237 research outputs found

    Modification of the zirconia ceramics by different calcium phosphate coatings:comparative study

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    The aim of this study was to characterize different calcium phosphate coatings and evaluate in vitro cell response of these materials to ceramics implants. The physical and chemical properties of calcium phosphate coatings formed by RF-magnetron sputtering of calcium phosphate tribasic, hydroxyapatite, calcium phosphate monobasic, calcium phosphate dibasic dihydrate and calcium pyrophosphate powders were characterized. Cell adhesion and cell viability were examined on calcium phosphate coatings using mesenchymal stem cells. The results of cytotoxicity measurements of the calcium phosphate coatings revealed that only the coating obtained by RF-magnetron sputtering of the calcium phosphate dibasic dihydrate and calcium phosphate tribasic powders possessed lower cell viability than the zirconia substrate. The coating formed by sputtering of the calcium phosphate tribasic powder demonstrated more cells adhered onto its surface compared with other calcium phosphate coatings

    Fabrication and properties of L-arginine-doped PCL electrospun composite scaffolds

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    The article describes fabrication and properties of composite fibrous scaffolds obtained by electrospinning of the solution of poly({\epsilon}-caprolactone) and arginine in common solvent. The influence of arginine content on structure, mechanical, surface and biological properties of the scaffolds was investigated. It was found that with an increase of arginine concentration diameter of the scaffold fibers was reduced, which was accompanied by an increase of scaffold strength and Young modulus. It was demonstrated that porosity and water contact angle of the scaffold are independent from arginine content. The best cell adhesion and viability was shown on scaffolds with arginine concentration from 0.5 to 1 % wt

    Immunological assessment of plant-derived avian flu H5/HA1 variants.

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    Polypeptide variants of the HA1 antigenic domain of the H5N1 avian influenza virus hemagglutinin (HA) molecule were produced in plants using transient and stable expression systems and fused with His/c-myc tags or with mouse or human Fc antibody fragments. The resulting peptides were purified and used for intramuscular immunization of mice. While the recombinant HA1 variants induced a significant serum humoral immune response in the mice, none of the HA1 preparations induced virus-neutralizing antibodies. Fusion with the Fc fragment improved overall yield of the constructs and allowed purification requiring only a single step, but led to no detectable fusion-related enhancement of immunogenicity or quality of immune response

    Relationship between IL1B gene polymorphism and smoking with the risk of myocardial infarction

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    Genotype and smoking determined risks of myocardial infarction in patients with ischemic heart disease. Homozygous genotype C (rs16944) of IL1B is associated with myocardial infarction (OR = 3,17 (95% Cl = 0,92-10,89); р < 0,01) and heterozygous carrier state of this allelic gene doesn't increase risks (OR = 1,36 (95% CI = 0,83-2,2); р = 0,01). Smoking 5 times increases risk of myocardial infarction (OR = 5,16 (95% CI = 1,05-25,39); p < 0,05) in homozygotes, and 1,5 times (OR = 1,46 (95% CI = 0,77-2,78); p < 0,05) - in heterozygotes of 511Т/С lL1B. Haplotype СТ (rs1143634 - rs16944) of IL1B is connected with the decrease of risk of myocardial infarction in nonsmoking patients (OR = 0,43 (95% DI = 0,19-0,95); р < 0,01)

    FREQUENCY DISTRIBUTION OF INTRONIC POLYMORPHISMS OF IL1-raVNTR AND IL-4VNTR IN RHEUMATIC MITRAL VALVE DISEASE IN CAUCASIAN POPULATION OF SIBERIA

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    A search for associations between allelic variations of immune response genes, and mitral stenosis associated with rheumatic heart disease, represents an important task when studying the pathogenesis of cardiovascular disorders among inhabitants of large industrial regions in Western Siberia. Among multiple polymorphisms of interleukin-encoding genes, a particular attention should be paid to association studies of some intronic polymorphisms with variable numbers of tandem repeats (VNTR). In this respect, genotyping of interleukin 1 receptor antagonist genes (IL-1ra86bp VNTR) and interleukin 4 (IL-470bp VNTR) has shown positive associations between the intron 2 IL-1ra*3R/3R microsatellite polymorphism, intron 3 IL-4*2R/2R variant, and the risk of mitral stenosis development in patients with rheumatic heart disease (OR = 12.71; p = 0.0001)

