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   1673篇
  免费   75篇
  国内免费   15篇
耳鼻咽喉   18篇
儿科学   30篇
妇产科学   23篇
基础医学   152篇
口腔科学   42篇
临床医学   107篇
内科学   547篇
皮肤病学   10篇
神经病学   123篇
特种医学   97篇
外科学   263篇
综合类   14篇
一般理论   6篇
预防医学   64篇
眼科学   37篇
药学   82篇
中国医学   5篇
肿瘤学   143篇
  2023年   17篇
  2022年   17篇
  2021年   50篇
  2020年   26篇
  2019年   42篇
  2018年   48篇
  2017年   32篇
  2016年   37篇
  2015年   33篇
  2014年   62篇
  2013年   82篇
  2012年   146篇
  2011年   150篇
  2010年   81篇
  2009年   78篇
  2008年   136篇
  2007年   161篇
  2006年   143篇
  2005年   118篇
  2004年   95篇
  2003年   70篇
  2002年   63篇
  2001年   9篇
  2000年   5篇
  1999年   8篇
  1998年   9篇
  1997年   6篇
  1996年   7篇
  1995年   7篇
  1994年   2篇
  1993年   4篇
  1992年   1篇
  1991年   1篇
  1988年   1篇
  1987年   2篇
  1986年   3篇
  1983年   1篇
  1980年   1篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1972年   1篇
  1971年   1篇
  1966年   1篇
  1956年   1篇
排序方式: 共有1763条查询结果,搜索用时 15 毫秒
21.
22.
23.
The purpose of this study was to evaluate the frequency of incidental findings (IFs) in emergency department (ED) imaging reports and evaluate the adherence of imaging recommendations to consensus societal guidelines for IFs. A retrospective review of consecutive ED computed tomography (CT) and ultrasonography (US) reports from two university-affiliated EDs over a 2-month period was performed. Each imaging report was reviewed in its entirety, and incidental findings were documented along with recommendations for additional imaging. Imaging recommendations were compared to published societal guidelines from the American College of Radiology (ACR) and Fleischner Society. Three thousand one hundred thirty-one total cases consisting of 1967 CTs and 1164 US contained 514 incidental findings (16.4 %), with 329 CT IFs (64 %) and 185 US IFs (36 %). The ovary was the most common organ for an IF (n?=?214, 42 %). Of all IFs, 347 (67.5 %) recommendations were concordant with societal guidelines and 167 (32.5 %) were discordant. 39.8 % of CT recommendations were discordant, while 19.5 % of US recommendations were discordant (p?<?0.0001). Incidental findings are commonly encountered in the emergent setting. Variable adherence to societal guidelines is noted. Targeted radiologist education and technological solutions may decrease rates of discordance.  相似文献   
24.
25.
Phosphorylation of the organic matrix proteins of dentin is important for the initiation of mineralization, but its relevance in later mineralization stages is controversial. The objective of this study was to analyze changes in the total matrix phosphate content during dentin development and to identify their origin. Amino acid and total matrix phosphate analyses of microdissected developing mantle and circumpulpal fetal bovine dentin specimens were performed. The amino acid composition showed few changes during mantle and circumpulpal dentin maturation. However, the total matrix phosphate content showed a significant, positive correlation with tissue maturation in both mantle and circumpulpal dentin, with a two- and a three-fold increase, respectively, being observed. The data indicate that changes occur in the pattern of phosphorylation of matrix proteins during dentin maturation, which we suggest may play a functional role in later stages of tooth mineralization.  相似文献   
26.
27.
28.

INTRODUCTION

Right ventricular (RV) rupture with mediastinitis, is a very rare but extremely dangerous (even fatal) complication, following CABG surgery.

PRESENTATION OF CASE

In this paper, we present the case of a post-trauma (after fall) RV rupture (without mediastinitis) in a patient who had undergone cardiac surgery several days ago. The cause of the rupture proved to be a broken bone piece from the lower sternal edge.

DISCUSSION

RV rupture post-operatively caused by broken bone pieces or bone dislocation may occur through two mechanisms: either penetration of the RV, or through the “sandpaper effect”. In order to prevent the rupture, we should be able to recognize patients with aggravating factors (age, weight) and choose intra-operatively a suitable closure technique.

CONCLUSION

We propose that the technique that could prevent such ruptures is the Robicsek technique.  相似文献   
29.
30.
Carbon nanotubes (CNTs) exhibit unique properties which have led to their applications in the biomedical field as novel delivery systems for diagnosis and therapy purposes. We have previously reported that the degree of functionalization of CNTs is a key factor determining their biological behaviour. The present study broadens the spectrum by investigating the impact of the diameter of CNTs using two series of multi-walled CNTs (MWNTs) with distinct differences in their diameters. Both MWNTs were doubly functionalized by 1,3-dipolar cycloaddition and amidation reactions, allowing the appended functional groups to be further conjugated with radionuclide chelating moieties and antibodies or antibody fragments. All constructs possessed comparable degree of functionalization and were characterized by thermogravimetric analysis, transmission electron microscopy, gel electrophoresis and surface plasmon resonance. The MWNT conjugates were radio-labelled with indium-111, which thereby enabled in vivo single photon emission computed tomography/computed tomography (SPECT/CT) imaging and organ biodistribution study using γ-scintigraphy. The narrow MWNTs (average diameter: 9.2 nm) demonstrated enhanced tissue affinity including non-reticular endothelial tissues compared to the wider MWNTs (average diameter: 39.5 nm). The results indicate that the higher aspect ratio of narrow MWNTs may be beneficial for their future biological applications due to higher tissue accumulation.  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