Application of dispersive liquid-liquid microextraction and CE with UV detection for the chiral separation and determination of the multiple illicit drugs on forensic samples

A new method was developed for pre-concentration, chiral separation and determination of multiple illicit drugs on forensic samples using dispersive liquid-liquid microextraction (DLLME) and capillary electrophoresis (CE) with Ultra Violet (UV) detection. The method was based on the formation of tiny droplets of an organic extractant in the prepared sample solution using water-immiscible organic solvent (chloroform) dissolved in water-miscible organic dispersive solvent (isopropyl alcohol). The organic phase, which extracted heroin, DL-methamphetamine, DL-3, 4-methylenedioxymethamphetamine and dl-ketamine from the prepared sample solution, was separated by centrifuging. The sedimented phase was transferred into a small volume CE auto-sampler vial with 10 μL of 1% HCl methanol solution and evaporated to dryness. The residue was reconstituted in lidocaine hydrochloride aqueous solution (internal standard) and introduced by electrokinetic injection into CE. Parameters affecting extraction efficiency were investigated and optimized. Under optimum conditions, linearity of the method was 0.15-6500 μg/L for all target analytes. The LODs (S/N=3) were 0.05-0.20 μg/L. Excellent repeatability (RSD ≤ 4.4%, n=5) was achieved. The feasibility of this method was demonstrated by analyzing spiked forensic samples. To our knowledge, it is the first time to combine DLLME with CE for chiral separation and determining illicit drugs on forensic samples.     

Computational Study of Fracture Characteristics in Infant Skulls Using a Simplified Finite Element Model

Skull fracture characteristics are associated with loading conditions (such as the impact point and impact velocity) and could provide indication of abuse or accident‐induced head injuries. However, correlations between fracture characteristics and loading conditions in infant and toddler are ill‐understood. A simplified computational model representing an infant head was built to simulate skull responses to blunt impacts. The fractures were decided through a first principal strain‐based element elimination strategy. Simulation results were qualitatively compared with test data from porcine heads. This simplified model well captured the fracture pattern, initial fracture position, and direction of fracture propagation. The model also very well described fracture characteristics found in studies with human infant cadaveric specimens. A series of parametric studies was conducted, and results indicated that the parameters studied had substantial effects on fracture patterns. Additionally, the jagged shapes of sutures were associated with strain concentrations in the skull.     

“竞争化”到“竞争中立化”:市场导向标准的困境及协调路径

市场导向条件经历了从美欧到西方世界小范围达成共识的过程,竞争是演进中的核心要素,竞争与贸易领域的天然联系是市场导向条件"竞争化"的原因。市场导向标准竞争中立化诠释了竞争中立从竞争领域向区域贸易规则渗透、再向多边贸易体制扩张的过程。区域自贸协定中的竞争中立以约束政府的方式规制国有企业,未能充分虑及经贸实际,使区域化协调国有企业规则的尝试面临重重困境。对多边补贴规则的修改是市场导向标准竞争中立化的新动态,恐将放大实践中矛盾与逻辑上的不自洽。WTO危机反映了规则静态与利益动态的冲突,以恪守多边主义为前提,采竞争与贸易"双轨"并行之策,在国际、国内层面协调国有企业规则,将有助于化解市场的导向分歧。     

伪装语音的自动话者识别研究

本文以语音自动话者识别系统为平台,对实际案件中出现频率较高的10种伪装语音类型进行自动话者识别测试。通过对20位发音人的正常语音和10种类型伪装语音的话者辨认和话者确认测试,分析不同语音伪装类型对自动话者识别的影响。该结果对于深入认识伪装语音的特性及其话者识别研究具有重要意义,也为自动话者识别技术的改进提供了参考。     

谈公安高校的警务化管理道路

通过对公安高校警务化管理概念的诠释,指出公安高校发展警务化管理模式,走警务化管理道路的必然性。继而提出实施警务化管理的具体措施,以完善公安高校的管理制度,促进学生个性化发展。     

公共权力及其异化治理的伦理选择

公共权力是一种维持、调整和发展社会生活基本秩序以追求社会公共利益的强制性力量,它与道德之间存在着一种双向的互动关系。公共权力背离维护和追求公共利益的目标就会形成公共权力的“异化”。公共权力异化形成的原因是多方面的,伦理方面的缺陷是其中重要的一种。从伦理角度加强对公共权力异化的治理将有助于公共权力的合理有效运行和价值目标的实现。     

历史学派与德国特殊发展道路

本文作者分析了德国历史学派的历史观实质及其民族（国家）主义的内在逻辑与德意志特殊道路的关系。作者认为,历史学派的民族（国家）主义为德国的特殊发展道路提供了一定的政策支持,但也为其悲剧性结局负有部分责任。这方面的研究可以引起中国经济学家客观地分析和探讨国家在经济发展中的作用。     

马立克氏病病毒gE蛋白单克隆抗体的制备及鉴定

为了获得分泌抗鸡马立克氏病病毒(MDV)gE囊膜糖蛋白单克隆抗体的杂交瘤细胞,将pGEX-6P-1表达的重组蛋白gE作为抗原,免疫BALB/c小鼠,通过淋巴细胞杂交瘤技术,共筛选获得4株能够稳定分泌抗MDV gE蛋白抗体的杂交瘤细胞株。抗体亚型鉴定结果表明,4株均为IgG1型,轻链为κ链。间接免疫荧光结果显示,4株杂交瘤细胞分泌的单克隆抗体均能特异性识别MDV,并具有一定的中和活性。本研究对MDV诊断、抗原表位分析及鉴定等具有重要的应用价值。     

H3亚型猪流感病毒血凝素基因在昆虫细胞中的表达及其间接ELISA检测方法的建立

根据GenBank上登录的H3亚型猪流感病毒HA基因序列设计了1对引物,经PCR扩增出HA基因目的片段,并将其克隆到pFastBacGP67C杆状病毒载体上,筛选阳性重组转座载体pFastBacGP67C-H3,转化至含有杆状病毒穿梭载体(bacmid)的DH10Bac感受态细胞,构建杆状病毒表达载体,获得重组转座子rBacmid-H3,在脂质体介导下转染处于对数生长期的sf9昆虫细胞,获得重组杆状病毒rBv-H3,将其感染sf9昆虫细胞,收获目的蛋白。经血凝试验、SDS-PAGE、Western-blot、免疫组织化学分析,结果表明,HA蛋白得到表达,且具有良好的免疫学活性。用表达的HA蛋白作为包被抗原,初步建立了H3亚型猪流感病毒的间接ELISA检测方法,通过对93份送检的疑似猪流感血清进行检测,结果显示,检出阳性率为46.24%。上述结果为建立快速、准确、简便的H3亚型猪流感鉴别诊断试剂盒奠定了基础。