死亡人体胸肌组织中rRNA亚基的稳定性评价

目的观察尸体胸大肌组织中rRNA各亚基表达水平的死后稳定性,探讨其在死亡时间推断中应用的价值。方法选取6例（3例成人、3例婴幼儿）外界温、湿度环境基本一致、死亡时间基本一致（24h以内）的个体,提取左侧胸大肌组织,在PBS缓冲液中低温冻存,分别在尸检即刻、2、3、4、5、6、7、8、9、10d提取微量组织保存于RNA固定液中,通过实时荧光定量RT-PCR技术检测rRNA 5srRNA、5.8srRNA、18srRNA、28srRNA亚基的表达水平。并分析年龄、死因对rRNA亚基表达水平的影响。结果死后各时间点rRNA各亚基的表达随死后经过时间延长无显著性降解,Ct值变化与死后经过时间无相关性（P值均大于0.05）,其中5s rRNA在18.503±2.655~20.937±2.340之间,5.8s rRNA在17.687±3.011~20.617±2.204之间,18s rRNA在16.457±3.920~22.330±2.571之间,28s rRNA在15.077±6.051~22.207±2.685之间。结论人体胸肌组织中rRNA各亚基稳定性好,其各亚基的表达量与死因、年龄无关,适于作为晚期死亡的推断的内参基因。     

Identification of blood stains and fetal tissue using genetic fingerprinting

Two cases from practical forensic serological investigations which could not be clarified by means of conventional serological methods, but could be resolved on the basis of the DNA finger print technique with oligonucleotide probes are presented. Both the comparison of the identity of the blood sample which had been stored for a long time and the determination of paternity in fetal material in a case of incest demonstrate the enormous possibilities of this method. However, some problems which still have not been resolved at least at present with regard to the evaluation and appraisal of the band patterns are also discussed.     

Comparative characteristics of various methods of sample preparation for determining ethanol in muscle tissue

Three methods for sample preparation for ethanol detection by gas chromatography are compared. The highest ethanol output was obtained after preparation by 5-min heating of the biological object and the internal reference object with addition of trichloroacetic acid as the acidifier. Relationship between the results of ethanol measurements and the degree of muscle crushing was evaluated.     

A laboratory incubation method for determining the rate of microbiological degradation of skeletal muscle tissue in soil

A controlled laboratory experiment is described, in principle and practice, which can be used for the of determination the rate of tissue decomposition in soil. By way of example, an experiment was conducted to determine the effect of temperature (12 degrees, 22 degrees C) on the aerobic decomposition of skeletal muscle tissue (Organic Texel x Suffolk lamb (Ovis aries)) in a sandy loam soil. Measurements of decomposition processes included muscle tissue mass loss, microbial CO2 respiration, and muscle tissue carbon (C) and nitrogen (N). Muscle tissue mass loss at 22 degrees C always was greater than at 12 degrees C (p < 0.001). Microbial respiration was greater in samples incubated at 22 degrees C for the initial 21 days of burial (p < 0.01). All buried muscle tissue samples demonstrated changes in C and N content at the end of the experiment. A significant correlation (p < 0.001) was demonstrated between the loss of muscle tissue-derived C (Ct) and microbially-respired C (Cm) demonstrating CO2 respiration may be used to predict mass loss and hence biodegradation. In this experiment Q10 (12 degrees C-22 degrees C) = 2.0. This method is recommended as a useful tool in determing the effect of environmental variables on the rate of decomposition of various tissues and associated materials.     

Identification of N,N-dimethylamphetamine formed by methylation of methamphetamine in formalin-fixed liver tissue by multistage mass spectrometry

Methamphetamine is methylated in the presence of unbuffered formalin solutions within hours at room temperature. The product, N,N-dimethylamphetamine, is also found in human liver exposed to methamphetamine followed by incubation with formalin. In the present study, a direct mass spectrometric method was developed to identify N,N-dimethylamphetamine in human liver before and after treatment with formalin. Human liver samples were obtained from four deaths that were investigated by the West Virginia Office of Chief Medical Examiner. Full toxicological analysis was conducted on samples from the decedents and methamphetamine was among the positive findings in each case. The method used to expose liver tissue to formaldehyde involved treating a small piece of liver from each case with formalin solution (20% v/v) for 24 h at room temperature. The formalin treated tissues were homogenized and the resulting suspension was sonicated for 5 min, and then centrifuged. Supernatant aliquots were directly analyzed by electrospray ionization (ESI) mass spectrometry without chromatographic isolation. Positive ion multistage mass spectra recorded in MS, MS/MS and MS/MS/MS (MS3) modes were used to confirm the presence of N,N-dimethylamphetamine and methamphetamine in the mixture. Liver tissue not treated with formalin did not contain a detectable level of N,N-dimethylamphetamine. Decreases in methamphetamine concentrations in liver tissue resulting from treatment with formalin were measured using deuterium-labeled methamphetamine as internal standard. The method can be completed in less than 2 h on thawed tissue. The results suggest that the process of fixing tissues with formalin may lead to false negative findings for methamphetamine.     

