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   1510篇
  免费   92篇
  国内免费   16篇
耳鼻咽喉   9篇
儿科学   65篇
妇产科学   33篇
基础医学   175篇
口腔科学   30篇
临床医学   162篇
内科学   317篇
皮肤病学   40篇
神经病学   62篇
特种医学   187篇
外国民族医学   1篇
外科学   128篇
综合类   18篇
一般理论   1篇
预防医学   64篇
眼科学   24篇
药学   147篇
中国医学   1篇
肿瘤学   154篇
  2023年   8篇
  2022年   8篇
  2021年   23篇
  2020年   20篇
  2019年   35篇
  2018年   55篇
  2017年   38篇
  2016年   18篇
  2015年   27篇
  2014年   47篇
  2013年   58篇
  2012年   83篇
  2011年   44篇
  2010年   60篇
  2009年   60篇
  2008年   59篇
  2007年   61篇
  2006年   55篇
  2005年   58篇
  2004年   45篇
  2003年   58篇
  2002年   37篇
  2001年   42篇
  2000年   54篇
  1999年   42篇
  1998年   38篇
  1997年   35篇
  1996年   34篇
  1995年   25篇
  1994年   24篇
  1993年   21篇
  1992年   28篇
  1991年   20篇
  1990年   29篇
  1989年   24篇
  1988年   17篇
  1987年   25篇
  1986年   26篇
  1985年   22篇
  1984年   18篇
  1983年   8篇
  1982年   9篇
  1981年   11篇
  1979年   12篇
  1978年   8篇
  1977年   13篇
  1976年   16篇
  1974年   8篇
  1972年   8篇
  1968年   7篇
排序方式: 共有1618条查询结果,搜索用时 265 毫秒
1.
2.
Two cell lines producing monoclonal antibodies have been established from peripheral blood of a negative Rhesus blood donor which has been immunized with positive Rhesus red blood cells. Two monoclonal antibodies Co II 8.8 and Co II 7.12 have been selected. Both are IgG1 antibodies, but recognize different epitopes on the Rhesus D antigen, apparently associated with different subunits of the D antigen. Thus the Co II 8.8, like the positive serum, immunoprecipitates an antigen of a relative molecular weight of 33 kDa, while the Co II 7.12 recognizes an antigen of Mr 42 kDa.  相似文献   
3.
4.
Involvement of the distal interphalangeal (DIP) joints was noted radiographically in 24 (43.6%) of 55 patients with polyarticular juvenile rheumatoid arthritis. DIP changes were apparent later in the course of the disease and were less severe than in other affected joints. Soft tissue swelling and joint space narrowing were the most frequent abnormalities in the DIP joints. Erosive changes and angular deformities were uncommon. There was no significant correlation between DIP joint involvement and sex, age at presentation, involvement of the hands and wrists at presentation, or positivity of either rheumatoid factor or antinuclear antibody. There was a strong correlation between the presence of extraarticular signs and symptoms and involvement of the DIP joints; however, this may reflect the greater severity of the disease in these patients generally.  相似文献   
5.
6.
PURPOSE: Cyclodextrins (CDs) are torus shaped cyclic oligosaccharides with a hydrophobic internal cavity and a hydrophilic external surface. We performed and analysed an antibiotic binding on Dacron (polyethyleneterephtalate, PET) vascular grafts, previously coated with CDs based polymers. METHODS: The CDs coating process was based on the pad-dry-cure method patented in our laboratory. The Dacron prostheses were immersed into a solution containing a polycarboxylic acid, a cyclodextrin and a catalyst, and placed into a thermofixation oven before impregnation with an antibiotic solution (Vancomycin). Biocompatibility tests were performed with L132 human epithelial cells. The antibiotic release in an aqueous medium was assessed by batch type experiments using UV spectroscopy. RESULTS: Viability tests confirmed that the CDs polymers coating the Dacron fibers were not toxic towards L132 cell. Cell proliferation was similar on coated and uncoated grafts. A linear release of Vancomycin was observed over 50 days. CONCLUSION: Our results demonstrate the feasibility of coating CDs onto vascular Dacron grafts. Biological tests show no toxicity of the different cyclodextrins coated. A linear release of antibiotics was depicted over 50 days, demonstrating that cyclodextrin grafting was an efficient drug delivery system.  相似文献   
7.
8.
9.
10.
Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by gradient centrifugation for use in assisted reproductive procedures. Efficacy was assessed in terms of percentages of sperm recovery, sperm vitality and motility, normal sperm morphology and normal sperm chromatin condensation. No significant difference was found in the recovery of spermatozoa for men with both normal sperm counts and oligozoospermia, between PVP-coated and silane-coated particle solutions. Iodixanol had significantly lower sperm recovery compared to the other products. Sperm vitality, progressive motility, normal morphology and normal chromatin condensation did not differ significantly between any of the sperm isolation products.   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