The persistence of fibres on skin in an outdoor deposition crime scene scenario

Textile fibres were transferred to a pig skin carcass and their persistence determined at daily intervals for up to a 12 day period during which time the carcass was left outdoors exposed to the prevailing weather conditions and animal activity. In the absence of strong winds and precipitation, the loss of fibres was found to be exponential. Stronger winds and heavier precipitation caused an increase in the rate of loss of fibres. The results of this study showed that the majority of fibres transferred to a body deposited outdoors, can be expected to be lost after the first 2 days, however, none of the experiments performed resulted in a complete loss of fibres, even after 12 days exposure. These persistence characteristics differed from those observed in a similar study using small sections of skin, rather than carcasses.The implications of the results of the present study in relation to the examination of fibre evidence in cases of homicide are discussed.     

家兔皮肤低电压电损伤组织病理学研究

目的研究不同数值低电压对家兔皮肤电损伤的组织病理学变化,为皮肤电损伤的法医学鉴定提供一定依据。方法选取家兔35只,随机分为36V、110V、220V生前和死后电击组各3组及正常对照组,共7组,每组5只。应用自制电击装置对家兔进行生前不同数值电压电击和死后不同时间电击,然后对电击处皮肤取材,常规石蜡包埋及HE染色制片并进行组织病理学观察研究。结果 36V生前和死后电击皮肤组织学未见改变;110V、220V生前和死后不同时间予以电击均出现电流斑改变;220V和110V生前与死后电流斑形态无差异;220V较110V电击皮肤电流斑明显。结论电流斑与电压的数值大小存在相关性,电压越高电流斑越明显,36V交流电不能形成电流斑;相同数值电压下电击,生前和死后组电流斑无明显形态学差异,电流斑在36V、110V、220V电压时不能用于区分电击损伤是否为生前或死后所致。     

The population,transfer and persistence of fibres on the skin of living subjects

Fibres were transferred to the bare arms of living subjects and their persistence determined at intervals up to 24 h, during which normal daily activity was undertaken. Decay curves showed an initial rapid loss followed by an apparently exponential decay. No target fibres were found to remain after 24 h. The length distribution showed a shift towards shorter fibre lengths and the differential shedding results for a polyester/cotton mixture showed a small bias towards the retention of cotton. The population of coloured fibres on bare skin was classified according to perceived colour, length, generic class and the presence or absence of delustrant.     

Bullet or bite--a contribution to the morphogenesis of gunshot dermal injury

Histopathologic studies of dermal dog bites revealed changes identical with those observed in distant gunshot skin entrance wounds and in a presternal skin stab wound made by a screwdriver. The similarity of the epithelial and collagen changes produced by these three totally different traumatizing, perforating agencies indicate that it is the bullet's penetrating and crushing power, and not its caloric content, that is responsible for the characteristic dermal collagen changes noted in these common injuries.     

电击伤与电击死的法医学研究进展

电击伤和电击死是法医实践工作中常遇到的案例,尽管有许多学者从电击伤(死)后各个组织器官的形态学以及分子水平的变化进行了大量的研究,但实际检案中,法医工作者对其诊断(主要是对无电流斑的死因推断)仍没有统一的标准和直接客观的特异性指标,且对电击工具的推断、生前电击和死后电击的鉴别以及电击死后死亡时间的判断都有一定的困难,故其一直是法医学研究的热点。本文针对以上问题对电击伤(死)的法医学研究进展做一综述,为对其进一步研究提供一些思路。     

人体皮肤切创纤维连接蛋白EDA、EDB的表达与损伤时间关系的研究

目的研究纤维连接蛋白(fibronectin,FN)可变剪接片段EDA、EDB在人体皮肤切创的表达情况,并摸索EDA、EDBmRNA在离体皮肤上最长检出时限,以期为早期损伤时间的推断提供实用的参考指标。方法采用DIG标记的反意RNA探针,原位杂交检测人体皮肤在损伤早期(从30min开始)FNEDA、EDBmRNA表达的变化。结果正常人体皮肤无EDA、EDBmRNA表达;在损伤早期(≤3h)FNEDA、EDB的表达随时间的延长而呈现一种不断上升的趋势;EDA、EDBmRNA主要出现在表皮基底层细胞;EDA、EDBmRNA在标本离体后4h就不能检测到。结论FNEDA、EDB可作为早期损伤时间推断的较理想的参考指标,但原位杂交的检测方法不适用于实际应用。     

大鼠皮肤钝器伤血管内皮生长因子表达变化的研究

目的观察大鼠皮肤钝器伤后VEGF表达的变化规律。方法应用免疫组化技术观察大鼠皮肤钝器伤后不同时间(1h、3h、6h、12h、1d、3d、5d、7d、9d)VEGF的表达情况,并用MIAS图像分析系统进行图象分析。 结果正常对照组大鼠皮肤有低水平VEGF表达,钝器伤后VEGF表达逐渐增加,于伤后7d达峰值,伤后9d开始下降。 结论皮肤钝器伤可诱导VEGF表达增加,其时序性变化可望作为一种客观指标用于法医学损伤时间的推断。     

