全文获取类型
收费全文 | 11307篇 |
免费 | 832篇 |
国内免费 | 959篇 |
专业分类
13098篇 |
出版年
2024年 | 22篇 |
2023年 | 161篇 |
2022年 | 429篇 |
2021年 | 709篇 |
2020年 | 415篇 |
2019年 | 553篇 |
2018年 | 543篇 |
2017年 | 356篇 |
2016年 | 513篇 |
2015年 | 801篇 |
2014年 | 927篇 |
2013年 | 904篇 |
2012年 | 1074篇 |
2011年 | 981篇 |
2010年 | 570篇 |
2009年 | 521篇 |
2008年 | 575篇 |
2007年 | 474篇 |
2006年 | 398篇 |
2005年 | 312篇 |
2004年 | 269篇 |
2003年 | 272篇 |
2002年 | 238篇 |
2001年 | 169篇 |
2000年 | 142篇 |
1999年 | 144篇 |
1998年 | 83篇 |
1997年 | 85篇 |
1996年 | 75篇 |
1995年 | 69篇 |
1994年 | 43篇 |
1993年 | 35篇 |
1992年 | 45篇 |
1991年 | 31篇 |
1990年 | 31篇 |
1989年 | 40篇 |
1988年 | 16篇 |
1987年 | 11篇 |
1986年 | 15篇 |
1985年 | 23篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1979年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Shi Yu Mao Xudong Cai Mingcheng Hu Shenqiang Lai Xiulan Chen Shiyi Jia Xianbo Wang Jie Lai Songjia 《Molecular and cellular biochemistry》2021,476(1):425-433
Molecular and Cellular Biochemistry - Skeletal muscle satellite cells (SMSCs), also known as a multipotential stem cell population, play a crucial role during muscle growth and regeneration. In... 相似文献
53.
54.
55.
56.
Liu Q He X Liu Y Du B Wang X Zhang W Jia P Dong J Ma J Wang X Li S Zhang H 《Biochemical and biophysical research communications》2008,377(3):775-779
Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91phox was dose-dependent. Meanwhile, the cytoplasmic subunit p47phox was translocated to the cell membrane and localized with p22phox and gp91phox to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy. 相似文献
57.
58.
Rongzhong Huang Hongchang Gao Lihua Ma Xiao Wang Jianmin Jia Mingju Wang Liang Zhang Xia Liu Peng Zheng Liu Yang Lei Yang Li Dan Xie Peng 《Metabolomics : Official journal of the Metabolomic Society》2014,10(1):33-41
Herpes simplex virus type 1 (HSV-1) is a large, neurotropic, double-stranded DNA virus that establishes a lifelong latent infection in neurons and glial cells. Previous studies reveal that several metabolic perturbations are associated with HSV-1 infection. However, the extracellular metabolic alterations associated with HSV-1 infection have not been systematically profiled in human cells. Here, a proton nuclear magnetic resonance-based metabonomic approach was applied to differentiate the extracellular metabonomic profiles of HSV-1 infected human oligodendroglia cells (n = 18) and matched control cells (n = 18) at three time points (12, 24, and 36 h post-infection). Resulting spectra were analyzed by chemometric and statistical methods. Metabonomic profiling revealed perturbations in 21 extracellular metabolites. Partial least squares discriminant analysis demonstrated that the whole metabolic patterns enabled statistical discrimination between HSV-1 infected human oligodendroglia cells and control cells. Eight extracellular metabolites, seven of which were amino acids, were primarily responsible for score plot discrimination between HSV-1 infected human oligodendroglia cells and control cells at 36 h post-infection: alanine, glycine, isoleucine, leucine, glutamate, glutamine, histidine, and lactate. HSV-1 infection alters amino acid metabolism in human oligodendroglia cells cultured in vitro. HSV-1 infection may disturb these host cellular pathways to support viral replication. Through elucidating the extracellular metabolic changes incident to HSV-1 infection, this study also provides future directions for investigation into the pathogenic mechanism of HSV-1. 相似文献
59.
Jia Xu Fengmei Lian Linhua Zhao Yufeng Zhao Xinyan Chen Xu Zhang Yun Guo Chenhong Zhang Qiang Zhou Zhengsheng Xue Xiaoyan Pang Liping Zhao Xiaolin Tong 《The ISME journal》2015,9(3):552-562
The gut microbiota is hypothesized to have a critical role in metabolic diseases, including type 2 diabetes (T2D). A traditional Chinese herbal formula, Gegen Qinlian Decoction (GQD), can alleviate T2D. To find out whether GQD modulates the composition of the gut microbiota during T2D treatment, 187 T2D patients were randomly allocated to receive high (HD, n=44), moderate (MD, n=52), low dose GQD (LD, n=50) or the placebo (n=41) for 12 weeks in a double-blinded trial. Patients who received the HD or MD demonstrated significant reductions in adjusted mean changes from baseline of fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) compared with the placebo and LD groups. Pyrosequencing of the V3 regions of 16S rRNA genes revealed a dose-dependent deviation of gut microbiota in response to GQD treatment. This deviation occurred before significant improvement of T2D symptoms was observed. Redundancy analysis identified 47 GQD-enriched species level phylotypes, 17 of which were negatively correlated with FBG and 9 with HbA1c. Real-time quantitative PCR confirmed that GQD significantly enriched Faecalibacterium prausnitzii, which was negatively correlated with FBG, HbA1c and 2-h postprandial blood glucose levels and positively correlated with homeostasis model assessment of β-cell function. Therefore, these data indicate that structural changes of gut microbiota are induced by Chinese herbal formula GQD. Specifically, GQD treatment may enrich the amounts of beneficial bacteria, such as Faecalibacterium spp. In conclusion, changes in the gut microbiota are associated with the anti-diabetic effects of GQD. 相似文献
60.