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   177796篇
  免费   16238篇
  国内免费   8110篇
耳鼻咽喉   2336篇
儿科学   4054篇
妇产科学   1971篇
基础医学   32727篇
口腔科学   5480篇
临床医学   13660篇
内科学   24277篇
皮肤病学   4657篇
神经病学   10459篇
特种医学   3889篇
外国民族医学   118篇
外科学   15424篇
综合类   26888篇
现状与发展   49篇
预防医学   5128篇
眼科学   3592篇
药学   14189篇
  29篇
中国医学   5595篇
肿瘤学   27622篇
  2024年   311篇
  2023年   2384篇
  2022年   4083篇
  2021年   6318篇
  2020年   5567篇
  2019年   5553篇
  2018年   5775篇
  2017年   6035篇
  2016年   6215篇
  2015年   7135篇
  2014年   10475篇
  2013年   11687篇
  2012年   10013篇
  2011年   11352篇
  2010年   9353篇
  2009年   9015篇
  2008年   9478篇
  2007年   9702篇
  2006年   8840篇
  2005年   8024篇
  2004年   7183篇
  2003年   6200篇
  2002年   5116篇
  2001年   4376篇
  2000年   3617篇
  1999年   3226篇
  1998年   3077篇
  1997年   2772篇
  1996年   2488篇
  1995年   2167篇
  1994年   1892篇
  1993年   1579篇
  1992年   1287篇
  1991年   1217篇
  1990年   944篇
  1989年   882篇
  1988年   824篇
  1987年   650篇
  1986年   608篇
  1985年   863篇
  1984年   773篇
  1983年   551篇
  1982年   593篇
  1981年   476篇
  1980年   391篇
  1979年   301篇
  1978年   208篇
  1977年   167篇
  1976年   134篇
  1975年   75篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
133.
According to the current World Health Organization (WHO), renal cell carcinomas (RCCs) that primarily affect adults are classified into 8 major subtypes. Additional emerging entities in renal neoplasia have also been recently recognized and these are discussed in further detail by Mehra et al (Emerging Entities in Renal Neoplasia, Surgical Pathology Clinics, 2015, Volume 8, Issue 4). In most cases, the diagnosis of a RCC subtype can be based on morphologic criteria, but in some circumstances the use of ancillary studies can aid in the diagnosis. This review discusses the morphologic, genetic, and molecular findings in RCCs previously recognized by the WHO, and provides clues to distinction from each other and some of the newer subtypes of RCC. As prognosis and therapeutic options vary for the different subtypes of RCC, accurate pathologic distinction is critical for patient care.  相似文献   
134.
An important part of fundamental research in catalysis is based on theoretical and modeling foundations which are closely connected with studies of single-crystalline catalyst surfaces. These so-called model catalysts are often prepared in the form of epitaxial thin films, and characterized using advanced material characterization techniques. This concept provides the fundamental understanding and the knowledge base needed to tailor the design of new heterogeneous catalysts with improved catalytic properties. The present contribution is devoted to development of a model catalyst system of CeO2 (ceria) on the Cu(111) substrate. We propose ways to experimentally characterize and control important parameters of the model catalyst—the coverage of the ceria layer, the influence of the Cu substrate, and the density of surface defects on ceria, particularly the density of step edges and the density and the ordering of the oxygen vacancies. The large spectrum of controlled parameters makes ceria on Cu(111) an interesting alternative to a more common model system ceria on Ru(0001) that has served numerous catalysis studies, mainly as a support for metal clusters.  相似文献   
135.
It has been suggested that tumour‐infiltrating lymphocytes (TILs) are associated with the progression of oral squamous cell carcinoma (OSCC). However, the prognostic value of TILs is inconclusive due to the heterogeneity of immune cells within the tumour microenvironment. In this meta‐analysis, we aimed to assess the prognostic value of TILs in OSCC. The PubMed, Cochrane, Embase, Scopus and Web of Science databases were searched up to April 20, 2019, and 33 studies were ultimately included in this meta‐analysis. Our pooled meta‐analysis showed that high infiltration of CD8+ TILs, CD45RO+ TILs and CD57+ TILs favoured better overall survival (OS). However, high infiltration of CD68+ macrophages and CD163+ macrophages was associated with poor prognosis in OSCC. These findings suggest that CD8+ TILs, CD45RO+ TILs, CD57+ TILs, CD68+ macrophages and CD163+ macrophages might serve as novel prognostic factors and therapeutic targets in OSCC.  相似文献   
136.
137.
皮肤鳞状细胞癌(cSCC)是角质形成细胞来源的恶性肿瘤之一。转录组是特定条件下细胞内全部转录产物的总和,包括编码mRNA和非编码RNA。研究发现,与正常细胞相比,鳞癌细胞在基因转录水平和模式上存在很大差异,具有不同转录表达谱。微小RNA(miRNA)可通过抑制转录产物的翻译,从而调控靶基因的表达,影响cSCC细胞的增殖、分化和凋亡等病理过程。越来越多的研究表明,miRNAs作为cSCC诊断、预测预后和治疗靶点的生物标志物,在临床上具有广阔的应用前景。本文通过回顾分析cSCC的miRNA表达谱,主要对其中经实验证实表达上调和下调的miRNAs在cSCC中的研究进展作一综述。  相似文献   
138.
Pulmonary immune-related adverse events represent rare but potentially severe side effects of immunotherapies. Diagnosis is often challenging, as symptoms and imaging features are not specific and may mimic other lung diseases, thus potentially delaying appropriate patient management. In this setting, an accurate imaging evaluation is essential for a prompt detection and correct management of these drug-induced lung diseases. The purpose of this article is to review the different types of pulmonary immune-related adverse events, describe their imaging characteristics on both high-resolution computed tomography and positron emission tomography/computed tomography and stress their underlying diagnostic challenge by presenting the mimickers.  相似文献   
139.
The first observations of altered metabolism in malignant cells were made nearly 100 years ago and therapeutic strategies targeting cell metabolism have been in clinical use for several decades.  In this review, we summarize our current understanding of cell metabolism dysregulation in childhood acute lymphoblastic leukemia (cALL). Reprogramming of cellular bioenergetic processes can be expected in the three distinct stages of cALL: at diagnosis, during standard chemotherapy, and in cases of relapse. Upregulation of glycolysis, dependency on anaplerotic energy sources, and activation of the electron transport chain have all been observed in cALL. While the current treatment strategies are tackling some of these aberrations, cALL cells are likely to be able to rewire their metabolism in order to escape therapy, which may contribute to a refractory disease and relapse. Finally, here we focus on novel therapeutic approaches emerging from our evolving understanding of the alterations of different metabolic networks in lymphoblasts.  相似文献   
140.
We report the case of a littoral‐cell angioma of the spleen, a recently described benign vascular tumour, whose imaging and pathological characteristics have been discussed only by a few authors. The diagnosis was made after elective splenectomy. The CT images, scintigraphy and histological specimens are presented, and differential diagnoses discussed.  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