创伤性脑损伤大鼠水通道蛋白4表达变化及法医学意义

目的观察大鼠颅脑损伤后不同时间内水通道蛋白4（AQP4）mRNA表达的变化，探讨AQP4在脑损伤经过时间推断中的意义。方法利用液压冲击法制作不同程度大鼠颅脑损伤模型，在伤后不同时间（0．5、2、6、12、24、48、72h），应用RT-PCR法检测脑组织AQP4 mRNA表达，同时以非损伤组做对照。结果不同程度颅脑损伤后0．5h脑组织AQP4 mRNA表达均开始上调（P〈0．01），6、12h依次增高，24h达到高峰，差异均有统计学意义（P〈0．01），72h时仍维持较高水平（P〈0．01）；0．5h时轻度、中度、重度脑损伤时AQP4 mRNA的表达差异两两之间无统计学意义（P〉0．05），2、6、12、24、48、72h轻度、中度、重度脑损伤时AQP4 mRNA的表达差异两两之间有统计学意义（P〈0．01）。结论颅脑损伤后AQP4 mRNA呈现出时序性变化，其变化规律可望成为法医学推断早期脑损伤时间的指标之一。     

大鼠实验性脑挫伤后不同时间脑apoE的表达

目的观察大鼠实验性脑挫伤后脑内apoE蛋白变化的时空性规律。方法采用自由落体撞击法致大鼠脑挫伤模型,观察伤后不同时间(0.5h、2h、6h、12h、24h、3d、7d、14d)apoE蛋白的变化,并用计算机图像分析技术作定量统计分析。结果伤后0.5h组脑皮质神经元apoE出现阳性表达,3d达到高峰,随后下降;伤后0.5h组在海马出现apoE强阳性反应,CA1区在伤后3d达到高峰,而CA2~CA4区在24h达到高峰,随后逐渐下降,伤后海马apoE表达以CA1区最强。结论挫伤后apoE时空性变化规律可作为脑损伤时间推断、早期诊断及生前伤和死后伤鉴别的一个新的参考指标。     

The effect of contextual cues on children's ability to remember an occurrence of a repeated event

Purpose. This study examined the usefulness of contextual cues in enhancing the accuracy of children's narrative accounts of an occurrence of a repeated event. Method. Children aged 6 to 7 years took part in the same staged event four times whereby 16 target details varied in each occurrence (e.g. the colour of a cloak varied each time). Three days later, the children's free recall of the final occurrence was elicited. This occurrence was identified in one of two ways. Either it was identified via the temporal term ‘last’, or else the term ‘last’ was combined with a feature related to the environmental context or setting that was unique to the occurrence (i.e., the interviewer referred to a new object that was worn throughout the occurrence or a new person who carried out the event). For each condition, performance was compared to that of children who experienced the event only once. Results. Children's memory of details specific to the target occurrence was better after the single than the repeated event. However for both event types, children who were given the contextual and temporal cue performed better than those who were given the temporal cue only. The benefit of using a contextual cue did not result in an increase in errors. Conclusion. Contextual cues (generated by an interviewer) can facilitate children's recall of an occurrence of an event. However, further research needs to determine whether this finding would generalize to a more practical situation where the child (rather than the interviewer) generates the cues.     

Magnesium, calcium and zinc fluctuations on skin induced injuries in correlation with time of induction

In the present study, fluctuations of trace elements Mg, Ca and Zn concentrations with time on skin-induced injuries was investigated. To accomplish this, 144 animals (pig) aged between 5-6 months scheduled for food provision process (slaughter) were used. At the gluteus area, injuries were induced prior to slaughter at intervals of 30 s, 30 min, 1, 2, 4, 8 h. Local anaesthesia and cold therapy for prompt relief of pain (ethylchloride, C2H5Cl) was applied. Postmortem tissue excision in and around the injured site was promptly performed. The tissue obtained was segmented into three zones of equal distances (2 cm) in between and weighed 3 g wet weight. Tissue specimens were analysed by atomic absorption spectroscopy for the three elements. The results were correlated with time of injury. Suggestive alterations in trace elements mean concentrations with time were confirmed. The ratios of the mean in twos (Ca/Zn, Ca/Mg, Mg/Zn) versus time were graphed. Effectively, the curves achieved by analysing postmortem tissues, serve to estimate the time of an injury induced in vivo.     

The use of melting point and refractive index determination to compare colourless polyester fibres

The incidence of polyesters encountered in forensic fibre examinations continues to increase. To meet different consumer needs such fibres can be subjected to many physical and chemical variations during production. Some of these variations are discussed. Accurate comparison of these fibres presents a particular problem to the forensic scientist. Melting point and refractive index determinations were made on various samples of colourless polyesters provided by different manufacturers to assess the comparative value of such information and to find out the possibility of relating it to modifications of the basic polymer. Melting points alone were found to be of little comparative value, but determination of both refractive indices n_∥ and n_⊥ does allow discrimination between samples. Consideration of both melting point and refractive index together may help to provide an insight into polymer variation, though this remains somewhat speculative.     

