全文获取类型
收费全文 | 109728篇 |
免费 | 6138篇 |
国内免费 | 71篇 |
专业分类
林业 | 5145篇 |
农学 | 3667篇 |
基础科学 | 594篇 |
13026篇 | |
综合类 | 15904篇 |
农作物 | 3838篇 |
水产渔业 | 5482篇 |
畜牧兽医 | 60423篇 |
园艺 | 1335篇 |
植物保护 | 6523篇 |
出版年
2018年 | 1645篇 |
2017年 | 1759篇 |
2016年 | 1624篇 |
2015年 | 1441篇 |
2014年 | 1665篇 |
2013年 | 4501篇 |
2012年 | 3136篇 |
2011年 | 3785篇 |
2010年 | 2472篇 |
2009年 | 2373篇 |
2008年 | 3561篇 |
2007年 | 3531篇 |
2006年 | 3315篇 |
2005年 | 3068篇 |
2004年 | 2896篇 |
2003年 | 2973篇 |
2002年 | 2759篇 |
2001年 | 3726篇 |
2000年 | 3606篇 |
1999年 | 2879篇 |
1998年 | 1171篇 |
1997年 | 1126篇 |
1996年 | 1052篇 |
1995年 | 1208篇 |
1994年 | 1091篇 |
1993年 | 1058篇 |
1992年 | 2293篇 |
1991年 | 2535篇 |
1990年 | 2501篇 |
1989年 | 2398篇 |
1988年 | 2214篇 |
1987年 | 2220篇 |
1986年 | 2201篇 |
1985年 | 2154篇 |
1984年 | 1757篇 |
1983年 | 1521篇 |
1982年 | 1019篇 |
1979年 | 1566篇 |
1978年 | 1255篇 |
1977年 | 1102篇 |
1976年 | 1153篇 |
1975年 | 1158篇 |
1974年 | 1419篇 |
1973年 | 1360篇 |
1972年 | 1357篇 |
1971年 | 1253篇 |
1970年 | 1287篇 |
1969年 | 1206篇 |
1968年 | 1053篇 |
1967年 | 1086篇 |
排序方式: 共有10000条查询结果,搜索用时 625 毫秒
991.
Sheep from local farms with and without previous exposure to pigs were tested for their skin and airway responses to a commercial Ascaris suum antigen. There was an immediate reaction to intradermal injection of the antigen in 90% of 101 sheep. A bronchial provocation test by aerosol of the same antigen was undertaken on 43 of the sheep with a positive skin reaction. About 70% of sheep showed an immediate airway response to the antigen as an aerosol, reflected as a significant increase in airway resistance and/or decrease of dynamic lung compliance. The mean peak airway resistance and mean lowest dynamic lung compliance were 165% above and 61% below their baselines, respectively. No significant changes were recorded when the same animals were given an aerosol of phosphate buffered saline. Similarly, no correlation was found between the degree of skin reaction and the magnitude of bronchoconstriction (p>0.05). The sheep with previous exposure to pigs showed no significant differences in airway responses to antigen challenge, although they showed significantly greater skin reactions than those without exposure to pigs. These results indicate that the majority of Romney sheep in the Manawatu have a natural skin and airway sensitivity to A. suum antigen and may therefore be used as an animal model to study human airway hypersensitivity. The origin of this sensitivity has yet to be determined. 相似文献
992.
993.
Nephrotoxicity in dogs associated with methoxyflurane anesthesia and flunixin meglumine analgesia 总被引:2,自引:2,他引:0
下载免费PDF全文
![点击此处可从《The Canadian veterinary journal. La revue veterinaire canadienne》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mathews KA Doherty T Dyson DH Wilcock B Valliant A 《The Canadian veterinary journal. La revue veterinaire canadienne》1990,31(11):766-771
Uremia unexpectedly developed in five dogs 24 hours after undergoing thoracotomy in a student laboratory. In all dogs general anesthesia had been maintained with methoxyflurane, muscle relaxation had been induced with gallamine, and each dog received a single intravenous dose of 1.0 mg/kg flunixin meglumine for analgesia upon termination of anesthesia. In a subsequent group of dogs undergoing an orthopedic procedure, we assessed the effects on renal function of methoxyflurane anesthesia plus oxymorphone, or of methoxyflurane or halothane anesthesia in combination with a single IM 1.0 mg/kg dose of flunixin meglumine. Significant elevations in serum urea and creatinine values, and necrosis of collecting ducts and loops of Henle, were noted only in the dogs receiving methoxyflurane and flunixin meglumine.
We conclude that the use of combination of methoxyflurane and flunixin meglumine is contraindicated in dogs.
相似文献994.
995.
996.
997.
998.
999.
1000.
Kolata GB 《Science (New York, N.Y.)》1981,214(4521):646-647