Time-lapse resistivity surveys over simulated clandestine graves

The aim of this study was to develop a better understanding of how electrical resistivity surveys can be used to locate clandestine graves. Resistivity surveys were conducted regularly over three simulated clandestine graves containing a pig cadaver, no cadaver and a pig cadaver wrapped in tarpaulin, respectively. Additionally, soil and groundwater samples were collected from two more simulated graves outside the survey area. The grave containing a pig cadaver was detectable from a low resistivity anomaly in the survey data. Groundwater data suggest that the resistivity anomaly associated with the surveyed pig grave was caused by a localised increase in groundwater conductivity. Wrapping a cadaver was found to initially change the resistivity response of a grave to a high resistivity anomaly. Resistivity surveys did not detect the disturbed soil in the grave that did not contain a cadaver. Although soil samples showed grave soil to be more porous than undisturbed soil, the lack of response from the grave that did not contain a cadaver suggests that disturbed soil was not responsible for the resistivity anomalies observed in this study. Resistivity surveys successfully detected all graves containing cadavers throughout the study, whilst also showing the potential to eliminate the need for mass excavation in a genuine search.     

人类DRB基因单核苷酸多态性研究

目的建立一种对单核苷酸多态性(SNPs)位点进行复合检测的方法,并对人类DRB基因的单核苷酸多态性进行研究。方法 应用荧光标记双脱氧核苷酸进行单碱基延伸反应,同步检测人类DRB基因10个单核苷酸多态性位点。结果 应用该方法检验了人类标准细胞株K562、9947A及其他法医学常见生物检材,包括血斑2份、精斑5份、烟蒂8份、毛发3份,各样品间未发现相同的单核苷酸多态性组合单倍型。DNA模板需要量仅为0.5~1.0ng。结论 该方法是对微量生物物证进行个体识别鉴定的理想方法。同时还可为法医学及其他研究领域进行单核苷酸多态性分析提供快速、高效的技术手段。     

血液中乌头碱、次乌头碱、新乌头碱的LC/MS/MS分析

目的　建立血液中乌头碱、次乌头碱、新乌头碱的LC/MS/MS分析方法。方法　用 1%三氯乙酸 乙腈萃取血液样品 ,采用电喷雾离子源 ,正离子MRM扫描。结果　本方法线性相关系数r≥ 0 992 2。最低检测浓度(LOQ ,S/N =5 )分别为乌头碱 2 0ng/ml ,次乌头碱 0 5ng/ml ,新乌头碱 0 5ng/ml。空白血添加回收率 91 2 5 %～10 3 1%,变异系数 (CV ,n =6) <10 93 %。结论　LC/MS/MS法灵敏可靠 ,样品处理快速简便 ,适用于血液中乌头碱、次乌头碱、新乌头碱的检测。     

毒鼠强诱导细胞DNA损伤的彗星电泳检测

目的　研究毒鼠强对小鼠淋巴细胞和脑细胞DNA的损伤作用。方法　分离健康小鼠的淋巴细胞和脑细胞 ,以彗星电泳的方法测定不同浓度毒鼠强处理后的细胞DNA损伤。结果　 1/2 0～ 1/2LD50 剂量组的毒鼠强均可引起淋巴细胞和脑细胞不同程度的DNA损伤 ,与对照组呈极显著性差异 (P <0 0 0 1)。结论　毒鼠强引起细胞DNA断裂损伤 ,并呈现明显的剂量 -效应关系。     

天津市法医DNA数据库的应用与发展

建立的天津市法医DNA数据库系统 ,将DNA分析技术的高效性与计算机系统的储存、高效检索的功能有机结合 ,实现了从受案到结案及建库的全程标准化、规范化、网络化管理。该系统启用一年多以来 ,为本地区侦查机关提供了百余起案件的破案线索 ,在多起重特大刑事案件的串并侦破中发挥了关键作用 ,技术破案率明显提高     

氯硝安定在生物体内的代谢

目的推测氯硝安定在生物体内的主要代谢方式,检测其代谢产物。方法取5只Wistar大鼠,连续3d给每只大鼠灌胃氯硝安定（剂量分别为1、2、2mg）,收集灌胃后24h内尿液;给3只大鼠各灌胃2mg氯硝安定,2h后处死,取血液和肝组织等检材;收集3名口服5mg氯硝安定的志愿者24h内尿液。分别对不同检材进行处理后,气相色谱/质谱联用（GC/MS）检测。结果在大鼠阳性尿液和志愿者阳性尿液中,均检出7-乙酰氨基氯硝安定和7-氨基氯硝基安定;在大鼠血液中,主要检出氯硝安定和7-氨基氯硝基安定;在大鼠肝组织中,主要检出7-乙酰氨基氯硝安定,还有少量7-氨基氯硝安定和氯硝安定。结论氯硝安定进入生物体后,其7位硝基被还原为氨基,氨基接着被乙酰化,形成7-氨基氯硝基安定和7-乙酰氨基氯硝安定代谢物,其中7-乙酰氨基氯硝安定为主要代谢物。     

刑事案件DNA检验采样与鉴定立法现状

人类DNA遗传特征多态性使DNA技术成为各国警方侦办案件的重要技术手段,但DNA检验鉴定采样合法性和结论可采性须由立法规定。众多国家和地区针对DNA采样和鉴定结论应用制定了相关法律法规。我国相关法律细则尚处空白,因此,应尽快制定我国DNA鉴定采样与应用法规,规范DNA鉴定样本采集与证据采信。     

Quantitative structure–activity relationship (QSAR) methodology in forensic toxicology: Modeling postmortem redistribution of structurally diverse drugs using multivariate statistics

Postmortem redistribution (PMR) constitutes a multifaceted process, which renders the analytical results of drug concentrations inaccurate to be interpreted by forensic toxicologists. The aim of the present study was to evaluate whether quantitative structure–activity relationship (QSAR) methodology could serve as an effective tool to estimate the ability of drugs to redistribute across tissue barriers during postmortem period on the basis of their molecular, physicochemical and structural properties. In this aspect, multivariate data analysis (MVDA) was applied to a set of 77 structurally diverse drugs. PMR data expressed by the central:peripheral concentration ratio (C:P ratio) was taken from the literature. An adequate and robust QSAR model (R² = 0.65, Q² = 0.56, RMSEE = 0.34) was established for 59 (77%) out of 77 drugs. Although the derived QSAR model presented limited applicability, it provided an informative illustration of the contributing molecular, physicochemical and structural properties in PMR process. Drugs with strong basic properties and enhanced molecular size, flexibility, lipophilicity and number of halogens were found to be susceptible to increased PMR. Due to the high complexity of PMR process, further QSAR studies need to focus on structurally related drugs to develop more specific models, which could serve as alternative tools to evaluate PMR for different chemical classes.     

男性性功能鉴定（附73例报告）

报道７３例男性性功能鉴定，对目前常用的检测方法，手淫法、血管活性药物海绵体内注射作出评价，并认为对手淫法能勃起者与海绵体内注射罂粟碱不能勃起者，有认定价值。性心理调查、配偶方接受检验对勃起功能障碍的类型有鉴别作用。