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   4752683篇
  免费   386098篇
  国内免费   15876篇
耳鼻咽喉   68209篇
儿科学   145030篇
妇产科学   124371篇
基础医学   715829篇
口腔科学   135420篇
临床医学   433127篇
内科学   866486篇
皮肤病学   112094篇
神经病学   400357篇
特种医学   188478篇
外国民族医学   967篇
外科学   728567篇
综合类   136184篇
现状与发展   24篇
一般理论   2699篇
预防医学   395801篇
眼科学   113011篇
药学   340795篇
  27篇
中国医学   12670篇
肿瘤学   234511篇
  2021年   56075篇
  2019年   58915篇
  2018年   74509篇
  2017年   57073篇
  2016年   63459篇
  2015年   76518篇
  2014年   111334篇
  2013年   176822篇
  2012年   128728篇
  2011年   133834篇
  2010年   126618篇
  2009年   128543篇
  2008年   121341篇
  2007年   129276篇
  2006年   138147篇
  2005年   133133篇
  2004年   133841篇
  2003年   124157篇
  2002年   114668篇
  2001年   184841篇
  2000年   182201篇
  1999年   165477篇
  1998年   74657篇
  1997年   70080篇
  1996年   67921篇
  1995年   63649篇
  1994年   57609篇
  1993年   53437篇
  1992年   123869篇
  1991年   118796篇
  1990年   113467篇
  1989年   110742篇
  1988年   102577篇
  1987年   100641篇
  1986年   95301篇
  1985年   93263篇
  1984年   76252篇
  1983年   67451篇
  1982年   51375篇
  1981年   47604篇
  1980年   44632篇
  1979年   67466篇
  1978年   52923篇
  1977年   46810篇
  1976年   43052篇
  1975年   43276篇
  1974年   49148篇
  1973年   46936篇
  1972年   44141篇
  1971年   40768篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
92.
93.
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   
94.
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   

95.
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   
96.
97.
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   

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