319 research outputs found

    Two Modes Near-zero Dispersion Flattened Photonic-crystal Fiber

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    Through massive computer simulation, a photonic-crystal fiber with seven air-hole defects as fiber core is proposed by using the software CUDOS based on the multipole method. In the given fiber parameters, the photonic-crystal fiber’s fundamental and second modes are dispersion flattened simultaneously in the communication O wave band, S wave band and C wave band. It is important in the relative application of multi-mode dispersion flattened photonic-crystal fiber

    Method of constructing braid group representation and entanglement in a Yang-Baxter sysytem

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    In this paper we present reducible representation of the n2n^{2} braid group representation which is constructed on the tensor product of n-dimensional spaces. By some combining methods we can construct more arbitrary n2n^{2} dimensional braiding matrix S which satisfy the braid relations, and we get some useful braiding matrix S. By Yang-Baxteraition approach, we derive a 9×9 9\times9 unitary R˘ \breve{R} according to a 9×9 9\times9 braiding S-matrix we have constructed. The entanglement properties of R˘ \breve{R}-matrix is investigated, and the arbitrary degree of entanglement for two-qutrit entangled states can be generated via R˘(θ,ϕ1,ϕ2) \breve{R}(\theta, \phi_{1},\phi_{2})-matrix acting on the standard basis.Comment: 9 page

    Prognostic value of growth differentiation factor-15 in Chinese patients with heart failure: A prospective observational study

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      Background: Growth differentiation factor-15 (GDF-15), a biomarker associated with remodeling, oxidative stress and inflammation, has been used to stratify heart failure (HF) patients. However, its prognostic value in Chinese HF patients is still unknown. Methods: GDF-15 levels were examined on admission in 272 consecutive HF patients in Beijing Hospital (a Chinese tertiary medical center) by a commercial enzyme-linked immunosorbent assay. We recorded the incidence of all-cause mortality and/or readmission for HF during a median follow-up period of 558 days. Patients were stratified according to the tertiles of GDF-15. Results: Fifty-three (19.5%) patients died and 103 (37.9%) patients had major adverse cardiac events (MACE) which included the composite outcome of all-cause mortality or readmission for HF at the end of follow-up. Kaplan-Meier survival curves showed that the third tertile of GDF-15 was associated with increased rate of all-cause mortality (compared with the first and second tertiles, log rank p = 0.001 and 0.001, respectively) or MACE (compared with the first and second tertiles, log rank p = 0.002 and p < 0.001, respectively). In addition, multivariate Cox regression model showed that the highest tertile of GDF-15 was independently associated with increased risk of all-cause death (hazard ratio = 5.95, 95% confidence interval 1.88–18.78, p = 0.002) compared with the lowest tertile after adjustment for related clinical variables such as age, renal function or N-terminal pro-B-type natriuretic peptide.  Conclusions: Plasma GDF-15 is an independent predictor of all-cause mortality in Chinese patients with HF. It may potentially be used to stratify and prognosticate HF patients

    VEGF Is Involved in the Increase of Dermal Microvascular Permeability Induced by Tryptase

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    Tryptases are predominantly mast cell-specific serine proteases with pleiotropic biological activities and play a critical role in skin allergic reactions, which are manifested with rapid edema and increases of vascular permeability. The exact mechanisms of mast cell tryptase promoting vascular permeability, however, are unclear and, therefore, we investigated the effect and mechanism of tryptase or human mast cells (HMC-1) supernatant on the permeability of human dermal microvascular endothelial cells (HDMECs). Both tryptase and HMC-1 supernatant increased permeability of HDMECs significantly, which was resisted by tryptase inhibitor APC366 and partially reversed by anti-VEGF antibody and SU5614 (catalytic inhibitor of VEGFR). Furthermore, addition of tryptase to HDMECs caused a significant increase of mRNA and protein levels of VEGF and its receptors (Flt-1 and Flk-1) by Real-time RT-PCR and Western blot, respectively. These results strongly suggest an important role of VEGF on the permeability enhancement induced by tryptase, which may lead to novel means of controlling allergic reaction in skin
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