Distinguishing Between Legally and Illegally Produced Gold in South Africa

The identification of gold‐bearing material is essential for combating the theft of gold in South Africa. Material seized in police operations is generally a mixture of gold from different mines, and as such cannot be traced back to a single location. ICP‐OES analysis of material dissolved by acid dissolution provided a database of gold compositions comprising gold from South African mines, illegal gold stolen from the mines, and commercial gold alloys and jewelery. Discrimination between legal and illegal gold was possible due to the presence of Pb, As, Sb, Sn, Se, and Te in the stolen material, elements which are not present in legally produced gold. The presence of these elements is a quick and simple way to distinguish between gold alloys based on refined gold, such as in commercially manufactured jewelery, and gold alloys containing a proportion of unrefined and therefore illegally obtained gold.     

N-cyanomethyl-N-methyl-1-(3',4'-methylenedioxyphenyl)-2-propylamine: an MDMA manufacturing by-product

This paper describes the structural elucidation of a compound produced during the synthesis of 3,4-methylenedioxymethylamphetamine (MDMA) via the reductive amination of 3,4-methylenedioxyphenyl-2-propanone (3,4-MDP-2-P) with methylamine and sodium cyanoborohydride. The compound was isolated from MDMA by column chromatography, proton and carbon nuclear magnetic resonance spectroscopy, LC/mass spectrometry, and total synthesis were used to identify the compound as N-cyanomethyl-N-methyl-1-(3',4'-methylenedioxyphenyl)-2-propylamine. This compound has been identified as a potential synthetic route marker for the reductive amination of 3,4-MDP-2-P with methylamine and sodium cyanoborohydride and as such it should prove valuable to forensic scientists engaged in profiling illicit drugs. Profiling MDMA can provide useful information to law enforcement agencies relating to synthetic route, precursor chemicals and reagents employed and may be used for comparative analyses of different drug seizures. This paper also describes the structural elucidation of the analogous methylamphetamine synthetic route marker compound, N-cyanomethyl-N-methyl-1-phenyl-2-propylamine, produced during the reductive amination of phenyl-2-propanone using methylamine and sodium cyanoborohydride.     

Fourier transform infrared reflectance spectra of latent fingerprints: a biometric gauge for the age of an individual

To determine if changes in fingerprint infrared spectra linear with age can be found, partial least squares (PLS1) regression of 155 fingerprint infrared spectra against the person's age was constructed. The regression produced a linear model of age as a function of spectrum with a root mean square error of calibration of less than 4 years, showing an inflection at about 25 years of age. The spectral ranges emphasized by the regression do not correspond to the highest concentration constituents of the fingerprints. Separate linear regression models for old and young people can be constructed with even more statistical rigor. The success of the regression demonstrates that a combination of constituents can be found that changes linearly with age, with a significant shift around puberty.     

日军遗华化学武器诉讼案及其前景析——兼论日本的战后责任问题

近年来,日军遗华化学武器致人伤亡事件不断发生,从1996年起中国受害者就开始在日本法院提起民间索赔诉讼,但迄今无一最终胜诉.民间赔偿不同于战争赔偿,中国受害者的民间索赔诉讼属日本未尽的战后责任问题,这不仅涉及受害者利益,而且关乎中日关系.2006年4月3日中国民间对日索赔联合会在北京成立,开启了中国民间对日索赔的国内诉讼程序.另一方面,中国政府也应从各方面给受害者的索赔诉讼提供支持,包括尝试国际求偿.但这一问题的解决最终还有赖于日本正确看待其侵略历史,彻底履行战争责任.     

Recommended Practices for Macerating Human Thyroid Cartilage

Visible abnormalities on the thyroid cartilage may be indicative of perimortem trauma including fractures or sharp force trauma. During autopsy, the thyroid cartilage must be freed of surrounding soft tissue before these abnormalities can be clearly observed. Several processing methods were first experimentally tested on pig ears to narrow down which might work best to process human thyroid cartilage. Several methods in the categories of hot water maceration, chemical/enzyme maceration, and dermestid beetles were then tested on a sample of 37 human thyroid cartilages. An adapted 22-point scoring system was used to score the efficacy of each processing method. Chemical maceration using bleach was found to be the best method for removing surrounding tissue from thyroid cartilage, with Arm & Hammer^TM powdered laundry detergent as a close second. These methods are inexpensive, quick, and easy to implement, making them a simple addition to busy medical examiner’s offices or forensic anthropology laboratories.     

使用覆盖剂控制物料堆扬尘污染的研究

通过对覆盖剂进行固化时间、固化强度、温度、雨淋、风洞等试验考察覆盖剂性能 ,获得应用参数。在试验室研究的基础上 ,分别对储量为 5 0 0 t、80 0 t、1 30 0 t煤堆进行应用试验 ,在冬季取暖用煤堆上起到了覆盖的作用 ,抑尘效果明显     

普通红外光谱法快速检验化学修饰后的毛发

该研究的目的是建立一种无损快速检验化学修饰后毛发的方法。将样品清洗后,染色使用仪器：傅立叶红外光谱仪水平ATR装置,扫描范围设定为4,000厘米-1到650厘米-1,扫描次数设定为32次,分辨率设定为4厘米-1;分别取适量毛发样品,置于水平ATR仪锗晶体表面上,并压平;样品扫描,采集样品红外光谱谱图;红外光谱谱图处理,基线自动校准,9点平滑处理。结果28种样品实验结果表明,重现性较好,能够区分不同处理的样品。     

大鼠死后脑组织的傅里叶变换红外光谱变化

目的应用傅里叶变换红外（Fourier transform infrared．FTIR）光谱技术分析大鼠死后脑组织随死亡时间推移的化学变化过程,为死亡时间推断的研究提供新的途径与数据。方法大鼠断颈处死后置于（30±2）℃环境下,在不同时间点提取大鼠脑皮质．运用FTIR光谱仪检测不同化学基团的变化。结果随着死亡时间的推移,大鼠脑组织FTIR光谱的主要吸收峰峰位没有明显变化．而其峰强有明显差异：（1）与核酸有关的谱带的相对峰强呈明显下降趋势;（2）酰胺Ⅰ、Ⅱ的峰强比（I1647/I1541）呈下降趋势;（3）1456和1398cm^-1谱带的峰强各自呈下降和上升趋势;（4）2852、2871、2923和2958cm^-1谱带的峰强相对于1647cm^-1而言．呈上升趋势。结论脑组织可以作为FTIR光谱技术分析死亡时间的适用检材。     

锦灯笼化学拆分组分的制备及抗菌作用研究

目的 研究中药锦灯笼各化学拆分组分的抗菌活性。方法 对锦灯笼化学组分进行拆分,检测其对金黄色葡萄球菌、耐药金黄色葡萄球菌、大肠杆菌、耐药大肠杆菌的最小抑菌浓度和最小杀菌浓度。结果 锦灯笼水提物组分、酸浆多糖组分、酸浆苦素组分对金黄色葡萄球菌和大肠杆菌有较强的抑制作用,且酸浆苦素组分还能抑制和杀死耐药金黄色葡萄球菌和耐药大肠杆菌。结论 锦灯笼各拆分组分具有一定的抗菌能力。