全文获取类型
收费全文 | 37022篇 |
免费 | 3514篇 |
国内免费 | 84篇 |
专业分类
耳鼻咽喉 | 455篇 |
儿科学 | 1503篇 |
妇产科学 | 1105篇 |
基础医学 | 5427篇 |
口腔科学 | 901篇 |
临床医学 | 4702篇 |
内科学 | 6762篇 |
皮肤病学 | 571篇 |
神经病学 | 3091篇 |
特种医学 | 986篇 |
外科学 | 4160篇 |
综合类 | 707篇 |
现状与发展 | 1篇 |
一般理论 | 56篇 |
预防医学 | 4574篇 |
眼科学 | 662篇 |
药学 | 2463篇 |
中国医学 | 104篇 |
肿瘤学 | 2390篇 |
出版年
2023年 | 210篇 |
2022年 | 312篇 |
2021年 | 669篇 |
2020年 | 424篇 |
2019年 | 651篇 |
2018年 | 742篇 |
2017年 | 625篇 |
2016年 | 589篇 |
2015年 | 671篇 |
2014年 | 1019篇 |
2013年 | 1502篇 |
2012年 | 2199篇 |
2011年 | 2267篇 |
2010年 | 1165篇 |
2009年 | 1031篇 |
2008年 | 1933篇 |
2007年 | 2013篇 |
2006年 | 2014篇 |
2005年 | 1955篇 |
2004年 | 1796篇 |
2003年 | 1685篇 |
2002年 | 1599篇 |
2001年 | 863篇 |
2000年 | 729篇 |
1999年 | 816篇 |
1998年 | 441篇 |
1997年 | 405篇 |
1996年 | 352篇 |
1995年 | 321篇 |
1994年 | 308篇 |
1993年 | 247篇 |
1992年 | 601篇 |
1991年 | 531篇 |
1990年 | 499篇 |
1989年 | 462篇 |
1988年 | 462篇 |
1987年 | 439篇 |
1986年 | 473篇 |
1985年 | 460篇 |
1984年 | 371篇 |
1983年 | 350篇 |
1982年 | 290篇 |
1981年 | 267篇 |
1980年 | 220篇 |
1979年 | 327篇 |
1978年 | 274篇 |
1977年 | 231篇 |
1974年 | 242篇 |
1973年 | 260篇 |
1972年 | 207篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Steven Z George John D Childs Deydre S Teyhen Samuel S Wu Alison C Wright Jessica L Dugan Michael E Robinson 《BMC musculoskeletal disorders》2007,8(1):92
Background
There are few effective strategies reported for the primary prevention of low back pain (LBP). Core stabilization exercises targeting the deep abdominal and trunk musculature and psychosocial education programs addressing patient beliefs and coping styles represent the current best evidence for secondary prevention of low back pain. However, these programs have not been widely tested to determine if they are effective at preventing the primary onset and/or severity of LBP. The purpose of this cluster randomized clinical trial is to determine if a combined core stabilization exercise and education program is effective in preventing the onset and/or severity of LBP. The effect of the combined program will be compared to three other standard programs. 相似文献32.
33.
L. C. Scott G. K. Wright G. S. Rai A. N. Exton-Smith J. M. Gardiner 《International journal of geriatric psychiatry》1991,6(8):583-588
Memory performance of elderly patients in the early stages of Alzheimer's disease (DAT) was compared with that of elderly control subjects. In explicit tests of recognition memory, which involve conscious recollection, the DAT patients were grossly impaired. In implicit tests of anagram solution and wordstem completion, which do not require conscious recollection, the DAT patients were not impaired. These findings further support the idea that a separate memory system, episodic memory, underlies conscious recollection, that it is this system which is most commonly damaged in amnesia, and that memory systems not involving conscious recollection may be spared in the early stages of Alzheimer's disease. 相似文献
34.
We report a case of multiple endocrine neoplasia type I and hypernephroma. Parathyroid hyperplasia, adrenocortical hyperplasia, a nodular goiter, multiple lipomas, a chromophobe adenoma of the pituitary and hypernephroma had all been diagnosed previously. All but the last are features consistent with the diagnosis of multiple endocrine neoplasia type I (Wermer's syndrome). The association of multiple endocrine neoplasia type I and hypernephroma may represent a new manifestation of this pleiotropic syndrome. 相似文献
35.
Ricardo J. Wray Jo Ellen Stryker Eric Winer George Demetri Karen M. Emmons 《Journal of cancer education》2007,22(1):21-24
Background. Accepted practices of informed consent often result in suboptimal patient understanding of research studies.Methods. This pilot study aimed to assess trial-specific tailored materials, compared to a widely used generic booklet about clinical
trials, randomly assigned to 118 candidates for cancer clinical trials. Study outcomes were: satisfaction with decision-making;
satisfaction with materials; and subjective understanding of the clinical trial.Results. There were no major differences between groups. Participants rated tailored materials higher as a useful reference.Conclusions. Trial-specific materials hold utility for reference during clinical trials. Studies of informed consent are feasible, although
important factors limit research. 相似文献
36.
