Search

The pandemic caused by a new strain of SARS-CоV-2 coronavirus has swept the whole world, however, despite the developed strategic directions for the treatment of coronavirus infection and intensive research in all countries, effective methods for treating this severe pathology have not yet been created. The list of drugs against COVID-19 practically does not use compounds that affect the renin-angiotensin system, in the functioning of which the ACE2 coronavirus binding receptor plays a central role. It is assumed that the virus, causing a decrease in the density of ACE2 receptors, leads to disruption of RAS activity. This review presents current research on the response of the immune system to infection with the SARS-CoV-2 virus, describes adaptive and innate cellular mechanisms, and describes a number of predictors of severe COVID-19. To write this review, a search was made in the PubMed database and the scientific electronic library eLibrary.ru. The selection of articles was carried out manually with the main goal of synthesizing data and describing the mechanisms of influence of SARS-CoV-2 on the renin-angiotensin system, and, as a result, on the activation of the adaptive and innate immune response. This review includes 53 publications, including methodological recommendations of the Ministry of Health of the Russian Federation, data from ongoing clinical trials and patents. Data from selected scientific sources were structured and visualized.

Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants. Ancient DNA data generation Before the LGM LGM in southwestern and western Europe Post-LGM in the Italian peninsula Post-LGM in western and central Europe Post-14 ka to Neolithic Phenotypically relevant variants Discussion and conclusions Methods

This work explores the strategy of adding physical coefficients as predictor variables in a Physics-Informed Neural Network (PINN) for the time-dependent Maxwell linear equations in case electric and magnetic fields present highly oscillatory behavior.

This study investigates the distributional effects of international organizations within their member countries. It addresses the issue empirically by examining the causal effect of International Monetary Fund (IMF) programs on income inequality. Introducing a new instrumental variable for IMF programs, I exploit time variation in the IMF’s liquidity and cross-sectional variation in a country’s probability of having a lending arrangement with the IMF. Using panel data for 155 countries over the 1973–2013 period, the results show that IMF programs substantially increase income inequality in democracies, while having no such effect in non-democracies. The size of this effect on democracies is smaller the more democratized the IMF’s decision-making processes are. These results are consistent with the theory that powerful, ‘democratically deficient’ international organizations that interfere in domestic politics are capable of restricting the responsiveness of democratic governments to the preferences of their citizens.

The article is focused on microbiological and silvicultural properties of bacterial wetwood of silver birch (Betula pendula), also known as European white birch. During the active phase of the disease, bacterial wetwood (i.e. bacterial dropsy, vascular parenchymatous bacteriosis or flux slime) is characterised by crust and periderm bloating, necrotic wet stains and abundance of exudate. The disease is more likely to occur in older (r = 0.56, p < 0.01) and less-dense (r = −0.29, p < 0.01) stands. The statistical model showed that the chance of bacterial wetwood increases with birch age by 0.36% per year. The stands with birch proportion of over 70% demonstrated 15.3% lower infection rate compared to the stands with lower birch presence. The stands with lower stocking demonstrated a higher proportion of infected tree distribution by 7.5% compared to the stands with higher birch representation. The most vulnerable were larger, older B. pendula trees with longitudinally fissured bark that grow on poorer soils and experience frequent water stress. Birch associations with Pteridium aquilinum and Vaccinium myrtillus were more susceptible to infection (31.6% and 44.3%, respectively), whereas associations with Brachypodium sylvaticum, Sphagnum palustre and Calluna vulgaris were at lower risk. Strong ecological and trophic association of bacterial wetwood was present between silver birch and Tremex spp., particularly Tremex fuscicornis. Mycobiota was represented by Rhizopus microsporus, Mucor mucedo, Penicillium aurantiogriseum, Penicillium purpurogenum and Acremonium strictum. Enterobacter, Xanthomonas, Pantoea and Bacillus spp. associated with bacterial wetwood of silver birch were isolated. Enterobacter nimipressuralis was found to be the primary causative agent through means of artificial infection, while other bacteria were found to be either weak pathogens or concomitant. E. nimipressuralis formed the largest number of colony-forming units (CFU) for bark and cambium (164 and 127 CFU, respectively) and was also found in a small amount as a vital obligate in the automicrobiota in healthy birch trees.

