Magnetization and specific heat of TbFe3(BO3)4: Experiment and crystal field calculations

We have studied the thermodynamic properties of single-crystalline TbFe3(BO3)4. Magnetization measurements have been carried out as a function of magnetic field (up to 50 T) and temperature up to 350K with the magnetic field both parallel and perpendicular to the trigonal c-axis of the crystal. The specific heat has been measured in the temperature range 2-300K with a magnetic field up to 9 T applied parallel to the c-axis. The data indicate a structural phase transition at 192 K and antiferromagnetic spin ordering at 40 K. A Schottky anomaly is present in the specific heat data around 20 K, arising due to two low-lying energy levels of the Tb3+ ions being split by f-d coupling. Below TN magnetic fields parallel to the c-axis drive a spin-flop phase transition, which is associated with a large magnetization jump. The highly anisotropic character of the magnetic susceptibility is ascribed mainly to the Ising-like behavior of the Tb3+ ions in the trigonal crystal field. We describe our results in the framework of an unified approach which is based on mean-field approximation and crystal-field calculations.Comment: 10 pages, 10 figures, 20 references, accepted by Phys. Rev.

Atorvastatin: old friend in the light of novel coronavirus infection’s pandemia

The COVID-19 (COronaVIrus Disease 2019) pandemic caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2) continues to be a global threat to people and health systems. As of March 21, 2022, there are more than 460 million cases and more than 6 million deaths worldwide, and more than 17 million and 360,000 respectively in the Russian Federation. Due to the rapid spread of the new coronavirus infection, since the beginning of the pandemic, tremendous efforts have been made to create new pharmacological agents to reduce morbidity and mortality, and tactics have been used to repurpose existing medications in treatment regimens for patients with COVID-19, particularly statins. Statins represent one of the most widely used and prescribed classes of drugs in the world. The hypolipidemic properties of statins are actively used to treat hyperlipidemia and primary and secondary prevention of cardiovascular diseases and their complications. Statins have a known safety profile, are inexpensive and accessible. In addition to their hypolipidemic effects, statins have a wide range of pleiotropic anti-inflammatory, antiviral, and antithrombotic effects potentially useful in the treatment of COVID-19. Presumably, the use of statins can reduce SARS-CoV-2-induced organ and tissue damage and improve lung function. The use of statins, particularly atorvastatin, as one of the most effective, widely prescribed and studied drugs in this class, as a safe, affordable and relatively inexpensive therapy may be a promising therapeutic approach in the fight against a new coronavirus infection

Nanоbiocomposite based on dihydroquercetin and arabinogalactan in the form of a gel for external use as a means for the treatment of chronic venous insufficiency in an experiment

Background. Due to the high prevalence of chronic venous insufficiency among the population, with a decrease in the quality of life of patients and their early disability, there is a need to develop modern effective and safe means for the prevention and treatment of this pathology. We have developed the optimal composition and technology of a gel for external use based on a nanobiocomposite of dihydroquercetin and arabinogalactan, which has a venoprotective effect. The article presents data on the results of a preclinical study of the safety and specific activity of the gel.The aim. To study the specific activity (decongestant, antitranssudative action) and safety of a gel for external use based on nanobiocomposite of dihydroquercetin and arabinogalactan used for the treatment of chronic venous insufficiency in the framework of preclinical studies.Materials and methods. The object of the study was a gel for external use based on dihydroquercetin and arabinogalactan nanobiocomposite. The study was conducted on 32 white male rats of the same age, for 15 days. The study of the pharmacological activity of a gel based on a nanobiocomposite of dihydroquercetin and arabinogalactan, was carried out on a model of acute venous stagnation in the tail of a rat (edema of non-inflammatory genesis), the dynamics of tail volume growth in the experimental and control group of animals was evaluated. The irritant effect of the gel on the skin of animals was also determined, the permeability of the capillaries of the skin was determined.Results. When studying the pharmacological activity of the gel on a model of acute venous stagnation in the tail, it was shown that a soft dosage form for external use developed on the basis of nanobiocomposite of dihydroquercetin and arabinogalactan has decongestant and antitranssudative activity. The presence of a locally irritating effect in the gel under study has not been established in the framework of the experiment.Conclusion. In the course of preclinical study of the gel of the nanobiocomposite dihydroquercetin and arabinogalactan on laboratory animals, its antitranssudative activity and safety have been proven

GUT MICROBIOTA AND HYGIENE THEORY OF ATOPY

The indigenous gut microbiota plays a key role in maintaining homeostasis in gastrointestinal tract. The review is devoted to factors influencing gut microbiota composition, involvement of microbiota in formation of systemic and mucosal immunity, the role of disturbances of microbial community in development of allergic disease

Outpatient Practice of Lipid-Lowering Therapy Prescription (According to the ARGO-3 Study)

