397 research outputs found

    Techniques and detectors for polarimetry in X-ray astronomy

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    Polarimeters flown so far were based on the Thomson scattering and Bragg diffraction with intrinsically limited sensitivity. In the present paper, we review the experiments based on those techniques and discuss possible optimization and implementation for X-ray astronomy

    An X-ray polarimeter for hard X-ray optics

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    Development of multi-layer optics makes feasible the use of X-ray telescope at energy up to 60-80 keV: in this paper we discuss the extension of photoelectric polarimeter based on Micro Pattern Gas Chamber to high energy X-rays. We calculated the sensitivity with Neon and Argon based mixtures at high pressure with thick absorption gap: placing the MPGC at focus of a next generation multi-layer optics, galatic and extragalactic X-ray polarimetry can be done up till 30 keV.Comment: 12 pages, 7 figure

    Assembly and test of the gas pixel detector for X-ray polarimetry

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    The gas pixel detector (GPD) dedicated for photoelectric X-ray polarimetry is selected as the focal plane detector for the ESA medium-class mission concept X-ray Imaging and Polarimetry Explorer (XIPE). Here we show the design, assembly, and preliminary test results of a small GPD for the purpose of gas mixture optimization needed for the phase A study of XIPE. The detector is assembled in house at Tsinghua University following a design by the INFN-Pisa group. The improved detector design results in a good uniformity for the electric field. Filled with pure dimethyl ether (DME) at 0.8 atm, the measured energy resolution is 18% at 6 keV and inversely scales with the square root of the X-ray energy. The measured modulation factor is well consistent with that from simulation, up to ~0.6 above 6 keV. The residual modulation is found to be 0.30±0.15% at 6 keV for the whole sensitive area, which can be translated into a systematic error of less than 1% for polarization measurement at a confidence level of 99%. The position resolution of the detector is about 80 μm in FWHM, consistent with previous studies and sufficient for XIPE requirements

    Absolute monocyte count and lymphocyte-monocyte ratio predict outcome in nodular sclerosis Hodgkin lymphoma: Evaluation based on data from 1450 patients

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    Objective: To verify whether absolute monocyte count (AMC) and lymphocyte-monocyte ratio (LMR) at diagnosis are valid prognostic parameters in classical Hodgkin lymphoma (cHL). Patients and Methods: Data were collected from 1450 patients with cHL treated in Israel and Italy from January 1, 1988, through December 31, 2007. Results: The median age of the patients was 33 years (range, 17-72 years), and 70% (1017) of the patients had nodular sclerosis (NS); the median follow-up duration was 87 months. The best cutoff value for AMC was 750 cells/mm3, and the best ratio for LMR was 2.1. The adverse prognostic impact of an AMC of more than 750 cells/mm(3) was confirmed for the entire cohort, and its clinical significance was particularly evident in patients with NS histology. The progression-free survival (PFS) at 10 years for an AMC of more than 750 cells/mm(3) was 65% (56%-72%), and the PFS at 10 years for an AMC of 750 cells/mm(3) or less was 81% (76%-84%; P<.001). The overall survival (OS) at 10 years for an AMC of more than 750 cells/mm3 was 78% (70%-85%), and the OS at 10 years for an AMC of 750 cells/mm(3) or less was 88% (84%-90%; P=.01). In multivariate analysis, both AMC and LMR maintained prognostic significance for PFS (hazard ratio [HR], 1.54, P=.006, and HR, 1.50, P=.006) after adjusting for the international prognostic score, whereas the impact on OS was confirmed (HR, 1.56; P=.04) only in patients with NS and an AMC of more than 750 cells/mm(3). Conclusion: This study confirms that AMC has prognostic value in cHL that is particularly significant in patients with NS subtype histology. This finding links the known impact of macrophages and monocytes in Hodgkin lymphoma with routine clinical practice

    Long-term results of the HD2000 trial comparing ABVD versus BEACOPP versus COPP-EBV-CAD in untreated patients with advanced hodgkin lymphoma: A study by fondazione Italiana Linfomi

