全文获取类型
收费全文 | 661篇 |
免费 | 22篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 17篇 |
妇产科学 | 5篇 |
基础医学 | 45篇 |
口腔科学 | 14篇 |
临床医学 | 100篇 |
内科学 | 120篇 |
皮肤病学 | 17篇 |
神经病学 | 98篇 |
特种医学 | 43篇 |
外科学 | 62篇 |
综合类 | 2篇 |
预防医学 | 40篇 |
药学 | 56篇 |
中国医学 | 1篇 |
肿瘤学 | 37篇 |
出版年
2021年 | 6篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 4篇 |
2015年 | 12篇 |
2014年 | 13篇 |
2013年 | 18篇 |
2012年 | 23篇 |
2011年 | 34篇 |
2010年 | 23篇 |
2009年 | 13篇 |
2008年 | 35篇 |
2007年 | 43篇 |
2006年 | 35篇 |
2005年 | 37篇 |
2004年 | 41篇 |
2003年 | 42篇 |
2002年 | 28篇 |
2001年 | 15篇 |
2000年 | 33篇 |
1999年 | 21篇 |
1998年 | 17篇 |
1997年 | 7篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 15篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 12篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1975年 | 7篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1971年 | 5篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
61.
Fast and robust registration of PET and MR images of human brain 总被引:8,自引:0,他引:8
In recent years, mutual information has proved to be an excellent criterion for registration of intra-individual images from different modalities. Multi-resolution coarse-to-fine optimization was proposed for speeding-up of the registration process. The aim of our work was to further improve registration speed without compromising robustness or accuracy. We present and evaluate two procedures for co-registration of positron emission tomography (PET) and magnetic resonance (MR) images of human brain that combine a multi-resolution approach with an automatic segmentation of input image volumes into areas of interest and background. We show that an acceleration factor of 10 can be achieved for clinical data and that a suitable preprocessing can improve robustness of registration. Emphasis was laid on creation of an automatic registration system that could be used routinely in a clinical environment. For this purpose, an easy-to-use graphical user interface has been developed. It allows physicians with no special knowledge of the registration algorithm to perform a fast and reliable alignment of images. Registration progress is presented on the fly on a fusion of images and enables visual checking during a registration. 相似文献
62.
63.
Diversity among clients in the American health care system is increasing as the population of the United States changes in composition. Health providers, educators, and supervisors are in unique positions to enhance patient education among members of diverse cultures by incorporating cultural research and health beliefs into patient and staff education. Using a culturally defined framework, health providers can more holistically assess the client and subsequently plan culturally appropriate care. 相似文献
64.
Hagelueken G Wiehlmann L Adams TM Kolmar H Heinz DW Tümmler B Schubert WD 《Proceedings of the National Academy of Sciences of the United States of America》2007,104(30):12276-12281
Crude oil spills represent a major ecological threat because of the chemical inertness of the constituent n-alkanes. The Gram-negative bacterium Pseudomonas aeruginosa is one of the few bacterial species able to metabolize such compounds. Three chromosomal genes, rubB, rubA1, and rubA2 coding for an NAD(P)H:rubredoxin reductase (RdxR) and two rubredoxins (Rdxs) are indispensable for this ability. They constitute an electron transport (ET) pathway that shuttles reducing equivalents from carbon metabolism to the membrane-bound alkane hydroxylases AlkB1 and AlkB2. The RdxR-Rdx system also is crucial as part of the oxidative stress response in archaea or anaerobic bacteria. The redox couple has been analyzed in detail as a model system for ET processes. We have solved the structure of RdxR of P. aeruginosa both alone and in complex with Rdx, without the need for cross-linking, and both structures were refined at 2.40- and 2.45-A resolution, respectively. RdxR consists of two cofactor-binding domains and a C-terminal domain essential for the specific recognition of Rdx. Only a small number of direct interactions govern mutual recognition of RdxR and Rdx, corroborating the transient nature of the complex. The shortest distance between the redox centers is observed to be 6.2 A. 相似文献
65.
Sobesky J Frackowiak M Zaro Weber O Hahn M Möller-Hartmann W Rudolf J Neveling M Grond M Schmulling S Jacobs A Heiss WD 《Cerebrovascular diseases (Basel, Switzerland)》2007,24(1):56-65
BACKGROUND: Predictors of outcome and safety in intravenous thrombolysis within 3 h in clinical routine is a matter of ongoing debate. Available reports contain small patient numbers or summarize heterogeneous multicenter data. METHODS: Four hundred and fifty patients received intravenous thrombolysis within 3 h after stroke. Pretreatment NIHSS score and detailed medical history were analyzed. Noncontrast CT was performed before thrombolysis, 24-36 h later and in case of clinical deterioration. Symptomatic intracranial hemorrhage (SICH; any bleeding with an NIHSS increase of > or =4 points) and clinical outcome (modified Rankin Scale, mRS) after 3 months were recorded. Logistic regression identified parameters predictive of independence (mRS 0-2) and SICH. RESULTS: Median onset to admission, door to needle and onset to treatment time was 75, 50 and 135 min, respectively. Direct presentation by emergency service (64%) was the fastest way of referral. Median pretreatment NIHSS was 11 points. Independence (mRS 0-2) was reached by 53%. Mortality was 11% (7% intracerebral, 4% extracerebral complications). Logistic regression identified low NIHSS, low age and absent diabetes as predictors of independence. Overall hemorrhagic complications and SICH were found in 18 and 4% of the patients, respectively. Extracerebral bleeding complications and allergic reactions were found in 3 and 1%, respectively. CONCLUSION: This largest single center report presents a sample in the range of the 3 h rt-PA cohort of all randomized controlled trials. Outcome was comparable to randomized studies with a higher rate of independence and a lower rate of mortality and SICH. 相似文献
66.
Erasmi AW Sievers HH Bechtel JF Hanke T Stierle U Misfeld M 《The Annals of thoracic surgery》2007,83(2):S752-6; discussion S785-90
67.
Types of reconstructive surgery of the aortic valve 总被引:1,自引:0,他引:1
68.
69.
70.