植物修复重金属与多环芳烃污染土壤强化措施研究进展

重金属和多环芳烃是土壤环境中的重要污染物，其复合污染土壤的修复已成为环境科学研究的热点问题。植物修复技术是目前修复土壤复合污染重要方法之一，但植物本身修复能力有限，需借助化学、微生物、基因工程等手段对其修复效果进行强化。本文对国内外近几年来植物修复重金属-多环芳烃复合污染强化措施研究成果进行综述，并重点讨论了植物根际生长促进菌及菌根在强化修复中的应用，在此基础上对未来该领域需要深入研究的科学问题进行了阐述。     

植物-微生物联合修复重金属污染土壤研究进展

通过总结近年来植物与菌根真菌、根瘤菌以及非共生微生物联合修复重金属污染土壤研究的最新成果，深入探究植物-微生物的联合修复机理。旨在为新发现的超富集植物构建微生物强化修复措施。认为以植物-微生物联合修复为核心，辅以一些化学强化措施是未来的发展方向。     

我国污染土壤生物修复技术研究现状及发展展望

以文献统计的方式对2006~2015年国内学者在中国知网和Web of science中发表的相关文献进行统计分析,综述了我国污染土壤生物修复技术的10年研究进展。结果显示:近10年我国土壤生物修复技术的研究热度不断上升,主要研究对象为重金属污染土壤和有机物污染土壤,总体分为机理研究和试验研究,且后者居多。在此基础上,本文简要介绍了当前主要研究的植物修复技术、微生物修复技术、动物修复技术、生物材料修复技术、生物组合修复技术及物理、化学、生物联合修复技术6种生物修复技术的原理、优缺点及研究现状等内容,并指出了未来生物修复技术在修复原理、针对性、经济性、风险、强化措施、应用范围等方面的发展方向。     

土壤重金属污染及防治措施

本文主要简述了土壤中重金属污染的来源、重金属存在的不同形态及在土壤-生物系统中重金属的生态效应。根据重金属污染特点，分析了目前土壤重金属污染防治措施中的优缺点。     

持久性有机污染物及修复技术

持久性有机污染物（POPs）具有致癌、致畸和致突变作用，对人类健康造成严重危害：本文介绍了持久性有机污染源的控制技术，以及土壤在受到污染后，所采用的生态修复方法，并详细介绍了物理修复、化学修复和生物修复技术及发展趋势。     

植物硫苷-黑芥子酶系统对环境胁迫的响应

硫苷-黑芥子酶系统是植物中一种特有的底物酶系统,其水解产物具有高度生物活性,该系统对植物的生长发育、生长素微调以及植物的防御保护等均有重要意义.目前对植物硫苷-黑芥子酶系统对环境胁迫的响应的研究多为对硫苷的研究,而对系统相关物质研究较少.本文对硫苷-黑芥子酶系统做了简单介绍,并对植物硫苷-黑芥子酶系统对病虫害和酸雨、水、温度、盐、重金属胁迫下的响应进行了综述.     

解译土壤质量演变规律，确保土壤资源持续利用

土壤质量演变机理及调控土壤质量相关技术的研究是国内现代土壤学研究的热点,也是各国政府非常关注的问题。土壤质量是土壤提供植物养分和生产生物物质的肥力质量;容纳、降解、净化各种污染物质促进生态平衡的环境质量;劝植物及人类安全的健康质量的综合量底。不继提高土训肥力质量是确保农业高产优质基础;努力改善土壤环境质量是确保土壤（水及空气）等资源可持续利用的关键;深入研究土壤健康质量的理论与相关技术是确保人畜安全和丰富健康的物质生活的重要途径之一。提高土壤质量是农业和伙在社会持续发展的需求。“土壤质量演变规律及土壤资源可持续利用”立为国家重点基础研究发展规划项目后的近两年中已取得了有价值的阶段性成果。     

基于绿色流域理念的三峡库区小流域综合治理模式探讨

三峡库区水土流失和面源污染问题严重威胁水库水安全,影响当地的农业和经济社会的发展。通过开展小流域综合治理可有效控制当地的水土流失与面源污染,本文结合绿色流域建设理念,从流域产业结构调整控污减排、坡耕地整治、农业面源污染控制、分散生活污水生态净化和流域自然沟渠及库周缓冲带截留等技术层面,探讨了建立"策源地控制、流通区削减、缓冲带截留"的综合治理体系的模式,分析了当前小流域综合治理和管理中存在的问题,并提出了相应的对策。     

