温州汉族人群D7S2846、D19S400和D18S535基因座的遗传多态性研究

目的研究D7S2846、D19S400和D18S535位点在温州汉族人群的遗传多态性。方法EDTA抗凝血样采自194名无血缘关系温州地区汉族个体,用chelex-100法提取DNA,PCR扩增,聚丙烯酰胺凝胶电泳,银染显色分析。结果D7S2846观察到6个等位基因及15种基因型;D19S400观察到10个等位基因及36种基因型;D18S535观察到8个等位基因及26种基因型。各基因座的杂合度(H)分别为:0.644、0.724、0.772;个人识别能力(Dp):0.854、0.940、0.938。结论三个STR基因座具有较高杂合度,等位基因分布符合Hardy-Weinberg平衡,在法医学应用和群体遗传学研究中有较高的价值。     

超生反应阶段骨骼肌机械性损伤的形态学研究

对20例1．25～8．30hpm具有超生反应能力的尸检骨骼肌和17例10～24hpm和48～60hpm不具超生反应能力的尸检骨骼肌进行机械性损伤刺激的形态学系列对比研究。结果表明，经机械打击刺激后，具超生兴奋性的肌肉，受打击部位的肌纤维出现类似典型生前伤征象的形态学改变，而不具超生兴奋性的肌纤维仅出现被动的肌纤维断裂等非活性肌纤维改变。通过对超生形态学反应的形成机理进行探讨，为进一步研究超生形态学的作用提示了前景。     

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。     

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.     

Guardians of the environment in Canada’s Chemical Valley

Citizens of the Aamjiwnaang First Nation fight for justice with their bodies at the frontlines of daily toxic exposure. This paper examines struggles for environmental and reproductive justice in the polluted heart of Canada’s ‘Chemical Valley’. These are as struggles over life, land and knowledge. Based upon community-engaged qualitative research, from a participatory action research approach, including field immersion, participant observation and 35 in-depth interviews with First Nations residents, I document the Aamjiwnaang First Nation’s citizens’ activities and practices on the ground as they cope with the impact of their contaminated surroundings on their health and habitat. This community-engaged scholarship lens brings into view the lived experiences and ongoing practices of resistance by the Anishinabek citizens who are surrounded by Chemical Valley. I situate these struggles within the green citizenship literature to assess three blind spots of green governmentality: greening citizenship, lifestyle blame and Western dualisms. I discuss the multiple edges of ecological citizenship and argue that citizens are simultaneously bound up within disciplinary power relations and place-based belonging. This place, although polluted, is crucial to practices of relational Anishinabek citizenship and the identity of indigenous citizens who call this place both ‘prison and home’.     

Latent Fingermark Aging Patterns (Part II): Color Contrast Between Ridges and Furrows as One Indicator of Degradation

Currently, no established methodology exists to determine degradation patterns of latent fingermarks by visual means. This article is the second in a series of reports exploring quantifiable degradation‐related parameters, which focuses on color contrast changes between fingermark ridges and furrows over time. Experiment variables included type of secretion (eccrine and sebaceous), substrate (glass and plastic), and exposure to natural light (dark, shade, and direct light). Fingermarks were sequentially visualized with titanium dioxide powder and photographed. Image histogram profiles were evaluated and combined with statistical analysis of color data values. Results indicate that sebaceous depositions on glass were generally less degraded by the effect of environmental conditions compared with those on plastic. In addition, aging in darkness was not always the best condition for preservation, and direct exposure to light seemed to inhibit visual degradation under certain conditions. Overall, the technique provided sufficient sensitivity to discern degradation patterns of fingermarks.     

早期死亡时间推断研究进展

死亡时间推断在判断案件的性质、划定侦查范围及锁定嫌疑人等方面至关重要,一直是法医病理学工作的重点和难点。早期死亡时间,即指死后24 h以内,由于距离案发时间更短,对其准确推断能促进案件的成功侦破,具有重要的法医学意义。近年来,国内外法医学者运用一系列新方法和新技术对早期死亡时间推断进行了大量研究。本文对体液生物化学、超生反应、代谢组学、影像学、遗传物质降解规律等方面的研究进展进行综述,以期为早期死亡时间推断的研究和应用提供新的思路。     

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。     

针刺调节缺血性脑卒中患者颅内动脉血流动力学参数临床观察

目的 采用经颅彩色多普勒检查评价针刺对缺血性脑卒中患者脑血流动力学参数的影响。方法 将100例缺血性脑卒中患者随机分为联合组和对照组,每组50例。联合组采用针刺风池、风府配合常规针刺治疗,对照组采用常规针刺治疗。采用改良爱丁堡+斯堪的纳维亚评分观察两组临床疗效;针刺后即刻、针刺2个疗程后,分别测定两组颅内各动脉平均血流速度(mean flow velocity,Vm)和血管搏动指数（pulsatility index,PI）。 结果 ①联合组临床疗效优于对照组（P<0.05）。②针刺后即刻,联合组各动脉Vm较针刺前均显著增加（P<0.01）,且联合组大脑后动脉(posterior cerebral artery,PCA)、大脑前动脉（anterior cerebral artery, ACA）、椎动脉（vertebral artery, VA）、基底动脉（basilar artery, BA）Vm较对照组显著增加（P<0.05,或P<0.01）;两组各动脉PI值与针刺前比较,及两组之间比较,差异均无统计学意义（P>0.05）。③针刺2个疗程后,两组各动脉Vm均较针刺前显著增加（P<0.01）;且联合组各动脉Vm均显著高于对照组（P<0.05）;联合组PCA、VA、BA的PI值较针刺前显著降低（P<0.05,或P<0.01）,且联合组PCA、VA的PI值显著低于对照组（P<0.05）。结论 针刺风池、风府配合常规针刺对缺血性脑卒中有较好的治疗作用,且脑血流量增加,脑血液循环改善明显。