双溶剂提取法偏差范围的实验分析

目的双溶剂提取法是鉴定圆珠笔油墨字迹相对书写时间的方法之一,该方法简单有效,但在实际办案中发现,提取率的范围对数据的偏差范围有着直接影响。本文旨在通过实验分析偏差范围。方法通过对多种牌号的圆珠笔油墨新书写的字迹样本和自然老化样本进行平行实验。结果得到了不同提取率范围内的圆珠笔油墨提取率偏差范围。结论为双溶剂提取法鉴定圆珠笔油墨相对书写时间的界定提供了较为可靠的实验依据。     

鸦片中主要成分的检验

本文采用Seppak C_(18)小柱固相萃取鸦片中的五种主要成分,以反相高效液相色谱法,甲醇—甲酸—三乙胺水(35:1.5:0.5:63)为流动相,检验五种成分,各成分均有良好的回收率。方法简单、快速、准确。     

The Role of Competition in Determining Corporate Governance Outcomes: Lessons from Australia's Corporate Governance System

Successive waves of corporate collapse in every decade of Australia's history suggest that there is a significant unresolved corporate governance problem in Australia. Corporate collapse has been followed by reform but with little effect on the overall pattern of collapse and reform every decade. This article suggests that one of the elements which entrenches corporate governance problems in Australia is the competitive environment in which companies operate, which currently is not regulating management. It is argued that this anti-competitive environment has two significant effects. First, key shareholders have retained controlling blocks of shares as the benefits of control and the costs of unconstrained management are high in such distorted markets. Secondly, management skills have stagnated, so that bad management and regular management failure have become features of the corporate governance system.     

Phenolphthalein False‐Positive Reactions from Legume Root Nodules

Presumptive tests for blood play a critical role in the examination of physical evidence and in the determination of subsequent analysis. The catalytic power of hemoglobin allows colorimetric reactions employing phenolphthalein (Kastle‐Meyer test) to indicate “whether” blood is present. Consequently, DNA profiles extracted from phenolphthalein‐positive stains are presumed to be from blood on the evidentiary item and can lead to the identification of “whose” blood is present. Crushed nodules from a variety of legumes yielded phenolphthalein false‐positive reactions that were indistinguishable from true bloodstains both in color quality and in developmental time frame. Clothing and other materials stained by nodules also yielded phenolphthalein false‐positive reactivity for several years after nodule exposure. Nodules from leguminous plants contain a protein (leghemoglobin) which is structurally and functionally similar to hemoglobin. Testing of purified leghemoglobin confirmed this protein as a source of phenolphthalein reactivity. A scenario is presented showing how the presence of leghemoglobin from nodule staining can mislead investigators.     

应用磁珠法提取陈旧骨骼DNA

目的探讨采用磁珠法提取陈旧骨骼DNA的可行性。方法取经土埋或室外暴露下存放1~5年不等的10根长骨,经水洗、刮净,钻取骨密质骨粉3g,应用EQ1000磁珠试剂盒提取DNA,经复合扩增,ABI 3130XL基因分析仪电泳分离,进行STR分型检测。结果 10根长骨均获得完整的STR分型,电泳图谱基线干净,除个别大片段基因座外,等位基因荧光信号分布均衡性较好。结论采用磁珠法提取陈旧骨骼的DNA,能满足分型要求,可在实际检案中选用。     

人骨骼及牙齿DNA提取方法的比较和优化

目的人骨骼和牙齿DNA提取方法的比较和优化。方法收集18份不同个体的长骨、30颗磨牙和同一个体2根股骨、8颗磨牙。利用TissueLyser-Ⅱ组织破碎仪和PreFiler Express BTA^TM法医DNA提取试剂盒（BTA法）,应用Automate Express^TM自动化法医DNA提取系统提取DNA,进行STR分型,与脱钙法进行比较,并进行实验条件优化。结果用TissueLyser-Ⅱ结合BTA法,约2.5h即可完成骨骼和牙齿的DNA提取,分型成功率分别为94.4%和96.7%。与脱钙法比较,两种方法获得DNA质量浓度和检出率比较接近（P〈0.05）,但BTA法在操作过程方面更具优势。最佳样本量为100mg,消化时间为2h。结论采用TissueLyser-Ⅱ组织破碎仪结合BTA法对骨骼和牙齿进行DNA提取和分型检验,能满足实际检案的要求,可在法医学实践中选择使用。     

快速溶剂萃取-气相色谱/质谱法分析血液中的4种滥用药物

目的 建立生物检材血液中滥用药物的快速溶剂萃取（ASE）方法.方法 通过优化快速溶剂萃取各参数,提取血液中的滥用药物进行GC/MS定性定量分析.结果 血液中美沙酮、可卡因、蒂巴因、海洛因4种滥用药物的平均回收率在87.8％～97.5％之间,滥用药物在0.4μg/mL～4.0μg/mL的浓度范围内线性良好.结论 该方法具有操作简便快捷,回收率高、重现性好等特点,可广泛应用于生物检材血液中滥用药物的检验鉴定.     

STR and Y-STR genotyping of 30–50-year-old semen stains

This study performed the semen discrimination test, short tandem repeat (STR) typing, and Y-chromosome specific-STR (Y-STR) typing on five, 30–50-year-old semen stains. All samples reacted positively with the SM test reagent, and we observed sperm heads in all samples microscopically. The quantity of DNA extracted from the 43- and 50-year-old samples was much lower than from the other samples. STR typing of the 30-, 32-, 32-, 43-, and 50-year-old semen samples detected a maximum of 13, 15, 15, 11, and 6 of 15 loci, respectively, while Y-STR typing detected 16, 16, 16, 10, and 10 of 16 loci. These results suggest that the semen discrimination test and STR and Y-STR typing can detect extremely old semen stains and are useful for forensic practice.     

正交试验法优选桃红四物汤的水提工艺

目的 优选桃红四物汤的水提工艺。方法 以芍药苷和浸膏得率为考察指标,以加水量、提取时间、提取次数为考察因素,采用正交试验优选桃红四物汤的最佳水提工艺。结果 桃红四物汤的最佳水提工艺为加12倍量水提取3次,每次1.5 h。结论 优选出的桃红四物汤的水提工艺合理,可为其工业化生产提供依据。