SWOT analysis of the Yandex distance learning system. Textbook

В статье на основе SWOT-анализа проанализированы факторы, определяющие внутреннюю и внешнюю среду функционирования образовательного сервиса.The article analyzes the factors that determine the internal and external environment of the educational service functioning on the basis of SWOT analysis

Kinetics of the urea–urease clock reaction with urease immobilized in hydrogel beads

Feedback driven by enzyme catalyzed reactions occurs widely in biology and has been well characterized in single celled organisms such as yeast. There are still few examples of robust enzyme oscillators in vitro that might be used to study nonlinear dynamical behavior. One of the simplest is the urea–urease reaction that displays autocatalysis driven by the increase in pH accompanying the production of ammonia. A clock reaction was obtained from low to high pH in batch reactor and bistability and oscillations were reported in a continuous flow rector. However, the oscillations were found to be irreproducible and one contributing factor may be the lack of stability of the enzyme in solution at room temperature. Here, we investigated the effect of immobilizing urease in thiol-poly(ethylene glycol) acrylate (PEGDA) hydrogel beads, prepared using emulsion polymerization, on the urea–urease reaction. The resultant mm-sized beads were found to reproduce the pH clock and, under the conditions employed here, the stability of the enzyme was increased from hours to days

Spacial and temporal dynamics of the volume fraction of the colloidal particles inside a drying sessile drop

Using lubrication theory, drying processes of sessile colloidal droplets on a solid substrate are studied. A simple model is proposed to describe temporal dynamics both the shape of the drop and the volume fraction of the colloidal particles inside the drop. The concentration dependence of the viscosity is taken into account. It is shown that the final shapes of the drops depend on both the initial volume fraction of the colloidal particles and the capillary number. The results of our simulations are in a reasonable agreement with the published experimental data. The computations for the drops of aqueous solution of human serum albumin (HSA) are presented.Comment: Submitted to EPJE, 7 pages, 8 figure

TEMPERATURE PROPERTIES OF A-KERATINE: EPR-RESEARCH

This scientific research is devoted to the study a wide signal of powder a-keratin. A comparative analysis of the temperature dependence of the hair and powder extracted from it has been held. The integral intensities of these samples have similar behavior. They are characterized by the presence of a maximum and can be described by the Curie. Consequently, the EPR centers that contribute to the wide component of the spectrum have the same origin and are associated with the protein structure

Polymorphism in the TRP8 gene in Kyrgyz population: putative association with highland adaptation

The human TRPM8 gene encodes a receptor mediating cold sensitivity, and this fact points to its putative role in cold adaptation. The structural variability of the TRPM8 gene for five single-nucleotide polymorphisms (SNPs) has been studied in Kyrgyz population. The SNPs are located in coding regions of the gene, and three of them are confined to a segment of 20 bp in exon 7. The frequencies of minor SNP alleles are: rs13004520 G/C = 0.06; rs28901637 А/Т = 0.13; rs11562975 G/C = 0.27; rs7593557 G/A = 0.21; rs11563071 С/G = 0.12. The analyzed sample of Kyrgyz population includes 275 individuals living at different altitudes and under drastically different climatic conditions. The frequency of the minor rs11562975 allele in highlanders (living above 2 800 m A. S. L.) is one-third lower than in residents of lower regions (760–2 800 m A. S. L.; p < 0.01). This result presumes a selective role of rs11562975 in cold adaptation. Comparison of haplotype frequencies in Kyrgyz people with Europeans, East Asians, and Africans shows a clear narrowing of genotype variation in Europeans in comparison to all others. Probably, this phenomenon is related to a population size decline (bottleneck effect) during the evolution. We consider the exon– intron structure of the TRPM8 gene. Epigenetic markers in the vicinity of the gene have been analyzed. Two strong binding sites for insulator ctcf proteins are present there. They are likely to be associated with chromatin conformation and alternative splicing regulation. A structure–functional characterization of genes for the TRP protein family is provided

Fibroblast growth factor 23 is associated with proteinuria and smoking in chronic kidney disease: An analysis of the MASTERPLAN cohort

Contains fulltext : 107913.pdf (postprint version ) (Open Access)BACKGROUND: Fibroblast growth factor 23 (FGF23) has emerged as a risk factor for cardiovascular disease and mortality throughout all stages of chronic kidney disease (CKD), independent from established risk factors and markers of mineral homeostasis. The relation of FGF23 with other renal and non-renal cardiovascular risk factors is not well established. METHODS: Using stored samples, plasma FGF23 was determined in 604 patients with moderate to severe kidney disease that participated in the MASTERPLAN study (ISRCTN73187232). The association of FGF23 with demographic and clinical parameters was evaluated using multivariable regression models. RESULTS: Mean age in the study population was 60 years and eGFR was 37 (+/- 14) ml/min/1.73 m(2). Median proteinuria was 0.3 g/24 hours [IQR 0.1-0.9]. FGF23 level was 116 RU/ml [67-203] median and IQR. Using multivariable analysis the natural logarithm of FGF23 was positively associated with history of cardiovascular disease (B = 0.224 RU/ml; p = 0.002), presence of diabetes (B = 0.159 RU/ml; p = 0.035), smoking (B = 0.313 RU/ml; p < 0.001), phosphate level (B = 0.297 per mmol/l; p = 0.0024), lnPTH (B = 0.244 per pmol/l; p < 0.001) and proteinuria (B = 0.064 per gram/24 hrs; p = 0.002) and negatively associated with eGFR (B = -0.022 per ml/min/1.73 m(2); p < 0.001). CONCLUSIONS: Our study demonstrates that in patients with CKD, FGF23 is related to proteinuria and smoking. We confirm the relation between FGF23 and other cardiovascular risk factors

