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   5761篇
  免费   214篇
  国内免费   44篇
耳鼻咽喉   49篇
儿科学   114篇
妇产科学   60篇
基础医学   654篇
口腔科学   117篇
临床医学   328篇
内科学   1619篇
皮肤病学   60篇
神经病学   421篇
特种医学   313篇
外科学   884篇
综合类   25篇
预防医学   185篇
眼科学   110篇
药学   388篇
中国医学   15篇
肿瘤学   677篇
  2023年   39篇
  2022年   57篇
  2021年   103篇
  2020年   71篇
  2019年   77篇
  2018年   106篇
  2017年   80篇
  2016年   99篇
  2015年   135篇
  2014年   158篇
  2013年   164篇
  2012年   311篇
  2011年   312篇
  2010年   165篇
  2009年   173篇
  2008年   261篇
  2007年   237篇
  2006年   255篇
  2005年   251篇
  2004年   253篇
  2003年   218篇
  2002年   257篇
  2001年   207篇
  2000年   201篇
  1999年   185篇
  1998年   78篇
  1997年   73篇
  1996年   60篇
  1995年   41篇
  1994年   40篇
  1993年   43篇
  1992年   133篇
  1991年   125篇
  1990年   100篇
  1989年   118篇
  1988年   81篇
  1987年   67篇
  1986年   78篇
  1985年   76篇
  1984年   62篇
  1983年   51篇
  1982年   23篇
  1980年   21篇
  1979年   52篇
  1978年   25篇
  1977年   30篇
  1976年   24篇
  1974年   24篇
  1971年   22篇
  1969年   21篇
排序方式: 共有6019条查询结果,搜索用时 15 毫秒
91.
A series of three adrenal tumors is reported. They were discovered incidentally on ultrasonography for screening. One case was a benign pheochromocytoma and the others were non-functioning adrenocortical adenomas. They were hypoechoic on ultrasonography and were 4.5 x 3.5 x 4.0, 3.0 x 2.5 x 2.5 and 3.5 x 2.5 x 2.0 cm. Non-functioning adrenal tumors of a diameter smaller than 3.0 cm generally tended not to require surgery. Ultrasonography is useful for screening and evaluating patients with an adrenal mass without surgery as well as is computed tomographic scan.  相似文献   
92.
93.
We report a rare case of a patient in whom severe subcutaneous and mediastinal emphysema occurred in association with summer-type hypersensitivity pneumonitis and in whom overdistention or disruption of alveoli with obliteration of the respiratory bronchioles was revealed on open lung biopsy. This case suggests that obstructive bronchiolitis with hypersensitivity pneumonitis is an etiologic factor of mediastinal emphysema.  相似文献   
94.
95.
Digestive Diseases and Sciences - Enoxaparin, a low molecular weight heparin, has been used to prevent thrombotic events during major surgery without increasing the rate of hemorrhage. On the other...  相似文献   
96.
Isolated brain-retrocerebral neurohemal complex of the silkworm of Bombyx mori was stimulated electrically and the released bombyxin (an insulin-like neuropeptide) was measured using time-resolved fluoroimmunoassay. The amount of bombyxin release depended on the number of stimulus pulses delivered to the axonal tract of the bombyxin-producing (BP) neurosecretory cells, and 17 fg of bombyxin per pulse was released from a cell. The titer of bombyxin in the hemolymph of bombyxin-II injected pupae decreased exponentially, the half-life being 170 min. To relate firing activity of a population of BP cells to the hormone titer in the hemolymph, bombyxin titer and its change in the hemolymph were calculated numerically. We assumed that the amount of bombyxin release was proportional to the firing rate of BP cells and the released bombyxin was inactivated with the same time course of injected bombyxin. Our calculations suggested that the hemolymph bombyxin titer may fluctuate dynamically and the mean titer is 380 pg/ml, a level which is close to the actually determined bombyxin titer at middle stages of pupal-adult development.  相似文献   
97.
98.
The Directigen Flu A + B kit, a rapid diagnostic device for influenza virus A and B was evaluated. The nasopharyngeal aspirates were obtained from 239 patients who visited our hospital, between January and March, 2000, presenting flu-like symptoms. Influenza virus AH1: 77 and AH3: 51 were isolated from 128 specimens and none from 111 specimens. Directigen Flu A + B showed 115 specimens positive and 106 specimens negative. The sensitivity and specificity of this kit were 89.8% (115/128) and 95.5% (106/111) compared with viral isolation. Agreement on positive and negative interpretations between Direction Flu A and this kit was 97.9% (234/239). In the evaluation of this kit for influenza B virus, 60 frozen nasopharyngeal aspirates collected from February to April, 1999 were used. The sensitivity and specificity of this kit were 88.9% (16/18) and 88.1% (37/42) compared with viral isolation. Agreement on positive and negative interpretations between FLU OIA and this kit was 91.7% (55/60). The Directigen A + B demonstrated sensitivity and specificity equivalent to the conventional kits in nasopharingeal aspirates. This kit can also differentiate influenza A and B viruses, a feature which is useful for treatment using anti-viral agents such as amantadine and neuraminidase inhibitor. To date, the kit is the most effective tool for the rapid diagnosis of influenza.  相似文献   
99.
100.
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