Effect of ambient polycyclic aromatic hydrocarbons and nicotine on the structure of Aβ42 protein

● B[a]P, nicotine and phenanthrene molecules altered the secondary structure of Aβ₄₂. ● β-content of the peptide was significantly enhanced in the presence of the PAHs. ● Nicotine made stable cluster with Aβ₄₂ peptide via hydrogen bonds. ● Phenanthrene due to its small size, interfered with the Aβ₄₂ monomer more strongly. Recent studies have correlated the chronic impact of ambient environmental pollutants like polycyclic aromatic hydrocarbons (PAHs) with the progression of neurodegenerative disorders, either by using statistical data from various cities, or via tracking biomarkers during in-vivo experiments. Among different neurodegenerative disorders, PAHs are known to cause increased risk for Alzheimer’s disease, related to the development of amyloid beta (Aβ) peptide oligomers. However, the complex molecular interactions between peptide monomers and organic pollutants remains obscured. In this work, we performed an atomistic molecular dynamics study via GROMACS to investigate the structure of Aβ₄₂ peptide monomer in the presence of benzo[a]pyrene, nicotine, and phenanthrene. Interestingly the results revealed strong hydrophobic, and hydrogen-bond based interactions between Aβ peptides and these environmental pollutants that resulted in the formation of stable intermolecular clusters. The strong interactions affected the secondary structure of the Aβ₄₂ peptide in the presence of the organic pollutants, with almost 50 % decrease in the α-helix and 2 %–10 % increase in the β-sheets of the peptide. Overall, the undergoing changes in the secondary structure of the peptide monomer in the presence of the pollutants under the study indicates an enhanced formation of Aβ peptide oligomers, and consequent progression of Alzheimer’s disease.     

Considering science needs to deliver actionable science

Conservation practitioners, natural resource managers, and environmental stewards often seek out scientific contributions to inform decision-making. This body of science only becomes actionable when motivated by decision makers considering alternative courses of action. Many in the science community equate addressing stakeholder science needs with delivering actionable science. However, not all efforts to address science needs deliver actionable science, suggesting that the synonymous use of these two constructs (delivering actionable science and addressing science needs) is not trivial. This can be the case when such needs are conveyed by people who neglect decision makers responsible for articulating a priority management concern and for specifying how the anticipated scientific information will aid the decision-making process. We argue that the actors responsible for articulating these science needs and the process used to identify them are decisive factors in the ability to deliver actionable science, stressing the importance of examining the provenance and the determination of science needs. Guided by a desire to enhance communication and cross-literacy between scientists and decision makers, we identified categories of actors who may inappropriately declare science needs (e.g., applied scientists with and without regulatory affiliation, external influencers, reluctant decision makers, agents in place of decision makers, and boundary organization representatives). We also emphasize the importance of, and general approach to, undertaking needs assessments or gap analyses as a means to identify priority science needs. We conclude that basic stipulations to legitimize actionable science, such as the declaration of decisions of interest that motivate science needs and using a robust process to identify priority information gaps, are not always satisfied and require verification. To alleviate these shortcomings, we formulated practical suggestions for consideration by applied scientists, decision makers, research funding entities, and boundary organizations to help foster conditions that lead to science output being truly actionable.     

基于环境监测实验室的高校实验室安全准入制度信息系统功能优化研究

梳理了高校实验室环境-安全-健康准入制度包含的管理内容,从人员管理、设备管理、试剂管理、实验环境管理角度进行了分析。根据现有实验室安全信息化系统运行情况,探讨了将实验室安全信息化系统与实验室信息化系统、设备管理信息化系统进行数据融合和功能优化的要点,重点分析了设备采购及管理系统、实验室安全教育与考试系统、实验室安全检查系统、试剂管理平台、实验室门禁管理系统在功能上的内在关联,从而通过试剂管理平台、实验室门禁控制系统、设备采购系统实现实验室环境-安全-健康准入制度的强制执行。研究发现,高校与环境监测实验室、院系实验室安全管理部门联合促进实验室安全信息化系统、实验室信息化系统、设备管理信息化系统的数据共享与功能升级,可以丰富实验室安全准入制度的内涵和管理手段,加强实验室安全准入制度的强制执行力,提高实验室安全管理效率。     

Enhanced debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by zero-valent zinc with ascorbic acid

• Highly efficient debromination of BDE-47 was achieved in the ZVZ/AA system. • BDE-47 debromination by the ZVZ/AA can be applied to a wide range of pH. • AA inhibits the formation of (hydr)oxide and accelerates the corrosion of ZVZ. • Reduction mechanism of BDE-47 debromination by the ZVZ/AA system was proposed. A new technique of zero-valent zinc coupled with ascorbic acid (ZVZ/AA) was developed and applied to debrominate the 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47), which achieved high conversion and rapid debromination of BDE-47 to less- or non-toxic forms. The reaction conditions were optimized by the addition of 100 mg/L ZVZ particles and 3 mmol/L AA at original solution pH= 4.00 using the solvent of methanol/H₂O (v:v= 4:6), which could convert approximately 94% of 5 mg/L BDE-47 into lower-brominated diphenyl ethers within a 90 min at the ZVZ/AA system. The high debromination of BDE-47 was mainly attributed to the effect of AA that inhibits the formation of Zn(II)(hydr)oxide passivation layers and promotes the corrosion of ZVZ, which leads to increase the reactivity of ZVZ. Additionally, ion chromatography and gas chromatography mass spectrometry analyses revealed that bromine ion and lower-debromination diphenyl ethers formed during the reduction of BDE-47. Furthermore, based on the generation of the intermediates products, and its concentration changes over time, it was proposed that the dominant pathway for conversion of BDE-47 was sequential debromination and the final products were diphenyl ethers. These results suggested that the ZVZ/AA system has the potential for highly efficient debromination of BDE-47 from wastewater.     

