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Atmospheric particle-bound polycyclic aromatic compounds over two distinct sites in Pakistan:Characteristics,sources and health risk assessment

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Journal of Environmental Sciences 2022年第2期34卷 1-15页

作者： Linda Maharjan Shichang Kang Lekhendra Tripathee Chaman Gul Huijun Zheng Quanlian Li pengfei Chen Mukesh Rai Ewerton Santos State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Chinese Academy of Sciences(CAS)Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100085China Himalayan Environment Research Institute Kathmandu 44600Nepal Reading Academy Nanjing University of Information Science&TechnologyNanjingJiangsu 210044China Departamento de Quimica Universidade Federal de SergipeSao CristovaoSergipe SE 49100-000Brazil

Much attention is drawn to polycyclic aromatic hydrocarbons(PAHs)as an air pollutant due to their toxic,mutagenic and carcinogenic ***,to understand the levels,seasonality,sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan,total suspended particle(TSP)samples were collected for over one year *** average total PAH concentrations were 31.5±24.4 and 199±229 ng/m^(3) in Karachi and Mardan,*** significantly lower concentration in Karachi was attributed to diffusion and dilution of the PAHs by the influence of clean air mass from the Arabian sea and high temperature,enhancing the volatilization of the particle phase PAHs to the gas ***,the higher concentration(^(-)6 times)in Mardan was due to large influence from local and regional emission sources.A clear seasonality was observed at both the sites,with the higher values in winter and post-monsoon due to higher emissions and less scavenging,and lower values during monsoon season due to the dilution *** ratios and principal component analysis indicated that PAHs in both sites originated from traffic and mixed combustion sources(fossil fuels and biomass).The average total Ba P equivalent concentrations(Ba P eq)in Karachi and Mardan were 3.26 and 34 ng/m^(3),respectively,which were much higher than the WHO guideline of 1 ng/m^(3).The average estimates of incremental lifetime cancer risk from exposure to airborne Ba P eq via inhalation indicated a risk to human health from atmospheric PAHs at both sites.

关键词： Total suspended particle Polycyclic aromatic hydrocarbons Sources Human health risk

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A microwell-based impedance sensor on an insertable microneedle for real-time in vivo cytokine detection

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Microsystems & Nanoengineering 2021年第6期7卷 139-150页

作者： Naixin Song pengfei Xie Wen Shen Hanju Oh yejia Zhang Flavia Vitale Mehdi Javanmard Mark G.Allen Department of Electrical and Systems Engineering University of PennsylvaniaPhiladelphiaPAUSA Department of Electrical and Computer Engineering Rutgers UniversityPiscatawayNJUSA Department of Physical Medicine and Rehabilitation University of PennsylvaniaPhiladelphiaPAUSA Department of Orthopedic Surgery University of PennsylvaniaPhiladelphiaPAUSA Corporal Michael J.Crescenz Veterans Affairs Medical Center PhiladelphiaPAUSA Department of Bioengineering School of Engineering and Applied ScienceUniversity of PennsylvaniaPhiladelphiaPAUSA Department of Neurology Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA

Impedance-based protein detection sensors for point-of-care diagnostics require quantitative specificity,as well as rapid or real-time ***,microfabrication of these sensors can lead to the formation of factors suitable for in vivo ***,we present microfabricated needle-shaped microwell impedance sensors for rapid-sample-to-answer,label-free detection of cytokines,and other *** microneedle form factor allows sensors to be utilized in transcutaneous or transvascular sensing *** vitro,experimental characterization confirmed sensor specificity and sensitivity to multiple proteins of *** characterization demonstrated sufficient microneedle robustness for transcutaneous insertion,as well as preserved sensor function *** further utilized these sensors to carry out real-time in vivo quantification of human interleukin 8(hIL8)concentration levels in the blood of transgenic mice that endogenously express *** assess sensor functionality,hIL8 concentration levels in serum samples from the same mice were quantified by *** agreement between real-time in vivo sensor readings in blood and subsequent ELISA serum assays was observed over multiple transgenic mice expressing hIL8 concentrations from 62 pg/mL to 539 ng/mL.

