Brittle Strength of the VVER Pressure Vessel Steels under Operation Conditions

Complex of mechanical tests and fractographic studies of various sample types were conducted for VVER pressure vessel steels. The brittle fracture sources (origins) were revealed: “non-metallic inclusions” and “structural boundaries”. The computational-experimental technique for evaluation of the local normal stress parameter that characterizes strength of the origin was performed. Values of the local normal stressfor the “structural boundary” origin type was demonstrated to be decreasing after thermal and radiation embrittlement due to decreasing in cohesive strength of grain boundaries by virtue of thermo- and radiation- stimulated diffusion of the impurities to grains boundaries. Keywords: reactor pressure vessel, fractography, local normal stress, brittle fracture, origi

Creation of Digital Opportunities for the Participation of Residents in the Region Development as a Factor of the Government Efficiency

No one better than people living in the region can know what is required for the development of the region. The modern government, oriented towards the development of an active civil society, should make this basic postulate the basis of a new management paradigm

Structure and Phase Composition of Zirconium Fuel Claddings in Initial State and after Creep Tests

The article's abstract is no available

The new technologies of high-throughput single-cell RNA sequencing

A wealth of genome and transcriptome data obtained using new generation sequencing (NGS) technologies for whole organisms could not answer many questions in oncology, immunology, physiology, neurobiology, zoology and other fields of science and medicine. Since the cell is the basis for the living of all unicellular and multicellular organisms, it is necessary to study the biological processes at its level. This understanding gave impetus to the development of a new direction – the creation of technologies that allow working with individual cells (single-cell technology). The rapid development of not only instruments, but also various advanced protocols for working with single cells is due to the relevance of these studies in many fields of science and medicine. Studying the features of various stages of ontogenesis, identifying patterns of cell differentiation and subsequent tissue development, conducting genomic and transcriptome analyses in various areas of medicine (especially in demand in immunology and oncology), identifying cell types and states, patterns of biochemical and physiological processes using single cell technologies, allows the comprehensive research to be conducted at a new level. The first RNA-sequencing technologies of individual cell transcriptomes (scRNA-seq) captured no more than one hundred cells at a time, which was insufficient due to the detection of high cell heterogeneity, existence of the minor cell types (which were not detected by morphology) and complex regulatory pathways. The unique techniques for isolating, capturing and sequencing transcripts of tens of thousands of cells at a time are evolving now. However, new technologies have certain differences both at the sample preparation stage and during the bioinformatics analysis. In the paper we consider the most effective methods of multiple parallel scRNA-seq using the example of 10XGenomics, as well as the specifics of such an experiment, further bioinformatics analysis of the data, future outlook and applications of new high-performance technologies

The Effect of Reducing Irradiation Temperature on the Structure and Radiation Embrittlement Mechanism of RPV Steels

A complex research of RPV 15Kh2NMFA class 1 steel in different states was performed: in the initial state and after irradiatiion at different temperatures (50-300∘C). Low temperature (50-140∘C) irradiation was shown to cause the formation of dislocation loops of ultrahigh density. At the same time radiation-induced precipitates, being the main radiation-induced hardening phase at irradiation temperature of VVER reactors (∼300∘C), were absent. This leads to a higher radiation embrittlement rate after low-temperature irradiation as compared with irradiation at operating temperatures of VVER-1000. The radiation embrittlement coefficient values are 8.7 and 1.45 for (120-140)∘C and (290-315)∘C irradiation temperature, respectively

Contribution of Hardening Mechanism to VVER-1000 RPV Welds Flux Effect

Systematic differences in the radiation embrittlement kinetics of steels irradiated with different fluxes requires a clear understanding and assessment of the mechanisms responsible for the flux effect. This paper presents results of research of hardening mechanism contribution to flux effect of VVER-1000 reactor pressure vessel (RPV) welds. Transmission electron microscopy (TEM) and atom probe tomography (APT) investigations were carried out. Studies of hardening phases of RPV-steel (VVER-1000) after accelerated irradiation allowed to estimate the contribution of the hardening mechanism to flux effect. Keywords: reactor pressure vessel, hardening mechanism, flux effec

GENDER-SPECIFIC INFLUENCE OF Aу MUTATION ON PROGENY METABOLIC PHENOTYPE, FETAL GROWTH AND PLACENTAL GENE EXPRESSION IN MICE

Obesity during pregnancy increases the risk of obesity in offspring. To correct the offspring development in obese mothers, it is necessary to reveal the molecular mechanisms that mediate the influence of the maternal environment on the offspring ontogenesis. Leptin levels increase with obesity. In C57Bl mice, the Ау mutation is associated with elevated blood levels of leptin in pregnant females and exerts a gender-specific effect on the metabolic phenotype of mature offspring. Aim: to study the influence of Ау mutation on sensitivity to diet-induced obesity in male and female offspring, on fetal and placental weight and on the expression of genes in the placentas of the fetuses of different sexes. Body weight and food intake on a standard and an obesogenic diet, fetal and placental weights on pregnancy days 13 and 18, and gene expression of glucose transporters (GLUT1, GLUT3), neutral amino acid transporters (SNAT1, SNAT2, SNAT4), insulin-like growth factor 2 IGF2 and its receptor IGF2R were measured in male and female offspring of и ɑ/ɑ (control) and Ау/ɑ mothers. Ay mutation influenced the body weight only in male offspring, which consumed a standard diet, and did not influence obesity development in both male and female offspring. The weight of fetuses and placentas in Ау/ɑ as compared to ɑ/ɑ  females was reduced on day 13 of pregnancy and was not different on day 18. On day 13 of pregnancy, the mRNA levels of the examined genes did not differ in placentas of male and female fetuses in ɑ/ɑ  females. In Ау/ɑ females, the gene expression of GLUT1, GLUT3, SNAT1 and SNAT4 was reduced in female placentas compared to male placentas. The results suggest that the sex-specific transcription response of placentas to elevated leptin levels in pregnant Ау/ɑ females can mediate the gender-specific impact of Ау mutation on the offspring metabolism in postnatal life