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Oxidative modification of caspase-9 facilitates its activation via disulfide-mediated interaction with Apaf-1 被引量:6
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作者 Yong Zuo Binggang Xiang Jie Yang Xuxu Sun Yumei Wang Hui Cang Jing Yi 《Cell Research》 SCIE CAS CSCD 2009年第4期449-457,共9页
Intracellular reactive oxygen species (ROS) are known to regulate apoptosis. Activation of caspase-9, the initial caspase in the mitochondrial apoptotic cascade, is closely associated with ROS, but it is unclear whe... Intracellular reactive oxygen species (ROS) are known to regulate apoptosis. Activation of caspase-9, the initial caspase in the mitochondrial apoptotic cascade, is closely associated with ROS, but it is unclear whether ROS regulate caspase-9 via direct oxidative modification. The present study aims to elucidate the molecular mechanisms by which ROS mediate caspase-9 activation. Our results show that the cellular oxidative state facilitates caspase-9 activation. Hydrogen peroxide treatment causes the activation of caspase-9 and apoptosis, and promotes an interac- tion between easpase-9 and apoptotic protease-activating factor 1 (Apaf-1) via disulfide formation. In addition, in an in vitro mitochondria-free system, the thiol-oxidant diamide promotes auto-cleavage of caspase-9 and the caspase-9/ Apaf-1 interaction by facilitating the formation of disulfide-linked complexes. Finally, a point mutation at C403 of caspase-9 impairs both H2O2-promoted caspase-9 activation and interaction with Apaf-1 through the abolition of disulfide formation. The association between cytochrome c and the C403S mutant is significantly weaker than that between cytochrome c and wild-type caspase-9, indicating that oxidative modification of caspase-9 contributes to apoptosome formation under oxidative stress. Taken together, oxidative modification of caspase-9 by ROS can medi- ate its interaction with Apaf-1, and can thus promote its auto-cleavage and activation. This mechanism may facilitate apoptosome formation and caspase-9 activation under oxidative stress. 展开更多
关键词 oxidative modification ROS CASPASE-9 apoptosis DISULFIDE
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Oxidation Modification of Polyacrylonitrile-Based Carbon Fiber and Its Electro-Chemical Performance as Marine Electrode for Electric Field Test 被引量:8
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作者 ZAI Xuerong LIU Ang +2 位作者 TIAN Yuhua CHAI Fanggang FU Yubin 《Journal of Ocean University of China》 SCIE CAS CSCD 2020年第2期361-368,共8页
A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characteriz... A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz^(1/2)@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect. 展开更多
关键词 carbon fiber electrode electro-chemical oxidation modification electro-chemical performance electric field response electric field test
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Compounded Surface Modification of ZK60 Mg Alloy by High Current Pulsed Electron Beam+Micro-plasma Oxidation 被引量:3
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作者 高波 郝仪 +3 位作者 涂赣峰 石为喜 于福晓 李世伟 《Plasma Science and Technology》 SCIE EI CAS CSCD 2010年第1期67-70,共4页
In this study, compounded surface modification technology-high current pulsed electron beam (HCPEB) + micro-plasma oxidation (MPO) was applied to treat ZK60 Mg alloys. The characteristics of the microstructure of... In this study, compounded surface modification technology-high current pulsed electron beam (HCPEB) + micro-plasma oxidation (MPO) was applied to treat ZK60 Mg alloys. The characteristics of the microstructure of ZK60 Mg alloy after single MPO and HCPEB+MPO compounded treatment were investigated by SEM. The results showed that the density of the ceramic layer of HCPEB+MPO-treated ZK60 Mg alloy was improved and defects were reduced compared to that under MPO treatment alone. Surface modified layer of ZK60 Mg alloys treated by HCPEB+MPO was divided into three zones, namely the top loose ceramic zone, middle compact zone and inside HCPEB-induced melted zone. Corrosion resistance of ZK60 Mg alloy before and after the compounded surface modification was measured in a solution of 3.5% NaCl by potentiodynamic polarization curves. It was found that the corrosion current density of ZK60 Mg alloys could be reduced by about three orders of magnitude, from 311μA/cm^2 of the original sample to 0.2μA/cm^2 of the HCPEB+MPO-treated sample. This indicates the great application potential of the HCPEB+MPO compounded surface modification technology in improving the corrosion resistance of ZK60 Mg alloys in the future. 展开更多
