To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-...To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-β-CD） was mixed with lithium salt, respectively, and then incubated at room temperature for 10 min to reach the equilibrium. In posi- tive mode, the electrospray ionization mass spectrometry （ESI-MS） results demonstrated that lithium ion can conjugate to α-, β-, DM-β- or TM-β-CD and form 1：1 stoichiometric non-covalent complexes. The binding of the complexes was further confirmed by collision- induced dissociation. The dissociation constants Kdl of four complexes （Li＋α-CD, Li＋β- CD, Li＋DM-β-CD, and Li＋TM-β-CD） were determined by mass spectrometric titration. The results showed Kdl were 18.7, 26.7, 33.6, 30.5 μmol/L for the complexes of Li＋ with α-CD, β-CD, DM-β-CD, and TM-β-CD, respectively. Kdl for the Li＋ complexes of/3-CD is smaller than that of DM-β-CD due to its steric effect of the partial substituted -CH3. The Kdl for the Li＋ complexes of DM-β-CD is nearly in agreement with that of TM-β-CD, indicating Li＋ is more likely to locate in the small rim of DM-β-CD＇s hydrophobic cavity. The DFT results showed through electrostatic interaction, one Li＋ can strongly conjugate to four neighboring oxygen atoms. For the （α-CD＋Li）＋ complex, one Li＋ may also situate the small rim of α-CD＇s hydrophobic cavity to form a non-specific host-guest complex.展开更多
The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru（II） complexes [Ru（terpy）（phen）X]＋ （terpy=2,2＇,6＇,2″-terpyridine...The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru（II） complexes [Ru（terpy）（phen）X]＋ （terpy=2,2＇,6＇,2″-terpyridine, phen=l,10-phenanthroline, and X=-C-=CH （1）, X=Cl （2）, X-CN （3）） were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the com- plexes in CHaCN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru-C, Ru-N, and Ru-Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for a, while the lowest unoccupied molecular orbital were π＊（terpy） type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nln are attributed to a dyz （Ru）＋Tr/p（X）--π＊ （terpy） transition with MLCT/XLCT （metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer） character, whereas that of 3 at 529 nm is related to a dyz （Ru）＋π（terpy）-π＊ （terpy） transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm （1）, 913 nm （2）, and 838 nm （3） have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru（II） complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand.展开更多
Single particle mass spectrometry has been widely used to determine the size and chemical compositions of at- mospheric aerosols; however, it is still rarely used for the microphysical properties measurement. In this ...Single particle mass spectrometry has been widely used to determine the size and chemical compositions of at- mospheric aerosols; however, it is still rarely used for the microphysical properties measurement. In this study, two methods were developed for determining aerosol effective density by a single particle aerosol mass spectrometer （SPAMS）. Method I retrieved effective density through comparison between measured light scattering intensities and Mie theoretical modelled par- tial scattering cross section. Method Ⅱ coupled a differential mobility analyzer （DMA） with SPAMS to simultaneously deter- mine the electric mobility and vacuum aerodynamic diameter, and thus the effective density. Polystyrene latex spheres, ammo- nium sulfate and sodium nitrate were tested by these methods to help validate their effectiveness for determining the aerosol effective density. This study effectively extends SPAMS measurements to include particle size, chemical composition, light scattering, and effective density, and thus helps us better understand the environment and climate effects of aerosols.展开更多
OBJECTIVE： To study the effect of Wuziyanzong treatment on the sperm quality and content of cal- cium ions （Ca2＋） in oligoasthenospermia rats. METHODS： A model of oligoasthenospermia was induced in 50 Sprague Daw...OBJECTIVE： To study the effect of Wuziyanzong treatment on the sperm quality and content of cal- cium ions （Ca2＋） in oligoasthenospermia rats. METHODS： A model of oligoasthenospermia was induced in 50 Sprague Dawley rats by treatment with tripterygium glycosides at 30 mg/kg per day for 8 weeks. They were divided randomly into a model group, a positive group （Huangjingzanyu capsule, 3.01 g/kg）, and low, medium and high dose Wuziyanzong treatment groups （2.30, 4.60, 9.20 g/kg crude drug respectively） with 10 in each group. Another 10 rats were used as a control group. The rats in the control and model groups were administered distilled water, while the rats in the remaining groups were administered Wuziyan- zong for 30 d. The epididymides were removed, spermatozoa recovered and the sperm density and viability were measured. The spermatozoa were pu- rified and the contents of Ca2~ in the cytoplasm and mitochondria were detected by flow cytometry and atomic absorption spectrometry, respectively. RESULTS： After 8 weeks of treatment with tripteryg- ium glycosides, the sperm density, sperm activity and the Ca2~ content of spermatozoa in the model rats were all significantly decreased compared with the control group （all P〈O.05）. After 30 d treatment, the sperm density and activity improved and the Ca2＋ content of sperm were increased significantly in the medium and high dose Wuziyanzong treat- ment groups in comparison with the model group （all P〈O.05）. CONCLUSION： The Wuziyanzong treatment in： creased sperm density, improved sperm viability and enhanced the content of Ca2＋ in the sperm cy- toplasm and mitochondria in this rat model of oli- goasthenospermia.展开更多
文摘To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-β-CD） was mixed with lithium salt, respectively, and then incubated at room temperature for 10 min to reach the equilibrium. In posi- tive mode, the electrospray ionization mass spectrometry （ESI-MS） results demonstrated that lithium ion can conjugate to α-, β-, DM-β- or TM-β-CD and form 1：1 stoichiometric non-covalent complexes. The binding of the complexes was further confirmed by collision- induced dissociation. The dissociation constants Kdl of four complexes （Li＋α-CD, Li＋β- CD, Li＋DM-β-CD, and Li＋TM-β-CD） were determined by mass spectrometric titration. The results showed Kdl were 18.7, 26.7, 33.6, 30.5 μmol/L for the complexes of Li＋ with α-CD, β-CD, DM-β-CD, and TM-β-CD, respectively. Kdl for the Li＋ complexes of/3-CD is smaller than that of DM-β-CD due to its steric effect of the partial substituted -CH3. The Kdl for the Li＋ complexes of DM-β-CD is nearly in agreement with that of TM-β-CD, indicating Li＋ is more likely to locate in the small rim of DM-β-CD＇s hydrophobic cavity. The DFT results showed through electrostatic interaction, one Li＋ can strongly conjugate to four neighboring oxygen atoms. For the （α-CD＋Li）＋ complex, one Li＋ may also situate the small rim of α-CD＇s hydrophobic cavity to form a non-specific host-guest complex.
