Development of a solid phase microextraction-gas chromatography-mass spectrometry method for the determination of pentachlorophenol in human plasma using experimental design

A new method, headspace solid-phase microextraction (HS-SPME) with in situ derivatization and gas chromatography-mass spectrometry (GC-MS), which was used for the determination of trace amount of pentachlorophenol (PCP) in human plasma was presented. The acetylation derivatization reaction was firstly optimized using a Doehlert design. Then a series of parameters relevant to the headspace SPME procedure, including fiber coating, extraction temperature, extraction time and salt addition, were optimized using a two-level full factorial design expanded further to a central composite design. The validation of method showed that the optimized method had good linearity (R(2)=0.999) within the concentration ranges 0.1-50.0ngml(-1), and was sensitive with the limit of detection of 0.02ngml(-1). Intra- and inter-day precision for pentachlorophenol in human plasma samples were not greater than 11.9% and 12.6%, respectively. The proposed method, to our knowledge, describes the first application of HS-SPME with GC-MS for analysis of PCP in blood plasma sample. Application of the method to real human plasma samples, PCP was successfully detected in some cases at concentration levels 1.2-6.3ngml(-1).     

Mixing regime shapes the community assembly process, microbial interaction and proliferation of cyanobacterial species Planktothrix in a stratified lake

Lake mixing influences aquatic chemical properties and microbial community composition,and thus, we hypothesized that it would alter microbial community assembly and interaction. To clarify this issue, we explored the community assembly processes and cooccurrence networks in four seasons at two depths(epilimnion and hypolimnion) in a mesotrophic and stratified lake(Chenghai Lake), which formed stratification in the summer and turnover in the winter. During the stratification period, the epilimni...     

Epilithic biofilm as a reservoir for functional virulence factors in wastewater-dominant rivers after WWTP upgrade

Virulence factors (VFs) confer upon pathogens the ability to cause various types of damage or diseases. Wastewater treatment plants (WWTPs) are important point sources for the emission of pathogens and VFs into receiving rivers. Conventional WWTP upgrades are often implemented to improve the water quality of receiving ecosystems. However, knowledge on the pathogens, VFs, and health risks to receiving aquatic ecosystems after upgrade remains limited. In this study, we investigated detailed pathogenic information, including taxa, pathogenicity, and health risk, in two wastewater-dominant rivers after WWTP upgrade. Using 16S rRNA gene sequencing, we screened 14 potential pathogens in water and epilithic biofilm samples, though they were significantly more enriched in the biofilms. Combining 16S rRNA and metagenomic sequencing data, we identified Pseudomonas and Aeromonas as the dominant pathogenic taxa carrying functional VFs (e.g., mobility and offensive) in the epilithic biofilm. Moreover, strong pathogen-specific VF-host co-occurrence events were observed in the epilithic biofilm samples, indicating the importance of biofilms as reservoirs and vehicles for VFs. Further, we demonstrated that mobility VF is crucial for biofilm formation and pathogens in biofilm carrying offensive VF may be highly invasive. Quantification and health risk assessment suggested that the skin contact risk of P. aeruginosa carrying VFs was higher than the acceptable probability of 10^?4 in both water and epilithic biofilm samples, which may threaten ecological and human health.     

核废料处置关系人类安全

随着核装置、核力量使用的普及,不仅存在着战争和对抗中由意想不到的差错、事故所造成的巨大危险,还有因核武器制造、核能和平利用过程中出现的种种事故、差错、疏忽大意而造成的惨状。如何处理核电站产生的核废料,成为令各国头疼的问题,全球科学家一直在研究如何处理核废料,中国也不例外。     

Improved lithium-ion batteries with coral-like anodes made of recycled spherical porous silicon coated with nitrogen-doped carbon

Environmental Chemistry Letters - With the development of the silicon smelting industry, the increase of microsilica waste has become a serious concern calling...     

基于云模型和TODIM的应急预案评估方法研究*

为提高应急预案评估的科学性，提出基于云模型和TODIM法的应急预案评估新方法,利用云模型表征语言评估信息，通过得分函数处理云值，提出基于云值的主客观权重计算方法，以弥补单一赋权法求解评估指标权重的不足；基于云模型和TODIM法对候选应急预案进行优劣排序，并验证本文方法的可行性和有效性。研究结果表明:基于云模型和TODIM法的应急预案评估新方法计算出的数值结果合理、准确，研究结果可为相关部门提高应急管理能力提供借鉴。     

Toughness Improvement of Epoxy Composites Using a Kind of Environment-Friendly Bio-Based Polyester Polyol

Journal of Polymers and the Environment - Epoxy resin (EP) is a thermosetting resin with prominent performances and wide applications. However, the inherent brittleness limits its development in...     

Analysis on ecological status and spatial–temporal variation of Tamarix chinensis forest based on spectral characteristics and remote sensing vegetation indices

Environmental Science and Pollution Research - The reserve of Tamarix forest, located in Changyi, China, is the only national marine special reserve taking Tamarix as the main object of protection....