4,358 research outputs found

    Comparative study of in situ and ex situ MgB2 films deposited by pulsed laser deposition

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    Two types of MgB2 films were prepared by pulsed laser deposition (PLD) with in situ and ex situ annealing processes respectively. Significant differences in properties between the two types of films were found. The ex situ MgB2 film has a Tc of 38.1K, while the in situ film has a depressed Tc of 34.5K. The resistivity at 40K for the in situ film is larger than that of the ex situ film by a factor of 6. The residual resistivity ratios (RRR) are 1.1 and 2.1 for the in situ and ex situ films respectively. The Jc-H curves of the in situ film show a much weaker field dependence than those of the ex situ film, attributable to stronger flux pinning in the in situ film. The small-grain feature and high oxygen level may be critical for the significant improvement of Jc in the in situ annealed MgB2 film.Comment: 6 pages, 6 figure

    CP Measurement in Quantum Teleportation of Neutral Mesons

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    Quantum teleportation using neutral pseudoscalar mesons shows novel connections between particle physics and quantum information. The projection basis, which is crucial in the teleportation process, is determined by the conservation laws of particle physics, and is different from the Bell basis, as in the usual case. Here we show that one can verify the teleportation process by CP measurement. This method significantly simplifies the high energy quantum teleportation protocol. Especially, it is rigorous, and is independent of whether CP is violated in weak decays. This method can also be applied to general verification of Einstein-Podolsky-Rosen correlations in particle physics.Comment: 7 page

    The Dynamical Yang-Baxter Relation and the Minimal Representation of the Elliptic Quantum Group

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    In this paper, we give the general forms of the minimal LL matrix (the elements of the LL-matrix are cc numbers) associated with the Boltzmann weights of the An−11A_{n-1}^1 interaction-round-a-face (IRF) model and the minimal representation of the An−1A_{n-1} series elliptic quantum group given by Felder and Varchenko. The explicit dependence of elements of LL-matrices on spectral parameter zz are given. They are of five different forms (A(1-4) and B). The algebra for the coefficients (which do not depend on zz) are given. The algebra of form A is proved to be trivial, while that of form B obey Yang-Baxter equation (YBE). We also give the PBW base and the centers for the algebra of form B.Comment: 23 page

    Evidence That Inhibition of p44/42 Mitogen-activated Protein Kinase Signaling Is a Factor in Proteasome Inhibitor-mediated Apoptosis

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    The proteasome is emerging as a target for cancer therapy because small molecule inhibitors of its catalytic activity induce apoptosis in both in vitro and in vivo models of human malignancies and are proving to have efficacy in early clinical trials. To further elucidate the mechanism of action of these inhibitors, their impact on signaling through the p44/42 mitogen-activated protein kinase (MAPK) pathway was studied. Proteasome inhibition with either carbobenzoxy-leucyl-leucyl-phenylalaninal or lactacystin led to a loss of dually phosphorylated, activated p44/42 MAPK in A1N4-myc human mammary and MDA-MB-231 breast carcinoma cells in a dose- and time-dependent fashion. This correlated with an induction of the dual specificity MAPK phosphatases (MKP)-1 and -2, and blockade of MKP induction using either actinomycin D or Ro-31-8220 significantly decreased loss of activated p44/42 MAPK. Inhibition of p44/42 MAPK signaling by use of the MAPK kinase inhibitors PD 98059 or U0126, or by use of a dominant negative MAPK construct, enhanced proteasome inhibitor-mediated apoptosis. Conversely, activation of MAPK by epidermal growth factor, or use of a mutant MAPK resistant to MKP-mediated dephosphorylation, inhibited apoptosis. These studies support a role for inactivation of signaling through the p44/42 MAPK pathway in proteasome inhibitor-mediated apoptosis

    Articular cartilage metabolism in patients with Kashin–Beck Disease: an endemic osteoarthropathy in China

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    SummaryObjectiveThe objective of this study was to investigate CD44 and proteoglycan metabolism in patients suffering from Kashin–Beck Disease (KBD), an endemic osteoarthropathy that affects 2.5 million of 30 million people living in the KBD regions of China.MethodsImmunohistochemical analyses of cluster of differentiation-44 (CD44), BC-13 and 3-B-3(−) expression were performed in cartilage sections harvested from KBD and normal patients. In addition, the serum levels of soluble CD44 (sCD44), interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and matrix metalloproteinase-1 were determined using a sandwich enzyme linked immunosorbent assay.ResultsHematoxylin & eosin and toluidine blue staining indicated that there was cell necrosis and proteoglycan loss in cartilage from both KBD children and adult cartilage. Strong immunohistochemical staining for CD44, BC-13 and 3-B-3(−) occurred in the majority of adult KBD patients and most KBD children. Furthermore, statistically significant elevated levels of sCD44, IL-1β and TNF-α were found in the sera of both adult and child KBD patients when compared to the levels of normal adult and child controls. Interestingly, IL-1β and TNF-α serum levels were all high in normal children from KBD regions when compared to normal children from non-KBD regions suggesting that unidentified factors (e.g., a genetic predisposition) may protect some people from KBD pathology.ConclusionOur results demonstrate that altered CD44, IL-1β and TNF-α metabolism occurs in the pathogenesis of KBD and there is an increased aggrecanase-generated proteoglycan loss from KBD adult and child cartilage. These primary metabolic changes are likely to be significant contributing factor causing pathological joint formation and instability that leads to secondary osteoarthritis in KBD patients

    Soliton Solutions on Noncommutative Orbifold $ T^2/Z_4

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    In this paper, we explicitly construct a series of projectors on integral noncommutative orbifold T2/Z4T^2/Z_4 by extended GHSGHS constrution. They include integration of two arbitary functions with Z4Z_4 symmetry. Our expressions possess manifest Z4Z_{4} symmetry. It is proved that the expression include all projectors with minimal trace and in their standard expansions, the eigen value functions of coefficient operators are continuous with respect to the arguments kk and qq. Based on the integral expression, we alternately show the derivative expression in terms of the similar kernal to the integral one.Since projectors correspond to soliton solutions of the field theory on the noncommutative orbifold, we thus present a series of corresponding solitons.Comment: 18 pages, no figure; referrences adde

    Parental Migration and Early Childhood Development in Rural China

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    Nearly one-quarter of all children under age 2 in China are left behind in the countryside as parents migrate to urban areas for work. We use a four-wave longitudinal survey following young children from 6 to 30 months of age to provide first evidence on the effects of parental migration on development, health, and nutritional outcomes in the critical first stages of life. We find that maternal migration has a negative effect on cognitive development: migration before children reach 12 months of age reduces cognitive development by 0.3 standard deviations at age 2. Possible mechanisms include reduced dietary diversity and engagement in stimulating activities, both known to be causally associated with skill development in early life. We find no effects on other dimensions of physical and social-emotional health

    Reconstructed Jets at RHIC

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    To precisely measure jets over a large background such as pile up in high luminosity p+p collisions at LHC, a new generation of jet reconstruction algorithms is developed. These algorithms are also applicable to reconstruct jets in the heavy ion environment where large event multiplicities are produced. Energy loss in the medium created in heavy ion collisions are already observed indirectly via inclusive hadron distributions and di-hadron correlations. Jets can be used to study this energy loss in detail with reduced biases. We review the latest results on jet-medium interactions as seen in A+A collisions at RHIC, focusing on the recent progress on jet reconstruction in heavy ion collisions.Comment: Proceedings for the 26th Winter Workshop on Nuclear Dynamic
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