全文获取类型
收费全文 | 1169篇 |
免费 | 56篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 47篇 |
妇产科学 | 20篇 |
基础医学 | 130篇 |
口腔科学 | 21篇 |
临床医学 | 135篇 |
内科学 | 307篇 |
皮肤病学 | 62篇 |
神经病学 | 30篇 |
特种医学 | 92篇 |
外科学 | 98篇 |
综合类 | 77篇 |
预防医学 | 69篇 |
眼科学 | 21篇 |
药学 | 90篇 |
1篇 | |
肿瘤学 | 42篇 |
出版年
2016年 | 8篇 |
2015年 | 13篇 |
2014年 | 10篇 |
2013年 | 27篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 23篇 |
2009年 | 28篇 |
2008年 | 9篇 |
2007年 | 28篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 7篇 |
2002年 | 7篇 |
2001年 | 8篇 |
1998年 | 31篇 |
1997年 | 30篇 |
1996年 | 33篇 |
1995年 | 34篇 |
1994年 | 32篇 |
1993年 | 32篇 |
1992年 | 22篇 |
1991年 | 28篇 |
1990年 | 17篇 |
1989年 | 18篇 |
1988年 | 24篇 |
1987年 | 29篇 |
1986年 | 22篇 |
1985年 | 17篇 |
1984年 | 17篇 |
1983年 | 19篇 |
1982年 | 21篇 |
1981年 | 24篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1965年 | 11篇 |
1963年 | 11篇 |
1959年 | 58篇 |
1958年 | 74篇 |
1957年 | 59篇 |
1956年 | 45篇 |
1955年 | 63篇 |
1954年 | 67篇 |
1949年 | 21篇 |
1948年 | 29篇 |
1947年 | 7篇 |
1946年 | 11篇 |
排序方式: 共有1256条查询结果,搜索用时 15 毫秒
1.
2.
3.
The effect of mutation on linkage disequilibrium 总被引:1,自引:0,他引:1
The standard formula for the approach to linkage equilibrium between two diallelic loci, initially at disequilibrium, is expressed in terms of their probability of recombination (Li, 1955). By a simple extension, we show how to incorporate the effects of mutation at one or both loci. It can thereby be inferred that in general these effects are unlikely to be of major importance, contrary to some recent suggestions. 相似文献
4.
JENNIFER ORLET FISHER PhD DIANE C. MITCHELL MS RD HELEN SMICIKLAS- WRIGHT PhD LEANN LIPPS BIRCH PhD 《Journal of the American Dietetic Association》2002,102(1)
Objective To evaluate parents’ fruit and vegetable intake and their use of pressure to eat in child feeding as predictors of their 5-year-old daughters’ fruit and vegetable, micronutrient, and fat intakes.Subjects Data were obtained from 191 non-Hispanic white families with 5-year-old girls.Design Parent data included reports of pressure in child feeding and their own fruit and vegetable intake. Girls’ intakes of fruits and vegetables, selected micronutrients, and fat were the main outcomes of interest.Statistical analysis Structural equation modeling was used to test a model describing relationships among parents’ fruit and vegetable intake, parents’ use of pressure in child feeding, and daughters’ fruit and vegetable, micronutrient, and fat intakes.Results The model provided a good fit to the data, revealing that girls’ fruit and vegetable intake was positively related to their parents’ reported fruit and vegetable intake. Parents who consumed fewer fruits and vegetables tended to report greater pressure in child feeding and had daughters who consumed fewer fruits and vegetables. Girls’ reported fruit and vegetable intakes were positively related to their micronutrient intakes and negatively associated with fat intake.Applications/conclusions This research demonstrates that parents’ own fruit and vegetable intake may encourage fruit and vegetable intake in their daughters, leading to higher micronutrient intakes and lower dietary fat intakes. Conversely, pressure to eat may discourage fruit and vegetable intake among young girls. J Am Diet Assoc. 2002;102:58–64. 相似文献
5.
Anulus fibrosus in bulging intervertebral disks 总被引:1,自引:0,他引:1
In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks. 相似文献
6.
The precise mode of action of topically applied steroids is unknown. We have applied clobetasol propionate 0.05% ointment (Dermovate; Glaxo Pharmaceuticals) under occlusion to the forearm skin of 10 healthy volunteers for 6 h and monitored transcutaneous oxygen tension at the site for 19 h after its removal. Compared to the ointment base, the steroid-treated area was significantly hypoxic up to 13 h after application. The profound hypoxia present at the site of application of clobetasol propionate 0.05% ointment may account for some of its anti-inflammatory effects, and its atrophogenicity. 相似文献
7.
8.
9.
10.
This report summarizes the results obtained by a preliminary statistical analysis of the first 800 cases studied by the Committee for the Evaluation of Anticoagulants in the Treatment of Coronary Thrombosis With Myocardial Infarction. In the analysis the incidence of deaths and of both thromboembolic and hemorrhagic complications has been compared in a “control” series of patients treated by conventional methods alone and in a series of “treated” patients who received anticoagulants (Dicumarol, heparin, or both) in addition to conventional therapy. The composition of the two groups was found to be essentially the same.The rates of deaths and the number of thromboembolic complications per 100 cases have been calculated for the control and treated groups as a whole, by week of illness, by age of patient, and by type and location of the specific thromboembolic complication. The percentage of patients developing one or more complications has also been analyzed. The results in every category studied indicate that the use of anticoagulants improves strikingly the outlook of the patient suffering a coronary occlusion with myocardial infarction.The incidence of hemorrhagic manifestations was also analyzed. It was found that about six minor or moderate hemorrhagic manifestations per 100 cases occur in patients not receiving anticoagulants. This incidence is about six per 100 higher in patients receiving anticoagulants. 相似文献