全文获取类型
收费全文 | 3311篇 |
免费 | 30篇 |
专业分类
林业 | 71篇 |
农学 | 1篇 |
324篇 | |
综合类 | 1128篇 |
农作物 | 22篇 |
水产渔业 | 37篇 |
畜牧兽医 | 1654篇 |
园艺 | 2篇 |
植物保护 | 102篇 |
出版年
2012年 | 213篇 |
2011年 | 281篇 |
2010年 | 41篇 |
2009年 | 28篇 |
2008年 | 214篇 |
2007年 | 242篇 |
2006年 | 208篇 |
2005年 | 223篇 |
2004年 | 215篇 |
2003年 | 196篇 |
2002年 | 209篇 |
2001年 | 120篇 |
2000年 | 166篇 |
1999年 | 59篇 |
1998年 | 13篇 |
1995年 | 11篇 |
1994年 | 16篇 |
1993年 | 22篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 21篇 |
1989年 | 19篇 |
1988年 | 14篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 45篇 |
1983年 | 37篇 |
1982年 | 20篇 |
1981年 | 25篇 |
1980年 | 13篇 |
1979年 | 20篇 |
1978年 | 26篇 |
1977年 | 27篇 |
1976年 | 33篇 |
1975年 | 18篇 |
1974年 | 24篇 |
1973年 | 20篇 |
1969年 | 12篇 |
1966年 | 15篇 |
1963年 | 20篇 |
1958年 | 17篇 |
1957年 | 11篇 |
1956年 | 14篇 |
1948年 | 13篇 |
1901年 | 10篇 |
1900年 | 19篇 |
1899年 | 25篇 |
1898年 | 26篇 |
1897年 | 35篇 |
1896年 | 11篇 |
排序方式: 共有3341条查询结果,搜索用时 671 毫秒
21.
22.
23.
24.
25.
26.
27.
28.
Little D Brown SA Campbell NB Moeser AJ Davis JL Blikslager AT 《American journal of veterinary research》2007,68(6):614-624
OBJECTIVE: To determine the effect of meloxicam and flunixin meglumine on recovery of ischemia-injured equine jejunum. ANIMALS: 18 horses. PROCEDURES: Horses received butorphanol tartrate; were treated IV with saline (0.9% NaCl) solution (SS; 12 mL; n = 6), flunixin meglumine (1.1 mg/kg; 6), or meloxicam (0.6 mg/kg; 6) 1 hour before ischemia was induced for 2 hours in a portion of jejunum; and were allowed to recover for 18 hours. Flunixin and SS treatments were repeated after 12 hours; all 3 treatments were administered immediately prior to euthanasia. Selected clinical variables, postoperative pain scores, and meloxicam pharmacokinetic data were evaluated. After euthanasia, assessment of epithelial barrier function, histologic evaluation, and western blot analysis of ischemia-injured and control jejunal mucosa samples from the 3 groups were performed. RESULTS: Meloxicam- or flunixin-treated horses had improved postoperative pain scores and clinical variables, compared with SS-treated horses. Recovery of transepithelial barrier function in ischemia-injured jejunum was inhibited by flunixin but permitted similarly by meloxicam and SS treatments. Eighteen hours after cessation of ischemia, numbers of neutrophils in ischemia-injured tissue were higher in horses treated with meloxicam or flunixin than SS. Plasma meloxicam concentrations were similar to those reported previously, but clearance was slower. Changes in expression of proteins associated with inflammatory responses to ischemic injury and with different drug treatments occurred, suggesting cyclooxygenase-independent effects. CONCLUSIONS AND CLINICAL RELEVANCE: Although further assessment is needed, these data have suggested that IV administration of meloxicam may be a useful alternative to flunixin meglumine for postoperative treatment of horses with colic. 相似文献
29.
30.
Corfield GS Read RA Eastley KA Richardson JL Robertson ID Day R 《Australian veterinary journal》2007,85(6):212-216
Hip palpation has been used to provide semiquantitative information regarding passive joint laxity and susceptibility to hip dysplasia. The purpose of this study was to: (1) evaluate the intra- and inter-examiner repeatability of the hip reduction angle measured at 4 months of age by three examiners using manual goniometry and an electromagnetic tracking system; (2) compare the hip reduction angle measured with manual goniometry to the hip reduction angle measured with the electromagnetic tracking system; and (3) evaluate the hip reduction angle, distraction index and Ortolani manoeuvre at 4 months of age as predictors of the development of hip osteoarthritis at 12 months of age in 11 Labrador Retriever dogs. Intra- and inter-examiner repeatability was demonstrated for both the manual and electromagnetic goniometric measurement of the hip reduction angle (coefficient of variation < 4.3% and < 6.1%; and P = 0.163 and P = 0.836 respectively). The hip reduction angle measured by manual goniometry was moderately correlated to the hip reduction angle measured by the electromagnetic tracking system (r = 0.603, P < 0.0000). The hip reduction angle measured by manual and electromagnetic goniometry was a poor predictor of osteoarthritis at 12 months of age (r = 0.231, P < 0.062, and r = 0.321, P < 0.01). The distraction index was moderately correlated with the development of osteoarthritis by 12 months of age (r = 0.493, P < 0.0000). The Ortolani sign was sensitive (100%) but not specific (41%) for the development of osteoarthritis at 12 months of age. The hip reduction angle did not further quantify the Ortolani manoeuvre as a predictor of osteoarthritis in Labrador Retrievers. 相似文献