5例内固定取出术后再骨折的因果关系鉴定

目的 分析骨折内固定取出术后再发骨折的原因,探讨再骨折因果关系评定的原则.方法 回顾分析5例骨折内固定取出术后再发骨折的原因及其与原发损伤的因果关系.结果 5例发生再骨折者多为中青年,无过早取内固定的情形,无明显外伤史(1例有轻微外伤).结论 内固定本身的因素导致骨折处的骨量下降、不恰当的内固定取出时机、不适当的功能锻炼及外伤都是再骨折的可能原因,在因果关系分析时需注意界定一因还是多因形式,并注意区别多因比例.     

Freezing skeletal muscle tissue does not affect its decomposition in soil: Evidence from temporal changes in tissue mass,microbial activity and soil chemistry based on excised samples

The study of decaying organisms and death assemblages is referred to as forensic taphonomy, or more simply the study of graves. This field is dominated by the fields of entomology, anthropology and archaeology. Forensic taphonomy also includes the study of the ecology and chemistry of the burial environment. Studies in forensic taphonomy often require the use of analogues for human cadavers or their component parts. These might include animal cadavers or skeletal muscle tissue. However, sufficient supplies of cadavers or analogues may require periodic freezing of test material prior to experimental inhumation in the soil. This study was carried out to ascertain the effect of freezing on skeletal muscle tissue prior to inhumation and decomposition in a soil environment under controlled laboratory conditions. Changes in soil chemistry were also measured. In order to test the impact of freezing, skeletal muscle tissue (Sus scrofa) was frozen (?20 °C) or refrigerated (4 °C). Portions of skeletal muscle tissue (～1.5 g) were interred in microcosms (72 mm diameter × 120 mm height) containing sieved (2 mm) soil (sand) adjusted to 50% water holding capacity. The experiment had three treatments: control with no skeletal muscle tissue, microcosms containing frozen skeletal muscle tissue and those containing refrigerated tissue. The microcosms were destructively harvested at sequential periods of 2, 4, 6, 8, 12, 16, 23, 30 and 37 days after interment of skeletal muscle tissue. These harvests were replicated 6 times for each treatment. Microbial activity (carbon dioxide respiration) was monitored throughout the experiment. At harvest the skeletal muscle tissue was removed and the detritosphere soil was sampled for chemical analysis. Freezing was found to have no significant impact on decomposition or soil chemistry compared to unfrozen samples in the current study using skeletal muscle tissue. However, the interment of skeletal muscle tissue had a significant impact on the microbial activity (carbon dioxide respiration) and chemistry of the surrounding soil including: pH, electroconductivity, ammonium, nitrate, phosphate and potassium. This is the first laboratory controlled study to measure changes in inorganic chemistry in soil associated with the decomposition of skeletal muscle tissue in combination with microbial activity.     

Identification of human skin from a tissue fragment by detection of squamous cell carcinoma-related antigen using an enzyme immunoassay

A new method of identifying human skin from a tissue fragment by detection of squamous cell carcinoma-related (SCC) antigen, using an enzyme immunoassay, was developed. When an extract was prepared from 0.1 g human skin homogenized with 1 ml of phosphate buffered saline, this method was able to detect SCC antigen in extracts diluted 10²-fold. There was no difference in the detection limit between individuals. Species specificity was good, and there was no cross reaction observed with skins from animals. Our method could also discriminate between skin and other organs or tissues, except for esophagus and lung. A practical case to which this method was applied is presented.     

Expertise in Fingerprint Identification

Although fingerprint experts have presented evidence in criminal courts for more than a century, there have been few scientific investigations of the human capacity to discriminate these patterns. A recent latent print matching experiment shows that qualified, court‐practicing fingerprint experts are exceedingly accurate (and more conservative) compared with novices, but they do make errors. Here, a rationale for the design of this experiment is provided. We argue that fidelity, generalizability, and control must be balanced to answer important research questions; that the proficiency and competence of fingerprint examiners are best determined when experiments include highly similar print pairs, in a signal detection paradigm, where the ground truth is known; and that inferring from this experiment the statement “The error rate of fingerprint identification is 0.68%” would be unjustified. In closing, the ramifications of these findings for the future psychological study of forensic expertise and the implications for expert testimony and public policy are considered.     

