北京汉族群体9个STR位点的频率分布及法医学应用

提供北京汉族群体9个STR基因座的频率分布资料，了解其在法医学中的应用价值。应用PCR技术对9个STR基因座分3组进行复合扩增，经PAG电泳分离、银染，扫描仪扫描，计算机判读并保存结果，对北京地区汉族无关个体9个基因座的基因频率分布进行调查。结果显示，上述9个基因座的杂合度为0．6419～0．8092，多态性信息总量为0．9999，鉴别机率为0．9999，匹配机率为2．0×10-9和非父排除率为0．9985。STR3组9个基因座的综合检验可应用于法医学个体识别和亲子鉴定，并达到同一认定的标准。     

斩断腐败“生物链”必须转变权力的运行机制

目前,腐败的"生物链"已经蔓延到各个领域,其发展趋势十分危险.只有转变权力的运行机制,才能遏制腐败"生物链"的蔓延,从而斩断腐败"生物链".     

Use of a commercially available hydrogel as a novel DNA surface sampling tool

A common requirement in the military, law enforcement, and forensic mission space is the need to collect trace samples from surfaces using a method that not only readily captures the sample but also retains its integrity for downstream identification and characterization. Additionally, collecting samples from three-dimensional objects (e.g., shell casings) is a challenge for which there is currently no validated standardized approach. Recently, hydrogels have been shown to have the potential for surface collection of trace bacterial spores, amino acids, and DNA. To test whether these hydrogels can serve as a viable collection medium for sampling DNA from surfaces, we carried out a series of preliminary tests examining collection efficiency and suitability of hydrogel material to recover samples of diluted, dried human DNA on a smooth polycarbonate surface. The recovery of surface DNA using a commercially available hydrogel was examined, and the efficiency compared to samples collected using a standard foam collection swab. DNA collected using the hydrogel and swab methods was then examined using quantitative polymerase chain reaction (qPCR) and short tandem repeat (STR) analysis to determine whether the collection material was compatible with these downstream processes. The hydrogel material used for this study collected the experimental DNA with comparable efficiency to standard collection swabs. In addition, qPCR and STR analyses demonstrated compatibility with the hydrogel collection and extraction process. These data suggest that hydrogels have the potential to be used as sample collection materials and deserve further characterization to elucidate their utility in collection from irregularly shaped, three-dimensional surfaces/materials.     

A systematic approach to improve downstream single-cell analysis for the DEPArray™ technology

Most commercially available STR amplification kits have never been fully validated for low template DNA analysis, highlighting the need for testing different PCR kits and conditions for improving single-cell profiling. Here, current strategies rely mainly on adjusting PCR cycle number and analytical threshold settings, with a strong preference for using 30 amplification cycles and thresholds at 30–150 RFU for allele detection. This study aimed to (1) determine appropriate conditions for obtaining informative profiles utilizing a dilution series, and (2) test the outcome on single cells using the DEPArray™ technology. Four routinely applied forensic STR kits were compared by using three different amplification volumes and DNA dilutions down to 3.0 pg, while two well-performing kits were used for single/pooled leucocyte and sperm cell genotyping. Besides reduced costs, the results demonstrate that a 50%–75% PCR volume reduction was beneficial for peak height evaluation. However, this was counteracted by an increased artifact generation in diluted DNA volumes. Regarding profile completeness, the advantage of volume reduction was only prominent in samples processed with Fusion 6C. For single and pooled cells, ESIFast and NGMDetect provided a solid basis for consensus profiling regarding locus failure, although locus dropouts were generally observed as stochastic events. Amplification volume of 12.5 μL was confirmed as appropriate in terms of peak heights and stutter frequencies, with increased stutter peaks being the main artifact in single-cell profiles. Limitations associated with these analyses are discussed, providing a solid foundation for further studies on low template DNA.     

