282 research outputs found

    Study of Faraday cups for fast ion beams provided by a LIS source

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    Faraday cups are widely utilized to characterize ion and electrons beams. Owing to the secondary electron emission (SEE) induced by the collision of beams with collectors, wrong measurements could emerge from these detectors. To overcome this problem a polarized grid is utilized in front the cup collector at a negative voltage with respect to the collector. Unfortunately, the high voltage connection of the Faraday cups is hard to obtain. Then, in this work we want to study the secondary emission on different Al ion collector designs having tilted surfaces with respect to beam axis. Tests were performed using ion beams accelerated by a power supply up to 40 kV. The results by the modified collector surfaces were compared to the ones performed with a simple flat collector. The results we obtained point out that the secondary electron emission enhanced on incident beam energy and on the angle with respect to the normal direction of the surface. The ratio of the SEE to angle value results constant for the accelerating voltage and the possibility to design an ion collector able to reset the SEE seems not to be reached

    Guidelines for the assessment of efficacy of clinical hypnosis applications

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    Research on the efficacy of hypnosis applications continues to grow, but there remain major gaps between the science and clinical practice. One challenge has been a lack of consensus on which applications of hypnosis are efficacious based on research evidence. In 2018, 6 major hypnosis organizations collaborated to form the Task Force for Establishing Efficacy Standards for Clinical Hypnosis. This paper describes a Guideline for the Assessment of Efficacy of Clinical Hypnosis Applications developed by the Task Force, which makes 10 specific recommendations. The guideline is intended to be a tool for those who want to assess the quality of existing evidence on the efficacy of clinical hypnosis for any particular indication. The paper also discusses methodological issues in the interpretation and implementation of these guidelines. Future papers will report on the other products of the Hypnosis Efficacy Task Force, such as best practice recommendations for outcomes research in hypnosis and an international survey of researchers and clinicians on current practice and attitudes about hypnosis

    PERIODONTITIS AND EARLY MORTALITY IN ADULTS WITH KIDNEY FAILURE TREATED WITH HEMODIALYSIS: A MULTINATIONAL OBSERVATIONAL STUDY

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    Introduction and Aims: Periodontitis is associated with cardiovascular mortality in the general population and adults with chronic diseases, however prognostic data for periodontitis in the setting of kidney failure are sparse. The aim of the study was to evaluate whether periodontitis was prognostic for all-cause and cardiovascular-related death in adults with kidney failure. Methods: ORALD is a multinational cohort study in adults with kidney failure treated with haemodialysis in Europe (France, Hungary, Italy, Poland, Portugal and Spain) and Argentina. Periodontitis was measured at baseline according to the World Health Organization Community Periodontal Index. The outcomes were all-cause and cardiovascular mortality. Analyses were conducted using a fixed-effect Cox proportional hazards analysis and additionally using a random effects model fitted using shared frailty to account for clustering within countries. Results: Periodontitis was evaluable in 3338 dentate participants of which 1355 (40.6%) had moderate to severe periodontitis. During 6150 person-years of follow-up, 650 deaths occurred of which 325 were cardiovascular. In multivariable analyses, moderate to severe periodontitis was associated with a lower hazard of all-cause (HR 0.76, 95% confidence interval 0.64 to 0.90) and cardiovascular (0.69, 0.54 to 0.87) mortality. There was evidence of decreasing mortality risks with more severe periodontal disease (P≤0.001 for trend). However, when analyses accounted for clustering of participants within countries, the associations between periodontitis and all-cause (0.92, 0.75 to 1.11) and cardiovascular (0.83, 0.63 to 1.09) mortality were not significant. Similar results were observed in analyses restricted to participants with 12 or more teeth and when competing risks for cardiovascular death were considered. Conclusions: Unlike in the general population, there is limited evidence that periodontitis is independently associated with increased all-cause or cardiovascular mortality in adults with kidney failure

    Clinical Relevance of Liver Involvement in the Clinical Course of Systemic Sclerosis