关键词： needle utilized insertion

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Study of titanium nitride for low-e coating application

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Chinese Science Bulletin 2007年第13期52卷 1860-1863页

作者： ZHEng pengfei ZHAO GaoLing ZHAng TianBo WU LiQing WAng JianXun HAN GaoRong State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027China

The paper reports our novel work on chemical vapor deposition coating of titanium nitride (TiN) thin film on glass for energy saving. TiN films were deposited on glass substrates by atmospheric pressure chemical vapor deposition (APCVD) using titanium tetrachloride (TiCl4) and ammonia (NH3) as precur-sors. As a result, TiN films with a thickness of 500 nm were obtained. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), four-point probe method and optical spectroscopy were respectively employed to study the crystallization, microstructure, surface mor-phology, electrical and optical properties of the coated TiN films. The deposited TiN films are of NaCl structure with a preferred (200) orientation. The particles in the film are uniform. The reflectivity of the TiN coating in the near-infrared (NIR) band can reach over 40%, the visible transmittance is approxi-mately 60%, and the visible reflectivity is lower than 10%. The sheet electrical resistance is 34.5Ω. According to Drude theory, the lower sheet resistance of 34.5 Ω gives a high reflectivity of 71.5% around middle-far infrared band. The coated films exhibit good energy-saving performance.

关键词：氮化钛大气压化学元素蒸汽

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The critical model size for simulating the structuredynamics correlation in bulk metallic glasses

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Science China Materials 2021年第6期64卷 1545-1555页

作者： Shengjun Sun pengfei Guan Beijing Computational Science Research Center Beijing 100193China

Computational simulation provides an effective way of understanding the disordered structure and structureproperty relationships for metallic glass ***,we systematically investigated the finite-size effects of the static structure and dynamical behaviors in a three-dimensional Cu50Zr50 model metallic glass via classical molecular dynamics(MD)*** was found that the local structure is insensitive to the system size while the dynamical properties present evident finite-size *** decoupling between local structure and relaxation dynamics in the investigated supercooling emerges when the system contains less than~2000 ***,the collapse can be observed between the structural relaxation time and the dynamical heterogeneity for different sized systems across the whole range of our *** results support the intrinsic link between the structural relaxation time and dynamic heterogeneity and reveal the critical simulated system size for representing the structural origins of dynamics in bulk metallic glass with ignorable surface effects.

关键词： metallic glass amorphous structure structural relaxation computational simulation

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Hybrid structure of iron single atoms and metallic titanium for photothermal ethanol steam reforming

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Science China Chemistry 2024年第3期67卷 848-854页

作者： Dachao yuan Guanda Han Zhixuan Wang Jianguo Zhao Kailuan Li pengfei Wang Jianjun Hao yaguang Li Jinhua ye College of Mechanical and Electrical Engineering Technology Innovation Center of Intelligent Agricultural EquipmentHebei Agricultural UniversityBaoding 071001China Research Center for Solar Driven Carbon Neutrality The College of Physics Science and TechnologyInstitute of Life Science and Green DevelopmentHebei UniversityBaoding 071002China International Center for Materials Nanoarchitectonics(WPI-MANA) National Institute for Materials Science(NIMS)1-1 NamikiTsukubaIbaraki 305-0044Japan Graduate School of Chemical Science and Engineering Hokkaido UniversitySapporo 060-0814Japan

Photothermal ethanol steam reforming(ESR) is currently limited by low intrinsic activity and strong solar energy ***,we synthesized Fe single atoms supported on CeO_(2)(SA Fe-CeO_(2)) to exhibit excellent low-temperature ESR activity with a hydrogen production rate of 512 mmol g^(-1)h^(-1) at 350℃,becuase of the high oxidation state of Fe single atoms to weaken the reaction barrier of ethanol ***,a heterostructure of SA Fe-CeO_(2) and Ti foil could eliminate 66% of infrared radiation via the size effect,thus achieving a 3.5 sun-driven temperature of 347℃.Consequently,the heterostructure of SA Fe-CeO_(2) and Ti foil shows a hydrogen generation rate of 984 mmol g^(-1)h^(-1) of ESR and 11.31% of solar-to-hydrogen energy conversion efficiency,which outperforms other photothermal ethanol-hydrogen production *** study provides a new path for designing active catalytic sites and trapping light energy of photothermal catalysts.

