Phytoplankton of the delta of the Mekong River during the dry season

Human activity has disturbed the functioning of river ecosystems all around the globe. The current global climatic fluctuations and local anthropogenic impact lead to rearrangement in the structure and functioning of aquatic communities. One of the most important components of aquatic ecosystems is phytoplankton as the main primary producer of the organic matter, the basis for trophic relations and indicator of changes in the environment. This article presents the first results of a study concerning the peculiarities of quantitative distribution of biomass and species composition of phytoplankton in the delta of the Mekong River at the beginning of the dry season (December of 2018). Diatoms dominated according to biomass practically in all the stations of selection of samples. The total biomass of phytoplankton on average accounted for 0.049 ± 0.007 mg/L at the abundance of 40 ± 7 103 ind./L. In practically all the studied plots, according to biomass, the dominating diatoms were first of all Aulacoseira granulata, A. islandica, Cyclotella meneghiniana, Cyclotella spp., and Oxyneis binalis. Among Chlorophyta, most often we found Chlorella sp. and Scenedesmus quadricauda, but their biomass was insignificant. We determined statistically significant correlation relationships between biomass of phytoplankton and hydrological parameters. Based on the Spearman’s rank correlation coefficient, we determined negative relations between the total biomass of phytoplankton with salinity and pH. Positive correlation was seen between the biomass of diatoms and turbidity, and also between the temperature and the biomass of chlorophytes and Dinophyta. The biomass of golden algae (Chrysophyceae) and Dinophyta positively correlated with the mineralization. Quantitative regression analysis confirmed the close relationship between the total biomass of phytoplankton, hydrophysical and hydrochemical parameters. Besides the importance of scientific data on biological diversity and ecology of plankton algae, the results we obtained are necessary for organizing biological monitoring in the delta of the Mekong River in the future

Immunological predictors of type 1 diabetes mellitus (literature review)

Background: Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease characterized by insulin deficiency due β-cell destruction and following hyperglycaemia. Specific markers of T1DM are pancreatic islet-targeting autoantibodies that are found months to years before symptom onset, and can be used to identify individuals who are at risk of developing T1DM.Aim: The study is aimed at the review of current knowledge of diabetes-related autoantibodies as biomarkers of T1DM.Materials and methods: Foreign and national clinical studies on this topic were included. PubMed, Medline and ­eLibrary were searched.Results: Modern ideas about known diabetes-specific autoantibodies as markers of autoimmune inflammation of β-cells of the pancreas were discussed. The analysis of their independent diagnostic value in predicting the occurrence of T1DM were carried out.Conclusion: There is no unified concept in the literature on this issue. Current data on autoantibodies in T1DM show a ­significant individual variability in the timing, dynamic changes and autoantibody composition in T1DM progression

Potential risk factors for diabetes mellitus type 1

Diabetes mellitus type 1 (T1D) develops as a result of the interaction of genetic and environmental factors. Genetic predisposition to T1D turns into clinical reality only in half of hereditary cases, which indirectly indicates the importance of external factors, the significance of which is periodically reviewed. Retrospective and prospective clinical foreign and national studies were included. PubMed, Medline and eLibrary were searched. Modern ideas about the possible impact of the main prenatal and postnatal environmental factors on the development of autoimmune response against insulin-producing islet cells and T1D were discussed. The risk of developing type 1 diabetes is determined by the complex interaction of environmental factors and genetic predisposition. The mechanisms of their influence remain rather unknown. Further research is needed to determine strategies of primary and secondary prevention of T1D

Omega phase formation in ti–3wt

It is well known that severe plastic deformation not only leads to strong grain refinement and material strengthening but also can drive phase transformations. A study of the fundamentals of α → ω phase transformations induced by high-pressure torsion (HPT) in Ti–Nb-based alloys is presented in the current work. Before HPT, a Ti–3wt.%Nb alloy was annealed at two different temperatures in order to obtain the α-phase state with different amounts of niobium. X-ray diffraction analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied for the characterisation of phase transitions and evolution of the microstructure. A small amount of the β-phase was found in the initial states, which completely transformed into the ω-phase during the HPT process. During HPT, strong grain refinement in the α-phase took place, as did partial transformation of the α- into the ω-phase. Therefore, two kinds of ω-phase, each with different chemical composition, were obtained after HPT. The first one was formed from the β-phase, enriched in Nb, and the second one from the α-phase. It was also found that the transformation of the α-phase into the ω-phase depended on the Nb concentration in the α-Ti phase. The less Nb there was in the α-phase, the more of the α-phase was transformed into the ω-phase

