The Progression of Postmortem Biochemistry Analysis in Forensic Discrimination of Cause of Death / 中山大学学报(医学科学版)

The discrimination of the cause of death is an important part in forensic medicine. With the advantages of simple operation， high test efficiency， and easy sensitivity to the death mechanism of the deceased， postmortem biochemistry analysis has become a significant auxiliary analysis method for discrimination of the cause of death. In this paper， we discuss the development status， advantages and current problems of postmortem biochemical analysis， and then describe the application prospect of postmortem biochemistry in the discrimination of the cause of death by posing feasible solutions， so that to provide an idea for this research.

Continuing education for forensic medical analysis of the constitutional appeals in Costa Rica / Formação acadêmica contínua para análise médico forense de recursos de amparo na Costa Rica / Formación académica continua para el análisis médico forense de recursos de amparo en Costa Rica

Introduction: Judicially demanding the right to health involves different elements and can lead to changes in continuing education programs. The current trend is to follow this pathway to access low-frequency and high-cost medications. In addition, the Constitutional Court of Costa Rica requests a technical concept from forensic doctors. Objective: To raise the need for continuous updating in specific theoretical-practical academic knowledge required by forensic doctors to guarantee the right to health services. Reflection: The training of forensic medical doctors is focused on evidence and encourages continuous education. Nevertheless, a commitment is necessary in continuing medical education programs such as literature search strategies, critical assessment of evidence, and academic practices that incorporate particular circumstances comparing them with scientific studies. These programs must take into account prevalent medications and pathologies as well as technical-scientific factors that differ in each service provider. Conclusion: A continuing education program about the interpretation and assessment of scientific evidence for proper decision making on health issues would allow medical doctors to judge existing health problems and choose a medication that is the most beneficial for a patient.

Introducción: La judicialización del derecho a la salud involucra a distintos actores y puede propiciar cambios en programas de educación continua; pues la tendencia actual es recurrir a esta vía para acceder a medicamentos de baja frecuencia y alto costo. Adicionalmente, en Costa Rica la Sala Constitucional solicita el criterio técnico a médicos forenses. Objetivo: Plantear la necesidad de actualización continua en conocimientos académicos teóricos-prácticos específicos que requiere el médico forense para garantizar el derecho a los servicios de salud. Reflexión: El médico forense cuenta con formación basada en evidencias y se incentiva su formación continua, sin embargo, es necesario un compromiso con los programas de educación médica continua: en estrategias de búsqueda de literatura, valoración crítica de la evidencia encontrada y práctica académica que incorpore las circunstancias particulares, comparándolo con los resultados de estudios científicos; tomando en cuenta medicamentos y patologías prevalentes y los factores técnico-científicos de divergencia entre los prestadores de servicios. Conclusión: Un programa de formación continua sobre interpretación y valoración de la evidencia científica para la toma de decisiones en salud, permitiría a estos especialistas responder con mejor criterio si un medicamento es el tratamiento más beneficioso para un paciente debido a sus problemas de salud.

Introdução: A judicialização do direito à saúde envolve diferentes atores e pode promover mudanças nos programas de educação continuada; porque a tendência atual é recorrer a esta via para ter acesso a medicamentos de baixa frequência e alto custo. Além disso, na Costa Rica, o Tribunal Constitucional solicita critérios técnicos aos médicos forenses. Objetivo: Levantar a necessidade de atualização contínua em conhecimentos acadêmicos teórico-práticos específicos que o médico forense necessita para garantir o direito aos serviços de saúde. Reflexão: O médico forense tem formação baseada em evidências e sua formação continuada é incentivada, porém é necessário o compromisso com programas de educação médica continuada: em estratégias de busca bibliográfica, avaliação crítica das evidências encontradas e prática acadêmica que incorpore as circunstâncias particulares , comparando-o com resultados de estudos científicos; levando em consideração medicamentos e patologias prevalentes e fatores técnico-científicos de divergência entre prestadores de serviços. Conclusão: Um programa de formação contínua sobre interpretação e avaliação de evidências científicas para a tomada de decisões em saúde, permitiria a estes especialistas responder com melhores critérios se um medicamento é o tratamento mais benéfico para um paciente devido aos seus problemas de saúde.

