全文获取类型
收费全文 | 5091篇 |
免费 | 278篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 215篇 |
妇产科学 | 79篇 |
基础医学 | 412篇 |
口腔科学 | 154篇 |
临床医学 | 539篇 |
内科学 | 1303篇 |
皮肤病学 | 66篇 |
神经病学 | 232篇 |
特种医学 | 126篇 |
外国民族医学 | 1篇 |
外科学 | 1085篇 |
综合类 | 73篇 |
一般理论 | 1篇 |
预防医学 | 319篇 |
眼科学 | 117篇 |
药学 | 319篇 |
中国医学 | 27篇 |
肿瘤学 | 278篇 |
出版年
2023年 | 37篇 |
2022年 | 92篇 |
2021年 | 185篇 |
2020年 | 91篇 |
2019年 | 149篇 |
2018年 | 215篇 |
2017年 | 123篇 |
2016年 | 145篇 |
2015年 | 138篇 |
2014年 | 291篇 |
2013年 | 298篇 |
2012年 | 461篇 |
2011年 | 495篇 |
2010年 | 270篇 |
2009年 | 200篇 |
2008年 | 330篇 |
2007年 | 328篇 |
2006年 | 314篇 |
2005年 | 237篇 |
2004年 | 247篇 |
2003年 | 210篇 |
2002年 | 224篇 |
2001年 | 31篇 |
2000年 | 13篇 |
1999年 | 27篇 |
1998年 | 30篇 |
1997年 | 28篇 |
1996年 | 24篇 |
1995年 | 17篇 |
1994年 | 16篇 |
1993年 | 16篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1977年 | 5篇 |
1974年 | 4篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1962年 | 2篇 |
排序方式: 共有5400条查询结果,搜索用时 15 毫秒
81.
Does continuous positive airway pressure by face mask improve patients with acute cardiogenic pulmonary edema due to left ventricular diastolic dysfunction? 总被引:10,自引:0,他引:10
OBJECTIVE: Continuous positive airway pressure (CPAP) by face mask is an effective method of treating severe cardiogenic pulmonary edema (CPE). However, to our knowledge, no study has provided a precise evaluation of the effects of CPAP on cardiac function in patients presenting with CPE and preserved left ventricular (LV) function. DESIGN: Prospective observational clinical study. SETTING: A 14-bed, medical ICU at a university hospital. PATIENTS: Nine consecutive patients presenting with hypoxemic acute CPE. INTERVENTIONS: All patients were selected for 30 min of CPAP with 10 cm H(2)O by mask with fraction of inspired oxygen adjusted for a cutaneous saturation > 90%. Doppler echocardiography was performed before CPAP application and during the last 10 min of breathing with CPAP. Two-tailed, paired t-tests were used to compare data recorded at baseline (oxygen alone) and after CPAP. MEASUREMENTS AND RESULTS: Four patients presented CPE with preserved left ventricular (LV) function (a preserved LV ejection fraction [LVEF] > 45%, and/or aortic velocity time integral > 17 cm in the absence of aortic stenosis or hypertrophic cardiomyopathy). Oxygenation and ventilatory parameters were improved by CPAP in all patients. Hemodynamic monitoring and Doppler echocardiographic analysis demonstrated that in patients with preserved LV systolic function, mean arterial pressure and LV end-diastolic volume were decreased significantly by CPAP (p < 0.04). In patients with LV systolic dysfunction, CPAP improved LVEF (p < 0.05) and decreased LV end-diastolic volume (p = 0.001) significantly. CONCLUSION: CPAP improves oxygenation and ventilatory parameters in all kinds of CPE. In patients with preserved LV contractility, the hemodynamic benefit of CPAP results from a decrease in LV end-diastolic volume (preload). 相似文献
82.
83.
84.
Samar Samir Youssef Asmaa Mostafa Abd El-Aal Amr Saad Moataza Hassan Omran Taher El Zanaty Sameh Mohamed Seif 《Disease markers》2013,35(5):431-437
Introduction. Hepatitis C virus (HCV) infection affects almost 3% of the world''s population with the highest prevalence in Egypt (15%). The standard therapy; pegylated interferon (PEG-IFN) and ribavirin, is effective in only 60% of Egyptian patients; moreover it is costly, prolonged, and has severe side effects, so prediction of response is essential to reduce burden of unfavorable treatment. Several viral and host factors have been proved to affect response to the treatment PEG-IFN and ribavirin; the strongest of them is polymorphisms near IL28B; nonetheless, nonresponse in patients with favorable IL28B is still unexplained, which implies the importance of studying other immunological factors that may correlate with response. Interleukin 12 (IL-12) is one of the most important proinflammatory cytokine presented with the initiation of immune response, determining Th1 and Th2 differentiation. A functional single nucleotide polymorphism (A/C) at the 3′ untranslated region (3′UTR) at position 1188 (NCBI SNP database no 3212227) was reported to be associated with responding more efficiently to antiviral combination therapy in HCV genotype 1 infected patients. The present study aims to evaluate association between this polymorphism with fibrosis stages, necroinflammation activity, response to the combined therapy, and gender in Egyptian HCV genotype 4. Material and Methods. A total of 133 Egyptian chronic HCV (CHCV) patients were treated with IFN/RBV and were followed up. IL12B 1188 A/C genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PRC-RFLP) analysis. Results. A nonsignificant trend for higher sustained virological response (SVR) was observed in patients homozygote for IL12B 1188 A/C SNP CC genotype (69% SVR versus 30.8% NR) only but not in AC and AA genotypes. No association was detected between IL12B 1188 A/C polymorphism and less severe fibrosis or less liver activity. By stratification of response according to gender genotype, a significant difference in response between males and females was seen among AA genotype carriers only due to high number of non responder females. Conclusion. IL12B CC genotype appears to have some influence on SVR achievement but not on severe fibrosis and severe necroinflamation activity. Females carrying A/A genotype of IL12B 1188 A/C SNP achieve less SVR than those carrying AC and CC genotypes. 相似文献
85.
86.
Schimmel Martin Walther Moritz Al-Haj Husain Nadin Igarashi Kensuke Wittneben Julia Abou-Ayash Samir 《Clinical oral investigations》2021,25(11):6297-6307
Clinical Oral Investigations - To analyze the retention forces between primary and secondary telescopic crowns milled from various materials and to compare them with the retention forces between... 相似文献
87.
Bouazzi Shema Tayal Bhupendar Hansen Thomas Fritz Vinther Michael Kisslo Joseph Gorcsan John Svendsen Jesper Hastrup Søgaard Peter Saba Samir Risum Niels 《The international journal of cardiovascular imaging》2021,37(6):1843-1851
The International Journal of Cardiovascular Imaging - Cardiac resynchronization therapy (CRT) reduces the risk of ventricular arrhythmias (VA) in heart failure (HF) patients with left bundle branch... 相似文献
88.
89.
90.