34 research outputs found

    A next-generation liquid xenon observatory for dark matter and neutrino physics

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    The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for weakly interacting massive particles, while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector

    Testes de função pulmonar e mortalidade após o transplante de células-tronco hematopoiéticas Hematopoietic stem cell transplantation: pulmonary function tests and post-transplant mortality

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    OBJETIVO: Verificar se os resultados dos testes de função pulmonar realizados em pacientes submetidos a transplante de células-tronco hematopoiéticas (TCTH) estão associados com a mortalidade após o procedimento. MÉTODOS: Estudo prospectivo no qual foram incluídos pacientes maiores de 15 anos submetidos a TCTH alogênico, entre janeiro de 2007 e março de 2008, no Hospital das Clínicas da Universidade Federal de Minas Gerais, em Belo Horizonte (MG), e que realizaram espirometria, medida de volumes pulmonares e medida de DLCO antes do TCTH. Os testes foram repetidos seis meses, um ano e dois anos após TCTH. Para a análise de sobrevida, foram utilizados o método de Kaplan-Meier e testes de log-rank bicaudal. O risco relativo (RR) e IC95% foram calculados por meio do ajuste do modelo de riscos proporcionais de Cox. O modelo de regressão de Cox foi utilizado na análise multivariada. RESULTADOS: Dos 54 pacientes incluídos, 40 (74,1%) apresentaram resultados normais de função pulmonar antes do TCTH. Ocorreram 23 óbitos (42,6%) em dois anos após o TCTH, sendo que 19 aconteceram antes de 100 dias. Dos 23 óbitos, 11 (47,8%) foram por septicemia e 10 (43,4%) por insuficiência respiratória aguda associada à septicemia. As únicas variáveis que mostraram associação significativa com mortalidade após TCTH foram alteração na espirometria antes do TCTH (RR = 3,2; p = 0,016) e doador não aparentado (RR = 9,0; p < 0,001). CONCLUSÕES:A realização da espirometria antes do TCTH fornece valores basais para comparações futuras. Alterações nesses resultados indicam um maior risco de mortalidade após o TCTH, embora esses não contraindicam o procedimento.<br>OBJECTIVE:To determine whether the results of pulmonary function tests carried out in patients subsequently submitted to hematopoietic stem cell transplantation (HSCT) are associated with post-HSCT mortality. METHODS: This was a prospective study involving patients older than 15 years of age who were submitted to allogenic HSCT between January of 2007 and March of 2008 at the Hospital das Clínicas da Universidade Federal de Minas Gerais, located in the city of Belo Horizonte, Brazil. Prior to HSCT, all of the patients underwent spirometry, determination of lung volumes, and determination of DLCO. Those same tests were repeated six months, one year, and two years after HSCT. Kaplan-Meier curves and two-tailed log-rank tests were used for survival analysis. The relative risk (RR) and 95% CI were calculated using the Cox proportional hazards model. The Cox regression model was used in the multivariate analysis. RESULTS:The pre-HSCT pulmonary function results were normal in 40 (74.1%) of the 54 patients evaluated, 19 (35.2%) of whom died within the first 100 days after HSCT. By the end of the two-year follow-up period, 23 patients (42.6%) had died, the most common causes of death being septicemia, observed in 11 (47.8%), and septicemia-related respiratory insufficiency, observed in 10 (43.4%). The only variables significantly associated with post-HSCT mortality were alterations in spirometry results prior to HSCT (RR = 3.2; p = 0.016) and unrelated donor (RR = 9.0; p < 0.001). CONCLUSIONS: Performing spirometry prior to HSCT provides baseline values for future comparisons. Although alterations in spirometry results reveal a higher risk of post-HSCT mortality, such alterations do not contraindicate the procedure

    A espirometria na avaliação pré e pós-transplante de medula óssea Pre-operative and post-operative spirometry in bone marrow transplant patients