关键词： photothermal catalysis single atoms heterostructure ethanol steam reforming iron

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A meta-analysis of the impacts of forest logging on soil CO2 efflux

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Research in Cold and Arid Regions 2020年第3期12卷 165-179页

作者： LongFei Chen y.ngZhou Xiang ZhiBin He Jun Du pengfei Lin Xi Zhu Linze Inland River Basin Research Station Chinese Ecosystem Research NetworkKey Laboratory of Eco-hydrology of Inland River BasinNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China School of Geography and Resources Guizhou Education UniversityGuiyangGuizhou 550018China

Soil CO2 efflux,the second largest flux in a forest carbon budget,plays an important role in global carbon *** logging is expected to have large effects on soil CO2 efflux and carbon sequestration in forest ***,a comprehensive understanding of soil CO2 efflux dynamics in response to forest logging remains elusive due to large variability in results obtained across individual ***,we used a meta-analysis approach to synthesize the results of 77 individual field studies to determine the impacts of forest logging on soil CO2 *** results reveal that forest logging significantly stimulated soil CO2 efflux of the growing season by 5.02%.However,averaged across all studies,nonsignificant effect was detected following forest *** large variation among forest logging impacts was best explained by forest type,logging type,and time since *** CO2 efflux in coniferous forests exhibited a significant increase(4.38%)due to forest logging,while mixed and hardwood forests showed no significant *** type also had a significant effect on soil CO2 efflux,with thinning increasing soil CO2 efflux by 12.05%,while clear-cutting decreasing soil CO2 efflux by 8.63%.The time since logging also had variable effects,with higher soil CO2 efflux for 2 years after logging,and lower for 3-6 years after logging;when exceeded 6 years,soil CO2 efflux *** significantly negative impacts of forest logging were detected on fine root biomass,the general positive effects on soil CO2 efflux can be explained by the accelerated decomposition of organic matter as a result of elevated soil temperature and organic substrate *** results demonstrate that forest logging had potentially negative effects on carbon sequestration in forest ecosystems.

关键词： soil respiration forest ecosystem thinning clear-cutting time since logging

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Copper-tetracyanoquinodimethane-derived copper electrocatalysts for highly selective carbon dioxide reduction to ethylene

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Nano Research 2022年第9期15卷 7910-7916页

作者： Xuewei Huang Dawei Wang Shuhao yan pengfei An Jianyu Han Zhiyu Guo Xinwei Li Zhongjun Chen Lin Chang Siyu Lu Zhiy.ng Tang Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou 450001China Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou 450001China CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049China

As one of the most promising CO_(2)utilization techniques,electrochemical CO_(2)reduction has recently received considerable *** is a unique electrocatalyst that can convert CO_(2)to value-added multi-carbon ***,Cu catalysts are always limited by the poor selectivity and ***,we report that using copper-tetracyanoquinodimethane(CuTCNQ)derived Cu nanoparticles as efficient electrocatalysts for conversion of CO_(2)to ethylene characteristic with high selectivity and stability,showing 56%Faradaic efficiency(FE)to C2H4 at−1.3 V *** hydrogen electrode(RHE).Upon the electrochemical CO_(2)reduction,CuTCNQ slowly reconstructs to Cu nanoparticles with abundant grain boundaries and residual Cu+on the *** calculation and operando characterization disclose that both as-formed Cu nanoparticle grain boundaries and residual Cu+endow the catalyst with high selectivity toward ***,during the reconstruction of CuTCNQ to Cu nanoparticles,the grain boundaries Cu surface is slowly refreshed by continual addition of Cu atoms,thus inhibiting the surface passivation and guaranteeing the electrocatalytic stability.

关键词： reconstruction grain boundary ethylene CO_(2)electroreduction

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Maltol as a Novel Agent Protecting SH-Sy5y Cells Against Hemin-induced Ferroptosis

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Chemical Research in Chinese Universities 2022年第4期38卷 1089-1096页

作者： HUA Cong WAng Xuanzhong LIAng Shipeng LI Chen CHEN Xi PIAO Meihua WAng Zhenchuan GE pengfei LUO Tianfei Department of Neurosurgery the First Hospital of Jilin UniversityChangchun130021P.R.China Research Center of Neuroscience the First Hospital of Jilin UniversityChangchun130021P.R.China Department of Anesthesiology the First Hospital of Jilin UniversityChangchun130021P.R.China Department of Neurology the First Hospital of Jilin UniversityChangchun130021P.R.China

Ferroptosis triggered by hemin is regarded as a primary factor accounting for neuronal death secondary to intracerebral ***,compounds with inhibitory effect on hemin-induced ferroptosis might be potential medicines to prevent neuronal death caused by intracerebral ***,we investigate whether maltol could alleviate hemin-induced SH-Sy5y cell ferroptosis and its potential *** is found that maltol effectively prevents hemin-induced SH-Sy5y cell ferroptosis via three *** first one is inhibiting intracellular iron increase via preventing upregulation of transferrin receptor,the second one is alleviating lipid peroxidation via attenuating H_(2)O_(2) generation by NOX4 and promoting H_(2)O_(2) clearance by catalase,and the third one is to reduce peroxidized lipids via maintaining GPX4/GSH ***,maltol is a novel agent preventing hemin-induced SH-Sy5y cell ferroptosis.

