全文获取类型
收费全文 | 314648篇 |
免费 | 62383篇 |
国内免费 | 14366篇 |
专业分类
耳鼻咽喉 | 3600篇 |
儿科学 | 7257篇 |
妇产科学 | 5679篇 |
基础医学 | 43373篇 |
口腔科学 | 9124篇 |
临床医学 | 42891篇 |
内科学 | 62025篇 |
皮肤病学 | 9991篇 |
神经病学 | 26130篇 |
特种医学 | 10688篇 |
外国民族医学 | 96篇 |
外科学 | 40019篇 |
综合类 | 34200篇 |
现状与发展 | 49篇 |
一般理论 | 67篇 |
预防医学 | 19260篇 |
眼科学 | 7945篇 |
药学 | 29542篇 |
164篇 | |
中国医学 | 11893篇 |
肿瘤学 | 27404篇 |
出版年
2024年 | 700篇 |
2023年 | 3546篇 |
2022年 | 8806篇 |
2021年 | 12700篇 |
2020年 | 13090篇 |
2019年 | 17659篇 |
2018年 | 17529篇 |
2017年 | 17725篇 |
2016年 | 18104篇 |
2015年 | 21310篇 |
2014年 | 23881篇 |
2013年 | 23574篇 |
2012年 | 21663篇 |
2011年 | 23260篇 |
2010年 | 20203篇 |
2009年 | 14432篇 |
2008年 | 14902篇 |
2007年 | 13846篇 |
2006年 | 13440篇 |
2005年 | 13306篇 |
2004年 | 9458篇 |
2003年 | 8485篇 |
2002年 | 7556篇 |
2001年 | 6875篇 |
2000年 | 6905篇 |
1999年 | 6766篇 |
1998年 | 3710篇 |
1997年 | 3725篇 |
1996年 | 2837篇 |
1995年 | 2622篇 |
1994年 | 2272篇 |
1993年 | 1519篇 |
1992年 | 2380篇 |
1991年 | 2067篇 |
1990年 | 1731篇 |
1989年 | 1510篇 |
1988年 | 1309篇 |
1987年 | 1204篇 |
1986年 | 970篇 |
1985年 | 791篇 |
1984年 | 519篇 |
1983年 | 401篇 |
1982年 | 239篇 |
1981年 | 222篇 |
1980年 | 200篇 |
1979年 | 260篇 |
1978年 | 153篇 |
1977年 | 125篇 |
1976年 | 110篇 |
1974年 | 121篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
Enrique Luengo Izaskun Buendia Cristina Fernndez‐Mendívil Paula Trigo‐Alonso Pilar Negredo Patrycja Michalska Borja Hernndez‐García Cristina Snchez‐Ramos Juan A. Bernal Tsuneya Ikezu Rafael Len Manuela G. Lpez 《Journal of pineal research》2019,67(1)
Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTauP301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTauP301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD. 相似文献
103.
104.
105.
106.
狼疮抗凝物是发生静脉血栓栓塞症的危险因素之一,在静脉血栓栓塞症患者中检测狼疮抗凝物,对治疗方案抉择和疗效预后判断等方面具有重要意义。目前尚无相关文献对狼疮抗凝物检测在静脉血栓栓塞症中的应用进展进行分析总结,为加深对此类患者的认识,更好地帮助临床医生对此类患者进行合理的诊治和管理,现就有关流行病学、检测注意事项及检测结果在静脉血栓栓塞症中的价值和相关治疗进行综述。 相似文献
107.
Very preterm children are at increased risk of reduced processing speed at 5 years of age,predicted by typical complications of prematurity and prenatal smoking
下载免费PDF全文
![点击此处可从《Acta paediatrica (Oslo, Norway : 1992)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
108.
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
109.
110.
Hsien-Chi Liao Jen-Hao Chuang Hsao-Hsun Hsu Ke-Cheng Chen Jin-Shing Chen 《Surgical endoscopy》2020,34(4):1641-1647
Thoracic empyema in uremic patients on maintenance hemodialysis is a challenging situation. The clinical characteristics are rarely reported, and the surgical outcomes remain unclear. We report our experience with video-assisted thoracoscopic surgery in these patients during 10-year period of time. Between 2005 and 2015, we retrospectively reviewed the clinical characteristics, bacteriological studies, and thoracoscopic surgical results of 23 empyema patients undergoing maintenance hemodialysis. The mean patient age was 67.1 ± 12.9 years. All patients had additional preexisting systemic diseases. The mean duration of hemodialysis was 34.7 ± 25.8 months. The infections causing empyema were pneumonia in 11 (47.8%), blood stream infection in 8 (34.8%), and uremic pleuritis in 4 (17.4%). Among the 22 identified microorganisms, the most common pathogen was methicillin-resistant Staphylococcus aureus (31.8%). After thoracoscopic surgery, 8 patients (34.8%) required additional procedures for complications, including 2 patients who required repeated thoracoscopy for hemothorax and 6 (26.1%) patients who required open drainage for residual empyema. The mean hospital stay was 62.4 days, and 6 patients (26.1%) died in the hospital. Univariate and multivariate analyses revealed that maintenance hemodialysis longer than 5 years was a significant factor associated with in-hospital mortality (odds ratio: 14.8, 95% confidence interval 1.5–151.6; p < 0.0001). While surgical management of thoracic empyema in uremic patients undergoing maintenance hemodialysis is associated with high rates of complication and mortality, thoracoscopic surgery is feasible, especially for patients undergoing hemodialysis for less than 5 years. 相似文献