Análisis de los criterios de valoración utilizados para casos de pensión vitalicia en un niño con Autismo. Reporte de un caso con enfoque médico legal / Analysis of the evaluation criteria used for life pension cases in a child with Autism. Report of a case with a forensic medical approach

El Trastorno del Espectro Autista (TEA), es trastorno del neurodesarrollo que se caracteriza por algún grado de dificultad en la interacción social y la comunicación, que comienza en el periodo de desarrollo temprano, y se clasifica según el grado de severidad en grado 1, 2 y 3, según lo establecido en el DSM-5. Dicho Trastorno se encuentra abarcado por la Ley 7125 de Pensión Vitalicia para Personas con Parálisis Profunda, y su reforma 8769. Con el objetivo de analizar los criterios establecidos para la valoración de estos procesos, se presenta el caso de una persona masculina de 6 años con diagnóstico de TEA, de quien se interpuso demanda para ser tomado en cuenta dentro de dicha Ley. En el mismo y tras el análisis respectivo, de acuerdo con los datos de la literatura científica actualizada, y de los criterios establecidos, se pudo constatar que si calificaba según lo indicado en la Ley 7125.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that is characterized by some degree of difficulty in social interaction and communication, which begins in the early development period, and is classified according to the degree of severity in grade 1, 2 and 3, as established in the DSM-5. Said Disorder is covered by Law 7125 of Life Pension for people with deep cerebral palsy, and its reform 8769. In order to analyze the criteria established for the assessment of these processes, the case of a 6-year-old male person with diagnosis of ASD, of whom a lawsuit was filed to be taken into account within said Law. In it and after the respective analysis, according to the data of the updated scientific literature, and the established criteria, it was possible to verify that if qualified as indicated in Law 7125.

Análisis médico legal de la fractura de órbita por "blow out" o estallido: reporte de caso / Medical-legal analysis of blow out fracture of the orbit: case report

La fractura orbitaria por estallido o fractura en "blow out" es una de las fracturas más comunes a nivel facial por lo que su importancia reside en saber identificarlas por el enmascaramiento clínico que podría o no, estar presente. Es de vital importancia complementar la valoración clínica con estudios de imagenología que confirmen las sospechas clínicas. De no hacerlo si el paciente no consulta a un servicio médico quirúrgico la pérdida de la capacidad funcional o la debilitación persistente en la salud ocasionada por la fractura no podrá ser validada en un Dictamen Médico Legal de Secuelas.

The orbital blow out fracture is one of the most common fractures at facial level, so its importance lies in knowing how to identify them due to the clinical masking that may or may not be present. It is of vital importance to complement the clinical evaluation with imaging studies to confirm the clinical suspicions. Otherwise, if the patient does not consult a surgical medical service, the loss of functional capacity or the persistent debilitation in health caused by the fracture cannot be validated in a Forensic Medical Report of Sequelae.

Valor añadido de las interconsultas con otras especialidades médicas en el peritaje médico legal / The added value of interconsultations with other medical specialties in forensic expertise

Resumen La pericia médico legal es compleja y su resultado debe estar fundamentado considerando el análisis de varios elementos de juicio, como: la historia médico legal, el examen físico, el análisis de los expedientes médicos, estudios de laboratorio e imágenes radiológicas y en algunos casos, inclusive una interconsulta realizada a otros especialistas. El perito médico forense utiliza la interconsulta a especialistas para solventar la brecha que existe entre el conocimiento profesional y específico que posee una especialidad y una interrogante médico legal, por lo que difiere en gran manera en el objetivo, formulación y resultado de una interconsulta médica hospitalaria. Por esta razón, esta reflexión pretende contextualizar la importancia del recurso de interconsulta médica dentro del análisis pericial forense, que es un tema poco conocido en la medicina asistencial, y justificar la relevancia de la educación médica continua para los médicos especialistas que realizan las interconsultas y para quienes las solicitan.

