检索结果-南通市图书馆

Science China Chemistry 2021年第12期64卷 2230-2238页

作者： Xu Liang Lan Mi Zhengyou Yu Minghan Wang Yuecong Hu Xinhe Zheng Yi shao Zhiwei Zhu yuanhua shao Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

Simplicity and stability of an analytical method are the key to practical *** order to achieve such a goal,a molecule with multifunction could be one of the *** this work,the multifunctional characteristics of branched polyethylenemine(bPEI)were employed for verification of this *** types of amines in the bPEI can be used to synthesize core-shell nanostructures(bPEI@Au and SiO_(2)@bPEI@Au)in a simple one-pot process within 1 h,and as coreactants with over 500-fold enhancement for electrochemiluminescent(ECL)*** on the remarkable performance of bPEI,a label-free ECL immunosensor and its array with the same assembly strategy were constructed for the simple and rapid determination of three acute myocardial infarction(AMI)biomarkers:cardiac troponin I(cTnI),human-type fatty acid binding protein(hFABP)and *** methods exhibited excellent stability and sensitivity with wide linear range and low limits of detection down to fg/mL level by the photomultiplier tube and pg/mL level by the electron-multiplying charge-coupled device.

关键词： simplicity multifunction branched polyethylenemine electrochemiluminescence AMI biomarkers

Recent Advances in Real-Time Analysis of Electrochemical Reactions by Electrochemical Mass Spectrometry

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2023年第2期41卷 214-224页

作者： Xianhao Zhang Jirui Zhan Zhengyou Yu Jintao Deng Meixian Li yuanhua shao Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Electrochemical mass spectrometry(EC-MS)is a powerful tool to capture and analyze the intermediates and products during elec-trochemical *** hyphenated technique combines electrochemistry with mass spectrometry using specific apparatuses,which helps researchers study mechanisms of redox reactions by in situ detecting chemical composition ***,various EC-MS methods have been applied in a series of electrochemical reactions to reveal the mechanisms,mainly in the areas of electro-chemical sensors,organic electrochemistry,and *** this review,we intend to summarize the recent advances in re-al-time analysis of different types of electrochemical reactions by EC-MS and offer an outlook on the perspectives in these areas.

关键词： Electrochemistry Mass spectrometry Sensors Reaction mechanisms Reactive intermediates Analytical chemistry

Probing non-polarizable liquid/liquid interfaces using scanning ion conductance microscopy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2020年第3期63卷 411-418页

作者： Yaxiong Gu Ye Chen Yifan Dong Junjie Liu Xianhao Zhang Mingzhi Li yuanhua shao Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The study of microscopic structure of a liquid/liquid interface is of fundamental importance due to its close relation to the thermodynamics and kinetics of interfacial charge transfer *** this article,the microscopic structure of a non-polarizable water/nitrobenzene(W/NB)interface was evaluated by scanning ion conductance microscope(SICM).Using SICM with a nanometer-sized quartz pipette filled with an electrolyte solution as the probe,the thickness of this type of W/NB interface could be measured at sub-nanometer scale,based on the continuous change of ionic current from one phase to another *** effects for thicknesses of the non-polarizable W/NB interfaces with different electrolyte concentrations,the Galvani potentials at the interface and the applied potentials on the probe were measured and systematically *** experimental setups,that is an organic phase up and an aqueous down,and a reverse version,were employed to acquire the approach *** data were compared with those of an ideal polarizable interface under the similar experimental conditions,and several characteristics of non-polarizable interfaces were *** thickness of a non-polarizable interface increases with the decrease of electrolyte concentration and the increase of applied potential,which is similar to the situation of a polarizable liquid/liquid *** also find that the Galvani potential across a non-polarizable interface can also influence the interfacial thickness,this phenomenon is difficult to observe when using polarizable *** importantly,by the comparison of two kinds of liquid/liquid interfaces,we experimentally proved that much more excess ions are gathered in the space charge layer of non-polarizable interfaces than in that of polarizable *** results are consistent with the predictions of molecular dynamic simulations and X-ray reflectivity measurements.

