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   3165657篇
  免费   252884篇
  国内免费   5410篇
耳鼻咽喉   45377篇
儿科学   99840篇
妇产科学   86275篇
基础医学   453720篇
口腔科学   91717篇
临床医学   293583篇
内科学   610934篇
皮肤病学   65955篇
神经病学   263168篇
特种医学   124575篇
外国民族医学   1104篇
外科学   469904篇
综合类   73654篇
现状与发展   4篇
一般理论   1436篇
预防医学   260258篇
眼科学   75028篇
药学   236825篇
  10篇
中国医学   5588篇
肿瘤学   164996篇
  2018年   32868篇
  2017年   25312篇
  2016年   27900篇
  2015年   31729篇
  2014年   45207篇
  2013年   69051篇
  2012年   93227篇
  2011年   98896篇
  2010年   57996篇
  2009年   55621篇
  2008年   93842篇
  2007年   100116篇
  2006年   100484篇
  2005年   98119篇
  2004年   94303篇
  2003年   90759篇
  2002年   89260篇
  2001年   142697篇
  2000年   147091篇
  1999年   124008篇
  1998年   34180篇
  1997年   30759篇
  1996年   30781篇
  1995年   31489篇
  1994年   29634篇
  1993年   27707篇
  1992年   100776篇
  1991年   98130篇
  1990年   94851篇
  1989年   91506篇
  1988年   85075篇
  1987年   83649篇
  1986年   79527篇
  1985年   75831篇
  1984年   57568篇
  1983年   49649篇
  1982年   30005篇
  1981年   26829篇
  1979年   54510篇
  1978年   38865篇
  1977年   32645篇
  1976年   30557篇
  1975年   32564篇
  1974年   39998篇
  1973年   38463篇
  1972年   36315篇
  1971年   33693篇
  1970年   31664篇
  1969年   29634篇
  1968年   27194篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
The International Journal of Cardiovascular Imaging - Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of...  相似文献   
2.
3.
4.
5.
6.
Aristodemou  E.  Retzepi  M.  Calciolari  E.  Donos  N. 《Clinical oral investigations》2022,26(8):5223-5235
Clinical Oral Investigations - To evaluate the effect of membrane occlusiveness and experimental diabetes on early and late healing following guided bone regeneration. A total of 30 Wistar rats...  相似文献   
7.
8.
9.
The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.  相似文献   
10.
Objective: Hepatocellular carcinoma (HCC) microenvironment has been recognized as a key contributor for cancer progression, metastasis, and drug resistance. The crosstalk between tumor cells, the vascular endothelial growth factor (VEGF), and the chemokine (C-C motif) ligand 2 (CCL2) signaling networks mediates immunoinhibitory impact and facilitates tumor angiogenesis. The current investigation aimed at exploring the potent anti-cancer activity of the newly designed nano-based anti-cancer therapy comprising anti-VEGF drug, avastin (AV), and CCR2 antagonist (CR) to counteract HCC and tracking its mode of action in vivo. Methods: The prepared AV, CR, and AVCR nanoprototypes were characterized by nanoscale characterization techniques in our previous work. Here, they are applied for unearthing their anti-cancer properties / mechanisms in hepatic cancer-induced rats via analyzing protein levels and genetic expression of the elements incorporated in the angiogenesis, apoptosis, and metastasis signalling pathways. Results: The present results revealed a significant down-regulation in the angiogenesis, survival and metastasis indices along with up-regulation in the pro-apoptotic mediators upon treatment of hepatic cancer-bearing rats with the novel synthesized nanomaterials when compared with the untreated counterparts. We showed across HCC model that anti-VEGF in combination with CCR2 antagonism therapy leads to sensitization and enhanced tumor response over anti-VEGF or CCR2 antagonism monotherapy, particularly in its nanoscale formulation. Conclusion: The present approach provides new mechanistic insights into the powerful anti-hepatic cancer advantage of the novel nanoprototypes which is correlated with modulating critical signal transduction pathways implicated in tumor microenviroment such as angiogenesis, apoptosis and metastasis. This research work presents a substantial foundation for future studies focused on prohibiting cancer progression and recovery by targeting tumor microenviroment.  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