Raman Spectroscopy as a Simple,Rapid, Nondestructive Screening Test for Methamphetamine in Clandestine Laboratory Liquids

Raman spectroscopy has found increased use in the forensic controlled substances laboratory in recent years due to its rapid and nondestructive analysis capabilities. Here, Raman spectroscopy as a screening test for methamphetamine in clandestine laboratory liquid samples is discussed as a way to improve the efficiency of a laboratory by identifying the most probative samples for further workup among multiple samples submitted for analysis. Solutions of methamphetamine in ethanol, diethyl ether, and Coleman fuel were prepared in concentrations ranging from 0.5% to 10% w/v, and Raman spectra of each were collected. A concentration‐dependant Raman peak was observed at 1003 per cm in each solution in 4% w/v and greater solutions. Case samples were analyzed and also found to reliably contain this diagnostic peak when methamphetamine was present. The use of this diagnostic indicator can save the forensic controlled substances laboratory time and materials when analyzing clandestine laboratory liquid submissions.     

Trajectory Reconstruction Through Analysis of Trace Evidence in Bullet–Intermediate Target Interaction by SEM/EDX

Abstract:  A young male was shot to death by a police officer with a Chinese Type 64 7.62 mm pistol when he was dealing with an aggravated assault arising from a traffic accident. By using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDX), trace deposits on the discharged bullet and the intermediate target, i.e., a concrete telegraph pole at the scene, were identified to be from each other. The result demonstrated the bullet causing the death ricocheted from the concrete telegraph pole before striking the victim, thus indicating the incident was accidental. The case report illustrates the evidential value of trace materials derived, respectively, from discharged bullets and intermediate targets in bullet–intermediate target interaction for trajectory reconstruction. In addition, it indicates that the SEM/EDX method with its nondestructive nature, compared to other methods, may be more helpful in certain situations in determining the origins of trace evidentially valuable deposits on substrates.     

Post-mortem investigation of calcium content in liver, heart, and skeletal muscle in accidental hypothermia cases

The identification of hypothermia as cause of the death was always quite problematic in the field of forensic medicine. The aim of the present study was to verify the determination of calcium content in post-mortem liver, heart, and skeletal muscle samples as the biochemical marker defining hypothermia as the cause of death. The study involved 43 autopsy cases in which the circumstances of death indicated the effects of overcooling. The control group consisted of material collected from the corpses of 30 persons who were not exposed to low temperatures but died due to technical injuries (n = 5), asphyxia (n = 6), intoxication with ethanol and other substances (n = 8), and acute myocardial infarction/ischemia (n = 11). The concentration of calcium in autopsy samples was determined applying flame atomic absorption spectroscopy. Our study showed no significant differences of calcium content in tissues of persons who died due to hypothermia, over those who died in normothermic conditions.     

红外线合成图像在变造文件检验中的应用与分析

在文件检验中,黑白红外线照相是一种检验变造文件的方法,然而,在某些情况下效果欠佳。为了提高检验的准确性,不妨可以应用红外线合成图像的方法。应用Photoshop图像处理方法,根据红外线彩色照相的感光原理和色彩再现过程,对数码照相机拍摄的可见光图像和红外线图像进行适当处理,即可生成红外线合成图像。这种图像可以反映字迹对可见光和红外线的吸收与反射情况,通过判断字迹颜色有否改变来检验书写色料的异同。由此可见,利用红外线合成图像方法检验某些变造文件,可以获得黑白红外线照相无法得到的检验结果,这对提高鉴定结论的准确性具有实际应用价值。     

Classification and individualization of black ballpoint pen inks using principal component analysis of UV-vis absorption spectra

The technique of principal component analysis has been applied to the UV-vis spectra of inks obtained from a wide range of black ballpoint pens available in the UK market. Both the pen ink and material extracted from the ink line on paper have been examined. Here, principal component analysis characterised each spectrum within a group through the numerical loadings attached to the first few principal components. Analysis of the spectra from multiple measurements on the same brand of pen showed excellent reproducibility and clear discrimination between inks that was supported by statistical analysis. Indeed it was possible to discriminate between the pen ink and the ink line from all brands examined in this way, suggesting that the solvent extraction process may have an influence on these results. For the complete set of 25 pens, interpretation of the loadings for the first few principal components showed that both the pen inks and the extracted ink lines may be classified in an objective manner and in agreement with the results of parallel thin layer chromatography studies. Within each class almost all inks could be individualised. Further work has shown that principal component analysis may be used to identify a particular ink from a database of reference UV-vis spectra and a strategy for developing this approach is suggested.     

