首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   287篇
  免费   33篇
林业   10篇
农学   10篇
基础科学   3篇
  18篇
综合类   11篇
农作物   1篇
水产渔业   3篇
畜牧兽医   256篇
园艺   2篇
植物保护   6篇
  2023年   2篇
  2022年   1篇
  2021年   1篇
  2020年   6篇
  2019年   11篇
  2018年   14篇
  2017年   10篇
  2016年   18篇
  2015年   8篇
  2014年   13篇
  2013年   28篇
  2012年   13篇
  2011年   11篇
  2010年   13篇
  2009年   11篇
  2008年   12篇
  2007年   8篇
  2006年   11篇
  2005年   3篇
  2004年   8篇
  2003年   3篇
  2002年   7篇
  2001年   7篇
  2000年   3篇
  1999年   12篇
  1998年   13篇
  1997年   16篇
  1996年   13篇
  1995年   7篇
  1994年   1篇
  1993年   8篇
  1992年   3篇
  1991年   3篇
  1990年   3篇
  1989年   8篇
  1988年   10篇
  1974年   1篇
排序方式: 共有320条查询结果,搜索用时 15 毫秒
61.
A polyprobe for the simultaneous detection by non-isotopic molecular hybridisation has been developed to detect any of the following six viruses causing important economic losses in tomato crops: Tomato spotted wilt virus, Tomato mosaic virus, Pepino mosaic virus, Cucumber mosaic virus, Potato Y virus and Parietaria mottle virus. The polyprobe detected all six viruses with similar sensitivity to that obtained using individual riboprobes. In addition, we evaluated the possible use of the tissue-printing as a sample preparation technique applied to routine diagnosis of tomato plants with the polyprobe. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
62.
Reply     
  相似文献   
63.
64.
65.
We have previously demonstrated that a Fasciola hepatica-derived adult worm antigen, which is cross-reactive with Schistosoma mansoni and designated FhSmIII(M), induces resistance to challenge infection with S. mansoni in mice. The current review concerns the methods developed to isolate and partially characterize a major component of FhSmIII(M), a 12-kDa polypeptide, as well as immunity studies involving this antigen. Utilizing conventional gel filtration, followed by diethylaminoethyl (DEAE) Sephadex A-120 and monitoring the fractions by polyacrylamide gel electrophoresis (PAGE) and enzyme-linked immunoelectrotransfer blot techniques (EITB), we were able to isolate the 12-kDa antigenic polypeptide to homogeneity. Conventional gel filtration chromatography was followed by high-pressure, liquid anion, exchange chromatography, when highly purified material was needed, although the effective yields diminished drastically with the latter. Mice, rabbits and calves with a primary infection of F. hepatica developed antibodies (detectable in enzyme linked immunosorbent assay (ELISA) to the F. hepatica 12-kDa polypeptide within 2 weeks of infection. Mice with a primary infection of S. mansoni developed significant, but low, levels of anti-12-kDa antibodies by 7 weeks post-infection. Immunization of mice with microgram amounts of this 12-kDa polypeptide in Freunds' adjuvant resulted in the development of up to 77% less S. mansoni worms than the controls. Treatment with either endoglycosidase H, neuraminidase or dithiothreitol had no effect on the protein's mobility on sodium dodecyl sulfate (SDS)-PAGE or in its recognition by antibodies, suggesting the absence of carbohydrate moieties or disulphide bonds in relation to its antigenic determinants. Degradation by proteinase K further confirmed its polypeptide nature and points to recombinant DNA technology for the large-scale manufacture of this potential vaccine. Further use of this antigen in immunity studies should greatly contribute to the clarification of the mechanisms involved in cross-resistance against schistosomiasis.  相似文献   
66.
67.
The effect on the early inflammatory response in the bovine mammary gland of a factor extracted from the cell wall of Staphylococcus aureus was studied. The insoluble factor was extracted from a 3h-culture, and was mixed with S. aureus from an overnight culture (OF) for experimental infection of a lactating quarter. Other quarters were infected with a 3h or an overnight culture (O). Five cows were used in the experiment. The O-quarters showed more severe clinical signs than seen in the 3h-and OF-quarters. Antitrypsin levels and NAGase concentrations were much reduced in the 3h-and OF-quarters. While the cell wall factor profoundly reduced the early inflammatory response, the effect on the final outcome of the infection was not determined.  相似文献   
68.
69.
70.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号