扫描电镜/X射线能谱仪检验电流斑规范化方法探讨

目的探讨电流斑皮肤金属化的机理、检材提取处理和扫描电镜/能谱仪检验规范化方法,对检验结果进行分析和价值判断。方法用扫描电镜/能谱检验,采用低倍大窗口覆盖损伤区域采集平均元素能谱图,并在可能的金属元素富集区域寻找球形金属颗粒。结果扫描电镜下可观察到散在的孔穴、细胞碎屑、龟裂、裂隙等特征,有些电流斑可检出金属元素,其中部分电流斑可发现球形金属颗粒。结论采用规范化的检材提取、处理和检验方法可消除随意性方法造成错检的可能。电流斑皮肤上异常含量的金属附着可支持病理检验符合电流斑表现的结论,同时也为电击导体的推断和金属元素成分比对提供依据。球形金属颗粒的发现揭示存在电弧高温的可能性极大,可强力支持病理检验符合电流斑表现的结论。     

扫描电镜下缢沟的形态特征

作者用光镜和扫描电镜对縊沟进行对比观察,得出如下结论:(1)扫描电镜下縊沟组织的改变具有较恒定的特征,出血及纤维蛋白检出率远较光镜为高;(2)在光镜下生活反应不明显的生前缢沟,在扫描电镜下其表面及断面均可见红细胞及纤维蛋白形成,并包裹红细胞。縊沟部位胶原纤维之间可见散在大小不等的圆球形脂肪样小滴。缢沟部位肥大细胞的形态改变,有助于生前与死后缢沟的鉴别诊断。     

意外电击死21例法医病理学分析

皮肤电流损伤是诊断电击死的主要依据。经对21例意外电击死案例进行系统法医病理学检查后发现：肉眼具典型电流斑者仅6例（29％），光镜下形态改变与其他学者描述基本一致。非典型电流斑形态多样化，以单纯性表皮剥脱多见。体内器官病理学变化缺乏特异性。     

水、油污中无电流斑电击死大鼠皮肤和心肌的病变

目的探讨水中、油污中无电流斑电击死法医学鉴定的病理形态学依据。方法 SD大鼠28只,分为水中、油污中无电流斑电击死各1组,典型电流斑组、正常对照组、死后电击组、死后水中、油污中电击各1组共7组。采用肉眼、光镜及投射电镜观察水中、油污中无电流斑电击死大鼠皮肤和心肌组织病理学改变,并与其它各组进行比较。结果采用肉眼观察,生前水中、油污中无电流斑电击死大鼠皮肤未见明显电流斑。普通光镜观察,可见电击中心部位表皮变性坏死、脱落,表皮细胞变薄、致密,表皮细胞或/和毛囊、汗腺、皮脂腺发生极性化改变。电镜观察,透明层和角质层分离脱落,基底细胞肿胀、细胞器减少、核固缩,汗腺导管上皮肿胀,棘细胞中粗面内质网扩张融合成泡状,线粒体肿胀空泡化;但光镜与电镜的变化与生前电击死比较不明显、典型。而死后电击组皮肤则无明显病理学改变。实验各组大鼠心肌的改变与皮肤改变类同。结论采用光镜和投透射电镜观察在潮湿环境中电击死的组织病理学改变,可为无电流斑电击死提供依据。     

电流斑的环境扫描电镜X射线能谱分析

目的利用环境扫描电镜-X射线能谱仪(environmental scanning electron microscope and energydispersive X-ray microanalyser,ESEM-EDX)研究电流斑微观形态特征及元素构成,以期为电流斑及电击死的鉴定提供更准确、客观的依据。方法用ESEM-EDX检测5例电流斑的扫描电镜形态、金属颗粒的形态及其元素组成。结果电流斑及周围皮肤可见电穿孔、金属熔珠,熔珠主要由铁、铜、铝等常见金属元素和金、钛、钡等人体少见的金属元素构成。结论 ESEM-EDX检测可为电击死的鉴定提供客观的依据。     

毛发枪弹损伤的环境扫描电镜研究

目的探讨毛发枪弹损伤微观形态与射击距离之间的关系。方法应用环境扫描电镜/能谱仪对64式手枪在0~200cm范围内射击造成的毛发损伤及附着物进行形态和成分分析。结果0~30cm射击,毛发表面粘附有大量密集分布的球形射击残留物颗粒,鳞片有严重斑纹状损伤和崩裂缺损;30~60cm射击,毛发表面粘附有较多散在分布的球形射击残留物颗粒,鳞片有轻微斑纹状损伤和崩裂缺损;100cm距离射击,毛发表面粘附有少数个别射击残留物颗粒,鳞片无斑纹状损伤;200cm距离射击,毛发表面无射击残留物。毛发枪弹射击断裂形态差异较大,大体分为剪切断裂和牵拉断裂两种类型,与射击距离无明显相关性。结论毛发表面粘附的大量球形射击残留物颗粒及其造成的鳞片斑纹状损伤对于法医学鉴定贴近距离射击((30cm)具有重要的实用价值。     

