This paper gives the mathematical reason that the probit analysis method of toxicity measurement is reasonable, and proposes a new approach to compute the interval estimation of median lethal dose and 95% lethal dose....This paper gives the mathematical reason that the probit analysis method of toxicity measurement is reasonable, and proposes a new approach to compute the interval estimation of median lethal dose and 95% lethal dose. Based on the dose-response function of pesticides, this study firstly establishes a model of the data generating progress in toxicity test and proves that when the linear models of the logarithm of probability value and dose have been estimated, the weighted linear regression should be used, it is the reason why there is the heteroscedasticity of random disturbance term in the regression model, and the weight is right the reciprocal of the variance for random disturbance term. Secondly, based on the numerical simulation method, this paper gives a new approach for the interval estimation of median lethal dose and 95% lethal dose.展开更多
By using an LKB2277 BioActivity Monitor (heat conduction microcalorimeter),stopped flow method,the thermogenetic curves of Escherichia coli growth at 37℃ inhibited by four kinds of heavy metal ions are determined,an...By using an LKB2277 BioActivity Monitor (heat conduction microcalorimeter),stopped flow method,the thermogenetic curves of Escherichia coli growth at 37℃ inhibited by four kinds of heavy metal ions are determined,and parameters such as growth rate constants,inhibitory ratio,half inhibitory concentration etc.were obtained.The experimental results show that heavy metal ions can inhibit Escherichia coli growth obviously,but low concentration of Cu 2+ has a promoting action.The half inhibitory concentrations of Zn 2+ ,Cd 2+ ,Hg 2+ and Cu 2+ are 28.3,10.9,3.19 and 69.6μg.mL -1 ,respectively.Judged from the rate constant,the half inhibitory concentration and the molecular mass,the inhibitory sequence is Hg 2+ >Cd 2+ >Zn 2+ >Cu 2+ .This microclorimetric bioassay for acute cellular toxicity is based on metabolic heat evolution from cultured cells.The assay is quantitative,inexpensive,and versatile;moreover,toxicological information can be obtained with cell from other species of interest.展开更多
文摘This paper gives the mathematical reason that the probit analysis method of toxicity measurement is reasonable, and proposes a new approach to compute the interval estimation of median lethal dose and 95% lethal dose. Based on the dose-response function of pesticides, this study firstly establishes a model of the data generating progress in toxicity test and proves that when the linear models of the logarithm of probability value and dose have been estimated, the weighted linear regression should be used, it is the reason why there is the heteroscedasticity of random disturbance term in the regression model, and the weight is right the reciprocal of the variance for random disturbance term. Secondly, based on the numerical simulation method, this paper gives a new approach for the interval estimation of median lethal dose and 95% lethal dose.
文摘By using an LKB2277 BioActivity Monitor (heat conduction microcalorimeter),stopped flow method,the thermogenetic curves of Escherichia coli growth at 37℃ inhibited by four kinds of heavy metal ions are determined,and parameters such as growth rate constants,inhibitory ratio,half inhibitory concentration etc.were obtained.The experimental results show that heavy metal ions can inhibit Escherichia coli growth obviously,but low concentration of Cu 2+ has a promoting action.The half inhibitory concentrations of Zn 2+ ,Cd 2+ ,Hg 2+ and Cu 2+ are 28.3,10.9,3.19 and 69.6μg.mL -1 ,respectively.Judged from the rate constant,the half inhibitory concentration and the molecular mass,the inhibitory sequence is Hg 2+ >Cd 2+ >Zn 2+ >Cu 2+ .This microclorimetric bioassay for acute cellular toxicity is based on metabolic heat evolution from cultured cells.The assay is quantitative,inexpensive,and versatile;moreover,toxicological information can be obtained with cell from other species of interest.
