The study This study is devoted to various methods for solving systems of linear algebraic equations built on a diagnostic matrix of parameters of an aeroengine gas-air path. Exact, iterative and ...optimization methods for solving SLAE for the performed problem were considered. Calculations were made according to various algorithms using object-oriented programming language Python (v3.6.9), proprietary multi-paradigm programming language MATLAB 2018b and computer-aided design system PTC MathCAD Prime 8.0.0.0. a mathematical analysis of the matrix under study was performed. Estimates of the above methods effectiveness were made on the average error basis. The results were analyzed and promising methods for solving the problem were identified.
Parkinsons disease is an important medico-social problem worldwide, with a lot of attention paid to preclinical studies to assess the efficacy of new treatments, including cell therapy. Study ...objective. To assess the migratory ability of multipotent mesenchymal stromal cells (MMSC) using different methods of administration in an experimental model of Parkinsons disease in laboratory rats. Materials and methods. MMSC, stained with the PKH26 fluorescent dye, were systemically (intravenously) or locally (intranasally and intrathecally) administered to experimental animals with rotenone-induced Parkinsons disease. The migratory ability of MMSC was assessed on days 1 and 21 after administration, using immunofluorescence microscopy. Results. The migratory ability of MMSC after both systemic and local administration was more pronounced in the animal group with the experimental model of Parkinsons disease compared with the control group. It was characterized by maximum accumulation of cells in the brain on the first day after administration, with viability preserved in the area of neuronal inflammation throughout 21 days. Conclusion. Local administration (intranasal and intrathecal) leads to faster accumulation of MMSC in the brain of both the animals with the experimental model of Parkinsons disease and healthy rats. Intravenous administration of cell cultures also helps to reveal the migratory properties of MMSC and can form the basis for planning further studies of cell therapy in Parkinsons disease.
The huge resources of natural gas trapped in hydrate form are widely distributed worldwide in permafrost and offshore sediments. Pressure reduction and thermal stimulation have been dominating the ...research into production methods over the latest decades. More recently, a novel approach has emerged based on conversion of in situ methane hydrate to carbon dioxide-dominated hydrate through injection of carbon dioxide. This work applied the free energy analysis to determine whether addition of nitrogen into the injection mixture would result in a win-win situation of simultaneous methane production and safe long term storage of CO2. Our evaluation of data from two permafrost and two offshore fields indicates that injection of carbon dioxide at concentrations exceeding 50 mol % and pressures ranging between 9 and 25 MPa will result in formation of new carbon dioxide-dominated hydrate for all of these fields. While only reservoir simulations implementing reliable thermodynamic models can verify whether given injection will result in substantial storage of carbon dioxide in the form of hydrate, thermodynamic models developed in this work have their own significance. Pressure and temperature dependencies of hydrate stability have frequently been reported in studies of hydrates in sediments as the only criteria. Extending these criteria to include the concentration dependency will make it possible to implement an efficient free energy minimization scheme able to probe local phase distributions. Since one of four hydrate reservoirs used in our thermodynamic analysis is located in Alaska, we have also investigated the upper limit of water that can be tolerated during transport under extreme conditions prevailing the winter seasons in this region. It was found that hydrate formation triggered by water adsorbing on rusty surfaces will dominate the tolerance limit, which will correspond to practically zero water concentration.
