全文获取类型
收费全文 | 4056940篇 |
免费 | 294364篇 |
国内免费 | 10066篇 |
专业分类
耳鼻咽喉 | 56600篇 |
儿科学 | 135273篇 |
妇产科学 | 112939篇 |
基础医学 | 568787篇 |
口腔科学 | 114001篇 |
临床医学 | 372692篇 |
内科学 | 786366篇 |
皮肤病学 | 94359篇 |
神经病学 | 329938篇 |
特种医学 | 154891篇 |
外国民族医学 | 1600篇 |
外科学 | 608102篇 |
综合类 | 90115篇 |
现状与发展 | 8篇 |
一般理论 | 1550篇 |
预防医学 | 319181篇 |
眼科学 | 93733篇 |
药学 | 296857篇 |
10篇 | |
中国医学 | 8371篇 |
肿瘤学 | 215997篇 |
出版年
2019年 | 31580篇 |
2018年 | 44335篇 |
2017年 | 33856篇 |
2016年 | 38744篇 |
2015年 | 43628篇 |
2014年 | 60901篇 |
2013年 | 92181篇 |
2012年 | 123580篇 |
2011年 | 131588篇 |
2010年 | 78957篇 |
2009年 | 74887篇 |
2008年 | 122488篇 |
2007年 | 130395篇 |
2006年 | 131934篇 |
2005年 | 127548篇 |
2004年 | 122834篇 |
2003年 | 118370篇 |
2002年 | 114776篇 |
2001年 | 189247篇 |
2000年 | 194608篇 |
1999年 | 164550篇 |
1998年 | 48428篇 |
1997年 | 42877篇 |
1996年 | 42768篇 |
1995年 | 41174篇 |
1994年 | 37936篇 |
1993年 | 35613篇 |
1992年 | 128925篇 |
1991年 | 124692篇 |
1990年 | 121205篇 |
1989年 | 116954篇 |
1988年 | 107648篇 |
1987年 | 105634篇 |
1986年 | 99147篇 |
1985年 | 95117篇 |
1984年 | 71623篇 |
1983年 | 60894篇 |
1982年 | 36220篇 |
1981年 | 32657篇 |
1979年 | 64406篇 |
1978年 | 45540篇 |
1977年 | 38661篇 |
1976年 | 36117篇 |
1975年 | 38342篇 |
1974年 | 45599篇 |
1973年 | 43655篇 |
1972年 | 41094篇 |
1971年 | 37874篇 |
1970年 | 35528篇 |
1969年 | 33351篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
C Potera 《Environmental health perspectives》2002,110(10):A567-A568
994.
995.
996.
997.
Hippocampal pathology in refractory temporal lobe epilepsy: T2-weighted signal change reflects dentate gliosis. 总被引:11,自引:0,他引:11
Regula S Briellmann Renate M Kalnins Samuel F Berkovic Graeme D Jackson 《Neurology》2002,58(2):265-271
BACKGROUND: The MR and pathologic features of hippocampal sclerosis (HS) are well described and include volume decrease and T2-weighted signal increase for MRI, and neuron cell loss and gliosis for pathology. OBJECTIVE: To confirm the established correlation between hippocampal volumes and neuron cell counts, and to study the still controversial association between signal change and gliosis. METHODS: The authors studied 44 patients (22 men and 22 women; mean age at surgery, 37 years) with refractory temporal lobe epilepsy. Quantitative assessment of hippocampal volumes and T2 relaxometry, and neuron and glial cell count in the region CA1 and molecular layer of the dentate gyrus was performed. The proportion of glial fibrillary acidic protein (GFAP)-positive glial cells (reactive astrocytes) was indicated. RESULTS: In a stepwise regression, the ipsilateral hippocampal volume was predicted best by the neuron cell count in the dentate gyrus (p = 0.005, r = 0.4). Hippocampal T2 time, however, was predicted best by the glial cell count in the dentate gyrus (p = 0.01, r = 0.4). None of the other cell counts contributed to either model. In the dentate, 31% of the glial cells were reactive astrocytes, whereas in CA1, 5% were reactive. CONCLUSION: The results confirmed the correlation between hippocampal volumes and neuron cell counts. T2-weighted signal increase in the hippocampus was mainly influenced by gliosis in the dentate gyrus, where a high proportion of glial cells show abnormal activity. This activity may reflect changes important in the development of hippocampal epileptogenicity. 相似文献
998.
