Acute Respiratory Obstruction due to Accidental Inhalation of Perlite: A Novel Mechanism for Upper Airway Occlusion with Cast Formation

A 56-year-old man died following a fall resulting in complete submersion into a deep pit containing insulation material, expanded perlite. The most striking finding at autopsy was of impacted, moist pale yellow perlite that extended from the epiglottis into the main bronchi resulting in complete obstruction of the larger and smaller airways with cast formation. Perlite inhalation differs from inhalation of inert materials such as sand and wheat due to its hygroscopic properties and ability to expand forming an occlusive cast. Subsequent analyses of perlite from the worksite and within the airways indicated that hydration of perlite and adsorption of organic molecules into the perlite glass flakes had formed an interlocking, three-dimensional structure that was likely responsible for triggering a coagulation–flocculation process causing strong cohesion between the aggregates of glass flakes. This unique mechanism was likely responsible for the formation of the plug of perlite that obstructed the upper airway.     

Comparison of three collection methods for the sodium rhodizonate detection of gunshot residues on hands

The aim of this study was to compare three gunshot residue (GSR) collection methods used in conjunction with chemographic detection applied by different regional Swiss police services. The specimens were collected from the hands of a shooter with either filter paper (Filter method) or adhesive foil. The adhesive foil was then either applied against photographic paper during visualisation (AF Photo method) or coated with a layer of polyvinyl alcohol (AF PVAL method). The experiments involved two conditions of the examined hands, i.e. dry and humidified. The residues were revealed using the sodium rhodizonate test (SRT). Preliminary tests assessing the possibility of conducting a confirmatory Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (SEM/EDX) analysis after the chemographic test were performed on a number of specimens by cutting positive spots and mounting them on stubs. Obtained results were compared in terms of effectiveness - number of positive spots, time requirements, quality of subsequent SEM-EDX analysis, ease of use and cost.The Filter method generally yielded a high-quality detection with both dry and humidified hands, as well as a simple, quick and efficient confirmation by SEM/EDX. The AF Photo performed well on dry hands, but not on humidified hands. The AF PVAL method performance was lower compared to the other methods in both examined conditions of the hands. The SEM/EDX analysis showed that the Filter and AF PVAL method provided satisfactory results when a sufficient carbon coating thickness was applied to the cuttings. It was also observed that the thinner the PVAL layer, the better the quality of the spectra and obtained images in SEM/EDX. Furthermore, the surface of the photographic paper did not seem to be conductive, even after the application of a thick layer of carbon.In conclusion, the Filter method gave the best overall results, but its application required slightly more time and expertise than the two other methods.     

试论电子货币及其在我国的发展

本文在对电子货币产生的背景、属性、作用进行概述的基础上 ,分析电子货币在我国的发展现状 ,揭示我国电子货币发展过程中存在的一些问题 ,提出当前我国电子货币发展过程中应采取的措施     

羊脑多头蚴的超微结构观察

为观察羊脑多头蚴的超微结构,寻找自然感染羊脑多头蚴的病羊,采集多头带绦虫续绦期幼虫,固定于25mL/L戊二醛中,分别取其头节、囊壁、颈部区,超薄切片后进行透射电镜观察。结果表明,羊脑多头蚴的囊壁结构具有微毛,远离头节的囊壁微毛与头节附近颈部区囊壁的微毛分布情况不同;囊壁可明显分为皮层、间质层、实质区;在实质区可观察到皮层细胞、实质细胞、成石灰小体细胞、焰细胞、成肌细胞以及排泄系统结构;头节中可观察到很发达的肌纤维结构,头节内部有类似于囊壁的皮层结构,并可见粗大微毛,细胞种类明显少于囊壁实质区,含颗粒的囊泡结构明显增多。证明羊脑多头蚴囊壁的结构和细胞种类与其他绦虫相似,但有比较发达的排泄系统;头节外表面无皮层结构,仅有呈环状围绕的纤维和囊泡结构。     

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     

屠宰猪肝和血清中乙型肝炎病毒及戊型肝炎病毒的检测

应用1对乙型肝炎病毒(HBV)S基因保守区的引物,采用PCR方法从屠宰猪肝、血清中检测到了HBV,序列分析表明,扩增片段与已发表的HBV S基因的同源性高达98%~100%。电镜负染色样品观察结果表明,在HBV表面抗原ELISA检测强阳性反应的血清样品中存在有形态、大小与人HBV Dane颗粒和小球状颗粒相似的病毒粒子。针对戊型肝炎病毒(HEV)ORF2/ORF3重叠区设计了简并引物,采用巢式RT-PCR对屠宰猪肝和血清样品进行了检测。结果表明,部分屠宰猪肝中存在HEV。     

人为删改和破坏的硬盘数据的恢复

随着信息产业的高速发展,计算机的应用已变得越来越普遍。传统的纸张存储信息的方式也被计算机存储所替代。而信息技术本身是一项非常前沿的技术,计算机存储数据的安全性也就很难保证的。通过人为的删改和破坏数据来销毁证据的案例屡屡发生。这也就对公安工作提出了新的挑战。被修改和破坏了的数据统称损坏数据。目前,数据存储体被损坏的类型主要有软损坏和硬损坏。本文针对这两个方面在数据存储原理、恢复原理、恢复方法等内容上进行了深入的探讨。     

电子政务在政府管理创新中的实现途径

充分发挥电子政务在政府管理创新中的作用,必须加强电子政务工作领导,合理设计电子政务的建设目标,健全相关工作机构,整合人才资源,提供资金保障.     

电流斑的光镜和扫描电镜观察以及能谱测定

为了找出电流斑在扫描电镜下的特征性改变,作者用扫描电镜和能谱测定,配合光镜观察,对电击死者的22个皮肤电流斑和尸体上造成的18个皮肤电流斑和金属灼伤,进行了对比观察。结果表明,光镜下电流斑的形态改变与过去学者所述基本一致。非典型的电流斑难与热灼伤相鉴别。扫描电镜下电流斑的形态特征为:(1)损伤底部和壁上可见散在的小孔穴,直径为30～100μm,深浅不一,边缘不规则;(2)损伤组织表面大量细胞碎屑和颗粒;(3)组织和脱落细胞表面有裂纹;(4)损伤区内有散在的异物颗粒沉积,其形态为球形、方形或不规则形,电子密度较大。作者认为这些改变是电流作用造成,热灼伤不具备这些改变,故在扫描电镜下极易区别电流斑和热灼伤。所有电流斑均可测出与导体化学组成相同的金属元素。作者提出,扫描电镜下的上述形态改变和能谱测定结果可以作为诊断电流斑的依据。     

应用扫描电镜能谱仪检测电击伤皮肤表面的金属元素——附一例案例报告

作者采用已知化学组成的导体对家兔进行触电试验。取受损部位的皮肤作常规处理,用带能谱的扫描电镜作金属离子测定,仪器型号为 JXA-840-LinK-860。对检出的金属元素,进行了定性和半定量分析,并观察了元素的分布。作者在一例人体电击伤皮肤活检标本上检出铁元素,而对照皮肤则无,从而认定是含铁的导体与皮肤接触。电击伤与热烫伤的超微结构变化能区别。