Experiment K-6-12. Morphometric studies of atrial or granules and hepatocytes. Part 1: Morphometric study of the liver; Part 2: The atrial granular accumulations

The livers of flight, F, rats from the Cosmos 1887 mission were markedly paler and heavier than those of the synchronous, S, and vivarium, V, controls. In the F group, microscopic study revealed extensive hepatocytic intracytoplasmic vacuolization which was moderate in the S and minimal in the V groups. The vacuoles were not sudanophilic and therefore were regarded as glycogenic in origin. To obtain objective data concerning the extent of the vacuolization, livers were examined by computer assisted morphometry. Measurements of profile area and perimeter of the hepatocyte nuclei and vacuoles were evaluated according to stereological principles. Results indicated that the volume density of the nuclei was less in the F group than in the S(p equal less than 0.0002) and V(p equal less than 0.001) groups. Mean volume of individual nuclei did not differ. Volume density of the vacuoles was greater in the F than in the V group (p equal less than 0.02) while their mean diameter was less (p equal less than 0.05). To ascertain the relationship between increase in liver weight of the flight animals and the results of this study, an assumption was made that the specific gravity of the vacuolar contents was similar to the other extranuclear components of the hepatocyte. On that basis, calculations showed that the elevated vacuolar volume density in the flight group did not cause the increased liver weight in those animals, but that the non-nuclear, non-vacuolar parenchymal compartment did contribute significantly. Factors that may have played a causal role in liver weight and vacuolar compartment increases are discussed

Influence of salicylic acid on phytochelatin synthesis in Zea mays during Cd stress

Abstract: Presoaking maize (Zea mays) seeds in salicylic acid (SA) reduces damage caused by cadmium. In the present work the possible role of phytochelatins (PCs) in SA-mediated protection against Cd toxicity was investigated. Seeds were presoaked in 0.5 mM SA, and seedlings were grown in hydroponic solution containing 0, 0.01, 0.015, or 0.025 mM Cd. Treatment with Cd increased the PC levels in maize roots, but only slight changes were observed in the leaves. Long-term exposure to Cd decreased the phytochelatin synthase (PCS) activity in the roots and led to an increase in PCS and glutathione reductase (GR) activities in maize leaves. Although presoaking seeds in SA solution before exposure to Cd may reduce the level of heavy metal injury and has an effect on the composition of individual PCs, this protection is not directly connected with the altered regulation of PCs

BRICS influence on global capitalist economy

The paper surveys the BRICS’ performance in the world during the last fifteen years. It analyses the economic environment as well as the possibility of rising of a possible new “global power”. The paper presents the statistical data on economic growth, international trade, population and currency reserves of the BRICS countrie

Optical spectra, crystal-field parameters, and magnetic susceptibility of the new multiferroic NdFe3(BO3)4

We report high-resolution optical absorption spectra for NdFe3(BO3)4 trigonal single crystal which is known to exhibit a giant magnetoelectric effect below the temperature of magnetic ordering TN = 33 K. The analysis of the temperature-dependent polarized spectra reveals the energies and, in some cases, symmetries and exchange splittings of Nd3+ 84 Kramers doublets. We perform crystal-field calculations starting from the exchange-charge model, obtain a set of six real crystal-field parameters, and calculate wave functions and magnetic g-factors. In particular, the values g(perpendicular) = 2.385, g(parallel) = 1.376 were found for the Nd3+ ground-state doublet. We obtain Bloc=7.88 T and |JFN|= 0.48 K for the values of the local effective magnetic field at liquid helium temperatures at the Nd3+ site and the Nd - Fe exchange integral, respectively, using the experimentally measured Nd3+ ground-state splitting of 8.8 cm-1. To check reliability of our set of crystal field parameters we model the magnetic susceptibility data from literature. A dimer containing two nearest-neighbor iron ions in the spiral chain is considered to partly account for quasi-one-dimensional properties of iron borates, and then the mean-field approximation is used. The results of calculations with the exchange parameters for Fe3+ ions Jnn = -6.25 K (intra-chain interactions) and Jnnn = -1.92 K (inter-chain interactions) obtained from fitting agree well with the experimental data.Comment: 13 pages, 8 figures, 2 table

