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   1462篇
  免费   103篇
  国内免费   10篇
耳鼻咽喉   21篇
儿科学   51篇
妇产科学   35篇
基础医学   230篇
口腔科学   82篇
临床医学   163篇
内科学   280篇
皮肤病学   12篇
神经病学   187篇
特种医学   23篇
外科学   101篇
综合类   5篇
预防医学   121篇
眼科学   28篇
药学   76篇
中国医学   5篇
肿瘤学   155篇
  2024年   2篇
  2023年   24篇
  2022年   43篇
  2021年   75篇
  2020年   29篇
  2019年   43篇
  2018年   48篇
  2017年   37篇
  2016年   53篇
  2015年   47篇
  2014年   62篇
  2013年   89篇
  2012年   147篇
  2011年   137篇
  2010年   73篇
  2009年   50篇
  2008年   84篇
  2007年   80篇
  2006年   86篇
  2005年   91篇
  2004年   77篇
  2003年   72篇
  2002年   54篇
  2001年   6篇
  2000年   1篇
  1999年   7篇
  1998年   9篇
  1997年   2篇
  1996年   9篇
  1995年   5篇
  1994年   2篇
  1993年   1篇
  1992年   3篇
  1990年   2篇
  1989年   1篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1977年   2篇
  1976年   3篇
  1975年   4篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1944年   1篇
  1942年   1篇
排序方式: 共有1575条查询结果,搜索用时 15 毫秒
71.
72.
European Archives of Oto-Rhino-Laryngology - Electrical stimulation-supported therapy is an often used modality. However, it still belongs to experimental methods in the human larynx. Data are...  相似文献   
73.
74.
BackgroundConventional swallowing therapy for patients with Parkinson's disease (PD) and swallowing difficulties has poor carryover to everyday life. Herein, we test the effectiveness of visual information while treating swallowing disturbances in patients with PD.MethodsForty two non-demented PD patients with swallowing disturbances were randomly divided into two groups. An experimental group received video-assisted swallowing therapy (VAST) and a control group (n = 21) was given conventional therapy. Both groups were given 6 interventional sessions by the same speech and swallowing therapist. Patients in the VAST group were exposed to video of the swallowing process in general as well as of their own, as part of all therapy sessions. Swallowing function was assessed before and post-intervention by fiberoptic endoscopic evaluation of swallowing (FEES). Quality of life, quality of care and the degree of pleasure from eating were also assessed by questioners pre and post-intervention.ResultsThere was a significant improvement in swallowing functions following both interventions. The FEESs demonstrated a significantly greater reduction in food residues in the pharynx in the VAST group compared to the conventional treatment group. There were significant group improvement in some parameters of the quality of life, quality of care and pleasure of eating scales.ConclusionIn cognitively intact patients with PD with swallowing disturbances VAST was associated with improved swallowing related QOL and less food residues in the pharynx.  相似文献   
75.

Introduction and objectives

Deeper understanding of the myocardial structure linking the morphology and function of the heart would unravel crucial knowledge for medical and surgical clinical procedures and studies. Several conceptual models of myocardial fiber organization have been proposed but the lack of an automatic and objective methodology prevented an agreement. We sought to deepen this knowledge through advanced computer graphical representations of the myocardial fiber architecture by diffusion tensor magnetic resonance imaging.

Methods

We performed automatic tractography reconstruction of unsegmented diffusion tensor magnetic resonance imaging datasets of canine heart from the public database of the Johns Hopkins University. Full-scale tractographies have been built with 200 seeds and are composed by streamlines computed on the vector field of primary eigenvectors at the diffusion tensor volumes. We also introduced a novel multiscale visualization technique in order to obtain a simplified tractography. This methodology retains the main geometric features of the fiber tracts, making it easier to decipher the main properties of the architectural organization of the heart.

Results

Output analysis of our tractographic representations showed exact correlation with low-level details of myocardial architecture, but also with the more abstract conceptualization of a continuous helical ventricular myocardial fiber array.

Conclusions

Objective analysis of myocardial architecture by an automated method, including the entire myocardium and using several 3-dimensional levels of complexity, reveals a continuous helical myocardial fiber arrangement of both right and left ventricles, supporting the anatomical model of the helical ventricular myocardial band described by F. Torrent-Guasp.  相似文献   
76.
77.
Metabolic Brain Disease - Worldwide, the excessive consumption of fat and/or sugar has increased considerably. Palatable high-fat diets (HFDs) lead to metabolic disturbances and obesity,...  相似文献   
78.
79.
Epithelial mesenchymal transition (EMT) is a process by which epithelial cells acquire mesenchymal properties, generating metastases. Transforming growth factor beta (TGF-β) is associated with this malignancy by having the ability to induce EMT. Metformin, has been shown to inhibit EMT in breast cancer cells. Based on this evidence we hypothesize that treatment with metformin and the silencing of TGF-β, inhibits the EMT in cancer cells. Canine metastatic mammary tumor cell line CF41 was stably transduced with a shRNA-lentivirus, reducing expression level of TGF-β1. This was combined with metformin treatment, to look at effects on cell migration and the expression of EMT markers. For in vivo study, unmodified or TGF-β1sh cells were injected in the inguinal region of nude athymic female mice followed by metformin treatment. The mice’s lungs were collected and metastatic nodules were subsequently assessed for EMT markers expression. The migration rate was lower in TGF-β1sh cells and when combined with metformin treatment. Metformin treatment reduced N-cadherin and increased E-cadherin expression in both CF41 and TGF-β1sh cells. Was demonstrated that metformin treatment reduced the number of lung metastases in animals bearing TGF-β1sh tumors. This paralleled a decreased N-cadherin and vimentin expression, and increased E-cadherin and claudin-7 expression in lung metastases. This study confirms the benefits of TGF-β1 silencing in addition to metformin as potential therapeutic agents for breast cancer patients, by blocking EMT process. To the best of our knowledge, we are the first to report metformin treatment in cells with TGF-β1 silencing and their effect on EMT.  相似文献   
80.
The authors investigated the role of resveratrol (RV), a natural poliphenolic molecule with several biological activities, in transforming growth factor-β (TGF-β)-induced proliferation and differentiation of ex vivo human pulmonary fibroblasts into myofibroblasts. The effects of RV treatment were evaluated by analyzing TGF-β-induced α-smooth muscle actin (α-SMA) expression and collagen production, as well as cell proliferation of both normal and idiopathic pulmonary fibrosis (IPF) lung fibroblasts. Results demonstrate that RV inhibits TGF-β-induced cell proliferation of both normal and pathological lung fibroblasts, attenuates α-SMA expression at both the mRNA and protein levels, and also inhibits intracellular collagen deposition. In order to understand the molecular mechanisms, the authors also investigated the effects of RV treatment on signaling pathways involved in TGF-β-induced fibrosis. The authors show that RV inhibited TGF-β-induced phosphorylation of both extracellular signal-regulated kinases (ERK1/2) and the serine/threonine kinase, Akt. Moreover, RV treatment blocked the TGF-β-induced decrease in phosphatase and tensin homolog (PTEN) expression levels.  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