Total flavonoids are the main pharmaceutical components of Trollius chinensis Bunge, and orientin and vitexin are the monomer components of total flavonoids in Trollius chinensis Bunge. In this study, an aged mouse mo...Total flavonoids are the main pharmaceutical components of Trollius chinensis Bunge, and orientin and vitexin are the monomer components of total flavonoids in Trollius chinensis Bunge. In this study, an aged mouse model was established through intraperitoneal injection of D-galactose for 8 weeks, followed by treatment with 40, 20, or 10 mg/kg orientin, vitexin, or a positive control （vitamin E） via intragastric administration for an additional 8 weeks. Orientin, vitexin, and vitamin E improved the general medical status of the aging mice and significantly increased their brain weights. They also produced an obvious rise in total antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase levels in the serum, and the levels of superoxide dismutase, catalase and glutathione peroxidase, Na＋-K＋-ATP enzyme, and Ca2＋-Mg2＋-ATP enzyme in the liver, brain and kidneys. In addition, they significantly reduced malondialdehyde levels in the liver, brain and kidney and lipofuscin levels in the brain. They also significantly improved the neuronal ultrastructure. The 40 mg/kg dose of orientin and vitexin had the same antioxidant capacity as vitamin E. These experimental findings indicate that orientin and vitexin engender anti-aging effects through their antioxidant capacities.展开更多
Liquid film cooling as an advanced cooling technology is widely used in space vehicles.Stable operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket engines.The sta...Liquid film cooling as an advanced cooling technology is widely used in space vehicles.Stable operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket engines.The stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right now.How to improve the stability of thin film has become a hot spot.In view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical study.The effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied respectively.It can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this paper.Besides,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of wave.What’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this process.Lastly,the maximum height and maximum slope angle of wave will level off as the gas velocity increases.Meanwhile,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.展开更多
Carbon materials have shown significant potential as catalysts for lithium-oxygen batteries(LOBs).However,the intrinsic carbon sites are typically inert,necessitating extensive modifications and resulting in a limited...Carbon materials have shown significant potential as catalysts for lithium-oxygen batteries(LOBs).However,the intrinsic carbon sites are typically inert,necessitating extensive modifications and resulting in a limited density of active sites.Here we present C_(60) as a metal-free cathode catalyst for LOBs,using density functional theory calculations and experimental verifications.The lithiation reactions on the pristine carbon sites of C_(60) are energetically favorable due to its curvedπ-conjugation over the pentagon-hexagon networks.The kinetic analysis specifically reveals low energy barriers for Li_(2)O_(2) decomposition and Li diffusion on C_(60).Consequently,C_(60) exhibits significantly higher catalytic activity than typical carbon materials such as graphene and carbon nanotubes.Our electrochemical measurements validate the predictions,notably demonstrating that the intrinsic activity of C_(60) is comparable to that of noble metals.展开更多
Lithium-sulfur batteries have been regarded as one of most promising next-generation energy storage devices because of their high energy density and low cost.However,polysulfide shuttling and slow kinetics hinder the ...Lithium-sulfur batteries have been regarded as one of most promising next-generation energy storage devices because of their high energy density and low cost.However,polysulfide shuttling and slow kinetics hinder the practical application.We fabricated hierarchically heterostructured CoSe_(2)/MoS_(2) nanoarrays on carbon clothes as the sulfur cathode host.The resulting heterostructures facilitate electron conduction and improve electrolyte wetting.More importantly,the composite heterostructures couple the strong poly-sulfide adsorption of CoSe_(2) and high catalytic activity of MoS_(2) to synergistically accelerate polysulfide conversion,demonstrating higher catalytic activity than their individual components.展开更多
Summary What is already known about this topic?Melioidosis,a tropical infectious disease caused by Burkholderia pseudomallei(BP)infection,is endemic in the southern coastal provincial-level administrative divisions(PL...Summary What is already known about this topic?Melioidosis,a tropical infectious disease caused by Burkholderia pseudomallei(BP)infection,is endemic in the southern coastal provincial-level administrative divisions(PLADs)of China.What is added by this report?Three melioidosis cases,including two in young children and one in a 19-year-old female,were reported in Anhui and Jiangxi(two inland PLADs of China)respectively,in 2021.None of the patients had a travel history to a melioidosis-endemic area.All the BP isolates belonged to the same sequence type(ST51),which had been reported from elsewhere in Southeast Asia.展开更多
