1,428 research outputs found
The Pathogenesis of Natural Killer/T Cell Lymphoma
Extranodal natural killer/T-cell lymphomas (NKTCL) are uncommon lymphomas with poor prognosis. In order to gain a better understanding of the molecular pathogenesis of NKTCL, we obtained and compared the global gene expression profile, global somatic mutation profile, and global methylation profile of normal NK cells, malignant NK cell lines, and NKTCL patient samples. We showed that the JAK-STAT pathway was constitutively activated in NKTCL through the cooperation between activation of signal transducer and activator of transcription proteins (STATs) via activating mutations and inactivation of STAT suppressor protein suppressor of cytokine signaling 6 (SOCS6) through promoter hypermethylation. Activating STAT3 and STAT5B mutations are associated with increased phosphorylated protein and a growth advantage to transduced cell lines or normal NK cells. Growth-promoting activity of the mutants can be partially inhibited by a JAK1/2 inhibitor or by expressing exogenous SOCS6. Molecular modelling and surface plasmon resonance measurements of the N642H STAT5B mutant indicate a marked increase in binding affinity of the phosphotyrosine-Y699 with the mutant protein. This is associated with the prolonged persistence of the mutant phosphoSTAT5B and marked increase of binding to target sites. We also showed that Blimp1, a tumor suppressor gene frequently inactivated in NKTCL by the combination of allelic deletion and promoter hypermethylation, has an effect on NK cell homeostasis, maturation and function using a NK-lineage specific Blimp1-knockout mouse model. Blimp1 knockout mice had a lower percentage of NK cells in peripheral lymphoid sites, such as spleen and peripheral blood, and higher percentage of NK cells in bone marrow when compared to wild-type mice. The maturation of NK cells was partially impaired in Blimp1 knockout mice. However, Blimp1-deficient NK cells proliferated better upon stimulation in vitro and in vivo, and had a potent cytotoxic ability. Together, these findings suggest potential pathways for therapeutic targeting in NKTCL patients
Weak Decays of Doubly Heavy Baryons:
The weak decays of a spin- doubly charm baryon () to a
spin- singly charm baryon () and a light vector meson ()
are studied under a phenomenological scheme. The contributions are classified
into different topological diagrams, among which the short distance ones are
calculated under the factorization hypothesis, and the long distance
contributions are modelled as final-state interactions (FSIs) which are
estimated with the one-particle-exchange model. In calculation the topological
contributions tend to fall in a hierarchy. The branching fractions or decay
widths are estimated, and it indicates that
and can be used as candidate
decays for searching and . Some decays that are
mainly activated by the long distance effects are found, observation on which
in future experiments can help to understand the role of FSIs in charm baryon
decays.Comment: 29 pages, 5 figures, 7 tables; version published in EPJ
Stabilizer formalism for generalized concatenated quantum codes
The concept of generalized concatenated quantum codes (GCQC) provides a
systematic way for constructing good quantum codes from short component codes.
We introduce a stabilizer formalism for GCQCs, which is achieved by defining
quantum coset codes. This formalism offers a new perspective for GCQCs and
enables us to derive a lower bound on the code distance of stabilizer GCQCs
from component codes parameters,for both non-degenerate and degenerate
component codes. Our formalism also shows how to exploit the error-correcting
capacity of component codes to design good GCQCs efficiently.Comment: 5 pages, 2 figures, International Symposium on Information Theory, 7
July - 12 July 2013, Istanbul, Turke
Radiation Damping of Soil - Foundations Interaction Systems
Based on the theory of wave scatter and the velocity, the wave radiation which is caused in soil of dynamic foundation and the range of the affected depth are presented in this paper. It is pointed out that the mass ratio of foundation and the location of the foundation in the layered soil, and its propagation velocity in the affected depth, are the major factors affecting radial damping of soil-foundation system on the half space
Anomalous gauge couplings of the Higgs boson at the CERN LHC: Semileptonic mode in WW scatterings
We make a full tree level study of the signatures of anomalous gauge
couplings of the Higgs boson at the CERN LHC via the semileptonic decay mode in
WW scatterings. Both signals and backgrounds are studied at the hadron level
for the Higgs mass in the range 115 GeV to 200 GeV. We carefully impose
suitable kinematical cuts for suppressing the backgrounds. To the same
sensitivity as in the pure leptonic mode, our result shows that the
semileptonic mode can reduce the required integrated luminosity by a factor of
3. If the anomalous couplings in nature are actually larger than the
sensitivity bounds shown in the text, the experiment can start the test for an
integrated luminosity of 50 inverse fb.Comment: PACS numbers updated. Version published in Phys.Rev.D79,055010(2009
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