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期刊论文 2

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2023 1

2007 1

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Overoxidized poly(3,4-ethylenedioxythiophene)-overoxidized polypyrrole composite films with enhanced electrocatalytic ability for rutin and luteolin determination

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 735-748 doi: 10.1007/s11705-022-2262-z

摘要: In this study, a simple and effective method was proposed to improve the electrocatalytic ability of overoxidized poly(3,4-ethylenedioxythiophene)-overoxidized polypyrrole composite films modified on glassy carbon electrode for rutin and luteolin determination. The composite electrode was prepared by cyclic voltammetry copolymerization with LiClO4-water as the supporting electrolyte. The peak current of rutin and luteolin on the composite electrode gradually decreased or even disappeared with the increase in the positive potential limit. After incubation in NaOH–ethanol solution with a volume ratio of 1:1, the composite electrodes prepared at positive potential limit greater than 1.5 V exhibited enhanced differential pulse voltammetry peak currents, reduced charge transfer resistance, larger effective specific surface area and higher electron transfer rate constant. The composite electrode prepared in the potential range of 0–1.7 V showed optimal electrocatalytic performance. The X-ray photoelectron spectroscopy results indicated that the content of –SO2/–SO and –C=N– groups in the composite film increased significantly after incubation. Further, the Raman spectra and Fourier transform infrared spectra revealed that the thiophene ring structure changed from benzene-type to quinone-type, and the quinone-type pyrrole ring was formed. The electrocatalytic mechanism of the composite film was proposed based on the experimental results and further verified by Density Functional Theory calculation.

关键词: overoxidized poly(3     4-ethylenedioxythiophene)-overoxidized polypyrrole     rutin     luteolin     incubation     electrocatalytic mechanism    

Study on the action of resistin-induced human umbilical vein endothelial cell dysfunction

LI Zhizhen, LI Fangping, YAN Li, LI Feng, LI Yan, CHENG Hua, FU Zuzhi

《医学前沿(英文)》 2007年 第1卷 第2期   页码 196-199 doi: 10.1007/s11684-007-0037-z

摘要: The aim of this paper was to investigate the effects of resistin on human umbilical vein endothelial cells (HUVECs), and to explore its role and mechanism of action in atherosclerosis. HUVECs were incubated with recombinant human resistin (0, 50, 100 ng/mL) for 24 h. ICAM-1, VCAM-1 and reactive oxygen species (ROS) were assayed by flow cytometer. ET-1, eNOS and iNOS mRNA expression were measured by semi-quantitative RT-PCR. Incubation of HUVECs with resistin resulted in an increase in ICAM-1 expression and ET-1 mRNA expression. However, resistin had no effect on VCAM-1 expression and ROS release. eNOS and iNOS mRNA expression were not altered by resistin stimulation. Adipokine resistin exerted a direct effect in promoting HUVEC dysfunction by promoting ICAM-1 and ET-1 expression. These data suggest that adipocyteendothelium cross-talk might play an important role in the pathogenesis of cardiovascular disease in diabetes mellitus.

关键词: endothelial     resistin stimulation     Incubation     pathogenesis     dysfunction    

标题 作者 时间 类型 操作

Overoxidized poly(3,4-ethylenedioxythiophene)-overoxidized polypyrrole composite films with enhanced electrocatalytic ability for rutin and luteolin determination

期刊论文

Study on the action of resistin-induced human umbilical vein endothelial cell dysfunction

LI Zhizhen, LI Fangping, YAN Li, LI Feng, LI Yan, CHENG Hua, FU Zuzhi

期刊论文