2,043 research outputs found

    Prognostic value of CAIX expression in oral squamous cell carcinoma: a systematic review and meta-analysis

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    Carbonic anhydrase IX (CAIX) is a hypoxia-related protein considered as a predictor for oral squamous cell carcinoma (OSCC) biological behaviour. Nevertheless, this prognostic value is still yet to be validated. We aim to quantify prognostic significance of CAIX overexpression in OSCC by meta-analysis. We performed searches in MEDLINE, EMBASE, SCOPUS, WOS, WHO’S databases, CPCI, and OATD from inception to August 2019. Overall survival (OS), disease-free survival (DFS), locoregional control (LC), and disease-specific survival (DSS) were considered as outcomes of interest. Overall 18 studies were included. CAIX overexpression was associated with worse OS (hazard ratio [HR] = 1.45 95% confidence interval [CI] 1.17–1.80) and DFS (HR = 1.98 95% CI 1.18–3.32). To the contrary, it was neither associated with LC (HR = 1.01 95% CI 0.50–2.02) nor with DSS (HR = 1.35 95% CI 0.78–2.33). Heterogeneity was negligible in all analyses except for DSS. Small studies effect was not significant for OS and DFS. This study shows that immunohistochemical CAIX assessment is a useful OSCC prognostic biomarkerS

    Determination of ππ\pi\pi scattering lengths from measurement of π+π−\pi^+\pi^- atom lifetime

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    The DIRAC experiment at CERN has achieved a sizeable production of π+π−\pi^+\pi^- atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave ππ\pi\pi scattering length difference ∣a0−a2∣=(.0.2533−0.0078+0.0080∣stat.−0.0073+0.0078∣syst)Mπ+−1|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1} has been attained, providing an important test of Chiral Perturbation Theory.Comment: 6 pages, 6 figure

    Study of WW boson production in association with beauty and charm

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    The associated production of a WW boson with a jet originating from either a light parton or heavy-flavor quark is studied in the forward region using proton-proton collisions. The analysis uses data corresponding to integrated luminosities of 1.0 and 2.0 fb−12.0\,{\rm fb}^{-1} collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, respectively. The WW bosons are reconstructed using the W→ΌΜW\to\mu\nu decay and muons with a transverse momentum, pTp_{\rm T}, larger than 20 GeV in the pseudorapidity range 2.0202.0 20 GeV and 2.2<η<4.22.2 < \eta < 4.2. The sum of the muon and jet momenta must satisfy pT>20p_{\rm T} > 20 GeV. The fraction of W+W+jet events that originate from beauty and charm quarks is measured, along with the charge asymmetries of the W ⁣+ ⁣bW\!+\!b and W ⁣+ ⁣cW\!+\!c production cross-sections. The ratio of the W+W+jet to Z+Z+jet production cross-sections is also measured using the Z→ΌΌZ\to\mu\mu decay. All results are in agreement with Standard Model predictions

    Study of B−→DK−π+π−B^{-}\to DK^-\pi^+\pi^- and B−→Dπ−π+π−B^-\to D\pi^-\pi^+\pi^- decays and determination of the CKM angle Îł\gamma

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    We report a study of the suppressed B−→DK−π+π−B^-\to DK^-\pi^+\pi^- and favored B−→Dπ−π+π−B^-\to D\pi^-\pi^+\pi^- decays, where the neutral DD meson is detected through its decays to the K∓π±K^{\mp}\pi^{\pm} and CP-even K+K−K^+K^- and π+π−\pi^+\pi^- final states. The measurement is carried out using a proton-proton collision data sample collected by the LHCb experiment, corresponding to an integrated luminosity of 3.0~fb−1^{-1}. We observe the first significant signals in the CP-even final states of the DD meson for both the suppressed B−→DK−π+π−B^-\to DK^-\pi^+\pi^- and favored B−→Dπ−π+π−B^-\to D\pi^-\pi^+\pi^- modes, as well as in the doubly Cabibbo-suppressed D→K+π−D\to K^+\pi^- final state of the B−→Dπ−π+π−B^-\to D\pi^-\pi^+\pi^- decay. Evidence for the ADS suppressed decay B−→DK−π+π−B^{-}\to DK^-\pi^+\pi^-, with D→K+π−D\to K^+\pi^-, is also presented. From the observed yields in the B−→DK−π+π−B^-\to DK^-\pi^+\pi^-, B−→Dπ−π+π−B^-\to D\pi^-\pi^+\pi^- and their charge conjugate decay modes, we measure the value of the weak phase to be Îł=(74−19+20)o\gamma=(74^{+20}_{-19})^{\rm o}. This is one of the most precise single-measurement determinations of Îł\gamma to date.Comment: 22 pages, 9 figures; All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-020.htm