关键词 ZK60 Mg alloy high current pulsed electron beam micro-plasma oxidation compounded surface modification corrosion resistance
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Oxidative coupling of methane:MO_x-modified (M=Ti,Mg,Ga,Zr) Mn_2O_3-Na_2WO_4/SiO_2 catalysts and effect of MO_x modification 被引量:1
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作者 Pengwei Wang Xin Zhang +2 位作者 Guofeng Zhao Ye Liu Yong Lu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第8期1395-1402,共8页
Mn_2O_3-Na_2WO_4/SiO_2 is considered as the most promising catalyst for the oxidative coupling of methane(OCM) process; however, it only has a better catalytic performance over 800 °C. To improve its low-temper... Mn_2O_3-Na_2WO_4/SiO_2 is considered as the most promising catalyst for the oxidative coupling of methane(OCM) process; however, it only has a better catalytic performance over 800 °C. To improve its low-temperature performance, an attempt has been made to modify the Mn_2O_3-Na_2WO_4/SiO_2 catalyst using TiO_2, MgO, Ga_2O_3, and ZrO_2. Among the synthesized catalysts, the TiO_2-modified Mn_2O_3-Na_2WO_4/SiO_2 catalyst shows markedly improved low-temperature OCM performance,achieving a high CH_4 conversion of ~23% and a good C_2-C_3 selectivity of ~73% at 700 °C(the catalyst bed temperature), along with promising stability for at least 300 h without signs of deactivation.In comparison with the unmodified Mn_2O_3-Na_2WO_4/SiO_2 catalyst, the TiO_2 modification results in significant improvement in the low-temperature activity/selectivity, whereas the MgO modification has almost no impact and the Ga_2O_3 and ZrO_2 modifications have a negative effect. The X-ray diffraction(XRD) and Raman results reveal that the formation of a MnTiO_3 phase and a MnTiO_3-dominated catalyst surface is crucial for the improvement of the low-temperature activity/selectivity in the OCM process. 展开更多
关键词 Oxidative coupling of methane Light olefins ETHYLENE Oxide modification MnTiO3
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Effects of Metal Oxide Modifications on Photoelectrochemical Properties of Mesoporous TiO2 Nanoparticles Electrodes for Dye-Sensitized Solar Cells
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作者 Tian-you Peng Ke Fan +2 位作者 De Zhao Li-juan Yu Ren-jie Li 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第5期609-616,I0004,共9页
Mesoporous TiO2 (m-TiO2) nanoparticles were used to prepare the porous film electrodes for dye-sensitized solar cells, and a second metal oxide (MgO, ZnO, A1203, or NiO) modifi- cation was carried out by dipping t... Mesoporous TiO2 (m-TiO2) nanoparticles were used to prepare the porous film electrodes for dye-sensitized solar cells, and a second metal oxide (MgO, ZnO, A1203, or NiO) modifi- cation was carried out by dipping the m-TiO2 electrode into their respective nitrate solution followed by annealing at 500 ℃. Experimental results indicated that the above second metal oxide modifications on m-TiO2 electrode are shown in all cases to act as barrier layer for the interracial charge transfer processes, but film electron transport and interfacial charge recombination characteristics under applied bias voltage were dependent significantly on the existing states and kinds of these second metal oxides. Those changes based on sec- ond metal oxide modifications showed good correlation with the current-voltage analyses of dye-sensitized solar cell, and all modifications were found to increase the open-circuit photo- voltage in various degrees, while the MgO, ZnO, and NiO modifications result in 23%, 13%, and 6% improvement in cell conversion efficiency, respectively. The above observations indi- cate that controlling the charge transport and recombination is very important to improve the photovoltaic performance of TiO2-based solar cell. 展开更多
