286 research outputs found

    Tratamiento endodóntico radical en pulpa no vital en una sola visita

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    1024x768 Introducción: la Endodoncia durante el último siglo refleja una tendencia a realizar el tratamiento endodóntico radical en dos o más visitas ante los diagnósticos que indican una pulpa no vital. La simplificación del procedimiento en cuanto al número de visitas se refiere fue posible teniendo en cuenta la historia de la enfermedad pulpar. Objetivo: evaluar la efectividad del tratamiento endodóntico radical en pulpa no vital, en una sola visita. Material y métodos: se realizó un estudio descriptivo de corte transversal a una muestra de 171 dientes provenientes de 157 pacientes que acudieron a dos clínicas estomatológicas del municipio Playa, los cuales presentaron diferentes patologías pulpares tributarias al objeto de la investigación; aplicándoseles el tratamiento endodóntico convencional en una sola sesión. Resultados: se obtuvo que el 81.87% de los pacientes tratados evolucionaron de forma asintomática, solo el 18.13% presentó algún signo de periodontitis apical antes de la semana de tratados. Al comparar estos resultados con otros autores se encontró similitud con escasa diferencia porcentual. Conclusiones: el tratamiento endodóntico en una visita para dientes con pulpa no vital es factible de realizar en cualquier patología pulpar, resultando favorable tanto para el operador como para el paciente. Palabras clave: tratamiento endodóntico radical, pulpa no vital, patología pulpar. Normal 0 21 false false false ES X-NONE X-NONE <!--[endif] --

    Tratamiento endodóntico radical en pulpa no vital en una sola visita

    No full text
    Introducción: la Endodoncia durante el último siglo refleja una tendencia a realizar el tratamiento endodóntico radical en dos o más visitas ante los diagnósticos que indican una pulpa no vital. La simplificación del procedimiento en cuanto al número de visitas se refiere fue posible teniendo en cuenta la historia de la enfermedad pulpar. Objetivo: evaluar la efectividad del tratamiento endodóntico radical en pulpa no vital, en una sola visita. Material y métodos: se realizó un estudio descriptivo de corte transversal a una muestra de 171 dientes provenientes de 157 pacientes que acudieron a dos clínicas estomatológicas del municipio Playa, los cuales presentaron diferentes patologías pulpares tributarias al objeto de la investigación; aplicándoseles el tratamiento endodóntico convencional en una sola sesión. Resultados: se obtuvo que el 81.87% de los pacientes tratados evolucionaron de forma asintomática, solo el 18.13% presentó algún signo de periodontitis apical antes de la semana de tratados. Al comparar estos resultados con otros autores se encontró similitud con escasa diferencia porcentual. Conclusiones: el tratamiento endodóntico en una visita para dientes con pulpa no vital es factible de realizar en cualquier patología pulpar, resultando favorable tanto para el operador como para el paciente

    Ticagrelor in patients with diabetes and stable coronary artery disease with a history of previous percutaneous coronary intervention (THEMIS-PCI) : a phase 3, placebo-controlled, randomised trial

