全文获取类型
收费全文 | 6639篇 |
免费 | 320篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 169篇 |
妇产科学 | 251篇 |
基础医学 | 918篇 |
口腔科学 | 133篇 |
临床医学 | 520篇 |
内科学 | 1701篇 |
皮肤病学 | 108篇 |
神经病学 | 548篇 |
特种医学 | 171篇 |
外科学 | 651篇 |
综合类 | 28篇 |
一般理论 | 1篇 |
预防医学 | 443篇 |
眼科学 | 161篇 |
药学 | 508篇 |
中国医学 | 34篇 |
肿瘤学 | 570篇 |
出版年
2023年 | 48篇 |
2022年 | 65篇 |
2021年 | 182篇 |
2020年 | 125篇 |
2019年 | 158篇 |
2018年 | 175篇 |
2017年 | 135篇 |
2016年 | 137篇 |
2015年 | 171篇 |
2014年 | 189篇 |
2013年 | 263篇 |
2012年 | 464篇 |
2011年 | 449篇 |
2010年 | 255篇 |
2009年 | 226篇 |
2008年 | 441篇 |
2007年 | 420篇 |
2006年 | 406篇 |
2005年 | 356篇 |
2004年 | 344篇 |
2003年 | 315篇 |
2002年 | 321篇 |
2001年 | 131篇 |
2000年 | 133篇 |
1999年 | 119篇 |
1998年 | 68篇 |
1997年 | 65篇 |
1996年 | 56篇 |
1995年 | 39篇 |
1994年 | 40篇 |
1993年 | 26篇 |
1992年 | 74篇 |
1991年 | 63篇 |
1990年 | 79篇 |
1989年 | 64篇 |
1988年 | 43篇 |
1987年 | 44篇 |
1986年 | 36篇 |
1985年 | 45篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 14篇 |
1980年 | 11篇 |
1979年 | 23篇 |
1978年 | 11篇 |
1976年 | 14篇 |
1971年 | 11篇 |
1969年 | 10篇 |
1968年 | 11篇 |
1966年 | 11篇 |
排序方式: 共有7017条查询结果,搜索用时 15 毫秒
121.
122.
123.
Javier Mallol Dirceu Solé Viviana Aguirre Herberto Chong Nelson Rosario Luis García-Marcos 《The Journal of asthma》2013,50(11):1214-1222
Objective:To identify changes in the prevalence and severity of recurrent wheezing (RW) in infants using data obtained from two surveys administered seven years apart. Methods: A cross-sectional, international, population-based study in infants aged 12–15 months was conducted. Data were obtained from two surveys (S1 and S2, in 2005 and 2012, respectively) using the same methodology in three large Latin American cities: Curitiba (Brazil), São Paulo (Brazil), and Santiago (Chile). Results: A decrease in the overall prevalence of RW was identified between S1 (23.3%) and S2 (20.4%), p = 0.004, but it was mainly driven by the reduction observed in São Paulo; in Curitiba and Santiago, this change was not significant. The mean prevalence of the following RW severity indicators remained high and stable: severe wheezing episodes (56.9% in S1 and 54.2% in S2, p = 0.32) and emergency department (ED) visits for wheezing (S1 = 68.1%, S2 70.9%, p = 0.21). A significant increase in admissions for wheezing (21.1% to 26.7%, p = 0.004) was observed. In Curitiba and São Paulo, there were significant increases in the prevalence of physician-diagnosed asthma and in the use of inhaled corticosteroids and oral antileukotrienes. Conclusions: The prevalence and severity of RW during the first year of life remained high over time, with remarkably high rates of ED visits, admissions for wheezing and use of asthma medications. This study suggests the need for considering early asthma diagnosis and to establish an appropriate treatment in infants with recurrent and severe asthma-like symptoms. 相似文献
124.
125.
126.
127.
Monica K. Silver Jennifer Fernandez Jason Tang Anna McDade Jason Sabino Zaira Rosario Carmen Vlez Vega Akram Alshawabkeh Jos F. Cordero John D. Meeker 《Environmental health perspectives》2021,129(5)
Background: Glyphosate (GLY) is the most heavily used herbicide in the world. Despite nearly ubiquitous exposure, few studies have examined prenatal GLY exposure and potentially adverse pregnancy outcomes. Preterm birth (PTB) is a risk factor for neonatal mortality and adverse health effects in childhood.Objectives: We examined prenatal exposure to GLY and a highly persistent environmental degradate of GLY, aminomethylphosphonic acid (AMPA), and odds of PTB in a nested case–control study within the ongoing Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) pregnancy cohort in northern Puerto Rico.Methods: GLY and AMPA in urine samples collected at (Visit 1) and (Visit 3) wk gestation (53 cases/194 randomly selected controls) were measured using gas chromatography tandem mass spectrometry. Multivariable logistic regression was used to estimate associations with PTB (delivery completed gestation).Results: Detection rates in controls were 77.4% and 77.5% for GLY and 52.8% and 47.7% for AMPA, and geometric means (geometric standard deviations) were 0.44 (2.50) and 0.41 for GLY and 0.25 (3.06) and 0.20 for AMPA, for Visits 1 and 3, respectively. PTB was significantly associated with specific gravity–corrected urinary GLY and AMPA at Visit 3, whereas associations with levels at Visit 1 and the Visits 1–3 average were largely null or inconsistent. Adjusted odds ratios (ORs) for an interquartile range increase in exposure at Visit 3 were 1.35 (95% CI: 0.99, 1.83) and 1.67 (95% CI: 1.26, 2.20) for GLY and AMPA, respectively. ORs for Visit 1 and the visit average were closer to the null.Discussion: Urine GLY and AMPA levels in samples collected near the 26th week of pregnancy were associated with increased odds of PTB in this modestly sized nested case–control study. Given the widespread use of GLY, multiple potential sources of AMPA, and AMPA’s persistence in the environment, as well as the potential for long-term adverse health effects in preterm infants, further investigation in other populations is warranted. https://doi.org/10.1289/EHP7295 相似文献
128.
129.
Antimicrobial photodynamic effect to treat residual pockets in periodontal patients: a randomized controlled clinical trial
下载免费PDF全文
![点击此处可从《Journal of clinical periodontology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
130.