Reduction Operators of Linear Second-Order Parabolic Equations

The reduction operators, i.e., the operators of nonclassical (conditional) symmetry, of (1+1)-dimensional second order linear parabolic partial differential equations and all the possible reductions of these equations to ordinary differential ones are exhaustively described. This problem proves to be equivalent, in some sense, to solving the initial equations. The ``no-go'' result is extended to the investigation of point transformations (admissible transformations, equivalence transformations, Lie symmetries) and Lie reductions of the determining equations for the nonclassical symmetries. Transformations linearizing the determining equations are obtained in the general case and under different additional constraints. A nontrivial example illustrating applications of reduction operators to finding exact solutions of equations from the class under consideration is presented. An observed connection between reduction operators and Darboux transformations is discussed.Comment: 31 pages, minor misprints are correcte

Features of COVID-19 course in patients with obesity and dysglycemia

Aim. To study the features of coronavirus disease 2019 (COVID-19) in patients with different severity of carbohydrate metabolism disorders (CMDs), taking into account the possible role of obesity in the acceleration of clinical and laboratory disorders.Material and methods. There were 137 consecutive patients admitted to the infectious disease hospital for COVID-19patients. Three 3 groups were formed: group 1 — 42 patients with concomitant type 2 diabetes (T2D); group 2 — 13 patients with concomitant prediabetes; group 3 — 82 patients without concomitant CMDs.Results. Patients with T2D tended to have a more severe disease course according to the SMRT-CO algorithm (p=0,089), which was associated with the longest hospital stay (p=0,038), the most pronounced (p=0,011) and prolonged (p=0,0001) decrease in oxygen saturation, the maximum percentage of lung injury at the beginning (p=0,094) and at the end (p=0,007) of hospitalization, the greater need for intensive care unit (p=0,050), as well as the highest increase in C-reactive protein and fibrinogen (hypercoagulability and systemic inflammation were noted in all groups). Patients with prediabetes in terms of COVID-19 severity occupied an intermediate position between those with T2D and without CMDs; at the same time, they most often needed the prescription of biological preparations (p=0,001). In the first and second groups, there were larger, compared with the control, proportions of obese people (61,9%, 53,8% and 30,5%, respectively, p=0,003). Prediabetes group had a strong correlation between the severity of viral pneumonitis according to SMRT-CO and the presence of obesity (R=0,69, p=0,009).Conclusion. In patients with impaired carbohydrate metabolism of any severity, COVID-19 is more severe. At the same time, persons with overt T2D are prone to the most severe COVID-19 course, while patients with prediabetes in terms of disease severity occupy an intermediate position between them and those without CMDs. Obesity is a strong risk factor for severe COVID-19 among patients with initial CMDs (prediabetes), which is partly mediated by prior liver dysfunction associated with the metabolic syndrome. The increase in proinflammatory changes and hypercoagulability is associated with COVID-19 severity in patients with and without CMDs. These disorders had the greatest severity and persistence in patients with T2D

Single step process for the synthesis of carbon nanotubes and metal/alloy-filled multiwalled carbon nanotubes

A single-step approach for the synthesis of multi-walled nanotubes (MWNT) filled with nanowires of Ni/ternary Zr based hydrogen storage alloy has been illustrated. We also demonstrate the generation of CO-free hydrogen by methane decomposition over alloy hydride catalyst. The present work also highlights the formation of single-walled nanotubes (SWNT) and MWNTs at varying process conditions. These carbon nanostructures have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), Energy dispersive X-ray analysis (EDX) and Raman spectroscopy. This new approach overcomes the existing multi-step process limitation, with possible impact on the development of future fuel cell, nano-battery and hydrogen sensor technologies

Neural Substrate of Cold-Seeking Behavior in Endotoxin Shock

Systemic inflammation is a leading cause of hospital death. Mild systemic inflammation is accompanied by warmth-seeking behavior (and fever), whereas severe inflammation is associated with cold-seeking behavior (and hypothermia). Both behaviors are adaptive. Which brain structures mediate which behavior is unknown. The involvement of hypothalamic structures, namely, the preoptic area (POA), paraventricular nucleus (PVH), or dorsomedial nucleus (DMH), in thermoregulatory behaviors associated with endotoxin (lipopolysaccharide [LPS])-induced systemic inflammation was studied in rats. The rats were allowed to select their thermal environment by freely moving in a thermogradient apparatus. A low intravenous dose of Escherichia coli LPS (10 µg/kg) caused warmth-seeking behavior, whereas a high, shock-inducing dose (5,000 µg/kg) caused cold-seeking behavior. Bilateral electrocoagulation of the PVH or DMH, but not of the POA, prevented this cold-seeking response. Lesioning the DMH with ibotenic acid, an excitotoxin that destroys neuronal bodies but spares fibers of passage, also prevented LPS-induced cold-seeking behavior; lesioning the PVH with ibotenate did not affect it. Lesion of no structure affected cold-seeking behavior induced by heat exposure or by pharmacological stimulation of the transient receptor potential (TRP) vanilloid-1 channel (“warmth receptor”). Nor did any lesion affect warmth-seeking behavior induced by a low dose of LPS, cold exposure, or pharmacological stimulation of the TRP melastatin-8 (“cold receptor”). We conclude that LPS-induced cold-seeking response is mediated by neuronal bodies located in the DMH and neural fibers passing through the PVH. These are the first two landmarks on the map of the circuitry of cold-seeking behavior associated with endotoxin shock

