Materials Literature
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Serine hydroxymethyltransferase (SHMT) catalyzes the reversible cleavage of serine to form glycine and single carbon groups that are essential for many biosynthetic pathways. SHMT requires both pyridoxal phosphate (PLP) and tetrahydropteroylpolyglutamate (H4PteGlun) as cofactors, the latter as a carrier of the single…
The Upack program package for crystal structure generation was used to build hypothetical crystal structures for 32 pyranoses and 24 polyalcohols. A subset of these was used to compare six force fields in their ability to reproduce the experimentally observed structures, preferably with low energies and high rankings…
The oxygen vacancy ordering process in the system CaTiO3-CaFeO2.5 has been studied as a function of composition and temperature. The samples (CaTi1−x Fe x O3−x/2 with 0 ⩽x⩽ 1) were annealed at temperatures between 900°C and 1400°C and characterized, after drop quench, by means of XRD, Mössbauer spectroscopy and TEM. V…
The solid state of comb copolymer-like systems obtained by blending poly(4-vinylpyridine) with pentadecylphenol was studied by a combination of techniques. Depending on the amount of pentadecylphenol, several regimes are present. For 0.5 ≤ x ≤ 1.0 ( x is the ratio between the number of phenol and pyridine groups) the…
Accurate lattice parameters have been determined between 2 K and 520 K for the negative thermal expansion compound ZrW 2 O 8 , by high-resolution neutron powder diffraction measurements. Two different analyses of the temperature dependence of the lattice constant i) in terms of Debye and Einstein contributions and ii)…
An iron(III) porphyrin complex with highly electron-withdrawing substituents on the porphyrin ligand efficiently catalyzes the hydroxylation of alkanes by H2O2 via enzyme mimetic oxidation reactions in aprotic solvent. An “isolated” high-valent iron(IV) oxo porphyrin cation radical intermediate, prepared in situ by re…
Several experiments were conducted to examine the effects of the molar ratio of citric acid to cations and of the pH value on the chemistry of a solution prepared by the Pechini method. Two types of precipitates, barium titanium citrate (BTC) and barium citrate, developed, depending on the experimental conditions. Cha…
The effect of disorder arising from the mismatch between the average sizes of the A-site cations in the rare-earth manganates, ${L}_{0.5}{A}_{0.5}{\mathrm{MnO}}_{3}$ $(L=\mathrm{rare}\mathrm{}\mathrm{earth},$ $A=\mathrm{alkaline}\mathrm{}\mathrm{earth})$, on their charge-ordering behavior has been investigated. Measur…
We report a smectic liquid crystal in which a tilt of the molecular orientation away from the layer normal in the Smectic C phase of up to 24 occurs with minimal layer contraction. This characteristic, accompanied by an exceptionally large underlying negative thermal layer expansion coefficient, enables the formation…
Electronic structures and optical properties of ZnO, SnO 2 and In 2 O 3 are investigated by using a first-principles calculation method based on the density functional theory. The dielectric functions dominated by electron interband transitions are analyzed in terms of the calculated electronic band structures and cha…
Abstract A novel fibrous silica with a gnarled surface structure and an inner tube with bundle-replicated stripes was prepared by sol-gel polymerization of tetraethoxysilane using collagen fibers as a template.
Cyanide-bridged trinuclear complexes containing square-planar platinum at the center were synthesized and identified by structure determinations. Their chemical building blocks were cis - and trans -PtL 2 X 2, Cp(dppe)FeX, Cp(PPh 3 ) 2 RuX (with X = Hal or CN), Pt(CN) 4 2 -, and Fe(CN) 6 3 - . Several of the intermedi…
The atomic and electronic structures of kappa‐Al 2 O 3 are determined using theoretical first‐principles techniques based on density‐functional theory (DFT), plane waves, and pseudopotentials. The obtained structure is confirmed by analysis of powder X‐ray diffraction data. The structure is orthorhombic with oxygen io…
We studied the interfacial tension between coexisting colloid-rich and polymer-rich fluid phases in a phase-separated colloid−polymer mixture. First, the location of the fluid−fluid binodal and the tie lines between the coexisting phases were determined using a recently proposed method that only requires the volumes o…
By using extensive molecular dynamics simulations, we have determined the violation of the fluctuation-dissipation theorem in a Lennard-Jones liquid quenched to low temperatures. For this we have calculated X ( C ), the ratio between a one-particle time-correlation function C and the associated response function. Our…
The structure of the μ-Al 4 Mn phase, which is an approximant of icosahedral and decagonal quasicrystals, is interpreted as a modulated crystal structure. It basically comprises modulated layers, in which the ordering of atomic vacancies takes place in the close-packed layers. The modulation is considered to be due to…
Poly(4-vinylpyridine) bearing an osmium complex was alternately assembled with poly(acrylic acid) on a gold substrate via hydrogen bonding. UV-Vis spectra were used to monitor the assembling process. X-ray diffraction patterns and AFM images showed that the multilayer film is of high quality with low surface roughness…
RuO 2 films prepared by reactive sputtering were annealed in air and vacuum and the changes of their crystal structure, chemical binding state and resistivity were studied. In air, the RuO 2 films maintain a rutile structure below 800°C. Crystal grain growth was found above 600°C and the minimum resistivity of 46 µΩcm…
Thermal diffusivity measurements on three polymer melts were made using the Forced Rayleigh Light Scattering technique. The polymers, which were tested at room temperature where they are in the molten state, included a polydimethylsiloxane and two polyisobutylenes. The optical setup and procedures developed in this st…
Abstract Experiments on zeolitization were conducted on four synthetic monocationic glasses (Na, K, Ca, or Mg-rich glass) with Si/Al molar ratios of 2.67, similar in acidity to many volcanic glasses of partially zeolitized Italian tuffs. The products of the hydrothermal treatment at 100, 150, and 200°C of single glass…