1,332 research outputs found

    Long-Term outcomes and durability of the mitroflow aortic bioprosthesis

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    [Abstract] Background. This study aims to determine the incidence and causes of structural valve deterioration (SVD) among all models of Mitroflow bioprostheses (A12/LX/DL), as well as to define their long-term clinical and hemodynamic performance. Methods and Results. We retrospectively reviewed a series of 1023 patients who underwent aortic valve replacement with Mitroflow bioprostheses between 2001 and 2014. A small aortic root was found in 22.4% of patients. There were two cases of severe patient-prosthesis mismatch. Only 31 patients developed SVD. The rate of incidence was 8.1 cases per 1000 patient-years. Cumulative incidence of SVD was 1.4% and 3% at five and 10 years, respectively. Freedom from SVD was 97.4% and 88.2% at five and 10 years, respectively. Anticalcification phospholipid reduction treatment (PRT) for model DL was a protective factor for SVD. Multivariable analysis confirmed age <70 years and use of 19 mm valve as independent predictors of SVD. Cumulative survival was 76.6% at five years and 42.3% at 10 years (mean follow-up 3.8 ± 3.1 years). In multivariable analysis, neither the use of small aortic prosthesis (p = 0.18) nor the occurrence of SVD (p = 0.85) was found to be independent predictors of long-term survival. Conclusions. Mitroflow valves demonstrate an acceptable rate of SVD and satisfactory long-term hemodynamic performance, particularly in patients with small aortic roots, age >70 years, and cases with severe left ventricular hypertrophy. PRT might contribute to improved long-term durability

    VNIR-SWIR using OreXpress spectroradiometer as a spectral approximation method to differentiate epithermal mineralization alteration phases. A case study from Jacinto and Big Golden Hill, Cuba

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    Spectral differences (range: 350-2500 nm) between the three alteration phases related to low and high sulfidation epithermal mineralization has been studied in the Jacinto deposit (Beatriz, Sur de Elena, and El Limon Nuevo veins) and the Big Golden Hill sector, respectively, located in the Cuban Cretaceous volcanic, CamagĂŒey and Las Tunas provinces. This study has revealed the following differences between the phases: (a) Phase I: associated with the lithological type of quartz with massive and/or brecciated texture, where gold mineralization develops. At 600-800 nm, the signals identified responds with goethite and at 1400, 1900 y 2200 nm, as montmorillonite and nontronite. The reflectance value is 30 -50%, although in the El LimĂłn Nuevo vein is 30-40%. (b) Phase II: Related to the argillic alteration zone composed by sericitic or silicified quartz and ferrous minerals such as limonite and hematite. It only occurs in Beatriz and Sur de Elena veins. At 600-800 nm, the signal is associated with ferrous minerals and at 1400, 1900, and 2200 nm, to clays minerals as montmorillonite, halloysite, and nontronite. The reflectance value is 30 – 50%. The difference between both Phases is in the amplitude and shape of the absorption feature at 1400 nm. (c) Phase III: it is located near the volcanic rock, composed by illite-smectite-quartz, without gold content and nearby to propylitic zone. At 600-800 nm, the feature indicates the presence of goethite and at 1400, 1900, and 2200 nm, to montmorillonite, illite, and nontronite. The reflectance value is 30 - 40%. The Big Golden Hill sector is characterized by peaks related to goethite and nontronite at 600-800 nm and pyrophyllite at 1400, 1950 and 2165 nm, typical of advanced argillic alteration. The reflectance value reaches 55%. This study represents one of the first applications of reflectance spcetroscopic techniques in Cuban mineral deposits

    Challenges in the Detection and Attribution of Northern Hemisphere Surface Temperature Trends Since 1850

