4,046 research outputs found

    Clinical Features and Genetic Analysis of 20 Chinese Patients with X-Linked Hyper-IgM Syndrome

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    X-linked hyper-IgM syndrome (XHIGM) is one type of primary immunodeficiency diseases, resulting from defects in the CD40 ligand/CD40 signaling pathways. We retrospectively analyzed the clinical and molecular features of 20 Chinese patients diagnosed and followed up in hospitals affiliated to Shanghai Jiao Tong University School of Medicine from 1999 to 2013. The median onset age of these patients was 8.5 months (range: 20 days–21 months). Half of them had positive family histories, with a shorter diagnosis lag. The most common symptoms were recurrent sinopulmonary infections (18 patients, 90%), neutropenia (14 patients, 70%), oral ulcer (13 patients, 65%), and protracted diarrhea (13 patients, 65%). Six patients had BCGitis. Six patients received hematopoietic stem cell transplantations and four of them had immune reconstructions and clinical remissions. Eighteen unique mutations in CD40L gene were identified in these 20 patients from 19 unrelated families, with 12 novel mutations. We compared with reported mutation results and used bioinformatics software to predict the effects of mutations on the target protein. These mutations reflected the heterogeneity of CD40L gene and expanded our understanding of XHIGM

    Strong decays of DsJ(2317)D_{sJ}(2317) and DsJ(2460)D_{sJ}(2460)

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    With the identification of (DsJ(2317),DsJ(2460)D_{sJ}(2317), D_{sJ}(2460)) as the (0+0^+, 1+1^+) doublet in the heavy quark effective field theory, we derive the light cone QCD sum rule for the coupling of eta meson with DsJ(2317)DsD_{sJ}(2317) D_s and DsJ(2460)Ds∗D_{sJ}(2460) D_s^{*} . Through η−π0\eta-\pi^0 mixing we calculate their pionic decay widths, which are consistent with the experimental values (or upper limits). Combining the radiative decay widths derived by Colangelo, Fazio and Ozpineci in the same framework, we conclude that the decay patterns of DsJ(2317,2460)D_{sJ}(2317, 2460) strongly support their interpretation as ordinary csˉc \bar s mesons.Comment: Comments and suggestions welcome

    The masses and axial currents of the doubly charmed baryons

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    The chiral dynamics of the doubly heavy baryons is solely governed by the light quark. In this work, We have derived the chiral corrections to the mass of the doubly heavy baryons up to N3^3LO. The mass splitting of Ξcc\Xi_{cc} and Ωcc\Omega_{cc} at the N2^2LO depends on one unknown low energy constant c7c_7. With the experimental mass of Ξcc(3520)\Xi_{cc}(3520) as the input, we estimate the mass of Ωcc\Omega_{cc} to be around 3.678 GeV. Moreover, we have also performed a systematical analysis of the chiral corrections to the axial currents and axial charges of the doubly heavy baryons. The chiral structure and analytical expressions will be very useful to the chiral extrapolations of the future lattice QCD simulations of the doubly heavy baryons.Comment: 10 pages, 2 tables, 3 figure. Accepted by Phys. Rev.

    Diffuse emission of TeV Neutrinos and Gamma-rays from young pulsars by Photo-meson interaction in the galaxy

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    It's generally believed that young and rapidly rotating pulsars are important sites of particle's acceleration, in which protons can be accelerated to relativistic energy above the polar cap region if the magnetic moment is antiparallel to the spin axis(μ⃗⋅Ω⃗<0\vec{\mu}\cdot\vec{\Omega}<0). To obtain the galactic diffusive neutrinos and gamma-rays for TeV, firstly,we use Monte Carlo(MC) method to generate a sample of young pulsars with ages less than 10610^6 yrs in our galaxy ; secondly, the neutrinos and high-energy gamma-rays can be produced through photomeson process with the interaction of energetic protons and soft X-ray photons (p+γ→Δ+→n+π+/p+π0p+\gamma\rightarrow \Delta^+\rightarrow n+\pi^+/p+\pi^0) for single pulsar, and these X-ray photons come from the neutron star surface. The results suggest that the diffusive TeV flux of neutrinos are lower than background flux, which indicated it is difficult to be detected by the current neutrino telescopes.Comment: 11pages,6figures. arXiv admin note: text overlap with arXiv:0812.1845 by other author
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