为有效防治小菜蛾(Plutella xylostella),减少其造成的经济损失,采用点滴注射法测定了亚致死浓度的溴氰菊酯对小菜蛾生长发育及生殖能力的影响,并检测了溴氰菊酯对小菜蛾的时间毒性效应。结果表明,采用溴氰菊酯亚致死浓度(12 h LC35,即1...为有效防治小菜蛾(Plutella xylostella),减少其造成的经济损失,采用点滴注射法测定了亚致死浓度的溴氰菊酯对小菜蛾生长发育及生殖能力的影响,并检测了溴氰菊酯对小菜蛾的时间毒性效应。结果表明,采用溴氰菊酯亚致死浓度(12 h LC35,即12 h暴露后导致个体死亡率为35%的浓度)处理小菜蛾幼虫后,幼虫存活期及雌、雄成虫寿命均显著下降,羽化率、化蛹率、卵孵化率及单雌日均产卵量显著降低。同时,对小菜蛾在1 d中的4个不同时间点在亚致死浓度12 h LC35条件[授时时间(ZTs):ZT2、ZT8、ZT14、ZT20,对应北京时间分别为6:00、12:00、18:00、24:00]点滴注射溴氰菊酯,发现在亚致死浓度12 h LC35条件下,ZT2处理组小菜蛾幼虫48 h后的死亡率高达65.97%,而ZT20处理组的死亡率为32.07%,并且ZT2组对小菜蛾幼虫期及成虫期的不良影响均显著高于ZT20组。此外,处理组超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性先升高后下降,但均高于对照组,谷胱甘肽硫转移酶(GST)活性均呈下降趋势,但ZT20处理组的SOD、CAT及GST活性均高于ZT2组。因此建议农业生产中选择早上进行施药,这可能会提高杀虫效率,在评估农药的杀虫效果时时间毒理学应该作为一个重要的考虑因素。该研究为小菜蛾的防治和农药合理施用提供了理论依据和支撑。展开更多
Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could ...Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could be employed as a starting material to prepare some other functional derivatives for improving the value of biomass resources.The isomerization of glucose to produce fructose is an important intermediate process during numerous high-value-added chemical preparations.Therefore,the development of efficient and selective catalysts for glucose isomerization is of great significance.Currently,glucose isomerase catalysts are limited by the harsh conditions required for microbial activity,which restricts further improvements in fructose yield.Additionally,heterogeneous Bronsted-base and Lewis-acid catalysts commonly employed in chemical isomerization methods often lead to the formation of undesirable by-products,resulting in reduced selectivity toward fructose.This study has demonstrated that lithium-loaded heterogeneous catalysts possess excellent isomerization capabilities under mild conditions.A highly efficient Li-C_(3)N_(4) catalyst was developed,achieving a fructose selectivity of 99.9% and a yield of 42.6% at 60℃ within 1.0 h-comparable to the performance of the enzymatic method.Characterization using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),proton nuclear magnetic resonance(^(1)H NMR),and inductively coupled plasma(ICP)analyses confirmed that lithium was stably incorporated into the g-C_(3)N_(4) framework through the formation of Li-N bonds.Further investigations using CO_(2) temperature-programmed desorption(CO_(2)-TPD),in situ Fourier-transform infrared spectroscopy(FT-IR)and 7Li magic angle spinning nuclear magnetic resonance(^(7)Li MAS NMR)indicated that the isomerization proceeded via a base-catalyzed mechanism.The Li species were found to interact with hydroxyl groups generated through hydrolysis and simultaneously coordinated with nitrogen atoms in the C_(3)N_(4) matrix,resulting in the formation of Li-N_(6)-H_(2)O active sites.These active sites facilitated the deprotonation of glucose to form an enolate intermediate,followed by a proton transfer step that generated fructose.This mechanism not only improved the efficiency of fructose production but also provided valuable insight into the catalytic role of lithium within the isomerization process.展开更多
