对签字笔墨水的分析回顾及展望

文章叙述了目前国内外签字笔墨水的发展及主要成分,并介绍了分析签字笔墨水的方法。通过化学法和TLC法可以确定签字笔墨水是水性还是中性;利用GC／MS法可以确定签字笔墨水中溶荆成分及其变化;利用拉曼光谱法可以鉴别墨水中染料或颜料成分;利用红外反射法可将29种墨水分为三类;利用扫描电镜法可以通过颜料形态的差别鉴别颜料基墨水。     

A Case of Contested Cremains Analyzed Through Metric and Chemical Comparison

Since the 1980s, cremation has become the fastest growing area of the U.S. funeral industry. At the same time, the number of litigations against funeral homes and cremation facilities has increased. Forensic anthropologists are often asked to determine whether the contents of an urn are actually cremated bone, and to address questions regarding the identity of the remains. This study uses both metric and chemical analyses for resolving a case of contested cremains. A cremains weight of 2021.8 g was predicted based on the decedent's reported stature and weight. However, the urn contents weighed 4173.5 g. The urn contents also contained material inconsistent with cremains (e.g., moist sediment, stones, ferrous metal). Analysis using XRD and SEM demonstrated that the urn contained thermally altered bone as well as inorganic material consistent with glass fiber cement. Although forensically challenging, cremains cases such as this one can be resolved using a multidisciplinary approach.     

Chemical Differentiation of Osseous and Nonosseous Materials Using Scanning Electron Microscopy–Energy-Dispersive X-Ray Spectrometry and Multivariate Statistical Analysis

Identification of osseous materials is generally established on gross anatomical features. However, highly fragmented or taphonomically altered materials may be problematic and may require chemical analysis. This research was designed to assess the use of scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM/EDX), elemental analysis, and multivariate statistical analysis (principal component analysis) for discrimination of osseous and nonosseous materials of similar chemical composition. Sixty samples consisting of osseous (human and nonhuman bone and dental) and non-osseous samples were assessed. After outliers were removed a high overall correct classification of 97.97% was achieved, with 99.86% correct classification for osseous materials. In addition, a blind study was conducted using 20 samples to assess the applicability for using this method to classify unknown materials. All of the blind study samples were correctly classified resulting in 100% correct classification, further demonstrating the efficiency of SEM/EDX and statistical analysis for differentiation of osseous and nonosseous materials.     

Determination of the sequence of intersecting lines using Focused Ion Beam/Scanning Electron Microscope

The aim of this study was to verify that the combination of focused ion beam (FIB) and scanning electron microscope/energy‐dispersive X‐ray (SEM/EDX) could be applied to determine the sequence of line crossings. The samples were transferred into FIB/SEM for FIB milling and an imaging operation. EDX was able to explore the chemical components and the corresponding elemental distribution in the intersection. The technique was successful in determining the sequence of heterogeneous line intersections produced using gel pens and red sealing ink with highest success rate (100% correctness). These observations show that the FIB/SEM was the appropriate instrument for an overall examination of document.     

Application of 3D documentation and geometric reconstruction methods in traffic accident analysis: with high resolution surface scanning, radiological MSCT/MRI scanning and real data based animation

The examination of traffic accidents is daily routine in forensic medicine. An important question in the analysis of the victims of traffic accidents, for example in collisions between motor vehicles and pedestrians or cyclists, is the situation of the impact. Apart from forensic medical examinations (external examination and autopsy), three-dimensional technologies and methods are gaining importance in forensic investigations. Besides the post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) for the documentation and analysis of internal findings, highly precise 3D surface scanning is employed for the documentation of the external body findings and of injury-inflicting instruments. The correlation of injuries of the body to the injury-inflicting object and the accident mechanism are of great importance. The applied methods include documentation of the external and internal body and the involved vehicles and inflicting tools as well as the analysis of the acquired data. The body surface and the accident vehicles with their damages were digitized by 3D surface scanning. For the internal findings of the body, post-mortem MSCT and MRI were used. The analysis included the processing of the obtained data to 3D models, determination of the driving direction of the vehicle, correlation of injuries to the vehicle damages, geometric determination of the impact situation and evaluation of further findings of the accident. In the following article, the benefits of the 3D documentation and computer-assisted, drawn-to-scale 3D comparisons of the relevant injuries with the damages to the vehicle in the analysis of the course of accidents, especially with regard to the impact situation, are shown on two examined cases.     

