To study the pesticide effect, action mode, structure-activity relationships (SARs) of anthranilic diamide insecticide and screen highly active pesticides, novel anthranilic diamide derivatives were synthesized.Bioass...To study the pesticide effect, action mode, structure-activity relationships (SARs) of anthranilic diamide insecticide and screen highly active pesticides, novel anthranilic diamide derivatives were synthesized.Bioassays indicated that all of the title compounds displayed 100% mortality against diamondback moth and oriental armyworm at 100 mg/L, among which 12 v and 12 w showed 100% insecticidal acitvity at 5 mg/L. Surprisingly compound 12 w exhibited better insecticidal acitvity than commercialized chlorantraniliprole against Pyrausta nubilalis (0.1 mg/L) and Cnaphalocrocis Medinalis (2 mg/L). 3 D-QSAR and SARs statistical analysis revealed that title compounds with R^2 fixed as methoxy had the highest probability possessing high activity. The calcium fluorescence measurements on neurons revealed that E series compounds containing pyrazinyl may have a molecular target different from caffeine on ryanodine receptors rather than the voltage-gated calcium channel present on cytomembran.展开更多
Objecive: To explore the effect of gibberellic acid(GA_3) and its inhibitor paclobutrazol(PBZ)on chemical composition and their pharmacological effects on Andrographis paniculata(Burm.f.) Wall. ex Nees, and to clarify...Objecive: To explore the effect of gibberellic acid(GA_3) and its inhibitor paclobutrazol(PBZ)on chemical composition and their pharmacological effects on Andrographis paniculata(Burm.f.) Wall. ex Nees, and to clarify action mode of andrographolide.Methods: The chemical composition was extracted by sequential extraction with hexane, dichloromethane, ethyl acetate and methanol, respectively. Andrographolide and its derivatives were evaluated by HPLC. Moreover, the metabolic profiling was analyzed by GC-MS. Inhibitory effect of crude extracts was tested against Staphylococcus aureus using agar well diffusion method. Mode of action was tested against mutant yeast by spotting assay. Andrographolide were tested for their mode of action against eukaryotes. Rsults: Among different solvents, dichloromethane gave the highest yield of crude(3.58% DW), with the highest andrographolide content(8.3 mg/g DW). The effect of plant hormone(10 mg/L GA_3 or PBZ) on phytochemical variations and bioactivity of Andrographis paniculata was demonstrated. It was found that PBZ promoted sesquiterpene compounds about 3.5 times over than GA_3 treatment. But inhibitory effect of extracts against Staphylococcus aureus was highest in GA_3 treated plants; andrographolide and 14-deoxy-11,12-didehydroandrographolide contents were significantly higher than those of water or PBZ. It was found that there were 11 strains involving in ergosterol biosynthesis, V-ATPase activity and homeostasis, and superoxide detoxification process. In this regard, andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis.Conclusions: It is found that GA_3 promotes andrographolide and 14-deoxy-11,12-didehydroandrographolide content while PBZ promotes sesquiterpene content. Andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis. It might also affect mitochondria electron transport chain, leading to the occurrence of ROS, which can further harm cell organelles. However, the library screening is the first step to investigate mode of action of andrographolide.展开更多
Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characteri...Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended, The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results.展开更多
