Asymptotic analysis of MMPP/M/1 retrial queueing system with unreliable server

In this paper, we study a single-server retrial queueing system with arrival Markov Modulated Poisson Process and an exponential law of the service time on an unreliable server. If the server is idle, an arrival customer occupies it for the servicing. When the server is busy, a customer goes into the orbit and waits a random time distributed exponentially. It is assumed that the server is unreliable, so it may fail. The server’s repairing and working times are exponentially distributed. The method of asymptotic analysis is proposed to find the stationary distribution of the number of customers in the orbit. It is shown that the asymptotic probability distribution under the condition of a long delay has the Gaussian form with obtained parameters

N-acetyltransferase 2 (NAT2) Gene Polymorphisms and the Effectiveness of Infertility Treatment in Patients with Peritoneal Endometriosis

Today, infertility has become a global issue. WHO ranks it the fifth among the major diseases of those below 60 years, after alcoholism, depression, injuries and eyesight disorders. Numerous studies conducted on the problems of infertility in endometriosis still do not offer clear answers regarding the pathogenesis and mechanisms of this disease and its influences on fertility. According to the survey results, point mutations of the NAT2 gene (NAT2*5 and NAT2*6) have been identified in 75.6% of the patients with infertility problems and the peritoneal form of endometriosis, that create “slow” allelic variants, which exceed the average index in the population. The peculiarities of the NAT2 gene polymorphisms have been proven to be associated with the effectiveness of the infertility treatment of female patients with peritoneal endometriosis. In the group of non-pregnant patients, the presence of с.341Т>C, c.481C>T, c.590G>A and c.803A>G heterozygous point mutations are 73.2, 73.2, 5.4, and 62.5%, respectively. The significant difference in the comparison of the allelic polymorphism during the various stages of the endometriosis was not identified. At stage III-IV endometriosis the frequency of three and more point substitutions was significantly higher. NAT2 gene polymorphisms can find use as an additional criterion for predicting the effectiveness of the infertility treatment of patients with peritoneal endometriosis

Angiotensin II and transforming growth factor β affect cardiovascular and renal disease in patients with type 2 diabetes mellitus: benefits of dpp-4 inhibitors treatment

BACKGROUND: Diabetes mellitus type 2 (T2DM) is associated with impaired glucose metabolism and peripheral insulin resistance, which is accompanied by an high risk of cardiovascular disease (CVD) and nephropathy. Metabolic syndrome and T2DM are accompanied by renin-angiotensin system (RAS) activation, which is also associated with increased risk of CVD and kidney damage. Obesity lead to a wide range of pathophysiological changes, that stimulate cardiac fibrosis, and various fibrosis processes initiation, including activation of transforming growth factor β (TGF-β). AIMS: To determine activity of angiotensin II (Ang II) and TGF-β in patients with obesity and T2DM and their association with heart and kidney damage. MATERIALS AND METHODS: Ang II and TGF-β were identified in the peripheral blood of 66 obese patients aged 48-65 years. The first group included 21 patients with coronary heart disease (CHD) and T2DM; The second group included 22 patients with T2DM and excluded CHD; The third group – 20 patients with normal glucose metabolism and excluded CHD. RESULTS: The values of TGF-β in the 1st group (patients with CHD) were statistically lower than in the group of metabolically healthy obesity (p=0.021). Patients who received DPP-4 inhibitors had a lower Ang II level compared to patients with other hypoglycemic therapy (p=0.005). TGF-β positively correlated with glomerular filtration rate (eGFR) in all patients (r=-0.414, p=0.006). TGF-β negatively correlated with the degree of internal carotid artery stenosis in patients of the 2nd group (r=-0.42, p=0.09) and LDL-cholesterol in all patients (r=-0.426, p=0.038). CONCLUSIONS: TGF-β negatively correlated with the factors that contribute to CVD progression. TGF-β correlated with pathological angiogenesis and changes in normal cardiac geometry in obesity, T2DM and CHD. DPP-4 inhibitors can improve the cardiovascular prognosis in this group of patients by affecting Ang II level. Low levels of TGF-β were associated with higher cardiovascular risk and were commonly found in patients with more severe nephropathy

