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Minimizing the effect of near-distance dielectric sensitivity on retrieving average aspect ratio of gold nanorod by optical extinction spectroscopy:in the case of CTAB adsorption

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Chinese Science Bulletin 2014年第16期59卷 1822-1831页

作者： zhijian hu Yinglu Ji Shuai Hou Xiaochun Wu CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and Technology

The aspect ratio(AR)is one of the most intriguing parameters of gold nanorods(GNRs),which plays an important role in determining localized surface plasmon(LSPR)*** of conventional imaging techniques,the optical extinction spectroscopy(OES)method has been developed for allowing fast statistically measuring the average AR under static *** this work,combining with the previous achievements in spectroscopic technique,we further analyze the effects of gold dielectric function and near distance dielectric *** former may reflect possible dielectric loss of real Au samples from ideal single *** latter reflects the cetyltrimethylammonium bromide(CTAB)adsorption on the surface of GNR induces different LSPR shifts below and above critical micelle concentration(CMC).However,their effect on the determination of AR has not been evaluated in OES *** average AR measurements as a function of absorbance of CTAB-GNRs and LSPR maximum below the CMC were *** results indicate that after considering these factors,the mean ARs obtained from spectroscopic techniques are closer to those obtained from imaging techniques.

关键词： CTAB 消光光谱吸附作用平均值纵横比纳米棒灵敏度近距离

Fabrication of chiral plasmonic oligomers using cysteine-modified gold nanorods as monomers

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Nano Research 2014年第11期7卷 1699-1705页

作者： Shuai Hou Tao Wen huiZhang Wenqi Liu Xiaona hu Rongyao Wang zhijian hu Xiaochun Wu CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and Technology Beijing 100190 China University of the Chinese Academy of Sciences Beijing 100049 China School of Physics Key Laboratory of Cluster Science of Ministry of Education Beijing Institute of Technology Beijing 100081 China

Generation of circular dichroism （CD） beyond the UV region is of great interest in developing chiral sensors and chiroptical devices. Herein, we demonstrate a simple and versatile method for fabrication of plasmonic oligomers with strong CD response in the visible and near IR spectral range. The oligomers were fabricated by triggering the side-by-side assembly of cysteine-modified gold nanorods. The modified nanorods themselves did not exhibit obvious plasmonic CD signals; however, the oligomers show strong CD bands around the plasmon resonance wavelength. The sign of the CD band was dictated by the chirality of the absorbed cysteine molecules. By adjusting the size of the oligomers, the concentration of chiral molecules, and/or the aspect ratio of the nanorods, the CD intensity and spectral range were readily tunable. Theoretical calculations suggested that CD of the oligomers originated from a slight twist of adjacent nanorods within the oligomer. Therefore, we propose that the adsorbed chiral molecules are able to manipulate the twist angles between the nanorods and thus modulate the CD response of the oligomers.

关键词： chiral nanostructures circular dichroism gold nanorods plasmon coupling self-assembly

Temperature-modulated inversion and switching of chiroptical responses in dynamic side-by-side oligomers of gold nanorods

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Nano Research 2023年第12期16卷 13392-13399页

作者： Hanbo Li Dejing Meng Chenqi Zhang Yinglu Ji Xinshuang Gao zhijian hu Xiaochun Wu CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Herein,a new strategy is proposed for achieving dynamic chiral controls in self-assembly systems of plasmonic nanorods based on *** enlarging Au{100}side facets of Au nanorod(AuNR)building block and changing surface ligand from often-used cetyltrimethylammonium bromide(CTAB)to cetylpyridinium chloride(CPC),inversion of chiroptical signal in side-by-side(SS)oligomers is *** the guide of chiral cysteine(Cys),Au{100}side facet-linked SS rods twist in the opposite direction compared with Au{110}side facet-linked *** high CPC concentration,by controlling the incubation temperature of chiral Cys,the dominant twist mode can be ***-difference time-domain(FDTD)simulations indicate the key role of the twisting dihedral angle of the oligomers in driving chiral signal *** low CPC concentration,a temperature-sensitive chiral switching is observed owing to the conformation change of the CPC ligand *** temperature-modulated chiral responses are based on the interactions of chiral molecules,achiral surface ligands,and exposed facets of the building *** rich dynamic tunability of chiroptical responses of plasmonic assemblies may find applications in stimulus-responsive nanodevices.