Эффективность и безопасность применения бовгиалуронидазы азоксимера (Лонгидаза) у пациентов с постковидным синдромом: результаты открытого проспективного контролируемого сравнительного многоцентрового клинического исследования DISSOLVE

Post-COVID syndrome develops after COVID-19 (COronaVIrus Disease 2019) and leads to cumulative effects in the form of shortness of breath and impaired lung function. Notably, patients with airway inflammation and COVID-19 were found to have increased concentrations of hyaluronic acid (HA). Since bovhyaluronidase azoximer (Longidase®) catalyzes the hydrolysis of HA, this drug has the potential to reduce HA levels and improve lung function in patients with post-COVID syndrome.The aim of the DISSOLVE trial, which was conducted early in the pandemic, was to investigate the efficacy and safety of bovhyaluronidase azoximer in patients with symptoms associated with post-COVID syndrome.Methods. An open, prospective, controlled, comparative, multicenter clinical trial (NCT04645368) included adult patients (n = 160) who had post-COVID syndrome. Patients in the treatment group (n = 81) received bovhyaluronidase azoximer, and individuals in the control group (n = 79) were followed up without intervention. The study included physical examination, evaluation of forced vital capacity (FVC), assessment of dyspnea with the Modified Medical Research Council Dyspnea Scale (mMRC), 6-minute walking test, and pulse oximetry. These indicators were measured on 3 visits, at days 1 (baseline), 75, and 180. In addition, the number of patients who experienced adverse events and serious adverse events were recorded.Results. Baseline patient characteristics in the treatment group and the control group were similar. In the treatment group, there was a statistically significant reduction in residual pulmonary abnormalities after visit 2 (day 75) and visit 3 (day 180). In addition, FVC, pulse oximetry values, and functional exercise tolerance increased statistically significantly at days 75 and 180 compared to baseline. The mMRC scores for dyspnea decreased statistically significantly in the treatment group over 75 days. The safety profile of the drug was reported to be favorable throughout the study. Conclusion. Treatment with bovhyaluronidase azoximer in patients with post-COVID syndrome showed improvement in FVC, pulse oximetry, functional exercise tolerance, and mMRC dyspnea.Постковидный синдром (ПКС) после перенесенного COVID-19 (COronaVIrus Disease 2019) – это состояние, которое развивается у пациентов, переболевших COVID-19 и приводит к кумулятивным эффектам в виде одышки и нарушения функции легких. Примечательно, что у пациентов с воспалением дыхательных путей и COVID-19 обнаружены более высокие концентрации гиалуроновой кислоты (ГК). Поскольку бовгиалуронидаза азоксимер (Лонгидаза®) катализирует гидролиз ГК, при назначении данного препарата потенциально можно ожидать снижение концентрации ГК и улучшения функции легких у пациентов с ПКС.Целью исследования DISSOLVE, которое проводилось на начальной стадии пандемии, явилось изучение эффективности и безопасности применения бовгиалуронидазы азоксимера у пациентов с симптомами, связанными с ПКС.Материалы и методы. В открытом проспективном контролируемом сравнительном многоцентровом клиническом исследовании (NCT04645368) принимали участие взрослые пациенты (n = 160), у которых выявлен ПКС. Пациенты, составившие группу лечения (n = 81), получали бовгиалуронидазу азоксимер, лица, составившие группы контроля (n = 79), наблюдались динамически. В рамках исследования выполнялось физикальное обследование, проводилась оценка показателей форсированной жизненной емкости легких (ФЖЕЛ), одышки по шкале модифицированного вопросника Британского медицинского исследовательского совета (Modified Medical Research Council Dyspnea Scale – mMRC), дистанции, пройденной при выполнении 6-минутного шагового теста, и пульсоксиметрии. Эти показатели измерялись в рамках 3 визитов: в 1-й (исходный уровень), 75-й и 180-й дни. Кроме того, регистрировалось число пациентов, у которых наблюдались нежелательные явления (НЯ) и серьезные НЯ.Результаты. Исходные характеристики у пациентов группы лечения и контрольной группы были сходными. В группе лечения отмечено статистически значимое снижение остаточных легочных изменений после визита 2 (75-й день) и визита 3 (180-й день); кроме того, показатели ФЖЕЛ, пульсоксиметрии и переносимости функциональных физических нагрузок статистически значимо увеличились на 75-й и 180-й дни относительно исходного уровня. Показатели одышки по шкале mMRC в группе лечения статистически значимо снизились в течение 75 дней. Профиль безопасности препарата отмечался как благоприятный на протяжении всего исследования.Заключение. При терапии бовгиалуронидазой азоксимером у пациентов с ПКС отмечено улучшение показателей ФЖЕЛ, пульсоксиметрии, переносимости функциональных физических нагрузок и оценки одышки по mMRC