全文获取类型
| 收费全文 | 169185篇 |
| 免费 | 10284篇 |
| 国内免费 | 691篇 |
专业分类
| 耳鼻咽喉 | 2184篇 |
| 儿科学 | 4458篇 |
| 妇产科学 | 3073篇 |
| 基础医学 | 20101篇 |
| 口腔科学 | 3186篇 |
| 临床医学 | 17396篇 |
| 内科学 | 34419篇 |
| 皮肤病学 | 2415篇 |
| 神经病学 | 16720篇 |
| 特种医学 | 6293篇 |
| 外国民族医学 | 8篇 |
| 外科学 | 28089篇 |
| 综合类 | 1920篇 |
| 一般理论 | 225篇 |
| 预防医学 | 13987篇 |
| 眼科学 | 3434篇 |
| 药学 | 10849篇 |
| 中国医学 | 216篇 |
| 肿瘤学 | 11187篇 |
出版年
| 2023年 | 931篇 |
| 2022年 | 1551篇 |
| 2021年 | 3772篇 |
| 2020年 | 2207篇 |
| 2019年 | 3587篇 |
| 2018年 | 4289篇 |
| 2017年 | 3076篇 |
| 2016年 | 3268篇 |
| 2015年 | 3680篇 |
| 2014年 | 5592篇 |
| 2013年 | 7792篇 |
| 2012年 | 12162篇 |
| 2011年 | 12797篇 |
| 2010年 | 7228篇 |
| 2009年 | 6459篇 |
| 2008年 | 11364篇 |
| 2007年 | 11935篇 |
| 2006年 | 11540篇 |
| 2005年 | 11224篇 |
| 2004年 | 10818篇 |
| 2003年 | 9826篇 |
| 2002年 | 9224篇 |
| 2001年 | 1378篇 |
| 2000年 | 1037篇 |
| 1999年 | 1500篇 |
| 1998年 | 1937篇 |
| 1997年 | 1568篇 |
| 1996年 | 1321篇 |
| 1995年 | 1183篇 |
| 1994年 | 1086篇 |
| 1993年 | 994篇 |
| 1992年 | 812篇 |
| 1991年 | 774篇 |
| 1990年 | 623篇 |
| 1989年 | 577篇 |
| 1988年 | 559篇 |
| 1987年 | 543篇 |
| 1986年 | 518篇 |
| 1985年 | 644篇 |
| 1984年 | 744篇 |
| 1983年 | 618篇 |
| 1982年 | 861篇 |
| 1981年 | 770篇 |
| 1980年 | 669篇 |
| 1979年 | 303篇 |
| 1978年 | 403篇 |
| 1977年 | 374篇 |
| 1976年 | 290篇 |
| 1975年 | 288篇 |
| 1973年 | 255篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
1.
Zhenzhen Zhang Mark Garzotto Tomasz M. Beer Philippe Thuillier Stephen Lieberman Motomi Mori 《Nutrition and cancer》2016,68(8):1309-1319
Animal and human studies suggest fish oil and green tea may have protective effect on prostate cancer. Fatty acid synthase (FAS) has been hypothesized to be linked to chemoprotective effects of both compounds. This study evaluated the independent and joint effects of fish oil (FO) and green tea supplement (epigallocatechin-3-gallate, EGCG) on FAS and Ki-67 levels in prostate tissue. Through a double-blinded, randomized controlled trial with 2 × 2 factorial design, 89 men scheduled for repeat prostate biopsy following an initial negative prostate biopsy were randomized into either FO alone (1.9 g DHA + EPA/day), EGCG alone (600 mg/day), a combination of FO and EGCG, or placebo. We used linear mixed-effects models to test the differences of prostate tissue FAS and Ki-67 by immunohistochemistry between pre- and post-intervention within each group, as well as between treatment groups. Results did not show significant difference among treatment groups in pre-to-post-intervention changes of FAS (P = 0.69) or Ki-67 (P = 0.26). Comparing placebo group with any of the treatment groups, we did not find significant difference in FAS or Ki-67 changes (all P > 0.05). Results indicate FO or EGCG supplementation for a short duration may not be sufficient to produce biologically meaningful changes in FAS or Ki-67 levels in prostate tissue. 相似文献
2.
3.
4.
5.
6.
7.
8.
Conall T. Morgan Brigitte Mueller Varsha Thakur Vitor Guerra Callaghan Jull Luc Mertens Mark Friedberg Fraser Golding Mike Seed Steven E.S. Miner Edgar T. Jaeggi Cedric Manlhiot Lynne E. Nield 《The Canadian journal of cardiology》2019,35(4):453-461
Background
The purpose of the study was to evaluate the association between fetal echocardiographic measurements and the need for intervention (primary coarctation repair, staged coarctation repair, or catheter intervention) in prenatally diagnosed coarctation of the aorta.Methods
A single-centre retrospective cohort study (2005-2015) of 107 fetuses diagnosed with suspected coarctation of the aorta in the setting of an apex-forming left ventricle and antegrade flow across the mitral and aortic valves.Results
Median gestational age at diagnosis was 32 weeks (interquartile range, 23-35 weeks). Fifty-six (52%) did not require any neonatal intervention, 51 patients (48%) underwent a biventricular repair. In univariable analysis, an increase in ascending aorta (AAo) peak Doppler flow velocity (odds ratio [OR], 1.40 [95% confidence interval [CI], 1.05-1.91] per 20 cm/s; P = 0.03) was associated with intervention. No intervention was associated with larger isthmus size (OR, 0.23; P < 0.001), transverse arch diameter (OR, 0.23; P < 0.001), and aortic (OR, 0.72; P = 0.02), mitral (OR, 0.58; P = 0.001), and AAo (OR, 0.53; P < 0.001) z-scores. In multivariable analysis, higher peak AAo Doppler (OR, 2.51 [95% CI, 1.54-4.58] per 20 cm/s; P = 0.001) and younger gestational age at diagnosis (OR, 0.81 [95% CI, 0.70-0.93] per week; P = 0.005) were associated with intervention, whereas a higher AAo z-score (OR, 0.65 [95% CI, 0.43-0.94] per z; P = 0.029) and transverse arch dimension (OR, 0.44 [95% CI, 0.18-0.97]; P = 0.05) decreased the risk of intervention.Conclusions
In prenatally suspected coarctation, the variables associated with intervention comprised smaller AAo and transverse arch size, earlier gestational age at diagnosis, and the additional finding of a higher peak AAo Doppler. 相似文献9.
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10.