Objective To propose a novel forensic diatom examination method, namely the protease-hydrogen peroxide （PHP） digestion method, and to explore its potential application in forensic practice. Methods The PHP digestion method was applied to process lung tissues and compared with the traditional nitric acid digestion method in terms of diatom quantity, recovery rate, proportion of diatom fragments, and recovery efficiency of different diatom genera. Results The PHP digestion method showed higher diatom quantity, recovery rate, and proportion of diatom fragments compared to the traditional nitric acid digestion method with statistical significance. The average diatom recovery rate was as high as 93.95%. In the lung tissues digested with nitric acid, there were 65 Achnanthes, 36 Nitzschia Ⅰ, 22 Nitzschia Ⅱ, 20 Diploneis and 8 Cymbella, showing significantly lower recovery rates compared to water samples which had 154 Achnanthes, 44 Nitzschia Ⅰ, 45 Nitzschia Ⅱ, 33 Diploneis and 23 Cymbella. However, with the PHP digestion method, only Nitzschia Ⅱ showed a lower recovery rate compared to water samples （P<0.05）. At the same time, the diatom recovery stability of the PHP digestion method was higher than that of the nitric acid digestion method. Conclusion The PHP digestion method is superior to the traditional nitric acid digestion method in the lung tissue diatom extraction efficiency. Additionally, it holds significant advantages in safety, environmental protection, and other aspects. It is expected to be applied in forensic drowning identification.

Objective To compare the application value of three image post-processing techniques volume rendering （VR）, multiplanar reformation （MPR） and curved planar reformation （CPR） in the identification of rib fracture malunion. Methods The types and numbers of rib fracture malunion in 75 patients were recorded, and the sensitivity, specificity, accuracy and Youden index of VR, MPR and CPR in the diagnosis of rib fracture malunion were compared. Receiver operator characteristic （ROC） curve was drawn and area under the curve （AUC） was calculated, and the detection rates of three image post-processing techniques for different types of rib fracture malunion were compared. Results A total of 243 rib fractures were malunion in 75 patients. The diagnostic sensitivity of VR, MPR and CPR for rib fracture malunion was 52.67%, 79.84% and 91.36%, the specificity was 99.58%, 97.89% and 99.15%, the accuracy was 83.66%, 91.76% and 96.51%, the Youden index was 0.52, 0.78 and 0.91, the AUC was 0.761, 0.889 and 0.953, respectively. Compared with VR, there were statistically significant differences in the number of broken rib end misalignment over 1/3, broken rib end overlap, broken rib end angulation and intercostal bridge detected in MPR （P<0.05）. Compared with VR, there was a statistically significant difference in the number of different types of rib fracture malunion detected by CPR （P<0.05）. Compared with MPR, there were statistically significant differences in the number of broken rib end misalignment over 1/3, broken rib end separation and intercostal bridge detected in CPR （P<0.05）. Conclusion The three image post-processing techniques are of great significance for the identification of rib fracture malunion. Especially CPR is highly effective in the diagnosis of rib fracture malunion, and can be used as the main post-processing technique for forensic clinical identification of rib fracture malunion.

