全文获取类型
收费全文 | 3759篇 |
免费 | 278篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 159篇 |
妇产科学 | 63篇 |
基础医学 | 405篇 |
口腔科学 | 87篇 |
临床医学 | 525篇 |
内科学 | 635篇 |
皮肤病学 | 27篇 |
神经病学 | 171篇 |
特种医学 | 318篇 |
外国民族医学 | 1篇 |
外科学 | 577篇 |
综合类 | 94篇 |
一般理论 | 2篇 |
预防医学 | 496篇 |
眼科学 | 52篇 |
药学 | 252篇 |
1篇 | |
肿瘤学 | 132篇 |
出版年
2021年 | 34篇 |
2020年 | 27篇 |
2019年 | 49篇 |
2018年 | 61篇 |
2017年 | 40篇 |
2016年 | 52篇 |
2015年 | 59篇 |
2014年 | 80篇 |
2013年 | 112篇 |
2012年 | 147篇 |
2011年 | 150篇 |
2010年 | 133篇 |
2009年 | 110篇 |
2008年 | 145篇 |
2007年 | 133篇 |
2006年 | 140篇 |
2005年 | 141篇 |
2004年 | 154篇 |
2003年 | 122篇 |
2002年 | 120篇 |
2001年 | 101篇 |
2000年 | 97篇 |
1999年 | 88篇 |
1998年 | 107篇 |
1997年 | 106篇 |
1996年 | 106篇 |
1995年 | 77篇 |
1994年 | 65篇 |
1993年 | 65篇 |
1992年 | 85篇 |
1991年 | 75篇 |
1990年 | 64篇 |
1989年 | 70篇 |
1988年 | 78篇 |
1987年 | 75篇 |
1986年 | 65篇 |
1985年 | 64篇 |
1984年 | 53篇 |
1983年 | 46篇 |
1982年 | 37篇 |
1981年 | 32篇 |
1980年 | 32篇 |
1979年 | 42篇 |
1977年 | 27篇 |
1976年 | 30篇 |
1975年 | 31篇 |
1974年 | 36篇 |
1973年 | 29篇 |
1972年 | 30篇 |
1966年 | 24篇 |
排序方式: 共有4050条查询结果,搜索用时 8 毫秒
1.
PJ Commerford 《Cardiovascular journal of Africa》2015,26(4):151-Aug;26(4):151
2.
Andrew M Briggs John D Wark Susan Kantor Rayson Teh Alison M Greig Nicola L Fazzalari Kim L Bennell 《Journal of clinical densitometry》2005,8(3):314-319
Analysis of apparent bone mineral density (BMD) in the lumbar spine is commonly based on anteroposterior (AP) scanning using dual-energy X-ray absorptiometry (DXA). Although not widely used, clinically important information can also be derived from lateral scanning. Vertebral bone density, and therefore strength, can may vary in different subregions of the vertebral body. Therefore, subregional BMD measurements might be informative about fracture risk. However, the intrarater and interrater precision of in vivo subregional BMD assessments from lateral DXA remains unknown. Ten normal, young (mean: 24 yr) and 10 older (mean: 63 yr) individuals with low BMD were scanned on one occasion using an AP/lateral sequence. Each lateral scan was reanalyzed six times at L2 by three raters to determine the intrarater and interrater precision in selecting seven regions of interest (subregions). Precision was expressed using percentage coefficients of variation (% CV) and intraclass correlation coefficients (ICC). Intrarater precision ranged from ICC(1,1) 0.971 to 0.996 (% CV: 0.50-3.68) for the young cohort and ICC(1,1) 0.934 to 0.993 (% CV: 1.46-5.30) for the older cohort. Interrater precision ranged from ICC(2,1) 0.804 to 0.915 (% CV: 1.11-2.35) for the young cohort and ICC(2,1) 0.912 to 0.984 (% CV: 1.85-4.32) for the older cohort. Scanning a subgroup of participants twice with repositioning was used to assess short-term in vivo precision. At L2, short-term in vivo precision ranged from ICC(1,1) 0.867 to 0.962 (% CV: 3.38-9.61), at L3 from ICC(1,1) 0.961 to 0.988 (% CV: 2.02-5.57) and using an L2/L3 combination from ICC(1,1) 0.942 to 0.980 (% CV: 2.04-4.61). This study demonstrated moderate to high precision for subregional analysis of apparent BMD in the lumbar spine using lateral DXA in vivo. 相似文献
3.
4.
5.
Specific MR imaging of human lymphocytes by monoclonal antibody-guided dextran-magnetite particles. 总被引:4,自引:0,他引:4
J W Bulte Y Hoekstra R L Kamman R L Magin A G Webb R W Briggs K G Go C E Hulstaert S Miltenyi T H The 《Magnetic resonance in medicine》1992,25(1):148-157
Human lymphocytes were labeled with biotinylated anti-lymphocyte-directed monoclonal antibodies, to which streptavidin and subsequently biotinylated dextran-magnetite particles were coupled. This labeling resulted in a strong and selective negative contrast enhancement of lymphocyte suspensions at 2.0 T, caused predominantly by the specific increase of R2 with a small but significant specific increase of R1. The R1 was found to decrease with increasing field strength. The immunolabeling procedure described here may be used for the selective signal depletion of target cells in MR imaging. 相似文献
6.
Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease. 相似文献
7.
Shelby D Reed Peter W Dillingham Andrew H Briggs David L Veenstra Sean D Sullivan 《Medical decision making》2003,23(3):252-264
Pharmacy and therapeutics committees commonly cite a lack of generalizability as a reason for not incorporating cost-effectiveness information into decision making. To address this concern, many committees undertake site-specific economic evaluations, which are often limited by small sample sizes and nonrandomized designs. We show how 2 complementary approaches were used to minimize these limitations in an economic evaluation of abciximab at 1 institution. Using a propensity score methodology, we selected patients who did not receive abciximab for the comparison cohort. Then, we adopted a Bayesian, hierarchical, random-effects model to integrate site-specific and clinical trial data. We applied the posterior distributions of effectiveness with local cost data in a traditional decision-analytic model. In 74% of the simulations, abciximab was cost-effective at 1 institution at the $50,000 per life year saved threshold, assuming a 50:50 split of patients undergoing coronary stenting and angioplasty. Among patients undergoing coronary stenting, the cost-effectiveness ratio of the addition of abciximab was at or below the $50,000 per life year saved threshold in 66.0% of the simulations. 相似文献
8.
9.
10.