Common beans are affected by many insect pests such as bean leaf beetle, aphids, legume pod borer and bean beetles. Traditional and cultural practices such as site selection, crop rotation, intercropping and seed sele...Common beans are affected by many insect pests such as bean leaf beetle, aphids, legume pod borer and bean beetles. Traditional and cultural practices such as site selection, crop rotation, intercropping and seed selection, sowing date are used to reduce the infestation of insect pests of common beans in the field and in storage rooms. Natural enemies such as predators, parasitoids and pathogens can control the insect pests. Synthetic pesticides such as cypermethion, carbaryl, and lambda-cyhalothrin have reported to be effective, but are toxic to people, destroy natural enemies and contaminate the environment. Botanical pesticides are the promising alternatives. This review paper explains toxicity, persistence and mode of actions of active ingredients of botanical pesticides. Rotenone from T. vogelii has the oral lethal dose (LD<sub>50</sub>) of 132 - 1500 mg/kg to mammals. It delays the electron transport chain in mitochondria of the insects and limits the cellular energy production. Azadirachtin is antifeedant and growth disruptor of insects. It has low toxicity to mammals. The oral LD<sub>50</sub> in mammals is greater than 3540 mg/kg. Azadirachtin displays strong effects on chemoreceptors of the insects. Pyrethrins are axonic poisons and have repellent effects to insects. It is less toxic to mammals with the LD<sub>50</sub> of about 1500 mg/Kg. It attacks the nervous systems of insects. Sesquiterpene lactones from T. diversifolia, Pentacyclic triterpenoids from Lantana camara, Vernodalin, Vernodalol and Epivernodalol from V. amygdalina have repellent and feeding deterrents chemicals which discourage the insects from feeding the crop. Most active ingredients of botanical pesticides have short life span in the environment.展开更多
Safety and practicability of the HELP procedure
Compared to standard plasma exchange, HELP-apheresis is much better tolerated, primarily be-cause heparin rather than citrate is used for anti-coagulation and t... Safety and practicability of the HELP procedure
Compared to standard plasma exchange, HELP-apheresis is much better tolerated, primarily be-cause heparin rather than citrate is used for anti-coagulation and therefore problems due to hypercalce-mia do not play a role.……展开更多
No herbicide with a new molecular site of action(SOA)has been introduced since the 1980s.Since then,the widespread evolution of resistance of weeds to most commercial herbicides has greatly increased the need for herb...No herbicide with a new molecular site of action(SOA)has been introduced since the 1980s.Since then,the widespread evolution of resistance of weeds to most commercial herbicides has greatly increased the need for herbicides with new SOAs.Two untried strategies for the discovery on new herbicide SOAs are discussed.Some primary metabolism intermediates are phytotoxic(e.g.,protoporphyrin IX and sphingoid bases),and,because of this,the in vivo concentrations of these compounds are maintained at very low levels by plants.The determination of all primary metabolite phytotoxicities and pool sizes will identify targets of interest.Targeting SOAs that result in accumulation of phytotoxic compounds is the first novel approach to herbicide discovery.The second approach is to identify potential SOAs with very low in vivo enzyme levels.We know that higher numbers of enzyme molecules for a SOA requires more herbicide to kill a plant.Modern proteomic methods can identify low enzyme level SOAs for biorational herbicide discovery.These approaches might be useful in discovery of herbicides more closely related to natural compounds and that can be used in lower doses.展开更多
