全文获取类型
收费全文 | 26891篇 |
免费 | 3237篇 |
国内免费 | 654篇 |
专业分类
耳鼻咽喉 | 101篇 |
儿科学 | 491篇 |
妇产科学 | 1303篇 |
基础医学 | 1428篇 |
口腔科学 | 195篇 |
临床医学 | 8107篇 |
内科学 | 3895篇 |
皮肤病学 | 308篇 |
神经病学 | 1011篇 |
特种医学 | 1634篇 |
外国民族医学 | 6篇 |
外科学 | 3000篇 |
综合类 | 4739篇 |
现状与发展 | 3篇 |
预防医学 | 1195篇 |
眼科学 | 493篇 |
药学 | 1325篇 |
49篇 | |
中国医学 | 271篇 |
肿瘤学 | 1228篇 |
出版年
2024年 | 96篇 |
2023年 | 553篇 |
2022年 | 1015篇 |
2021年 | 1228篇 |
2020年 | 1527篇 |
2019年 | 1297篇 |
2018年 | 1266篇 |
2017年 | 1295篇 |
2016年 | 1255篇 |
2015年 | 1272篇 |
2014年 | 2197篇 |
2013年 | 1997篇 |
2012年 | 1528篇 |
2011年 | 1689篇 |
2010年 | 1323篇 |
2009年 | 1230篇 |
2008年 | 1270篇 |
2007年 | 1276篇 |
2006年 | 1089篇 |
2005年 | 874篇 |
2004年 | 739篇 |
2003年 | 687篇 |
2002年 | 562篇 |
2001年 | 469篇 |
2000年 | 377篇 |
1999年 | 380篇 |
1998年 | 314篇 |
1997年 | 294篇 |
1996年 | 251篇 |
1995年 | 204篇 |
1994年 | 184篇 |
1993年 | 157篇 |
1992年 | 118篇 |
1991年 | 113篇 |
1990年 | 94篇 |
1989年 | 69篇 |
1988年 | 68篇 |
1987年 | 49篇 |
1986年 | 58篇 |
1985年 | 90篇 |
1984年 | 63篇 |
1983年 | 21篇 |
1982年 | 45篇 |
1981年 | 33篇 |
1980年 | 23篇 |
1979年 | 21篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
Yuanqing Yao Jun Qian Shunkang Rong Yuwen Huang Bo Xiong Gang Yang Dengqing Zhang Shimin Deng Jie Tan Que Zhu Changming Deng Dichuan Liu Haitao Ran Zhigang Wang Jing Huang 《Ultrasound in medicine & biology》2019,45(2):490-499
Stellate ganglion (SG) modification has been investigated for arrhythmia treatment. In this study, transesophageal SG imaging and intervention were explored using a homemade 30F integrated focused ultrasonic catheter in healthy mongrel canines in vivo. Anatomic details of SGs were ultrasonically imaged and evaluated. SG had a heterogeneous echoic structure and characteristic profiles sketched by hyper-echoic outlines in an ultrasonogram. Left SGs in the experimental group were successfully ablated through the esophagus under ultrasonic guidance provided by the catheter itself. Two weeks after the ablation, the QT and QTc of the experimental group decreased compared with those of the sham group and at baseline (both p values < 0.001). Histologic examination revealed that left SGs were destroyed. No major complications were observed. This approach may be further explored as a method for ganglia remodeling evaluation and as a strategy of ganglia modification for arrhythmia and for other diseases. 相似文献
25.
《Journal of Cardiovascular Computed Tomography》2019,13(5):254-260
Invasive coronary plaque imaging such as intravascular ultrasound and optical coherence tomography has been widely used to observe culprit or non-culprit coronary atherosclerosis, as well as optimize stent sizing, apposition and deployment. Coronary computed tomographic angiography (CTA) is non-invasively available to assess coronary artery disease (CAD) and has become an appropriate strategy to evaluate patients with suspected CAD. Given recent technologies, semi-automated plaque software is available to identify coronary plaque stenosis, volume and characteristics and potentially allows to be used for the assessment of more details of plaque information, progression and future risk as a surrogate tool of the invasive imaging modalities. This review article aims to focus on various evidence in coronary plaque imaging by coronary CTA and describes how accurate coronary CTA can classify coronary atherosclerosis. 相似文献
26.
Adilson Cunha Ferreira Edward Araujo Júnior Wellington P. Martins João Francisco Jordão Antônio Hélio Oliani Simon E. Meagher 《The journal of maternal-fetal & neonatal medicine》2015,28(14):1706-1710
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality. 相似文献
27.
28.
BackgroundPre-operative carbohydrate (CHO) drinks have shown some benefits peri-operatively and have been incorporated into many Enhanced Recovery after Surgery (ERAS) programmes. We assessed the gastric emptying of pre-operative CHO drinks prior to elective caesarean delivery using ultrasonography.MethodsAfter a standard overnight fast, non-labouring pregnant women awaiting elective caesarean delivery underwent a standardised gastric ultrasound assessment at baseline and then every 20 min for 2 h after consuming 400 mL of a CHO drink. The gastric emptying was determined at each time-point both qualitatively and quantitatively. The primary outcome was the time taken for participants to return to a qualitative fasted Perlas grade of 0 or 1.ResultsThe gastric emptying of 40 participants was analysed. At baseline, all patients had a qualitative grade of either 0 or 1. All patients had returned to either grade 0 or 1 by 100 min. At 120 min the antral right lateral decubitus (RLD) cross-sectional area (CSA) was 8.03 cm2 (95th percentile; 95% CI 7.4 to 8.3 cm2) and gastric volume per kg was 1.57 mL/kg (95th percentile; 95% CI 1.4 to 2.2). At 120 min there was no statistically significant difference from baseline for the RLD CSA (P=0.38) or gastric volume per kg (P=0.27).ConclusionsThe gastric emptying of this cohort of pregnant women suggests that 400 mL of a CHO drink can be safely consumed up to two hours before elective surgery. This study can help inform future peri-operative fasting guidelines for pregnant patients. 相似文献
29.
30.