WnC0＇± （n= 1-6） clusters are investigated by using the density functional theory （DFT） at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within th...WnC0＇± （n= 1-6） clusters are investigated by using the density functional theory （DFT） at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within the same size, and constituted by substituting a C atom for one W atom in the structures of Wn＋1 clusters. The natural bond orbital （NBO） charge analyses indicate that the direction of electron transfer is from the W atom to the 2p orbital of the C atom. In addition, the calculated infrared spectra of the WnC0＇± （n= 2-6） clusters manifest that the vibrational frequencies of neutral, anionic and cationic clusters are similar in a range of 80 cm-1-864 cm-1. The high frequency, strong peak modes are found to be an almost stretched deformation of the carbide atom. Finally, the polarizabilities of WnC0＇± （n= 1-6） clusters are also discussed.展开更多
The stable structures and stabilities of AgnH2S（n = 1-10） clusters have been calculated using the B3P86-DFT method. The results predicate that the stable geometries of AgnH2 S clusters can be got by directly adding ...The stable structures and stabilities of AgnH2S（n = 1-10） clusters have been calculated using the B3P86-DFT method. The results predicate that the stable geometries of AgnH2 S clusters can be got by directly adding the H2 S molecule on different sites of Agn clusters. Agn clusters would like to bond with sulfur atom and the H2 S molecules are partial to adsorb at the top site in the clusters. After adsorption, the structures of Agn clusters and H2 S molecule keep the original structures except Ag9. The binding energy of AgnH2 S is distinctly larger than that of pure Agn clusters. The second difference in energy and the HOMO and LUMO gaps of Agn and AgnH2 S exhibit an obvious odd-even oscillation, which demonstrate that the stabilities of even-numbered silver clusters are relatively more stable than the neighboring odd-numbered silver clusters. Mulliken population analysis shows that charges always transfer from the H2 S molecule to Agn clusters in all clusters.展开更多
Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycer...Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycerol-1- yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure of the latter was determined by 1H NMR spectroscopy and by synthesis using phenylhydrazine hydrochloride instead of NNBPHH. Condensation of D-glucose and 4,5-dichloro-o-phenylenediamine gave 6,7-dichloro-2-(D-arabino-tetritol-1-yl)quinoxaline, which upon condensation with NNBPHH gave the corresponding 6,7-dichloro-3-(D-erythro-glycerol-1-yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure and mechanism of formation of these compounds are discussed.展开更多
γ-Aminobutyric acid（GABA）,plays a key role in all stages of life,also is considered the main inhibitory neurotransmitter.GABA activates two kind of membrane receptors known as GABAA and GABAB,the first one is respo...γ-Aminobutyric acid（GABA）,plays a key role in all stages of life,also is considered the main inhibitory neurotransmitter.GABA activates two kind of membrane receptors known as GABAA and GABAB,the first one is responsible to render tonic inhibition by pentameric receptors containing α4-6,β3,δ,or ρ1-3 subunits,they are located at perisynaptic and/or in extrasynaptic regions.The biophysical properties of GABAA tonic inhibition have been related with cellular protection against excitotoxic injury and cell death in presence of excessive excitation.On this basis,GABAA tonic inhibition has been proposed as a potential target for therapeutic intervention of Huntington＇s disease.Huntington＇s disease is a neurodegenerative disorder caused by a genetic mutation of the huntingtin protein.For experimental studies of Huntington＇s disease mouse models have been developed,such as R6/1,R6/2,Hdh Q92,Hdh Q150,as well as YAC128.In all of them,some key experimental reports are focused on neostriatum.The neostriatum is considered as the most important connection between cerebral cortex and basal ganglia structures,its cytology display two pathways called direct and indirect constituted by medium sized spiny neurons expressing dopamine D1 and D2 receptors respectively,they display strong expression of many types of GABAA receptors,including tonic subunits.The studies about of GABAA tonic subunits and Huntington＇s disease into the neostriatum are rising in recent years,suggesting interesting changes in their expression and localization which can be used as a strategy to delay the cellular damage caused by the imbalance between excitation and inhibition,a hallmark of Huntington＇s disease.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51072072)
文摘WnC0＇± （n= 1-6） clusters are investigated by using the density functional theory （DFT） at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within the same size, and constituted by substituting a C atom for one W atom in the structures of Wn＋1 clusters. The natural bond orbital （NBO） charge analyses indicate that the direction of electron transfer is from the W atom to the 2p orbital of the C atom. In addition, the calculated infrared spectra of the WnC0＇± （n= 2-6） clusters manifest that the vibrational frequencies of neutral, anionic and cationic clusters are similar in a range of 80 cm-1-864 cm-1. The high frequency, strong peak modes are found to be an almost stretched deformation of the carbide atom. Finally, the polarizabilities of WnC0＇± （n= 1-6） clusters are also discussed.
