Extraction of cesium from nitric acid solutions by bis-[4(5),4′(5′)-alkanoylbenzo]-21-crown-7 in nitrobenzene or nitromethane was investigated.The results show that under the conditions of higher acidity and higher ...Extraction of cesium from nitric acid solutions by bis-[4(5),4′(5′)-alkanoylbenzo]-21-crown-7 in nitrobenzene or nitromethane was investigated.The results show that under the conditions of higher acidity and higher sodium concentration,the extraction efficiency of bis-[4(5),4′(5′)-alkanoylbenzo]-21-crown-7 was superior to that of DB21C7.The composition of the complexes was determined indirectly by measuring the conductance of cesium nitrate-crown ether in nitromethane solution.It indicated that these crown ethers probably formed 1∶1∶1 Cs^+∶crown∶nitrae complex ion pair in the organic phase.The extraction equilibrium was also discussed.展开更多
This manuscript reviews the function and fundamental characteristics of the neurotrophins and their receptors to introduce the reader to the differential effects exhibited by the neurotrophins;brain-derived neurotroph...This manuscript reviews the function and fundamental characteristics of the neurotrophins and their receptors to introduce the reader to the differential effects exhibited by the neurotrophins;brain-derived neurotrophic factor and neurotrophin 4/5 when acted together after sequential presentation.The neurotrophin 4/5 exhibits an inhibitory action on the modulatory effect of brain-derived neurotrophic factor in corticostriatal synapses when they are administered sequentially(brain-derived neurotrophic factor to neurotrophin 4/5).This inhibitory effect has not been previously documented and is relevant for these neurotrophins as both of them stimulate the TrkB receptor.The additive effect of these neurotrophins is also discussed and occurs when neurotrophin 4/5 exposure is followed by brain-derived neurotrophic factor in a mouse model of striatal degeneration.Occlusive and additive effects of both neurotrophins are accompanied by changes in the expression of the TrkB receptor isoforms,specifically TrkB-T1 and TrkB-FL,as well as differences in phosphorylation levels of the TrkB receptor.The results of the experiments described raise several questions to inquire about the role that TrkB-T1 receptor plays in striatal physiology,as well as the functional relevance of the interaction of brain-derived neurotrophic factor and neurotrophin 4/5 in the brain and more specifically at the striatal circuits in normal as well as pathological conditions.展开更多
Study was carried out in rabbits to determine whether 3,4’,5-trihydroxystibene-3-β-nono-D-glucoside(PD)has wasodilative action using volumetric method.The result showed PD(1.71 mol/L)caused a right shift of the cumu...Study was carried out in rabbits to determine whether 3,4’,5-trihydroxystibene-3-β-nono-D-glucoside(PD)has wasodilative action using volumetric method.The result showed PD(1.71 mol/L)caused a right shift of the cumulative concentration-reponse curve of uorepinephfine(NE)and lowered the maximal response of rabbit’s pulmonary arteries.It implies that PD couldinhibit the vasoconstfictive effect of NE in a noncompetitive manner.PD dilated the pulmonaryarteries(4.09 and 5.12mmol/L)and the carotid(5.12mmol/L)of rabbits.This PD-induced relax-ation of puhnonary artenes was weakened by propranolol(87.8μmol/L).展开更多
文摘Extraction of cesium from nitric acid solutions by bis-[4(5),4′(5′)-alkanoylbenzo]-21-crown-7 in nitrobenzene or nitromethane was investigated.The results show that under the conditions of higher acidity and higher sodium concentration,the extraction efficiency of bis-[4(5),4′(5′)-alkanoylbenzo]-21-crown-7 was superior to that of DB21C7.The composition of the complexes was determined indirectly by measuring the conductance of cesium nitrate-crown ether in nitromethane solution.It indicated that these crown ethers probably formed 1∶1∶1 Cs^+∶crown∶nitrae complex ion pair in the organic phase.The extraction equilibrium was also discussed.
基金supported by Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica Grants No.216515 and IN 211718。
文摘This manuscript reviews the function and fundamental characteristics of the neurotrophins and their receptors to introduce the reader to the differential effects exhibited by the neurotrophins;brain-derived neurotrophic factor and neurotrophin 4/5 when acted together after sequential presentation.The neurotrophin 4/5 exhibits an inhibitory action on the modulatory effect of brain-derived neurotrophic factor in corticostriatal synapses when they are administered sequentially(brain-derived neurotrophic factor to neurotrophin 4/5).This inhibitory effect has not been previously documented and is relevant for these neurotrophins as both of them stimulate the TrkB receptor.The additive effect of these neurotrophins is also discussed and occurs when neurotrophin 4/5 exposure is followed by brain-derived neurotrophic factor in a mouse model of striatal degeneration.Occlusive and additive effects of both neurotrophins are accompanied by changes in the expression of the TrkB receptor isoforms,specifically TrkB-T1 and TrkB-FL,as well as differences in phosphorylation levels of the TrkB receptor.The results of the experiments described raise several questions to inquire about the role that TrkB-T1 receptor plays in striatal physiology,as well as the functional relevance of the interaction of brain-derived neurotrophic factor and neurotrophin 4/5 in the brain and more specifically at the striatal circuits in normal as well as pathological conditions.
基金This project was supprted by the Natonal Natural Science Foundation of China No 3880738
文摘Study was carried out in rabbits to determine whether 3,4’,5-trihydroxystibene-3-β-nono-D-glucoside(PD)has wasodilative action using volumetric method.The result showed PD(1.71 mol/L)caused a right shift of the cumulative concentration-reponse curve of uorepinephfine(NE)and lowered the maximal response of rabbit’s pulmonary arteries.It implies that PD couldinhibit the vasoconstfictive effect of NE in a noncompetitive manner.PD dilated the pulmonaryarteries(4.09 and 5.12mmol/L)and the carotid(5.12mmol/L)of rabbits.This PD-induced relax-ation of puhnonary artenes was weakened by propranolol(87.8μmol/L).
