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   4214185篇
  免费   340993篇
  国内免费   16511篇
耳鼻咽喉   57684篇
儿科学   135340篇
妇产科学   112872篇
基础医学   650284篇
口腔科学   116314篇
临床医学   393167篇
内科学   756686篇
皮肤病学   104171篇
神经病学   355621篇
特种医学   162476篇
外国民族医学   626篇
外科学   628493篇
综合类   123416篇
现状与发展   24篇
一般理论   2612篇
预防医学   365167篇
眼科学   97258篇
药学   293390篇
  31篇
中国医学   11716篇
肿瘤学   204341篇
  2021年   56045篇
  2020年   35684篇
  2019年   58747篇
  2018年   73972篇
  2017年   56554篇
  2016年   62267篇
  2015年   75669篇
  2014年   110117篇
  2013年   175848篇
  2012年   120619篇
  2011年   125706篇
  2010年   125302篇
  2009年   126687篇
  2008年   111014篇
  2007年   117859篇
  2006年   126071篇
  2005年   121237篇
  2004年   121781篇
  2003年   111454篇
  2002年   100745篇
  2001年   143839篇
  2000年   138562篇
  1999年   129941篇
  1998年   69502篇
  1997年   66291篇
  1996年   64343篇
  1995年   59858篇
  1994年   54117篇
  1993年   50294篇
  1992年   95380篇
  1991年   92379篇
  1990年   88467篇
  1989年   85942篇
  1988年   79842篇
  1987年   78247篇
  1986年   74668篇
  1985年   73275篇
  1984年   62612篇
  1983年   56313篇
  1982年   46779篇
  1981年   43756篇
  1980年   41093篇
  1979年   54743篇
  1978年   45287篇
  1977年   39894篇
  1976年   37425篇
  1975年   36792篇
  1974年   40769篇
  1973年   39645篇
  1972年   37224篇
排序方式: 共有10000条查询结果,搜索用时 15 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