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   4283326篇
  免费   351078篇
  国内免费   17087篇
耳鼻咽喉   58537篇
儿科学   138222篇
妇产科学   114309篇
基础医学   660448篇
口腔科学   116693篇
临床医学   396519篇
内科学   773512篇
皮肤病学   105689篇
神经病学   362766篇
特种医学   165660篇
外国民族医学   816篇
外科学   641188篇
综合类   127686篇
现状与发展   24篇
一般理论   2588篇
预防医学   367407篇
眼科学   99045篇
药学   298161篇
  27篇
中国医学   12471篇
肿瘤学   209723篇
  2021年   56333篇
  2020年   35846篇
  2019年   58984篇
  2018年   74474篇
  2017年   57005篇
  2016年   62986篇
  2015年   76139篇
  2014年   110686篇
  2013年   176433篇
  2012年   124579篇
  2011年   129750篇
  2010年   126202篇
  2009年   127629篇
  2008年   114791篇
  2007年   121642篇
  2006年   130414篇
  2005年   125153篇
  2004年   125434篇
  2003年   115099篇
  2002年   104088篇
  2001年   154915篇
  2000年   150406篇
  1999年   138778篇
  1998年   71196篇
  1997年   67582篇
  1996年   65395篇
  1995年   60896篇
  1994年   54913篇
  1993年   51043篇
  1992年   100158篇
  1991年   95967篇
  1990年   91742篇
  1989年   88867篇
  1988年   82295篇
  1987年   80380篇
  1986年   76092篇
  1985年   74736篇
  1984年   63629篇
  1983年   56809篇
  1982年   47097篇
  1981年   43854篇
  1980年   41163篇
  1979年   54486篇
  1978年   44742篇
  1977年   39538篇
  1976年   36996篇
  1975年   36003篇
  1974年   39604篇
  1973年   38427篇
  1972年   35843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