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Aim: to assess the prevalence of V617F somatic mutation of the JAK2 gene in pregnant women.Materials and methods. This non-interventional study was performed in the framework of routine clinical practice and included 1532 samples of venous blood from pregnant women who applied for medical assistance at Krasnoyarsk Regional Clinical Center for Maternal and Child Welfare. We used blood samples left after all routine laboratory tests had been done. These leftovers were pooled in the way that ensured an equal ratio of nucleated cells. Each pool contained 7 separate blood samples. The unused samples that remained after the pooling were frozen and stored at –20°C until the end of entire testing procedure. The V617F JAK2 mutation was detected by the real-time allele-specific polymerase chain reaction test.Results. Among the examined pregnant women, 6 (0.4 %) were identified as carriers of V617F JAK2 mutation. Three women with this mutation suffered from infertility for 4, 5, and 10 years; two of them had repeated miscarriages in the first trimester of pregnancy. The 6 women – carriers of this mutations had no concomitant genetic polymorphisms typical of thrombophilia (factors FII, FV), and no abnormal coagulation characteristics. Analysis of their medical records showed that in the past, two of these women had gestational hypertension, one developed a clinical picture of preeclampsia, and another one (with the maximum presence of the mutant allele) had a history of acute lymphoblastic leukemia followed by stable remission.Conclusion. The routine laboratory detection of the V617F JAK2 mutation can facilitate timely identification of the increased risk of pregnancy pathology, as well as timely diagnosis of hematological cancer.

The JAK2 V617F somatic mutation is one of the most frequent markers of CHIP (clonal hematopoiesis of indeterminate potential). CHIP is characterized by the presence of a myeloid cells clone in peripheral blood in the absence of the sufficient reasons to diagnose the hematologic disease. The CHIP is proposed as a potential independent risk factor for vascular pathology. The aim of this study is to identify carriers of JAK2 V617F mutation among patients admitted for planned hospitalization at the Federal Center of Cardiovascular Surgery of Krasnoyarsk. Materials and methods. The study included 930 venous blood samples. JAK2 V617F mutation was detected by using the allele - specific real time polymerase chain reaction. Results. JAK2 V617F mutation was detected in 15 (1.6%) patients, but only two of them had blood cell count that could cause a hematological disease to be suspected. Conclusion. The inclusion of the JAK2 V617F mutation detection in the complex of laboratory tests of the cardiovascular patients can facilitate the timely identification of patients with increased thrombotic risk, as well as the timely diagnosis of myeloproliferative diseases.

Glasses of the 6Na2O-(24-х)B2O3-70SiO2-хFe2O3 system with x ranging from 2 to 10 mol % are studied by dilatometry and X-ray powder diffractometry. The density of the glass is measured and the molar volume is calculated. The heat treatment of the glass is carried out at 550 and 700°C for 96 and 2 h, respectively. Magnetite is formed in the heat-treated glasses and its content increases with the growth of the Fe2O3 concentration. In the glasses containing from 4 to 8 mol. % of Fe2O3, cristobalite is formed after treatment at 700°C for 2 h. An increase in the density and the glass transition temperature and a decrease in the molar volume is observed with the growth of the iron oxide content. [ABSTRACT FROM AUTHOR]

Methanotrophs are aerobic to micro-aerophilic bacteria, which oxidize and utilize methane, the second most important greenhouse gas. The community structure of the methanotrophs in rice fields worldwide has been studied mainly using culture-independent methods. Very few studies have focused on culturing methanotrophs from rice fields. We developed a unique method for the cultivation of methanotrophs from rice field samples. Here, we used a modified dilute nitrate mineral salts (dNMS) medium, with two cycles of dilution till extinction series cultivation with prolonged incubation time, and used agarose in the solid medium. The cultivation approach resulted in the isolation of methanotrophs from seven genera from the three major groups: Type Ia (Methylomonas , Methylomicrobium , and Methylocucumis), Type Ib (Methylocaldum and Methylomagnum), and Type II (Methylocystis and Methylosinus). Growth was obtained till 10–6–10–8 dilutions in the first dilution series, indicating the culturing of dominant methanotrophs. Our study was supported by 16S rRNA gene-based next-generation sequencing (NGS) of three of the rice samples. Our analyses and comparison with the global scenario suggested that the cultured members represented the major detected taxa. Strain RS1, representing a putative novel species of Methylomicrobium , was cultured; and the draft genome sequence was obtained. Genome analysis indicated that RS1 represented a new putative Methylomicrobium species. Methylomicrobium has been detected globally in rice fields as a dominant genus, although no Methylomicrobium strains have been isolated from rice fields worldwide. Ours is one of the first extensive studies on cultured methanotrophs from Indian rice fields focusing on the tropical region, and a unique method was developed. A total of 29 strains were obtained, which could be used as models for studying methane mitigation from rice fields and for environmental and biotechnological applications. [ABSTRACT FROM AUTHOR]

