Materials Literature
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In plant and mammalian cells, excess lysine is catabolized by a pathway that is initiated by two enzymes, namely, lysine-ketoglutarate reductase and saccharopine dehydrogenase. In this study, we report the cloning of an Arabidopsis cDNA encoding a bifunctional polypeptide that contains both of these enzyme activities…
The room-temperature structures of Pb(Zr x Ti1−x )O3 ceramics are shown to be tetragonal for x ≤ 0·52 and rhombohedral for x ≥ 0·530 while both the rhombohedral phase (R-phase) and the tetragonal phase (T-phase) coexist at x = 0·525 corresponding to the morphotropic phase boundary (MPB). Ceramics with x = 0·530 and 0·…
Abstract Alkali metal intercalated compounds of a layer structured perovskite, KCa2Nb3O10, have been prepared by the reaction with n-butyllithium or alkali metal azides, AN3 (A = Li and Na). The magnetic susceptibility measurements showed that the compounds became superconductors with transition temperatures ranging f…
meso -α,α,α,α-Tetrakis(2-hydroxy-1-naphthyl)porphyrin ( 1 ) and 5,15- cis -bis(2-hydroxy-1-naphthyl)-10,20-diphenylporphyrin ( 2 ) were prepared as receptors for ubiquinone analogues. UV−vis, IR, NMR, and X-ray crystal data reveal that these porphyrins bind a series of quinones with a cofacial structure linked by hydr…
HslVU in Escherichia coli a new two-component ATP-dependent protease composed of two heat-shock proteins, the HslU ATPase and the HslV peptidase which is related to proteasome beta-type subunits. Here we show that the reconstituted HslVU enzyme degrades not only certain hydrophobic peptides but also various polypeptid…
Group 6 metal atoms, generated by laser ablation, react with CO 2 to give the insertion products OMCO and O 2 M(CO) 2 (M = Cr, Mo, or W) which have been isolated in argon matrices and identified by the effects of isotopic substitution on their infrared spectra. These assignments have been supported by DFT calculations…
A chemically induced dynamic electron spin polarization (CIDEP) study has been accomplished on radical-excited triplet pairs (RTP) in systems of metalloporphyrins, MgTPP, ZnTPP, and ZnOEP, and pyridine-substituted nitronyl nitroxide radicals, nit-R (R = o-py, m-py, and p-py), by X- (9.5 GHz) and W-band (95 GHz) time-r…
Information concerning the oxidation of o-xylene and naphthalene, the two main processes for producing phthalic anhydride, is updated and analyzed. New techniques for the preparation of catalysts, all based in the impregnation method and involving the control of parameters such as pH and ionic strength of solutions, a…
PbZr 0.56 Ti 0.44 O 3 (PZT) epitaxial ferroelectric thin films on a LaAlO3 (100) substrate, covered by a metallic oxide electrode La0.5Sr0.5CoO3 (LSCO) are demonstrated in this work. The films are fabricated by the sol–gel method and effort was focused on thermal processing to obtain the desired epitaxial heterostruct…
The molecular orientation and aggregation behavior of 5-(4- N -octadecyl-pyridyl)-10,15,20-tri- p -tolylporphyrin (porphyrin 338a) in mono- and multilayer Langmuir−Blodgett (LB) films have been investigated by employing ultraviolet−visible (UV−vis) and infrared (IR) spectroscopies. It has been found that the porphyrin…
Two microscopic techniques, muon spin relaxation and neutron diffraction, including small-angle neutron scattering (SANS), have been used to probe into the relevant mechanisms that determine the macroscopic behavior in the series $({\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Tb}}_{x}{)}_{2/3}{\mathrm{Ca}}_{1/3}{\mathrm{M…
Biochemical and enzymatic characterization of the novel proprotein convertase rat PC7 (rPC7) was carried out using vaccinia virus recombinants overexpressed in mammalian BSC40 cells. Pro-PC7 is synthesized as a glycosylated zymogen (101 kDa) and processed into mature rPC7 (89 kDa) in the endoplasmic reticulum. No endo…
Abstract High resolution and high efficiency planar display, one of the national priorities for advanced technologies and commercial applications, require highly efficient phosphor materials with crystalline monodispersive fine particles [1,2]. Europium oxide activated yttrium oxide (Y2O3:Eu) is a potential red-emissi…
Experimental current-voltage and current-light intensity characteristics of Schottky diodes with the structure: metal (Al) - porous silicon - n-type silicon substrate are presented. The measurements are carried out with a pulsed current in the high current densities conditions, which usually lead to irreversible break…
It is shown that the nonstationary thermoelectric power with characteristic rise and fall times of the order of seconds in multilayered structures with p - n junctions can be several orders of magnitude greater than the stationary thermoelectric power in a homogeneous semiconductor. This effect can be observed in poly…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTSupramolecular Transformations of Vesicles from Amino Acid Based Double Chain AmphiphilesClaudio Cescato, Peter Walde, and Pier Luigi LuisiView Author Information Institut für Polymere, ETH-Zentrum, Universitätstrasse 6, CH-8092 Zürich, Switzerland Cite this: Langmuir 1997, 13,…
Abstract The corrosion behaviour of different FeNi alloys containing between 35 and 82 wt% nickel has been investigated in a humidity test between room temperature and 80°C. It has been found that higher nickel contents improve the corrosion behaviour. The poor corrosion behaviour of the low nickel containing alloys c…
The equilibrium geometries, vibrational frequencies, and infrared and Raman intensities for P 4 O 6 and P 4 O 10 were calculated using the Hartree−Fock self-consistent-field method. The computed geometries are in good agreement with experimental measurements. Scaling the ab initio vibrational frequencies of P 4 O 10 t…
Acoustic emission signal analysis has been used to measure the effect impact damage has on the burst pressure of 146 mm (5.75 in.) diameter graphite/epoxy and the organic polymer, Kevlar/epoxy filament wound pressure vessels. Burst pressure prediction models were developed by correlating the differential acoustic emis…
Semiconducting compounds based on silicides of 3d transition metals (MnSi 1.75 and CoSi) are promising thermoelectric materials for mass-produced thermoelectric generators. Their practical use has been delayed so far by the lack of reliable switching. Electrochemical surface treatment technology and metal deposition w…