全文获取类型
收费全文 | 1367篇 |
免费 | 101篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 107篇 |
妇产科学 | 8篇 |
基础医学 | 190篇 |
口腔科学 | 20篇 |
临床医学 | 152篇 |
内科学 | 195篇 |
皮肤病学 | 9篇 |
神经病学 | 256篇 |
特种医学 | 52篇 |
外科学 | 202篇 |
综合类 | 6篇 |
预防医学 | 134篇 |
眼科学 | 11篇 |
药学 | 43篇 |
中国医学 | 1篇 |
肿瘤学 | 41篇 |
出版年
2023年 | 7篇 |
2022年 | 17篇 |
2021年 | 43篇 |
2020年 | 30篇 |
2019年 | 55篇 |
2018年 | 42篇 |
2017年 | 46篇 |
2016年 | 49篇 |
2015年 | 45篇 |
2014年 | 68篇 |
2013年 | 72篇 |
2012年 | 101篇 |
2011年 | 114篇 |
2010年 | 82篇 |
2009年 | 68篇 |
2008年 | 105篇 |
2007年 | 108篇 |
2006年 | 61篇 |
2005年 | 64篇 |
2004年 | 45篇 |
2003年 | 45篇 |
2002年 | 29篇 |
2001年 | 20篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有1474条查询结果,搜索用时 156 毫秒
41.
Van Herck SL Geysens S Delbaere J Tylzanowski P Darras VM 《Molecular and cellular endocrinology》2012,349(2):289-297
We used the chick embryo to study the mechanisms regulating intracellular TH availability in developing brain. TH-transporters OATP1C1 and MCT8, and deiodinases D1, D2, and D3 were expressed in a region-specific way, well before the onset of endogenous TH secretion. Between day 4 and 10 of development MCT8 and D2 mRNA levels increased, while OATP1C1 and D3 mRNA levels decreased. D2 and D3 mRNAs were translated into active protein, while no D1 activity was detectable. Injection of THs into the yolk 24 h before sampling increased TH levels in the brain and resulted in decreased OATP1C1 and increased MCT8 expression in 4-day-old embryos. A compensatory response in deiodinase activity was only observed at day 8. We conclude that THs are active in the early embryonic brain and TH-transporters and deiodinases can regulate their availability. However, the absence of clear compensatory mechanisms at day 4 makes the brain more vulnerable for changes in maternal TH supply. 相似文献
42.
Sandra J.E. Langeslag Marcus Schmidt Akhgar Ghassabian Vincent W. Jaddoe Albert Hofman Aad van der Lugt Frank C. Verhulst Henning Tiemeier Tonya J.H. White 《Human brain mapping》2013,34(12):3299-3307
It has been shown in adults that individual differences in intelligence are related to the integrity of the interaction between parietal and frontal brain regions. Since connectivity between distant brain regions strengthens during childhood, it is unclear when in the course of development this relationship emerges. Thus, the goal of this study was to determine whether parietal‐frontal functional connectivity is associated with intelligence in young children. We performed independent component analyses on resting‐state fMRI data of 115 children (6–8 years old) to select seed and target regions for a seed/target region correlation analysis. We found that higher nonverbal intelligence was associated with increased functional connectivity between right parietal and right frontal regions, and between right parietal and dorsal anterior cingulate regions. The association between intelligence and functional connectivity between certain brain regions was stronger in girls than boys. In conclusion, we found that connectivity between the parietal and frontal lobes is critically involved in intelligence in young children. Hum Brain Mapp 34:3299–3307, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
43.
44.
45.
46.