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    Since 2007, the Intergovernmental Panel on Climate Change (IPCC) has heavily relied on the comparison between global climate model hindcasts and global surface temperature (ST) estimates for concluding that post-1950s global warming is mostly human-caused. In Connolly et al., we cautioned that this approach to the detection and attribution of climate change was highly dependent on the choice of Total Solar Irradiance (TSI) and ST data sets. We compiled 16 TSI and five ST data sets and found by altering the choice of TSI or ST, one could (prematurely) conclude anything from the warming being "mostly human-caused" to "mostly natural." Richardson and Benestad suggested our analysis was "erroneous" and "flawed" because we did not use a multilinear regression. They argued that applying a multilinear regression to one of the five ST series re-affirmed the IPCC's attribution statement. They also objected that many of the published TSI data sets were out-of-date. However, here we show that when applying multilinear regression analysis to an expanded and updated data set of 27 TSI series, the original conclusions of Connolly et al. are confirmed for all five ST data sets. Therefore, it is still unclear whether the observed warming is mostly human-caused, mostly natural or some combination of both.Fil: Connolly, Ronan. Center For Environmental Research And Earth Sciences; Estados UnidosFil: Soon, Willie. Center For Environmental Research And Earth Sciences; Estados Unidos. Institute of Earth Physics and Space Science; HungrĂ­aFil: Connolly, Michael. Center For Environmental Research And Earth Sciences; Estados UnidosFil: Baliunas, Sallie. Harvard-Smithsonian Center For Astrophysics; Estados UnidosFil: Berglund, Johan. No especifĂ­ca;Fil: Butler, C. J.. No especifĂ­ca;Fil: Cionco, Rodolfo Gustavo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂ­ficas; Argentina. Universidad TecnolĂłgica Nacional. Facultad Regional San NicolĂĄs. Grupo de Estudios Ambientales; ArgentinaFil: Elias, Ana Georgina. Universidad Nacional de TucumĂĄn. Instituto de FĂ­sica del Noroeste Argentino. - Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet Noa Sur. Instituto de FĂ­sica del Noroeste Argentino; ArgentinaFil: Fedorov, Valery M.. Universidad Estatal de Moscu Mijail Vasilievich Lomonosov (mgu);Fil: Harde, Hermann. Helmut-Schmidt-University; AlemaniaFil: Henry, Gregory W.. Tennessee State University; Estados UnidosFil: Hoyt, Douglas V.. No especifĂ­ca;Fil: Humlum, Ole. University of Oslo; NoruegaFil: Legates, David R.. University of Delaware; Estados UnidosFil: Scafetta, Nicola. UniversitĂ  degli Studi di Napoli Federico II; ItaliaFil: Solheim, Jan-Erik. The Arctic University of Norway; NoruegaFil: Szarka, LĂĄszlĂł. Institute of Earth Physics and Space Science; HungrĂ­aFil: Velasco Herrera, VĂ­ctor M.. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Yan, Hong. Chinese Academy of Sciences; RepĂșblica de ChinaFil: Zhang, Weijia. Shaoxing University; Chin

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

    Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

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    Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

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    This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat

    Measurements of the Electroweak Diboson Production Cross Sections in Proton-Proton Collisions at root s=5.02 TeV Using Leptonic Decays

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    The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302 pb(-1). Events with two, three, or four charged light leptons (electrons or muons) in the final state are analyzed. The WW, WZ, and ZZ total cross sections are measured as sigma(WW) = 37:0(-5.2)(+5.5) (stat)(-2.6)(+2.7) (syst) pb, sigma(WZ) = 6.4(-2.1)(+2.5) (stat)(-0.3)(+0.5)(syst) pb, and sigma(ZZ) = 5.3(-2.1)(+2.5)(stat)(-0.4)(+0.5) (syst) pb. All measurements are in good agreement with theoretical calculations at combined next-to-next-to-leading order quantum chromodynamics and next-to-leading order electroweak accuracy

    Measurement of the top quark mass using events with a single reconstructed top quark in pp collisions at root s=13 TeV

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    Abstract:A measurement of the top quark mass is performed using a data sample en-riched with single top quark events produced in thetchannel. The study is based on proton-proton collision data, corresponding to an integrated luminosity of 35.9 fb−1, recorded at√s= 13TeV by the CMS experiment at the LHC in 2016. Candidate events are selectedby requiring an isolated high-momentum lepton (muon or electron) and exactly two jets,of which one is identified as originating from a bottom quark. Multivariate discriminantsare designed to separate the signal from the background. Optimized thresholds are placedon the discriminant outputs to obtain an event sample with high signal purity. The topquark mass is found to be172.13+0.76−0.77GeV, where the uncertainty includes both the sta-tistical and systematic components, reaching sub-GeV precision for the first time in thisevent topology. The masses of the top quark and antiquark are also determined separatelyusing the lepton charge in the final state, from which the mass ratio and difference aredetermined to be0.9952+0.0079−0.0104and0.83+1.79−1.35GeV, respectively. The results are consistentwithCPTinvariance
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