β-肾上腺素能兴奋剂的作用机理及应用效果(上)     

王若军  郭年藩 《中国畜牧兽医》1993,(6)

β-肾上腺素能兴奋剂(β-adrenergic ago-nist,BAA)简称β-兴奋剂,或β-激动剂,是一类结构和生理功能类似肾上腺素(adrenalin或 epinephnine)和去甲肾上腺素(nora-drenalin 或 norepinephnine)的苯乙醇胺类衍生物(phenethanolamines),因能与动物体内大多数组织细胞膜上的β-肾上腺素能受体结合而得名(Wellenreiter,1991)(另可见本刊1988,6:12;1989,6:3;1991,3:29——编者注)。虽然早在本世纪50年代末期就发现,儿茶酚胺类物质(肾上腺素和去甲肾上腺素)能刺激脂肪组织释放脂肪酸,并增加蛋白质沉  相似文献   

家畜精液保存技术的研究     

K.F.Weitze  郭年藩 《中国畜牧兽医》1993,(1)

简要综述哺乳动物精液新鲜保存和低温保存技术的发展。精液保存技术始于本世纪初的精液低温保存试验,以后的重要发展是基于发现甘油的低温保护作用,而建立的冷冻保存技术。以牛、猪、兔精子为主,讨论精子代谢、膜功能和细胞结构特性与保存效果间的关系。  相似文献   

Cyromazine防治蘑菇虫害的潜力     

White  PF 黄建军 《国外农学:国外食用菌》1992,(1):14-16

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肉鸡新型促生长添加剂     

郭年藩 《国外畜牧科技》1993,20(4):30-31

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家畜卵和胚胎冷冻的现行方法及有待研究的问题   总被引：2，自引：0，他引：2  

Niema.  H 郭年藩 《国外畜牧科技》1991,18(5):11-17

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Women's Place in Agriculture: Farm Women     

Barlett PF 《Science (New York, N.Y.)》1986,234(4779):1015

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Huxley as Scientist: T. H. Huxley's Place in Natural Science     

Rehbock PF 《Science (New York, N.Y.)》1985,228(4696):172

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Clostridial myositis following ivermectin administration          下载免费PDF全文

Nation PN  Frelier PF  Schoonderwoerd M 《The Canadian veterinary journal. La revue veterinaire canadienne》1983,24(9):295

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Characterization of multidrug resistant Salmonella recovered from diseased animals     

Zhao S  McDermott PF  White DG  Qaiyumi S  Friedman SL  Abbott JW  Glenn A  Ayers SL  Post KW  Fales WH  Wilson RB  Reggiardo C  Walker RD 《Veterinary microbiology》2007,123(1-3):122-132

Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one antimicrobial, and 265 (70%) to three or more antimicrobials. Resistance was most often observed to tetracycline (78%), followed by streptomycin (73%), sulfamethoxazole (68%), and ampicillin (54%), and to a lesser extent chloramphenicol (37%), kanamycin (37%), amoxicillin-clavulanic acid (20%), and ceftiofur (17%). With regards to animal of origin, swine Salmonella isolates displayed the highest rate of resistance, being resistant to at least one antimicrobial (92%), followed by those recovered from turkey (91%), cattle (77%), chicken (68%), and equine (20%). Serovars commonly showing multidrug resistance (MDR) to > or =9 antimicrobials were S. Uganda (100%), S. Agona (79%), and S. Newport (62%), compared to S. Heidelberg (11%) and S. Typhimurium (7%). Class-1 integrons were detected in 43% of all isolates, and were found to contain aadA, aadB, dhfr, cmlA and sat1 gene cassettes alone or in various combinations. All ceftiofur resistant isolates (n=66) carried the bla(CMY) beta-lactamase gene. A total of 230 PFGE patterns were generated among the 380 isolates tested using XbaI, indicating extensive genetic diversity across recovered Salmonella serovars, however, several MDR clones were repeatedly recovered from different diseased animals.  相似文献   

Comparison of the chemical constituents of aged pu-erh tea, ripened pu-erh tea, and other teas using HPLC-DAD-ESI-MSn     

Zhang L  Li N  Ma ZZ  Tu PF 《Journal of agricultural and food chemistry》2011,59(16):8754-8760

Pu-erh tea is a popular beverage in southwestern China and South Asian countries. To explain the differences of aged pu-erh tea and ripened pu-erh tea, the chemical constituents of these teas were identified by HPLC-DAD-ESI-MS(n). In addition, HPLC was used to determine the contents of the major polyphenols, gallic acid, caffeine, and theobromine, in various types of teas. These results showed that the majority of chemical constituents in ripened pu-erh tea and aged pu-erh tea were similar, but the contents of catechins and gallic acid presented significant differences between these two teas. After fermentation by microorganism, the levels of catechins in ripened pu-erh tea were decreased, but the contents of gallic acid and caffeine were conversely elevated compared with aged pu-erh tea.  相似文献