Ferroptosis,an iron-dependent form of regulated cell death,is prevented by activity of the glutathione-dependent phospholipid hydroperoxidase GPX4(Glutathione peroxidase 4)in the cytosol and mitochondria,and by the gl...Ferroptosis,an iron-dependent form of regulated cell death,is prevented by activity of the glutathione-dependent phospholipid hydroperoxidase GPX4(Glutathione peroxidase 4)in the cytosol and mitochondria,and by the glutathione-independent CoQ10 oxidoreductase FSP1 at the plasma membrane.In their recent paper published in Nature,Mao et al.report that DHODH(Dihydroorotate dehydrogenase)coordinates with GPX4 to block ferroptosis in the mitochondrial inner membrane by reducing ubiquinone to form ubiquinol in cancer cells,thus providing a novel targeted strategy for treating cancer.展开更多
Figure 1.Discovery of novel and potent DHODHi and their anti-influenza A virus activities.(A)The discovery and design of S312 and S416.The detailed descriptions of the discovery workflow are in Method.Binding analysis...Figure 1.Discovery of novel and potent DHODHi and their anti-influenza A virus activities.(A)The discovery and design of S312 and S416.The detailed descriptions of the discovery workflow are in Method.Binding analysis of S312(B)and S416(C).Thermodynamic analysis of the binding of S312 and S416 to DHODH was carried out at 25 C on a MicroCal iTC200 instrument.Kinetic analysis of the binding of S312 and S416 to DHODH was performed with a Biacore T200 instrument.展开更多
High activity and productivity of MoVNbTeO_(x) catalyst are challenging tasks in oxidative dehydrogenation of ethane(ODHE)for industrial application.In this work,phase-pure M1 with 30 wt%CeO_(2) composite catalyst was...High activity and productivity of MoVNbTeO_(x) catalyst are challenging tasks in oxidative dehydrogenation of ethane(ODHE)for industrial application.In this work,phase-pure M1 with 30 wt%CeO_(2) composite catalyst was treated by oxygen plasma to further enhance catalyst performance.The results show that the oxygen vacancies generated by the solid-state redox reaction between M1 and CeO_(2) capture active oxygen species in gas and transform V^(4+)to V^(5+)without damage to M1 structure.The space-time yield of ethylene of the plasma-treated catalyst was significantly increased,in which the catalyst shows an enhancement near~100% than that of phase-pure M1 at 400℃ for ODHE process.Plasma treatment for catalysts demonstrates an effective way to convert electrical energy into chemical energy in catalyst materials.Energy conversion is achieved by using the catalyst as a medium.展开更多
LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane,giving 84%ethane conversion and 74%ethene yield at 923 K.Results indicated that the stro...LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane,giving 84%ethane conversion and 74%ethene yield at 923 K.Results indicated that the stronger the basicity of LiC1-based catalysts,the better the catalytic performance.展开更多
An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation （ODH） is described.The experimental set...An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation （ODH） is described.The experimental set-up,specially designed for steady-state and transient studies is presented.The preparation method,the characterization and the performances in steady-state and transient regimes of catalysts based on V2W4O194-Lindqvist isopolyanion used as a precursor and supported on alumina are reported.The influence of the preparation method of the catalyst and the role of water in the feed gas are more particularly discussed.展开更多
用均匀沉淀法制备了片状复合氧化镍 NiMO（M = Li，Sr，Y，Fe，La）催化剂，并研究了其对乙烷氧化脱氢制乙烯的催化性能.采用 X 射线衍射（XRD）、扫描电子显微镜（SEM）、程序升温还原（H2-TPR）和程序升温脱附（O2-TPD）等方法对镍基...用均匀沉淀法制备了片状复合氧化镍 NiMO（M = Li，Sr，Y，Fe，La）催化剂，并研究了其对乙烷氧化脱氢制乙烯的催化性能.采用 X 射线衍射（XRD）、扫描电子显微镜（SEM）、程序升温还原（H2-TPR）和程序升温脱附（O2-TPD）等方法对镍基催化剂进行了表征. X 射线衍射和扫描电子显微镜检测结果表明：助剂的加入对催化剂的形貌影响不大，仍为片状结构；平均粒径为5~10 nm.程序升温还原和脱附表征结果表明：助剂 Li，Sr并未进入 NiO 晶格；而助剂 Y，Fe，La 与 Ni 之间具有相互作用，因而影响催化剂的理化性质和催化活性.其中， Fe 掺杂的片状氧化镍催化剂对乙烯的选择性和收率均有所改善，340℃时 NiFeO 催化剂上的乙烯收率可达18.2%.展开更多
