OBJECTIVES: To study the annual variation of diatoms in Zhangweixin River, to provide theoretical support by using diatom examination to estimate the time and place of the corpse entering water, and to establish a diatom database. METHODS: Samples were taken from 4 sampling sites in Decheng section of Zhangweixin River for 12 consecutive months. Non-metric multi-dimensional scaling (NMDS) analysis was performed on the species and content of diatom samples. Based on the sampling site of Tianqu Road, Sprensen similarity coefficient analysis was conducted with the data of other 3 sites in Decheng section and Leling section of Zhangweixin River and Ningjin section in previous studies. RESULTS: The number of diatom species was positively correlated with diatom content. The average diatom content in different months ranged from 1 054 to 13 041/10 mL, and the species composition ranged from 8 to 16, with differences in dominant species. The similarity coefficient of diatom species within 2 km were all higher than 0.956 52, which could not be distinguished effectively. The similarity coefficients of Leling section and Ningjin section were 0.736 84 and 0.588 24 respectively, which could be effectively distinguished. CONCLUSIONS The species and content of diatom vary in different months in Zhangweixin River, and the composition of diatom species is different in different basins, which can provide reference for estimating the time and place of the corpse entering water in the river.
Cadaver ; Diatoms ; Drowning/diagnosis* ; Humans ; Rivers ; Water

Autopsy ; Drowning/diagnosis* ; Forensic Pathology ; Humans ; Lung ; Postmortem Changes ; Water

Drowning is the death caused by asphyxiation due to fluid blocking the airway. In the practice of forensic medicine, it is the key to determine whether the corpse was drowned or entered the water after death. At the same time, the drowning site inference and postmortem submersion interval (PMSI) play an important role in the investigating the identity of the deceased, narrowing the investigation scope, and solving the case. Based on diatoms testing, molecular biology, imaging and artificial intelligence and other technologies, domestic and foreign forensic scientists have done relative research in the identification of the cause of death, drowning site inference and PMSI, and achieved certain results in forensic medicine application. In order to provide a reference for future study of bodies in the water, this paper summarizes the above research contents.
Artificial Intelligence ; Diatoms ; Drowning/diagnosis* ; Forensic Pathology ; Humans ; Lung ; Water

Diatom test is the main laboratory test method in the diagnosis of drowning in forensic medicine. It plays an important role in differentiating the antemortem drowning from the postmortem drowning and inferring drowning site. Artificial intelligence (AI) automatic diatom test is a technological innovation in forensic drowning diagnosis which is based on morphological characteristics of diatom, the application of AI algorithm to automatic identification and classification of diatom in tissues and organs. This paper discusses the morphological diatom test methods and reviews the research progress of automatic diatom recognition and classification involving AI algorithms. AI deep learning algorithm can assist diatom testing to obtain objective, accurate, and efficient qualitative and quantitative analysis results, which is expected to become a new direction of diatom testing research in the drowning of forensic medicine in the future.
Artificial Intelligence ; Autopsy ; Diatoms ; Drowning/diagnosis* ; Humans ; Lung

OBJECTIVES: To explore the research hotspots and development trends of the field of forensic drowning from 1991 to 2020 by bibliometrics methods. METHODS: Based on Web of Science, CNKI database, Wanfang Data knowledge service platform, python 3.9.2, CiteSpace 5.8.R3, Gephi 0.9.2, etc. were used to analyze the publishing trends, countries/regions, institutions, authors and topics of the study on drowning. RESULTS: A total of 631 English literature were obtained, including 59 articles from Chinese authors, and 386 Chinese literature were obtained. The Chinese and English journals with the largest number of related literatures were Chinese Journal of Forensic Science (80 articles) and Forensic Science International (106 articles), respectively. Japan published the most articles in English, and China ranked third. Osaka City Univ (Japan, 28 articles) published the most English articles, and Guangzhou Forens Sci Inst (China, 22 articles) ranked second. Among Chinese literature, Guangzhou Forens Sci Inst (32 articles) published the most. The topic analysis of Chinese and English literature showed that diatom examination, virtual autopsy, postmortem biochemical examination, the nature of death, and postmortem submersion interval were the hot spots of current research, but English literature had more studies on new technologies and methods, while Chinese literature was more inclined to practice, application and experience summary. CONCLUSIONS The number of literature in forensic medicine on drowning is relatively stable. The scope of international and domestic collaborations in this field is still limited. The automated examination of diatoms, the establishment of diatom DNA barcodes and virtual autopsy will be the most important research hotspots in the coming period and are expected to achieve breakthroughs in drowning diagnosis, drowning location inference, postmortem submersion interval estimation, etc.
Bibliometrics ; China/epidemiology* ; Drowning/diagnosis* ; Forensic Medicine ; Humans ; Publications

OBJECTIVES: To retrospectively analyze diatom test cases of corpses in water and discuss the value of quantitative analysis of diatoms in the diagnosis of drowning. METHODS: A total of 490 cases of water-related death were collected. They were divided into drowning group and postmortem immersion group according to the cause of death. Diatoms in lung, liver, kidney tissue and water sample were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy (MD-VF-Auto SEM) method. The ratios of content of diatoms in lung tissue and water sample (C_L/C_D) were calculated. RESULTS: The results of diatom test for three organs (lung, liver and kidney) were all positive in 400 cases (85.5%); the content of diatom in lung, liver, kidney tissues, and water samples of drowning group were (113 235.9±317 868.1), (26.7±75.6), (23.3±52.2) and (12 113.3±21 760.0) cells/10 g, respectively; the species of diatom were (7.5±2.8), (2.6±1.9), (2.9±2.1) and (8.9±3.0) types, respectively; the C_L/C_D of drowning group and postmortem immersion group were (100.6±830.7) and (0.3±0.4), respectively. CONCLUSIONS Quantitative analysis of diatoms can provide supportive evidence for the diagnosis of drowning, and the parameter C_L/C_D can be introduced into the analysis to make a more accurate diagnosis of drowning.
Autopsy ; Diatoms ; Drowning/diagnosis* ; Humans ; Lung ; Retrospective Studies ; Water