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。     

一例非典型的皮肤电流斑的案例报告

<正> 典型的电流斑,根据其大体形态和组织病理学的特征,结合案情,确定并无困难。有时,由于案情不清,损伤形态不典型或受腐败影响,要确立电击伤的诊断,则有一定困难。但通过特殊的仪器检查,综合判定,亦能作出正确诊断。现将作者所遇一例不典型的电流损伤,采用扫描电镜和能谱测定,报告于后。现场尸检 1986年6月26日下午,某地从河中捞上一具无名男尸,尸体上身罩着     

电击死大鼠皮肤超微结构及心肌HIF-2α、H-FABP的表达变化

目的观察电击死大鼠皮肤超微结构,检测心肌细胞中缺氧诱导因子-2α(hypoxia-inducible factor-2α,HIF-2α)和心脏型脂肪酸结合蛋白(heart type-fatty acid-binding protein,H-FABP)的表达变化,为电击死的法医学鉴定提供依据。方法建立大鼠电击模型,将72只大鼠随机分为对照组、电击死组和死后电击组,每组又分为死后即刻、死后30 min和死后60 min 3个亚组。采用HE染色法观察大鼠皮肤改变,应用扫描电镜观察大鼠皮肤超微结构的改变,用免疫组织化学染色方法检测大鼠心肌HIF-2α、H-FABP的表达情况。结果电击死组和死后电击组皮肤的肉眼所见及HE染色结果均无明显差异,在扫描电镜下可见大量细胞碎屑,细胞界限不清,表面可见枯焦状龟裂,散在圆形和椭圆形小孔,边缘不规则,散在大量球形异物颗粒。与对照组相比,电击死各亚组HIF-2α表达均增多,且在死后即刻达到高峰,死后电击组仅在死后即刻表达增多,但低于电击死后即刻(P0.05)。与对照组相比,电击死和死后电击各亚组H-FABP表达均明显降低,在电击死组的表达均低于相应时间点死后电击组(P0.05)。结论电击可引起心肌HIF-2α表达升高、H-FABP表达降低,对电击死的判定以及生前电击和死后电击的鉴别具有法医学意义。     

无明显电流斑电损伤鉴定的研究进展

低压电电击死的法医学鉴定在形态上主要依据皮肤电流斑来确定,但在实际工作中尚有电流斑不明显,甚至缺如的案例,使鉴定工作产生一定难度.本文依据文献资料对电击伤的机制及无明显电流斑的电损伤的各种相关指标进行综述。     

Internal current mark in a case of suicide by electrocution.

Fatalities caused by electrocution often lack specific morphologic evidence. Investigation of the death scene along with technical inspection of the electrical apparatus may help in clarifying the cause and manner of death. Cutaneous current marks may be the only sign of low voltage associated fatalities. The authors report a case of an electrician who committed suicide by electrocution using a time switch after oral ingestion of diazepam. Electrodes (coins) were fixed with adhesive tape at the height of the heart to the front and back of the left side of the chest. Autopsy revealed a blackish linear mark on the pleura parietalis of the inner side of the thoracic cavity, connecting the cutaneous current marks. Current-related and heat-related changes, such as hypercontraction bands of the intercostal muscles and coagulative changes of the perineurium of peripheral nerves, were found at histologic examination. Taking into consideration that the body had been under the influence of low-voltage current for 7 days, the morphologic alteration on the pleura parietalis was in accordance with an internal current mark, indicating the main route of current flow through the body. To the authors' knowledge, such a current-related phenomenon has not been reported to occur on an inner body surface before.     

扫描电子显微镜下生前和死后枪弹创的对比观察

本文用扫描电镜,对11例生前枪弹创和12例死后不同时间形成的枪弹创作对比观察。结果发现,生前枪弹创有大量红细胞和血小板凝块,纤维蛋白网形成,死后10min内的枪弹创亦有少许散在红细胞和纤维蛋白形成,很少见纤维蛋白网。死后25min的标本仍可见稀疏的红细胞,但无纤维蛋白形成。作者认为在扫描电镜下诊断生前枪弹创,需全面观察,综合分析。     

Is there a real danger of concealing gunshot residue (GSR) particles by skin debris using the tape-lift method for sampling GSR from hands?

