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Synchronous detection of glutathione/hydrogen peroxide for monitoring redox status in vivo with a ratiometric upconverting nanoprobe

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Nano Research 2019年第4期12卷 931-938页

作者： Judun Zheng Yunxia Wu Da xing tao Zhang MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University Guangzhou 510631 China College of Biophotonics South China Normal University Guangzhou 510631 China

Cellular redox status presents broad implications with diverse physiological and pathological processes. Simultaneous detection of both the oxidative and reductive species of redox couples, especially the most representative pair glutathione/hydrogen peroxide (GSH/H2O2), is crucial to accurately map the cellular redox status. However, it still remains challenging to synchronously detect GSH/H2O2 in vivo due to lack of a reliable measuring tool. Herein, a ratiometric nanoprobe (UCNP-TB) possessing simultaneous delectability of GSH/H2O2 is established based on a multi-spectral upconverti ng nano phosphor (UCNP-OA) as the lumin esce nee res onance energy tran sfer (LRET) donor and two dye molecules as the acceptors, including a GSH-sensitive dye (TCG) and a H2O2-sensitive dye (BCH). With the as-prepared UCNP-TB, real-time and synchronous monitoring the variation of GSH and H2O2 in vitro and in living mice can be achieved using the ratio of the upcon versi on lumin esce nee (UCL) at 540 and 650 nm to that at 800 nm as the detecti on sign al, respectively, providi ng highly inhere nt reliability of the sensing results by self-calibrati on. Moreover, the nan oprobe is capable of mappi ng the redox status within the drug-resista nt tumor and the drug-induced hepatotoxic liver via ratiometric UCL imaging. Thus, this nan oprobe would provide a reliable tool to elucidate the redox state in vivo.

关键词： redox status glutathione hydrogen peroxide upconversion imaging nanoprobe

Facile synthesis of flake-like dihydrate zinc oxalate particles

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International Journal of Minerals,Metallurgy and Materials 2019年第2期26卷 234-240页

作者： xing Chen Xin Liu Kai huang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Global Energy Research Institute Future Science and Technology Park Beijing Key Lab of Green Recycling and Extraction of Metals University of Science and Technology Beijing

Monodispersed dihydrated zinc oxalate(ZnC_2O_4·2H_2O) particles with characteristic morphology were synthesized by aging a mixed solution of zinc nitrate(Zn(NO_3)_2) and sodium oxalate(Na_2C_2O_4) in the presence of a citrate ligand, with an average flat size of approximately 10–15 μm. The important parameters, including the solution pH values and the concentration of the zinc ions and citrate ligand, were investigated using a series of experiments. It is verified that the citrate ligand significantly affects the morphology of zinc oxalate particles, probably via its multiple roles of chelating, dispersing, and selective absorption. Thermodynamic equilibrium of the distribution of zinc species in an aqueous solution of Zn(Ⅱ)-citrate-oxalate-H_2O was estimated to explain the experimental results and to clarify the size and morphological evolution mechanism of the precipitated particles.

关键词： facile synthesis zinc oxalate flaky morphology citrate ligand one-pot synthesis

Experimental investigation of surface roughness effects on flow behavior and heat transfer characteristics for circular microchannels

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Chinese Journal of Aeronautics 2016年第6期29卷 1575-1581页

作者： Yuan xing tao Zhi Li Haiwang Tian Yitu National Key Laboratory of Science and Technology on Aero-Engine Beihang University Collaborative Innovation Center for Advanced Aero-Engine of China of Aerodynamics Beihang University

This paper experimentally investigates the effect of surface roughness on flow and heat transfer characteristics in circular microchannels. All test pieces include 44 identical, parallel circular microchannels with diameters of 0.4 mm and 10 mm in length. The surface roughness of the microchannels is R= 0.86, 0.92, 1.02 lm, and the Reynolds number ranges from 150 to *** show that the surface roughness of the circular microchannels has remarkable effects on the performance of flow behavior and heat transfer. It is found that the Poiseuille and Nusselt numbers are higher when the relative surface roughness is larger. For flow behavior, the friction factor increases consistently with the increasing Reynolds number, and it is larger than the constant theoretical value for macrochannels. The Reynolds number for the transition from laminar to turbulent flow is about 1500, which is lower than the value for macrochannels. For the heat transfer property, Nusselt number also increases with increasing Reynolds number, and larger roughness contributes to higher Nusselt number.