关键词： micro/nano pipettes scanning ion conductance microscopy microstructure of a non-polarizable liquid/liquid interface

C-dots assisted synthesis of gold nanoparticles as labels to catalyze copper deposition for ultrasensitive electrochemical sensing of proteins

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第4期61卷 476-482页

作者： Xiaoli Qin Yifan Dong Minghan Wang Zhiwei Zhu Meixian Li Xiangjian Chen Di Yang yuanhua shao Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking University Institute of Cardiovascular Disease First Affiliated Hospital of Nanjing Medical University

We report an ultrasensitive protocol for electrochemical sensing using the hydroxyl-rich C-dots assisted synthesis of gold nanoparticles(C-dots@AuNP) as labels with copper depositon reaction. The C-dots catalyzing copper deposition reaction was implemented for the first time. We constructed a sandwich-type immunosensor on the chitosan modified glassy carbon electrode(GCE) by glutaraldehyde(GA) crosslinking, with C-dots@AuNP as biolabels. Copper was deposited on the catalytic surfaces of second antibody-conjugated C-dots@AuNP nanoparticles through CuSO_4-ascorbic acid reduction, because both C-dots and AuNPs could strongly catalyze the CuSO_4 and ascorbic acid to form Cu particles, which amplified the detection signal. Then the corresponding antigen was quantified based on simultaneous chemical-dissolution/cathodic-preconcentration of copper for insitu analysis using anodic stripping square wave voltammetry(ASSWV) directly on the modified electrode. Under optimized conditions, these electrodes were employed for sandwich-type immunoanaly sis, pushing the lower limits of detection(LODs)down to the fg mL^(-1) level for human immunoglobulin G(IgG) and cardiac troponin I(cTnI), a cardiac biomarker. These novel sensors have good stability and acceptable accuracy and reproducibility, suggesting potential applications in clinical diagnostics.

关键词： gold nanoparticles with C-dots as labels copper deposition reaction for signal enhancement human immunoglobulin G human cardiac troponin I

Genome-Wide Analysis of BURP Domain-Containing Genes in Populus trichocarpa

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2011年第9期53卷 743-755页

作者： yuanhua shao Guo Wei Ling Wang Qing Dong Yang Zhao Beijiu Chen Yan Xiang Laboratory of Modern Biotechnology School of Forestry and Landscape ArchitectureAnhui Agricultural UniversityHefei 230036China Key Laboratory of Biomass Improvement and Conversion Anhui Agriculture UniversityHefei 230036China

BURP domain-containing proteins have a conserved structure and are found extensively in *** functions of the proteins in this family are diverse,but remain unknown in Populus *** the present study,a complete genome of *** was analyzed bioinformatically.A total of 18 BURP family genes,named PtBURPs,were identified and characterized according to their physical positions on the *** chromosomes.A phylogenetic tree was generated from alignments of PtBURP protein sequences,while phylogenetic relationships were also examined between PtBURPs and BURP family genes in other plants,including rice,soybean,maize and *** genes in *** were classified into five classes,namely PG1β-like,BNM2-like,USP-like,RD22-like and BURP *** multiple expectation maximization for motif elicitation（MEME） and multiple protein sequence alignments of PtBURPs were also *** from the transcript level analyses of 10 PtBURP genes under different stress conditions revealed the expression patterns in poplar and led to a discussion on genome duplication and evolution,expression profiles and function of PtBURP genes.

关键词： abiotic stress bioinformatics BURP gene Populus trichocarpa.

