Relationships between the allozyme and phenotypic diversities of Picea ajanensis populations

The structures of Picea ajanensis populations were compared based on allozyme analysis of vegetative buds and morphometric analysis of generative organs. Six cenopopulations of P. ajanensis were investigated in areas with various levels of volcanic impact in the Kamchatka Peninsula. The genetic structures of spruce populations and phenotypes were determined by analysis of ten enzyme systems (PGM, GOT, HK, LAP, MDH, SKDH, IDH, GDH, PGI and SOD). Phenotypic variability of spruce populations was estimated based on the composition of morphotypes that were identified by using geometric morphometrics of cone-scale shapes. Pairwise comparison of samples of cones from 170 trees from six populations revealed 12 morphotypes differing in the shape of cone scales. Comparative assessment of variability and similarity of populations was carried out based on the frequency of occurrence of phenotypes and frequency of alleles of polymorphic loci. Correlations of the genetic and phenotypic distance matrices between different phenotypes were revealed. This observation was consistent with the genetic determination of the shape of cone scales in spruce. Genetic differences between the morphotypes with regard to nine polymorphic loci (Got-2, Skdh-1, Idh-2, Pgm-2, Mdh-1, Mdh-3, Pgm- 1, Pgi-2, and Hk) were not significant. Statistically significant differences between the morphotypes were revealed for two loci: Pgm-2 and Mdh-1. Differences in the genetic diversity of spruce populations generally corresponded to differences in their phenotypic diversity. The high levels of genetic and phenotypic diversity characterized a stable population structure of spruce in the area of weak volcanic influence. Changes in the genetic structure and low levels of the phenotypic diversity of spruce were observed under catastrophic volcanic impact

Possible Metal/Insulator Transition at B=0 in Two Dimensions

We have studied the zero magnetic field resistivity of unique high- mobility two-dimensional electron system in silicon. At very low electron density (but higher than some sample-dependent critical value, $n_{cr}\sim 10^{11}$ cm$^{-2}$), CONVENTIONAL WEAK LOCALIZATION IS OVERPOWERED BY A SHARP DROP OF RESISTIVITY BY AN ORDER OF MAGNITUDE with decreasing temperature below 1--2 K. No further evidence for electron localization is seen down to at least 20 mK. For $n_s<N_{cr}$, the sample is insulating. The resistivity is empirically found to SCALE WITH TEMPERATURE BOTH BELOW AND ABOVE $n_{cr}$ WITH A SINGLE PARAMETER which approaches zero at $n_s=n_{cr}$ suggesting a metal/ insulator phase transition.Comment: 10 pages; REVTeX v3.0; 3 POSTSCRIPT figures available upon request; to be published in PRB, Rapid Commu

Level and correlations of soluble suppression of tumorigenicity 2 protein in heart failure and its relationship with clinical and paraclinical characteristics of patients

Aim. To establish the correlations of the soluble suppression of tumorigenicity 2 protein (sST2) and N-terminal pro-brain natriuretic peptide (NT-proBNP) with some clinical and paraclinical characteristics of patients with heart failure (HF).Material and methods. The study included 130 patients with HF (men — 54, women — 76, mean age, 64,3±8,3 years) from the regional registry of HF patients in the Voronezh Oblast. All patients underwent echocardiography and general clinical investigations. In addition, the serum levels of sST2 and NT-proBNP were determined and their correlations with other parameters were studied.Results. The blood level of sST2 in HF patients was 339,8 [266;405] pg/ml. In the study sample of patients with HF, sST2 levels correlated with right atrial (r=0,49) and right ventricular (r=0,32) sizes, left ventricular end-diastolic dimension (r=0,34) and volume (r=0,33), left ventricular early diastolic filling rate (r=-0,35), blood calcium level (r=-0,55) and functional class of exertional angina (r=-0,37).Conclusion. The data obtained may indicate a pathogenetic relationship between sST2 and systolic and diastolic dysfunction of the left ventricle and right heart

Two interacting quasiparticles above the Fermi sea

We study numerically the interaction and disorder effects for two quasiparticles in two and three dimensions. The dependence of the interaction-induced Breit-Wigner width on the excitation energy above the Fermi level, the disorder strength and the system size is determined. A regime is found where the width is practically independent of the excitation energy. The results allow to estimate the two quasiparticle mobility edge.Comment: revtex, 4 pages, 4 figure

Biomarkers ST2 and interleukin 33 for assessing the severity of cardiac inflammation and fibrosis in patients with chronic heart failure

Chronic heart failure (CHF) is a pathology that affects more than 37 million people worldwide. Despite the introduction of new drugs into practice, that have proven their effectiveness in the treatment of patients with CHF, the life expectancy of these patients is growing at a slow pace. At the same time, the insufficient effect of neurohormonal blockers for the treatment of patients with CHF with preserved ejection fraction (CHFpEF), which prevails in the general structure of CHF, indicates a significant role of unidentified pathological processes in the development of this form of the disease. In recent years, the role of cardiac fibrosis has been actively studied within the framework of the investigation of the pathogenesis of CHFpEF, the probable biomarkers of which are interleukin (IL) 33 and suppression of tumorigenicity 2 (ST2). This literature review examines the influence of the IL-33/ ST2 interaction as a biomarker of cardiac fibrosis on the course of CHF and the possibilities of its practical application

