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<正>近年来,随着植物信息数字化的普及,植物学领域出现了众多名称索引系统,如英国皇家植物园(邱园)和密苏里植物园共同创办并维护的The Plant List(http://www.theplantlist.org/),密苏里植物园维护的Tropicos(http://www.tropicos.org/),邱园、哈佛大学标本馆和澳大利亚国家标本馆共同维护的The International Plant Names Index(IPNI,http://www.ipni.org/),中国科学院植物研究所维护的中国高等植物信息系统(http://www.etaxonomy.ac.cn/)等,这  相似文献   

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Principles of oxygen consumption, oxygen transport, suspension, and mixing are discussed in the context of propagating aggregates of plant tissue in liquid suspension bioreactors. Although micropropagated plants have a relatively low biological oxygen demand (BOD), the relatively large tissue size and localization of BOD in meristematic regions will typically result in oxygen mass transfer limitations in liquid culture. In contrast to the typical focus of bioreactor design on gas–liquid mass transfer, it is shown that media-solid mass transfer limitations limit oxygen available for aerobic plant tissue respiration. Approaches to improve oxygen availability through gas supplementation and bioreactor pressurization are discussed. The influence of media components on oxygen availability are also quantified for plant culture media. Experimental studies of polystyrene beads in suspension in a 30-l air-lift and stirred bioreactors are used to illustrate design principles for circulation and mixing. Potential limitations to the use of liquid suspension culture due to plant physiological requirements are acknowledged.  相似文献   

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植物功能基因组研究方法及进展   总被引:4,自引:0,他引:4  
随着植物功能基因组研究的深入,T-DNA标签、转座子标签、反义RNA技术、基因敲除、基因陷阱和TILLING技术等多种研究方法获得了建立,并随着植物功能基因组学的不断发展而进一步完善.综述了各类研究方法的原理,并对这些方法的优缺点进行了比较与分析.  相似文献   

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Protozoan-borne diseases are prominent amongst diseases caused by parasites. Given their alarming morbidity and mortality statistics, there is ever growing interest in new therapies against these diseases. Whilst synthetic drugs such as benznidazole and melarsoprol have had a profound influence on the clinical setup, there has been significant interest in the phytochemical platform to also deliver such drug candidates. The plant family Amaryllidaceae is recognizable for its isoquinoline alkaloids, which exhibit attractive molecular architectures and interesting biological properties. This survey focuses on the antiprotozoal activities of 73 of such substances described in 18 different species of the Amaryllidaceae. Of these, 2-O-acetyllycorine was identified as the most potent (IC50 0.15 μg/mL against Trypansoma brucei brucei). Also considered are structure-activity relationships which have served to modulate activities, as well as the plausible mechanisms that underpin these effects and afford insight to the Amaryllidaceae alkaloid antiprotozoal pharmacophore.  相似文献   

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Nuclear polyhedrosis virus (Baculovirus) (NPV) preparations, designed for biological control of insects, have to be standardized by bioassay in nearly the same way asBacillus thuringiensis preparations. Specific problems and bioassay techniques of NPV preparations are discussed. It seems necessary to use a standard reference sample in each bioassay. For each particular NPV virus an experimental standard reference preparation could be prepared by those laboratories already involved in biological control studies of a given virus. They should pay particular attention to the study of storage conditions.
Résumé Les préparations à base de virus à polyèdres nucléaires (Baculovirus) destinées à la lutte biologique contre les insectes, doivent être étalonnées par des essais biologiques selon une méthodologie analogue à celle utilisée pour les préparations à base deBacillus thuringiensis. Les problèmes spécifiques aux virus et les techniques de titrage biologique qui leur sont adaptées sont discutés. Il semble nécessaire d'employer dans chaque cas une préparation de référence. Pour chaque virus à polyèdres nucléaires cette préparation de référence est à mettre au point par les laboratoires qui sont déjà concernés par les recherches sur l'utilisation en lutte biologique du virus considéré. Une attention particulière doit être portée à l'étude des conditions de conservation de ces étalons.


In cooperation with the Texas Agricultural Experiment Station, Texas A & M University, College Station 77843. Paper read at the Symposium “Standardization and Safety of Microbial Pesticides” XVth. International Congress of Entomology, Washington 19–27 August 1976.  相似文献   

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The restoration of degraded ecosystems is considered a key strategy to contribute to ecological integrity and human well-being. To support restoration practice, 10 “Principles to guide the UN Decade on Ecosystem Restoration 2021–2030” were conceived through a consultative process and put forward by a group of leading international restoration actors. The extent to which these principles can inform successful restoration activities on the ground, however, remains largely unknown. Using a combination of qualitative and quantitative data collection methods, we probed 32 stakeholders who plan, manage, and implement restoration in Rwanda to elicit which factors they perceive as most important for successful restoration based on the UN Decade principles. Using the Q-methodology, we discovered that participants overall agreed that the UN Decade principles are relevant to inform successful ecosystem restoration in the study area. Further, the Q-study revealed three distinct groups of stakeholders with different priorities in terms of opinions on restoration aims, stakeholder involvement, and relevant spatial scales. Based on semi-structured interviews, we identified four considerations for successful restoration that require special attention in future restoration interventions in the study area: (1) restoring historical conditions, (2) collecting baseline data, (3) increasing local communities' sense of ownership, and (4) pursuing a long-term vision for restoration activities. To address these considerations and thereby harvest the potential of ecosystem restoration to benefit both people and nature in the long run, diverse stakeholders with different priorities for restoration need to come together to discuss possible differences in their perceived priorities, perspectives, and approaches.  相似文献   

