Determination of postmortem interval from old skeletal remains by image analysis of luminol test results.

The luminol test is routinely used in forensic serology to locate blood traces and identify blood stains not visible to the naked eye; its sensitivity is reported as ranging from 1:100,000 to 1:5,000,000. To evaluate the possibility of correlating the postmortem interval with blood remnants in bone tissue, the luminol test was performed on 80 femurs with a known time of death, grouped in five classes. Powdered bone (30 mg) was recovered from compact tissue of the mid-shaft of each femur and was treated with 0.1 mL of Luminol solution (Sirchie Finger Print Laboratories, Inc.). The reactions were observed in a dark room and filmed by a TV camera equipped with a recording tape. An intense chemiluminescence was observed after a few seconds in all 20 femurs with a PMI ranging from 1 month to 3 years. On the 20 femurs with a PMI ranging from 10-15 years, a clear chemiluminescence was visible with the naked eye in 80% of the sample. Among the 20 femurs with a PMI ranging from 25 to 35 years, a weaker chemiluminescence appeared in 7 femurs (33% of the sample). In the 10 femurs with a PMI ranging from 50 to 60 years, a faint reaction was observed only in a single femur. In none of the ten femurs with a PMI over 80 years was chemiluminescence observed. The image of each reaction was computerized and analyzed for gray scale. The results of image analysis show a possible quantitative relationship between the PMI and luminol chemiluminescence in powdered bone.     

Illuminating the health and safety of luminol

Luminol is a reagent that is used to enhance areas of non-visible bloodstaining and it is one of the most sensitive of such reagents available to the forensic scientist. However, its use, particularly within the UK and some other European countries, has been limited, predominantly due to concerns about the health and safety of the reagent. This paper reviews the literature currently available regarding the health and safety of luminol, and in the authors' view demonstrates that there are no significant health and safety concerns with the preparation of luminol solution and its application at the crime scene or in the laboratory, providing suitable precautions are taken.     

Inhibition of bleach-induced luminol chemiluminescence

The luminol chemiluminescence presumptive test for blood is based on the mild peroxidase activity of hemoglobin in basic peroxide solution. However, this test is subject to interference by strong oxidants, certain transition metal ions, and true peroxidases. This paper reports methods for reducing the interference caused by hypochlorite-containing bleaches. Amines such as 1,2-diaminoethane react rapidly with hypochlorite without interfering significantly with the hemoglobin-catalyzed oxidation. Thus, addition of 0.1 mol/L 1,2-diaminoethane to a standard luminol-peroxide spray lead to almost complete inhibition of hypochlorite-induced chemiluminescence while satisfactory chemiluminescence was still observed from bloodstains. If time allows, an alternative method for reducing interference from hypochlorite bleach is to wait several days until the bloodstains have dried thoroughly, by which time the hypochlorite will have decomposed.     

Evaluation of the catalytic decomposition of H2O2 through use of organo-metallic complexes--a potential link to the luminol presumptive blood test

Hair testing for drugs of abuse is performed in Lombardy by eleven analytical laboratories accredited for forensic purposes, the most frequent purposes being driving license regranting and workplace drug testing. Individuals undergoing hair testing for these purposes can choose the laboratory in which the analyses have to be carried out. The aim of our study was to perform an interlaboratory exercise in order to verify the level of standardization of hair testing for drugs of abuse in these accredited laboratories; nine out of the eleven laboratories participated in this exercise. Sixteen hair strands coming from different subjects were longitudinally divided in 3-4 aliquots and distributed to participating laboratories, which were requested to apply their routine methods. All the participants analyzed opiates (morphine and 6-acetylmorphine) and cocainics (cocaine and benzoylecgonine) while only six analyzed methadone and amphetamines (amphetamine, methamphetamine, MDMA, MDA and MDEA) and five Δ(9)-tetrahydrocannabinol (THC). The majority of the participants (seven labs) performed acidic hydrolysis to extract the drugs from the hair and analysis by GC-MS, while two labs used LC-MS/MS. Eight laboratories performed initial screening tests by Enzyme Multiplied Immunoassay Technique (EMIT), Enzyme-linked Immunosorbent Assay (ELISA) or Cloned Enzyme Donor Immunoassay (CEDIA). Results demonstrated a good qualitative performance for all the participants, since no false positive results were reported by any of them. Quantitative data were quite scattered, but less in samples with low concentrations of analytes than in those with higher concentrations. Results from this first regional interlaboratory exercise show that, on the one hand, individuals undergoing hair testing would have obtained the same qualitative results in any of the nine laboratories. On the other hand, the scatter in quantitative results could cause some inequalities if any interpretation of the data is required.     

