Effects of Helicobacter pylori

Infection of Helicobacter pylori (H. pylori) changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects of H. pylori on the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation. Objective. To investigate the effects of Helicobacter pylori (H. pylori) and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells. Methods. H. pylori and a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. The siRNA-treated AGS cells were cocultured with H. pylori and cell proliferation was measured by an MTT assay. Results. The proliferation of AGS cells was accelerated by coculturing with H. pylori for 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected by H. pylori for 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing with H. pylori for 24 and 48 h compared with the control group. Conclusions. Coculture of H. pylori altered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect of H. pylori on proliferation of epithelial cells. These results indicate that the effects of H. pylori on the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium

Hierarchical porous carbons derived from leftover rice for high performance supercapacitors

Abstract(#br)Biomass-derived porous carbons have been extensively investigated as potential electrode materials of electrochemical energy storage devices. Herein, hierarchical porous carbons with high specific surface area and large mesoporosity are successfully prepared from leftover rice, a common meal surplus, benefiting from its unique swelled structure and the activation effect of potassium hydroxide. The hierarchical porous carbons exhibit outstanding electrochemical energy storage performances in 1 M TEABF 4 /PC (propylene carbonate) electrolyte, including a high specific capacitance of 153.2 F g −1 at 0.2 A g −1 based on the active material, a high specific energy density of 22.6 Wh kg −1 at a power density of 21,503 W kg −1 based on the cells and over 87% capacitance retentions after 10,000 cycles at 1 A g −1 . Such excellent electrochemical performances demonstrate that leftover rice can be potentially applied as bioresource for high property porous carbon electrode materials of supercapacitors

Manifold Path Guiding for Importance Sampling Specular Chains

Complex visual effects such as caustics are often produced by light paths containing multiple consecutive specular vertices (dubbed specular chains), which pose a challenge to unbiased estimation in Monte Carlo rendering. In this work, we study the light transport behavior within a sub-path that is comprised of a specular chain and two non-specular separators. We show that the specular manifolds formed by all the sub-paths could be exploited to provide coherence among sub-paths. By reconstructing continuous energy distributions from historical and coherent sub-paths, seed chains can be generated in the context of importance sampling and converge to admissible chains through manifold walks. We verify that importance sampling the seed chain in the continuous space reaches the goal of importance sampling the discrete admissible specular chain. Based on these observations and theoretical analyses, a progressive pipeline, manifold path guiding, is designed and implemented to importance sample challenging paths featuring long specular chains. To our best knowledge, this is the first general framework for importance sampling discrete specular chains in regular Monte Carlo rendering. Extensive experiments demonstrate that our method outperforms state-of-the-art unbiased solutions with up to 40x variance reduction, especially in typical scenes containing long specular chains and complex visibility.Comment: 14 pages, 19 figure

Constructing multidimensional conducting networks on LiCoO 2 cathode for enhanced rate performance and cycle stability

Abstract(#br)The effects of different assemblies of Super P, carbon nanotubes (CNTs) and graphene as hybrid conductive additives on the rate performance and cyclic stability of LiCoO 2 (LCO) cathode material were systematically investigated. The results indicated that adding graphene, CNTs or mixture of them into the conventional Super P conductive agent was effective to reduce the overall mass ratio of the carbonaceous conductive additive in the LCO electrode while significantly improving the rate performance and cycle stability. The best electrochemical performance was achieved on the electrode with 1 wt% (G + SP) and 1 wt% CNTs. Microstructural investigations indicated that a multidimensional conducting network had been constructed within this cathode, which provided efficient electronic and ionic transportation pathways, as evidenced by the reduced transport resistance and improved Li-ion diffusion dynamics. With this composition, a high discharge capacity of 118 mA h g −1 was obtained at a current density of 10 C (1400 mA g −1 ), and a high capacity retention of 92.3% was maintained after 100 cycles at 1 C