食品安全与国家安全

近年来连续不断地发生食品安全事件,伤害了消费者的身心健康,影响了中国产品的出口贸易,丑化了中国产品的国际形象,在一定程度上威胁了我国的国家安全.从国家安全的角度来分析食品安全问题,预防和减少食品安全事件的发生,就要加强国家间交流,积极建立合作平台;对内提升食品安全意识,对外改善食品国际形象;建立国家食品安全体系,加强政府监管,提高我国的食品质量,从而更有效地维护国家安全.     

In the Line of Fire—21st-Century Approach to an Ancient War Injury

Abstract:  Authentic black-powder muzzle-loader weapons or replicas are used today primarily for re-enactments of historic battles. A lay actor playing the role of a Prussian infantryman sustained life-threatening gunshot injuries during a recent re-enactment of a historic battle of the Sixth Coalition. As only blank historic muzzle-loading weaponry was used, the origin of the missile causing the wounding was initially unclear. Further investigation revealed a ramrod that had been propelled out of the barrel of another gunner's smooth-bore gun as cause of injury. The ramrod was hurled on a trajectory of more than 20 m, breaking the victim's shouldered barrel and hitting the victim resulting in severe abdominal, thoracic, and upper limb injuries. The critical incidents while handling muzzle-loading weaponry leading to premature discharge are elucidated. Furthermore, this report demonstrates how actual diagnostics and subsequent surgical treatment enabled this infantryman to survive an injury to which his comrades-in-arms would have succumbed 200 years ago.     

基于网络药理学及分子对接探究银翘散“异病同治”小儿急性上呼吸道感染及小儿病毒性心肌炎作用机制

目的 采用网络药理学与分子对接方法探究银翘散“异病同治”小儿急性上呼吸道感染(acute upper respiratory infection in children, AURIC)及小儿病毒性心肌炎(viral myocarditis in children, VMC)的共同分子机制。方法 利用TCMSP数据库及CNKI数据库筛选银翘散的活性成分及靶点;通过GeneCards数据库和OMIM数据库分别筛选AURIC和VMC的相关靶点,获取银翘散与AURIC、VMC三者的交集靶点;利用Cytoscape 3.9.1软件构建“银翘散—成分—靶点”网络,分析重点活性成分;使用STRING数据库通过构建交集靶点的PPI网络以分析核心靶点;使用DAVID数据库对交集靶点进行GO功能和KEGG通路富集分析;利用Autodock Tools软件对核心靶点及主要成分进行分子对接。结果 筛选出银翘散129个活性成分,264个作用靶点;银翘散与AURIC、VMC共119个交集靶点;银翘散—成分—靶点网络的构建得出槲皮素、山柰酚、木犀草素、柚皮素、豆甾醇为排名前5的主要成分;PPI网络构建后得出STAT...     

Evaluation of Four Fingerprint Development Methods for Touch Chemistry Using Matrix‐Assisted Laser Desorption Ionization/Time‐of‐Flight Mass Spectrometry,

Four preparation techniques for MALDI/TOF mass spectrometry were compared to determine the ability to gather intelligence for investigations through the chemical analysis of latent fingerprints, defined as “touch chemistry.” Compatible fingerprint development processes used for identification along with new techniques are necessary to evaluate touch chemistry. Ten volunteers deposited fingerprints from solvent residues containing drugs and explosives onto microscope slides. The developers included (A) fingerprint powder, (B) MALDI matrix, (C) fingerprint powder and lifting, and (D) cyanoacrylate fuming with fingerprint powder. Qualitative identification was based on ion images and spectra. The highest average detection rates (88%) were found using methods A and B. Methods C (52%) or D (18%) had limited success. Results demonstrate the importance of imaging coupled to extracted mass spectral data in detecting analytes in deposited fingerprints. Overall, the results suggest continued development of touch chemistry applications could prove useful for gathering intelligence and forensically relevant information.     

灰尘鞋印直显与荧光显现研究

本文根据邻菲(口罗)啉在弱酸条件下与Fe~(2 )反应生成稳定的桔红色给合物的原理,对遗留在各种纸张、本色木、地板砖.地板革等承受客体上的灰尘鞋印进行显现,获得较佳效果.对微弱或潜在灰尘鞋印,用上述方法处理后,再用荧光粉末刷涂,用多波段光源显现效果更佳.     