文摘为有效防治小菜蛾(Plutella xylostella),减少其造成的经济损失,采用点滴注射法测定了亚致死浓度的溴氰菊酯对小菜蛾生长发育及生殖能力的影响,并检测了溴氰菊酯对小菜蛾的时间毒性效应。结果表明,采用溴氰菊酯亚致死浓度(12 h LC35,即12 h暴露后导致个体死亡率为35%的浓度)处理小菜蛾幼虫后,幼虫存活期及雌、雄成虫寿命均显著下降,羽化率、化蛹率、卵孵化率及单雌日均产卵量显著降低。同时,对小菜蛾在1 d中的4个不同时间点在亚致死浓度12 h LC35条件[授时时间(ZTs):ZT2、ZT8、ZT14、ZT20,对应北京时间分别为6:00、12:00、18:00、24:00]点滴注射溴氰菊酯,发现在亚致死浓度12 h LC35条件下,ZT2处理组小菜蛾幼虫48 h后的死亡率高达65.97%,而ZT20处理组的死亡率为32.07%,并且ZT2组对小菜蛾幼虫期及成虫期的不良影响均显著高于ZT20组。此外,处理组超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性先升高后下降,但均高于对照组,谷胱甘肽硫转移酶(GST)活性均呈下降趋势,但ZT20处理组的SOD、CAT及GST活性均高于ZT2组。因此建议农业生产中选择早上进行施药,这可能会提高杀虫效率,在评估农药的杀虫效果时时间毒理学应该作为一个重要的考虑因素。该研究为小菜蛾的防治和农药合理施用提供了理论依据和支撑。
基金supported by the National Natural Science Foundation of China(22278419)the Key Core Technology Research(Social Development)Foundation of Suzhou(2023ss06)the Suzhou National Joint Laboratory for Green and Low-carbon Wastewater Treatment and Resource Utilization Technology,Suzhou University of Science and Technology(SZLSDT202404).
文摘Fully utilizing renewable biomass energy is important for saving energy,reducing carbon emissions,and mitigating climate change.As the main hydrolysate of cellulose,a primary component of lignocellulose,glucose could be employed as a starting material to prepare some other functional derivatives for improving the value of biomass resources.The isomerization of glucose to produce fructose is an important intermediate process during numerous high-value-added chemical preparations.Therefore,the development of efficient and selective catalysts for glucose isomerization is of great significance.Currently,glucose isomerase catalysts are limited by the harsh conditions required for microbial activity,which restricts further improvements in fructose yield.Additionally,heterogeneous Bronsted-base and Lewis-acid catalysts commonly employed in chemical isomerization methods often lead to the formation of undesirable by-products,resulting in reduced selectivity toward fructose.This study has demonstrated that lithium-loaded heterogeneous catalysts possess excellent isomerization capabilities under mild conditions.A highly efficient Li-C_(3)N_(4) catalyst was developed,achieving a fructose selectivity of 99.9% and a yield of 42.6% at 60℃ within 1.0 h-comparable to the performance of the enzymatic method.Characterization using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),proton nuclear magnetic resonance(^(1)H NMR),and inductively coupled plasma(ICP)analyses confirmed that lithium was stably incorporated into the g-C_(3)N_(4) framework through the formation of Li-N bonds.Further investigations using CO_(2) temperature-programmed desorption(CO_(2)-TPD),in situ Fourier-transform infrared spectroscopy(FT-IR)and 7Li magic angle spinning nuclear magnetic resonance(^(7)Li MAS NMR)indicated that the isomerization proceeded via a base-catalyzed mechanism.The Li species were found to interact with hydroxyl groups generated through hydrolysis and simultaneously coordinated with nitrogen atoms in the C_(3)N_(4) matrix,resulting in the formation of Li-N_(6)-H_(2)O active sites.These active sites facilitated the deprotonation of glucose to form an enolate intermediate,followed by a proton transfer step that generated fructose.This mechanism not only improved the efficiency of fructose production but also provided valuable insight into the catalytic role of lithium within the isomerization process.