    Photoproduction evidence for and against hidden-strangeness states near 2 GeV

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    Experimental evidence from coherent diffractive proton scattering has been reported for two narrow baryonic resonances which decay predominantly to strange particles. These states, with masses close to 2.0 GeV would, if confirmed, be candidates for hidden strangeness states with unusual internal structure. In this paper we examine the literature on strangeness photoproduction, to seek additional evidence for or against these states. We find that one state is not confirmed, while for the other state there is some mild supporting evidence favoring its existence. New experiments are called for, and the expected photoproduction lineshapes are calculated.Comment: 9 pages, RevTex, five postscript figures, submitted to PR

    Scintillating properties of frozen new liquid scintillators

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    The light emission from scintillators which are liquid at room temperature was studied in the interval between +20+20~∘^{\circ}C and −120-120~∘^{\circ}C, where the phase transition from liquid to solid takes place. The light yield measured at −120-120~∘^{\circ}C is about twice as much as that observed at +20+20~∘^{\circ}C. By cooling the scintillator from +20+20~∘^{\circ}C to −120-120~∘^{\circ}C and then heating it from −120-120~∘^{\circ}C to +20+20~∘^{\circ}C, the light yield varies in steps at well defined temperatures, which are different for the cooling and heating processes. These hysteresis phenomena appear to be related to the solvent rather than to the dopant. The decay time of scintillation light was measured at +20+20~∘^{\circ}C and −120-120~∘^{\circ}C. Whilst at room temperature most of the light is emitted with a decay time of 6--8 ns, at −120-120~∘^{\circ}C a slower component, with a decay time of 25--35 ns, becomes important

    Charm production nearby threshold in pA-interactions at 70 GeV

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    The results of the SERP-E-184 experiment at the U-70 accelerator (IHEP, Protvino) are presented. Interactions of the 70 GeV proton beam with C, Si and Pb targets were studied to detect decays of charmed D0D^0, D‾0\overline D^0, D+D^+, D−D^- mesons and Λc+\Lambda _c^+ baryon near their production threshold. Measurements of lifetimes and masses are shown a good agreement with PDG data. The inclusive cross sections of charm production and their A-dependencies were obtained. The yields of these particles are compared with the theoretical predictions and the data of other experiments. The measured cross section of the total open charm production (σtot(cc‾)\sigma _{\mathrm {tot}}(c\overline c) = 7.1 ±\pm 2.3(stat) ±\pm 1.4(syst) μ\mu b/nucleon) at the collision c.m. energy s\sqrt {s} = 11.8 GeV is well above the QCD model predictions. The contributions of different species of charmed particles to the total cross section of the open charm production in proton-nucleus interactions vary with energy.Comment: 4 pages, 6 pages, 38th International Conference on High Energy Physics 3-10 August 2016, Chicago, US

    PURINERGIC REGULATION OF BASIC PHYSIOLOGICAL AND PATHOLOGICAL PROCESSES

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    Purinergic signaling has been actively studied over recent years. It happens, due to its involvement in pathogenesis of various diseases and pathologies such as infectious and non-infectious inflammation, tumor growth, graft-versus-host disease, autoimmune disorders, cardiovascular calcification etc. It has been shown that the purinergic system mediates fine tuning of the immune cell populations, like as cytokine and chemokine secretion, elimination of intracellular pathogens and mechanisms of programmed cell death. Novel approaches to therapy and disease prevention are based on studies of appropriate developmental mechanisms, including role of purinergic system in their regulation. This review contains analysis of recent achievements elucidating the role of purinergic regulation in pathogenesis of basic pathological conditions and diseases, as well as trends in development of new therapeutic approaches based on present knowledge
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