关键词： plasmonic circular dichroism gold nanorods chiral oligomers cetylpyridinium chloride temperature stimulus

A Well Productivity Model for Multi-Layered Marine and Continental Transitional Reservoirs with Complex Fracture Networks

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1313-1330页

作者： huiyan Zhao Xuezhong Chen zhijian hu Man Chen Bo Xiong Jianying Yang Sichuan Changning Natural Gas Development Company Limited PetroChina Southwest Oil and Gas Field CompanyYibin644399China Sichuan Shale Gas Exploration and Development Company Limited PetroChina Southwest Oil and Gas Field CompanyNeijiang641100China New Energy Division PetroChina Southwest Oil and Gas Field CompanyChengdu610051China

Using the typical characteristics of multi-layered marine and continental transitional gas reservoirs as a basis,a model is developed to predict the related well production *** model relies on the fractal theory of tortuous capillary bundles and can take into account multiple gas flow mechanisms at the micrometer and nanometer scales,as well as the flow characteristics in different types of thin layers(tight sandstone gas,shale gas,and coalbed gas).Moreover,a source-sink function concept and a pressure drop superposition principle are utilized to introduce a coupled flow model in the reservoir.A semi-analytical solution for the production rate is obtained using a matrix iteration method.A specific well is selected for fitting dynamic production data,and the calculation results show that the tight sandstone has the highest gas production per unit thickness compared with the other types of ***,desorption and diffusion of coalbed gas and shale gas can significantly contribute to gas production,and the daily production of these two gases decreases rapidly with decreasing reservoir ***,the gas production from fractures exhibits an approximately U-shaped distribution,indicating the need to optimize the spacing between clusters during hydraulic fracturing to reduce the area of overlapping fracture *** coal matrix water saturation significantly affects the coalbed gas production,with higher water saturation leading to lower production.

关键词： Marine-continental transitional reservoir multi-layered reservoir seepage mechanisms apparent permeability hydraulic horizontal well productivity model

Gold nanorods core/AgPt alloy nanodots shell： A novel potent antibacterial nanostructure

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Nano Research 2013年第11期6卷 822-835页

作者： Xiaona hu Yuyun Zhao zhijian hu Aditya Saran Shuai Hou Tao Wen Wenqi Liu Yinglu Ji Xingyu Jiang Xiaochun Wu CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and Technology Beijing 100190 China CAS Key Laboratory for Biological Effects of Nanamaterials and Nanosafety National Center for Nanoscience and Technology Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

In the light of the current problems of silver nanoparticles （Ag NPs） in terms of antibacterial performance, we have designed a novel trimetallic corelshell nanostructure with AgPt alloy nanodots epitaxially grown on gold nanorods （Au@PtAg NRs） as a potential antibacterial agent. Both Escherichia coli （E. coli） and Staphylococcus aureus （S. aureus） were studied. The antibacterial activity exhibits an obvious composition-dependence. On increasing the Ag fraction in the alloy shell up to 80%, the antibacterial activity gradually increases, demonstrating a flexible way to tune this activity. At 80% Ag, tile antibacterial activity is better than that of a pure Ag shell. The improved antibacterial ability mainly results from the high exposure of silver on the shell surface due to the dot morphology. We thus demonstrate that forming alloys is an effective way to improve antibacterial activity while retaining high chemical stability for Ag-based nanomaterials. Furthermore, due to the tunable localized surface plasmonic response in the near-infrared （NIR） spectral region, additional control over antibacterial activity using light--such as photothermal killing and photo- triggered silver ion release--is expected. As a demonstration, highly enhanced antibacterial activity is shown by utilizing the NIR photothermal effect of the nanostructures. Our results indicate that such tailored nanostructures will find a role in the future fight against bacteria, including the challenge of the increasing severity of multidrug resistance.

