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   329篇
  免费   11篇
林业   7篇
农学   4篇
  11篇
综合类   184篇
水产渔业   2篇
畜牧兽医   126篇
园艺   2篇
植物保护   4篇
  2019年   1篇
  2018年   1篇
  2017年   5篇
  2016年   5篇
  2015年   3篇
  2014年   4篇
  2013年   13篇
  2012年   15篇
  2011年   22篇
  2010年   13篇
  2009年   10篇
  2008年   11篇
  2007年   20篇
  2006年   16篇
  2005年   7篇
  2004年   9篇
  2003年   9篇
  2002年   15篇
  2001年   8篇
  2000年   14篇
  1999年   3篇
  1998年   15篇
  1997年   4篇
  1996年   8篇
  1995年   3篇
  1994年   7篇
  1993年   9篇
  1992年   16篇
  1991年   20篇
  1990年   24篇
  1989年   5篇
  1988年   1篇
  1986年   1篇
  1984年   3篇
  1983年   1篇
  1982年   1篇
  1979年   1篇
  1978年   2篇
  1977年   3篇
  1974年   2篇
  1973年   1篇
  1972年   3篇
  1969年   2篇
  1967年   1篇
  1963年   1篇
  1942年   1篇
  1941年   1篇
排序方式: 共有340条查询结果,搜索用时 15 毫秒
61.
62.
Problem-oriented reptile medicine is an explicit, definable process focused on the identification and resolution of a patient's problems. This approach includes gathering case information, clearly defining the problems, making plans to address each problem, and following up with the case over time. Case information and published literature serve as evidence to support clinical decisions and pathophysiological rationale. This article describes the problem-solving process used to diagnose and treat a green iguana (Iguana iguana) that presents with ovostasis.  相似文献   
63.
64.
65.
Excessive exercise may induce osteoarthritis, which is a leading cause of lameness and decreased use in horses. The purpose of this study was to utilize a sheep model to determine the effects of circular and linear exercise on biochemical markers in serum and synovial fluid (SF). Twenty lambs (5 months) were assigned to three groups: circular exercise (C, 8.5 m diameter; n = 8), straight-line exercise (S, treadmill; n = 8) and nonexercised control (CON, n = 4). Lambs (C and S) were exercised up to 8 weeks at 1.3 m/s for up to 30 minutes, 6 days per week. Serum and SF from a metacarpophalangeal (MCP) joint was collected. Serum total protein (P = .66), Collagen Type II cleavage [3/4] fragments concentrations (P = .44) and lysyl oxidase (LOX) (P = .15) activity were not different among treatment groups throughout the study. There was a polynomial response to serum LOX over time (R2 = 0.7464). There were no differences in SF total protein (P = .94, right MCP; P = .68, left MCP) or SF LOX specific activities (P = .9, right MCP; P = .93, left MCP) among groups throughout the study. However, SF LOX specific activity did increase over time (P = .001) for all treatment groups. These results indicated that the biochemical markers utilized in this study were unable to detect differences between groups with respect to exercise protocols. However, the LOX activity did increase over time possibly as a result of growth.  相似文献   
66.
Vascular perfusion was assessed in 10 dogs without prostatic abnormalities and 26 dogs with prostatic disease using contrast‐enhanced ultrasound. The time to reach peak contrast intensity (TTP) and peak perfusion intensity (PPI) were measured, and histological biopsies were collected from each dog. Biopsies confirmed normal prostate (n = 10), benign prostatic hyperplasia (n = 11), mixed benign pathology (n = 9), prostatitis (n = 1), prostatic malignancy [adenocarcinoma (n = 4); leiomyosarcoma (n = 1)]. In normal dogs, mean PPI was 16.8% ± 5.8 SD, and mean TTP was 33.6 ± 6.4 s. Benign conditions overall were not statistically different from normal dogs (p > 0.05); for benign prostatic hyperplasia, mean PPI was 16.9 ± 3.8%, and mean TTP was 26.2 ± 5.8 s; for mixed benign pathology mean PPI was 14.8 ± 7.8%, and mean TTP was 31.9 ± 9.7 s; for prostatitis, PPI was 14.2%, and TTP was 25.9 s. The malignant conditions overall had perfusion values that differed from the normal dogs (p < 0.05), although evaluation of the data for individual malignancies did not demonstrate a consistent trend; for adenocarcinomas, the PPI was numerically higher with a mean of 23.7 ± 1.9%, and the mean TTP was 26.9 ± 4.8 s, whilst for the dog with leiomyosarcoma values were numerically lower with a PPI of 14.1% and TTP of 41.3 s. Contrast‐enhanced ultrasound appears to offer some ability to document differences in perfusion that may differentiate between malignant and benign lesions, although studies with larger numbers of animals are required to confirm this contention.  相似文献   
67.
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