Evolutionary Relationships Between the Laccase Genes of Polyporales: Orthology-Based Classification of Laccase Isozymes and Functional Insight From Trametes hirsuta

Laccase is one of the oldest known and intensively studied fungal enzymes capable of oxidizing recalcitrant lignin-resembling phenolic compounds. It is currently well established that fungal genomes almost always contain several non-allelic copies of laccase genes (laccase multigene families); nevertheless, many aspects of laccase multigenicity, for example, their precise biological functions or evolutionary relationships, are mostly unknown. Here, we present a detailed evolutionary analysis of the sensu stricto laccase genes (CAZy – AA1_1) from fungi of the Polyporales order. The conducted analysis provides a better understanding of the Polyporales laccase multigenicity and allows for the systemization of the individual features of different laccase isozymes. In addition, we provide a comparison of the biochemical and catalytic properties of the four laccase isozymes from Trametes hirsuta and suggest their functional diversification within the multigene family

The efficacy of high-dose cabergoline treatment of prolactinomas resistant to standard doses: a clinical observation

Hyperprolactinemia (HP) is one of the most common neuroendocrine disorders. In 60% of cases, pathological HP is caused by pituitary prolactin-secreting adenoma. Therapy with agonists of dopamine type 2 receptors (D2 receptor agonists) is a method of choice for the treatment of pathological HP which allows to achieve prolactin normalization and reduction of pituitary adenoma in most cases. However, 15-20% of patients are resistant to D2 receptor agonists, and the question of overcoming this resistance is highly relevant. Different approaches are considered to solve this problem, one - is to increase the dose of D2 receptor agonists up to the maximally tolerated. In this article, we present a clinical observation of a patient with a partial resistance to D2 receptor agonists who demonstrated a good response to treatment with high doses of cabergoline

Особенности естественного возобновления в сосново-липовых и лиственнично-липовых насаждениях города Москвы

Problems of natural renewal of tree species (pine-linden and larch-linden stands) were studied in the territory of Forest experimental station, Moscow Timiryazev Agricultural Academy. Natural regeneration of tree species is one of the most urgent problems of forestry and forest park management in urban areas. Reforestation refers to complex natural processes that affect all components of biogeocenoses. The purpose of the research was to study natural regeneration in mixed stands in Moscow. Methods and results of field surveys of forest stands in permanent trial plots were described. The forest stands of permanent trial plots are mature and overmature, therefore at present there is a loss of large-sized pine and larch trees. Due to greater durability, larch falls off more slowly compared to pine. Further growth of pine-linden and larch-linden plantations depends on quantity and quality of undergrowth, its viability and growing conditions. In Forest experimental station, natural renewal prevails, represented mainly by the following species: maple and linden. Saplings of pine, larch, oak, and birch appear on some permanent test plots, but soon die due to unfavorable conditions. Oak undergrowth is also unreliable due to powdery mildew infection. The greatest loss of growth occurs in unfavorable growing conditions due to increased recreational loads.Рассмотрены проблемы естественного возобновления древесных пород на примере сосново-­липовых и лиственнично-­липовых насаждений Лесной опытной дачи Тимирязевской сельскохозяйственной академии. Естественное возобновление древесных пород — одна из актуальнейших проблем ведения лесного и лесопаркового хозяйства на урбанизированных территориях. Лесовосстановление относится к сложным природным процессам, оказывающим влияние на все компоненты биогеоценозов. Цель исследования — изучение естественного возобновления в смешанных насаждениях в условиях Москвы. Описаны методы и результаты полевых обследований лесных насаждений постоянных пробных площадей. Древостои постоянных пробных площадей относятся к спелым и перестойным, поэтому в настоящее время наблюдается отпад крупномерных деревьев сосны и лиственницы. Ввиду большей долговечности лиственница отпадает медленнее по сравнению с сосной. Дальнейшая динамика сосново-­липовых и лиственнично-­липовых насаждений зависит от количества и качества подроста, а также показателей его жизнеспособности и условий произрастания. В Лесной опытной даче преобладает естественное возобновление, представленное, главным образом, следующими породами: кленом и липой. Всходы сосны, лиственницы, дуба, березы появляются на некоторых постоянных пробных площадях, но вскоре погибают из-за неблагоприятных условий. Подрост дуба также является неблагонадежным из-за поражения мучнистой росой. Наибольшие потери прироста подроста по высоте происходят в неблагоприятных условиях произрастания, в результате утраты жизнеспособности из-за повышенных рекреационных нагрузок

