全文获取类型
收费全文 | 10952篇 |
免费 | 713篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 135篇 |
儿科学 | 239篇 |
妇产科学 | 160篇 |
基础医学 | 1622篇 |
口腔科学 | 686篇 |
临床医学 | 926篇 |
内科学 | 2419篇 |
皮肤病学 | 228篇 |
神经病学 | 1136篇 |
特种医学 | 220篇 |
外科学 | 1399篇 |
综合类 | 16篇 |
一般理论 | 2篇 |
预防医学 | 999篇 |
眼科学 | 139篇 |
药学 | 753篇 |
中国医学 | 49篇 |
肿瘤学 | 553篇 |
出版年
2024年 | 8篇 |
2023年 | 105篇 |
2022年 | 94篇 |
2021年 | 284篇 |
2020年 | 185篇 |
2019年 | 265篇 |
2018年 | 436篇 |
2017年 | 286篇 |
2016年 | 306篇 |
2015年 | 295篇 |
2014年 | 379篇 |
2013年 | 556篇 |
2012年 | 899篇 |
2011年 | 1103篇 |
2010年 | 542篇 |
2009年 | 319篇 |
2008年 | 814篇 |
2007年 | 836篇 |
2006年 | 670篇 |
2005年 | 688篇 |
2004年 | 602篇 |
2003年 | 488篇 |
2002年 | 459篇 |
2001年 | 145篇 |
2000年 | 166篇 |
1999年 | 132篇 |
1998年 | 48篇 |
1997年 | 42篇 |
1996年 | 33篇 |
1995年 | 31篇 |
1994年 | 28篇 |
1993年 | 13篇 |
1992年 | 48篇 |
1991年 | 57篇 |
1990年 | 37篇 |
1989年 | 24篇 |
1988年 | 20篇 |
1987年 | 18篇 |
1986年 | 18篇 |
1985年 | 15篇 |
1984年 | 19篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 15篇 |
1978年 | 15篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Micro‐evolution of the hepatitis B virus genome in hepatitis B e‐antigen‐positive carriers: Comparison of genotypes B and C at various immune stages
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
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
8.
Luana Lopes Padilha Elcio Oliveira Vianna Andressa Talícia Machado Vale Joelma Ximenes Prado Teixeira Nascimento Antônio Augusto Moura da Silva Cecilia Claudia Costa Ribeiro 《Pediatric allergy and immunology》2020,31(5):480-488
Studies on the exposure of children to sugar-sweetened beverages (SSBs) at an early age may contribute to better understand the common causes and the temporal order of the relationships between obesity and asthma in early childhood. The objective of this study was to estimate the association between SSB and child asthma traits in the 2nd year of life, modeling direct and indirect pathways mediated by the highest BMI-z of the child and allergic inflammation. Data from the BRISA cohort, São Luís-MA, Brazil (n = 1140), were obtained from the baseline and from the follow-up performed at the 2nd year of life. The main explanatory variable was the calories from added sugars in SSBs as a percentage of the total daily energy intake. The outcome child asthma traits was a latent variable deduced from four indicators: medical diagnosis of asthma, wheezing, emergency visit due to intense wheezing, and medical diagnosis of rhinitis. A high percentage of daily calories from sugars added to SSBs was directly associated with higher values of child asthma traits (standardized coefficient (SC = 0.073; P = .030)). High levels of eosinophils were also directly associated with child asthma traits (SC = 0.118; P = .049). No mediation pathways were observed via greater BMI-z or eosinophil counts. Therefore, early exposure of children to SSB may contribute to increased risk of childhood asthma, preceding the link between sugar consumption and overweight/obesity, not yet evident in children in the first 2 years of life. 相似文献
9.
Victor Aboyans Louis Labrousse Philippe Lacroix Jér?me Guilloux Seifeddine Sekkal Alexandre Le Guyader Elisabeth Cornu Marc Laskar 《European journal of cardio-thoracic surgery》2006,30(2):300-304
BACKGROUND: Despite major improvement in surgical techniques and intensive care management, stroke remains one of the most devastating complications of coronary artery bypass grafting (CABG). We aimed to determine factors predicting the occurrence of stroke during CABG. A special interest was focused on preoperative therapies. METHODS: We prospectively enrolled 810 consecutive candidates for CABG alone in a specific database, including all pre- and perioperative data (history, clinical, therapeutic, cardiac catheterization, surgical and intensive care data). Univariate tests and then multiple logistic regression analysis were used to determine independent predictive factors. RESULTS: During the first postoperative month, stroke occurred in 11 cases and transient ischemic attack (TIA) in 4 additive cases (cumulative rate: 1.85%). After the multivariate analysis, the following factors remained significant (p<0.05) in the predictive model, with corresponding odds ratios between brackets: redo cardiac surgery (7.45), unstable cardiac status (4.74), past history of cerebrovascular disease (4.14), past history of peripheral arterial disease (3.55), whereas the presence of preoperative statins was protective (0.24, 95% IC: 0.07-0.78). The addition of perioperative data (aortic calcification, postoperative arrhythmia, on/off-pump surgery) did not change the final predictive model. CONCLUSION: To our knowledge, this is the first real-world observational report highlighting the interest of statins for the prevention of stroke in the very special situation of CABG. Even though according to randomized trials coronary patients have a benefit from these drugs, a special level of interest should be directed towards those presenting the above-mentioned risk factors. 相似文献
10.
Jér?me Dumortier Marie-Claude Gagnieu Janine Salandre Olivier Guillaud Philipe Guillem Mustapha Adham Olivier Boillot 《Liver transplantation》2006,12(9):1342-1346
Gastrointestinal (GI) disorders are one of the main adverse events in patients treated by mycophenolic acid (MPA). The aim of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in liver transplant patients presenting GI side-effects Since January 2003, stable liver transplant patients receiving MMF and presenting GI disorders, without evidence of other origin than MMF were enrolled. Conversion was performed without a washout period at an equimolar daily dosage. Thirty-six patients were included after a median delay of 45 months after liver transplantation (LT) (16 women and 20 men, median age of 47 years). Diarrhoea was the main clinical symptom (n = 28, 77.7%). At the time of inclusion, patients were treated with MMF since 18 months (range 3-28) and GI disorders were known for 9 months (range 3-12). After a median follow-up of 12 months after conversion, GI disorders were resolved in 20 patients (55%), improved in 6 patients (17%) and not modified or worsened in 10 patients (28%). Our results strongly suggest that conversion from MMF to EC-MPS in liver transplant patients can improve gastrointestinal disorders in a majority of the patients, and therefore might be considered as the best therapeutic option. 相似文献