Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Phys Rev Lett ; 129(22): 222501, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493444

RESUMO

The Cryogenic Underground Observatory for Rare Events (CUORE) at Laboratori Nazionali del Gran Sasso of INFN in Italy is an experiment searching for neutrinoless double beta (0νßß) decay. Its main goal is to investigate this decay in ^{130}Te, but its ton-scale mass and low background make CUORE sensitive to other rare processes as well. In this Letter, we present our first results on the search for 0νßß decay of ^{128}Te, the Te isotope with the second highest natural isotopic abundance. We find no evidence for this decay, and using a Bayesian analysis we set a lower limit on the ^{128}Te 0νßß decay half-life of T_{1/2}>3.6×10^{24} yr (90% CI). This represents the most stringent limit on the half-life of this isotope, improving by over a factor of 30 the previous direct search results, and exceeding those from geochemical experiments for the first time.


Assuntos
Granisetron , Meia-Vida , Teorema de Bayes
3.
Arch Cardiol Mex ; 92(1): 99-112, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34187049

RESUMO

BACKGROUND: Hypertension, hyperglycemia, dyslipidemia, overweight, obesity, and tobacco (smoking, chewing, and vaping), together with a pro-inflammatory and procoagulant state, are the main risk factors related to atherosclerotic cardiovascular disease. OBJECTIVE AND METHODS: A group of experts from the Americas, based on their clinical expertise in cardiology, cardiovascular prevention, and cardiometabolic (CM) diseases, joined together to develop these practical recommendations for the optimal evaluation and treatment of residual CM risk factors in Latin America, using a modified Delphi methodology (details in electronic TSI) to generate a comprehensive CM risk reduction guideline, and through personalized medicine and patient-centered decision, considering the cost-benefit ratio The process was well defined to avoid conflicts of interest that could bias the discussion and recommendations. RESULTS: Residual risk reduction should consider therapeutic options adapted to specific patient needs, based on five treatment objectives: triglyceride-rich lipoproteins, inflammation, impaired glucose metabolism, high blood pressure, and prothrombotic status. Comprehensive control of all CM risk factors should be a priority to deal with this important public health problem and prevent premature deaths. The recommendations in this paper address the evidence-based treatment of CM risk and are intended for clinical application in Latin American countries.


Antecedentes: Un grupo de factores de riesgo cardiometabólicos (hipertensión, hiperglucemia, dislipidemia, sobrepeso, obesidad y tabaco (fumado, masticado, vaporizado), junto con un estado proinflamatorio y procoagulante, son los principales factores de riesgo relacionados con la enfermedad cardiovascular aterosclerótica. Objetivo y métodos: Basándose en su experiencia en cardiología, prevención cardiovascular y enfermedades cardiometabólicas, un grupo de expertos de las Américas se unió para desarrollar estas recomendaciones prácticas para la evaluación y tratamiento óptimos de los factores de riesgo cardiometabólicos residuales en América Latina, utilizando una metodología Delphi modificada con el objetivo de generar una guía integral de pautas para la reducción del riesgo cardiometabólico, mediante la medicina personalizada y la decisión centrada en el paciente teniendo en cuenta la relación costo-beneficio. El proceso fue bien definido para evitar conflictos de intereses que podrían sesgar la discusión y las recomendaciones. Resultados: La reducción del riesgo residual debe considerar opciones terapéuticas adaptadas a las necesidades específicas del paciente, basadas en 5 objetivos de tratamiento: lipoproteínas ricas en triglicéridos inflamación, metabolismo de la glucosa, presión arterial alta y estado protrombótico. El Control integral de todos los factores de riesgo cardiometabólicos debe ser una prioridad para hacer frente a este importante problema de salud pública y prevenir las muertes prematuras. Las recomendaciones de este documento abordan el tratamiento basado en evidencia del riesgo cardiometabólico y están destinadas a la aplicación clínica en los países de América Latina.


Assuntos
Aterosclerose , Cardiologia , Consenso , Endotélio , Humanos , América Latina , Lipídeos , Estados Unidos
4.
Phys Rev Lett ; 126(17): 171801, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988435

RESUMO

We measured two-neutrino double beta decay of ^{130}Te using an exposure of 300.7 kg yr accumulated with the CUORE detector. Using a Bayesian analysis to fit simulated spectra to experimental data, it was possible to disentangle all the major background sources and precisely measure the two-neutrino contribution. The half-life is in agreement with past measurements with a strongly reduced uncertainty: T_{1/2}^{2ν}=7.71_{-0.06}^{+0.08}(stat)_{-0.15}^{+0.12}(syst)×10^{20} yr. This measurement is the most precise determination of the ^{130}Te 2νßß decay half-life to date.