Relationship of depressive disorders with hypertension, its control and other metabolic risk factors in the Tyumen Oblast population of men and women. Data from the study “Epidemiology of Cardiovascular Diseases and their Risk Factors in Regions of Russian Federation” (ESSE-RF)

Aim. To study the association between depression and metabolic cardiovascular risk factors, hypertension (HTN) and its control in a random sample of Tyumen Oblast population of men and women aged 25-64 years.Material and methods. The study object was a random sample of the population of the Tyumen and the Tyumen Oblast aged 25-64 years, examined as part of the ESSE-RF epidemiological study. The study included 1658 participants. Among them, 30,3% (n=503) were men, while 69,7% (n=1155) — women. Mean age was 48,9±11,4 years. The prevalence of metabolic risk factors (hyperlipidemia, carbohydrate metabolism disorder, obesity), hypertension and the likelihood of its control in men and women with different levels of depressive disorders diagnosed using the HADS scale were assessed.Results. Compared with participants without depression, persons with psychological disorders were significantly more likely to have HTN (55,5% vs 47,6%, p&lt;0,01), elevated levels of total cholesterol (TC) (63,9% vs 54,0%, p&lt;0,01) and low-density lipoproteins (LDL) (66,7% vs 60,3%, p&lt;0,05), carbohydrate metabolism disorders (8,3% vs 5,2% p&lt;0,05), obesity (49,2% vs 37,7%, p&lt;0,01). Significantly more often hypertensive subjects without depression took antihypertensive drugs effectively (odds ratio (OR) — 1,747, 95% confidence interval (CI), 1,001-3,053) and controlled blood pressure (OR — 1,533, 95% CI, 1,05-2,36). There was no association between the use of antihypertensives and the level of depressive disorders. Among women with depression (HADS&gt;7), dyslipidemia (65,5% vs 57,4% for TC, p&lt;0,05; 71,0% vs 62,9% for LDL, p&lt;0,05), carbohydrate metabolism disorders (10,1% vs 5,2%, p&lt;0,01), obesity (53,3% vs 43,2%, p&lt;0,01), HTN (60,6% vs 45,6%, p&lt;0,01) were more common. Men with clinical depression were more likely to have HTN (69,0% vs 47,7%, p&lt;0,05), with a high level of depression — hyperlipidemia (58,9% vs 46,7% for TC, p&lt;0,05; 67,1% vs 53,9% for LDL, p&lt;0,05). Women with elevated depression levels were less likely to take antihypertensive drugs (30% vs 49,4%, p&lt;0,01) and control hypertension (13,8% vs 21,2%, p&lt;0,05).Conclusion. The data obtained confirm the association of depressive disorders with metabolic risk factors and the likelihood of HTN control, which is especially significant among women

Modulation of Human Mesenchymal Stem Cell Immunogenicity through Forced Expression of Human Cytomegalovirus US Proteins

BACKGROUND: Mesenchymal stem cells (MSC) are promising candidates for cell therapy, as they migrate to areas of injury, differentiate into a broad range of specialized cells, and have immunomodulatory properties. However, MSC are not invisible to the recipient's immune system, and upon in vivo administration, allogeneic MSC are able to trigger immune responses, resulting in rejection of the transplanted cells, precluding their full therapeutic potential. Human cytomegalovirus (HCMV) has developed several strategies to evade cytotoxic T lymphocyte (CTL) and Natural Killer (NK) cell recognition. Our goal is to exploit HCMV immunological evasion strategies to reduce MSC immunogenicity. METHODOLOGY/PRINCIPAL FINDINGS: We genetically engineered human MSC to express HCMV proteins known to downregulate HLA-I expression, and investigated whether modified MSC were protected from CTL and NK attack. Flow cytometric analysis showed that amongst the US proteins tested, US6 and US11 efficiently reduced MSC HLA-I expression, and mixed lymphocyte reaction demonstrated a corresponding decrease in human and sheep mononuclear cell proliferation. NK killing assays showed that the decrease in HLA-I expression did not result in increased NK cytotoxicity, and that at certain NK∶MSC ratios, US11 conferred protection from NK cytotoxic effects. Transplantation of MSC-US6 or MSC-US11 into pre-immune fetal sheep resulted in increased liver engraftment when compared to control MSC, as demonstrated by qPCR and immunofluorescence analyses. CONCLUSIONS AND SIGNIFICANCE: These data demonstrate that engineering MSC to express US6 and US11 can be used as a means of decreasing recognition of MSC by the immune system, allowing higher levels of engraftment in an allogeneic transplantation setting. Since one of the major factors responsible for the failure of allogeneic-donor MSC to engraft is the mismatch of HLA-I molecules between the donor and the recipient, MSC-US6 and MSC-US11 could constitute an off-the-shelf product to overcome donor-recipient HLA-I mismatch

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe