Materials Literature
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The Jonscher power law, or ``universal dielectric response'' (UDR) behavior was studied for a range of ${\mathrm{CeO}}_{2}$ solid solutions with ${\mathrm{Y}}^{3+}$ and ${\mathrm{Gd}}^{3+}$ dopants, with particular emphasis on dilute systems which possess relatively simple defect structures. The results show power-law…
X-ray-absorption fine-structure spectra were measured and analyzed for several FeCo cyanides ${M}_{x}{\mathrm{Co}}_{y}{\mathrm{Fe}(\mathrm{CN})}_{6}\ensuremath{\cdot}z{\mathrm{H}}_{2}\mathrm{O}$ $(M=\mathrm{Na},$ K, Rb) which are known to exhibit interesting magnetic properties depending on temperature. X-ray-absorpti…
The optical reorientation of nematic liquid crystals doped with azo dyes is studied. It is shown that in the presence of absorption both the trans and cis isomers enhance significantly the optical torque; they contribute, however, with opposite signs to the net enhancement and tend to cancel each other's effect. The a…
The composition and thickness of thin iron oxide films on polycrystalline pure iron were evaluated from Fe 2p spectra as measured by x-ray photoelectron spectroscopy. To this end the experimental spectra were reconstructed from reference spectra of the constituents Fe0, Fe2+ and Fe3+. The background contributions in t…
Abstract Previous analysis of published experimental results on compaction and relaxation of textile reinforcements allowed the effects of some processing parameters on the mechanical behavior of the reinforcements to be identified. However, a limited number of relaxation results are available; also, the effect of som…
A pulsed electro-acoustic system is described which enables electric fields up to to be generated in thin (100- ) insulating plaque samples with measurement of the dynamic net space charge density, as a function of temperature and of distance through the thickness of the sample, and the external circuit charging curre…
With the aim of bridging the gap between protein sequence and structural analyses, we have developed a tool to aid the identification of new protein sequences by recognizing distant homologues using structural information. The tool generates sequence annotated by structure (SAS) files, applying structural information…
New silicone derivatives that generate no toxic gas during combustion have been developed for use as flame retardants in the aromatic thermoplastics (polycarbonate and its derivatives, acrylonitrile–butadiene–styrene, polystyrene) used in many electronic devices. A special silicone with a branched chain structure, a p…
OBJECTIVE: To compare transient blood-brain barrier disruption (BBBD) by hypertonic mannitol with pharmacological modification of the blood-tumor barrier by the vasoactive peptide bradykinin for delivery of small and large agents to nude rat intracerebral xenografts. METHODS: Female nude rats (n = 104) with 6-day intr…
We study the effect of finite chain length on the collapse transition of stiff-chain macromolecules by means of a Monte Carlo simulation within the framework of the bond fluctuation lattice model. Variable stiffness of the chains was modeled by introducing a potential depending on the angle between successive bonds an…
Enhanced conductivity in conjugated polymer blends can be achieved by supramolecular self-assembly. The authors demonstrate that the morphology of the conducting polymer blend can be modified by crosslinking of one of its components. Ionic crosslinking of the conducting component—poly(3,4-ethylenedioxythiophene) doped…
Eukaryotic sulfatases carry an alpha-formylglycine residue that is essential for activity and is located within the catalytic site. This formylglycine is generated by posttranslational modification of a conserved cysteine residue. The arylsulfatase gene of Pseudomonas aeruginosa also encodes a cysteine at the critical…
The transition from localized to itinerant electronic behavior is shown to be first-order. In a perovskite, segregation into localized-electron and itinerant-electron phases can be accomplished by cooperative atomic displacements. Sr 1 - x Ca x VO 3 and La 1 - x Nd x CuO 3 illustrate single-valent perovskites that exh…
The corrosion tendencies of metals are related with their position in the electromotive series. These electrode potential degrees may change due to the compositions of the alloys, the surrounding media, or due to alterations in the composition because of recurrent casting. Therefore in this research, the electrode pot…
The physical and chemical characteristics of material surfaces are thought to play important roles in biomaterial-mediated tissue responses. To understand the importance of discrete biomaterial chemical characteristics in modifying host tissue responses, we constructed surfaces bearing different functional groups usin…
A silver colloid (mean particle size 6 nm) is prepared via photochemical reduction of Ag + ions. After total silver ion reduction, the colloid exhibits an extraordinarily intense surface plasmon absorption band. The absorption band is strongly damped by small concentrations of carbon disulfide, thiophenol, and diethyl…
Alternating current impedance spectroscopy and electron microscopy were used to investigate the effect of grain boundaries in LSGM‐based materials. The impurity LaSrGa 3 O 7 existing in the samples La 0.8 Sr 0.2 Ga 1‐ y Mg y ‐O 3–0.5(0.2+ y ) ( y = 0.05–0.10) gives a contribution to a perfect or depressed grain‐bounda…
PURPOSE: To evaluate the clinical utility and morphologic accuracy of gadolinium-enhanced excretory magnetic resonance (MR) urography after low-dose diuretic injection and to correlate the results with those of conventional urography. MATERIALS AND METHODS: In 71 patients with urologic symptoms, excretory MR urography…
Pure silica MCM-48 and MCM-41 materials were prepared using GEMINI surfactants, with the general formula [C n H 2 n +1 N + (CH 3 ) 2 −(CH 2 ) s −N + (CH 3 ) 2 C m H 2 m +1 ].2Br -, abbreviated as GEM n - s - m . The alkyl chain length ( n, m ) determines the pore size, whereas the length of the spacer ( s ) influences…
The three-dimensional structure of betaine aldehyde dehydrogenase, the most abundant aldehyde dehydrogenase (ALDH) of cod liver, has been determined at 2.1 A resolution by the X-ray crystallographic method of molecular replacement. This enzyme represents a novel structure of the highly multiple ALDH, with at least 12…