激光拉曼光谱对苯骈杂氮（堇）类药物的定性检测

目的 建立用拉曼光谱检测苯骈杂氮革类药物的定性方法.方法 利用激光拉曼光谱仪对10种苯骈杂氮革类药物进行检验.结果 10种苯骈杂氮（萆）类药物的主成分均能被拉曼准确检出.结论 该法能较好地对苯骈杂氮革类药物固体样品快速定性分析.     

常用彩色激光打印机打印文件暗记特征的初步研究

目的收集当前我国常用不同品牌和型号的彩色激光打印机打印样本,研究打印文件上暗记特征的提取分析及其变化规律,探讨彩色激光打印文件暗记特征在鉴定实践中的应用及其在打印文件防伪措施中的价值。方法使用显微镜、文检仪及有关图像处理技术分别检验了彩色激光打印机的打印文件样本。结果彩色激光打印机打印文件上会出现暗记特征,且不同品牌的暗记特征出现规律、形态特征和点阵特征不同。结论暗记特征可作为初步鉴别彩色激光打印机品牌型号及打印时间的依据,具有防伪价值,但其在鉴定实践中还存在一定的局限性,有待进一步研究。     

Visualisation by confocal microscopy of traces on bullets and cartridge cases

The capabilities of confocal scanning laser microscopy for the visualisation of marks on bullets and cartridge cases were investigated. Confocal microscopy provides solutions to important limitations of conventional comparison microscopy with grazing light incidence, as generally used for the examination of these marks. It is expected that confocal microscopy, thanks to its broad applicability within the field of firearms investigation and its capability of non-destructively gathering quantitative three-dimensional information, will lead to a more complete and objective forensic examination of bullets and cartridge cases.     

基于拉曼光谱的血液遗留时间研究与模型预测

目的针对犯罪现场血液遗留时间的判断问题,实验以不同遗留时间的血液为研究对象,建立基于拉曼光谱的血液遗留时间的辨别方法。方法采集遗留时间为0.5h~240h的指尖血液样本,获取其拉曼光谱数据,经校正和平滑处理后,对数据进行归一化。利用RSD值评价光谱的稳定性,选取前10个主成分和6个重要波段分别建立模型,利用预测集测试模型效果。结果相同遗留时间血液的拉曼光谱具有较好的稳定(RSD<0.2),不同遗留时间血液的拉曼光谱在680cm^-1等6个波段有明显的强度变化。前10个主成分建立的PLSR模型,其r²=0.9927。6个重要波段建立的PLSR模型,预测集效果r²=0.8797。结论利用拉曼光谱结合建模分析是一种无损快速的评估血液遗留时间的方法。     

Effects of histological staining on the analysis of human DNA from archived slides

Abstract: Archived slides of cell smears treated with histological stains for sperm detection are often the only source of DNA available when cold cases are reopened. There have been conflicting reports as to the negative effects of particular histological stains on DNA recovery and quality from human cells, making stain selection an important consideration for forensic laboratories. This study investigates the effect of several staining systems on DNA recovery from histological slide samples stored from 0 to 10 weeks. DNA profiles obtained after analysis of these samples with AmpFlSTR^® Identifiler? and increased cycle AmpFlSTR^® SGM Plus? short tandem repeat (STR) profiling systems and the effects that these stains have on DNA quantity and quality over time are described. Results indicate that Christmas Tree and Hematoxylin and Eosin stains do not have significantly different effects on DNA quality after 10‐week storage of slides. This research will assist scientists to select staining systems that have minimal deleterious effects on the DNA recovered.     

同源激光雕刻橡塑印章印文的鉴别方法

目的找出同源激光雕刻橡塑印章印文之间的特征差异,建立检验鉴定此类印章印文的鉴别方法。方法制作14枚同源激光雕刻橡塑印章,借助文件仪、显微数字分析仪等仪器观察分析其盖印的印文样本。结果找出了各种细节特征差异。结论同源性激光雕刻橡塑印章因其规格性特征符合很好,检验鉴定要以细节特征比对为主。     

Variation in the Measurement of Cranial Volume and Surface Area Using 3D Laser Scanning Technology

Abstract: Three‐dimensional (3D) laser scanner models of human crania can be used for forensic facial reconstruction, and for obtaining craniometric data useful for estimating age, sex, and population affinity of unidentified human remains. However, the use of computer‐generated measurements in a casework setting requires the measurement precision to be known. Here, we assess the repeatability and precision of cranial volume and surface area measurements using 3D laser scanner models created by different operators using different protocols for collecting and processing data. We report intraobserver measurement errors of 0.2% and interobserver errors of 2% of the total area and volume values, suggesting that observer‐related errors do not pose major obstacles for sharing, combining, or comparing such measurements. Nevertheless, as no standardized procedure exists for area or volume measurements from 3D models, it is imperative to report the scanning and postscanning protocols employed when such measurements are conducted in a forensic setting.     

Study of Color Laser Printer and Photocopier Class Using a Pattern Location Measurement Method

A trace code pattern location measurement approach is proposed. It includes a method that can precisely extract the trace code pattern to identify the color laser printer or photocopier class. In this study, we collected 379 samples from 15 brands, including 129 models and 196 printers or photocopiers. The trace code pattern class is identified. Four class characteristics are used to identify the print source: (i) the relation between the pattern and print output direction; (ii) observation of the shape features from among the trace code pattern units; (iii) the feature arrangement from among the trace code pattern units; and (iv) the arrangement relation of the trace code pattern. Blind testing shows that the accuracy of the proposed method is approximately 96.9% for the Questioned Document Examiners, and 84.3% in the non‐Questioned Document Examiners. It is thus an effective technique for determining a print's color laser printer or photocopier source class.     

Raman Spectroscopic Differences between Ephedrine and Pseudoephedrine

Ephedrine (EPH) and pseudoephedrine (PSE) were studied by micro‐Raman spectroscopy and UV resonance Raman spectroscopy excited at 785 and 360 nm, respectively. Raman bands at approximately 245 and 410 cm^?1 for ephedrine have apparent differences from the same bands at approximately 215, 265, 350, 450, and 555 cm^?1 for pseudoephedrine, and these differences can be applied to distinguish between EPH and PSE. Additionally, density functional theory was used for the Raman calculations to obtain results identical to the experimental spectra. This work is expected to expand the applications of Raman spectroscopy in forensic science.     

Estimating Biological Characteristics With Virtual Laser Data

Laser scanning technology is increasingly being used in forensic anthropological research to obtain virtual data for archival purposes and post hoc measurement collection. This research compared the measurement accuracy of two laser scanners—the FARO Focus^3D 330X and the FARO Freestyle^3D—against traditionally obtained (i.e., by hand) control data (N = 454). Skeletal data were collected to address a novel question: the ability of laser scanning technology to produce measurements useful for biological characteristic estimation, such as sex and stature. Results indicate that both devices produced measurements very similar to control (c. 3‐mm average absolute error), but also illuminate a tendency to under‐measure. Despite these findings, the virtual data produced sex and stature estimates that varied little from control‐produced estimates, signifying the usefulness of virtual data for preliminary biological identification when the skeletal elements are no longer available for physical analysis.