全文获取类型
收费全文 | 19783篇 |
免费 | 3662篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 432篇 |
儿科学 | 461篇 |
妇产科学 | 618篇 |
基础医学 | 1658篇 |
口腔科学 | 340篇 |
临床医学 | 4112篇 |
内科学 | 4164篇 |
皮肤病学 | 461篇 |
神经病学 | 1971篇 |
特种医学 | 722篇 |
外科学 | 2473篇 |
综合类 | 559篇 |
现状与发展 | 2篇 |
一般理论 | 11篇 |
预防医学 | 2854篇 |
眼科学 | 256篇 |
药学 | 848篇 |
1篇 | |
中国医学 | 100篇 |
肿瘤学 | 1541篇 |
出版年
2023年 | 447篇 |
2022年 | 187篇 |
2021年 | 372篇 |
2020年 | 594篇 |
2019年 | 305篇 |
2018年 | 720篇 |
2017年 | 745篇 |
2016年 | 779篇 |
2015年 | 902篇 |
2014年 | 970篇 |
2013年 | 1394篇 |
2012年 | 898篇 |
2011年 | 833篇 |
2010年 | 802篇 |
2009年 | 901篇 |
2008年 | 841篇 |
2007年 | 733篇 |
2006年 | 735篇 |
2005年 | 661篇 |
2004年 | 536篇 |
2003年 | 458篇 |
2002年 | 397篇 |
2001年 | 484篇 |
2000年 | 474篇 |
1999年 | 453篇 |
1998年 | 400篇 |
1997年 | 406篇 |
1996年 | 441篇 |
1995年 | 345篇 |
1994年 | 260篇 |
1993年 | 207篇 |
1992年 | 333篇 |
1991年 | 350篇 |
1990年 | 313篇 |
1989年 | 316篇 |
1988年 | 266篇 |
1987年 | 272篇 |
1986年 | 284篇 |
1985年 | 272篇 |
1984年 | 207篇 |
1983年 | 189篇 |
1982年 | 133篇 |
1981年 | 131篇 |
1980年 | 109篇 |
1979年 | 179篇 |
1978年 | 114篇 |
1977年 | 104篇 |
1975年 | 103篇 |
1974年 | 105篇 |
1973年 | 105篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Hartley Dean MA PhD Keir Gale BA Roger Woods BA MA 《Health & social care in the community》1996,4(6):338-346
The new complaints procedures which local authority social services departments have been required to introduce represent an important mechanism for managing the change of culture associated with recent community care reforms. They also represent a new genre in mechanisms of redress for welfare recipients. This paper reports the findings of a study which has observed considerable diversity in the ways in which local authorities are interpreting the nature and purposes of the new procedures and, in particular, the functions of review panels established under those procedures. Variations in the composition of panels, in the style of review panel proceedings, in perceptions of the panels' powers, and in the ways that complaints and complainants are constituted are all discussed. Attention is drawn to four competing interpretations of the review panels' role and to the need for these to be clarified and prioritised. 相似文献
12.
Cell survival and DNA double-strand break repair following X-ray or neutron irradiation of V79 cells
We have investigated the effects of 250kVp X-rays and 2.3 MeV (mean energy) neutrons on the cell survival, DNA double-strand break (dsb) induction and repair (using the Kohn neutral elution technique) in V79 cells. The lethal effects of neutrons were shown to be significantly greater than for a similar dose of X-rays (RBE = 3.55 at 10 per cent survival). However, the RBE for dsb induction, in a dose range of 10-50 Gy, was 1. On investigating the repair of DNA dsb induced by either X-ray or neutron irradiation, clear differences in the pattern of repair were found. Both a fast and a slow component of repair were seen in both cases; the former, however, was reduced following neutron irradiation and, since the amount of slow repair was similar in both cases, this resulted in proportionally more unrejoined breaks after neutrons. These experiments were carried out with elution buffer at pH 9.6; however, when similar experiments were performed at pH 7.2 the results obtained support our earlier findings. We suggest that these differences in DNA dsb repair reflect basic differences in the nature of the lesions induced by high- and low-LET ionizing radiations. 相似文献
13.
Claude Earl Fox 《Public health reports (Washington, D.C. : 1974)》1995,110(5):562-Oct;110(5):562
14.