Objective To establish the identification method of tumor tissue origin based on commonly used STR typing kits. Methods ForenSeq^TM DNA Signature Prep kit was used to detect the typing of 27 autosomal STR loci in 55 paired tumor tissue samples （tumor tissue paired with normal tissue of the same individual） and 75 unrelated individual whole blood samples. The genotyping data of full sibling pairs and parent-child pairs of 55 tumor tissues were simulated. The number of total identical alleles （A_n ） and identity by state （IBS） scores were calculated within the paired carcinoma （PC）, the tumor-unrelated individual （UI）, the tumor-simulated full sibling （FS） and the tumor-simulated parent-offspring （PO） groups. The tumor tissue origin identification and prediction models of 8 commonly used STR typing kits were established based on the statistical results obtained above, and an attempt was made to establish a specific model for tumor tissue origin identification. The accuracy, sensitivity and specificity were verified and evaluated using the additional 23 paired tumor tissue samples. Results （1） In any kit, there was no statistically significant difference in the number of loci shared with 0 identical allele （A₀） between the PC and PO groups. The number of loci shared with 1 identical allele （A₁）, 2 identical alleles （A₂）, and IBS scores were statistically significant different between the PC group and the UI, FS and PO groups. （2） The A_n and IBS scores of different STRs varied in different groups. The A₂ levels of 13 STRs （CSF1PO, D12S391, D19S433, D20S482, D2S1338, D3S1358, D4S2408, D7S820, D8S1179, FGA, TH01, TPOX, vWA） in PC group were higher than those of other STR loci. The A₂ levels of two STRs （D6S1043, Penta E） in UI group were significantly lower than those of other STR loci. （3） The tumor tissue origin identification and prediction models of 8 commonly used STR typing kits and the identification model of tumor tissue origin with 15 STR loci （15-STRs） were successfully established, with sensitivity of 100%, specificity of 97.56%-99.88%, and accuracy of 97.59%-99.89%. Among them, the 15-STRs model had 100% sensitivity, 99.88% specificity, and 99.89% accuracy, which were higher than those of commonly used commercial kits. Conclusion This study successfully establishes the tumor tissue origin identification methods with 8 commonly used STR typing kits, which expands the application of tumor tissue origin identification. In addition, the differences of different loci in the identification of tumor tissue origin were compared, and 15 STR loci which were particularly suitable for the identification of tumor tissue origin were selected, providing the data basis for the establishment of tumor origin tracing kits in future.

Objective To establish the structural confirmation methods of three suspected new psychoactive substances （NPSs）, and explore a more general qualitative testing method. Methods Infrared absorption spectroscopy （IR）, gas chromatography-mass spectrometry （GC-MS）, ¹H-nuclear magnetic resonance spectroscopy （¹H-NMR）, ¹³C-nuclear magnetic resonance spectroscopy （¹³C-NMR）, ¹⁹F-nuclear magnetic resonance spectroscopy （¹⁹F-NMR） and other techniques were used to identify the composition and structure of 5 samples containing suspected NPS submitted by public security bureaus. Results NPSs were found in the above 5 samples, and 3 were confirmed as NPS included in the newly listed controlled substances on July 1, 2024, namely 2-（methylamino）-2-（2-methylphenyl）cyclohexan-1-one （2-MDCK）, 2-（ethylamino）-2-（2-fluorophenyl）cyclohexan-l-one （2-FXE）, 1-（3,4-methylenedioxyphenyl）-2-（dimethylamino）pentan-1-one （dipentylone）, respectively. The first two substances were phencyclidine NPS, and the third substance was synthetic cathinone NPS. Conclusion This study systematically summarizes the distinguishing features of the infrared absorption spectrometry, nuclear magnetic resonance spectroscopy and mass spectrometry of three NPSs, which can provide a reference for the qualitative identification of unknown substances.

Objective To provide a longitudinal evaluation tool based on the frequency of aggressive behavior for the aggression assessment of schizophrenia patients. Methods The Life History of Aggression was translated and revised to form the Life History of Aggression-Chinese Version （LHA-CV） based on 369 patients diagnosed with schizophrenia in the Chengdu community and compulsory medical institution. The reliability of LHA-CV was analyzed by means of split-half reliability, test-retest reliability and inter-evaluator consistency. The validity was analyzed by item analysis, construct validity and criterion validity. Results Item analysis found that LHA-CV had good homogeneity and discriminant validity. Exploratory factor analysis found that the Kaiser-Meyer-Olkin （KMO） test value was 0.80, and the Bartlett’s sphericity test χ²=1 203.46 （P<0.05）, and it revealed four factors including non-physical aggression, physical aggression, self-directed aggression and antisocial behavior/consequences. The factor loadings for all 11 items were greater than 0.40. Confirmatory factor analysis was performed on the factor model, Chi-square degree of freedom （χ²/df） was 3.61, root mean square error of approximation （RMSEA） was 0.07, goodness-of-fit index （GFI） was 0.92, comparative fit index （CFI） was 0.90, incremental fit index （IFI） was 0.90, and the discriminant validity of each factor was good. The criterion validity test showed the total score of LHA-CV was positively correlated with the aggressive behavior level of MacArthur Community Violence Instrument, the total score of Buss-Perry Aggression Scale, and the score of Antisocial Personality Disorder Subscale of Personality Diagnostic Questionnaire-4th Edition Plus （PDQ-4+_ASPD, P<0.05）. The Cronbach’s α coefficient of non-physical aggression, physical aggression, self-directed aggression, antisocial behavior/consequences and LHA-CV total score were 0.82, 0.73, 0.74, 0.56 and 0.79, respectively. The test-retest reliability, Spearman-Brown split-half reliability and intra-class correlation coefficient of LHA-CV total score were 0.82 （P<0.05）, 0.66 and 0.99, respectively. Conclusion LHA-CV has good reliability and validity, and can be used as an evaluation tool for longitudinally assessing aggressive behavior in schizophrenia patients.

