Objective To explore the characteristics of incorrect opinions in re-examination cases,analyze the reasons,characteristics,and commonalities of different forensic opinions in the same injury case during re-examination,and provide references for similar case acceptance,forensic procedures,analysis and argumentation,and the application of relevant provisions.Methods A retrospective analysis was conducted on the re-examination cases of human injury degree accepted by the Forensic Judicial Appraisal Center of Guizhou Medical University and West China Forensic Medical Appraisal Center of Sichuan University from January 2020 to December 2024.Results Among the 81 collected re-examination cases of human injury degree,the injury types mainly included fractures,soft tissue injuries,tendon injuries,craniocerebral injuries,nerve injuries,joint injuries,and organ injuries.Of these,74 cases were entrusted by the public security system,and 72 cases used primary injuries as the basis for assessment.Seven cases had more than 3 appraisals and 74 cases had two appraisals,of which 53 cases had inconsistent opinions between the previous and current appraisals,including 29 cases with an upgraded injury grade and 24 cases with a downgraded injury grade.Conclusion When accepting re-examination cases,forensic experts need to choose relevant objective examination techniques in forensic clinical medicine,such as clinical imaging techniques,to determine whether imaging data serves as key evidence in the case,and seek assistance from experts in related fields when necessary.In the case acceptance stage,it is necessary to collect and review key assessment materials such as medical records,the first assessment opinion,and interrogation records.Forensic experts should also enhance their understanding of legal provisions,timing of assessment,their image-reading ability,and work to standardize the forensic assessment process.

Objective To construct an age prediction model for adolescents using radiomics from oral panoramic radiographs.Methods Panoramic radiographic images of 441 adolescent patients aged 11.00～13.99 years were imported into the open-source software 3D Slicer for segmentation of regions of interest(ROI).Python was used to extract all features from the ROIs of all patients.The patients were randomly divided into a training set and a test set at a ratio of 7∶3.Machine learning methods were applied to analyze the correlation between radiomics features and age characteristics to build the age prediction model.Results Out of 863 two-dimensional radiomics features,10 were selected.Three machine learning methods—support vector machine,random forest,and logistic regression—were used to train the model on the training set,and the best machine learning model was chosen.The performance of the machine learning models was evaluated using the Area Under Curve(AUC).In the test set,the AUCs for females were 0.795,0.830,and 0.795 for the three methods respectively,while for males,they were 0.830,0.864,and 0.846.Conclusion The radiomics model based on oral panoramic radiographs demonstrates good diagnostic efficacy and can be used for age prediction.

Duplicate judicial expertise has always been a difficult problem in the judicial circle.In some major,complex and difficult criminal cases,due to the objection to the appraisal conclusion,in order to ensure the impartiality and objectivity of the conclusion,the case handling organ often still needs to submit a re-appraisal.Based on the case,this paper puts forward some analysis opinions on the judicial expertise ideas of multiple cases for reference and discussion.Repeated forensic examinations have always been a challenge in the judicial system.In some major,complex,and difficult criminal cases,due to disagreements with previous assessment opinions,case-handling authorities often need to request re-evaluations to ensure the fairness and objectivity of assessment conclusions.This paper,combined with case examples,proposes several analytical perspectives on assessment approaches for cases requiring multiple evaluations,for reference and discussion among colleagues.

Objective To establish an online gel permeation chromatography-gas chromatography/mass spectrometry(GPC-GCMS)method for the determination of etomidate in blood.Methods Blood samples were extracted with acetonitrile,dehydrated with anhydrous sodium sulfate,purified with an online GPC system,and then analyzed by GCMS using large volume injection.The external standard curve method was used for quantification.Results The detection limit of etomidate was 0.002 μg/mL,with good linearity in the concentration range of 0.01～5 μg/mL and a correlation coefficient of 0.9992.The extraction recovery rates ranged between 90%and 120%.In an actual case,the content of etomidate detected in the blood sample was 0.024 μg/mL.Conclusion This method is fast,simple,accurate,and stable,providing a reliable basis for the determination of etomidate content in blood.