A J Fox 《Scandinavian journal of social medicine》1990,18(1):1-8
In England and Wales interest in differences in health between different sectors of the community can be traced back to analyses of vital registration records in the 1840s. Increased attention in recent years to differences between socio-economic groups, in part in response to initiatives by the World Health Organisation, has again exposed the limitations of traditional data. National data on this topic are now based on the OPCS Longitudinal Study, a record linkage study as used in a number of countries. Such studies provide more reliable measures of differences, cover a wider range of social dimensions, and also allow different explanations of differences to be investigated. Analyses of differences in mortality are complemented by longitudinal analyses of differences in health and morbidity now deriving from other studies such as the birth cohort studies which provide a basis for investigating processes. The time is ripe for more effort to be put into international comparisons of differences. 相似文献
15.
Effect of a glutamine-supplemented enteral diet on methotrexate-induced enterocolitis 总被引:15,自引:0,他引:15
A D Fox S A Kripke J De Paula J M Berman R G Settle J L Rombeau 《JPEN. Journal of parenteral and enteral nutrition》1988,12(4):325-331
Administration of an elemental diet to rats given methotrexate (MTX), 20 mg/kg intraperitoneally (ip), results in 100% mortality from severe enterocolitis. Previous studies indicate that glutamine (GLN), which is not present in elemental diets, is the preferred oxidative substrate for the gut and may facilitate intestinal recovery after injury. This study investigated the effects of a glutamine-supplemented elemental diet (GLN-ED) on nutritional status, intestinal morphometry, bacterial translocation and survival in this lethal model of intestinal injury. Three experiments were performed. In the first experiment, rats received an intragastric elemental diet supplemented with either 2% GLN or an equivalent amount of glycine (Control). After 4 days animals received either MTX, 20 mg/kg ip, or saline ip and were killed 3 days later. The GLN-ED resulted in significantly decreased weight loss, improved nitrogen retention, and increased mucosal weight, protein, and DNA content of the jejunum and colon. In the second experiment rats were assigned to diet as in the first experiment, but all animals received MTX. Control diet animals died within 120 hrs of MTX administration. The GLN-ED group had significantly longer survival time and decreased mortality. In the third experiment animals were assigned to diet and MTX as in the first experiment. Ninety-six hrs later aortic blood cultures revealed enteric bacteremia in animals administered MTX. GLN-ED resulted in a significant reduction in the incidence of bacteremia. These experiments showed that a GLN-ED significantly improved nutritional status, decreased intestinal injury, decreased bacterial translocation, and resulted in improved survival in a lethal model of enterocolitis. 相似文献
16.
Pseudomonas corneal abscess can result in a rapid downhill clinical course despite institution of appropriate medical measures. In this situation the clinician is faced with surgical intervention. A series of patients treated and stabilized through conjunctival flap therapy are presented. The role of conjunctival flap therapy in halting the progression of this entity is described. 相似文献
17.
18.
Experiments were performed to determine the diurnal variation of, as well as the influence of total darkness on, tonic accommodation. In general, under both conditions trend analysis showed that variations in tonic accommodation over time were either nonsystematic in nature or could be best described by a simple linear function. Given the relatively small range of mean tonic accommodation values over time (0.5 to 1.1 D), the results demonstrate the robustness and stability of tonic accommodation under naturally occurring viewing conditions during the course of a day. In contrast, during the 2-hr period in total darkness, tonic accommodation exhibited a three-fold increase in mean range (0.6 to 2.5 D) as well as a significant increasing linear trend in some subjects, suggesting less stability of tonic accommodation in the absence of visual stimuli. 相似文献
19.
20.
Mary T Fox Angela Cooper Brathwaite Souraya Sidani 《Revue canadienne de recherche en sciences infirmières》2004,36(3):20-30
Repeated measures designs are often used to evaluate the effectiveness of interventions. In these designs, the outcomes are measured on several occasions before and after implementation of the intervention. Two statistical methods, the repeated measures analysis of variance (RM-ANOVA) and hierarchical linear models (HLM), can be used to analyze the data. The authors provide an overview of the statistical models underlying RM-ANOVA and HLM and discuss the strengths and limitations of each. They propose that the 2 methods are complementary in determining the effectiveness of interventions. 相似文献