The effect of the laser-induced structures’ surface morphology on the luminescence of thermostable polybenzimidazoles

This study was performed in the framework of the RFBR grant Mol_а 18-33-00645

Tunneling decay in a magnetic field

We provide a semiclassical theory of tunneling decay in a magnetic field and a three-dimensional potential of a general form. Because of broken time-reversal symmetry, the standard WKB technique has to be modified. The decay rate is found from the analysis of the set of the particle Hamiltonian trajectories in complex phase space and time. In a magnetic field, the tunneling particle comes out from the barrier with a finite velocity and behind the boundary of the classically allowed region. The exit location is obtained by matching the decaying and outgoing WKB waves at a caustic in complex configuration space. Different branches of the WKB wave function match on the switching surface in real space, where the slope of the wave function sharply changes. The theory is not limited to tunneling from potential wells which are parabolic near the minimum. For parabolic wells, we provide a bounce-type formulation in a magnetic field. The theory is applied to specific models which are relevant to tunneling from correlated two-dimensional electron systems in a magnetic field parallel to the electron layer.Comment: 16 pages, 11 figure

Apolipoprotein A-I increases the activity of lysosomal glycosidases in the liver of mice with BCG-induced tuberculosis inflammation

This work shows the ability of apolipoprotein A-I to influence the activity of lysosomal glycosidases in the liver of mice in a model of BCG-induced tuberculous inflammation. The aim of the investigation was to study the activity of lysosomal glycosidases in the liver of mice using a model of BCG-induced tuberculous inflammation after intravenous administration of apolipoprotein A-I. Material and methods. The studies were performed on male CBA mice weighing 20-22 g. Disseminated tuberculous inflammation was modeled by a single intraperitoneal injection of 0.5 mg of BCG vaccine. The activity of lysosomal glycosidases was assessed spectrofluorimetrically by the content of hydrolysis products of the corresponding fluorogenic substrates. Results. Tuberculous inflammation led to a pronounced decrease in the activity of lysosomal glycosidases in the liver. Thus, β-galactosidase was decreased 2.3 times, β-glucosidase – 2.8 times, β-glucuronidase – 2.5 times compared with healthy animals. Intravenous injection of apolipoprotein A-I to animals against the background of BCG infection prevented a significant decrease in the enzymatic activity of glycosidases and these values practically did not differ from the control values. Conclusions. Enzymatic activity of lysosomal glycosidases in the group of mice with intravenous administration of apolipoprotein A-I against the background of BCG infection was 1.5–2 times higher than the corresponding indicators in the group of animals with BCG-infection without administration of apolipoprotein A-I, i.e. without treatment

Association of Heart Rate Variability with the Psychosocial Stress Level in Men 41-44 Years Old Living in Moscow

Aim. Research of the association of heart rate variability (HRV) with the level of psychosocial stress (PS) and other indicators of the risk of cardiovascular diseases in a sample of 41-44-year-old men living in Moscow.Material and methods. A total of 299 men aged 41-44 years were examined. The study included a clinical examination and a survey using a standard questionnaire. The categorization of risk factors (RF) for cardiovascular diseases (CVD) was carried out in accordance with generally accepted criteria The psychosocial stress was assessed using the Reeder scale. Depending on the psychosocial stress level, all surveyed men were divided into 3 groups by terciles: group 1 (3,28-4,0 points) – mild stress, group 2 (2,71-3,14) – moderate stress, group 3 (1,28-2,57) – severe stress. The analysis of HRV was performed on the basis of a short recording of an electrocardiogram using the original software package.Results. Nonparametric ANOVA showed that the mean [M (95% CI)] values of the HRV time domain (SDNN, rMSSD and the state of regulatory reserves) were lower in the group of men with high PS compared with the group with low PS [25.3 ms (20.9-29.7) versus 40.5 ms (30.7-50.3), p=0.007; 29.5 ms (24.6-34.3) versus 49.5 ms (36.7-62.3), p=0.030; and 46.7 (44.7-48.6) versus 49.7 (48.1-51.4), p=0.019; respectively]. On the contrary, the mean values [M (95% CI)] of the integral indicators of HRV (SI and IVR) were higher in the group of men with high PS [635.8 c.u. (556.2-715.4) versus 488.9 (423.8-554.1), p=0.005; 1172.6 (1045.1-1300.1) versus 904.7 (790.0-1019.4), p=0.003; respectively]. The results of correlation and multiple regression analysis confirmed that these HRV indicators are statistically significantly associated not only with PS, but also with other indicators (age, waist / hip ratio, diastolic blood pressure). However, their predictive value turned out to be low, and the proportion of the explained variance of HRV indices ranged from 2.5 to 13.1%.Conclusion. The weakening of the autonomous regulation of the heart rate with a decrease in the activity of the parasympathetic link, the activation of the central circuit of regulation with the prevalence of sympathetic influences, a decrease in the functional reserves of the heart rate regulation system are associated with an increase in the level of PS and other indicators of the risk of cardiovascular diseases

Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

Coagulation Disorders in Infective Endocarditis: Role of Pathogens, Biomarkers, Antithrombotic Therapy (Systematic Review)

The issue of antithrombotic therapy in patients with infective endocarditis has been studied for over 75 years. During that time studying of pathogenesis of the disease and its embolic complications, lead to the introduction of the concept of “immunothrombosis”. That mechanism allows infective agents (mostly bacteria) to be cloaked from the immune system and to multiply freely, leading to growth of vegetation, thus resulting in higher chance of fragmentation. Small-scale experimental and clinical studies on the correction of hemostatic disorders in infective endocarditis, that were performed in 20th century, didn’t show any significant results, that could affect clinical practice. However, reinterpretation of available data on coagulative system will allow to have elements of hemostasis as an application point in treating infective endocarditis. The article will discuss latest insights on the role of hemostasis system in pathophysisology of infective endocarditis, its effects on the development of the embolic complications, perspectives for diagnostics and treatment

Poly(ADP-Ribose) Polymerase 1 (PARP-1) Regulates Ribosomal Biogenesis in Drosophila Nucleoli

Poly(ADP-ribose) polymerase 1 (PARP1), a nuclear protein, utilizes NAD to synthesize poly(AD-Pribose) (pADPr), resulting in both automodification and the modification of acceptor proteins. Substantial amounts of PARP1 and pADPr (up to 50%) are localized to the nucleolus, a subnuclear organelle known as a region for ribosome biogenesis and maturation. At present, the functional significance of PARP1 protein inside the nucleolus remains unclear. Using PARP1 mutants, we investigated the function of PARP1, pADPr, and PARP1-interacting proteins in the maintenance of nucleolus structure and functions. Our analysis shows that disruption of PARP1 enzymatic activity caused nucleolar disintegration and aberrant localization of nucleolar-specific proteins. Additionally, PARP1 mutants have increased accumulation of rRNA intermediates and a decrease in ribosome levels. Together, our data suggests that PARP1 enzymatic activity is required for targeting nucleolar proteins to the proximity of precursor rRNA; hence, PARP1 controls precursor rRNA processing, post-transcriptional modification, and pre-ribosome assembly. Based on these findings, we propose a model that explains how PARP1 activity impacts nucleolar functions and, consequently, ribosomal biogenesis

Analysis of adherence to the measures of non-specific prevention of coronavirus infection by students of the Ural State Medical University based on a questionnaire

The article analyzes the results of a survey of students of the Faculty of Medicine of the Ural State Medical University on the topic of adherence to non-specific prophylaxis of coronavirus infection.В статье проанализированы результаты анкетирования студентов медико-профилактического факультета Уральского государственного медицинского университета на тему приверженности неспецифической профилактики коронавирусной инфекции

Multifunctional light beam control device by stimuli-responsive liquid crystal micro-grating structures

There is an increasing need to control light phase with tailored precision via simple means in both fundamental science and industry. One of the best candidates to achieve this goal are electro-optical materials. In this work, a novel technique to modulate the spatial phase profile of a propagating light beam by means of liquid crystals (LC), electro-optically addressed by indium-tin oxide (ITO) grating microstructures, is proposed and experimentally demonstrated. A planar LC cell is assembled between two perpendicularly placed ITO gratings based on microstructured electrodes. By properly selecting only four voltage sources, we modulate the LC-induced phase profile such that non-diffractive Bessel beams, laser stretching, beam steering, and 2D tunable diffraction gratings are generated. In such a way, the proposed LC-tunable component performs as an all-in-one device with unprecedented characteristics and multiple functionalities. The operation voltages are very low and the aperture is large. Moreover, the device operates with a very simple voltage control scheme and it is lightweight and compact. Apart from the demonstrated functionalities, the proposed technique could open further venues of research in optical phase spatial modulation formats based on electro-optical materials.This work was supported by the Comunidad de Madrid and FEDER Program (S2018/NMT-4326), the Ministerio de Economía y Competitividad of Spain (TEC2016-77242-C3-1-R and TEC2016-76021-C2-2-R), the FEDER/Ministerio de Ciencia, Innovación y Universidades and Agencia Estatal de Investigación (RTC2017-6321-1, PID2019-109072RB-C31 and PID2019-107270RB-C21). The authors also acknowledge the support by the Ministry of National Defense of Poland (GBMON/13-995/2018/WAT), Military University of Technology (Grant no. 23-895)