OBJECTIVES: To identify the drop-off location of victims in drowning cases, and confirm whether it is a fatal drowning or the victim is thrown into the water after death by detecting part of 5.8S sequence and second internal transcribed spacer （ITS2） （5.8S+ITS2） of diatom rDNA in water and organs. METHODS: Two cases identified by diatom examination, which received by Nanjing Municipal Public Security Bureau Forensic Center, were taken as the research objects. The difference of the population structure of algae in water and human tissue was analysed by length polymorphism of 5.8S+ITS2 marker. RESULTS: In case 1, similar species of diatom were detected from victim's lung and liver tissues and the water sample. Two kinds of DNA fragments with length of 330 bp and 376 bp were detected from victim's lung tissue and the water sample using 5.8S+ITS2 marker, which could confirm the victim was drowning before death. In case 2, there was no diatom found in victim's lung and liver tissues. Only one kind of DNA fragment with length of 331 bp and low relative fluorescence unit （RFU） was obtained from victim's lung tissue using 5.8S+ITS2 marker, thus the victim was thrown into the water after death. CONCLUSIONS The experimental results of the two cases in present study are consistent with the actual facts and the result of the diatom microscopic examination. The difference of population structure of specific microorganism in water and human tissue can be detected by 5.8S+ITS2 marker, which can help to identify the drop-off location of victims in drowning cases, and confirm whether it is a fatal drowning or the victim is thrown into the water after death.
DNA, Ribosomal/analysis* ; Diatoms/genetics* ; Drowning/diagnosis* ; Humans ; Liver ; Lung

To know the value of the solubilization method using tissue solubilizer Soluene-350 in diagnosis of drowning, mice (ICR) were drowned artificially with the fresh water of Chungju district. Chlorophyta (or green algae), such as Oocystis and Eudorina, as well as diatoms, such as Diatoma, Synedra and Cyclotella were detected with other algae including Microcystis, Oscillatoria, Trachlomonas, Altenaria and Cephalodella in the water of Daeje-ji(Dae-je pond). This method is useful in detection of green algae and other kinds of algae for diagnosis of drowning in submerged bodies among legal autopsy cases.
Animals ; Autopsy ; Chlorophyta* ; Chungcheongbuk-do* ; Diagnosis* ; Diatoms ; Drowning* ; Fresh Water ; Mice ; Microcystis ; Oscillatoria ; Rivers* ; Water

The diagnosis of drowning is one of the most difficult in forensic pathology. One of the most common autopsy findings in drowning cases is a heavy, edematous lung as the result of water that is aspirated into the lungs before death. There are several controversial findings and arguments about the lung weight as a marker of drowning. The aim of the present study is to examine the difference in the lungs to the spleen weight ratio between seawater and freshwater drowning, compared with asphyxiation and acute cardiac death. This study compared the weight ratio of the lungs to the spleen for 29 cases of drowning (24 males, 5 females), 30 cases of mechanical asphyxiation (16 males, 14 females), and 37 cases of acute cardiac death (30 males, 7 females). This study presented significant differences in the lungs to the spleen weight ratio between drowning and the other causes of death . Therefore, these findings suggest that the ratio may be a useful index for accurate diagnosis of death by drowning.
Autopsy ; Cause of Death ; Death ; Diagnosis ; Drowning* ; Forensic Pathology ; Fresh Water ; Humans ; Lung* ; Male ; Seawater ; Spleen* ; Water

This is a comparative study based on the data of legal autopsies performed at the National Institute of Scientific Investigation, Seoul, during the year of 2000. In South Korea, the pathologists usually do not attend the death scene, and the scene investigation is performed only by the law enforcement agency. The latter collects the information needed for clarifying the cause and manner of death. The authors tried to estimate the efficiency of the death investigation through the discrepancy between the presumed and the most possible cause of death. We presumed the cause of death on the ground of police investigation and external examination by the general physicians, The most possible cause of death means the best diagnosis after autopsy by pathologists, with the consideration of police information. Followings are the summary of the results. The coincidence rate with the most possible death are over 90% in presumed trauma, asphyxia, thermal injuries, electrocution, starvation/neglect, and over 80% in drowning and natural deaths. The rate was low in medical injuries(26.6%) and poisoning(67.2%). 7.3 to 8.2% were natural in presumed blunt trauma, traffic injury and fall down injuries. Among 48 cases of presumed ligature strangulation, 6 were other type of asphyxia or other injuries, and 2 unknown. The coincidence rate was only 30.8% in acute alcohol poisoning. 5.9% of presumed fire death was proved other type of violent injuries. In the field of medical practices, only 6.3% of accused general medical procedures were proved dead due to themselves. But the rate was increased up to 49.0% in presumed surgery/anesthetic deaths. 12.9% were violent death in presumed natural death, and 64.6% were dead due to violent causes in the cases of no presumable cause of death.
Asphyxia ; Autopsy* ; Cause of Death* ; Diagnosis ; Drowning ; Fires ; Humans ; Korea ; Law Enforcement ; Ligation ; Poisoning ; Police ; Seoul