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    Background: Patients with stable coronary artery disease and diabetes with previous percutaneous coronary intervention (PCI), particularly those with previous stenting, are at high risk of ischaemic events. These patients are generally treated with aspirin. In this trial, we aimed to investigate if these patients would benefit from treatment with aspirin plus ticagrelor. Methods: The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS) was a phase 3 randomised, double-blinded, placebo-controlled trial, done in 1315 sites in 42 countries. Patients were eligible if 50 years or older, with type 2 diabetes, receiving anti-hyperglycaemic drugs for at least 6 months, with stable coronary artery disease, and one of three other mutually non-exclusive criteria: a history of previous PCI or of coronary artery bypass grafting, or documentation of angiographic stenosis of 50% or more in at least one coronary artery. Eligible patients were randomly assigned (1:1) to either ticagrelor or placebo, by use of an interactive voice-response or web-response system. The THEMIS-PCI trial comprised a prespecified subgroup of patients with previous PCI. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, or stroke (measured in the intention-to-treat population). Findings: Between Feb 17, 2014, and May 24, 2016, 11 154 patients (58% of the overall THEMIS trial) with a history of previous PCI were enrolled in the THEMIS-PCI trial. Median follow-up was 3·3 years (IQR 2·8–3·8). In the previous PCI group, fewer patients receiving ticagrelor had a primary efficacy outcome event than in the placebo group (404 [7·3%] of 5558 vs 480 [8·6%] of 5596; HR 0·85 [95% CI 0·74–0·97], p=0·013). The same effect was not observed in patients without PCI (p=0·76, p interaction=0·16). The proportion of patients with cardiovascular death was similar in both treatment groups (174 [3·1%] with ticagrelor vs 183 (3·3%) with placebo; HR 0·96 [95% CI 0·78–1·18], p=0·68), as well as all-cause death (282 [5·1%] vs 323 [5·8%]; 0·88 [0·75–1·03], p=0·11). TIMI major bleeding occurred in 111 (2·0%) of 5536 patients receiving ticagrelor and 62 (1·1%) of 5564 patients receiving placebo (HR 2·03 [95% CI 1·48–2·76], p<0·0001), and fatal bleeding in 6 (0·1%) of 5536 patients with ticagrelor and 6 (0·1%) of 5564 with placebo (1·13 [0·36–3·50], p=0·83). Intracranial haemorrhage occurred in 33 (0·6%) and 31 (0·6%) patients (1·21 [0·74–1·97], p=0·45). Ticagrelor improved net clinical benefit: 519/5558 (9·3%) versus 617/5596 (11·0%), HR=0·85, 95% CI 0·75–0·95, p=0·005, in contrast to patients without PCI where it did not, p interaction=0·012. Benefit was present irrespective of time from most recent PCI. Interpretation: In patients with diabetes, stable coronary artery disease, and previous PCI, ticagrelor added to aspirin reduced cardiovascular death, myocardial infarction, and stroke, although with increased major bleeding. In that large, easily identified population, ticagrelor provided a favourable net clinical benefit (more than in patients without history of PCI). This effect shows that long-term therapy with ticagrelor in addition to aspirin should be considered in patients with diabetes and a history of PCI who have tolerated antiplatelet therapy, have high ischaemic risk, and low bleeding risk

    The CMS Statistical Analysis and Combination Tool: COMBINE

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    International audienceThis paper describes the COMBINE software package used for statistical analyses by the CMS Collaboration. The package, originally designed to perform searches for a Higgs boson and the combined analysis of those searches, has evolved to become the statistical analysis tool presently used in the majority of measurements and searches performed by the CMS Collaboration. It is not specific to the CMS experiment, and this paper is intended to serve as a reference for users outside of the CMS Collaboration, providing an outline of the most salient features and capabilities. Readers are provided with the possibility to run COMBINE and reproduce examples provided in this paper using a publicly available container image. Since the package is constantly evolving to meet the demands of ever-increasing data sets and analysis sophistication, this paper cannot cover all details of COMBINE. However, the online documentation referenced within this paper provides an up-to-date and complete user guide

    Search for long-lived heavy neutrinos in the decays of B mesons produced in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search for long-lived heavy neutrinos (N) in the decays of \PB mesons produced in proton-proton collisions at s\sqrt{s} = 13 TeV is presented. The data sample corresponds to an integrated luminosity of 41.6 fb1^{-1} collected in 2018 by the CMS experiment at the CERN LHC, using a dedicated data stream that enhances the number of recorded events containing B mesons. The search probes heavy neutrinos with masses in the range 1 <\ltmNm_\mathrm{N}<\lt 3 GeV and decay lengths in the range 102^{-2}<\ltcτc\tau<\lt 104^{4} mm, where τN\tau_\mathrm{N} is the N proper mean lifetime. Signal events are defined by the signature B \toB\ell_\mathrm{B}NX; N \to±π\ell^{\pm} \pi^{\mp}, where the leptons B\ell_\mathrm{B} and \ell can be either a muon or an electron, provided that at least one of them is a muon. The hadronic recoil system, X, is treated inclusively and is not reconstructed. No significant excess of events over the standard model background is observed in any of the ±π\ell^{\pm}\pi^{\mp} invariant mass distributions. Limits at 95% confidence level on the sum of the squares of the mixing amplitudes between heavy and light neutrinos, VN2\vert V_\mathrm{N}\vert^2, and on cτc\tau are obtained in different mixing scenarios for both Majorana and Dirac-like N particles. The most stringent upper limit VN2\vert V_\mathrm{N}\vert^2 <\lt 2.0×\times105^{-5} is obtained at mNm_\mathrm{N} = 1.95 GeV for the Majorana case where N mixes exclusively with muon neutrinos. The limits on VN2\vert V_\mathrm{N}\vert^2 for masses 1 <\lt mNm_\mathrm{N} <\lt 1.7 GeV are the most stringent from a collider experiment to date