基金supported by the National Natural Science Foundation of China(11247229,11304246)the Scientific Research Program Fund by Shaanxi Provincial Education Department(2013JK0629)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(2014JQ6206)the Innovation and Entrepreneurship Training Project of Provincial College Students
文摘The stable structures and stabilities of AgnH2S（n = 1-10） clusters have been calculated using the B3P86-DFT method. The results predicate that the stable geometries of AgnH2 S clusters can be got by directly adding the H2 S molecule on different sites of Agn clusters. Agn clusters would like to bond with sulfur atom and the H2 S molecules are partial to adsorb at the top site in the clusters. After adsorption, the structures of Agn clusters and H2 S molecule keep the original structures except Ag9. The binding energy of AgnH2 S is distinctly larger than that of pure Agn clusters. The second difference in energy and the HOMO and LUMO gaps of Agn and AgnH2 S exhibit an obvious odd-even oscillation, which demonstrate that the stabilities of even-numbered silver clusters are relatively more stable than the neighboring odd-numbered silver clusters. Mulliken population analysis shows that charges always transfer from the H2 S molecule to Agn clusters in all clusters.
文摘Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycerol-1- yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure of the latter was determined by 1H NMR spectroscopy and by synthesis using phenylhydrazine hydrochloride instead of NNBPHH. Condensation of D-glucose and 4,5-dichloro-o-phenylenediamine gave 6,7-dichloro-2-(D-arabino-tetritol-1-yl)quinoxaline, which upon condensation with NNBPHH gave the corresponding 6,7-dichloro-3-(D-erythro-glycerol-1-yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure and mechanism of formation of these compounds are discussed.
基金the programs for the postdoctoral fellowships-Chilean CONICYT-FONDECYT#3140218,Mexican CONACYT#164978 and DID-UACh S-2015-81Sistema Nacional de Investigadores#58512 to Abraham Rosas-Arellano+2 种基金supported by USACH PhD fellowshipsupported with a PhD fellowship from CONACYT(#299627)FONDECYT grants 1151206 and 1110571 to Maite A.Castro
文摘γ-Aminobutyric acid（GABA）,plays a key role in all stages of life,also is considered the main inhibitory neurotransmitter.GABA activates two kind of membrane receptors known as GABAA and GABAB,the first one is responsible to render tonic inhibition by pentameric receptors containing α4-6,β3,δ,or ρ1-3 subunits,they are located at perisynaptic and/or in extrasynaptic regions.The biophysical properties of GABAA tonic inhibition have been related with cellular protection against excitotoxic injury and cell death in presence of excessive excitation.On this basis,GABAA tonic inhibition has been proposed as a potential target for therapeutic intervention of Huntington＇s disease.Huntington＇s disease is a neurodegenerative disorder caused by a genetic mutation of the huntingtin protein.For experimental studies of Huntington＇s disease mouse models have been developed,such as R6/1,R6/2,Hdh Q92,Hdh Q150,as well as YAC128.In all of them,some key experimental reports are focused on neostriatum.The neostriatum is considered as the most important connection between cerebral cortex and basal ganglia structures,its cytology display two pathways called direct and indirect constituted by medium sized spiny neurons expressing dopamine D1 and D2 receptors respectively,they display strong expression of many types of GABAA receptors,including tonic subunits.The studies about of GABAA tonic subunits and Huntington＇s disease into the neostriatum are rising in recent years,suggesting interesting changes in their expression and localization which can be used as a strategy to delay the cellular damage caused by the imbalance between excitation and inhibition,a hallmark of Huntington＇s disease.
