The boundary integral theory for slow and rapid curved solid/liquid interfaces propagating into binary systems

The boundary integral method for propagating solid/liquid interfaces is detailed with allowance for the thermo-solutal Stefan-type models. Two types of mass transfer mechanisms corresponding to the local equilibrium (parabolic-type equation) and local non-equilibrium (hyperbolic-type equation) solidification conditions are considered. A unified integro-differential equation for the curved interface is derived. This equation contains the steady-state conditions of solidification as a special case. The boundary integral analysis demonstrates how to derive the quasi-stationary Ivantsov and Horvay–Cahn solutions that, respectively, define the paraboloidal and elliptical crystal shapes. In the limit of highest Péclet numbers, these quasi-stationary solutions describe the shape of the area around the dendritic tip in the form of a smooth sphere in the isotropic case and a deformed sphere along the directions of anisotropy strength in the anisotropic case. A thermo-solutal selection criterion of the quasi-stationary growth mode of dendrites which includes arbitrary Péclet numbers is obtained. To demonstrate the selection of patterns, computational modelling of the quasi-stationary growth of crystals in a binary mixture is carried out. © 2018 The Author(s) Published by the Royal Society. All rights reserved.Russian Science Foundation, RSF: 16-11-1009550WM1541Data accessibility. This article has no additional data. Authors’ contributions. All authors contributed equally to the present review paper. Competing interests. The authors declare that they have no competing interests. Funding. This work was supported by the Russian Science Foundation (grant no. 16-11-10095) and the German Space Center Space Management under contract no. 50WM1541

Realization of potential of enterprise structure development as the criterion of ensuring the object-differentiated approach to rendering the state support : the Russian Federation

The objective of the research. Undertaken in the conditions of an economic crisis and sanctions restrictions the attempts of system optimization of business activity state regulation in Russia still don't contribute to increase in business sector efficiency and to full accomplishment of all assigned social and economic functions. In the article the author rationalizes the point, assuming that in the basis of state regulation system the implementation level of entrepreneurial structure capacity, as the most adequate criterion of rendering the state support of business activity, which besides shall carry an object-differentiated nature, shall be laid. Short description of methodology. In the article authors offer an original interpretation of the concept "potential of enterprise structure development" and a method to calculate an indicator "the realization level of potential of enterprise structure development" as key criterion at realizing an object-differentiated approach to rendering the state support of enterprise structures. Compilation of the most important research results and their significance. In the article based on the formed differentiation criteria of measures of the state support of entrepreneurial structures authors offer the measures system differentiated on the bases of the implementation level of potential of entrepreneurial structures development and the importance of this structure in strategic priorities system of territorial development on preferential creation of institutional conditions for an entrepreneurship development; on internal capacity development of entrepreneurial structures; on direct support of business activity.peer-reviewe

Structural and Functional Organization of the Vestibular Apparatus in Rats Subjected to Weightlessness for 19.5 Days Aboard the Kosmos-782 Satellite

The vestibular apparatus was investigated in rats subjected to weightlessness for 19.5 days. The vestibular apparatus was removed and its sections were fixed in a glutaraldehyde solution for investigation by light and electron microscopes. Structural and functional charges were noted in the otolith portions of the ear, with the otolith particles clinging to the utricular receptor surface and with the peripheral arrangement of the nucleolus in the nuclei of the receptor cells. It is possible that increased edema of the vestibular tissue resulted in the destruction of some receptor cells and in changes in the form and structure of the otolith. In the horizontal crista, the capula was separated

Dynamics of antioxidant status indices in orienteering team members

The present research is devoted to the study of the dynamics of antioxidant status indices in sportsmen going in for orienteering in the state of their maximum tiredness (right after competition) and after rest. The article presents the results of the research of malondialdehyde (MDA), catalase (C), superoxide dismutase (SOD) andglutathione-S-transferase (GST) content in venous blood erythrocytes. We revealed significant differences in the activity of enzymes of antioxidant defense system and malondialdehyde content depending on the previous level of physical activity. It was determined that restoration processes of an organism after the period of intensive physical activity were characterized by the decrease of MDA content and increase of the activity of enzymes of antioxidant defense system

On the unsteadiness time of primary dendritic growth

The evolution of the growth rate of a dendritic tip for nonisothermal crystal growth from the moment of crystal formation to the moment when the growth rate attains its steady-state value is considered. Gibbs-Thomson condition for highly nonequilibrium rapidly moving crystallization of a pure one-component liquid is used to determine the time dependence of the growth rate of a dendritic tip. It is shown that the dependence of the growth rate on overcooling has the form of an exponential law. Under the condition of constant overcooling an estimation of the time of reaching the steady-state regime of growth is obtained. The analytically derived velocity of growth as a function of time coincides with numerical calculations

Can pancreas be the source of hepatocytes?

The possibility of hepatocytes differentiation from pancreatic cells is discussed in the review. Both liver and pancreas develop from endoderm so there could be a common stem cell giving rise to both pancreatic and liver cells. Different experimental models are used to study the possibility of hepatocytes development in pancreas such as influence of peroxisomes proliferation stimulators, hyperexpression of keratinocyte growth factor in pancreatic islets, Cu depletion-repletion model, etc.). There is no enough data to confirm which particular pancreatic cell type can be the source of hepatocytes. Literature data allow supposing that hepatocytes can arise in pancreas from three different sources: acinar, endocrine or ductular cells

Pharmacoepidemiological study of the safety of drug use in children by analyzing the Russian database of spontaneous reports

Purpose. To study the structure of serious adverse drug reactions and «off label» drug use in children by means of analysis of the national pharmacovigilance database. Materials and methods. We analyzed 341 spontaneous reports about serious adverse reactions in children, submitted to the Russian pharmacovigilance database in 2012, and 467 suchlike spontaneous reports registered in 2015. Results. Children of preschool age have higher risk of medical therapy complications. Most frequently, skin (33,4% in 2012 and 38,7% in 2015) and organism as a whole (21,4 and 21,1%, respectively) were involved in the pathological process. Antimicrobial drugs for systemic use (43,5% in 2012 and 43,8% in 2015) and drugs for nervous system (25,1 and 26,1% respectively) often caused them. Unexpected serious adverse reactions accounted for 16,9% of all complications in children in 2012, 10,8% in 2015. It was established that 58,7% of suspected medicines in 2012 and 47,5% in 2015, the use of which was associated with the development of serious complications in pharmacotherapy in children, were prescribed with deviations from the recommendations of approved prescribing drug information. The main types of «off-label» drug use were inappropriate indications, deviations from the recommended dosage regimen, the use of a drug in the age group of patients, wherein the drug has not been approved, and the use of a drug in the presence of contraindications to its use. Conclusion. Our research confirms that the practice of «off-label» drug use in children is an independent risk factor for developing adverse drug reactions. It is shown that the method of spontaneous reporting can help to identify the problems of drug safety and to develop recommendations for minimizing the risk of complications of pharmacotherapy in pediatric practice