Objective To investigate the roles of Rho/Rock signaling pathway in silica-induced Epithelial-mesenchymal transition （EMT） in human bronchial epithelial cells （BEC） in vitro. Methods Human BEC were incubated with ...Objective To investigate the roles of Rho/Rock signaling pathway in silica-induced Epithelial-mesenchymal transition （EMT） in human bronchial epithelial cells （BEC） in vitro. Methods Human BEC were incubated with silica with various concentrations for indicated times. Cell viability was assayed by MTT test. Morphologic Changes were observed by microscope. Mesenchymal marker a-smooth muscle actin （a-SMA）, vimentin （Vim）, and epithelial marker E-cadherin （E-cad） were analyzed by Western Blot. The pull-down assay was used to measure Rho activity. In the prevention experiments, the specific inhibitor for Rho effector ROCK （Y27632） was used to inhibit the activity of Rho. Results Human BEC stimulated with silica were converted from a ＂cobblestone＂ epithelial structure into an elongated fibroblast-like shape structure. Incubation of human BEC with silica induced de novo expression of a-SMA and Vim, and loss of E-cad. Also, silica treatment resulted in Rho activation in human BEC. Y27632 up-regulated the E-cad expression but attenuated a-SMA and Vim expression in silica-stimulated cells. Conclusion The activation of Rho/ROCK signaling pathways is most likely involved in Silica-induced EMT in human bronchial epithelial cells.展开更多
Epithelial-mesenchymal transition （EMT） plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells （BECs）; however, the underlying mechanism...Epithelial-mesenchymal transition （EMT） plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells （BECs）; however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTr assay, western blot, electrophoretic mobility shift assay （EMSA）, and small interfering RNA （siRNA） transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI silica-induced expression siRNA upregulated the siRNA inhibited the of Snail. Moreover, SNAI expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker a-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.展开更多
The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined...The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined by means of scanning electron microscopy performed in backscattered electron mode. The embedded particles distribution was shown to be the densest and the most uniform in laminar low flow mode and when the nozzle is at a distance of 5 mm close from the cathode. Excrescences observed on the composite surface are due to the wave-like flow of the jet on the cathode surface. The silica content of the nickel composite coatings was assessed by energy dispersive X-ray spectroscopy. The amount of particles embedded in the coating decreases with an increasing Reynolds number and as the nozzle-to-sample distance d becomes larger. A maximum rate of 4.43 wt% of silica has been successfully loaded at a distance d equal to 5 mm in the Ni-SiO2 composite coating.展开更多
In an effort to reduce thermal shrinkage and improve electrochemical performance of porous polypropylene （PP） separators for lithium-ion batteries, a new composite separator is developed by introducing ceramic coate...In an effort to reduce thermal shrinkage and improve electrochemical performance of porous polypropylene （PP） separators for lithium-ion batteries, a new composite separator is developed by introducing ceramic coated layers on both sides of PP separator through a dip-coating process. The coated layers are comprised of heat-resistant and hydrophilic silica nanoparticles and polyvinylidene fluoride-hexafluoropropylene （PVDF-HFP） binders. Highly porous honeycomb structure is formed and the thickness of the layer is only about 700 nm. In comparison to the pristine PP separator, the composite separator shows significant reduction in thermal shrinkage and improvement in liquid electrolyte uptake and ionic conduction, which play an important role in improving cell performance such as discharge capacity, C-rate capability, cycle performance and coulombic efficiency.展开更多
