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1.
Until recently, the majority of research on the biological control of aerial plant diseases was focused on control of bacterial pathogens. Such research led to the commercialization of the biocontrol agent Pseudomonas fluorescens A506, as BlightBan A506™, for control of fire blight of pear. In contrast, chemical fungicides typically have provided adequate control of most foliar fungal pathogens. However, fungicide resistance problems, concerns regarding pesticide residues and revocation of registration of certain widely used fungicides have led to increased activity in the development of biocontrol agents of foliar fungal pathogens. Much of this activity has centered around the use of Trichoderma spp and Gliocladium spp to control Botrytis cinerea on grape and strawberry. The biocontrol agent Trichoderma harzianum T39 is commercially available in Israel, as Trichodex ™, for control of grey mold in grapes and may soon be registered for use in the US. Also targeted primarily against a foliar disease of grapes, in this case powdery mildew caused by Uncinula necator, is the biocontrol agent Ampelomyces quisqualis AQ10, marketed as AQ10  TM biofungicide. Another promising development in the area of foliar disease control, though one which is not yet commercialized, is the use of rhizobacteria as seed treatments to induce systemic resistance in the host plant, a strategy which can protect the plant against a range of bacterial and fungal pathogens. Received 06 February 1997/ Accepted in revised form 05 June 1997  相似文献   

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Hepatitis C virus (HCV) is the leading cause of chronic liver disease worldwide and the leading indication for liver transplantation. The hallmark of the disease is its propensity to evolve into chronicity, probably because viral heterogeneity allows the virus to escape immune-mediated neutralization. Treatment with interferon alpha (IFN-alpha) has been disappointing, but higher and more frequent doses, and combination therapies, including nucleoside analogs, might lead to improved suppression of HCV RNA levels. Molecular analysis of HCV before and during treatment has indicated that high viral RNA levels and the presence of HCV genotype 1 are independent predictors of poor treatment outcome. New antiviral agents in development include inhibitors of HCV replicative enzymes, such as protease, helicase and polymerase, as well as several genetic approaches, such as ribozymes and antisense oligonucleotides. The main hindrance to drug development for hepatitis C is the lack of a small animal model or a productive tissue culture system for assessing drug action.  相似文献   

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Hepatitis A virus detection in food: current and future prospects   总被引:2,自引:0,他引:2  
Hepatitis A virus (HAV) is responsible for around half of the total number of hepatitis infections diagnosed worldwide. HAV infection is mainly propagated via the faecal-oral route and as a consequence of globalisation, transnational outbreaks of foodborne infections are reported with increasing frequency. Molecular procedures are now available and should be employed for the direct surveillance of HAV in food and environmental samples.  相似文献   

5.
Major results of the authors' findings on the implementation of biotechnological potential of aerobic methylobacteria and methanotrophs for obtaining forage proteins, biopolymers (polybutyrate and polysaccharides), enzymes (oxidoreductases), and bioprotectors (ectoin), as well as for degrading toxic C1 and Cn compounds have been reviewed. Unique features of the structural and functional organization of the metabolism of extremophilic (tolerant) methylotrophs are discussed, with a view for their prospective use in various fields of modern biotechnology, including biocatalysis and nanotechnology.  相似文献   

6.
Rice (Oryza sativa L.) and maize (Zey mays) are grown in 3.5 million hectares (Mha) in Asia that includes 1.5 Mha in South Asia. These crops are grown in sequence on the same land in the same year either in double–or triple-crop systems to meet the rice demand of a rapidly expanding human population and maize demand of livestock and poultry. The objective of this review is to provide a comprehensive overview of the current state of technical knowledge on agro-ecosystems and adaptation, area and distribution, yield potential and yield gaps, and nutrient management for rice-maize (R-M) systems in South Asia. Rice-maize systems are emerging all around South Asia but in particular are developing quite rapidly in Bangladesh and South and North India. Yield potential of rice and maize, as estimated by ORYZA2000 and Hybrid Maize models, reaches up to 15 and 22 t ha-1, respectively. However, data from several environments in India reveal gaps between potential and attainable yields of maize of upto 100% and between attainable and actual yields of upto 25–50%. Nutrient demand of R-M system is high due to high nutrient removal by high-yielding maize. Nutrient balance studies for these highly–productive and nutrient-extractive systems are scarce in South Asia. The review outlines principles of nutrient management for R-M systems, and identifies development, refinement, and dissemination of the integrated plant nutrition system technologies based on site-specific nutrient management principles as priorities for future research to increase yield, profitability, and sustainability of R-M systems.  相似文献   