网络空间供应链国际规范研究——构建供应链生态系统总体安全观

随着全球信息通信产业的深度融合,供应链已日益成为网络空间中主要的安全威胁来源,各国在供应链安全领域对国际规范的需求日益提升。然而,以2015年联合国信息安全政府专家组报告为共识基础的"GGE供应链规范"由于在内容上过于专注西方国家所重视的技术攻击威胁,忽视了中国等发展中国家避免对环境进行干预和扰乱的需求,导致了"技术安全观"与"环境安全观"之间的倾向差异。加之存在条文表述上的模糊与缺陷,"GGE供应链规范"无法满足当前的现实安全需要。应当在兼顾各方立场的基础上,构建供应链生态系统总体安全观,并厘定新的总规范表述以统领整个体系架构。     

15重快速STR复合扩增体系的构建

目的建立一套15重快速STR复合扩增体系。方法选择14个常染色体基因座以及1个性别基因座,采用Fast Start Taq DNA聚合酶系统,以DNA标准品9947A为模板,通过筛选扩增条件、选择热启动酶用量、调整引物平衡、优化快速扩增程序、筛选反应缓冲液、选择反应体系以及筛选添加剂等一系列复合扩增实验,比较各条件下等位基因丢失和非特异性扩增情况。结果在以1 ng DNA为模板、0.4μL聚合酶及10×Fast Start高保真反应缓冲液构成10μL快速体系的条件下,32 min即可获得标准DNA全部15个STR基因座的完整分型,无等位基因丢失和非特异性扩增现象,等位基因均衡性良好。同时,5%甘油、0.01%明胶、0.05%明胶和5 mmol/L硫酸铵可作为PCR扩增过程中拟加入的反应添加剂。结论本研究建立的15重快速STR复合扩增体系可以明显缩短反应时间,提高样品检测效率。     

对现场勘查见证人制度的反思

本文介绍了现场勘查见证人制度的立法初衷,阐明了该制度在实践运行中出现的问题。而后笔者结合我国的现实条件对该制度是否具备合理性、实用性、有效性进行了反思,并指该制度本质上存在着难以弥补的缺陷、运行中会遇到无法消除的障碍。最后,笔者在比较权衡了域外相关制度后,秉承破旧立新之精神,建议废除现场勘查中的见证人制度,并用证据监管链条程序和勘查同步录像与庭审播放制度取而代之。     

口蹄疫病毒单链抗体基因的构建及其推导蛋白三维结构的分子模拟

用口蹄疫病毒(FMDV)Asial/JS/China/2005株灭活抗原免疫家兔,从兔脾细胞中提取RNA作为模板,通过PCR及重叠PCR方法构建出FMDV的单链抗体基因.测序结果显示,序列中有重链可变区(VH)及轻链可变区(VL)基因,经Blast比较,发现VH、VL的相似性最高分别可达81.0%和93.0%,且在序列中有连接VH及VL的柔性接头(Gly_4Ser)_3.用EXPASY软件包预测了推导蛋白的特性.运用Swiss-pdb viewer软件的SWISS-Model处理器对构建的单链抗体基因推导的蛋白序列进行了三维结构的分子模拟.拉马钱德兰图证明,所模拟的单链抗体的三维结构较为合理.     

三种贝类原虫多重PCR检测方法的建立

根据基因库中单孢子虫、派琴虫和马尔太虫的基因序列,分别设计了3对特异性引物,通过对多重PCR扩增条件的优化,建立了可同时检测鉴别这3种原虫的多重PCR方法.用该技术对同一样品中的单孢子虫、派琴虫和马尔太虫模板进行扩增,结果均同时得到3条大小与试验设计相符的244 bp(单孢子虫)、596 bp(派琴虫)和478 bp(马尔太虫)的特异性扩增带,对其他贝类病原核酸的扩增结果为阴性.敏感性试验结果表明,该技术最低能检测到10 pg的单孢子虫、派琴虫和马尔太虫DNA,提示该技术适用于这3种原虫的临床快速检测和鉴别诊断.     

群体性突发事件的机理研究

群体性突发事件的发生不是孤立事件,而是一系列时间相继发生的结果。借用美国海因里希的事故因果连锁分析模型和社会物理学的社会燃烧理论进行探讨分析,结论是：任何事件的产生都必须具备三个基本条件,一是燃烧材料,二是助燃剂,三是点火温度。三个基本条件缺一不可。在因果连锁模型中把社会环境不稳定状态视为“燃烧物质”,而信息熵视为“助燃剂”,群体性突发事件视为“点火温度”。明确每一个方面的机理机制,提出治理措施,才能把问题解决好。