Titanium dioxide(TiO 2) samples of different crystal forms were prepared by hydrolysis tetrabutyl titanate in various water to alkoxide ratios and sintering the hydrolysis product at different temperatures. The photo...Titanium dioxide(TiO 2) samples of different crystal forms were prepared by hydrolysis tetrabutyl titanate in various water to alkoxide ratios and sintering the hydrolysis product at different temperatures. The photocatalysts coated on hollow glass beads and loaded with platinum varying from 0.2% to 2.4% by weight.The photocatalytic degradation rate of sodium pentachlorophenolate (PCP-Na) depends on the preparing conditions such as: sintering temperatures, water to alkoxide ratios( R ), platinum content and the size. The proper conditions of preparation photocatalysts are as follows: the ratio of TiO 2 : sodium silicate : hollow glass beads : platinum is 10:5:20:0.15(w/w), R is 100, sintering temperature is 650℃, and the size of hollow glass is 0.5-1 mm. Under these conditions, the ratio between acatase and rutile of the photocatalyst is 2:1, and the photocatalytic activity is high.展开更多
Reactive oxygen species(ROS)play a vital role in cell signaling and redox regulation,but when present in excess,lead to numerous pathologies.Detailed quantitative characterization of mitochondrial superoxide anion(O^(...Reactive oxygen species(ROS)play a vital role in cell signaling and redox regulation,but when present in excess,lead to numerous pathologies.Detailed quantitative characterization of mitochondrial superoxide anion(O^(·-)_(2))production in fetal pulmonary artery endothelia cells(PAECs)has never been reported.The aim of this study is to assess mitochondrial O^(·-)_(2)pro-duction in cultured PAECs over time using a novel quantitative optical approach.The rate,the sources,and the dynamics of O^(·-)_(2)production were assessed using targeted metabolic modulators of the mitochondrial electron transport chain(ETC)complexes,specifically an uncoupler and inhibitors of the various ETC complexes,and inhibitors of extra-mitochondrial sources of O^(·-)_(2).After stabilization,the cells were loaded with nanomolar mitochondrial-targeted hydroethidine(Mito-HE,MitoSOX)online during the experiment without washout of the residual dye.Time-lapse fuorescence microscopy was used to monitor the dynamic changes in O^(·-)_(2)fluorescence intensity over time in PAECs.The transient behaviors of the fuorescence time course showed exponential increases in the rate of O^(·-)_(2) production in the presence of the ETC uncoupler or inhibitors.The most dramatic and the fastest increase in O^(·-)_(2)production was observed when the cells were treated with the uncoupling agent,PCP.We also showed that only the complex IV inhibitor,KCN,attenuated the marked surge in O^(·-)_(2)production induced by PCP.The results showed that mitochondrial respiratory complexes I,III and IV are sources of O^(·-)_(2) production in PAECs,and a new observation that ROS production during uncoupling of mitochondrial res-piration is mediated in part via complex IV.This novel method can be applied in other studies that examine ROS production under stress condition and during ROS mediated injuries in vritro.展开更多
文摘Titanium dioxide(TiO 2) samples of different crystal forms were prepared by hydrolysis tetrabutyl titanate in various water to alkoxide ratios and sintering the hydrolysis product at different temperatures. The photocatalysts coated on hollow glass beads and loaded with platinum varying from 0.2% to 2.4% by weight.The photocatalytic degradation rate of sodium pentachlorophenolate (PCP-Na) depends on the preparing conditions such as: sintering temperatures, water to alkoxide ratios( R ), platinum content and the size. The proper conditions of preparation photocatalysts are as follows: the ratio of TiO 2 : sodium silicate : hollow glass beads : platinum is 10:5:20:0.15(w/w), R is 100, sintering temperature is 650℃, and the size of hollow glass is 0.5-1 mm. Under these conditions, the ratio between acatase and rutile of the photocatalyst is 2:1, and the photocatalytic activity is high.
基金supported by a grant from UWM research growth initiative(101×290)to MR,grants R01 HL057268 and Muma Endowed Chair in Neonatology to GGK,NIH grant P01-GM-066730-12 to AKSC,and NIH grant 1R15HL129209 to SHA.
文摘Reactive oxygen species(ROS)play a vital role in cell signaling and redox regulation,but when present in excess,lead to numerous pathologies.Detailed quantitative characterization of mitochondrial superoxide anion(O^(·-)_(2))production in fetal pulmonary artery endothelia cells(PAECs)has never been reported.The aim of this study is to assess mitochondrial O^(·-)_(2)pro-duction in cultured PAECs over time using a novel quantitative optical approach.The rate,the sources,and the dynamics of O^(·-)_(2)production were assessed using targeted metabolic modulators of the mitochondrial electron transport chain(ETC)complexes,specifically an uncoupler and inhibitors of the various ETC complexes,and inhibitors of extra-mitochondrial sources of O^(·-)_(2).After stabilization,the cells were loaded with nanomolar mitochondrial-targeted hydroethidine(Mito-HE,MitoSOX)online during the experiment without washout of the residual dye.Time-lapse fuorescence microscopy was used to monitor the dynamic changes in O^(·-)_(2)fluorescence intensity over time in PAECs.The transient behaviors of the fuorescence time course showed exponential increases in the rate of O^(·-)_(2) production in the presence of the ETC uncoupler or inhibitors.The most dramatic and the fastest increase in O^(·-)_(2)production was observed when the cells were treated with the uncoupling agent,PCP.We also showed that only the complex IV inhibitor,KCN,attenuated the marked surge in O^(·-)_(2)production induced by PCP.The results showed that mitochondrial respiratory complexes I,III and IV are sources of O^(·-)_(2) production in PAECs,and a new observation that ROS production during uncoupling of mitochondrial res-piration is mediated in part via complex IV.This novel method can be applied in other studies that examine ROS production under stress condition and during ROS mediated injuries in vritro.
