2,958 research outputs found

    Crosstalk Impacts on Homogeneous Weakly-Coupled Multicore Fiber Based IM/DD System

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    We numerically discussed crosstalk impacts on homogeneous weakly-coupled multicore fiber based intensity modulation/direct-detection (IM/DD) systems taking into account mean crosstalk power fluctuation, walk-off between cores, laser frequency offset, and laser linewidth.Comment: 3 pages, 11 figures

    Link prediction in evolving networks based on popularity of nodes

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    Link prediction aims to uncover the underlying relationship behind networks, which could be utilized to predict missing edges or identify the spurious edges. The key issue of link prediction is to estimate the likelihood of potential links in networks. Most classical static-structure based methods ignore the temporal aspects of networks, limited by the time-varying features, such approaches perform poorly in evolving networks. In this paper, we propose a hypothesis that the ability of each node to attract links depends not only on its structural importance, but also on its current popularity (activeness), since active nodes have much more probability to attract future links. Then a novel approach named popularity based structural perturbation method (PBSPM) and its fast algorithm are proposed to characterize the likelihood of an edge from both existing connectivity structure and current popularity of its two endpoints. Experiments on six evolving networks show that the proposed methods outperform state-of-the-art methods in accuracy and robustness. Besides, visual results and statistical analysis reveal that the proposed methods are inclined to predict future edges between active nodes, rather than edges between inactive nodes

    An explicit evolution from N\'eel to striped antiferromagnetic states in the spin-1/2 J1J_{1}-J2J_{2} Heisenberg model on the square lattice

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    The frustrated spin-1/21/2 J1J2J_1-J_2 Heisenberg model on the square lattice has been extensively studied since 1988 because of its close relationship to the high-temperature superconductivity in cuprates and more importantly involved novel phase of matter in its own right, namely, quantum spin liquid (QSL), one of hot topics in condensed matter physics in recent years. However, the phase diagram of the model, particularly in the maximally frustrated regime J2/J10.5J_2/J_1 \sim 0.5, is quite controversial, and more seriously the nature of the QSL is not clear at all. Here we provide a pattern picture, on one hand, to show explicitly how the system evolves from the N\'eel antiferromagnetic (AFM) state at small J2J_2 to the striped AFM one at large J2J_2; on the other hand, to uncover the nature of the QSL if it exists in the intermediate J2J_2 coupling regime. For simplicity, we show our results by taking the square lattice L=Lx×LyL=L_x \times L_y with size Lx=Ly=4L_x=L_y=4 here and periodic boundary condition is considered, and furthermore, exact diagonalization is employed to confirm the correctness of our picture. Our results indicate that the highly frustration regime is characterized by diagonal two-domain, while the N\'eel AFM state has a diagonal single-domain and the striped AFM state shows itself as a diagonal four-domain, namely, completely diagonal antiferromagnetic order, in the present case. Increasing the system size, the number of the diagonal domains increases correspondingly, but the diagonal single-domain for the N\'eel AFM state and the diagonal Lx(y)L_{x(y)}-domain for the striped AFM state remain unchanged. Our results shed light on the understanding of the QSL.Comment: 6 pages, 4 figure

    Impaired atrial electromechanical function and atrial fibrillation promotion in alloxan-induced diabetic rabbits

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    Background: Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF). However, the underlying mechanisms are still not clearly elucidated. The aim of this study was to evaluate the atrial electromechanical function, atrial electrophysiological changes and AF inducibility in alloxan-induced diabetic rabbits. Methods: In 8 alloxan-induced diabetic rabbits and 8 controls, we evaluated atrial electromechanical function by tissue Doppler imaging. Isolated Langendorff-perfused rabbit hearts were prepared to measure atrial refractory effective period (AERP) and its dispersion (AERPD), interatrial conduction time (IACT) and vulnerability to AF. Atrial interstitial fibrosis was evaluated by Sirius-Red staining. Results: Compared with controls, left atrial lateral wall Pa’-start interval (Pastart) and right atrial wall Pastart were increased in diabetic rabbits. AERPD was increased and IACT was prolonged in diabetic rabbits. Inducibility of AF in diabetic group was significant higher than controls (6/8 vs. 1/8, p < 0.05). Extensive interstitial fibrosis was observed in the DM group (p < 0.01). Correlation analysis showed that right atrial wall Pastart, Pa’-peak interval (Papeak) and total electromechanical activity (TEMA); left atrial lateral wall Papeak and TEMA, left atrial posterior wall TEMA, and IACT were correlated with atrial areas of fibrosis. Conclusions: Atrial electromechanical function is impaired in diabetic rabbits, and is associated with atrial fibrosis and interatrial electrical conduction delay

