全文获取类型
收费全文 | 27671篇 |
免费 | 2678篇 |
国内免费 | 437篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 737篇 |
妇产科学 | 248篇 |
基础医学 | 2446篇 |
口腔科学 | 561篇 |
临床医学 | 4270篇 |
内科学 | 2698篇 |
皮肤病学 | 80篇 |
神经病学 | 3491篇 |
特种医学 | 1074篇 |
外国民族医学 | 2篇 |
外科学 | 1182篇 |
综合类 | 2462篇 |
现状与发展 | 1篇 |
一般理论 | 22篇 |
预防医学 | 6397篇 |
眼科学 | 153篇 |
药学 | 3284篇 |
22篇 | |
中国医学 | 814篇 |
肿瘤学 | 714篇 |
出版年
2024年 | 64篇 |
2023年 | 602篇 |
2022年 | 561篇 |
2021年 | 1435篇 |
2020年 | 1380篇 |
2019年 | 1367篇 |
2018年 | 1219篇 |
2017年 | 1326篇 |
2016年 | 1190篇 |
2015年 | 1207篇 |
2014年 | 1780篇 |
2013年 | 2891篇 |
2012年 | 1542篇 |
2011年 | 1614篇 |
2010年 | 1201篇 |
2009年 | 1095篇 |
2008年 | 1202篇 |
2007年 | 1169篇 |
2006年 | 1048篇 |
2005年 | 838篇 |
2004年 | 698篇 |
2003年 | 665篇 |
2002年 | 542篇 |
2001年 | 437篇 |
2000年 | 431篇 |
1999年 | 356篇 |
1998年 | 313篇 |
1997年 | 278篇 |
1996年 | 209篇 |
1995年 | 230篇 |
1994年 | 184篇 |
1993年 | 180篇 |
1992年 | 171篇 |
1991年 | 145篇 |
1990年 | 126篇 |
1989年 | 120篇 |
1988年 | 127篇 |
1987年 | 106篇 |
1986年 | 108篇 |
1985年 | 117篇 |
1984年 | 96篇 |
1983年 | 69篇 |
1982年 | 78篇 |
1981年 | 42篇 |
1980年 | 39篇 |
1979年 | 53篇 |
1978年 | 25篇 |
1977年 | 24篇 |
1976年 | 27篇 |
1975年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
R. Raininko I. Elovaara E. Poutiainen A. Virta L. Valanne M. Haltia J. Lhdevirta 《European journal of neurology》1997,4(2):143-151
The course of the organic brain disease caused by human immunodeficency virus (HIV-1) was evaluated in a follow-up study. The primary material included 200 consecutive HIV-1 infected persons. Sixty-one subjects, in whom other brain-affecting factors were excluded, consented to the follow-up. They underwent 278 radiologic examinations: computed tomography, magnetic resonance imaging, or a combination of both (mean 4.6 examinations/subject). Clinical neurologic status and, in 40 subjects, cognitive performance were repeatedly evaluated. Sixteen subjects were followed up until death and 11 of them were autopsied. Median follow-up time was 27 mo (range 2.5–66 mo). The most common radiologic finding was atrophy, found in 19 subjects at study entry and developing in 10 subjects during the study. Twenty-four subjects (39%) showed the development and/or progression of atrophy. Atrophic changes progressed most rapidly in acquired immunodeficiency syndrome (AIDS), but mild developing/progressive atrophy was found even in 33% of asymptomatic or neurologically intact subjects. Cognitive and radiologic worsening were simultaneous in 6/7 subjects with declining neuropsychologic test performance. Signal intensity changes including HIV-1 leukoencephalopathy appeared in AIDS patients with clear cognitive decline. 相似文献
102.
阿魏酸在血瘀证兔体内的药代动力学 总被引:2,自引:0,他引:2
为验证及研究症治药动学假说(syndromeandTreatmentPharmacokinetics,S&TPK)的客观性和基本规律,本文以RP-HPLC法同时测定了活血祛瘀药物阿魏酸在正常及高分子右旋糖酐所制血瘀症(微循环障碍)兔体内经时浓度,以MCPKP药动学程序在COMPAQ80386机上自动拟合了药动学参数。统计结果表明,与正常组相比,阿魏酸在血瘀症兔体内的分布容积(V_1和V_B)及消除速率(CLB)显著减小(P<0.05),半衰期(t_(1/2β)及相同时间段曲线下面积(AUQ)非常显著增加(P<0.01)。结论:实验结果基本符合S&TPK的观点:即同一药物在不同证兔体内的药代动力学参数经统计学处理有显著差异。 相似文献
103.
Louisa Sims 《Early child development and care》1994,98(1):79-96
This study examines young children's perceptions of work through a specific example. Reception class children at an inner city school were shown pictures of the same figure washing in four different contexts, ranging from housework to paid employment, in order to examine early classifications and conceptual systems relating to the concept of work and to ascertain whether these were gender related. Individual children varied in the complexity of their ideas, but the majority had not yet began to form hierarchical classifications of work which favour paid employment. There was evidence however that some children were beginning to devalue traditional women's work, suggesting that gender stereotypes are still prevalent amongst this age group, despite efforts by the educational system to counter this. 相似文献
104.
