全文获取类型
收费全文 | 10588篇 |
免费 | 752篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 301篇 |
妇产科学 | 297篇 |
基础医学 | 1439篇 |
口腔科学 | 249篇 |
临床医学 | 1312篇 |
内科学 | 2106篇 |
皮肤病学 | 263篇 |
神经病学 | 1102篇 |
特种医学 | 211篇 |
外科学 | 957篇 |
综合类 | 65篇 |
一般理论 | 16篇 |
预防医学 | 1326篇 |
眼科学 | 182篇 |
药学 | 689篇 |
中国医学 | 38篇 |
肿瘤学 | 747篇 |
出版年
2024年 | 16篇 |
2023年 | 133篇 |
2022年 | 226篇 |
2021年 | 469篇 |
2020年 | 267篇 |
2019年 | 362篇 |
2018年 | 377篇 |
2017年 | 280篇 |
2016年 | 320篇 |
2015年 | 325篇 |
2014年 | 408篇 |
2013年 | 600篇 |
2012年 | 849篇 |
2011年 | 839篇 |
2010年 | 484篇 |
2009年 | 375篇 |
2008年 | 650篇 |
2007年 | 637篇 |
2006年 | 585篇 |
2005年 | 555篇 |
2004年 | 473篇 |
2003年 | 446篇 |
2002年 | 403篇 |
2001年 | 45篇 |
2000年 | 48篇 |
1999年 | 44篇 |
1998年 | 73篇 |
1997年 | 70篇 |
1996年 | 63篇 |
1995年 | 54篇 |
1994年 | 42篇 |
1993年 | 49篇 |
1992年 | 40篇 |
1991年 | 36篇 |
1990年 | 28篇 |
1989年 | 35篇 |
1988年 | 33篇 |
1987年 | 29篇 |
1986年 | 30篇 |
1985年 | 31篇 |
1984年 | 36篇 |
1983年 | 40篇 |
1982年 | 36篇 |
1981年 | 37篇 |
1980年 | 42篇 |
1978年 | 18篇 |
1977年 | 23篇 |
1975年 | 16篇 |
1973年 | 16篇 |
1972年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
Alice J Hausman Ph.D. M.P.H. Howard Spivak M.D. Deborah Prothrow-Stith M.D. James Roeber M.S. 《The Journal of adolescent health》1992,13(8):668-675
This paper describes the implementation of a community-based youth violence prevention project that utilized an educational curriculum and a mass media campaign. The extent of penetration of the intervention into target areas and the degree of contamination of control areas are assessed, and the most frequently contacted forms of educational outreach are identified. Two sources of data, provider interviews and a random digit dialed telephone survey, were used to track the source and extent of teens' exposure to the intervention. Agency provider data revealed that 40% of the 92 contacted agencies actually conducted violence prevention education, reaching 22% of the target area teens. Approximately one-half of the surveyed teens reported some exposure to the program, with 13% of the teens in target areas reporting participation in interactive educational activities associated with the project. The most common source of exposure was the media campaign. Most teens report a single exposure, usually to the media campaign, although 29% report contact with more than one form of violence prevention education. While the project did not achieve community saturation, the data show that the community-based model of intervention for violence prevention is feasible and effective in reaching teenagers. This research highlights some difficulties in evaluating prevention programs, including reconciling community ownership with project identification, the ethics of curtailing services for control purposes, and factors influencing recall of participation. 相似文献
14.
Impaired cortisol stress response in fish from environments polluted by PAHs,PCBs, and mercury 总被引:6,自引:0,他引:6
Alice Hontela Joseph B. Rasmussen Céline Audet Gaston Chevalier 《Archives of environmental contamination and toxicology》1992,22(3):278-283
The cortisol stress response to capture was investigated in two species of fish (Perca flavescens and Esox lucius) from sites polluted by high levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and mercury, and from reference sites in the St. Lawrence river system. Fish from the reference sites exhibited the normal elevation of serum cortisol in response to the acute stress of capture and had large pituitary corticotropes. In contrast, fish from the most polluted sites were unable to increase their serum cortisol in response to the acute stress of capture and their pituitary corticotropes were atrophied. These results suggest that a life-long exposure to chemical pollutants may lead to an exhaustion of the cortisol-producing endocrine system, possibly as a result of prolonged hyperactivity of the system. 相似文献
15.