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Bacillus thuringiensis preparations are standardized by bioassay based on a comparison with a reference standard preparation. By this way the standardization of industrial formulations is satisfactory in order to maintain a constant quality within a given product. International standardization is quite another problem and cannot be achieved by facing only standardized titration methods, since other factors, particularly the used strains, contribute to different host activity. An account is given of the actual situation with historical backgrounds and some suggestions are made to avoid possible pitfall. Essentially it would be most useful to demonstrate the biological activity differences of different products. This work could be done by the different specialized laboratories with the help of internationally distributed standard preparations of each proposed serotype and using various technics and multiple test insects.  相似文献   

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Lineage-specific traits determine how plants interact with their surrounding environment. Unrelated species may evolve similar phenotypic characteristics to tolerate, persist in, and invade environments with certain characteristics, resulting in some traits becoming relatively more common in certain types of habitats. Analyses of these general patterns of geographical trait distribution have led to the proposal of general principles to explain how plants diversify in space over time. Trait–environment correlation analyses quantify to what extent unrelated lineages have similar evolutionary responses to a given type of habitat. In this synthesis, I give a short historical overview on trait–environment correlation analyses, from some key observations from classic naturalists to modern approaches using trait evolution models, large phylogenies, and massive data sets of traits and distributions. I discuss some limitations of modern approaches, including the need for more realistic models, the lack of data from tropical areas, and the necessary focus on trait scoring that goes beyond macromorphology. Overcoming these limitations will allow the field to explore new questions related to trait lability and niche evolution and to better identify generalities and exceptions in how plants diversify in space over time.  相似文献   

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CONVENTIONAL ANTIPSYCHOTIC DRUGS, used for a half century to treat a range of major psychiatric disorders, are being replaced in clinical practice by modern “atypical” antipsychotics, including aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone among others. As a class, the newer drugs have been promoted as being broadly clinically superior, but the evidence for this is problematic. In this brief critical overview, we consider the pharmacology, therapeutic effectiveness, tolerability, adverse effects and costs of individual modern agents versus older antipsychotic drugs. Because of typically minor differences between agents in clinical effectiveness and tolerability, and because of growing concerns about potential adverse long-term health consequences of some modern agents, it is reasonable to consider both older and newer drugs for clinical use, and it is important to inform patients of relative benefits, risks and costs of specific choices.Antipsychotic drugs are useful for treating a range of severe psychiatric disorders. Applications include the short-term treatment of acute psychotic, manic and psychotic-depressive disorders as well as agitated states in delirium and dementia and the long-term treatment of chronic psychotic disorders including schizophrenia, schizoaffective disorder and delusional disorders. Newer, “second-generation” antipsychotic drugs have largely replaced older phenothiazine, thioxanthene and butyrophenone neuroleptics in clinical practice (1,2 The development of modern antipsychotic drugs was stimulated by a landmark 1988 study that showed clozapine to be superior in efficacy to chlorpromazine in schizophrenia patients resistant to high doses of haloperidol and to have none of the adverse neurologic effects typical of older antipsychotic agents.3 Clozapine was considered “atypical” in having a very low risk of adverse extrapyramidal symptoms. This term has since been applied broadly and uncritically to antipsychotic drugs marketed in the past decade, despite their striking chemical, pharmacologic and clinical heterogeneity.4 In this overview we consider the neuropharmacology, efficacy and adverse effects of conventional antipsychotics and specific modern antipsychotic drugs.Table 1  相似文献   

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Controlled atmosphere (CA) storage is of use for commodities which potentially can undergo rapid and unacceptable biochemical change. In air, the oxygen status of most plant material, including fleshy storage organs and fruits, suffices, even in the centre, for cytochrome oxidase to be fully saturated. Conflict of evidence exists as to possible O2 and CO2 gradients in fruit which, though physiologically unimportant in air, could be important under CA conditions. CA storage gives possible control of internal O2 from o to about 80–95%; internal CO2 from about 3–4 to 100%; and both simultaneously to intermediate values. Calculated molarities of dissolved O2, CO2 and ethylene are given for various atmospheres. The differences in the O2 concentrations recommended for different varieties of apple are not readily explicable. Varietal differences in susceptibility to CO2 injury could possibly result from anatomical, rather than biochemical, differences. This could be determined partly by resolving the conflict of evidence mentioned above. Variability of plant material prevents precise control of intercellular atmosphere; recommended atmospheres can be designed only to avoid completely anaerobic conditions and a harmful level of CO2 in the centre of the least permeable individual fruit or vegetable. Effects of low O2 and high CO2 are briefly described.  相似文献   

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