In recent years, RNA markers have been widely employed for tissue origin identification in forensics. RNA molecules are diverse and can be detected in dried biological stains. They show characteristics such as tissue specificity, spatiotemporal dynamic expression, multi-copy numbers and high polymorphic genetics. Based on these characteristics, RNA genetic markers that combine polymorphism with body fluid specificity have been successfully applied to identify target body fluids in the multi-donor mixed stains. In addition, RNA genetic markers with both multi-copy characteristics and polymorphism have shown promising results in individual identification using anucleate samples such as hair shafts. However, the application of RNA polymorphic genetic markers still faces several key challenges, including the selection of appropriate RNA and polymorphic loci, and optimization of their practical use in forensics. This paper reviews the application of RNA polymorphisms in individual identification and systematically analyzes its advantages, limitations, and the main challenges that need to be addressed in the future. The goals are to further review and consolidate findings from studies of RNA polymorphisms, to advance theoretical development and methodological innovation of RNA polymorphisms in individual identification and to provide references for forensic individual identification.
1 案 例 1.1 简要案情及病史摘要 史某,男,63岁,某年7月6日午后在小区进行屋面及相关设施改造施工,室外工作2 h后,突发呼吸急促、晕厥.入院时体温41 ℃.当日气温29～38 ℃.
ObjectiveTo investigate the epidemiological and forensic characteristics of rotator cuff injuries caused by road traffic accidents, and to explore the timing and influencing factors of disability assessment of rotator cuff injuries.MethodsA retrospective analysis was conducted on 173 cases of rotator cuff injury caused by road traffic accidents. Factors analyzed included the time of post-injury assessment, the degree of functional loss of shoulder joint movement in six directions, the treatment methods, the presence or absence of combined shoulder injuries and the type of combined shoulder injuries, and the type of rotator cuff injury. The Kruskal-Wallis test and Wilcoxon rank sum test were used to analyze the differences in functional loss among the six directions of shoulder joint movement. The t-test was used to compare the differences in functional loss between the conservative treatment and the surgical treatment, as well as between cases with and without combined shoulder injuries. One-way analysis of variance （ANOVA） and Student-Newman-Keuls （SNK） test were used to analyze the differences in functional loss of shoulder joint movement among the injury types of contusion, mild tear, moderate tear and severe tear. One-way ANOVA and least significant difference （LSD） test were used to analyze the differences according to the number of involved rotator cuff tendons （1, 2, 3, or 4 tendons） and post-injury assessment time （3-<6 months, 6-<9 months, 9-<12 months, and ≥12 months）.ResultsThe median assessment time after injury was 290.00 days. Among the six directions of shoulder joint movement, statistically significant differences in the degree of functional loss were observed between abduction up, extension back and external rotation compared with adduction, as well as between external rotation and forward flexion up （P<0.05）. There was no statistically significant difference in the degree of functional loss between conservative treatment and surgical treatment, or among different post-injury assessment times （P>0.05）. However, there were significant differences between the non-combined shoulder injury and combined shoulder injury, different types of rotator cuff injuries, and the different numbers of involved rotator cuff tendons （P<0.05）. Treatment methods had no significant effect on the degree of functional loss of shoulder joint movement, whereas combined shoulder injuries, more severe rotator cuff injuries, and involvement of a greater number of rotator cuff tendons were associated with more severe functional loss of shoulder joint movement.ConclusionRotator cuff injuries caused by road traffic accidents exhibit the epidemiological and forensic characteristics including delayed diagnosis after injury, prolonged post-injury assessment time, and the rotator cuff injuries being mainly mild to moderate tears （≤3 cm） and involving 1 or 2 tendons. Combined shoulder injuries are mostly characterized by greater tuberosity fractures of the humerus, long head of the biceps tendon injuries and shoulder dislocations. The recommended timing for disability assessment in cases involving rotator cuff tears and/or surgical treatment should be appropriately extended. The presence or absence of combined shoulder injuries, the types of rotator cuff injury, and the number of involved rotator cuff tendons should be emphasized in forensic clinical identification.
1 案 例 1.1 简要案情 唐某,男,28岁,因"被殴打致全身多处受伤6 h"入院治疗.自述被人用拳脚、啤酒瓶、井盖殴打致伤.其病历资料中未见有关颈部损伤(如因扼颈等外力作用所致)的记录,曾行CT检查,报告诊断为舌骨前缘左侧骨折.