This study investigated the influence factors on the seismic response and deformation modes of retaining walls using large-scale model shaking table tests. Experimental results showed that the distribution of peak sei...This study investigated the influence factors on the seismic response and deformation modes of retaining walls using large-scale model shaking table tests. Experimental results showed that the distribution of peak seismic earth pressures along the height of a wall was a single peak value curve. The seismic earth pressures on a gravel soil retaining wall were larger than the pressures on the weathered granite and quartz retaining walls. Also, the peak seismic earth pressure increased with increases in the peak ground acceleration and the wall height. The measured seismic active earth pressures on a rock foundation retaining wall were larger than the calculated values, and the action position of resultant seismic pressure was higher than 0.33 H. In the soil foundation retaining wall, the measured seismic earth pressures were much smaller than the calculated values, while the action position was slightly higher than 0.33 H. The soil foundation retaining wall suffered base sliding and overturning under earthquake conditions, while overturning was the main failure mode for the rock foundation retaining walls.展开更多
糖尿病是一种在全球范围内广泛流行的慢性代谢疾病,其发病率持续上升,对患者健康和社会经济造成重大负担。桑叶(Morus alba L.)作为传统中药材,含有多种生物活性成分,包括多酚类(如黄酮与酸酚),生物碱、多糖及氨基酸等,近年来在糖尿病...糖尿病是一种在全球范围内广泛流行的慢性代谢疾病,其发病率持续上升,对患者健康和社会经济造成重大负担。桑叶(Morus alba L.)作为传统中药材,含有多种生物活性成分,包括多酚类(如黄酮与酸酚),生物碱、多糖及氨基酸等,近年来在糖尿病治疗领域受到广泛关注。大量基础与临床研究表明,桑叶不仅具有显著的降血糖作用,还能通过改善胰岛β细胞功能、调节糖脂代谢、优化肠道菌群结构,以及发挥抗氧化与抗炎作用,在糖尿病综合管理中表现出多靶点干预潜力。尽管桑叶在糖尿病防治中的应用前景广阔,但其具体分子机制仍待系统地阐明,同临床应用的安全性与有效性亦需要更多高质量的研究予以验证。本文综述了桑叶的主要活性成分及其作用机制,结合近年研究进展,系统地探讨其在糖尿病治疗中的多重药理效应及未来应用前景,旨在为桑叶在糖尿病综合治疗中的深入开发与合理利用提供理论参考和研究导向。展开更多
为了规避网络广告延时效应带来的不确定性风险,企业往往会采用效果付费(cost per action, CPA)方式进行网络推广。本文在CPA模式下研究考虑延时效应的供应链网络广告决策与协调问题。首先,建立含有时间延迟的品牌信誉动态模型和效果依...为了规避网络广告延时效应带来的不确定性风险,企业往往会采用效果付费(cost per action, CPA)方式进行网络推广。本文在CPA模式下研究考虑延时效应的供应链网络广告决策与协调问题。首先,建立含有时间延迟的品牌信誉动态模型和效果依赖的网络广告投入成本模型,并构建CPA模式下供应链网络广告微分博弈模型,再利用最优控制理论求解得到分散式决策与集中式决策下供应链系统的最优网络广告策略、定价策略、品牌信誉以及利润。其次,对决策结果进行综合比较分析,明确供应链系统的最佳决策机制,参照最佳决策供应链系统,设计一种动态批发价格契约,使供应链实现完美协调。最后,通过数值算例验证研究结果的有效性,对网络广告投入、品牌信誉、利润以及协调参数进行灵敏度分析。研究发现,与传统广告研究结论不同,CPA模式下制造商的最优网络广告投入高度依赖于时间,且遵循“逐降-早停”原则;CPA模式下短暂的网络广告延时效应和良好的销售效果可以增加双方合作的积极性,进而企业倾向于整体获利最大的集中式决策机制。本文研究成果为供应链企业网络推广实践提供了重要的理论指导。展开更多
基金supported by the National Natural Science Foundation of China(Nos. 20772060 and 21172114)
文摘To study the pesticide effect, action mode, structure-activity relationships (SARs) of anthranilic diamide insecticide and screen highly active pesticides, novel anthranilic diamide derivatives were synthesized.Bioassays indicated that all of the title compounds displayed 100% mortality against diamondback moth and oriental armyworm at 100 mg/L, among which 12 v and 12 w showed 100% insecticidal acitvity at 5 mg/L. Surprisingly compound 12 w exhibited better insecticidal acitvity than commercialized chlorantraniliprole against Pyrausta nubilalis (0.1 mg/L) and Cnaphalocrocis Medinalis (2 mg/L). 3 D-QSAR and SARs statistical analysis revealed that title compounds with R^2 fixed as methoxy had the highest probability possessing high activity. The calcium fluorescence measurements on neurons revealed that E series compounds containing pyrazinyl may have a molecular target different from caffeine on ryanodine receptors rather than the voltage-gated calcium channel present on cytomembran.
