An accurate and reasonable technique combining direct absorption spectroscopy and laser-induced fluorescence（LIF）methods is developed to quantitatively measure the concentrations of hydroxyl in CH;/air flat laminar ...An accurate and reasonable technique combining direct absorption spectroscopy and laser-induced fluorescence（LIF）methods is developed to quantitatively measure the concentrations of hydroxyl in CH;/air flat laminar flame. In our approach, particular attention is paid to the linear laser-induced fluorescence and absorption processes, and experimental details as well. Through measuring the temperature, LIF signal distribution and integrated absorption, spatially absolute OH concentrations profiles are successfully resolved. These experimental results are then compared with the numerical simulation. It is proved that the good quality of the results implies that this method is suitable for calibrating the OH-PLIF measurement in a practical combustor.展开更多
Reactive oxygen species (ROS), including the hydroxyl radical ( · OH), are known to be potential modulators of apoptosis. However, the biochemical mechanisms underlying apoptosis induced by ...Reactive oxygen species (ROS), including the hydroxyl radical ( · OH), are known to be potential modulators of apoptosis. However, the biochemical mechanisms underlying apoptosis induced by ·OH, namely how the radical induces a cell to die, are poorly understood. The present work highlights the changes of the energy/redox status during apoptosis by exogenous ·OH treatment. HeLa cells were induced to undergo typical apoptosis by ·OH generated directly via the Fe 2+ mediated Fenton reaction. The thermodynamics study indicated that the ·OH treatment increased the cellular heat output in the first hours, and then the cellular thermodynamics shifted to endothermic. The data demonstrates that the mitochondria are actively involved in ·OH treatment induced apoptosis, with the cellular oxygen consumption rapidly decreasing after the ·OH treatment for only 0.5 h. But DNA fragmentation, which is the major characteristic of apoptosis, took place 16 h after ·OH treatment. The results suggest that alteration of the energy/redox metabolism and the energy/redox status may be the primary causes among the early events of ·OH induced apoptosis.展开更多
In order to evaluate the eco-toxicological effects of Roundup® on Carassius auratus (C. auratus), fish were exposed to 32 μg/L Roundup®, isopropylamine salt of glyphosate (G.I.S) and polyoxyethylene ami...In order to evaluate the eco-toxicological effects of Roundup® on Carassius auratus (C. auratus), fish were exposed to 32 μg/L Roundup®, isopropylamine salt of glyphosate (G.I.S) and polyoxyethylene amine (POEA) over different periods (0.5, 1, 3, 7 and 14 d). Hydroxyl radical (·OH), malondialdehyde (MDA) and acetylcholinesterase (AChE) in liver were detected in this study. Results showed that the generation of ·OH increased before 7 d, but without significantly difference. ·OH was induced at 1 d for POEA group, 3 d for Roundup® group and 7 d for G.I.S group. At 14 d, ·OH generation returned to normal levels. MDA contents all increased significantly (p < 0.01) during 7 days and then reached a normal level at 14 d. AChE activity in all group tests revealed a significant inhibition (p < 0.01) after 7 days exposure and then rebounded a little, but remained below the control after 14 days exposure. The rate of AChE inhibition range from 13% - 42% in Roundup®, 6% - 40% in G.I.S, and 21% - 54% in POEA, suggesting that POEA was more toxic compared to Roundup® and G.I.S. 32 μg/L Roundup® exposure led to the change of physiological and biochemical indexes in C. auratus, which was a reversible process in the long run.展开更多
Catalytic ozonation of Reactive Red X-3B in aqueous solution had been carried out in an ozone oxidation reactor where Mn-Fe-ceramic honeycomb was used as the catalysts. The presence of Mn-Fe-ceramic honeycomb catalyst...Catalytic ozonation of Reactive Red X-3B in aqueous solution had been carried out in an ozone oxidation reactor where Mn-Fe-ceramic honeycomb was used as the catalysts. The presence of Mn-Fe-ceramic honeycomb catalyst could obviously improve the deco- loration efficiency of Reactive Red X-3B and the utilization efficiency of ozone compared to the results from non-catalytic ozonation. Adsorption of Reactive Red X-3B had no obviously influence on the degradation efficiency. Addition of tert-butanol significantly decreased the degradation efficiency, indicating that the degradation of Reactive Red X-3B followed the mechanism of hydroxyl radical （OH.） oxidation. The operating variables such as reaction pressure and ozone supply had a positive influence on the degradation efficiency, mainly attributing to facilitate the ozone decomposition and OH. formation.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11272338)the Science and Technology on Scramjet Key Laboratory Funding,China(Grant No.STSKFKT 2013004)the China Scholarship Council
文摘An accurate and reasonable technique combining direct absorption spectroscopy and laser-induced fluorescence（LIF）methods is developed to quantitatively measure the concentrations of hydroxyl in CH;/air flat laminar flame. In our approach, particular attention is paid to the linear laser-induced fluorescence and absorption processes, and experimental details as well. Through measuring the temperature, LIF signal distribution and integrated absorption, spatially absolute OH concentrations profiles are successfully resolved. These experimental results are then compared with the numerical simulation. It is proved that the good quality of the results implies that this method is suitable for calibrating the OH-PLIF measurement in a practical combustor.