基金supported by the Foundation of Zhangjiakou Science and Technology Committee, No.0711046D-9 and No.11110015D
文摘Total flavonoids are the main pharmaceutical components of Trollius chinensis Bunge, and orientin and vitexin are the monomer components of total flavonoids in Trollius chinensis Bunge. In this study, an aged mouse model was established through intraperitoneal injection of D-galactose for 8 weeks, followed by treatment with 40, 20, or 10 mg/kg orientin, vitexin, or a positive control （vitamin E） via intragastric administration for an additional 8 weeks. Orientin, vitexin, and vitamin E improved the general medical status of the aging mice and significantly increased their brain weights. They also produced an obvious rise in total antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase levels in the serum, and the levels of superoxide dismutase, catalase and glutathione peroxidase, Na＋-K＋-ATP enzyme, and Ca2＋-Mg2＋-ATP enzyme in the liver, brain and kidneys. In addition, they significantly reduced malondialdehyde levels in the liver, brain and kidney and lipofuscin levels in the brain. They also significantly improved the neuronal ultrastructure. The 40 mg/kg dose of orientin and vitexin had the same antioxidant capacity as vitamin E. These experimental findings indicate that orientin and vitexin engender anti-aging effects through their antioxidant capacities.
文摘Liquid film cooling as an advanced cooling technology is widely used in space vehicles.Stable operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket engines.The stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right now.How to improve the stability of thin film has become a hot spot.In view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical study.The effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied respectively.It can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this paper.Besides,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of wave.What’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this process.Lastly,the maximum height and maximum slope angle of wave will level off as the gas velocity increases.Meanwhile,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.
基金supports from the National Key R&D Program of China(No.2019YFA0308000)the National Natural Science Foundation of China(No.21873050)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Carbon materials have shown significant potential as catalysts for lithium-oxygen batteries(LOBs).However,the intrinsic carbon sites are typically inert,necessitating extensive modifications and resulting in a limited density of active sites.Here we present C_(60) as a metal-free cathode catalyst for LOBs,using density functional theory calculations and experimental verifications.The lithiation reactions on the pristine carbon sites of C_(60) are energetically favorable due to its curvedπ-conjugation over the pentagon-hexagon networks.The kinetic analysis specifically reveals low energy barriers for Li_(2)O_(2) decomposition and Li diffusion on C_(60).Consequently,C_(60) exhibits significantly higher catalytic activity than typical carbon materials such as graphene and carbon nanotubes.Our electrochemical measurements validate the predictions,notably demonstrating that the intrinsic activity of C_(60) is comparable to that of noble metals.
基金the National Natural Science Foundation of China(Nos.21776121 and 22075131)The numerical calculations were carried out at the computing facilities in the High-Performance Computing Center(HPCC)of Nanjing University.
文摘Lithium-sulfur batteries have been regarded as one of most promising next-generation energy storage devices because of their high energy density and low cost.However,polysulfide shuttling and slow kinetics hinder the practical application.We fabricated hierarchically heterostructured CoSe_(2)/MoS_(2) nanoarrays on carbon clothes as the sulfur cathode host.The resulting heterostructures facilitate electron conduction and improve electrolyte wetting.More importantly,the composite heterostructures couple the strong poly-sulfide adsorption of CoSe_(2) and high catalytic activity of MoS_(2) to synergistically accelerate polysulfide conversion,demonstrating higher catalytic activity than their individual components.
基金Supported by the National Science and Technology Major Project(2018ZX10714-002)the National Natural Science Foundation of China(81573208).
文摘Summary What is already known about this topic?Melioidosis,a tropical infectious disease caused by Burkholderia pseudomallei(BP)infection,is endemic in the southern coastal provincial-level administrative divisions(PLADs)of China.What is added by this report?Three melioidosis cases,including two in young children and one in a 19-year-old female,were reported in Anhui and Jiangxi(two inland PLADs of China)respectively,in 2021.None of the patients had a travel history to a melioidosis-endemic area.All the BP isolates belonged to the same sequence type(ST51),which had been reported from elsewhere in Southeast Asia.