Objective To explore the causes of related medical damage risks and preventive measures by analyzing the identification results of medical damage in 20 urological death cases. Methods A retrospective analysis was conducted on 20 death cases of medical damage identification involving urology diagnosis and treatment accepted by the Judicial Appraisal Center, School of Forensic Medicine, Guizhou Medical University, and Academy of Forensic Science from 2010 to 2023. Results Among the 20 cases, the male-to-female ratio was 1.5∶1. The age of the identified persons ranged from 37 to 84 years old, with an average age of 59.2 years. There were 21 medical institutions involved, with 81.0% being tertiary medical institutions. The statistical results of the causes of death showed that 60.0% deaths were due to infectious shock or hemorrhagic shock. Conclusion The causative potency analysis of medical damage in urological death cases is closely related to the patients’ diseases, the death consequences of medical damage, and medical errors. Analyzing characteristics of typical cases can improve the comprehensive analysis ability of forensic examiners in similar cases, help them understand the rationality and compliance of medical behaviors in different situations, in order to make more accurate and comprehensive judgments.

Objective To analyze the characteristics of forensic clinical sex identification cases after sex reassignment surgery for transsexualism, discuss the main point of forensic clinical sex identification in China based on domestic and foreign sex change policies and related cases, so as to standardize relevant identification. Methods A total of 39 cases of forensic clinical sex identification were collected from Center for Forensic Science, Shanghai Medical College of Fudan University in recent years, and the ratio of sex, identification time, the location of surgery, secondary sex characteristic and other information were statistically analyzed. Results Transgender woman accounted for 97.4% of the cases, and 94.9% of the cases were operated in Thailand. All cases were identified after the sex reassignment surgery, and at least one of the secondary sex characteristics was consistent with the postoperative primary sexual characters. There were only 2 cases in which auxiliary examination was applied. Conclusion Forensic clinical sex identification should be based on the principle that the primary and secondary sex characteristics are consistent with the changed sex.

Cerebrocardiac syndrome refers to secondary cardiac damage caused by various craniocerebral injury lesions, which can exacerbate existing heart disease. In the practice of forensic pathology, cerebral-cardiac interaction is often ignored in cases of death with a short time after craniocerebral injury, especially those with underlying heart disease. This article reviews the pathogenesis of cerebrocardiac syndrome by summarizing recent research results of cerebrocardiac syndrome at home and abroad and discusses its significance in the field of forensic medicine. The aim is to provide assistance for forensic medicine practice of cerebrocardiac syndrome.

Skin and hair are the outermost interfaces between the human body and the external environment with many microorganisms distributed. These body surface microorganisms have individual specificity and spatial temporal stability and can be transferred to the surface of other objects through contact, and can be easily found at the crime scene, which helps to construct the connection between the suspect and the crime scene. When the sample is degraded or the DNA quantity is too low to obtain sufficient human DNA evidence, the highly amplified copies of body surface microbiome analysis can be used as an adjunct to human DNA typing without affecting DNA extraction and typing, and provide useful information for narrowing the range of suspects. This paper reviews the forensic characteristics and analytical methods of body surface microbiome, the research progress on the application of body surface microbiome to forensic individual identification, and puts forward the challenges of applying body surface microbiome to forensic practice.