Mitigation effects of coenzyme Q10(CoQ10)on spiromesifen(SPM)-induced acute toxicity to zebrafish at different life stages,as well as abnormal development,especially impaired development of heart and notochord,oxidati...Mitigation effects of coenzyme Q10(CoQ10)on spiromesifen(SPM)-induced acute toxicity to zebrafish at different life stages,as well as abnormal development,especially impaired development of heart and notochord,oxidative stress and apoptosis in embryos were investigated using a semi-static method.Results showed that CoQ10 can remarkably reduce the acute toxicity of SPM to zebrafish embryos,larvae and adults by 3.20-,2.09-and 1.51-fold,respectively.CoQ10 can effectively alleviate the SPM-induced abnormal spontaneous movement,decreased heartbeat,delayed hatching,growth inhibition and various teratogenic effects of zebrafish embryos.At the stage of zebrafish embryo,CoQ10 significantly increases superoxide dismutase(SOD)activity and expression levels of genes related to anti-oxidation(Cat&Cu/Zn-sod),anti-apoptosis(mcl1a&mcl1b),heart development(cmlc1,actc1a&erbb4a)and angiogenesis(vegfaa,vegfd&kdrl),which are inhibited by SPM.Additionally,CoQ10 reduces malondialdehyde(MDA)content and caspase-3 activity of embryos,as well as expression levels of pro-apoptosis(Cas3,Cas9,P53&bax)and notochord(tbxta&col2a)related genes raised by SPM.The results indicate that CoQ10 can mitigate the acute toxicity of SPM to zebrafish,and alleviate the abnormal development of heart and notochord of embryos by reducing oxidative stress and apoptosis,as well as regulating the expression of related genes.展开更多
The gas explosion in residential building has always been a highly concerned problem.Explosions in homogeneous mixtures have been extensively studied.However,mixtures are often inhomogeneous in the practical scenarios...The gas explosion in residential building has always been a highly concerned problem.Explosions in homogeneous mixtures have been extensively studied.However,mixtures are often inhomogeneous in the practical scenarios due to the differences in the densities of methane and air.In order to investigate the effects of gas explosions in inhomogeneous mixtures,experimental studies involving gas leakage and explosion are conducted in a full-scale residential building to reproduce the process of gas explosion.By fitting the dimensionless buoyancy as a function of dimensionless height and dimensionless time,a distribution model of gas in large-scale spaces is established,and the mechanism of inhomogeneous distribution of methane is also be revealed.Furthermore,the stratified reconstruction method(SRM)is introduced for efficiently setting up inhomogeneous concentration fields in FLACS.The simulation results highlight that for the internal overpressure,the distribution of methane has no effect on the first overpressure peak(ΔP1),while it significantly influences the subsequent overpressure peak(ΔP2),and the maximum difference between the overpressure of homogeneous and inhomogeneous distribution is174.3%.Moreover,the initial concentration distribution also has a certain impact on the external overpressure.展开更多
Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane ex...Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane explosion protection by using an experimental platform and adjusting the blockage rate and spacing of the obstacles.It aims to reduce the risk of gas explosions in urban underground spaces.The results of the study show that the flame propagation peak speed and peak overpressure are reduced with the decrease in the blocking rate of the flexible obstacle when the blocking rate of the flexible obstacle is less than or equal to the blocking rate of the rigid obstacle,with the decrease in the spacing,the better the protection effect of the methane explosion.When the blockage rate of the flexible obstacle is greater than the blockage rate of the rigid obstacle and spacing is less than the height of the flexible obstacle,rigid and flexible obstacles are connected as a whole,increasing the strength of the explosion.This study can provide a theoretical basis and scientific guidance for optimizing rigid and flexible object hybrid layouts and methane explosion protection technology in urban underground spaces.展开更多
基金Supported by National Key Research and Development Program of China(No.2017YFD0200504)。
文摘Mitigation effects of coenzyme Q10(CoQ10)on spiromesifen(SPM)-induced acute toxicity to zebrafish at different life stages,as well as abnormal development,especially impaired development of heart and notochord,oxidative stress and apoptosis in embryos were investigated using a semi-static method.Results showed that CoQ10 can remarkably reduce the acute toxicity of SPM to zebrafish embryos,larvae and adults by 3.20-,2.09-and 1.51-fold,respectively.CoQ10 can effectively alleviate the SPM-induced abnormal spontaneous movement,decreased heartbeat,delayed hatching,growth inhibition and various teratogenic effects of zebrafish embryos.At the stage of zebrafish embryo,CoQ10 significantly increases superoxide dismutase(SOD)activity and expression levels of genes related to anti-oxidation(Cat&Cu/Zn-sod),anti-apoptosis(mcl1a&mcl1b),heart development(cmlc1,actc1a&erbb4a)and angiogenesis(vegfaa,vegfd&kdrl),which are inhibited by SPM.Additionally,CoQ10 reduces malondialdehyde(MDA)content and caspase-3 activity of embryos,as well as expression levels of pro-apoptosis(Cas3,Cas9,P53&bax)and notochord(tbxta&col2a)related genes raised by SPM.The results indicate that CoQ10 can mitigate the acute toxicity of SPM to zebrafish,and alleviate the abnormal development of heart and notochord of embryos by reducing oxidative stress and apoptosis,as well as regulating the expression of related genes.