Jeffrey N Baldwin David M Scott Sangeeta Agrawal Jean K Bartek R Ellen Davis-Hall Thomas P Reardon Edward M DeSimone 《Substance Abuse》2006,27(3):27-37
Alcohol and other drug (AOD) use behaviors of health professions students (HPS) were assessed by surveying both university-based HPS and other nursing programs in a Midwestern state in 1999. Response was 2,646 (56.4%) of surveyed students. Family history of alcohol-related and drug-related problems were reported by 39.8% and 13.9%, respectively, with 42.6% of respondents reporting one or both. Among nursing respondents, 48.1%, 19.2% and 51.1%, respectively, reported family problems with alcohol, drugs, or one or both. Past-year alcohol use was comparable to undergraduate college students (UCS) nationally (83%); heavy drinking, tobacco and recreational drug use by HPS were lower. Past year drug use was highest among medical students. Marijuana was the predominant illicit drug; medical students and males most often reported use. Health professions educational systems should proactively address student AOD prevention, education and assistance needs. 相似文献
37.
New indole alkaloid glycosides from Nauclea orientalis 总被引:4,自引:0,他引:4
Two new indole alkaloid glycosides, 10-hydroxystrictosamide and 6'-O-acetylstrictosamide, as well as the known alkaloids strictosamide and vincosamide were isolated from the leaves of Nauclea orientalis L. The structures of the isolated compounds were determined using spectroscopic methods, mainly 1D- and 2D-NMR spectroscopy. 相似文献
38.
Anne T. Berg Shlomo Shinnar‡§ Eugene D. Shapiro Morton E. Salomon‡ Ellen F. Crain‡ W. Allen Hauser§ 《Epilepsia》1995,36(4):334-341
Summary We conducted a matched casecontrol study to identify risk factors for first febrile seizures, with special emphasis on characteristics of the acute illness episode. Cases were identified through hospital emergency departments; controls were identified through outpatient clinics and emergency departments. Sixtynine children with first febrile seizures and no history of previous unprovoked seizures were matched for age (±6 months), site of routine pediatric care, and date of visit (±weeks) with 1 or 2 febrile controls who had no history of previous febrile or unprovoked seizures. Medical records for the index visit were reviewed, and parents were interviewed by telephone. Illness characteristics examined included height of temperature, type of underlying illness, contact with a physician during the illness but before the index visit, and use of acetaminophen or decongestants. Family history of febrile and of unprovoked seizures, sociodemographic characteristics, daycare use, and selected preand perinatal variables were also studied. On multivariable analysis, significant independent risk factors were height of temperature, history of febrile seizures in a firstor in a higher degree relative. Gastroenteritis as the underlying illness had a significant inverse (i.e., protective) association with febrile seizures. Maternal smoking during pregnancy was a marginally significant predictor of febrile seizures. 相似文献
39.
40.
R. Riise S. Andreasson M. Borgstrom A. Wright N. Tommerup T. Rosenberg K. Tornqvist 《The British journal of ophthalmology》1997,81(5):378-385
AIMS—To describe the variation of the phenotype within families with several individuals with Bardet-Biedl syndrome.
METHODS—The phenotypes of affected siblings in 11 Scandinavian families were compared with two or more members who had at least three of the features: retinal dystrophy, polydactyly, obesity, hypogenitalism, and mental retardation. Individuals without retinal dystrophy were excluded.
RESULTS—Intrafamilial variation of expressivity of the features obesity, polydactyly, abnormal radiograms of the extremities, hypogenitalism, short stature, paraplegia, and dental abnormalities was found. The retinal dystrophy varied with respect to both the onset of symptoms and the course of the disease. The morphology of the fundus, however, was consistent within the families. The disorder showed statistically significant genetic linkage to the BBS4 locus on chromosome 15 in the affected siblings in two of the families, but the clinical features in these patients did not differ from the other cases of Bardet-Biedl syndrome.
CONCLUSION—Comparison of siblings with the Bardet-Biedl syndrome showed variation of the typical features. In addition, the course of retinal dystrophy varied. No distinctive clinical features were found to separate the BBS4 phenotype from the remaining patients.
相似文献
METHODS—The phenotypes of affected siblings in 11 Scandinavian families were compared with two or more members who had at least three of the features: retinal dystrophy, polydactyly, obesity, hypogenitalism, and mental retardation. Individuals without retinal dystrophy were excluded.
RESULTS—Intrafamilial variation of expressivity of the features obesity, polydactyly, abnormal radiograms of the extremities, hypogenitalism, short stature, paraplegia, and dental abnormalities was found. The retinal dystrophy varied with respect to both the onset of symptoms and the course of the disease. The morphology of the fundus, however, was consistent within the families. The disorder showed statistically significant genetic linkage to the BBS4 locus on chromosome 15 in the affected siblings in two of the families, but the clinical features in these patients did not differ from the other cases of Bardet-Biedl syndrome.
CONCLUSION—Comparison of siblings with the Bardet-Biedl syndrome showed variation of the typical features. In addition, the course of retinal dystrophy varied. No distinctive clinical features were found to separate the BBS4 phenotype from the remaining patients.
相似文献