全文获取类型
收费全文 | 12565篇 |
免费 | 736篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 207篇 |
儿科学 | 325篇 |
妇产科学 | 275篇 |
基础医学 | 1870篇 |
口腔科学 | 319篇 |
临床医学 | 1159篇 |
内科学 | 2728篇 |
皮肤病学 | 463篇 |
神经病学 | 1033篇 |
特种医学 | 588篇 |
外国民族医学 | 2篇 |
外科学 | 1491篇 |
综合类 | 61篇 |
一般理论 | 3篇 |
预防医学 | 917篇 |
眼科学 | 291篇 |
药学 | 863篇 |
中国医学 | 19篇 |
肿瘤学 | 721篇 |
出版年
2023年 | 63篇 |
2022年 | 164篇 |
2021年 | 275篇 |
2020年 | 148篇 |
2019年 | 235篇 |
2018年 | 288篇 |
2017年 | 229篇 |
2016年 | 335篇 |
2015年 | 342篇 |
2014年 | 401篇 |
2013年 | 537篇 |
2012年 | 786篇 |
2011年 | 739篇 |
2010年 | 433篇 |
2009年 | 422篇 |
2008年 | 640篇 |
2007年 | 675篇 |
2006年 | 640篇 |
2005年 | 564篇 |
2004年 | 532篇 |
2003年 | 465篇 |
2002年 | 495篇 |
2001年 | 362篇 |
2000年 | 323篇 |
1999年 | 342篇 |
1998年 | 132篇 |
1997年 | 125篇 |
1996年 | 60篇 |
1995年 | 78篇 |
1994年 | 54篇 |
1993年 | 51篇 |
1992年 | 159篇 |
1991年 | 152篇 |
1990年 | 142篇 |
1989年 | 133篇 |
1988年 | 99篇 |
1987年 | 122篇 |
1986年 | 92篇 |
1985年 | 101篇 |
1984年 | 75篇 |
1983年 | 87篇 |
1982年 | 52篇 |
1981年 | 48篇 |
1979年 | 77篇 |
1975年 | 42篇 |
1974年 | 49篇 |
1973年 | 59篇 |
1972年 | 43篇 |
1971年 | 46篇 |
1969年 | 43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.
Cost‐Effectiveness and Cost‐Utility Analysis of Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome: Results From the PRECISE Study
下载免费PDF全文
![点击此处可从《Neuromodulation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Furio Zucco MD Roberta Ciampichini MSc Angelo Lavano MD Amedeo Costantini MD Marisa De Rose MD Paolo Poli MD Gianpaolo Fortini MD Laura Demartini MD Enrico De Simone MD Valentino Menardo MD Piero Cisotto MD Mario Meglio MD Luciana Scalone PhD Lorenzo G. Mantovani DSc 《Neuromodulation》2015,18(4):266-276
3.
4.
5.
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6.
Harinakshi Sanikini David C. Muller Marisa Sophiea Sabina Rinaldi Antonio Agudo Eric J. Duell Elisabete Weiderpass Kim Overvad Anne Tjønneland Jytte Halkjær Marie-Christine Boutron-Ruault Franck Carbonnel Iris Cervenka Heiner Boeing Rudolf Kaaks Tilman Kühn Antonia Trichopoulou Georgia Martimianaki Anna Karakatsani Valeria Pala Domenico Palli Amalia Mattiello Rosario Tumino Carlotta Sacerdote Guri Skeie Charlotta Rylander María-Dolores Chirlaque López Maria-Jose Sánchez Eva Ardanaz Sara Regnér Tanja Stocks Bas Bueno-de-Mesquita Roel C.H. Vermeulen Dagfinn Aune Tammy Y.N. Tong Nathalie Kliemann Neil Murphy Marc Chadeau-Hyam Marc J. Gunter Amanda J. Cross 《International journal of cancer. Journal international du cancer》2020,146(4):929-942
Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5–25 kg/m2: HR = 1.94, 95% CI: 1.25–3.03) and women (HR = 2.66, 95% CI: 1.15–6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99–6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52–4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35–14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76–18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14–0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32–0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04–3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers. 相似文献
7.
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
8.
9.
10.
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