Bilirubin and cardiovascular risk

This literature review demonstrates the results of experimental and clinical studies, as well as data from meta-analyzes on the effect of bilirubin levels on cardiovascular system. Recent studies provided a new look at the role of bilirubin in cardiovascular disease. Modern concepts consider bilirubin as a powerful endogenous antioxidant with anti-inflammatory effects, capable of influencing the course of atherosclerotic cardiovascular diseases and reducing ischemic damage. The change in bilirubin levels affects the coronary blood flow, the development of collateral circulation and the morphology of coronary plaques. A low bilirubin level is associated with an increase in left ventricular mass and a decrease in its contractility, which, in turn, leads to heart failure and increases the risk of rehospitalizations. Taking into account the above effects of bilirubin, there was interest in assessing the effect of its blood level on the risk of atherosclerotic cardiovascular diseases. Recent studies have attempted to create risk stratification models for adverse cardiovascular events based on bilirubin levels

Piezoelectric actuation of graphene-based polar structures: frequency and geometry effects

The work was financially supported by the Russian Foundation for Basic Research within the project 16-29-14050 ofr. The equipment of the Ural Center for Shared Use “Modern nanotechnology” of UrFU was used

Spin injection into a ballistic semiconductor microstructure

A theory of spin injection across a ballistic ferromagnet-semiconductor-ferromagnet junction is developed for the Boltzmann regime. Spin injection coefficient $\gamma$ is suppressed by the Sharvin resistance of the semiconductor $r_N^*=(h/e^2)(\pi^2/S_N)$, where $S_N$ is the Fermi-surface cross-section. It competes with the diffusion resistances of the ferromagnets $r_F$, and $\gamma\sim r_F/r_N^*\ll 1$ in the absence of contact barriers. Efficient spin injection can be ensured by contact barriers. Explicit formulae for the junction resistance and the spin-valve effect are presented.Comment: 5 pages, 2 column REVTeX. Explicit prescription relating the results of the ballistic and diffusive theories of spin injection is added. To this end, some notations are changed. Three references added, typos correcte

Acute Coronary Syndrome during the Pandemic New Coronavirus Infection

The experience of managing patients with COVID-19 around the world has shown that, although  respiratory symptoms predominate  during the manifestation of infection, then many patients can develop serious damage  to the cardiovascular system. However, coronary artery disease (CHD) remains the leading cause of death worldwide. The purpose of the review is to clarify the possible pathogenetic links between COVID-19 and acute coronary syndrome (ACS), taking into account which will help to optimize the management of patients with comorbid  pathology. Among the body's responses to SARS-CoV-2 infection, which increase the likelihood of developing  ACS,  the role of systemic inflammation, the quintessence  of which is a "cytokine storm" that can destabilize  an atherosclerotic  plaque is discussed.  Coagulopathy, typical for patients with Covid-19, is based on immunothrombosis, caused by a complex  interaction between neutrophilic  extracellular  traps and von Willebrandt  factor in conditions  of systemic inflammation. The implementation  of a modern strategy  for managing patients with ACS,  focused on the priority of percutaneous interventions (PCI), during  a pandemic is experiencing great  difficulties  due to the formation  of time delays  before  the start of invasive  procedures  due to the epidemiological situation. Despite this, the current European,  American and Russian recommendations for the management of infected patients with ACS confirm the inviolability of the position of PCI as the first choice for treating patients with ACS and the undesirability  of replacing  invasive treatment with thrombolysis

Hypertensive crisis as cerebrovascular disease risk factor

Objective. To assess main epidemiological indicators for hypertensive crises (HC) in the population of productive age and to study possible correlations of crisis associated arterial hypertension (AH) with clinical and instrumental phenomenon of chronic cerebrovascular diseases. Materials and methods. Data of several studies presented: cross-sectional studies of 726 people aged 35-64 and 415 people aged 40-59. Observational cohort study of 109 patients aged 57.4±5.8 with uncomplicated AH. For the detection of HC in anamnesis, there were used special criteria which widens standard HC definition for additional account of light and mild severity cases. Results. Overall AH prevalence was 45% (95% CI 41-51), in men - 48% (40.2-55.9), in women - 45% (38.4-51.6). History of HC in anamnesis was 11.8% (95% CI 9-15.2), in men 8.8% (5.4-14) and in women - 13.8% (10-18.7). Proportion of HC associated AH defined at the level of 25-30% of all AH cases. The most prevalence of HC associated AH was found in people with “high normal” (130-139/85-89) arterial pressure - 37%. Prevalence of the complaints on headaches, dizziness, poor memory and lower intellectual productivity was higher in people with HC. Chronic cerebrovascular disease was found 2-fold frequently in HC associated AH. But in generally analysis of possible correlations of HC with clinical and instrumental phenomenon of chronic cerebrovascular diseases didn’t revealed any statistically significant differences. Conclusion. HC burden for healthcare system is serious, because it is important risk factor for cerebrovascular diseases and associated with significant lowering of the quality of life. Prevalence of the HC cases with light and mild severity is underestimated. Despite that the study of the most prevalent forms of HC (rare, light and mild severity) didn’t find any associations with morphological or persistent clinical pathology, functional phenomenon were found statistically significant frequently