Effects of luminol on the subsequent analysis of bloodstains.

The effects of luminol upon additional presumptive chemical tests, subsequent confirmatory blood tests, species determination by immunoelectrophoresis, ABO typing by absorption elution, and genetic marker analysis by multienzyme system electrophoresis were examined. Results indicate that luminol does not affect additional presumptive chemical tests, confirmatory tests, species determination, or ABO typing, but does affect certain genetic marker systems.     

用复合扩增方法检测4个Y-STR基因座单倍型

目的建立复合扩增Y-STR基因座的体系,获得中国汉族人的单倍型频率。方法复合扩增DYS439、DYS390、GATA-A7.2和DYS3934个基因座,用聚丙烯酰胺凝胶电泳和银染法进行基因分型。结果调查中国汉族558名无关男性个体,4个基因座分别检出7、7、7和6个等位基因,共180种单倍型,其单倍型的个体识别率为0.9853。结论该复合扩增体系在建立Y染色体STR数据库、在群体遗传研究和法医学鉴定中有应用意义。     

荧光复合扩增检测3个Y—STR基因座单倍型

目的建立检测3个Y-STR基因座Y-GATA-A7.1、DYS456和DYS443的荧光复合扩增体系,并获取中国汉族人群单倍型频率分布。方法用荧光标记引物对郑州地区203名汉族男性无关个体进行3个基因座复合扩增,ABI3100型遗传分析仪检测、分型。结果Y-GATA-A7.1、DYS456和DYS443基因座分别检出5、6和6个等位基因,其基因多样性(GD值)分别为0.6692、0.5839和0.7053。三个基因座构成的单倍型共有44种,单倍型多样性(HD值)为0.9523。结论建立的3个Y-STR基因座荧光标记复合扩增系统具有很高的识别能力,可应用于法医学实践。     

流动注射—化学方光法检测人体血清内枸橼酸芬太尼

目的建立灵敏测定生物样品中皮克级枸橼酸芬太尼的方法。方法使用流动注射-化学发光法、鲁米诺-溶解氧体系检测芬太尼,蠕动泵流速2.0mL/min,鲁米诺与NaOH混合后被六通阀定量注入系统直至形成稳定基线,同时将样品推进送入混合管。碱性混合液被送入化学发光流通池产生化学发光,光电倍增管和光度计即检测到发光信号强度。结果在1.0～700pg/mL线性范围内,化学发光强度与芬太尼浓度呈线性关系,且发光强度随浓度增大呈增敏趋势,检出限低至0.3pg/mL。相对标准偏差在3.0%以内。分析过程可在30s内完成,采样频率120次/h。回收率98.9%～103.1%。结论该方法已经成功应用于检测人体血清中的枸橼酸芬太尼。     

Identification of hemoglobin derivatives by means of electrofocusing

A method for the identification and quantitation of hemoglobin derivatives is described. Samples diluted 1 in 100 were applied to precoated polyacrylamide-gel plates containing an Ampholine gradient of pH 3.5 – 9.5 and focused for 1.5 h at a constant 40 W. All hemoglobins under investigation were characterized by specific patterns which allow them to be differentiated. Electrofocusing is recommended for screening tests, but quantitative evaluation using densitometry is possible as well.     

