首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12287篇
  免费   1349篇
  国内免费   1382篇
  2024年   33篇
  2023年   154篇
  2022年   407篇
  2021年   670篇
  2020年   549篇
  2019年   598篇
  2018年   610篇
  2017年   481篇
  2016年   615篇
  2015年   857篇
  2014年   952篇
  2013年   967篇
  2012年   1114篇
  2011年   989篇
  2010年   683篇
  2009年   541篇
  2008年   637篇
  2007年   542篇
  2006年   507篇
  2005年   389篇
  2004年   409篇
  2003年   403篇
  2002年   379篇
  2001年   249篇
  2000年   174篇
  1999年   199篇
  1998年   117篇
  1997年   106篇
  1996年   96篇
  1995年   99篇
  1994年   74篇
  1993年   58篇
  1992年   55篇
  1991年   48篇
  1990年   41篇
  1989年   44篇
  1988年   27篇
  1987年   22篇
  1986年   19篇
  1985年   8篇
  1984年   13篇
  1983年   15篇
  1982年   13篇
  1981年   12篇
  1980年   6篇
  1979年   7篇
  1977年   4篇
  1975年   6篇
  1974年   4篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 325 毫秒
1.
2.
3.
4.
The aim of the study was to explore the mechanism of mesenchymal stem cell‐derived exosomes (MSC‐EXO) to protect against experimentally induced pulmonary hypertension (PH). Monocrotaline (MCT)‐induced rat model of PH was successfully established by a single intraperitoneal injection of 50 mg/kg MCT, 3 weeks later the animals were treated with MSC‐EXO via tail vein injection. Post‐operation, our results showed that MSC‐EXO could significantly reduce right ventricular systolic pressure (RVSP) and the right ventricular hypertrophy index, attenuate pulmonary vascular remodelling and lung fibrosis in vivo. In vitro experiment, the hypoxia models of pulmonary artery endothelial cell (PAEC) and pulmonary vascular smooth muscle cell (PASMC) were used. We found that the expression levels of Wnt5a, Wnt11, BMPR2, BMP4 and BMP9 were increased, but β‐catenin, cyclin D1 and TGF‐β1 were decreased in MSC‐EXO group as compared with MCT or hypoxia group in vivo or vitro. However, these increased could be blocked when cells were transfected with Wnt5a siRNA in vitro. Taken together, these results suggested that the mechanism of MSC‐EXO to prevent PH vascular remodelling may be via regulation of Wnt5a/BMP signalling pathway.  相似文献   
5.
Hyperthermic treatment at 43 degrees C suppressed the growth of Ehrlich ascites tumor (EAT) cells in vitro. Incubation of EAT cells at 43 degrees C for as little as 1.5 h totally abolished the transplantability of the tumor. At the same time, the rate of cellular glucose uptake, the density of glucose transporter on the cells as well as the extent of thymidine, uridine and leucine incorporation were significantly reduced.  相似文献   
6.
7.
8.
9.
Many studies have verified that microRNAs contribute a lot to neuropathic pain progression. Furthermore, nerve-related inflammatory cytokines play vital roles in neuropathic pain progression. miR-183 has been identified to have a common relationship with multiple pathological diseases. However, the potential effects of miR-183 in the process of neuropathic pain remain undetermined. Therefore, we performed the current study with the purpose of finding the functions of miR-183 in neuropathic pain progression using a chronic sciatic nerve injury (CCI) rat model. We demonstrated that miR-183 expression levels were evidently reduced in CCI rats in contrast with the control group. Overexpression of miR-183 produced significant relief of mechanical hyperalgesia, as well as thermal hyperalgesia in CCI rats. Furthermore, neuropathic pain-correlated inflammatory cytokine expression levels containing interleukin-6 (IL-6) and interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2) were obviously inhibited by upregulation of miR-183. Meanwhile, dual-luciferase reporter assays showed MAP3K4 was a direct downstream gene of miR-183. The expression levels of MAP3K4 were modulated by the increased miR-183 negatively, which lead to the downregulation of IL-6, IL-1β, and COX-2, and then reduced neuropathic pain progression, respectively. Overall, our study pointed out that miR-183 was a part of the negative regulator which could relieve neuropathic pain by targeting MAP3K4. Thus it may provide a new clinical treatment for neuropathic pain patients clinical therapy.  相似文献   
10.
Diabetic nephropathy (DN), a major cause of end-stage chronic renal failure, is histologically characterized by glomerulosclerosis. To investigate the molecular mechanisms of DN, it is important to establish a stable model of glomerulosclerosis in mice, because genomic manipulation techniques (such as gene destruction or transgene insertion) are well established in rodent species. In this study, we found that repeated administrations of streptozotocin led to early onset of glomerular sclerotic lesions in C57BL/6 mice, accompanied with renal dysfunction. During the natural course of DN, glomerular endothelial cells decreased at 10 weeks after the start of streptozotocin-injections, whereas myofibroblastic mesangial cells became evident. Our results provide an animal tool to elucidate the molecular mechanisms of DN, for example to investigate vascular pathology in diabetic glomerular diseases.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号