兽用抗生素在土壤中的环境行为、生态毒性及危害调控

长期以来,集约化畜禽养殖行业广泛使用抗生素来预防和治疗传染性疾病或促进动物生长,导致其随畜禽粪便大量地进入农田土壤中,造成一系列的生态毒理效应,以及诱导抗性细菌和抗性基因的产生和增长,对人类健康带来潜在威胁.本文系统综述了兽用抗生素在土壤环境中的迁移和降解行为与机理,对植物、土壤动物与微生物的毒性效应,以及抗生素危害调控方法及其机理.抗生素在土壤中的环境行为主要包括吸附/解吸、微生物降解与非生物降解,它们与土壤的理化性质(pH、有机质含量等)以及抗生素本身结构和化学性质(官能团、疏水性等)密切相关.抗生素对植物、土壤动物与微生物的毒理效应主要取决于抗生素的种类和浓度以及土壤的理化性质等.抗生素在堆肥和厌氧消化过程中主要通过微生物降解和水解被去除.此外,畜禽粪便中的抗生素还可通过高温热解的方式被高效地分解.生物炭和石墨烯基复合材料则可以通过氢键、表面络合、静电作用、离子交换等作用吸附固定土壤中的抗生素,调控其危害.在对当前研究进展总结的基础上,本文提出了抗生素污染研究中尚待解决的重要问题,并对未来的研究方向作出展望.     

金属-有机框架材料的合成及其在水中重金属吸附的应用研究现状

金属-有机框架材料(MOFs)具有设计合成方法多样、合成后易于改性、对重金属吸附量大、平衡时间短等优点,已被广泛研究和应用。近年来,MOFs在水中重金属吸附中的应用研究,成为了十分热门的课题。水稳性是反映吸附材料在水中稳定性的重要参数,具有良好的水稳性是MOFs成功地应用于去除水中重金属离子的前提。本文结合近十年MOFs在重金属吸附领域的研究情况,从MOFs的合成、水稳性、在重金属吸附中的应用、再生与重复利用几个方面,综述了MOFs的合成方法、MOFs的合成后修饰、MOFs的水稳性、MOFs对水中As、Pb、Hg、Cd、Cr、Cu等重金属离子的吸附,以及MOFs的再生等的研究现状,并提出了今后MOFs在重金属吸附领域的研究方向,为MOFs在重金属吸附领域中合成与应用提供参考。     

Instar-specific defensive secretions of stink bugs (Heteroptera: Pentatomidae)

Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C₆ and C₈ (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.     

Ecological and evolutionary dynamics of fig communities

Summary I review the status of five topics in fig research: pollen-vector versus seed production, flowering phenology and wasp population dynamics, monoecy versus dioecy, parasite pressure, and fig wasp behavior. I raise several new questions based on recent research on two components of fig reproduction: pollen-donation (male) and seed-production (female) success. I focus on how these two components of reproductive success depend on the flowering phenology of the figs and the population dynamics of the pollinator wasps.     

Implications of toxins in the ecology and evolution of plant pathogenic microorganisms: Bacteria

This review attempts to rationalise what is known about bacterial phytotoxins and associate it with the ecology and possible evolution of the producing organisms. Study of non-toxin producing variants gives insight into the ecological role of the toxin. Elucidation of chemical structures of phytotoxins has shown that many exist as families of analogous compounds. Studies on the variation of chemical structures and how they are distributed across species and genera can lead to development of hypotheses on evolutionary relationships. Knowledge on biosynthetic pathways to tosins allows recognition of specific enzymatic steps involved in developing the characteristic features of the structures. Phytotoxins often have a potent biochemical activity, and in some cases the producing organism has associated mechanisms to prevent action of the toxin upon itself; in such cases toxigenesis is clearly not a chance event. The various aspects of bacterial toxigenesis indicate that bacterial phytotoxins are special secondary metabolic products that play beneficial roles to the producing organisms in their various ecological niches.     

Fluorinated analogs of insect sex pheromones

Summary The syntheses of fluorinated mimics of pheromones ofSpodoptera littoralis, Diparopsis castanea, Laspeyresia pomonella, Bombyx mori andThaumetopoea pityocampa are described. These analogs showed biological activities similar to those of the natural pheromones in laboratory assays (EAG).We gratefully acknowledge Comisión Asesora de Investigación Cientifica y Técnica for financial support (Grant No. 3296/79) and Consejo Superior de Investigaciones Cientificas for predoctoral and postdoctoral fellowship (to G.F. and M.R.). We also thank Mr J. Baltá and Ms R. Murgó for their collaboration in the EAG work.     

Complement evasion by the Lyme disease spirocheteBorrelia burgdorferi grown in host-derived tissue co-cultures: role of fibronectin in complement-resistance

The effectiveness of complement-mediated killing ofBorrelia burgdorferi, the causative agent of Lyme disease, in the presence of host-derived tissues was studied. Second and high passage forms ofB. burgdorferi 297 isolate were grown in a LEW/N rat joint tissue co-culture system and in artificial BSK medium. Guinea pig complement and third week immune serum from hamsters with experimental Lyme disease were added to the cultures. Both high and low passage borrelia grown in BSK medium died and did not revive after 3 weeks incubation in BSK medium. However, 5–12% of tissue co-cultured borrelia survived the first complement-mediated lysis. Repeated re-growth and lysis cycles in tissue co-culture resulted in isolation of an 85% complement-resistant population ofB. burgdorferi. Joint tissue culture supernatant collected on the third day of tissue culture, and fibronectin (25 g/ml), also protected spirochetes from complement-mediated lysis in contrast to BSK or fresh co-culture medium. Complement-mediated lysis may not be an effective mechanism in eradication of borrelia, and the chronicity of Lyme disease may be due to resistance ofB. burgdorferi variants to host immune defense mechanisms in the presence of host-derived tissues.     

