<Emphasis Type="Italic">Stenotrophomonas maltophilia</Emphasis>: a new potential biocontrol agent of <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis>, causal agent of potato brown rot

Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro, four isolates of S. maltophilia (PD3531, PD3532, PD3533, and PD3534) appeared antagonistic. The isolate (PD3533) was screened as the most promising antagonist for the in vivo tests. In the greenhouse, the antagonist was applied directly to soil or by bacterization of potato eyepieces. Stenotrophomonas maltophilia significantly suppressed potato brown rot in Egyptian clay soil but not in Dutch clay soil. Survival of a rifampicin and chloramphenicol-resistant S. maltophilia strain PD4560 was investigated in two pairs of clay soils, conventionally and organically managed, from Egypt and the Netherlands. The survival of S. maltophilia was significantly less in Dutch than in Egyptian soils, while the converse occurred for R. solanacearum. These results are in agreement with those obtained in the in vivo biocontrol tests. In conclusion, S. maltophilia may be useful for control of brown rot in the area where it was originally isolated, the Nile Delta in Egypt.     

膨胀石墨的多孔结构及其应用

膨胀石墨作为一种多孔材料，有望在溢油吸收、脱除废气、催化剂载体等多方面得到广泛应用。综述了有关膨胀石墨孔结构的研究结果以及它在有关领域的应用。     

丝素蛋白作为药物载体的研究进展

丝素蛋白作为一种具有优良性能的天然高分子材料,在生物医学领域被深入研究。丝素蛋白材料形态易塑,生物相容性良好,生物降解性可控且降解产物无毒,因此是理想的药物载体。本文综述了丝素膜、丝素凝胶、丝素纳米纤维和丝素微球等不同类型的药物载体,并展望了其研究和应用前景。     

Flavobacterium psychrophilum in rainbow trout, Oncorhynchus mykiss (Walbaum), hatcheries: studies on broodstock, eggs, fry and environment

The occurrence of Flavobacterium psychrophilum at four rainbow trout hatcheries was investigated to provide more knowledge about the reservoirs and transmission of this bacterium. Broodstock were sampled at stripping (including both unfertilized and fertilized eggs), and the offspring were then sampled at the eyed egg and fry stages. Water and surface samples (e.g. hatchery trays) were also sampled. Flavobacterium psychrophilum was found in ovarian fluid and milt, indicating that broodstock may serve as a reservoir and are latent carriers of the pathogen. Flavobacterium psychrophilum was not found on or inside eggs, but further egg studies will be necessary to elucidate the possibility of vertical transmission of the pathogen. Flavobacterium psychrophilum was isolated from water samples, but only from water that had been in close contact with farmed rainbow trout or eggs. Flavobacterium psychrophilum isolates were characterized and compared with well-characterized strains, using degradation of elastin, serotype and ribotype profiles. Different ribotypes of F. psychrophilum were found between hatcheries, but a common ribotype A was found at all four hatcheries. Different ribotypes were found in broodstock without clinical disease, whereas only a few ribotypes (mostly ribotype A) were found in diseased fry. The same ribotype A was found in broodstock, in water samples from hatchery trays and in fry, which suggests the possibility of transmission of F. psychrophilum between broodstock and offspring.     

两种生物膜工艺对污染物去除效果的比较研究

在室温下,用竹丝、塑料两种材料作为生物膜载体,使用SBR工艺对比研究这两种生物膜处理工艺去除污染物的实验结果及作用机理。实验结果表明:竹丝填料反应器对高锰酸盐指数、NH3-N(氨氮)、硝酸盐氮、亚硝酸盐氮、TP(总磷)的去除率分别为31.8%~51.9%、53.3%~71.9%、69.2%~84.0%、21.1%~33.3%、51.1%~74.5%,与塑料填料反应器相比具有明显的优势。因为竹丝填料是天然载体,其具有亲水基团和良好的生物亲和性,并且生物量多,这就使得微生物容易在竹丝填料上生长并快速形成生物膜,并且其生物膜的总体性能要比塑料填料反应器内生物膜的总体性能要好。总的来看,塑料填料反应器的处理效果不如竹丝填料反应器。     

低压电力线载波通信的集散控制数据交换研究

低压电力线载波通信的集散控制数据交换平台,由若干集散控制接口单元组成,集散控制接口单元具有低压电力线载波通信功能及RS485总线通信功能,集散控制接口单元之间利用PL2102实现低压电力线载波通信,通过低压电力线完成上位机和下位机之间的数据交换.     

免疫诊断用羧化聚苯乙烯载体微球的制备

采用“无乳化剂”乳液聚合法合成了表面“清洁”的聚苯乙烯-丙烯酸胶乳微球,并对影响微球粒径、单体转化率的诸因素进行了探讨.结果表明:所合成的胶乳微球呈圆球状,粒径大小可控制在0.1～0.6μm范围内,且单分散性良好.调节单体的含量和亲疏水性可控制微球粒径和表面性能.将此微球分别与血清抗原共价偶联,其抗原效价高于有乳化剂的胶乳微球.这表明免疫化的无乳化剂微球具有良好的生物特异性.     

聚丁二炔晶体中的光生载流子及光导

以聚丁－２，４－已二炔－１，６－二醇酯ｏｆ，２，４－ｈｅｘａｄｉｙｎｅ－６－ｄｉｏｌ，缩写为ＰＤＡ－ＴＳ为例，研究了聚丁二炔单昌中的光生载流子及光导；在分析了双分子成对复合的Ｏｎｓａｇｅｒ模型的局限性之后，提出了一个新的载流子光产生模型，并用它首次解释了稳态光电流Ｉｐｈ对入射光子能量ｇω的依赖关系。     

五省（区）应用C·肉毒杀鼠素灭治草地害鼠的效果

１９９６年４月青海省草原总站，青海省兽医生物药品厂派员辽宁彰武，内蒙古乌审，河北沽源，新疆昌吉和乌苏。四川石渠等地，在当地的支持和配合下，应用Ｃ·肉毒杀鼠素进行灭鼠试验和推广应用。结果表明：毒素饵适宜的浓度为０．１％￣０．１２％；小麦，草颗粒、滨藜籽、玉米糁均可作为载体；