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   9469篇
  免费   514篇
  国内免费   35篇
耳鼻咽喉   110篇
儿科学   226篇
妇产科学   116篇
基础医学   1280篇
口腔科学   175篇
临床医学   617篇
内科学   2220篇
皮肤病学   211篇
神经病学   1261篇
特种医学   203篇
外科学   1334篇
综合类   56篇
一般理论   1篇
预防医学   243篇
眼科学   256篇
药学   814篇
中国医学   98篇
肿瘤学   797篇
  2023年   61篇
  2022年   60篇
  2021年   169篇
  2020年   99篇
  2019年   135篇
  2018年   180篇
  2017年   135篇
  2016年   167篇
  2015年   174篇
  2014年   216篇
  2013年   278篇
  2012年   432篇
  2011年   505篇
  2010年   267篇
  2009年   286篇
  2008年   484篇
  2007年   545篇
  2006年   533篇
  2005年   527篇
  2004年   500篇
  2003年   473篇
  2002年   453篇
  2001年   245篇
  2000年   272篇
  1999年   240篇
  1998年   108篇
  1997年   102篇
  1996年   60篇
  1995年   53篇
  1994年   61篇
  1993年   50篇
  1992年   145篇
  1991年   148篇
  1990年   163篇
  1989年   171篇
  1988年   149篇
  1987年   154篇
  1986年   172篇
  1985年   155篇
  1984年   95篇
  1983年   80篇
  1982年   51篇
  1980年   41篇
  1979年   75篇
  1978年   46篇
  1977年   42篇
  1972年   52篇
  1971年   46篇
  1969年   50篇
  1968年   39篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
International Journal of Clinical Oncology - The practice of cancer diagnosis disclosure to children has been changed with the times. The regulations of clinical trials in the 2000s might change...  相似文献   
2.
3.
4.

Purpose

Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.

Methods and Materials

First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation.

Results

The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction.

Conclusions

The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target.  相似文献   
5.
6.
7.
8.
9.
10.
The Carpentier-Edwards pericardial bioprosthesis has been markedly improved in the long-term results and valve-related complications including valve dysfunction, compared to the previous generation bioprosthesis. We report a patient in whom transient prosthetic valve regurgitation and hemolysis occurred early after mitral valve replacement using a Carpentier-Edwards pericardial bioprosthesis and were resolved by preservative therapy. The patient was a 77-year-old female diagnosed with severe mitral valve stenosis and insufficiency. She underwent mitral valve replacement with a Carpentier-Edwards pericardial bioprosthesis. Opening and closing of the three leaflets looked good on intraoperative transesophageal echocardiography (TEE). The only prosthetic valve regurgitation was evident at the central region where the leaflets form coaptation, and no abnormal findings were seen. Serum lactate dehydrogenase (LDH) was decreased to 405 U/l after surgery. However, LDH again began to increase on the 3rd day after surgery and it increased to 1,830 U/l on the 14th day after surgery. Hemolytic urine was detected on 10th day after surgery. PVL was not detected, but moderate abnormal regurgitation from the outside of the stent pocket was detected on TEE. Revision of valve replacement was considered, but LDH thereafter to 393 U/l on 41st day after surgery. The TEE was repeated, and only a trace of central jet was detected without abnormal regurgitation, unlike the previous examination. The patient did not develop any complications thereafter and was discharged on 47th day after surgery. LDH was nearly normal at the time of discharge.  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