181 research outputs found
Effect of Li2O–Al2O3–GeO2–P2O5 glass crystallization on stability versus molten lithium
Glass and glass-ceramic NASICON-type electrolytes of Li1.5Al0.5Ge1.5(PO4)3 composition were obtained by melt quenching and glass crystallization, respectively. The stability of the solid electrolytes to molten metallic Li was studied by immersing the samples and holding them at 230 °C for 72 h. Li|glass|Li and Li|glass-ceramics|Li electrochemical cells were assembled and their resistance was measured by impedance spectroscopy at 200 °C for 9 days. It was established that, unlike the glass, the glass-ceramics did not change in its phase composition and molecular structure after the tests. It is shown that Li1.5Al0.5Ge1.5(PO4)3 glass-ceramics is chemically stable in contact with metallic Li. © 2019 Elsevier B.V.Russian Science Foundation, RSF: 18-73-00099The reported study was funded by the Russian Science Foundation according to the research project No. 18-73-00099 . The authors are grateful to Antonov B.D. and Vovkotrub E.G. The research has been carried out with the equipment of the Shared Access Center “Composition of Compounds” of Institute of High Temperature Electrochemistry of the Ural Branch of the RAS, Ekaterinburg, Russian Federation
Clustering of the Russian regions by information and communication technologies indicators – infrastructure and Internet access
In the context of the digitalization of the economy, it is important to systematize indicators that will fully assess the work of the regions of the Russian Federation in the direction of the country’s information development. The article presents a system for assessing state entities within the framework of infrastructure and access to the Internet network throughout the country. The authors analyze the heterogeneity of the regional structure of Russia in terms of digitalization indicators. The use of advanced statistical parametric and non-parametric methods made it possible to determine the stratification of regions. The paper compares the level of development of information and communication technologies in groups (layers) of regions according to the indicators included in the block “information and communication technologies infrastructure and access”, obtained as a result of monitoring the development of the information society in the Russian Federation. Researchers conduct a factor analysis to identify the main components that affect the level of development of information and communication technologies in the Russian regions
Features of Forming a Cubic Li7La3Zr2O12 Film by Tape Casting
Thin films of Li7La3Zr2O12 solid electrolyte were obtained by tape casting.The optimal heat treatment mode without films’ deformation was proposed.The highest conductivity values were observed for the Li7La3Zr2O12 film annealed at 800 °С – 1.5·10–5 S·cm–1 at 215 °С.Received: 13.10.23. Revised: 07.11.23. Accepted: 17.11.23. Available online: 21.11.23.Currently, interest to lithium and lithium-ion all-solid-state power sources is rapidly growing all over the world. However, several issues should be addressed before all-solid-state batteries production: high resistance values of the solid electrolyte membrane and poor contact between electrolyte and electrode materials. The transition to thin-film technologies is one of the promising ways to solve these problems. Tape casting can be proposed to obtain thin-film solid electrolytes. In this research, the features of the structure formation, morphology and lithium-ion conductivity of Li7La3Zr2O12 films were investigated. Li7La3Zr2O12 films with the thickness of 35 μm were obtained by tape casting on Ni substrate. The influence of organic components’ content on homogeneous coatings formation was established. Heat treatment conditions for dried films were chosen based on differential scanning calorimetry and optical dilatometry. Phase change from tetragonal to cubic modification occurs after annealing the Li7La3Zr2O12 films at 700 °C and higher. The annealed Li7La3Zr2O12 films have developed surface, which can lead to improved contact between the solid electrolyte and an electrode in an electrochemical cell. Li7La3Zr2O12 films annealed at 800 °C have the highest lithium-ion conductivity values (2.5·10–7 and 1.5·10–5 S·cm–1 at 90 and 215 °С, respectively). The technology of Li7La3Zr2O12 films formation with the thickness of ~23 μm by tape casting was developed.This research was funded by the Research Program No. 122020100210-9 (IHTE UB RAS), Russian Academy of Sciences, Ural Branch, Russia.The research has been carried out with the equipment of the Shared Access Center “Composition of Compounds” at the IHTE UB RAS
The relationship of emotional orientation, styles of humor with emotional burnout in teachers of preschool educational institutions
The article considers the problem of burnout among preschool teachers. The professional work of PEI teachers is distinguished by a high emotional burden, increased requirements for maintaining a professional level, as well as an insufficiently high public assessment of social status.В статье рассмотрена проблема эмоционального выгорания у педагогов дошкольного образования. Профессиональный труд педагогов ДОУ отличает высокая эмоциональная напряженность, повышенные требования к поддержанию профессионального уровня, а также недостаточно высокая общественная оценка социального статуса
