243 research outputs found

    Effectiveness of Search for Unrelated Donor of Hematopoietic Stem Cells using Russian System Bone Marrow Donor Search: Experience of RM Gorbacheva Scientific Research Institute of Pediatric Hematology and Transplantation

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    Background & Aims. The key condition for allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the presence of HLA-compatible related or unrelated donor. If related donor is not found, further search is carried out in the Bone Marrow Donor Worldwide (BMDW) international data base, which is not effective enough (about 80–85 %), because of genotype specificity of Russian Federation residents. The recruitment procedure using BMDW takes a lot of time and is expensive. Therefore, there are good reasons to develop an alternative Russian data base, Bone Marrow Donor Search (BMDS), which includes data from Russian bone marrow donor registries and has a good potential. The aim is to evaluate the effectiveness of hematopoietic stem cell (HSC) donor search and transplant quality using the BMDS search system. Methods. 34 allo-HSCT recipients with malignancies and hematological diseases were enrolled in the study in RM Gorbacheva Scientific Research Institute of Pediatric Hematology and Transplantation from November, 2012, to March, 2016. A HLA-compatible donor was found for each patient in the BMDS (www.bmds.info), which includes data from 13 Russian registries of HSC donors. Results. 34 allo-HSCTs were performed from unrelated donors recruited using Russian registries: 1 in 2012; 3 in 2013; 5 in 2014; 21 in 2015; and 4 in the 1st quarter of 2016. The greatest effectiveness of the BMDS search was in 2015 (14 %, n = 17). In 30 cases (88.2 %) a complete 10/10 compatibility for 5 HLA-gene loci was observed; in 4 cases (11.8 %) there was an incomplete compatibility (9/10). AB0 compatibility was only in 7 cases (20.6 %). In 15 cases (44.1 %) bone marrow was used for transplant harvesting; in 19 cases (55.9 %) peripheral blood stem cells were harvested by means of cytapheresis. The CD34+ count in the transplant was 1.2–12.0 x 106 CD34+ cell/kg (median: 5.0 x 106 CD34+ cell/kg). Engraftment was observed in 79.4 % of cases (n = 27), graft failure in 17.7 % of cases (n = 6), and early posttransplant mortality in 2.9 % of cases (n = 1). Conclusion. There was an increasing efficiency of search for a HLA-compatible unrelated HSC donor using a Russian BMDS search system for Russian residents with a graft quality similar to the one found in the international BMDW database

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Top-quark physics at the CLIC electron-positron linear collider

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    ABSTRACT: The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies √s = 380 GeV, 1.5 TeV, and 3 TeV. Its aim is to explore the energy frontier, providing sensitivity to physics beyond the Standard Model (BSM) and precision measurements of Standard Model processes with an emphasis on Higgs boson and top-quark physics. The opportunities for top-quark physics at CLIC are discussed in this paper. The initial stage of operation focuses on top-quark pair production measurements, as well as the search for rare flavour-changing neutral current (FCNC) top-quark decays. It also includes a top-quark pair production threshold scan around 350 GeV which provides a precise measurement of the top-quark mass in a well-defined theoretical framework. At the higher-energy stages, studies are made of top-quark pairs produced in association with other particles. A study of t̄tH production including the extraction of the top Yukawa coupling is presented as well as a study of vector boson fusion (VBF) production, which gives direct access to high-energy electroweak interactions. Operation above 1 TeV leads to more highly collimated jet environments where dedicated methods are used to analyse the jet constituents. These techniques enable studies of the top-quark pair production, and hence the sensitivity to BSM physics, to be extended to higher energies. This paper also includes phenomenological interpretations that may be performed using the results from the extensive top-quark physics programme at CLIC.the Spanish Ministry of Economy, Industry and Competitiveness under projects MINEICO/FEDER-UE, FPA2015-65652-C4-3-R, FPA2015-71292-C2-1-Pand FPA2015-71956-REDT; and the MECD grant FPA2016-78645-P, Spai

    Scaled momentum distributions for K-S(0) and Λ /̄ Λ in DIS at HERA

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    Scaled momentum distributions for the strange hadrons K0S and Λ/Λ¯ were measured in deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 330 pb−1. The evolution of these distributions with the photon virtuality, Q 2, was studied in the kinematic region 10 < Q 2  < 40000 GeV2 and 0.001 < x < 0.75, where x is the Bjorken scaling variable. Clear scaling violations are observed. Predictions based on different approaches to fragmentation were compared to the measurements. Leading-logarithm parton-shower Monte Carlo calculations interfaced to the Lund string fragmentation model describe the data reasonably well in the whole range measured. Next-to-leading-order QCD calculations based on fragmentation functions, FFs, extracted from e + e − data alone, fail to describe the measurements. The calculations based on FFs extracted from a global analysis including e + e −, ep and pp data give an improved description. The measurements presented in this paper have the potential to further constrain the FFs of quarks, anti-quarks and gluons yielding K0S and Λ/Λ¯ strange hadrons

    A QCD analysis of ZEUS diffractive data

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    Deep inelastic scattering with leading protons or large rapidity gaps at HERA

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    Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA

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    The production of D-+/-- and D-0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb(-1). The measurements cover the kinematic range 5 < Q(2) < 1000 GeV2, 0.02 < y < 0.7, 1.5 < p(T)(D) < 15 GeV and |eta(D)| < 1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F-2(c (c) over bar), to the proton structure function, F-2
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