全文获取类型
收费全文 | 52948篇 |
免费 | 3859篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 429篇 |
儿科学 | 1972篇 |
妇产科学 | 1841篇 |
基础医学 | 6466篇 |
口腔科学 | 662篇 |
临床医学 | 9128篇 |
内科学 | 9612篇 |
皮肤病学 | 776篇 |
神经病学 | 4888篇 |
特种医学 | 943篇 |
外国民族医学 | 33篇 |
外科学 | 4720篇 |
综合类 | 670篇 |
一般理论 | 82篇 |
预防医学 | 7339篇 |
眼科学 | 621篇 |
药学 | 3053篇 |
1篇 | |
中国医学 | 90篇 |
肿瘤学 | 3590篇 |
出版年
2023年 | 313篇 |
2022年 | 454篇 |
2021年 | 1019篇 |
2020年 | 683篇 |
2019年 | 1116篇 |
2018年 | 1268篇 |
2017年 | 868篇 |
2016年 | 1002篇 |
2015年 | 1077篇 |
2014年 | 1492篇 |
2013年 | 2501篇 |
2012年 | 3571篇 |
2011年 | 3813篇 |
2010年 | 2021篇 |
2009年 | 1889篇 |
2008年 | 3350篇 |
2007年 | 3819篇 |
2006年 | 3665篇 |
2005年 | 3543篇 |
2004年 | 3434篇 |
2003年 | 3250篇 |
2002年 | 3089篇 |
2001年 | 480篇 |
2000年 | 360篇 |
1999年 | 483篇 |
1998年 | 699篇 |
1997年 | 542篇 |
1996年 | 468篇 |
1995年 | 406篇 |
1994年 | 394篇 |
1993年 | 406篇 |
1992年 | 322篇 |
1991年 | 291篇 |
1990年 | 276篇 |
1989年 | 237篇 |
1988年 | 246篇 |
1987年 | 254篇 |
1986年 | 219篇 |
1985年 | 250篇 |
1984年 | 243篇 |
1983年 | 258篇 |
1982年 | 286篇 |
1981年 | 277篇 |
1980年 | 224篇 |
1979年 | 187篇 |
1978年 | 144篇 |
1977年 | 159篇 |
1976年 | 137篇 |
1975年 | 119篇 |
1973年 | 122篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
131.
132.
133.
This study identified thalamocortical projections activated by respiratory afferents. Cortical evoked potentials were recorded in the right primary somatosensory cortex of the cat following electrical stimulation of the left C5 root of the phrenic nerve. The majority of primary sites were located in the vicinity of the postcruciate dimple, in area 3a near the 3a/3b border, corresponding to the trunk region of the cortical body map. Retrograde fluorescent tracers injected at the sites of primary activation produced labeled cells in the oralis nucleus of the ventroposterior complex [4]. Control injections made in adjacent cortical areas not activated by phrenic stimulation resulted in labeling in the ventroposterior complex which did not overlap that seen with injections of primary activation sites. We conclude that respiratory muscle afferents in the phrenic nerve elicit activity in the trunk region of primary somatosensory cortex via specific thalamocortical projections originating in the oralis portion of the thalamic ventroposterior complex. 相似文献
134.
135.
The relationship of drinking and birth outcome in a US national sample of expectant mothers 总被引:3,自引:0,他引:3
Vivian B. Faden Barry I. Graubard & Mary Dufour 《Paediatric and perinatal epidemiology》1997,11(2):167-180
Alcohol consumption by pregnant women and birth outcome were studied in 9953 livebirths, 3309 fetal deaths and 5332 infant deaths from the 1988 National Maternal and Infant Health Survey. In crude analyses, race, age, mother's education, prenatal care, parity, low birthweight, gestational age, smoking and alcohol consumption during pregnancy were significantly related to the occurrence of fetal deaths and infant deaths. Among women having livebirths, race, age, mother's education, prenatal care, prematurity, gestational age, smoking and alcohol consumption during pregnancy were significantly related to having a low birthweight baby (< 2500 g). In this group, women who drank more during pregnancy also smoked more, were younger and less educated than women who drank at lower levels or not at all. The relationship of alcohol consumption during pregnancy and infant birthweight for those women having livebirths was studied using multivariable linear regression. The results indicated that race, mother's education, baby's sex, parity, mother's height, mother's body mass index and smoking, but not alcohol consumption, were significantly related to birthweight. Multivariable logistic regressions were performed for the occurrence of low birthweight, fetal death and infant death. The effect of alcohol was significant in all these analyses. These results indicate that alcohol has an important relationship with birth outcome, but that for the drinking reported in this study, the alcohol effect on mean birthweight is small relative to that of other risk factors, accounting for the non-significant result in the multiple linear regression. 相似文献
136.
Pam Almada Karen Carafoli John B Flattery Douglas A French Mary McNamara 《Journal for nurses in staff development》2004,20(6):268-273
Newly graduated nurses often finish orientation and then believe they still need more support and mentoring than is available. Retention rates suffer as they think it must be better elsewhere. This article reports a community hospital's implementation of an education-based preceptor program. A convenience sample of 40 new graduates participated in the study. Qualitative and quantitative findings indicate a high level of satisfaction (mean visual analogue scale score 93.7), 29% increase in retention, and 9.5% decrease in vacancy. 相似文献
137.
Maura Jones Moyle Susan Ellis Weismer Julia L Evans Mary J Lindstrom 《J. Speech Lang. Hear. Res.》2007,50(2):508-528
PURPOSE: This study examined the longitudinal relationships between lexical and grammatical development in typically developing (TD) and late-talking children for the purposes of testing the single-mechanism account of language acquisition and comparing the developmental trajectories of lexical and grammatical development in late-talking and TD children. METHOD: Participants included 30 children identified as late talkers (LTs) at 2;0 (years;months), and 30 TD children matched on age, nonverbal cognition, socioeconomic status, and gender. Data were collected at 5 points between 2;0 and 5;6. RESULTS: Cross-lagged correlational analyses indicated that TD children showed evidence of bidirectional bootstrapping between lexical and grammatical development between 2;0 and 3;6. Compared with the TD group, LTs exhibited less evidence of syntactic bootstrapping. Linear mixed-effects modeling of language sample data suggested that the relationship between lexical and grammatical growth was similar for the 2 groups. CONCLUSION: Lexical and grammatical development were strongly related in both groups, consistent with the single-mechanism account of language acquisition. The results were mixed in terms of finding longitudinal differences in lexical-grammatical relationships between the TD and late-talking children; however, several analyses suggested that for late-talking children, syntactic growth may be less facilitative of lexical development. 相似文献
138.
Thanh GN Ton Mary Anne Rossing Deborah J Bowen Sengkeo Srinouanprachan Kristine Wicklund Federico M Farin 《Behavioral and brain functions : BBF》2007,3(1):22-10
Background
Genes involved in dopaminergic neurotransmission have been suggested as candidates for involvement in smoking behavior. We hypothesized that alleles associated with reduced dopaminergic neurotransmission would be more common in continuing smokers than among women who quit smoking. 相似文献139.
140.