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The possibility of sorption extraction of nickel from leaching solutions of oxidized nickel ores of the Buruktal deposit is considered. Ionite Lewatit TP220 with bis-picolylamine functional groups is effective for nickel recovery against the background of high iron contents. Lewatit TP220 is mechanically strong enough for use in the resin-in-pulp process. Nickel sorption with satisfactory performance occurs both in the variant of sorption leaching and extraction from clarified solutions. At sorption from the pulp, the capacity for nickel was 5.44 mg/g, for iron, 25.17 mg/g. The use of 20% sulfuric acid provides quantitative nickel desorption. To obtain a higher quality nickel-containing product, it is recommended to additionally purify the resulting eluates from iron.

Photodegradation of 5-Methoxypsoralen (5-MOP), 4', 5'-dimethyl-3,4-cyclogeksilpsoralen (KC5) and 4'-methyl-3,4 cycloheptylpsoralen (KC4) has been carried out in an XeBr exilamps, both in the presence of H2O2, and a kinetic model, which explains the dependence of the pseudo-first order kinetic parameter on the substrate concentration and other operational variables, has been developed. In the development of the model, mass transfer of 5-MOP, KC5 and KC4from the bulk solution to the wall of the vessel was assumed as the step determining the rate of the photodegradation process, which successfully explains some singularities observed in the experimental results.By fitting the experimental data to the model, a detailed study of the influence of all operational variables on the pseudo-first order kinetic parameter has been done, in good agreement with the model hypotheses.

Formation of triplet states in aqueous herbicide solutions excited by nanosecond radiation of 4th harmonic of Nd:YAG laser (wavelength 266 nm) is revealed by the pump-probe method. During photosensitized 8-MOP oxidation of herbicides, formation of triplet states of the photosensitizer and of the hydrated electron is observed in the process of two-step photoionization of 8-MOP.

The protein kinase SLK (LOSK) phosphorylates the 1A isoform of the p150Gluedsubunit of dynactin and targets it to the centrosome, where it maintains microtubule radial organization. In addition, dynactin phosphorylation is involved in Golgi reorientation in polarized cells.

Abstract: Surface acoustic waves are used to study the transformation of the surface of a high-resistance (semi-insulating) gallium arsenide in situ in the course of the thermal deposition of gold in vacuum. It is demonstrated that the surface modifications that involve the formation of the Au-Ga liquid phase and solid solutions based on Au3Ga, Au7Ga2, etc. result in variations in the parameters (amplitude and phase) of the transmitted acoustic wave and can be identified using such variations.

This article presents the results of a systematic synthesis study of elastomeric crosslinkable polysilicon olefins, the related thermal crosslinking kinetics, and the main permeability parameters recorded for inorganic gases (He, N2, O2, and CO2) and C1–C7 hydrocarbons. Poly(vinyl allyl dimethylsilane) (PVADMS; glass‐transition temperature < 273°K) was obtained by the anionic polymerization of bifunctional vinyl allyl dimethylsilane monomer. The polymers were amorphous, high molecular compounds with mixed carbo‐heterochain structures containing double bonds capable of intermolecular crosslinking under a thermal treatment. Thus, thermally crosslinked polymers exhibited a high resistance toward exposure to organic vapors, unlike noncrosslinked PVADMS. IR spectroscopy was used to investigate the polymer structural changes induced by the thermal treatment. An original technique based on a differential method was used to measure gas permeability during thermal crosslinking. PVADMS possessed higher permeability for C1–C7 hydrocarbons than for inorganic gases (excluding CO2), even after crosslinking. Permeability coefficients ranging from 140 to 1780 Barrer for He and CH4 were found before crosslinking; the thermal crosslinking induced a nonlinear permeability decrease that could be correlated with the disappearance of the double bonds in the polymer structures, that is, cis‐CH&dbond;CH&bond;, trans‐CH&dbond;CH&bond;, and CH2&dbond;CH&bond; in the side‐chain position. According to the found properties, PVADMS could be used as a prospective material for the preparation of highly permeable selective membranes suitable for lower hydrocarbon and volatile organic compound recovery from various chemical and petrochemical process streams. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 927–935, 2005

Gas permeation, sorption, and free volume was studied in a series of glassy vinylic type Si-containing polymers. They included p-substituted derivatives of polystyrene, which were compared with polystyrene, and poly(vinylphenyldimethyl silane). The strongest increase in permeability and diffusion coefficients were observed for the polymer containing the Si(CH3)3 group directly attached to phenylene ring. An introduction of spacers between phenylene ring and Si(CH3)3 group results in much lower gas permeability. Positron annihilation study of free volume in these polymers showed that lifetime spectra are composed of four components. It implies that size distribution of free volume in these polymers, which are characterized by a modest level of gas permeability, is bimodal, a feature previously observed only for extra large free volume and permeability materials such as poly(trimethylsilyl propyne). © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1612–1620, 2000