5.
Phys Rev Lett ; 124(12): 122501, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32281829

RESUMO

We report new results from the search for neutrinoless double-beta decay in ^{130} Te with the CUORE detector. This search benefits from a fourfold increase in exposure, lower trigger thresholds, and analysis improvements relative to our previous results. We observe a background of (1.38±0.07)×10^{-2} counts/(keV kg yr)) in the 0νßß decay region of interest and, with a total exposure of 372.5 kg yr, we attain a median exclusion sensitivity of 1.7×10^{25} yr. We find no evidence for 0νßß decay and set a 90% credibility interval Bayesian lower limit of 3.2×10^{25} yr on the ^{130} Te half-life for this process. In the hypothesis that 0νßß decay is mediated by light Majorana neutrinos, this results in an upper limit on the effective Majorana mass of 75-350 meV, depending on the nuclear matrix elements used.

6.
Phys Rev Lett ; 120(13): 132501, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29694201

RESUMO

The CUORE experiment, a ton-scale cryogenic bolometer array, recently began operation at the Laboratori Nazionali del Gran Sasso in Italy. The array represents a significant advancement in this technology, and in this work we apply it for the first time to a high-sensitivity search for a lepton-number-violating process: ^{130}Te neutrinoless double-beta decay. Examining a total TeO_{2} exposure of 86.3 kg yr, characterized by an effective energy resolution of (7.7±0.5) keV FWHM and a background in the region of interest of (0.014±0.002) counts/(keV kg yr), we find no evidence for neutrinoless double-beta decay. Including systematic uncertainties, we place a lower limit on the decay half-life of T_{1/2}^{0ν}(^{130}Te)>1.3×10^{25} yr (90% C.L.); the median statistical sensitivity of this search is 7.0×10^{24} yr. Combining this result with those of two earlier experiments, Cuoricino and CUORE-0, we find T_{1/2}^{0ν}(^{130}Te)>1.5×10^{25} yr (90% C.L.), which is the most stringent limit to date on this decay. Interpreting this result as a limit on the effective Majorana neutrino mass, we find m_{ßß}<(110-520) meV, where the range reflects the nuclear matrix element estimates employed.

7.
J Laryngol Otol ; 131(3): 264-267, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28007041

RESUMO

OBJECTIVE: The aetiology and outcomes for patients with acquired subglottic stenosis are highly variable. This study aimed to identify risk factors for subglottic stenosis and patient characteristics that predict long-term clinical outcomes. METHODS: A retrospective review was performed on 63 patients with subglottic stenosis and 63 age-matched controls. Patient demographics and clinical characteristics were compared. Subglottic stenosis patients were further grouped according to tracheostomy status (i.e. tracheostomy never required, tracheostomy initially required but patient eventually decannulated, and tracheostomy-dependent). Patient factors from these three groups were then compared to evaluate risk factors for long-term tracheostomy dependence. RESULTS: Compared to controls, patients with subglottic stenosis had a significantly higher body mass index (30.8 vs 26.0 kg/m2; p < 0.001) and were more likely to have diabetes (23.8 per cent vs 7.94 per cent; p = 0.01). Comparing tracheostomy outcomes within the subglottic stenosis group, body mass index trended towards significance (p = 0.08). Age, gender, socio-economic status, subglottic stenosis aetiology and other co-morbidities did not correlate with outcome. CONCLUSION: Obesity and diabetes are significant risk factors for acquiring subglottic stenosis. Further investigations are required to determine if obesity is also a predictor for failed tracheostomy decannulation in subglottic stenosis.


Assuntos
Laringoestenose/etiologia , Traqueostomia/estatística & dados numéricos , Adulto , Idoso , Índice de Massa Corporal , Estudos de Casos e Controles , Complicações do Diabetes/complicações , Feminino , Humanos , Laringoestenose/patologia , Laringoestenose/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Traqueostomia/métodos
8.
Phys Rev Lett ; 115(10): 102502, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26382673

RESUMO

We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of (130)Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1±0.3 keV FWHM and 0.058±0.004(stat)±0.002(syst)counts/(keV kg yr), respectively. The median 90% C.L. lower-limit half-life sensitivity of the experiment is 2.9×10(24) yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of (130)Te and place a Bayesian lower bound on the decay half-life, T(1/2)(0ν)>2.7×10(24) yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of (130)Te from the Cuoricino experiment we obtain T(1/2)(0ν)>4.0×10(24) yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, m(ßß)<270-760 meV.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...