Abstract The medical-legal report is complex and its result must be based on the análisis of various elements of judgment, such as: the legal medical history, the physical examination, the analysis of the medical records, laboratory and radiological images and in some cases, even an interconsultation with other specialists. The forensic medical expert uses the interconsultation with specialists to solve the gap that exists between the professional and specific knowledge that a specialty has and a legal medical question, for which it differs greatly in the objective, formulation and result of a hospital medical interconsultation. For this reason, this reflection aims to contextualize the importance of the resource of medical interconsultation within the forensic expert analysis, which is a little-known topic in healthcare medicine, and to justify the relevance of continuing medical education for medical specialists who perform interconsultations and for those who request them.

Exploration and Practice of the "One Combination, Two Highlights, Three Combinations, Four in One" Innovative Talents Training Mode in Forensic Medicine / 法医学杂志

Talent is one of the basic and strategic supports for building a modern socialist country in all aspects. Since the 1980s, the establishment of forensic medicine major and the cultivation of innovative talents in forensic medicine have become hot topics in higher education in forensic medicine. Over the past 43 years, the forensic medicine team of Shanxi Medical University has adhered to the joint education of public security and colleges, and made collaborative innovation, forming a training mode of "One Combination, Two Highlights, Three Combinations, Four in One" for innovative talents in forensic medicine. It has carried out "5+3/X" integrated reform, and formed a relatively complete talent training innovation mode and management system in teaching, scientific research, identification, major, discipline, team, platform and cultural construction. It has made a historic contribution to China's higher forensic education, accumulated valuable experience for the construction of first-class major and first-class discipline of forensic medicine, and provided strong support for the construction of the national new forensic talent training system. The popularization of this training mode is conducive to the rapid and sustainable development of forensic science, and provides more excellent forensic talents for national building, regional social development and the discipline construction of forensic science.

Research Progress on Biological Matrix Reference Materials in Forensic Toxicology / 法医学杂志

Biological matrix reference material is a reference material that combines the target material with the biological matrix. The biological matrix reference material has higher consistency with the authentic specimens in forensic toxicology, and its application has a positive effect on improving the accuracy of test results. This paper reviews the research on the matrix reference materials corresponding to three common biological test materials (blood, urine and hair). In order to provide reference for the development and application of biological matrix reference materials in forensic toxicology, this paper mainly introduces the research progress of preparation technology of biological matrix reference materials and some existing products and their parameters evaluation.

Progress in the Application of Magnetic Nanoparticles in Forensic Trace Analysis / 法医学杂志

Given the complexity of biological samples and the trace nature of target materials in forensic trace analysis, a simple and effective method is needed to obtain sufficient target materials from complex substrates. Magnetic nanoparticles (MNPs) have shown a wide range of application value in many research fields, such as biomedicine, drug delivery and separation, due to their unique superparamagnetic properties, stable physical and chemical properties, biocompatibility, small size, high specific surface area and other characteristics. To apply MNPs in the pretreatment of forensic materials, maximize the extraction rate of the target materials, and minimize interference factors to meet the requirements of trace analysis of the target materials, this paper reviews the application of MNPs in the fields of forensic toxicological analysis, environmental forensic science, trace evidence analysis and criminal investigation in recent years, and provides research ideas for the application of MNPs in forensic trace analysis.

Analysis of Forty-Two Psychoactive Substances in a Single Hair by Micro-Segmental Technique / 法医学杂志

