The aim of the present study was to investigate whether S-adenosylmethionine (SAM) was able to suppress activated human hepatic stellate cells (HSCs). Human LX-2 HSCs were cultured with SAM or ...NSC23766, and were transfected with plasmids encoding ras-related C3 botulinum toxin substrate 1 (Rac1) protein or an empty expression vector. Cell proliferation was detected by Cell Counting Kit-8. Cell migration and invasion were determined using the Transwell assay. The expression levels of Rac1 and Smad3/4 were detected by reverse transcription-quantitative polymerase chain reaction (PCR) or western blotting. The methylation status of Rac1 promoters was measured by methylation-specific PCR. The results demonstrated that SAM and NSC23766 suppressed the expression of Smad3/4 in LX-2 cells. The overexpression of Rac1 enhanced the proliferation, migration and invasion of LX-2 cells. In addition, compared with the control groups, a marked increase was observed in the protein expression levels of Smad3/4 in the LX-2 cells transfected with Rac1 plasmids. The methylation-specific PCR findings showed that SAM increased the methylation of Rac1 promoters. The results of the present study suggested that Rac1 enhanced the expression of Smad3/4 in activated HSCs; however, this increase may be suppressed by SAM-induced methylation of Rac1 promoters.
In broadband satellite multimedia (BSM) system, burst time plan (BTP) is always periodically generated. We find that this method can have a great effect on the system response ability to bandwidth ...requests. A general analysis model of BTP generation method is given. An optimized BTP generation (O-BTPG) method is presented by deducing the optimal bandwidth allocation period (BAP) and bandwidth allocation latency (BAL) without considering the signaling overhead caused by BTP. Then a novel asynchronous BTP generation (A-BTPG) method in which the BTP is generated asynchronously according to the traffic load from users` bandwidth requests is proposed. Simulation results show that A-BTPG can flexibly realize a trade-off between the system response ability and BTP signaling overhead. What`s more, it can be widely used in various regenerative onboard switching BSM systems
In broadband satellite multimedia (BSM) system, burst time plan (BTP) is always periodically generated. We find that this method can have a great effect on the system response ability to bandwidth ...requests. A general analysis model of BTP generation method is given. An optimized BTP generation (O-BTPG) method is presented by deducing the optimal bandwidth allocation period (BAP) and bandwidth allocation latency (BAL) without considering the signaling overhead caused by BTP. Then a novel asynchronous BTP generation (A-BTPG) method in which the BTP is generated asynchronously according to the traffic load from users' bandwidth requests is proposed. Simulation results show that A-BTPG can flexibly realize a trade-off between the system response ability and BTP signaling overhead. What's more, it can be widely used in various regenerative onboard switching BSM systems. Keywords: Broadband Satellite Multimedia (BSM); bandwidth allocation; multiple access; burst time plan (BTP)
An antibody phage-display library was constructed from the B cells of convalescent severe acute respiratory syndrome (SARS) patients and screened using inactivated SARS coronavirus (CoV) virions as ...antigens. More than 80 positive clones were isolated from the library and one of them, scFv H12, was extensively characterized. scFv H12 bound to SARS-CoV with high affinity (equilibrium dissociation constant, Kd=73.5 nM), and neutralized SARS virions in vitro. The facts that scFv H12 bound to the SARS-S1 protein under non-reducing conditions and that it did not bind to monomeric S1 protein under reducing conditions strongly suggest that scFv H12 recognizes a conformational epitope shared by oligomeric S1 proteins. This study should aid in the manufacture of neutralizing antibody, provide a better understanding the immunological characteristics of SARS protein and facilitate the design of a SARS vaccine.
Aiming at the fusion of long-exposure images and short-exposure images under low-light conditions, an image fusion method based on block matching is proposed to fuse low-light image pairs into a ...better image. Firstly, based on pyramid multi-scale model Two-way ghost detection algorithm, which reduces the influence of noise and underexposure on ghost detection, and is used to accurately detect the inconsistent region between image pairs due to object motion in low-light scenes; then reconstruct the ghost region by block matching algorithm Finally, the Poisson fusion algorithm for improving the edge characteristics is used to extract the information in the double-exposure image to generate the resulting image. Experimental results show that the method effectively preserves the edge sharpness of the short-exposure image and maintains the color of the long-exposure image. Brightness and detail.
When taking pictures in a low-light scene with artificial lighting, we often encounter the following problem: we can use short exposure setting which yields a dim, noise image but with a sharp ...outline, or we can use a longer exposure setting which yields a bright, saturated image but with blurred areas. In many cases, none of those images is good enough. Good brightness and color information are retained in longer-exposure images, whereas sharp outlines are retained in shorter ones. In this paper, we present a patch-based method to combine such image pair into a better one. In our method, we firstly perform a coarse-to-fine strategy to detect inconsistent pixels caused by moving objects, then we draw information from the two exposures based on a novel patch-based technique. Experimental results show that the proposed method effectively preserves sharp edges of the short-exposure image, and maintains the color, brightness, and details of the long-exposure image.
We consider the problem of transmit power allocation for the multi-beam broadband multimedia satellite communication systems. An efficient power allocation strategy based on the different traffic ...demand of each beam is proposed to guarantee the fairness of the system. First we solve this convex optimization problem by dual methods, and then use a heuristic algorithm to obtain the optimum power allocation of each beam, and also compare the capacity distribution of each beam when the link conditions (rain attenuation) are different.
In review of the four-level supply chain composed by many suppliers, the sole manufacture, the sole wholesaler and the sole retailer, the question of business cooperation which can optimize ...allocation of resources is studied under the random market demand. Using Shapley value method can realize the distribution of interests between enterprises. With the same average cost of suppliers, the interests of the whole supply chain is the same, has nothing to do with the number of suppliers. The more the number of suppliers, the more interests of the suppliers overall distributed, thus the interests of other enterprise can be reduced.
With the development of broadband multimedia satellite communication, people focuse more and more on how to make better use of the bandwidth and guarantee the Qos. The bandwidth request methods of ...different businesses are not the same: When confronted with the real-time demanded multimedia services, the adopt of the peak distribution may waste the bandwidth, thus it's necessary to find more efficient methods; and how to further reduce the transmission delay for the non-real-time business in case of the reliable transmission also need our continuous study. This paper discusses different request and distribution methods in the broadband satellite communication systems: FODA, FEEDERS and DRIFS, and briefly analyzes and compares their performance.
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