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1.
毛发毒品的分析在毒品检验中具有独特优势,而毛发与毒品的结合状况及毒品聚集于毛发的机制影响其检测的准确性和灵敏性。对毒品与毛发的结合位点、毒品与毛发结合的差异性因素以及外界因素对毒品与毛发结合的影响进行了综述。  相似文献   

2.
吗啡类毒品是我国滥用人数较多,也是危害性较大的毒品品种。与传统的人体体液检材(血液、尿液、唾液等)相比,毛发检材以其易获得性、易保存、易重复取样、长时间的检测窗口等优势逐渐应用于司法鉴定、毒驾检测、临床毒物分析等领域。本文整理归纳了近十年来(2007年~2017年)发表的测定人毛发中吗啡类毒品滥用物质相关文献,并从毛发样品的前处理方法、毛发样品的色谱检测方法、受试者毛发样本检测、毛发检测结果与毒品滥用关系判断等方面进行综述分析,为相关领域研究提供参考。  相似文献   

3.
毒驾成为影响我国交通安全的重要因素,而毒驾的法庭评定标准尚未建立,特别是毒品代谢物浓度对驾驶行为的影响尚不明确。随着法庭科学的发展,许多研究者对代谢动力学进行了研究,并取得了一定的成果。本文综述毒品代谢动力学研究及其在法庭科学中的应用状况,概要介绍毒品代谢动力学的研究现状、研究方法及研究成果,并提出结合驾驶行为能力和心理测验,开展临床的毒品代谢动力学、吸毒人员"代谢指纹图谱"及其与驾驶行为能力关系的研究,完善毒驾检测技术标准,构建合理阈值,进一步提出毒驾的法庭判定标准。  相似文献   

4.
分子印迹技术具有优越的识别性和选择性,在毒品检测中具有重要的研究潜力。分子印迹技术应用与打击毒品犯罪相结合,已成为当今法庭科学工作者研究的热点问题。本文阐述了分子印迹技术的基本原理,并对其在固相萃取、吸附分析、化学发光、传感器、色谱分析等毒品检测技术中的应用情况进行了综合概括,并展望了分子印迹技术领域的发展趋势。  相似文献   

5.
随着法庭科学的发展以及近年来涉及毒品、毒物等中毒案件的增加,许多研究者对毒物代谢动力学进行研究,并取得了一定的成果.本文综述毒物代谢动力学研究及其在法庭科学中的应用状况,概要介绍毒物代谢动力学的研究现状、研究方法及研究成果,以期为相关研究及实践提供参考和借鉴.  相似文献   

6.
固相萃取是近年发展起来的一种样品前处理技术,主要用于样品的分离和富集,能够将生物检材中的目标待测物有效的与杂质组分分离,具有较高的回收率,其样品预处理过程简单,操作便捷。在法庭科学领域,可根据生物检材,如生物体液、组织、毛发等基质的性质,选择相应的固相萃取方法;同时亦可根据目标待测物,如目标待测物的酸碱性,选用不同的固相萃取方法。色谱法是一种分离和分析方法,它利用不同物质在不同相态的选择性分配,使混合物中的不同组分根据其性质不同而分离。质谱法在分析中可提供丰富的结构信息。固相萃取-色谱质谱联用技术集固相萃取与色谱质谱检测技术优点于一体,可实现对复杂基质中的特定毒物与非特定毒物进行高效萃取、净化与检测,具有检材消耗少、检测速度快、灵敏度高等特点,已被广泛应用于环境监测、药物分析、法庭科学领域等,成为当前毒物筛查的重要手段,具有选择性好、灵敏度高、基质效应低等特点,且易实现在线分析,特别适用于法庭毒物分析中单一毒物或多种毒物的筛查。本文综述了固相萃取-色谱质谱联用技术在法庭科学毒物毒品分析中的应用进展,以供同行参考。  相似文献   

