A series of Co_(3) O_(4) catalysts was prepared by ammonia(Co-AP) and oxalate(Co-OP) precipitation,solgel(Co-SG),and urea hydrothermal(Co-UH) methods,and their physicochemical properties were characterised by numerous...A series of Co_(3) O_(4) catalysts was prepared by ammonia(Co-AP) and oxalate(Co-OP) precipitation,solgel(Co-SG),and urea hydrothermal(Co-UH) methods,and their physicochemical properties were characterised by numerous techniques including X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen sorption,X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction of H_(2)(H_(2)-TPR),temperature-programmed desorption of O_(2)(O_(2)-TPD),and temperature-programmed desorption of NH_(3)(NH_(3)-TPD).The catalytic activity of each catalyst was estimated for the catalytic combustion of vinyl chloride(VC) emissions.The crystallite size of the Co_(3) O_(4) catalyst was found to be well correlated with the amounts of surface-adsorbed oxygen species and number of acid sites on the catalyst surface,and consequently,determined several physicochemical properties of the catalyst.Of the catalysts studied here,the Co-AP catalyst exhibits the smallest crystallite size,which increases the specific surface area and the concentration of Co^(2+) on the catalyst surface.This,in turn,enhances the redox property,oxygen mobility,and the number of acid sites associated with the Co-AP catalyst.In fact,the Co-AP catalyst exhibits the best catalytic activity for VC combustion at 360℃and does not produce any chlorinated by-products.展开更多
AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed...AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed to measure the percentage of NK cells and the changes in their absolute number in mouse liver.The cytotoxicity of hepatic and splenic NK cells was assessed against YAC-1 target cells via a 4 h 51Cr-release assay.RESULTS:The restraint stress stimulation induced the apoptosis of NK cells in the liver and the spleen,which decreased the cell number.The number and percentage of NK cells in the spleen decreased.However,the number of NK cells in the liver decreased,whereas the percentage of NK cells was significantly increased.The apoptosis of NK cells increased gradually with prolonged stress time,and the macrophage-1(Mac-1)+NK cells were more susceptible to apoptosis than Mac-1-NK cells.Large numbers of Mac-1-NK cells in the liver,which are more resistant to stress-induced apoptosis,were observed than the Mac-1-NK cells in the spleen.The stress stimulation diminished the killing activity of NK cells in the spleen was significantly decreased,but the retention of numerous Mac-1-NK cells in the liver maintained the killing ability.CONCLUSION:Significant stress-induced apoptosis was observed among Mac-1+NK cells,but not Mac-1-NK cells in the mouse liver.Stress stimulation markedly decreased the killing activity of NK cells in the spleen but remained unchanged in the liver.展开更多
Background:Safflower is a traditional medicine that is widely used to treat various diseases.Safflower polysaccharide is one of the effective constituents of safflower.This study explored the anti-tumor effect of saff...Background:Safflower is a traditional medicine that is widely used to treat various diseases.Safflower polysaccharide is one of the effective constituents of safflower.This study explored the anti-tumor effect of safflower polysaccharide and its possible mechanism.Methods:The MTT assay was used to detect the proliferation of hepatocellular carcinoma cells(SMMC-7721 cells).We observed cell apoptosis with a fluorescence microscope.And we used qRT-PCR and western blot to detect the expression of cell cycle related factors.Results:Safflower polysaccharide could inhibit the growth of SMMC-7721 cells in a dose-dependent manner and induce its apoptosis.Compared with the blank group,the cell proliferation-related protein of CDC25B and Survivin were down-regulated in SMMC-7721 cells treated with safflower polysaccharide,while the cell apoptosis-related protein levels of P53 and P38MAPK were up-regulated(P<0.05).In addition,safflower polysaccharide inhibited the protein levels of CDC2(P<0.05).Conclusion:Safflower polysaccharide can inhibit the growth of hepatocellular carcinoma cells by inhibiting proliferation and promoting apoptosis,and the P38MAPK pathway may play an important role in this process.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2016YFC0204300)the National Natural Science Foundation of China(Nos.21922602 and 21577035)the Fundamental Research Funds for the Central Universities(No.222201717003)。
文摘A series of Co_(3) O_(4) catalysts was prepared by ammonia(Co-AP) and oxalate(Co-OP) precipitation,solgel(Co-SG),and urea hydrothermal(Co-UH) methods,and their physicochemical properties were characterised by numerous techniques including X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen sorption,X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction of H_(2)(H_(2)-TPR),temperature-programmed desorption of O_(2)(O_(2)-TPD),and temperature-programmed desorption of NH_(3)(NH_(3)-TPD).The catalytic activity of each catalyst was estimated for the catalytic combustion of vinyl chloride(VC) emissions.The crystallite size of the Co_(3) O_(4) catalyst was found to be well correlated with the amounts of surface-adsorbed oxygen species and number of acid sites on the catalyst surface,and consequently,determined several physicochemical properties of the catalyst.Of the catalysts studied here,the Co-AP catalyst exhibits the smallest crystallite size,which increases the specific surface area and the concentration of Co^(2+) on the catalyst surface.This,in turn,enhances the redox property,oxygen mobility,and the number of acid sites associated with the Co-AP catalyst.In fact,the Co-AP catalyst exhibits the best catalytic activity for VC combustion at 360℃and does not produce any chlorinated by-products.
