4,111 research outputs found

    Efficacy and safety of the combination of reduced duration prophylaxis followed by immuno-guided prophylaxis to prevent cytomegalovirus disease in lung transplant recipients (CYTOCOR STUDY) : An open-label, randomised, non-inferiority clinical trial

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    Introduction Prolonged use of antivirals to prevent the development of cytomegalovirus (CMV) disease in lung transplant patients has been shown to have significant side effects, for which alternatives are being sought to reduce their use. The monitoring of cell immunity against CMV could be an alternative as it has shown to be useful in identifying transplant patients at low risk of infection, who could benefit from shorter prophylaxis. The aim of the CYTOCOR study is to demonstrate that the combination of a reduced prophylaxis strategy with subsequent CMV-specific immunological monitoring would allow CMV infection to be controlled in lung transplant patients as effectively as the usual strategy (prophylaxis followed by pre-emptive therapy), while reducing the side effects of antivirals due to the shorter duration of prophylaxis. Methods and analysis Phase III randomised, open, multicentre, parallel, non-inferiority clinical trial to study the efficacy and safety of the combination of a prophylaxis strategy up to month +3 post-transplant followed by immuno-guided prophylaxis using the QuantiFERON-CMV technique up to month +12 post-transplant to prevent CMV disease in CMV-seropositive lung transplant recipients. This strategy will be compared with a combination of a usual prophylaxis strategy up to month +6 post-transplant followed by pre-emptive therapy up to month +12. To study the incidence of CMV disease, patients will be followed up to 18 months post-transplantation. A total of 150 patients are expected to be recruited for the study. Ethics and public dissemination The clinical trial has been approved by the Research Ethics Committees and authorised by the Spanish Agency of Medicines and Medical Devices (AEMPS). If the hypothesis of this clinical trial is verified, the dissemination of the results could change clinical practice by increasing knowledge about the safety and efficacy of discontinuing valganciclovir prophylaxis in lung transplant recipients. Trial registration number NCT03699254

    Efficacy and safety of the combination of reduced duration prophylaxis followed by immuno-guided prophylaxis to prevent cytomegalovirus disease in lung transplant recipients (CYTOCOR STUDY): an open-label, randomised, non-inferiority clinical trial.

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    INTRODUCTION: Prolonged use of antivirals to prevent the development of cytomegalovirus (CMV) disease in lung transplant patients has been shown to have significant side effects, for which alternatives are being sought to reduce their use. The monitoring of cell immunity against CMV could be an alternative as it has shown to be useful in identifying transplant patients at low risk of infection, who could benefit from shorter prophylaxis. The aim of the CYTOCOR study is to demonstrate that the combination of a reduced prophylaxis strategy with subsequent CMV-specific immunological monitoring would allow CMV infection to be controlled in lung transplant patients as effectively as the usual strategy (prophylaxis followed by pre-emptive therapy), while reducing the side effects of antivirals due to the shorter duration of prophylaxis. METHODS AND ANALYSIS: Phase III randomised, open, multicentre, parallel, non-inferiority clinical trial to study the efficacy and safety of the combination of a prophylaxis strategy up to month +3 post-transplant followed by immuno-guided prophylaxis using the QuantiFERON-CMV technique up to month +12 post-transplant to prevent CMV disease in CMV-seropositive lung transplant recipients. This strategy will be compared with a combination of a usual prophylaxis strategy up to month +6 post-transplant followed by pre-emptive therapy up to month +12. To study the incidence of CMV disease, patients will be followed up to 18 months post-transplantation. A total of 150 patients are expected to be recruited for the study. ETHICS AND PUBLIC DISSEMINATION: The clinical trial has been approved by the Research Ethics Committees and authorised by the Spanish Agency of Medicines and Medical Devices (AEMPS).If the hypothesis of this clinical trial is verified, the dissemination of the results could change clinical practice by increasing knowledge about the safety and efficacy of discontinuing valganciclovir prophylaxis in lung transplant recipient

    Experimental study of the collision 11Be + 64Zn around the Coulomb barrier

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    In this paper details of the experimental procedure and data analysis of the collision of 11Be+64Zn around the Coulomb barrier are described and discussed in the framework of different theoretical approaches. In a previous work [ A. Di Pietro et al. Phys. Rev. Lett. 105 022701 (2010)], the elastic scattering angular distribution of the collisions 9, 10Be+64Zn as well as the angular distribution for the quasielastic scattering and transfer/breakup cross sections for the 11Be+64Zn reaction were briefly reported. The suppression of the quasielastic angular distribution in the Coulomb-nuclear interference angular region observed in the collision of the 11Be halo nucleus with respect to the other two beryllium isotopes was interpreted as being caused by a long-range absorption owing to the long decay length of the 11Be wave function. In this paper, new continuum-discretized coupled-channel calculations of the 11Be+64Zn reaction are reported in the attempt to interpret the effect of coupling with the breakup channels on the measured cross sections. The calculations show that the observed suppression of the Coulomb-nuclear interference peak is caused by a combined effect of Coulomb and nuclear couplings to the breakup channels

    Evidence of strong effects of the 11Be halo structure on reaction processes at energies around the Coulomb barrier

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    The collision induced by the three Beryllium isotopes, 9, 10, 11Be, on 64Zn target were investigated at Ec.m. ≈ 1.4 the Coulomb barrier. Elastic scattering angular distributions were measured for the 9, 10Be collisions whereas, in the 11Be case the quasielastic scattering angular distribution was obtained. A strong damping of the quasielastic cross-section was observed in the 11Be case, especially in the angular range around the Coulomb-nuclear interference peak. In this latter case a large total-reaction cross-section is found, more than a factor of two larger than the ones extracted in the reactions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the 11Be case could be attributed to transfer and/or break-up events

    Elastic Scattering and Reaction Mechanisms of the Halo Nucleus 11Be around the Coulomb Barrier

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    Collisions induced by 9, 10, 11Be on a 64Zn target at the same c.m. energy were studied. For the first time, strong effects of the 11Be halo structure on elastic-scattering and reaction mechanisms at energies near the Coulomb barrier are evidenced experimentally. The elastic-scattering cross section of the 11Be halo nucleus shows unusual behavior in the Coulomb-nuclear interference peak angular region. The extracted total-reaction cross section for the 11Be collision is more than double the ones measured in the collisions induced by 9, 10Be. It is shown that such a strong enhancement of the total-reaction cross section with 11Be is due to transfer and breakup processes

    Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

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    The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
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