7.
海洛因来源鉴定的新方法   总被引:2,自引:2,他引:0  
毒品来源的鉴定是指对毒品样品中包含的来源信息进行提取拜分析,这有助于打击毒品犯罪.海洛因是危害我国的主要毒品,它的来源鉴定更引起人们的关注.本文介绍了国际上研究海洛因来源的三种方法,即研究海洛因样品中的各种有机杂质及其相对比例;研究海洛因样品中的痕量无机元素;研究海洛因及吗啡的稳定同位素相对比值.第三种方法能够反映样品的地域性特点,因而在来源鉴定方面有突出的优势.气相色谱-燃烧-同位素比值质谱法是同位素比值测定方法中用于海洛因来源鉴定的最佳手段.这一技术还可用于其他微量物证(如炸药、药品、油品等)的来源鉴别,因而在法庭科学领域内显示了广阔的应用前景.  相似文献   

8.
强化制毒案件现场勘查五意识   总被引:1,自引:0,他引:1  
安全意识制毒案件现场会有各种制毒原料、配剂和化学品,甚至制造毒品的反应都在进行中。这些原料、配剂和化学品,有易燃易爆气体、有毒有害液体,有的有强腐蚀性。在现场勘查中必须对这些物质进行安全处理。目前侦查员对制毒案件现场勘查存在的危险还普遍缺乏认识,在勘查制毒案件现场  相似文献   

9.
WTO争端解决机制(DSU机制)运作至今,在实践中面临一些亟待解决的新问题,"法庭之友"陈述在争端解决机制中的地位正是问题之一。WTO成员国对专家组和上诉机构是否可以采纳"法庭之友"制度一直存在争论。"法庭之友"制度在DSU机制中缘何存在并发展,本文从实证和理论角度对此进行了分析,为我国如何对待"法庭之友"提出了应对之策。  相似文献   

10.
笔者于2004年7月受公安部派遣参加了联合国科索沃维和任务,有幸在任务区警察局总部的法庭科学部门工作近一年,指导和参加了维和民警被杀、爆炸等重特大案件的现场勘查工作。本文从实践的角度结合切身体会将任务区的现场勘查工作进行介绍,以供大家交流学习。  相似文献   

11.
The forensic application of DNA-typing for the identification of dog hair provides objective evidence in the characterisation of traces found at crime scenes. During the past few years forensic dog identity testing has been improved considerably using multiplex PCR systems. However, DNA-typing from samples of one up to 10 dog hairs is often problematic in forensic science. A single dog hair contains very small quantities of DNA or the hair sample consists of hairs with roots of bad quality or even of broken hairshafts without roots. Here we describe an experimental study about dog hairs by means of a Ca(2+) improved DNA-extraction method, quantification and amplification.  相似文献   

12.
The influence on drug incorporation of melanin affinity, lipophilicity, and membrane permeability is of paramount importance. Despite their high lipophilicity, some drugs have quite low incorporation rate into hair, suggesting that the higher incorporation rates of basic drugs (cocaine, amphetamines.) than neutral (steroids, benzodiazepines, cannabinoids…) or acidic ones are strongly related to the penetrating ability of the drug to break through the membrane based on the pH gradient between blood and the acidic hair matrix. When using hair analysis as a matrix during investigative analysis, e.g. workplace drug testing, doping, driving under the influence, drug-facilitated crime, the question of importance is to know whether the analytical procedure was sensitive enough to identify traces of drugs; this is particularly important when the urine sample(s) of the subject was positive and the hair sample(s) was negative. It has been accepted in the forensic community that a negative hair result cannot exclude the administration of a particular drug, or one of its precursors and the negative findings should not overrule a positive urine result. Nevertheless, the negative hair findings can, on occasion, cast doubt on the positive urine analysis, resulting in substantial legal debate and various consequences for the subject. The concept of minimal detectable dosage in hair is of interest to document the negative findings, but limited data is currently available in the scientific literature. Such data includes cocaine, codeine, ketamine, some benzodiazepines and some unusual compounds. Until laboratories will have sensitive enough methodologies to detect a single use of drug, care should be taken to compare urine and hair findings.  相似文献   

13.
We present a review of the literature on procedures for obtaining short tandem repeat (STR) genotypes from keratinised hair, being either hair shaft or telogen phase (naturally shed) hairs without associated scalp, follicle or sheath cells. Both the hair shaft and the telogen hair club have been subjected to the DNA-degrading keratinisation process and are more likely to be found at a crime scene than anagen (plucked) or catagen phase hairs. We discuss human hair structure, the human hair growth cycle, the keratinisation process and their implications for DNA extraction procedures, PCR amplification strategies and the interpretation of STR genotypes. Knowledge gaps and areas requiring research are identified and are the subject of a second article in this series.  相似文献   

