固根萃取技术在系统药、毒物分析中的应用

根据反相色谱法及离子交换色谱法的原理,研制了一种固相萃取小柱,建立了筛分系统,可以同时完成对复杂体系中酸性、中性及碱性药、毒物的一次革取净化及富集,适应于系统毒物及药物筛分工作的需要。并对筛分柱的草取机理进行了初步的实验论证。     

120例强奸案法医学回顾分析

强奸案的证据通常应具备暴力证据和性交证据,机械性损伤、使用药物和生物检材等是构成暴力证据和性交证据的重要组成部分。由于加害人实施强奸时手段的不同以及个体性行为的差异,损伤的类型、形态、部位及生物检材的种类、遗留部位、遗留客体也会呈现不同特征。如果不仔细地检查和提取,就会使这些物证灭失。本文通过对120例强奸案件的分析,总结了案件中损伤、药物、生物检材的发现、提取和检验的相关信息与技术细节问题,同时结合案情对案件发生的时段、地点、环境、区域、作案手段与方法、嫌疑人和受害人的职业特点等进行了讨论,希望对法医学鉴定工作和民警办理案件有所帮助。     

Passive forensics in image and video using noise features: A review

Due to present of enormous free image and video editing software on the Internet, tampering of digital images and videos have become very easy. Validating the integrity of images or videos and detecting any attempt of forgery without use of active forensic technique such as Digital Signature or Digital Watermark is a big challenge to researchers. Passive forensic techniques, unlike active techniques, do not need any preembeded information about the image or video. The proposed paper presents a comprehensive review of the recent developments in the field of digital image and video forensic using noise features. The previously existing methods of image and video forensics proved the importance of noises and encourage us for the study and perform extensive research in this field. Moreover, in this paper, forensic task cover mainly source identification and forgery detection in the image and video using noise features. Thus, various source identification and forgery detection methods using noise features are reviewed and compared in this paper for image and video. The overall objective of this paper is to give researchers a broad perspective on various aspects of image and video forensics using noise features. Conclusion part of this paper discusses about the importance of noise features and the challenges encountered by different image and video forensic method using noise features.     

Rethinking ‘Crowding Out’ and the Return of ‘Private Affluence and Public Squalor’

This article traces the history of ‘crowding out’, and its use as a justification for austerity and state deflation from its origins in the 1920s to its latest post-2010 incarnation. It examines why governments have kept turning to austerity and continue to justify it on the grounds that public sector activity crowds out more productive private activity, despite the accumulated evidence that this traditional pro-market formulation has failed to deliver its stated goals. It examines three other embedded forms of crowding out that have been highly damaging—leading to weakened social resilience and more fragile economies—but which have been ignored by both governments and mainstream political economists.     

Mitochondrial DNA Extraction from Burial Soil Samples at Incremental Distances: A Preliminary Study

Preservation variance of soil DNA is neglected in the literature, and exceptional cases exaggerate amplification capabilities. This study sought to amplify a short mitochondrial fragment (212 bp) specific to Sus scrofa domesticus from the soil surrounding decomposing pig remains from an open‐air locale. Samples collected above the body at incremental distances after 145 days of initial placement yielded pig DNA. A secondary sampling was collected in 2017, approximately 768 days after burial. Inhibition tests corroborated that pig DNA was no longer present in the soil resulting in a loss of original DNA between 145 and 768 days. The results provide evidence that genetic material leaches out radially from the source and DNA fragments longer than 200 bp do not persist in soil for a relatively short timeframe in western Montana. The conclusions support the collection of soil in crime scene investigation procedures within the first few months of decomposition.     

Microwave-assisted extraction and differential scanning calorimetry in the chemical identification of sliming agents apprehended in the south region of Brazil