关键词 Dye-sensitized solar cell Metal oxide modification Photoelectrochemical prop-erty Mesoporous TiO2 nanoparticle
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Oxidative modification of high density lipoprotein induced by cultured human arterial smooth muscle cells
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作者 江渝 刘红 +4 位作者 彭家和 叶治家 何凤田 董燕麟 刘秉文 《Journal of Medical Colleges of PLA(China)》 CAS 2003年第2期73-76,共4页
Objective: To observe the oxidative modification of high density lipoprotein (HDL) induced by cultured human arterial smooth muscle cells (SMCs). Methods: HDL cocultured with SMCs at 37℃ in 48 h was subjected, and na... Objective: To observe the oxidative modification of high density lipoprotein (HDL) induced by cultured human arterial smooth muscle cells (SMCs). Methods: HDL cocultured with SMCs at 37℃ in 48 h was subjected, and native HDL (N-HDL) served as control. Oxidative modification of HDL was identified by using agarose gel electrophoresis. Absorbances of conjugated diene (CD) and lipid hydroperoxide (LOOH) were measured with ultraviolet spectrophotometry at 234 and 560 nm respectively, and fluorescence intensity of thiobarbuturic acid reaction substance (TBARS) with fluorescence spectrophotometry at 550 nm emission wavelength with excitation at 515 nm. Results: In comparison with N-HDL, the electrophoretic mobility of SMCs-cocultured HDL was increased, and the contents of CD, LOOH and TBARS HDL were very significantly higher than those of the control HDL (P<0.01). Conclusion: Oxidative modification of HDL can be induced by human arterial SMCs. 展开更多
关键词 high density lipoprotein human arterial smooth muscle cell oxidative modification cell culture
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Study on Coconut Shell Activated Carbon Temperature Swing Adsorption of Benzene and Formaldehyde 被引量:1
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作者 Zhiguang Yang Gaojun Yan +7 位作者 Xueping Liu Zhengyuan Feng Xinfeng Zhu Yanli Mao Songtao Chen Zhisheng Yu Ruimei Fan Linlin Shan 《Journal of Renewable Materials》 SCIE EI 2022年第12期3573-3585,共13页
Adsorption can be used to recover effectively the volatile organic gases(VOCs)in the exhaust gas from factories through using an appropriate adsorption bed.Due to form a physical or chemical bond,adsorption occurs bet... Adsorption can be used to recover effectively the volatile organic gases(VOCs)in the exhaust gas from factories through using an appropriate adsorption bed.Due to form a physical or chemical bond,adsorption occurs between the porous solid medium and the liquid or gas multi component fluid mixture.The regeneration capa-city of the adsorbent is as important as the adsorption capacity and it determines the economics of the adsorption system.The regeneration of adsorbent can be realized through changing the pressure or temperature of the system.Here,activated carbon samples from coconut shell were prepared and characterized.Benzene or formal-dehyde in the mixed air was used as the adsorption object,and the adsorption experiment was carried out in a U-shaped bed.Discussed how adsorption was affected by activated carbon type,adsorbate and temperature.The results show that oxidation modifed activated carbon can increase the adsorption effect of form aldehyde,but will reduce the ad sorption effect of benzene,because their ad sorption mechanism is different.At 30℃,the saturated adsorption apacity of AC-0 for benzene is 437.0 mg/g.and that of AC-1 for formaldehyde is 670.5 mg/g.In the experimental range,it is found that the adsorption capacity increases with the decrease of temperature,and their changes are very consistent with the ftted ExpDecay1 function. 展开更多
关键词 Activated carbon ADSORPTION BENZENE FORMALDEHYDE oxidation modification
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Oxidatively Modified Very Low Density Lipoprotein Enhances Monocyte Adhesion to Endothelial Cells
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作者 冯友梅 张志兵 +3 位作者 王淳本 宗义强 袁敏 冯宗忱 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 1995年第3期129-132,共4页
