全文获取类型
收费全文 | 1498篇 |
免费 | 72篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 48篇 |
妇产科学 | 39篇 |
基础医学 | 179篇 |
口腔科学 | 80篇 |
临床医学 | 145篇 |
内科学 | 367篇 |
皮肤病学 | 48篇 |
神经病学 | 99篇 |
特种医学 | 146篇 |
外科学 | 141篇 |
综合类 | 74篇 |
预防医学 | 98篇 |
眼科学 | 27篇 |
药学 | 46篇 |
中国医学 | 4篇 |
肿瘤学 | 50篇 |
出版年
2023年 | 11篇 |
2022年 | 20篇 |
2021年 | 28篇 |
2020年 | 21篇 |
2019年 | 31篇 |
2018年 | 31篇 |
2017年 | 22篇 |
2016年 | 50篇 |
2015年 | 36篇 |
2014年 | 48篇 |
2013年 | 89篇 |
2012年 | 60篇 |
2011年 | 72篇 |
2010年 | 56篇 |
2009年 | 48篇 |
2008年 | 59篇 |
2007年 | 65篇 |
2006年 | 43篇 |
2005年 | 38篇 |
2004年 | 42篇 |
2003年 | 29篇 |
2002年 | 43篇 |
2001年 | 24篇 |
2000年 | 26篇 |
1999年 | 24篇 |
1998年 | 56篇 |
1997年 | 51篇 |
1996年 | 36篇 |
1995年 | 28篇 |
1994年 | 33篇 |
1993年 | 36篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 17篇 |
1989年 | 38篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 16篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1972年 | 6篇 |
1963年 | 6篇 |
1941年 | 11篇 |
排序方式: 共有1596条查询结果,搜索用时 15 毫秒
81.
OBJECTIVE: To analyze variations in early neonatal mortality, stillbirth rates, and a set of indicators collected from obstetric hospitals affiliated to the Brazilian National Unified Health System (SUS) for their monitoring through the Hospital Data System (SIH/SUS) and Live Births Data System (SINASC). METHODS: One-hundred and thirty five hospitals in the state of Rio de Janeiro were assessed in 1997. Factor analysis was conducted using principal components. Score distribution for the first two components were established, which allowed to classify hospitals according to maternal risk profile and care outcomes. RESULTS: Hospitals affiliated to SUS were responsible for 77.8% of all deliveries in the state of Rio de Janeiro and 23% of them performed fewer than 100 deliveries a year. Among hospitals of extreme high maternal risk and low performance, there were several units considered as referral centers for high-risk pregnancy. It was also observed that 5% of hospital units with low complexity infrastructures showed a profile of high maternal risk and questionable care outcomes. CONCLUSIONS: The Hospital Information Data System affiliated to the National Unified Health System has proven to be an important information source for monitoring hospital stillbirth and early neonatal mortality rates as well as for planning surveillance actions for health services providing obstetric and/or neonatal care. 相似文献
82.
83.
84.
Cocaine use in pregnancy in Amsterdam 总被引:1,自引:0,他引:1
BJ Smit K Boer AM van Huis ISE Lie-A-Ling SC Schmidt 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S404):32-35
To study the effects of cocaine use in pregnancy in Amsterdam, clinical data on cocaine-using pregnant women ( n = 21) and their offspring ( n = 23) were obtained retrospectively (1987–1994) at the Academic Medical Center, Amsterdam. Infants exposed to cocaine had a median gestational age of 39 weeks and a median birth weight of 3090 g. There were six preterm infants, two small-for-gestational-age infants and five infants with a small head circumference. Three infants had a congenital malformation. One infant (Potter's syndrome) died shortly before birth. One infant had congenital syphilis, four had intracerebral abnormalities on ultrasound and four had abnormal neurologic symptoms in the neonatal period. One infant died after 21 days of life. At follow-up four infants showed abnormal development. In 12 of the 23 infants (52%), one or more possible effects of cocaine were found. 相似文献
85.
