植物精油的研究开发新进展

植物精油是一类纯天然的植物提取混合物,化学组成比较复杂.迄今为止,其在食品、医药、果蔬保鲜、日常用品、人体保健等方面得到了广泛的开发和利用.概述了植物精油及其单组分的研究利用新进展.预计不久的将来植物精油在人类生活中必将具有广阔的应用前景.     

厌氧-好氧法污水处理厂优化运行数值模拟研究

利用FCASM3-Hydro耦合模型分别模拟研究了氧传递系数(K_(La))、污泥停留时间(SRT)、缺氧池与好氧池HRT比对杭州某厌氧-好氧法(A/O)污水处理厂营养物质去除效果的影响.结果表明,曝气量大小是影响A/O脱氮除磷效果的主要因素,在低曝气量(<2g·m~(-3))水平下,氨氮去除率将随着好氧池内曝气量的增加而提高;好氧池内曝气量过低(<0.3 g·m~(-3))或过高(>2 g·m~(-3)),都不利于磷酸盐的去除.通过对比分析模拟结果得到了该A/O污水处理厂的最佳运行工况为:K_(La)=250D~(-1)、SRT=10d,缺氧池与好氧池HRT比为1:8.     

Current Understandings on Magnesium Deficiency and Future Outlooks for Sustainable Agriculture

The productivity of agricultural produce is fairly dependent on the availability of nutrients and efficient use. Magnesium (Mg²⁺) is an essential macronutrient of living cells and is the second most prevalent free divalent cation in plants. Mg²⁺ plays a role in several physiological processes that support plant growth and development. However, it has been largely forgotten in fertilization management strategies to increase crop production, which leads to severe reductions in plant growth and yield. In this review, we discuss how the Mg²⁺ shortage induces several responses in plants at different levels: morphological, physiological, biochemical and molecular. Additionally, the Mg²⁺ uptake and transport mechanisms in different cellular organelles and the role of Mg²⁺ transporters in regulating Mg²⁺ homeostasis are also discussed. Overall, in this review, we critically summarize the available information about the responses of Mg deficiency on plant growth and development, which would facilitate plant scientists to create Mg²⁺-deficiency-resilient crops through agronomic and genetic biofortification.     

燃煤火电厂锅炉“四管”的高温腐蚀

燃煤火电厂锅炉的高温腐蚀主要发生在受热面的“四 管”,即水冷壁管、过热器管、再热器管和省煤器管.腐蚀的主要类型是硫腐蚀、氯腐蚀、 水蒸汽腐蚀和钒腐蚀.本文综述了燃煤火电厂锅炉存在的典型高温腐蚀现象和机理,并简要 的介绍了一般防腐蚀措施.     

液氯消毒和紫外线消毒在实践中的应用比较

为了有效保护水体,防止传染性病原菌对人们的危害,降低水源的总大肠菌群数和粪大肠菌群数,对污水处理厂出水进行消毒是十分必要的,文章通过介绍液氯消毒和紫外线消毒,并针对这两种消毒方式在广州污水厂的应用实践的比较,提出对于污水处理厂出水消毒的建议。     

Myth and reality of the hybrid desalination process

The paper discusses some misconceptions that have contributed to the continued use of thermal desalination processes and promotion of the hybrid desalination process for new plants being built or considered at Middle East locations. The misconceptions are examined both on the basis of fundamental thermodynamic principles and in terms of practical engineering parameters. The analysis shows that there is no economic or performance advantage in the installation of greenfield hybrid power/thermal desalination/ seawater reverse osmosis (SWRO) plants in preference to power/SWRO plants, because the latter would produce water more cheaply under all conditions and at all fuel costs, and would provide more operational flexibility than the former. The paper identifies situations where the hybrid desalination process can be fully justified: in existing power/desalination plants, where aging boilers and multistage flash (MSF) units need to be repaired or replaced, through retrofitting and repowering. In such situations, abandonment of the MSF process would result in a reduction in the power output of the plant. The paper refers to previous work which showed that the repowering of a typical existing power/desalination station with refurbishment/replacement of the MSF units, together with the addition of SWRO units, would result in a several-fold increase in the water and power output and a dramatic improvement in the fuel efficiency, without any additions to the existing seawater intake system. The paper emphasizes the importance of test stations/demonstration plants at existing power/desalination stations in the Middle East in order to obtain data and make improvements in the technology of higher temperature SWRO, with the feed obtained from the cooling water returning from the power plant condenser and the thermal desalination plant. The paper shows that the potential benefits would easily justify the investment in research and development required to validate this concept.     

Distinct Evolutionary Profiles and Functions of microRNA156 and microRNA529 in Land Plants

MicroRNA156 (miR156) and miR529 have high sequence similarity and recognize overlapping sites in the same target genes, SQUAMOSA promoter binding protein-like (SPL or SBP box) genes, making it difficult to accurately distinguish their roles in regulatory networks that affect numerous biological functions. Here, we collected data about miR156 and miR529 family members from representative land plants and performed sequence comparisons, phylogenetic analysis, small RNA sequencing, and parallel analysis of RNA ends (PARE) analysis to dissect their evolutionary and functional differences. Although miR156 and miR529 are highly similar, there are differences in their mismatch-sensitive regions, which are essential for target recognition. In land plants, miR156 precursors are conserved mainly within the hairpin region, whereas miR529 precursors are conserved outside the hairpin region, including both the 5’ and 3’ arms. Phylogenetic analysis showed that MIR156 and MIR529 evolved independently, through divergent evolutionary patterns. The two genes also exhibit different expression patterns, with MIR529 preferentially expressed in reproductive tissues and MIR156 in other tissues. PARE analysis revealed that miR156 and miR529 possess specific targets in addition to common targets in maize, pointing to functional differences between them. Based on our findings, we developed a method for the rapid identification of miR529 and miR156 family members and uncovered the evolutionary divergence of these families, providing insights into their different regulatory roles in plant growth and development.     

Saliva Proteomics as Fluid Signature of Inflammatory and Immune-Mediated Skin Diseases

Saliva is easy to access, non-invasive and a useful source of information useful for the diagnosis of serval inflammatory and immune-mediated diseases. Following the advent of genomic technologies and -omic research, studies based on saliva testing have rapidly increased and human salivary proteome has been partially characterized. As a proteomic protocol to analyze the whole saliva proteome is not currently available, the most common aim of the proteomic analysis is to discriminate between physiological and pathological conditions. The salivary proteome has been initially investigated in several diseases: oral squamous cell carcinoma and oral leukoplakia, chronic graft-versus-host disease, and Sjögren’s syndrome. Otherwise, salivary proteomics studies in the dermatological field are still in the initial phase, thus the aim of this review is to collect the best research evidence on the role of saliva proteomics analysis in immune-mediated skin diseases to understand the direction of research in this field. The results of PRISMA analysis reported herein suggest that human saliva analysis could provide significant data for the diagnosis and prognosis of several immune-mediated and inflammatory skin diseases in the next future.