全文获取类型
收费全文 | 3802篇 |
免费 | 387篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 193篇 |
妇产科学 | 87篇 |
基础医学 | 571篇 |
口腔科学 | 157篇 |
临床医学 | 320篇 |
内科学 | 888篇 |
皮肤病学 | 118篇 |
神经病学 | 335篇 |
特种医学 | 128篇 |
外科学 | 510篇 |
综合类 | 28篇 |
预防医学 | 355篇 |
眼科学 | 40篇 |
药学 | 239篇 |
中国医学 | 15篇 |
肿瘤学 | 182篇 |
出版年
2023年 | 25篇 |
2022年 | 42篇 |
2021年 | 112篇 |
2020年 | 87篇 |
2019年 | 149篇 |
2018年 | 143篇 |
2017年 | 109篇 |
2016年 | 95篇 |
2015年 | 122篇 |
2014年 | 137篇 |
2013年 | 172篇 |
2012年 | 217篇 |
2011年 | 212篇 |
2010年 | 134篇 |
2009年 | 99篇 |
2008年 | 210篇 |
2007年 | 209篇 |
2006年 | 173篇 |
2005年 | 184篇 |
2004年 | 140篇 |
2003年 | 141篇 |
2002年 | 134篇 |
2001年 | 119篇 |
2000年 | 117篇 |
1999年 | 87篇 |
1998年 | 37篇 |
1997年 | 34篇 |
1996年 | 25篇 |
1995年 | 33篇 |
1994年 | 34篇 |
1993年 | 40篇 |
1992年 | 72篇 |
1991年 | 50篇 |
1990年 | 54篇 |
1989年 | 45篇 |
1988年 | 54篇 |
1987年 | 49篇 |
1986年 | 47篇 |
1985年 | 36篇 |
1984年 | 22篇 |
1983年 | 25篇 |
1982年 | 17篇 |
1979年 | 11篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1974年 | 9篇 |
1972年 | 12篇 |
1970年 | 16篇 |
1969年 | 10篇 |
1968年 | 13篇 |
排序方式: 共有4201条查询结果,搜索用时 31 毫秒
991.
Compaction of cold asphalt mixtures is a subject that has not been thoroughly studied, and, for this reason, requires new efforts from researchers to have a better understanding. Unlike hot mixtures, cold mixtures and mainly recycled mixtures require specific considerations for compaction. There is a lack of consensus about the methodology to select the optimum premix water and emulsion contents. In the absence of specific regulations, the use of soil tests or hot mixtures procedures is common. For these reasons, this investigation’s main goal was to evaluate two compaction methods used to design cold recycled mixtures with emulsion: the modified Proctor procedure and the gyratory compaction. It was concluded that both methods could be useful to study compactability since consistent results were obtained by applying the maximum bulk density criterion. However, the higher bulk densities achieved, the smaller specimens used, and the suitability of the gyratory specimens to be later tested for mechanical properties make them preferable to the modified Proctor samples. A new approach has been proposed using iso-density lines on dual-axis premix water content-emulsion content graphs that facilitates the study of the influence on compactability of these two factors combined. These contributions can alleviate the laboratory works during the design of cold recycled asphalt mixtures and contribute to a more in-depth knowledge of the combined effect of premix water and emulsion contents on the compactability of cold recycled mixtures with emulsion. 相似文献
992.
