1,957 research outputs found

    New Hepatitis E Virus Genotype in Bactrian Camels, Xinjiang, China, 2013

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    Intensive Cytokine induction in Pandemic H1N1 Influenza Virus Infection Accompanied by Robust Production of IL-10 and IL-6

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    BACKGROUND: The innate immune system is the first line of defense against viruses by inducing expression of cytokines and chemokines. Many pandemic influenza H1N1 virus [P(H1N1)] infected severe cases occur in young adults under 18 years old who were rarely seriously affected by seasonal influenza. Results regarding host cytokine profiles of P(H1N1) are ambivalent. In the present study we investigated host cytokine profiles in P(H1N1) patients and identified cytokines related to disease severity. METHODS AND PRINCIPAL FINDINGS: We retrieved 77, 59, 26 and 26 sera samples from P(H1N1) and non-flu influenza like illness (non-ILIs) cases with mild symptoms (mild patients), P(H1N1) vaccinees and healthy individuals, respectively. Nine and 16 sera were from hospitalized P(H1N1) and non-ILIs patients with severe symptoms (severe patients). Cytokines of IL-1, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IFN-γ and TNF-α were assayed by cytokine bead array, IL-17 and IL-23 measured with ELISA. Mild P(H1N1) patients produced significantly elevated IL-2, IL-12, IFN-γ, IL-6, TNF-α, IL-5, IL-10, IL-17 and IL-23 versus to healthy controls. While an overwhelming IL-6 and IL-10 production were observed in severe P(H1N1) patients. Higher IL-10 secretion in P(H1N1) vaccinees confirmed our observation that highly increased level of sera IL-6 and IL-10 in P(H1N1) patients may lead to disease progression. CONCLUSION AND SIGNIFICANCE: A comprehensive innate immune response was activated at the early stage of P(H1N1) infection with a combine Th1/Th2/Th3 cytokines production. As disease progression, a systemic production of IL-6 and IL-10 were observed in severe P(H1N1) patients. Further analysis found a strong correlation between IL-6 and IL-10 production in the severe P(H1N1) patients. IL-6 may be served as a mediator to induce IL-10 production. Highly elevated level of sera IL-6 and IL-10 in P(H1N1) patients may lead to disease progression, but the underlying mechanism awaits further detailed investigations

    Inclusive Search for Anomalous Production of High-pT Like-Sign Lepton Pairs in Proton-Antiproton Collisions at sqrt{s}=1.8 TeV

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    We report on a search for anomalous production of events with at least two charged, isolated, like-sign leptons with pT > 11 GeV/c using a 107 pb^-1 sample of 1.8 TeV ppbar collisions collected by the CDF detector. We define a signal region containing low background from Standard Model processes. To avoid bias, we fix the final cuts before examining the event yield in the signal region using control regions to test the Monte Carlo predictions. We observe no events in the signal region, consistent with an expectation of 0.63^(+0.84)_(-0.07) events. We present 95% confidence level limits on new physics processes in both a signature-based context as well as within a representative minimal supergravity (tanbeta = 3) model.Comment: 15 pages, 4 figures. Minor textual changes, cosmetic improvements to figures and updated and expanded reference

    Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV

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    We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1 integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115 GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let

    Measurement of the WZWZ Cross Section and Triple Gauge Couplings in ppˉp \bar p Collisions at s=1.96\sqrt{s} = 1.96 TeV

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    This Letter describes the current most precise measurement of the WZWZ production cross section as well as limits on anomalous WWZWWZ couplings at a center-of-mass energy of 1.96 TeV in proton-antiproton collisions for the Collider Detector at Fermilab (CDF). WZWZ candidates are reconstructed from decays containing three charged leptons and missing energy from a neutrino, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector (7.1 fb−1^{-1} of integrated luminosity), 63 candidate events are observed with the expected background contributing 8±18 \pm 1 events. The measured total cross section σ(ppˉ→WZ)=3.93−0.53+0.60(stat)−0.46+0.59(syst)\sigma (p \bar p \to WZ) = 3.93_{-0.53}^{+0.60}(\text{stat})_{-0.46}^{+0.59}(\text{syst}) pb is in good agreement with the standard model prediction of 3.50±0.213.50\pm 0.21. The same sample is used to set limits on anomalous WWZWWZ couplings.Comment: Resubmission to PRD-RC after acceptance (27 July 2012

    A search for resonant production of ttˉt\bar{t} pairs in $4.8\ \rm{fb}^{-1}ofintegratedluminosityof of integrated luminosity of p\bar{p}collisionsat collisions at \sqrt{s}=1.96\ \rm{TeV}$

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    We search for resonant production of tt pairs in 4.8 fb^{-1} integrated luminosity of ppbar collision data at sqrt{s}=1.96 TeV in the lepton+jets decay channel, where one top quark decays leptonically and the other hadronically. A matrix element reconstruction technique is used; for each event a probability density function (pdf) of the ttbar candidate invariant mass is sampled. These pdfs are used to construct a likelihood function, whereby the cross section for resonant ttbar production is estimated, given a hypothetical resonance mass and width. The data indicate no evidence of resonant production of ttbar pairs. A benchmark model of leptophobic Z \rightarrow ttbar is excluded with m_{Z'} < 900 GeV at 95% confidence level.Comment: accepted for publication in Physical Review D Sep 21, 201

    Precision Top-Quark Mass Measurements at CDF

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    We present a precision measurement of the top-quark mass using the full sample of Tevatron s=1.96\sqrt{s}=1.96 TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb−1fb^{-1}. Using a sample of ttˉt\bar{t} candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the WW boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with {\it in situ} calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, \mtop = 172.85 \pm0.71(stat) 0.71 (stat) \pm0.85(syst)GeV/c2. 0.85 (syst) GeV/c^{2}.Comment: submitted to Phys. Rev. Let
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