M Hansrani K Overbeck J Smout G Stansby 《European journal of vascular and endovascular surgery》2002,24(5):377-382
INTRODUCTION: Intravascular brachytherapy (IVBT) utilises the percutaneous insertion of a radioactive source to inhibit myointimal hyperplasia in arteries treated by balloon angioplasty or stenting. A systematic review was performed of trials of IVBT in patients with Peripheral Arterial Disease (PAD). METHODS: Search strategy - the reviewers searched Medline, Embase, the Cochrane Peripheral Vascular Diseases Group trials register, DARE, CCT and NHS EED for clinical studies and trials of adjuvant IVBT in PAD. Two reviewers assessed trial quality independently. RESULTS: Fourteen clinical trials were identified by the search, representing five clinical studies (all allocated D for not randomised) and one randomised controlled trial (allocated A). The randomised trial showed a benefit for IVBT compared with placebo (OR 0.35, 95% CI 0.24-0.53). In the non-randomised studies, 12 month cumulative patency rates ranged from 60-87%. There were few technical complications. In the only report involving IVBT and routine concurrent stent insertion acute thrombosis occurred in 7 (21%) of patients. CONCLUSION: Early reports have confirmed the safety and technical feasibility of IVBT. However, follow-up is too short at present to assess the durability and long-term complications of this new therapeutic option. 相似文献
999.
1000.
E J Buchmann R C Pattinson N Nyathikazi 《Suid-Afrikaanse tydskrif vir geneeskunde》2002,92(11):897-901
BACKGROUND: The recent amalgamation of data by users of the Perinatal Problem Identification Programme (PPIP) throughout South Africa has culminated in the publication of the Saving Babies report. OBJECTIVES: To determine the absolute rate of death from intrapartum-related birth asphyxia, and the contribution of intrapartum-related asphyxia to total perinatal mortality in South African hospitals, and to identify the primary obstetric causes and avoidable factors for these deaths. METHODS: The amalgamated PPIP data for the year 2000 were obtained from 27 state hospitals (6 metropolitan, 12 town and 9 rural) in South Africa. In PPIP-based audit, all perinatal deaths are assigned primary obstetric causes and avoidable factors, and these elements were obtained for all deaths resulting from intrapartum-related birth asphyxia. RESULTS: There were 123,508 births in the hospitals surveyed, with 4,142 perinatal deaths among infants > or = 1,000 g, giving a perinatal mortality rate of 33.5/1,000 births. The perinatal mortality rate from intrapartum-related birth asphyxia was 4.8/1,000 births. The most frequent avoidable factors were delay by mothers in seeking attention during labour (36.6%), signs of fetal distress interpreted incorrectly (24.9%), inadequate fetal monitoring (18.0%) and no response to poor progress in labour (7.0%). The perinatal mortality rates for metropolitan, town, and rural areas were 30.0, 39.4 and 30.9/1,000 births respectively. The contribution of intrapartum-related birth asphyxia to perinatal mortality in these areas was 10.8%, 16.7% and 26.4% respectively. CONCLUSION: The high rates of perinatal death from intrapartum-related birth asphyxia in South Africa are typical of those in underdeveloped countries, with the most serious deficiencies in rural areas. Most of these deaths are avoidable and the reduction of these rates presents an important challenge to providers of perinatal care in this country. Areas worthy of research and action include provision of mothers' waiting facilities in rural regions, improvements in fetal monitoring, partogram-based labour management, and the establishment of midwifery staffing norms for South African labour units. 相似文献