全文获取类型
收费全文 | 214009篇 |
免费 | 55448篇 |
国内免费 | 9237篇 |
专业分类
耳鼻咽喉 | 2946篇 |
儿科学 | 6023篇 |
妇产科学 | 3340篇 |
基础医学 | 31114篇 |
口腔科学 | 7518篇 |
临床医学 | 30889篇 |
内科学 | 43477篇 |
皮肤病学 | 8587篇 |
神经病学 | 19809篇 |
特种医学 | 7148篇 |
外国民族医学 | 56篇 |
外科学 | 27963篇 |
综合类 | 23620篇 |
现状与发展 | 41篇 |
一般理论 | 47篇 |
预防医学 | 13710篇 |
眼科学 | 4943篇 |
药学 | 20397篇 |
104篇 | |
中国医学 | 8535篇 |
肿瘤学 | 18427篇 |
出版年
2024年 | 371篇 |
2023年 | 1833篇 |
2022年 | 5163篇 |
2021年 | 7985篇 |
2020年 | 9697篇 |
2019年 | 14670篇 |
2018年 | 14413篇 |
2017年 | 15269篇 |
2016年 | 15546篇 |
2015年 | 17507篇 |
2014年 | 19119篇 |
2013年 | 19001篇 |
2012年 | 14421篇 |
2011年 | 15273篇 |
2010年 | 15851篇 |
2009年 | 10880篇 |
2008年 | 9433篇 |
2007年 | 8655篇 |
2006年 | 8396篇 |
2005年 | 8288篇 |
2004年 | 6236篇 |
2003年 | 6175篇 |
2002年 | 5532篇 |
2001年 | 4671篇 |
2000年 | 4308篇 |
1999年 | 3724篇 |
1998年 | 2045篇 |
1997年 | 1926篇 |
1996年 | 1609篇 |
1995年 | 1468篇 |
1994年 | 1249篇 |
1993年 | 805篇 |
1992年 | 1178篇 |
1991年 | 972篇 |
1990年 | 822篇 |
1989年 | 711篇 |
1988年 | 671篇 |
1987年 | 579篇 |
1986年 | 480篇 |
1985年 | 382篇 |
1984年 | 231篇 |
1983年 | 186篇 |
1982年 | 99篇 |
1981年 | 110篇 |
1980年 | 87篇 |
1979年 | 128篇 |
1978年 | 61篇 |
1977年 | 66篇 |
1976年 | 51篇 |
1974年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
93.
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
94.
Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep 下载免费PDF全文
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
95.
96.
97.
目的:探讨miR-26b参与原发性肝细胞肝癌(HCC)侵袭的机制。方法:在细胞培养液中培养人肝细胞系HL-7702和HCC细胞各系Hepb-3、HuH-7、MHCC97-L、MHCC97-H。实时荧光定量PCR法(qRT-PCR)检测miR-26b的表达水平;用miR-26b mimics、miR-26b inhibitors和Notch1-siRNA分别转染HCC细胞;MTT实验检测转染后HCC细胞的活力;采用Western blot检测Notch1受体蛋白表达水平的变化;Transwell小室测定不同处理后的HCC细胞的侵袭能力。结果:人正常肝细胞系HL-7702和HCC细胞系Hepb-3、HuH-7、MHCC97-L、MHCC97-H中的miR-26b相对表达含量随其侵袭和迁移能力的升高而依次下降;抑制miR-26b的表达,Notch1受体蛋白表达明显增高,而此时HCC细胞的侵袭性显著增强;相反,上调miR-26b的表达,Notch1受体蛋白表达明显降低,而HCC细胞侵袭性显著下降;miR-26b可能通过调控Notch1信号通路调节HCC细胞侵袭性。结论:miR-26b通过负调控Notch1信号通路抑制HCC细胞侵袭能力,为HCC侵袭的机制奠定了理论基础,miR-26b可能成为HCC治疗的新靶点。 相似文献
98.
Spontaneous generation of functional osteoclasts from synovial fluid mononuclear cells as a model of inflammatory osteoclastogenesis 下载免费PDF全文
Stinne R. Greisen Halldór Bjarki Einarsson Malene Hvid Ellen‐Margrethe Hauge Bent Deleuran Tue Wenzel Kragstrup 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(9):779-786
In osteoimmunology, osteoclastogenesis is understood in the context of the immune system. Today, the in vitro model for osteoclastogenesis necessitates the addition of recombinant human receptor activator of nuclear factor kappa‐B ligand (RANKL) and macrophage colony‐stimulating factor (M‐CSF). The peripheral joints of patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) are characterized by an immune‐mediated inflammation that can lead to bone destruction. Here, we evaluate spontaneous in vitro osteoclastogenesis in cultures of synovial fluid mononuclear cells (SFMCs) activated only in vivo. SFMCs were isolated and cultured for 21 days at 0.5–1.0 × 106 cells/mL in culture medium. SFMCs and healthy control peripheral blood monocytes were cultured with RANKL and M‐CSF as controls. Tartrate‐resistant acid phosphatase (TRAP) positive multinucleated cells were found in the SFMC cultures after 21 days. These cells expressed the osteoclast genes calcitonin receptor, cathepsin K, and integrin β3, formed lacunae on dentin plates and secreted matrix metalloproteinase 9 (MMP9) and TRAP. Adding RANKL and M‐CSF potentiated this secretion. In conclusion, we show that SFMCs from inflamed peripheral joints can spontaneously develop into functionally active osteoclasts ex vivo. Our study provides a simple in vitro model for studying inflammatory osteoclastogenesis. 相似文献
99.
100.
PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease 下载免费PDF全文