关键词： Maltol Ferroptosis Hemin Brain hemorrhage Neuron

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Measurement and Interpretation of Connectivity of Chinese Cities in World City Network,2010

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Chinese Geographical Science 2013年第3期23卷 261-273页

作者： Ben DERUDDER Peter J TAyLOR Michael HOyLER NI pengfei LIU Xingjian ZHAO Miaoxi SHEN Wei Frank WITLOX Department of Geography Ghent University School of the Built and Natural Environment Northumbria University Department of Geography Loughborough University Chinese Academy of Social Sciences Department of Geography University of Cambridge South China University of Technology ESSCA School of Management

This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which business services firms play the crucial role in city network formation, information is gathered about the presence of global service firms in cities. This information is converted into data to provide the′service value′of a city for a firm′s provision of corporate services in a 526(cities)×175(firms) matrix. These data are then used as the input to the interlocking network model in order to measure cities′connectivity and its predominant geographical orientation. Here we focus on the position of some key Chinese cities in this regard, and discuss and interpret results in the context of the urban dimensions of the′opening up′of the Chinese economy.

关键词： world city network advanced producer services Shanghai Hong Kong Beijing

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A paper-based microfluidic platform with shapememory-polymer-actuated fluid valves for automated multi-step immunoassays

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Microsystems & Nanoengineering 2019年第1期5卷 238-249页

作者： Hao Fu pengfei Song Qiy.ng Wu Chen Zhao Peng Pan Xiao Li Nicole yKLi-Jessen Xinyu Liu Department of Mechanical and Industrial Engineering University of TorontoTorontoONM5S 3G8Canada Department of Mechanical Engineering McGill UniversityMontrealQCH3A 0C3Canada Department of Electrical and Electronic Engineering Xi’an Jiaotong-Liverpool University215123 SuzhouJiangsuChina School of Communication Sciences and Disorders McGill UniversityMontrealQC H3A 1G1Canada Institute of Biomaterials and Biomedical Engineering University of TorontoTorontoON M5S 3G9Canada Present address:Department of Chemistry Stanford UniversityStanfordCA 94305USA

Smart fluid manipulation with automatically controlled paper valves will enable automated and multi-step immunoassays on paper-based microfluidic *** this work,we present an integrated paper-based microfluidic platform with shape-memory polymer(SMP)-actuated fluid valves capable of automated colorimetric enzyme-linked immunosorbent assays(ELISAs).A single-layer microfluidic paper-based analytical device(μPAD)was designed to store all the reagents on the chip,and sequentially transfer reagents to a paper test zone following a specific ELISA protocol through automatic fluidic flow control by the multiple SMP-actuated *** actuation of a paper valve was based on the thermally responsive,duel-state shape transformation of a SMP sheet attached to the root of a paper cantilever beam for driving a hydrophilic paper bridge to connect and disconnect two paper channels.A portable colorimetric reader was developed to control the on-chip valve operations,quantify the colorimetric signal output,display the assay result,and wirelessly transmit the data to a smart phone for the application of *** operations of the paper valve and the entireμPAD were demonstrated with success rates of 97%and 93%,respectively.A detection mechanism for valve malfunction was designed and confirmed effective to identify any mal-operation of individual valves,thus rendering our platform reliable in real *** device calibration,we conducted direct ELISAs of rabbit IgG in phosphate-buffered saline(PBS),and achieved a low limit of detection(LOD)of 27 pM(comparable to that of standard and paper-based ELISAs).In order to demonstrate the clinical application of our multi-step immunoassay platform,we also conducted sandwich ELISAs to quantify the protein level of an inflammatory cytokine,namely tumor necrosis factor(TNF)-α,in surgically injured laryngeal tissues of *** protein levels of TNF-αwere shown similar between the conventional andμPAD ELISAs.

关键词： rabbit automated operations

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