Synthesis of Gold Glyconanoparticles Based on the Condensation Products of D-Lactose and D-Maltose with SH-Containing Hydrazides

Russian Journal of General Chemistry - A procedure has been developed for the synthesis of gold glyconanoparticles with an average particle size of 16–24 nm and low polydispersity index on...     

Characterization of Glycosyltransferase Activity of Wild-Type Leuconostoc mesenteroides Strains from Bulgarian Fermented Vegetables

Glycosyltransferase activity of 13 Leuconostoc mesenteroides strains isolated from Bulgarian fermented vegetables was investigated. All the strains displayed a mucoid phenotype on sucrose-containing agar media. Strains were characterized according to carbohydrate fermentation, species-specific multiple PCR using several primers, repetitive element-PCR fingerprinting using (GTG)₅ primers and glycosyltransferase activity. Level of activity and cellular localization (soluble or cell-associated) were variable among strains. Precipitation of exopolysaccharides produced from sucrose by the soluble fractions from these strains allowed recovery of only glucans and further characterization by ¹H and ¹³C NMR analysis and enzymatic digestion with dextranase revealed dextran production. However, levans could be detected in presence of raffinose as fructosyl donor. Both fructosyltransferase and glucosyltransferase encoding genes were detected by PCR and both active enzymes were detected after functional characterization by SDS-PAGE electrophoresis and in situ polymer production after incubation with sucrose. This work therefore showed that concomitant production of glucosyltransferase and fructosyltransferase is widespread in L. mesenteroides strains.     

Production of phenol compounds by alkaline treatment of technical hydrolysis lignin and wood biomass

Aqueous alkaline depolymerization of technical hydrolysis lignin (THL) was carried out with a 5% NaOH solution at a temperature of 180°C for 6 hours, the ratio between the biomass and depolymerizing agent being 1:8. The poplar wood sawdust was treated under the same conditions for 2 hours, where anthraquinone was added as a catalyst (0.5 wt %). The poplar wood bark was treated for 4 hours, without anthraquinone. Compounds contained in the aqueous phase were extracted three times by means of toluene for a ratio between the organic and aqueous phases equal to 1:5, 1:5 and 1:5. The compounds 2-methoxyphenol, 2,6-dimethoxyphenol, 4-hydroxy-3-methoxybenzaldehyde, 1-(4-hydroxy-3-methoxyphenyl)ethanone, 4-hydroxy-3,5-dimethoxybenzaldehyde, etc., were identified through GC-MS analysis in obtained extracts. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 144–146, March–April, 2008.     

Concerning the principle of linear summation of partial fracture with uniform stress increase in polymers

It is established that the Bailey integral depends importantly on the molecular weight of the polymer: at the same stress growth rate the Bailey integral is the greater, the higher the molecular weight of the polymer. The dependence of the Bailey integral on the rate of increase of stress is given.     

Die Retention von Indan- und Inden-Kohlenwasserstoffen auf graphitiertem thermischen Ruß

Zusammenfassung Es werden die Werte der Retentionsvolumina, der Retentionsindices und andere thermodynamische Adsorptionscharakteristiken von zehn Indan- und Inden-Kohlenwasserstoffen mit 9–11 Kohlenstoffatomen auf graphitiertem thermischem Ruß (GTR) bestimmt. Es wurde festgestellt, daß auf GTR die Kohlenwasserstoffe der Inden-Reihe am stärksten adsorbiert werden und am schwächsten cis-Hydrandan, was mit den Besonderheiten der geometrischen Struktur dieser Verbindungen zusammenhängt. Es wird die Möglichkeit der Anwendung von GTR für die vollständige Trennung der cis- und trans-Isomeren von Hydrindan gezeigt.

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Retention of indan and indan-type hydrocarbons on graphitized thermal carbon black

Summary The retention volumes, retention indices and other thermodynamic values characteristic of the adsorption of ten indan-hydrocarbons having 9–11 carbon atoms were determined on graphitized thermal carbon black (GTCB). It is shown that GTCB adsorbs strongest the hydrocarbons of the indan series and weakest cis hydrindan. This is related to the peculiarities of the geometric structure of the compounds. The possibility of the application of GTCB for the complete separation of cis and trans hydrindan is shown.

     

Aktivierung der Farbstoffadsorption durch reaktionsfähige Polymere

Ohne Zusammenfassung     

Generating porosity in metal oxides thin films through introduction of polymer micelles

The generation of porosity in Nb₂O₅ sol–gel films through introduction of polymer micelles of commercially available copolymer Pluronic PE6800 [poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)] was studied using direct observation of film morphology by Transmission Electron Microscopy and indirect calculations of free volume fraction by optical means. Mesoporous Nb₂O₅ films were deposited by the sol–gel and spin-coating methods and templated with aqueous solutions of Pluronic PE6800 with concentrations below and above critical micelle concentration determined by the modified dye solubilization method. The influence of the duration of the postdeposition annealing on total pore volumes was investigated by reflectance measurements and consequent calculation of optical properties and free volume fraction by Bruggeman effective medium theory. The possible application of the films in optical sensing of vapors has been demonstrated through reflectance measurements prior to and after acetone vapors exposure.     

Phosphorus within planetary boundaries

ABSTRACT

In this paper the screening calculations of the removal time of phosphorus from water bodies of federal districts of Russia are presented. Calculations are made using the matrix algebra based approach and are applied as a tool for the estimation of the fate of phosphates in different environmental media (water, air, soil, biota, etc.). The results show that the use of phosphate fertilizers is sometimes quite high in the most vulnerable federal districts. It means that the application of fertilizers in order to increase the yield of agriproducts should be accompanied by detailed assessment of the risks of eutrophication. Calculations have shown high vulnerability in the district of the Lake Baika.     

Properties of Systems Ba(HCOO)2-M(HCOO)2-H2O (M = Ca or Mg) at 25°C

The systems Ba(HCOO)₂-Ca(HCOO)₂-H₂O and Ba(HCOO)₂-Mg(HCOO)₂-H₂O were studied at 25°C by the solubility method. The effect of the ionic radii of doubly charged metals on the formation of double salts containing barium formate was considered.     

Mixed antiplane boundary‐value problem for a piecewise‐homogeneous elastic body with a semi‐infinite interfacial crack

Antiplane stress state of a piecewise‐homogeneous elastic body with a semi‐infinite crack along the interface is considered. The longitudinal displacements along one of the crack edges on a finite interval, adjacent to the crack tip, are known. Shear stresses are applied to the body along the crack edges and at infinity. The problem reduces to a Riemann–Hilbert boundary‐value matrix problem with a piecewise‐constant coefficient for a complex potential in the class of symmetric functions. The complex potential is found explicitly using a Gaussian hypergeometric function. The stress state of the body close to the singular points is investigated. The stress intensity factors are determined. Copyright © 2016 John Wiley & Sons, Ltd.