关键词： Circular Flow behavior Heat transfer Microchannels Roughness

Facile synthesis of monodispersed copper oxalate flaky particles in the presence of EDTA

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International Journal of Minerals,Metallurgy and Materials 2018年第7期25卷 762-769页

作者： xing Chert Kai huang Cheng-yan Wang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Lab of Green Recycling and Extraction of Metals University of Science and Technology BeijingBeijing 100083China

Monodispersed copper oxalate paxticles with flaky morphology were prepared via a simple one-pot synthesis method. Scanning electron microscope （SEM）, X-ray diffraction （XRD）, and fourier tza^sform infraJced （FTIR） spectra were used to characterize paxticle mor- phology, size, phase composition, and functional groups. It was found that the presence of ethylenediaminetetzaacetic acid （EDTA） and the solution pH value had strong influence on the morphological and size evolution of the precipitated particles. On the basis of controlled re- lease of copper ions from a Cu2＋-EDTA complex and Weimazn＇s law, a stzategy for the controlled synthesis of monodispersed copper oxa- late paxticles was designed by refemng to the basic mode of the St0ber method. The inherent nature of crystallization to form the flaky solid in the early stage of precipitation as well as the driving force of the long-lasting low supersaturation in the growth stage was proposed to ex- plain the size and morphological evolution of the copper oxalate precipitates. Thermodynamic equilibrium concentrations of copper（II） spe- cies in the Cu（II）-EDTA-oxalate-H20 solution system were calculated to help explain the possible formation mechaNsm of copper oxalate precipitates.

关键词： copper oxalate flaky morphology ethylenediaminetetzaacetic acid one-pot synthesis

An experimental study on the impact behavior of cavitation inside tip clearance of a hydrofoil

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Journal of Hydrodynamics 2023年第6期35卷 1208-1214页

作者： Yan-tao Cao Liang-hao Xu Xiao-xing Peng National Key Laboratory on Ship Vibration and Noise China Ship Scientific Research CenterWuxi214082China Taihu Laboratory of Deepsea Technological Science Wuxi214082China

Tip clearance cavitation is one of the most common cavitation phenomena exist on duct propellers,pumps and some hydraulic turbines,which may lead to erosion of the *** to the influence of the nearby wall,cavitation inside the tip clearance is more complicated than other cases without *** far,the understanding about the impact mechanism of tip clearance cavitation is still *** this paper,to obtain the impact behavior of tip clearance cavitation,a high-speed camera was used to capture the cavitation behavior inside the tip clearance of a hydrofoil,and surface paint coating peeling method was applied to show the impact *** indicated that cavitation around the tip of the hydrofoil was composed of a tip separation cavity and a tip leakage vortex cavity,and the one with contribution to impact was the tip separation *** the comprehensive analysis of the paint peeling region and dynamic behavior of tip separation cavity,the impact was found to be related to the local collapse and rebound of the cloud cavitation shed from the attached *** addition,the influence of tip clearance size on the behavior of tip clearance cavitation was also *** the tip clearance size increased,the tip separation cavity tended to transfer from sheet cavitation to vortex *** findings can provide a sound basis for evaluating the erosion risk arising from the tip clearance cavitation.

关键词： Tip clearance cavitation impact region impact behavior tip clearance size

Procyanidin B2 protects against diet-induced obesity and non-alcoholic fatty liver disease via the modulation of the gut microbiota in rabbits

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World Journal of Gastroenterology 2019年第8期25卷 955-966页

作者： Ya-Wei xing Guang-tao Lei Qing-Hua Wu Yu Jiang Man-Xiang huang Department of Gastroenterology The Second Xiangya HospitalCentral South UniversityChangsha 410011Hunan ProvinceChina Department of Cardiovascular Medicine The Second Affiliated Hospital of Nanchang UniversityNanchang 330006Jiangxi ProvinceChina

BACKGROUND Procyanidins have beneficial effects on metabolic syndrome and antimicrobial activity,but the mechanisms underlying these effects are *** To investigate the effects of procyanidin B2(PB2)on non-alcoholic fatty liver disease and to explore the possible *** Thirty male New Zealand white rabbits were randomized into three *** of them were fed either a high-fat-cholesterol diet(HCD)or chow ***-fed rabbits were treated with vehicle or PB2 daily for 12 *** weight and food intake were evaluated once a *** biomarkers,such as total cholesterols,triglycerides,and aspartate transaminase,were *** rabbits were sacrificed and histological parameters of liver were assessed by hematoxylin and eosin-stained ***,several lipogenic genes and gut microbiota(by 16S rRNA sequencing)were investigated to explore the possible *** The HCD group had higher body weight,liver index,serum lipid profile,insulin resistance,serum glucose,and hepatic steatosis compared to the CHOW ***2 treatment prevented HCD-induced increases in body weight and hypertriglyceridemia in association with triglyceride accumulation in the ***2 also ameliorated low-grade inflammation,which was reflected by serum lipopolysaccharides and improved insulin *** rabbit liver,PB2 prevented the upregulation of steroid response element binding protein 1c and fatty acid synthase and the downregulation of carnitine palmitoyltransferase,compared to the HCD ***,HCD led to a decrease of Bacteroidetes in gut ***2 significantly improved the proportions of Bacteroidetes at the phylum level and Akkermansia at the genus *** Our results indicate the possible mechanism of PB2 to improve HCD-induced features of metabolic syndrome and provide a new dietary supplement.