从14例脊柱损伤看隐性损伤对评残的影响

医疗单位对损伤的救治会产生最直接的影响 ,特别是一部分今后可能涉及法律诉讼的损伤。笔者从近二年 30 6例伤残鉴定案件中筛选出 14例脊柱损伤的案件进行回顾性分析 ,发现机体损伤后 ,由于处置不当 ,致使伤者在原有的损伤基础上 ,形成新的损伤。在隐性损伤中 ,医源性原因所致的隐性损伤为主要原因之一。它对评残有直接的影响 ,应当引起同仁和医疗单位的重视。一般资料笔者以 1999年 1月～ 2 0 0 0年 11月在我院进行伤残鉴定的 30 6例案件为基础 ,采用《职工工伤与职业病致残程度鉴定》、《道路交通事故受伤人员伤残评定》和《江苏省人体损…     

从14例脊柱损伤看隐性损伤对评残的影响

医疗单位对损伤的救治会产生最直接的影响,特别是一部分今后可能涉及法律诉讼的损伤.笔者从近二年306例伤残鉴定案件中筛选出14例脊柱损伤的案件进行回顾性分析,发现机体 损伤后,由于处置不当,致使伤者在原有的损伤基础上,形成新的损伤.在隐性损伤中,医 源性原因所致的隐性损伤为主要原因之一.它对评残有直接的影响,应当引起同仁和医疗单位的重视.     

The effect of metal salt treatment on the photoluminescence of DFO-treated fingerprints

Ninhydrin developed fingerprints can be enhanced by treatment with a zinc or cadmium salt. The resulting fingerprint luminescence has been attributed to the induced coplanarity of the bicyclic indanedione rings of Ruhemann's purple due to complexation with the metal ions. This paper explores whether this effect also occurs in the 1,8-diaza-9-fluorenone (DFO)-amino acid adduct (1), formed from the reaction of DFO with amino acids. Molecular modeling studies of (1) indicate a relatively small out-of-plane angle of 24 degrees. 1H NMR studies indicate (1) is asymmetric about the C2 axis in contrast to what has been previously reported. Little, if any, enhancement of luminescence was observed with Zn, Cd, Ru or Eu treated DFO developed latent fingerprints. This lack of enhancement was also borne out by solution luminescence studies. Given this lack of enhancement of luminescence, solutions of (1) and the four metal ions above were analyzed by electrospray mass spectrometry (ESMS). This indicated the formation of predominantly 1:1 complexes of (1) with both Zn and Cd, and the 2:1 complex with ruthenium. No evidence of a Eu complex was found by ESMS.     

The individuality of fibres used to provide forensic evidence--not all blue polyesters are the same.

Fibres used in forensic casework suffer from a disadvantage common to other forms of trace evidence--it is not possible to state with absolute certainty that they originate from a specific source. Target fibre studies, population studies and research on 'blocks of colour' have effectively demonstrated the polymorphism of textile fibres (particularly man-made ones) and have shown that when a fibre is believed to have a specific putative source, the chance that it has originated from a different source purely by coincidence is extremely remote. A study by Houck MM (Houck MM, Inter-comparison of unrelated fibre evidence. Forensic Science International 2003; 135: 146-149) has shown that no coincidental matching fibres were recovered from items of clothing examined in 20 unrelated crimes. The study involved over two million comparisons. This work goes a step further, and using the example of blue polyester fibres shows that even within a very narrow segment of the whole general fibre population, many examples of a specific colour/type of man-made fibre taken from random sources can be compared and the chance of any two being the same is very low. These studies should help to show the specificity and value of transferred fibres in providing forensic evidence.     

暴力性伤害流行病学研究进展

一、概述 暴力性伤害(Assaultive Injury)是非法故意或过失严重伤害他人健康的犯罪行为,是世界各国刑罚打击的重点,是现代社会发展中的一个突出问题.     

创伤性脑损伤大鼠P300检测与海马microRNA表达变化

目的探讨创伤性脑损伤后大鼠海马microRNA的表达变化与认知功能障碍的相关性。方法 25只SD大鼠随机分为假手术组和伤后1h、1d、3d、5d组,采用Feeney自由落体法建立创伤性脑损伤动物模型。各组大鼠于设定的损伤时间点检测事件相关电位P300,应用基因芯片技术检测海马microRNA的表达情况,筛选特异性表达的microRNA。结果各组大鼠伤后P300的潜伏期延长,波幅下降,以伤后1d为甚。与假手术组相比,伤后各实验组microRNA表达谱具有显著差异。其中miR-21、miR-16、let-7b的表达与P300潜伏期变化存在显著相关,伤后1d为差异性表达的关键时间点。结论 microRNA可能在创伤性脑损伤后发生的认知功能障碍中发挥调控作用,有望为脑损伤后认知功能的法医学鉴定提供新的思路。     

ApoE的研究进展及其在脑外伤发生中的意义

载脂蛋白E（ApoE）是血浆中主要的载脂蛋白之一,参与机体的脂质代谢及调节胆固醇平衡,其基因多态性与多种疾病相关,在神经系统的正常生长和损伤后的修复过程起重要作用.近来发现其免疫反应性与脑损伤时间有一定规律性,可望将其作为法医检案中判定脑损伤时间的客观指标.