42 research outputs found

    Physics of B_c mesons

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    In the framework of potential models for heavy quarkonium the mass spectrum for the system (bˉc\bar b c) is considered. Spin-dependent splittings, taking into account a change of a constant for effective coulomb interaction between the quarks, and widths of radiative transitions between the (bˉc\bar b c) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector BcB_c^* and pseudoscalar BcB_c states are estimated, scaling relation for leptonic constants of heavy quarkonia is derived, and the leptonic constant fBcf_{B_c} is evaluated. The BcB_c decays are considered in the framework of both the potential models and the QCD sum rules, where the significance of Coulomb-like corrections is shown. The relations, following from the approximate spin symmetry for the heavy quarks in the heavy quarkonium, are analysed for the form factors of the semileptonic weak exclusive decays of BcB_c. The BcB_c lifetime is evaluated with the account of the corrections to the spectator mechanism of the decay, because of the quark binding into the meson. The total and differential cross sections of the BcB_c production in different interactions are calculated. The analytic expressions for the fragmentational production cross sections of BcB_c are derived. The possibility of the practical BcB_c search in the current and future experiments at electron-positron and hadron colliders is analysed.Comment: 81 page, latex, ihep.sty is required and attached in the end of the file after \end{document}, figures are not availabl

    Genomic analyses of Mycobacterium tuberculosis from human lung resections reveal a high frequency of polyclonal infections

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    Polyclonal infections occur when at least two unrelated strains of the same pathogen are detected in an individual. This has been linked to worse clinical outcomes in tuberculosis, as undetected strains with different antibiotic resistance profiles can lead to treatment failure. Here, we examine the amount of polyclonal infections in sputum and surgical resections from patients with tuberculosis in the country of Georgia. For this purpose, we sequence and analyse the genomes of Mycobacterium tuberculosis isolated from the samples, acquired through an observational clinical study (NCT02715271). Access to the lung enhanced the detection of multiple strains (40% of surgery cases) as opposed to just using a sputum sample (0-5% in the general population). We show that polyclonal infections often involve genetically distant strains and can be associated with reversion of the patient's drug susceptibility profile over time. In addition, we find different patterns of genetic diversity within lesions and across patients, including mutational signatures known to be associated with oxidative damage; this suggests that reactive oxygen species may be acting as a selective pressure in the granuloma environment. Our results support the idea that the magnitude of polyclonal infections in high-burden tuberculosis settings is underestimated when only testing sputum samples

    Comparing the genetic typing methods for effective surveillance and rabies control in Georgia

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    A full nucleoprotein gene sequencing of 68 isolates collected from passive rabies surveillance system in Georgia between 2015 and 2016 identified two distinct dog rabies phylogroups, GEO_V1 and GEO_V2, which both belonged to the cosmopolitan dog clade. GEO_V1 was found throughout the country and was further divided into four sub-phylogroups that overlapped geographically; GEO_V2 was found in the southeast region and was closely related to dog rabies in Azerbaijan. A sequence analysis of the full N gene, partial nucleoprotein gene of N-terminal and C-terminal, and the amplicon sequences of pan-lyssavirus RT-qPCR LN34 showed that all four sequencing approaches provided clear genetic typing results of canine rabies and could further differentiate GEO_V1 and GEO_V2. The phylogenetic analysis results vary and were affected by the length of the sequences used. Amplicon sequencing of the LN34 assay positive samples provided a rapid and cost-effective method for rabies genetic typing, which is important for improving rabies surveillance and canine rabies eradication globally

    Rifapentine access in Europe: growing concerns over key tuberculosis treatment component

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    [No abstract available]Support statement: C. Lange is supported by the German Center of Infection Research (DZIF). All other authors have no funding to declare for this study. Funding information for this article has been deposited with the Crossref Funder Registry

    THE APPLICATION OF VASOPRESSIN FOR CORRECTION OF THE CONSEQUENCES OF THE INFLUENCE OF PSYCHOGENIC INJURY OF MOTHERS ON THE BEHAVIOR OF THE offspring

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    Vital stress (mental trauma) causes depressive-like elements in the behavior of rats and psychoemotional disorders in their offspring. Pups born to females after stress experienced a month before pregnancy are characterized by a depleted behavior structure, a decline in research activity, and a decrease in motor activity. The revealed violations in the psychoemotional sphere of mothers are stopped by injecting stressed females intranasally with 1-deamino 8-D arginine-vasopressin at a dose of 2·10-7 mg within 5 days after mental trauma. Course therapy with vasopressin in mothers contributes to the normalization of behavior in their one-month-old offspring.</jats:p
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