Opisthorchis felineus infection, risks, and morbidity in rural Western Siberia, Russian Federation

The liver fluke, Opisthorchis felineus, is widely distributed throughout Europe and large parts of the Russian Federation. In Western Siberia, information about opisthorchiasis is lacking although infection may lead to severe liver and bile duct diseases. We aimed to assess the current prevalence of O. felineus infection along with associated risk factors and morbidity in rural Western Siberia.; We conducted a community-based, cross-sectional study in the rural Shegarskiy district, Tomsk Oblast, Russian Federation. All household members (≥ 7 years) present on the survey day were enrolled (n = 600). Two stool samples per person were examined for helminth eggs, using PARASEP (DiaSys Ltd, UK). The number of eggs per gram (EPG) of feces was recorded. Each study participant was interviewed to determine risk factors, using a pre-tested questionnaire. An abdominal ultrasonography examination of liver and bile ducts was performed with a mobile, high resolution ultrasound device. In total, 488 persons completed assessments (two stool samples, completed questionnaires); of those, 436 individuals had an ultrasonography (US) examination.; We observed a prevalence of O. felineus infection of 60.2%. Significant risk factors for infection were the consumption of river fish (odds ratio from adjusted analysis [aOR] 2.4, 95% CI 1.52-3.95, p<0.001), particularly stock fish (OR from multivariable analysis [mOR] 3.2, 95% CI 2.63-3.80, p<0.001), smoked fish (mOR 1.5, 95% CI 1.24-1.72, p<0.001), frozen fish (mOR 1.6, 95% CI 1.29-2.02, p<0.001), and raw fish (mOR 1.4, 95% CI 1.05-1.84, p = 0.02); and fishing activities (mOR 1.2, 95% CI 1.03-1.43, p = 0.019). Women had a higher risk of infection than men. Infection was associated positively with age and negatively with socio-economic status. The respondents' general awareness of opisthorchiasis was quite high (93.2%), but their knowledge about infection transmission and prevention was insufficient. Children aged 7-18 years old had a lower level of awareness compared to adults. The abdominal ultrasonography results demonstrated a strong association between O. felineus infection and gallbladder stones (mOR 2.8, 95% CI 1.33-6.04, p = 0.007) and periductal fibrosis of intrahepatic bile ducts (mOR 1.9, 95% CI 1.08-3.46, p = 0.026).; O. felineus infection is highly prevalent in rural regions of Western Siberia, and associated with severe hepatobiliary pathology. Identified risk factors will be used to develop a comprehensive targeted O. felineus infection control program

Environmental aspects of molecular composition of humic acids isolated from lake sediments of a permafrost-affected area of the Arctic

Humic substances are ubiquitous in terrestrial and aquatic ecosystems. Humic acids (HAs) actively interact with organic and inorganic components of lake sediments. This interaction depends on the molecular structure and elemental composition of HAs. The presented research focuses on the investigation of the composition and molecular structure of humic acids isolated from lakes located in the Lena Delta in the Russian Arctic. The findings of the research are needed to estimate the potential capacity of humic acids to bind microelements, particularly toxic metals, in stable compounds. Surface sediment samples (0–10 cm) were collected from 8 lakes by Van Veen grab during the summer period of the “Expedition LENA 2019”. We analyzed elemental composition of the HAs samples. The results showed that the studied HAs of lake sediments are characterized by low nitrogen content and prevalence of aliphatic fragments in their molecular structure. Furthermore, it was found that the studied humic acids are less mature, showing mineralization processes dominant over humification, and have relatively low potential to complexation compared with soils of the Lena Delta as well as lake sediments of territories with more boreal climate conditions