В работе исследовано влияние гидродробеструйной обработки на предел выносливости при изгибе и растяжении-сжатии в случае симметричного цикла цилиндрических образцов с круговым надрезом полукруглого профиля радиуса 0,3 мм. Образцы диаметром 10 мм для испытаний на усталость изготавливались из сталей 30ХГСА, 12Х18Н10Т, ЭИ961, 45 и алюминиевых сплавов В93, Д16Т. Влияние поверхностного упрочнения на предел выносливости образцов с надрезом оценивалось по двум критериям: остаточным напряжениям на поверхности надреза и среднеинтегральным остаточным напряжениям, вычисленным по толщине поверхностного слоя опасного сечения образцов, равной критической глубине нераспространяющейся трещины усталости. По результатам определения остаточных напряжений и предела выносливости образцов с надрезом установлено, что коэффициенты влияния поверхностного упрочнения на приращение предела выносливости при изгибе и растяжении-сжатии по обоим критериям примерно одинаковы. Однако коэффициент влияния по критерию среднеинтегральных остаточных напряжений изменяется в значительно меньших пределах, чем коэффициент влияния по критерию остаточных напряжений на поверхности концентратора. Поэтому для оценки влияния поверхностного упрочнения на предел выносливости деталей с концентраторами напряжений следует использовать критерий среднеинтегральных остаточных напряжений. На примере образцов при наличии и отсутствии наклёпа в опасном сечении показано, что в условиях концентрации напряжений наклёп не оказывает влияния на предел выносливости поверхностно упрочнённой детали. На предел выносливости таких деталей оказывают влияние только сжимающие остаточные напряжения.

The influence of roller strengthening on endurance limit under bending of the 25 mm and 50 mm diameter shafts made of steel 20 and 25 mm diameter shafts made of steel 40X with a pressurized hub has been examined. Its been stated that the endurance limit of roller strengthened shafts with a pressurized hub depends not only on a value of compressive residual stresses in their dangerous section but on the character of its distribution. The valuation of a surface hardening influence on the endurance limit of shafts by the surface residual stresses criterion and the average integral residual stresses criterion has been shown that the average integral residual stresses criterion calculated through the parts dangerous section surface layer thickness equal the critical depth of the non-propagating fatigue crack can be recommended for the hardened shafts with a pressurized hub endurance limit increase prediction. Its been shown that on a diameter of a shaft with a pressurized hub raising it is necessary to increase a thickness of a hardened surface layer with compressive residual stresses.

RNAs contain post-transcriptional modifications, which fulfill a variety of functions in translation, secondary structure stabilization and cellular stress survival. Here, 2-methylthiocytidine (ms2C) is identified in tRNA of E. coli and P. aeruginosa using NAIL-MS (nucleic acid isotope labeling coupled mass spectrometry) in combination with genetic screening experiments. ms2C is only found in 2-thiocytidine (s2C) containing tRNAs, namely tRNAArgCCG, tRNAArgICG, tRNAArgUCU and tRNASerGCU at low abundances. ms2C is not formed by commonly known tRNA methyltransferases. Instead, we observe its formation in vitro and in vivo during exposure to methylating agents. More than half of the s2C containing tRNA can be methylated to carry ms2C. With a pulse-chase NAIL-MS experiment, the repair mechanism by AlkB dependent sulfur demethylation is demonstrated in vivo. Overall, we describe ms2C as a bacterial tRNA modification and damage product. Its repair by AlkB and other pathways is demonstrated in vivo by our powerful NAIL-MS approach., Bacterial tRNA is modified by thiolation of nucleosides. Here the authors identify 2-methylthiocytidine in bacterial tRNA using nucleic acid isotope labeling coupled mass spectrometry. Exposure to methylating agents converts 2-thiocytidine to 2-methylthiocytidine, which is repaired by demethylase AlkB in vivo.