微波消解ICP-MS法测定人发中的汞

目的建立人发中汞的电感耦合等离子体质谱分析方法。方法采用微波消解法处理样品,以铟（115In）作内标,用电感耦合等离子体质谱分析人发中的汞含量。结果方法检出限为0.0032μg/g,准确度通过测定人发标准物质GBW07601、GBW09101b进行验证,检测结果与标准参考值相符。结论该方法快捷、高效,灵敏度、准确度高,适用于人发中汞含量的检测。     

基于DNA预测人类可见外表特征的综述

本文介绍了基于DNA预测人类可见外表特征的法医学动机及筛选预测性DNA标记的科学挑战,讨论了目前认为很有应用前景的研究结果,比如现在科学水平只能达到通过高度关联的DNA标记准确预测性别、红色头发颜色、蓝色和棕色虹膜颜色。同时也讨论了现在看来不太有前景的应用,比如成年人的身高、人类面部特征等,为我国法医工作者今后进行相关研究提供一些参考。     

Trichophyton Mentagrophytes Perforates Hair of Adult Corpses in the Gaseous Period*

Abstract: Despite the substantial literature on mycology, there are still limited reports of the interaction between fungi and human hosts in the postmortem period. Thus, the main goal of this study was to investigate the in vitro perforation test using Trichophyton mentagrophytes on hair from adult corpses in the postmortem period (gaseous period). The protocol was carried out with positive (prepubescent children’s hair) and negative controls (healthy adult hair) as well. One strain of Trichophyton rubrum was also used as a negative perforation control. Perforations were found in all the hair samples from corpses and prepubescent children after 12–14 days exposure to T. mentagrophytes and were absent in the hair samples of healthy adults. Furthermore, hair perforation was not observed with T. rubrum. Our preliminary findings suggest the use of T. mentagrophytes as a potential marker of the death interval in forensic science.     

Segmental Hair Analysis—Interpretation of the Time of Drug Intake in Two Patients Undergoing Drug Treatment

The present study involved segmental testing of hair in two clinical cases with known dosage histories. Hair analysis confirmed the first patient's exposure to the prescribed sertraline and citalopram for several months. Citalopram was generally distributed along the hair shaft in accordance with the drug ingestion period. By contrast, “false” positive results were observed for sertraline in distal hair segments, corresponding to a period of no sertraline exposure, which may indicate incorporation from sweat or sebum, which transport the drugs along the hair surface. The second patient received various drugs during her treatment for brain cancer. Metoclopramide, morphine, oxazepam, paracetamol, sumatriptan, tramadol, and zopiclone, which had been part of the therapy, were all detected in the proximal hair segment. The results of these two cases indicated that results—especially concerning the time of drug intake—must be interpreted with caution and allow for the possibility of incorporation from sweat or sebum.     

度冷丁在豚鼠毛发中的分布研究

目的探讨度冷丁在毛发中的分布状况。方法通过动物实验-给豚鼠持续腹腔注射度冷丁,探讨度冷丁在豚鼠毛发中出现与消失的时间过程及注射剂量与毛发中的含量关系。结果给豚鼠隔日连续腹腔注射度冷丁7次,第4天可在豚鼠毛发中检出度冷丁,第8天达浓度高峰,停止注射后第5天检不出度冷丁;豚鼠毛发中度冷丁含量与度冷丁的注射剂量有关,但无明显的线性关系。结论研究结果为实际案例分析结果的评价提供依据。     

Elucidation of the effect of heat exposure on hair colored by permanent and semipermanent colorants using surface-enhanced Raman spectroscopy

Confirmatory identification of hair colorants can be used to establish a connection between a suspect and the crime science or demonstrate the absence of such connections. A growing body of evidence shows that surface-enhanced Raman spectroscopy (SERS) could be a confirmatory, minimally destructive, and fully noninvasive analysis of hair colorants. In SERS, a signal that provide the information about the chemical structure of both permanent and semipermanent dyes present on hair is enhanced by a million-fold using noble metal nanostructures. However, it is unclear whether the information of hair colorants can be revealed if hair was contaminated or exposed to harsh environments such as sunlight and heat. In this work, we determine the effect of a short- and long-term heat exposure on SERS-based analysis of hair colored with blue and red permanent and semipermanent dyes. We found that short and especially long-term heat exposure at 220°C could alter chemical structure, and consequently SERS spectra, of permanent and semipermanent colorants. This thermal degradation of permanent dyes complicates their direct identification using SERS. We also found that partial least squares discriminant analysis can be used to overcome this issue allowing for highly accurate identification of both permanent and semipermanent dyes on colored hair that was exposed to 220°C for 6–12 min. These results show that heat exposure of colored hair should be strongly considered upon their SERS-based examination to avoid both false positive or false negative identification of chemical dyes.     

"髡刑"探源:以法人类学为视角

髡,剃发也,是中国古代的一种刑罚。对于髡刑,学者有不同意见,其实髡刑是将犯人的长发剪为长三寸左右的短发。根据法人类学的材料,髡所以成为刑罚,与古人对头发的迷信观念有关。髡刑虽没有肉体痛苦,但由于古人相信头发是人体精气之所在,剃去头发将伤害生命和健康,所以受刑者会遭受精神上的痛苦。从这种意义上讲,髡刑是一种精神刑罚。     

Differentiation of Morphologically Similar Human Head Hairs from Two Demographically Similar Individuals Using Amino Acid Ratios,

Human hair is frequently encountered as forensic evidence and can contribute valuable information to investigators. Conventional forensic hair analyses include microscopic hair comparison (MHC) and DNA analysis. However, MHC is not supported by statistics and DNA analysis cannot always be performed. Recent studies have demonstrated that evaluation of differences in the hair proteins may offer an alternate method to these analyses. In this study, an evaluation of the amino acids present in hair was investigated as an approach to differentiate morphologically indistinguishable hair samples from two demographically similar individuals. Proteins in the hair were digested using hydrochloric acid, and the resulting amino acids were derivatized with N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) for analysis using gas chromatography-mass spectrometry (GC-MS). Eight derivatized amino acids were detected and quantified relative to an internal standard, L-norvaline, and used to construct twenty-eight amino acid ratios. Hair samples were collected from four areas of the head on various days over the course of one month, and no significant differences in amino acid ratios (p-value > 0.05) were observed among the areas of the head, and the ratios were consistent over the time period of this study. Additionally, fifteen of these amino acid ratios were found to be significantly different between the two individuals when compared using a two-sample t-test (p-value ≤ 0.05). These data indicate that amino acid analysis was able to differentiate two morphologically similar hair samples from different individuals and demonstrates the applicability of this method to distinguish similar hair samples when DNA analysis cannot be performed.