In this paper, we consider a service system facing several classes of customers in which the arrival rate and service time depend on the workload in the system, while the chance of return is a function of the service time. We first model the problem as a multiclass multiserver queueing network and investigate its stability by examining the conditions under which the Markov chain representing the network is positive recurrent. We then examine the impact of the relationship among the workload, service time, arrival rate, and the chance of return on the dynamics of the system using a fluid approach. We first characterize all equilibria of the system and show that the system may shift between several equilibrium states. We establish that all equilibria can be easily determined and demonstrate conditions under which an equilibrium is stable. We then prove that, surprisingly, the stability of an equilibrium and the congestion in the system may depend on the amount of time a customer spends outside of the system before returning for rework. However, we show that if the relationship between the workload and service time in a system facing a single class of customers is nondecreasing, the long‐run behavior of the system is not affected by how long it takes until a customer returns. [ABSTRACT FROM AUTHOR]

We extend the general stochastic matching model on graphs introduced in Mairesse and Moyal (2016), to matching models on multigraphs, that is, graphs with self-loops. The evolution of the model can be described by a discrete time Markov chain whose positive recurrence is investigated. Necessary and sufficient stability conditions are provided, together with the explicit form of the stationary probability in the case where the matching policy is 'First Come, First Matched'. [ABSTRACT FROM AUTHOR]

Glasses of the 6Na2O · хB2O3 · (86 – x)SiO2 · 8Fe2O3 compositions, where x varies from 16 to 31 mol %, are studied by X-ray powder diffractometry and dilatometry. The glasses were preliminarily held at a temperature of 550°C for 8–144 h. It is determined that there are crystalline phases of magnetite and hematite in the studied glasses in addition to the amorphous component. The hematite content gradually decreases as the amount of SiO2 increases and it completely disappears when the SiO2 concentration is higher than 65 mol %. As the duration of the heat treatment increases, the amount of magnetite does not change. At the maximum duration of the heat treatment (144 h), crystallization of the silica phases—tridymite and cristobalite—is observed for all the studied glasses. The stability of the glass transition temperature of all glasses with an increase of the duration of the heat treatment indicates that the coexisting phases of phase-separated glass reach their equilibrium compositions after 8 hours. The crystallization of silica in the glasses is accompanied by a decrease in the glass transition temperature of the low-viscosity phase. [ABSTRACT FROM AUTHOR]

Background. The role of methane in global warming has become paramount to the environment and the human society, especially in the past few decades. Methane cycling microbial communities play an important role in the global methane cycle, which is why the characterization of these communities is critical to understand and manipulate their behavior. Methanotrophs are a major player in these communities and are able to oxidize methane as their primary carbon source. Results. Lake Washington is a freshwater lake characterized by a methane-oxygen countergradient that contains a methane cycling microbial community. Methanotrophs are a major part of this community involved in assimilating methane from lake water. Two significant methanotrophic species in this community are Methylobacter and Methylomonas. In this work, these methanotrophs are computationally studied via developing highly curated genome-scale metabolic models. Each model was then integrated to form a community model with a multi-level optimization framework. The competitive and mutualistic metabolic interactions among Methylobacter and Methylomonas were also characterized. The community model was next tested under carbon, oxygen, and nitrogen limited conditions in addition to a nutrient-rich condition to observe the systematic shifts in the internal metabolic pathways and extracellular metabolite exchanges. Each condition showed variations in the methane oxidation pathway, pyruvate metabolism, and the TCA cycle as well as the excretion of formaldehyde and carbon di-oxide in the community. Finally, the community model was simulated under fixed ratios of these two members to reflect the opposing behavior in the two-member synthetic community and in sediment-incubated communities. The community simulations predicted a noticeable switch in intracellular carbon metabolism and formaldehyde transfer between community members in sediment- incubated vs. synthetic condition. Conclusion. In this work, we attempted to predict the response of a simplified methane cycling microbial community from Lake Washington to varying environments and also provide an insight into the difference of dynamics in sediment-incubated microcosm community and synthetic co-cultures. Overall, this study lays the ground for in silico systems-level studies of freshwater lake ecosystems, which can drive future efforts of understanding, engineering, and modifying these communities for dealing with global warming issues. [ABSTRACT FROM AUTHOR]

