213 research outputs found

    Cascaded Entanglement Enhancement

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    We present a cascaded system consisting of three non-degenerate optical parametric amplifiers (NOPAs) for the generation and the enhancement of quantum entanglement of continuous variables. The entanglement of optical fields produced by the first NOPA is successively enhanced by the second and the third NOPAs from -5.3 dBdB to -8.1 dBdB below the quantum noise limit. The dependence of the enhanced entanglement on the physical parameters of the NOPAs and the reachable entanglement limitation for a given cascaded NOPA system are calculated. The calculation results are in good agreement with the experimental measurements.Comment: 5 pages, 4 figure

    Experimental realization of three-color entanglement at optical fiber communication and atomic storage wavelengths

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    Multi-color entangled states of light including low-loss optical fiber transmission and atomic resonance frequencies are essential resources for future quantum information network. We present the experimental achievement on the three-color entanglement generation at 852 nm, 1550 nm and 1440 nm wavelengths for optical continuous variables. The entanglement generation system consists of two cascaded non-degenerated optical parametric oscillators (NOPOs). The flexible selectivity of nonlinear crystals in the two NOPOs and the tunable property of NOPO provide large freedom for the frequency selection of three entangled optical beams, so the present system is possible to be developed as practical devices used for quantum information networks with atomic storage units and long fiber transmission lines.Comment: 4pages, 4 figure

    A Quasi-Monte-Carlo-Based Feasible Sequential System of Linear Equations Method for Stochastic Programs with Recourse

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    A two-stage stochastic quadratic programming problem with inequality constraints is considered. By quasi-Monte-Carlo-based approximations of the objective function and its first derivative, a feasible sequential system of linear equations method is proposed. A new technique to update the active constraint set is suggested. We show that the sequence generated by the proposed algorithm converges globally to a Karush-Kuhn-Tucker (KKT) point of the problem. In particular, the convergence rate is locally superlinear under some additional conditions

    Exercise Activates p53 and Negatively Regulates IGF-1 Pathway in Epidermis within a Skin Cancer Model

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    Citation: Yu M, King B, Ewert E, Su X, Mardiyati N, Zhao Z, et al. (2016) Exercise Activates p53 and Negatively Regulates IGF-1 Pathway in Epidermis within a Skin Cancer Model. PLoS ONE 11(8): e0160939. doi:10.1371/journal.pone.0160939Exercise has been previously reported to lower cancer risk through reducing circulating IGF-1 and IGF-1-dependent signaling in a mouse skin cancer model. This study aims to investigate the underlying mechanisms by which exercise may down-regulate the IGF-1 pathway via p53 and p53-related regulators in the skin epidermis. Female SENCAR mice were pair-fed an AIN-93 diet with or without 10-week treadmill exercise at 20 m/min, 60 min/day and 5 days/week. Animals were topically treated with TPA 2 hours before sacrifice and the target proteins in the epidermis were analyzed by both immunohistochemistry and Western blot. Under TPA or vehicle treatment, MDM2 expression was significantly reduced in exercised mice when compared with sedentary control. Meanwhile, p53 was significantly elevated. In addition, p53-transcriptioned proteins, i.e., p21, IGFBP-3, and PTEN, increased in response to exercise. There was a synergy effect between exercise and TPA on the decreased MDM2 and increased p53, but not p53-transcripted proteins. Taken together, exercise appeared to activate p53, resulting in enhanced expression of p21, IGFBP-3, and PTEN that might induce a negative regulation of IGF-1 pathway and thus contribute to the observed cancer prevention by exercise in this skin cancer model

    Rarefied flow separation in microchannel with bends

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    Based on an accurate numerical solution of the kinetic equation using well-resolved spatial and velocity grids, the separation of rarefied gas flow in a microchannel with double rectangular bends is investigated over a wide range of Knudsen and Reynolds numbers. Rarefaction effects are found to play different roles in flow separation (vortex formation) at the concave and convex corners. Flow separations near the concave and convex corners are only observed for a Knudsen number up to and, respectively. With further increase of the Knudsen number, flow separation disappears. Due to the velocity slip at the solid walls, the concave (convex) vortex is suppressed (enhanced), which leads to the late (early) onset of separation of rarefied gas flows with respect to the Reynolds number. The critical Reynolds numbers for the emergence of concave and convex vortices are found to be as low as and, respectively. The slip velocity near the concave (convex) corner is found to increase (decrease) when the Knudsen number increases. An adverse pressure gradient appears near the concave corner for all the examined Knudsen numbers, while for the convex corner it only occurs when the Knudsen number is less than. Due to the secondary flow and adverse pressure gradient near the rectangular bends, the mass flow rate ratio between the bent and straight channels of the same length is a non-monotonic function of the Knudsen number. Our results clarify the diversified and often contradictory observations reported in the literature about flow rate enhancement and vortex formation in bent microchannels

    VPA mediates bidirectional regulation of cell cycle progression through the PPP2R2A-Chk1 signaling axis in response to HU

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    Cell cycle checkpoint kinases play a pivotal role in protecting against replicative stress. In this study, valproic acid (VPA), a histone deacetylase inhibitor (HDACi), was found to promote breast cancer MCF-7 cells to traverse into G2/M phase for catastrophic injury by promoting PPP2R2A (the B-regulatory subunit of Phosphatase PP2A) to facilitate the dephosphorylation of Chk1 at Ser317 and Ser345. By contrast, VPA protected normal 16HBE cells from HU toxicity through decreasing PPP2R2A expression and increasing Chk1 phosphorylation. The effect of VPA on PPP2R2A was at the post-transcription level through HDAC1/2. The in vitro results were affirmed in vivo. Patients with lower PPP2R2A expression and higher pChk1 expression showed significantly worse survival. PPP2R2A D197 and N181 are essential for PPP2R2A-Chk1 signaling and VPA-mediated bidirectional effect on augmenting HU-induced tumor cell death and protecting normal cells

    Lack of evidence of hepatitis in patients with oral lichen planus in China: a case control study

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    Background: China has been one of the countries with high prevalence of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) liver disease. And lichen planus is an extrahepatic manifestation of patients with chronic HCV infection. This case-control study was conducted to investigate the relationship between oral lichen planus (OLP) and HBV/HCV infection in China. Material and Methods: A total of 776 patients, including 150 patients with OLP (Group OLP), 429 inpatients from the Trauma Ward of Oral and Maxillofacial Surgery Department (Group A), 110 patients with other oral mucosal diseases, but without a reported association with HCV infection (Group B) and 87 patients with oral lichenoid lesion (Group OLL), were compared with their seroprevalence of anti-HCV antibody (HCVAb), hepatitis B surface antigen (HBsAg) and the parameters of liver functions. Moreover, the clinical characteristics of OLP were also observed, such as gender, age, chief complaint, course of the disease, clinical type, sites involved and so on. Results: The positive rates of HCVAb and HBsAg in OLP patients were 0.7% and 4%, respectively. Neither HCVAb nor HBsAg was associated with OLP as demonstrated by both the univariate and the multivariate analyses. The clinical features and liver functions of OLP patients with negative or positive HBsAg were nearly the same. Conclusions: Our findings verify that there is no association between OLP and hepatitis and there is no need to run a screening test for HCV or HBV in OLP patients in Chin
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