Chlorfenapyr is a broad-spectrum insecticide and acaricide derived from natural pyrrole derivatives. After entering the body, it is rapidly converted into the active metabolite tralopyril. At present, there is no specific antidote for chlorfenapyr poisoning. The mortality rate associated with this substance is relatively high, because of the latent period following exposure. In recent years, cases of poisoning caused by chlorfenapyr have been increasing. Based on relevant domestic and international research, this paper systematically reviews the toxicological effects, toxicity data, poisoning symptoms, in vivo processes of chlorfenapyr, as well as the toxicological data from typical cases, with the aim of providing a reference for forensic identification.
1 案 例 1.1 简要案情 某男婴,4月龄,因"腹泻半个月,发热4 d"入院.入院时查体:体温38.0 ℃,双眼球结膜未见充血,口唇略干燥,咽部充血,颈软,无皮疹改变.入院当日查血常规示:白细胞26.1×109/L↑(参考值4.3×109～14.2×109/L),红细胞4.0×1012/L(参考值3.3×1012～5.2×1012/L),血小板774×109/L↑(参考值183×109～614×109/L).
1 案 例 1.1 简要案情 某年1月7日19时许,群众报警称村民孙某(男,83岁,丧偶,独居)死于家中,生殖器被割.经查,1月6日上午11时许,孙某辱骂同村的张某(女,60岁)并向其裸露下体,张某当即扬言要往孙某身上泼大粪并割掉其生殖器;14时许,张某和丈夫王某(男,63岁)往孙某家大门及其身上泼大粪,在推门的过程中,大门将孙某撞倒在地,此后孙某一直未外出.调取案发现场附近监控显示,双方争执推搡后不久便听到孙某间断发出呼救声,且渐微弱,直至当日夜间呼救声消失.
ObjectiveTo investigate the abnormal genotyping and its causes at the Amelogenin locus in male samples.MethodsA total of 23 647 blood samples from unrelated male individuals were analyzed using the STRtyper-21G kit, and 38 samples with abnormal Amelogenin locus were identified. These samples were retested and classified using GlobalFilerTM and PowerPlex® 21 kits. Additional sex chromosome STR genotyping and Sanger sequencing were performed for samples with abnormal genotypes. Sequence-tagged site （STS） testing was conducted for samples suspected of Amel-Y microdeletions.ResultsAmong above 38 samples, except for Amelogenin locus, all samples showed normal male sex chromosome STR typing. The detection rate of abnormal genotyping was 0.161% （38/23 647）, which were categorized into three major types. Among them, 30 cases had Amel-X deletion: 5 cases had C→T mutation at position 372; 2 cases had G→A mutation at position 293; 23 cases had A→G mutation at position 304. There were 2 cases of Amel-Y deletion: 1 case of insertion mutation of TTAA at position 387, and 1 case of microdeletion of the short arm containing Amel-Y. Six cases of abnormal Amel-X/Y peak ratios were identified: using the STRtyper-21G kit, the abnormalities appeared as low Amel-X with absent Amel-Y, normal Amel-X with absent Amel-Y, normal Amel-X with low Amel-Y, respectively. However, retesting with GlobalFilerTM and PowerPlex® 21 kits consistently showed normal Amel-X with low Amel-Y. The GlobalFilerTM profiling showed that the peak heights of Amel-Y were comparable to those of the Y-InDel and DYS391 markers, and no abnormalities were detected by sequencing.ConclusionAmelogenin genotyping abnormalities occur at a measurable frequency in the population and are mainly associated with mutations, which can be categorized as Amel-X deletion, Amel-Y deletion, and Amel-X/Y peak ratio abnormality. Regarding normal Amel-X peaks with lower Amel-Y peaks, the possibility of mosaic loss of chromosome Y （mLOY） in samples, which is commonly observed in elderly males, should be considered and given attention.
ObjectiveTo observe stage-specific changes in the intestinal microbiota of nude mice after death and to develop a postmortem interval （PMI） estimation model based on “rupture points”, thereby exploring a new model for PMI estimation.MethodsA total of 108 nude mice were sacrificed, and cecal contents were collected at 18 time points （0, 24, 41, 48, 55, 65, 72, 79, 89, 96, 103, 113, 120, 144, 168, 192, 216, and 240 h postmortem）. 16S rRNA gene amplicon sequencing was used to analyze the changes in intestinal microbiota. Based on microbial abundance, a random forest model was employed for cross-validation to identify signature bacterial genera. A segmented regression model was then constructed to estimate PMI and compared with a direct regression model.ResultsBoth α- diversity and β-diversity analyses indicated significant changes in the relative abundance of intestinal microbiota during the periods of 0-103 h and 113-240 h postmortem in nude mice. The segmented regression model built using the random forest algorithm achieved an R2 of 0.96 and a mean absolute error （MAE） of 9.83 h for PMI estimation. In contrast, the direct regression model yielded an R2 of 0.81 and an MAE of 16.91 h.ConclusionMicrobial succession during cadaver decomposition exhibits clear temporal and stage-specific characteristics. A segmented regression model for PMI estimation using “rupture points” can improve the accuracy of PMI estimation in nude mice.
