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   16686篇
  免费   778篇
  国内免费   75篇
耳鼻咽喉   100篇
儿科学   206篇
妇产科学   166篇
基础医学   2004篇
口腔科学   375篇
临床医学   1058篇
内科学   3795篇
皮肤病学   1120篇
神经病学   1659篇
特种医学   688篇
外科学   2729篇
综合类   97篇
预防医学   459篇
眼科学   168篇
药学   1590篇
中国医学   37篇
肿瘤学   1288篇
  2022年   96篇
  2021年   244篇
  2020年   140篇
  2019年   177篇
  2018年   244篇
  2017年   190篇
  2016年   272篇
  2015年   278篇
  2014年   373篇
  2013年   417篇
  2012年   659篇
  2011年   686篇
  2010年   396篇
  2009年   344篇
  2008年   684篇
  2007年   738篇
  2006年   728篇
  2005年   749篇
  2004年   776篇
  2003年   786篇
  2002年   734篇
  2001年   606篇
  2000年   663篇
  1999年   637篇
  1998年   281篇
  1997年   183篇
  1996年   177篇
  1995年   169篇
  1994年   144篇
  1993年   126篇
  1992年   460篇
  1991年   402篇
  1990年   409篇
  1989年   432篇
  1988年   405篇
  1987年   374篇
  1986年   319篇
  1985年   289篇
  1984年   174篇
  1983年   157篇
  1982年   93篇
  1979年   167篇
  1978年   80篇
  1977年   85篇
  1975年   70篇
  1974年   73篇
  1973年   81篇
  1972年   84篇
  1970年   74篇
  1969年   69篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.

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   
3.
4.
5.
6.
neurogenetics - Mediator (MED) is a key regulator of protein-coding gene expression, and mutations in MED subunits are associated with a broad spectrum of diseases. Because mutations in MED17...  相似文献   
7.
We report a 53-year-old woman with severe Graves' ophthalmopathy accompanied by uncontrolled myasthenia gravis. She presented remarkable exophthalmos, chemosis, and restriction of eye movement. Despite plasma exchange, steroid pulse therapy, local injection of steroid, and irradiation, ocular symptoms did not ameliorate. Since optic neuropathy was seen, orbital decompression surgery was performed in the left eye. Bilateral chemosis was improved after the surgery. Five years after surgery, there was no ocular palsy in the operated left eye, but in the contralateral eye. For the good prognosis of the eye movement, orbital decompression might be recommended in the severe Graves' ophthalmopathy accompanied by the optic neuropathy and/or ophthalmoplegia with proptosis.  相似文献   
8.
9.
A nationwide survey of transient hyperammonemia in newborns was carried out in Japan. A total of 18 patients, consisting of 12 male and 6 female infants, were reported from 11 facilities. These neonates exhibited hyperammonemia with plasma ammonia levels in the range from 124 to 6256 micrograms/dl. Four newborn infants of the 18 died in the neonatal period, and an additional one died in the early infancy. Among the 13 infants who were alive at the time of this survey, 6 had neurological sequelae, including mental retardation, spastic quadriplegia and epilepsy. The multivariate analysis revealed that the Apgar score at 1 minute, peak plasma ammonia concentration, birth weight and sex were significant factors affecting the prognosis of life.  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