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    Liver involvement in systemic sclerosis (SSc) is rare. We evaluated the prevalence of liver fibrosis and hepatic autoimmunity in SSc patients in a retrospective observational cohort (97 SSc or mixed connective tissue disease with sclerodermic manifestations patients undergoing transient elastography, evaluating liver stiffness (LS) and controlled attenuation parameter (CAP), due to clinical indications along with biochemistry assessments and major antibodies associated to liver autoimmunity). Among them, 11 had LS ≥ 7.5 kPa and 5 showed an LS compatible with cirrhosis (LS ≥ 12.5 kPa). Predictors of LS ≥ 7.5 fibrosis were alcohol consumption (>14 or >7 alcoholic units/week for men and women, respectively), waist circumference (>102 or >88 cm for men and women, respectively), elevated alkaline phosphatase, and anti-La and anti-mitochondrial antibody (AMA) positivity. Six patients had CAP values compatible with severe steatosis (≥280 dB/m). Waist circumference, body mass index and diabetes mellitus were significant predictors of steatosis. Out of 97 patients, 19 were positive for AMA, 4 for anti-Sp100, 1 for anti-Gp210 and 7 were diagnosed with primary biliary cholangitis. Among SSc patients, hepatic fibrosis biomarkers and AMA prevalence are relatively high, suggesting the opportunity of performing a transient elastography and a screening for hepatic autoimmunity at diagnosis and/or during disease progression

    Internal alignment and position resolution of the silicon tracker of DAMPE determined with orbit data

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    The DArk Matter Particle Explorer (DAMPE) is a space-borne particle detector designed to probe electrons and gamma-rays in the few GeV to 10 TeV energy range, as well as cosmic-ray proton and nuclei components between 10 GeV and 100 TeV. The silicon-tungsten tracker-converter is a crucial component of DAMPE. It allows the direction of incoming photons converting into electron-positron pairs to be estimated, and the trajectory and charge (Z) of cosmic-ray particles to be identified. It consists of 768 silicon micro-strip sensors assembled in 6 double layers with a total active area of 6.6 m2^2. Silicon planes are interleaved with three layers of tungsten plates, resulting in about one radiation length of material in the tracker. Internal alignment parameters of the tracker have been determined on orbit, with non-showering protons and helium nuclei. We describe the alignment procedure and present the position resolution and alignment stability measurements

    Unraveling the complexity of tyrosine kinase inhibitor-resistant populations by ultra-deep sequencing of the BCR-ABL kinase domain

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    In chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia, tyrosine kinase inhibitor (TKI) therapy may select for drug-resistant BCR-ABL mutants. We used an ultra-deep sequencing (UDS) approach to resolve qualitatively and quantitatively the complexity of mutated populations surviving TKIs and to investigate their clonal structure and evolution over time in relation to therapeutic intervention. To this purpose, we performed a longitudinal analysis of 106 samples from 33 patients who had received sequential treatment with multiple TKIs and had experienced sequential relapses accompanied by selection of 1 or more TKI-resistant mutations. We found that conventional Sanger sequencing had misclassified or underestimated BCR-ABL mutation status in 55% of the samples, where mutations with 1% to 15% abundance were detected. A complex clonal texture was uncovered by clonal analysis of samples harboring multiple mutations and up to 13 different mutated populations were identified. The landscape of these mutated populations was found to be highly dynamic. The high degree of complexity uncovered by UDS indicates that conventional Sanger sequencing might be an inadequate tool to assess BCR-ABL kinase domain mutation status, which currently represents an important component of the therapeutic decision algorithms. Further evaluation of the clinical usefulness of UDS-based approaches is warranted

    The DArk Matter Particle Explorer mission

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    The DArk Matter Particle Explorer (DAMPE), one of the four scientific space science missions within the framework of the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences, is a general purpose high energy cosmic-ray and gamma-ray observatory, which was successfully launched on December 17th, 2015 from the Jiuquan Satellite Launch Center. The DAMPE scientific objectives include the study of galactic cosmic rays up to 10\sim 10 TeV and hundreds of TeV for electrons/gammas and nuclei respectively, and the search for dark matter signatures in their spectra. In this paper we illustrate the layout of the DAMPE instrument, and discuss the results of beam tests and calibrations performed on ground. Finally we present the expected performance in space and give an overview of the mission key scientific goals.Comment: 45 pages, including 29 figures and 6 tables. Published in Astropart. Phy
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