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   3135篇
  免费   259篇
  国内免费   56篇
耳鼻咽喉   28篇
儿科学   66篇
妇产科学   53篇
基础医学   407篇
口腔科学   44篇
临床医学   416篇
内科学   586篇
皮肤病学   31篇
神经病学   300篇
特种医学   234篇
外国民族医学   1篇
外科学   402篇
综合类   88篇
预防医学   290篇
眼科学   35篇
药学   282篇
中国医学   2篇
肿瘤学   185篇
  2022年   34篇
  2021年   93篇
  2020年   49篇
  2019年   57篇
  2018年   89篇
  2017年   44篇
  2016年   53篇
  2015年   66篇
  2014年   93篇
  2013年   144篇
  2012年   168篇
  2011年   212篇
  2010年   107篇
  2009年   104篇
  2008年   130篇
  2007年   212篇
  2006年   151篇
  2005年   175篇
  2004年   131篇
  2003年   103篇
  2002年   120篇
  2001年   72篇
  2000年   76篇
  1999年   62篇
  1998年   53篇
  1997年   38篇
  1996年   24篇
  1995年   23篇
  1994年   19篇
  1993年   24篇
  1992年   42篇
  1991年   45篇
  1990年   31篇
  1989年   43篇
  1988年   52篇
  1987年   37篇
  1986年   35篇
  1985年   27篇
  1984年   38篇
  1983年   32篇
  1982年   19篇
  1981年   24篇
  1980年   17篇
  1979年   29篇
  1978年   25篇
  1977年   36篇
  1976年   25篇
  1975年   17篇
  1974年   15篇
  1973年   18篇
排序方式: 共有3450条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
A 26-year-old man who presented with a 2-year history of intermittent gynecomastia with recent onset of fever, night sweats, and abdominal distension was found to have a left-sided adrenocortical carcinoma with metastases to the liver and spine. Sudden death occurred 1 month after his presentation. At autopsy a saddle pulmonary thromboembolus was found occluding the pulmonary outflow tract, with smaller more peripheral pulmonary thromboemboli. No tumor deposits were identified in the thromboemboli. The thromboemboli had arisen from a tongue of tumor that had grown through the left adrenal vein into the inferior vena cava. Despite a high rate of angio-invasion there are very few reports of sudden death resulting from this phenomenon in patients with adrenocortical carcinoma.  相似文献   
8.
We describe a novel human zinc finger cNDA, C2H2-171. This cDNA represents an mRNA which encodes a protein of 484 amino acids and a calculated molecular weight of 54 kD. Four zinc finger-like domains are found in the C-terminal end of the protein. At the N-terminus, C2H2-171 contains a POZ/tramtrack-like domain similar to that found in the tumor associated zinc finger proteins LAZ-3/BCL-6 and PLZ-F, as well as in non-zinc finger proteins. C2H2-171 RNA is preferentially expressed in the brain, and increases during the course of murine development, with maximal expression in the adult. C2H2-171 RNA is differentially expressed in brain regions, with the highest level of expression in the cerebellum. C2H2-171 RNA was expressed at high levels in primary cerebellar granule cell neurons compared to astrocytes. The gene encoding C2H2-171 is highly conserved in vertebrates, and maps to the terminus of human chromosome 1 (1q44-ter). This chromosomal location is associated with a number of cytogenetic aberrations including those involving brain developmental anomalies and tumorigenesis. These data suggest that C2H2-171 may play an important role in vertebrate brain development and function.  相似文献   
9.
Study Objective . To investigate the effect of simultaneously administered didanosine (ddI) on the absorption of a single dose of itraconazole. Design . Randomized, crossover, unblinded single-dose pharmacokinetic study in healthy volunteers. Comparisons of itraconazole alone and itraconazole with simultaneous ddI were performed on days 1 and 15. Setting . A university medical center. Patients . Seven healthy men and women. Six subjects (86%) completed the study; one was removed due to the development of a rash. Interventions . Volunteers received a single 200-mg oral dose of itraconazole or itraconazole with concomitant oral ddI 300 mg (two 150-mg tablets) dispersed in 240 ml water. Each regimen was separated by a 2-week washout period. Serum samples were obtained frequently for 12 hours after the dose. Measurements and Main Results . Concentrations of itraconazole were determined using a microbiologic assay. Individual concentrations in serum versus time data were evaluated by linear regression analysis. Peak serum concentration and time to peak were determined by visual inspection of each individual's serum concentration-time curve. A mean ± SD peak serum itraconazole concentration of 0.90 ± 0.30 μg/ml was observed at 3.0 ± 0.7 hours when itraconazole was administered alone, compared with undetectable levels in all patients during therapy with ddI. Conclusions . Simultaneous oral administration of ddI significantly decreases absorption of itraconazole. These drugs should not be administered concurrently.  相似文献   
10.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响.  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