Longitudinal drift of Tayler instability eigenmodes as a possible explanation for super-slowly rotating Ap stars

Rotation periods inferred from the magnetic variability of some Ap stars are incredibly long, exceeding ten years in some cases. An explanation for such slow rotation is lacking. This paper attempts to provide an explanation of the super-slow rotation of the magnetic and thermal patterns of Ap stars in terms of the longitudinal drift of the unstable disturbances of the kink-type (Tayler) instability of their internal magnetic field. The rates of drift and growth were computed for eigenmodes of Tayler instability using stellar parameters estimated from a structure model of an A star. The computations refer to the toroidal background magnetic field of varied strength. The non-axisymmetric unstable disturbances drift in a counter-rotational direction in the co-rotating reference frame. The drift rate increases with the strength of the background field. For a field strength exceeding the (equipartition) value of equal Alfven and rotational velocities, the drift rate approaches the proper rotation rate of a star. The eigenmodes in an inertial frame show very slow rotation in this case. Patterns of magnetic and thermal disturbances of the slowly rotating eigenmodes are also computed. The counter-rotational drift of Tayler instability eigenmodes is a possible explanation for the observed phenomenon of super-slowly rotating Ap stars.Comment: Accepted in A&

LIPID INFILTRATION OF HEPATOCYTES IN THE MORPHOGENESIS OF CHRONIC HEPATITIS C

The aim of the study was to investigate structurally functional features of lipidic infiltration of hepatocytes in a morphogenesis of chronic hepatitis C. Material and methods. A clinical and morphological study of 199 patients with HCV infection markers (139 men and 60 women aged from 20 till 65 years) was conducted. In all cases, a comprehensive study including analysis of blood biochemical parameters, serological markers of HCV replication in blood and liver, viremia level, number of the infected hepatocytes and HCV genotypes was performed. Diagnostic complex included clinical, biochemical, immunoserological methods. Results and discussion. The results of the analysis of structural and functional features of lipid-containing hepatocytes and indicators of replication of virus particles of chronic hepatitis C are provided. For its reproduction HCV enters into complex relationships with the metabolic apparatus of the cell, in which lipid metabolism and related structures – lipid droplets play an important role. The only structural marker that correlates with indicators of virus replication is subcytolemmal small-vesicular lipid infiltration, which can reflect a virus-induced increase in lipid metabolism in the host cell for the effective production of infectious active viral particles

Mismatch repair and repair of insertion/deletion loops in eukaryotic DNA

The mismatch repair (MMR) system detects non-Watson - Crick base pairs as well as the defects, appearing in course of DNA replication, and helps to eliminate them by catalyzing the excision of the defect-containing region of daughter DNA and its error-free resynthesis. Thus, MMR remarkably improves the fidelity of replication. After separation, both strands contain non-repairable damages and the mismatches may generate DnA mutation in 50 % of cell progeny after next replication. MMR dysfunction causes surge of mutation rate, abnormal recombination, and cancer in humans and animals. Therefore, the main MMR efficiency parameter is mismatch correction before the next replication cycle. Mismatch detection is made by the MSH2 protein, which forms a heterodimer with either MSH6 or MSH3 (Mut S), depending on the damage (MSH6 is needed for the amendment of single base mispairs, whereas both MSH3 and MSH6 can correct IDLs). A heterodimer of MLH1 and PMS2 (Mut L) controls the interaction between the mismatch-detecting complex of proteins and other proteins essential for MMR, including exonuclease 1, helicase, nuclear antigen of proliferating cells, single-stranded DNA-binding protein and DNA polymerases δ and ε. MLH1 can form a heterodimer with two additional proteins - MLH3 and PMS1. PMS2 is required for the correction of single based mismatches, and PMS2 and MLH3 contribute to the correction of IDLs. The Nobel Prize in Chemistry 2015 was awarded for the studies of DNA repair, i.a. MMR

Metabolic Risk Factors and Their Impact on Quality of Life in Patients with Pancreatic Cancer, Acute or Exacerbated Chronic Pancreatitis