    Differential branching fraction and angular analysis of the decay B0→K∗0ÎŒ+Ό−

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    The angular distribution and differential branching fraction of the decay B 0→ K ∗0 ÎŒ + ÎŒ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

    Observation of J/ψpJ/\psi p resonances consistent with pentaquark states in Λb0→J/ψK−p{\Lambda_b^0\to J/\psi K^-p} decays

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    Observations of exotic structures in the J/ψpJ/\psi p channel, that we refer to as pentaquark-charmonium states, in Λb0→J/ψK−p\Lambda_b^0\to J/\psi K^- p decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final-state that reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/ψpJ/\psi p mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380±8±294380\pm 8\pm 29 MeV and a width of 205±18±86205\pm 18\pm 86 MeV, while the second is narrower, with a mass of 4449.8±1.7±2.54449.8\pm 1.7\pm 2.5 MeV and a width of 39±5±1939\pm 5\pm 19 MeV. The preferred JPJ^P assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after referee's comments, now 19 figure

    Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at √s=7 TeV

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    Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the form of an enhancement of pairs of like-sign charged pions with small four-momentum difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source is investigated, determining both the correlation radius and the chaoticity parameter. The measured correlation radius is found to increase as a function of increasing charged-particle multiplicity, while the chaoticity parameter is seen to decreas

    Search for hidden-sector bosons in B0 ⁣→K∗0ÎŒ+Ό−B^0 \!\to K^{*0}\mu^+\mu^- decays

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    A search is presented for hidden-sector bosons, χ\chi, produced in the decay B0 ⁣→K∗(892)0χ{B^0\!\to K^*(892)^0\chi}, with K∗(892)0 ⁣→K+π−K^*(892)^0\!\to K^{+}\pi^{-} and Ï‡â€‰âŁâ†’ÎŒ+Ό−\chi\!\to\mu^+\mu^-. The search is performed using pppp-collision data corresponding to 3.0 fb−1^{-1} collected with the LHCb detector. No significant signal is observed in the accessible mass range 214≀m(χ)≀4350214 \leq m({\chi}) \leq 4350 MeV, and upper limits are placed on the branching fraction product B(B0 ⁣→K∗(892)0χ)×B(Ï‡â€‰âŁâ†’ÎŒ+Ό−)\mathcal{B}(B^0\!\to K^*(892)^0\chi)\times\mathcal{B}(\chi\!\to\mu^+\mu^-) as a function of the mass and lifetime of the χ\chi boson. These limits are of the order of 10−910^{-9} for χ\chi lifetimes less than 100 ps over most of the m(χ)m(\chi) range, and place the most stringent constraints to date on many theories that predict the existence of additional low-mass bosons.Comment: All figures and tables, along with supplementary material, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-036.htm

    Measurement of the mass and lifetime of the Ωb−\Omega_b^- baryon

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    A proton-proton collision data sample, corresponding to an integrated luminosity of 3 fb−1^{-1} collected by LHCb at s=7\sqrt{s}=7 and 8 TeV, is used to reconstruct 63±963\pm9 Ωb−→Ωc0π−\Omega_b^-\to\Omega_c^0\pi^-, Ωc0→pK−K−π+\Omega_c^0\to pK^-K^-\pi^+ decays. Using the Ξb−→Ξc0π−\Xi_b^-\to\Xi_c^0\pi^-, Ξc0→pK−K−π+\Xi_c^0\to pK^-K^-\pi^+ decay mode for calibration, the lifetime ratio and absolute lifetime of the Ωb−\Omega_b^- baryon are measured to be \begin{align*} \frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\ \tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the uncertainties are statistical, systematic and from the calibration mode (for τΩb−\tau_{\Omega_b^-} only). A measurement is also made of the mass difference, mΩb−−mΞb−m_{\Omega_b^-}-m_{\Xi_b^-}, and the corresponding Ωb−\Omega_b^- mass, which yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2. \end{align*} These results are consistent with previous measurements.Comment: 11 pages, 5 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-008.htm

    Measurement of the Bs0→J/ψηB_{s}^{0} \rightarrow J/\psi \eta lifetime

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    Using a data set corresponding to an integrated luminosity of 3fb−13 fb^{-1}, collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 7 and 8 TeV, the effective lifetime in the Bs0→J/ψηB^0_s \rightarrow J/\psi \eta decay mode, τeff\tau_{\textrm{eff}}, is measured to be τeff=1.479±0.034 (stat)±0.011 (syst)\tau_{\textrm{eff}} = 1.479 \pm 0.034~\textrm{(stat)} \pm 0.011 ~\textrm{(syst)} ps. Assuming CPCP conservation, τeff\tau_{\textrm{eff}} corresponds to the lifetime of the light Bs0B_s^0 mass eigenstate. This is the first measurement of the effective lifetime in this decay mode.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-017.htm
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