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   3472256篇
  免费   295625篇
  国内免费   13344篇
耳鼻咽喉   47507篇
儿科学   110459篇
妇产科学   90318篇
基础医学   553518篇
口腔科学   94014篇
临床医学   319320篇
内科学   613842篇
皮肤病学   91828篇
神经病学   297098篇
特种医学   135484篇
外国民族医学   295篇
外科学   530032篇
综合类   103358篇
现状与发展   24篇
一般理论   2408篇
预防医学   300091篇
眼科学   79102篇
药学   238778篇
  26篇
中国医学   9380篇
肿瘤学   164343篇
  2021年   55092篇
  2020年   35123篇
  2019年   58095篇
  2018年   71524篇
  2017年   54536篇
  2016年   59944篇
  2015年   74093篇
  2014年   108222篇
  2013年   173442篇
  2012年   95857篇
  2011年   96729篇
  2010年   117433篇
  2009年   121656篇
  2008年   83594篇
  2007年   87445篇
  2006年   97151篇
  2005年   92942篇
  2004年   94471篇
  2003年   84996篇
  2002年   74826篇
  2001年   104221篇
  2000年   96988篇
  1999年   96766篇
  1998年   64917篇
  1997年   62859篇
  1996年   61031篇
  1995年   56431篇
  1994年   50702篇
  1993年   47347篇
  1992年   68839篇
  1991年   66069篇
  1990年   62633篇
  1989年   61746篇
  1988年   57562篇
  1987年   56319篇
  1986年   53674篇
  1985年   53254篇
  1984年   48969篇
  1983年   45041篇
  1982年   42066篇
  1981年   39712篇
  1980年   37396篇
  1979年   41393篇
  1978年   36730篇
  1977年   33272篇
  1976年   30536篇
  1975年   29406篇
  1974年   31009篇
  1973年   30074篇
  1972年   28295篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.  相似文献   
93.
Introduction: The Hedgehog (HH) pathway constitutes a collection of signaling molecules which critically influence embryogenesis. In adults, however, the HH pathway remains integral to the proliferation, maintenance, and apoptosis of adult stem cells including hematopoietic stem cells.

Areas covered: We discuss the current understanding of the HH pathway as it relates to normal hematopoiesis, the pathology of acute myeloid leukemia (AML), the rationale for and data from combination therapies including HH pathway inhibitors, and ultimately the prospects that might offer promise in targeting this pathway in AML.

Expert opinion: Efforts to target the HH pathway have been focused on impeding this disposition and restoring chemosensitivity to conventional myeloid neoplasm therapies. The year 2018 saw the first approval of a HH pathway inhibitor (glasdegib) for AML, though for an older population and in combination with an uncommonly-used therapy. Several other clinical trials with agents targeting modulators of HH signaling in AML and MDS are underway. Further study and understanding of the interplay between the numerous aspects of HH signaling and how it relates to the augmented survival of AML will provide a more reliable substrate for therapeutic strategies in patients with this poor-risk disease.  相似文献   

94.
Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.  相似文献   
95.
96.
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.  相似文献   

97.
98.
99.
100.
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