黄花棘豆表面活性物质的初步研究

以黄花棘豆为原材料提取植物源表面活性剂OOR,并研究了其对农药的增效作用。初步研究表明,黄花棘豆粗取物的最佳提取溶剂为甲醇,粗提物产出率为5.94%。OOR在农药中的最佳添加量为3 mL/L,在此用量下,20%杀虫双水剂300倍液药后1～10 d对桃蚜的防效提高8.39～12.31百分点,对菜青虫的防效提高11.49～14.25百分点;75%百菌清可湿性粉剂600倍液对番茄早疫病的防效提高10.30百分点,对叶霉病的防效提高12.10百分点;在确保10%草甘膦水剂对藜的株防效和鲜重防效达90.00%以上的条件下,用药量可降至9 L/hm2,对水量可降至450 kg/hm2。     

Spatial Multi-scale Relative Humidity Values for Concrete Structures

According to the spatial features of environmental actions, on the basis of the spatial multi-scale model framework (including the global environment, regional environment, engineering environment, surface environment and internal environment of concrete) and the mathematic model for environmental actions, the spatial multi-scale relative humidity values for concrete structures were studied. That is, based on the influential factors of relative humidity on the different spatial scales, the relative humidity values in concrete were deduced by adjustment step by step from the values on the global environment to the regional environment, the engineering environment and the surface environment of concrete. It was found that using the superposition method of conventional statistic model and spatial residual error, the quantitive relationship of relative humidity values in the regional environmental scale and the engineering environmental scale can be established effectively. Moreover, the relative humidity values on the surface of concrete structural elements are related with the temperature values on the surface of concrete structural elements, and the difference of relative humidity values between the surface and the inner part of concrete should be considered in the durability assessment of concrete structures.     

五脉地椒粗提物对果蔬病原菌的抑制作用

采用冷浸法以体积分数75%的乙醇提取五脉地椒浸膏,依次用石油醚、氯仿、乙酸乙酯、正丁醇萃取,减压浓缩得到5种粗提物组分,测定5种萃取物对油菜菌核病菌、黄瓜枯萎病菌、苹果斑点落叶病菌和葡萄轮斑病菌的抑制作用。抑菌试验(生长速率法)结果表明,石油醚、氯仿、乙酸乙酯和正丁醇萃取物对菌丝的生长均有明显抑制作用,水萃取物的抑菌作用不明显;在质量浓度10 mg/mL下,氯仿、乙酸乙酯和正丁醇萃取物对4种菌丝生长的抑制率均在60%以上,其中乙酸乙酯萃取物对黄瓜枯萎病菌的抑制率可达100%。     

Do we have the tools to manage resistance in the future?

Pesticide resistance is a major factor affecting world food and fibre production, but that has been contained so far by the availability of diverse modes of action. Overcoming resistance by switching to a new mode of action is a concept easily grasped by growers but threatened by losses through resistance and new registration requirements. Opportunities for innovation and development of a diversity of novel modes of action exist through harnessing recent advances, fundamental to all eukaryotes and largely funded for medical rather than agricultural objectives, in understanding cell biology and development. The cystoskeleton, cell wall synthesis, signal transduction and RNAi are discussed as examples where new targets are now exposed. However, new modes of action will be delivered not only by sprayer or seed treatment but also through transgenic crops, although these still need to be transferred from experiment to practice. Improvements in modelling protein structures and target-site changes, supplemented by rapid diagnostics to detect resistance early, will improve resistance risk management and integrate chemical, biopesticide, transgenic and conventional breeding around the concept of diversity in modes of action. However, before agronomy can translate this into practical antiresistance strategies, there is a need to direct more resources to the biochemistry and cell biology of pests, diseases and weeds to translate these new discoveries into key tools needed to manage resistance in the future.     

What have the mechanisms of resistance to glyphosate taught us?

