Materials Literature
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Dissimilatory sulfite reductase D (DsrD) from Desulfovibrio vulgaris has been crystallized for a neutron diffraction study. The initial crystals obtained were too small for the neutron experiment. In order to obtain a larger crystal (>1 mm3), a combination of two techniques was developed to determine the optimum cryst…
Plants of the Dorstenia genus, used in traditional medicine and as food ingredient in Africa, are rich in polyphenolic compounds which can be involved in prevention of disease and food spoilage through their antioxidant activity. The antiradical activities of extracts of Dorstenia psilurus. D. ciliata and a phenolic c…
A random tunneling algorithm (RTA) is derived from the terminal repeller unconstrained subenergy tunneling (TRUST) algorithm, and the parallelization of the RTA is implemented with an island parallel paradigm. Combined with the techniques of angular moving, the parallel random tunneling algorithm (PRTA) is applied to…
Structural refinement of proteins involves the minimization of a target function that combines X-ray data with a set of restraints enforcing stereochemistry and packing. Electrostatic interactions are not ordinarily included in the target function, partly because they cannot be calculated reliably without a descriptio…
Using synchrotron radiation, X-ray data have been collected from Pyrococcus furiosus ornithine carbamoyltransferase (Pfu OTCase) to a maximal resolution of 1.87 A, allowing the refinement of a previous structure at 2.7 A [Villeret et al. (1998), Proc. Natl Acad. Sci. USA, 95, 2801-2806]. Thanks to the high resolution…
The three-dimensional crystal structure of the triple-point mutant of the catalytic subunit of human protein kinase CK2alpha has been determined at 2.4 A resolution. Microcrystals of mutant CK2 catalytic subunit were obtained by a protein-crystallization method based on thin-film nanotechnology. These microcrystals (o…
Anticipating a continuing increase in the number of structures solved by molecular replacement in high-throughput crystallography and drug-discovery programs, a user-friendly web service for automated molecular replacement, map improvement, bias removal and real-space correlation structure validation has been implemen…
Titanium−silicon binary oxide thin films of differing TiO 2 content were prepared by using an ionized cluster beam (ICB) deposition method using multi-ion sources under a dry preparation process. From the results of UV−vis absorption measurements, binary oxide thin films with low TiO 2 content showed much higher trans…
Microstructural Design for Enhanced Elevated Temperature Properties in Sand-castable Magnesium Alloys - C. Bettles & M. Gibson Thermodynamic Database for Mg-alloys: Progress and Application to Mg-Al-Ca-Si Alloy Development - R. Schmid-Fetzer & J. Grobner Development of the New Creep Resistant Alloy AS31 - CV. Agalakov…
Collection of quality data on high-energy synchrotron sources requires the selection of a cryoprotectant that allows protein crystals to be cryocooled without damage to the crystal and with suppression of ice formation. The use of sodium malonate as a versatile cryoprotectant for salt-grown protein crystals is present…
Fisher's information is a statistical quantity related to maximum-likelihood theory. It is a matrix defined as the expected value of the squared gradient of minus the log-likelihood function. This matrix is positive semidefinite for any parameter value. Fisher's information is used in the quasi-Newton scoring method o…
The (TCNE)(2)(2)(-) dimer dianion formed by connecting two TCNE(-) anions via a four-center, two-electron pi-orbital bond is studied using ab initio theoretical methods and a model designed to simulate the stabilization due to surrounding counterions. (TCNE)(2)(2)(-) is examined as an isolated species and in a solvati…
A procedure to obtain homogeneous free-standing polypyrrole (ppy) films 10−20 μm thick is described. The resulting films have mechanical characteristics good enough to be used as a working electrode for electrochemical measurements and applications. Structures and uniformity of both film surfaces and the cross section…
A zinc complex of (3-pyridyl)porphyrin with an alkynyl sidearm (1) preferentially formed a cyclic tetramer in toluene, which showed supramolecular thermochromism at ambient temperatures of 0-100 degrees C. Because of an appropriate extension of pi-electronic conjugation of the porphyrin chromophore, the thermal-induce…
The tetranuclear CuZ cluster catalyzes the two-electron reduction of N2O to N2 and H2O in the enzyme nitrous oxide reductase. This study shows that the fully reduced 4CuI form of the cluster correlates with the catalytic activity of the enzyme. This is the first demonstration that the S = 1/2 form of CuZ can be furthe…
The adsorption of H 2 O on the oxygen-terminated polar surface of ZnO, ZnO(000-1), has been studied by He atom scattering (HAS), low-energy electron diffraction (LEED), adsorption probability measurements, He atom reflectivity measurements as a function of exposure and surface temperature (He atom thermal desorption m…
We present an \textit{exactly solvable} model of a monomer-monomer $A + B \to \emptyset$ reaction on a 2D inhomogeneous, catalytic substrate and study the equilibrium properties of the two-species adsorbate. The substrate contains randomly placed catalytic bonds of mean density $q$ which connect neighboring adsorption…
We study using first-principles total-energy calculations, diffusion-reaction processes involved in the thermal nitridation of SiO2. We consider NO, NH, N2 and atomic N in different charge states as the nitriding species in alpha-quartz. Our results show that none of neutral species react with the SiO2 network remaini…
We overview recent results on intrinsic frictional properties of adsorbed monolayers, composed of mobile hard-core particles undergoing continuous exchanges with a vapor phase. In terms of a dynamical master equation approach we determine the velocity of a biased impure molecule - the tracer particle (TP), constrained…
Connective tissues (CTs), which define bodily shape, must respond quickly, robustly and reversibly to deformations caused by internal and external stresses. Fibrillar (elastin, collagen) elasticity under tension depends on molecular and supramolecular mechanisms. A second intra-/inter-molecular pair, involving proteog…