Аim: to evaluate metabolic risk factors and their impact on quality of life in patients with pancreatic cancer (PC) and in patients with acute or exacerbated chronic pancreatitis.Materials and methods. Forty-five patients with PC (group 1) and 141 patients with acute pancreatitis or exacerbated chronic pancreatitis (group 2) in an observational multicenter clinical cross-sectional uncontrolled study were examined. Clinical, laboratory and instrumental examination of patients and assessment of risk factors (lipid profile, blood plasma glucose, obesity, arterial hypertension) were carried out in accordance with clinical recommendations. Patients completed the SF-36 questionnaire once to assess quality of life at hospital admission before treatment.Results. In group 1, indicators of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) in blood serum (3.7 ± 0.2; 2.2 ± 0.2 and 0.8 ± 0.1 mmol/L) were lower than in group 2 (5.1 ± 0.1; 3.1 ± 0.1 and 1.2 ± 0.1 mmol/L; p < 0.05). Arterial hypertension was more common in group 1 (55.6 %) than in group 2 (34.8 %; p = 0.013). The presence of arterial hypertension increases the chance of having PC by 2.7 times (p < 0.05). Body mass index parameters, including obesity, as well as parameters of triglycerides, and fasting plasma glucose, did not differ between the groups. Logistic regression analysis revealed a direct relationship with PC HDL hypocholesterolemia (Exp B = 4.976; p < 0.001) and arterial hypertension (Exp B = 2.742; p = 0.027) and an inverse relationship — with hypercholesterolemia (Exp B = 0.204; p = 0.002). The chance of having PC was not associated with age, fasting plasma glucose ³ 7.0 mmol/L, obesity. Quality of life indicators were higher in group 1 than in group 2 on four SF-36 scales: bodily pain (68.1 ± 5.1 and 36.8 ± 2.0; p < 0.001), general health (51.1 ± 2.5 and 38.0 ± 1.7 points; p < 0.001), social functioning (74.7 ± 3.0 and 64.5 ± 2.2 points; p = 0.007), role emotional functioning (28.2 ± 5.2 and 12.5 ± 3.1 points; p = 0.007) and in the general domain “physical component of health” (40.2 ± 1.0 and 33.6 ± 0.8 points; p < 0.001). In group 1 with HDL hypocholesterolemia compared with its absence, the indicators of role emotional functioning (22.2 ± 5.1 and 51.9 ± 13.7 points; p = 0.020) were lower, with arterial hypertension compared with its absence — role physical functioning (5.0 ± 4.0 and 25.5 ± 7.5 points; p = 0.036) and role emotional functioning (16.0 ± 5.1 and 43.3 ± 8.8 points; p = 0.007) were lower.Conclusions. In patients with PC arterial hypertension was more common and the levels of total cholesterol, LDL-C and HDL-C were lower than in patients with acute or exacerbated chronic pancreatitis. The chance of having PC is directly associated with HDL hypocholesterolemia, with arterial hypertension, inversely — with hypercholesterolemia, and is not associated with age, fasting plasma glucose ³ 7 mmol/L, or obesity. In patients with PC, quality of life indicators were higher on four SF-36 scales and on the general domain “physical component of health” than in the group with acute or exacerbated chronic pancreatitis. In patients with PC metabolic factors significantly worsened self-assessment of quality of life in terms of role functioning; in patients with acute or exacerbated chronic pancreatitis there was no such association

PSYCHOPHYSIOLOGIC AND IMMUNOLOGIC CHARACTERISTICS IN PATIENTS WITH BRONCHIAL ASTHMA AND IN HEALTHY MEN WITH DIFFERENT FUNCTIONAL ASYMMETRY OF THE HEMISPHERES OF THE BRAIN

On the basis of the analysis of own and literary data, proved the interaction psychophysiologic and immunologic parameters in healthy people and in patients with bronchial asthma. The main accent was made on the investigation of the role of the functional asymmetry of a brain, as the base phenomenon defining features of mental, vegetative and immunologic activity

СТРУКТУРА МЕСТОРОЖДЕНИЯ СУПЕРКВАРЦИТОВ БУРАЛ-САРДЫК (ВОСТОЧНЫЙ САЯН)

