Research Progress on Molecular Changes in Pulmonary Hypoxia and Cause of Death Identification in Mechanical Asphyxia / 法医学杂志

Lung is the largest organ of the respiratory system. During hypoxia, pulmonary cells undergo rapid damage changes and activate the self-rescue pathways, thus leading to complex biomacromolecule modification. Death from mechanical asphyxia refers to death due to acute respiratory disorder caused by mechanical violence. Because of the absence of characteristic signs in corpse, the accurate identification of mechanical asphyxia has always been the difficulty in forensic pathology. This paper reviews the biomacromolecule changes under the pulmonary hypoxia condition and discusses the possibility of application of these changes to accurate identification of death from mechanical asphyxia, aiming to provide new ideas for related research.

Sex Estimation of Medial Aspect of the Ischiopubic Ramus in Adults Based on Deep Learning / 法医学杂志

OBJECTIVES@#To investigate the reliability and accuracy of deep learning technology in automatic sex estimation using the 3D reconstructed images of the computed tomography (CT) from the Chinese Han population.@*METHODS@#The pelvic CT images of 700 individuals (350 males and 350 females) of the Chinese Han population aged 20 to 85 years were collected and reconstructed into 3D virtual skeletal models. The feature region images of the medial aspect of the ischiopubic ramus (MIPR) were intercepted. The Inception v4 was adopted as the image recognition model, and two methods of initial learning and transfer learning were used for training. Eighty percent of the individuals' images were randomly selected as the training and validation dataset, and the remaining were used as the test dataset. The left and right sides of the MIPR images were trained separately and combinedly. Subsequently, the models' performance was evaluated by overall accuracy, female accuracy, male accuracy, etc.@*RESULTS@#When both sides of the MIPR images were trained separately with initial learning, the overall accuracy of the right model was 95.7%, the female accuracy and male accuracy were both 95.7%; the overall accuracy of the left model was 92.1%, the female accuracy was 88.6% and the male accuracy was 95.7%. When the left and right MIPR images were combined to train with initial learning, the overall accuracy of the model was 94.6%, the female accuracy was 92.1% and the male accuracy was 97.1%. When the left and right MIPR images were combined to train with transfer learning, the model achieved an overall accuracy of 95.7%, and the female and male accuracies were both 95.7%.@*CONCLUSIONS@#The use of deep learning model of Inception v4 and transfer learning algorithm to construct a sex estimation model for pelvic MIPR images of Chinese Han population has high accuracy and well generalizability in human remains, which can effectively estimate the sex in adults.

Forensic Examination of Six Homicide Injection Cases / 法医学杂志

OBJECTIVES@#To retrospectively analyze homicide cases of death after injection and provide reference for forensic identification.@*METHODS@#Six homicide cases of death after injection which were investigated by the Criminal Investigation Team of Shanghai Public Security Bureau were collected and analyzed, including case situation, scene investigation, autopsy and other materials.@*RESULTS@#The 6 cases were premeditated crimes, 5 cases took place in private spaces, and 5 cases involved the victims approached by suspects' decoy. There were no obvious abnormalities at the scene of the 6 cases. In 6 cases, the victim's body surface injury was mild or no, lividity color was abnormal, and the needlestick injury showed different manifestations from conventional medical measures.@*CONCLUSIONS@#Death after injection is a highly concealed crime and easy to be ignored. For the suspected injection injury found in autopsy, it is necessary to carefully examine, identify and analyze, be alert to the situation of injecting poison (drug) and do a good job in evidence fixation and material extraction.

Individual Identification in Facial Appearance Biometrics Based on Macroscopical Comparison / 法医学杂志

Individual identification is one of the research hotspots in the practice of forensic science, and the judgment is usually built on the comparison of the unique biological characteristics of the individual, such as fingerprints, iris and DNA. With the dramatic increase in the number of cases related to video image investigations, there is an increasing need for the technology to identify individuals based on the macroscopic comparison of facial appearance biometrics. At present, with the introduction of computer three-dimensional (3D) modeling and 3D superimposition comparison technology, considerable progress has been made in individual identification methods based on macroscopic comparison of facial appearance biometrics. This paper reviews individual facial appearance biometric methods based on macroscopical comparison, comprehensively analyzes the advantages and limitations of different methods, and puts forward recommendations and prospects for subsequent research.

Application of Diatoms Quantitative Analysis in the Diagnosis of Drowning / 法医学杂志

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 (CL/CD) 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 CL/CD 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 CL/CD can be introduced into the analysis to make a more accurate diagnosis of drowning.

Research Progress of Automatic Diatom Test by Artificial Intelligence / 法医学杂志

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.

