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   32103篇
  免费   1725篇
  国内免费   215篇
耳鼻咽喉   279篇
儿科学   492篇
妇产科学   599篇
基础医学   4099篇
口腔科学   728篇
临床医学   2000篇
内科学   8268篇
皮肤病学   563篇
神经病学   2382篇
特种医学   1239篇
外科学   5741篇
综合类   156篇
一般理论   1篇
预防医学   903篇
眼科学   676篇
药学   2153篇
中国医学   95篇
肿瘤学   3669篇
  2023年   177篇
  2022年   311篇
  2021年   671篇
  2020年   450篇
  2019年   529篇
  2018年   659篇
  2017年   529篇
  2016年   666篇
  2015年   714篇
  2014年   933篇
  2013年   1097篇
  2012年   1758篇
  2011年   1874篇
  2010年   1023篇
  2009年   868篇
  2008年   1580篇
  2007年   1684篇
  2006年   1626篇
  2005年   1666篇
  2004年   1692篇
  2003年   1582篇
  2002年   1523篇
  2001年   929篇
  2000年   973篇
  1999年   907篇
  1998年   416篇
  1997年   336篇
  1996年   293篇
  1995年   248篇
  1994年   220篇
  1993年   209篇
  1992年   590篇
  1991年   497篇
  1990年   513篇
  1989年   511篇
  1988年   452篇
  1987年   371篇
  1986年   369篇
  1985年   371篇
  1984年   268篇
  1983年   195篇
  1982年   103篇
  1979年   170篇
  1978年   135篇
  1977年   128篇
  1974年   93篇
  1972年   95篇
  1971年   97篇
  1968年   98篇
  1967年   96篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Background: Gait disorders are common in Parkinson’s disease patients who respond poorly to dopaminergic treatment. Blockade of adenosine A2A receptors is expected to improve gait disorders. Istradefylline is a first-in-class selective adenosine A2A receptor antagonist with benefits for motor complications associated with Parkinson’s disease.

Research design and methods: This multicenter, open-label, single-group, prospective interventional study evaluated changes in total gait-related scores of the Part II/III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Freezing of Gait Questionnaire (FOG-Q) in 31 Parkinson’s disease patients treated with istradefylline. Gait analysis by portable gait rhythmogram was performed.

Results: MDS-UPDRS Part III gait-related total scores significantly decreased at Weeks 4–12 from baseline with significant improvements in gait, freezing of gait, and postural stability. Significant decreases in MDS-UPDRS Part II total scores and individual item scores at Week 12 indicated improved daily living activities. At Week 12, there were significant improvements in FOG-Q, new FOG-Q, and overall movement per 48 h measured by portable gait rhythmogram. Adverse events occurred in 7/31 patients.

Conclusions: Istradefylline improved gait disorders in Parkinson’s disease patients complicated with freezing of gait, improving their quality of life. No unexpected adverse drug reactions were identified.

Trial registration: UMIN-CTR (UMIN000020288).  相似文献   

2.
3.
4.
5.

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   
6.
7.
8.
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.  相似文献   
9.

Background

There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).

Methods

Patients with AEG and UGC who were judged as non-sarcopenic before surgery were reassessed the presence of postoperative development of sarcopenia 6 months after surgery. Patients were divided into the development group or non-development group, and clinicopathological factors and prognosis between these two groups were analyzed.

Results

The 5-year overall survival rates were significantly poorer in the development group than non-development group (68.0% vs. 92.6%, P?=?0.0118). Multivariate analyses showed that postoperative development of sarcopenia was an independent prognostic factor for poor overall survival (P?=?0.0237).

Conclusions

Postoperative development of sarcopenia was associated with a poor prognosis in patients with AEG and UGC.  相似文献   
10.
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