Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and G...Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and Gel-filtration chromatography.The chemical characterizations of AGNP were tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE),high-pressure gel-filtration chromatography,MALDI-TOF-MS and HPLC.In vitro antioxidant effects were tested in simple antioxidant assay including 2,2-diphenylpicrylhydrazyl radical scavenging,superoxide radical(O2^-)scavenging,hydroxyl radical(OH)scavenging,and ferric-reducing ability.Results:The results showed which the content of AGNP measured by Bradford method was 2.42 mg/m L and the subunit molecular weight of AGNP measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE)was 15 kD.The AGNP molecular weight was 15,114 Da both of SDS-PAGE and mass spectrum purity.The result of high-pressure gel-filtration chromatography demonstrated that the molecular weight of AGNP was 31,086 Da,which implied that AGNP was a homodimer.The in vitro Antioxidant results indicated that AGNP had obvious effects to remove the free radicals in vitro.Conclusion:In conclusion,AGNP had more powerful antioxidant capacity and it can be used as an effective natural antioxidant to alleviate oxidative stress.展开更多
It is critical to developing electrocatalysts with highly active and cost-effective for oxygen evolution to resolve environmental pollution and energy issues,in which FeNi-based nanomaterials hold a great promise.Here...It is critical to developing electrocatalysts with highly active and cost-effective for oxygen evolution to resolve environmental pollution and energy issues,in which FeNi-based nanomaterials hold a great promise.Herein,(Fe_(0.33 )Ni_(0.67))S_(2) and(Fe_(0.33 )Ni_(0.67))S_(2)/reduced graphene oxide(rGO)-x%(x=10,20) composites,which exhibited highly efficient oxygen evolution reaction(OER)electrocatalytic activity under alkaline conditions,were synthesized via a hydrothermal approach and following thermal treatment with sulfur powders.Benefiting from the integrated structure of(Fe_(0.33 )Ni_(0.67))S_(2)and support of conductive graphene backbones,(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%electrocatalyst showed the best OER activity with an overpotential of 172 mV at 10 mA·cm^(-2)and Tafel slopes of 45 mV·decade^(-1).The composition,phase,and surface structure of the catalyst were characterized before and after OER reaction.The results indicated that crystal phase of the catalyst was reconstructed to the amorphous crystalline features after OER,with oxidation of iron-nickel sulfide and appearance of Ni-Fe oxo/hydroxide species,which may play a crucial role in the high OER performance as the catalytic-active.Moreover,in a two-electrode system towards overall water splitting with(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%/NF and Pt/C/NF as the anode and cathode,respectively,the catalysts exhibited excellent catalytic performance with the voltage of only 1.42 V at 10 mA·cm^(-2).展开更多
Non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction method.Crystal structures and morphologies were investigated by Xray diffraction(...Non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction method.Crystal structures and morphologies were investigated by Xray diffraction(XRD)and scanning electron microscopy(SEM),respectively.The main crystalline phase is monoclinic Nd(Mg_(1/2)Sn_(1/2))O_(3) with a double perovskite structure(P21/n space group)for the NMS system proved by XRD.The sample at x=0.01 has the best crystallinity and evenly distributed crystal grains observed by SEM.The optimum performances(ε_(r)=19.87,Q×f=41840 GHz,f=12.05 GHz)are obtained at x=0.01.Lattice vibrational modes of the Raman spectra were assigned and illustrated,in detail.The dielectric properties obtained by fitting infrared reflectance spectra with the help of four-parameter semi-quantum model are consistent with the calculated values by microscopic polarization and damping coefficients.The reverse translational vibration of the NdeMgO_(6),the F_(5u)^((5)) mode,provides the greatest contribution to the dielectric response.The relationships between crystal structures and dielectric properties were mainly established using lattice vibrational modes as a media.展开更多
基金financial support from the Jilin Provincial Key Laboratory of Biomacromolecules of Chinese Medicine, Local Standard Project of Chinese Medicinal Materials in Jilin Province (No. PZ-2016-03 and No. JLPZGF-2018-004)The Science and Technology Development Plan Project of Jilin Province (No. 20190101010JH, No. 20190304095YY)+1 种基金The National Key Research and Development Program of China (2017YFC1702106)the National Traditional Chinese Medicine Standardization Project of China (No. ZYBZH-C-JL-22 and No. ZYBZH-C-HEB-11)
文摘Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and Gel-filtration chromatography.The chemical characterizations of AGNP were tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE),high-pressure gel-filtration chromatography,MALDI-TOF-MS and HPLC.In vitro antioxidant effects were tested in simple antioxidant assay including 2,2-diphenylpicrylhydrazyl radical scavenging,superoxide radical(O2^-)scavenging,hydroxyl radical(OH)scavenging,and ferric-reducing ability.Results:The results showed which the content of AGNP measured by Bradford method was 2.42 mg/m L and the subunit molecular weight of AGNP measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE)was 15 kD.The AGNP molecular weight was 15,114 Da both of SDS-PAGE and mass spectrum purity.The result of high-pressure gel-filtration chromatography demonstrated that the molecular weight of AGNP was 31,086 Da,which implied that AGNP was a homodimer.The in vitro Antioxidant results indicated that AGNP had obvious effects to remove the free radicals in vitro.Conclusion:In conclusion,AGNP had more powerful antioxidant capacity and it can be used as an effective natural antioxidant to alleviate oxidative stress.
