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   344篇
  免费   11篇
林业   18篇
农学   3篇
  64篇
综合类   49篇
农作物   16篇
水产渔业   12篇
畜牧兽医   168篇
园艺   9篇
植物保护   16篇
  2024年   1篇
  2023年   3篇
  2022年   9篇
  2021年   9篇
  2020年   11篇
  2019年   9篇
  2018年   8篇
  2017年   9篇
  2016年   7篇
  2015年   7篇
  2014年   11篇
  2013年   23篇
  2012年   31篇
  2011年   19篇
  2010年   11篇
  2009年   17篇
  2008年   24篇
  2007年   23篇
  2006年   12篇
  2005年   18篇
  2004年   18篇
  2003年   16篇
  2002年   23篇
  2001年   1篇
  2000年   1篇
  1999年   3篇
  1998年   3篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1989年   4篇
  1988年   1篇
  1986年   1篇
  1984年   1篇
  1982年   3篇
  1980年   1篇
  1975年   1篇
  1967年   1篇
  1966年   2篇
  1963年   1篇
  1961年   1篇
排序方式: 共有355条查询结果,搜索用时 15 毫秒
351.
The Escumite bean (Phaseolus acutifolius) is an edible legume which in raw form is highly toxic to rats. Proteins were separated by DEAE cellulose and affinity chromatography. Hemagglutinating activity, trypsin inhibitory effect, cytotoxicity on human peripheral lymphocytes and on intestinal epithelial cells of rats, and mitogenic activity were assayed with each protein fraction. Hemagglutinins and trypsin inhibitory fractions showed differential toxicity with lymphocytes as compared to intestinal epithelial cells. A protein fraction without the previous activities was cytotoxic mainly to intestinal epithelial cells.  相似文献   
352.
Summary An extracellular protein-lipopolysaccaride antigen (PLP) was purified from culture fluids ofVerticillium dahliae. Antiserum produced in rabbits to the PLP detected the antigen in homogenates of tubers, stems and leaves ofV. dahliae-infected potato plants but not in extracts of healthy potato tissue or extracts of potato plants infected by other fungal pathogens. The antigen was not detectable in extracts of potato isolates ofV. tricorpus, V. nigrescens andV. nubilum or various other fungi. The antigen was shown to be different from cross-reactive antigens detected by antisera to mycelial antigens. When used as a tool for specific diagnosis ofV. dahliae infection in potato, antiserum to PLP was more reliable than that prepared against fungal body antigens. Publication of the Agricultural Research Organization No 245-E.  相似文献   
353.
354.
Objective  To test the hypothesis that in DBA/2J mice, oxidative stress decreases glutamine synthetase (GS) levels resulting in a loss of neuronal glutamate and that the antioxidant α-luminol (GVT®) decreases this stress and glutamate loss in some types of glaucoma.
Animals  DBA/2J mice were separated into two groups, of which one was not treated, and the other treated with GVT in the drinking water. At 7 months of age, retinas were examined from five untreated DBA/2J mice, seven GVT-treated mice, and five C57BL/6 mice (negative controls).
Methods  Serial 0.5 μm plastic sections were immunogold stained for glutamate, GS, and total glutathione, followed by image analysis for staining patterns and density.
Results  Focal decreases in glutamate immunostaining were common in the inner nuclear layer (INL) of DBA/2J retinas, but not in C57BL/6 or GVT-treated DBA/2J retinas. Decreases in glutathione and GS immunostaining were found in DBA/2J retinal regions where neuronal glutamate immunostaining was reduced. Retinas from GVT-treated DBA/2J had no significant decreases in INL levels of glutamate, glutathione, or GS.
Conclusions  Retinas of dogs with primary glaucoma are reported to have focal depletion of neuronal glutamate. In DBA/2J mice, similar changes occur prior to the development of clinical disease. In these focal glutamate-depleted regions, levels of glutathione and GS are also reduced, consistent with the hypothesis that oxidative stress contributes to retinal changes in glaucoma. The ability of GVT, an antioxidant, to inhibit retinal abnormalities in DBA/2J mice provides further support for this hypothesis.  相似文献   
355.
Objective – To analyze thromboelastograms (TEGs) of naturally occurring cases of immune-mediated hemolytic anemia (IMHA) in order to identify whether a hypercoagulable state was present and whether its presence was associated with differences in survival.
Design – Retrospective study spanning January 2000 to June 2008. Medical records of dogs were evaluated. Endpoints were considered death or discharge from the hospital.
Setting – Academic teaching hospital.
Animals – Thirty-nine dogs with a diagnosis of IMHA and at least one TEG performed during hospitalization were included.
Interventions – None.
Measurements and Main Results – Four values were evaluated from the TEG: the R time (R), K time (K), alpha angle (α), and maximum amplitude. From these values, a coagulation index (CI) was calculated to classify patients as normocoagulable, hypercoagulable, or hypocoagulable. Thirty-three of 39 patients were hypercoagulable based on the CI. The 6 remaining dogs were normocoagulable. The patients with a normocoagulable CI had an increased mortality rate (100%) when compared with the hypercoagulable patients using Fisher's exact test ( P =0.02). Additionally, prolongation of partial thromboplastin time did not preclude hypercoagulable TEG values.
Conclusions – The majority of dogs with IMHA were hypercoagulable as measured by TEG. A normal CI was associated with a worse outcome in this patient population. TEG may provide additional and complementary information to prothrombin time and partial thromboplastin time relating to coagulation status in dogs with IMHA and may help predict prognosis and potentially guide clinical decisions to utilize anticoagulant drugs.  相似文献   
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