Convergence to equilibrium for many particle systems

The goal of this paper is to give a short review of recent results of the authors concerning classical Hamiltonian many particle systems. We hope that these results support the new possible formulation of Boltzmann's ergodicity hypothesis which sounds as follows. For almost all potentials, the minimal contact with external world, through only one particle of $N$, is sufficient for ergodicity. But only if this contact has no memory. Also new results for quantum case are presented

Estimations of electron-positron pair production at high-intensity laser interaction with high-Z targets

Electron-positron pairs' generation occuring in the interaction of $10^{18}$-$10^{20}$~W/cm$^2$ laser radiation with high-Z targets are examined. Computational results are presented for the pair production and the positron yield from the target with allowance for the contribution of pair production processes due to electrons and bremsstrahlung photons. Monte-Carlo simulations using the PRIZMA code confirm the estimates obtained. The possible positron yield from high-Z targets irradiated by picosecond lasers of power $10^2$-$10^3$~TW is estimated to be $10^9$-$10^{11}$

The use of endovascular thrombectomy among the patients with acute ischemic stroke caused by the occlusion of large cerebral vessels

The effectiveness and complications of endovascular thrombectomy were analyzed. The obtained results show the reduction in mortality and disability among the patients after endovascular treatmen

Heat Capacity of PbS: Isotope Effects

In recent years, the availability of highly pure stable isotopes has made possible the investigation of the dependence of the physical properties of crystals, in particular semiconductors, on their isotopic composition. Following the investigation of the specific heat ($C_p$, $C_v$) of monatomic crystals such as diamond, silicon, and germanium, similar investigations have been undertaken for the tetrahedral diatomic systems ZnO and GaN (wurtzite structure), for which the effect of the mass of the cation differs from that of the anion. In this article we present measurements for a semiconductor with rock salt structure, namely lead sulfide. Because of the large difference in the atomic mass of both constituents ($M_{\rm Pb}$= 207.21 and ($M_{\rm S}$=32.06 a.m.u., for the natural isotopic abundance) the effects of varying the cation and that of the anion mass are very different for this canonical semiconductor. We compare the measured temperature dependence of $C_p \approx C_v$, and the corresponding derivatives with respect to ($M_{\rm Pb}$ and $M_{\rm S}$), with \textit{\textit{ab initio}} calculations based on the lattice dynamics obtained from the local density approximation (LDA) electronic band structure. Quantitative deviations between theory and experiment are attributed to the absence of spin-orbit interaction in the ABINIT program used for the electronic band structure calculations.Comment: 17 pages including 10 Fig

Effect of extracts from microalgae on cytokine levels in female C57Bl6 mice

Microalgae from the freshwater basins and seas are a valuable source of broad-spectrum biologically active substances that can affect the cells of immune system and their functional state. Cytokines are involved in all vital processes proceeding in the living cells (proliferation, maturation, differentiation, apoptosis/ necrosis). A study was performed in order to assess the effects of standard food formula for experimental animals supplemented with oil extract of microalgae from various systematic groups upon the levels of cytokines in blood serum, culture media conditioned by immunocytes, as well as kidney and liver tissues. The standard food was impregnated in oil extracts of microalgae (C. vulgaris, Coelastrella sp., A. platensis, C. closterium, and P. purpureum). In control series, the food was impregnated with pure vegetable oil. The animals were fed these foods for 12 days. Blood, spleen and thymus were taken to isolate immunocytes, kidneys and liver, and dimethyl sulfoxide extracts of the cells were produced. The conditioned media of splenocytes and thymocytes were obtained by adding concanavalin A (0 and 10 μg/ml) to the cultured cells. The levels of NO, IL-1β, IL-10, TNFα, and NO were determined in serum, conditioned media, and tissue extracts. In serum, the influence of microalgae on the levels of IL-1β and TNFα was revealed. Activation of immunocytes in experimental groups was followed by changes in IL-1β, TNFα and IL-10 production. Changes of cytokine and NO levels were revealed in liver and kidney extracts in experimental groups. Thus, microalgae extracts of various systematic groups affect the levels of cytokines in blood serum, cultural media conditioned by splenocytes and thymocytes, kidney and liver tissues

Rex Eris Si Recte Facias, Si Non Facias Non Eris

The authors consider some of the most important features of the interaction between the government and Church using a case study of the Russian state in the Early Modern times, analyzing the two main directions of this interaction, that is, the confessionalization of the society and the creation of a "tsarist discourse

