全文获取类型
收费全文 | 211566篇 |
免费 | 15362篇 |
国内免费 | 754篇 |
专业分类
耳鼻咽喉 | 2300篇 |
儿科学 | 5507篇 |
妇产科学 | 4324篇 |
基础医学 | 27236篇 |
口腔科学 | 4532篇 |
临床医学 | 20178篇 |
内科学 | 45139篇 |
皮肤病学 | 2758篇 |
神经病学 | 20575篇 |
特种医学 | 6993篇 |
外国民族医学 | 13篇 |
外科学 | 32970篇 |
综合类 | 3439篇 |
现状与发展 | 2篇 |
一般理论 | 291篇 |
预防医学 | 19131篇 |
眼科学 | 4431篇 |
药学 | 14566篇 |
1篇 | |
中国医学 | 383篇 |
肿瘤学 | 12913篇 |
出版年
2023年 | 846篇 |
2022年 | 1410篇 |
2021年 | 3450篇 |
2020年 | 2112篇 |
2019年 | 3404篇 |
2018年 | 3988篇 |
2017年 | 3219篇 |
2016年 | 3419篇 |
2015年 | 4077篇 |
2014年 | 6116篇 |
2013年 | 8863篇 |
2012年 | 13173篇 |
2011年 | 14370篇 |
2010年 | 8132篇 |
2009年 | 7328篇 |
2008年 | 13632篇 |
2007年 | 14465篇 |
2006年 | 13986篇 |
2005年 | 14451篇 |
2004年 | 13850篇 |
2003年 | 12941篇 |
2002年 | 12468篇 |
2001年 | 1933篇 |
2000年 | 1501篇 |
1999年 | 2084篇 |
1998年 | 2845篇 |
1997年 | 2456篇 |
1996年 | 2214篇 |
1995年 | 1965篇 |
1994年 | 1766篇 |
1993年 | 1668篇 |
1992年 | 1240篇 |
1991年 | 1186篇 |
1990年 | 1072篇 |
1989年 | 978篇 |
1988年 | 1043篇 |
1987年 | 1053篇 |
1986年 | 1029篇 |
1985年 | 1117篇 |
1984年 | 1491篇 |
1983年 | 1474篇 |
1982年 | 1830篇 |
1981年 | 1650篇 |
1980年 | 1569篇 |
1979年 | 833篇 |
1978年 | 972篇 |
1977年 | 951篇 |
1976年 | 848篇 |
1975年 | 689篇 |
1974年 | 681篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
Preventing sports injury has rarely been cited as an appropriate action to respond to the obesity epidemic, and in fact a recent letter has suggested that those playing sport are as responsible for their predicament as those who are obese. This opinion piece argues that it is time for better prevention and management of sports injury to be seen as part of the complex solution to preventing obesity, rather than being a self-inflicted problem that governments should continue to ignore. 相似文献
93.
94.
95.
John P Elliott Hugh S Miller Suzanne Coleman Debbie Rhea Diana Abril Karen Hallbauer Niki B Istwan Gary J Stanziano 《Journal of perinatology》2005,25(10):626-630
OBJECTIVE: To assess the impact of activity restriction (AR) on the incidence of preterm birth in women treated for preterm labor testing negative for fetal fibronectin (fFN). STUDY DESIGN: Women who were diagnosed with preterm labor and tocolyzed with magnesium sulfate were concurrently screened with fFN for the purpose of subsequent management. Included were consenting patients with negative fFN, gestational age 23 0/7-33 6/7 weeks, cervical dilation < or =3 cm, and minimal vaginal bleeding. Patients were randomized to AR or no AR. Primary study outcome was incidence of preterm delivery and interval from randomization to delivery. RESULTS: A total of 73 women with negative fFN were randomized (36 with AR, 37 without AR). The overall preterm birth rate was 40%, with 44.4% of patients with AR and 35.1% of patients without AR delivering preterm, p=0.478. CONCLUSION: Maternal AR did not impact pregnancy outcome. The incidence of preterm birth in symptomatic women testing fFN negative was higher than previously reported. 相似文献
96.
Gil Zalsman Yung-yu Huang Jill M Harkavy-Friedman Maria A Oquendo Steven P Ellis J John Mann 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2005,(1):100-103
Monoamine oxidase A gene promoter (MAOA-uVNTR) and catechol-O-methyltransferase V158M (COMT-V158M) gene functional polymorphisms are reported to be associated with impulsive-aggression, but a biological intermediate effect remains to be determined. This study assessed the association of these polymorphisms with cerebrospinal fluid (CSF) monoamine metabolites as endophenotypes. Ninety-eight Caucasian psychiatric subjects were assessed for Axis I and II diagnosis. Subjects were genotyped for the functional polymorphisms, MAOA-uVNTR and COMT-V158M. CSF was obtained by lumbar puncture. Relationships of the two polymorphism to monoamine metabolites: HVA, 5-HIAA, and MHPG were examined. The higher-expressing MAOA-uVNTR genotype was associated with higher CSF-HVA levels in males only (n = 46) (195.80 pmol/ml, SD = 61.64 vs. 161.13, SD = 50.23, respectively; P = 0.042). No association was found with diagnosis. COMT-V158M had no association with CSF monoamine metabolites. The association of MAOA-uVNTR with dopaminergic activity in males is a preliminary finding that needs to be replicated in a larger sample of Caucasian males and relationships sought with clinical phenotypes. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299:1/suppmat/index.html. 相似文献
97.
98.
99.
100.
Population-based association studies are powerful tools for the genetic mapping of complex diseases. However, this method is sensitive to potential confounding by population structure. While statistical methods that use genetic markers to detect and control for population structure have been the focus of current literature, the utility of self-defined race/ethnicity in controlling for population structure has been controversial. In this study of 1334 individuals, who self-identified as either African American, European American or Hispanic, we demonstrated that when the true underlying genetic structure and the self-defined racial/ethnic groups were roughly in agreement with each other, the self-defined race/ethnicity information was useful in the control of population structure. 相似文献