A review of measurement methods for peracetic acid (PAA)

• Physical and chemical properties and application of peracetic acid solution. • Determination method of high concentration peracetic acid. • Determination method of residual peracetic acid (low concentration). Peroxyacetic acid has been widely used in food, medical, and synthetic chemical fields for the past several decades. Recently, peroxyacetic acid has gradually become an effective alternative disinfectant in wastewater disinfection and has strong redox capacity for removing micro-pollutants from drinking water. However, commercial peroxyacetic acid solutions are primarily multi-component mixtures of peroxyacetic acid, acetic acid, hydrogen peroxide, and water. During the process of water treatment, peroxyacetic acid and hydrogen peroxide (H₂O₂) often coexist, which limits further investigation on the properties of peroxyacetic acid. Therefore, analytical methods need to achieve a certain level of selectivity, particularly when peroxyacetic acid and hydrogen peroxide coexist. This review summarizes the measurement and detection methods of peroxyacetic acid, comparing the principle, adaptability, and relative merits of these methods.     

不同类型活性炭处理废水中重金属离子的研究进展

重金属对人体的显著毒性和难降解的特性,使重金属水体污染成为全球性关注的环境问题。本文综述了重金属废水的危害、来源及常用处理方法,比较了不同类型活性炭处理废水中重金属离子的差异,阐述了不同类型活性炭处理技术的优势和特点,并对今后的重金属废水处理技术研究方向进行了展望。     

Efficiency of mercapto flavor compounds in removing acrylamide under high temperature and low humidity conditions

Acrylamide (AA) is a potential human carcinogen, genotoxicant, and neurotoxicant. Thus, the aim of this study was to examine the ability of mercapto flavor compounds to remove AA released from consumer packaging into food products. Four mercapto flavor compounds including 1,2-ethanedithiol, 1-butanethiol, 2-methyl-3-furanthiol, and 2-furanmethanethiol were employed to extract AA in model system using high temperature and low humidity. Our study showed that mercaptans were effective in eliminating AA in our model system. In order to remove 0.2 μmol AA, the optimal conditions in the reaction system were mercaptan flavor chemicals at 5 μmol, temperature 180 °C, and reaction time 25 min. In the presence of a higher pH, the greater was the amount of AA eliminated. Evidence indicates that employment of mercapto flavor chemicals under certain temperature and pH conditions is a reliable method to remove any unwanted AA from food products.     

Combined use of earthworm (Alma millsoni) and bacterium (Bacillus sp.) improved the bioremediation of spent engine oil contaminated soil

This study was carried out to assess the effectiveness of the combined use of earthworm (Alma millsoni) and bacterium (Bacillus sp.) in the bioremediation of spent engine oil (SEO) contaminated soils. A. millisoni were collected from the Botanical Garden of University of Ibadan, Nigeria. The stock culture of hydrocarbonoclastic Bacillus sp. was used for the bioremediation study. A set-up of eight pots containing 1000?g soil sample and 20?g of cow dung were mixed with 100, 75, 50 and 0?mL SEO respectively. Each of the set up was subjected to bioremediation agents; A. millisoni alone, Bacillus sp alone, A. millisoni and Bacillus sp, no treatment (control) in duplicate. Treatment of 100?ml SEO contaminated soil with combined A. millisoni and Bacillus sp resulted in significantly (P? bacterium > vermi-remediating agents. Earthworms exposed to 100?mLSEO-contaminated soil had higher CAT, SOD, and GPx activities compared to the control. Findings indicated that A. millisoni with Bacillus sp. can synergistically improve bioremediation of SEO contaminated soils.     

植物内重金属的赋存形态及分布特征分析方法研究进展

植物内重金属分析不仅有助于阐述重金属迁移转化规律,揭示植物修复机理,也是监测评价大气、水及土壤环境重金属污染状况的重要依据。研究针对植物样品中重金属赋存形态及分布特征的分析方法进行综述,分别介绍了其原理、优缺点及应用。提出制定统一高效的分析检测方法,深化植物内重金属的赋存形态及分布特征与环境相关性的研究以及建立数据共享平台是植物样品重金属信息分析方法的未来发展方向。     

Fieldwork after conflict: contextualising the challenges of access and data quality

Despite sustained scholarly interest in post‐conflict states, there has not been a thorough review and analysis of associated methodology and the challenges of conducting research in these contexts. Addressing this gap, this paper directs attention to the particular effects of these settings on access and data quality and their ramifications for the resulting scholarship. It assesses the intrinsic challenges of performing fieldwork in these environments, drawing on both relevant social science literature and the authors’ experiences of carrying out research in Afghanistan and Timor‐Leste. The study demonstrates that the post‐conflict environment moulds research design and, consequently, influences how questions are answered as well as the questions asked. Moreover, it highlights ways to mitigate these issues. This work is of relevance to scholars planning to engage in field research and to researchers reflecting upon their work, as well as to policymakers who are considering undertaking programmes or commissioning research in post‐conflict areas.