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   503篇
  免费   25篇
  国内免费   23篇
耳鼻咽喉   1篇
儿科学   54篇
基础医学   56篇
口腔科学   13篇
临床医学   91篇
内科学   118篇
皮肤病学   13篇
神经病学   3篇
特种医学   106篇
外科学   30篇
综合类   7篇
预防医学   18篇
眼科学   1篇
药学   26篇
肿瘤学   14篇
  2019年   4篇
  2018年   3篇
  2017年   4篇
  2016年   4篇
  2015年   4篇
  2014年   10篇
  2013年   17篇
  2012年   9篇
  2011年   17篇
  2010年   24篇
  2009年   17篇
  2008年   8篇
  2007年   23篇
  2006年   11篇
  2005年   12篇
  2004年   5篇
  2003年   5篇
  2002年   3篇
  2001年   10篇
  2000年   6篇
  1999年   14篇
  1998年   42篇
  1997年   42篇
  1996年   35篇
  1995年   17篇
  1994年   25篇
  1993年   16篇
  1992年   14篇
  1991年   8篇
  1990年   9篇
  1989年   10篇
  1988年   27篇
  1987年   11篇
  1986年   8篇
  1985年   7篇
  1984年   10篇
  1983年   8篇
  1982年   14篇
  1981年   9篇
  1980年   6篇
  1978年   3篇
  1977年   5篇
  1976年   4篇
  1975年   2篇
  1954年   2篇
  1953年   1篇
  1952年   1篇
  1948年   1篇
  1947年   1篇
  1943年   1篇
排序方式: 共有551条查询结果,搜索用时 15 毫秒
41.
42.
43.
Strand L, Jenkins A, Grude N, Allum A‐G, Mykland H‐C, Nowrouzian FL, Kristiansen B‐E. Emergence of fluoroquinolone‐resistant clonal group A: clonal analysis of Norwegian and Russian E. coli isolates. APMIS 2010; 118: 571–77. We describe a study of urinary tract and intestinal isolates of Escherichia coli from Norway and Russia using automated ribotyping, single nucleotide polymorphism analysis for clonal group A (CgA) supplemented with phylogrouping, virulence gene profiling and resistance profiling. CgA comprised 19% of the Norwegian UTI isolates from 2001. Two highly multiresistant fluoroquinolone‐resistant CgA isolates were found. Ribotypes clustered into four major and six minor groups (ribogroups). Fluoroquinolone‐resistant isolates and phylogroups A and B1 were associated with ribogroup RA. Ribogroup RB predominated among Russian UTI isolates and was predominantly phylogroup A and depleted in P‐fimbriae. Ribogroup RC predominated among Norwegian UTI isolates and was rich in virulence factors (S‐fimbriae, haemagglutinin and haemolysin) and predominantly phylogroup B2 and D. Ribogroup RG was associated with CgA and predominantly phylogroup D. Ribogroups RD, RE and RF had too few members for statistical analysis. The correlation between ribotype and phylogenetic group was not as strong as reported in other studies.  相似文献   
44.

Background  

This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity.  相似文献   
45.
Magnetic resonance (MR) imaging was performed on 14 patients with histologically proved osteosarcoma (mean age, 14.4 years). There was excellent correlation of intramedullary tumor extent as determined with MR imaging and pathologic examination (r = 99%). This was facilitated by the presence of a chemical shift artifact at the tumor-marrow interface on the T1-weighted images. The correlation between CT and pathologic findings was not as good (r = 84%). In a single patient, however, a 10-cm length of sclerotic bone was incorrectly interpreted as being tumor. If this case is excluded, the correlation between CT and pathologic findings improves significantly (r = 96%). T2-weighted images were optimal in demonstrating soft-tissue bulk and breach of the epiphysis or cortex. Vascular involvement was also readily defined. The T2 value of the tumor soft-tissue component decreased in patients who were deemed to have responded well to therapy. Two patients with very high T2 values after chemotherapy developed wide-spread metastatic disease and died. Phosphorus-31 MR spectroscopy of five patients with osteosarcoma showed elevated levels of phosphomonoesters (PMEs), inorganic phosphate (Pi), and phosphodiesters (PDEs). PME and PDE peak areas decreased in three patients after chemotherapy, while Pi peak areas increased.  相似文献   
46.
Role of point A in the era of computerized dosimetry   总被引:1,自引:0,他引:1  
Potish  RA; Gerbi  BJ 《Radiology》1986,158(3):827-831
  相似文献   
47.
白花丹参化学成分的研究   总被引:30,自引:0,他引:30  
从白花丹参(Salvia miltiorrhiza f.alba)中分离出14个二萜醌类化合物,其中2个为新化合物,由光谱分析推定为1,2,15,16-四氢丹参醌(Ⅰ)和丹参醛(Ⅱ);另一个化合物Ⅲ与R0-090680的结构相同。化合物Ⅰ和Ⅲ对淋巴白血病细胞P388均有较强的抑制作用。  相似文献   
48.
Radioimmunoimaging of fresh canine venous thrombi with a murine monoclonal antibody specific for human and dog fibrin has been reported. Successful imaging of canine deep venous thrombi 1, 3, and 5 days old at the time of antibody injection is reported. Images were positive in all dogs, and the uptake of fibrin-specific antibody was equivalent to that of fresh thrombi.  相似文献   
49.
Human blood groups: incidental receptors for viruses and bacteria   总被引:2,自引:0,他引:2  
  相似文献   
50.
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