摘要：
A facile and efficient electrochemical platform based on multi-walled carbon nanotube (MWCNT)-poly-L-lysine (PLL) hybrids was prepared for studying on the immobilization and in vitro electrochemical behavior of cells. The PLL/MWCNT hybrids form a reticulate structure on the electrode surface, which provides a biocompatible and efficient microenvironment for cell immobilization. In contrast to the cells/glass carbon (GC) electrode, the cells/PLL/MWCNT hybrid-modified GC electrode exhibits a negatively shifted peak potential and a greatly enhanced peak current, indicating better electrochemical property of the PLL/MWCNT for evaluating the electrochemical behavior of cells. The effect of anticancer drug (adriamycin, ADR) treatment on the electrochemical signal of human breast cancer MCF-7 cells was evaluated. The ADR treatment leads to obviously decrease of the cell voltammetric response, being well accordant with the results obtained from conventional in vitro cytotoxicity assay. The proposed method may provide a simple way to quantitatively study the in vitro cell viability and cytotoxicity of ADR or other anticancer drugs.
期刊：
Journal of Mathematical Control Science and Applications,2018年4(2):137-148 ISSN：0974-0570
作者机构：
School of Mathematical Science and Computing Technology, Central South University, Changsha, Hunan 410075, China;Institute of Mathematics and Physics, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
关键词：
Leggett-Williams fixed point theorem;Neutral functional differential equation;Periodic solution
摘要：
A method is described for the determination of microRNA. It is based on the use of organic electrochemical transistors (OECTs) fabricated on a flexible poly(ethylene terephthalate) substrate. A gold electrode was modified with gold nanoparticles to immobilize the capture DNA probe and then served as the gate of the device. The detection of microRNA21 was realized by monitoring the change of the drain-source current after hybridization of capture DNA with microRNA21. Under optimal conditions, this biosensor exhibits good sensitivity and specificity. It works in the 5 pM to 20 nM microRNA concentration range and has a 2 pM detection limit.
作者机构：
[胡云楚; 王文磊; 陈秋菊; 王琼] School of Science, Central South University of Forestry and Technology, Changsha, 410004, China;[马莉萍; 谢奇龙] School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
[Hu, Y.] S;School of Science, Central South University of Forestry and Technology, Changsha, China
摘要：
Aqueous complexes between ferric (Fe(III)) and arsenate (As(V)) are indispensable for understanding the mobility of arsenic (As) in Fe(III)-As(V)-rich systems. In this study, aqueous Fe(III)-As(V) complexes, FeH2AsO42+ and FeHAsO4+, were postulated based on the qualitative analysis of UV-Vis spectra in both Fe(III)-As(V)-HClO4 and Fe(III)-As(V)-H2SO4 systems. Subsequently, monodentate structures were evidenced by Fe K-edge EXAFS and modeled as [FeH2AsO4(H2O)(5)](2+) and [FeHAsO4(H2O)(5)](+) by DFT. The feature band at similar to 280 nm was verified as electron excitation chiefly from Fe-As-bridged O atoms to d-orbital of Fe in [FeH2AsO4(H2O)(5)](2+) and [FeHAsO4(H2O)(5)](+). The structural and spectral information of Fe(III)-As(V) complexes will enable future speciation analysis in Fe(III)-As(V)-rich system. (C) 2017 Published by Elsevier Ltd.
作者机构：
[Wang, Qi] Cent S Univ, Sch Math Sci & Comp Technol, Changsha 410075, Hunan, Peoples R China.;[Dai, Binxiang] Cent S Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Dai, Binxiang] C;Cent S Univ Forestry & Technol, Inst Math & Phys, Changsha 410004, Hunan, Peoples R China.
关键词：
Neutral population model;finite and infinite delays;k-set contractive operator;positive periodic solution
摘要：
In this paper, by using the theory of abstract continuous theorem of k-set contractive operator and some analysis techniques, we obtain some sufficient conditions for the existence of positive periodic solutions for a neutral population model.
