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   2559502篇
  免费   180405篇
  国内免费   5071篇
耳鼻咽喉   34965篇
儿科学   84114篇
妇产科学   69681篇
基础医学   365784篇
口腔科学   74368篇
临床医学   229973篇
内科学   489642篇
皮肤病学   59028篇
神经病学   200542篇
特种医学   99380篇
外国民族医学   460篇
外科学   388129篇
综合类   54700篇
现状与发展   5篇
一般理论   787篇
预防医学   185311篇
眼科学   60896篇
药学   193326篇
  13篇
中国医学   6417篇
肿瘤学   147457篇
  2021年   19168篇
  2019年   19887篇
  2018年   29549篇
  2017年   22825篇
  2016年   25788篇
  2015年   29184篇
  2014年   39351篇
  2013年   57583篇
  2012年   80057篇
  2011年   83850篇
  2010年   49676篇
  2009年   45969篇
  2008年   78003篇
  2007年   83595篇
  2006年   84227篇
  2005年   81075篇
  2004年   77916篇
  2003年   74600篇
  2002年   71889篇
  2001年   131044篇
  2000年   133944篇
  1999年   111380篇
  1998年   29362篇
  1997年   25651篇
  1996年   25493篇
  1995年   24306篇
  1994年   22210篇
  1993年   20737篇
  1992年   83334篇
  1991年   80402篇
  1990年   78175篇
  1989年   75028篇
  1988年   68154篇
  1987年   66463篇
  1986年   62798篇
  1985年   59517篇
  1984年   43651篇
  1983年   37141篇
  1982年   20960篇
  1979年   39028篇
  1978年   26908篇
  1977年   23360篇
  1976年   21219篇
  1975年   23194篇
  1974年   27630篇
  1973年   26601篇
  1972年   24898篇
  1971年   23269篇
  1970年   21489篇
  1969年   20328篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
21.
22.
23.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Heavy metal concentrations in surface soils of Reserved Forests (RFs) have a significant impact on...  相似文献   
24.
Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer-related mortality in the United States. Across the globe, people in the age group older than 50 are at a higher risk of CRC. Genetic and environmental risk factors play a significant role in the development of CRC. If detected early, CRC is preventable and treatable. Currently, available screening methods and therapies for CRC treatment reduce the incidence rate among the population, but the micrometastasis of cancer may lead to recurrence. Therefore, the challenge is to develop an alternative therapy to overcome this complication. Nanotechnology plays a vital role in cancer treatment and offers targeted chemotherapies directly and selectively to cancer cells, with enhanced therapeutic efficacy. Additionally, nanotechnology elevates the chances of patient survival in comparison to traditional chemotherapies. The potential of nanoparticles includes that they may be used simultaneously for diagnosis and treatment. These exciting properties of nanoparticles have enticed researchers worldwide to unveil their use in early CRC detection and as effective treatment. This review discusses contemporary methods of CRC screening and therapies for CRC treatment, while the primary focus is on the theranostic approach of nanotechnology in CRC treatment and its prospects. In addition, this review aims to provide knowledge on the advancement of nanotechnology in CRC and as a starting point for researchers to think about new therapeutic approaches using nanotechnology.  相似文献   
25.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
26.
27.
Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.  相似文献   
28.
ABSTRACT

Objective: Dry eye is reported to be associated with several neurological diseases. The aim of this study is to evaluate the patients with hemiplegia after stroke for dry eye and compare their results with a control group.

Materials and methods: Forty-five patients with hemiplegia and 45 individuals as the control group were included in the study. Tear function tests (Schirmer and tear breakup time) and a dry eye questionnaire for dry eye symptoms (ocular surface disease index) were performed and the results of the two groups were compared.

Results: Schirmer test results were significantly lower in the post-stroke hemiplegia group compared to the control group (11.3 ± 8.2 mm and 20.6 ± 11.6 mm, respectively, p < .001). Tear breakup time results were significantly lower in the post-stroke hemiplegia group compared to the control group (7.9 ± 3.1 s and 12.1 ± 4.3 s, respectively, p < .001). Ocular surface disease index scores were not significantly different between hemiplegia and control groups (21.6 ± 20.0 and 19.8 ± 13.9, respectively, p = .635). Schirmer scores lower than 10 mm (60% and 30%, p < .001) and tear breakup time results lower than 10 s (65.6% and 28.9%, p < .001) were also higher in the hemiplegia group compared to control group.

Conclusion: We found lower Schirmer test and tear breakup time results and similar OSDI scores in hemiplegia patients compared to controls. Hemiplegia patients may have dry eye without typical symptoms. This should be taken into consideration in the follow-up and rehabilitation of post-stroke hemiplegia patients.  相似文献   
29.
30.
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