105.
Social problem solving as a moderating variable between negative life stress and depressive symptoms
Arthur M. Nezu Christine M. Nezu Lisa Saraydarian Kathleen Kalmar George F. Ronan 《Cognitive therapy and research》1986,10(5):489-498
The present study sought to investigate the moderating function that social problem-solving effectiveness serves in relation to negative stressful life events and depressive symptomatology. It was also hypothesized that knowledge of problem solving would improve upon the prediction of level of depressive symptoms beyond the assessment of stressful events. Results involving 462 undergraduate students provide support for both predictions. Specifically, findings from a multiple regression analysis indicated that (1) differences in reported depressive mood between subjects under high and low stress levels were minimal for individuals characterized as effective problem-solvers, relative to those persons with problem-solving scores reflective of ineffective problem solving; and (2) assessment of problem-solving scores and their interaction with stress level provided for an additional three times the amount of explained variance in predicting depression scores beyond life stress scores. Additionally, a cross-validation of the regression analysis was conducted and found to result in a minimal amount of shrinkage that could be due to samplespecific characteristics.We would like to extend our appreciation to two anonymous reviewers for their helpful comments on an earlier draft of this article. The study was supported in part by a grant funded by Fairleigh Dickinson University to the first author. 相似文献
106.
In myoelectrically operated prosthetic systems control performance decreases with an increasing number of possible movements.
A test has been designed that allows quantification of two related qualities of performance. A predefined amount of training
was given to 40 nondisabled volunteers without previous prosthetic experience. After training they attempted the test. The
two parameters measured were the response time and the control accuracy corresponding to the different movements. It is concluded
that even with a very limited amount of training fairly complex control systems can be operated with acceptable performance. 相似文献
107.
农村公共卫生投融资机制存在的问题及对策 总被引:1,自引:0,他引:1
宁德斌 《中国卫生质量管理》2007,14(5):63-66
当前,农村公共卫生投融资规模不能适应农村居民的卫生服务需要,投融资结构不合理,致使投融资效果不佳,不利于农村卫生事业的发展。为此,需要从四个方面改革农村公共卫生投融资机制:一是要建立健全国家财政投资保障制度,发挥财政在农村公共卫生投资中的主体作用;二是要改革运行模式,拓宽融资渠道;三是要改善投资结构,优化资源配置;四是要创新管理体制,提高农村公共卫生服务能力。 相似文献
108.
The effect of laser refractive surgery on the on-field performance of professional baseball players.
BACKGROUND: The aim of this study was to determine the effect of laser refractive surgery on the offensive performance of professional baseball players. METHODS: Extensive search of the public media was conducted to determine which major league baseball players had undergone laser refractive surgery and when the procedure was performed. Baseball performance data were then used to determine presurgery and postsurgery baseball performance averages. A total of 17 position players were identified; however, 5 of these players were not considered in the analysis owing to insufficient playing experience either before or after the laser procedure. RESULTS: No statistically significant or practically significant difference was found between the presurgery and postsurgery means on either on-base percentage (P = 0.31), batting average (P = 0.39), slugging percentage (P = 0.66) or on-base plus slugging (OPS; P = 0.997) of major league baseball players. CONCLUSIONS: These preliminary findings suggest that professional baseball players should not expect a laser refractive surgical procedure to significantly improve their offensive baseball performance, despite the elimination of glasses or contact lens wear. 相似文献
109.
Tourette syndrome and neuropsychological performance 总被引:3,自引:0,他引:3
R A Bornstein G B Baker T Bazylewich A B Douglass 《Acta psychiatrica Scandinavica》1991,84(3):212-216
This study examined performance on a battery of neuropsychological tests in a sample of 28 patients with Tourette's syndrome (TS). Test scores were converted to age-corrected T-scores to control for the effect of age on test performance. The frequency of abnormal test performances was variable, but more frequent on motor and sensory tasks. Symptom severity as measured by the Tourette Syndrome Global Scale was inversely related to neuropsychological performance. In general, neuropsychological performance was mildly below average. The pattern of performance was similar to previous studies of TS patients. 相似文献
110.
Beth Hoskins Dudley F. Peeler Kathia Lawson Angie M. Barnes Ing K. Ho 《Brain research bulletin》1991,27(2):279-281
The effects of haloperidol on motor and functioning and cognitive functioning were studied in young (3-5 months old) and aged (20-22 months old) male mice by examining haloperidol-induced catalepsy and haloperidol-induced decrements in performance on a radial arm maze. The aged mice were much more sensitive to these adverse effects of haloperidol than were the young mice. Studies of the distribution of radioactivity from [3H]haloperidol to the brain indicated that the differences in sensitivity to this drug were not due to pharmacokinetic differences. The results demonstrate that mice are suitable for studies of aging-induced changes in the behavioral effects of neuroleptic agents. 相似文献