Ans Pauwels Stijn Verleden Ricard Farre Bart M. Vanaudenaerde Dirk Van Raemdonck Geert Verleden Daniel Sifrim Lieven J. Dupont 《Journal of cystic fibrosis》2013,12(6):700-705
CF patients are often treated with proton pump inhibitors (PPIs) to reduce acidic gastro-esophageal reflux (GER) and bronchial aspiration of duodeno-gastric contents is common in CF. We have previously demonstrated that gastric juice (GJ) from patients “on” PPI can induce interleukin-8 (IL-8) production by bronchial epithelial cells in culture. We hypothesized that such effect would be more pronounced in CF patients known to have high inflammatory susceptibility. We aimed to evaluate the effect of GJ on IL-8 production by primary bronchial epithelial cells (PBEC), derived from a CF patient and a healthy subject.MethodsPBEC obtained from one donor (normal PBEC) and one receptor (CF-PBEC) for lung transplantation were stimulated with GJ from patients “off” and “on” PPI. IL-8 levels were measured in the supernatant.ResultsGJ from patients “on” PPI provoked a significant higher IL-8 production compared to GJ from patients “off” PPI, both in normal PBEC [462 (200–1468) vs. 11 (4–28) pg/ml, p = 0.0001] as in CF-PBEC [1468 (841–2449) vs. 85 (26–131) pg/ml, p < 0.0001]. Exposure of the cells to GJ “off” PPI and “on” PPI provoked significantly higher IL-8 production in the CF-PBEC compared to the normal PBEC [“off” PPI 85 (26–131) vs. 11 (4–28) pg/ml, p = 0.01; “on” PPI 1468 (841–2449) vs. 462 (200–1468) pg/ml, p = 0.01]. Filtration (0.20 μm) of the GJ “on” PPI, to eliminate large particles and bacterial sub-products, resulted in a significant decrease of IL-8 production.ConclusionPatients with CF, treated with PPIs, have GJ with high pH and high endotoxin levels. These patients often have GER and bronchial aspiration. The aspirated material (GJ “on” PPI) has a significantly enhanced inflammatory effect on CF bronchial epithelial cells in culture. As chronic PPI treatment in CF may result in a paradoxically increased inflammatory effect in the airways, alternative anti-reflux therapies should be considered in CF. 相似文献
47.
Stijn de Laat Ellen Freriksen Mathijs P.J. Vervloed 《Research in developmental disabilities》2013,34(2):855-863
This study aimed to explore Dutch students’ attitudes toward deaf, blind, paralyzed or intellectually disabled persons and to determine whether age, self-esteem, gender, religion and familiarity with a disabled person have a significant effect on these attitudes. The attitudes of 200 high school and 144 university students were determined with two questionnaires, the CATCH and MAS. Only the CATCH was applicable with all four disabled groups. Two factors were found: behavior–positive affect and cognition–negative affect. With regard to the first factor respondents had more positive attitudes toward deaf, blind and paralyzed persons than toward intellectually disabled persons. The cognition and negative affect factor showed that respondents had more positive attitudes toward deaf and blind persons than toward paralyzed and intellectually disabled persons. Being older and familiarity with a disabled person had a significant positive effect on attitudes, while self-esteem and gender had only a partial effect and having religious beliefs was not a significant predictor in this study. 相似文献
48.
Childhood peer network characteristics: genetic influences and links with early mental health trajectories
下载免费PDF全文
![点击此处可从《Journal of child psychology and psychiatry, and allied disciplines》网站下载免费的PDF全文](/ch/ext_images/free.gif)
49.
This study investigates the effects of six types of social support on distress and posttraumatic stress disorders in security guards who did and did not encounter a critical incident. Three types of social support were significantly related to distress and posttraumatic stress disorder: emotional support in problem situations, instrumental support, and social companionship. Emotional support in problem situations paradoxically appeared to have an aggravating effect on distress and posttraumatic stress, whereas instrumental support and social companionship had a mitigating outcome. 相似文献
50.
Delbaere I Vansteelandt S De Bacquer D Verstraelen H Gerris J De Sutter P Temmerman M 《Human reproduction (Oxford, England)》2007,22(8):2080-2083
Birth weight is the single most important risk indicator for neonatal and infant mortality and morbidity, which has led to the idiom that 'every ounce counts'. Birth weight in turn, however, tends to vary widely across populations as a result of differential fetal growth velocity with such demographic factors as ethnicity, maternal and paternal height and altitude of residence. Accordingly, it has been acknowledged that the appraisal of birth weight should rely on its position relative to the birth weight distribution of the background population. This is commonly done by standardizing birth weight through its deviation from the population mean in the given gestational age stratum, as can be obtained from population-customized birth weight nomograms. This issue was recently revisited in 'Human Reproduction' through a plea for reporting birth weight as z-scores. In this article, we argue that adjustment for factors, such as gestational age, which may lie on the causal pathway from exposures present at the time of conception [e.g. single-embryo transfer (SET) versus double-embryo transfer (DET)] to birth weight, may induce bias, regardless of whether the adjustment happens via stratification, regression or through the use of z-scores. 相似文献