94 research outputs found

    Modulation of Circumstellar Extinction in a Young Binary System with a Low-Mass Companion in a Noncoplanar Orbit

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    The cyclic activity model of a young star with the low-mass secondary component (q = M2/M1 <= 0.1) accreting a matter from circumbinary disk is considered. It is assumed that the orbit is circular and the disk and orbital planes are non-coplanar. Sets of hydrodynamics models of such a system have been calculated by the SPH method and then the variations of the circumstellar extinction and phase light curves were determined. The calculations showed that depending on the model parameters and orientation of the system in regards to an observer the different in shape and amplitude light curves can be observed. An important property of the considered models is also the dependence of the mass accretion rate onto the components on the phase of the orbital period. The results of the calculation can be used for analysis of the cyclic activity of UX Ori stars and young stars with the long-lasting eclipses.Comment: 14 pages, 7 figure

    Advantages of physical activity of varying intensity for patients with type 1 diabetes and its influence on glucose metabolism

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    Patients with type 1 diabetes mellitus (T1DM) have many benefits from regular exercise, including improved quality of life, lower blood pressure, improved lipid profile, increased insulin sensitivity, decreased insulin dose requirements, improved endothelial function, and reduced risk of micro- and macrovascular complications, as well as overall mortality. Despite these benefits, T1DM patients often do not get enough physical activity (PA) and are less physically active than their non-diabetic peers. The main reason for the low PA in patients with T1DM is the difficulty of glycemic management and the fear of developing hypoglycemia during exercise. Different types of training, such as moderate to high intensity exercise, high intensity interval training, have different effects on glycemic activity during exercise, which can be used to prevent the development of hypoglycemic reactions during and after exercise, along with carbohydrate intake and insulin dose adjustment. Higher-intensity exercise, as well as greater frequency and duration, are associated with a greater reduction in the risk of overall and cardiovascular mortality. Regular physical activity has a positive effect on reducing the risk of micro- and macrovascular complications, general and cardiovascular mortality in patients with type 1 diabetes, regardless of the quality of glycemic control, which can be used for prevention of T1DM complications

    Peculiarities of the COVID-19 course and consequences in overweight and obese patients. Lessons from the current pandemic

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    Treatment difficulties of COVID-19 have determined the need to identify predictive risk factors for the development of aĀ complicated disease course, critical conditions and death. Endocrine and metabolic abnormalities associated with obesity, including impaired insulin sensitivity, chronic inflammation and impaired lipid and fatty acid metabolism, increase immunological dysregulation and make these patients more susceptible to developing infectious diseases. Research data allows us to single out obesity as a risk factor for the aggravated course of COVID-19, as well as a longer period before the virus elimination, and, therefore, the risk of virus transmission. Potentiation of cardiovascular risk factors, an increase in the production of pro-inflammatory cytokines, coagulopathy are factors in the development of unfavorable outcomes in such patients.This review presents literature data on the features of the course and the mechanisms of development of complications in patients with new coronavirus infection and obesity. Taking into account the need to restore metabolic health to increase the adaptive and resistant capacities of the body in the face of the threat of a new increase in the prevalence of COVID-19, the possibilities of treating obesity using a combined preparation containing sibutramine and metformin in one tablet, are discussed

    Dietary fiber is a reliable and apparent element of treatment for patients with type 2 diabetes mellitus and cardiovascular diseases: an easy solution to a complicated problem

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    Cardiovascular diseases are a frequent comorbid condition in patients with type 2 diabetes mellitus (t2DM). This problem tends to remain acute because of the progression of t2DM, which increases the chances of cardiovascular events. Medicine today has a range of innovative hypoglycemic drugs, which proved their safety and effectiveness towards diseases of cardiovascular system. However, high cardiovascular mortality demonstrates that the medication is not enough effective. Partly lack of success may be explained by not enough work with unmodified risk factors, such as physical activity, smoking and excessive and wrong nutrition. Studies about dietary fiber (DF) let us discuss their including in the dietary plan of patients with t2DM and cardiovascular diseases. One of the promising DF types is Cyamopsis tetragonoloba extract. It showed its effectiveness concerning carbohydrate metabolism and lipid profile, improving, metabolic features of t2DM patients and lowering the risks of cardiovascular events. What is more, the advantage of Cyamopsis tetragonoloba extract is easy to use and has no side effects

