Thermal solution of Kashpir shale in pressurized benzene under supercritical conditions

The results of the thermal solution of oil shale in benzene in a flow unit under supercritical conditions are reported. It was found that the conversion of shale organic matter into liquid products increased by a factor of 2.5 with an increase in the solvent pressure from 5 to 15 MPa.     

Biomechanical regularities in the distribution of tension in various topographic zones of the eyelids in children in health and myopia of different degree

The authors assessed the method for life-time study of the biomechanical characteristics of ocular tissues in 281 children (562 eyes) aged 7 to 14 years. The method for assessing the biomechanics of the eyelids is described. In detail. The rates of propagation of acoustic waves in normal tissue and in 1.0 to 6.0 diopters myopia are presented. A correlation has been revealed between the increase of the velocity of acoustic surface waves, propagating in the horizontal direction in the internal segment of the orbital area of the upper eyelids, and the value of clinical refraction in myopia. The authors consider clinical signs of myopia-screwing up one's eyes and a wider lid slit-from a biomechanical viewpoint.     

Evaluation of the Remaining Life of Collectors and Steam Generators of Units Nos. 5 and 6 Of the Kozlodui Nuclear Power Station in Bulgaria with Allowance for the Special Features of Their Service

Metal Science and Heat Treatment -     

Structural and Molecular Kinetic Features of Activities of DNA Polymerases

DNA polymerases catalyze DNA synthesis during the replication, repair, and recombination of DNA. Based on phylogenetic analysis and primary protein sequences, DNA polymerases have been categorized into seven families: A, B, C, D, X, Y, and RT. This review presents generalized data on the catalytic mechanism of action of DNA polymerases. The structural features of different DNA polymerase families are described in detail. The discussion highlights the kinetics and conformational dynamics of DNA polymerases from all known polymerase families during DNA synthesis.     

Qualitative characteristics of power-generating coals from some deposits in Mongolia

The results of a study of the chemical composition and technological properties of coals from the Khar Tarvagatai, Nuurst Khotgor, and Khushuut deposits are presented in this article.     

Planar supramolecular systems based on geometrical isomers of crown-containing oligothiophenes

The properties of ultrathin films of two geometric isomers of oligothiophene derivatives containing two crowned styryl fragments in 2- (I) or 3- (II) positions of thiophene rings (Fig. 1) are studied in this work. The ability of these compounds to form stable monolayers at the air/water interface is shown. The structural organization of crown-substituted oligothiophenes in monolayers is determined by the π-π-stacking interaction of hydrophobic styrylthiophene fragments and interaction of hydrophilic macrocycles with the water subphase. Analysis of ultrathin film physicochemical characteristics has shown that the difference in the structure of oligothiophene molecules leads to the formation of distinct monolayer architectures with various electrochemical and optical characteristics. Two types of aggregates (H and J) are generated in monolayers formed from different geometrical isomers at the air/water interface. The effect of barium cation presence in the subphase on the oligomer aggregation in monolayer is discussed. The phase diagrams characterizing the behavior from two-dimensional mixtures of studied crown-substituted oligothiophenes and amphiphilic spreader are plotted basing on compression isotherms accompanied by absorbance and fluorescence spectra of monolayers of different composition. The ability to fine tune the emitted radiation parameters is demonstrated. The obtained results show the efficiency of application of geometrical isomers for investigation of the fundamental “structure-property” ratio of planar supramolecular systems, which is important for organic optics and electronics.     

The Role of Natural Polymorphic Variants of DNA Polymerase β in DNA Repair

DNA polymerase β (Polβ) is considered the main repair DNA polymerase involved in the base excision repair (BER) pathway, which plays an important part in the repair of damaged DNA bases usually resulting from alkylation or oxidation. In general, BER involves consecutive actions of DNA glycosylases, AP endonucleases, DNA polymerases, and DNA ligases. It is known that protein–protein interactions of Polβ with enzymes from the BER pathway increase the efficiency of damaged base repair in DNA. However natural single-nucleotide polymorphisms can lead to a substitution of functionally significant amino acid residues and therefore affect the catalytic activity of the enzyme and the accuracy of Polβ action. Up-to-date databases contain information about more than 8000 SNPs in the gene of Polβ. This review summarizes data on the in silico prediction of the effects of Polβ SNPs on DNA repair efficacy; available data on cancers associated with SNPs of Polβ; and experimentally tested variants of Polβ. Analysis of the literature indicates that amino acid substitutions could be important for the maintenance of the native structure of Polβ and contacts with DNA; others affect the catalytic activity of the enzyme or play a part in the precise and correct attachment of the required nucleotide triphosphate. Moreover, the amino acid substitutions in Polβ can disturb interactions with enzymes involved in BER, while the enzymatic activity of the polymorphic variant may not differ significantly from that of the wild-type enzyme. Therefore, investigation regarding the effect of Polβ natural variants occurring in the human population on enzymatic activity and protein–protein interactions is an urgent scientific task.     

Peculiarities of Granulation of the PAP-2 Aluminum Powder in the Technology of the Al–Al2O3 Powder Composite with a Layered Structure

Russian Journal of Non-Ferrous Metals - An analysis of modern scientific-and-technical information evidences great prospects for using composite materials (CMs) based on the Al–Al2O3 system....