High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The...High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The method enables the determination of their particle size, including their ligand shells, in solution. The results are consistent with the blue shift of the absorption bands, as well as Transmission Electron Microscope (TEM) experiments. The sizes of the cluster molecules were estimated from space filling models constructed from the results of a single crystal X-ray structure determination. DLS gave comparable results for the size of both types of compound, indicating that it is potentially an important additional measurement technique to TEM, which uses harsh measurement conditions, and to powder X-ray diffraction, which is difficult to interpret below 5 nm.展开更多
Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorp...Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorption energies are also calculated. It is found that the cluster Al6Si can adsorb six CO molecules. The thermal stability of the（CO）6@Al6Si complexes is examined using the atom centered density matrix propagation molecular dynamics calculations at 373 K. The results show that two isomers of Al6Si cluster can solidly adsorb six CO molecules, and the other isomer adsorbs four ones. Therefore, the Al6Si cluster is a promising candidate for eliminating CO effectively.展开更多
Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The ...Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The results obtained by differential scanning calorimetry (DSC) showed that the thermal denaturation temperature of lysozyme had been elevated 8.47 K through hydration of lysozyme with processed water whose structure had been changed so it was called "structured water" compared to ordinary water. The reason is that structured water changed the dipole moment of water molecules and easily formed cyclic water hexamer or cage-like water hexamer, so that the interacting force of maintaining three-dimensional conformation of lysozyme could be reinforced.展开更多
This study examined the neuroprotective effect of cluster of differentiation molecule 200 （CD200） against methamphetamine （METH）-induced neurotoxicity. In the in vitro experiment, neuron-microglia cultures were tr...This study examined the neuroprotective effect of cluster of differentiation molecule 200 （CD200） against methamphetamine （METH）-induced neurotoxicity. In the in vitro experiment, neuron-microglia cultures were treated with METH （20 μmol/L）, METH （20 μmol/L）＋CD200-Fc （10 μg/mL） or CD200-Fc （10 μg/mL）. Those untreated served as control. Microglia activation expressed as the ratio of MHC-Ⅱ/CD11b was assessed by flow cytometry. The cytokines （IL-1β, TNF-α） secreted by activated microglia were detected by enzyme-linked immunosorbent assay （ELISA）. In the in vivo experiment, 40 SD rats were divided into control, METH, METH＋CD200-Fc and CD200-Fc groups at random. Rats were intraperitoneally injected with METH （15 mg/kg 8 times at 12 h interval） in METH group, with METH （administered as the same dose and time as the METH group） and CD200-Fc （1 mg/kg at day 0, 2, 4 after METH injection） in METH＋CD200-Fc group, with CD200-Fc （1 mg/kg injected as the same time as the METH＋CD200-Fc group） or with physiological saline solution in the control group. The level of striatal dopamine （DA） in rats was measured by high-performance liquid chromatography （HPLC）. The microglial cells were immunohistochemically detected for the expression of Iba-1, a marker for microglial activation. The results showed that METH could increase the microglia activation in the neuron-microglia cultures and elevate the secretion of IL-1β and TNF-α, which could be attenuated by CD200-Fc. Moreover, CD200-Fc could partially reverse the striatal DA depletion induced by METH and reduce the number of activated microglia, i.e. Iba-1-positive cells. It was concluded that CD200 may have neuroprotective effects against METH-induced neurotoxicity by inhibiting microglial activation and reversing DA depletion in striatum.展开更多
文摘High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The method enables the determination of their particle size, including their ligand shells, in solution. The results are consistent with the blue shift of the absorption bands, as well as Transmission Electron Microscope (TEM) experiments. The sizes of the cluster molecules were estimated from space filling models constructed from the results of a single crystal X-ray structure determination. DLS gave comparable results for the size of both types of compound, indicating that it is potentially an important additional measurement technique to TEM, which uses harsh measurement conditions, and to powder X-ray diffraction, which is difficult to interpret below 5 nm.
基金supported by the National Natural Science Foundation of China(Nos.NSFC-11574125 and NSFC-11374132)the Taishan Scholar Project of Shandong Province(ts201511055)
文摘Based on the density functional theory with generalized gradient approximation, the stable geometrical structures of one or more CO molecules adsorbed on the Al6Si cluster are investigated and the corresponding adsorption energies are also calculated. It is found that the cluster Al6Si can adsorb six CO molecules. The thermal stability of the（CO）6@Al6Si complexes is examined using the atom centered density matrix propagation molecular dynamics calculations at 373 K. The results show that two isomers of Al6Si cluster can solidly adsorb six CO molecules, and the other isomer adsorbs four ones. Therefore, the Al6Si cluster is a promising candidate for eliminating CO effectively.
文摘Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The results obtained by differential scanning calorimetry (DSC) showed that the thermal denaturation temperature of lysozyme had been elevated 8.47 K through hydration of lysozyme with processed water whose structure had been changed so it was called "structured water" compared to ordinary water. The reason is that structured water changed the dipole moment of water molecules and easily formed cyclic water hexamer or cage-like water hexamer, so that the interacting force of maintaining three-dimensional conformation of lysozyme could be reinforced.
基金supported by grants from the National Natural Science Foundation of China(No.30572090 and No.30872918)
文摘This study examined the neuroprotective effect of cluster of differentiation molecule 200 （CD200） against methamphetamine （METH）-induced neurotoxicity. In the in vitro experiment, neuron-microglia cultures were treated with METH （20 μmol/L）, METH （20 μmol/L）＋CD200-Fc （10 μg/mL） or CD200-Fc （10 μg/mL）. Those untreated served as control. Microglia activation expressed as the ratio of MHC-Ⅱ/CD11b was assessed by flow cytometry. The cytokines （IL-1β, TNF-α） secreted by activated microglia were detected by enzyme-linked immunosorbent assay （ELISA）. In the in vivo experiment, 40 SD rats were divided into control, METH, METH＋CD200-Fc and CD200-Fc groups at random. Rats were intraperitoneally injected with METH （15 mg/kg 8 times at 12 h interval） in METH group, with METH （administered as the same dose and time as the METH group） and CD200-Fc （1 mg/kg at day 0, 2, 4 after METH injection） in METH＋CD200-Fc group, with CD200-Fc （1 mg/kg injected as the same time as the METH＋CD200-Fc group） or with physiological saline solution in the control group. The level of striatal dopamine （DA） in rats was measured by high-performance liquid chromatography （HPLC）. The microglial cells were immunohistochemically detected for the expression of Iba-1, a marker for microglial activation. The results showed that METH could increase the microglia activation in the neuron-microglia cultures and elevate the secretion of IL-1β and TNF-α, which could be attenuated by CD200-Fc. Moreover, CD200-Fc could partially reverse the striatal DA depletion induced by METH and reduce the number of activated microglia, i.e. Iba-1-positive cells. It was concluded that CD200 may have neuroprotective effects against METH-induced neurotoxicity by inhibiting microglial activation and reversing DA depletion in striatum.