    Dark sector searches with the CMS experiment

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    Astrophysical observations provide compelling evidence for gravitationally interacting dark matter in the universe that cannot be explained by the standard model of particle physics. The extraordinary amount of data from the CERN LHC presents a unique opportunity to shed light on the nature of dark matter at unprecedented collision energies. This Report comprehensively reviews the most recent searches with the CMS experiment for particles and interactions belonging to a dark sector and for dark-sector mediators. Models with invisible massive particles are probed by searches for signatures of missing transverse momentum recoiling against visible standard model particles. Searches for mediators are also conducted via fully visible final states. The results of these searches are compared with those obtained from direct-detection experiments. Searches for alternative scenarios predicting more complex dark sectors with multiple new particles and new forces are also presented. Many of these models include long-lived particles, which could manifest themselves with striking unconventional signatures with relatively small amounts of background. Searches for such particles are discussed and their impact on dark-sector scenarios is evaluated. Many results and interpretations have been newly obtained for this Report.Astrophysical observations provide compelling evidence for gravitationally interacting dark matter in the universe that cannot be explained by the standard model of particle physics. The extraordinary amount of data from the CERN LHC presents a unique opportunity to shed light on the nature of dark matter at unprecedented collision energies. This Report comprehensively reviews the most recent searches with the CMS experiment for particles and interactions belonging to a dark sector and for dark-sector mediators. Models with invisible massive particles are probed by searches for signatures of missing transverse momentum recoiling against visible standard model particles. Searches for mediators are also conducted via fully visible final states. The results of these searches are compared with those obtained from direct-detection experiments. Searches for alternative scenarios predicting more complex dark sectors with multiple new particles and new forces are also presented. Many of these models include long-lived particles, which could manifest themselves with striking unconventional signatures with relatively small amounts of background. Searches for such particles are discussed and their impact on dark-sector scenarios is evaluated. Many results and interpretations have been newly obtained for this Report

    Search for flavor-changing neutral current interactions of the top quark mediated by a Higgs boson in proton-proton collisions at 13 TeV

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    International audienceA search for flavor-changing neutral current interactions of the top quark (t) and the Higgs boson (H) is presented. The search is based on proton-proton collision data collected in 2016-2018 at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, and corresponding to an integrated luminosity of 138 fb1^{-1}. Events containing a pair of leptons with the same-sign electric charge and at least one jet are considered. The results are used to constrain the branching fraction (B\mathcal{B}) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark. No significant excess above the estimated background was found. The observed (expected) upper limits at 95% confidence level are found to be 0.072% (0.059%) for B\mathcal{B}(t \to Hu) and 0.043% (0.062%) for B\mathcal{B}(t \to Hc). These results are combined with two other searches performed by the CMS Collaboration for flavor-changing neutral current interactions of top quarks and Higgs bosons in final states with a pair of photons or of bottom quarks. The resulting observed (expected) upper limits at 95% confidence level are 0.019% (0.027%) for B\mathcal{B}(t \to Hu) and 0.037% (0.035%) for B\mathcal{B}(t \to Hc). These results constitute the most stringent limits on these branching fractions to date

