全文获取类型
收费全文 | 2309篇 |
免费 | 174篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 58篇 |
妇产科学 | 38篇 |
基础医学 | 444篇 |
口腔科学 | 35篇 |
临床医学 | 201篇 |
内科学 | 467篇 |
皮肤病学 | 84篇 |
神经病学 | 165篇 |
特种医学 | 265篇 |
外科学 | 284篇 |
综合类 | 19篇 |
一般理论 | 2篇 |
预防医学 | 116篇 |
眼科学 | 22篇 |
药学 | 151篇 |
中国医学 | 15篇 |
肿瘤学 | 82篇 |
出版年
2022年 | 16篇 |
2021年 | 25篇 |
2020年 | 22篇 |
2019年 | 32篇 |
2018年 | 54篇 |
2017年 | 26篇 |
2016年 | 34篇 |
2015年 | 48篇 |
2014年 | 61篇 |
2013年 | 95篇 |
2012年 | 94篇 |
2011年 | 109篇 |
2010年 | 50篇 |
2009年 | 47篇 |
2008年 | 94篇 |
2007年 | 95篇 |
2006年 | 105篇 |
2005年 | 92篇 |
2004年 | 87篇 |
2003年 | 88篇 |
2002年 | 84篇 |
2001年 | 46篇 |
2000年 | 36篇 |
1999年 | 41篇 |
1998年 | 29篇 |
1997年 | 29篇 |
1996年 | 31篇 |
1995年 | 25篇 |
1994年 | 30篇 |
1993年 | 12篇 |
1992年 | 30篇 |
1991年 | 28篇 |
1990年 | 25篇 |
1989年 | 12篇 |
1988年 | 22篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 19篇 |
1984年 | 14篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1976年 | 12篇 |
1974年 | 12篇 |
1932年 | 21篇 |
1930年 | 12篇 |
1928年 | 13篇 |
1924年 | 14篇 |
1923年 | 11篇 |
1922年 | 14篇 |
1884年 | 15篇 |
排序方式: 共有2492条查询结果,搜索用时 15 毫秒
31.
32.
33.
Christian A. Skrabal Amir Khosravi Bernd Westphal Gustav Steinhoff 《Scandinavian cardiovascular journal : SCJ》2013,47(4):224-229
Objectives. In this study, the immuno- and neuroprotective effect of a novel cardiopulmonary bypass coating was investigated. Design. Thirty nine patients scheduled for elective coronary artery bypass grafting were randomly assigned to either PMEA-coated (n?=?19) or non-coated CPB circuits (n?=?20). Pericardial suction blood was separated and retransfused only if needed at the end of operation. Neurocognitive functions were examined preoperatively and 7–10 days postoperatively using a standard neuropsychological test battery. Assuming an inflammatory etiology, the most cogent inflammatory markers were perioperatively analyzed. Results. Postoperatively, patients of the PMEA-coated group performed better in Go/NoGo and Mini-Mental-test than patients of the non-coated group (p?<?0.04). Other neurocognitive testing did not reveal significant differences between the groups. Although most inflammatory parameters showed a significant intraindividual increase during or shortly after CPB, there was no difference in inflammatory alteration between the groups. Conclusions. PMEA-coating of cardiopulmonary bypass surfaces revealed some minor benefits in preservation of neurocognitive functions after surgery. The immediate inflammatory response remained mostly unaffected. Suction blood separation may additionally contribute to proper postoperative outcome. 相似文献
34.
35.
36.
Diffusion‐prepared stimulated‐echo turbo spin echo (DPsti‐TSE): An eddy current‐insensitive sequence for three‐dimensional high‐resolution and undistorted diffusion‐weighted imaging 下载免费PDF全文
Qinwei Zhang Bram F. Coolen Maarten J. Versluis Gustav J. Strijkers Aart J. Nederveen 《NMR in biomedicine》2017,30(7)
In this study, we present a new three‐dimensional (3D), diffusion‐prepared turbo spin echo sequence based on a stimulated‐echo read‐out (DPsti‐TSE) enabling high‐resolution and undistorted diffusion‐weighted imaging (DWI). A dephasing gradient in the diffusion preparation module and rephasing gradients in the turbo spin echo module create stimulated echoes, which prevent signal loss caused by eddy currents. Near to perfect agreement of apparent diffusion coefficient (ADC) values between DPsti‐TSE and diffusion‐weighted echo planar imaging (DW‐EPI) was demonstrated in both phantom transient signal experiments and phantom imaging experiments. High‐resolution and undistorted DPsti‐TSE was demonstrated in vivo in prostate and carotid vessel wall. 3D whole‐prostate DWI was achieved with four b values in only 6 min. Undistorted ADC maps of the prostate peripheral zone were obtained at low and high imaging resolutions with no change in mean ADC values [(1.60 ± 0.10) × 10?3 versus (1.60 ± 0.02) × 10?3 mm2/s]. High‐resolution 3D DWI of the carotid vessel wall was achieved in 12 min, with consistent ADC values [(1.40 ± 0.23) × 10?3 mm2/s] across different subjects, as well as slice locations through the imaging volume. This study shows that DPsti‐TSE can serve as a robust 3D diffusion‐weighted sequence and is an attractive alternative to the traditional two‐dimensional DW‐EPI approaches. 相似文献
37.
The older patient's experience of the healthcare chain and information when undergoing colorectal cancer surgery according to the enhanced recovery after surgery concept 下载免费PDF全文
38.
39.
Werz O Tretiakova I Michel A Ulke-Lemee A Hörnig M Franke L Schneider G Samuelsson B Rådmark O Steinhilber D 《Proceedings of the National Academy of Sciences of the United States of America》2005,102(37):13164-13169
5-Lipoxygenase (5-LO) is a tightly regulated enzyme in the synthesis of bioactive lipids from arachidonic acid. Here, we demonstrate that 5-LO is regulated by caspases, which are signaling molecules that control critical biological processes by means of specific limited proteolysis. Cell splitting of the Epstein-Barr virus-transformed B lymphocytic cell line BL41-E95-A caused a pronounced, but transient, reduction of functional 5-LO protein, accompanied by the appearance of a 62-kDa 5-LO cleavage product. In parallel, splitting of BL41-E95-A cells induced activation of caspase-6 (casp-6) and casp-8. Caspase activation and 5-LO degradation were blocked by the protein-synthesis inhibitor cycloheximide, and cell-permeable peptide inhibitors of casp-6 and casp-8 prevented 5-LO cleavage. Activation of casp-6 and casp-8 was connected to subsequent enhancement of cell proliferation, whereas selective caspase inhibition blocked cell growth. Last, isolated human 5-LO was cleaved by recombinant casp-6 in vitro to a 58-kDa fragment. Based on site-directed mutagenesis studies, 5-LO is cleaved by casp-6 after Asp-170, which in a homology-based 3D model of 5-LO is located on the enzyme periphery. We suggest that splitting of BL41-E95-A cells induces de novo synthesis of a protein involved in the activation of casp-6, which cleaves 5-LO. 相似文献
40.
MP2C, a plant protein phosphatase 2C, functions as a negative regulator of mitogen-activated protein kinase pathways in yeast and plants 下载免费PDF全文