Joaquín A. Marrón-Ponce Mario Flores Gustavo Cediel Carlos Augusto Monteiro Carolina Batis 《Journal of the Academy of Nutrition and Dietetics》2019,119(11):1852-1865
BackgroundUltra-processed foods are highly palatable and can be consumed anywhere at any time, but typically have a poor nutritional profile. Therefore, their contribution to total energy intake has been proposed as an indicator for studying overall dietary quality.ObjectiveThe aim of this study was to investigate the associations between the energy contribution from ultra-processed foods and the intake of nutrients related to chronic non-communicable diseases in Mexico.DesignThis study used a secondary analysis of cross-sectional data from the 2012 Mexican National Health and Nutrition Survey.Participants/settingThis study included participants aged 1 year and older (n=10,087) who had completed a 1-day 24-hour recall.Main outcome measuresIntake from added sugar (% kcal), total fat (% kcal), saturated fat (% kcal), protein (% kcal), dietary fiber (g/1,000 kcal), and dietary energy density (kcal/g) were measured.Statistical analysisMultiple linear regression models adjusted for sociodemographic variables were fitted to assess the association between quintiles of energy contribution from ultra-processed foods and nutrient intake.ResultsMean reported energy contribution from ultra-processed foods to the Mexican population’s diet ranged from 4.5% kcal in quintile 1 (Q1) to 64.2% kcal in quintile 5 (Q5). An increased energy contribution from ultra-processed foods was positively associated with intake from added sugar (Q1: 7.4% kcal; Q5: 17.5% kcal), total fat (Q1: 30.6% kcal; Q5: 33.5% kcal) and saturated fat (Q1: 9.3% kcal; Q5: 13.2% kcal), as well as dietary energy density (Q1: 1.4 kcal/g; Q5: 2.0 kcal/g) (P≤0.001); and inversely associated with intake from protein (Q1: 15.1% kcal; Q5: 11.9% kcal) and dietary fiber (Q1: 16.0 g/1,000 kcal; Q5: 8.4 g/1,000 kcal) (P≤0.001).ConclusionsIn the Mexican population, an increased energy contribution from ultra-processed foods was associated with a lower dietary quality with regard to intake of nutrients related to chronic non-communicable diseases. Future research is needed to identify barriers to eating a variety of unprocessed and minimally processed foods for the Mexican population, as well as effective public health strategies and policies to overcome these barriers. 相似文献
993.
994.
Ginés Elvira Ruiz César Caro Martínez Pedro J. Flores Blanco Juan José Cerezo Manchado Helena Albendín Iglesias Alejandro Lova Navarro Francisco Arregui Montoya Arcadio García Alberola Domingo A. Pascual Figal José Luis Bailén Lorenzo Sergio Manzano-Fernández 《European journal of clinical investigation》2019,49(10):e13161
995.
Flavia Sirotheau Correa Pontes Lucas Lacerda de Souza Lorena Paula de Paula Elieser de Melo Galvão Neto Priscilla Flores Silva Gonçalves Hélder Antônio Rebelo Pontes 《Journal of cranio-maxillo-facial surgery》2018,46(10):1753-1757
Purpose
To integrate the available data published on central odontogenic fibroma (COF) into a comprehensive analysis of its clinical/radiologic/histological features.Methods
An electronic search was undertaken in September 2017. Eligibility criteria included publications reporting cases of COF having enough clinical, radiological and histological information to confirm the diagnosis. Demographic data, lesion site and size, treatment approach, and recurrence were analysed. The cases included in the analysis presented follow-up time. Concerning recurrence analysis, tumour location, cortical bone perforation, lesion locularity, radiopacities, lesions associated with a tooth, tooth displacement, histological type and treatment used were evaluated.Results
Eighty-three publications reporting 173 COFs were included. Lesions were slightly more prevalent in men than women (M:?F – 1.13:?1); mean age was 31.6 years, with the highest prevalence in the second decade of life. Lesions were more prevalent in the posterior mandible. The difference in recurrence rate (when information about recurrence was provided) presented a statistically significant result for COF for location, cortical bone perforation and locularity of the lesion.Conclusions
Our paper highlights that patients with COF who present a lesion located in the maxilla with multilocular aspects and cortical bone perforation tend to show a higher recurrence rate. 相似文献996.
Major bleeding risk prediction using Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease equations in acute coronary syndrome 下载免费PDF全文
997.
J. M. García y Sánchez C. L. Gómez Rodríguez J. Romero Flores 《Journal of maxillofacial and oral surgery》2015,14(2):487-496
Introduction
The present work consists of the specific design of a surgical guide for modified oblique Le fort III osteotomy (MOLFIIIO), developed previously in the Stereolithography model of the patient. The guides are designed to perform an osteotomy for the orbital floor, zygoma and pterygomaxillary fossa. The fundamental objective of the malar guides will be: symmetrical orbitozygomatic osteotomies bilaterally. Regarding the guide of the orbital floor, it is of primary importance to begin the osteotomy 5 mm ahead of the inferior orbital fissure (IOF) in orbital antero posterior direction, crossing the orbital floor. The pterygomaxillary fossa guide, will cover the internal face of the malar bone exactly in the posterior portion of the butres (hidden portion) toward the IOF. This guide will be useful, revolutionize and make it easier and secure to access the osteotomy of the area for a lot of surgeons who fear manipulating the pterigomaxillary fossa in its upper third, due to the fear of damaging the internal maxillary artery, that will be reduced to a minimum with the guides.Materials and Methods
Initially requires a CT scan, for designed the model patient stereolithography. The guides are prepared from self-curing acrylic and monomer.Conclusion
Surgical guides are very useful for MOLFIIIO, as being custom, manage to make a stable symmetrical bilateral cut, decreasing the possibility of injury to vascular structures and shorten the surgical time. 相似文献998.