Forensic medical expert opinion is becoming more and more important in litigation activities,and the errors related to forensic medical expert opinion have also aroused the attention of relevant parties in legal proceedings.The concept of errors in forensic medical examination is controversial and often leads to the association of responsibility.Therefore,relevant studies do not agree to use the concept of errors in forensic medical examination,and the error rate derived from it is more likely to cause controversy.There may be deviations in all aspects of forensic medical examination,including instruments,equipment,technical methods,cognition,etc.These biases can have additive effects,and eventually the errors in forensic medical examination change from quantitative to qualitative,resulting in gross errors in forensic medical examination.It is of great significance to strengthen the evaluation of forensic medical technology and methods,strictly regulate the access of forensic medical technology and methods,and strengthen the quality control,training and cross-examination of forensic medical examination for reducing errors in forensic medical examination and improving the quality of opinions of forensic medical examination.

Objective To establish a supported liquid-liquid extraction-ultra-performance liquid chromatography-tandem mass spectrometry(SLE-UPLC-MS/MS)method for detecting methoxetamine(MXE,2-(3-methoxyphenyl)-2-(ethylamino)cyclohexanone)and 2-oxo-PCE(2-(ethylamino)-2-phenylcyclohexan-1-one)in blood.Methods Blood samples were extracted and purified using supported liquid-liquid extraction columns.An electrospray ionization source and multiple reaction monitoring mass spectrometry were used for qualitative and quantitative analysis of MXE and 2-oxo-PCE in blood samples.Results The limits of detection for MXE and 2-oxo-PCE in blood were 0.15 ng/mL and 0.17 ng/mL,respectively.Both compounds showed good linearity in the range of 0.5-500 ng/mL(r2>0.999),with recovery rates ranging from 90.7%to 98.4%.Conclusion The established qualitative and quantitative analytical method is simple,rapid,reliable,and highly sensitive,making it suitable for the detection and identification of MXE and 2-oxo-PCE in blood.

Objective Human facial morphology is an appearance phenotype with high heritability,high diversity,and complexity.Traditional facial morphological genetic analysis is mostly based on facial landmark measurements,using linear regression for genome-wide association studies,but this method extracts limited facial morphological feature information.This study established an extraction method for multidimensional facial representations and validated the correlation between 473 single-nucleotide polymorphisms(SNPs)previously reported to be significantly associated with facial features and facial representations in the Han Chinese population.Methods After acquiring facial 3D images,3D morphable face models and HR-net network were used to align and quantify the 3D images,obtaining high-density 3D facial point cloud data.After unsupervised clustering of the point cloud,principal component analysis was applied to reduce dimensionality and extract multidimensional morphological phenotypes for each facial region.Based on these multidimensional phenotypes,partial least squares regression(PLSR)and canonical correlation analysis(CCA)were used for genetic association analysis.Results A total of 10 SNPs were validated to be significantly associated with facial morphology in Han Chinese,of which 7 SNPs were validated by the PLSR method,2 SNPs were validated by the CCA method,and 1 SNP was validated by both methods.Conclusion Among the 10 significantly associated SNP sites,9 related facial morphological regions were consistent with previous reports in other populations,indicating that genes affecting complex facial morphology have cross-population effects.

Objective To establish a forensic age inference method based on age-related changes in maxillofacial CBCT imaging of Han population in North China.Methods CBCT imaging data of Han people aged 7～50 years were collected from September 2021 to September 2023.Mimics 17.0 software was used to perform 3D reconstruction on 480 cases that met the inclusion criteria(420 cases in the experimental group,60 cases in the blind test group,with a 50%male-to-female ratio)and obtain measured values for 16 indicators.The data were then statistically analyzed using SPSS 27.0 to identify age-related significant indicators and establish regression equations.Results Regression equations based on age-related significant indicators were established for different genders and age intervals.The accuracy of the equations decreased as the age interval increased.The blind test accuracy rates of regression equations for males across different age groups ranged between 62.6%and 80.6%,while for females,they ranged between 55.3%and 76.6%.Conclusion This study enriches maxillofacial skeletal data for Chinese population and establishes multivariate age inference regression equations based on significant indicators of age-related changes in maxillofacial CBCT,providing a new reference basis and inference method for forensic age assessment.