    Metabolic and cardiovascular features of the course of type 2 diabetes mellitus in men with hypogonadism

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    Introduction. Androgenic deficiency is an important pathogenetic element in the development of metabolic syndrome and cardiovascular diseases in men. It has been proven that in male patients with type 2 diabetes, hypogonadism develops much more often. Objective ā€“ to study the metabolic and cardiovascular features of the course of type 2 diabetes mellitus (T2DM) in men with androgen deficiency.Materials and methods. The study included 124 men with type 2 diabetes. To diagnose hypogonadism, the levels of total testosterone (T), sex hormone binding globulin (SHBG), albumin and luteinizing hormone (LH) were measured. Free testosterone (free T) levels were calculated using a calculator from Ghent University Hospital, Belgium. A retrospective analysis of case histories was carried out (spectrum of late complications, the presence of heart attacks and strokes, laboratory data ā€“ total cholesterol (CS), triglycerides (TG), fasting blood plasma glucose, basal insulin level, glycated hemoglobin (HbA1c)). The HOMA-IR index was used to determine the degree of insulin resistance.Results. The average age of men was 57.39 Ā± 9.41 years. The incidence of laboratory-confirmed hypogonadism is 50.81%. An average positive correlation was found between androgen deficiency and the incidence of non-fatal cardiovascular events (r = 0.45, p &lt; 0.05). There was no statistically significant relationship between the presence of hypogonadism and the incidence and degree of late complications of T2DM. Patients with low T levels tended to have higher HOMA-IR values compared to patients with normal T levels (p &lt; 0.05). At the same time, the indicators of carbohydrate and lipid metabolism did not differ significantly in these groups (p &gt; 0.05).Conclusions. The revealed incidence of hypogonadism in men with T2DM corresponds to the data of international studies. The presence of a significant correlation between low testosterone levels and cardiovascular events in patients with T2DM suggests that hypogonadism can be used as an additional criterion for cardiovascular risk. Testosterone deficiency exacerbates insulin resistance, which can lead to weight gain and impair carbohydrate metabolism

    Formation of 24Mg* in the Splitting of 28Si Nuclei by 1-GeV Protons

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    The 28Si(p, p' gamma)24Mg reaction has been studied at the ITEP accelerator by the hadron-gamma coincidence method for a proton energy of 1 GeV. Two reaction products are detected: a 1368.6-keV gamma-ray photon accompanying the transition of the 24Mg* nucleus from the first excited state to the ground state and a proton p' whose momentum is measured in a magnetic spectrometer. The measured distribution in the energy lost by the proton in interaction is attributed to five processes: the direct knockout of a nuclear alpha cluster, the knockout of four nucleons with a total charge number of 2, the formation of the DeltaSi isobaric nucleus, the formation of the Delta isobar in the interaction of the incident proton with a nuclear nucleon, and the production of a pi meson, which is at rest in the nuclear reference frame. The last process likely corresponds to the reaction of the formation of a deeply bound pion state in the 28P nucleus. Such states were previously observed only on heavy nuclei. The cross sections for the listed processes have been estimated.Comment: 14 pages, 3 figures submitted to JETP Letter

    On the Complexity of Query Result Diversification

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    Query result diversification is a bi-criteria optimization problem for ranking query results. Given a database D, a query Q and a positive integer k, it is to find a set of k tuples from Q(D) such that the tuples are as relevant as possible to the query, and at the same time, as diverse as possible to each other. Subsets of Q(D) are ranked by an objective function defined in terms of relevance and diversity. Query result diversification has found a variety of applications in databases, information retrieval and operations research. This paper studies the complexity of result diversification for relational queries. We identify three problems in connection with query result diversification, to determine whether there exists a set of k tuples that is ranked above a bound with respect to relevance and diversity, to assess the rank of a given k-element set, and to count how many k-element sets are ranked above a given bound. We study these problems for a variety of query languages and for three objective functions. We establish the upper and lower bounds of these problems, all matching, for both combined complexity and data complexity. We also investigate several special settings of these problems, identifying tractable cases. 1

    Evaluation of the Efficacy and Safety of Initial Empirical Antibiotic Therapy for Community-Acquired Pneumonia in Middle-Aged People