Application of Artificial Intelligence Automatic Diatom Identification System in Practical Cases / 法医学杂志

Objective To discuss the application of artificial intelligence automatic diatom identification system in practical cases, to provide reference for quantitative diatom analysis using the system and to validate the deep learning model incorporated into the system. Methods Organs from 10 corpses in water were collected and digested with diatom nitric acid; then the smears were digitally scanned using a digital slide scanner and the diatoms were tested qualitatively and quantitatively by artificial intelligence automatic diatom identification system. Results The area under the curve （AUC） of the receiver operator characteristic （ROC） curve of the deep learning model incorporated into the artificial intelligence automatic diatom identification system, reached 98.22% and the precision of diatom identification reached 92.45%. Conclusion The artificial intelligence automatic diatom identification system is able to automatically identify diatoms, and can be used as an auxiliary tool in diatom testing in practical cases, to provide reference to drowning diagnosis.

Research Progress on Age Estimation Based on DNA Methylation / 法医学杂志

Age estimation is of great significance in the fields of criminal investigation and forensic identification. It can provide the age information of individuals to judicial departments to facilitate the development of judicial work. In recent years, age estimation methods expanded from the morphological level to the molecular biology level. With the rapid development of epigenetics represented by DNA methylation, and the advancement of DNA methylation detection technology together with the detection platform, many age estimation methods based on DNA methylation biomarkers, or using several biological fluids, such as blood, blood stains, saliva, semen stains, etc. are developed. Currently, researches related to age estimation based on DNA methylation are relatively widely carried out. This paper summarizes the researches on age estimation based on DNA methylation, in order to provide references for related studies and forensic applications.

Adult Stature Estimation by Multiple Parameters of Body Torso Segment / 法医学杂志

OBJECTIVES@#To promote the further research on body stature estimation and the innovative applications based on the distances between the anatomical landmarks on body torso surface.@*METHODS@#A specification for the collection of distances between the anatomical landmarks on body torso surface was established. The data of 933 cases of adult population in Yangtze River Delta region were collected. Multiple linear regression method was used to statistical analyse and establish the regression equation of stature estimation.@*RESULTS@#A regression equation about 5 variables including gender （x₁）, cervical vertebrae-coccyx line （x₂）, sterna-pubis line （x₃）, distance between acromion and iliospinale anterius （x₄） and shoulder breadth （x₅）, and stature （y） was established, y=105.406+5.414 x₁+0.436 x₂+0.286 x₃+0.225 x₄+ 0.193 x₅.@*CONCLUSIONS@#The method is suitable for the rapid, simple and accurate estimation of stature for the forensic experts.

Brief discussion on the proof standard of traditional evidence of forensic pathology in murder cases / 复旦学报（医学版）

Objective In the legal proceedings of murder cases,we often encounter the problem of proof standard in traditional forensic pathology in deep research,which is lack of systemic discussion in domestic academic field.This paper aimed to discuss this problem.Methods We compared the relevant characteristics of different legal systems on the standard of proof system,analyzed the elements of the forensic pathology evidence related to murder cases,and discussed the problem with the author's judicial practice experience.Results We believe that the cause of death,death time,injury and injury tools are the three most important forensic pathology evidences in the murder of the standard system as the "three pillars".Conclusions Division of standards in traditional forensic pathology evidence in the murder is of great significance to raise the sense of evidence of forensic medicine,and if it exists major flaws in the evidence of forensic pathology,the evidence can be corrected or the proceedings can be terminated at the very beginning of the litigation phase,which is of great value to the savings of judicial resources.

A forensic analysis of alcohol-positive fatal cases in Shanghai during 2007 to 2016 / 复旦学报（医学版）

Objective To characterize alcohol-related deaths which were not caused by traffic accident in Shanghai and to provide data support for alcohol-related policy and intervention.Methods All alcohol-positive fatal deaths collected in 2007-2016 from Shanghai Public Security Bureau were classified based on blood alcohol concentration (BAC) and distributed by year,gender,age,season,cause of death (COD),manner of death (MOD) and combined drugs.Results There was no significant correlation of alcohol BAC with year or season.Males (88.4％) were more than females (11.6％).Age of 20-39 years (57.1％),mechanical injury (70.1％),homicide (64.6％) and combined illicit use (37.2％) were the largest proportions in respective categories of age,COD,MOD and drug combination.With the BAC rising,mechanical injury and homicide showed decreased proportions,while burn and accidents showed increased proportions.Conclusions Male and the age of 20-39 years are the major populations for alcohol-related deaths in Shanghai.With the rise of BAC,mechanical injury and homicide decrease,while burn and accident increase.Among the combined use of alcohol and drugs,death from acute intoxication should be paid special attention.