The article presents the results of geological and structural studies of the northwestern part of the Gargan quartziferous province, wherein the Bural-Sardyk deposit is located. The early views on this deposit of high-quality siliceous raw materials have been amended using the new data. This deposit is associated with quartzites of the Meso-Proterozoic Irkut formation and discordantly overlaps the Gargan block. According to the detailed study results on the cover of the Oka-Urik interfluve area, its structure is predetermined by physical and mechanical properties of the rocks, and the degree of rock dislocation depends on the rock viscosity. Most of its section is composed of viscous quartzites that create the structural framework of the study area. Such viscous rocks are not prone to folding. An alternative is detachment taking place concordantly to layering. The only interlayer is composed of limestones that underwent intense plastic deformation reflected in multi-folding. Actually, limestones mark a zone of plastic detachment. The authors propose an interpretation of the formation of the deposit structure. The main deformation event was preceded by the sediment transformation stage in conditions of diagenesis and catagenesis due to the influence of a lithostatic load. Primary recrystallization under lithogenesis led to the formation of high-purity silicon rocks. At the next stage, the rocks were subjected to longitudinal compression in the PT conditions of green-shale metamorphism. This stage is mainly evidenced by sublayer detachments. In parallel with that process, quartzites experienced super-plastic flow and recrystallization, which led to the formation of super-quartzites. The bodies of super-quartzites tend to be layered and less discordant. Such a structural position suggests the possibility of detecting latent manifestations of super-quartzites at different levels in the quartzites of the Irkut formation. Tectonic detachments are observed in the sedimentary cover and do not reach the foundation. Based on these features, there are reasons to use the thin-skinned tectonic model. Rock deformation occurred under stress oriented from the northwest to the southeast. This is indicated by the position of the axial surfaces of the folds, as well as the orientations of the maximum compression axis and the crystallographic axes of quartz. Macro- and microstructural data indicate that the tectonic transport of matter was directed to the southeast. The research results were used for compiling a new geological map of the deposit.В статье изложены результаты геолого-структурных исследований северо-западной части Гарганской кварцитоносной провинции, в которой находится месторождение Бурал-Сардык. Полученные данные меняют ранние воззрения на его структуру. Месторождение высококачественного кремнистого сырья Бурал-Сардык связано с кварцитами иркутной свиты, которая относится к среднему рифею и с несогласием перекрывает Гарганскую глыбу. Детальное изучение структуры чехла на Ока-Урикском междуречье показало, что она предопределена физико-механическими свойствами пород свиты. Было установлено, что степень дислокации пород обусловлена их вязкостью. Большая часть разреза сложена кварцитами, которые являются вязкими и создают структурный каркас района. Кварцитам как вязким породам не свойственна складчатость. Альтернативой ей являются срывы, согласные слоистости. Известняки (единственный прослой) подверглись интенсивной пластичной деформации с формированием многопорядковой складчатости. По существу, они маркируют зону пластичного срыва. Для образования структуры месторождения предлагается следующая интерпретация. Главному деформационному событию предшествовала стадия преобразования осадков в условиях диагенеза и катагенеза под влиянием литостатической нагрузки. Первичная перекристаллизация в условиях литогенеза привела к формированию высокочистых кремниевых пород. На следующей стадии породы подвергаются продольному сжатию в РТ-условиях зеленосланцевого метаморфизма. Это проявилось главным образом в образовании субслойных срывов. Синхронно с этим кварциты испытали суперпластическое течение и рекристаллизацию, что привело к формированию суперкварцитов. Тела суперкварцитов имеют тенденцию располагаться по слоистости и реже дискордантно. Такая структурная позиция позволяет предполагать возможность обнаружения скрытых проявлений суперкварцитов на разных уровнях в кварцитах иркутной свиты. Тектонические срывы картируются в осадочном чехле и не затрагивают фундамент. Эти признаки позволяют сопоставлять ее с моделью тонкошкурой тектоники (thin-skinned tectonic model). Деформация пород осуществлялась в процессе стресса, ориентированного с северо-запада на юго-восток. На это указывает положение осевых поверхностей складок, ориентировка оси максимального сжатия и кристаллографических осей кварца. Макро- и микроструктурные данные показывают, что тектонический транспорт вещества был направлен на юго-восток. Результаты исследований были использованы при составлении новой геологической карты месторождения