Simulation and experimental verification of the dependence of collection efficiency on the shape of a dual micropipette

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2011年第8期54卷 1311-1318页

作者： GAO Zhao LI Bo ZHAO WenBo CHEN Yong HU Mo LIANG ZhongWei ZHOU ShuLin shao yuanhua College of Chemistry and Molecular Engineering Peking University Beijing 100871 China School of Mathematical Sciences Peking University Beijing 100871 China Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

The current responses of a generation/collection (G/C) system based on dual micropipettes are simulated by the boundary element (BE) method, from which the collection efficiencies for various pipettes with different geometries are calculated. The influence of the shape of a dual micropipette on the collection efficiency, such as curvature and symmetry of the pipette, as well as the thickness of glassy band between generator and collector, is presented and discussed in detail. Moreover, the simulation results have been tested using the experiments of potassium and sodium ions transfers facilitated by dibenzo-18-crown-6 (DB18C6) at the water/1,2-dichloroethane (W/DCE) interface. These results demonstrate that the BE method is an efficient and useful approach for the simulation of collection efficiency of symmetric geometries of dual micropipettes operating in the G/C mode under transport conditions of diffusion control. However, there are still some problems for the cases of asymmetric dual micropipettes, which show rather large differences between the values of simulated and experimental ones. This work also indicates that such an ionic G/C technique should have advantages in applications when the dual pipettes have symmetric geometries.

关键词： boundary element method dual micropipettes collection efficiency simulation

A new strategy to improve the sensitivity and selectivity of dopamine detection

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2015年第5期58卷 892-898页

作者： Xiang Xie Jing Gu Wenbo Zhao Shujuan Liu Yonghui Qiao Xinyu Zhu Xiaohong Yin Zhiwei Zhu Meixian Li yuanhua shao Institute of Nuclear Chemistry and Physics China Academy of Engineering Physics Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Peking University

We applied the combination of in situ electrochemical liquid-phase microextraction and square-wave voltammetric stripping analysis for the first time as a highly sensitive and selective approach for the detection of dopamine. A mixed gel of graphene sheets and an ionic liquid of 1-octyl-3-methylimidazolium hexaflurophosphate(OMim PF6) was used as a micro liquid-phase to pre-concentrate dopamine by controlled potential electrolysis from an aqueous solution(as a donor phase), followed by square-wave voltammetric stripping detection. Under optimized conditions, a linear calibration curve was obtained in the range of 0.05 to 1.0 ?mol/L in the presence of excess ascorbic acid and uric acid. The detection limit has been found to be 8.0 nmol/L(S/N=3).

关键词： dopamine detection graphene/OMimPF6 gel-modified electrode electrochemical microextraction square-wavevoltammetric stripping

Research on the Public Perception of Yangzhou Historical and Cultural Districts Based on Network Review Text Analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Landscape Research 2023年第3期15卷 36-41页

作者： WU Tao shao yuanhua College of Horticulture and Landscape Architecture Yangzhou UniversityYangzhouJiangsu 225009China

The historical and cultural districts of a city serve as important cultural heritage and tourism *** paper focused on four such districts in Yangzhou and performed semantic analysis on online public comments using ROST CM6 *** to the high frequency words,attention preference of district site elements,activities and feelings in Yangzhou historical and cultural districts were *** the analysis of semantic network and public emotional tendency,the relationship between the protection and utilization of Yangzhou historical and cultural districts and the perception and demand of users were discussed,and some suggestions for the protection,utilization and renewal of historical and cultural districts were put forward.

关键词： Yangzhou historical and cultural districts Text analysis Public perception Protection and renewal

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

扫描电化学显微镜及其最新进展

分析化学 1999年第11期27卷 1348-1355页

作者：邵元华中国科学院长春应用化学研究所电分析化学开放研究实验室国家电化学和光谱研究分析中心长春130022

对扫描电化学显微镜技术的基本原理、仪器设备、最新的研究进展和发展展望进行了评述.

关键词：扫描电化学显微镜技术图像异相反应动力学评述

ION CURRENT RECTIFICATION AND ION TRANSFER REACTION AT LIQUID/LIQUID INTERFACES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

ION CURRENT RECTIFICATION AND ION TRANSFER REACTION AT LIQUI...