Phosphotungstic acid is an excellent proton conductor that can be incorporated into porous supports, and nanocomposite proton exchange membrane materials made from mesoporous silica impregnated with phosphotungstic ac...Phosphotungstic acid is an excellent proton conductor that can be incorporated into porous supports, and nanocomposite proton exchange membrane materials made from mesoporous silica impregnated with phosphotungstic acid have been suggested for use in fuels cells operating> 100 ℃. In this work, quasielastic neutron scattering was used to study proton self-diffusion in mesoporous disordered and P6 mm symmetry silica impregnated with two concentrations of phosphotungstic acid. Overall, the silica structure had a significantly greater effect on proton conduction and diffusion than phosphotungstic acid concentration, with higher proton conduction occurring for the P6 mm symmetry silica samples. Quasielastic neutron scattering revealed two populations of protons diffusing through each sample, and that proton conduction is limited by the slower of these populations, which diffuse via a jump-diffusion mechanism. Whilst the fundamental jump-diffusion mechanism by which these slower protons moved was found to be similar for both silica supports and phosphotungstic acid concentrations, the faster diffusion occurring in P6 mm structured silica arises from a lower residence time of protons moving between sites in the jump-diffusion model, suggesting a lower energy barrier.展开更多
对4个草地早熟禾(P oa p ra tensis)品种男爵(B aron)、黑石(B lackstone)、肯塔基(K en tucky)和蓝月(B luem oon)的叶表皮超微结构及其对干旱的适应特性进行研究。结果表明:气孔器的开闭状态与干旱胁迫有关,而与品种的气孔器密度无关...对4个草地早熟禾(P oa p ra tensis)品种男爵(B aron)、黑石(B lackstone)、肯塔基(K en tucky)和蓝月(B luem oon)的叶表皮超微结构及其对干旱的适应特性进行研究。结果表明:气孔器的开闭状态与干旱胁迫有关,而与品种的气孔器密度无关;品种间的硅质乳突密度和大小差异显著,密度大的品种,可以有效防止叶表面水分过度散失,但硅质乳突大小与气孔的运动调节无直接关系。展开更多
This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities locate...This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities located in the Al-Qassim Region of Saudi Arabia (Uyun Al-Jawa, Al-Fuwailiq, Al-Sulaibiya, and Al-Qawara), from three distinct depths (the earth’s surface, 50 cm, and 100 cm). The percentages of silicon in these places vary between the highest value for silicon dioxide, which is 74.47 m/m%, and 34.8 m/m% for silicon in Al-Qawara city at a depth of 100 cm. We used an x-ray fluorescence (XRF) instrument to evaluate the samples. There are high percentage of both silica and silicon in the Nafud desert. Studies have shown that these ratios can help investors benefit from an element of Silicon and silicon dioxide, so the sands of the Nafud desert is sufficient for extracting Silicon and silica in huge quantities. This may transform the Kingdom into a leading country in the global computer technology industry that depends on silicon extracted from the desert sands, the most important of which are microcomputer data processing devices.展开更多
基金supported by the National Natural Science Foundation of China(No30700661)
文摘Objective To investigate the roles of Rho/Rock signaling pathway in silica-induced Epithelial-mesenchymal transition （EMT） in human bronchial epithelial cells （BEC） in vitro. Methods Human BEC were incubated with silica with various concentrations for indicated times. Cell viability was assayed by MTT test. Morphologic Changes were observed by microscope. Mesenchymal marker a-smooth muscle actin （a-SMA）, vimentin （Vim）, and epithelial marker E-cadherin （E-cad） were analyzed by Western Blot. The pull-down assay was used to measure Rho activity. In the prevention experiments, the specific inhibitor for Rho effector ROCK （Y27632） was used to inhibit the activity of Rho. Results Human BEC stimulated with silica were converted from a ＂cobblestone＂ epithelial structure into an elongated fibroblast-like shape structure. Incubation of human BEC with silica induced de novo expression of a-SMA and Vim, and loss of E-cad. Also, silica treatment resulted in Rho activation in human BEC. Y27632 up-regulated the E-cad expression but attenuated a-SMA and Vim expression in silica-stimulated cells. Conclusion The activation of Rho/ROCK signaling pathways is most likely involved in Silica-induced EMT in human bronchial epithelial cells.
基金supported by the National Natural Science Foundation of China(No.30700661,81170023,81470266)China Postdoctoral Science Foundation(2014M562139)Hunan Province Natural Science Foundation(14JJ2041)
文摘Epithelial-mesenchymal transition （EMT） plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells （BECs）; however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTr assay, western blot, electrophoretic mobility shift assay （EMSA）, and small interfering RNA （siRNA） transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI silica-induced expression siRNA upregulated the siRNA inhibited the of Snail. Moreover, SNAI expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker a-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.
