The Stability of Collected Human Scent Under Various Environmental Conditions*,†

Abstract: Human scent evidence collected from objects at a crime scene is used for scent discrimination with specially trained canines. Storage of the scent evidence is usually required yet no optimized storage protocol has been determined. Storage containers including glass, polyethylene, and aluminized pouches were evaluated to determine the optimal medium for storing human scent evidence of which glass was determined to be the optimal storage matrix. Hand odor samples were collected on three different sorbent materials, sealed in glass vials and subjected to different storage environments including room temperature, ?80°C conditions, dark storage, and UVA/UVB light exposure over a 7‐week period. Volatile organic compounds (VOCs) in the headspace of the samples were extracted and identified using solid‐phase micro‐extraction–gas chromatography/mass spectrometry (SPME–GC/MS). Three‐dimensional covariance mapping showed that glass containers subjected to minimal UVA/UVB light exposure provide the most stable environment for stored human scent samples.     

Fragrance transfer between fabrics for forensic reconstruction applications

Sexual assault is a serious crime that often has low conviction rates. Recent literature has demonstrated that there is potential for fragrances to be valuable in forensic reconstructions where there has been contact between individuals. However, developing appropriate evidence bases for understanding the nature of fragrance transfer in these contexts is needed. This article presents three experiments that address the transfer process of fragrances that have been transferred from a primary piece of fabric onto a secondary piece of fabric, in a manner that could occur during an assault. The three variables studied were the ageing time of the fragrances on the first fabric prior to transfer, the contact time between the two fabrics, and lastly the fabric type (of the primary material and the recipient material). The transfer was evaluated using a validated solid phase micro-extraction gas chromatography–mass spectrometry (SPME GC–MS) method. The findings demonstrated that all three variables had an impact on the transfer of fragrances between clothing fabrics. Generally, lower volatility compounds were transferred and recovered in larger amounts than higher volatility compounds. All fragrance compounds were successfully recovered from a secondary piece of fabric even when the contact time was as short as 10 s, and even when the perfume was aged on the primary fabric for as long as 48 h. The nature of the fragrance transfer also depended on the fabric type, so that a clear discrimination was observed between the fragrance transfer that occurred onto a natural fabric (cotton) and onto a synthetic fabric (polyester).     

固相萃取-气相色谱-质谱法检验人血浆中的右美托咪定

目的采用固相萃取结合气相色谱-质谱法(SPE-GC/MS)检验人血浆中盐酸右美托咪定。方法采用SPE提取血浆,用GC-MS/MS方法测定。结果盐酸右美托咪定在0.2μg/m L~5.0μg/m L范围内与峰面积呈现良好的线性关系(r2=0.999 1),检出限为20.0ng/m L,回收率为86.1%~91.5%,日内日间精密度均小于7.86%。结论本方法操作简单,结果准确,可以作为测定人血浆中右美托咪定的方法。     

武汉市建国以来社会治安状况分析

本文通过对武汉市建国以来社会治安状况的分析,说明社会政治、经济、文化等因素的发展变化直接影响到社会治安状况,社会治安状况是社会各种综合关系的外在反映;犯罪是与社会物质文化生活的条件相联系的。因此,用发展的眼光分析社会治安状况,可有效地消除人们对社会治安状况的恐慌感和失望症并找出综合治理治安状况的有效方法。     

基于BEMD二次分解与维纳滤波相结合的图像去噪算法

目的提出基于二维经验模态分解(BEMD)与维纳滤波相结合的图像去噪算法并验证其去噪效果。方法通过对含噪的图像进行BEMD尺度分解,提取前两阶含噪的尺度分量,使用维纳滤波进行一次去噪,然后再次进行BEMD分解和滤波去噪,从而达到去噪的目的。将本文提出的算法与经典算法进行比较,验证该算法的可行性和鲁棒性。结果实验表明,该算法不仅能够有效降低图像的噪声,而且能很好地保持图像信息。结论本文提出的图像去噪算法思路新颖,效果良好,在法庭科学图像处理领域有很好的参考和应用价值。     

毛细管气相色谱柱的保养与维护

综述了毛细管气相色谱柱的保养与维护.就毛细管柱分析使用中常遇到的一些问题,例如如何避免色谱柱的断裂,固定相的损伤,色谱柱的污染以及如何解决一些不能避免的问题和应采取的措施、步骤.     

大体积水系中微量农药的固相萃取柱选择

目的选择适用提取水样中微量有机农药的固相萃取柱。方法考察了HLB、GDX403、GDX103、C18、C8、C6等6种固相萃取柱提取水体中甲拌磷、治螟磷、残杀威、呋喃丹、氯氰菊酯、氰戊菊酯的回收率。结果采用Oasis HLB固相萃取柱提取水体中常见21种农药,回收率均基本达到60%以上。结论该方法可用于实际案件大体积水系中微量有机农药的提取检测。     

Instrumentalizing Fukushima: Comparing Media Coverage of Fukushima in Germany,France, the United Kingdom,and Switzerland

According to the theory of instrumental actualization in mediated conflicts, the mass media tend to exaggerate events consistent with the editorial line. This theory was tested using press coverage in Germany, Switzerland, France, and the United Kingdom on the Japanese seaquake, the tsunami it caused, and the nuclear disaster of Fukushima. Within a period of seven weeks after the seaquake, the coverage in the four countries in 27 national newspapers and magazines on the three events was analyzed. As hypothesized from theory, German and Swiss media concentrated on Fukushima and stressed its relevance to domestic nuclear plants, whereas French and British media placed a greater emphasis on the tsunami and rarely related the nuclear catastrophe in Japan to domestic nuclear programs. In addition, there were remarkable correlations between the views of journalists and the bias of statements on nuclear energy presented in their news sections. Findings are discussed and related to the theory of public opinion and political decisions in liberal democracies.     

新民主主义社会和社会主义初级阶段之异同

文章阐述了新民主主义社会与今天我们所处的社会主义初级阶段之间的异同关系 ,即 :关于社会的主要矛盾问题 ;关于两个不同时期的区分标准问题 ;关于社会经济基础问题 ;关于资本主义和私营经济问题 ;关于生产力、生产关系、上层建筑等问题。     

SPME结合衍生化检测尿液中吗啡成份

目的　建立尿液中吗啡检验的方法。方法　利用固相微萃取头富集尿液中吗啡 ,经醋酸酐衍生后进行GC/MS分析。结果　利用此方法可检测到吗啡含量为 5ug/ml的尿样。结论　该方法可用于吸毒人员尿液中吗啡的快速检验。