175 research outputs found

    Tick-borne encephalitis virus genome The nucleotide sequence coding for virion structural proteins

    Get PDF
    AbstractRNA of a flavivirus, tick-borne encephalitis virus (TBEV; strain Sofjin), was subjected to reverse transcription and the DNA copy was transformed into double-stranded DNA by the action of E. coli DNA-polymerase I (Klenow fragment). This DNA was annealed with plasmid pBR322. The recombinant plasmids were cloned in E. coli K802. The nucleotide sequence of the inserts of the clones, coding for region structural proteins C, M, E and nonstructural protein NS1, was determined by the Maxam-Gilbert method. The genes of structural proteins form a compact cluster. Homology has been studied of the TBEV sequences found with the structures of proteins and RNAs of other flaviviruses, yellow fever virus and West Nile virus, and a high degree of homology was found

    Critical point in ferroelectric Langmuir-Blodgett polymer films

    Get PDF
    The ferroelectric critical point has been found in a ferroelectric polymer by exploring the influence of the electric field on the paraelectric-ferroelectric phase transition. Dielectric and pyroelectric measurements on 30-monolayer-thick films of the crystalline copolymer poly(vinylidene fluoride-trifluoroethylene) grown by Langmuir-Blodgett deposition show a single hysteresis loop below the zero-field phase transition temperature Tc0=80±10 °C, double hysteresis loops between Tc0 , and the critical temperature Tcr=145±5 °C, and no hysteresis above Tcr where the critical electric field is Ecr=0.93±0.1X109 V/m

    Variations in genome fragments coding for RNA polymerase in human and simian hepatitis A viruses

    Get PDF
    AbstractThe genome of hepatitis A virus (HAV) isolated from spontaneously infected African vervet monkey (Cercopithecus aethiops) has been cloned and partially sequenced. Comparison of genome fragments (1248 and 162 bp) from the 3D (RNA polymerase) region with the corresponding parts of human HAV genomes revealed a high degree of heterogeneity: there were altogether 257 nucleotide changes leading to 44 substitutions in predicted amino acid sequence, i.e. 89% amino acid identity. This divergence is considered to be significantly greater than genomic variations usually found among human HAV strains, where amino acid identity in the 3D region is over 98%

    Nucleotide sequence of the Galleria mellonella nuclear polyhedrosis virus origin of DNA replication

    Get PDF
    AbstractThe initiation sites of the Galleria mellonella L. nuclear polyhedrosis virus (G.m. NPV) DNA replication were revealed. For this purpose SCLd 135 cells permitting the G.m. NPV productive reproduction were transformed by the recombinant plasmids containing the viral genome individual fragments in pRSF 2124 and pBR 322 vectors. It was revealed that 2 of the 32 recombinant plasmids can autonomously replicate in the eucaryotic cells. According to the Maxam-Gilbert method the DNA G.m. NPV fragment (1300 bp) primary structure of pHBR plasmid was determined. The structure analysis revealed the typical regulator signals as in the replicons. The possible regulation mechanisms of the DNA G.m. NPV synthesis initiation was supposed

    Measurement of main parameters of the \psi(2S) resonance

    Get PDF
    A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the \psi(2S): \Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, \Gamma = 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments

    Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector

    Full text link
    We report results of a search for narrow resonances in e+ e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained (at 90 % C.L.)

    Measurement of RudsR_{\text{uds}} and RR between 3.12 and 3.72 GeV at the KEDR detector

    Get PDF
    Using the KEDR detector at the VEPP-4M e+ee^+e^- collider, we have measured the values of RudsR_{\text{uds}} and RR at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than 3.3%3.3\% at most of energy points with a systematic uncertainty of about 2.1%2.1\%. At the moment it is the most accurate measurement of R(s)R(s) in this energy range

    New precise determination of the \tau lepton mass at KEDR detector

    Full text link
    The status of the experiment on the precise τ\tau lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the τ+τ\tau^+\tau^- cross section behaviour around the production threshold. The preliminary result based on 6.7 pb1^{-1} of data is mτ=1776.800.23+0.25±0.15m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15 MeV. Using 0.8 pb1^{-1} of data collected at the ψ\psi' peak the preliminary result is also obtained: ΓeeBττ(ψ)=7.2±2.1\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1 eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau0

    Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)

    Get PDF
    The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson.Comment: 7 pages, 6 figure
    corecore