OBJECTIVES@#To establish an LC-MS/MS method based on single hair micro-segmental technique, and verify the detection of 42 psychoactive substances in 0.4 mm hair segments.@*METHODS@#Each piece of single hair was cut into 0.4 mm segments and extracted by sonication and the segments were immersed in dithiothreitol-containing extraction medium. Mobile phase A was the aqueous solution containing 20 mmol/L ammonium acetate, 0.1% formic acid, and 5% acetonitrile. Mobile phase B was acetonitrile. An electrospray ionization source in positive ion mode was used for data acquisition in multiple reaction monitoring (MRM) mode.@*RESULTS@#The 42 psychoactive substances in hair had a good linear relationship within their respective linear ranges (r>0.99), the limits of detection were 0.2-10 pg/mm, the limits of quantification were 0.5-20 pg/mm, the intra-day and inter-day precisions were 1.5%-12.7%, the intra-day and inter-day accuracies were 86.5%-109.2%, the recovery rates were 68.1%-98.2%, and the matrix effects were 71.3%-111.7%. The method was applied to hair samples collected from one volunteer at 28 d after a single dose of zolpidem, with zolpidem detected in 5 hairs was 1.08-1.60 cm near the root tip, and the concentration range was 0.62-20.5 pg/mm.@*CONCLUSIONS@#The micro-segmental technique of single hair analysis can be applied to the investigation of drug-facilitated sexual assault cases.

Structural Analysis and Characterization of 4-F-α-PVP Analog 4-F-3-Methyl-α- PVP Hydrochloride / 法医学杂志

OBJECTIVES@#To identify 1-(4-fluorophenyl)-2-(1-pyrrolidinyl) pentan-1-one (4-F-α-PVP) analog 1-(4-fluoro-3-methyl phenyl)-2-(1-pyrrolidinyl) pentan-1-one (4-F-3-Methyl-α-PVP) hydrochloride without reference substance.@*METHODS@#The direct-injection electron ionization-mass spectrometry (EI-MS), GC-MS, electrospray ionization-high resolution mass spectrometry (ESI-HRMS), ultra-high performance liquid chromatography-high resolution tandem mass spectrometry (UPLC-HRMS/MS), nuclear magnetic resonance (NMR), ion chromatography and Fourier transform infrared spectroscopy (FTIR) were integrated utilized to achieve the structural analysis and characterization of the unknown compound in the sample, and the cleavage mechanism of the fragment ions was deduced by EI-MS and UPLC-HRMS/MS.@*RESULTS@#By analyzing the direct-injection EI-MS, GC-MS, ESI-HRMS and UPLC-HRMS/MS of the compound in the samples, it was concluded that the unknown compound was a structural analog of 4-F-α-PVP, possibly with one more methyl group in the benzene ring. According to the analysis results of 1H-NMR and 13C-NMR, it was further proved that the methyl group is located at the 3-position of the benzene ring. Since the actual number of hydrogen in 1H-NMR analysis was one more than 4-F-3-Methyl-α-PVP neutral molecule, it was inferred that the compound existed in the form of salt. Ion chromatography analysis results showed that the compound contained chlorine anion (content 11.14%-11.16%), with the structural analysis of main functional group information by FTIR, the unknown compound was finally determined to be 4-F-3-Methyl-α-PVP hydrochloride.@*CONCLUSIONS@#A comprehensive method using EI-MS, GC-MS, ESI-HRMS, UPLC-HRMS/MS, NMR, ion chromatography and FTIR to identify 4-F-3-Methyl-α-PVP hydrochloride in samples is established, which will be helpful for the forensic science laboratory to identify this compound or other analog compounds.

Correlation between Elbow Flexor Muscle Strength and Needle Electromyography Parameters after Musculocutaneous Nerve Injury / 法医学杂志

