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   11143篇
  免费   370篇
  国内免费   69篇
耳鼻咽喉   49篇
儿科学   400篇
妇产科学   250篇
基础医学   740篇
口腔科学   175篇
临床医学   736篇
内科学   2711篇
皮肤病学   172篇
神经病学   542篇
特种医学   210篇
外科学   1585篇
综合类   807篇
一般理论   5篇
预防医学   1721篇
眼科学   210篇
药学   792篇
  2篇
中国医学   235篇
肿瘤学   240篇
  2023年   100篇
  2022年   180篇
  2021年   314篇
  2020年   304篇
  2019年   748篇
  2018年   643篇
  2017年   384篇
  2016年   207篇
  2015年   224篇
  2014年   441篇
  2013年   448篇
  2012年   386篇
  2011年   420篇
  2010年   331篇
  2009年   319篇
  2008年   308篇
  2007年   297篇
  2006年   245篇
  2005年   177篇
  2004年   108篇
  2003年   119篇
  2002年   88篇
  2001年   97篇
  2000年   92篇
  1999年   61篇
  1998年   54篇
  1997年   43篇
  1996年   41篇
  1995年   38篇
  1994年   39篇
  1993年   41篇
  1992年   27篇
  1991年   28篇
  1989年   17篇
  1988年   22篇
  1987年   19篇
  1986年   17篇
  1985年   285篇
  1984年   483篇
  1983年   401篇
  1982年   400篇
  1981年   340篇
  1980年   316篇
  1979年   390篇
  1978年   283篇
  1977年   195篇
  1976年   283篇
  1975年   249篇
  1974年   255篇
  1973年   243篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
41.
创新药物药动学高通量筛选   总被引:5,自引:0,他引:5  
高通量筛选体系在创新药物药动学筛选中的应用是新药开发研究的一个重要领域。本文回顾了国外创新药物药动学筛选及高通量筛选体系在药动学筛选中的应用,指出药动学的体外高通量筛选在新药开发研究的早期是一种行之有效的方法,不仅可以降低候选化合物的淘汰率,缩短研究开发的周期,降低开发费用,还可以根据筛选的结果对先导化合物结构改造或修饰提出建议,以获得具有良好药动学特性的新候选化合物。  相似文献   
42.
Summary A new liposuction cannula which can be used both with the syringe and with the machine has been produced by the author.  相似文献   
43.
In in vitro and animal experiments the tissue effects of the 1.318m Nd-YAG laser were compared to those of the standard 1.064m Nd-YAG laser in order to evaluate the advantages of the new wavelength with a ten times higher absorption in water for gastroenterological tumour treatment. Under irradiation parameters related to clinical endoscopic practice, the laser of the wavelength 1.318m needs for both vaporization and coagulation significantly less energy than the 1.064m laser. Since vaporization at 1.318m is always accompanied by a higher coagulation effect compared to 1.064m the risk of late necrosis and resulting perforation appears to be increased.  相似文献   
44.
45.
46.
Structural anomalies of mitotic chromosomes from two tumorigenic cell lines of the German cockroach (Blattella germanica) is described. Aberrations, such as unpairable marker chromosomes, double minutes, di- and tricentrics, ring chromosomes, tri- and quadriradials, and chromosome and chromatid gaps and breaks, were observed in varying proportions. This study reports that the double minute chromosomes (DMs) are associated with insect tumor cells, similar to the findings in both murine and human tumor cells.  相似文献   
47.
48.
Severe but atypical osteoarthritic deformities were found in each of 12 femoral heads removed during total hip arthroplasty for Mseleni disease. Although degenerative and regenerative changes were present throughout the cartilage, there was a paucity of eburnation. Histomorphometric analysis of bone at the line of excision indicated that mild osteomalacia was present in four of the 12 specimens. The percentage of the endosteum occupied by osteoid was 9.7 +/- 7.96 (SD) in the patients with Mseleni disease, compared with 5.6 +/- 4.33 in seven African black and 4.1 +/- 2.13 in 13 American white control subjects. The mean thickness of the osteoid seams was not increased. The findings suggest that osteomalacia is not a major pathogenetic factor in Mseleni disease.  相似文献   
49.
Antibodies against pneumococcal polysaccharides were measured by ELISA in Papua New Guinean children with pneumonia aged 0-14 months, in age-matched healthy Papua New Guinean controls and in healthy expatriate children living in Papua New Guinea. At 0-5 months of age, the IgG antibody titres against six of the eight polysaccharides measured were significantly lower in pneumonia patients than in both control groups. Antibody titres in 6-14-month-old Papua New Guinean controls were significantly lower than in control Papua New Guineans aged 0-5 months for five of the eight polysaccharides tested. In the 6-14-months age group the antibody titre was significantly lower in pneumonia patients than in controls for only one polysaccharide. For seven of the eight serotypes tested, antibody levels in expatriate controls did not decline with age. Antibody responses of Papua New Guinean children aged 6-18 months to a 23-valent pneumococcal vaccine were serotype dependent. Fold increases in response to the vaccine were greatest for the IgA isotype. IgG antibody responses were greater than three fold to four of the eight serotypes tested.  相似文献   
50.
中国圆蝇亚科妙蝇属四新种(双翅目:蝇科)   总被引:1,自引:0,他引:1  
在整理采自中国西部成蝇标本中,发现蝇科圆蝇亚科Mydaeinae妙蝇属Myospila Rondani,1856的4新种:春妙蝇Myospilavernatasp.nov.,黑前股妙蝇Myospila ateripraefemurasp.nov.,似净妙蝇Myospil alautoidessp.nov.,峨眉妙蝇Myospilaemeishanensissp.nov。前3种模式标本存中国科学院上海生命科学研究院植物生理生态研究所;后1种模式标本存军事医学科学院微生物流行病研究所医学昆虫标本馆。  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