To study the relationship between the late postmortem interval （PMI） and trimethyl-amine-nitrogen （TMA-N） in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different po...To study the relationship between the late postmortem interval （PMI） and trimethyl-amine-nitrogen （TMA-N） in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals （PMI） by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance （A value） and TMA-N at the concentration of 1-10 mg/L （R2=0.9991）. Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7d since death, the best correlation between PMI and TMA-N concentration was found in muscles. With PMI as an independent variable, the cubic polynomial regression equation was y=-0.457x3 ＋6.519x2-24.574x＋27.207 （R2=0.969）. During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x3-9.153x2＋55.727x-95.819 （R2=0.953）. It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.展开更多
To study the relationship between changes of microbial ATP in four kinds of murine tis-sues and the postmortem interval （PMI）, healthy SD rats were sacrificed and their muscles, livers, spleens and kidneys were samp...To study the relationship between changes of microbial ATP in four kinds of murine tis-sues and the postmortem interval （PMI）, healthy SD rats were sacrificed and their muscles, livers, spleens and kidneys were sampled at different postmortem intervals. The concentration of microbial ATP was detected using bioluminescent assay and the data was statistically analyzed. The concentra-tion of microbial ATP in muscle increased with PMI time. The peak appeared at the 7th day after death, and at the 10th day, microbial ATP in muscle tissue increased again. In internal organs, the peaks of microbial ATP were observed at the 8th day after death and the level decreased during 8–10 d. The differences in microbial ATP concentration in liver, spleen and kidney were not statistically significant. During day 0 to day 9 after death, the correlation was best between PMI and microbial ATP in muscle. With PMI as the independent variable, the cubic polynomial regression equation was Y=0.02X3–0.166X2–0.666X＋13.412 （R2=0.989, P〈0.01）. In internal organs, the best correlation was found between PMI and microbial ATP during day 0 to day 10. With PMI as the independent variable, the cubic polynomial regression equation was Y=0.016X3–0.127X2–0.809X＋13.324 （R2=0.986, P〈0.01）. There existed high correlations between PMI and microbial ATP concentration in rat tissues. Since only a small amount of tissue was needed for the detection and the sample was not affected by self-decomposition, the method may extend the time range of PMI estimation.展开更多
Summary： Relationship between ATP changes of rabbit blood and postmortem interval （PMI） was studied. Twenty-four healthy rabbits were sacrificed and randomly divided into 3 groups with 8 rab- bits of each group. Th...Summary： Relationship between ATP changes of rabbit blood and postmortem interval （PMI） was studied. Twenty-four healthy rabbits were sacrificed and randomly divided into 3 groups with 8 rab- bits of each group. The bodies of three groups were placed in calorstat at temperature of 15℃, 25℃ and 35℃, respectively. The blood from the right ventricle was sampled through indwelling needle each 4 h until 72 h after death. ATP levels in the blood samples were measured by using ATP fluo- rescence rapid detection technique at different PMIs. Blood ATP levels slightly increased in the early stage after death and then constantly declined at all temperatures （15℃, 25℃, and 35℃）. Cubic polynomial regression equations with log[ATP] as dependent variable （y） and PMI as independent variable （x） at different temperatures and the optimal time period were established as followed： Under 15℃ and during 16-64 h after death, y=-3.027×10^-5x^3＋0.003x^2-0.096x-10.625 （Ra^2=0.992, P〈0.001）; under 25℃ and during 8-56 h after death, y=-2.921×10^-5x^3＋0.002x^2- 0.059x-11.186 （Ra^2=0.989, P〈0.001）; under 35℃ and during 4-36 h after death, y=-9.769×10^-5x^3＋ 0.005x^2 -0.117x-11.166 （Ra^2=0.991, P〈0.001）. The changes in ATP levels in blood collected from right ven- tricle of rabbit cadavers showed relatively stable and regular degradation within 72 h after death at different temperatures.展开更多
Corneal opacity is one of the most commonly used parameters for estimating postmortem interval （PMI）. This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processi...Corneal opacity is one of the most commonly used parameters for estimating postmortem interval （PMI）. This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images. Corneal regions were extracted from images of rabbits＇ eyes and described by color-based and texture-based features, which could represent the changes of cornea at different PMI. A KNN classifier was used to reveal the association of image features and PMI. The result of the classification showed that the new method was reliable and effective.展开更多
To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classi...To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classified into male and female groups,different age groups(21-day,42-day and 63-day group),and tissues in vitro and in vivo groups.The rats were sacrificed by cervical dislocation,whose bodies were kept in a controlled environmental chamber set at(20±2) ℃ and 50% humidity.The liver,kidney,spleen,myocardium,brain,lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem.With the change of PMI,no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points.All the experimental groups showed no significant changes when compared with the controls.The gender,age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.展开更多
基金supported by a grant from the Health Department of Hubei Province (No. JX2B02).