Very low density lipoprotein (VLDL) was incubated with CuCl2(10 μmol/L) at room temperature for 24 hours.The thiobarbituric acid reactive substance (TBARS) was much higher and the electrophoretic mobility was much fa... Very low density lipoprotein (VLDL) was incubated with CuCl2(10 μmol/L) at room temperature for 24 hours.The thiobarbituric acid reactive substance (TBARS) was much higher and the electrophoretic mobility was much faster in VLDL after incubation with CuCl2 than that in VLDL without incubation with CuCl2.It demonstrated that VLDL was oxidatively modified by Cu2+. Endothelial cells were pretreated with normal VLDL ( N-VLDL ) and oxidatively modified VLDL (OVLDL) and then the adhesion of monocyte to endothelial cells was assayed. We observed that O-VLDL at all the concentrations used enhanced monocyte adhesion to endothelial cells significantly. The results suggest that oxidative modification of VLDL may play a role in the early stage of atherogenesis by increasing monocyte adhesion to endothelial cells. 展开更多
关键词 oxidative modification VLDL MONOCYTE endothelial cells ADHESION
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FERONIA-mediated TIR1/AFB2 oxidation stimulates auxin signaling in Arabidopsis 被引量:1
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作者 Baiyan Lu Shengnan Wang +8 位作者 Hanqian Feng Jing Wang Kaixing Zhang Yilin Li Ping Wu Minmin Zhang Yanshu Xia Chao Peng Chao Li 《Molecular Plant》 SCIE CSCD 2024年第5期772-787,共16页
The phytohormone auxin plays a pivotal role in governing plant growth and development.Although the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX(TIR1/AFB)receptors function in both the nucleus and cytoplasm,the ... The phytohormone auxin plays a pivotal role in governing plant growth and development.Although the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX(TIR1/AFB)receptors function in both the nucleus and cytoplasm,the mechanism governing the distribution of TIR1/AFBs between these cellular compartments remains unknown.In this study,we demonstrate that auxin-mediated oxidation of TIR1/AFB2 is essential for their targeting to the nucleus.We showed that small active molecules,reactive oxygen species(ROS)and nitric oxide(NO),are indispensable for the nucleo-cytoplasmic distribution of TIR1/AFB2 in trichoblasts and root hairs.Further studies revealed that this process is regulated by the FERONIA receptor kinase–NADPH oxidase signaling pathway.Interestingly,ROS and NO initiate oxidative modifications in TIR1C140/516 and AFB2C135/511,facilitating their subsequent nuclear import.The oxidized forms of TIR1C140/516 and AFB2C135/511 play a crucial role in enhancing the function of TIR1 and AFB2 in transcriptional auxin responses.Collectively,our study reveals a novel mechanism by which auxin stimulates the transport of TIR1/AFB2 from the cytoplasm to the nucleus,orchestrated by the FERONIA–ROS signaling pathway. 展开更多
关键词 FERONIA TIR1/AFBs oxidative modification nucleo-cytoplasmic distribution root hair development
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Magnetic modification of diamagnetic agglomerate forming powder materials
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作者 Ivo Safarik Eva Baldikova +1 位作者 Kristyna Pospiskova Mirka Safarikova 《Particuology》 SCIE EI CAS CSCD 2016年第6期169-171,共3页
A simple method for the magnetic modification of various types of powdered agglomerate forming dia- magnetic materials was developed. Magnetic iron oxide particles were prepared from ferrous sulfate by microwave assis... A simple method for the magnetic modification of various types of powdered agglomerate forming dia- magnetic materials was developed. Magnetic iron oxide particles were prepared from ferrous sulfate by microwave assisted synthesis. A suspension of the magnetic particles in water soluble organic solvent (methanol, ethanol, propanol, isopropyl alcohol, or acetone) was mixed with the material to be modified and then completely dried at elevated temperature. The magnetically modified materials were found to be stable in water suspension at least for 2 months. 展开更多
关键词 Magnetic modification Magnetic separation Powdered material Magnetic iron oxide Microwave assisted synthesis