ObjectiveTo identify biomarkers for sudden death in leukemia through common genes across leukemia subtypes using bioinformatics technology, and to validate them in a specific case repository of sudden death in leukemia, thereby providing reference for cause of death determination in leukemia-related sudden death and cause of death analysis in medical malpractice cases.MethodsDifferentially expressed genes （DEGs） common across different types of leukemia were identified using the GEO database （GSE13159 dataset）. Enrichment analyses were performed using the Gene Ontology （GO） and the Kyoto Encyclopedia of Genes and Genomes （KEGG） databases, and enriched pathways were mapped to routine clinical laboratory parameters. Case data from patients who died suddenly due to stroke, respiratory failure, sudden cardiac death, and infectious shock, were collected and divided into the case group （leukemia sudden death group） and the control group （non-leukemia sudden death group） for validation. The Wilcoxon rank sum test and univariate logistic regression were used to screen biomarkers. A multivariate logistic regression model was constructed based on univariate logistic regression results to predict whether a sudden death patient had leukemia. Model performance was evaluated using receiver operator characteristic （ROC） curves and area under the curve （AUC）.ResultsA total of 540 DEGs shared across four leukemia subtypes were significantly enriched in pathways related to cell cycle, inflammatory immunity, and coagulation. The pathway enrichment results showed clear correspondence with routine clinical laboratory parameters. Compared with the control group, the case group exhibited overall characteristics of low white blood cell counts （mean: 2.42×109/L）, low platelet counts （mean: 23×109/L）, and low interleukin-6 （IL-6） levels （mean: 386.0 pg/mL）. Based on the univariate logistic regression results, IL-6 and platelet count were included in a multivariate logistic regression model. The model yielded an AUC of 0.828.ConclusionThe enrichment pattern of DEGs in leukemia sudden death biomarkers is consistent with the shared molecular mechanisms of uncontrolled leukemia cell proliferation, immune evasion, and hypercoagulable state. The combination of blood routine test parameters and IL-6 can be used for the differential diagnosis of sudden death in leukemia, providing objective evidence for auxiliary determination of cause of death in leukemia sudden death cases and offering a quantitative reference for cause of death analysis in medical malpractice identification.
ObjectiveTo establish a high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） method for detecting chlormezanone in blood samples.MethodsAcetonitrile was added to the samples to precipitate proteins. After vortex and ultrasonication, the mixture was centrifuged, and the supernatant was collected. It was then filtered using a 0.22 μm polytetrafluoroethylene membrane. Separation was performed using an InfinityLab Poroshell 120 EC-C18 column （100 mm×4.6 mm, 2.7 μm）. The mobile phase consisted of phase A （0.1% formic acid） and phase B （acetonitrile）, with gradient elution at a flow rate of 0.4 mL/min. The mass spectrometer was operated with an electrospray ionization in positive ion mode and multiple reaction monitoring mode.ResultsChlormezanone in blood samples showed good linearity within the tested range, with the correlation coefficients （r） all greater than 0.999. The limit of detection and the limit of quantitation of chlormezanone were 22.83 ng/mL and 100 ng/mL, respectively. The matrix effects were 2.1%-3.9% and recoveries were 88.8%-92.3%. Using this method, the mass concentration mass of chlormezanone detected in a positive sample was 1 217.23 ng/mL.ConclusionThis method requires simple sample preparation and a small sample volume, and offers a wide linear range, making it suitable for the detection of chlormezanone in blood.
1 案 例 1.1 简要案情 李某,男,21岁,某年9月1日在一起交通事故中受伤(骑电动自行车与一辆小轿车迎面相撞),对方逃逸.次年1月13日,李某于某司法鉴定中心进行残疾等级评定,鉴定意见:李某因交通事故致主动脉夹层,已行胸主动脉腔内修复术、主动脉造影术,构成八级残疾;其小肠破裂已行小肠部分切除术、肠吻合术,构成九级残疾.现受某市公安局委托,为明确肇事方刑事责任,对李某的人体损伤程度及因果关系进行法医临床鉴定.