基金financially supported by Agricultural Research Development Agency(Public Organization)or"ARDA"(Grant No.CRP6005020350)
文摘Objecive: To explore the effect of gibberellic acid(GA_3) and its inhibitor paclobutrazol(PBZ)on chemical composition and their pharmacological effects on Andrographis paniculata(Burm.f.) Wall. ex Nees, and to clarify action mode of andrographolide.Methods: The chemical composition was extracted by sequential extraction with hexane, dichloromethane, ethyl acetate and methanol, respectively. Andrographolide and its derivatives were evaluated by HPLC. Moreover, the metabolic profiling was analyzed by GC-MS. Inhibitory effect of crude extracts was tested against Staphylococcus aureus using agar well diffusion method. Mode of action was tested against mutant yeast by spotting assay. Andrographolide were tested for their mode of action against eukaryotes. Rsults: Among different solvents, dichloromethane gave the highest yield of crude(3.58% DW), with the highest andrographolide content(8.3 mg/g DW). The effect of plant hormone(10 mg/L GA_3 or PBZ) on phytochemical variations and bioactivity of Andrographis paniculata was demonstrated. It was found that PBZ promoted sesquiterpene compounds about 3.5 times over than GA_3 treatment. But inhibitory effect of extracts against Staphylococcus aureus was highest in GA_3 treated plants; andrographolide and 14-deoxy-11,12-didehydroandrographolide contents were significantly higher than those of water or PBZ. It was found that there were 11 strains involving in ergosterol biosynthesis, V-ATPase activity and homeostasis, and superoxide detoxification process. In this regard, andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis.Conclusions: It is found that GA_3 promotes andrographolide and 14-deoxy-11,12-didehydroandrographolide content while PBZ promotes sesquiterpene content. Andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis. It might also affect mitochondria electron transport chain, leading to the occurrence of ROS, which can further harm cell organelles. However, the library screening is the first step to investigate mode of action of andrographolide.
文摘Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended, The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results.
文摘Common beans are affected by many insect pests such as bean leaf beetle, aphids, legume pod borer and bean beetles. Traditional and cultural practices such as site selection, crop rotation, intercropping and seed selection, sowing date are used to reduce the infestation of insect pests of common beans in the field and in storage rooms. Natural enemies such as predators, parasitoids and pathogens can control the insect pests. Synthetic pesticides such as cypermethion, carbaryl, and lambda-cyhalothrin have reported to be effective, but are toxic to people, destroy natural enemies and contaminate the environment. Botanical pesticides are the promising alternatives. This review paper explains toxicity, persistence and mode of actions of active ingredients of botanical pesticides. Rotenone from T. vogelii has the oral lethal dose (LD<sub>50</sub>) of 132 - 1500 mg/kg to mammals. It delays the electron transport chain in mitochondria of the insects and limits the cellular energy production. Azadirachtin is antifeedant and growth disruptor of insects. It has low toxicity to mammals. The oral LD<sub>50</sub> in mammals is greater than 3540 mg/kg. Azadirachtin displays strong effects on chemoreceptors of the insects. Pyrethrins are axonic poisons and have repellent effects to insects. It is less toxic to mammals with the LD<sub>50</sub> of about 1500 mg/Kg. It attacks the nervous systems of insects. Sesquiterpene lactones from T. diversifolia, Pentacyclic triterpenoids from Lantana camara, Vernodalin, Vernodalol and Epivernodalol from V. amygdalina have repellent and feeding deterrents chemicals which discourage the insects from feeding the crop. Most active ingredients of botanical pesticides have short life span in the environment.
文摘 Safety and practicability of the HELP procedure
Compared to standard plasma exchange, HELP-apheresis is much better tolerated, primarily be-cause heparin rather than citrate is used for anti-coagulation and therefore problems due to hypercalce-mia do not play a role.……
文摘No herbicide with a new molecular site of action(SOA)has been introduced since the 1980s.Since then,the widespread evolution of resistance of weeds to most commercial herbicides has greatly increased the need for herbicides with new SOAs.Two untried strategies for the discovery on new herbicide SOAs are discussed.Some primary metabolism intermediates are phytotoxic(e.g.,protoporphyrin IX and sphingoid bases),and,because of this,the in vivo concentrations of these compounds are maintained at very low levels by plants.The determination of all primary metabolite phytotoxicities and pool sizes will identify targets of interest.Targeting SOAs that result in accumulation of phytotoxic compounds is the first novel approach to herbicide discovery.The second approach is to identify potential SOAs with very low in vivo enzyme levels.We know that higher numbers of enzyme molecules for a SOA requires more herbicide to kill a plant.Modern proteomic methods can identify low enzyme level SOAs for biorational herbicide discovery.These approaches might be useful in discovery of herbicides more closely related to natural compounds and that can be used in lower doses.