    A Novel Latin Square Image Cipher

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    In this paper, we introduce a symmetric-key Latin square image cipher (LSIC) for grayscale and color images. Our contributions to the image encryption community include 1) we develop new Latin square image encryption primitives including Latin Square Whitening, Latin Square S-box and Latin Square P-box ; 2) we provide a new way of integrating probabilistic encryption in image encryption by embedding random noise in the least significant image bit-plane; and 3) we construct LSIC with these Latin square image encryption primitives all on one keyed Latin square in a new loom-like substitution-permutation network. Consequently, the proposed LSIC achieve many desired properties of a secure cipher including a large key space, high key sensitivities, uniformly distributed ciphertext, excellent confusion and diffusion properties, semantically secure, and robustness against channel noise. Theoretical analysis show that the LSIC has good resistance to many attack models including brute-force attacks, ciphertext-only attacks, known-plaintext attacks and chosen-plaintext attacks. Experimental analysis under extensive simulation results using the complete USC-SIPI Miscellaneous image dataset demonstrate that LSIC outperforms or reach state of the art suggested by many peer algorithms. All these analysis and results demonstrate that the LSIC is very suitable for digital image encryption. Finally, we open source the LSIC MATLAB code under webpage https://sites.google.com/site/tuftsyuewu/source-code.Comment: 26 pages, 17 figures, and 7 table

    External Application of Traditional Chinese Medicine for Venous Ulcers: A Systematic Review and Meta-Analysis

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    Objective. To evaluate the effectiveness of external application of traditional Chinese medicine (EA-TCM) on venous ulcers. Methods. Seven databases were searched until April 2015 for randomized controlled trials (RCTs) of EA-TCM for venous ulcers. Risk of bias was assessed using Cochrane Handbook guidelines. Study outcomes were presented as risk ratios (RRs) for dichotomous data or mean differences (MDs) for continuous data. Results. Sixteen of 193 potentially relevant trials met the inclusion criteria; however, their methodological qualities were low. Comparison of the same intervention strategies revealed significant differences in total effectiveness rates between EA-TCM and conventional therapy groups (RR = 1.22, 95% confidence interval [CI] = 1.16–1.29, and P<0.00001). Compared to conventional therapy, EA-TCM combined with conventional therapy had a superior total effectiveness rate (RR = 1.11, 95% CI = 1.04–1.19, and P=0.003). There were no significant differences in recurrence rates during followup and final pain measurements between the experimental and those in the control groups (RR = 0.86, 95% CI = 0.31–2.39, and P=0.85; MD −0.75, 95% CI = −2.15–0.65, and P=0.29). Conclusion. The evidence that EA-TCM is an effective treatment for venous ulcers is encouraging, but not conclusive due to the low methodological quality of the RCTs. Therefore, more high-quality RCTs with larger sample sizes are required

    Ischemic postconditioning attenuates liver warm ischemia-reperfusion injury through Akt-eNOS-NO-HIF pathway

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    <p>Abstract</p> <p>Background</p> <p>Ischemic postconditioning (IPO) has been demonstrated to attenuate ischemia/reperfusion (I/R) injury in the heart and brain, its roles to liver remain to be defined. The study was undertaken to determine if IPO would attenuate liver warm I/R injury and its protective mechanism.</p> <p>Methods</p> <p>Mice were divided into sham, I/R, IPO+I/R (occlusing the porta hepatis for 60 min, then treated for three cycles of 10 sec brief reperfusion consecutively, followed by a persistent reperfusion); L-NAME+ sham (L-NAME, 16 mg/kg, i.v., 5 min before repefusion); L-NAME+I/R; and L-NAME+ IPO. Blood flow of caudate and left lobe of the liver was blocked. Functional and morphologic changes of livers were evaluated. Contents of nitric oxide, eNOS and iNOS in serum were assayed. Concentration of eNOS, iNOS, malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in hepatic tissue were also measured. Expressions of Akt, p-Akt and HIF-1α protein were determined by western blot. Expressions of TNF-α and ICAM-1 were measured by immunohistochemistry and RT-PCR.</p> <p>Results</p> <p>IPO attenuated the dramatically functional and morphological injuries. The levels of ALT was significantly reduced in IPO+I/R group (p < 0.05). Contents of nitric oxide and eNOS in serum were increased in the IPO+I/R group (p < 0.05). IPO also up-regulated the concentration of eNOS, activity of SOD in hepatic tissue (p < 0.05), while reduced the concentration of MDA (p < 0.05). Moreover, protein expressions of HIF-1α and p-Akt were markedly enhanced in IPO+I/R group. Protein and mRNA expression of TNF-α and ICAM-1 were markedly suppressed by IPO (p < 0.05). These protective effects of IPO could be abolished by L-NAME.</p> <p>Conclusions</p> <p>We found that IPO increased the content of NO and attenuated the overproduction of ROS and I/R-induced inflammation. Increased NO contents may contribute to increasing HIF-1α level, and HIF-1α and NO would simultaneously protect liver from I/R injury. These findings suggested IPO may have the therapeutic potential through Akt-eNOS-NO-HIF pathway for the better management of liver I/R injury.</p