OBJECTIVES@#To explore the changes of elbow flexor muscle strength after musculocutaneous nerve injury and its correlation with needle electromyography (nEMG) parameters.@*METHODS@#Thirty cases of elbow flexor weakness caused by unilateral brachial plexus injury (involving musculocutaneous nerve) were collected. The elbow flexor muscle strength was evaluated by manual muscle test (MMT) based on Lovett Scale. All subjects were divided into Group A (grade 1 and grade 2, 16 cases) and Group B (grade 3 and grade 4, 14 cases) according to their elbow flexor muscle strength of injured side. The biceps brachii of the injured side and the healthy side were examined by nEMG. The latency and amplitude of the compound muscle action potential (CMAP) were recorded. The type of recruitment response, the mean number of turns and the mean amplitude of recruitment potential were recorded when the subjects performed maximal voluntary contraction. The quantitative elbow flexor muscle strength was measured by portable microFET 2 Manual Muscle Tester. The percentage of residual elbow flexor muscle strength (the ratio of quantitative muscle strength of the injured side to the healthy side) was calculated. The differences of nEMG parameters, quantitative muscle strength and residual elbow flexor muscle strength between the two groups and between the injured side and the healthy side were compared. The correlation between elbow flexor manual muscle strength classification, quantitative muscle strength and nEMG parameters was analyzed.@*RESULTS@#After musculocutaneous nerve injury, the percentage of residual elbow flexor muscle strength in Group B was 23.43% and that in Group A was 4.13%. Elbow flexor manual muscle strength classification was significantly correlated with the type of recruitment response, and the correlation coefficient was 0.886 (P<0.05). The quantitative elbow flexor muscle strength was correlated with the latency and amplitude of CMAP, the mean number of turns and the mean amplitude of recruitment potential, and the correlation coefficients were -0.528, 0.588, 0.465 and 0.426 (P<0.05), respectively.@*CONCLUSIONS@#The percentage of residual elbow flexor muscle strength can be used as the basis of muscle strength classification, and the comprehensive application of nEMG parameters can be used to infer quantitative elbow flexor muscle strength.

Causes of death in patients with autoimmune and rheumatic diseases—a 16-year autopsy-based study

ABSTRACT Introduction the autopsy is an essential medical procedure; however, its use has declined over the decades. In autoimmune and rheumatological diseases, anatomical and microscopic diagnosis is critical to diagnose of the cause of death. For this reason, our objective is to describe the cause of death in patients diagnosed with autoimmune and rheumatic diseases who underwent an autopsy in a Pathology reference center in Colombia. Materials and methods a retrospective and descriptive study of autopsy reports. Results between January 2004 and December 2019, 47 autopsies of patients with autoimmune and rheumatological diseases were performed. Systemic lupus erythematosus and rheumatoid arthritis were the most common diseases. The leading cause of death was related to infections, being opportunistic infections in the majority of the cases. Conclusions our autopsy-based study was focused on patients with autoimmune and rheumatological conditions. Infections are the leading cause of death, particularly opportunistic infections, diagnosed mainly by microscopy. Thus, the autopsy should continue to be considered the "gold standard" to determine the cause of death in this population.

Identification of Human Body Fluid Stains and Non-Biological Stains by Three-Dimensional Fluorescence Spectroscopy / 法医学杂志

OBJECTIVES@#To establish a rapid and nondestructive identification method for human body fluid stains and non-biological stains using three-dimensional fluorescence spectroscopy.@*METHODS@#The collected three-dimensional fluorescence spectrum data of human saliva, 3% blood, coffee and Fanta® stains were processed with dimensionality reduction. After wavelet transform, spectral denoising and feature extraction, the classification formula was established. The Fisher discriminant was used for spectrum matching and recognition to establish the analysis method to distinguish stain types.@*RESULTS@#According to the results of data training and comparison, all the recognition accuracies of Fanta®, coffee, saliva and blood were more than 91.39%. Among them, saliva reached 100% recognition accuracy.@*CONCLUSIONS@#Three-dimensional fluorescence spectroscopy is a potential method for rapid and nondestructive identification of biological and non-biological stains.

Analysis of the Development Trend in Forensic Odontology Based on CiteSpace / 法医学杂志