•Injection of CO2 into CH4 hydrate for simultaneous energy production and CO2 storage.•Addition of N2 to the CO2 limits formation of new hydrate for injection gas.•CO2/CH4 swapping kinetics is sensitive to amounts of N2 in injection gas.•Thermodynamic limitations due to N2 depends on specific hydrate reservoir characteristics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The associations of the β-adducin C1797T polymorphism with blood pressure (BP) and various indexes of sodium homeostasis were investigated in 388 men and 456 women, aged 18 to 60 years, recruited ...from three European populations (Cracow, Poland, n = 300; Novosibirsk, Russian Federation, n = 274; Mirano, Italy; n = 270). Phenotypes included 24-h ambulatory BP and urinary excretion of electrolytes and aldosterone. Subjects were genotyped for the β-adducin polymorphism. Both a population-based association study and a family-based analysis were performed. Urinary sodium excretion was higher in Cracow than in Mirano (241 v 185 mmol/24 h, P < .05) and intermediate in Novosibirsk (206 mmol/24 h). The β-adducin T allele (15.2% v 9.1%, P < .0001) was more prevalent in Mirano than in the two Slavic centers. In both population-based and family-based association analyses, there was significant heterogeneity between Slavic and Italian subjects in the phenotype–genotype relationships with β-adducin. In the Slavic centers, 24-h systolic BP was higher in T allele carriers than in CC homozygotes (122.3 v 119.7 mm Hg, P = .03), whereas this was not the case in Mirano (121.8 v 122.9 mm Hg, P = .42). In Slavic (212.6 v 233.1 mmol/24 h) as well as in Italian (166.1 v 191.5 mmol/24 h) participants, 24-h sodium excretion was lower (P = .01) in T allele carriers than in CC homozygotes. These results were confirmed in the family-based analysis of offspring using a quantitative transmission disequilibrium test. In conclusion, the frequency of the β-adducin T allele and salt intake differ across European populations. Thus, both variation in genetic background and salt intake may explain the observed heterogeneity in the phenotype–genotype relationships. Genetic determinants of complex quantitative traits such as BP can only be investigated within their epidemiologic context.
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GEOZS, IJS, NUK, OILJ, PNG, SBCE, UL, UM, UPUK
BACKGROUNDAdducin is a membrane skeleton protein consisting of α- and β- or α- and γ-subunits. Mutations in α- and β-adducin are associated with hypertension. In the European Project on Genes in ...Hypertension, we investigated whether polymorphisms in the genes encoding α-adducin (Gly460Trp), β-adducin (C1797T) and γ-adducin (A386G), alone or in combination, affected pulse pressure (PP), an index of vascular stiffness.
METHODSWe measured peripheral and central PP by conventional sphygmomanometry and applanation tonometry, respectively. We randomly recruited 642 subjects (162 nuclear families and 70 unrelated individuals) from three European populations. In multivariate analyses, we used generalized estimating equations and the quantitative transmission disequilibrium test.
RESULTSPeripheral and central PP averaged 46.1 and 32.6 mmHg, respectively. Among carriers of the α-adducin Trp allele, peripheral and central PP were 5.8 and 4.7 mmHg higher in γ-adducin GG homozygotes than in their AA counterparts, due to an increase in systolic pressure. γ-Adducin GG homozygosity was associated with lower urinary Na/K ratio among α-adducin Trp allele carriers and with higher urinary aldosterone excretion among α-adducin GlyGly homozygotes. Sensitivity analyses in founders and offspring separately, and tests based on the transmission of the γ-adducin G allele across families, confirmed the interaction between the α- and γ-adducin genes.
CONCLUSIONSIn α-adducin Trp allele carriers, peripheral and central PP increased with the γ-adducin G allele. This epistatic interaction is physiologically consistent with the heterodimeric structure of the protein and its influence on transmembranous sodium transport.
Hypertension is a chronic age-related disorder, affecting nearly 20% of all adult Europeans. This disease entails debilitating cardiovascular complications and is the leading cause for drug ...prescriptions in Europeans older than 50 years. Intensive research over the past two decades has so far failed to identify common genetic polymorphisms with a major impact on blood pressure or associated cardiovascular phenotypes, suggesting that multiple genes each with a minor impact, along with gene-gene and gene-environment interactions, play a role. The European Project on Genes in Hypertension (EPOGH) is a large-scale, family-based study in which participants from seven different populations were phenotyped and genotyped according to standardized procedures. This review article summarizes the initial 5-year findings and puts these observations into perspective against other published studies. The EPOGH demonstrated that phenotype-genotype relations strongly depend on host factors such as gender and lifestyle, in particular salt intake as reflected by the 24-h urinary excretion of sodium. The EPOGH therefore highlights the concept that phenotype-genotype relations can only be studied within a defined ecogenetic context.
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