and Ebro Delta, Spain. Unlike what has been observed in pure cultures of phototrophic bacteria, the prevalence of hydroxyvalerate (HV) repeati…
Dynamic processes in crystalline solids are reflected in the atomic displacement amplitudes determined, together with the atomic coordinates, by crystal structure analysis. The interpretation of such amplitudes poses two severe problems: (a) The relative phases of the atomic displacements are lost; and (b) the amplitu…
We report scanning tunneling microscopy and complementary spectroscopic measurements on TiO 2 (110) surfaces. We show data on (i) a surface restructuring process that results from annealing in oxygen; (ii) Pt clusters, grown at room temperature and encapsulated upon high temperature annealing; and (iii) adsorption of…
The rate at which a facetted tetragonal cavity of nonequilibrium shape approaches a cubic equilibrium (Wulff) shape via surface diffusion was modeled. The shape relaxation rate of a facetted “stretched cylinder” was also modeled. For the first geometry, only an approximate solution based on linearizing the mean potent…
Polypyrrole films containing tetrafluoroborate were electrochemically synthesized, and stress generated in the film under application of an electric voltage was measured in air under various strains. It was found that the film generated contractile stress in response to the applied voltage that reached 6.1 MPa under 2…
Abstract As part of a study to establish an effective use of underutilized resources, purple sea urchin test collagen was prepared by limited pepsin digestion and characterized. This collagen consisted of two α chains and has a chain composition of (α1)2α2 heterotrimer. The primary structure of the purple sea urchin c…
A synchrotron radiation X-ray powder diffractometer for samples of very small amount has been developed to collect high-quality diffraction patterns under extreme conditions, i.e. at low temperature and/or high pressure. A new cylindrical imaging plate (CIP) is used as a detector, in addition to a conventional flat-ty…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPorphodimethene−Porphyrin Interconversion: A Tetrapyrrolic Redox-Switchable MacrocycleMichael Harmjanz, Hubert S. Gill, and Michael J. ScottView Author Information Department of Chemistry, University of Florida Gainesville, Florida 32611-7200 Cite this: J. Am. Chem. So…
A new N- and S-containing heterocyclic compound, CAHMT, was synthesized and evaluated as a corrosion inhibitor for oil-well tubular steel (N-80) and mild steel (MS) at 105°C ± 2°C by the weight loss method. Potentiodynamic polarization measurements were carried out at room temperature for both steels in the presence o…
Using computer simulations we investigate the microscopic structure of the singular director field within a nematic droplet. As a theoretical model for nematic liquid crystals we take hard spherocylinders. To induce an overall topological charge, the particles are either confined to a two-dimensional circular cavity w…