Correlation between RNA Expression Level and Early PMI in Human Brain Tissue / 法医学杂志

OBJECTIVES@#To explore the correlation between the expression levels of several RNA markers in human brain tissue and early postmortem interval （PMI）.@*METHODS@#Twelve individuals with known PMI （range from 4.3 to 22.5 h） were selected and total RNA was extracted from brain tissue. Eight commonly used RNA markers were chosen including β-actin, GAPDH, RPS29, 18S rRNA, 5S rRNA, U6 snRNA, miRNA-9 and miRNA-125b, and the expression levels were detected in brain tissue by real-time fluorescent quantitative PCR. The internal reference markers with stable expression in early PMI were screened using geNorm software and the relationship between its expression level and some relevant factors such as age, gender and cause of death were analyzed. RNA markers normalized by internal reference were inserted into the mathematic model established by previous research for PMI estimation using R software. Model quality was judged by the error rate calculated with estimated PMI.@*RESULTS@#5S rRNA, miRNA-9 and miRNA-125b showed quite stable expression and their expression levels had no relation with age, gender and cause of death. The error rate of estimated PMI using β-actin was 24.6%, while GAPDH was 41.0%.@*CONCLUSIONS@#5S rRNA, miRNA-9 and miRNA-125b are suitable as internal reference markers of human brain tissue owing to their stable expression in early PMI. The expression level of β-actin correlates well with PMI, which can be used as an additional index for early PMI estimation.

Pathological Features of Myocardial Contraction Band Necrosis in Sudden Cardiac Death / 法医学杂志

OBJECTIVE@#To investigate the pathological features and significance of myocardial contraction band necrosis in sudden cardiac death.@*METHODS@#Using HE and PTAH staining, the distribution sites and pathological features of myocardial contraction band necrosis were observed. The data were analyzed according to the extent of necrosis.@*RESULTS@#The locations, pathological features and the extent of necrosis were similar in different sudden death cases. The locations were related with sites of myocardial damage. The papillary muscles of left ventricular were most occurred, followed by the anterior wall of left ventricular. In the sudden death cases caused by stress cardiomyopathy, the extent of myocardial contraction band necrosis was lighter than the others. Most cases were predominantly level 1, the others were level 2.@*CONCLUSION@#Used as the diagnosis basis of acute myocardial ischemia, the myocardial contraction band necrosis has important significance to determination of death.

Correlation between age and general morphology of transverse section of cartilago costalis / 法医学杂志

OBJECTIVE@#To study the correlation between age and general morphology of transverse section of cartilago costalis and its forensic significance.@*METHODS@#Eighty-six corpses' cartilago costalis from the routine postmortem examination were collected and the morphological features of their transverse section were observed.@*RESULTS@#With the increased age, there were regular changes in the color, structure, and material of the general morphology of transverse section of cartilago costalis. But the changes were not affected by gender.@*CONCLUSION@#The good correlation between general morphology of transverse section of cartilago costalis and age can be used to estimate age of the deceased rapidly.

Analysis of false-positive hyoid fractures: 12 forensic identification cases / 法医学杂志

OBJECTIVE@#To study the causes of false-positive hyoid fractures and forensic identification.@*METHODS@#Twelve cases of false-positive hyoid fractures were collected and analyzed.@*RESULTS@#Improper dissection technique (4 cases) and congenital separation (8 cases) were the main reasons for false-positive hyoid fractures.@*CONCLUSION@#True fractures can be differentiated from false-positive hyoid fractures. False-positive hyoid fracture caused by improper dissection technique can be identified through examination of peripheral muscle, soft tissue hemorrhage, and the characteristics of fracture end.

Correlation between five RNA markers of rat's skin and PMI at different temperatures / 法医学杂志

OBJECTIVE@#To explore the correlation between postmortem interval (PMI) and five RNA markers of rat's skin--β-actin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 18S ribosomal RNA(18S rRNA), 5S ribosomal RNA (5S rRNA), and microRNA-203 (miR-203), at different temperatures.@*METHODS@#Eighteen SD rats were randomly divided into three environmental temperature groups: 4 °C, 15 °C and 35 °C, respectively. Skin samples were taken at 11 time points from 0 h to 120 h post-mortem. The total RNA was extracted from the skin samples and the five RNA levels were detected by real-time fluorescent quantitative PCR. Proper internal reference was selected by geNorm software. Regression analysis of the RNA markers was conducted by GraphPad software.@*RESULTS@#5S rRNA and miR-203 were most suitable internal references. A good linear relationship between PMI and RNA levels (β-actin and GAPDH) was observed in two groups (4 °C and 15 °C), whereas the S type curve relationship between the expression levels of the two markers (β-actin and GAPDH) and PMI was observed in the 35 °C group. The partial linear relationship between 18S rRNA and PMI was observed in the groups (15 °C and 35 °C).@*CONCLUSION@#Skin could be a suitable material for extracting RNA. The RNA expression levels of β-actin and GAPDH correlate well with PMI, and these RNA markers of skin tissue could be additional indice for the estimation of PMI.

