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   4979374篇
  免费   394684篇
  国内免费   14774篇
耳鼻咽喉   70261篇
儿科学   161100篇
妇产科学   133762篇
基础医学   747861篇
口腔科学   139764篇
临床医学   454188篇
内科学   905672篇
皮肤病学   119619篇
神经病学   410833篇
特种医学   195405篇
外国民族医学   915篇
外科学   757752篇
综合类   142526篇
现状与发展   23篇
一般理论   2867篇
预防医学   416668篇
眼科学   119009篇
药学   354415篇
  26篇
中国医学   12730篇
肿瘤学   243436篇
  2021年   56436篇
  2019年   58878篇
  2018年   75503篇
  2017年   57849篇
  2016年   64209篇
  2015年   76618篇
  2014年   111132篇
  2013年   176487篇
  2012年   140149篇
  2011年   148803篇
  2010年   131041篇
  2009年   130625篇
  2008年   134902篇
  2007年   144911篇
  2006年   152650篇
  2005年   147700篇
  2004年   148117篇
  2003年   137425篇
  2002年   126956篇
  2001年   187709篇
  2000年   184981篇
  1999年   167289篇
  1998年   74853篇
  1997年   69770篇
  1996年   68011篇
  1995年   63348篇
  1994年   57458篇
  1993年   53385篇
  1992年   125314篇
  1991年   121657篇
  1990年   117553篇
  1989年   114545篇
  1988年   106081篇
  1987年   104136篇
  1986年   98799篇
  1985年   96842篇
  1984年   78596篇
  1983年   69704篇
  1982年   52077篇
  1981年   48307篇
  1980年   45435篇
  1979年   70835篇
  1978年   55366篇
  1977年   48193篇
  1976年   45333篇
  1975年   46241篇
  1974年   52462篇
  1973年   50408篇
  1972年   47150篇
  1971年   44107篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   

92.
93.
94.
95.
96.
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   
97.
98.
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   
99.
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field.  相似文献   
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