1,111 research outputs found

    Leukocytes phagocytic activity under moderate hypotension conditions in some representatives of bony fish, amphibians and reptiles

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    The leukocytes phagocytic activity against Bacillus subtilis and agromerulated latex particles in representatives of bony fish, amphibians and reptiles under reduced medium osmolarity conditions was studied. It was found that in moderate hypotension compared with isotonia, the white blood cells absorption capacity of the fish was not changed, but it was reduced for amphibians and reptile

    The role of cytokines in the pathogenesis of malignant neoplasms

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    The paper analyzes the literature data on the role of cytokines in the pathogenesis of malignant neoplasms (MN). Cytokines are biologically active, hormone-like proteins that regulate a wide range of processes occurring in the body. Cytokines determine the type and duration of the immune response, stimulation or suppression of cell growth, their differentiation, and functional activity. The complex of cytokines produced in the tumor microenvironment plays an important role in the pathogenesis of MN. The spectra of biological activities of cytokines overlap in most cases. The same process in a cell can be stimulated by more than one cytokine, creating a favorable environment for the initiation and progression of MN. The immune system can recognize transformed cells. Various cytokines correspond to specifc pathways activated by receptors on the cell surface, which in turn cause intracellular signaling cascades that affect target cellular functions. Cytokine genes are mutually related to oncogenes. Cytokines, which are released in response to infection, inflammation, or during an immune response to an antigen, can inhibit tumor development. In turn, cytokines, which weaken apoptosis and promote invasion and metastasis, promote tumor growth. Cytokines are involved in the initiation, development and metastasis of malignant neoplasms through various mechanisms

    Theory and Phenomenology of Vector Mesons in Medium

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    Electromagnetic probes promise to be direct messengers of (spectral properties of) hot and dense matter formed in heavy-ion collisions, even at soft momentum transfers essential for characterizing possible phase transitions. We examine how far we have progressed toward this goal by highlighting recent developments, and trying to establish connections between lattice QCD, effective hadronic models and phenomenology of dilepton production.Comment: 8 pages latex incl. 12 ps/eps files; invited plenary talk at Quark Matter 2006 conference, Shanghai (China), Nov. 14-20, 200

    QCD in the nuclear medium and effects due to Cherenkov gluons

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    The equations of in-medium gluodynamics are proposed. Their classical lowest order solution is explicitly shown for a color charge moving with constant speed. For nuclear permittivity larger than 1 it describes emission of Cherenkov gluons resembling results of classical electrodynamics. The values of the real and imaginary parts of the nuclear permittivity are obtained from the fits to experimental data on the double-humped structure around the away-side jet obtained at RHIC. The dispersion of the nuclear permittivity is predicted by comparing the RHIC, SPS and cosmic ray data. This is important for LHC experiments. Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near rho-meson, observed in the SPS experiment with excess in the low-mass wing of the resonance. This feature is predicted to be common for all resonances. The "color rainbow" quantum effect might appear according to higher order terms of in-medium QCD if the nuclear permittivity depends on color.Comment: 29 p., 4 figs; for "Phys. Atom. Nucl." volume dedicated to 80th birthday of L.B. Okun; minor corrections on pp. 11 and 13 in v

    Non-invasive characterization of transverse beam emittance of electrons from a laser-plasma wakefield accelerator in the bubble regime using betatron x-ray radiation

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    We propose and use a technique to measure the transverse emittance of a laser-wakefield accelerated beam of relativistic electrons. The technique is based on the simultaneous measurements of the electron beam divergence given by v/vv_{\perp}/v_{\parallel}, the measured longitudinal spectrum γ\gamma_\parallel and the transverse electron bunch size in the bubble rr_{\perp}. The latter is obtained via the measurement of the source size of the x-rays emitted by the accelerating electron bunch in the bubble. We measure a \textit{normalised} RMS beam transverse emittance <0.5<0.5 π\pi mm\:mrad as an upper limit for a spatially gaussian, spectrally quasi-monoenergetic electron beam with 230 MeV energy in agreement with numerical modeling and analytic theory in the bubble regime.Comment: 4 pages, 5 figure

    Dileptons in High-Energy Heavy-Ion Collisions

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    The current status of our understanding of dilepton production in ultrarelativistic heavy-ion collisions is discussed with special emphasis on signals from the (approach towards) chirally restored and deconfined phases. In particular, recent results of the CERN-SPS low-energy runs are compared to model predictions and interpreted. Prospects for RHIC experiments are given.Comment: Invited talk at ICPAQGP, Jaipur, India, Nov. 26-30, 2001; 1 Latex and 9 eps-/ps-files Reoprt No.: SUNY-NTG-02-0

    Creation of reference specimens of the sorption properties of nanoporous silica gels

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    A technique for the synthesis of nanoporous silica gels is developed. Reference specimens are created and an estimate of their metrological characteristics is performed. © 2013 Springer Science+Business Media New York

    Modification of the rho meson detected by low-mass electron-positron pairs in central Pb-Au collisions at 158 A GeV/c

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    We present a measurement of e+ee^+e^- pair production in central Pb-Au collisions at 158AA GeV/cc. As reported earlier, a significant excess of the e+ee^+e^- pair yield over the expectation from hadron decays is observed. The improved mass resolution of the present data set, recorded with the upgraded CERES experiment at the CERN-SPS, allows for a comparison of the data with different theoretical approaches. The data clearly favor a substantial in-medium broadening of the ρ\rho spectral function over a density-dependent shift of the ρ\rho pole mass. The in-medium broadening model implies that baryon induced interactions are the key mechanism to in-medium modifications of the ρ\rho-meson in the hot fireball at SPS energy.Comment: Revised versio

    Hydrogels Based on Polyacrylamide and Calcium Alginate: Thermodynamic Compatibility of Interpenetrating Networks, Mechanical, and Electrical Properties

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    The synthesis and physicochemical properties of hydrogels with interpenetrated physical and chemical networks were considered in relation to their prospective application as biomimetic materials in biomedicine and bioengineering. The study was focused on combined hydrogels based on natural polysaccharide—calcium alginate (CaAlg) and a synthetic polymer–polyacrylamide (PAAm). The series of hydrogels with varying proportions among alginate and polyacrylamide have been synthesized, and their water uptake has been characterized depending on their composition. The equilibrium swelling and re-swelling in water after drying were considered. The compatibility of alginate and polyacrylamide in the combined blend was studied by the thermodynamic approach. It showed a controversial combination of negative enthalpy of mixing among PAAm and CaAlg with positive Gibbs energy of mixing. Mechanical and electrical properties of the combined gels with double networking were studied as relevant for their prospective use as scaffolds for tissue regeneration and working bodies in actuators. The storage modulus and the loss modulus were determined in the oscillatory compression mode as a function of proportions among natural and synthetic polymers. Both moduli substantially increased with the content of CaAlg and PAAm. The electrical (Donnan) potential of hydrogels was measured using the capillary electrode technique. The Donnan potential was negative at all compositions of hydrogels, and its absolute values increased with the content of CaAlg and PAAm. © 2023 by the authors.Russian Science Foundation, RSF: 20-12-00031; Ministry of Health of the Russian Federation: 121032300335-1The study was supported by the Russian Science Foundation (grant 20-12-00031). The mechanical and electrical measurements on gels were funded under the program of the Ministry of Health of the Russian Federation (project 121032300335-1)
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