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Dihydrotanshinone I preconditions myocardium against ischemic injury via PKM2 glutathionylation sensitive to ROS 被引量:3
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作者 Xunxun Wu Lian Liu +4 位作者 Qiuling Zheng Hui Ye Hua Yang Haiping Hao Ping Li 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2023年第1期113-127,共15页
Ischemic preconditioning(IPC)is a potential intervention known to protect the heart against ischemia/reperfusion injury,but its role in the no-reflow phenomenon that follows reperfusion is unclear.Dihydrotanshinone I(... Ischemic preconditioning(IPC)is a potential intervention known to protect the heart against ischemia/reperfusion injury,but its role in the no-reflow phenomenon that follows reperfusion is unclear.Dihydrotanshinone I(DT)is a natural compound and this study illustrates its role in cardiac ischemic injury from the aspect of IPC.Pretreatment with DT induced modest ROS production and protected cardiomyocytes against oxygen and glucose deprivation(OGD),but the protection was prevented by a ROS scavenger.In addition,DT administration protected the heart against isoprenaline challenge.Mechanistically,PKM2 reacted to transient ROS via oxidization at Cys423/Cys424,leading to glutathionylation and nuclear translocation in dimer form.In the nucleus,PKM2 served as a co-factor to promote HIF-1a-dependent gene induction,contributing to adaptive responses.In mice subjected to permanent coronary ligation,cardiac-specific knockdown of Pkm2 blocked DT-mediated preconditioning protection,which was rescued by overexpression of wild-type Pkm2,rather than Cys423/424-mutated Pkm2.In conclusion,PKM2 is sensitive to oxidation,and subsequent glutathionylation promotes its nuclear translocation.Although IPC has been viewed as a protective means against reperfusion injury,our study reveals its potential role in protection of the heart from no-reflow ischemia. 展开更多
关键词 Dihydrotanshinone I Ischemic preconditioning PKM2 GLUTATHIONYLATION Myocardial ischemia ROS Oxidation modification Nuclear translocation
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Influence of high-temperature oxidation of SiC powders on curing properties of SiC slurry for digital light processing 被引量:4
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作者 Zhang-Ao SHI Jia-Min WU +1 位作者 Zhi-Qiang FANG Yu-Sheng SHI 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2023年第1期169-181,共13页
Fabrication of silicon carbide(SiC)ceramics by digital light processing(DLP)technology is difficult owing to high refractive index and high ultraviolet(UV)absorptivity of SiC powders.The surface of the SiC powders can... Fabrication of silicon carbide(SiC)ceramics by digital light processing(DLP)technology is difficult owing to high refractive index and high ultraviolet(UV)absorptivity of SiC powders.The surface of the SiC powders can be coated with silicon oxide(SiO_(2))with low refractive index and low UV absorptivity via high-temperature oxidation,reducing the loss of UV energy in the DLP process and realizing the DLP preparation of the SiC ceramics.However,it is necessary to explore a high-temperature modification process to obtain a better modification effect of the SiC powders.Therefore,the high-temperature modification behavior of the SiC powders is thoroughly investigated in this paper.The results show that nano-scale oxide film is formed on the surface of the SiC powders by short-time high-temperature oxidation,effectively reducing the UV absorptivity and the surface refractive index(nʹ)of the SiC powders.When the oxidation temperature is 1300℃,compared with that of unoxidized SiC powders,the UV absorptivity of oxidized SiC powders decreases from 0.5065 to 0.4654,and a curing depth of SiC slurry increases from 22±4 to 59±4μm.Finally,SiC green bodies are successfully prepared by the DLP with the the oxidized powders,and flexural strength of SiC sintered parts reaches 47.9±2.3 MPa after 3 h of atmospheric sintering at 2000℃without any sintering aid. 展开更多
关键词 silicon carbide(SiC)powders oxidation modification digital light processing(DLP) ultraviolet(UV)absorptivity curing depth