Methodological foundations of teaching "histology" subject in foreign medical students

МЕДИЦИНСКИЕ УЧЕБНЫЕ ЗАВЕДЕНИЯОБРАЗОВАНИЕ МЕДИЦИНСКОЕСТУДЕНТЫ МЕДИЦИНСКИХ УЧЕБНЫХ ЗАВЕДЕНИЙИНОСТРАННЫЕ СТУДЕНТЫГИСТОЛОГИЯ /ОБУЧГИСТОЛОГИЯ (ДИСЦИПЛИНА)МЕТОДИКА ПРЕПОДАВАНИ

Mathematical modeling of three-layer beam hydroelastic oscillations

The problem of hydroelastic oscillations of three-layer beam interacting with viscous liquid layer is set up and analytically solved. The problem presents the equation system of a three-layer beam and Navier-Stokes equations. The following boundary conditions are chosen: the no-slip conditions, the conditions for pressure at the edges, the simply supported edges conditions. The problem is solved for the steady-state harmonic regime. The frequency dependent distribution functions of the beam deflection are constructed. The given function allows investigating the resonance hydroelastic oscillations of a three-layer beam, as well as its deflected mode

Inversionless light amplification and optical switching controlled by state-dependent alignment of molecules

We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant light while the excited ones remain emitting. The suitable class of molecules is discussed, the equation for the gain factor is derived, and the magnitude of the inversionless amplification is estimated for the typical experimental conditions. Such switching of the sample from absorbing to amplifying via transparent state is shown to be possible both with the aid of dc and ac control electric fields.Comment: AMS-LaTeX v1.2, 4 pages with 4 figure

Análisis de la propiedad estatal en la Federación de Rusia

The aim of the article is to compare the role of state property in developed countries and to obtain a more reliable estimate of the real share of the public sector in the Russian economy based on the dynamics of its change over the period from 2005 to 2017. The estimates obtained by the authors on the share of state property in the Russian economy show that the private sector plays the main role in the Russian economy. However, higher efficiency of the economy can be achieved by combining all the advantages of private and public partnership. On the basis of the study, we can conclude that Russia is gradually adopting the North American model of public sector participation in the economy, which is characterized by its specialization in purely state functions – defense and social infrastructure.El objetivo del artículo es comparar el papel de la propiedad estatal en los países desarrollados y obtener una estimación más confiable de la participación real del sector público en la economía rusa en función de la dinámica de su cambio durante el período comprendido entre 2005 y 2017. Las estimaciones obtenidas por los autores sobre la participación de la propiedad estatal en la economía rusa muestran que el sector privado desempeña el papel principal en la economía rusa. Sin embargo, se puede lograr una mayor eficiencia de la economía combinando todas las ventajas de la asociación pública y privada. Sobre la base del estudio, podemos concluir que Rusia está adoptando gradualmente el modelo norteamericano de participación del sector público en la economía, que se caracteriza por su especialización en funciones puramente estatales: defensa e infraestructura social

Magnetization and specific heat of TbFe3(BO3)4: Experiment and crystal field calculations

We have studied the thermodynamic properties of single-crystalline TbFe3(BO3)4. Magnetization measurements have been carried out as a function of magnetic field (up to 50 T) and temperature up to 350K with the magnetic field both parallel and perpendicular to the trigonal c-axis of the crystal. The specific heat has been measured in the temperature range 2-300K with a magnetic field up to 9 T applied parallel to the c-axis. The data indicate a structural phase transition at 192 K and antiferromagnetic spin ordering at 40 K. A Schottky anomaly is present in the specific heat data around 20 K, arising due to two low-lying energy levels of the Tb3+ ions being split by f-d coupling. Below TN magnetic fields parallel to the c-axis drive a spin-flop phase transition, which is associated with a large magnetization jump. The highly anisotropic character of the magnetic susceptibility is ascribed mainly to the Ising-like behavior of the Tb3+ ions in the trigonal crystal field. We describe our results in the framework of an unified approach which is based on mean-field approximation and crystal-field calculations.Comment: 10 pages, 10 figures, 20 references, accepted by Phys. Rev.