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   2713篇
  免费   136篇
  国内免费   20篇
耳鼻咽喉   23篇
儿科学   77篇
妇产科学   82篇
基础医学   358篇
口腔科学   62篇
临床医学   235篇
内科学   593篇
皮肤病学   56篇
神经病学   300篇
特种医学   18篇
外科学   300篇
综合类   14篇
一般理论   1篇
预防医学   226篇
眼科学   161篇
药学   164篇
中国医学   12篇
肿瘤学   187篇
  2024年   2篇
  2023年   21篇
  2022年   60篇
  2021年   115篇
  2020年   58篇
  2019年   82篇
  2018年   111篇
  2017年   66篇
  2016年   60篇
  2015年   72篇
  2014年   115篇
  2013年   128篇
  2012年   215篇
  2011年   244篇
  2010年   157篇
  2009年   92篇
  2008年   144篇
  2007年   178篇
  2006年   145篇
  2005年   174篇
  2004年   158篇
  2003年   144篇
  2002年   136篇
  2001年   9篇
  2000年   12篇
  1999年   22篇
  1998年   25篇
  1997年   10篇
  1996年   19篇
  1995年   8篇
  1994年   7篇
  1993年   9篇
  1992年   7篇
  1991年   8篇
  1990年   10篇
  1989年   3篇
  1988年   4篇
  1987年   4篇
  1985年   5篇
  1984年   2篇
  1983年   6篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1978年   3篇
  1977年   2篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1963年   2篇
排序方式: 共有2869条查询结果,搜索用时 46 毫秒
31.
32.
33.
Hydatidosis is a parasitic infection caused by the tapeworm larva of Echinococcus spp. Its relevance lies in its wide distribution, great number of clinical cases and outstanding morbility. Hydatid infection of the orbit comprises far less than 1% of the total incidence. This is a case of a patient from Argentina complaining of a two-week evolution proptosis of the right eye. A microscopic examination revealed the presence of protoscolices of Echinococcus spp. in the fluid obtained during the surgical proceedings. The patient was treated with oral albendazole. To our knowledge, this is the first case of occular hydatidosis diagnosed in the city of Buenos Aires, Argentina.  相似文献   
34.
35.
36.
Over the last decade, the use of portable ultrasound scanners has enhanced the concept of point of care ultrasound (PoC-US), namely, “ultrasound performed at the bedside and interpreted directly by the treating clinician.” PoC-US is not a replacement for comprehensive ultrasound, but rather allows physicians immediate access to clinical imaging for rapid and direct solutions. PoC-US has already revolutionized everyday clinical practice, and it is believed that it will dramatically change how ultrasound is applied in daily practice. However, its use and teaching are different from continent to continent and from country to country. This World Federation for Ultrasound in Medicine and Biology position paper discusses the current status and future perspectives of PoC-US. Particular attention is given to the different uses of PoC-US and its clinical significance, including within emergency and critical care medicine, cardiology, anesthesiology, rheumatology, obstetrics, neonatology, gynecology, gastroenterology and many other applications. In the future, PoC-US will be more diverse than ever and be included in medical student training.  相似文献   
37.
Graefe's Archive for Clinical and Experimental Ophthalmology - The purpose of this study is to share our experience on the use of different orbital decompression techniques, as well as the...  相似文献   
38.
Retrospective electrocardiogram‐gated, 2D phase‐contrast (PC) flow MRI is routinely used in clinical evaluation of valvular/vascular disease in pediatric patients with congenital heart disease (CHD). In patients not requiring general anesthesia, clinical standard PC is conducted with free breathing for several minutes per slice with averaging. In younger patients under general anesthesia, clinical standard PC is conducted with breath‐holding. One approach to overcome this limitation is using either navigator gating or self‐navigation of respiratory motion, at the expense of lengthening scan times. An alternative approach is using highly accelerated, free‐breathing, real‐time PC (rt‐PC) MRI, which to date has not been evaluated in CHD patients. The purpose of this study was to develop a 38.4‐fold accelerated 2D rt‐PC pulse sequence using radial k‐space sampling and compressed sensing with 1.5 × 1.5 × 6.0 mm3 nominal spatial resolution and 40 ms nominal temporal resolution, and evaluate whether it is capable of accurately measuring flow in 17 pediatric patients (aortic valve, pulmonary valve, right and left pulmonary arteries) compared with clinical standard 2D PC (either breath‐hold or free breathing). For clinical translation, we implemented an integrated reconstruction pipeline capable of producing DICOMs of the order of 2 min per time series (46 frames). In terms of association, forward volume, backward volume, regurgitant fraction, and peak velocity at peak systole measured with standard PC and rt‐PC were strongly correlated (R2 > 0.76; P < 0.001). Compared with clinical standard PC, in terms of agreement, forward volume (mean difference = 1.4% (3.0% of mean)) and regurgitant fraction (mean difference = ?2.5%) were in good agreement, whereas backward volume (mean difference = ?1.1 mL (28.2% of mean)) and peak‐velocity at peak systole (mean difference = ?21.3 cm/s (17.2% of mean)) were underestimated by rt‐PC. This study demonstrates that the proposed rt‐PC with the said spatial resolution and temporal resolution produces relatively accurate forward volumes and regurgitant fractions but underestimates backward volumes and peak velocities at peak systole in pediatric patients with CHD.  相似文献   
39.
The aim of this study was to characterize the in vivo volumetric distribution of three folate-based biosensors by different imaging modalities (X-ray, fluorescence, Cerenkov luminescence, and radioisotopic imaging) through the development of a tridimensional image reconstruction algorithm. The preclinical and multimodal Xtreme imaging system, with a Multimodal Animal Rotation System (MARS), was used to acquire bidimensional images, which were processed to obtain the tridimensional reconstruction. Images of mice at different times (biosensor distribution) were simultaneously obtained from the four imaging modalities. The filtered back projection and inverse Radon transformation were used as main image-processing techniques. The algorithm developed in Matlab was able to calculate the volumetric profiles of 99mTc-Folate-Bombesin (radioisotopic image), 177Lu-Folate-Bombesin (Cerenkov image), and FolateRSense? 680 (fluorescence image) in tumors and kidneys of mice, and no significant differences were detected in the volumetric quantifications among measurement techniques. The imaging tridimensional reconstruction algorithm can be easily extrapolated to different 2D acquisition-type images. This characteristic flexibility of the algorithm developed in this study is a remarkable advantage in comparison to similar reconstruction methods.  相似文献   
40.
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