OBJECTIVES@#To realize the dynamic visualization of forensic odontology based on the bibliometrics methods, and capture the research hotspots and identify the future development trend.@*METHODS@#Literature articles published from January 1995 to December 2020 were searched according to specific subject words in the core data set of Web of Science. The visualization analysis of publishing country, institution, discipline, author, co-cited journal and keywords was performed by CiteSpace 5.7.R5W software.@*RESULTS@#The annual analysis of publications showed an upward trend of forensic odontology research literature year by year, with the number of annual publications more than 110 in the last five years. Developed countries were the main source of contributions and the average centrality was greater than 0.2. The research of forensic odontology involved multiple disciplines, including stomatology, biology, computer science and medical imaging, with a distinct interdisciplinary feature. A total of 115 nodes were obtained by keyword cluster analysis. The principal line of forensic odontology mainly included individual identification and age estimation and the emergence of hotspots was closely related to new technologies. Population-based odontology investigation, improvement of traditional dental age estimation method and dental age estimation based on new technology were popular research in forensic odontology.@*CONCLUSIONS@#Developing countries urgently need to increase the focus on related research. It may be an important direction for the development of forensic odontology to establish and enrich the regional dental database, develop new odontology identification technology combined with frontier and high-end technology, and develop the identification program based on advanced information technology.

Research Progress of Metabolomics Techniques Combined with Machine Learning Algorithm in Wound Age Estimation / 法医学杂志

Wound age estimation is the core content in the practice of forensic medicine. Accurate estimation of wound age is a scientific question that needs to be urgently solved by forensic scientists at home and abroad. Metabolomics techniques can effectively detect endogenous metabolites produced by internal or external stimulating factors and describe the dynamic changes of metabolites in vivo. It has the advantages of strong operability, high detection efficiency and accurate quantitative results. Machine learning algorithm has special advantages in processing high-dimensional data sets, which can effectively mine biological information and truly reflect the physiological, disease or injury state of the body. It is a new technical means for efficiently processing high-throughput big data. This paper reviews the status and advantages of metabolomic techniques combined with machine learning algorithm in the research of wound age estimation, and provides new ideas for this research.

Forensic Analysis of Eighteen Tubal Pregnancy-Related Medical Damage / 法医学杂志

OBJECTIVES@#To analyze the cases of medical damage after misdiagnosis of tubal pregnancy, to explore the causes of medical damage, the causal relationship between medical malpractice and the damage consequences, as well as the causative potency, in order to provide evaluation ideas for forensic identification of such cases.@*METHODS@#Eighteen cases of forensic identification of tubal pregnancy related medical damage were collected and retrospectively analyzed from the aspects of age, maternity history, fertility requirements, risk factors, diagnosis and treatment, medical malpractice, damage consequences, and causative potency.@*RESULTS@#All 18 cases were tubal pregnancy, of which 17 cases had medical malpractice, resulting in 14 cases of affected tubal resection, 2 cases of hemorrhagic shock death, 1 case of intrauterine fetal death and affected tubal resection. The other case had the consequence of affected tubal resection, but there was no malpractice in the treatment.@*CONCLUSIONS@#Correct diagnosis is helpful to make appropriate treatment plan, prevent disease progression and reduce serious adverse consequences and the occurrence of medical disputes. Scientific and reasonable analysis of the causal relationship between medical malpractice and damage consequences and the causative potency is of great significance to the successful settlement of medical disputes.

UPLC-MS/MS Method for Detection of Etomidate and Its Metabolite Etomidate Acid Quantity in Blood / 法医学杂志

OBJECTIVES@#To establish a method for the simultaneous quantitative analysis of etomidate and its metabolite etomidate acid in blood, and to discuss its application value in actual cases.@*METHODS@#Acetonitrile precipitate protein method was used, and C18 column was selected. Gradient elution was performed with acetonitrile and 5 mmol/L ammonium acetate within 6 min. Electrospray ionization source in positive ion mode was used. The internal standard etomidate acid-d5 was obtained by etomidate-d5 alkaline hydrolysis reaction. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for quantitative analysis. The methodological verification was conducted.@*RESULTS@#Etomidate and etomidate acid in blood showed good linear relationship in the quantitative linear range (r>0.999), with the lower limit of quantification was 2.5 ng/mL and 7.5 ng/mL, respectively. The accuracy, precision, recovery rate, and matrix effect of the method met the professional verification standards. The practical application results showed that etomidate and etomidate acid could be detected in the blood of the abusers, and their mass concentrations ranged from 17.24 to 379.93 ng/mL.@*CONCLUSIONS@#The method established in this study can simultaneously quantify etomidate and etomidate acid in blood, which is simple and convenient to operate with accuracy. It can meet the detection needs of actual cases and provide technical support for law enforcement to crack down on etomidate abuse.

