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   97篇
  免费   4篇
  国内免费   1篇
农学   1篇
  8篇
综合类   8篇
农作物   10篇
畜牧兽医   72篇
园艺   2篇
植物保护   1篇
  2021年   4篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   2篇
  2015年   4篇
  2014年   4篇
  2013年   7篇
  2012年   4篇
  2011年   9篇
  2010年   3篇
  2009年   4篇
  2008年   4篇
  2007年   5篇
  2006年   3篇
  2005年   6篇
  2004年   4篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1998年   2篇
  1997年   4篇
  1996年   2篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
  1991年   4篇
  1990年   1篇
  1989年   4篇
  1988年   3篇
  1979年   1篇
  1970年   1篇
  1964年   1篇
排序方式: 共有102条查询结果,搜索用时 104 毫秒
41.
SUMMARY An Australian bovine herpesvirus 1 (BHV1) isolate with a defined (427 base pair) deletion in the protein coding region of the thymidine kinase gene was obtained by standard marker rescue procedures. After selection in the presence of the nucleotide analogue 5iodo-deoxy-uridine the virus was analysed by hybridisation with three differential oligonucleotide probes, restriction endonuclease profile studies and DNA sequence analysis. The virus elicited an immune response in recipient animals after either intramuscular or intravenous administration and produced no significant deleterious side-effects when administered at a dose sufficient to stimulate the host immune response. The safety and immunogenicity of the recombinant BHV1 virus 39B1 were similar to those reported for other registered BHV1 vaccines and the virus would appear to be suitable for the production of a vaccine seed lot and more exhaustive field trials as a prelude to commercial vaccine production and registration.  相似文献   
42.
Long-acting selenium treatments for sheep   总被引:1,自引:0,他引:1  
An intraruminal selenium (Se) pellet and a subcutaneous depot of barium selenate, equivalent to 1.6 mg Se/kg body weight, were each effective in maintaining increased blood Se concentrations for at least 200 weeks in ewes at pasture. These treatments given to the ewes 23 to 26 weeks before lambing increased the Se status of their lambs for 4 to 6 months.  相似文献   
43.
Wombats are a grazing marsupial with a diet rich in silicates, which is highly abrasive and results in a higher rate of tooth attrition than in other grazing marsupials such as kangaroos. Any interference in the natural wear process, such as malocclusion or loss of teeth, causes overgrowth of teeth. The small mouth opening of the wombat makes access to the caudal mouth difficult and overgrowth of cheek teeth can be difficult to treat effectively. This case report describes a technique that greatly improves access to allow dental treatment of all overgrown teeth with minimal complications.  相似文献   
44.
Seven new amino alcohol compounds, pseudoaminols A–G (1–7), were isolated from the ascidian Pseudodistoma sp. collected off the coast of Chuja-do, Korea. Structures of these new compounds were determined by analysis of the spectroscopic data and from chemical conversion. The presence of an N-carboxymethyl group in two of the new compounds (6 and 7) is unprecedented among amino alcohols. Several of these compounds exhibited moderate antimicrobial activity and cytotoxicity, as well as weak inhibitory activity toward Na+/K+-ATPase.  相似文献   
45.
46.
Human umbilical cord blood-derived mesenchymal stem cells (MSCs) are known to possess the potential for multiple differentiations abilities in vitro and in vivo. In canine system, studying stem cell therapy is important, but so far, stem cells from canine were not identified and characterized. In this study, we successfully isolated and characterized MSCs from the canine umbilical cord and its fetal blood. Canine MSCs (cMSCs) were grown in medium containing low glucose DMEM with 20% FBS. The cMSCs have stem cells expression patterns which are concerned with MSCs surface markers by fluorescence-activated cell sorter analysis. The cMSCs had multipotent abilities. In the neuronal differentiation study, the cMSCs expressed the neuronal markers glial fibrillary acidic protein (GFAP), neuronal class III β tubulin (Tuj-1), neurofilament M (NF160) in the basal culture media. After neuronal differentiation, the cMSCs expressed the neuronal markers Nestin, GFAP, Tuj-1, microtubule-associated protein 2, NF160. In the osteogenic & chondrogenic differentiation studies, cMSCs were stained with alizarin red and toluidine blue staining, respectively. With osteogenic differentiation, the cMSCs presented osteoblastic differentiation genes by RT-PCR. This finding also suggests that cMSCs might have the ability to differentiate multipotentially. It was concluded that isolated MSCs from canine cord blood have multipotential differentiation abilities. Therefore, it is suggested that cMSCs may represent a be a good model system for stem cell biology and could be useful as a therapeutic modality for canine incurable or intractable diseases, including spinal cord injuries in future regenerative medicine studies.  相似文献   
47.
48.
A simple column method employing Amberlite XAD-1 (60–120 mesh) resin for the simultaneous extraction of coprostanol and algal chlorophyll a was proposed and evaluated. The results showed that the efficiencies of the column extraction for these two water quality indicators were comparable to or better than the conventional hexane liquid/liquid partitioning and aqueous acetone extraction for the respective compounds. Furthermore, the column technique was time-saving and more economical.  相似文献   
49.
Alcohol oxidations are typically performed with stoichiometric reagents that generate heavy-metal waste and are usually run in chlorinated solvents. A water-soluble palladium(II) bathophenanthroline complex is a stable recyclable catalyst for the selective aerobic oxidation of a wide range of alcohols to aldehydes, ketones, and carboxylic acids in a biphasic water-alcohol system. The use of water as a solvent and air as the oxidant makes the reaction interesting from both an economic and environmental point of view.  相似文献   
50.
We have been unable to detect porphyrins in 13 grams of the bulk fine lunar sample from the Sea of Tranquillity under conditions in which less than 10-(1J) mole per gram of lunar sample could have been detected. By appropriate extraction, however, the lunar sample yields a material which exhibits absorption maxima at 310 and 350 nanometers and a fluorescence maximum at 410 nanometers.  相似文献   
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