文摘The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined by means of scanning electron microscopy performed in backscattered electron mode. The embedded particles distribution was shown to be the densest and the most uniform in laminar low flow mode and when the nozzle is at a distance of 5 mm close from the cathode. Excrescences observed on the composite surface are due to the wave-like flow of the jet on the cathode surface. The silica content of the nickel composite coatings was assessed by energy dispersive X-ray spectroscopy. The amount of particles embedded in the coating decreases with an increasing Reynolds number and as the nozzle-to-sample distance d becomes larger. A maximum rate of 4.43 wt% of silica has been successfully loaded at a distance d equal to 5 mm in the Ni-SiO2 composite coating.
基金supported by the Tsinghua University Initiative Scientific Research Program(Grant No.2012THZ08129)
文摘In an effort to reduce thermal shrinkage and improve electrochemical performance of porous polypropylene （PP） separators for lithium-ion batteries, a new composite separator is developed by introducing ceramic coated layers on both sides of PP separator through a dip-coating process. The coated layers are comprised of heat-resistant and hydrophilic silica nanoparticles and polyvinylidene fluoride-hexafluoropropylene （PVDF-HFP） binders. Highly porous honeycomb structure is formed and the thickness of the layer is only about 700 nm. In comparison to the pristine PP separator, the composite separator shows significant reduction in thermal shrinkage and improvement in liquid electrolyte uptake and ionic conduction, which play an important role in improving cell performance such as discharge capacity, C-rate capability, cycle performance and coulombic efficiency.
基金support from Australian Research Council Discovery Project DP120102325the Centre forMicroscopy and Microanalysis at the University of Queensland+1 种基金Curtin Universitythe Australian Institute for Nuclear Science and Engineering for support through a Post-Graduate Research Award
文摘Phosphotungstic acid is an excellent proton conductor that can be incorporated into porous supports, and nanocomposite proton exchange membrane materials made from mesoporous silica impregnated with phosphotungstic acid have been suggested for use in fuels cells operating> 100 ℃. In this work, quasielastic neutron scattering was used to study proton self-diffusion in mesoporous disordered and P6 mm symmetry silica impregnated with two concentrations of phosphotungstic acid. Overall, the silica structure had a significantly greater effect on proton conduction and diffusion than phosphotungstic acid concentration, with higher proton conduction occurring for the P6 mm symmetry silica samples. Quasielastic neutron scattering revealed two populations of protons diffusing through each sample, and that proton conduction is limited by the slower of these populations, which diffuse via a jump-diffusion mechanism. Whilst the fundamental jump-diffusion mechanism by which these slower protons moved was found to be similar for both silica supports and phosphotungstic acid concentrations, the faster diffusion occurring in P6 mm structured silica arises from a lower residence time of protons moving between sites in the jump-diffusion model, suggesting a lower energy barrier.
文摘对4个草地早熟禾(P oa p ra tensis)品种男爵(B aron)、黑石(B lackstone)、肯塔基(K en tucky)和蓝月(B luem oon)的叶表皮超微结构及其对干旱的适应特性进行研究。结果表明:气孔器的开闭状态与干旱胁迫有关,而与品种的气孔器密度无关;品种间的硅质乳突密度和大小差异显著,密度大的品种,可以有效防止叶表面水分过度散失,但硅质乳突大小与气孔的运动调节无直接关系。
文摘This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities located in the Al-Qassim Region of Saudi Arabia (Uyun Al-Jawa, Al-Fuwailiq, Al-Sulaibiya, and Al-Qawara), from three distinct depths (the earth’s surface, 50 cm, and 100 cm). The percentages of silicon in these places vary between the highest value for silicon dioxide, which is 74.47 m/m%, and 34.8 m/m% for silicon in Al-Qawara city at a depth of 100 cm. We used an x-ray fluorescence (XRF) instrument to evaluate the samples. There are high percentage of both silica and silicon in the Nafud desert. Studies have shown that these ratios can help investors benefit from an element of Silicon and silicon dioxide, so the sands of the Nafud desert is sufficient for extracting Silicon and silica in huge quantities. This may transform the Kingdom into a leading country in the global computer technology industry that depends on silicon extracted from the desert sands, the most important of which are microcomputer data processing devices.