基金Supported by The National Natural Science Foundation of China,No.30671899,No.30540012
文摘AIM:To investigate the stress-induced apoptosis of natural killer(NK)cells and the changes in their killing activity in mouse livers.METHODS:A restraint stress model was established in mice.Flow cytometry was employed to measure the percentage of NK cells and the changes in their absolute number in mouse liver.The cytotoxicity of hepatic and splenic NK cells was assessed against YAC-1 target cells via a 4 h 51Cr-release assay.RESULTS:The restraint stress stimulation induced the apoptosis of NK cells in the liver and the spleen,which decreased the cell number.The number and percentage of NK cells in the spleen decreased.However,the number of NK cells in the liver decreased,whereas the percentage of NK cells was significantly increased.The apoptosis of NK cells increased gradually with prolonged stress time,and the macrophage-1(Mac-1)+NK cells were more susceptible to apoptosis than Mac-1-NK cells.Large numbers of Mac-1-NK cells in the liver,which are more resistant to stress-induced apoptosis,were observed than the Mac-1-NK cells in the spleen.The stress stimulation diminished the killing activity of NK cells in the spleen was significantly decreased,but the retention of numerous Mac-1-NK cells in the liver maintained the killing ability.CONCLUSION:Significant stress-induced apoptosis was observed among Mac-1+NK cells,but not Mac-1-NK cells in the mouse liver.Stress stimulation markedly decreased the killing activity of NK cells in the spleen but remained unchanged in the liver.
基金This research was funded by the National Natural Science Foundation of China(81704054)China postdoctoral science foundation(2014M551288)+1 种基金Postdoctoral Scientific Research Developmental Fund(LBH-Q19184)Foundation for Innovative Talents of Heilongjiang University of Chinese Medicine(054321).
文摘Background:Safflower is a traditional medicine that is widely used to treat various diseases.Safflower polysaccharide is one of the effective constituents of safflower.This study explored the anti-tumor effect of safflower polysaccharide and its possible mechanism.Methods:The MTT assay was used to detect the proliferation of hepatocellular carcinoma cells(SMMC-7721 cells).We observed cell apoptosis with a fluorescence microscope.And we used qRT-PCR and western blot to detect the expression of cell cycle related factors.Results:Safflower polysaccharide could inhibit the growth of SMMC-7721 cells in a dose-dependent manner and induce its apoptosis.Compared with the blank group,the cell proliferation-related protein of CDC25B and Survivin were down-regulated in SMMC-7721 cells treated with safflower polysaccharide,while the cell apoptosis-related protein levels of P53 and P38MAPK were up-regulated(P<0.05).In addition,safflower polysaccharide inhibited the protein levels of CDC2(P<0.05).Conclusion:Safflower polysaccharide can inhibit the growth of hepatocellular carcinoma cells by inhibiting proliferation and promoting apoptosis,and the P38MAPK pathway may play an important role in this process.