Interval approach to processing the noised thermophysical data
The paper deals with application of numerical methods to processing the experimental data on the thermophysical properties of several chemical substances and their compounds (cryolites, rare earth compounds, and alkali halides). The main aim of investigations is in estimating the parameters of dependencies between the heat of fusion and the melting temperature of these chemical substances. The data are corrupted by the measuring errors. Procession is implemented under conditions of uncertainty: there is no any information on probabilistic properties of the corrupting factors, samples of measurements are short, and only approximate functions are known that describes mentioned dependencies. Under such conditions, the standard statistical methods can be applied formally. To obtain guarantied results in parameters estimation, the interval analysis methods and procedures are used. © 2020 American Institute of Physics Inc.. All rights reserved.The work was supported by the RFBR grants, projects nos. 18-01-00410 and 18-03-00785 А
Diversity and occurrence of methylotrophic yeasts used in genetic engineering
Methylotrophic yeasts have been used as the platform for expression of heterologous proteins since the 1980’s. They are highly productive and allow producing eukaryotic proteins with an acceptable glycosylation level. The first Pichia pastoris-based system for expression of recombinant protein was developed on the basis of the treeexudate-derived strain obtained in the US southwest. Being distributed free of charge for scientific purposes, this system has become popular around the world. As methylotrophic yeasts were classified in accordance with biomolecular markers, strains used for production of recombinant protein were reclassified as Komagataella phaffii. Although patent legislation suggests free access to these yeasts, they have been distributed on a contract basis. Whereas their status for commercial use is undetermined, the search for alternative stains for expression of recombinant protein continues. Strains of other species of methylotrophic yeasts have been adapted, among which the genus Ogataearepresentatives prevail. Despite the phylogenetic gap between the genus Ogataeaand the genus Komagataellarepresentatives, it turned out possible to use classic vectors and promoters for expression of recombinant protein in all cases. There exist expression systems based on other strains of the genus Komagataellaas well as the genus Candida. The potential of these microorganisms for genetic engineering is far from exhausted. Both improvement of existing expression systems and development of new ones on the basis of strains obtained from nature are advantageous. Historically, strains obtained on the southwest of the USA were used as expression systems up to 2009. Currently, expression systems based on strains obtained in Thailand are gaining popularity. Since this group of microorganisms is widely represented around the world both in nature and in urban environments, it may reasonably be expected that new expression systems for recombinant proteins based on strains obtained in other regions of the globe will appear
Production of subtilisin proteases in bacteria and yeast
In this review, we discuss the progress in the study and modif ication of subtilisin proteases. Despite longstanding applications of microbial proteases and a large number of research papers, the search for new protease genes, the construction of producer strains, and the development of methods for their practical application are still relevant and important, judging by the number of citations of the research articles on proteases and their microbial producers. This enzyme class represents the largest share of the industrial production of proteins worldwide. This situation can explain the high level of interest in these enzymes and points to the high importance of designing domestic technologies for their manufacture. The review covers subtilisin classif ication, the history of their discovery, and subsequent research on the optimization of their properties. An overview of the classes of subtilisin proteases and related enzymes is provided too. There is a discussion about the problems with the search for (and selection of) subtilases from natural strains of various microorganisms, approaches to (and specifics of) their modif ication, as well as the relevant genetic engineering techniques. Details are provided on the methods for expression optimization of industrial subtilases of various strains: the details of the most important parameters of cultivation, i. e., composition of the media, culture duration, and the inf luence of temperature and pH. Also presented are the results of the latest studies on cultivation techniques: submerged and solid-state fermentation. From the literature data reviewed, we can conclude that native enzymes (i. e., those obtained from natural sources) currently hardly have any practical applications because of the decisive advantages of the enzymes modified by genetic engineering and having better properties: e. g., thermal stability, general resistance to detergents and specif ic resistance to various oxidants, high activity in various temperature ranges, independence from metal ions, and stability in the absence of calcium. The vast majority of subtilisin proteases are expressed in producer strains belonging to different species of the genus Bacillus. Meanwhile, there is an effort to adapt the expression of these enzymes to other microbes, in particular species of the yeast Pichia pastoris
