全文获取类型
收费全文 | 12122篇 |
免费 | 819篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 221篇 |
儿科学 | 441篇 |
妇产科学 | 237篇 |
基础医学 | 1657篇 |
口腔科学 | 329篇 |
临床医学 | 1227篇 |
内科学 | 2566篇 |
皮肤病学 | 227篇 |
神经病学 | 1170篇 |
特种医学 | 454篇 |
外国民族医学 | 1篇 |
外科学 | 1831篇 |
综合类 | 109篇 |
一般理论 | 3篇 |
预防医学 | 875篇 |
眼科学 | 187篇 |
药学 | 751篇 |
1篇 | |
中国医学 | 8篇 |
肿瘤学 | 691篇 |
出版年
2021年 | 163篇 |
2020年 | 104篇 |
2019年 | 170篇 |
2018年 | 200篇 |
2017年 | 145篇 |
2016年 | 153篇 |
2015年 | 189篇 |
2014年 | 263篇 |
2013年 | 402篇 |
2012年 | 592篇 |
2011年 | 580篇 |
2010年 | 310篇 |
2009年 | 309篇 |
2008年 | 520篇 |
2007年 | 556篇 |
2006年 | 573篇 |
2005年 | 552篇 |
2004年 | 558篇 |
2003年 | 489篇 |
2002年 | 426篇 |
2001年 | 402篇 |
2000年 | 376篇 |
1999年 | 331篇 |
1998年 | 122篇 |
1997年 | 111篇 |
1996年 | 94篇 |
1995年 | 93篇 |
1992年 | 239篇 |
1991年 | 226篇 |
1990年 | 214篇 |
1989年 | 259篇 |
1988年 | 207篇 |
1987年 | 203篇 |
1986年 | 208篇 |
1985年 | 210篇 |
1984年 | 133篇 |
1983年 | 157篇 |
1982年 | 93篇 |
1981年 | 85篇 |
1980年 | 92篇 |
1979年 | 159篇 |
1978年 | 99篇 |
1976年 | 85篇 |
1974年 | 93篇 |
1973年 | 84篇 |
1972年 | 90篇 |
1971年 | 85篇 |
1970年 | 84篇 |
1969年 | 86篇 |
1966年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Hanna Lee Mary K. Tan Andrew T. Yan Paul Angaran Paul Dorian Claudia Bucci Jean C. Gregoire Alan D. Bell Martin S. Green Peter L. Gross Allan Skanes Charles R. Kerr L. Brent Mitchell Jafna L. Cox Vidal Essebag Brett Heilbron Krishnan Ramanathan Carl Fournier Shaun G. Goodman 《The Canadian journal of cardiology》2019,35(2):160-168
Background
Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.Methods
We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).Results
Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.Conclusions
Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation. 相似文献2.
3.
4.
5.
Characterization of gp 50, a major glycoprotein present in rat brain synaptic membranes, with a monoclonal antibody 总被引:4,自引:0,他引:4
Philip W. Beesley Toni Paladino Claude Gravel Richard A. Hawkes James W. Gurd 《Brain research》1987,408(1-2):65-78
Several cell lines secreting monoclonal antibodies (Mabs) against a major forebrain synaptic membrane (SM) glycoprotein, gp 50, have been raised. Western blots show that the Mabs react with a polypeptide doublet of Mrs 49 and 45 kDa. These polypeptides exist solely in a concanavalin A (Con A) binding form. Removal of the Con A receptors by digestion with endo-beta-N-acetylglucosaminidase H (endo H) lowers the Mrs of the glycoprotein doublet to 36.5 and 34 kDa. Western blots of 2D polyacrylamide gels indicate that gp 50 exists in several isoforms. Solid phase radioimmunoassay (RIA) and Western blots of brain subcellular fractions show the antigenic material to be concentrated in the SM fraction, but to be present in much lower amounts in synaptic junctions and postsynaptic densities. Gp 50 appears to be brain specific. Regional distribution studies show that it is present in all brain regions but is two-fold concentrated in cerebellum, brainstem and midbrain compared to forebrain. Immunocytochemical studies of several brain regions show that gp 50-like immunoreactivity is neuron specific and is concentrated in selected neuronal species, particularly granule cells. In both cerebellar and hippocampal granule cells gp 50-like immunoreactivity is localized in the perikarya and primary dendrites. Though immunocytochemistry did not show staining of synaptic regions this may be due to masking of the reactive epitope. The results are discussed in terms of the molecular properties of gp 50 and its subcellular localization in brain tissue. 相似文献
6.
C. Fischer W. Gross J. Krüger M. Cremer F. Vogel T. Grimm 《Annals of human genetics》2006,70(2):237-248
For several genetic diseases two biological phenomena have been recognised as important: germline mosaicism; and different new mutation rates in males and females depending on mutation type. Both principles have been investigated separately and their influence on risk estimation in families has been exemplified in the literature. The aim of this paper is to present a general model that includes mosaicism and different new mutation rates. Mosaicism is introduced by defining additional alleles at the disease locus in combination with adapted segregation rules. Taking Duchenne muscular dystrophy as an example, we derive the conditions which have to be fulfilled for a population in mutation selection equilibrium. Our approach describes the model at the population level and not in individual subjects. This has the advantage of being able to use well known algorithms for the calculation of likelihoods in pedigrees, and to include additional diagnostic information such as marker genotypes and carrier deletion test results. We demonstrate the impact of the new model on a typical pedigree. In families where the patient is not available, the distinction between point mutations and deletions is important, since often molecular diagnostic tests for females can only screen for deletions. Negative deletion test results can now be included in the risk calculations. 相似文献
7.
Health care use among young children in day care. Results in a randomized trial of early intervention 总被引:2,自引:0,他引:2
Exposure of young children to group day-care settings increases the risk of illness and may result in higher use of medical care. These observations raise concerns that the use of such settings for early intervention programs for low-birth-weight infants may increase the already high burden of medical care costs incurred by these children and their families. To address the question of medical care use associated with center-based care, we examined the hospital-based and ambulatory care reported for participants of the Infant Health and Development Program. This project is a multisite randomized trial of an early intervention program for preterm low-birth-weight infants with an intervention including 2 years of center-based care. The Intervention group did not differ in hospital-based care and averaged only two more physicians' visits over the 3-year observation period than the comparison group. We conclude that early intervention programs involving high-quality group care are not accompanied by substantial increases in health care use. 相似文献
8.
Immunologic contact urticaria to fish 总被引:1,自引:0,他引:1
9.
Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis
Barbara Bordini Susanna Stea Manuela De Clerico Sergio Strazzari Antonio Sasdelli Aldo Toni 《BMC musculoskeletal disorders》2007,8(1):69
Background
Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure. 相似文献10.