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   251312篇
  免费   21835篇
  国内免费   854篇
耳鼻咽喉   2673篇
儿科学   6572篇
妇产科学   6425篇
基础医学   30411篇
口腔科学   4992篇
临床医学   37279篇
内科学   51240篇
皮肤病学   3738篇
神经病学   23132篇
特种医学   8209篇
外国民族医学   15篇
外科学   37184篇
综合类   3667篇
现状与发展   2篇
一般理论   296篇
预防医学   22321篇
眼科学   4822篇
药学   15878篇
  1篇
中国医学   409篇
肿瘤学   14735篇
  2023年   1734篇
  2022年   1585篇
  2021年   3963篇
  2020年   2914篇
  2019年   3830篇
  2018年   5603篇
  2017年   4976篇
  2016年   5313篇
  2015年   6089篇
  2014年   8156篇
  2013年   11453篇
  2012年   15023篇
  2011年   16504篇
  2010年   9860篇
  2009年   9234篇
  2008年   15419篇
  2007年   16249篇
  2006年   15687篇
  2005年   15977篇
  2004年   15306篇
  2003年   14258篇
  2002年   13688篇
  2001年   2910篇
  2000年   2254篇
  1999年   3002篇
  1998年   3594篇
  1997年   3300篇
  1996年   2995篇
  1995年   2655篇
  1994年   2315篇
  1993年   2104篇
  1992年   1714篇
  1991年   1678篇
  1990年   1512篇
  1989年   1378篇
  1988年   1365篇
  1987年   1355篇
  1986年   1328篇
  1985年   1448篇
  1984年   1715篇
  1983年   1700篇
  1982年   1990篇
  1981年   1823篇
  1980年   1684篇
  1979年   1014篇
  1978年   1121篇
  1977年   1099篇
  1976年   986篇
  1975年   844篇
  1974年   811篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Central post stroke pain is often difficult to manage satisfactorily with conventional treatment modalities for pain. In the last decade functional neurosurgery has offered hope with motor cortex stimulation achieving significant alleviation of pain in some patients. Unfortunately this has led to the neglect of chronic stimulation of deep grey matter as another modality of treating this condition. In this article we present our experience with motor cortex stimulation and that with deep grey matter stimulation in patients with post stroke pain. We argue that both modalities have a significant role and that what is required are better methods of identifying particular patients who are more likely to respond to one or the other.  相似文献   
42.
43.
44.
Seventy-four 8th- and 10th-grade students attending a private girls' school in Hawaii were queried about their perceptions of and preparation for menstruation using a questionnaire administered in a health education class. Eighty percent had already started menstruating. The most frequently cited perceptions by the respondents referred to both the inconveniences and the normalcy of menstruation. Many were first informed about menstruation by their mothers and stated that they also first informed their mothers when they started menstruating. Surprise, fear, and embarrassment were common initial reactions, while strong negative or positive emotions were more rare. Only 35% wanted boys and girls together during class discussion, but 89% stated that boys needed to be informed about menstruation. The most frequent reasons cited for noncoed settings were the girls' concern about their comfort in openly discussing menstruation. Thirty-eight percent thought parents should inform other siblings when they started menstruation, although almost half gave specific conditions the parents should consider. The majority thought the fifth to sixth grades were the best times to introduce menstruation content.  相似文献   
45.
46.
47.
48.
49.
Advance directives such as living wills are attractive in that they give us a sense of control over our futures. But they also tend to obscure conflicts between a patient's competent wishes and later, incompetent interests. They allow caregivers to avoid evaluating quality of life in assessing the best interests of incompetent patients.  相似文献   
50.
Reactive oxygen species: a breath of life or death?   总被引:7,自引:0,他引:7  
New insights into cancer cell-specific biological pathways are urgently needed to promote development of rationally targeted therapeutics. Reactive oxygen species (ROS) and their role in cancer cell response to growth factor signaling and hypoxia are emerging as verdant areas of exploration on the road to discovering cancer's Achilles heel. One of the distinguishing and near-universal hallmarks of cancer growth is hypoxia. Unregulated cellular proliferation leads to formation of cellular masses that extend beyond the resting vasculature, resulting in oxygen and nutrient deprivation. The resulting hypoxia triggers a number of critical adaptations that enable cancer cell survival, including apoptosis suppression, altered glucose metabolism, and an angiogenic phenotype. Ironically, recent investigations suggest that oxygen depletion stimulates mitochondria to elaborate increased ROS, with subsequent activation of signaling pathways, such as hypoxia inducible factor 1alpha, that promote cancer cell survival and tumor growth. Because mitochondria are key organelles involved in chemotherapy-induced apoptosis induction, the relationship between mitochondria, ROS signaling, and activation of survival pathways under hypoxic conditions has been the subject of increased study. Insights into mechanisms involved in ROS signaling may offer novel avenues to facilitate discovery of cancer-specific therapies. Preclinical and clinical evaluation of agents that modify ROS signaling in cancer offers a novel avenue for intervention. This review will cover recent work in ROS-mediated signaling in cancer cells and its potential as a target for developmental therapeutics.  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