Sex assessment from the acetabular rim by means of image analysis

Determining sex from skeletal remains is one of the most important steps in archaeological and forensic anthropology. The present study considers the diagnostic value of the acetabulum based on its planar image and related metric data. For this purpose, 83 adult os coxae of known age were examined. Digital photos of the acetabular area were taken, with each bone in a standardized orientation. Technical drawing software was used to trace the acetabular rim and to measure the related dimensions (area, perimeter, longitudinal and transverse maximum width). The measurements were subjected to SPSS discriminant and classification function analysis. There were significant differences (p相似文献   

A more sensitive method for the quantitation of genomic DNA by Alu amplification

Current procedures for human DNA quantitation reach their limit at 150 pg DNA, which is above the limit of the PCR profiling range using Profiler-Plus (Applied Biosystems, CA). This study tested the potential for the use of primate specific Alu sequences in forensic science for the sensitive detection and quantitaion of DNA. A fluorescently labelled primer pair was designed enabling high efficiency amplification of the core Alu sequence within primate DNA. Quantitation was performed by measurement of fluorescence intensity and comparison to a series of standard template DNA amounts via the construction of a standard curve. The new Alu-based quantitation protocol developed has shown its feasibility in more sensitively quantitating (100-2.5 pg) unknown amounts of human DNA for forensic use. The method is compatible with the use and throughput of current forensic procedures.     

PCR扩增SON基因3’非编码区进行种属鉴定

根据人 DNA的 SON基因碱基序列选择性设计一对特异性引物 ,并对人和猕猴、阿拉伯狒狒、猪、牛、羊、马、驴、骡、狗、猫、兔、大白鼠、小白鼠、豚鼠等 14种哺乳类动物染色体 DNA的 SON基因 3’非编码区中的种属特异性区域进行 PCR扩增 ,扩增产物经 SSCP分离银染色技术检测 ,观察到人和 14种哺乳类动物的 SSCP图谱有明显不同。本方法可以对人和上述 14种哺乳类动物进行种属鉴定 ,适合于法医学种属鉴定的应用     

运用二重PCR和DNA芯片技术检测ABO基因型

目的以玻片为载体,用寡核苷酸探针杂交技术检测ABO基因型。方法根据ABO基因座外显子6和外显子7的3个SNP点的序列分布特征设计4条寡核苷酸探针,制成分型芯片。将待测样品DNA用末端标记了Cy5的引物进行二重PCR扩增,产物与芯片上的探针进行杂交,根据杂交产生的荧光信号确定样品的ABO基因型。结果利用ABO芯片,可对血斑、毛发等微量检材进行ABO基因型检测。对115名汉族无关个体的调查表明,ABO基因型的分布符合Hardy-Weinberg平衡,等位基因杂合度观察值和期望值分别为0.591、0.616,多态信息含量为0.544,二联体和三联体非父排除率分别为0.188、0.334,个体识别能力为0.777。结论通过DNA芯片检测ABO基因型的技术适用于法医学样本,可满足高通量的检测需求。     

如何认定以危险方法危害公共安全罪

我国刑法第114条规定拟危险方法危害公共安全罪,鉴于该罪在立法上并无明确的构成要件,因此,有必要时该罪的构成特征及司法认定进行分析探讨,以有助于司法机关正确运用本罪.     

如何认定以危险方法危害公共安全罪

我国刑法第114条规定拟危险方法危害公共安全罪，鉴于该罪在立法上并无明确的构成要件，因此，有必要时该罪的构成特征及司法认定进行分析探讨，以有助于司法机关正确运用本罪。     

依间接证据认定协同行为的证明结构

作为垄断协议的一种高级形式——协同行为,其在实施中往往不会遗留直接证据。如何利用间接证据来证明公司间的价格行为属于协同行为成为现代各国反垄断机构的挑战性的课题。利用欧美等国家(地区)的相关判例,并借助于间接证据的特殊分类及在分类证据组合上的特殊性来推定某些行为属于卡特尔,是解决这一难题的有效方法。