Aim. To study the frequency of prescriptions of various types of lipid-lowering therapy and their effectiveness in outpatient clinical practice based on the results of a questionnaire of primary care physicians.Material and methods. The study was performed in 2022 in 75 constituent entities of the Russian Federation with the participation of 1117 doctors working in outpatient clinics. Most of the doctors had work experience of 10-20 years or more. Doctors of polyclinics (therapists and cardiologists, etc.) before the start of the study received instructions, questionnaires for filling out, developed by the National Atherosclerosis Society. The frequency of prescriptions by primary care physicians of various types of lipid-lowering therapy and their effectiveness in terms of the frequency of achieving target levels of low-density lipoprotein cholesterol (LDL-C) was studied based on the results of a questionnaire.Results. Monotherapy with statins was prescribed in 55.2% of cases, free combination of rosuvastatin with ezetimibe – in 17.2%, single pill combination of rosuvastatin with ezetimibe – in 23.2%, combination therapy with PCSK9 inhibitors – in 4.1% of cases. Target levels of LDL-C ˂ 1.8 mmol/l and ˂ 1.4 mmol/l were achieved with statin monotherapy in 42.6% and 28.2% of cases, respectively, free combination of rosuvastatin with ezetimibe – in 61.7% and 39 .5%, a fixed combination of rosuvastatin with ezetimibe – in 67.8% and 48.5%, combination therapy with PCSK9 inhibitors – in 96.8% and 92.8% of cases.Conclusion. The single pill combination of rosuvastatin with ezetimibe is more effective in achieving target levels of LDL-C compared with statin monotherapy and therapy with free combination of statin with ezetimibe. Despite the fact that the target values of LDL-C when prescribing a combination with PCSK9 inhibitors were achieved in 96.8% and 92.8% of cases, they were used quite rarely at the outpatient stage of treatment in the Russian Federation

SEROEPIDEMIOLOGICAL RESEARCH AND ANALYSIS CHARACTERISTIC OF KEFIR, AS A VALUABLE PROBIOTIC PRODUCT AND ITS BIOLOGICAL PROPERTIES

We present new data on the on the microbial composition and properties of probiotic kefir fungi fermented milk drink kefir, namely antikancerogenik, antimutagenic, antigenotoxic and radio-protecting, antioxidant, antihypertensive, hypoglycemic, anti-inflammatory, in wound healing, antimicrobial, and preventable and antiallergic biological effects

Эффективность высокоинтенсивной терапии розувастатином для вторичной профилактики сердечно-сосудистых осложнений у пациентов очень высокого риска

According to the latest international and Russian guidelines for the treatment of dyslipidemias, statins are defined as the main group of drugs that significantly reduce the level of low-density lipoprotein cholesterol (LDL-C) effectively prevent atherosclerotic cardiovascular diseases (CVD) and complications and can slow down the progression of atherosclerosis. The principle “the lower LDL-C, the better” is especially relevant in categories of patients with very high and extreme cardiovascular risk, and therefore, in order to achieve target LDL-C values (≤1.4 is optimal ≤1.0) in this category of patients, high-intensity lipid-lowering therapy should be used. Rosuvastatin remains the most effective statin. Its use makes possible to achieve target lipid values at the starting dose of treatment, enhances adherence to treatment, and also reduces the frequency of side effects associated with the use of high doses of other statins. In addition, the proven ability of rosuvastatin to reduce the volume of atherosclerotic plaque, by reducing the level of pro-inflammatory cytokines and C-reactive protein, normalizing endothelial function, antiplatelet action, that is, rosuvastatin, in addition to its powerful lipid-lowering effect, has anti-inflammatory and anti-ischemic effects. Also, rosuvastatin can be successfully used in the presence of comorbidities, including chronic kidney disease and chronic heart failure. Taking into consideration the urgency of the fight against the COVID-19 pandemic (coronavirus Disease 2019), which covered 220 countries, due to the lack of effective etiotropic drugs, the possibility of using statins, including rosuvastatin, for the treatment of comorbid patients with COVID-19, was evaluated.Согласно последним международным и российским рекомендациям по лечению дислипидемий, статины определены в качестве основной группы лекарственных препаратов, значимо снижающих уровень холестерина липопротеидов низкой плотности (ХС ЛНП) крови, эффективных для профилактики сердечно-сосудистых заболеваний (ССЗ) и сердечно-сосудистых осложнений (ССО), позволяющих затормозить прогрессирование атеросклероза. Принцип «чем ниже ХС ЛНП, тем лучше» особенно актуален у категорий пациентов очень высокого и экстремального сердечно-сосудистого риска, в связи с чем для достижения целевых значений ХС ЛНП (≤ 1,4 оптимально ≤ 1,0) у этой категории пациентов должна применяться высокоинтенсивная гиполипидемическая терапия. Наиболее эффективным представителем статинов остается розувастатин. Его применение позволяет добиваться целевых значений липидов на стартовой дозе лечения, способствует повышению приверженности к лечению, а также уменьшению частоты побочных эффектов, связанных с применением высоких доз других статинов. Кроме того, доказанной является способность розувастатина уменьшать объем атеросклеротической бляшки за счет снижения уровня провоспалительных цитокинов и С-реактивного белка, нормализации функции эндотелия, дезагрегантного действия, т. е. розувастатин, помимо мощного гиполипидемического воздействия, обладает противовоспалительным и антиишемическим эффектами. Также розувастатин может успешно применяться при наличии сопутствующей патологии, включая хроническую болезнь почек и хроническую сердечную недостаточность. Учитывая актуальность борьбы с пандемией COVID-19 (COronaVIrus Disease 2019), охватившей 220 стран, в связи с отсутствием эффективных этиотропных препаратов оценена возможность применения статинов, в т. ч. и розувастатина, для лечения коморбидных пациентов с COVID-19