Objective To explore the value of dual-energy CT Bone Marrow Edema in quantitatively evaluating the timing of rib fracture evolution.Methods Sixty patients with thoracic trauma were scanned by dual-energy CT.Using CT Bone Marrow Edema technique,bone marrow CT values were standardized and quantified in both the Bone Marrow Edema area at the rib fracture site and in normal areas 1 cm on both sides of the fracture.The increments of standardized CT values for Bone Marrow Edema and VNCa were obtained for three stages of healing.The numerical variables were statistically described,and both the standardized CT value increments and VNCa standardized CT value increments were compared between the three stages and between each pair of stages.Diagnostic efficacy for stages with significant differences was evaluated using the area under the receiver operating characteristic(ROC)curve(AUC),and Cut-offvalues were calculated.Results There were significant differences in standardized CT value increments and VNCa standardized CT value increments across the three stages of Bone Marrow Edema(H=10.788,p=0.005;F=115.787,p=0.000).The standardized CT value increment of Bone Marrow Edema showed significant differences between the cartilaginous callus stage(fibrous callus stage)and the bony callus-remodeling stage(H=54.958,p=0.003),while the other pairwise comparisons showed no statistical significance(H=-25.603,p=0.183;H=29.354,p=0.113,respectively).However,the VNCa standardized CT value increments showed statistical significance across all three pairwise comparisons(all p=0.000).The ROC curve for differentiating the cartilaginous callus stage(fibrous callus stage)from the bony callus-remodeling stage using Bone Marrow Edema standardized CT value increment had an AUC of 0.652,with a Cut-offvalue of 81.575 Hu.The ROC curve for distinguishing the hematoma inflammation stage from the cartilaginous callus stage(fibrous callus stage)using VNCa standardized CT value increment had an AUC of 0.668,with a Cut-offvalue of 55.700 Hu.The ROC curve for differentiating the cartilaginous callus stage(fibrous callus stage)from the bony callus-remodeling stage using VNCa standardized CT value increment had an AUC of 0.905,with a Cut-offvalue of 37.625 Hu.Conclusion Dual-energy CT Bone Marrow Edema can quantitatively evaluate the timing of rib fracture evolution,and the differences in standardized CT value increments at different stages can provide a theoretical basis for forensic identification of fractures at different time periods.The Cut-offvalues of standardized CT value increments can,to some extent,predict the time stage of a fracture,providing quantitative evidence for forensic experts in the identification of rib fractures.

Objective To investigate the application of offline solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry for detecting four synthetic cannabinoids(5F-ADB,5F-MDMB-PICA,4F-MDMB-BUTINACA,and MDMB-4en-PINACA)and their marker metabolites in urban wastewater.Methods Samples were pre-treated using an Oasis PRiME HLB column(60 mg,3CC)and analyzed by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry.The mobile phases consisted of 0.02%formic acid-2 mmol/L ammonium formate aqueous solution and acetonitrile solution,with a WATERS ACQUITY UPLCHSS T3 column.Analysis was conducted in positive ionization mode of the ESI ion source,combining multiple reaction monitoring(MRM),information-dependent acquisition(IDA),and enhanced product ion(EPI)scanning modes for qualitative and quantitative analysis of the eight target compounds.Results Good linearity was observed for 4F-MDMB-BUTINACA-M,5F-ADB,5F-ADB-M,and 5F-MDMB-PICA in the concentration range of 1～250 ng/L;for MDMB-4en-PINACA in the range of 5～250 ng/L;and for 4F-MDMB-BUTINACA,5F-MDMB-PICA-M,and 4F-MDMB-BUTINACA-M in the range of 1～500 ng/L.The recovery rates of samples spiked with different concentrations of the eight target compounds ranged from 87.68%to 104.68%,with matrix effects between 88.61%and 112.78%.Both intra-day and inter-day precision were less than 5%.Conclusion The established method demonstrates good accuracy and reproducibility,making it suitable for qualitative and quantitative detection of four synthetic cannabinoids and their metabolites in urban wastewater.