Objective To study the plasma metabolomics of mice poisoned by different dosage of the combination of diazepam and ethanol,and to reveal the toxicological mechanisms of combined poisoning of diazepam and ethanol.Methods Female Kunming mice were randomly divided into blank group,single and combined poisoning group(n=6),Based on the LD50 of diazepam co-administered with graded ethanol doses,mice in the single-drug and combined groups received oral gavage at 1/2,1,and 2 × LD50.Retro-orbital blood samples(～500 μL)were collected within 24 hours post-administration and analyzed by UPLC-QE-MS technology.Principal component analysis and orthogonal partial least squares discriminant analysis were used to identify differential metabolites and associated metabolic pathways.Results A total of 387 differential metabolites were identified in the combined poisoning group of diazepam and ethanol implicating the key pathways including tryptophan metabolism,phenylalanine metabolism,arginine and proline metabolism,Glycerophospholipid metabolism,phenylalanine,tyrosine and tryptophan biosynthesis.Conclusion Combined diazepam and ethanol poisoning exerts significant systemic effects by disrupting neurotransmitters conduction,exacerbating oxidative stress response and dysregulating energy metabolism.

Objective To establish a high-throughput non-targeted screening and prioritization method for emerging pollutants(EPs)in sewage using direct injection high-resolution mass spectrometry(HRMS).Methods The sewage samples were filtered by membrane filter and directly subjected to the liquid chromatography-time-of-flight mass spectrometer based on a method modified from our previous study.A C18 chromatographic column was applied for a gradient elution separation,and accurate mass and mass spectral fragment information were obtained through the MS full scan mode and MS/MS DIA data collection mode.After peak detection and alignment,the features from the raw data through open source software MZmine 3,and then high-throughput screening strategies such as MassBank and PubChem databases were used for compound annotation.Finally,the candidate features were confirmed with chemical standards by compared their retention time and mass spectrum fragmentation ion peaks.Results 13 EPs were identified,including 7 industrial chemicals,4 pharmaceuticals,1 pesticide and 1 metabolite.High detection rates were observed for metformin(86.2％),2-hydroxybenzothiazole(79.3％),1,2-benzisothiazole-3-one(72.4％),and 1,2-benzisothiazole-3-one(72.4％).The quantitative concentration range of EPs was 1.37～19.05 ng/mL,with the high concentrations observed for melamine(19.05 ng/mL)and furosemide(18.49 ng/mL).Ecological risk assessment identified 1,2-benzisothiazol-3-one,4-aminoacetophenone,creatinine,2-hydroxybenzothiazole,and furosemide as key pollutants.Conclusion This direct injection coupled with HRMS workflow enables efficient non-targeted screening and prioritization of emerging EPs in sewage samples,highlighting five ecotoxicologically critical EPs.The methodology enhances environmental monitoring capabilities and provide critical technical support for interdisciplinary research such as environmental forensics and health risk assessment.

Objective To establish a sensitive,accurate and rapid detection method for 10 drugs and metabolites in hair with triple quadrupole tandem mass spectrometry,addressing the identification of drugs in real hair samples.Methods After cryogenic grinding and ultrasonic extraction,hair was separated by Restek Allure PFPP column(100 mm × 2.1 mm,5 μm).The mobile phase A was 20 mmol/L ammonium acetate,0.1％formic acid and 5％acetonitrile aqueous solution.The mobile phase B was acetonitrile.An electrospray ionization source was used for data acquisition in scheduled MRM mode.Results The method showed good linearity for all analytes within the validated range(R2＞0.995),with the limits of detection ranging from 0.5 to 6 pg/mg,the limits of quantification ranging from 2.5 to 10 pg/mg.Accuracy ranged from 89.1％to 114.6％,with intra-day precision ranging from 0.2％to 11.7％,inter-day precision ranging from 4.0％to 15.8％.the matrix effects ranging from 89.4％to 118.4％,the recoveries ranging from 63.6％～112.1％.Totally 20 cases were detected positive in 196 actual hair samples.Conclusion The time-scheduled scanning method exhibits high stability and sensitivity,enabling high-throughput detection,and is suitable for forensic toxicology laboratories to identify drugs in hair.

Objective To compare regression models for age estimation constructed based on the Pulp Dentinal Index(PDI)of the first permanent molars and explore a more accurate and applicable novel method.Methods A total of 900 Cone Beam Computed Tomography(CBCT)image datasets from adult Han Chinese individuals(455 males and 445 females)residing in Sichuan province,China,were collected from the Affiliated Hospital of North Sichuan Medical College.The PDI of the first permanent molars were measured using Mimics software.Regression analysis was performed with age as the dependent variable and PDI as the independent variable to establish and validate the optimal mathematical model for age estimation.Results Strong correlations were observed between the PDI of all four first permanent molars and age,with the correlation being stronger for maxillary teeth compared to mandibular teeth,and the highest correlation found in the left maxillary first molar among females(r=0.881).Significant differences in PDI were identified between maxillary and mandibular positions as well as between genders(P＜0.05),but not between left and right positions(P＞0.05).Among the 11 mathematical models constructed,the cubic regression model outperformed others,with the left maxillary first molar model demonstrating the best performance(Age=73.93-70.79x-68.75x2+94.33x3),yielding a mean absolute error(MAE)of 4.88 years.Conclusion Among the 11 regression models constructed in this study based on CBCT-measured PDI values of the first permanent molars,the cubic regression model exhibited the highest accuracy,with an MAE of 4.88 years.