Protein-O-mannosyltransferases in virulence and development

Protein-O-mannosyltransferases (Pmt proteins) catalyse the addition of mannose to serine or threonine residues of secretory proteins. This modification was described first for yeast and later for other fungi, mammals, insects and recently also for bacteria. O-mannosylation depends on specific isoforms of the three Pmt1, 2 and 4 subfamilies. In fungi, O-mannosylation determines the structure and integrity of cell walls, as well as cellular differentiation and virulence. O-mannosylation of specific secretory proteins of the human fungal pathogen Candida albicans and of the bacterial pathogen Mycobacterium tuberculosis contributes significantly to virulence. In mammals and insects, Pmt proteins are essential for cellular differentiation and development, while lack of Pmt activity causes Walker-Warburg syndrome (muscular dystrophy) in humans. The susceptibility of human cells to certain viruses may also depend on O-mannosyl chains. This review focuses on the various roles of Pmt proteins in cellular differentiation, development and virulence. Received 6 September 2007; received after revision 3 October 2007; accepted 5 October 2007     

Schistosoma mansoni: A chemoattractive factor released by males and its receptor in females

Chemoattraction between developing (23- to 28-day-old) and adult (10- to 12-week-old)Schistosoma mansoni males and females has been described previously. We report here on in vitro attraction of mature worms to released products of worms of the opposite sex. In the absence of a stimulus worms migrated randomly and did not show any preference in their orientation. Males were not significantly attracted to released products of females. Females exhibited greatest attraction to released products of males, and some attraction to the lipid fraction of released products of males. The aqueous fraction of male-released products slightly repelled females. Prior exposure to released products of males rendered females unresponsive to subsequent exposure, suggesting receptor saturation. These findings have important potential implicatons for the control of schistosomiasis by intercepting attraction and mating between males and females.     

Lipid transfer in plants

Summary Plant cells contain cytosolic proteins, called lipid transfer proteins (LTP), which are able to facilitate in vitro intermembrane transfer of phospholipids. Proteins of this kind from three plants, purified to homogeneity, have several properties in common: molecular mass around 9 kDa, high isoelectric point, lack of specificity for phospholipids, and binding ability for fatty acids. The comparison of their amino acid sequences revealed striking homologies and conserved domains which are probably involved in their function as LTPs. These proteins could play a major role in membrane biogenesis by conveying phospholipids from their site of biosynthesis to membranes unable to form these lipids. Immunochemical methods were used to establish an in vivo correlation between membrane biogenesis and the level of LTP or the amount of LTP synthesized in vitro from mRNAs. The recent isolation of a full-length cDNA allows novel approaches to studying the participation of LTPs in the biogenesis of plant cell membranes.     

Autophagy: molecular mechanisms,physiological functions and relevance in human pathology

Autophagy is a degradative mechanism mainly involved in the recycling and turnover of cytoplasmic constituents from eukaryotic cells. Over the last years, yeast genetic screens have considerably increased our knowledge about the molecular mechanisms of autophagy, and a number of genes involved in fundamental steps of the autophagic pathway have been identified. Most of these autophagy genes are present in higher eukaryotes indicating that this process has been evolutionarily conserved. In yeast, autophagy is mainly involved in adaptation to starvation, but in multicellular organisms this route has emerged as a multifunctional pathway involved in a variety of additional processes such as programmed cell death, removal of damaged organelles and development of different tissue-specific functions. Furthermore, autophagy is associated with a growing number of pathological conditions, including cancer, myopathies and neurodegenerative disorders. The physiological and pathological roles of autophagy, as well as the molecular mechanisms underlying this multifunctional pathway, are discussed in this review.Received 12 January 2004; received after revision 29 January 2004; accepted 4 February 2004     

Animal models in interferon research: Some current trends

Conclusions Concepts about interferon have changed dramatically over the years. Initially it was considered to be an antiviral protein which selectively inhibited the replication of viruses²⁴. Over the years we have discovered an increasing number of interferons and many different biological activities. Other regulatory proteins have been detected and the interferons have become part of an interacting family of biological response-modifying proteins. Because of the complexity of these systems, animal experiments are the only way to assess the clinical potential of interferons (and interferon-like molecules). It is important that the animal experiments should not be too restricted in scope, because interferon has now proved to have activity in conditions other than viral infections, for example against tumors and infections other than those caused by viruses.