全文获取类型
收费全文 | 26630篇 |
免费 | 2744篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 326篇 |
儿科学 | 789篇 |
妇产科学 | 519篇 |
基础医学 | 3550篇 |
口腔科学 | 540篇 |
临床医学 | 3151篇 |
内科学 | 4611篇 |
皮肤病学 | 252篇 |
神经病学 | 2886篇 |
特种医学 | 919篇 |
外科学 | 4210篇 |
综合类 | 674篇 |
一般理论 | 5篇 |
预防医学 | 2972篇 |
眼科学 | 521篇 |
药学 | 1675篇 |
中国医学 | 14篇 |
肿瘤学 | 1796篇 |
出版年
2021年 | 351篇 |
2020年 | 216篇 |
2019年 | 398篇 |
2018年 | 486篇 |
2017年 | 341篇 |
2016年 | 344篇 |
2015年 | 412篇 |
2014年 | 575篇 |
2013年 | 954篇 |
2012年 | 1320篇 |
2011年 | 1273篇 |
2010年 | 700篇 |
2009年 | 691篇 |
2008年 | 1191篇 |
2007年 | 1162篇 |
2006年 | 1144篇 |
2005年 | 1056篇 |
2004年 | 1093篇 |
2003年 | 1041篇 |
2002年 | 895篇 |
2001年 | 884篇 |
2000年 | 921篇 |
1999年 | 740篇 |
1998年 | 327篇 |
1997年 | 279篇 |
1996年 | 299篇 |
1995年 | 279篇 |
1994年 | 245篇 |
1993年 | 279篇 |
1992年 | 636篇 |
1991年 | 620篇 |
1990年 | 592篇 |
1989年 | 597篇 |
1988年 | 565篇 |
1987年 | 587篇 |
1986年 | 518篇 |
1985年 | 524篇 |
1984年 | 393篇 |
1983年 | 345篇 |
1982年 | 235篇 |
1981年 | 206篇 |
1980年 | 206篇 |
1979年 | 363篇 |
1978年 | 202篇 |
1977年 | 205篇 |
1976年 | 227篇 |
1975年 | 183篇 |
1974年 | 240篇 |
1973年 | 228篇 |
1972年 | 187篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
M M Smith J E Thompson D Thomas M Castillo D Carrier S K Mukherji D Gilliam 《AJNR. American journal of neuroradiology》1997,18(2):327
Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did. 相似文献
5.
S G Thompson G Calori J M Thomson F Haverkate F Duckert 《Thrombosis and haemostasis》1991,65(2):149-152
As an adjunct to a European multicentre prospective study, five quality assessment (QA) exercises, spanning a period of 2.5 years, were undertaken. In these, fifteen laboratories from eight countries each performed ten haemostatic factor assays. The design of the QA exercises allowed the between-duplicate, between-day and between-laboratory coefficients of variation (CVs) to be calculated. The between-duplicate CV decreased by a factor of one quarter, and the between-day CV by a factor of one third, over the five exercises. The activated partial thromboplastin time (APTT) assay consistently showed the lowest CVs, while there was notable improvement in the between-day CVs for von Willebrand factor related antigen (vWF R:Ag) and factor VIII clotting activity (VIII:C). However, the between-laboratory CV, assessing extent of agreement between the different laboratories, did not apparently improve over the five exercises. Thus, while QA exercises may be very useful in improving the performance of haemostatic assays according to criteria which an individual laboratory can assess, improving agreement on haemostatic assay results between laboratories may be more difficult to achieve. 相似文献
6.
7.
S S Schreiber S Maren G Tocco T J Shors R F Thompson 《Brain research. Molecular brain research》1991,11(1):89-91
In the present study we examined the relationship between the induction of long-term potentiation (LTP) in the dentate gyrus of anesthetized rats and activation of immediate early genes (IEGs; c-fos and zif/268) using several different high-frequency stimulation paradigms. Stimulation parameters that effectively induced LTP were not associated with IEG activation. Conversely, stimulation parameters that failed to induce LTP consistently resulted in IEG activation. These results suggest that there is a negative correlation between IEG activation and LTP, and that activation of IEGs is neither necessary nor sufficient for the induction of LTP. 相似文献
8.
K J Meador J L Thompson D W Loring A M Murro D W King B B Gallagher G P Lee J R Smith H F Flanigin 《Neurology》1991,41(6):869-872
Although there has been extensive examination of the behavioral and physiologic correlates of hippocampal theta activity in animals, the human literature consists of a single case study. We investigated the differential effects of four behavioral states on human hippocampal theta activity in 16 epilepsy surgery patients. Behavioral conditions included resting eyes closed (RC), resting eyes open (RO), eyes open with auditory word activation (AW), and eyes open with visuospatial activation (VS). Hippocampal theta activity decreased during both RO and VS compared to both RC and AW. There were reciprocal changes in delta activity. Comparisons of RO to VS and of RC to AW were nonsignificant. The results demonstrate state-specific changes in human hippocampal theta and are consistent with the animal literature that relates hippocampal theta to sensorimotor integration and forebrain volitional mechanisms. 相似文献
9.
Joanne Dollard Jacquie Smith David R Thompson Simon Stewart 《European Journal of Cardiovascular Nursing》2004,3(1):27-42
BACKGROUND: Cardiac rehabilitation (CR) has an evidence base but traditional models may not readily apply to people living in rural and remote regions. AIM:: To outline published comprehensive and non-hospital based CR models used for people discharged from hospital after a cardiac event that have potential relevance to those living in rural and remote areas in Australia. METHODS: The PubMed database was searched using Medical subject headings (MeSH) terms and the key word 'cardiac rehabilitation' limited to clinical trials. Articles were retrieved if they included at least two components of CR and were not based in an outpatient setting. RESULTS: No CR models specifically developed for rural and remote areas were identified. However, 14 studies were found that outlined 11 non-conventional comprehensive CR models. All provided CR in a home-based setting. Health professionals provided support via telephone contact or home visits, and via resources such as the Heart Manual. Reported outcomes from these CR programs varied: ranging from an increase in knowledge of risk factors, to improvements in physical activity, decreased risk factor profile, improved psychological and social functioning and reductions in health service costs and mortality. CONCLUSION: Home-based, CR models have the most substantive evidence base and, therefore the greatest potential to be developed and made accessible to eligible people living in rural and remote areas. 相似文献
10.