全文获取类型
收费全文 | 4440篇 |
免费 | 448篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 96篇 |
妇产科学 | 109篇 |
基础医学 | 514篇 |
口腔科学 | 78篇 |
临床医学 | 457篇 |
内科学 | 867篇 |
皮肤病学 | 55篇 |
神经病学 | 237篇 |
特种医学 | 143篇 |
外科学 | 676篇 |
综合类 | 133篇 |
预防医学 | 444篇 |
眼科学 | 197篇 |
药学 | 357篇 |
中国医学 | 97篇 |
肿瘤学 | 457篇 |
出版年
2023年 | 40篇 |
2022年 | 20篇 |
2021年 | 82篇 |
2020年 | 68篇 |
2019年 | 112篇 |
2018年 | 103篇 |
2017年 | 90篇 |
2016年 | 92篇 |
2015年 | 133篇 |
2014年 | 153篇 |
2013年 | 190篇 |
2012年 | 267篇 |
2011年 | 269篇 |
2010年 | 184篇 |
2009年 | 172篇 |
2008年 | 266篇 |
2007年 | 291篇 |
2006年 | 235篇 |
2005年 | 258篇 |
2004年 | 203篇 |
2003年 | 206篇 |
2002年 | 163篇 |
2001年 | 119篇 |
2000年 | 117篇 |
1999年 | 120篇 |
1998年 | 54篇 |
1997年 | 44篇 |
1996年 | 39篇 |
1995年 | 26篇 |
1994年 | 34篇 |
1993年 | 32篇 |
1992年 | 90篇 |
1991年 | 80篇 |
1990年 | 70篇 |
1989年 | 53篇 |
1988年 | 66篇 |
1987年 | 62篇 |
1986年 | 45篇 |
1985年 | 43篇 |
1984年 | 26篇 |
1983年 | 28篇 |
1982年 | 27篇 |
1981年 | 16篇 |
1979年 | 19篇 |
1978年 | 15篇 |
1977年 | 10篇 |
1976年 | 17篇 |
1974年 | 12篇 |
1972年 | 12篇 |
1970年 | 11篇 |
排序方式: 共有4950条查询结果,搜索用时 328 毫秒
1.
Ngai-Yin Chan Chi-Chung Choy Ho-Chuen Yuen Hoi-Fan Chow Ho-Fai Fong 《The Canadian journal of cardiology》2019,35(4):396-404
Background
Persistent iatrogenic atrial septal defect (iASD) is a common but poorly characterized complication after cryoballoon (CB) pulmonary vein isolation (PVI) procedures. We therefore investigate its prevalence, evolution, risk factors, and clinical outcomes in a prospective longitudinal study.Methods
A total of 108 patients (41 women, mean age 57 ± 11.3) underwent CB PVI for AF. Serial transesophageal echocardiography (TEE) was performed 9 months and then annually until 6 years after the procedure to study the characteristics of persistent iASD.Results
Persistent iASD occurred in 33 (30.6%) patients 9 months after CB PVI. Spontaneous closure of iASD was found in 6 (22.2%) and 3 (15.8%) patients 2 and 3 years after the procedures, respectively. No spontaneous closure was observed on 4, 5, and 6-year TEE follow-up. The projected long-term persistence rate of iASD after CB PVI was therefore 20% (30.6% × 0.778 × 0.842). Using multivariate logistic regression, a higher number of cryoapplications (≥ 2 minutes) was the only independent predictor of persistent iASD 9 months after CB PVI (odds ratio [OR] 1.207; 95% confidence interval [CI], 1.033-1.411, P = 0.018). Two (1.9%) patients with significantly larger iASD size than the others (long diameter 12.6 ± 0.8 vs 3.7 ± 1.5 mm, P < 0.001; short diameter 10.9 ± 0.2 vs 3 ± 1.1 mm, P < 0.001) required percutaneous closure because of exertional dyspnea and right ventricular enlargement. Over 129.7 patient-years follow-up, during which iASD persisted, there was no occurrence of neurologic events.Conclusions
Approximately one fifth of patients undergoing CB PVI will have permanently persistent iASD. Patients with defect sizes of greater than 10 mm may need percutaneous closure due to significant left-to-right shunting. 相似文献2.
3.
4.
5.
