Materials Literature
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N-Acetylneuraminate lyase [N-acetylneuraminic acid aldolase EC 4.1.3.3] from Escherichia coli was purified by protamine sulfate treatment, fractionation with ammonium sulfate, column chromatography on DEAE-Sephacel, gel filtration on Ultrogel AcA 44, and preparative polyacrylamide gel electrophoresis. The purified enz…
Coulometric titration technique has been employed for the determination of the parameter, P\ominus, defined as the oxygen partial pressure at which the n-type and ionic conductivities are equal, for various commercial zirconia electrolytes in the temperature range from 1243 to 1873 K. Measured values of the parameter,…
We report on elastic neutron scattering results showing that the intermediate phase of quartz existing in a 1.3 K range between the α and β phases is in fact incommensurate. Six satellites are observed around most Bragg peaks along the three [100] directions of reciprocal space. The modulation corresponds to the super…
Although clinical trials using macromolecular conjugates of cytotoxic drugs in a treatment of malignant disease are fragmentary at best, a number of carrier systems that have been examined in vitro, in tissue culture, and in vivo animal experiments demonstrate great promise and warrant further extensive examination. T…
To deepen our understanding of Ca2+-activation in calmodulin-dependent reactions, the properties of Ca binding to calmodulin were examined by dual-wavelength spectrophotometry using a Ca indicator, tetramethylmurexide. The Scatchard plot for Ca binding to calmodulin was linear, indicating the occurrence of homogeneous…
We present 1H and 77Se NMR relaxation data on oriented (TMTSF)2ClO4 single crystals in the relaxed state. The data show the existence of three distinct regimes for the nuclear relaxation rate T-11. In the high temperature part (T > 25 K) the Korringa law seems to be well satisfied whereas in the lower temperature part…
Abstract The changes in the structure and morphology of a random copolymer containing 92 mol % glycolide units and 8 mol % lactide units as a function of in vitro hydrolysis have been studied. A number of techniques, such as wide‐angle x‐ray diffraction, small‐angle x‐ray scattering, density measurements, infrared spe…
Abstract Secondary porosity in sandstones is created by subsurface dissolution of grains or cement by pore water that is undersaturated with respect to one or more of the major mineral phases. Such undersaturated pore water may be derived from: (1) meteoric water driven by a hydrostatic head; (2) compactional pore wat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrganometallic compounds of the lanthanides. Part 17. Tris[(tetramethylethylenediamine)lithium] hexamethyl derivatives of the rare earthsHerbert Schumann, Jochen Mueller, Norbert Bruncks, Harald Lauke, Joachim Pickardt, H. Schwarz, and Klaus EckartCite this: Organometallics…
The details of a method of preparing anodic aluminum oxide membranes are presented. The porous oxide layer consists of close-packed cells of oxide, hexagonal in shape, each of which contains a single pore formed perpendicularly to the surface of the aluminum substrate. This special structural feature is essentially im…
We have measured the forces F as a function of surface separation D acting between two smooth curve mica sheets, immersed in aqueous electrolyte medium (potassium nitrate), both in the absence and in the presence of polyelectrolyte (poly-L-lysine, M= 90 000) adsorbed onto the surfaces from solution. Forces between the…
Films of Prussian Blue (PB) deposited by electroreduction in the absence of K + have absorbance maxima at 730 nm which narrow and shift on voltammetric cycling in KCI solution to 690 nm, these absorptions being deemed diagnostic of 'insoluble' and 'soluble' PB respectively. Spectroelectro- chemistry shows that the ini…
Abstract Anhand der Ergebnisse von Modellversuchen mit Bodenproben aus verschiedenen Ober‐ und Unterbodenhorizonten unterschiedlichen Stoffbestandes werden die für die Löslichkeit und Bindung der Schwermetalle Cu, Zn, Cd und Pb unter oxidierenden Bedingungen wichtigsten Einflußgrößen ermittelt. Das Löslichkeitsverhalt…
Carbon films were deposited using mass-separated C+ ions of 300 and 600 eV. The films have diamond-like characteristics such as transparency in the visible spectral region with wavelengths longer than about 650 nm and in the infrared, and high electrical resistivity. Transmission electron diffraction analysis shows th…
An alignment method for smectic liquid crystals is described. Alignment is obtained by the deposition of a certain class of polymer on a substrate followed by unidirectional rubbing. Only linear polymers capable of being elongated in bulk samples are found to produce alignment. The quality of alignment is found to be…
The electrochemical polymerization of pyrrole on a platinum electrode covered with a film of poly(vinyl chloride) produces a dark brown, ductile, and flexible composite polymer film with an electrical conductivity comparable to polypyrrole, and mechanical properties very simllar to poly(vinyl chloride).
Abstract The modification of an amorphous random ethylene‐propylene rubbery copolymer (EPM) has been accomplished by solution grafting of maleic anhydride molecules promoted by radical initiators, The resulting EPM‐g‐succinic anhydride (EPM‐g‐SA) and EPM have been used to obtain binary polyamide 6/EPM or polyamide 6/E…
Electron microscopic examination of epiphyseal cartilage tissue processed by high pressure freezing, freeze substitution, and low temperature embedding revealed a substantial improvement in the preservation quality of intracellular organelles by comparison with the results obtained under conventional chemical fixation…
The stability of the SDW phases in (TMTSF)2ClO4 can be interpreted by simple arguments of anisotropic Fermi surfaces nesting : first, we show that anion ordering, by introducing new Bragg's reflexions, perturbs the nesting and lowers the SDW stability. Then, we improve Gor'kov and Lebed's argument on the effect of a m…
For a simple anisotropic metal model with two open nested Fermi surfaces, it is shown that the tendency to spin density wave formation increases when a magnetic field is applied, which could lead to a series of phase transitions as functions of the field value. The results are suggested as an explanation of the phase…