Salvatore Brugaletta Josep Gomez-Lara Luis Ortega-Paz Victor Jimenez-Diaz Marcelo Jimenez Pilar Jiménez-Quevedo Roberto Diletti Vicente Mainar Gianluca Campo Antonio Silvestro Jaume Maristany Xacobe Flores Loreto Oyarzabal Antonio De Miguel-Castro Andrés Iñiguez Antonio Serra Luis Nombela-Franco Alfonso Ielasi Manel Sabaté 《Journal of the American College of Cardiology》2021,77(9):1165-1178
BackgroundOutcomes data for a durable-polymer everolimus-eluting stent (EES) at extended long-term follow-up in patients with ST-segment elevation myocardial infarction (STEMI) are unknown.ObjectivesThe aim of this study was to assess the 10-year outcomes of patients enrolled in the EXAMINATION (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) trial.MethodsThe EXAMINATION-EXTEND (10-Years Follow-Up of the EXAMINATION Trial) study is an investigator-driven 10-year follow-up of the EXAMINATION trial, which randomly assigned 1,498 patients with STEMI in a 1:1 ratio to receive either EES (n = 751) or bare-metal stents (n = 747). The primary endpoint was a patient-oriented composite endpoint of all-cause death, any myocardial infarction, or any revascularization. Secondary endpoints included a device-oriented composite endpoint of cardiac death, target vessel myocardial infarction, or target lesion revascularization; the individual components of the combined endpoints; and stent thrombosis.ResultsComplete 10-year clinical follow-up was obtained in 94.5% of the EES group and 95.9% of the bare-metal stent group. Rates of the patient-oriented composite endpoint and device-oriented composite endpoint were significantly reduced in the EES group (32.4% vs. 38.0% [hazard ratio: 0.81; 95% confidence interval: 0.68 to 0.96; p = 0.013] and 13.6% vs. 18.4% [hazard ratio: 0.72; 95% confidence interval: 0.55 to 0.93; p = 0.012], respectively), driven mainly by target lesion revascularization (5.7% vs. 8.8%; p = 0.018). The rate of definite stent thrombosis was similar in both groups (2.2% vs. 2.5%; p = 0.590). No differences were found between the groups in terms of target lesion revascularization (1.4% vs. 1.3%; p = 0.963) and definite or probable stent thrombosis (0.6% vs. 0.4%; p = 0.703) between 5 and 10 years.ConclusionsAt 10-year follow-up, EES demonstrated confirmed superiority in combined patient- and device-oriented composite endpoints compared with bare-metal stents in patients with STEMI requiring primary percutaneous coronary intervention. Between 5- and 10-year follow-up, a low incidence of adverse cardiovascular events related to device failure was found in both groups. (10-Years Follow-Up of the EXAMINATION Trial; NCT04462315) 相似文献
999.
Human papillomavirus infections in Mexican women with normal cytology,precancerous lesions,and cervical cancer: Type‐specific prevalence and HPV coinfections 下载免费PDF全文
Adriana Aguilar‐Lemarroy Verónica Vallejo‐Ruiz Elva I Cortés‐Gutiérrez Manuel Eduardo Salgado‐Bernabé Norma Patricia Ramos‐González Laura Ortega‐Cervantes Rafael Arias‐Flores Irma M Medina‐Díaz Fernando Hernández‐Garza Gerardo Santos‐López Patricia Piña‐Sánchez On behalf of the IMSS Research Network on HPV 《Journal of medical virology》2015,87(5):871-884
1000.
Jeffrey J. Gaynor Gaetano Ciancio Giselle Guerra Junichiro Sageshima Lois Hanson David Roth Michael J. Goldstein Linda Chen Warren Kupin Adela Mattiazzi Lissett Tueros Sandra Flores Luis J. Barba Adrian Lopez Jose Rivas Phillip Ruiz Rodrigo Vianna George W. Burke III 《Diabetologia》2015,58(2):334-345