全文获取类型
收费全文 | 12101篇 |
免费 | 812篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 178篇 |
儿科学 | 405篇 |
妇产科学 | 405篇 |
基础医学 | 1915篇 |
口腔科学 | 175篇 |
临床医学 | 1336篇 |
内科学 | 2483篇 |
皮肤病学 | 295篇 |
神经病学 | 1099篇 |
特种医学 | 201篇 |
外科学 | 917篇 |
综合类 | 98篇 |
一般理论 | 23篇 |
预防医学 | 1256篇 |
眼科学 | 245篇 |
药学 | 1025篇 |
中国医学 | 18篇 |
肿瘤学 | 891篇 |
出版年
2023年 | 127篇 |
2022年 | 364篇 |
2021年 | 534篇 |
2020年 | 303篇 |
2019年 | 374篇 |
2018年 | 381篇 |
2017年 | 349篇 |
2016年 | 347篇 |
2015年 | 402篇 |
2014年 | 540篇 |
2013年 | 735篇 |
2012年 | 1032篇 |
2011年 | 1047篇 |
2010年 | 541篇 |
2009年 | 467篇 |
2008年 | 757篇 |
2007年 | 791篇 |
2006年 | 759篇 |
2005年 | 676篇 |
2004年 | 614篇 |
2003年 | 530篇 |
2002年 | 495篇 |
2001年 | 53篇 |
2000年 | 31篇 |
1999年 | 45篇 |
1998年 | 80篇 |
1997年 | 70篇 |
1996年 | 57篇 |
1995年 | 41篇 |
1994年 | 52篇 |
1993年 | 35篇 |
1992年 | 26篇 |
1991年 | 13篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 14篇 |
1987年 | 11篇 |
1985年 | 12篇 |
1984年 | 12篇 |
1983年 | 22篇 |
1982年 | 25篇 |
1981年 | 20篇 |
1980年 | 19篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1974年 | 14篇 |
1973年 | 12篇 |
1972年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep
下载免费PDF全文
![点击此处可从《Journal of pineal research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Flavio Torres Alejandro González‐Candia Camilo Montt Germán Ebensperger Magdalena Chubretovic María Serón‐Ferré Roberto V. Reyes Aníbal J. Llanos Emilio A. Herrera 《Journal of pineal research》2015,58(3):362-373
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN. 相似文献
5.
Inflammation but not obesity or insulin resistance is associated with increased plasma fibroblast growth factor 23 concentration in the elderly
下载免费PDF全文
![点击此处可从《Clinical endocrinology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
6.
7.
8.
9.
Béla Nagy Zsolt Bene Zsolt Fejes Sonya L. Heltshe David Reid Nicola J. Ronan Yvonne McCarthy Daniel Smith Attila Nagy Elizabeth Joseloff György Balla János Kappelmayer Milan Macek Scott C. Bell Barry J. Plant Margarida D. Amaral István Balogh 《Journal of cystic fibrosis》2019,18(2):271-277
Background
We have recently shown that human epididymis protein 4 (HE4) levels correlate with the severity of cystic fibrosis (CF) lung disease. However, there are no data on how HE4 levels alter in patients receiving CFTR modulating therapy.Methods
In this retrospective clinical study, 3 independent CF patient cohorts (US-American: 29, Australian: 12 and Irish: 19 cases) were enrolled carrying at least one Class III CFTR CF-causing mutation (p.Gly551Asp) and being treated with CFTR potentiator ivacaftor. Plasma HE4 was measured by immunoassay before treatment (baseline) and 1–6?months after commencement of ivacaftor, and were correlated with FEV1 (% predicted), sweat chloride, C-reactive protein (CRP) and body mass index (BMI).Results
After 1?month of therapy, HE4 levels were significantly lower than at baseline and remained decreased up to 6?months. A significant inverse correlation between absolute and delta values of HE4 and FEV1 (r?=??0.5376; P?<?.001 and r?=??0.3285; P?<?.001), was retrospectively observed in pooled groups, including an independent association of HE4 with FEV1 by multiple regression analysis (β?=??0.57, P?=?.019). Substantial area under the receiver operating characteristic curve (ROC-AUC) value was determined for HE4 when 7% mean change of FEV1 (0.722 [95% CI 0.581–0.863]; P?=?.029) were used as classifier, especially in the first 2?months of treatment (0.806 [95% CI 0.665–0.947]; P?<?.001).Conclusions
This study shows that plasma HE4 levels inversely correlate with lung function improvement in CF patients receiving ivacaftor. Overall, this potential biomarker may be of value for routine clinical and laboratory follow-up of CFTR modulating therapy. 相似文献10.