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   4213733篇
  免费   340959篇
  国内免费   16510篇
耳鼻咽喉   57681篇
儿科学   135318篇
妇产科学   112860篇
基础医学   650242篇
口腔科学   116300篇
临床医学   393108篇
内科学   756572篇
皮肤病学   104167篇
神经病学   355589篇
特种医学   162451篇
外国民族医学   626篇
外科学   628450篇
综合类   123400篇
现状与发展   24篇
一般理论   2611篇
预防医学   365107篇
眼科学   97255篇
药学   293360篇
  31篇
中国医学   11716篇
肿瘤学   204334篇
  2021年   56041篇
  2020年   35683篇
  2019年   58743篇
  2018年   73971篇
  2017年   56554篇
  2016年   62262篇
  2015年   75663篇
  2014年   110109篇
  2013年   175837篇
  2012年   120596篇
  2011年   125680篇
  2010年   125291篇
  2009年   126685篇
  2008年   110996篇
  2007年   117837篇
  2006年   126042篇
  2005年   121213篇
  2004年   121761篇
  2003年   111441篇
  2002年   100728篇
  2001年   143824篇
  2000年   138554篇
  1999年   129930篇
  1998年   69500篇
  1997年   66286篇
  1996年   64340篇
  1995年   59853篇
  1994年   54110篇
  1993年   50291篇
  1992年   95375篇
  1991年   92367篇
  1990年   88455篇
  1989年   85936篇
  1988年   79832篇
  1987年   78232篇
  1986年   74655篇
  1985年   73262篇
  1984年   62598篇
  1983年   56306篇
  1982年   46779篇
  1981年   43755篇
  1980年   41092篇
  1979年   54735篇
  1978年   45282篇
  1977年   39891篇
  1976年   37423篇
  1975年   36790篇
  1974年   40761篇
  1973年   39642篇
  1972年   37220篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
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   
92.
93.
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   

94.
95.
96.
97.
98.
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer.  相似文献   
99.
100.
Secondary tricuspid regurgitation (TR) caused by right ventricular enlargement in the setting of left heart disease/pulmonary hypertension has been well described. In contrast, that associated with right atrial enlargement—atrial functional TR (AF‐TR)—remains largely underappreciated. AF‐TR most often occurs in the setting of lone atrial fibrillation, although it is also seen in its absence (idiopathic AF‐TR). Several recent studies have found that the prevalence, hemodynamic significance, and prognosis of AF‐TR are not inconsequential, suggesting increased physician awareness of this novel clinical entity is warranted. This article discusses the pathogenesis, echocardiographic findings, and treatment of this underappreciated cause of secondary TR.  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