加减薯蓣丸治疗轻中度肾精亏虚证老年期痴呆的磁共振波谱研究

目的 采用氢质子磁共振波谱（1H magnetic resonance spectroscopy,1H MRS）检查结合神经心理学量表的方法,评价加减薯蓣丸对老年期痴呆患者的治疗效果。方法 收集2015年12月至2017年4月湖北省中医院脑病科及老年病科的血管性痴呆（vascular dementia,VD）及阿尔茨海默病（Alzheimers disease,AD）肾精亏虚证患者各20例,另选认知功能正常者20例作为对照组。入选老年期痴呆患者在内科治疗的基础上予以加减薯蓣丸治疗。对老年期痴呆患者治疗前后及对照组受试者进行简易精神状态评价量表（mini mental state examination,MMSE）、日常生活能力量表（activities of daily living,ADL）、痴呆证候分型量表（syndromes differentiation scale for dementia,SDSD）评估及1H MRS检查。结果 加减薯蓣丸显著升高VD及AD患者降低的MMSE评分（P＜0.05）,降低其升高的SDSD评分（P＜0.05）,但对ADL评分的改善作用无统计学意义（P＞0.05）。1H MRS检查表明,加减薯蓣丸显著升高VD和AD患者双侧额叶下降的N 乙酰天门冬氨酸（N aspart acetyl,NAA）/肌酸（creatine,Cr）水平（P＜0.05）,而降低双侧额叶升高的胆碱复合物（choline,Cho）/Cr作用无统计学意义（P＞0.05）。加减薯蓣丸对VD患者和AD患者MMSE、SDSD、ADL评分和双侧额叶NAA/Cr、Cho/Cr的作用差异无统计学意义（P＞0.05）。结论 加减薯蓣丸改善轻中度老年期痴呆患者认知功能的机制可能与促进损伤的神经细胞修复有关。     

健全社会管理格局，创新社会管理体系——“我国社会管理格局和管理体系构建”课题研究报告

本专题研究探讨转型期我国社会管理格局和体系构建问题,内容包括社会管理格局和体系构建的理论基础、我国社会管理格局和体系的现状、问题与挑战、中西方社会管理格局和体系的历史沿革与经验教训、转型期我国社会管理格局和体系构建的对策思考四个部分.作者指出,转型期我国社会管理格局和体系的重构是一件困难而复杂的工作,要解放思想,下大力气,推进社会管理体制改革,健全社会管理格局.创新社会管理体系,沿着党的十七大报告所指引的"健全党委领导、政府负责、社会协同、公众参与的社会管理格局,健全基层社会管理体制"的方向前进.     

大鼠死后皮肤傅里叶变换红外光谱变化与死亡时间的关系

目的运用傅里叶变换红外(Fourier transform infrared,FTIR)光谱技术分析大鼠死后15d内背部皮肤的光谱变化,以此推断死亡时间。方法大鼠麻醉后颈椎脱臼处死,置于温度为25℃、湿度为50%的环境中,分别于不同时间点提取其背部皮肤,收集红外光谱数据,并利用机器学习技术对数据进行分析。结果大鼠死后背部皮肤组织光谱吸收峰的峰位未发生明显改变,其强度随死亡时间延长而发生变化;偏最小二乘(partial least squares,PLS)回归构建的死亡时间推断模型决定系数(R2)为0.92,预测均方根误差为1.30 d。根据模型中的变量投影重要性(variable importance for projection,VIP)指标确定推断死亡时间的贡献波段为1760~1700cm-1、1660~1640cm-1、1580~1540cm-1和1460~1420cm-1。结论应用FTIR技术检测大鼠死后皮肤组织的光谱学改变,为死亡时间推断提供了一种新的思路。     

Use of styryl 11 and STaR 11 for the luminescence enhancement of cyanoacrylate-developed fingermarks in the visible and near-infrared regions

In current casework, most post-cyanoacrylate stains rely on luminescence emission in the visible region (400-700 nm). While traditional stains such as rhodamine 6G work well under most circumstances, some surfaces may generate background luminescence under the same conditions. Detection in the near-infrared region (NIR > 700 nm) has shown to be effective in minimizing the interferences from such surfaces. The laser dye styryl 11 generated strongly luminescent fingermarks when applied after cyanoacrylate fuming on all surfaces tested. When compared to rhodamine 6G, the dye was superior only when viewed in the NIR. Styryl 11 was subsequently combined with rhodamine 6G, and the mixed stain formulation (named StaR 11 by the authors) induced stronger luminescence compared with styryl 11 alone with an ability to visualize in both the visible and NIR regions. Reliable and consistent results were obtained when using either styryl 11 alone or the STaR 11 mixture. The enhancement achieved did not otherwise vary depending on the source of the fingermark secretions. With visualization possible in both the visible and NIR regions, the styryl 11/rhodamine 6G mixture showed significant potential as a post-cyanoacrylate stain.     

家兔死后心肌酰胺A带的傅里叶变换红外光谱图像分析

目的 应用傅里叶变换红外光谱成像系统研究家兔心肌酰胺A带变化与死亡时间的关系.方法 将32只家兔处死后取出心脏,20℃保存,于48h内不同时间点取样并制作切片.用傅里叶变换红外光谱成像系统绘制酰胺A带图像,分析研究死后酰胺A带阳性与阴性面积比的变化规律. 结果 48h内随死亡时间(x)的延长,酰胺A带的阳性与阴性面积比...