全文获取类型
收费全文 | 20229篇 |
免费 | 1674篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 181篇 |
儿科学 | 658篇 |
妇产科学 | 412篇 |
基础医学 | 2935篇 |
口腔科学 | 263篇 |
临床医学 | 2630篇 |
内科学 | 3583篇 |
皮肤病学 | 275篇 |
神经病学 | 2264篇 |
特种医学 | 424篇 |
外科学 | 2137篇 |
综合类 | 364篇 |
一般理论 | 26篇 |
预防医学 | 2420篇 |
眼科学 | 383篇 |
药学 | 1464篇 |
中国医学 | 23篇 |
肿瘤学 | 1503篇 |
出版年
2023年 | 141篇 |
2022年 | 221篇 |
2021年 | 497篇 |
2020年 | 270篇 |
2019年 | 441篇 |
2018年 | 474篇 |
2017年 | 350篇 |
2016年 | 350篇 |
2015年 | 433篇 |
2014年 | 571篇 |
2013年 | 904篇 |
2012年 | 1341篇 |
2011年 | 1326篇 |
2010年 | 690篇 |
2009年 | 643篇 |
2008年 | 1074篇 |
2007年 | 1182篇 |
2006年 | 1081篇 |
2005年 | 1041篇 |
2004年 | 999篇 |
2003年 | 908篇 |
2002年 | 893篇 |
2001年 | 326篇 |
2000年 | 334篇 |
1999年 | 296篇 |
1998年 | 229篇 |
1997年 | 186篇 |
1996年 | 172篇 |
1995年 | 141篇 |
1994年 | 130篇 |
1993年 | 127篇 |
1992年 | 255篇 |
1991年 | 270篇 |
1990年 | 254篇 |
1989年 | 256篇 |
1988年 | 260篇 |
1987年 | 231篇 |
1986年 | 229篇 |
1985年 | 167篇 |
1984年 | 176篇 |
1983年 | 151篇 |
1982年 | 135篇 |
1981年 | 135篇 |
1980年 | 112篇 |
1979年 | 137篇 |
1978年 | 110篇 |
1976年 | 99篇 |
1975年 | 100篇 |
1974年 | 140篇 |
1973年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Olga A. Klein Avril Drummond Jacqueline R. Mhizha-Murira Laura Mansford Roshan dasNair 《Neuropsychological rehabilitation》2019,29(4):491-512
While previous randomised controlled trials and meta-analyses offer only limited evidence for the effectiveness of cognitive rehabilitation, qualitative studies examining patient perspectives report more positive outcomes. This meta-synthesis of qualitative studies examined patient perspectives of cognitive rehabilitation for memory, attention, and executive function problems in people with multiple sclerosis. Using set eligibility criteria, we screened electronic databases, reference lists, and academic networks for relevant papers. Seven papers (195 participants) were selected. Two independent researchers conducted quality appraisals of papers. Data analysis, guided by the thematic synthesis approach, yielded six main themes. These suggested that patients benefitted from the group environment in rehabilitation. Cognitive rehabilitation facilitated the participants’ reflection and awareness of their cognitive deficits, and was associated with increased knowledge and understanding of their illness. Increased strategy use was reported and associated with improvements in cognitive functioning and greater confidence and perseverance. Participants reported emotional and social improvements, and felt more optimistic. Overall, these changes had a positive impact on participants’ quality of life. This synthesis of qualitative studies indicates that people with multiple sclerosis who experience cognitive deficits benefit from cognitive rehabilitation programmes. This finding must, however, be viewed in light of the limitations of this meta-synthesis. The meta-synthesis was registered in the PROSPERO database under CRD42017040148. 相似文献
3.
4.
5.
Thomas Asendorf Robin Henderson Heinz Schmidli Tim Friede 《Statistics in medicine》2019,38(9):1503-1528
In some diseases, such as multiple sclerosis, lesion counts obtained from magnetic resonance imaging (MRI) are used as markers of disease progression. This leads to longitudinal, and typically overdispersed, count data outcomes in clinical trials. Models for such data invariably include a number of nuisance parameters, which can be difficult to specify at the planning stage, leading to considerable uncertainty in sample size specification. Consequently, blinded sample size re-estimation procedures are used, allowing for an adjustment of the sample size within an ongoing trial by estimating relevant nuisance parameters at an interim point, without compromising trial integrity. To date, the methods available for re-estimation have required an assumption that the mean count is time-constant within patients. We propose a new modeling approach that maintains the advantages of established procedures but allows for general underlying and treatment-specific time trends in the mean response. A simulation study is conducted to assess the effectiveness of blinded sample size re-estimation methods over fixed designs. Sample sizes attained through blinded sample size re-estimation procedures are shown to maintain the desired study power without inflating the Type I error rate and the procedure is demonstrated on MRI data from a recent study in multiple sclerosis. 相似文献
6.
Sarah E. Henderson Shana A. Hall Jessica M. Callegari James A. Desjardins Sidney J. Segalowitz Karen L. Campbell 《Psychophysiology》2022,59(1):e13947
Recent work suggests that while voluntary episodic memory declines with age, involuntary episodic memory, which comes to mind spontaneously without intention, remains relatively intact. However, the neurophysiology underlying these differences has yet to be established. The current study used electroencephalography (EEG) to investigate voluntary and involuntary retrieval in older and younger adults. Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization cover task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later reported which sounds brought the paired picture to mind during the localization task. Reaction times on the localization task were slower for voluntary than involuntary retrieval and for paired than unpaired sounds, possibly reflecting increased attentional demands of voluntary retrieval and interference from reactivation of the associated pictures respectively. For the EEG analyses, young adults showed greater alpha event-related desynchronization (ERD) during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD regardless of intention. Additionally, older adults showed greater ERD for paired than unpaired sounds at occipital sites, likely reflecting visual reactivation of the associated pictures. Young adults did not show this alpha ERD memory effect. Taken together, these data suggest that involuntary memory is largely preserved with age, but this may be due to older adults' greater recruitment of top-down control even when demand for such control is limited. 相似文献
7.
van der Heijden Amber A. W. A. de Bruijne Martine C. Nijpels Giel Hugtenburg Jacqueline G. 《International journal of clinical pharmacy》2019,41(4):963-971
International Journal of Clinical Pharmacy - Background Drug-related problems (DRP) following hospital discharge may cause morbidity, mortality and hospital re-admissions. It is unclear whether a... 相似文献
8.
9.
10.