基金the financial support from National Natural Science Foundation of China(Grant No.52378488)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX22_0222)。
文摘The gas explosion in residential building has always been a highly concerned problem.Explosions in homogeneous mixtures have been extensively studied.However,mixtures are often inhomogeneous in the practical scenarios due to the differences in the densities of methane and air.In order to investigate the effects of gas explosions in inhomogeneous mixtures,experimental studies involving gas leakage and explosion are conducted in a full-scale residential building to reproduce the process of gas explosion.By fitting the dimensionless buoyancy as a function of dimensionless height and dimensionless time,a distribution model of gas in large-scale spaces is established,and the mechanism of inhomogeneous distribution of methane is also be revealed.Furthermore,the stratified reconstruction method(SRM)is introduced for efficiently setting up inhomogeneous concentration fields in FLACS.The simulation results highlight that for the internal overpressure,the distribution of methane has no effect on the first overpressure peak(ΔP1),while it significantly influences the subsequent overpressure peak(ΔP2),and the maximum difference between the overpressure of homogeneous and inhomogeneous distribution is174.3%.Moreover,the initial concentration distribution also has a certain impact on the external overpressure.
基金supported by the National Natural Science Foundation of China(Grant No.52274177)Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202401501)+1 种基金Chongqing Graduate Student Research Innovation Program(Grant No.CYS240800)The Science and Technology Innovation Project for Graduate Students of Chongqing University of Science and Technology(Grant No.YKJCX2420702).
文摘Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane explosion protection by using an experimental platform and adjusting the blockage rate and spacing of the obstacles.It aims to reduce the risk of gas explosions in urban underground spaces.The results of the study show that the flame propagation peak speed and peak overpressure are reduced with the decrease in the blocking rate of the flexible obstacle when the blocking rate of the flexible obstacle is less than or equal to the blocking rate of the rigid obstacle,with the decrease in the spacing,the better the protection effect of the methane explosion.When the blockage rate of the flexible obstacle is greater than the blockage rate of the rigid obstacle and spacing is less than the height of the flexible obstacle,rigid and flexible obstacles are connected as a whole,increasing the strength of the explosion.This study can provide a theoretical basis and scientific guidance for optimizing rigid and flexible object hybrid layouts and methane explosion protection technology in urban underground spaces.
文摘构建准确的滑坡预测模型和确定环境因子的贡献程度,对滑坡易发性评价具有重要意义。在以往研究中,最大熵物种分布(maximum entropy model,MaxEnt)模型因其对样本量要求低、预测精度高和可避免模型过度拟合等优点,被广泛运用在生态学领域。以沅陵县为研究区,基于342处滑坡灾害点数据和9个环境变量,分别采用确定性系数(certainty factor,CF)模型、逻辑回归(Logistic)模型和MaxEnt模型对沅陵县进行滑坡易发性分区预测。同时采用刀切法(Jackknife)检验环境因子对预测结果的贡献程度,确定滑坡地质灾害的主要影响因素。结果表明:确定性系数模型、逻辑回归模型和MaxEnt模型的受试者特征曲线(receiver operating characteristic,ROC)下面积(area under the curve,AUC)值分别为0.827、0.803、0.911,3种模型的预测精度均较高,且MaxEnt模型精度最高,表现较好;河流是影响研究区滑坡灾害发生贡献程度最高的环境因子;滑坡灾害主要发育在以河流为中心向外延伸100 m范围内,集中分布在沅江、深溪和兰溪附近。研究能为沅陵县地质灾害易发性评价提供一种新的方法。
