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   77258篇
  免费   4567篇
  国内免费   33篇
林业   3242篇
农学   2421篇
基础科学   476篇
  8902篇
综合类   12225篇
农作物   2838篇
水产渔业   3569篇
畜牧兽医   42261篇
园艺   859篇
植物保护   5065篇
  2018年   1070篇
  2017年   1185篇
  2016年   1065篇
  2015年   959篇
  2014年   1206篇
  2013年   2930篇
  2012年   2109篇
  2011年   2437篇
  2010年   1685篇
  2009年   1769篇
  2008年   2466篇
  2007年   2342篇
  2006年   2165篇
  2005年   2064篇
  2004年   1991篇
  2003年   2108篇
  2002年   1947篇
  2001年   2367篇
  2000年   2277篇
  1999年   1854篇
  1998年   813篇
  1997年   856篇
  1996年   761篇
  1995年   954篇
  1994年   796篇
  1993年   822篇
  1992年   1609篇
  1991年   1751篇
  1990年   1715篇
  1989年   1674篇
  1988年   1581篇
  1987年   1537篇
  1986年   1606篇
  1985年   1506篇
  1984年   1327篇
  1983年   1108篇
  1982年   781篇
  1979年   1182篇
  1978年   900篇
  1977年   859篇
  1976年   806篇
  1975年   837篇
  1974年   1043篇
  1973年   1088篇
  1972年   1035篇
  1971年   960篇
  1970年   932篇
  1969年   908篇
  1968年   760篇
  1967年   853篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
31.
32.
The medical records of 38 horses with puncture wounds of the navicular bursa were reviewed. Only 12 horses had a satisfactory outcome (breeding or riding). Of the remaining 26 horses, 19 were euthanized, five were sold due to persistent severe lameness, one died, and one was lost to long-term follow-up. Different combinations of conservative management prior to surgical debridement and drainage of the navicular bursa were unsuccessful in resolving the condition. Horses that were treated surgically within 1 week of the injury and had a hind leg affected had the best chance of a satisfactory outcome. Additional wound debridement was necessary in 15 horses after initial surgical treatment. The most common complications encountered were navicular bone osteomyelitis and sepsis of the deep digital flexor tendon. Thirteen of 14 horses that had rupture of the deep digital flexor tendon and subluxation of the distal interphalangeal joint had an unsatisfactory outcome. One mare subsequently developed ankylosis of the distal interphalangeal joint and was a useful brood mare. Two horses that had biaxial palmar digital neurectomy because of persistent lameness were later euthanized because of navicular bone fracture and rupture of the deep digital flexor tendon. Results from limited numbers of bacterial cultures and antibiotic sensitivities suggest that penicillin and an aminoglycoside antibiotic should be used as initial antibiotic therapy. Immediate surgical debridement and appropriate antibiotic treatment are recommended as the minimum therapy for penetrating wounds of the navicular bursa in horses.  相似文献   
33.
Characterization of monoclonal antibodies directed against swine leukocytes   总被引:3,自引:0,他引:3  
Hybridomas were produced from fusions of the SP2/0 mouse myeloma with splenic cells from: 1) an outbred Sprague Dawley rat immunized with swine peripheral blood mononuclear (PBM) cells; 2) a (CBA/NDub X BALB/c Dub) F1 mouse immunized with concanavalin A (Con A) activated swine PBM cells and 3) a (BALB/c Dub X C3H/He Dub) F1 mouse immunized with swine thymocytes. The resulting supernatants were screened by a microcytotoxicity assay for activity against swine PBM cells. Four hybridomas (MSA1, MSA2, MSA3 and MSA4) were selected, cloned and characterized by their cell reactivity and effect on mitogenic assays. MSA1 and MSA2 belong to the rat IgG2b subclass. MSA3 and MSA4 are of the mouse IgG2a subclass. These monoclonal antibodies reacted in the following manner: MSA1 with monocytes, granulocytes, red blood cells and bone marrow cells; MSA2 with subset of T cells; MSA3 with B cells and subsets of T cells and monocytes (class II molecule) and MSA4, a pan-T cell reagent (E-rosette receptor). The involvement of the various cell types reactive to the different monoclonal antibodies in the mitogenic response of swine PBM cells to Con A, phytohemagglutinin (PHA) or pokeweed mitogen (PWM) was investigated by cellular depletion with monoclonal antibody plus complement. Cellular depletion of PBM cells with the following monoclonal antibodies plus complement treatment resulted in: MSA1, almost total reduction in the mitogenic response to low doses of Con A or PWM; MSA2, partial reduction in the proliferative responses to any concentration of Con A, PHA or PWM; MSA3, partial reduction in proliferative responses to low concentrations of Con A or PWM and 4) MSA4, total elimination of any proliferative response to Con A, PHA or PWM.  相似文献   
34.
35.
36.
37.
38.
39.
40.
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