Pathogen detection using a liquid array technology

Abstract: Low concentrations of microbial pathogens in pure and mixed samples were detected using a bead‐based, liquid array technology. A 20‐bp sequence in the 23S rRNA gene, rrl, was amplified in four microorganisms: Bacillus cereus, Escherichia coli, Salmonella enterica and Staphylococcus aureus. PCR products were positively identified with the Luminex^® 100? system. The system could detect very low amounts of DNA and the instrument response was proportional to the input concentration. The lower limit of detection (LLD) was determined to be 0.5 ng for B. cereus and E. coli and 2 ng for S. enterica. The LLD for S. aureus was not determined as the instrument response was still above the threshold when quantities of DNA as low as 0.25 ng were used. The platform positively identified organisms present in mixed samples even when the minor component was overshadowed by a 10‐fold excess of the major component.     

中国边疆跨境非传统安全：挑战与应对

中国边疆邻国众多、民族多样、文化多元,地缘政治与周边环境复杂。在深度全球化时代,各国利益相互镶嵌,安全互依互保。随着中国全面扩大对外开放以及"一带一路"倡议的推进,边疆跨境非传统安全问题愈加复杂多元,互为关联,关涉政治、经济、文化、生态、公共卫生等诸多领域,涵盖地缘、认同、利益与网络等不同安全场域,并融入周边安全、国际安全与人类安全之中。在新形势下,边疆跨境非传统安全及其治理呈现出越来越多的新问题与新难题,只有以总体国家安全观为指导,促进国际与国内相涉行为体之间的协同共治,加强边疆跨境非传统安全全方位、多层次的体系性治理,才能有利于推进维护总体国家安全。     

Quantitation of Synthetic Cannabinoids in Plant Materials Using High Performance Liquid Chromatography with UV Detection (Validated Method)

Plant based products laced with synthetic cannabinoids have become popular substances of abuse over the last decade. Quantitative analysis for synthetic cannabinoid content in the laced materials is necessary for health hazard assessments addressing overall exposure and toxicity when the products are smoked. A validated, broadly applicable HPLC‐UV method for the determination of synthetic cannabinoids in plant materials is presented, using acetonitrile extraction and separation on a commercial phenylhexyl stationary phase. UV detection provides excellent sensitivity with limits of quantitation (LOQs) less than 10 μg/g for many cannabinoids. The method was validated for several structural classes (dibenzopyrans, cyclohexylphenols, naphthoylindoles, benzoylindoles, phenylacetylindoles, tetramethylcyclopropylindoles) based on spike recovery experiments in multiple plant materials over a wide cannabinoid contents range (0.1–81 mg/g). Average recovery across 32 cannabinoids was 94% for marshmallow leaf, 95% for damiana leaf, and 92% for mullein leaf. The method was applied to a series of case‐related products with determined amounts ranging from 0.2 to >100 mg/g.     

Comparison of Chemical and Heating Methods to Enhance Latent Fingerprint Deposits on Thermal Paper

A comparison is made of proprietary methods to develop latent fingerprint deposits on the inked side of thermal paper using either chemical treatment (Thermanin) or the application of heat to the paper (Hot Print System). Results with a trial of five donors show that the application of heat produces statistically significantly more fingerprint ridge detail than the chemical treatment for both fingerprint deposits aged up to 4 weeks and for a nine sequence depletion series. Subjecting the thermal paper to heat treatment with the Hot Print System did not inhibit subsequent ninhydrin chemical development of fingerprint deposits on the noninked side of the paper. A further benefit of the application of heat is the rapid development of fingerprint deposits (less than a minute) compared with up to 12 h for the Thermanin chemical treatment.