文摘Reactive oxygen species (ROS), including the hydroxyl radical ( · OH), are known to be potential modulators of apoptosis. However, the biochemical mechanisms underlying apoptosis induced by ·OH, namely how the radical induces a cell to die, are poorly understood. The present work highlights the changes of the energy/redox status during apoptosis by exogenous ·OH treatment. HeLa cells were induced to undergo typical apoptosis by ·OH generated directly via the Fe 2+ mediated Fenton reaction. The thermodynamics study indicated that the ·OH treatment increased the cellular heat output in the first hours, and then the cellular thermodynamics shifted to endothermic. The data demonstrates that the mitochondria are actively involved in ·OH treatment induced apoptosis, with the cellular oxygen consumption rapidly decreasing after the ·OH treatment for only 0.5 h. But DNA fragmentation, which is the major characteristic of apoptosis, took place 16 h after ·OH treatment. The results suggest that alteration of the energy/redox metabolism and the energy/redox status may be the primary causes among the early events of ·OH induced apoptosis.
基金The research was funded through the National Science Foundation of China(No.21077051,51278241)the Jiangsu Natural Science Foundation(No.BK2011057).
文摘In order to evaluate the eco-toxicological effects of Roundup® on Carassius auratus (C. auratus), fish were exposed to 32 μg/L Roundup®, isopropylamine salt of glyphosate (G.I.S) and polyoxyethylene amine (POEA) over different periods (0.5, 1, 3, 7 and 14 d). Hydroxyl radical (·OH), malondialdehyde (MDA) and acetylcholinesterase (AChE) in liver were detected in this study. Results showed that the generation of ·OH increased before 7 d, but without significantly difference. ·OH was induced at 1 d for POEA group, 3 d for Roundup® group and 7 d for G.I.S group. At 14 d, ·OH generation returned to normal levels. MDA contents all increased significantly (p < 0.01) during 7 days and then reached a normal level at 14 d. AChE activity in all group tests revealed a significant inhibition (p < 0.01) after 7 days exposure and then rebounded a little, but remained below the control after 14 days exposure. The rate of AChE inhibition range from 13% - 42% in Roundup®, 6% - 40% in G.I.S, and 21% - 54% in POEA, suggesting that POEA was more toxic compared to Roundup® and G.I.S. 32 μg/L Roundup® exposure led to the change of physiological and biochemical indexes in C. auratus, which was a reversible process in the long run.
文摘Catalytic ozonation of Reactive Red X-3B in aqueous solution had been carried out in an ozone oxidation reactor where Mn-Fe-ceramic honeycomb was used as the catalysts. The presence of Mn-Fe-ceramic honeycomb catalyst could obviously improve the deco- loration efficiency of Reactive Red X-3B and the utilization efficiency of ozone compared to the results from non-catalytic ozonation. Adsorption of Reactive Red X-3B had no obviously influence on the degradation efficiency. Addition of tert-butanol significantly decreased the degradation efficiency, indicating that the degradation of Reactive Red X-3B followed the mechanism of hydroxyl radical （OH.） oxidation. The operating variables such as reaction pressure and ozone supply had a positive influence on the degradation efficiency, mainly attributing to facilitate the ozone decomposition and OH. formation.
