Want security , avirulent , without remain or little remain 要安全,无毒,无残留或少残留
2.
Now many laboratories have used avirulent strains of s . typhimurium to deliver h . pylori antigens as a way of stimulating an immune response to those determinants 以鼠伤寒沙门氏菌标准株基因组dna作为模板，采用pcr的方法克隆了鼠伤寒沙门氏菌asd基因，经序列分析与文献报道一致。
3.
One of these pr genes , pr - la , responds not only to avirulent pathogen , but also to some chemicals , such as sa ( salicylic acid ) and bth ( benzothiadiazole ) etc . , and the responding ability to the inducers is controlled by its promoter 其中一个pr基因pr - 1a ，不仅受病原菌诱导，而且受一些化学剂如sa 、 bth等化学剂的诱导，其诱导应答由其启动子控制，因此pr - 1a启动子可以应用于植物化学诱导系统中。
4.
Most of plants , when attacked by avirulent pathogens , usually produce a hypersensitive response ( hr ) at the locus attacked and develop a systemic acquired resistance ( sar ) throughout entire plant by expressing a set of defense genes including pathogenesis - related ( pr ) genes 植物受到病原菌侵染后，感染部位产生过敏性坏死反应，在其它部位产生系统获得性抗性并伴随抗性基因包括病程相关蛋白( pathogen - relatedprotein )基因的表达。
5.
Finally , avirulent and virulent plant , bacteria of pseudomonas solanaceanim was investigated by chromatography . the result showed that there are two peaks when both bacteria was eluted , but their peak area ratio was quite different . when virulent bacteria was subject to chromatography after vibration by ultrasonic wave , both chromatographial behaviors of both avirulent and virulent pseudomonas solanaceanim were same basically , which showed a equilibrial peak and a eluting one 最后，表征了植物病原菌? ?青枯菌的强、弱致病菌株，结果显示强、弱菌都有两个洗脱峰，但峰面积比例有明显的差异，强弱致病菌株经振荡后，其色谱行为基本相似，表现为一个穿透峰和一个洗脱峰。
6.
Newcastle disease virus ( ndv ) strain 695 , a thermostable nature avirulent strain , were replicated in embryonated chicken eggsand its rna was extracted from allantoic fluid . referred to the reported sequence of f gene , a pair of primers were designed and synthesized . f gene of ndv b95 strain was amplified by rt - pcr , the pcr products were checked by agrose gel electrophoresis and purified by agrose gel fracion method 利用从国外引进的新城疫热稳定性天然弱毒b _ ( 95 )株接种spf鸡胚繁殖病毒，经处理后提取病毒的基因组rna ，参考国内外发表的ndv融合蛋白基因序列，设计一对特异性引物，经反转录聚合酶链式反应( rt - pcr )扩增出约1700bp大小的特异性片段，将此片段回收纯化后，利用t - a克隆技术将其克隆到pgem - t - easy克隆载体中，再转化大肠杆菌jm109感受态细胞，转化后经分子量比较、 pcr鉴定和酶切分析筛选阳性克隆。
7.
Electron microscopy showed that virulent pseudomonas solanaceanim grown in gathering form and avirulent pseudomonas solanaceanim did in free form . so that two different monomers were estimated to comprise pseudomonas solanaceanim the research above will expand application of traditional hplc and deepen its potential in bacteria studying 结合电镜观察，证明强致病菌株主要是以聚集形式生长，而弱致病菌株则以游离分散的形式生长，并可以推测青枯菌可能存在两种不同的单体。
8.
In recent years , the outbreak of nd appear some new characters , it is reported that the amount of immunity defeat on nd increased , even chicks with high hi titer can be infected by ndv virulent strain . the gene - engineering vaccine is badly needed to control nd outbreak . so newcastle disease virus strain b95 , a naturally avirulent and heat stable strain , was introduced from australia 新城疫是国际兽疫局公布的16种烈性传染病之一。近年来，新城疫的爆发出现了许多新特点，免疫失败报道增多，甚至抗体水平较高的鸡群也发病。为控制新城疫的爆发，急需研制基因工程苗。
9.
This test chooses general industrial vc / vac copolymer as raw material , various supplement material additives are also the common conventional avirulent additive on industry ; the plastic material processing routine is also the universal method to make the thermoplastic plate of low temperature of vc / vac copolymer that accords with medical requirement that its softening temperature is 55 本试验选用氯醋共聚树脂为主要原材料，所用辅料添加剂也是工业上常见的无毒性常规添加剂；采用常规的塑料加工成型方法及设备制造出软化点为55的、符合医用要求的低温热塑性氯醋共聚树脂板材。
10.
From dead chickens , one virrus was isolated by using eggs and chicken embryo fibroblast . lt was able to agglutinate chicken ' s erythrocytes and this heamagglutination could be inhibited by newcastle disease antiserum . this strain ' s biological property was tested by barren spot , cross - enutralization and cross - heamagglution inhibited and it was found that it was homological with the standard newcastle disease virus ( ndv ) virulent strain and avirulent strain but it had some diference with the standard strain 本实验采用spf鸡胚及鸡胚原代成纤维细胞，从河北省某鸡场新城疫免疫抗体很高的病死鸡的脑组织中分离得到一株病毒。此株病毒能凝集鸡的红细胞，并且这种凝集可以被特异性抗血清所抑制。