ABSTRACT: This paper reports on the effectiveness of a teacher development project in promoting implementation of a comprehensive school health education curriculum among inner city elementary school teachers. The longitudinal evaluation design provides empirical data on the efficacy of a strategy to reduce teachers' concerns and promote use of the curriculum at the classroom level. Data were collected at various points throughout the project period from 156 school staff from five schools. Results from analyses of repeated measures of teachers' feelings of preparedness to teach specific health topics, and the observed relationship between both high and improved feelings of preparation and reported health teaching suggest that teacher development efforts including training and ongoing reinforcement to increase teachers' feelings of preparedness can have significant classroom effects. 相似文献
16.
17.
18.
Brigitte Schiller Chun He David J. Salant Alice Lim Jessy J. Alexander Richard J. Quigg 《The Journal of experimental medicine》1998,188(7):1353-1358
Crry (complement receptor 1–related protein/gene y) is a key cellular complement regulator in rodents. It is also present in Fx1A, the renal tubular preparation used to immunize rats to induce active Heymann nephritis (HN), a model of membranous nephropathy. We hypothesized that rats immunized with anti-Fx1A develop autoantibodies (auto-Abs) to Crry as well as to the megalin-containing HN antigenic complex, and that anti-Crry Abs promote the development of injury in HN by neutralizing the complement regulatory activity of Crry. Rats immunized with Fx1A lacking Crry remained free of proteinuria and glomerular deposits of C3 during a 10-wk follow-up despite typical granular immunoglobulin (Ig)G deposits in glomeruli. Anti-Fx1A auto-Abs were present in their sera at levels that were not different from sera pooled from proteinuric rats with HN induced with nephritogenic Fx1A. Passive administration of sheep anti-Crry Abs to rats immunized with Crry-deficient Fx1A led to proteinuria and glomerular C3 deposition, which were not seen in such rats injected with preimmune IgG, nor in rats with collagen-induced arthritis injected with anti-Crry IgG. To directly examine the role of Crry in HN, rats were immunized with Crry-deficient Fx1A reconstituted with rCrry. This led to typical HN, with 8 out of 15 rats developing proteinuria within 14 wk. Moreover, the extent of glomerular C3 deposition correlated with proteinuria, and anti-Crry Abs were present in glomerular eluates. Thus, Crry is a key nephritogenic immunogen in Fx1A. Formation of neutralizing auto-Abs to Crry impairs its function, leading to unrestricted complement activation by Abs reactive with the HN antigenic complex on the epithelial cell surface. 相似文献
19.
Hexane and methanol extracts of heartwood, bark/sapwood and leaves of twelve taxa of Juniperus from the United States were assayed for antifungal and antibacterial activities. The hexane extract of the heartwood of several junipers appeared comparable in antibacterial activity to streptomycin. Antibacterial activity of the hexane extracts from the bark/sapwood of J. monosperma and J. californica were comparable to streptomycin. No appreciable antibacterial activities were found in the leaf extracts from any species examined. No antifungal activities comparable to amphotericin B were found in either hexane or methanol extracts of the heartwood nor from the bark/sapwood. Antifungal activity against Cryptococcus neoformans comparable to amphotericin B was found in the hexane extract of the leaves of J. occidentalis var. australis. The methanol extracts from the leaves of J. osteosperma and J. californica had antifungal activities comparable to amphotericin B against Trichophyton mentagrophytes. 相似文献
20.
John E. Geltosky Richard S. Smith Alice Whalley Gary Rhodes 《Journal of clinical laboratory analysis》1987,1(2):153-162
A simple enzyme immunoassay has been developed based on measuring antibodies to synthetic peptides corresponding to sequences in the Epstein-Barr nuclear antigen (EBNA). This assay, which is reproducible, quantitative, and simple to perform and interpret, can be an effective tool to aid in the diagnosis of infectious mononucleosis and nasopharyngeal carcinoma. 相似文献