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    Ī²-lactam antibiotics, including cephalosporins, are the drugs of choice for empirical antibiotic therapy (ABT) in patients with community-acquired pneumonia. Unreasonable and irrational use of antibiotics leads to an increased risk of adverse reactions, contributes to the growth of antibiotic resistance.The aim of the study was to analyse data on the efficacy and safety of initial empirical ABT using cephalosporins for community-acquired pneumonia in middle-aged patients of multidisciplinary hospitals in Moscow.Materials and methods: the authors analysed 177 archived medical records of the patients admitted to three multidisciplinary hospitals (I.V. Davydovsky City Clinical Hospital, City Clinical Hospital 52 and City Clinical Hospital 4) in Moscow from 2017 to 2019 and prescribed mono- and/or combination therapy including a cephalosporin antibiotic as a starting therapy for community-acquired pneumonia. The initial ABT was considered effective if a patientā€™s body temperature normalised within 48ā€“72 h following initiation of treatment and safe if no adverse reactions developed during the period of inpatient treatment.Results: the combination of ceftriaxone and azithromycin was the most frequently prescribed ABT regimen; its effectiveness was 71.9%. Ceftriaxone monotherapy was the second in frequency of prescription; its effectiveness amounted to 77.2%. The third regimen included cefotaxime and azithromycin and was effective in 70% of cases. The patients who needed a change in initial ABT had a significantly higher incidence of developing severe community-acquired pneumonia and complications. The study results indicate that the structure of comorbidity did not affect the effectiveness of initial empirical ABT. Streptococcus pneumoniae was found to be the most common causative agent of community-acquired pneumonia in the studied population (44.8% of cases). Only 13% of the patients faced adverse reactions associated with the use of antibiotics as part of the initial empirical ABT; the most common were leukopenia and diarrhoea.Š”onclusions: the results of the study indicate the feasibility of mono- and/or combination ABT including a cephalosporin antibiotic as a starting empirical therapy for community-acquired pneumonia due to its effectiveness and favourable safety profile

    Retrospective Analysis of the Safety of Antibacterial Medicinal Products for Elderly Patients with Community-Acquired Lower Respiratory Tract Infections

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    Cephalosporins are the empirical antibiotic therapy (ABT) of choice for patients with community-acquired pneumonia (CAP). When treated with antibiotics, elderly patients, especially those with comorbidities, are at higher risk of developing adverse drug reactions (ADRs).The aim of the study was to analyse data on the safety and efficacy of initial empirical ABT with cephalosporins in elderly patients over 75 years old with CAP admitted to multidisciplinary hospitals in Moscow.Materials and methods. The retrospective study included 305 medical records of patients with CAP admitted to three multidisciplinary hospitals in Moscow in 2017ā€“2019 and prescribed initial mono- and/or combination ABT including a cephalosporin. Initial ABT was considered effective if the body temperature normalised within 48ā€“72 h from the start of treatment. It was considered safe if there were no ADRs during hospital stay.Results. Mostly, patients were prescribed ceftriaxone monotherapy or ceftriaxone and azithromycin combination therapy. These ABT regimens were effective in 69.07% and 78.10% of the cases, respectively. Patients with severe CAP needed their initial ABT adjusted significantly more often than those with non-severe CAP. The initial ABT was changed for a number of reasons, including ineffectiveness, ADRs, abscesses formed as a complication of CAP, sputum culture results enabling causal ABT, secondary hospital-acquired infections, and exacerbated chronic infections. All patients had comorbidities, and the most prevalent were arterial hypertension (83.9%), coronary heart disease (45.6%), chronic heart failure (44.9%), cerebrovascular disease (40.9%), atrial fibrillation (26.9%), diabetes mellitus (21.3%), and chronic obstructive pulmonary disease (19.0%). Initial ABT was significantly more often considered ineffective in patients with chronic heart failure and cerebrovascular disease. The most common causative agent of CAP in the study population was Streptococcus pneumoniae (31.9%). In 16% of patients, the authors identified ADRs associated with the antibiotics used as initial therapy. The most common were diarrhoea, anaemia, leucopenia, and hepatopathy. Ceftriaxone was associated with ADRs in 11% of patients.Conclusions. The study results suggest that initial mono- and/or combination ABT including a cephalosporin is effective and relatively safe; therefore, this treatment option is expedient for elderly patients with CAP. For this population, the safety of ABT may be improved through the wider use of existing markers of ADRs and the identification of new ones
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