To address problems such as fragmented research training, a disconnect between theory and practice, weak value guidance, and a limited international perspective in the traditional training of high-level forensic medicine professionals, the forensic medicine program at Hebei Medical University constructed a new graduate training model titled “Leading Goose Navigation and Four-Dimensional Synergy”. This model leverages the “Leading Goose” effect of high-level academic leaders, such as academicians, to establish strategic focus and a spiritual highland. It reshapes the educational ecosystem by taking research-based education to integrate the innovation chain, practical training to forge professional competence, ideological education to shape professional conviction, and international education to broaden international horizons as specific paths for “Four-Dimensional Synergy”. Using case study and comparative analysis methods, postgraduate cohorts from 2020 to 2023 （N=109） were selected as the post-reform samples and retrospectively compared with data from cohorts between 2015 and 2019. Empirical results showed a 98.6% increase in per capita SCI paper publications and a 16.58% increase in the professional match rate of employment, along with significantly enhanced professional commitment and international perspective. Furthermore, this model demonstrates potential for extension to undergraduate education and evolution through “Forensic Medicine + AI” interdisciplinary integration, providing a valuable reference for cultivating top innovative talents in applied disciplines in the new era.
ObjectiveTo construct a multimodal forensic pathology database based on artificial intelligence （AI） technology and explore methods for integrating pre-trained models into multimodal databases.MethodsA hybrid storage architecture consisting of MySQL, Redis and OSS was employed to manage desensitized multimodal data. Data entry was optimized using optical character recognition （OCR） and natural language processing （NLP） technologies. OCR performance was evaluated and optimized using cosine distance, character error rate （CER）, and word error rate （WER） to meet practical operational requirements. An intelligent retrieval model was developed using the ChatGLM3-6B model and retrieval-augmented generation （RAG） technology. Model performance was evaluated using ranking metrics including Precision@K, Recall@K, discounted cumulative gain （DCG）, and normalized discounted cumulative gain （NDCG）.ResultsThe database demonstrated satisfactory baseline performance. The response times were maintained within 150 ms for single-query condition and within 2 s for multiple-query conditions. The average disk read throughput reached 950 MB/s. In concurrent performance tests, the database achieved a maximum throughput of 1 200 queries per second （QPS）, meeting multimodal data management demands. OCR evaluation showed high recognition accuracy; for high-quality documents, the cosine distance, CER, and WER achieved 0.02, 1.5%, and 3.2%, respectively. Intelligent retrieval results indicated that Precision@K remained consistently high （0.69-1.00）, while NDCG values remained above 0.87 for all evaluations. When K=100, the NDCG surpassed 0.95 for all queries, meeting expected performance requirements.ConclusionThe multimodal forensic pathology database constructed in this study demonstrates good stability and operational efficiency and can meet the requirements of routine forensic practice for multimodal data storage, management, and analysis. The intelligent retrieval capabilities, based on pre-trained large language models （LLMs）, can be applied to conversational information retrieval from forensic reports and related documents, providing a novel approach to the management and analysis of multimodal databases.
The abuse of new psychoactive substances is severe globally. Among phenethylamine compounds, mescaline and its analogues are a class of substances that are often overlooked, yet their abuse has shown a gradual increase in recent years. This paper reviews mescaline and its analogues from three aspects: their basic information, pharmacological and toxicological properties, and detection methods. The aim is to provide insights for future research on mescaline and its analogues, as well as to provide references for forensic examination involving these substances.
1 案 例 1.1 简要案情 某年7月1日,萧某(男,32岁)、张某(女,32岁)夫妇在租住的单元房内被发现时已死亡,屋内物品杂乱,表面广泛沾染血迹,尸体及周围物品表面血量较多.根据调查监控及询访相关人员推断两人生前活动轨迹如下:前晚在外与朋友聚餐喝酒,结束后回到住处,直至单元楼电梯内两人状态均正常;当晚,同层及上层邻居听见男人哀号及凳子摔在墙壁上的声音.萧某有吸毒史.