    Observation of double J/ψ\psi meson production in pPb collisions at sNN\sqrt{s_\mathrm{NN}} = 8.16 TeV

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    International audienceThe first observation of the concurrent production of two J/ψ\psi mesons in proton-nucleus collisions is presented. The analysis is based on a proton-lead (pPb) data sample recorded at a nucleon-nucleon center-of-mass energy of 8.16 TeV by the CMS experiment at the CERN LHC and corresponding to an integrated luminosity of 174.6 nb1^{-1}. The two J/ψ\psi mesons are reconstructed in their μ+μ\mu^+\mu^- decay channels with transverse momenta pTp_\mathrm{T}>\gt 6.5 GeV and rapidity y\lvert y \rvert<\lt 2.4. Events where one of the J/ψ\psi mesons is reconstructed in the dielectron channel are also considered in the search. The pPb \to J/ψ\psiJ/ψ\psi+X process is observed with a significance of 5.3 standard deviations. The measured inclusive fiducial cross section, using the four-muon channel alone, is σ\sigma(pPb\to J/ψ\psiJ/ψ\psi+X)= 22.0 ±\pm 8.9 (stat) ±\pm 1.5 (syst) nb. A fit of the data to the expected rapidity separation for pairs of J/ψ\psi mesons produced in single (SPS) and double (DPS) parton scatterings yields σSPSpPbJ/ψJ/ψ+X\sigma^{\mathrm{pPb}\to\mathrm{J}/\psi\mathrm{J}/\psi+\mathrm{X}}_\text{SPS} = 16.5 ±\pm 10.8 (stat) ±\pm 0.1 (syst) nb and σDPSpPbJ/ψJ/ψ+X\sigma^{\mathrm{pPb}\to \mathrm{J}/\psi\mathrm{J}/\psi+\mathrm{X}}_\text{DPS} = 5.4 ±\pm 6.2 (stat) ±\pm 0.4 (syst) nb, respectively. This latter result can be transformed into a lower bound on the effective DPS cross section, closely related to the squared average interparton transverse separation in the collision, of σeff\sigma_\text{eff}>\gt 1.0 mb at 95% confidence level

    Search for new resonances decaying to pairs of merged diphotons in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search is presented for an extended Higgs sector with two new particles, X and ϕ\phi, in the process X \toϕϕ\phi\phi\to(γγ)(γγ)(\gamma\gamma)(\gamma\gamma). Novel neural networks classify events with diphotons that are merged and determine the diphoton masses. The search uses LHC proton-proton collision data at s\sqrt{s} = 13 TeV collected with the CMS detector, corresponding to an integrated luminosity of 138 fb1^{-1}. No evidence of such resonances is seen. Upper limits are set on the production cross section versus the resonance masses, representing the most sensitive search in this channel

    Constraints on the Higgs boson self-coupling from the combination of single and double Higgs boson production in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceThe Higgs boson (H) trilinear self-coupling, λ3\lambda_3, is constrained via its measured properties and limits on the HH pair production using the proton-proton collision data collected by the CMS experiment at s\sqrt{s} = 13 TeV. The combination of event categories enriched in single-H and HH events is used to measure κλ\kappa_\lambda, defined as the value of λ3\lambda_3 normalized to its standard model prediction, while simultaneously constraining the Higgs boson couplings to fermions and vector bosons. Values of κλ\kappa_\lambda outside the interval -1.2 <\ltκλ\kappa_\lambda<\lt 7.5 are excluded at 2σ\sigma confidence level, which is compatible with the expected range of -2.0 <\ltκλ\kappa_\lambda<\lt 7.7 under the assumption that all other Higgs boson couplings are equal to their standard model predicted values. Relaxing the assumption on the Higgs couplings to fermions and vector bosons the observed (expected) κλ\kappa_\lambda interval is constrained to be within -1.4 <\ltκλ\kappa_\lambda<\lt 7.8 (-2.3 <\ltκλ\kappa_\lambda<\lt 7.8) at 2σ\sigma confidence level
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