Relationship between PMI and relative expression of myocardial various RNAs in rats died of different causes / 法医学杂志

OBJECTIVE@#To observe the changes of relative expression of myocardial various RNAs in rats died of different causes and their relationship with PMI.@*METHODS@#The rat models were established in which the rats were sacrificed by broken neck, asphyxia, and hemorrhagic shock. Total RNAs were extracted from myocardium. The quantitative real time PCR was used to calculate threshold cycle values of RNAs including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin, inducible nitric oxide synthase (iNOS), hypoxia-inducible factor-1 (HIF-1), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and U6 small nuclear RNA (U6 snRNA) and to study the changes of the relative expressions of various indexes with PMI.@*RESULTS@#U6 snRNA with stable expression level could be used as appropriate internal control. In the early PMI, the relative expression of GAPDH, HIF-1, iNOS, TNF-alpha, and IL-6 more characteristically increased in groups of asphyxia and hemorrhagic shock than in group of broken neck, but the quantity of beta-actin decreased in all groups. In the late PMI, all the relative expressions significantly declined in correlation with the degradation of RNA.@*CONCLUSION@#The characteristic changes of each RNA expression can be used as references to estimate PMI in deaths by different causes.

Forensic analysis of 24 dismembered homicide cases in Shanghai / 法医学杂志

OBJECTIVE@#To explore the characteristics of the dismembered homicide cases in Shanghai and to provide the valuable guidance for forensic pathological practices.@*METHODS@#Twenty-four cases of dismembered homicides were selected from 2005 to 2012 in Institute of Forensic Science, Shanghai Public Security Bureau. The general information of the victims and suspects, cause of death, criminal motive, postmortem body parts, tools and information of discarding body parts were retrospectively analyzed.@*RESULTS@#Among the 24 dismembered homicide cases, victims were female in 16 cases, and suspects were male in 23 cases and were acquaintances in 22 cases. The main causes of death were mechanical asphyxia and traumatic brain injury. Most of the criminal motives were emotional disputes. The number of postmortem body parts was commonly from 20 to 30. The tools were mainly sharp instruments, including kitchen knives used in 20 cases. The postmortem body parts were discarded to different transregional areas, mainly using vehicles.@*CONCLUSION@#The dismembered homicide cases in Shanghai show the following characteristics: the number of postmortem body parts is in large quantity; the methods of dismembered corpse are complex and different; the job characteristics of suspects are difficult to determine; the distance from homicide scene is far and the vehicles are commonly used.

Analysis of 27 death cases of the abandoned babies in Shanghai / 法医学杂志

OBJECTIVE@#To analyze and summarize the characteristics of the death cases of the abandoned babies in Shanghai, and to explore the main points and features in forensic investigation.@*METHODS@#Twenty-seven death cases of the abandoned babies were selected from 2007 to 2011 in the Institute of Forensic Science of Shanghai Public Security Bureau. The cases were retrospectively analyzed in the respects of scene of abandonment, cause of death and manner of death, etc.@*RESULTS@#Among the death cases of the abandoned babies in Shanghai, most of the infants were alive with young unmarried mothers. The main cause of death was mechanical asphyxia, and homicide occurred more commonly.@*CONCLUSION@#It is significantly difficult to determine the cause and manner of death in such cases, needing to be a comprehensive analysis on the case background, the investigation of scene and the examination of injury, etc.

Evaluation on stability of internal controls in human cardiac muscle by real-time RT-PCR during early postmortem interval / 法医学杂志

OBJECTIVE@#To explore the stability of internal controls in human cardiac muscle by real-time RT-PCR during early postmortem interval (PMI) in order to find the most stable marker.@*METHODS@#Ten individuals with similar environmental conditions (the average store temperature: 25 degrees C) and different PMI ranging from 4.3 to 22.3 h were selected. Total RNA was extracted from each sample and six commonly internal controls were used including beta-actin, GAPDH, B2M, U6, 18S rRNA and HSA-miR-1, and the expression was detected in cardiac muscle by real-time RT-PCR. The expression stability of internal controls was evaluated using genormPLUS software during early PMI. The internal control with the most stability was selected. The relationship between the most stable marker and its expression level affected by some other parameters such as age, gender and cause of death was also analyzed.@*RESULTS@#The U6 showed the most stable expression during early PMI in cardiac muscle, and its expression level was not affected by those parameters including age, gender and cause of death (P > 0.05).@*CONCLUSION@#U6 may be a valuable internal control for the study of relationship between PMI determination and degradation of nucleic acid in human cardiac muscle by real-time RT-PCR.