Objective To investigate the applicability of the K~+ concentration in aqueous humor to estimate postmortem interval(PMI).Methods 30 White New-Zealand rabbit were sacrificed by air embolism and divided into 10 groups.Aqueous humor and vitreous humor were sampled at 0.5h,1h,3h,6h,8h,12h,16h,20h,and 24h after death.The concentration of potassium,sodium and calcium were analyzed by an autoanalyzer and the data were statistically processed by SPSS software for Windows.Results Increase in potassiam concentration in aqueous humor was correlated with the postmortem interval(R~2=0.956).Conclusion Measurement of potassium concentration in aqueous humor may be used for PMI estimation.

It is a challenge to determine the cause of death in cases caused by both injury and disease in forensic pathology examinations.Here,we retrospectively analyzed 140 such cases enrolled in the Sun Yat-sen University Forensic Identification Center from 2013 to 2021.It was found that the cases caused by both injury and disease accounted for 2.89%of the total number of cases during the same period.The male-to-female ratio was 5.09.Cardiovascular disease accounted for 71.43%of the death-leading diseases,and coronary heart disease accounted for 49.29%.Among the three types of injury and disease relationship,the proportion of disease-based and injury-assisted cases accounted for more than half(65.86%),and the proportion of injury and disease with the same effect cases was the least(12.14%).Medical treatment was involved in as more as 82.86%of the cases.Re-identification were carried out in 10.71%of the cases,53.33%of which were with a≤24-hour-survival time,higher than the proportion(20.80%)of this survival time in initial identification cases(x2 = 13.84,P = 0.000 2).This study revealed the epidemiological characteristics of cases caused by both injury and disease,and supplied useful data for improving the level of forensic identification in such cases.

ObjectiveTo clearly identify the difference between rescue injuries and agonal injuries and to avoid duplicate identifications and misidentifications. MethodsBased on the forensic pathological data of 5 923 cases of death cause identification from 2013 to 2022 in Sun Yat-sen University Forensic Identification Center and Guangzhou Tianhe District Branch of Guangzhou Public Security Bureau， this study retrospectively studied the characteristics of rescue injuries and agonal injuries seen in cause of death identification and their influence on cause of death identification. ResultsAmong all the 5 923 cases， 640 cases were found to have rescue injuries or agonal injuries， and 624 cases received treatment， of which 609 cases were found to have rescue injuries （97.60%）， 44 cases were found to have agonal injuries， and 13 cases were found to have both types of injuries. Among the 640 cases， 441 were male and 199 were female. The age of death was discontinuously distributed from 0 to 95 years old. The leading cause of death was disease， followed by mechanical injury and asphyxia. The main manifestations of rescue injuries were rib and sternum fractures， soft tissue injuries in the prechest area or face， and pericardial rupture. The most common injuries in agonal stage were falling after unconsciousness， inhalation of foreign body in respiratory tract or multiple violent injuries. Among the 640 cases， 19 cases were repeatedly identified， including 15 cases of rescue injuries， 6 cases of agonal injuries， and 2 cases of both types of injuries. Compared with the cases where neither type of injuries was detected， the repeated identification rate of treatment injuries and agonal injuries was significantly increased （χ²=4.04， P=0.044； χ²=43.49， P<0.001）. Among the 640 cases， 11 cases （1.72%） were misidentified as the initial injuries in the first identification， and 13 cases had combined rescue injuries or agonal injuries that were involved in death. ConclusionsBy elucidating the epidemiological characteristics of the two types of injuries， this study proved that the two types of injuries were associated with higher rates of repeated identification and misidentification， which provided a reference for reducing repeated identification and misidentification and improving the accuracy of cause of death identification.