文摘The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru（II） complexes [Ru（terpy）（phen）X]＋ （terpy=2,2＇,6＇,2″-terpyridine, phen=l,10-phenanthroline, and X=-C-=CH （1）, X=Cl （2）, X-CN （3）） were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the com- plexes in CHaCN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru-C, Ru-N, and Ru-Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for a, while the lowest unoccupied molecular orbital were π＊（terpy） type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nln are attributed to a dyz （Ru）＋Tr/p（X）--π＊ （terpy） transition with MLCT/XLCT （metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer） character, whereas that of 3 at 529 nm is related to a dyz （Ru）＋π（terpy）-π＊ （terpy） transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm （1）, 913 nm （2）, and 838 nm （3） have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru（II） complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand.
基金supported by the"Strategic Priority Research Program(B)"of the Chinese Academy of Sciences(Grant No.XDB05020205)the National Natural Science Foundation of China(Grant No.41405131)the China Postdoctoral Science Foundation(Grant No.2014M550442)
文摘Single particle mass spectrometry has been widely used to determine the size and chemical compositions of at- mospheric aerosols; however, it is still rarely used for the microphysical properties measurement. In this study, two methods were developed for determining aerosol effective density by a single particle aerosol mass spectrometer （SPAMS）. Method I retrieved effective density through comparison between measured light scattering intensities and Mie theoretical modelled par- tial scattering cross section. Method Ⅱ coupled a differential mobility analyzer （DMA） with SPAMS to simultaneously deter- mine the electric mobility and vacuum aerodynamic diameter, and thus the effective density. Polystyrene latex spheres, ammo- nium sulfate and sodium nitrate were tested by these methods to help validate their effectiveness for determining the aerosol effective density. This study effectively extends SPAMS measurements to include particle size, chemical composition, light scattering, and effective density, and thus helps us better understand the environment and climate effects of aerosols.
基金Supported by the National Natural Science Foundation of China(Grant No.81173387)the Natural Science Foundation of Anhui college of TCM(Grant No.2010ZR002A)
文摘OBJECTIVE： To study the effect of Wuziyanzong treatment on the sperm quality and content of cal- cium ions （Ca2＋） in oligoasthenospermia rats. METHODS： A model of oligoasthenospermia was induced in 50 Sprague Dawley rats by treatment with tripterygium glycosides at 30 mg/kg per day for 8 weeks. They were divided randomly into a model group, a positive group （Huangjingzanyu capsule, 3.01 g/kg）, and low, medium and high dose Wuziyanzong treatment groups （2.30, 4.60, 9.20 g/kg crude drug respectively） with 10 in each group. Another 10 rats were used as a control group. The rats in the control and model groups were administered distilled water, while the rats in the remaining groups were administered Wuziyan- zong for 30 d. The epididymides were removed, spermatozoa recovered and the sperm density and viability were measured. The spermatozoa were pu- rified and the contents of Ca2~ in the cytoplasm and mitochondria were detected by flow cytometry and atomic absorption spectrometry, respectively. RESULTS： After 8 weeks of treatment with tripteryg- ium glycosides, the sperm density, sperm activity and the Ca2~ content of spermatozoa in the model rats were all significantly decreased compared with the control group （all P〈O.05）. After 30 d treatment, the sperm density and activity improved and the Ca2＋ content of sperm were increased significantly in the medium and high dose Wuziyanzong treat- ment groups in comparison with the model group （all P〈O.05）. CONCLUSION： The Wuziyanzong treatment in： creased sperm density, improved sperm viability and enhanced the content of Ca2＋ in the sperm cy- toplasm and mitochondria in this rat model of oli- goasthenospermia.