The intensive use of glyphosate alone to manage weeds has selected populations that are glyphosate resistant. The three mechanisms of glyphosate resistance that have been elucidated are (1) target-site mutations, (2) gene amplification and (3) altered translocation due to sequestration. What have we learned from the selection of these mechanisms, and how can we apply those lessons to future herbicide-resistant crops and new mechanisms of action? First, the diversity of glyphosate resistance mechanisms has helped further our understanding of the mechanism of action of glyphosate and advanced our knowledge of plant physiology. Second, the relatively rapid evolution of glyphosate-resistant weed populations provides further evidence that no herbicide is invulnerable to resistance. Third, as new herbicide-resistant crops are developed and new mechanisms of action are discovered, the weed science community needs to ensure that we apply the lessons we have learned on resistance management from the experience with glyphosate. Every new weed management system must be evaluated during development for its potential to select for resistance, and stewardship programs should be in place when the new program is introduced. Copyright © 2011 Society of Chemical Industry     

昆虫毒素的研究与应用

昆虫毒素是一类宝贵的药用资源,具有巨大的开发利用潜力.综述了昆虫毒素的主要活性成分、药理作用及临床应用进展,并对其发展前景进行了展望.     

粪肠球菌生物被膜的研究进展

生物被膜是粪肠球菌致病机制的一个重要原因,临床上许多生物医学材料相关感染和某些慢性顽固性感染性疾病都与其密切相关。在生物膜中的细菌不仅耐抗生素,还可耐抗体的杀菌作用,严重危害动物以及人类的健康。对粪肠球菌生物被膜的历史、生物膜特性及作用进行了综述。     

中草药提取物与酶复合物对牛乳房炎病原菌的抑菌效果

对广西壮族自治区某奶牛场的临床型乳房炎病牛奶样中分离鉴定的金黄色葡萄球菌、大肠埃希菌和无乳链球菌进行12种常用抗生素的药敏试验和中草药提取物与酶复合物体外抑菌研究.结果表明,引起奶牛乳房炎的3种病原菌对青霉素类药物有耐药性,而对庆大霉素、头孢类、环丙沙星等药物敏感.通过正交试验筛选出的中草药提取物与酶的最佳复配物(复配物I)对金黄色葡萄球菌、大肠埃希菌和无乳链球菌有明显的抑菌效果,抑制作用较强,其最低杀菌质量浓度(MBC)分别为7.82、31.25和62.50 g/L,抑菌环直径分别为(23.4±0.2)、(14.2±0.1)和(14.5±0.1)mm.     

亮叶杨桐研究进展

亮叶杨桐(石崖茶)是一种天然野生珍贵名茶,近年来,对石崖茶的需求日趋增加,而野生资源难以满足市场需求,市场发展潜力大。从生物学特性、适生条件、化学成分、药理作用等方面,阐述了亮叶杨桐的研究概况,对亮叶杨桐今后研究的方向提出了建议,以期为从事亮叶杨桐研究和生产的工作者提供参考。     

12个金针菇菌株亲缘关系研究

采用平板对峙培养法和PAGE技术研究了12个金针菇菌株间的亲缘关系。平板对峙培养法研究结果表明:12个菌株间存在不同程度的拮抗现象,无拮抗或拮抗效果不明显的菌株组合为:1号和6号、2号和4号、7号和10号、3号和5号。基于12个菌株的酯酶同工酶图谱的聚类分析结果表明,12个菌株在遗传距离为D=0.39处明显地聚成5组。其中,Ⅰ组为1号和6号,呈现Ec、Ed、Ei、Ek、El特征带;Ⅱ组为2号和4号,呈现Ec、Ed、Ef～Ei、El特征带;Ⅲ组为7号、8号、9号和10号,呈现Ed、Eh、Ei和El特征带;Ⅳ组为3号、5号和11号,呈现Ea、Ed～Ei、El特征带;Ⅴ组为12号,呈现Ed、Ee、Ei和El特征带。拮抗关系法和酯酶同工酶图谱聚类分析结果基本一致。此外,12个金针菇菌株的酯酶同工酶图谱中,谱带d、i、l为12个菌株所共有,说明这3条谱带为金针菇的标志性谱带,其相对迁移率分别为0.479、0.744、0.905。