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    Purpose The randomized HD2000 trial compared six cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine), four escalated plus two standard cycles of BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone), and six cycles of COPPEBV- CAD (cyclophosphamide, lomustine, vindesine, melphalan, prednisone, epidoxorubicin, vincristine, procarbazine, vinblastine, and bleomycin; CEC) in patients with advanced-stage Hodgkin lymphoma. After a median follow-up of 42 months, patients who received BEACOPP were reported to have experienced better progression-free survival (PFS) but not better overall survival (OS) results than those receiving ABVD. Wehere report a post hoc analysis of this trial after a median follow-up of 10 years. Patients and Methods Three hundred seven patients were enrolled, 295 of whom were evaluable. At the time of our analysis, the median follow-up for the entire group was 120 months (range, 4 to 169 months). Results The 10-year PFS results for the ABVD, BEACOPP, and CEC arms were 69%, 75%, and 76%, respectively; corresponding OS results were 85%, 84%, and 86%. Overall, 13 second malignancies were reported: one in the ABVD arm and six each in the BEACOPP and CEC arms. The cumulative risk of developing secondmalignancies at 10 years was 0.9%, 6.6%, and 6% with ABVD, BEACOPP, and CEC, respectively; the risk with either BEACOPP or CEC was significantly higher than that reported with ABVD (P = .027 and .02, respectively). Conclusion With these mature results, we confirm that patients with advanced Hodgkin lymphoma have similar OS results when treated with ABVD, BEACOPP, or CEC. However, with longer follow-up, we were not able to confirm the superiority of BEACOPP over ABVD in terms of PFS, mainly because of higher mortality rates resulting from second malignancies observed after treatment with BEACOPP and CEC

    Gleam: the GLAST Large Area Telescope Simulation Framework

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    This paper presents the simulation of the GLAST high energy gamma-ray telescope. The simulation package, written in C++, is based on the Geant4 toolkit, and it is integrated into a general framework used to process events. A detailed simulation of the electronic signals inside Silicon detectors has been provided and it is used for the particle tracking, which is handled by a dedicated software. A unique repository for the geometrical description of the detector has been realized using the XML language and a C++ library to access this information has been designed and implemented.Comment: 10 pages, Late

    A photoelectric polarimeter for XEUS: a new window in x-ray sky

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    XEUS is a large area telescope aiming to rise X-ray Astronomy to the level of Optical Astronomy in terms of collecting areas. It will be based on two satellites, locked on a formation flight, one with the optics, one with the focal plane. The present design of the focal plane foresees, as an auxiliary instrument, the inclusion of a Polarimeter based on a Micropattern Chamber. We show how such a device is capable to solve open problems on many classes of High Energy Astrophysics objects and to use X-ray sources as a laboratory for a substantial progress on Fundamental Physics.Comment: 12 pages, 7 figure

    Predicting lymphoma in Sjögren's syndrome and the pathogenetic role of parotid microenvironment through precise parotid swelling recording

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    Objective: Parotid swelling (PSW) is a major predictor of non-Hodgkin lymphoma (NHL) in primary Sjögren's syndrome (pSS). However, since detailed information on the time of onset and duration of PSW is scarce, this was investigated to verify whether it may lead to further improved prediction. NHL localisation was concomitantly studied to evaluate the role of the parotid gland microenvironment in pSS-related lymphomagenesis. Methods: A multicentre study was conducted among patients with pSS who developed B cell NHL during follow-up and matched controls that did not develop NHL. The study focused on the history of salivary gland and lachrymal gland swelling, evaluated in detail at different times and for different durations, and on the localisation of NHL at onset. Results: PSW was significantly more frequent among the cases: at the time of first referred pSS symptoms before diagnosis, at diagnosis, and from pSS diagnosis to NHL. The duration of PSW was evaluated starting from pSS diagnosis, and the NHL risk increased from PSW of 2-12 months to > 12 months. NHL was prevalently localised in the parotid glands of the cases. Conclusion: A more precise clinical recording of PSW can improve lymphoma prediction in pSS. PSW as a very early symptom is a predictor, and a longer duration of PSW is associated with a higher risk of NHL. Since lymphoma usually localises in the parotid glands, and not in the other salivary or lachrymal glands, the parotid microenvironment appears to be involved in the whole history of pSS and related lymphomagenesis

    POLARIX: a small mission of x-ray polarimetry

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    X-Ray Polarimetry can be now performed by using a Micro Pattern Gas Chamber in the focus of a telescope. It requires large area optics for most important scientific targets. But since the technique is additive a dedicated mission with a cluster of small telescopes can perform many important measurements and bridge the 40 year gap between OSO-8 data and future big telescopes such as XEUS. POLARIX has been conceived as such a pathfinder. It is a Small Satellite based on the optics of JET-X. Two telescopes are available in flight configuration and three more can be easily produced starting from the available superpolished mandrels. We show the capabilities of such a cluster of telescopes each equipped with a focal plane photoelectric polarimeter and discuss a few alternative solutions.Comment: 9 pages, 5 figure

    How immunological profle drives clinical phenotype of primary Sjögren’s syndrome at diagnosis: analysis of 10,500 patients (Sjögren Big Data Project)

