Hair analysis for cocaine: factors in laboratory contamination studies and their relevance to proficiency sample preparation and hair testing practices

Since the introduction in 2001 of a urine-based detection method for recombinant erythropoietin (rHuEPO), transfusion-doping practices have regained interest. To address this problem, an efficient antidoping test designed to obtain direct proof of allogeneic blood transfusion was developed and validated. This test, based on flow cytometry analysis of red blood cell (RBCs) phenotypes, was used to determine the absence or the presence of numerous RBCs populations in a blood sample. A such, it may constitute a direct proof of an abnormal blood population resulting from homologous transfusion. Single-blind and single-site studies were carried out to validate this method as a forensic quality standard analysis and to allow objective interpretation of real cases. The analysis of 140 blood samples containing different percentages (0-5%) of a minor RBCs population were carried on by four independent analysts. Robustness, sensitivity, specificity, precision and stability were assessed. ISO-accredited controls samples were used to demonstrate that the method was robust, stable and precise. No false positive results were observed, resulting in a 100% specificity of the method. Most samples containing a 1.5% minor RBCs population were unambiguously detected, yielding a 78.1% sensitivity. These samples mimicked blood collected from an athlete 3 months after a homologous blood transfusion event where 10% of the total RBCs present in the recipient originated in the donor. The observed false negative results could be explained by differences in antigen expression between the donor and the recipient. False negatives were more numerous with smaller minor RBCs populations. The method described here fulfils the ISO-17025 accreditation and validation requirements. The controls and the methodology are solid enough to determine with certainty whether a sample contains one or more RBCs populations. This variable is currently the best indicator for homologous blood transfusion doping.     

信号肽对O型口蹄疫病毒重组表位蛋白在CHO中表达及分泌的影响

构建融合不同信号肽的O型口蹄疫病毒重组表位蛋白真核表达载体,筛选不同的分泌型信号肽以提高O型口蹄疫病毒重组表位蛋白在中国仓鼠卵巢细胞(Chinese hamster ovary cell,CHO)中的表达并使其分泌到CHO培养基中。通过PCR方法将10种不同的分泌型信号肽与串联表位基因的5′端相连,分别构建了真核表达载体并转染哺乳动物细胞CHO,采用Western-blot检测CHO培养基中重组表位蛋白累积量,研究结果表明,O型口蹄疫病毒重组表位蛋白在CHO中成功分泌表达,不同的分泌型信号肽明显改变O型口蹄疫病毒重组表位蛋白在CHO培养基中的累积SCGB1D1 isoform信号肽介导的O型口蹄疫病毒重组表位蛋白表达量最高。综上所述,合适的分泌型信号肽促进O型口蹄疫病毒重组表位蛋白在CHO中的分泌。     

时尚背后的信仰

运用现代主义时尚理论、后现代主义时尚理论及相关社会学理论,对时尚以及其与现代社会的关系进行多视角解读,进而阐明＂神圣信仰＂的纯粹性在现代消费社会中逐渐消弭的根源。     

住房按揭贷款逾期风险识别与管理研究——基于借款人学历视角的实证检验

住房按揭贷款市场向来关注借款人学历水平，但有关学历与借款人行为内在关系的研究却相对不足。以住房公积金贷款为例，利用某重点城市2005-2014年住房公积金贷款还款数据，构建Cox比例风险模型，从总体影响、被动逾期、主动逾期、年龄效应等多个维度，对借款人学历与其还款逾期行为之间的联系进行系统性实证检验。研究结果表明，在偿还住房按揭贷款的过程中，高学历借款人的信用水平相对更优，他们的被动逾期和主动逾期行为发生概率均相对更低，并且这一规律在年轻借款人群体中更加明显。因此，商业银行、住房公积金中心等（准）金融机构可以充分利用学历信号在识别借款人信用过程中的上述作用，进一步加强住房按揭贷款风险防控，更好地实现金融服务供需有效匹配，提高授信方资金安全性和受信方金融可得性。     

法医线粒体DNA检测的系统效能及应用价值

线粒体DNA（mitochondrial DNA，mtDNA）遗传标记的检测在法医学实践中有着重要的价值。线粒体DNA异质性的出现，对检测体系的系统效能存在着影响，主要表现在对所检测样本的单倍型的认同及个体识别概率的计算上。通过建立mtDNA数据库，找出异质性在人群中的发生频率，并使检测异质性的方法标准化．对线粒体DNA的更有效检测具有重要意义；线粒体DNA编码区多态性位点在提高线粒体DNA系统效能中具有独到之处。因此，更进一步地进行mtDNA编码区多态性的探索．将进一步提高线粒体DNA检测的系统效能。     

