29 research outputs found

    Results of the BiPo-1 prototype for radiopurity measurements for the SuperNEMO double beta decay source foils

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    The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in 208^{208}Tl and 214^{214}Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8 m2m^2 of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in 208^{208}Tl. After more than one year of background measurement, a surface activity of the scintillators of A\mathcal{A}(208^{208}Tl) == 1.5 μ\muBq/m2^2 is reported here. Given this level of background, a larger BiPo detector having 12 m2^2 of active surface area, is able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of A\mathcal{A}(208^{208}Tl) << 2 μ\muBq/kg (90% C.L.) with a six month measurement.Comment: 24 pages, submitted to N.I.M.

    Spectral modeling of scintillator for the NEMO-3 and SuperNEMO detectors

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    We have constructed a GEANT4-based detailed software model of photon transport in plastic scintillator blocks and have used it to study the NEMO-3 and SuperNEMO calorimeters employed in experiments designed to search for neutrinoless double beta decay. We compare our simulations to measurements using conversion electrons from a calibration source of 207Bi\rm ^{207}Bi and show that the agreement is improved if wavelength-dependent properties of the calorimeter are taken into account. In this article, we briefly describe our modeling approach and results of our studies.Comment: 16 pages, 10 figure

    ATLAS detector and physics performance: Technical Design Report, 1

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    The heart in Anderson Fabry disease

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    Anderson Fabry disease is a life threatening, X-linked inborn metabolic defect of the lysosomal enzyme á{alpha}-galactosidase A. The deficiency of {alpha}-galactosidase A leads to a progressive accumulation of globotriaosylceramide (Gb(3)), the major glycosphingolipid substrate of the enzyme, within vulnerable cells, tissues, and organs, including the cardiovascular system. Cardiac involvement is frequent and patients with cardiac affection develop progressive hypertrophic infiltrative cardiomyopathy, valvular abnormalities, arrhythmias, and conduction abnormalities and may develop coronary heart disease. Hemizygous male patients have no detectable {alpha}-galactosidase A activity, while affected heterozygous females may have normal level of {alpha}-galactosidase A activity. Death occurs in male patients at 45 to 50 years, about 15 to 20 years earlier than in female patients due to a vicious circle from chronic renal insufficiency, arterial hypertension, atherosclerotic lesions and cerebrovascular hemorrhage or insults, and cardiomyopathy.    Cardiac involvement in hetero- and hemizygotes will be discussed as well as the influence of enzyme replacement of {alpha}-galactosidase A

    Recurrent in-stent restenosis is not associated with the angiotensin-converting enzyme D/I, angiotensinogen Thr174Met and Met235Thr, and the angiotensin-II receptor 1 A1166C polymorphism

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    Although great progress has been made in reducing renarrowing of the lumen after stenting of coronary arteries, a considerable number of patients develop recurrent in-stent stenosis. Several studies suggest that neointimal proliferation is the crucial pathophysiological process underlying restenosis after stenting. The renin-angiotensin-aldosterone system (RAS) has been implicated in the development of neointimal hyperplasia. We tested the hypothesis that polymorphisms of the RAS genes are associated with recurrent in-stent restenosis (ISR). Coronary stent implantation was performed in 272 patients with clinical symptoms or objective signs of ischemia. At follow-up angiography 6 months after stenting, 81 patients (29.8%) revealed in-stent restenosis. These patients underwent balloon angioplasty and were scheduled for a further 6 months of follow up. One year after initial stenting of the coronary artery, 39 patients displayed no significant angiographic ISR, whereas 42 patients developed recurrent in-stent restenosis (RISR). The survey of specific functional polymorphisms of the RAS, namely the angiotensin-I converting enzyme (ACE) D/I, the angiotensinogen (AGT) T174M and M235T, and A1166C of the angiotensin-II receptor 1 (AGTR1), revealed that the incidence RISR in the high-risk cohort was not associated with any of the polymorphisms examined in this study
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