法医学杂志最新文献

Objectives: To establish a chromatography-tandem mass spectrometry method for detecting chlorfenapyr and its metabolite tralopyril in blood, and to investigate the toxicokinetics in rats.

Methods: Chlorfenapyr (8 mg/kg) was administered orally to rats, and blood samples were collected from rats' canthus vein at 5 min, 15 min, 30 min, 1 h, 3 h, 6 h, 12 h, 24 h and 48 h after administration. The blood samples were extracted using 100 μL of 5% formic acid solution and 400 μL of acetonitrile. Chlorfenapyr was qualitatively and quantitatively detected by triple quadrupole gas chromatography-tandem mass spectrometry (GC-MS/MS) and tralopyril was detected by triple quadrupole liquid chromatography-tandem mass spectrometry (LC-MS/MS). The DAS 3.0 software was used to fit the toxicokinetic equations and calculate the toxicokinetic parameters.

Results: Chlorfenapyr was detectable from 5 min to 24 h with a peak time of 1 h. Tralopyril was detectable from 15 min to 48 h with a peak time of 3 h. The toxicokinetic process of chlorfenapyr in rat blood conformed to a first-order absorption one-compartment open model, with the toxicokinetic equation described as C=e^-0.265t-e^-0.175t. Tralopyril conformed to the first-order absorption three-compartment model, and the toxicokinetic equation was C=47 361.069e^-2.209t-35 404.962e^-1.486t+11 956.363e^-0.512t. In the equations, C stands for the concentration of the target substance in the blood, e is the natural constant (≈2.718 28), and t stands for time.

Conclusions: This study optimized the detection method for chlorfenapyr and its metabolite tralopyril in blood. The toxicokinetic equations and parameters of chlorfenapyr and tralopyril can provide a reference for the estimation of oral intake time of chlorfenapyr.

The objective assessment of hearing loss is one of the critical components in forensic clinical research. Auditory brainstem response (ABR) is an important method for objectively assessing hearing levels. It is divided into various types based on different stimulus signals, each with its own characteristics and applications. Among them, narrow-band Chirp ABR, due to its frequency specificity, fulfills the basic requirements for objective assessment of forensic audiology, promising to be an important method of objective hearing assessment in forensic medicine. This article reviews the development history, characteristics and clinical applications of Chirp ABR, and envisions its application prospects in forensic auditory identification.

New psychoactive substances (NPS) have the characteristics of rapid turnover, wide varieties, and high abuse potential. It has become a major threat to global public safety. Currently, the forensic identification of NPS faces certain challenges in detection methods for effectiveness, sensitivity, accuracy and resistance to matrix interference. Novel functional materials (NFM), with their high specific surface area, designability, specific recognition capability and signal amplification effects, provide a new path for advancing rapid detection techniques for NPS. This paper systematically reviews the innovative applications of NFM in the rapid detection of NPS over the past decade. By summarizing and analyzing the research and applications of NFM in laboratory detection and on-site rapid screening, it outlines the characteristics and advantages of different types of materials. Combined with the development trends of NFM in intelligent material design, interdisciplinary integration and portable integrated devices, it provides theoretical references for the development of rapid detection methods for NPS, which is conducive to improving the rapid detection ability of NPS in "anti-drug combat".

Objectives: To obtain differential spectral characteristics of etomidate and its structural analogues, and to establish a rapid identification method using surface-enhanced Raman spectroscopy (SERS) combined with machine learning algorithms for distinguishing etomidate and its analogues.

Methods: Silver nanoparticles (AgNPs) were used as the SERS substrate to collect SERS spectra of etomidate, metomidate, propoxate, and isopropoxate at two concentrations of 1×10^-4 and 1×10^-5 mol/L. SERS spectra were also obtained from blood and urine samples containing 1×10^-5 mol/L of etomidate, metomidate, propoxate, and isopropoxate, as well as from confiscated e-cigarette oil containing etomidate. Uniform manifold approximation and projection (UMAP) was employed for nonlinear dimensiona-lity reduction and visualization, and a classification model based on the XGBoost algorithm was constructed to enable discriminant analysis of these four structurally highly similar compounds.

Results: Minor characteristic peak shifts (5-3 cm^-1) were identified in the range of 1 398-811 cm^-1. Qualitative identification of the compounds in serum, urine and e-cigarette oil samples was achieved without pretreatment. After UMAP dimensionality reduction, distinct clustering separation among different substances was observed. The XGBoost model achieved 100% classification accuracy on the test set. Feature weight analysis revealed that C-N stretching vibration (841 cm^-1), C=O stretching vibration (1 367 cm^-1), and C-O-C asymmetric vibration (1 049 cm^-1) were the key spectral bands for discrimination.

Conclusions: The combination of SERS and machine learning can effectively amplify subtle differences in molecular structures, enabling rapid and accurate identification of etomidate and its analogues. This approach is suitable for on-site rapid screening in forensic toxicology.