Using polyvinyl alcohol(PVA) and sodium dodecyl suifae(SDS) as the surfactans respectively, nano-size amorphous molybdenum dioxide powders were prepared by y-radiation method at ambient pressure and room temperature, ...Using polyvinyl alcohol(PVA) and sodium dodecyl suifae(SDS) as the surfactans respectively, nano-size amorphous molybdenum dioxide powders were prepared by y-radiation method at ambient pressure and room temperature, and the products were characterized by use of laser Raman spectra(LRS), X-ray powder diffraction(XRD) and transmisson electron micrograph(TEM). The experimental results reveal that the relative pure satnples can be obtained using PVA as sdrictant, and the average particle size is about 10nm, but using SDS as swhctant, the samples with the average particle size 30nm are a mixture of MoO2 and MoO3. This suggestes PVA is prior to SDS in the preparaion of nano-sized amorphous molybdenum dioxide powders by γ-radiation method.展开更多
BACKGROUND:With the objective of developing a locally- produced radioactive stent,the present study used in vivo animal experiments to explore apoptosis of proliferative smooth muscle cells resulting from facilitation...BACKGROUND:With the objective of developing a locally- produced radioactive stent,the present study used in vivo animal experiments to explore apoptosis of proliferative smooth muscle cells resulting from facilitation of the expression of genes caused byγ-radiation in order to prevent bile duct restenosis.We therefore explored the effects and significance ofγ-radiation on the activity of caspase-3,Fas and Bcl-2 genes in apoptosis of proliferative smooth muscle cells in the bile duct walls of dogs. METHODS:Twelve dogs were randomly divided into 2 groups(6 in each group).A postinjury bile duct stenosis model was established and radioactive 103 Pd( 103 palladium) or ordinary bile duct stents were implanted into the bile ducts.HE staining,RT-PCR and immunohistochemistry were used to detect the proliferation and apoptosis of bile duct smooth muscle cells in proliferative endomembrane and the expression of related caspase-3,Bcl-2 and Fas genes. RESULTS:The expression of caspase-3 and Fas genes in the bile duct tissues of dogs with radioactive stents was higher than that of dogs with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the bile ducts.The expression of the Bcl-2 gene in the bile duct tissues of dogs with radioactive stents was lower than that in those with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the dogs with low Bcl-2 gene expression. CONCLUSIONS:Radiation increases the activity of caspase-3 and Fas genes and is associated with apoptosis. The radioactive 103 Pd stent may facilitate apoptosis of proliferative smooth muscle cells in the bile ducts of dogs by activating these genes.The Bcl-2 gene expression level is correlated with the occurrence of apoptosis and the radiosusceptibility of cells.展开更多
Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants.However,the effects of biologica...Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants.However,the effects of biological pretreatment （sterilization） on organic matter often have a negative impact on such experiments.Based on the principle of water total organic carbon （TOC） analysis,the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated.The results revealed that two conventional physical sterilization treatments,autoclaving and 60 Co γ-radiation sterilization,led to the direct decomposition of some organic pollutants,resulting in remarkable errors in the analysis of TOC in water samples.Furthermore,the extent of the errors varied with the intensity and the duration of sterilization treatments.Accordingly,a novel sterilization method for water samples,0.45 μm micro-filtration coupled with ultraviolet radiation （MCUR）,was developed in the present study.The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters.Before and after sterilization treatments,the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.展开更多
文摘Using polyvinyl alcohol(PVA) and sodium dodecyl suifae(SDS) as the surfactans respectively, nano-size amorphous molybdenum dioxide powders were prepared by y-radiation method at ambient pressure and room temperature, and the products were characterized by use of laser Raman spectra(LRS), X-ray powder diffraction(XRD) and transmisson electron micrograph(TEM). The experimental results reveal that the relative pure satnples can be obtained using PVA as sdrictant, and the average particle size is about 10nm, but using SDS as swhctant, the samples with the average particle size 30nm are a mixture of MoO2 and MoO3. This suggestes PVA is prior to SDS in the preparaion of nano-sized amorphous molybdenum dioxide powders by γ-radiation method.
文摘BACKGROUND:With the objective of developing a locally- produced radioactive stent,the present study used in vivo animal experiments to explore apoptosis of proliferative smooth muscle cells resulting from facilitation of the expression of genes caused byγ-radiation in order to prevent bile duct restenosis.We therefore explored the effects and significance ofγ-radiation on the activity of caspase-3,Fas and Bcl-2 genes in apoptosis of proliferative smooth muscle cells in the bile duct walls of dogs. METHODS:Twelve dogs were randomly divided into 2 groups(6 in each group).A postinjury bile duct stenosis model was established and radioactive 103 Pd( 103 palladium) or ordinary bile duct stents were implanted into the bile ducts.HE staining,RT-PCR and immunohistochemistry were used to detect the proliferation and apoptosis of bile duct smooth muscle cells in proliferative endomembrane and the expression of related caspase-3,Bcl-2 and Fas genes. RESULTS:The expression of caspase-3 and Fas genes in the bile duct tissues of dogs with radioactive stents was higher than that of dogs with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the bile ducts.The expression of the Bcl-2 gene in the bile duct tissues of dogs with radioactive stents was lower than that in those with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the dogs with low Bcl-2 gene expression. CONCLUSIONS:Radiation increases the activity of caspase-3 and Fas genes and is associated with apoptosis. The radioactive 103 Pd stent may facilitate apoptosis of proliferative smooth muscle cells in the bile ducts of dogs by activating these genes.The Bcl-2 gene expression level is correlated with the occurrence of apoptosis and the radiosusceptibility of cells.
基金supported by the National Natural Science Foundation of China (No. 40821140540)the National High Technology Research and Development Program (863) of China (No. 2007AA10Z218)
文摘Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants.However,the effects of biological pretreatment （sterilization） on organic matter often have a negative impact on such experiments.Based on the principle of water total organic carbon （TOC） analysis,the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated.The results revealed that two conventional physical sterilization treatments,autoclaving and 60 Co γ-radiation sterilization,led to the direct decomposition of some organic pollutants,resulting in remarkable errors in the analysis of TOC in water samples.Furthermore,the extent of the errors varied with the intensity and the duration of sterilization treatments.Accordingly,a novel sterilization method for water samples,0.45 μm micro-filtration coupled with ultraviolet radiation （MCUR）,was developed in the present study.The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters.Before and after sterilization treatments,the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.