Owing to the importance of process intensification in the natural gas associated processes, the present contribution aims to investigate the production of an important natural gas downstream product in an improved sys...Owing to the importance of process intensification in the natural gas associated processes, the present contribution aims to investigate the production of an important natural gas downstream product in an improved system.Accordingly, a membrane-assisted reactor for the oxidative dehydrogenation of ethane is presented. The presented system includes a membrane for axial oxygen dosing into the reaction side. Such a strategy would lead to optimum oxygen distribution along the reactor length and prevention of hot spot formation as well. A feasibility study is conducted by developing a validated mathematical model composed of mass and energy balance equations. The effects of various operating variables are investigated by a rigorous sensitivity analysis.Then, by applying the genetic algorithm, a multi-objective optimization procedure is implemented to obtain the optimum operating condition. Considerable increase in the ethane conversion and ethylene yield are the advancements of membrane-assisted oxidative dehydrogenation reactor working under the optimum condition.More than 30% increase in the ethane conversion is obtained. Furthermore, the ethylene yield is enhanced up to 0.45.展开更多
In the oxygen diffusion hardened condition,untreated and laser surface melted pure titanium alloy (TA4) by Nd:YAG pulsed laser,are hardened at temperatures of 650 to 700℃ with the end result being a passive,mechanica...In the oxygen diffusion hardened condition,untreated and laser surface melted pure titanium alloy (TA4) by Nd:YAG pulsed laser,are hardened at temperatures of 650 to 700℃ with the end result being a passive,mechanically stable,abrasion resistant oxide ceramic rutile surface layer.The thickness of this surface layer depends on the time,temperature,and the microstructure of the Ti substrate.This paper describes the results of x-ray diffraction analysis,scanning electron microscope (SEM),microhardness measurements,and corrosion resistance measurements of hardened pure and laser treated Ti substrate.The oxygen diffusion hardened titanium alloy after laser surface melted samples (L-TA4) had a more pronounced grain structure and significantly higher roughness values than the untreated pure TA4 (U-TA4)samples.The L-TA4 samples also exhibited at least equivalent corrosion behavior and a definite increase in surface hardness compared to the U-TA4 samples.The results of this work suggest that laser surface melting plays a key role for effective oxygen diffusion hardening at 650-700℃ for pure and laser treated pure Ti alloys.展开更多
基金This work was supported by research grants from the National Natural Science Foundation of China(31930057 to F.W.and 31970689 to J.M.).
文摘Ferroptosis,an iron-dependent form of regulated cell death,is prevented by activity of the glutathione-dependent phospholipid hydroperoxidase GPX4(Glutathione peroxidase 4)in the cytosol and mitochondria,and by the glutathione-independent CoQ10 oxidoreductase FSP1 at the plasma membrane.In their recent paper published in Nature,Mao et al.report that DHODH(Dihydroorotate dehydrogenase)coordinates with GPX4 to block ferroptosis in the mitochondrial inner membrane by reducing ubiquinone to form ubiquinol in cancer cells,thus providing a novel targeted strategy for treating cancer.
文摘Figure 1.Discovery of novel and potent DHODHi and their anti-influenza A virus activities.(A)The discovery and design of S312 and S416.The detailed descriptions of the discovery workflow are in Method.Binding analysis of S312(B)and S416(C).Thermodynamic analysis of the binding of S312 and S416 to DHODH was carried out at 25 C on a MicroCal iTC200 instrument.Kinetic analysis of the binding of S312 and S416 to DHODH was performed with a Biacore T200 instrument.
基金supported by the National Natural Science Foundation of China (No.21776156).
文摘High activity and productivity of MoVNbTeO_(x) catalyst are challenging tasks in oxidative dehydrogenation of ethane(ODHE)for industrial application.In this work,phase-pure M1 with 30 wt%CeO_(2) composite catalyst was treated by oxygen plasma to further enhance catalyst performance.The results show that the oxygen vacancies generated by the solid-state redox reaction between M1 and CeO_(2) capture active oxygen species in gas and transform V^(4+)to V^(5+)without damage to M1 structure.The space-time yield of ethylene of the plasma-treated catalyst was significantly increased,in which the catalyst shows an enhancement near~100% than that of phase-pure M1 at 400℃ for ODHE process.Plasma treatment for catalysts demonstrates an effective way to convert electrical energy into chemical energy in catalyst materials.Energy conversion is achieved by using the catalyst as a medium.