Glasses in the Na2O-B2O3-SiO2-Fe2O3 system with a constant SiO2 content 70 mol% were synthesized using conventional melting in platinum crucibles in SiC-furnace in air. After synthesis and annealing, glasses were heat treated at 550°C for 96-144 hrs to promote phase separation. A tentative region of phase separation for this temperature was outlined. X-ray powder diffractometry results showed three iron-containing phases (Fe3O4, FeSiO3 and β-Fe2O3) forming in the investigated glasses with magnetite being the main phase as it is observed in most of the glasses. Chemical durability studies showed that compositions of phase-separated glasses suitable for synthesis of porous glasses, both iron-free and iron-containing lie in between 4 and 8 mol% of Na2O. Bulk samples of porous glasses were obtained within the chosen region having the following parameters: specific surface area 40-185 m2/g, porosity 30%-45%, pore diameter 3-14 nm. The parameters of porous structure of iron-containing porous glasses are of the same order of magnitude as the porous glass used for the multiferroic nanocomposite synthesis. [ABSTRACT FROM AUTHOR]

Abstract—The influence of exposure to mobile phone radiation on in vitro platelet aggregation has been studied. It has been shown that a 30-min exposure of blood samples to mobile phone radio frequency waves increases ADP-induced platelet aggregation in groups of healthy volunteers and patients with stroke, whereas platelet aggregation in JAKV617F-positive patients with polycythemia vera is significantly suppressed and is eventually completely inhibited. The mechanisms that underlie this phenomenon may be associated with cell oxidative stress and anomalies the JAK2 signal transduction pathway in malignized blood cells. The results indicate that it is important to set safety standards for the use of mobile devices by patients with various diseases. [ABSTRACT FROM AUTHOR]

Many-server queuing networks with general service and abandonment times have proven to be a realistic model for scenarios such as call centers and health-care systems. The presence of abandonment makes analytical treatment difficult for general topologies. Hence, such networks are usually studied by means of fluid limits. The current state of the art, however, suffers from two drawbacks. First, convergence to a fluid limit has been established only for the transient, but not for the steady state regime. Second, in the case of general distributed service and abandonment times, convergence to a fluid limit has been either established only for a single queue, or has been given by means of a system of coupled integral equations which does not allow for a numerical solution. By making the mild assumption of Coxian-distributed service and abandonment times, in this paper we address both drawbacks by establishing convergence in probability to a system of coupled ordinary differential equations (ODEs) using the theory of Kurtz. The presence of abandonments leads in many cases to ODE systems with a global attractor, which is known to be a sufficient condition for the fluid and the stochastic steady state to coincide in the limiting regime. The fact that our ODE systems are piecewise affine enables a computational method for establishing the presence of a global attractor, based on a solution of a system of linear matrix inequalities. [ABSTRACT FROM AUTHOR]

Personal health record (PHR) systems offer a technology for personal health information management (PHIM) activities. Despite efforts to increase the use of PHR systems as a mechanism to support better patient-centered care and improve information management across the continuum of care, PHR adoption remains low. The purpose of this study was to explore how to design a PHR system that can adequately support personal health information management activities. Using a mixed-methods approach (questionnaires and interviews), we identified the factors affecting a person’s intention to use PHRs and also described the personal health information management activities among people from a wide age range in the United States. Results indicated that the intention to use PHR systems was affected by system-related factors, such as perceived usefulness, health information understandability, personalization, and patient–clinician communication support, and user-related factors, such as social influence, self-efficacy, and willingness to share. Furthermore, five types of personal health information management activities were found, including storage, organization, maintenance, retrieval, and sharing. Informed by the study findings, we developed seven design recommendations to improve PHR systems. Future studies can focus on further validating these findings using other methods and be based on larger and more representative PHR users. [ABSTRACT FROM AUTHOR]