Two new species of heliobacteria isolated from cyanobacterial mats of two alkaline sulfidic hot springs are formally described. Strains BR4 and BG29 are assigned to anoxygenic phototrophic bacteria of the familyHeliobacteriaceae, since they possess the unique properties of this taxon: strict anaerobiosis, formation of bacteriochlorophyllg, the lack of extensive intracytoplasmic membranes and chlorosomes, an unusual cell wall structure, and phylogenetic relatedness to the low G+C gram-positive eubacteria. Based on the 16S rDNA sequence similarity, strains BR4 and BG29 are assigned to the genusHeliobacteriumand described as two new species of this genus:Heliobacterium sulfidophilumsp. nov. andHeliobacterium undosumsp. nov. The G+C content of the DNA is 51.3 mol % inHbt. sulfidophilumand 57.2-57.7 mol % inHbt. undosum.The cells ofHbt. sulfidophilumare rods, and the cells ofHbt. undosumare slightly twisted spirilla or short rods. Both new bacteria are motile by peritrichous flagella.Hbt. sulfidophilumproduces endospores. The new bacteria are strict anaerobes growing photoheterotrophically on a limited range of organic compounds. In the dark, they can switch from photosynthesis to the slow fermentation of pyruvate. Biotin is required as a growth factor. Both species are highly tolerant to sulfide (up to 2 mM at pH 7.5) and oxidize it photoheterotrophically to elemental sulfur; photoautotrophic growth was not observed. The temperature optimal for growth ofHbt. sulfidophilumandHbt undosumis 30–35‡C, and the optimal pH is 7–8.

Several samples of microbial mat obtained from soda lakes of the Kunkurskaya steppe (Chita region) abundantly populated by purple bacteria were screened for the presence of heterotrophic alkaliphiles capable of oxidizing sulfur compounds to sulfate. This capacity was found in only one pigmented strain, ALG 1, isolated on medium with acetate and thiosulfate at pH 10. The strain was found to be a strictly aerobic and obligately heterotrophic alkaliphile. Growth on medium with acetate was possible within a narrow pH range from 8.5 to 10.4. The strain formed a reddish orange carotenoid and bacteriochlorophylla.Pigments were synthesized only at high concentrations of nitrogen-containing organic compounds (peptone or yeast extract). The production of bacteriochlorophyllawas maximal under microaerobic conditions in darkness. Strain ALG 1 could oxidize sulfide, thiosulfate, sulfite, and elemental sulfur to sulfate. In heterotrophically growing culture (pH 10), thiosulfate was not oxidized until the late logarithmic phase. The sulfur-oxidizing activity was maximal at the most alkaline pH values. The notable increase in the efficiency of organic carbon utilization observed in the presence of thiosulfate suggested that the bacterium was a sulfur-oxidizing lithoheterotroph. The phylogenetic analysis of the 16S rRNA gene showed strain ALG 1 to be a member of the α-3 subgroup of Proteobacteria and to constitute a distinct branch located between nonsulfur purple bacteriaRhodobacterandRhodovulum. Based on the unique phenotypic properties and the results of phylogenetic analysis, the alkaliphilic isolate ALG 1 was assigned to a new genus and speciesRoseinatronobacter thiooxidanswith the type strain DSM-13087

Abstract: A novel alkaliphilic heliobacterium was isolated from microbial mats of a low-salt alkaline Siberian soda lake. Cells of the new organism were tightly coiled when grown in coculture with a rod-shaped bacterium, but grew as short filaments when finally obtained in pure culture. The new phototroph, designated strain BT-H1, produced bacteriochlorophyll g and a neurosporene-like pigment, and lacked internal photosynthetic membranes. Similar to other heliobacteria, strain BT-H1 grew photoheterotrophically on a limited range of organic compounds including acetate and pyruvate. Sulfide was oxidized to elemental sulfur and polysulfides under photoheterotrophic conditions; however, photoautotrophic growth was not observed. Cultures of strain BT-H1 were alkaliphilic, growing optimally at pH 9, and unlike other heliobacteria, they grew optimally at a temperature of 25 �C rather than at 40 �C or above. Analysis of the 16S rRNA gene sequence of the new organism showed that it groups within the heliobacterial clade. However, its branching order was phylogenetically basal to all previously investigated species of heliobacteria. The G+C content of the DNA of strain BT-H1 (44.9 mol%) was also quite distinct from that of other heliobacteria. This unique assemblage of properties implicates strain BT-H1 as a new genus and species of the heliobacteria, Heliorestis daurensis, named for its unusual morphology (“restis” is Latin for “rope”) and for the Daur Steppe in Russia in which these soda lakes are located.