ObjectiveTo evaluate the applicability of four commonly used RNA sequencing normalization methods in forensic age estimation, and to provide a reference for optimizing the accuracy and precision of age estimation models.MethodsPeripheral blood samples were collected from 147 unrelated Chinese Han individuals. After RNA sequencing, gene expression levels were normalized using four methods: counts per million （CPM）, fragments per kilobase of transcript per million mapped reads （FPKM）, transcripts per million （TPM）, and trimmed mean of M-values （TMM）. Spearman correlation analysis was used to screen age-related mRNAs. Three age estimation models were constructed using least absolute shrinkage and selection operator （LASSO）, support vector machine （SVM）, and extreme gradient boosting （XGBoost）, respectively, to compare the performance of the four normalization methods.ResultsThe four normalization methods screened different numbers of potential age-related markers. The TMM method screened the largest number of 2 912 markers. The number of potential markers screened was 2 897 and 1 481 for CPM and FPKM, respectively. The TPM method screened the fewest markers with the number of 338. Age estimation models constructed based on these markers exhibited mean absolute errors （MAE） ranging from 4.38 to 8.62 years in the training set and from 5.85 to 9.29 years in the test set. The TMM method performed the best among the three models, especially in the XGBoost model; it achieved an MAE of 4.38 years in the training set and 5.85 years in the test set for the XGBoost model.ConclusionDifferent normalization methods have a large impact on the construction of forensic age estimation models. The TMM normalization method can effectively improve prediction accuracy and is recommended as the preferred method for forensic age estimation.
ObjectiveTo explore the method of postmortem submersion interval （PMSI） estimation for bodies from the Jingzhou reach of the Yangtze River, utilizing an aquatic decomposition score.MethodsA total of 105 cases of known PMSI bodies recovered from the Jingzhou reach of the Yangtze River were collected from the cases handled by the Jingzhou Branch of Yangtze River Shipping Public Security Bureau from 2018 to 2022. Considering the average monthly temperature, these cases were categorized into summer and winter groups, with the threshold set at 20 ℃. For each case, the total aquatic decomposition score （TADS） was assessed using the aquatic decomposition score table. The relationship between TADS and PMSI was explored using statistical approach, and two regression equations were established respectively through the natural logarithmic transformation of PMSI. Six bodies recovered in 2023 from the Jingzhou reach of the Yangtze River were selected to verify the equations.ResultsIn both summer and winter groups, PMSI was positively correlated with TADS （R2>0.70）. The regression equation of summer group was TADS=5.117+4.825×ln（PMSI）, and for the winter group, it was TADS=3.191+3.967×ln（PMSI）.ConclusionThe decomposition degree of the bodies can be used to estimate PMSI combined with the feature of water temperature of the Jingzhou reach of the Yangtze River.
ObjectiveTo use uncertainty as an indicator to evaluate the main factors affecting data quality in the quantitative analysis of 12 volatile components in blood, including ethanol and toluene, and to assess the impact of different quality parameters, such as different hardware platforms on analytical results.MethodsTwo established headspace gas chromatography platforms were used following the method specified in Examination Methods for Ethanol, Methanol, n-Propanol, Acetone, Isopropanol and n-Butanol in Blood and Urine （GB/T 42430—2023） for analysis. According to the requirements of Guidance on Quantifying Uncertainty in Chemical Analysis （CNAS-GL006：2019） and Evaluation and Expression of Uncertainty in Measurement （JJF 1059.1—2012）, the uncertainty of the whole process of 12 volatile components quantitative analysis such as ethanol and toluene in blood was calculated. The differences of individual uncertainty components and the same uncertainty components across different hardware platforms were compared sequentially, and the results were verified by quantitative analysis of actual samples.ResultsThere was no significant difference in the uncertainty components of quantitative analysis of 12 volatile components, whether it was a hardware platform composed of domestic or imported instruments. Among them, the relative standard uncertainty of type A introduced by repeatability tests and analysts ranged from 2.81×10-3 to 9.28×10-3; the type B relative combined standard uncertainties introduced by the standard solution and internal standard solution were 5.65×10-3 to 1.15×10-2, 4.85×10-3, respectively, the type B relative standard uncertainties introduced by the calibration curve and equipment were 1.45×10-2 to 2.47×10-2 and 5.00×10-3, respectively. The overall relative combined standard uncertainty of each component ranged from 1.74×10-2 to 3.07×10-2.ConclusionIn the analysis of 12 volatile components in blood, including ethanol and toluene, calibration curve fitting is the dominant source of uncertainty. Reasonable parallel operation can effectively control the uncertainty. The selection of different hardware platforms and other quality parameters does not significantly affect the quantitative results of 12 volatile components in blood.