    Heating of multi‐species upflowing ion beams observed by Cluster on March 28, 2001

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149495/1/epp320083.pd

    Tectonic controls on block rotation and sheeted sill emplacement in the Xigaze Ophiolite (Tibet): the construction mode of slow-spreading and ultraslow-spreading oceanic crusts

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    Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 22(3), (2021): e2020GC009297, https://doi.org/10.1029/2020GC009297.The internal structure of oceanic crusts is not well understood due to the limitation of deep drilling. However, that of ophiolites, i.e., on-land ancient analogs of oceanic lithosphere, could be precisely mapped and measured. The Xigaze ophiolite in Tibet has been regarded as “peculiar”, due to the sheeted sill complex in its upper crust, and non-sheeted diabase sills/dikes crosscutting its mantle and lower crust, which are geometrically different from the primarily vertical sheeted dike complex. Based on extensive field observations, here we present petrological and geochemical data for the Xigaze ophiolite to decipher the origin of sheeted sill complex and its implications for the construction of oceanic crusts. Diabases in the Xigaze ophiolite could be subdivided into sheeted sills, Group 1 non-sheeted dikes, and Group 2 non-sheeted sills, based on their orientations. These diabases cut other lithologies, and hence belong to the latest-stage products. Based on petrological, geochemical, and structural data, we highlight the important role of detachment fault in the generation of sheeted and non-sheeted sills. During the formation of oceanic crust, large block exhumation, multi-stage rotations, and foundering are argued here as key mechanisms for the generation of Xigaze sheeted and non-sheeted dikes/sills, all of which are in the evolution of detachment fault systems. These processes are also not uncommon for asymmetrical segments at modern slow-spreading and ultraslow-spreading ridges, but are rare at symmetrical segments. Due to the evolution of detachment fault, the internal structures of (ultra)slow-spreading ridges are more complex than those at fast-spreading ridges.This study was financially supported by the National Natural Science Foundation of China (42025201 and 41802062), Key Research Program of Frontier Sciences from CAS (QYZDB-SSW-DQC032), Major Research project on Tethys Geodynamic System from NSFC (91755000), and Open Fund Project of State Key Laboratory of Lithospheric Evolution (201707).2021-07-2

    Large-scale plasma proteomic profiling identifies a high-performance biomarker panel for Alzheimer's disease screening and staging

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    INTRODUCTION: Blood proteins are emerging as candidate biomarkers for Alzheimer's disease (AD). We systematically profiled the plasma proteome to identify novel AD blood biomarkers and develop a high-performance, blood-based test for AD. METHODS: We quantified 1160 plasma proteins in a Hong Kong Chinese cohort by high-throughput proximity extension assay and validated the results in an independent cohort. In subgroup analyses, plasma biomarkers for amyloid, tau, phosphorylated tau, and neurodegeneration were used as endophenotypes of AD. RESULTS: We identified 429 proteins that were dysregulated in AD plasma. We selected 19 “hub proteins” representative of the AD plasma protein profile, which formed the basis of a scoring system that accurately classified clinical AD (area under the curve = 0.9690–0.9816) and associated endophenotypes. Moreover, specific hub proteins exhibit disease stage-dependent dysregulation, which can delineate AD stages. DISCUSSION: This study comprehensively profiled the AD plasma proteome and serves as a foundation for a high-performance, blood-based test for clinical AD screening and staging
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