AIM: To assess the feasibility and safety of radiofrequency ablation (RFA) in treatment of secondary splenomagely and hypersplenism.METHODS: Sixteen healthy mongrel dogs were randomly divided into two groups, group Ⅰ...AIM: To assess the feasibility and safety of radiofrequency ablation (RFA) in treatment of secondary splenomagely and hypersplenism.METHODS: Sixteen healthy mongrel dogs were randomly divided into two groups, group Ⅰ (n=4) and group Ⅱ (n=12).Congestive splenomegaly was induced by ligation of splenic vein and its collateral branches in both groups. At the end of 3rd week postoperation, RFA in spleen was performed in group Ⅱ via laparotomy, complications of RFA were observed,CT scan was performed and the spleens were obtained.The radiofrequency (RF) thermal lesions and histopathology of spleen were examined regularly.RESULTS: No complication or death was observed in both groups; CT revealed that the splenomegaly lasted over 2months after ligation of splenic vein; the segmental RF lesions included hyperintense zone of coagulative necrosis and more extensive peripheral hypointense infarcted zone, the latter was called 'bystander effect'. The infarcted zone would be absorbed and subsequently disappeared in 4-6 weeks after RFA accompanied with shrinkage of the remnant spleen.The fundamental histopathological changes of splenic lesions caused by RF thermal energy included local coagulative necrosis, peripheral thrombotic infarction zone, subsequent tissue absorption and fibrosis in the zone of thrombotic infarction, the occlusion of vessels in remnant viable spleen,deposition of extensive fibrous protein, and disappearance of congestive splenic sinusoid - 'splenic carnification'. Those pathologic changes were underline of shrinkage of spleen.CONCLUSION: It is feasible and safe to perform RFA in spleen to treat experimental splenomegaly and hypersplenism. The RFA could be safely performed clinically via laparotomy or laparoscopic procedure while spleen was strictly separated from surrounding organs.展开更多
The ultrafine platinum nanoparticles deposited on the surfaces of carbonnanotubes (Pt/CNTs) were prepared by a chemical precipitation method and used as the catalyst ofproton exchange membrane fuel cell. The depositin...The ultrafine platinum nanoparticles deposited on the surfaces of carbonnanotubes (Pt/CNTs) were prepared by a chemical precipitation method and used as the catalyst ofproton exchange membrane fuel cell. The depositing process parameters such as the solution pH value,Pt content and treatment temperature were analyzed. The experimental results show that the optimumprocess parameters to prepare Pt/CNTs are the solution pH value of 7.0, the theoretical Pt contentof 25 percent (mass fraction) and the heating temperature of 500 deg C, under the conditions thebest performance of the proton exchange membrane fuel cell can be obtained and its voltage can reach580 mV at a current density of 500 mA/cm^2.展开更多
基金the"Tenth-Five"Fundamental Medical Scientific Research Projects of PLA,China,No.02Z005
文摘AIM: To assess the feasibility and safety of radiofrequency ablation (RFA) in treatment of secondary splenomagely and hypersplenism.METHODS: Sixteen healthy mongrel dogs were randomly divided into two groups, group Ⅰ (n=4) and group Ⅱ (n=12).Congestive splenomegaly was induced by ligation of splenic vein and its collateral branches in both groups. At the end of 3rd week postoperation, RFA in spleen was performed in group Ⅱ via laparotomy, complications of RFA were observed,CT scan was performed and the spleens were obtained.The radiofrequency (RF) thermal lesions and histopathology of spleen were examined regularly.RESULTS: No complication or death was observed in both groups; CT revealed that the splenomegaly lasted over 2months after ligation of splenic vein; the segmental RF lesions included hyperintense zone of coagulative necrosis and more extensive peripheral hypointense infarcted zone, the latter was called 'bystander effect'. The infarcted zone would be absorbed and subsequently disappeared in 4-6 weeks after RFA accompanied with shrinkage of the remnant spleen.The fundamental histopathological changes of splenic lesions caused by RF thermal energy included local coagulative necrosis, peripheral thrombotic infarction zone, subsequent tissue absorption and fibrosis in the zone of thrombotic infarction, the occlusion of vessels in remnant viable spleen,deposition of extensive fibrous protein, and disappearance of congestive splenic sinusoid - 'splenic carnification'. Those pathologic changes were underline of shrinkage of spleen.CONCLUSION: It is feasible and safe to perform RFA in spleen to treat experimental splenomegaly and hypersplenism. The RFA could be safely performed clinically via laparotomy or laparoscopic procedure while spleen was strictly separated from surrounding organs.
基金This work was financially supported by the State Key Project for Fundamental Research of the Ministry of Science and Technology (No. G20000264-04)
文摘The ultrafine platinum nanoparticles deposited on the surfaces of carbonnanotubes (Pt/CNTs) were prepared by a chemical precipitation method and used as the catalyst ofproton exchange membrane fuel cell. The depositing process parameters such as the solution pH value,Pt content and treatment temperature were analyzed. The experimental results show that the optimumprocess parameters to prepare Pt/CNTs are the solution pH value of 7.0, the theoretical Pt contentof 25 percent (mass fraction) and the heating temperature of 500 deg C, under the conditions thebest performance of the proton exchange membrane fuel cell can be obtained and its voltage can reach580 mV at a current density of 500 mA/cm^2.
