A three-dimensional motion force tester for animal was used to measure the reaction forces of the feet of a Chinese toad (B. gargarizans) against a horizontal solid surface on which it crawled. The motion behavior of ...A three-dimensional motion force tester for animal was used to measure the reaction forces of the feet of a Chinese toad (B. gargarizans) against a horizontal solid surface on which it crawled. The motion behavior of the Chinese toad was recorded by a high-speed camera on line. The motor function of every foot was analyzed. It was found that the lateral force represents the control ability of side-to-side locomotion, controls the lateral movement, and maintains a stable state for the sustainable creeping gesture. The forefeet play the assistant role and the hind feet play the main role in driving. The normal force of the forefeet is significantly greater than that of the hind feet, so the forefeet play the main role in supporting the body and the hind feet play the assistant role. The normal force is significantly greater than the lateral force and the driving force as well. There is little change for the friction force and the support angle of the all four feet. The average value of the support angle is 70°–80°. The Chinese toad’s vola friction coefficient of the forefeet is less than that of the hind feet. The above results indicate that the difference in kinematics and the material characteristic of the contact skin of the Chinese toad. The results could be useful to the structure design and gait optimization of some robots.展开更多
Sexual selection is critical to both reproduction and evolution.The effects of male–male competition and female choice regarding body size have been examined in a large number of taxa,including toad species.Males and...Sexual selection is critical to both reproduction and evolution.The effects of male–male competition and female choice regarding body size have been examined in a large number of taxa,including toad species.Males and females have different optimal reproductive strategies,achieving breeding advantages in discrepant ways.Further,the relative contributions of intra-and inter-sexual size selection vary among species.Thus,to understand the mechanisms affecting mating success,it is important to consider both male–male and male–female interactions simultaneously and elucidate their interrelationship.In this study,we measured body sizes of all mated and unmated individuals in a population of Asiatic toad(Bufo gargarizans)and counted fertilized eggs of several clutches.Based on correlation and regression techniques,we tested for female choice and intra-sexual competition among males relative to body size gradients,and we compared the relative importance of these two processes for mating success.Our results reveal that male–male competition and female choice simultaneously contribute to sexual selection in toads.Furthermore,both interactions are most intense among smaller toads.The synergistic trends of male–male competition and female choice support the mutual mate choice hypothesis and works to stabilize body size in B.gargarizans.Normal distributions of breeding success relative to body size were detected for both sexes,suggesting that medium-sized individuals enjoy a reproductive advantage in the population studied.展开更多
Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydrox...Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydroxy-11 -oxobufa-2,20,22-trienolide （2）, and 5β,12β-12,14-dihydroxy-11 -oxobufa-2,20,22- trienolide （3） on the basis of extensive spectroscopic analysis, especially 1D NMR and 2D NMR data. In addition, all three compounds were tested for their cytotoxic activities against A549 and HepG2 cancer cell lines. Compounds 2 and 3 showed significant cytotoxicities with IC50 values less than 10 μmol/L on both cancer cells.展开更多
利用生物机能实验系统对用不同浓度的蟾酥溶液处理后的蟾蜍的心率和心电图各项指标进行测定和分析，结果表明：在一定范围内，随着蟾酥浓度的增大，蟾蜍的心率加快；心电图中 R 波的电压峰值降低、Q-T 间期的时值缩短；而 P-R 间期、QRS...利用生物机能实验系统对用不同浓度的蟾酥溶液处理后的蟾蜍的心率和心电图各项指标进行测定和分析，结果表明：在一定范围内，随着蟾酥浓度的增大，蟾蜍的心率加快；心电图中 R 波的电压峰值降低、Q-T 间期的时值缩短；而 P-R 间期、QRS 期的时值延长.并且这些变化在给药后1-1.5 h 达到最大，在2 h 时，各指标均有所恢复.由此可见，蟾酥对蟾蜍的心电活动有一定的影响.展开更多
基金supported by the Development Foundation of Science and Technology in Jilin Province of China (Grant No 20100711)the National 985 Project in Jilin University of China and the Graduate Innovation Foundation of National 985 Project in Jilin University of China (Grant No 20080105)
文摘A three-dimensional motion force tester for animal was used to measure the reaction forces of the feet of a Chinese toad (B. gargarizans) against a horizontal solid surface on which it crawled. The motion behavior of the Chinese toad was recorded by a high-speed camera on line. The motor function of every foot was analyzed. It was found that the lateral force represents the control ability of side-to-side locomotion, controls the lateral movement, and maintains a stable state for the sustainable creeping gesture. The forefeet play the assistant role and the hind feet play the main role in driving. The normal force of the forefeet is significantly greater than that of the hind feet, so the forefeet play the main role in supporting the body and the hind feet play the assistant role. The normal force is significantly greater than the lateral force and the driving force as well. There is little change for the friction force and the support angle of the all four feet. The average value of the support angle is 70°–80°. The Chinese toad’s vola friction coefficient of the forefeet is less than that of the hind feet. The above results indicate that the difference in kinematics and the material characteristic of the contact skin of the Chinese toad. The results could be useful to the structure design and gait optimization of some robots.