OBJECTIVE: Cardiac catheterization has begun to be employed for therapeutic purposes since the middle sixties. In this paper the authors review the current indications, technique and results related to each of the interventional procedures. It also includes a brief sample of the Instituto Dante Pazzanese experience for illustrative purpose. METHODS: The main procedures that are addressed include balloon and blade atrial septostomy (Rashkind and Park procedures), pulmonary valvuloplasty, aortic valvuloplasty, mitral valvuloplasty (for rheumatic mitral stenosis), angioplasty for coarctation of aorta with or without stent implantation, angioplasty for pulmonary artery stenosis with or without stent implantation, percutaneous occlusion of the patent ductus arteriosus, percutaneous occlusion of atrial septal defects and balloon dilation of stenosed Blalock-Taussig shunts. The authors make a review of the most important papers published in the literature about Interventional Pediatric Cardiology, including their own experience. RESULTS: Good or excelent therapeutic results are achieved for pulmonic stenosis, coarctation of aorta, patent ductus arteriosus, atrial septal defects and pulmonary branch stenosis. Satisfactory palliations are obtained for aortic stenosis, rheumatic mitral stenosis and complex congenital heart diseases that require balloon atrial septostomy. CONCLUSIONS: Due to the recent technological development, pediatric therapeutic heart catheterization makes it possible to treat or palliate about 30% of all congenital or acquired heart diseases with encouraging results, sparing some patients from the need of cardiac surgery. 相似文献
86.
87.
88.
Esteves MB Marques-Santos LF Affonso-Mitidieri OR Rumjanek VM 《Anais da Academia Brasileira de Ciências》2005,77(2):281-292
Lymphocytes activated by mitogenic lectins display changes in transmembrane potential, an elevation in the cytoplasmic Ca2+ concentrations, proliferation and/or activation induced cell death. Low concentrations of ouabain (an inhibitor of Na+,K+-ATPase) suppress mitogen-induced proliferation and increases cell death. To understand the mechanisms involved, a number of parameters were analyzed using fluorescent probes and flow cytometry. The addition of 100 nM ouabain to cultures of peripheral blood lymphocytes activated with 5 microg/ml phytohemagglutinin (PHA) did not modify the increased expression of the Fas receptor or its ligand FasL induced by the mitogen. However, treatment with ouabain potentiated apoptosis induced by an anti-Fas agonist antibody. A synergy between ouabain and PHA was also observed with regard to plasma membrane depolarization. PHA per se did not induce dissipation of mitochondrial membrane potential but when cells were also exposed to ouabain a marked depolarization could be observed, and this was a late event. It is possible that the inhibitory effect of ouabain on activated peripheral blood lymphocytes involves the potentiation of some of the steps of the apoptotic process and reflects an exacerbation of the mechanism of activation-induced cell death. 相似文献
89.
90.
Cefaly DF Barata Tde J Tapety CM Bresciani E Navarro MF 《Journal of applied oral science : revista FOB》2005,13(1):15-19
The aim of this study was to evaluate the performance of two different glass-ionomer cements: a high-density (Ketac Molar - ESPE) and a resin-modified cement (Fuji VIII - GC) using the Atraumatic Restorative Treatment technique to restore multisurface cavities in permanent teeth. A total of 60 ART restorations (30 with each material) were placed in schoolchildren (9-16 years of age) by two operators. After a period of 6 months, two independent examiners evaluated 59 restorations according to the criteria used in previous ART studies. Data were submitted to McNemar and Fischer tests. The success rate of the treatment was 98.3%. One restoration (Ketac Molar) was replaced by another material and was recorded as failure. The success rates of the restorations were 100% and 96.6% for Fuji VIII and Ketac Molar, respectively. There was no statistically significant difference in the restorations success between baseline and 6 months (p>0.05). In the same way, no significant differences were found between materials, cavity types or operators (p>0.05). The ART approach was highly appropriate and effective in restorations involving two or more tooth surfaces, after 6 months. The results showed a promising performance of the ART technique with both materials. 相似文献