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   1799704篇
  免费   132803篇
  国内免费   2991篇
耳鼻咽喉   26046篇
儿科学   55498篇
妇产科学   49839篇
基础医学   257317篇
口腔科学   52012篇
临床医学   159139篇
内科学   340568篇
皮肤病学   38716篇
神经病学   140839篇
特种医学   71941篇
外国民族医学   370篇
外科学   277303篇
综合类   43314篇
现状与发展   3篇
一般理论   507篇
预防医学   133349篇
眼科学   42382篇
药学   140560篇
  7篇
中国医学   4074篇
肿瘤学   101714篇
  2018年   17302篇
  2016年   15438篇
  2015年   17576篇
  2014年   24559篇
  2013年   36491篇
  2012年   49620篇
  2011年   52314篇
  2010年   30664篇
  2009年   28790篇
  2008年   48827篇
  2007年   52648篇
  2006年   53087篇
  2005年   51240篇
  2004年   49661篇
  2003年   47681篇
  2002年   46069篇
  2001年   86855篇
  2000年   88958篇
  1999年   74729篇
  1998年   20065篇
  1997年   18035篇
  1996年   17968篇
  1995年   16916篇
  1994年   15753篇
  1993年   14906篇
  1992年   59296篇
  1991年   57503篇
  1990年   56513篇
  1989年   54575篇
  1988年   50129篇
  1987年   49075篇
  1986年   46420篇
  1985年   44244篇
  1984年   32986篇
  1983年   28161篇
  1982年   16559篇
  1981年   14795篇
  1979年   31508篇
  1978年   21977篇
  1977年   19140篇
  1976年   17047篇
  1975年   19011篇
  1974年   22882篇
  1973年   22000篇
  1972年   21007篇
  1971年   19641篇
  1970年   18417篇
  1969年   17897篇
  1968年   16005篇
  1967年   14545篇
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
21.
22.
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   
23.
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   
24.
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   
25.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
26.
27.
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   
28.
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