基金supported by the National Natural Science Foundation of China(31071934)
文摘Sexual selection is critical to both reproduction and evolution.The effects of male–male competition and female choice regarding body size have been examined in a large number of taxa,including toad species.Males and females have different optimal reproductive strategies,achieving breeding advantages in discrepant ways.Further,the relative contributions of intra-and inter-sexual size selection vary among species.Thus,to understand the mechanisms affecting mating success,it is important to consider both male–male and male–female interactions simultaneously and elucidate their interrelationship.In this study,we measured body sizes of all mated and unmated individuals in a population of Asiatic toad(Bufo gargarizans)and counted fertilized eggs of several clutches.Based on correlation and regression techniques,we tested for female choice and intra-sexual competition among males relative to body size gradients,and we compared the relative importance of these two processes for mating success.Our results reveal that male–male competition and female choice simultaneously contribute to sexual selection in toads.Furthermore,both interactions are most intense among smaller toads.The synergistic trends of male–male competition and female choice support the mutual mate choice hypothesis and works to stabilize body size in B.gargarizans.Normal distributions of breeding success relative to body size were detected for both sexes,suggesting that medium-sized individuals enjoy a reproductive advantage in the population studied.
基金supported by National Natural Science Foundation of China(No.81102518)Postdoctoral Granted Financial Support(No.20110490915)the Guangdong High Level Talent Scheme(R.W.J.)
文摘Three new C-3 dehydrated bufadienolides were isolated from the venom of Bufo bufo gargarizans. Their structures were elucidated as 5β,12β-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide （1）, 5β,12β- 12,14-dihydroxy-11 -oxobufa-2,20,22-trienolide （2）, and 5β,12β-12,14-dihydroxy-11 -oxobufa-2,20,22- trienolide （3） on the basis of extensive spectroscopic analysis, especially 1D NMR and 2D NMR data. In addition, all three compounds were tested for their cytotoxic activities against A549 and HepG2 cancer cell lines. Compounds 2 and 3 showed significant cytotoxicities with IC50 values less than 10 μmol/L on both cancer cells.
文摘目的对蟾酥(Venenum Bufonis)中吲哚烷胺类生物碱进行提取分离和结构鉴定。方法蟾酥水溶性部分经HP 20树脂柱,制备薄层色谱,高效液相色谱分离和精制,得到6个吲哚烷胺生物碱,通过理化常数和光谱数据,分析鉴定了其化学结构。结果蟾酥水提取物中分离得到6个生物碱,分别鉴定为蟾毒色胺(bufotenine,Ⅰ)、蟾毒色胺内盐(bufotenidine,Ⅱ)b、ufobutanoic acid(Ⅲ)、5羟色胺(serotonin,Ⅳ)b、ufotenine N oxide(Ⅴ)、N甲基5羟色胺(Ⅵ)。结论化合物Ⅴ和Ⅵ为首次从蟾酥中分离得到。首次对蟾酥色胺内盐及bufotenine N oxide的1H1、3C NMR数据进行归属。
文摘利用生物机能实验系统对用不同浓度的蟾酥溶液处理后的蟾蜍的心率和心电图各项指标进行测定和分析，结果表明：在一定范围内，随着蟾酥浓度的增大，蟾蜍的心率加快；心电图中 R 波的电压峰值降低、Q-T 间期的时值缩短；而 P-R 间期、QRS 期的时值延长.并且这些变化在给药后1-1.5 h 达到最大，在2 h 时，各指标均有所恢复.由此可见，蟾酥对蟾蜍的心电活动有一定的影响.