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Resource utilization of flue gas calcium-based desulfurization ash:a comprehensive review 被引量:1
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作者 Dong-xiang Meng Ru-fei Wei +2 位作者 Fei-hu Zhang Hong-ming Long Yuan-yuan Zhou 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2023年第3期405-418,共14页
Calcium-based desulfurization ash(CDA)is mainly produced in dry and semi-dry flue gas desulfurization processes.The property of CDA is extremely unstable because its main component,calcium sulfite,makes it difficult t... Calcium-based desulfurization ash(CDA)is mainly produced in dry and semi-dry flue gas desulfurization processes.The property of CDA is extremely unstable because its main component,calcium sulfite,makes it difficult to be directly applied to the field of building materials.The modification of desulfurization ash can be realized by high-temperature oxidation and wet oxidation.After modification,CDA can be widely used in building materials.Hydrothermal oxidation has broad development prospects because it can complete the oxidation of CDA and the removal of impurity elements at the same time.CDA can be used to prepare high value-added products of calcium sulfate whiskers and ecological rubber fillers. 展开更多
关键词 Calcium-based desulfurization ash Oxidation modification Building material Calcium sulfate whisker Flue gas desulfurization
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Tailoring biochar by PHP towards the oxygenated functional groups(OFGs)-rich surface to improve adsorption performance 被引量:2
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作者 Xinyue Xiong Zhanglin Liu +7 位作者 Li Zhao Mei Huang Lichun Dai Dong Tian Jianmei Zou Yongmei Zeng Jinguang Hu Fei Shen 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第6期3097-3100,共4页
In this work,a modification method of H_(3)PO_(4)plus H_(2)O_(2)(PHP)was introduced to targetedly form abundant oxygenated functional groups(OFGs)on biochar,and methylene blue(MB)was employed as a model pollutant for ... In this work,a modification method of H_(3)PO_(4)plus H_(2)O_(2)(PHP)was introduced to targetedly form abundant oxygenated functional groups(OFGs)on biochar,and methylene blue(MB)was employed as a model pollutant for adsorption to reflect the modification performance.Results indicated that parent biochars,especially derived from lower temperatures,substantially underwent oxidative modification by PHP,and OFGs were targetedly produced.Correspondingly,approximately 21.5-fold MB adsorption capacity was achieved by PHP-modified biochar comparing with its parent biochar.To evaluate the compatibility of PHP-modification,coefficient of variation(CV)based on MB adsorption capacity by the biochar from various precursors was calculated,in which the CV of PHP-modified biochars was 0.0038 comparing to0.64 of the corresponding parent biochars.These results suggested that the PHP method displayed the excellent feedstock compatibility on biochar modification.The maximum MB adsorption capacity was454.1 mg/g when the H_(3)PO_(4)and H_(2)O_(2)fraction in PHP were 65.2%and 7.0%;the modification was further intensified by promoting temperature and duration.Besides,average 94.5%H_(3)PO_(4)was recovered after 10-batch modification,implying 1.0 kg H_(3)PO_(4)(85%)in PHP can maximally modify 2.37 kg biochar.Overall,this work offered a novel method to tailor biochar towards OFGs-rich surface for efficient adsorption. 展开更多
关键词 BIOCHAR Oxidative modification Phosphoric acid Hydrogen peroxide Oxygenated functional groups
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The Potential Effect of Puerarin in Preventing Atherosclerosis 被引量:1
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作者 ZHU Qing-lei(朱庆磊) +7 位作者 HE Ai-xia(何爱霞) HAN Hui-rong(韩慧蓉) LU Xin-ran(吕欣然) WANG Shi-wen(王士雯) 《Chinese Journal of Integrative Medicine》 SCIE CAS 2002年第4期290-294,共5页
