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1.
Forensic laboratories do not have the infrastructure to process or store contaminated DNA samples that have been recovered from a crime scene contaminated with chemical or biological warfare agents. Previous research has shown that DNA profiles can be recovered from blood exposed to several chemical warfare agents after the agent has been removed. The fate of four toxic agents, sulfur mustard, sodium 2-fluoroacetate, sarin, and diazinon, in a lysis buffer used in Promega DNA IQ extraction protocol was studied to determine if extraction would render the samples safe. Two independent analytical methods were used per agent, selected from GC-MS, 1H NMR, 19F NMR, (31)P NMR, or LC-ES MS. The methods were validated before use. Determinations were carried out in a semi-quantitative way, by direct comparison to standards. Agent levels in the elution buffer were found to be below the detectable limits for mustard, sarin, sodium 2-fluoroacetate or low (<0.02 mg/mL) for diazinon. Therefore, once extracted these DNA samples could be safely processed in a forensic laboratory.  相似文献   
2.
Abstract: The chemical profiling of illicit drugs is an important analytical tool to support the work of investigating and law enforcement authorities. In our work, comprehensive two‐dimensional gas chromatography–time‐of‐flight mass spectrometry (GC × GC‐TOFMS) combined with nontargeted, pixel‐based data analysis was adapted for the chemical profiling of 3,4‐methylenedioxymethamphetamine (MDMA). The validity and benefit of this approach was evaluated by analyzing a well‐investigated set of MDMA samples. Samples were prepared according to a harmonized extraction protocol to ensure the comparability of the chemical signatures. The nontargeted approach comprises preprocessing followed by analysis of variances as a fast filter algorithm for selection of a variable subset followed by partial least squares discriminant analysis for reduction to promising marker compounds for discrimination of the samples according to their chemical profile. Forty‐seven potential marker compounds were determined, covering most of the target impurities known from the harmonized one‐dimensional profiling as well as other compounds not previously elucidated.  相似文献   
3.
    
A series of incidents over the past two decades has indicated that some terrorist groups are interested in acquiring and using improvised chemical devices (ICDs). Although the 1993 Chemical Weapons Convention (CWC) is a disarmament treaty that is legally binding only on sovereign states that join it voluntarily, the Convention fortuitously includes several provisions that can help its members to prevent chemical terrorism or to manage the consequences of an attack. This article examines the articles of the CWC that are relevant to counterterrorism and discusses how their implementation could be improved at the national and international levels. The article also addresses the role that the CWC secretariat, the Organization for the Prohibition of Chemical Weapons (OPCW) in The Hague, currently plays in preventing and responding to incidents of chemical terrorism, and the political factors that constrain its activities in the counterterrorism field.  相似文献   
4.
    
The analysis of amino acids present in fingerprints has been studied several times. In this paper, we report a method for the analysis of amino acids using an fluorenylmethyloxycarbonyl chloride‐derivatization for LC separation and MS detection. We have obtained good results with regard to the calibration curves and the limit of detection and LOQ for the target compounds. The extraction of the amino acids from the substrates used proved to be very efficient. Analysis of the derivatized amino acids enabled us to obtain full amino acid profiles for 20 donors. The intervariability is as expected rather large, with serine as the most abundant constituent, and when examining the total profile of the amino acids per donor, a characteristic pattern can be observed. Some amino acids were not detected in some donors, or fell out of the range of the calibration curve, where others showed a surprisingly high amount of material in the deposition analyses. Further investigations will have to address the intravariability of the amino acid profiles of the fingerprints from donors. By the development of the analytical method and the application to the analysis of fingerprints, we were able to gain insight in the variability of the constituents of fingerprints between the donors.  相似文献   
5.
    
《Digital Investigation》2014,11(2):120-140
In this paper, we present a passive approach for effective detection and localization of region-level forgery from video sequences possibly with camera motion. As most digital image/video capture devices do not have modules for embedding watermark or signature, passive forgery detection which aims to detect the traces of tampering without embedded information has become the major focus of recent research. However, most of current passive approaches either work only for frame-level detection and cannot localize region-level forgery, or suffer from high false detection rates for localization of tampered regions. In this paper, we investigate two common region-level inpainting methods for object removal, temporal copy-and-paste and exemplar-based texture synthesis, and propose a new approach based on spatio-temporal coherence analysis for detection and localization of tampered regions. Our approach can handle camera motion and multiple object removal. Experiments show that our approach outperforms previous approaches, and can effectively detect and localize regions tampered by temporal copy-and-paste and texture synthesis.  相似文献   
6.
    
