陕北黄土区小檗属植物资源调查与播种育苗试验

经调查,陕北黄土区小哭属(Berberis)植物资源有6种,蕴藏量3000担左右。可分为抗旱、中生和湿生3种生态类型。播种育苗试验,种子沙藏处理比热水浸种和干播,平均出苗率分别提高9%和15%,平均提前5天、10天。     

PKS-NRPS数据库的研究进展

非核糖体多肽合成酶(NRPS)和聚酮合成酶(PKS)是调控次级代谢物聚酮类物质和非核糖体多肽合成的关键酶。随着生物息学的快速发展,国外的NRPS-PKS数据库和预测软件不断推出。本文对几个重要NRPS和PKS领域的数据库与预测软件的研究做一综述     

白背飞虱危害对水稻产量结构的影响

白背飞虱［Ｓｏｇａｔｅｌｌａｆｕｒｃｉｆｅｒａ（Ｈｏｒｖａｔｈ）］是太湖稻区的主要害虫之一,近年来,随着耕作制度的变化及水稻品种的变更,白背飞虱跃升为太湖稻区水稻生长前期的优势种群。目前国内的研究多侧重于褐飞虱的危害及其防治,关于白背飞虱危害对水稻产量的影响,国内鲜见报道［１,２］。为了探明白背飞虱在水稻不同生育期危害时,不同虫口密度与产量的关系,作者于１９９７年进行了白背飞虱危害对水稻产量结构影响的研究。１　材料与方法供试水稻品种为Ｓ０１５。试验田共分２８小区,小区面积２０ｍ２。选取均匀饱满的…     

浅谈钢铁生产与环境保护

随着我国经济的高速发展,钢铁产能大幅度增长,随之带来是环境保护及生产成本问题.一个好的企业既要有拳头产品又要不断进行企业的升级改造,降低企业生产对环境的污染,加大企业循环再利用的投入,使钢铁生产日趋完善,达到企业生产健康发展的良性循环轨道上.     

不同来源微粒子孢子间血清学关系的比较研究

应用玻片凝集法和酶标抗体法比较了几种不同来源微粒子孢子间的血清学关系，包括本所保存的家蚕微粒子孢子（ＢｍＮ．ｂ），从安徽绩溪和江苏东台的饲养蚕中收集到的微粒子孢子和从四川收集到的蓝叶虫（ｐｈｙｌｌｏｂｒｏｔｉａｃａｒｍａｔａＢａｌｙ）微粒子孢子。结果表明，绩溪、东台微粒子孢子与ＢｍＮ．ｂ之间具有相同的血清学关系，而蓝叶虫微粒子孢子与ＢｍＮ．ｂ之间无血清学关系。     

森林生态系统土壤碳库对氮沉降的响应研究进展

大气氮沉降的不断加剧,改变了土壤理化性质,直接影响植物的生长与发育,间接影响了陆地生态系统碳库,进而可能改变全球气候变化进程。森林是陆地生态系统的主体,因此,弄清氮沉降如何影响森林生态系统碳库,对预测全球气候变化具有重要意义。笔者旨在详细分析氮沉降对森林生态系统土壤碳库输入和输出的影响,阐述氮沉降对森林生态系统凋落物分解、细根周转和土壤呼吸的影响研究进展和作用机制。截至目前,关于氮沉降对于陆地生态系统的影响研究报道较多,且国内外诸多学者也在森林生态系统土壤碳库对氮沉降的响应领域开展了较多试验研究,但多集中于碳输入和输出的总量分析,而对输入和输出各个组分的研究相对较少。笔者综述了国内外有关森林生态系统碳库输入和输出各组分对氮沉降响应的相关研究,为进一步揭示其响应机制和途径提供参考依据。     

Synergistic effects of Miconazole and Polymyxin B on microbial pathogens

The therapeutic value of antibiotics depends on the susceptibility of the infecting microorganism and the pharmacological profile of the drugs. To assess the value of an antibiotic combination of polymyxin B and miconazole this study examined the in vitro synergistic potential of the two drugs on Gram-negative and Gram-positive bacteria and yeast. Antifungal and antibacterial activity was tested by minimum inhibitory concentration (MIC) of broth macrodilution and urea broth microdilution, by fluorescence microscopy and flow cytometry. Synergism was calculated using the fractional inhibitory concentration index (FICi). With Staphylococcus intermedius as target we found up to an eightfold reduction of the individual MICs when both drugs were combined. However, the FICi was 0.63 suggesting no real interaction between the two drugs. With Escherichia coli, Pseudomonas aeruginosa, and Malassezia pachydermatis as targets the antimicrobial drug combination reduced the MICs of polymyxin B and miconazole from fourfold to hundredfold resulting in FICi between 0.06 and 0.5 which defines a synergistic action. Thus, if polymyxin B and miconazole are combined their effect is greater than the sum of the effects observed with polymyxin B and miconazole independently, revealing bactericidal and fungicidal synergism. Our results indicate a strong therapeutic value for the combination of these antimicrobial agents against Gram-negative bacteria and yeast and a weaker value against Gram positive bacteria for clinical situations where these pathogens are involved.     

Limited awareness of animal influenza prevention and control among Dai Lue smallholder farmers in Southwest China

Awareness of animal influenza and its prevention and control is important for ensuring livestock health, production and welfare. In China, a country stereotyped as a major source of emerging zoonotic infectious diseases, research on the public understanding of animal influenza is limited to the Han, the main ethnic group. The present qualitative study in Southwest China investigated awareness of animal influenza among the Dai, an ethnic minority. The participants (15 men and 10 women, ages 18–83) were smallholder farmers of pigs and poultry in rural areas of Jinghong, Xishuangbanna, Yunnan Province. A mixture of interviews and group discussions took place in homes and villages. The participants were asked about their knowledge of avian influenza (H7N9), swine influenza (H1N1), precautions taken to protect against influenza, procedures when animals were sick and perceived risk of animal influenza. The data were analysed following coding and thematic analysis. The findings demonstrated a limited understanding of animal health and welfare among participants. Specifically, they were largely unaware of animal influenza (H7N9, H1N1) including its causes, symptoms, prevention and treatment. The farmers were also uninformed of the risks they faced and unknowingly engaged in behaviours which increased direct or indirect exposure to infected animals, a risk factor for human infection. They also reported poor usage of veterinary services. In order to guarantee the health, welfare and production of their livestock, immediate action is needed to enable Dai smallholder farmers to prevent and respond to animal influenza effectively and timely.