Physico-chemical properties of actin cleaved with bacterial protease from E. coli A2 strain
The 36 kDa fragment of actin molecule obtained with the protease from E. coli A2 strain [(1988) FEBS Lett. 228, 172] was shown to begin with Val-43 and retain the COOH-terminal amino acid residues of the parent molecule. The E. coli protease split actin preserves the NH2-terminal part of the polypeptide chain as well as the native conformation of actin molecule. However, the E. coli protease split actin failed to polymerize in 0.1 M KCl, suggesting that integrity of actin molecule between Gly-42 and Val-43 is crucial for actin polymerization. © 1991
Wheat-barley hybridization – the last forty years
Abstract Several useful alien gene transfers have
been reported from related species into wheat (Triticum
aestivum), but very few publications have dealt
with the development of wheat/barley (Hordeum
vulgare) introgression lines. An overview is given
here of wheat 9 barley hybridization over the last
forty years, including the development of
wheat 9 barley hybrids, and of addition and translocation
lines with various barley cultivars. A short
summary is also given of the wheat 9 barley hybrids
produced with other Hordeum species. The meiotic
pairing behaviour of wheat 9 barley hybrids is presented,
with special regard to the detection of wheat–
barley homoeologous pairing using the molecular
cytogenetic technique GISH. The effect of in vitro
multiplication on the genome composition of intergeneric
hybrids is discussed, and the production and
characterization of the latest wheat/barley translocation
lines are presented. An overview of the agronomical
traits (b-glucan content, earliness, salt tolerance,
sprouting resistance, etc.) of the newly developed
introgression lines is given. The exploitation and
possible use of wheat/barley introgression lines for
the most up-to-date molecular genetic studies
(transcriptome analysis, sequencing of flow-sorted
chromosomes) are also discussed
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Gender differences in the pharmacological actions of pegylated glucagon-Like peptide-1 on endothelial progenitor cells and angiogenic precursor cells in a combination of metabolic disorders and lung emphysema
In clinical practice, the metabolic syndrome (MetS) is often associated with chronic obstructive pulmonary disease (COPD). Although gender differences in MetS are well documented, little is known about sex-specific differences in the pathogenesis of COPD, especially when combined with MetS. Consequently, it is not clear whether the same treatment regime has comparable efficacy in men and women diagnosed with MetS and COPD. In the present study, using sodium glutamate, lipopolysaccharide, and cigarette smoke extract, we simulated lipid metabolism disorders, obesity, hyperglycemia, and pulmonary emphysema (comorbidity) in male and female C57BL/6 mice. We assessed the gender-specific impact of lipid metabolism disorders and pulmonary emphysema on angiogenic precursor cells (endothelial progenitor cells (EPC), pericytes, vascular smooth muscle cells, cells of the lumen of the nascent vessel), as well as the biological effects of pegylated glucagon-like peptide 1 (pegGLP-1) in this experimental paradigm. Simulation of MetS/COPD comorbidity caused an accumulation of EPC (CD45−CD31+CD34+), pericytes, and vascular smooth muscle cells in the lungs of female mice. In contrast, the number of cells involved in the angiogenesis decreased in the lungs of male animals. PegGLP-1 had a positive effect on lipids and area under the curve (AUC), obesity, and prevented the development of pulmonary emphysema. The severity of these effects was stronger in males than in females. Furthermore, PegGLP-1 stimulated regeneration of pulmonary endothelium. At the same time, PegGLP-1 administration caused a mobilization of EPC (CD45−CD31+CD34+) into the bloodstream in females and migration of precursors of angiogenesis and vascular smooth muscle cells to the lungs in male animals. Gender differences in stimulatory action of pegGLP-1 on CD31+ endothelial lung cells in vitro were not observed. Based on these findings, we postulated that the cellular mechanism of in vivo regeneration of lung epithelium was at least partly gender-specific. Thus, we concluded that a pegGLP-1-based treatment regime for metabolic disorder and COPD should be further developed primarily for male patients
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