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   19268篇
  免费   1158篇
  国内免费   138篇
耳鼻咽喉   162篇
儿科学   433篇
妇产科学   383篇
基础医学   2229篇
口腔科学   787篇
临床医学   1872篇
内科学   4146篇
皮肤病学   404篇
神经病学   1180篇
特种医学   437篇
外国民族医学   5篇
外科学   2514篇
综合类   492篇
一般理论   14篇
预防医学   1592篇
眼科学   753篇
药学   1823篇
中国医学   216篇
肿瘤学   1122篇
  2024年   31篇
  2023年   251篇
  2022年   703篇
  2021年   1093篇
  2020年   730篇
  2019年   882篇
  2018年   1050篇
  2017年   742篇
  2016年   800篇
  2015年   808篇
  2014年   1077篇
  2013年   1244篇
  2012年   1705篇
  2011年   1732篇
  2010年   1025篇
  2009年   788篇
  2008年   1144篇
  2007年   1019篇
  2006年   856篇
  2005年   722篇
  2004年   570篇
  2003年   468篇
  2002年   395篇
  2001年   54篇
  2000年   68篇
  1999年   67篇
  1998年   52篇
  1997年   48篇
  1996年   45篇
  1995年   38篇
  1994年   21篇
  1993年   33篇
  1992年   25篇
  1991年   19篇
  1990年   23篇
  1989年   22篇
  1988年   17篇
  1987年   10篇
  1986年   14篇
  1985年   12篇
  1984年   20篇
  1983年   17篇
  1982年   16篇
  1981年   11篇
  1980年   12篇
  1979年   14篇
  1978年   10篇
  1976年   10篇
  1974年   10篇
  1973年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Rosai–Dorfman disease (RDD) is a rare and self-limiting disease process that presents most commonly in young patients as massive, painless, cervical lymphadenopathy. Extranodal involvement may also occur. Histopathologic evaluation is the main diagnostic modality. We report an unusual presentation of RDD with cervical lymphadenopathy and an incidentally discovered sinonasal mass, clinically worrisome for malignancy. We emphasize that a high index of clinical suspicion is critical for accurate diagnosis of RDD. Clinicians and pathologists should consider RDD in a differential diagnosis of cervical lymphadenopathy, especially in young patients.  相似文献   
93.
94.
European Journal of Epidemiology - Initial results from various phase-III trials on vaccines against SARS-CoV-2 are promising. For proper translation of these results to clinical guidelines, it is...  相似文献   
95.
Thrombomodulin (TM), an anticoagulant factor on endothelial cells, is known to be expressed in non-endothelial cells as well. In neoplastic cells of lung adenocarcinomas, TM is expressed but its correlation with growth potential has not been studied. As TM expression has a negative correlation with cell proliferation in lung squamous cell carcinomas, we examined its growth effect on lung adenocarcinoma cells of the A549 cell line by inhibiting TM expression with antisense oligodeoxynucleotides (ODN). In the antisense ODN transfected cells, the expression of TM mRNA was decreased to 49% at 12 h and 47% at 24 h, which was in accordance with TM expression at the protein level. By IdU (5-iodo-2'-deoxyuridine) incorporation assay, the growth of A549 cells was found to have decreased to 36% of the control level at 24 h post-transfection. The suppression of cell growth was maintained in a concentration-dependent manner for 48 h after transfection, when the expression of TM started to rebound. In the transfected cells, the G1 phase cell count was reduced to 60.7%, compared with 68.2% in the control transfectants. These results suggest that TM expression may play a suppressive role in the proliferation activity of A549 lung adenocarcinoma cells.  相似文献   
96.
A new triterpenoidal saponin having hederagenin as the aglycone was isolated from the roots of SYMPHYTUM OFFICINALE L. The structure of this saponin was elucidated by FAB-MS, (1)H-, (13)C-NMR, 2D-NMR analyses and chemical studies as 3- O-[beta- D-glucopyranosyl-(1-->4)-alpha- L-arabinopyranosyl]-hederagenin 28- O-[beta- D-glucopyranosyl-(1-->6)-beta- D-glucopyranosyl] ester.  相似文献   
97.
98.
99.
Mega-Liposuction: Analysis of 1520 Patients   总被引:1,自引:0,他引:1  
Fifteen hundred and twenty cases of liposuction/liposculpture were performed at Dr. M. Erfan & Bagedo Hospitals and King Abdulaziz University Hospital in Jeddah from January 1983 to December 1994. These cases were mostly females. The age group was from 16–65 years. Multiple procedures were performed in 11.68% of these cases. The change in hemoglobin and the hematocrit ratio pre- and post-operatively, and the incidence of complications, were studied. The percentage of surface area operated upon rather than the amount of fat removed was the most important relevant factor.  相似文献   
100.
Raloxifene, a new selective estrogen receptor modulator.   总被引:5,自引:0,他引:5  
There is evidence from observational studies that estrogen replacement therapy in postmenopausal women can reduce the rates of morbidity and mortality of atherosclerotic heart disease. The mechanism of this cardiovascular protective effect is not yet established, but favorable actions of hormone therapy on plasma lipids and vascular endothelial function have been proposed. Estrogens can also increase the risk of breast and uterine carcinoma. The new selective estrogen receptor modulator (SERM) raloxifene appears to have benefits similar to estrogen on plasma lipids and osteoporosis, but it does not affect the rate of uterine carcinoma as does tamoxifen and estrogen. Animal studies suggest an anti-atherosclerotic action of raloxifene, but this needs to be confirmed in long-term human studies.  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