Experiments were carried out to assess the danger of concealing GSR particles by skin debris using the tape-lift method for sampling GSR from hands. Thirty discrete spherical particles (from GSR and from the debris of oxygen cutting of steel) sized from 8 to 30 microns were mounted on a double-side adhesive coated stubs in known locations using a stereomicroscope. These stubs were then used for dabbing hands 50 times. Some of the particles or parts thereof were covered by skin flakes, however, all particles could be detected using the backscattered electron image (BEI) in the scanning electron microscope (SEM). Also, all could be identified by the energy dispersive X-ray spectroscopy (EDX).     

骨砍创金属颗粒的检测

目的 应用扫描电镜/X射线能谱仪(SEM/EDX)对菜刀砍击骨质后遗留在创面上的金属微粒进行检测.方法 3种不同材质菜刀各取5把,对猪大腿骨进行砍击,使用SEM/EDX对骨创面上附着的金属颗粒元素以及菜刀自身所含元素进行定性及定量检验,并对结果进行比对分析.结果 菜刀样本同型号之间元素重量百分比相比较,结果无统计学差异(P＞0.05);创面附着金属颗粒与菜刀自身所含元素种类特征相同;其所占重量的百分比一致(P＞0.05);结论 骨骼创面遗留金属颗粒的元素种类及其百分比含量,可以作为区分菜刀类致伤工具的重要依据.     

苏木素碱性品红苦味酸（HBFP）染色法对诊断心肌早期缺血的评价

法医病理学检验中,常需一种诊断心肌早期缺血性损害的准确方法,以便解决疑为心肌早期缺血,迅速死亡的案例.这些案例往往因为HE染色病变不典型,难以作出急性心肌缺血的诊断.为此,我们采用Lie等介绍的苏木素碱性苦味酸(HBFP)染色法,对26例法医尸体解剖的心肌组织切片进行研究,并同HE染色进行了对比观察.期望在诊断早期心肌缺血方面作出一恰当的评价.     

大鼠索沟生活反应的免疫组化研究

在４０只Ｗｉｓｔａｔ大鼠颈部制成５分钟至１小时生前索沟损伤模型、应用免疫组化技术（ＳＡＢＣ），观察不同损伤时间索沟常规石蜡切片上纤维连结蛋白（Ｆｎ）和纤维蛋白原（Ｆｂ）的阳性着色和分布情况。结果发现，生前索沟损伤５分钟即能在索沟部真皮组织内发现Ｆｎ和Ｆｂ阳性反应，随着损伤时间的延长，阳性反应加深。Ｆｎ和Ｆｂ最强的着色是带状显于索沟表面表皮剥脱处，除个别死后索沟真皮内有Ｆｂ的弱阳性着色外所有对照组均未见阳性反应。结果表明Ｆｎ和Ｆｂ可以作为生前和死后索沟的鉴别指标。     

对纤维蛋白诊断生前伤的评价——45例枪弹创组织的MSB染色和扫描电镜对比观察

生活反应是诊断生前伤的主要根据.近二十年来,法医病理学在研究生前伤和死后伤的诊断中,采用了多种新兴技术,如扫描电镜技术、酶组织化学技术、酶标技术、电泳技术等,促使生前伤的诊断水平有明显提高.伤后存活1小时死亡者,大部分皆可获得明确诊断;立即死亡或在濒死期形成的损伤,由于生活反应甚微,或受腐败等     

Identify the injury implements by SEM/EDX and ICP-AES

The forensic investigator is frequently confronted with the discrimination and deduction of injury implements, which is one of the most important physical testimonies in courts. The usual method used in actual cases is from points of morphology. In the forensic discrimination of injury implements, such as metal implements, the analysis and comparison of elements are expected to provide excellent results, and simultaneous multi-elemental analysis is required to analyze various kinds of elements. This study was designed to establish discrimination and deduction of metal injury implements by scanning electron microscope/energy disperse X-ray microanalyzer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Examined metal particles in five wounds made on the skin of domestic pigs, respectively, using Cu-Zn or Cr-Ni coated and carbon steel kitchen implements by EDX. For carbon steel kitchen implements, analyzed five samples from the back and blade separately in the contents and varieties of elements by ICP-AES. In the wounds by the coated implements, the special particles only containing Cu, Zn or Cr, Ni were found. In the wounds by carbon steel kitchen implements, the particles containing Fe, Cr, Si or Fe, Mn, Si were found. The differences of contents of elements between the back and blade was no significant except No. 5 for carbon steel kitchen implements, and the significant differences of elements exited in Cr, Mn, Si, Cu, Mo among the stainless kitchen knives, Mn, Si among the other kitchen implements and for the blade of No. 5 knife, relative standard deviations (R.S.D.s) were significantly different in Mn, Si, Mo, Ti, S, P, Ni. Using EDX to examine the particles in wounds can deduce the categories of metal injury implements, and we can still deduce the different implements in the same category by ICP-AES.