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    To evaluate the influence of the main immunological markers on the disease phenotype at diagnosis in a large international cohort of patients with primary Sjögren´s syndrome (SjS).METHODS:The Big Data Sjögren Project Consortium is an international, multicentre registry created in 2014. As a first step, baseline clinical information from leading centres on clinical research in SjS of the 5 continents was collected. The centres shared a harmonised data architecture and conducted cooperative online efforts in order to refine collected data under the coordination of a big data statistical team. Inclusion criteria were the fulfillment of the 2002 classification criteria. Immunological tests were carried out using standard commercial assays.RESULTS:By January 2018, the participant centres had included 10,500 valid patients from 22 countries. The cohort included 9,806 (93%) women and 694 (7%) men, with a mean age at diagnosis of primary SjS of 53 years, mainly White (78%) and included from European countries (71%). The frequency of positive immunological markers at diagnosis was 79.3% for ANA, 73.2% for anti-Ro, 48.6% for RF, 45.1% for anti- La, 13.4% for low C3 levels, 14.5% for low C4 levels and 7.3% for cryoglobulins. Positive autoantibodies (ANA, Ro, La) correlated with a positive result in salivary gland biopsy, while hypocomplementaemia and especially cryoglo-bulinaemia correlated with systemic activity (mean ESSDAI score of 17.7 for cryoglobulins, 11.3 for low C3 and 9.2 for low C4, in comparison with 3.8 for negative markers). The immunological markers with a great number of statistically-significant associations (p<0.001) in the organ-by-organ ESS- DAI evaluation were cryoglobulins (9 domains), low C3 (8 domains), anti-La (7 domains) and low C4 (6 domains).CONCLUSIONS:We confirm the strong influence of immunological markers on the phenotype of primary SjS at diagnosis in the largest multi-ethnic international cohort ever analysed, with a greater influence for cryoglobulinaemic-related markers in comparison with Ro/La autoantibodies and ANA. Immunological patterns play a central role in the phenotypic expression of the disease already at the time of diagnosis, and may guide physicians to design a specific personalised management during the follow-up of patients with primary SjS.Fil: Brito Zerón, Pilar. Hospital Sanitas CIMA; España. Universidad de Barcelona; EspañaFil: Acar Denizli, Nihan. Mimar Sinan Fine Arts University; TurquíaFil: Ng, Wan Fai. University of Newcastle; Reino UnidoFil: Zeher, Margit. University of Debrecen; HungríaFil: Rasmussen, Astrid. Oklahoma Medical Research Foundation; Estados UnidosFil: Mandl, Thomas. Lund University; SueciaFil: Seror, Raphaele. Université Paris Sud; FranciaFil: Xiaolin, Li. Anhui Provincial Hospital; ChinaFil: Baldini, Chiara. Università degli Studi di Pisa; ItaliaFil: Gottenberg, Jaques. Université de Strasbourg; Francia. Centre National de la Recherche Scientifique; FranciaFil: Danda, Debashish. Christian Medical College & Hospital; IndiaFil: Quartuccio, Luca. University Hospital “Santa María della Misericordia”; ItaliaFil: Priori, Roberta. Università degli Studi di Roma "La Sapienza"; ItaliaFil: Hernandez Molina, Gabriela. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; MéxicoFil: Armagan, Berkan. Hacettepe University. Faculty of Medicine.Department of Internal Medicine; TurquíaFil: Kruize, Aike. University Medical Center Utrecht; Países BajosFil: Kwok, Seung Ki. The Catholic University of Korea; Corea del SurFil: Kvarnström, Marika. Karolinska University Hospital.Department of Medicine.Unit of Rheumatology. Karolinska Institutet ; SueciaFil: Praprotnik, Sonja. University Medical Centre; EsloveniaFil: Sene, Damien. Université Paris Diderot - Paris 7; FranciaFil: Bartoloni, Elena. Università di Perugia; ItaliaFil: Solans, R.. Hospital Vall d’Hebron; ItaliaFil: Rischmueller, M.. University of Western Australia; AustraliaFil: Suzuki, Y.. Kanazawa University Hospital; JapónFil: Isenberg, D. A.. University College London; Estados UnidosFil: Valim, V.. Federal University of Espírito Santo; BrasilFil: Wiland, P.. Wroclaw Medical Hospital; PoloniaFil: Nordmark, G.. Uppsala Universitet; SueciaFil: Fraile, G.. Hospital Ramón y Cajal; EspañaFil: Retamozo, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; Argentina. Hospital Privado Centro Medico de Córdoba; Argentina; Argentina. Instituto Universitario de Ciencias Biomédicas de Córdoba; Argentin
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