关键词： AgPt gold nanorods antibacterial activities composition-dependence photothermal effect

Genetic variants in promoter region of TFR2 is associated with the risk of non-alcoholic fatty liver disease in a Chinese Han population:a case–control study

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Gastroenterology Report 2022年第1期10卷 536-543页

作者： Xinting Pan Hewei Peng Junchao Zhang Yunli Wu zhijian hu Xian-E.Peng Department of Epidemiology and Health Statistics Fujian Provincial Key Laboratory of Environment Factors and CancerSchool of Public HealthFujian Medical UniversityFuzhouP.R.China The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province Mengchao Hepatobiliary Hospital of Fujian Medical UniversityFuzhouP.R.China Key Laboratory of Ministry of Education for Gastrointestinal Cancer Fujian Medical UniversityFuzhouP.R.China

Background Iron overload is frequently observed in non-alcoholic fatty liver disease(NAFLD).Transferrin receptor 2(TFR2)is an important key factor in iron *** aimed to investigate whether TFR2 single nucleotide polymorphisms(SNPs)contribute to susceptibility to NAFLD in a Chinese Han *** Five tag SNPs(rs10247962,rs4434553,rs2075672,rs1052897,and rs3757859)in the TFR2 gene were selected and genotyped in a case–control study on participants who visited two affiliated hospitals of Fujian Medical University between June 2011 and August *** score matching and inverse probability of treatment weighting analyses were used to verify the risk associated with TFR2 *** Logistic regression analyses suggested that subjects with the rs4434553 GA or GG genotype had a lower risk of NAFLD than those carrying the AA genotype(odds ratio=0.630,95%confidence interval=0.504–0.788).Moreover,the rs4434553 GA or GG genotype was negatively correlated with body mass index,hepatic steatosis index,and serum ferritin(b=-0.363,P=0.008;b=-1.040,P=0.009;b=-35.258,P=0.015,respectively),and positively associated with serum hepcidin level(b=35.308,P<0.001).Moreover,rs10247962 and rs1052897 had multiplicative interactions with age in relation to the risk of NAFLD(P for interactions,0.041 and 0.034,respectively).The cumulative effects of the rs10247962,rs1052897,and rs4434553 SNPs were positively associated with the risk of NAFLD(adjusted P_(trend)=0.012).Conclusions In this Chinese Han population,the rs4434553 polymorphism in TFR2 may be an independent influencing factor associated with the susceptibility to *** ageing effect on the development of NAFLD may be inhibited by SNPs rs10247962 and rs1052897.

关键词： NAFLD transferrin receptor 2 single nucleotide polymorphism gene-environment interaction

Ferroxidase-like activity of Au nanorod/Pt nanodot structures and implications for cellular oxidative stress

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Nano Research 2015年第12期8卷 4024-4037页

作者： Jianbo Liu Xiumei Jiang Liming Wang zhijian hu Tao Wen Wenqi Liu Junjie Yin Chunying Chen Xiaochun Wu CAS Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and Technology Beijing 100190 China College of Opto-electronic Engineering Zaozhuang University Zaozhuang 277100 China CAS Key Laboratory for Biological Effects ofNanomaterials & Nanosafety National Center for Nanoscience and Technology Beijing 100190 China Division of Analytical Chemistry Office of Regulatory Science Center for Food Safety and Applied Nutrition US Food and Dru~ Administration College Park MD 20740 USA I

Platinum nanoparticles （NPs） are reported to mimic various anfioxidant enzymes and thus may produce a positive biological effect by reducing reactive oxygen species （ROS） levels. In this manuscript, we report Pt NPs as an enzyme mimic of ferroxidase by depositing platinum nanodots on gold nanorods （Au@Pt NDRs）. Au@Pt NDRs show pH-dependent ferroxidase-like activity and have higher activity at neutral pH values. Cytotoxicity results with human cell lines （lung adenocarcinoma A549 and normal bronchial epithelial cell line HBE） show that Au@Pt NDRs are taken up into cells via endocytosis and translocate into the endosome/lysosome. Au@Pt NDRs have good biocompatibility at NDR particle concentrations lower than 0.15 nM. However, in the presence of H202, lysosome- located NDRs exhibit peroxidase-like activity and therefore increase cytotoxicity. In the presence of FeE＋, the ferroxidase-like activity of the NDRs protects cells from oxidative stress by consuming H202. Thorough consideration should be given to this behavior when employinK Au@Pt NDRs in biological svstems.