关键词： Procyanidin Rabbit Non-alcoholic fatty liver disease Gut microbiota 16S rRNA

Optimization of reaction conditions for the electroleaching of manganese from low-grade pyrolusite

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International Journal of Minerals,Metallurgy and Materials 2015年第11期22卷 1121-1130页

作者： xing-ran Zhang Zuo-hua Liu xing Fan Xin Lian Chang-yuan tao College of Chemistry and Chemical Engineering Chongqing University Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization

In the present study, a response surface methodology was used to optimize the electroleaching of Mn from low-grade pyrolusite. Ferrous sulfate heptahydrate was used in this reaction as a reducing agent in sulfuric acid solutions. The effect of six process variables, including the mass ratio of ferrous sulfate heptahydrate to pyrolusite, mass ratio of sulfuric acid to pyrolusite, liquid-to-solid ratio, current density, leaching temperature, and leaching time, as well as their binary interactions, were modeled. The results revealed that the order of these factors with respect to their effects on the leaching efficiency were mass ratio of ferrous sulfate heptahydrate to pyrolusite 〉 leaching time 〉 mass ratio of sulfuric acid to pyrolusite 〉 liquid-to-solid ratio 〉 leaching temperature 〉 current density. The optimum conditions were as follows： 1.10：1 mass ratio of ferrous sulfate heptahydrate to pyrolusite, 0.9：1 mass ratio of sulfuric acid to pyrolusite, liquid-to-solid ratio of 0.7：1, current density of 947 A/m^2, leaching time of 180 min, and leaching temperature of 73°C. Under these conditions, the predicted leaching efficiency for Mn was 94.1%; the obtained experimental result was 95.7%, which confirmed the validity of the model.

关键词： pyrolusite manganese ore treatment electroleaching reaction conditions optimization

Convergence to the Rarefaction Wave for a Model of Radiating Gas in One-dimension

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Acta Mathematicae Applicatae Sinica 2016年第2期32卷 239-256页

作者： Fei-min huang xing LI Academy Mathematics and Systems Science the Chinese Academy of Sciences College of Mathematics and Statistics Shenzhen University

In this paper, a sequence of solutions to the one-dimensional motion of a radiating gas are con- structed. Furthermore, when the absorption coefficient a tends to oo, the above solutions converge to the rarefaction wa... 详细信息

关键词： rarefaction wave compressible euler system radiating gas, hyperbolic-elliptic system

Carbon dioxide reforming of methane over Ni/Mo/SBA-15-La_2O_3 catalyst:Its characterization and catalytic performance

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Journal of Natural Gas Chemistry 2011年第5期20卷 465-470页

作者： Jian huang Renxiong Ma tao huang Anrong Zhang Wei huang Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan 030024 Shanxi China Institute of Engineering Thermophysics ＆ Chinese Academy of Sciences Beijing 100190 China Department of Applied Chemistry Yuncheng University Yuncheng 044000 Shanxi China

The Ni/Mo/SBA-15 catalyst was modified by La2O3 in order to improve its thermal stability and carbon deposition resistance during the CO2 reforming of methane to syngas. The catalytic performance, thermal stability, structure, dispersion of nickel and carbon deposition of the modified and unmodified catalysts were comparatively investigated by many characterization techniques such as N2 adsorption, H2-TPR, CO2-TPD, XRD, FT-IR and SEM. It was found that the major role of La2O3 additive was to improve the pore structure and inhibit carbon deposition on the catalyst surface. The La2O3 modified Ni/Mo/SBA-15 catalyst possessed a mesoporous structure and high surface area. The high surface area of the La2O3 modified catalysts resulted in strong interaction between Ni and Mo-La, which improved the dispersion of Ni, and retarded the sintering of Ni during the CO2 reforming process. The reaction evaluation results also showed that the La2O3 modified Ni/Mo/SBA-15 catalysts exhibited high stability.

关键词： CO2-reforming SBA-15 molecular sieve carbon deposition La-promoted