4,050 research outputs found
Clinical Features and Genetic Analysis of 20 Chinese Patients with X-Linked Hyper-IgM Syndrome
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 and
With the identification of () as the (,
) doublet in the heavy quark effective field theory, we derive the light
cone QCD sum rule for the coupling of eta meson with and
. Through 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
strongly support their interpretation as ordinary mesons.Comment: Comments and suggestions welcome
The masses and axial currents of the doubly charmed baryons
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 NLO. The mass splitting of and
at the NLO depends on one unknown low energy constant .
With the experimental mass of as the input, we estimate the
mass of 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
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(). 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
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 () 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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