全文获取类型
收费全文 | 1559篇 |
免费 | 138篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 38篇 |
妇产科学 | 17篇 |
基础医学 | 281篇 |
口腔科学 | 13篇 |
临床医学 | 323篇 |
内科学 | 275篇 |
皮肤病学 | 15篇 |
神经病学 | 186篇 |
特种医学 | 13篇 |
外科学 | 168篇 |
综合类 | 26篇 |
一般理论 | 7篇 |
预防医学 | 142篇 |
眼科学 | 25篇 |
药学 | 72篇 |
中国医学 | 3篇 |
肿瘤学 | 89篇 |
出版年
2023年 | 8篇 |
2022年 | 19篇 |
2021年 | 22篇 |
2020年 | 21篇 |
2019年 | 36篇 |
2018年 | 44篇 |
2017年 | 35篇 |
2016年 | 32篇 |
2015年 | 45篇 |
2014年 | 54篇 |
2013年 | 66篇 |
2012年 | 100篇 |
2011年 | 107篇 |
2010年 | 73篇 |
2009年 | 54篇 |
2008年 | 92篇 |
2007年 | 94篇 |
2006年 | 88篇 |
2005年 | 95篇 |
2004年 | 123篇 |
2003年 | 106篇 |
2002年 | 89篇 |
2001年 | 13篇 |
2000年 | 17篇 |
1999年 | 14篇 |
1998年 | 21篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1973年 | 3篇 |
1968年 | 3篇 |
1964年 | 3篇 |
1963年 | 3篇 |
1960年 | 6篇 |
排序方式: 共有1702条查询结果,搜索用时 15 毫秒
11.
12.
13.
The use of medical records in research can yield information that is difficult to obtain by other means. When such records are released to investigators in identifiable form, however, substantial privacy and confidentiality risks may be created. These risks become more common and more serious as medical records move to an electronic format. In 1996, the state of Minnesota enacted legislation with respect to consent requirements for the use of medical records in research. This legislation has been widely criticized because--it is claimed--it creates an unnecessary impediment to research. In this article, we show that these arguments rest upon misinterpretation and/or misrepresentation of the 1996 legislation. A consent requirement had actually been present in Minnesota since 1976 (though codified in a patient rights statute rather than a privacy statute). The 1996 law does not require specific consent, as often claimed, but rather only a general authorization. The campaign against the Minnesota legislation appears to have been motivated by concern with respect to the then impending federal privacy rule. The HIPAA rule, as enacted, is in fact less stringent with respect to consent than the Minnesota consent law. On the other hand, the Minnesota consent law has not been effectively applied or enforced. As we change the way we manage sensitive medical information, new efforts are needed to provide protection against the confidentiality risks in research. Patient consent is an important tool in this regard. New instrumentalities are needed to solicit and document consent. 相似文献
14.
15.
Decline in episodic memory, the encoding and retrieval of autobiographical events, is a hallmark of normal cognitive aging. Although the primary causes of this decline remain elusive, event-related brain potential (ERP) studies have contributed to an understanding of age-related episodic memory failure. These data reveal that, although the retrieval-based episodic memory (EM) effect does not differ dramatically between young and older adults, the acquisition-related data suggest a decline in episodic encoding (i.e., semantic elaboration) with increasing age. We conclude that, at the current state of knowledge, encoding deficiencies are more important than retrieval deficits in understanding the causes of episodic memory decline in the older adult. 相似文献
16.
Olaf M Hoffmann Doreen Becker Joerg R Weber 《Journal of cerebral blood flow and metabolism》2007,27(11):1792-1797
Alterations of blood flow contribute to major clinical complications in invasive infections such as sepsis and bacterial meningitis. As a unique feature streptococci -- in particular, Streptococcus pneumoniae, the most frequent pathogen in bacterial meningitis -- release hydrogen peroxide (H(2)O(2)) because of the absence of functional catalase. In a 6 h rat model of experimental meningitis, we studied the impact of bacterial H(2)O(2) production on regional cerebral blood flow (rCBF) and intracranial pressure (ICP). Compared to wild-type D39 pneumococci, the increase of rCBF was diminished in meningitis induced by the H(2)O(2) defective SpxB(-) mutant (maximum increase, 135% +/- 17% versus 217% +/- 23% of the individual baseline; P<0.01) or after treatment of D39-induced meningitis with H(2)O(2)-degrading catalase or with tetraethylammonium (TEA), a blocker of calcium-sensitive potassium channels, which mediate H(2)O(2)-induced vasodilation. Catalase did not significantly reduce the remaining rCBF increase caused by SpxB(-), supporting the predominant role of bacterial H(2)O(2). We conclude that in addition to host-sided mediators, bacterial-derived H(2)O(2) acts as a potent vasodilator, which accounts for a certain proportion of the early cerebral hyperperfusion in pneumococcal meningitis. 相似文献
17.
Dewey Marc; Taubert Teodora; Hammerschmidt Robert; Dubel Hans-Peter 《European heart journal》2007,28(5):552
A 62-year-old man with typical angina pectoris was referredfor imaging of the coronary arteries to detect stenoses. Multislicecomputed tomography (CT) demonstrated significant 相似文献
18.
19.
20.