The GC-MS method was used to identify the addition products of methyldichlorosilane to vinyl acetate. Radiation-induced addition of methyldichlorosilane to vinyl acetate produces 2-methyldichlorosilylethyl ethyl ether. The reaction follows a radical-chain mechanism. The ratio of the rate constants of methyldichlorosilyl radical addition to C=C and C=O to vinyl acetate amounts to 0.4±0.1 (303 K).

The investigated structures look like patterns with separated circular windows, opened in SiO2 covering GaAs surface with thin metal film (Au) deposited above (honey-comb structures). The method of precise chemical analysis developed and used in this work allowed to determine the total quantity of Ga in Au layer rubbed off the substrate. It was found that at the initial stage of heating (up to 400°C) Ga migration from windows (Au on GaAs) into Au on SiO2 had not been observed but physical and chemical reactions with forming of Au-Ga eutectic compound were found in Au layer on GaAs. The melting temperatures and specific melting heat were calculated from experimental data (T0 = 340°C;Q0 = 3.5kcal/mol). After temperature increasing Ga migration in Au on SiO2 was noticed and identified as a result of diffusion process with Au-GaAs windows as ‘sources’ and Au on SiO2 as ‘drains’. The process of Ga migration manifests itself for 500A˚Au and 0.2–0.3 μm SiO2 thickness as the grain boundary diffusion with activation energy ∼ 7.3 kcal/mol.

Conclusions 1.The reaction of NiCl2 and CoCl2 with Al(i-Bu)3 in the presence of small amounts of dienes has been studied.2.The reaction of NiCl2 with Al(i-Bu)3 in the presence of a diene results in the formation ofp-alkylnickel chlorides, in which the alkenyl ligand contains an oligomer of the diene and an H atom or an isobutyl group, with yields of ~ 100%. The compounds synthesized are fairly stable with respect to deoxygenated water and aqueous solutions of HCl and H2SO4 and do not undergo disproportionation reactions.3.The reaction of CoCl2 with Al(i-Bu)3 in the presence of 1,3-pentadiene results in the predominant formation of organocobalt compounds which do not contain chlorine and which are less stable with respect to deoxygenated water and aqueous solutions of acids.

Radical interaction of methyldichlorosilane with 1-hexene (B) and acetylene (C) is shown to form addition products. The calculated Arrhenius parameters for the relative rate constant of the addition reaction amount to lg AB/AC=0.0±0.2 and EB−EC=−7.8±0.5 kJ M−1.

BackgroundThe variability of the pharmacological response to beta 2 (β2)-agonists may be due to the polymorphism of the gene of β2 adrenergic receptor (ADRβ2). The objective of our research was to evaluate the significance of ADRβ2gene polymorphism in the 16th amino acid position in the efficiency of broncholytic therapy by β2-agonists among children with bronchial asthma.Materials and methodsWe defined the type of ADRβ2gene among 208 children with bronchial asthma of various severity by means of polymerase chain reaction. The distribution of the patients into two groups was carried out subject to the efficiency of the β2-agonists based short-term therapy during the exacerbation of bronchial asthma. 171 children received the inhaled glucocorticoids.ResultsSingled out statistically significant differences of the genotype distribution. The Gly/Gly16 homozygous allele was discovered twice as often in the group with an insufficient response to β2-agonists than in the group with a good response (66 vs 38%, P<0.001), while the distribution of heterozygous allele was detected the opposite pattern (55 vs 28%, P<0.001). In the Arg/Arg16 genotype distribution, there were no considerable differences in both groups (6% in each group). In the subgroups of children, receiving the high doses of the inhaled glucocorticoids, there was a trend for the prevalence of Gly/Gly16 homozygous allele prevalence.ConclusionWe have discovered the association of the Gly/Gly16 genotype of the ADRβ2gene with an insufficient effect of broncholytic therapy by means of short-term β2-agonists; we also revealed the participation of the Gly16 allele in the phenotype formation with the severe run of bronchial asthma and tolerance towards the therapy both by β2-agonists and inhaled glucocorticoids.