Objective To analyze and compare the efficacy of DNA barcode,i.e.,Cytochrome b(Cytb)and 12S ribosomal RNA(12S rRNA)gene sequences,in the species identification of wildlife.Methods DNA extraction,quantification,PCR amplification of Cytb and 12S rRNA gene fragments,Sanger sequencing,and sequence alignment analysis were performed on ten wildlife samples.Results Both gene fragments were successfully amplified in six samples,while Cytb alone was successfully amplified in 1 sample,and 12S rRNA alone in 3 samples.Sequence analysis indicated that Cytb enabled species-level identification for 6 samples(Gallinula chloropus,Streptopelia orientalis,Phasianus colchicus,Falco naumanni,Myiopsitta monachus and Lynx lynx)and genus-level identification for 1 sample(Lepus).In contrast,12S rRNA achieved species-level identificaggion for 8 samples(Gallinula chloropus,Lepus sinensis,Phasianus colchicus,Myiopsitta monachus,Muntiacus reevesi,Macaca mulatta and Lynx lynx),representing seven species,and genus-level identification for 1 sample(Falco).However,by combining Cytb and 12S rRNA,all samples could be identified to the species level.Conclusion When applying DNA barcodes to wildlife identification,the Cytb and 12S rRNA gene regions analyzed here can effectively identify common species such as Gallinula chloropus and Streptopelia orientalis,but face difficulties in distinguishing closely related species within the same genus.Therefore,when conducting wildlife species identification,it is recommended to use two or more DNA barcode markers.

Objective To establish a 103-plex InDel-SNP composite marker amplification system based on Ion Torrent PGM/S5 sequencing platform targeting fragment length less than 175bp,providing an efficient analytical tool for forensic individual identification and paternity identification.Methods Using the human genome GRCh38 as the reference sequence,InDel-SNP composite marker loci suitable for Chinese population were screened from 22 pairs of autosomes and sex chromosomes by using dbSNP database with East Asian population as the target population.Population genetic data of 267 unrelated individuals of Han nationality in Shandong province were investigated,and genetic relationship was verified using 16 real triplet families.Results The 103-plex InDel-SNP composite marker detection system developed in this study,based on the second-generation sequencing platform,exhibits notable features including high sensitivity,excellent stability,strong specificity,and wide applicability to conventional test materials.It effectively enables the determination of typing results for degraded and mixed samples.Conclusion All 16 parent triplet pairs demonstrated adherence to Mendelian inheritance law without any observed allelic dropout or mutation.This detection system holds significant value for forensic individual identification and paternity testing.

Errors in forensic medical examination have been reported both domestically and internationally,leading to criminal wrongful convictions.As the ancients said,"No one is a saint without faults".No one is perfect,and people will make mistakes.Errors in forensic medical examination are an objective phenomenon,and we should have a correct understanding of them.There are many reasons that can cause errors in forensic medical examination,including the eligibility,competence and cognitive bias of forensic medical examiner.Errors in forensic medical examination are subjective,multidimensional,and relative.The evaluation criteria for errors in forensic medical examination should be based on three aspects:errors related to human behavior,errors caused by technical errors involving instruments,and errors related to more fundamental methodological factors inherent in the relevant field.A quality management system for forensic medical examination should be established,and a fault-tolerant mechanism for actively detecting,reporting,and correcting errors should be established.Training for forensic medical examiners should be strengthened,and a forensic communication mechanism between forensic medical examiner and relevant parties should be established to minimize the occurrence of errors in forensic medical examination.

Through a comprehensive analysis of four cases involving repeated forensic clinical identification on the degree of human injury,disability grade,causal relationship of injury and disease,medical damage liability dispute,the reasons for the emergence of different appraisal opinions are explored.According to the reasons for the disputed conclusion,the deviation or error of the appraisal opinion can be classified in a variety of ways.Among them,the inherent limitations of theories and methods used as appraisal bases,the lack of operational skills or cognitive ability of appraisers,the unclear provisions of appraisal standards and the lack of adequacy and validity in the process of analysis and reasoning are the key reasons for the deviation or error of appraisal opinions.In light of these findings,it is necessary to strengthen the review of expert opinions in judicial practice and form a powerful error correction mechanism.

There are quality deficiencies,disagreements,and even errors in forensic medical examination and identification,especially in fields that rely mainly on professional judgment,where subjective factors heighten vulnerability to,quality issues.In this situation,the most effective way to reduce quality defects and errors is to construct and apply systematic targeted quality control methods reasonably.This study focuses on the field of forensic medical examination and identification,which is mainly based on professional judgment.By summarizing the quality control methods provided in international standards and the existing experience and research results in the field of forensic science,it provides quality control methods for personnel competency,cognitive bias,standardized documentation,and expression of opinions.It also discusses key considerations for carrying out quality control activities,providing reference for preventing quality problems and opinion errors in forensic medical examination and dentification activities.

Objective To investigate a rapid detection method for compressed Nitrous oxide(N2O).Methods The GC-MS system was employed under conventional chromatographic conditions(without replacing standard columns or utilizing headspace sampling)by directly injecting a small gas sample for analysis.N2O identification was performed via NIST spectral library matching,while qualitative and quantitative purity assessments were achieved by monitoring the relative abundance variation of the characteristic fragment ion m/z 30 to eliminate CO2 interference.Results The fragment ion m/z 30 demonstrated specificity for N2O identification.A linear correlation was observed between the peak area of m/z 30 and N2O purity(y=22.741x-1.4565,R2=0.912 6),enabling quantitative purity determination.Additionally,the abundance of m/z30 exhibited a correlation with N2O in CO2 mixtures(y=0.7787x-0.0387,R2=0.722 2).Conclusion Conventional N2O identification typically requires dedicated GC-MS systems,gas-specific chromatographic columns,and headspace sampling.This study successfully utilized routine chromatographic conditions for organic toxicant screening to achieve rapid N2O analysis.The proposed method holds practical significance for compressed N2O identification in forensic and analytical applications.