7.
Plants are valuable sources of a variety of chemicals including drugs, flavours, pigments and agrochemicals. Some of the biochemical reactions occurring in plant cells are complex and cannot be achieved by synthetic routes. In vitro plant cell and organ cultures and plant enzymes act as suitable biocatalysts to perform these complex reactions. A wide variety of chemical compounds including aromatics, steroids, alkaloids, coumarins and terpenoids can undergo biotransformations using plant cells, organ cultures and enzymes. The biocatalyst-mediated reactions are regiospecific and stereospecific. Reaction types include oxidations, reductions, hydroxylations, methylations, acetylations, isomerizations, glycosylations and esterfications. Genetic manipulation approaches to biotransformation offer great potential to express heterologous genes and to clone and overexpress genes for key enzymes. Biotransformation efficiencies can further be improved using molecular techniques involving site-directed mutagenesis and gene manipulation for substrate specificity.  相似文献   

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Genome-wide data sets are increasingly being used to identify biological pathways and networks underlying complex diseases. In particular, analyzing genomic data through sets defined by functional pathways offers the potential of greater power for discovery and natural connections to biological mechanisms. With the burgeoning availability of next-generation sequencing, this is an opportune moment to revisit strategies for pathway-based analysis of genomic data. Here, we synthesize relevant concepts and extant methodologies to guide investigators in study design and execution. We also highlight ongoing challenges and proposed solutions. As relevant analytical strategies mature, pathways and networks will be ideally placed to integrate data from diverse -omics sources to harness the extensive, rich information related to disease and treatment mechanisms.  相似文献   

10.
The International Plant Proteomics Organization (INPPO) is a non-profit-organization consisting of people who are involved or interested in plant proteomics. INPPO is constantly growing in volume and activity, which is mostly due to the realization among plant proteomics researchers worldwide for the need of such a global platform. Their active participation resulted in the rapid growth within the first year of INPPO's official launch in 2011 via its website (www.inppo.com) and publication of the 'Viewpoint paper' in a special issue of PROTEOMICS (May 2011). Here, we will be highlighting the progress achieved in the year 2011 and the future targets for the year 2012 and onwards. INPPO has achieved a successful administrative structure, the Core Committee (CC; composed of President, Vice-President, and General Secretaries), Executive Council (EC), and General Body (GB) to achieve INPPO objectives. Various committees and subcommittees are in the process of being functionalized via discussion amongst scientists around the globe. INPPO's primary aim to popularize the plant proteomics research in biological sciences has also been recognized by PROTEOMICS where a section dedicated to plant proteomics has been introduced starting January 2012, following the very first issue of this journal devoted to plant proteomics in May 2011. To disseminate organizational activities to the scientific community, INPPO has launched a biannual (in January and July) newsletter entitled 'INPPO Express: News & Views' with the first issue published in January 2012. INPPO is also planning to have several activities in 2012, including programs within the Education Outreach committee in different countries, and the development of research ideas and proposals with priority on crop and horticultural plants, while keeping tight interactions with proteomics programs on model plants such as Arabidopsis thaliana, rice, and Medicago truncatula. Altogether, the INPPO progress and upcoming activities are because of immense support, dedication, and hard work of all members of the INPPO community, and also due to the wide encouragement and support from the communities (scientific and non-scientific).  相似文献   

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足迹家族研究综述   总被引:6,自引:3,他引:6  
方恺 《生态学报》2015,35(24):7974-7986
综合测度人类社会的可持续发展状态是生态经济学者追求的重要目标。足迹家族由生态足迹、碳足迹和水足迹等一系列足迹类指标整合而成,旨在为决策者系统评估与权衡人类活动的环境影响提供理论和技术支持。从理论探索、整合实践和分类比较等三方面对足迹家族的研究现状进行了综述;在此基础上围绕极具争议的足迹定义、计算方法和加权方式等问题,深入分析了阻碍当前研究进一步推进的关键性因素;指出未来应从建立足迹类型学、完善跨区域投入产出模型、细化产品和机构环境足迹标准等方面入手,推动实现足迹家族的量化整合;并首次提出了足迹家族与行星边界耦合的构想,以期为监测和预警人类活动的生态阈值、促进环境影响评价向可持续性评价转变提供科学依据。  相似文献   

12.
Recent modern techniques of propagation have been developed which could help growers to meet the demand of the horticultural industry in the next century. An overview on the in vitro propagation via thin cell layer, meristem culture, regeneration via organogenesis and somatic embryogenesis is presented. Available methods for the transfer of genes could significantly simplify the breeding procedures and overcome some of the agronomic and environmental problems, which other wise would not be achievable through conventional propagation methods. The development and remarkable achievements with biotechnology in ornamental pot plants made during the three decades have been reviewed. The usefulness of the pot plants in commercial industry as well as propagation techniques, screening for various useful characteristics and selection of somaclonal variation is also discussed.  相似文献   