In this paper, we generalize the Gaussian Variance Approximation (GVA), developed by Massey and Pender [16], to Jackson networks with abandonment. We approximate the queue length process with a multivariate Gaussian distribution and thus, we are able to estimate the mean and covariance matrix of the entire network with more accuracy than the associated fluid and diffusion limits of Mandelbaum, Massey, and Reiman [14]. We also show how the GVA method can be used to construct staffing schedules that approximately stabilize salient performance measures such as the probability of delay and the abandonment probabilities for the entire network. Unlike the work of Feldman et al. [5] which uses Monte Carlo simulation to stabilize the delay probabilities, our method does not require simulation and only requires the numerical integration of ${1 \over 2}(N^2 + 3N)$ differential equations for an N-dimensional network, which is more computationally efficient. Lastly, to confirm our approximations are accurate, we perform several numerical experiments for a wide range of parameter settings. [ABSTRACT FROM AUTHOR]

Glasses with the (8- x)NaO · xFeO ∙ 22BO ∙ 70SiO compositions, where the FeO content varies from 2 to 6 mol %, which were heat-treated at the temperatures of 550 and 700°С for 144 and 2 h, respectively, have been studied by dilatometry, electron microscopy, and X-ray powder diffractometry. It has been shown that, with an increase in the total concentration of FeO in the glass, there is a trend to the transition from an interconnected to a droplet-matrix phase-separated structure. The crystal line phases of FeO, FeSiO, and β-FeO are formed depending on composition, while the latter is observed only in the glass with the equivalent contents of NaO and FeO. There is a minimum on the glass transition temperature dependence of the composition at equimolar (4 mol %) contents of NaO and FeO. [ABSTRACT FROM AUTHOR]

The article discusses study focusing on the prevalence of the 46/1 haplotype (HT) in myeloproliferative neoplasms (MPN) patients with different Janus kinase 2 (JAK2V617F) allele burden. Topics discussed include the low JAK2V617F allele burden in people with no hematological disease manifestations, the extraction and evaluation on genomic DNA in the study, and the assessment of the sensitivity of mutant allele detection in the study.

The aim of this review was to elucidate the role of copper and iron in regulating methane (CH4) oxidation and subsequent biopolymer (i.e. polyhydroxyalkanoate [PHA]) accumulation in methanotrophic bacteria. Specifically, the review emphasizes the 'copper switch mechanism' that alters CH4 oxidizing enzyme activities, that is soluble- and particulate methane monooxygenases, in type II methanotrophic bacteria. Both copper and iron are essential nutrients and reports demonstrate that addition of either can improve PHA accumulation. However, based on analyses of available data, a major knowledge gap regarding a clear understanding of the interactive effects in regulating methane monooxygenase enzyme activities/gene expressions was identified in this review. [ABSTRACT FROM AUTHOR]

Soil-based wastewater treatment systems, or leachfields, rely on microbial processes for improving the quality of wastewater before it reaches the groundwater. These processes are affected by physicochemical system properties, such as O2 availability, and disturbances, such as the presence of antimicrobial compounds in wastewater. We examined the microbial community structure of leachfield mesocosms containing native soil and receiving domestic wastewater under intermittently-aerated (AIR) and unaerated (LEACH) conditions before and after dosing with tetracycline (TET). Community structure was assessed using phospholipid fatty acid analysis (PLFA), analysis of dominant phylotypes using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and cloning and sequencing of 16S rRNA genes. Prior to dosing, the same PLFA biomarkers were found in soil from AIR and LEACH treatments, although AIR soil had a larger active microbial population and higher concentrations for nine of 32 PLFA markers found. AIR soil also had a larger number of dominant phylotypes, most of them unique to this treatment. Dosing of mesocosms with TET had a more marked effect on AIR than LEACH soil, reducing the size of the microbial population and the number and concentration of PLFA markers. Dominant phylotypes decreased by ∼15% in response to TET in both treatments, although the AIR treatment retained a higher number of AIR and LEACH soil, and fewer than 25% of the clones from either treatment were homologous with isolates of known genus and species. These included human pathogens, as well as bacteria involved in biogeochemical transformations of C, N, S and metals, and biodegradation of various organic contaminants. Our results show that intermittent aeration has a marked effect on the size and structure of the microbial community that develops in a native leachfield soil. In addition, there is a differential response of the microbial communities of AIR and LEACH soil to tetracycline addition which may be linked to changes in function. [ABSTRACT FROM AUTHOR]