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  • Author: Ping Gao x
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An Experimental Study Of The Compression Properties Of Polyurethane-Based Warp-Knitted Spacer Fabric Composites

Abstract

The present work has reported the compression properties of polyurethane-based warp-knitted spacer fabric composites (PWSF). In order to investigate the effect of structural parameters of fabric on the compression performance of composites, a series of warp-knitted spacer fabrics (WSF) with different structural parameters including spacer yarn inclination angle, thickness, fineness of spacer yarns, and outer layer structure have been involved. The produced composites have been characterized for compression properties. The energy-absorption performance during the compression process has been determined as a function of the efficiency and the compression stress obtained from compression tests. The results show that the composites based on spacer fabrics having smaller spacer yarns inclination angle, higher fabric thickness, finer spacer yarn, and larger mesh in outer layers perform better with respect to energy-absorption properties at lower stress level, whereas at higher stress level, the best energy-absorption abilities are obtained in case of spacer fabrics constructed of larger spacer yarn inclination angle, lower fabric thickness, coarser spacer yarn, and smaller mesh in surface layers.

Open access
Molecular Pathogenesis of Liver Steatosis Induced by Hepatitis C Virus

Abstract

Liver steatosis is a pathological hallmark in patients with chronic hepatitis C (CHC). Increased lipid uptake, decreased lipid secretion, increased lipid synthesis and decreased lipid degradation are all involved in pathogenesis of steatosis induced by hepatitic C virus (HCV) infection. Level of low density lipoprotein receptor (LDL-R) and activity of peroxisome proliferator-activated receptor (PPAR) α is related to liver uptake of lipid from circulation, and affected by HCV. Secretion via microsomal triglyceride transfer protein (MTTP), and formation of very low density lipoprotein (VLDL) have been hampered by HCV infection. Up-regulation of lipid synthesis related genes, such as sterol regulatory element-binding protein (SREBP)-1, SREBP-2, SREBP-1c, fatty acid synthase (FASN), HMG CoA reductase (HMGCR), liver X receptor (LXR), acetyl-CoA carboxylase 1 (ACC1), hepatic CB (1) receptors, retinoid X receptor (RXR) α, were the main stay of liver steatosis pathogenesis. Degradation of lipid in liver is decreased in patients with CHC. There is strong evidence that heterogeneity of HCV core genes of different genotypes affect their effects of liver steatosis induction. A mechanism in which steatosis is involved in HCV life cycle is emerging.

Open access
The rtA181 Mutation Produces Similar Clinical and Cellular Characteristics in Patients infected with Hepatitis B Virus Genotypes B and C

Abstract

Objective to investigate the association between HBV genotypes and characteristics of rtA181 mutation.

Methods Total of 85 chronic hepatitis B (CHB) patients who appeared rtA181 mutation after nucleos(t)ide analogs (NAs) therapy were enrolled in this study. Levels of serum ALT, AST, HBV DNA and HBsAg titers were monitored during therapy. HBV reverse transcriptase genes were amplified and sequenced to identify genotypes and resistance mutations. Virions and HBsAg in HepG2 cell with rtA181 mutation were also compared between genotypes B and C.

Results The majority of sera contained HBV genotypes B (15.7%) and C (84.3%). There were no significant difference of rtA181 mutant patterns between genotypes (P > 0.05). After emergence of rtA181 mutation, serum ALT, AST, HBV DNA levels and HBsAg titers were decreased than that at baseline (P < 0.05), while these characteristics were not different between genotypes B and C (P > 0.05). In cellular experiment, there were no significant differences between genotypes B and C not only in HBV virions but also in HBsAg titres (P > 0.05).

Conclusions No differences of clinical characteristics and cellular results were found in rtA181 mutation of HBV genotypes B and C.

Open access