13.
The current NCCLS document, M11 A2, describes two methods for susceptibility testing of anaerobic bacteria. The reference method utilizes an agar dilution procedure, which is labor intensive and not convenient for testing individual patient isolates. The broth microdilution method does not support the growth of 15–40% clinical isolates and demonstrates poor correlation with the reference method for some members of the Bacteroides fragilis group with β-lactam agents and clindamycin. Etest is a new technique that incorporates an antibiotic gradient onto a plastic strip and utilizes agar media. This method is easily performed, permits growth of all anaerobes, and provides quantitative MICs for rapidly growing strains after overnight (20 hr) incubation. This method is convenient and reliable and enables the laboratory to provide the clinician with MIC data for individual patient isolates within a clinically relevant time period.  相似文献   

14.
Pangolins are unique placental mammals with eight species existing in the world, which have adapted to a highly specialized diet of ants and termites, and are of significance in the control of forest termite disaster. Besides their ecological value, pangolins are extremely important economic animals with the value as medicine and food. At present, illegal hunting and habitat destruction have drastically decreased the wild population of pangolins, pushing them to the edge of extinction. Captive breeding is an important way to protect these species, but because of pangolin’s specialized behaviors and high dependence on natural ecosystem, there still exist many technical barriers to successful captive breeding programs. In this paper, based on the literatures and our practical experience, we reviewed the status and existing problems in captive breeding of pangolins, including four aspects, the naturalistic habitat, dietary husbandry, reproduction and disease control. Some recommendations are presented for effective captive breeding and protection of pangolins.  相似文献   

15.
Fertility estimation: a review of past experience and future prospects   总被引:1,自引:0,他引:1  
Fertility has many components and stages which require that males and females be functionally capable of carrying out all critical stages if each generational reproductive cycle is to be completed. To accomplish this, the male must produce and ejaculate normal fertile sperm. The female must produce, store and ovulate normal fertilizable oocytes. Furthermore, the female must provide a reproductive system compatible with sperm transport, capacitation, and fertilization of the oocytes, embryo and fetal development, and finally birth of healthy young. Reproductive success or failure at several of these points can be estimated quantitatively on a population basis, and in a few situations on an individual basis. It is important that fertility estimates be determined accurately and with precision to be most useful to researchers and managers of animal enterprises. Many studies have underestimated the biological relationship of fertility to other traits because the estimates lacked precision. Many in vitro manipulations of sperm in artificial insemination, of gametes in various assisted reproductive technologies, and of embryos in embryo transfer are utilized in animal breeding programs. Accurate estimation of reproductive efficiency of these in vitro procedures also is important. Conditions surrounding different sets of fertility estimates almost certainly will be different. These conditions should be described as precisely as possible, and appropriate controls included in all experiments. When possible, experiments should be replicated over time and place to determine the repeatability of the various criteria used to estimate fertility and reproductive efficiency. Advances in genomic information and molecular biology should facilitate characterizing more fully inherent potential fertility of animals at birth. In vitro tests will improve, and automated techniques will facilitate making multiple determinations possible on a large scale. Reliability of fertility estimates will increase, with the potential for enhanced animal reproductive performance through more accurate selection, genetic engineering, and enlightened animal care. Simultaneously, it is important to recognize that prediction of future fertility is more hazardous than estimating fertility, as a completely new set of circumstances may occur which are not predictable. Because fertility estimation may be applied under a myriad of conditions, principles and factors affecting fertility will be emphasized in this review as being more useful than a compilation of numerical examples.  相似文献   

16.
Despite setbacks, the clinical development of antiangiogenic agents has accelerated remarkably over the past 3-4 years. Consequently, there are currently three direct inhibitors of the VEGF pathway approved for use in cancer therapy. Other agents that block the VEGF pathway are in advanced stages of clinical development and have shown promising results. With these exciting developments come crucial questions regarding the use of these new molecular-targeted agents, alone or in combination with standard cytotoxic or targeted agents. Importantly, the mechanisms of action of anti-VEGF therapy remain unknown. Here, we discuss several potential mechanisms of action such as tumor vascular normalization, bone marrow-derived cell recruitment blockade and cytostatic effects of anti-VEGF therapy. We review the current progress, the major stumbling blocks and the future directions for anti-cancer therapy using anti-VEGF agents, emphasizing clarification of the underlying molecular mechanisms of action and biomarker identification and validation.  相似文献   

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Three of the four currently approved drugs for the treatment of African trypanosomiasis (sleeping sickness) were developed over 50 years ago. All of the current therapies are unsatisfactory for various reasons, including unacceptable toxicity, poor efficacy, undesirable route of administration, and drug resistance. The possible modes of action of these drugs are briefly reviewed, as are the possible mechanisms of resistance. The intermediate and long-term prospects for the development of safer, effective drugs are discussed.  相似文献   

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