Search

Legumin (L) and vicilin (V), the reserve proteins of dry vetch seeds (DS) are not affected by proteolytic enzymes of DS, but L and V isolated from germinated seeds (GS) are hydrolysed by these enzymes. Supporting evidence of modification of reserve proteins during germination demonstrated earlier comes from these results. This modification can apparently be considered as the stage preceding the hydrolysis of reserve proteins.

1. The possibility has been demonstrated of producing wear-resistant coatings on parts by the technique of gas-powder deposition of boron carbide. 2. The structure of the deposited layer contains no free boron carbide particles and consists of a eutectic and a dendritic zone; boron carbide particles cover only the surface of the layer. 3. The wear resistance of alloys produced by the deposition of boron carbide and mechanical mixtures of the carbide and iron powder on a steel substrate is approximately the same, but is higher than that of boron carbide coatings on nickel-containing alloys.

The reflectivity spectra (polarisation E ⟂ c) of the homologous group of rhombohedral crystals Bi2Te3, Bi2Se3, and Sb2Te3 have been investigated in the range 0.7 to 12.5 eV. The complex structure of the two reflectivity main maxima, lying in the range 1 to 5 and 6 to 11 eV, respectively, and its similarity in all three crystals have been established. The energy variation of the reflectivity peaks in dependence of the atomic composition shows the anomalous decrease of the interband gaps in Sb2Te3 respective to Bi2Te3. The results obtained are discussed in terms of published bismuth telluride band structure. [Russian Text Ignored].

Epigene s is in Paleozoic and Riphean deposits of the Russian Platform is divided into an upper and lower zone. The upper zone shows only initial epigenesis, its mineralogical composition and fabric being relatively unaltered since diagenesis. It is characterized by unaltered diagenetic montmorillonite, kaolinite, and dickite; preservation of elastic framework; high porosity; and ground water deposition of sulfates in porous sands. The lower zone is marked by the appearance of new mineralogical and textural features. Among these are: regenerated quartz cement and packed mosaic structure; reduction in porosity; hydromicatization of kaolinite in polymictie rocks and its dickitization in pure quartz rocks; replacement of sulfate by quartz; alteration of glauconite to muscovite and chlorite; appearance of peculiar gravityoriented corrosion structures, such as microstylolites. Zones of deep - seated epigenesis in platforms are different from those in foredeeps and in the marginal portions of geosynclines. In t...

1. Polynucleotide polypeptides consisting of a nascent peptide and transfer RNA (tRNA) were isolated from an Escherichia coli cell-free system after polypeptide synthesis directed by an endogenous messenger. 2. The possibility of releasing this compound without breakage of the ribosome structure (without deproteinization by detergent or phenol) was demonstrated. 3. A method for the separation of peptidyl-tRNA from free tRNA was developed on the basis of gel filtration through a column of Sephadex G-200 in the presence of sodium dodecyl sulfate. 4. The hydrolysis of peptidyl-tRNA at various pH values was studied and results on the kinetics of hydrolysis are presented.

SUMMARY The structure of multilayer polytype modifications of layer silicates may be regarded as the result of a combination of regularly oriented single layers. Accordingly, the optical constants of a single layer (of a monolayer polytype modification) may be used for the calculation of optical constants of any other multilayer polytype modification of a given type of layers. The formulas connecting the constants of a polytype modification of layer silicates have enabled the establishment of the main parameters (Ng, Nm, Np, 2V) of the muscovites 1M and 2M2 according to the known optical constants of the muscovite 2M1, and the computation of the new constants of kaolinite and nacrite based on the known parameters of dickite. The optical constants established theoretically were confirmed by direct measurements for muscovite 1M, muscovite 2M2 (gambelite) and kaolinite. The optically positive character of kaolinite with +2V = 25° has been established. The assumption of the optical mixibility of finely dispersed polyminerallic media, in which the dimensions of monotype crystals are smaller than the visible light waves, made it possible to determine the quantitative relations of clay minerals in the mixtures based on optical constants of oriented aggregates.

1. The formation of zinc-chromium catalysts with various chromic anhydride contents were studied by the method of thermal chromatography. 2. Zinc-chromium catalysts eliminate water in two steps during heating in inert medium, followed by step-wise decomposition of the series of zinc chromates formed during preparation to a spinel phase of zinc chromite. The content of nonstoichiometric oxygen was calculated. 3. The process of formation of zinc-chromium catalysts in a reducing medium consists of an easier and more profound step-wise elimination of oxygen; the spinel phase of zinc chromite is formed at a substantially lower temperature in reducing medium. Considering the results obtained, the literature data on the topochemical reactions that occur during processes of formation of zinc-chromium catalysts are discussed.