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    OBJETIVO: Analisar os resultados da espirometria de pacientes submetidos a transplante de medula óssea e verificar sua importância na detecção de complicações pulmonares e sua correlação com a evolução dos pacientes. MÉTODOS:Foram analisados retrospectivamente os resultados da espirometria em 120 pacientes, maiores de doze anos, de ambos os sexos, e comparados com o tipo de transplante de medula óssea, doença de base, sorologia para citomegalovírus, fonte de células para o transplante, tabagismo, infecção pulmonar, doença pulmonar prévia, duração da doença hematológica, quimioterapia utilizada, regime de condicionamento, doença do enxerto contra o hospedeiro aguda e crônica e óbito. RESULTADOS: Dezesseis pacientes apresentaram alterações da espirometria antes do transplante, sendo 5% com obstrução pura, 5,8% com restrição pura e 2,5% com obstrução com redução da capacidade vital. Após o transplante 29 pacientes apresentaram alterações desses exames. A chance de alteração da espirometria foi maior nos pacientes com doença do enxerto contra o hospedeiro aguda (p = 0,02), idade menor que 30 anos (p = 0,02), sexo feminino (p = 0,02) e naqueles que receberam células tronco (p = 0,01). As presenças de doença pulmonar prévia e doença do enxerto contra o hospedeiro crônica associaram-se com aumento da mortalidade. Alterações prévias da espirometria não estiveram relacionadas com o óbito pós-transplante. CONCLUSÃO: As alterações detectadas na espirometria não foram capazes de predizer a ocorrência de complicações pulmonares e óbito pós-transplantes. Também não foram determinantes para a não realização do procedimento. A espirometria simples realizada na avaliação desses pacientes parece ter pouca importância prática.<br>OBJECTIVE: To analyze the spirometry findings in patients undergoing bone marrow transplant, determining the importance of such findings in predicting postoperative pulmonary complications and looking for correlations with postoperative outcomes. METHODS:The spirometry findings in 120 male and female patients, all above the age of 12, were evaluated retrospectively and compared in terms of the following parameters: the type of bone marrow transplant; the underlying disease; cytomegalovirus serology; source of the transplanted cells; smoking; pulmonary infection; history of lung disease; duration of the hematological disease; chemotherapy employed; conditioning regimen; acute or chronic rejection of the transplant; and post-operative mortality. RESULTS: In the pre-operative spirometry, 16 patients (13.3%) presented alterations: 6 (5%) presented pure obstruction; 7 (5.8%) presented pure restriction; and 3 (2.5%) presented obstruction accompanied by a reduction in vital capacity. In the post-operative spirometry, 29 patients (24.2%) presented alterations. The chance of presenting post-operative spirometry alterations was greater in patients presenting acute transplant rejection (p = 0.02), patients older than 30 (p = 0.02), female patients (p = 0.02) and patients receiving stem cells (p = 0.01). Having a history of lung disease was found to be associated with greater mortality, as was suffering from chronic transplant rejection. No relationship was found between pre-operative spirometry alterations and post-operative mortality. CONCLUSION: In bone marrow transplant patients, the alterations found through pre-operative spirometry were not predictive of post-operative pulmonary complications or mortality. Nor were such alterations determinant of whether or not a given patient was a good candidate for bone marrow transplant. Simple spirometry seems to be of little practical importance in the evaluation of such patients

    Predictors of Fatigue Severity in Early Systemic Sclerosis: A Prospective Longitudinal Study of the GENISOS Cohort

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    OBJECTIVES: Longitudinal studies examining the baseline predictors of fatigue in SSc have not been reported. Our objectives were to examine the course of fatigue severity over time and to identify baseline clinical, demographic, and psychosocial predictors of sequentially obtained fatigue scores in early SSc. We also examined baseline predictors of change in fatigue severity over time. METHODS: We analyzed 1090 longitudinal Fatigue Severity Scale (FSS) scores belonging to 256 patients who were enrolled in the Genetics versus Environment in Scleroderma Outcomes Study (GENISOS). Predictive significance of baseline variables for sequentially obtained FSS scores was examined with generalized linear mixed models. Predictors of change in FSS over time were examined by adding an interaction term between the baseline variable and time-in-study to the model. RESULTS: The patients' mean age was 48.6 years, 47% were Caucasians, and 59% had diffuse cutaneous involvement. The mean disease duration at enrollment was 2.5 years. The FSS was obtained at enrollment and follow-up visits (mean follow-up time = 3.8 years). Average baseline FSS score was 4.7(±0.96). The FSS was relatively stable and did not show a consistent trend for change over time (p = 0.221). In a multivariable model of objective clinical variables, higher Medsger Gastrointestinal (p = 0.006) and Joint (p = 0.024) Severity Indices, and anti-U1-RNP antibodies (p = 0.024) were independent predictors of higher FSS. In the final model, ineffective coping skills captured by higher Illness Behavior Questionnaire scores (p<0.001), higher self-reported pain (p = 0.006), and higher Medsger Gastrointestinal Severity Index (p = 0.009) at enrollment were independent predictors of higher longitudinal FSS scores. Baseline DLco % predicted was the only independent variable that significantly predicted a change in FSS scores over time (p = 0.013), with lower DLco levels predicting an increase in FSS over time. CONCLUSIONS: This study identified potentially modifiable clinical and psychological factors that predict longitudinal fatigue severity in early SSc
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