14.
Analysis of mitochondrial DNA (mtDNA) sequence from human hairs has proven to be a valuable complement to traditional hair comparison microscopy in forensic cases when nuclear DNA typing is not possible. However, while much is known about the specialties of hair biology and mtDNA sequence analysis, there has been little correlation of individual information. Hair microscopy and hair embryogenesis are subjects that are sometimes unfamiliar to the forensic DNA scientist. The continual growth and replacement of human hairs involves complex cellular transformation and regeneration events. In turn, the analysis of mtDNA sequence data can involve complex questions of interpretation (e.g., heteroplasmy and the sequence variation it may cause within an individual, or between related individuals. In this paper we review the details of hair developmental histology, including the migration of mitochondria in the growing hair, and the related interpretation issues regarding the analysis of mtDNA data in hair. Macroscopic and microscopic hair specimen classifications are provided as a possible guide to help forensic scientists better associate mtDNA sequence heteroplasmy data with the physical characteristics of a hair. These same hair specimen classifications may also be useful when evaluating the relative success in sequencing different types and/or forms of human hairs. The ultimate goal of this review is to bring the hair microscopist and forensic DNA scientist closer together, as the use of mtDNA sequence analysis continues to expand.  相似文献   

15.
The use of average curvature measurements for the forensic comparison of curly hairs has been reported, but a method, in which various types of hair form are quantitatively examined and objectively interpreted for hair comparison, has not been reported to date. In the present study, numerical data on hair form from Japanese subjects were obtained by image analysis and a morphological comparison of these head hairs was investigated. Head hairs obtained from eight Japanese males were measured for length (L), distance (D) and area (A) using a Kontron Imaging System KS400. From the three measurements mentioned above, three indexes, L/D, A/D and 2(A/L), were examined. The inter-individual variations for each value were investigated by a t-test and the availability of six values for the forensic comparison of hair form was evaluated by a stepwise linear discrimination analysis. Six values obtained from hair form by an image analysis showed large intra-individual variations. However, these six values were found to be useful for discriminating between two individuals, since the six values showed larger inter-individual variations than intra-individual variations. Discrimination on each comparison using a stepwise linear discrimination analysis was performed for some of the values and the results indicated conspicuous inter-individual variations between the two individuals. On 11 of 28 comparisons, 30 hairs from one individual could be completely distinguished from hairs of another individual, when a two-way comparison was employed. These results confirm that hair form could be quite useful in the forensic comparison of hair morphology, and suggest that numerical data obtained from hair form by image analysis are very important values for constructing a screening procedure for evidential hairs. The use of an objective measure of hair form will be especially useful for Japanese head hairs since they are generally thought to show very limited variation in morphological features.  相似文献   

16.
A large body of research has described the influence of context information on forensic decision‐making. In this study, we examined the effect of context information on the search for and selection of traces by students (N = 36) and crime scene investigators (N = 58). Participants investigated an ambiguous mock crime scene and received prior information indicating suicide, a violent death or no information. Participants described their impression of the scene and wrote down which traces they wanted to secure. Results showed that context information impacted first impression of the scene and crime scene behavior, namely number of traces secured. Participants in the murder condition secured most traces. Furthermore, the students secured more crime‐related traces. Students were more confident in their first impression. This study does not indicate that experts outperform novices. We therefore argue for proper training on cognitive processes as an integral part of all forensic education.  相似文献   