基金financially supported by the National Natural Science Foundation of China (No.52002363)the Aeronautical Science Foundation of China (No.2020Z054025002)+1 种基金Shandong Provincial Natural Science Foundation Project (No. ZR2021ME083)the Undergraduate Innovation Training Program Fund of Liaocheng University (No.cxcy2021108)
文摘It is critical to developing electrocatalysts with highly active and cost-effective for oxygen evolution to resolve environmental pollution and energy issues,in which FeNi-based nanomaterials hold a great promise.Herein,(Fe_(0.33 )Ni_(0.67))S_(2) and(Fe_(0.33 )Ni_(0.67))S_(2)/reduced graphene oxide(rGO)-x%(x=10,20) composites,which exhibited highly efficient oxygen evolution reaction(OER)electrocatalytic activity under alkaline conditions,were synthesized via a hydrothermal approach and following thermal treatment with sulfur powders.Benefiting from the integrated structure of(Fe_(0.33 )Ni_(0.67))S_(2)and support of conductive graphene backbones,(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%electrocatalyst showed the best OER activity with an overpotential of 172 mV at 10 mA·cm^(-2)and Tafel slopes of 45 mV·decade^(-1).The composition,phase,and surface structure of the catalyst were characterized before and after OER reaction.The results indicated that crystal phase of the catalyst was reconstructed to the amorphous crystalline features after OER,with oxidation of iron-nickel sulfide and appearance of Ni-Fe oxo/hydroxide species,which may play a crucial role in the high OER performance as the catalytic-active.Moreover,in a two-electrode system towards overall water splitting with(Fe_(0.33 )Ni_(0.67))S_(2)/rGO-20%/NF and Pt/C/NF as the anode and cathode,respectively,the catalysts exhibited excellent catalytic performance with the voltage of only 1.42 V at 10 mA·cm^(-2).
基金supported by National Natural Science Foundation of China(Grant 11874240)Guangxi Information Materials Key Laboratory Open Research Fund(171007-K)+3 种基金State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF201811)the Opening Project of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(Grant No.KLIFMD201803)the Natural Science Foundation of Shandong Province,China(No.ZR2016EMM21)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(No.2016RCJJ002).
文摘Non-stoichiometric Nd_((1+x))(Mg_(1/2)Sn_(1/2))O_(3)(-0.04=x≤0.04,NMS)ceramics were fabricated via a conventional solid-state reaction method.Crystal structures and morphologies were investigated by Xray diffraction(XRD)and scanning electron microscopy(SEM),respectively.The main crystalline phase is monoclinic Nd(Mg_(1/2)Sn_(1/2))O_(3) with a double perovskite structure(P21/n space group)for the NMS system proved by XRD.The sample at x=0.01 has the best crystallinity and evenly distributed crystal grains observed by SEM.The optimum performances(ε_(r)=19.87,Q×f=41840 GHz,f=12.05 GHz)are obtained at x=0.01.Lattice vibrational modes of the Raman spectra were assigned and illustrated,in detail.The dielectric properties obtained by fitting infrared reflectance spectra with the help of four-parameter semi-quantum model are consistent with the calculated values by microscopic polarization and damping coefficients.The reverse translational vibration of the NdeMgO_(6),the F_(5u)^((5)) mode,provides the greatest contribution to the dielectric response.The relationships between crystal structures and dielectric properties were mainly established using lattice vibrational modes as a media.