Pedro Fong Cheng N. Ao Kai I. Tou Ka M. Huang Chi C. Cheong Li R. Meng 《Oncology research》2019,27(2):237-251
The aim of this study was to investigate the inhibition effects of cordycepin and its derivatives on endometrial
cancer cell growth. Cytotoxicity MTT assays, clonogenic assays, and flow cytometry were used to observe
the effects on apoptosis and regulation of the cell cycle of Ishikawa cells under various concentrations of
cordycepin, cisplatin, and combinations of the two. Validated in silico docking simulations were performed
on 31 cordycepin derivatives against adenosine deaminase (ADA) to predict their binding affinities and hence
their potential tendency to be metabolized by ADA. Cordycepin has a significant dose-dependent inhibitory
effect on cell proliferation. The combination of cordycepin and cisplatin produced greater inhibition effects
than did cordycepin alone. Apoptosis investigations confirmed the ability of cordycepin to induce the apoptosis of Ishikawa cells. The in silico results indicate that compound MRS5698 is least metabolized by ADA
and has acceptable drug likeness and safety profiles. This is the first study to confirm the cytotoxic effects of
cordycepin on endometrial cancer cells. This study also identified cordycepin derivatives with promising pharmacological and pharmacokinetic properties for further investigation in the development of new treatments for
endometrial cancer 相似文献
6.
Michael WK. Fong Jacint Sala-Padro Melissa Bartley Mark AJ. Dexter Andrew F. Bleasel Chong H. Wong 《Epileptic Disord》2019,21(4):347-352
Aims. Small encephaloceles of the anterior temporal pole have been increasingly recognised as an underlying epileptogenic substrate in patients with medically refractory epilepsy. The current report aims to expand on the current knowledge by emphasising that seizure semiology in such patients can vary significantly. Methods. Patients were selected from an epilepsy surgery database between 2012 and 2017. Results. Of the 143 patients who underwent epilepsy surgery, six patients had a temporal encephalocele. Four of these patients had stereo-EEG implantation. Of the four patients studied, each had a seizure semiology discordant with an ictal focus in the temporal lobe. Intracranial EEG assessment demonstrated, irrespective of this semiology, seizures originated from the anterior temporal pole. Seizures were observed to rapidly propagate to the orbitofrontal cortex, insula, temporo-occipital junction, and posterior language regions. Engagement of the mesial temporal structures could occur early or late, however, a good surgical outcome was achieved following a focused lesionectomy in either situation. Conclusion. The major finding was that seizures arising from anterior temporal encephaloceles can have an extra-temporal semiology. The varied clinical semiology and the rapid propagation to seemingly distant cortical regions could be explained by the connectivity of the anterior temporal lobe. 相似文献
7.
Shannon Gravely James F. Thrasher K. Michael Cummings Janine Ouimet Ann McNeill Gang Meng Eric N. Lindblom Ruth Loewen Richard J. OConnor Mary E. Thompson Sara C. Hitchman David Hammond Bryan W. Heckman Ron Borland Hua‐Hie Yong Tara Elton‐Marshall Maansi Bansal‐Travers Coral Gartner Geoffrey T. Fong 《Addiction (Abingdon, England)》2019,114(Z1):71-85
8.
9.
Cindy H.T. Yeung Simon Fong Paul R.V. Malik Andrea N. Edginton 《Maternal & child nutrition》2020,16(2)
Despite the many benefits of breast milk, mothers taking medication are often uncertain about the risks of drug exposure to their infants and decide not to breastfeed. Physiologically based pharmacokinetic models can contribute to drug‐in‐milk safety assessments by predicting the infant exposure and subsequently, risk for toxic effects that would result from continuous breastfeeding. This review aimed to quantify breast milk intake feeding parameters in term and preterm infants using literature data for input into paediatric physiologically based pharmacokinetic models designed for drug‐in‐milk risk assessment. Ovid MEDLINE and Embase were searched up to July 2, 2019. Key study reference lists and grey literature were reviewed. Title, abstract and full text were screened in nonduplicate. Daily weight‐normalized human milk intake (WHMI) and feeding frequency by age were extracted. The review process retrieved 52 studies. A nonlinear regression equation was constructed to describe the WHMI of exclusively breastfed term infants from birth to 1 year of age. In all cases, preterm infants fed with similar feeding parameters to term infants on a weight‐normalized basis. Maximum WHMI was 152.6 ml/kg/day at 19.7 days, and weighted mean feeding frequency was 7.7 feeds/day. Existing methods for approximating breast milk intake were refined by using a comprehensive set of literature data to describe WHMI and feeding frequency. Milk feeding parameters were quantified for preterm infants, a vulnerable population at risk for high drug exposure and toxic effects. A high‐risk period of exposure at 2–4 weeks of age was identified and can inform future drug‐in‐milk risk assessments. 相似文献
10.