Associative connection of infectious and inflammatory diseases in pregnancy and severe preeclampsia

Materials and methods. This retrospective case-control study enrolled 50 women with severe preeclampsia and 50 control women with spontaneous singleton pregnancy. Median age of women ranged from 20 to 35 years. All women did not have a history of hypertension, autoimmune, metabolic, renal, or cardiac diseases, and preeclampsia before this pregnancy. We have analyzed χ2, odds ratio (OR) and its 95% confidence intervals (95% Cl). Results. We found significant association between maternal systemic infectious and severe preeclampsia (OR = 49.6; 95% Cl 13.05-188.64). The risk of severe preeclampsia were significantly lower in patients with local infections of the lower genital tract (OR = 4.5; 95% Cl 1.49-6.71). Asymptomatic bacteriuria is associated with the highest risk of severe preeclampsia (OR = 17.0; 95% Cl 4.66-61.81). Acute gravidarum pyelonephritis showed lower association with severe preeclampsia (OR = 5.4; 95% Cl 1.69-10.54). We did not observe increased risk of severe preeclampsia with acute respiratory infections (OR = 2.0; 95% Cl 0.71-4.69). Acute non-specific bacterial vaginitis and acute candidiasis vulvovaginitis were found to be risk factors of severe preeclampsia (OR = 6.7; 95% Cl 1.90-11.02 and OR = 4.3; 95% Cl 1.45-9.99 respectively). Cytomegalovirus infection (2 %), toxoplasmosis (2 %), Chlamydia trachomatis cervicitis (4 %), acute Trichomonas colpitis (2 %) and bacterial vaginosis (4 %) were found only in patients with severe preeclampsia. Conclusion. Our data support that acute maternal infection is associated with an increased risk of severe preeclampsia in healthy women with singleton pregnancy. Systemic inflammatory response might be the main potential mechanisms related to infections and enhanced development of severe preeclampsia. Further research is required to elucidate the underlying mechanism of this association

Studying of the Polylactide or Polyglycylidactide Surface Layer Biodegradation in Neutral Media for the Subsequent Layered Composite Creation

  The processes of biodegradation in phosphate buffer with pH 7.4 and 0.9 wt.% NaCl of polymer polylactide or polyglycylidactide films for the subsequent creation of a layered composite with a biodegradable layer on the basis of a nickel-free shape memory alloy TiNbTaZr were studied. The structure of the samples was determined by SEM and an optical microscope. For polylactide films the rate of biodegradation did not depend on the mass of the film. A gradual decrease in the rate of biodegradation at any mass with a similar dependence on time is noted. With an increase in the mass of films based on poly(glycolide-lactide) the rate of biodegradation increased. And even at the initial stage the dissolution rate is 2-3 times higher than in pure polylactide. On day 180, complete dissolution of the polyglycolidelactide was observed (even a precipitate was not observed) and completely entire polylactide films, however, lost  their transparency, was noted

Disturbance of meromixis in saline Lake Shira (Siberia, Russia): possible reasons and ecosystem response

Saline Lake Shira (Southern Siberia, Russia) was meromictic through the observation period 2002-2015. During the under-ice periods of 2015 and 2016, complete mixing of the water column was recorded for the first time, and hydrogen sulphide temporarily disappeared from the water column of the lake; i.e. in those years the lake turned to holomixis. In the summer of 2015, a sharp increase in chlorophyll a, organic carbon, zooplankton, and phytoflagellates was observed in the lake, which was probably due to the release of nutrients from the monimolimnion. Purple sulfur bacteria completely disappeared from the lake after the first mixing in 2015, and did not reappear despite the restoration of meromixis in 2017. Thus, it was demonstrated that purple sulfur bacteria are sensitive to the weakening of the stratification of Lake Shira. Based on the data of the seasonal monitoring of temperature and salinity profiles over the period 2002-2017, it was presumed that the main cause of deep mixing in 2015 was the weakening of the salinity gradient due to strong wind impact and early ice retreat in the spring of 2014. In addition, it was shown that in previous years a significant contribution to the maintenance of meromixis was made by an additional influx of fresh water, which caused a rise in the lake level in the period 2002-2007. Thus, we identified a relationship between the stratification regime of the lake and the change in its level, which provides valuable information both for the forecast of water quality and for reconstruction of the Holocene climate humidity in this region of Southern Siberia from the sediment cores of Lake Shira