计算机网络犯罪规制中的“未经授权”与“超越授权”——中美比较研究

件和基础是行为人未经授权或超越授权访问计算机网络。中美两国在规制计算机网络犯罪的访问行为上都有关于“未经授权”和“超越授权”的规定,对比两国立法和司法条文以及法院判解,我国规定的“未经授权”和“超越授权”只是概念式存在,司法解释没有予以定义,司法实践也未形成明确认定标准。科学借鉴美国立法和司法经验,结合中国实际完善我国规定的“未经授权”与“超越授权”:以程序编码设限作为判断计算机访问未经授权的标准;“超越授权”是指行为人在获得授权使用计算机时,利用这一授权使用的机会去获取计算机信息系统中的数据或控制计算机信息系统,但行为人的数据获取或控制行为并没有得到授权。     

Death caused by a signal rocket--not an isolated case*

Fatalities related to sporting events are predominantly caused by blunt force injuries especially due to the emotional involvement of crowd, but occasionally other types of trauma are reported as well. A case of very rare trauma caused by shooting with a hand-held parachute signal rocket during a football match is presented. A 17-year-old football fan sustained fatal injuries, a combination of mechanical trauma caused by rocket penetration, as well as extensive thermal burning of the thoracic viscera. Analysis of the event was based on autopsy findings and evidence produced by medicolegal and ballistic experts. Improper use of a hand-held signal rocket, designed for marine distress signals, may cause serious injuries either mechanically, due to explosion, or as a result of thermal discharge. In the reported case, pattern of injuries is discussed, and medical finding corroborated to other available evidence. The presented case is a reminder that the forensic pathologist should be informed accordingly on the type and features of weapon suspected to produce injury, to be able to understand traumatic changes, and look for potential presence of foreign bodies at postmortem examination.     

蕨麻多糖对小鼠免疫细胞信号转导相关分子的影响

以50、100、200、400μg/mL的蕨麻多糖对小鼠脾淋巴细胞在体外分别孵育4、8、12、24 h,测定了细胞培养液中一氧化氮(NO)、6-酮-PGF1α及血栓素B2(TXB2)的水平和细胞内cGMP的含量,测定了加入蕨麻多糖后2、5、10 min时细胞内游离钙离子(Ca2 )的浓度。结果显示,蕨麻多糖能明显促进小鼠脾淋巴细胞分泌一氧化氮,显著升高小鼠脾淋巴细胞内cGMP及钙离子的水平,对细胞内TXB2的产生有抑制作用,能够调整花生四烯酸体系向6-酮-PGF1α一端偏移。提示蕨麻多糖能够增强脾淋巴细胞的免疫作用。     

A New Tool for Coding and Interpreting Injuries in Fatal Airplane Crashes: The Crash Injury Pattern Assessment Tool Application to the Air France Flight AF447 Disaster (Rio de Janeiro–Paris), 1st of June 2009

For investigation of air disasters, crash reconstruction is obtained using data from flight recorders, physical evidence from the site, and injuries patterns of the victims. This article describes a new software, Crash Injury Pattern Assessment Tool (CIPAT), to code and analyze injuries. The coding system was derived from the Abbreviated Injury Score (AIS). Scores were created corresponding to the amount of energy required causing the trauma (ER), and the software was developed to compute summary variables related to the position (assigned seat) of victims. A dataset was built from the postmortem examination of 154/228 victims of the Air France disaster (June 2009), recovered from the Atlantic Ocean after a complex and difficult task at a depth of 12790 ft. The use of CIPAT allowed to precise cause and circumstances of deaths and confirmed major dynamics parameters of the crash event established by the French Civil Aviation Safety Investigation Authority.     

Age and lineup type differences in the own-race bias

The own-race bias (ORB) suggests that recognition for faces of one's own race is superior to recognition of other-race faces. A popular explanation for the ORB is amount of interracial contact, which may have cohort effects for older and younger adults. We compared White younger and older adults on the ORB utilizing a hybrid facial recognition and full diagnostic lineup (i.e., simultaneous and sequential target absent and target present lineups) paradigm. Both younger and older adults demonstrated an ORB. Signal detection estimates suggest younger adults compared to older adults have better discrimination accuracy for own-race over other-race faces. Interracial contact did not explain recognition for younger adults, but was related to a shift in response criterion for older adults.