全文获取类型
收费全文 | 28366篇 |
免费 | 2169篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 233篇 |
儿科学 | 1028篇 |
妇产科学 | 865篇 |
基础医学 | 3514篇 |
口腔科学 | 430篇 |
临床医学 | 5148篇 |
内科学 | 4917篇 |
皮肤病学 | 387篇 |
神经病学 | 2666篇 |
特种医学 | 522篇 |
外科学 | 2275篇 |
综合类 | 392篇 |
一般理论 | 64篇 |
预防医学 | 3930篇 |
眼科学 | 343篇 |
药学 | 1604篇 |
中国医学 | 26篇 |
肿瘤学 | 2257篇 |
出版年
2023年 | 161篇 |
2022年 | 220篇 |
2021年 | 489篇 |
2020年 | 415篇 |
2019年 | 714篇 |
2018年 | 738篇 |
2017年 | 553篇 |
2016年 | 660篇 |
2015年 | 727篇 |
2014年 | 915篇 |
2013年 | 1446篇 |
2012年 | 1984篇 |
2011年 | 2006篇 |
2010年 | 1108篇 |
2009年 | 1007篇 |
2008年 | 1885篇 |
2007年 | 2020篇 |
2006年 | 2015篇 |
2005年 | 1911篇 |
2004年 | 1794篇 |
2003年 | 1724篇 |
2002年 | 1625篇 |
2001年 | 240篇 |
2000年 | 201篇 |
1999年 | 232篇 |
1998年 | 397篇 |
1997年 | 279篇 |
1996年 | 275篇 |
1995年 | 258篇 |
1994年 | 226篇 |
1993年 | 222篇 |
1992年 | 136篇 |
1991年 | 114篇 |
1990年 | 112篇 |
1989年 | 119篇 |
1988年 | 103篇 |
1987年 | 82篇 |
1986年 | 105篇 |
1985年 | 121篇 |
1984年 | 103篇 |
1983年 | 110篇 |
1982年 | 137篇 |
1981年 | 134篇 |
1980年 | 137篇 |
1979年 | 52篇 |
1978年 | 57篇 |
1977年 | 56篇 |
1976年 | 60篇 |
1975年 | 50篇 |
1974年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
101.
102.
103.
104.
Fracture of the hip is frequently a catastrophic event in the elderly, often resulting in death within a year and of the survivors, few regain pre-fracture quality of life. Although less appreciated, fractures of the spine result in significant morbidity and are also associated with increased mortality compared with individuals without a fracture. In recent years there has been an explosion in the development of new drugs for the treatment of osteoporosis. Recombinant human parathyroid hormone (1–34) (20 μg/day) is a recent addition to this armamentarium with a novel mechanism of action, which was approved by the US FDA for the treatment of post-menopausal osteoporosis and male osteoporosis secondary to hypogonadism in November 2002. It is the first osteoporosis treatment that leads to the formation of new bone with architecture similar to normal bone. Intense efforts have been made to understand the effect of teriparatide on antiresorptive therapy and vice versa. Although these relationships are not completely understood, the results of recent studies allow clinicians to begin to optimize therapeutic gains in bone mineral density and improve anti-fracture efficacy. 相似文献
105.
Kalaichelvi Ganesalingam Ann Sanson Vicki Anderson Keith Owen Yeates 《Journal of the International Neuropsychological Society》2007,13(2):298-311
This study builds on our earlier investigation (see Ganesalingam et al., 2006). We showed previously that children with moderate to severe traumatic brain injuries (TBI) had poorer self-regulation and social and behavioral functioning than their uninjured peers and that self-regulation predicted significant variance in parent- and teacher-rated social and behavioral outcomes, regardless of the presence or absence of TBI. In this study, we examine self-regulation as a mediator of the relationship between TBI and the outcomes. Participants included 65 children with moderate to severe TBI and 65 children without TBI matched for age and gender. Participants were between 6 and 11 years of age. Children completed an assessment of cognitive, emotional, and behavioral self-regulation, and social and behavioral functioning. Mediation was assessed using a bootstrapping approach (a relatively novel statistical method for assessing specific indirect effects in models with multiple mediators). Analyses indicated that, after controlling for socioeconomic status (SES), aspects of self-regulation accounted for individual variation in the outcomes, and acted as a significant mediator of the effects of TBI on the outcomes. Self-regulatory deficits may reflect the relative vulnerability of the prefrontal cortex to TBI and may help account for post-injury difficulties in social and behavioral functioning. 相似文献
106.
GABAergic Transmission in the Nucleus Accumbens Is Involved in the Termination of Ethanol Self-Administration in Rats 总被引:6,自引:0,他引:6
Clyde W. Hodge Ann M. Chappelle Herman H. Samson 《Alcoholism, clinical and experimental research》1995,19(6):1486-1493
Long-Evans rats ( n = 12) were trained to lever-press on a fixed-ratio 4 schedule of reinforcement with ethanol (10% v/v) presented as the reinforcer. After implantation of bilateral stainless-steel guide cannulae aimed at the nucleus accumbens, site-specific microinjections of muscimol (1–30 ng) and bicuculline (1–10 ng) were tested for effects on ethanol-reinforced responding. Baseline response patterns were characterized by initial high rates that terminated abruptly after ∼20 min. Muscimol administration in the nucleus accumbens decreased the total number of ethanol-reinforced responses and obtained reinforcers. Bicuculline also decreased ethanol-reinforced responses and reinforcers at the highest dose tested. When a dose of bicuculline (1 ng) that was ineffective by itself was coadministered with an effective dose of muscimol (10 ng), the muscimol-induced decreases in responding were blocked. Analysis of response patterns showed that muscimol decreased ethanol self-administration by terminating responding, normally lasting 20 min, after ∼10 min with no changes in local response rate. Bicuculline decreased total responding by producing parallel, but nonsignificant, changes in time course and response rate. These data suggest that GABAergic transmission in the nucleus accumbens is involved in the termination, but not the onset or maintenance of ethanol self-administration. The specificity of this effect gives emphasis to the importance of measuring behavioral parameters, as well as products of behavior (such as intake volume) in the study of ethanol self-administration. 相似文献
107.
108.
Role Play is an issues-related forum to engender dialogue about the roles assumed by nurses who care for children and their families. 相似文献
109.
Previous studies examining the association between social comparison processes and body image dissatisfaction have yielded inconsistent findings. This study examined whether such discrepancies are due to either the use of identical comparison targets for all subjects or variability in body mass. Specifically, 216 subjects were randomly assigned to one of three experimental conditions: self-generated upward comparison group, self-generated downward comparison group, or control group. Dependent variables were measures of body image. Results indicated that increasing body mass and trait comparison tendencies were associated with increased body dissatisfaction. However, the experimental manipulation did not affect body image ratings. Results suggest that social comparison processes may operate similarly over a range of body mass index (BMI) values. 相似文献
110.
A randomized, double-blind, placebo-controlled clinical trial was conducted to determine the effects of a low-dose (<2 times the Recommended Dietary Allowance) micronutrient supplement containing trace minerals (zinc and selenium) and/or vitamins/provitamins (vitamin C, α-tocopherol, and β-carotene) on the incidence of respiratory and urogenital infections in institutionalized elderly. After 2 years, there was a significant decrease in the mean number of infections in elders given trace elements (p < 0.01) but not vitamins. 相似文献