Materials Literature
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The automation of protein structure determination is an essential component for high-throughput structural analysis in protein X-ray crystallography and is a key element in structural genomics. This highly challenging undertaking relies at present on the availability of high-quality native and derivatized protein crys…
TlNiO 3 has been prepared under high oxygen pressure. This perovskite has been characterized by high-resolution neutron powder diffraction (NPD), Mössbauer spectroscopy, and magnetic measurements. The crystal structure was refined in the monoclinic P 2 1 / n space group, containing two crystallographic sites for Ni 3+…
Abstract Motivated by recent experiments (Spontak, R. J.; Smith, S. D. J Polym Sci Part B: Polym Phys 2001, 39, 947) on morphological and mechanical properties of multiblock copolymers (AB) n , we theoretically elucidate the links between microscopically determined properties, such as the bridging fraction of chains,…
Abstract The structural properties of poly(vinyl acetate) (PVAc) films filled with different levels of MgBr 2 or MgCl 2 were investigated. Differential scanning calorimetry revealed that, at certain filling levels of MgBr 2 or MgCl 2 , two new transitions appeared. The first one was due to the α relaxation ( T α ) ass…
The third generation of novel photo-responsive water-soluble stilbene dendrimer (trans- and cis-G3 WSD) undergoes unusual one-way trans-to-cis isomerization to give 100% of cis isomer at the photostationary state on UV irradiation in water.
It is hypothesized that surface residues with high conformational entropy, specifically lysines and glutamates, impede protein crystallization. In a previous study using a model system of Rho-specific guanine nucleotide dissociation inhibitor (RhoGDI), it was shown that mutating Lys residues to Ala results in enhanced…
An important component of a fully automated system for structure solution and phase improvement through density modification is a capability for identification of non-crystallographic symmetry as early in the process as possible. Algorithms exist for finding NCS in heavy-atom sites, but currently require of the order…
Based on a recently ascertained understanding of the parameters that control flame generated deposition of Na 2 SO 4, NaCl, or Na 2 CO 3 onto cooled surfaces immersed in flames, a new process has been developed to inhibit their formation. It is seen that no alkali sulfate is formed if tungsten salts are added to a fla…
The intensely sweet protein thaumatin has been crystallized at 293 K in the presence of sodium tartrate and 25%(v/v) glycerol for X-ray diffraction data collection at 100 K. A comparison of the three-dimensional structure model derived from a crystal grown in the presence of glycerol with that of a control deprived of…
Epitaxially grown heterostructures consisting of alternating layers of ${\mathrm{LaMnO}}_{3}$ (LMO, 9 or 15 unit cells) and ${\mathrm{SrMnO}}_{3}$ (SMO, 4 or 6 unit cells) on a ${\mathrm{SrTiO}}_{3}(100)$ (STO(100)) substrate have been studied by a combination of high resolution transmission electron microscopy (HRTEM…
Statistical density modification is a technique for phase improvement through a calculation of the posterior probability of the phases, given experimental phase information and expectations about features of the electron-density map. The technique can take advantage of both estimates of electron density in the map and…
Abstract PFPE‐ b ‐PVDF and PFPE‐ b ‐poly(VDF‐ co ‐HFP) block copolymers [where PFPE, PVDF, VDF, and HFP represent perfluoropolyether, poly(vinylidene fluoride), vinylidene fluoride (or 1,1‐difluoroethylene), and hexafluoropropylene] were synthesized by radical (co)telomerizations of VDF (or VDF and HFP) with an iodine…
Electroconvection in an unusual nematic compound with strongly positive dielectric anisotropy and negative anisotropy of the conductivity is investigated. For homeotropic alignment, where one has a direct transition to rolls or squares depending on the frequency of the applied voltage, we present a quantitative theory…
GDP-D-mannose 4,6-dehydratase catalyzes the first step in the de novo synthesis of GDP-L-fucose, the activated form of L-fucose, which is a component of glycoconjugates in plants known to be important to the development and strength of stem tissues. We have determined the three-dimensional structure of the MUR1 dehydr…
Thermodynamic basicities of several new nonplanar water soluble tetraaryltetracyclohexano- (Ar(4)TCHP) and tetraaryltetrabenzoporphyrins (Ar(4)TBP) have been measured and correlated with their structural parameters. While the degrees of nonplanarity in these porphyrins are similar, Ar(4)TCHPs exhibit significantly hig…
The first results of a medium-scale structural genomics program clearly demonstrate the value of using a medium-throughput crystallization approach based on a two-step procedure: a large screening step employing robotics, followed by manual or automated optimization of the crystallization conditions. The structural ge…
Spray pyrolysis, an aerosol decomposition technique, was first used to synthesize ZnS:Mn 2+ particles, and their optical properties were characterized. The effects of process parameters on the properties of ZnS:Mn 2+ particles were systematically investigated for Mn 2+ doping concentrations of 0−8 at. %. The results s…
Abstract The reaction of diallyl amine with 1,3‐propane sultone led to the synthesis of the zwitterionic monomer 3‐( N , N ‐diallylammonio)propanesulfonate. The sulfobetaine was cyclopolymerized in water in the presence of sodium chloride with t ‐butylhydroperoxide as an initiator to afford a polysulfobetaine (PSB) in…
We report the infrared (IR) response of bulk samples of multiwalled boron nitride nanotubes, produced by a substitution reaction from single walled carbon nanotubes, which is dominated by two characteristic BN-vibrations at 800 and 1372 cm-1.
Trichloroethylene (TCE) decomposition over a MnOx/ gamma-Al2O3 catalyst in a fixed-bed reactor was conducted in this study. The MnOx/gamma-Al2O3 powders were prepared by the incipient wetness impregnation method with aqueous solution of manganese nitrate. The catalysts were characterized by DTA-TGA, XRD, porosity anal…