Over the past decades, consume of slimming agents considerably increased in several countries, including Brazil, due to weight-loss and stimulant properties. Since these drugs are controlled to prevent illicit and indiscriminate use, there is a parallel illegal market that uses the Internet and irregular pharmacies in order to distribute these formulations. Slimming agents produced by these illegal sources are known for being manufactured with little or none quality control resulting in uncertain and unknown formulations. For forensic purposes, apprehended pharmaceuticals have to undergo a process of chemical identification that can be difficult due to its complex matrix. In this sense, application of assisted energies in the extraction step such as microwave irradiation can be a promising method to increase the recuperation of the target molecules of the sample. Therefore, the aim of this research was to identify four slimming agents apprehended in Brazil by means of visual inspection, Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry and Gas Chromatography – Mass Spectrometry. Moreover, the efficiency of solid-liquid extraction and microwave-assisted extraction was compared. It should be noted that our work was one of the few to use Differential Scanning Calorimetry and the application of microwave irradiation in the analysis of apprehended materials. Results showed that the majority of the samples was counterfeit being composed of one or several adulterants or contaminants. Initially, visual inspection resourcefully screened the slimming agents for possible signs of falsification, however it failed to detect fraudulent products that were very similar to veridical medicines. Sequentially, Fourier Transform Infrared Spectroscopy detected functional groups present in the samples while the presence or absence of the alleged active ingredients were successfully measured with Differential Scanning Calorimetry and, thus, providing a full chemical screening of the apprehended materials. Gas Chromatography- Mass Spectrometry confirmed the presence of adulterants such as caffeine, fluoxetine and phenolphthalein as well as contaminants such as sulfurol in the falsified samples. Finally, comparison of extraction procedures indicated that microwave-assisted extraction increased the recovery of compounds detected in chromatographic analysis to a greater extent than solid-liquid extraction.     

Efficiency of Casework Direct Kit for extraction of touch DNA samples obtained from cars steering wheels

Analysis of STR profiles obtained from touch DNA has been very useful to the elucidation of crimes. Extraction method may be determinant for the recovery of genetic material collected from different surfaces. Vehicle theft is one of the most common crimes in São Paulo city, Brazil, but collection of biological traces in car steering wheels is not considered, because of the belief that profiles generated won’t be able to identify the thief, only the owner. This study aimed to analyze the efficacy of extraction methods for obtaining DNA profiles in samples collected from steering wheels. Eight criminal acts were simulated with 2 different individuals each (mixture of victim and thief), in duplicate, in order to compare two extraction methods: DNA IQ™ and Casework Direct Kit (both Promega Corporation). Genetic material was collected by double swab method and quantified by Quantifiler™Trio (ThermoFisher Scientific). Amplification was conducted with PowerPlex® Fusion System (Promega). It was possible to obtain STR profiles for all experiments. The mixtures were compared with reference profiles to evaluated how many alleles of each donor were observed. Samples extracted with Casework Direct Kit obtained STR profiles with higher averages of alleles for primary and secondary donors (88.7% and 59.9%, respectively) than those extracted with DNA IQ™ (60.4% and 38.1%, respectively). This could be explained by the differences established in the protocols of both methods, since DNA IQ™ is based on successive washes and can result in loss of DNA, whereas Casework Direct Kit minimizes this problem. We concluded that Casework Direct Kit was more efficient for processing touch DNA samples than DNA IQ™.     

Full STR profile of a 67-year-old bone found in a fresh water lake

DNA extraction from and DNA typing of fresh water-exposed aged bone specimens poses a challenging task and is not very well examined. This study presents a new method to extract typable DNA from such problematic bone specimens. The procedure comprises low-heat drilling and cryogrinding, mild lysis conditions, and silica-column-based DNA cleaning. DNA quantity is assessed by quantitative PCR prior to short tandem repeat (STR) amplification. The procedure was employed with a 67-year-old tibia bone fragment recovered from a fresh water lake and succeeded to produce a full STR profile using the MPX-SP1 and MPX-SP2 mini-STR kits and a partial profile with 12 successfully amplified STRs using the Identifiler STR kit. The new method for the extraction of DNA from aged fresh water-exposed bone specimens presented herein was successfully applied to prepare DNA of sufficient quality and quantity to generate a full STR profile.     

应用分子印迹固相萃取法提取血液中大隆和溴敌隆

目的采用分子印迹固相萃取,UPLC/MS分析,检验血液中大隆和溴敌隆。方法以大隆为模板分子,丙烯酰胺为单体,二甲基亚砜为有机溶剂,按照模板分子与单体摩尔配比关系为1∶4合成大隆分子印迹聚合物,作为固相萃取剂萃取血液中大隆和溴敌隆,以2×1mL去离子水、1mL 30%甲醇去离子水洗涤杂质,2×1mL 1%甲酸/甲醇洗脱,提取血中目标物后进行UPLC/MS分析检测。结果溴敌隆和大隆回收率均在90%以上,在50～500ng/mL浓度范围内线性关系良好r,2溴敌隆为0.998 4,大隆为0.991,检测限（S/N=5/1）低于10ng/mL。结论本方法回收率高,基质效应降低,杂质干扰少,可用于血液中低浓度大隆和溴敌隆的检验。