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   4690篇
  免费   288篇
  国内免费   29篇
耳鼻咽喉   82篇
儿科学   84篇
妇产科学   110篇
基础医学   611篇
口腔科学   79篇
临床医学   397篇
内科学   1224篇
皮肤病学   144篇
神经病学   534篇
特种医学   112篇
外科学   525篇
综合类   6篇
一般理论   1篇
预防医学   227篇
眼科学   40篇
药学   297篇
中国医学   14篇
肿瘤学   520篇
  2023年   41篇
  2022年   98篇
  2021年   174篇
  2020年   101篇
  2019年   125篇
  2018年   140篇
  2017年   127篇
  2016年   134篇
  2015年   176篇
  2014年   195篇
  2013年   280篇
  2012年   374篇
  2011年   368篇
  2010年   175篇
  2009年   177篇
  2008年   276篇
  2007年   280篇
  2006年   245篇
  2005年   225篇
  2004年   186篇
  2003年   177篇
  2002年   149篇
  2001年   91篇
  2000年   73篇
  1999年   69篇
  1998年   35篇
  1997年   20篇
  1996年   15篇
  1995年   25篇
  1994年   16篇
  1993年   12篇
  1992年   36篇
  1991年   35篇
  1990年   32篇
  1989年   33篇
  1988年   26篇
  1987年   30篇
  1986年   25篇
  1985年   27篇
  1984年   17篇
  1983年   17篇
  1979年   14篇
  1978年   11篇
  1976年   10篇
  1975年   9篇
  1974年   12篇
  1973年   11篇
  1971年   13篇
  1969年   11篇
  1968年   7篇
排序方式: 共有5007条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background: Drugs are routinely combined in anesthesia and pain management to obtain an enhancement of the desired effects. However, a parallel enhancement of the undesired effects might take place as well, resulting in a limited therapeutic usefulness. Therefore, when addressing the question of optimal drug combinations, side effects must be taken into account.

Methods: By extension of a previously published interaction model, the authors propose a method to study drug interactions considering also their side effects. A general outcome parameter identified as patient's well-being is defined by superposition of positive and negative effects. Well-being response surfaces are computed and analyzed for varying drugs pharmacodynamics and interaction types. In particular, the existence of multiple maxima and of optimal drug combinations is investigated for the combination of two drugs.

Results: Both drug pharmacodynamics and interaction type affect the well-being surface and the deriving optimal combinations. The effect of the interaction parameters can be explained in terms of synergy and antagonism and remains unchanged for varying pharmacodynamics. For all simulations performed for the combination of two drugs, the presence of more than one maximum was never observed.  相似文献   

5.
6.
Forty consecutive adult patients under the age of 50 with acute non-lymphoblastic leukemia (ANLL) in first complete remission, underwent autologous bone marrow transplantation (ABMT) between March 1984 and April 1990. The conditioning regimen employed included cyclophosphamide and total body irradiation, followed by the administration of unpurged ABMT. The median time from diagnosis to transplant was 7 months (3-15 months), and the median time from complete remission to ABMT was 4 months (range 3-9 months). Twenty-two (51%) patients remain in complete remission 6-81 months (median 24 months) after ABMT.

The causes of death were, recurrent leukemia (11 patients), parenchymal toxicities such as acute respiratory distress syndrome and veno-occlusive disease (3 patients), hemorrhage (2 patients) and infection (2 patients). Eleven patients relapsed after 3-12 months (median 5 months). This study has produced survival data comparable to those of other institutions employing TBI for either allo or autotransplants.  相似文献   
7.
In Italy mifepristone is not yet marketed. Gynaecologists in our hospital asked to use this medication as a less traumatic method for voluntary abortions. We followed the standard procedure defined by the Italian Health Ministry (IMH) for purchasing drugs from abroad but encountered several unexpected barriers. Starting from this case, this paper is aimed at identifying these barriers which we found to be not only professional, but also ethical, religious and moral.  相似文献   
8.
We present the clinical case of a patient affected by mitral and aortic valvular disease submitted to double valvular replacement. This patient was also affected by congenital deficiency of factor X. We describe the normal problems encountered in cardiac surgery and the specific implications of this clinical case.  相似文献   
9.
10.
Differential Cellular Gene Expression in Ganglioglioma   总被引:1,自引:0,他引:1  
Summary:  Purpose:  Gangliogliomas (GGs) are neuronal-glial tumors highly associated with epilepsy. We hypothesized that the expression of select gene families including neurotransmitter receptor subunits and growth factors would be distinct in neurons and astrocytes within GG compared with adjacent cortex and that these changes would yield insights into seizure onset and lesion formation.
Methods:  Candidate gene expression was defined in single immunohistochemically labeled neurons and astrocytes microdissected from GG specimens compared with neurons and astrocytes microdissected from morphologically intact cortex adjacent to the GG or normal control cortex.
Results:  Differential expression of 16 genes including glutamate transporter (EAAC1) and receptor (NMDA2C, mGluR5), growth factor (hepatocyte growth factor), and receptor (platelet derived growth factor receptor β, fibroblast growth factor receptor 3) mRNAs was detected in GG neurons compared with control neurons. In astrocytes, altered expression of p75NGF, mGluR3, TGFβ3 and Glt-1 mRNAs was detected. Nestin mRNA, a gene that exhibits enhanced expression in balloon cell cortical dysplasia, was increased in GG neurons. Because of the morphological similarities between GG and cortical dysplasia, we show that there is activation of the mTOR cascade in GG as evidenced by enhanced expression of phospho-p70S6kinase and phosphoribosomal S6 proteins.
Conclusion:  We find differential candidate gene expression in neurons and astrocytes in GG compared with adjacent cortex and show that there is activation of the mTOR pathway. These changes highlight pathways that may be pivotal for epileptogenesis and lesion growth.  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