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   564篇
  免费   60篇
林业   24篇
农学   11篇
基础科学   3篇
  88篇
综合类   61篇
农作物   20篇
水产渔业   34篇
畜牧兽医   319篇
园艺   13篇
植物保护   51篇
  2023年   9篇
  2022年   16篇
  2021年   30篇
  2020年   33篇
  2019年   36篇
  2018年   28篇
  2017年   22篇
  2016年   26篇
  2015年   20篇
  2014年   15篇
  2013年   28篇
  2012年   45篇
  2011年   48篇
  2010年   30篇
  2009年   19篇
  2008年   35篇
  2007年   26篇
  2006年   21篇
  2005年   20篇
  2004年   23篇
  2003年   14篇
  2002年   14篇
  2001年   6篇
  1999年   5篇
  1998年   2篇
  1997年   3篇
  1993年   3篇
  1992年   3篇
  1991年   1篇
  1990年   5篇
  1989年   2篇
  1988年   3篇
  1987年   2篇
  1986年   1篇
  1985年   4篇
  1984年   2篇
  1981年   1篇
  1980年   3篇
  1975年   1篇
  1974年   2篇
  1973年   2篇
  1969年   1篇
  1967年   2篇
  1966年   1篇
  1958年   1篇
  1950年   1篇
  1939年   1篇
  1926年   1篇
  1903年   2篇
  1900年   1篇
排序方式: 共有624条查询结果,搜索用时 406 毫秒
1.
2.
3.
A 2-month-old, intact male Merino sheep was presented for acute inappetence and pyrexia. Contrast-enhanced abdominal computed tomography identified reticulorumenal intramural gas with suspected ruminal ulceration, arborizing portal venous gas, and mild peritoneal fluid. The lamb was treated medically for presumptive ulcerative reticulorumenitis and non-septic peritonitis. Over 10 days, the lamb initially showed mild improvement before clinical deterioration and was ultimately euthanized. Definitive diagnosis of necrotizing, ulcerative reticulorumenitis was made via necropsy with histopathology. An underlying cause was not determined.Key clinical message:Contrast-enhanced computed tomography was effective in identifying gastric emphysema and portal venous gas associated with reticuloruminal ulceration.  相似文献   
4.
5.
ObjectiveTo compare the quality of postoperative analgesia and sedation after preoperative saphenous and sciatic nerve blockade, preoperative lumbosacral epidural injection and perioperative intravenous (IV) morphine, lidocaine and ketamine infusions in dogs undergoing stifle arthroscopy and tibial plateau leveling osteotomy (TPLO) under general anesthesia.Study designProspective, blinded, randomized, clinical comparison study.AnimalsA total of 45 dogs weighing 33.9 (15.9–56.7) kg and aged 5.2 (1.0–12.0) years, mean (range), undergoing elective unilateral TPLO for spontaneous cranial cruciate ligament rupture.MethodsClient-owned dogs were enrolled. Dogs were randomly assigned to one of three groups: group MLK, perioperative IV morphine, lidocaine and ketamine infusion; group EPID, lumbosacral epidural with ropivacaine and morphine; or group SSNB, saphenous and sciatic nerve blockade with ropivacaine. Routine stifle arthroscopy followed by TPLO surgery was performed. Sedation and pain scores were assessed at 0, 2, 4, 8 and 24 hours following extubation. Rescue analgesia was administered as prescribed by Glasgow composite pain score–short form score >5.ResultsSedation scores for MLK were higher than EPID and SSNB. Pain scores for SSNB were lower than those for EPID and MLK. No significant differences were found in anesthesia duration or surgery duration among groups. No dogs required rescue analgesia.Conclusions and clinical relevanceAlthough analgesia was adequate in all groups, the best combination of analgesia without increased sedation was recorded for SSNB.  相似文献   
6.
7.
8.
OBJECTIVE: To compare measurements of myeloperoxidase (MPO) in plasma, laminar tissues, and skin obtained from control horses and horses given black walnut heartwood extract (BWHE). ANIMALS: 22 healthy 5- to 15-year-old horses. PROCEDURES: Horses were randomly assigned to 4 groups as follows: a control group given water (n = 5) and 3 experimental groups given BWHE (17) via nasogastric intubation. Experimental groups consisted of 5, 6, and 6 horses that received BWHE and were euthanatized at 1.5, 3, and 12 hours after intubation, respectively. Control horses were euthanatized at 12 hours after intubation. Plasma samples were obtained hourly for all horses. Laminar tissue and skin from the middle region of the neck were harvested at the time of euthanasia. Plasma and tissue MPO concentrations were determined via an ELISA; tissue MPO activity was measured by use of specific immunologic extraction followed by enzymatic detection. RESULTS: Tissues and plasma of horses receiving BWHE contained significantly higher concentrations of MPO beginning at hour 3. Laminar tissue and skin from horses in experimental groups contained significantly higher MPO activity than tissues from control horses. Concentrations and activities of MPO in skin and laminar tissues were similar over time. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, BWHE administration causes increases in MPO concentration and activity in laminar tissue and skin and the time of increased MPO concentration correlates with emigration of WBCs from the vasculature. These findings support the hypothesis that activation of peripheral WBCs is an early step in the pathogenesis of acute laminitis.  相似文献   
9.
10.
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