基金the National Program on Key Research Project of China (Grant No. 2016YFC0802206)the open research fund of MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University and Doctoral Innovation Fund Program of Southwest University of Science and Technology (Grant No. 16zx7123)
文摘This study investigated the influence factors on the seismic response and deformation modes of retaining walls using large-scale model shaking table tests. Experimental results showed that the distribution of peak seismic earth pressures along the height of a wall was a single peak value curve. The seismic earth pressures on a gravel soil retaining wall were larger than the pressures on the weathered granite and quartz retaining walls. Also, the peak seismic earth pressure increased with increases in the peak ground acceleration and the wall height. The measured seismic active earth pressures on a rock foundation retaining wall were larger than the calculated values, and the action position of resultant seismic pressure was higher than 0.33 H. In the soil foundation retaining wall, the measured seismic earth pressures were much smaller than the calculated values, while the action position was slightly higher than 0.33 H. The soil foundation retaining wall suffered base sliding and overturning under earthquake conditions, while overturning was the main failure mode for the rock foundation retaining walls.
文摘糖尿病是一种在全球范围内广泛流行的慢性代谢疾病,其发病率持续上升,对患者健康和社会经济造成重大负担。桑叶(Morus alba L.)作为传统中药材,含有多种生物活性成分,包括多酚类(如黄酮与酸酚),生物碱、多糖及氨基酸等,近年来在糖尿病治疗领域受到广泛关注。大量基础与临床研究表明,桑叶不仅具有显著的降血糖作用,还能通过改善胰岛β细胞功能、调节糖脂代谢、优化肠道菌群结构,以及发挥抗氧化与抗炎作用,在糖尿病综合管理中表现出多靶点干预潜力。尽管桑叶在糖尿病防治中的应用前景广阔,但其具体分子机制仍待系统地阐明,同临床应用的安全性与有效性亦需要更多高质量的研究予以验证。本文综述了桑叶的主要活性成分及其作用机制,结合近年研究进展,系统地探讨其在糖尿病治疗中的多重药理效应及未来应用前景,旨在为桑叶在糖尿病综合治疗中的深入开发与合理利用提供理论参考和研究导向。
文摘为了规避网络广告延时效应带来的不确定性风险,企业往往会采用效果付费(cost per action, CPA)方式进行网络推广。本文在CPA模式下研究考虑延时效应的供应链网络广告决策与协调问题。首先,建立含有时间延迟的品牌信誉动态模型和效果依赖的网络广告投入成本模型,并构建CPA模式下供应链网络广告微分博弈模型,再利用最优控制理论求解得到分散式决策与集中式决策下供应链系统的最优网络广告策略、定价策略、品牌信誉以及利润。其次,对决策结果进行综合比较分析,明确供应链系统的最佳决策机制,参照最佳决策供应链系统,设计一种动态批发价格契约,使供应链实现完美协调。最后,通过数值算例验证研究结果的有效性,对网络广告投入、品牌信誉、利润以及协调参数进行灵敏度分析。研究发现,与传统广告研究结论不同,CPA模式下制造商的最优网络广告投入高度依赖于时间,且遵循“逐降-早停”原则;CPA模式下短暂的网络广告延时效应和良好的销售效果可以增加双方合作的积极性,进而企业倾向于整体获利最大的集中式决策机制。本文研究成果为供应链企业网络推广实践提供了重要的理论指导。