The Effects of Polymer Pigmentation on Fingermark Development Techniques

The effectiveness of latent fingerprint development techniques is heavily influenced by the physical and chemical properties of the deposition surface. The use of powder suspensions is increasing for development of prints on a range of surfaces. We demonstrate that carbon powder suspension development on polymers is detrimentally affected by the presence of common white pigment, titanium dioxide. Scanning electron microscopy demonstrates that patches of the compound are clearly associated with increased levels of powder adhesion. Substrates with nonlocalized titanium dioxide content also exhibit increased levels of carbon powder staining on a surface‐wide basis. Secondary ion mass spectrometry and complementary techniques demonstrate the importance of levels of the pigment within the top 30 nm. The association is independent of fingermark deposition and may be related to surface energy variation. The detrimental effect of the pigment is not observed with small‐particle reagent (MoS₂ SPR) or cyanoacrylate (superglue) fuming techniques that exploit different development mechanisms.     

A novel method for the analysis of discharged smokeless powder residues

A novel method for the estimation of intermediate-long firing distance range is proposed. The method is based on the characterization and chemical analysis of the smokeless powder particles on the target. An adhesive lifter is applied to collect the suspected gunshot residues (GSRs) from the surface of an object, and a Modified Griess Test (MGT) is carried out after alkaline hydrolysis on the adhesive lifter. Visualized particles are removed from the adhesive lifter under a microscope. Two systems are used for the analysis of organic discharge residues from the smokeless powder: (1) gas chromatography/thermal energy analysis (GC/TEA) for the analysis of nitroglycerine (NG) and 2,4-dinitrotoluene (2,4-DNT), (2) gas chromatography/mass spectrometry (GC/MS) for the identification of organic components such as DNT, NG, and some stabilizers. By using this procedure and confirming that the suspected particles are indeed GSR, one can estimate the intermediate-long firing distance of c. 0.75-3 m in the presence of very few particles and provide information for the classification of ammunition type in casework.     

A Systematic Study to Understand the Effects of Particle Size Distribution of Magnetic Fingerprint Powders on Surfaces with Various Porosities

This study intends to design magnetite (Fe₃O₄)‐based magnetic fingerprint powders with different particle size distributions. It also investigates the influence of particle size distribution on the visualization of latent fingermarks with as little background staining as possible on the surfaces with various porosities in a systematic way. Two strategies were used to prepare the magnetic fingerprint formulations for this study: milling of coarse magnetite particles for different durations, and mixing of sieved fine particles with different size ranges with coarse particles. Particle size analyses of the prepared magnetic powders, optical microscopy‐based roughness analysis of the surfaces and SEM measurements of the visualized fingerprints and representative powders were performed. Mag2 of the formulations prepared through milling and Mag5 and Mag6 of the formulations prepared through sieving and mixing were more successful in the development of latent prints than the rest of the solutions.     

Quantitative Phase Analysis by the Rietveld Method for Forensic Science

Quantitative phase analysis (QPA) is helpful to determine the type attribute of the object because it could present the content of the constituents. QPA by Rietveld method requires neither measurement of calibration data nor the use of an internal standard; however, the approximate crystal structure of each phase in a mixture is necessary. In this study, 8 synthetic mixtures composed of potassium nitrate and sulfur were analyzed by Rietveld QPA method. The Rietveld refinement was accomplished with a material analysis using diffraction program and evaluated by three agreement indices. Results showed that Rietveld QPA yielded precise results, with errors generally less than 2.0% absolute. In addition, a criminal case which was broken successfully with the help of Rietveld QPA method was also introduced. This method will allow forensic investigators to acquire detailed information of the material evidence, which could point out the direction for case detection and court proceedings.     

Forensic DNA Analysis of Wheat Flour as Commonly Used in White Powder Cases

In the wake of terrorist attacks using anthrax and ricin, white powder is often encountered in cases of malicious mischief and terrorist threats. Wheat flour is a common white powder encountered in such criminal investigations. We used DNA analysis to investigate wheat flour samples for identification and discrimination as trace evidence. Species identification of commercially available wheat flour was carried out by sequencing a partial region of the ribulose bisphosphate carboxylase large subunit gene (rbcL). Samples were discriminated using short tandem repeat (STR) analysis. The rbcL sequences of all wheat flour samples were identical and showed a high level of similarity to known wheat (Triticum aestivum L.) sequences. Furthermore, flours had characteristic patterns in STR analyses, with specific cultivars showing distinctive patterns. These results suggested that the identification of wheat flour species is possible using rbcL sequencing, and that STR analysis is useful for discriminating between samples.