基金supported by the Ministry of Science and Technology of China(No.2005CB221408)the Science and Technology Projects of Hunan Province(No.2007FJ4151)
文摘LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane,giving 84%ethane conversion and 74%ethene yield at 923 K.Results indicated that the stronger the basicity of LiC1-based catalysts,the better the catalytic performance.
基金supported by CNRS standing for Centre National de la Recherche Scientifique (France),CAPES standing for Coordenao de Aperfeioamento de Pessoal de Nível Superior (Brazil),CNPq standing for Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil) and FINEP standing for Financiadora de Estudos e Projetos (Brazil)
文摘An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation （ODH） is described.The experimental set-up,specially designed for steady-state and transient studies is presented.The preparation method,the characterization and the performances in steady-state and transient regimes of catalysts based on V2W4O194-Lindqvist isopolyanion used as a precursor and supported on alumina are reported.The influence of the preparation method of the catalyst and the role of water in the feed gas are more particularly discussed.
文摘用均匀沉淀法制备了片状复合氧化镍 NiMO（M = Li，Sr，Y，Fe，La）催化剂，并研究了其对乙烷氧化脱氢制乙烯的催化性能.采用 X 射线衍射（XRD）、扫描电子显微镜（SEM）、程序升温还原（H2-TPR）和程序升温脱附（O2-TPD）等方法对镍基催化剂进行了表征. X 射线衍射和扫描电子显微镜检测结果表明：助剂的加入对催化剂的形貌影响不大，仍为片状结构；平均粒径为5~10 nm.程序升温还原和脱附表征结果表明：助剂 Li，Sr并未进入 NiO 晶格；而助剂 Y，Fe，La 与 Ni 之间具有相互作用，因而影响催化剂的理化性质和催化活性.其中， Fe 掺杂的片状氧化镍催化剂对乙烯的选择性和收率均有所改善，340℃时 NiFeO 催化剂上的乙烯收率可达18.2%.
文摘Owing to the importance of process intensification in the natural gas associated processes, the present contribution aims to investigate the production of an important natural gas downstream product in an improved system.Accordingly, a membrane-assisted reactor for the oxidative dehydrogenation of ethane is presented. The presented system includes a membrane for axial oxygen dosing into the reaction side. Such a strategy would lead to optimum oxygen distribution along the reactor length and prevention of hot spot formation as well. A feasibility study is conducted by developing a validated mathematical model composed of mass and energy balance equations. The effects of various operating variables are investigated by a rigorous sensitivity analysis.Then, by applying the genetic algorithm, a multi-objective optimization procedure is implemented to obtain the optimum operating condition. Considerable increase in the ethane conversion and ethylene yield are the advancements of membrane-assisted oxidative dehydrogenation reactor working under the optimum condition.More than 30% increase in the ethane conversion is obtained. Furthermore, the ethylene yield is enhanced up to 0.45.
基金Foundation item:National Nature Science Foundation of China(50801050)
文摘In the oxygen diffusion hardened condition,untreated and laser surface melted pure titanium alloy (TA4) by Nd:YAG pulsed laser,are hardened at temperatures of 650 to 700℃ with the end result being a passive,mechanically stable,abrasion resistant oxide ceramic rutile surface layer.The thickness of this surface layer depends on the time,temperature,and the microstructure of the Ti substrate.This paper describes the results of x-ray diffraction analysis,scanning electron microscope (SEM),microhardness measurements,and corrosion resistance measurements of hardened pure and laser treated Ti substrate.The oxygen diffusion hardened titanium alloy after laser surface melted samples (L-TA4) had a more pronounced grain structure and significantly higher roughness values than the untreated pure TA4 (U-TA4)samples.The L-TA4 samples also exhibited at least equivalent corrosion behavior and a definite increase in surface hardness compared to the U-TA4 samples.The results of this work suggest that laser surface melting plays a key role for effective oxygen diffusion hardening at 650-700℃ for pure and laser treated pure Ti alloys.
