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831.
832.
833.
To observe the antiviral action of 16 kinds of Chinese medicinal herbs (Houttuynia cordata Thunb,Flos Chrysanthemi,Flos Lonicerae Confusae,Anemarrhena asphodeloides,CassiaTwig,Herba Ephedrae,Radix Paeoniae Rubra,Bupleurum chinense,Dryopteris setosa,Folium Isatidis, Gardenia jasminoides Ellis,Mntha haplocalyx Briq,Paeonia suffruticosa Andr,Cornu Bubali, Herba Senecionis Scandentis,Radix Gentianae) against porcine reproductive and respiratory syndrome virus (PRRSV), the blocking, inhibiting and killing roles were detected in present study in vitro. The results showed that 13 kinds of Chinese medicinal herbs had antiviral actions against PPRSV except Paeonia suffruticosa Andr, Herba Senecionis Scandentis and Folium Isatidis, and Houttuynia cordata Thunb, Flos Chrysanthemi, Anemarrhena asphodeloides, CassiaTwig and Radix Paeoniae Rubra exhibited the best antiviral actions followed by Herba Ephedrae, Bupleurum chinense and Dryopteris setosa.  相似文献   
834.
835.
A strain of highly cellulolytic decomposing bacteria was obtained by the congo red flat plate straining and shake flasking method screened from the ox dung which named N12. It had been identified as Bacillus which belonged to Bacillus pumilus sp. by morphologic characteristics observation,physiology and biochemical experiment and also 16S rRNA genetic analyze.The conditions of producing cellulase on strain N12 were also been studied in this test.When the contents of carbon and nitrogen sources were 0.5% maizena and 1% yeast powder,and also the nitial pH was 3.0,the fermentation temperature was 42 ℃,at the same time the fermentation time was 54 h,it had the highest enzyme activity.  相似文献   
836.
In order to study biological characteristics of Tibetan Mastiff somatic cells and preserve genetic resource, two fibroblast cell strains from Tibetan Mastiff were established by tissue culture. In vitro culture cell morphology, hyperplasia ability and some biological characteristics were researched. Tibetan Mastiff cells in vitro culture appeared typical morphology of fibroblast cells, grew well and had strong hyperplasia ability. Population doubling time of the cells was 46.1 h. Vimentin expression in the cells was confirmed by immunofluorescence staining. The rate of F5 cells with normal diploidy (2n=78) was 91.4%. Moreover, longer X chromosome belonged to submetacentric chromosome, but Y chromosome did telocentric chromosome. Tibetan Mastiff cell strains eslablished in the study offered the materials for the Tibetan Mastiff somatic cell nuclear transfer research.  相似文献   
837.
The pregnancy rates at 20 and 50 days were tested by sampling 91 hybridization sows more than 16 days using the intuitive, fast, accurate and non-invasive portable veterinary B ultrasound instrument in the pig breeding farm had 300 sows. The results showed that the nonpregnant diagnostic accuracy rate was 100% at 18 to 20 days, and the pregnant diagnostic accuracy rate was 100% at 40 to 50 days. According the diagnostic results, the pregnancy, disease, estrus, nonpregnancy and non-estrused sows were took the appropriate measures such as nursing, treatment, supplementary breeding and sensuality, the non-productive days of the individuals and groups of sows were improved by above measures. The study built a intuitive, fast, accurate sows early pregnancy diagnosis technology, which improved the fertility of the individuals and groups of sows increased the economic benefit of pig farm.  相似文献   
838.
1株肠炎沙门氏菌噬菌体的污水分离及生物学特性研究   总被引:2,自引:2,他引:0  
Using double-layer plate method, a phage against Salmonella enteritidis was isolated from sewage water, and its biological characteristics were studied. The plaques of isolated phage were transparent with clear boundary, and were about 2 mm in diameter at 12 h. The morphological properties of phage were examined by electron microscope, and showed that the phage had an isometric polyhedral no-enveloped head with diameter of about 54 nm, and a long noncontractile tail with size of about 110 nm. The test of optimal multiplicity of infection showed when MOI equaled 2, the number of phage offspring was higher. One-step growth kinetics was determined according to the results of one-step growth experiment, which showed that the latent period was about 10 min, the rise period was about 100 min, and the average bust size was about 61. The phage against S.enteritidis was successfully isolated from the sewage water in this study, which would provide materials for the further biological control researches of S.enteritidis using corresponding phage.  相似文献   
839.
To seek out proteins which interact with structural proteins of porcine epidemic diarrhea virus (PEDV) in Vero E6 cells and study the mechanisms of viral infection.We created a Vero E6 cDNA yeast hybrid library. The total RNA of Vero E6 was extracted using Trizol method, and double strands cDNA was synthesized by SMART technique. We created a Vero E6 cDNA library by using homologous recombination in yeast. The results showed that the titer of cDNA library was 9.7×108 CFU with the average of inserted fragments about 1.6 kb, and the recombination rate was 87%. These data indicated that the yeast two-hybrid cDNA library of Vero E6 was successfully constructed and might be useful for screening the host proteins interacting with structure protein of PEDV.  相似文献   
840.
<正>无论从市场消费者的需求,还是从节省饲料资源的角度,今后以瘦肉型猪为目标的种猪选育方针是不可动摇的。几十年来,我国从国外引进的大量优良的瘦肉型种猪对提高我国养猪生产水平做出了很大贡献。但是,国内一些人在"重引种、轻选育"的错误思想指导下,形成了"引种—退化—再引种"的恶性循环。这些国外高性能的品种,由于过度的选育致使抗逆性越来越差,引进的种猪表现出对中国环境的不适应,  相似文献   
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