Regularities in Eyewitness Identification

What do eyewitness identification experiments typically show? We address this question through a meta-analysis of 94 comparisons between target-present and target-absent lineups. The analyses showed that: (a) correct identifications and correct-nonidentifications were uncorrelated, (b) suspect identifications were more diagnostic with respect to the suspect’s guilt or innocence than any other response, (c) nonidentifications were diagnostic of the suspect’s innocence, (d) the diagnosticity of foil identifications depended on lineup composition, and (e) don’t know responses were nondiagnostic with respect to guilt or innocence. Results of diagnosticity analyses for simultaneous and sequential lineups varied for full-sample versus direct-comparison analyses. Diagnosticity patterns also varied as a function of lineup composition. Theoretical, forensic, and legal implications are discussed.     

论毒品犯罪的共犯认定思路

毒品犯罪中,在各参与主体共同策划、分工协作、共同完成犯罪的典型情况下,认定共犯关系并不困难,但在各相关主体之间联络松散、行为相对独立、利益关联度弱的边际地带,共犯关系的认定疑难复杂、界限模糊。从共同犯罪的本质出发,共同犯罪意志是危害行为的参与者成立共犯的内在依据。在司法实践中,对他人实施的毒品犯罪行为客观上起到了帮助或者促进作用的行为,要认定为毒品犯罪共犯,应当具备以下三个条件:一是对行为人而言,应当具有参与到他人实施的毒品犯罪中的意思表示;二是各共同参与人对于相互配合共同完成该毒品犯罪达成了合意;三是对其他参与者而言,行为人实施该行为的主要意义在于帮助毒品犯罪的完成。只有按照上述思路进行司法认定,才能够真正做到不枉不纵,罚当其罪。     

宏基因组学在法医学鉴定中的应用

随着分子生物学与基因组学的发展,宏基因组学在法医学与法医学鉴定中逐渐扮演着重要的角色。近年来,宏基因组学作为研究环境微生物菌群构成与多样性、各成员之间相互关系及与环境之间相互关系的分支学科,在法医学鉴定相关领域的应用也逐渐兴起,并带来了新的契机。本文对宏基因组学研究策略及其在法医学鉴定中个体识别、案发现场生物斑迹来源鉴定及药物滥用检测等方面的应用现状进行了综述,旨在进一步阐明宏基因组学在法医学中的作用与应用价值。     

Polymorphism of isoenzymes in preserved muscle tissues

In muscles preserved in formalin enzymes were not found to be active. In muscles treated by ethanol the ESD, GLO, GPT and PGP enzymes were active. The best results were obtained in the case of acetone treatment. The phenotypes ESD, GLO, GPT and PGP in tissues corresponded with the ones in the comparative blood samples.     

辽宁省各方言片区方音区分研究

根据《中国语言地图集》,总结辽宁省所涉及的3个官话区的语音特点,将省内各县、市归入对应的方言小片,分别从声、韵、调等方面研究各小片的语音特征,并提出了各小片间相互区别的方音特点。     

辨认程序与辨认结论正确性的审查

辨认结论与一般的言词证据可能由同一个人作出,但辨认与提供证言却存在着不同的心理基础,辨认主要建立在"再认"之上,而提供言词则主要建立在"再现"之上.合理的辨认有较高的可信度,但是辨认过程的许多因素都会影响辨认的真实性.遵循合法的程序,遵守符合心理规律的辨认规则是获得正确辨认的程序保障;把握辨认的心理机制,审查辨认过程的影响因素,可以评价辨认证据的真实性程度.     

Diaphragmatic muscle fibre necrosis in SIDS

Observations of acute muscle fibre necrosis, as seen in 242 sudden infant death syndrome (SIDS) cases is described. The lesion is a focal acute anoxic muscle fibre coagulative necrosis in some cases followed by myocytolysis, central vacuolation, macrophage and phagocytic cell infiltrate, stromal condensation and scarring.     

司法鉴定的基本问题研究

司法鉴定的基本理论即支持司法鉴定存在与发展的内在要求,是司法鉴定最基础的内容,而与司法鉴定有关的其他理论和价值都是建立在这一基础之上的。不从基础着手而擅对司法鉴定制度进行改革与完善,则如空中楼阁,缺少理论基础的支撑。进一步讲,也不会达到真正有效的改革与完善,因为这些理由和建议难免牵强、无力。只有从根本出发,抓住司法鉴定的基本问题,才能从根本上对司法鉴定制度进行改革与完善,并且使这种改革与完善更加具有说服力。     

Identification of Knots

A review is given of the importance of knot identification in crime investigation. After a brief account of the history of knots and knot-tiers, the investigation of knots at crime scenes is described and a classification based on number of crossing points presented.