Objective To study the activity of Puerarin (Pue) in scavenging oxygen free radical (OFR) and its inhibitory effect on the oxidative modification of low density lipoprotein (LDL). Methods Riboflavin-light system was... Objective To study the activity of Puerarin (Pue) in scavenging oxygen free radical (OFR) and its inhibitory effect on the oxidative modification of low density lipoprotein (LDL). Methods Riboflavin-light system was used to generate superoxide anion, and Fenton reaction to generate hydroxyl free radical to study the activity of Pue in scavenging OFR. Hydrogen peroxide-induced hemolysis was used to study the effect of Pue on erythrocyte hemolysis and malondialdehyde (MDA) production. And ultraviolet ray and cupric sulfate were used to cause the oxidative modification of LDL for studying the inhibitory effect of Pue on LDL oxidative modification. Results (1) Pue could, at concentration of 0. 01 – 1.0 mmol/L, scavenge superoxide anion radical and at concentration of 7.5–75μmol/L scavenge hydroxyl radical in a concentration dependent manner. (2) Pue could, at concentration of 0.1–10 mmol/L, inhibit significantly oxidative hemolysis and MDA production of erythrocyte induced by hydrogen peroxide. (3) Pue of 0.01–1.0 mmol/L could inhibit the oxidative modification of LDL in a concentration dependent manner. Conclusion Pue has an anti-peroxidation effect and shows a potential effect in preventing atherosclerosis. 展开更多
关键词 PUERARIN ANTIOXIDATION active oxygen free radical low density lipoprotein oxidative modification
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Cerium based shells with palladium cores encapsulated:an efficient catalyst for carbon monoxide oxidation 被引量:1
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作者 汪淼 沈美庆 +3 位作者 王建强 魏光曦 李航 王军 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第12期1114-1119,共6页
Pd@Zr/Ce O2 core-shell catalyst prepared by hydrothermal method was applied in CO oxidation reaction, exhibiting high CO oxidation activity at low temperature.XRD(X-ray diffraction) analysis demonstrated that the re... Pd@Zr/Ce O2 core-shell catalyst prepared by hydrothermal method was applied in CO oxidation reaction, exhibiting high CO oxidation activity at low temperature.XRD(X-ray diffraction) analysis demonstrated that the remarkable enhancement of catalytic performance was found to depend on the presence of more oxygen vacancies in the core-shell structure, which contributed higher content of and ready release of active oxygen species at low temperature, confirmed by H2-TPR(temperature programed reduction) results.Interestingly, introducing a small amount of zirconium(0.5 wt.%) exhibited a significant improvement of catalytic activity because the introduction of Zr further improved the amount of crystal defects and promoted the migration of oxygen species. 展开更多
关键词 Pd@CeO2 core-shell catalyst Zr modification low-temperature CO oxidation activity oxygen vacancies rare earths
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Plasticityimprovement of a Zr-based bulk metallic glass by micro-arc oxidation
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作者 Yong-jiang Huang Peng Xue +4 位作者 Xiang Cheng Ya-ming Wang Fu-yang Cao Zhi-liang Ning Jian-fei Sun 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2017年第4期416-420,共5页
Mciro-arc oxidation(MAO)was used to coat porous films on the surface of a Zr-based bulk metallic glass sample.The compressive test results indicated that,compared with the as-cast sample,the MAO treated one exhibite... Mciro-arc oxidation(MAO)was used to coat porous films on the surface of a Zr-based bulk metallic glass sample.The compressive test results indicated that,compared with the as-cast sample,the MAO treated one exhibited higher deformation capacity,associated with multiple shear bands with higher density on the side surface and well-developed vein patterns with smaller size on the fractured surface.The pore in the MAOed film and the matrix/coating interface initiated the shear bands and impeded the rapid propagation of shear bands,thus favoring the enhanced plasticity of the MAO treated sample.The obtained results demonstrated that MAO can be considered as an effective method to finely tune the mechanical performance of monolithic bulk metallic glasses. 展开更多
关键词 Bulk metallic glass Micro-arc oxidation Plasticity Surface modification Shear band
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