关键词： Au@Pt nanostructure ferroxidase peroxidase antioxidant activity biological effect

The role of pathological tau in synaptic dysfunction in Alzheimer’s diseases

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Translational Neurodegeneration 2021年第4期10卷 584-594页

作者： Moxin Wu Manqing Zhang Xiaoping Yin Kai Chen zhijian hu Qin Zhou Xianming Cao Zhiying Chen Dan Liu Department of Medical Laboratory Affiliated Hospital of Jiujiang UniversityJiujiang 332000China Jiujiang Clinical Precision Medicine Research Center Jiujiang 332000China Medical College of Jiujiang University Jiujiang 332000China Department of Neurology Affiliated Hospital of Jiujiang UniversityJiujiang 332000China Department of Dermatology Wuhan No.1 HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Department of Medical Genetics Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Alzheimer's disease(AD)is a neurodegenerative disease characterized by progressive cognitive decline,accompanied by amyloid-β(Aβ)overload and hyperphosphorylated tau accumulation in the *** dysfunction,an important pathological hallmark in AD;is recognized as the main cause of the cognitive *** evidence suggests that synaptic dysfunction could be an early pathological event in *** tau,which is detached from axonal microtubules and mislocalized into pre-and postsynaptic neuronal compartments,is suggested to induce synaptic dysfunction in several ways,including reducing mobility and release of presynaptic vesicles,decreasing glutamatergic receptors,impairing the maturation of dendritic spines at postsynaptic terminals,disrupting mitochondrial transport and function in synapses,and promoting the phagocytosis of synapses by ***,we review the current understanding of how pathological tau mediates synaptic dysfunction and contributes to cognitive decline in *** propose that elucidating the mechanism by which pathological tau impairs synaptic function is essential for exploring novel therapeutic strategies for AD.

关键词： Pathological tau Synaptic dysfunction Synaptic plasticity Alzheimer's disease

Temperature dependent Raman and photoluminescence of vertical WS2/MoS2 monolayer heterostructures

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Science Bulletin 2017年第1期62卷 16-21页

作者： zhijian hu Yanjun Bao Ziwei Li Yongji Gong Rui Feng Yingdong Xiao Xiaochun Wu Zhaohui Zhang Xing Zhu Pulickel M. Ajayan Zheyu Fang State Key Laboratory for Mesoscopic Physics School of PhysicsPeking UniversityCollaborative Innovation Center of Quantum MatterBeijing 100871China Key Laboratory of Nanoscale Measurement and Standardization National Center for Nanoscience and Technology Beijing 100190China Department of Materials Science and NanoEngineering Rice UniversityHouston7X 77005USA

Heterostructures from two-dimensional transition-metal dichalcogenides MX2 have emerged as a hot topic in recent years due to their various fascinating properties. Here, we investigated the temperature dependent Raman and photoluminescence （PL） spectra in vertical stacked WS2/MoS2 monolayer heterostructures. Our result shows that both E^g and Alg modes of WS2 and MoS2 vary linearly with tem- perature increasing from 300 to 642 K. The PL measurement also reveals strong temperature dependencies of the PL intensity and peak position. The activation energy of the thermal quenching of the PL emission has been found to be equal to 69.6 meV. The temperature dependence of the peak energy well follows the band- gap shrinkage of bulk semiconductor.

关键词： Temperature-dependent Raman spectra Photoluminescence Transition metal dichalcogenides Heterostructures