文摘To study the relationship between the late postmortem interval （PMI） and trimethyl-amine-nitrogen （TMA-N） in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals （PMI） by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance （A value） and TMA-N at the concentration of 1-10 mg/L （R2=0.9991）. Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7d since death, the best correlation between PMI and TMA-N concentration was found in muscles. With PMI as an independent variable, the cubic polynomial regression equation was y=-0.457x3 ＋6.519x2-24.574x＋27.207 （R2=0.969）. During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x3-9.153x2＋55.727x-95.819 （R2=0.953）. It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.
基金supported by a grant from the Health Department of Hubei Province, China (No JX2B02)
文摘To study the relationship between changes of microbial ATP in four kinds of murine tis-sues and the postmortem interval （PMI）, healthy SD rats were sacrificed and their muscles, livers, spleens and kidneys were sampled at different postmortem intervals. The concentration of microbial ATP was detected using bioluminescent assay and the data was statistically analyzed. The concentra-tion of microbial ATP in muscle increased with PMI time. The peak appeared at the 7th day after death, and at the 10th day, microbial ATP in muscle tissue increased again. In internal organs, the peaks of microbial ATP were observed at the 8th day after death and the level decreased during 8–10 d. The differences in microbial ATP concentration in liver, spleen and kidney were not statistically significant. During day 0 to day 9 after death, the correlation was best between PMI and microbial ATP in muscle. With PMI as the independent variable, the cubic polynomial regression equation was Y=0.02X3–0.166X2–0.666X＋13.412 （R2=0.989, P〈0.01）. In internal organs, the best correlation was found between PMI and microbial ATP during day 0 to day 10. With PMI as the independent variable, the cubic polynomial regression equation was Y=0.016X3–0.127X2–0.809X＋13.324 （R2=0.986, P〈0.01）. There existed high correlations between PMI and microbial ATP concentration in rat tissues. Since only a small amount of tissue was needed for the detection and the sample was not affected by self-decomposition, the method may extend the time range of PMI estimation.
基金supported by the National Natural Science Foundation of China (No. 81072505)
文摘Summary： Relationship between ATP changes of rabbit blood and postmortem interval （PMI） was studied. Twenty-four healthy rabbits were sacrificed and randomly divided into 3 groups with 8 rab- bits of each group. The bodies of three groups were placed in calorstat at temperature of 15℃, 25℃ and 35℃, respectively. The blood from the right ventricle was sampled through indwelling needle each 4 h until 72 h after death. ATP levels in the blood samples were measured by using ATP fluo- rescence rapid detection technique at different PMIs. Blood ATP levels slightly increased in the early stage after death and then constantly declined at all temperatures （15℃, 25℃, and 35℃）. Cubic polynomial regression equations with log[ATP] as dependent variable （y） and PMI as independent variable （x） at different temperatures and the optimal time period were established as followed： Under 15℃ and during 16-64 h after death, y=-3.027×10^-5x^3＋0.003x^2-0.096x-10.625 （Ra^2=0.992, P〈0.001）; under 25℃ and during 8-56 h after death, y=-2.921×10^-5x^3＋0.002x^2- 0.059x-11.186 （Ra^2=0.989, P〈0.001）; under 35℃ and during 4-36 h after death, y=-9.769×10^-5x^3＋ 0.005x^2 -0.117x-11.166 （Ra^2=0.991, P〈0.001）. The changes in ATP levels in blood collected from right ven- tricle of rabbit cadavers showed relatively stable and regular degradation within 72 h after death at different temperatures.
文摘Corneal opacity is one of the most commonly used parameters for estimating postmortem interval （PMI）. This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images. Corneal regions were extracted from images of rabbits＇ eyes and described by color-based and texture-based features, which could represent the changes of cornea at different PMI. A KNN classifier was used to reveal the association of image features and PMI. The result of the classification showed that the new method was reliable and effective.
基金Acknowledgement This research was supported by the National Natural Science Foundation of China （No. 81072509） and the Shanghai Key Laboratory of Forensic Medicine （No. KF0905）.
文摘To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classified into male and female groups,different age groups(21-day,42-day and 63-day group),and tissues in vitro and in vivo groups.The rats were sacrificed by cervical dislocation,whose bodies were kept in a controlled environmental chamber set at(20±2) ℃ and 50% humidity.The liver,kidney,spleen,myocardium,brain,lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem.With the change of PMI,no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points.All the experimental groups showed no significant changes when compared with the controls.The gender,age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.