This paper discusses the gradational relationship of regional facies of sedimentary epigenesis (diagenesis) and of low grade metamorphism with particular emphasis on the arenaceous sediments. Formation of stable mineral assemblages representative of each facies is dependent upon the bulk composition of the original rock and the conditions under which changes take place. Rock families are classified into: 1) quartz-kaolinite; 2) lithoclastics; 3) acidic arkoses; 4) intermediate arkoses; 5) volcanic graywackes. processes of mineral transformation listed in order of increasing intensity are: a) early epigenesis;, b) deep (late) epigenesis; c) early metagenesis; d) late metagenesis. Each rock family develops a distinct mineral assemblage or facies during different stages of epigenesis and metagenesis. They are as follows: 1) quartz-kaolinite family — a) inherited composition, b) quartz-dickite, 9) quartz-pyrophyllite, d) cyanite; 2) lithoclastic family — a) inherited composition, b) chlorite-hydromica, c) mus...

SUMMARY This paper presents the main trends in epigenetic research in the U.S.S.R. in the last years: 1 Study of epigenetic zonality in thick series of sedimentary rocks of various ages and tectonic regions, (zones of unaltered clay matrix, of altered clay matrix, of quartzitic structures and hydromica-chloritic cement, and of prick-like structures and phyllite-like schists). 2 Principles of stadial analysis and mineral indicators of different epigenetic stages (clay minerals, organic matter, zeolites, feldspars, sulfides). 3 Facies of regional epigenesis connecting the main petrographic families of unaltered terrigenic rocks (quartz sandstones with kaolinitic matrix and the same composition of associated clays, acidic arkoses with hydromicaceous clays, lithoclastic sands with several matrix components and associated clays, and volcanogenic greywackes) with “related” facies of regional metamorphism. 4 Some practical aspects of epigenesis are: for petroleum geology: maximum depth of burial according to porosity, interruption of quartz, feldspar, sphene, epidote, carbonate, biotite, and clay mineral epigenesis by oil migration; and for ore geology: (a) initial epigenesis: ore impregnation (e.g., volkonskoite in wood remains) due to intrastratal solution of heavy minerals and leaching of rock fragments; (b) deep epigenesis: e.g., galena impregnations due to release of trace elements during dissolution of rock forming minerals e.g., feldspars; and (c) metagenesis: “Alpine” veins across and along bedding, filled, e.g., with copper ores.

The useful signal is provided by SiC, which is proportional to the measured quantity; in general, the value of the output voltage varies not only with the concentration of the component but also with the external temperature, pressure, and so on, as well as with the supply voltage, the concentrations of other components, and so on. This gives rise to additional errors of measurement. When the parameters vary, the output voltage of the bridge varies not only due to U01 but also due to change in S 1.

The enzyme hydrolysing N-benzoyl-D,L-arginine-p-nitroanilide (BAPA). is isolated from vetch seedlings and 1600-fold purified by means of chromatography on DEAE-cellulose, hdroxyapatite and gel filtration through Sephadex G-100. The preparation is chromatographically homogenous, but disc electrophoresis in polyacrylamide gel revealed an insignificant contamination by inactive proteins. The data of disc electrophoresis in polyacrylamide gel in the presence of sodium dodecylsulphate have shown that BAPAase has a quaternary structure containing, probably, four subunits identical in their molecular weight. BAPAase has a narrow substrate specificity: it hydrolyses BAPA, benzoyl-D,L,-argininenaphtylamide, benzoyl-L-arginyglycine CBZ-L-arginylglycine histones and protamine, but does not attack L-arginyl-p-nitroanilide benzoyl-L-arginineamide, tosyl-L-arginine methyl ester and casein.

Hydrolysis of L-phenylalanyl-p-nitroanilide (PPA) and glycyl-p-nitroanilide by extracts from resting vetch seeds was shown to be the effect of two different arylamidases. One of them, PPAase, was 2000-fold purified on hydroxylapatide, DEAE-cellulose and by gel filtration through Sephadex G-100. The preparation obtained was nearly homogenous chromatographycally. Molecular weight of PPAase, as shown by means of gel filtration, was 66000, K(m) was calculated to be 1.64-10-4 M. PPAase was inhibited by SH-reagents and partially by o-oxyquinoline. Some increase in the enzyme activity was observed in the presence of Ca2+, Mg2+ and Mn2+ in low concentrations. The enzyme hydrolysed amino acid arylamides with hydrophobic side groups and some dipeptides, which had at least one hydrophobic amino acid and did not contain amino acids with polar group.