牛伪狂犬病的实验室诊断

对不明原因役牛猝死症病料组织触片镜检和分离培养皆未发现细菌;乳胶凝集试验检查发现3份送检血清皆为伪狂犬病病毒(PrV)抗体阳性;ELISA检测结果,其中2份为PrV gE抗体阳性,而且这2份血清PrV中和抗体也为阳性;以脑组织制备DNA模板进行PCR,扩增到特异性的PrV DNA片段;对健康成年兔接种病牛脑、肺等病料,表现典型的伪狂犬病症状.综合流行病学、细菌学、血清学、分子生物学和动物试验结果,确诊为牛伪狂犬病.     

用多聚酶链反应检测非洲猪瘟病毒的研究

用HindⅢ对非洲猪瘟病毒核酸的重组质粒pRPEL2进行酶切后,将第5片段插入到pT7/T3α-19上而得到亚克隆重组质粒pT7 ASFH5。用双脱氧末端终止法测定了该插入片段的核苷酸序列。在此基础上选择了一段含194bp的片段作为扩增模板,并人工合成了该片段两端含20个碱基的寡核苷酸作为引物,从而建立了诊断非洲猪瘟病毒的多聚酶链反应。与核酸杂交相比,该方法不但更为快速和简便,而且灵敏度提高了一千万倍左右.     

扩增X—Y同源Amelogenin基因内含子在性别鉴定中的应用研究

本文用一对针对X－Y同源的Amelogenin基因第一内含子的引物，于同一试管中分别扩增出针对于x和Y染色体的特异性DNA片段：106bp及112bp的PCR产物，经聚丙烯酰胺凝胶电泳后用银染法观察扩增结果，取得了满意的效果．对50pgDNA模板室温放置16年的血痕及单根毛发、烟头等检材均可得到明确的性别鉴定结果．本实验证明该方法简便、灵敏、可靠、特别适用于腐败降解检材的法医学性别鉴定．     

9个Y-STR基因座荧光复合扩增系统的法医学应用

目的建立9个Y-STR基因座的复合扩增系统,提高Y-STR的法医学检测效能。方法6-FAM标记DYS434、Y-GATA-A10、DYS438、DYS439,HEX标记DYS531、DYS557、DYS448,TAMRA标记DYS456、DYS444引物,PCR复合扩增,毛细管电泳得到结果,考察扩增系统的个体识别能力、灵敏度、特异性、组织同一性。结果所建立的9个Y-STR复合扩增系统分型清晰,单倍型多样性达0.9968,特异性好,灵敏度高(0.5ngDNA),并且在男女混合斑检验上较常染色体STR分型更有优势。结论9个Y-STR复合扩增系统具有较高的识别能力,对建立Y染色体STR数据库,研究群体遗传学和进行法医学混合斑物证鉴定有重要意义。     

Characterization of the N+3 stutter product in the trinucleotide repeat locus DYS392

Stutter products generated during DNA amplification by the polymerase chain reaction (PCR) may complicate mixture interpretation. The PCR amplification of the DYS392 locus typically results in three distinct detectable PCR products: the true allele product (N), a stutter product three bases smaller (N-3), and a reproducible low-level product, three bases larger (N+3). Sequence analysis of the N+3 product demonstrated that its sequence is one TAT repeat longer than the true allele product. Our experiments demonstrated that the quantity of both N-3 and N+3 stutter increased as the allele number increased. The percent stutter also increased as the magnesium concentration was increased in the reaction, as well as when the amount of input DNA was decreased. As both stutter products behave in a similar and reproducible fashion, the same rules that apply to the interpretation of N-3 stutter products in short tandem repeat analysis, can be applied to N+3 stutters. The characterization of the DYS392 N+3 product is the first detailed published study of a stutter product larger than the true allele.     

广东广西地区5个群体9个STR基因座的频率调查

目的 调查广东汉族、广西汉族、广西侗族、广西壮族、广西苗族5个群体9个STR基因座多态性,探讨其在法医学检验中的应用价值。方法 应用AmpFISTR Profiler PlusTM荧光标记复合扩增系统,对广东广西5个群体4个民族的1191个无关个体的血样DNA进行9个STR基因座的复合扩增;用ABI 3100遗传分析仪对扩增产物进行分型,统计9个STR基因座的群体遗传学参数。结果 9个STR基因座在广东广西地区5个群体中的累积偶合率为1.51×10-11～8.08×10-11,累积非父排除率为0.99981—0.99990。,结论 该9个STR基因座可满足汉族、壮族、侗族、苗族群体法医学的个体识别及亲权鉴定的需要。     

北京市科级公务员量化考核研究

量化考核是公务员考核的一个难点,也是目前我国基层政府公务员考核工作需认真面对并要切实加以解决的一个重点。本文对近些年北京市公务员管理部门和部分行政机关开展的科级公务员量化考核的实践做了一个初步的经验性总结,并试图在理论上对目前北京市公务员量化考核的不足和下一步应该改进的政策建议加以分析和说明,旨在推进北京市公务员量化考核的实践,进一步完善北京市公务员的考核制度。     

激光显微切割技术与低体系扩增方法的法医学应用探索

目的建立减少DNA低体积扩增过程中产生气泡的方法。方法采用激光显微切割技术、PALM系统收集目标细胞,并在1μL～1.5μL低体积扩增样本,加入扩增液0.7μL～0.8μL。结果低体积扩增反应中的失败位点比例为2.3%,比常规反应位点时常会产生气泡导致该位点样本扩增失败且达30%以上的比例显著降低。结论低体积扩增方法可以减少或克服扩增过程中气泡的产生,提高扩增成功率。     

关于社会科学中量化研究的深层思考

在量化研究中,研究者通常从特定的研究假设出发,通过对抽象概念的操作化定义确定变量,并运用问卷、量表、结构式访谈与观察等方法收集资料,然后进行统计分析来检验研究假设。本文旨在探讨量化研究的本体论前提,并从认识论和方法论视角分析量化研究中的可靠性和有效性问题。     

An innovative transfer DNA experimental design and qPCR assay to identify primary,secondary, and tertiary DNA transfer

“Touch DNA” is a form of trace DNA that is presumed to be deposited when an individual touches something and leaves behind DNA-containing skin cells, sweat, or other fluids. While touch DNA is often the result of direct contact (i.e., primary transfer), it can also be indirectly transferred between surfaces or individuals (e.g., secondary or tertiary transfer). Even experts cannot distinguish between different types of transfer and do not fully understand which variables affect direct versus indirect transfer or how often each type of transfer occurs. In this study, we utilize an innovative protocol that combines a paired male and female transfer DNA experimental design with an Amelogenin qPCR assay to generate data on primary, secondary, and tertiary DNA transfer. We report frequencies of indirect DNA transfer and also investigate the potential effects of participant age, self-identified ethnicity, and skin conditions on DNA transfer. Out of 22 experimental trials, we detected primary transfer (male + female) in 71% of trials, secondary DNA transfer in 50% of trials, and tertiary DNA transfer in 27% of trials. No significant associations were found between primary DNA transfer and age, self-identified ancestry, or skin conditions, however, all individuals with sloughing skin conditions demonstrated primary DNA transfer and we suggest this variable be explored in larger samples. These results contribute to a better understanding of the conditions under which secondary and tertiary DNA transfer occurs and can be used to propose realistic DNA transfer scenarios in court cases.