全文获取类型
收费全文 | 14271篇 |
免费 | 730篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 245篇 |
儿科学 | 311篇 |
妇产科学 | 239篇 |
基础医学 | 2082篇 |
口腔科学 | 296篇 |
临床医学 | 1319篇 |
内科学 | 3096篇 |
皮肤病学 | 629篇 |
神经病学 | 1340篇 |
特种医学 | 749篇 |
外国民族医学 | 2篇 |
外科学 | 1619篇 |
综合类 | 69篇 |
一般理论 | 6篇 |
预防医学 | 739篇 |
眼科学 | 398篇 |
药学 | 1120篇 |
中国医学 | 13篇 |
肿瘤学 | 777篇 |
出版年
2022年 | 130篇 |
2021年 | 213篇 |
2020年 | 117篇 |
2019年 | 189篇 |
2018年 | 224篇 |
2017年 | 217篇 |
2016年 | 312篇 |
2015年 | 317篇 |
2014年 | 403篇 |
2013年 | 540篇 |
2012年 | 792篇 |
2011年 | 758篇 |
2010年 | 518篇 |
2009年 | 490篇 |
2008年 | 759篇 |
2007年 | 797篇 |
2006年 | 813篇 |
2005年 | 686篇 |
2004年 | 669篇 |
2003年 | 611篇 |
2002年 | 680篇 |
2001年 | 421篇 |
2000年 | 356篇 |
1999年 | 412篇 |
1998年 | 195篇 |
1997年 | 174篇 |
1996年 | 104篇 |
1995年 | 111篇 |
1994年 | 80篇 |
1993年 | 71篇 |
1992年 | 175篇 |
1991年 | 169篇 |
1990年 | 157篇 |
1989年 | 144篇 |
1988年 | 121篇 |
1987年 | 129篇 |
1986年 | 100篇 |
1985年 | 117篇 |
1984年 | 97篇 |
1983年 | 94篇 |
1982年 | 71篇 |
1981年 | 60篇 |
1980年 | 60篇 |
1979年 | 89篇 |
1977年 | 54篇 |
1975年 | 56篇 |
1974年 | 58篇 |
1973年 | 65篇 |
1972年 | 49篇 |
1971年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Michels Guido Horn Rudolf Helfen Andreas Hagendorff Andreas Jung Christian Hoffmann Beatrice Jaspers Natalie Kinkel Horst Greim Clemens-Alexander Knebel Fabian Bauersachs Johann Busch Hans-Jörg Kiefl Daniel Spiel Alexander O. Marx Gernot Dietrich Christoph F. 《Der Anaesthesist》2022,71(4):307-310
Die Anaesthesiologie - 相似文献
2.
3.
Stress Testing Versus CT Angiography in Patients With Diabetes and Suspected Coronary Artery Disease
Abhinav Sharma Adrian Coles Nishant K. Sekaran Neha J. Pagidipati Michael T. Lu Daniel B. Mark Kerry L. Lee Hussein R. Al-Khalidi Udo Hoffmann Pamela S. Douglas 《Journal of the American College of Cardiology》2019,73(8):893-902
Background
The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.Objectives
The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.Methods
PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.Results
Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).Conclusions
In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550) 相似文献4.
5.
6.
Stephen R. Thomas Ronald G. Pratt Ronald W. Millard R. C. Samaratunga Yoseph Shiferaw Leland C. Clark Richard E. Hoffmann 《Journal of magnetic resonance imaging : JMRI》1994,4(4):631-635
Oxygen-sensitive F-19 magnetic resonance imaging of perfluorocarbon compounds requires that fluorocarbon T1 changes correlate with the local Po2 and not with the composition of the surrounding aqueous phase. The influence of various bioconstituents and paramagnetic ions within the aqueous phase on the F-19 fluorocarbon phase T1 for PFC emulsions was evaluated at 0.14 and 0.66 T. T1 was measured for FC-43, perflubron, and a fluorinated surfactant. Controlled variables introduced in the aqueous phase included annex solution constituents, blood, pH changes, and Gd-DTPA. For a constant Po2, the F-19 T1s were independent of the emulsion constituents, blood concentration, and pH. For FC-43 and perflubron, F-19 T1 was independent of the Gd-DTPA concentration, while the aqueous phase T1 decreased by more than an order of magnitude. XMO-10 (smallest emulsion particle size) showed a slight decrease in F-19 T1 with increasing Gd-DTPA concentration at 0.66 T. 相似文献
7.
8.
3-(Methylnitrosamino)propionitrile: occurrence in saliva of betel quid chewers, carcinogenicity, and DNA methylation in F344 rats 总被引:1,自引:0,他引:1
3-(Methylnitrosamino)propionitrile (MNPN), a potent carcinogen in F344 rats, was detected for the first time in the saliva of betel quid chewers at levels ranging from 0.5 to 11.4 micrograms/liter. The tumorigenic properties of MNPN and its potential to methylate DNA in F344 rats were evaluated. Groups of 21 male and 21 female rats were given 60 s.c. injections over a 20-week period (total doses 0.055 and 0.23 mmol per rat). The experiment was terminated after 106 weeks. MNPN at the higher dose induced 18 (86%) malignant tumors of the nasal cavity in male and 15 (71%) in female rats. The lower dose induced nine (43%) liver tumors. Groups of four or five male F344 rats were treated with a single s.c. or i.v. injection of MNPN (0.4 mmol/kg). MNPN was also administered to rats by swabbing the oral cavity (2.21 mmol/kg). The levels of 7-methylguanine and O6-methylguanine, formed 0.5-36 h after treatment, were measured in the liver, nasal mucosa, esophagus, and oral issues. The highest levels of methylated guanines were detected in the nasal cavity independent of the route of administration. The results of this study demonstrate that MNPN is present in the saliva of betel quid chewers and is a potent carcinogen in F344 rats. 相似文献
9.
Background
In order to reduce systematic errors (such as language bias) and increase the precision of the summary treatment effect estimate, a comprehensive identification of randomised controlled trials (RCT), irrespective of publication language, is crucial in systematic reviews and meta-analyses. We identified trials in the German general health care literature. 相似文献10.
Parastoo Jangouk Thomas Dehmel Gerd Meyer Zu Hörste Andreas Ludwig Helmar C. Lehmann Bernd C. Kieseier 《Glia》2009,57(16):1765-1774
The disintegrin and metalloproteinase 10 (ADAM10) is a membrane‐anchored metalloproteinase with both proteolytic and disintegrin characteristics. Here, we investigate the expression, regulation, and functional role of ADAM10 in axonal outgrowth and myelination of the peripheral nerve. Expression pattern analysis of 11 ADAM family members in co‐cultures of rat dorsal root ganglia (DRG) neurons and Schwann cells (SCs) demonstrated the most pronounced mRNA expression for ADAM10. In further studies, ADAM10 was found to be consistently upregulated in DRG‐SC co‐cultures before the induction of myelination. Neurons as well as SCs widely expressed ADAM10 at the protein level. In neurons, the expression of ADAM10 was exclusively limited to the axons before the induction of myelination. Inhibition of ADAM10 activity by the hydroxamate‐based inhibitors GI254023X and GW280264X resulted in a significant decrease in the mean axonal length. These data suggest that ADAM10 represents a prerequisite for myelination, although its activity is not required during the process of myelination itself as demonstrated by expression analysis of myelin protein zero (P0) and Sudan black staining. Hence, during the process of myelin formation, ADAM10 is highly upregulated and appears to be critically involved in axonal outgrowth that is a requirement for myelination in the peripheral nerve. © 2009 Wiley‐Liss, Inc. 相似文献