Identification and comparison of electrical tapes using instrumental and statistical techniques: I. Microscopic surface texture and elemental composition

Comparisons of polyvinyl chloride electrical tape typically rely upon evaluating class characteristics such as physical dimensions, surface texture, and chemical composition. Given the various techniques that are available for this purpose, a comprehensive study has been undertaken to establish an optimal analytical scheme for electrical tape comparisons. Of equal importance is the development of a quantitative means for sample discrimination. In this study, 67 rolls of black electrical tape representing 34 different nominal brands were analyzed via scanning electron microscopy and energy dispersive spectroscopy. Differences in surface roughness, calendering marks, and filler particle size were readily apparent, including between some rolls of the same nominal brand. The relative amounts of magnesium, aluminum, silicon, sulfur, lead, chlorine, antimony, calcium, titanium, and zinc varied greatly between brands and, in some cases, could be linked to the year of manufacture. For the first time, quantitative differentiation of electrical tapes was achieved through multivariate statistical techniques, with 36 classes identified within the sample population. A single-blind study was also completed where questioned tape samples were correctly associated with known exemplars. Finally, two case studies are presented where tape recovered from an improvised explosive device is compared with tape recovered from a suspect.     

Interpretation of automotive light bulb examination results: an intriguing case

During the examination of light bulbs from a vehicle involved in a road accident, the headlights did not reveal any evidence regarding whether they were energized or not. Additionally, a police officer turned the lights on after the accident to verify their functioning, thus damaging some of the evidence. By examining the vehicle, it was determined that the park lights could provide answers regarding the conditions of the headlights. After observations, it was concluded that the park lights and headlights were off at the time of the impact. This case report demonstrates how important it is to integrate the circumstances surrounding the case into the interpretation of the results. Nevertheless, it also demonstrates the necessity for examining both the vehicle and all light bulbs in order to reach the most pertinent and proper conclusion.     

补肾方含药血清处理的大鼠成骨细胞miRNA差异表达

目的 筛选补肾方含药血清干预的大鼠成骨细胞中差异表达的miRNA,为补肾方治疗骨质疏松症提供可供选择的目标miRNA,以探讨其通过调控靶基因表达发挥治疗效应的机制。方法 经细胞性状鉴定的原代大鼠成骨细胞用含药血清干预,采用miRNA芯片检测补肾方含药血清干预3 d与干预1 d的成骨细胞miRNA表达水平,并挑选差异表达2倍以上的miRNA进行定量PCR验证。结果 培养的原代细胞具有典型的成骨细胞性状特征。与对照血清相比,补肾方含药血清干预3 d的成骨细胞共有24个2倍以上表达差异的miRNA,其中上调的16个,下调的8个。差异表达2倍以上的miRNA定量PCR结果与芯片数据一致。结论 补肾方通过成骨细胞中差异表达的miRNA调控靶基因改善骨质疏松症。     

薄层扫描法测定伊痛舒口服液中阿魏酸的含量

建立伊痛舒口服液的含量测定方法。方法：采用薄层扫描法对伊痛舒口服液中阿魏酸进行定量。结果：阿魏酸在０．９－５．６μｇ呈良好的线性关系，平均回收率为９８．８６％。，结论：该方法简便，灵敏，准确，可作为伊痛舒口服液质量控制的方法。     

轻燕减肥胶囊质量标准研究

目的：制定轻燕减肥胶囊的质量标准。方法：采用薄层色谱法对防己、大黄、陈皮进行定性鉴别；并建立粉防己碱含量的检测方法，采用薄层扫描法测定。层析条件：硅胶Ｇ薄层板，氯仿－丙酮－甲醇（６：１：１）为展开剂，稀碘化铋钾为显色剂，双波长反射法锯齿扫描，λＳ＝４．９５ｎｍ，λＲ＝６００ｎｍ，ＳＸ＝３。结果：粉防己碱的量在０．５～３．２μｇ范围内具有良好的线性关系，ｒ＝０．９９９９，平均回收率为９５．１％，ＲＳ