17.
In forensic analyses, determining the level of consensus among examiners for hair comparison conclusions and ancestry identifications is important for assessing the scientific validity of microscopical hair examinations. Here, we present data from an interlaboratory study on the accuracy of microscopical hair comparisons among a subset of experienced hair examiners currently analyzing hair in forensic laboratories across the United States. We examined how well microscopical analysis of hair can reliably be used to differentiate hair samples, many of which were macroscopically similar. Using cut hair samples, many sharing similar macroscopic and microscopic features, collected from individuals who share the same mitochondrial haplogroup as an indication of genetic relatedness, we tested multiple aspects that could impact hair comparisons. This research tested the extent to which morphological features related to ancestry and hair length influence conclusions. Microscopical hair examinations yielded accurate assessments of inclusion/exclusion relative to the reference samples among 85% of the pairwise comparisons. We found shorter hairs had reduced levels of accuracy and hairs from populations examiners were not familiar with may have impacted their ability to resolve features. The reliability of ancestry determinations is not yet clear, but we found indications that the existing categories are only somewhat related to current ethnic and genetic variation. Our results provide support for the continued utility of microscopical comparison of hairs within forensic laboratories and to advocate for a combined analytical approach using both microscopical analysis and mtDNA data on all forensic analyses of hair.  相似文献   

18.
Several types of biological samples, including hair strands, are found at crime scenes. Apart from the identification of the value and the contributor of the probative evidence, it is important to prove that the time of shedding of hair belonging to a suspect or victim matches the crime window. To this end, to estimate the ex vivo aging of hair, we evaluated time‐dependent changes in melanin‐derived free radicals in blond, brown, and black hairs by using electron paramagnetic resonance spectroscopy (EPR). Hair strands aged under controlled conditions (humidity 40%, temperature 20–22°C, indirect light, with 12/12 hour of light/darkness cycles) showed a time‐dependent decay of melanin‐derived radicals. The half‐life of eumelanin‐derived radicals in hair under our experimental settings was estimated at 22 ± 2 days whereas that of pheomelanin was about 2 days suggesting better stabilization of unpaired electrons by eumelanin. Taken together, this study provides a reference for future forensic studies on determination of degradation of shed hair in a crime scene by following eumelanin radicals by utilizing the non‐invasive, non‐destructive, and highly specific EPR technique.  相似文献   

19.
Recovery of trace DNA and its application to DNA profiling of shoe insoles   总被引:6,自引:0,他引:6  
In recent years, the analysis of trace amounts of DNA has become a necessary and useful forensic tool. DNA profiles can be obtained from items that have been worn or handled, due to the presence of transferred DNA derived from skin cells. Shoeprints collected from crime scenes that match a suspects shoe can link a shoe to the crime scene. A DNA profile from inside the shoe can link a wearer to a shoe thus increasing the evidential value of the forensic evidence. In this work, variation in the amount of DNA recovered from hands and feet of different individuals is investigated. Sites for sampling DNA from shoe insoles are compared and a protocol for the subsequent sampling and extraction is developed. Finally, a case study is described where DNA analysis of shoe insoles has provided forensic evidence.  相似文献   

20.
Tramadol is a centrally acting synthetic analgesic with mu-opioid receptor agonist activity, it is a widely prescribed analgesic used in the treatment of moderate to severe pain and as an alternative to opiates. Tramadol causes less respiratory depression than morphine at recommended doses. Its efficacy and low incidence of side effects lead to its unnecessary prescribing in patients with mild pain. Tramadol was classified as a "controlled drug" long after its approval for use in Jordan. Analysis of drugs of abuse in hair has been used in routine forensic toxicology as an alternative to blood in studying addiction history of drug abusers. A method for the determination of tramadol in hair using solid phase extraction and gas chromatography-mass spectrometry (GC-MS) is presented, the method offers excellent precision (3.5-9.8%, (M)=6.77%), accuracy (6.9-12%, M=9.4%) and limit of detection 0.5 ng/mg. The recovery was in the range of 87-94.3% with an average of 90.75%. The calibration curve was linear over the concentration range 0.5-5.0 ng/mg hair with correlation coefficient of 0.998. The developed method was tested on 11 hair samples taken from patients using tramadol as prescribed by their physician along with other different drugs in treating chronic illnesses. Tramadol was detected in all hair samples at a concentration of 0.176-16.3 ng/mg with mean concentration of 4.41 ng/mg. The developed method has the potential of being applied in forensic drug hair testing. In Jordan, hair drug testing started to draw the attention of legal authorities which stimulated forensic toxicologists in recent years to develop methods of analysis of drugs known or have the potential to be abused.  相似文献   

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