The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of ...The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.展开更多
Parkinson's disease(PD)is one of the most common neurodegenerative diseases.The loss of dopaminergic(DAergic)neurons in the substantia nigra and the decrease of dopamine(DA)levels accelerate the process of PD.L-Er...Parkinson's disease(PD)is one of the most common neurodegenerative diseases.The loss of dopaminergic(DAergic)neurons in the substantia nigra and the decrease of dopamine(DA)levels accelerate the process of PD.L-Ergothioneine(EGT)is a natural antioxidant derived from microorganisms,especially in edible mushrooms.EGT can penetrate blood-brain barrier and its levels are significantly decreased in the plasma of PD patients.Therefore,we speculated that EGT could ameliorate PD,and determined its effect on PD development by using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced PD mouse models and neurotoxin 1-methyl-4-phenylpyridinium(MPP^(+))-induced cell models.Our results show that EGT alleviated MPTP-induced behavioral dysfunction in mice.Mechanistically,we innovatively revealed that EGT was a key regulator of DJ-1.EGT restored DA levels by activating the DJ-1-nuclear receptor-related factor 1(Nurr1)axis.Furthermore,it reduced reactive oxygen species(ROS)levels by regulating the DJ-1-nuclear factor erythroid 2-related factor 2(Nrf2)pathway,which inhibited oxidative stress-induced DAergic neuronal apoptosis.Combined treatment with DJ-1-si RNA transfection revealed that blocking DJ-1 reversed EGT upregulated Nurr1 and Nrf2 expression in the nucleus,which significantly decreased the benefits of EGT.Taken together,our study suggests that EGT can ameliorate PD and be considered as a strategy for PD treatment.展开更多
Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki r...Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki reaction.The structures of the new compounds synthesized were confirmed by elemental analysis,IR,1H NMR and MS.This new method makes a feature of low cost and readily available starting material,fewer steps,mild condition,easiness to operate and higher yield.展开更多
基金supported by the National Natural Science Foundation of China under agreement number 22378026the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180508).
文摘The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)CO_(3) solid base catalyst is a well-known heterogeneous catalytic reaction.In this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous reactor.Internal and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst support.Then,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were investigated.Moreover,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic model.Finally,the activation energy for each reaction involved in the dimerization reaction was calculated.The activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,respectively.The effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model simulation.By comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.
基金supported by the National Natural Science Foundation of China(U22A20272,82173807,82170497)。
文摘Parkinson's disease(PD)is one of the most common neurodegenerative diseases.The loss of dopaminergic(DAergic)neurons in the substantia nigra and the decrease of dopamine(DA)levels accelerate the process of PD.L-Ergothioneine(EGT)is a natural antioxidant derived from microorganisms,especially in edible mushrooms.EGT can penetrate blood-brain barrier and its levels are significantly decreased in the plasma of PD patients.Therefore,we speculated that EGT could ameliorate PD,and determined its effect on PD development by using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced PD mouse models and neurotoxin 1-methyl-4-phenylpyridinium(MPP^(+))-induced cell models.Our results show that EGT alleviated MPTP-induced behavioral dysfunction in mice.Mechanistically,we innovatively revealed that EGT was a key regulator of DJ-1.EGT restored DA levels by activating the DJ-1-nuclear receptor-related factor 1(Nurr1)axis.Furthermore,it reduced reactive oxygen species(ROS)levels by regulating the DJ-1-nuclear factor erythroid 2-related factor 2(Nrf2)pathway,which inhibited oxidative stress-induced DAergic neuronal apoptosis.Combined treatment with DJ-1-si RNA transfection revealed that blocking DJ-1 reversed EGT upregulated Nurr1 and Nrf2 expression in the nucleus,which significantly decreased the benefits of EGT.Taken together,our study suggests that EGT can ameliorate PD and be considered as a strategy for PD treatment.
文摘Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki reaction.The structures of the new compounds synthesized were confirmed by elemental analysis,IR,1H NMR and MS.This new method makes a feature of low cost and readily available starting material,fewer steps,mild condition,easiness to operate and higher yield.