Proteomic Difference Analysis of Whole Blood and Bloodstains / 法医学杂志

OBJECTIVES@#To study the changes of protein levels in peripheral blood after it dried.@*METHODS@#The proteins from whole blood and bloodstains were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and normalized by the label-free quantification (LFQ) method. The differential proteins were analyzed by using R 4.2.1 software, limma and edgeR package. The analysis of biological function, signaling pathway and subcellular localization for the differential proteins was then performed.@*RESULTS@#A total of 623 and 596 proteins were detected in whole blood and bloodstains, respectively, of which 31 were statistically significant in the quantitative results, including 10 up-regulated and 21 down-regulated proteins in bloodstains.@*CONCLUSIONS@#The protein abundances in whole blood and bloodstains are highly correlated, and the variation of protein abundances may be related to the changes of endogenous and structural proteins in cells. The application of proteomics technology can assist the screening and identification of protein biomarkers, thereby introducing new biomarkers for forensic research.

Research Progress on Machine Learning Assisted Non-Targeted Screening Strategy for Identification of Fentanyl Analogs / 法医学杂志

In recent years, the types and quantities of fentanyl analogs have increased rapidly. It has become a hotspot in the illicit drug control field of how to quickly identify novel fentanyl analogs and to shorten the blank regulatory period. At present, the identification methods of fentanyl analogs that have been developed mostly rely on reference materials to target fentanyl analogs or their metabolites with known chemical structures, but these methods face challenges when analyzing new compounds with unknown structures. In recent years, emerging machine learning technology can quickly and automatically extract valuable features from massive data, which provides inspiration for the non-targeted screening of fentanyl analogs. For example, the wide application of instruments like Raman spectroscopy, nuclear magnetic resonance spectroscopy, high resolution mass spectrometry, and other instruments can maximize the mining of the characteristic data related to fentanyl analogs in samples. Combining this data with an appropriate machine learning model, researchers may create a variety of high-performance non-targeted fentanyl identification methods. This paper reviews the recent research on the application of machine learning assisted non-targeted screening strategy for the identification of fentanyl analogs, and looks forward to the future development trend in this field.

Rapid Determination of Bucinnazine in Blood by UPLC-MS/MS / 法医学杂志

OBJECTIVES@#To establish a rapid method for the analysis of bucinnazine in blood by UPLC-MS/MS and to apply the method to the practical case.@*METHODS@#After the internal standard was added to blood, the protein was precipitated with 900 μL mixed solution (Vacetonitrile∶Vwater=8∶2). After vortex and centrifugation, the protein was measured through 0.22 μm filter membrane. The separation was performed on C18 chromatography column, with acetonitrile and 5 mmol/L ammonium acetate containing 0.1% formic acid aqueous as mobile phase gradient elution at the flow rate of 0.4 mL/min. Multiple reaction monitoring scan was performed in electrospray positive ion mode, quantitative measurement was performed by internal standard method, and methodological verification was carried out.@*RESULTS@#The linear relationship of bucinnazine in blood was good in the range of 0.5-200 μg/L, the correlation coefficient (r) was 0.999 7, the limit of detection was 0.1 μg/L, the limit of quantitation was 0.5 μg/L, and the recovery was 78.3%-83.8% at 1, 10 and 100 μg/L mass concentration levels. The matrix effect was 69.4%-73.8%, the intra-day precision was 1.9%-2.8%, and the inter-day precision was 2.8%-3.2%, the accuracy was 3.1%-3.5%. The stability test results of 1 and 100 μg/L mass concentrations at -25 ℃ showed that the accuracy (bias) of 10 d was less than 4.5%.@*CONCLUSIONS@#This method has the advantages of simple pre-treatment process, fast sample processing speed, high sensitivity of instrument analysis, good stability of content determination and reliable identification results, and can meet the needs of case identification.