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   54篇
  免费   0篇
  2021年   3篇
  2020年   6篇
  2019年   3篇
  2018年   1篇
  2017年   1篇
  2015年   2篇
  2014年   3篇
  2013年   9篇
  2012年   6篇
  2011年   4篇
  2010年   4篇
  2009年   4篇
  2008年   2篇
  2006年   2篇
  2005年   1篇
  2004年   1篇
  2001年   1篇
  1982年   1篇
排序方式: 共有54条查询结果,搜索用时 15 毫秒
51.

Background

Acute mental stress may contribute to the cardiovascular disease progression via autonomic nervous system controlled negative effects on the endothelium. The joint effects of stress-induced sympathetic or parasympathetic activity and endothelial function on atherosclerosis development have not been investigated. The present study aims to examine the interactive effect of acute mental stress-induced cardiac reactivity/recovery and endothelial function on the prevalence of carotid atherosclerosis.

Methods

Participants were 81 healthy young adults aged 24-39 years. Preclinical atherosclerosis was assessed by carotid intima-media thickness (IMT) and endothelial function was measured as flow-mediated dilatation (FMD) using ultrasound techniques. We also measured heart rate, respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) in response to the mental arithmetic and speech tasks.

Results

We found a significant interaction of FMD and cardiac RSA recovery for IMT (p = 0.037), and a significant interaction of FMD and PEP recovery for IMT (p = 0.006). Among participants with low FMD, slower PEP recovery was related to higher IMT. Among individuals with high FMD, slow RSA recovery predicted higher IMT. No significant interactions of FMD and cardiac reactivity for IMT were found.

Conclusions

Cardiac recovery plays a role in atherosclerosis development in persons with high and low FMD. The role of sympathetically mediated cardiac activity seems to be more important in those with impaired FMD, and parasympathetically mediated in those with relatively high FMD. The development of endothelial dysfunction may be one possible mechanism linking slow cardiac recovery and atherosclerosis via autonomic nervous system mediated effect.  相似文献   
52.
CD59 is a crucial complement regulatory protein that inhibits the terminal step of the complement activation cascade by interfering with the binding of C9 to C5b-8, thus preventing the formation of the membrane attack complex (MAC). We recently reported that the mouse genome contains two Cd59 genes, while the human and rat genomes each contain only one Cd59 gene (Qian et al. 2000). Here, we describe the genomic structure, comparative activity, and tissue distribution of these two mouse genes, designated Cd59a and Cd59b. The mouse Cd59 genes encompass a total of 45.6 kb with each gene having four exons. Cd59a spans 19 kb, and Cd59b spans 15 kb, with approximately 11.6 kb of genomic DNA separating the two genes. The overall sequence similarity between Cd59a and Cd59b is approximately 60%. The sequence similarity between exon 2, exon 3, and exon 4 and the respective flanking regions between the two genes is over 85%, but exon 1 and its flanking regions are totally different. Comparative studies of the activity of both genes as inhibitors of MAC formation revealed that Cd59b has a specific activity that is six times higher than that of Cd59a. Using polyclonal antibodies specific to either Cd59a or Cd59b, we showed that Cd59a and Cd59b are both widely expressed in the kidneys, brain, lungs, spleen, and testis, as well as in the blood vessels of most mouse tissues. Interestingly, testicular Cd59a appeared to be expressed exclusively in spermatids, whereas Cd59b was expressed in more mature sperm cells. These results suggest that even though Cd59a and Cd59b are expressed in multiple tissues, they may play some different roles, particularly in reproduction. Received: 9 February 2001 / Accepted: 18 April 2001  相似文献   
53.
Acetoacetate (AA) is a ketone body, which generates reactive oxygen species (ROS). ROS production is impacted by the formation of covalent bonds between amino groups of biomacromolecules and reducing sugars (glycation). Glycation can damage DNA by causing strand breaks, mutations, and changes in gene expression. DNA damage could contribute to the pathogenesis of various diseases, including neurological disorders, complications of diabetes, and aging. Here we studied the enhancement of glucose-mediated DNA glycation by AA for the first time. The effect of AA on the structural changes, Amadori and advanced glycation end products (AGEs) formation of DNA incubated with glucose for 4 weeks were investigated using various techniques. These included UV–Vis, circular dichroism (CD) and fluorescence spectroscopy, and agarose gel electrophoresis. The results of UV–Vis and fluorescence spectroscopy confirmed that AA increased the DNA-AGE formation. The NBT test showed that AA also increased Amadori product formation of glycated DNA. Based on the CD and agarose gel electrophoresis results, the structural changes of glycated DNA was increased in the presence of AA. The chemiluminescence results indicated that AA increased ROS formation. Thus AA has an activator role in DNA glycation, which could enhance the adverse effects of glycation under high glucose conditions.  相似文献   
54.
The aim of this study was synthesis of two new water-soluble fluorescent palladium and platinum complexes with formulas of [Pt(DACH)(FIP)](NO3)2 and [Pd(DACH)(FIP)](NO3)2, respectively, where FIP is 2-(furan-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline and DACH is 1R,2R-diaminocyclohexane. Fluorescence spectroscopy, circular dichroism (CD), thermal denaturation measurement, ionic strength, and kinetic study displayed groove binding of Pt complex on DNA, while due to binding of Pd complex, B form of DNA convert to Z form. Due to electrostatic interaction of Pd complex with DNA, the DNA form is converted and it provides enough space for Pd complex to insert between base stacking of DNA. UV–vis study shows two complexes could denature the DNA at low concentrations in exothermic process and Pt complex is more active than Pd complex. Finally, the anticancer and growth inhibitory activities of synthesized complexes were investigated against human colon cancer cell line HCT116 after incubation time of 24 h using MTT assay and higher activity was observed for the platinum complex. Interaction of the two metal derivative complexes was studied by molecular docking and molecular dynamics simulation. The results showed that Pt complexes have higher negative docking energy and higher tendency for interaction with DNA, and exert more structural change on DNA.  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