58 research outputs found

    Protective Effect of Calculus Bovis Sativus

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    Calculus Bovis Sativus (CBS) is a commonly used traditional Chinese medicine, which has been reported to exhibit antispasmodic, fever-reducing, anti-inflammatory, and gallbladder-repairing effects. The present study aims to investigate the protective effect of CBS on dextran sulphate sodium- (DSS-) induced ulcerative colitis (UC) in mice. C57BL/6 male mice were exposed to 5% DSS in drinking water. CBS was given orally at 50 and 150 mg/kg once per day for 7 days. Body weight, disease activity index (DAI), colon length, colonic myeloperoxidase (MPO) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) and nitric oxide (NO) levels were measured. Administration of CBS significantly reserved these changes, decreased the MPO activity and MDA and NO level, and increased the SOD activity in the colon tissue. Histological observation suggested that CBS alleviated edema, mucosal damage, and inflammatory cells infiltration induced by DSS in the colon. Moreover, CBS significantly downregulated the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1β and IL-6 in the colon tissue. Our data suggested that CBS exerted protective effect on DSS-induced UC partially through the antioxidant and anti-inflammatory activities

    Pathogenic Connexin-31 Forms Constitutively Active Hemichannels to Promote Necrotic Cell Death

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    Mutations in Connexin-31 (Cx31) are associated with multiple human diseases including erythrokeratodermia variabilis (EKV). The molecular action of Cx31 pathogenic mutants remains largely elusive. We report here that expression of EKV pathogenic mutant Cx31R42P induces cell death with necrotic characteristics. Inhibition of hemichannel activity by a connexin hemichannel inhibitor or high extracellular calcium suppresses Cx31R42P-induced cell death. Expression of Cx31R42P induces ER stress resulting in reactive oxygen species (ROS) production, in turn, to regulate gating of Cx31R42P hemichannels and Cx31R42P induced cell death. Moreover, Cx31R42P hemichannels play an important role in mediating ATP release from the cell. In contrast, no hemichannel activity was detected with cells expressing wildtype Cx31. Together, the results suggest that Cx31R42P forms constitutively active hemichannels to promote necrotic cell death. The Cx31R42P active hemichannels are likely resulted by an ER stress mediated ROS overproduction. The study identifies a mechanism of EKV pathogenesis induced by a Cx31 mutant and provides a new avenue for potential treatment strategy of the disease

    Cooperative Beamforming for Physical-Layer Security in Power-Constrained Wireless Sensor Networks with Partial Relay Selection

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    We investigate the physical-layer security of a wireless sensor network comprised of a source-destination pair, multiple decode-and-forward (DF) relays, and an eavesdropper. When the relays forward the source signal to the destination, they should dissipate certain power for driving their physical circuits (e.g., amplifiers and filters), in addition to the transmit power required for emitting radio signals. However, no existing work considers the circuit power when exploiting relays for enhancing the wireless security against eavesdropping. We thus propose the relay-selection based cooperative beamforming framework, where partial relays are selected to forward the source signal in a beamforming manner. We present two relay-selection strategies, namely, the exponential-complexity exhaustive search and linear-complexity relay ordering. For comparison purposes, we also evaluate the conventional all-relay based and best-relay based beamforming schemes, where all relays or only the best one is selected to assist the source-destination transmission. It is shown that the proposed beamforming schemes significantly outperform the conventional all-relay and best-relay based beamforming schemes in terms of secrecy capacity. Additionally, the relay-ordering based beamforming scheme almost achieves the same secrecy capacity as the exhaustive-search method, but with a reduced computational complexity

    A Prediction Model for Internal Cracks during Slab Continuous Casting

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    Slab continuous casting internal cracking is a common quality defect in the production process. The ability to predict the quality of each continuous casting product and assess whether it is suitable for hot delivery or needs to be cleaned down will greatly increase the rolled product rate and reduce the scrap rate and production management cost. According to the quality defects of internal cracks during slab continuous casting and based on the solidification and heat transfer simulations, stress and strain calculations and theoretical analysis of metallurgical processes related to continuous casting combined with an abnormal casting event expert system, the internal crack generation index of the slice unit is used to predict the crack occurrence rating of each sized slab. Moreover, the internal crack prediction model for the slab is successfully developed and applied in a domestic steel mill. The accuracy of the model prediction reached 86.85%. This method achieved the organic combination of theoretical analysis and an expert system and provides an important theoretical tool for the prediction of crack quality defects in slab continuous casting; the method can be applied in slab continuous casting production

    Manganese Oxide on Carbon Fabric for Flexible Supercapacitors

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    We report the fabrication of uniform large-area manganese oxide (MnO2) nanosheets on carbon fabric which oxidized using O2 plasma treatment (MnO2/O2-carbon fabric) via electrodeposition process and their implementation as supercapacitor electrodes. Electrochemical measurements demonstrated that MnO2/O2-carbon fabric exhibited capacitance as high as 275 F/g at a scan rate of 5 mV/s; in addition, it showed an excellent cycling performance (less than 20% capacitance loss after 10,000 cycles). All the results suggest that MnO2/O2-carbon fabric is a promising electrode material which has great potential for application on flexible supercapacitors

    A Fast Sparse Coding Method for Image Classification

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    Image classification is an important problem in computer vision. The sparse coding spatial pyramid matching (ScSPM) framework is widely used in this field. However, the sparse coding cannot effectively handle very large training sets because of its high computational complexity, and ignoring the mutual dependence among local features results in highly variable sparse codes even for similar features. To overcome the shortcomings of previous sparse coding algorithm, we present an image classification method, which replaces the sparse dictionary with a stable dictionary learned via low computational complexity clustering, more specifically, a k-medoids cluster method optimized by k-means++. The proposed method can reduce the learning complexity and improve the feature’s stability. In the experiments, we compared the effectiveness of our method with the existing ScSPM method and its improved versions. We evaluated our approach on two diverse datasets: Caltech-101 and UIUC-Sports. The results show that our method can increase the accuracy of spatial pyramid matching, which suggests that our method is capable of improving performance of sparse coding features

    Metallurgical and Mining Industry Underground Multi-Target Recognition of Ground Penetrating Radar Based on Multi-Feature Information Fusion

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    Abstract A multi-parameter feature and recognition method is established for GPR underground targets based on multi-feature information fusion ideas specific to complexity and diversity of detecting environment and underground media as well as non-stationarity and aperiodicity of GPR echo signals. This method carries out multi-parameter feature fusion by selecting power spectrum, wavelet packet energy spectrum and higher-order spectrum, and on this basis, executes recognition and classification with the wavelet neural network. The experimental results show that compared with single-parameter feature recognition methods, this method can effectively realize recognition of the tubular bodies, spheroids as well as geologic bodies made of metal, plastic, cement and other materials
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