EFFECT OF ERYTHROPOIETIN ON CYTOKINE PRODUCTION BY STEM CELLS

Erythropoietin (EPO) is mainly used to stimulate erythropoiesis. Its cytoprotective effects upon other cells of the human body and animals were recently shown, in particular, anti-apoptotic effect was observed. EPO effect upon the cells is mediated by interaction with erythropoietin receptor, with a complex forming a heterodimeric bond with β-common chain (CD131). In the present work, we studied the changes in erythropoietin receptor expression, and production spectrum of biologically active molecules in bone marrow mononuclear cells (BM-MNC) of patients with coronary heart disease. The flow cytometric assays showed that short-term incubation of BM-MNC with erythropoietin caused increased expression of the erythropoietin receptors on hematopoietic stem cells and tended to reduce the number of endothelial progenitor cells carrying the erythropoietin receptors. Solid-phase enzyme immunoassay in conditioned media from BM-MNC revealed that long-term (72 hours) exposure of BM-MNC to erythropoietin promoted increased production of IL-1β, PDGF-AB, and Epo, if compared to the basal production level (p < 0.05). Short-term incubation of BM-MNC with erythropoietin (60 minutes) caused a significant increase in the IL-1β, PDGF-AB and CXCL-12 / SDF-1α production levels, as well as significant reduction in the IL-10 production levels compared to the basal levels (p < 0.05)

Effect of erythropoietin on bone marrow mononuclear cells

Stem/progenitor cells are considered an alternative method of heart failure therapy by promoting regeneration of damaged myocardium in myocardial infarction. Effectiveness of cell therapy depends on the population composition and functional activity of the cell graft, and, in turn, it depends on the conditions of microenvironment. Cultivation of stem/progenitor cells with erythropoietin stimulates proliferative potential causing in vitro resistance to hypoxia, and in vivo stimulation of angiogenesis. We aimed for assessing effects of erythropoietin upon hematopoietic cells. We studied some effects of short-term incubation of bone marrow mononuclear cells (BM-MNCs) in patients with coronary heart disease (CHD) with erythropoietin upon cellular phenotype, cell cycle, apoptosis and their proliferative potential. BM-MNCs were isolated from bone marrow aspirate from patients with CHD in a density gradient, then incubated for 60 minutes with erythropoietin (33.4 IU/ml). Using flow cytometric assay of the total BM-MNCs pool, we have shown there endothelial progenitor cells at different stages of maturation and differentiation, mesenchymal stem cells are. Their total number did not exceed 30%. Short-term incubation of BM-MNCs with erythropoietin reduces expression of CD184 “homing receptor” molecules on CD34+ cells, and causes increase of CD184 on CD31+ cells in the BM-MNCs pool (p < 0.05). In addition, erythropoietin has been shown to cause a delay of CD34+ cells in the resting phase (G0G1), reduce a proportion of cells in the synthetic phase (S) and mitosis (G2/M) (p<0.05), and does not affect apoptosis, as shown by Annexin V-FITC Apoptosis Detection Kit. Erythropoietin had no significant effects on expression on BM-MNCs surface molecules involved in providing adhesion, such as CD18, CD29, CD44, CD49a, CD54, CD62E, CD146, and CD202b. MTT-method has shown that the short-term preincubation of BM-MNCs with erythropoietin contributed to a significant decrease in proliferative activity of BM-MNCs (p < 0.05). However, there was a tendency towards increased resistance of erythropoietin-pretreated BM-MNCs to oxidative stress induced by hydrogen peroxide. We have also revealed a correlation between the numbers of endothelial progenitor cells at different stages of differentiation, and numbers of hematopoietic stem cells in the total BM-MNCs pool. The number of CD34+/CD133+, CD34- / CD31+, CD45+/EpoR+, and CD34+/EpoR+ in BM-MNCs pool are dependent on the age of patients. Hence, a short-term incubation of BM-MNCs with erythropoietin promotes the cells to be retained in resting phase of the cell cycle, thus, in turn, helping to reduce proliferative potential of BM-MNCs

Dynamical Phases of Driven Vortices Interacting with Periodic Pinning

The finite temperature dynamical phases of vortices in films driven by a uniform force and interacting with the periodic pinning potential of a square lattice of columnar defects are investigated by Langevin dynamics simulations of a London model. Vortices driven along the [0,1] direction and at densities for which there are more vortices than columnar defects ($B>B_{\phi}$) are considered. At low temperatures, two new dynamical phases, elastic flow and plastic flow, and a sharp transition between them are identified and characterized according to the behavior of the vortex spatial order, velocity distribution and frequency-dependent velocity correlationComment: 4 pages with 4 figures. To be published in Phys. Rev. B Rapid Communication