The ingestion of corrosive substances may produce severe burns to the upper aerodigestive tract and stomach, particularly if the pH is greater than 12 or less than two. There is a biphasic age grouping with adult cases most often involving self‐harm and pediatric cases accidental ingestion. Three cases are reported to demonstrate characteristic features following the ingestion of potassium hydroxide, glacial acetic acid and Lysol®, respectively. All deaths were due to the effects of caustic burns to the upper aerodigestive tract, esophagus and stomach with perforation and/or hemorrhage. The extent of injuries in these cases depends on the nature, amount, and concentration of the agent and on the exposure time. A point to note at autopsy is that tissue damage may also occur from postmortem exposure. Typical injuries involve perioral, limb, and trunk burns, with extensive aerodigestive liquefactive/coagulative necrosis causing hemorrhage and perforation.  相似文献   
7.
目的研究荧光钙血迹蓝钠试剂增强潜在灰尘水渍混合鞋印、灰尘尿渍混合鞋印、灰尘血渍混合鞋印的普适性。方法采用高压微雾雾化法,雾化增强常见的8种地板上的20%w/w灰尘含量的灰尘水渍、灰尘尿渍和灰尘血渍混合鞋印,并与平面扫描提取技术相比较。结果增强后的鞋印花纹清晰,呈亮蓝色,提取效果明显优于自然光下拍照提取,略优于平面扫描提取技术。结论荧光钙血迹蓝钠试剂能够有效增强潜在多介质混合鞋印,是一种便捷高效的潜在混合鞋印增强提取方法。  相似文献   
8.
二十世纪八十年代后,毒品在中国又开始死灰复燃。针对日益严重的毒品违法犯罪,国家制定了一系列法律法规,在禁毒斗争中发挥了巨大作用。但是,由于毒品问题的特殊性和我国国情,仅全国统一禁毒立法还不够,尚需地方立法的细化和补充。本文根据对天津毒品问题的分析和对其他省、市、自治区已有地方禁毒立法的研究比较,指出了制定天津地方禁毒立法的必要性,提出了天津禁毒条例的体系设想,力求为天津的禁毒立法提供某些启示和借鉴,推动我市地方禁毒立法进程。  相似文献   
9.
易制毒化学品犯罪及其惩治对策   总被引:2,自引:0,他引:2  
目前 ,我国易制毒化学品种类较多 ,管理难度大 ,管理漏洞多 ,易制毒化学品犯罪日趋严重。易制毒化学品犯罪的主要特点是涉及数量大 ,品种多 ,主体复杂 ,隐蔽性强。严厉惩治易制毒化学品犯罪 ,必须提高认识 ,加强领导 ,堵住漏洞 ,严格对缉毒人员的培训 ,提高查缉能力 ,同时要完善相关的法律、法规。  相似文献   
10.
    
X-ray photoelectron spectroscopy (XPS) is a widely used technique to characterize the surface chemistry of materials. It plays a crucial role in accessing qualitative and quantitative information and in detecting the presence of chemical functional groups on the surface of any material. The forensic methods available to detect and identify elements and organic/inorganic compounds are often destructive, so evidence cannot be re-analyzed. However, XPS allows rapid analysis of samples without damaging them. Recently, an increasing number of forensic researchers have begun to study certain chemical information on fingermarks. In this study, the authors aimed to present the applicability and power of XPS imaging in fingermark analysis which can also provide specific information about the fingermark chemical composition. Herein, monochromated X-ray (Al Kα) spot size was fixed at 50 μm. XPS mapping resulted in the acquisition of spectra at each pixel, in an array of 41 × 30 pixels with a step size of 50 μm. Then, a simple discussion has been made about how the scanned surface spectrum and basic snapshot spectra are used to identify different components at a fingertip of a scanned surface area (~3 mm2). Hence, a fingermark pattern contaminated with caffeine, TiO2, and Pb/PbO deposited on the silicon wafer can be chemically mapped and visualized by XPS using principal component analysis (PCA). Thus, the present study showed the possible applicability of XPS for the identification of illicit drugs of abuse, gunshot residue, and skin care products on latent fingermark by mimicking a crime scene evidence.  相似文献   
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