Mesoporous LaMnO3 perovskite catalysts with high surface area were synthesized by using the recently developed hard templating method designated as ＂nanocasting＂.Ordered mesoporous silica designated as SBA-15 was us...Mesoporous LaMnO3 perovskite catalysts with high surface area were synthesized by using the recently developed hard templating method designated as ＂nanocasting＂.Ordered mesoporous silica designated as SBA-15 was used as the hard template.It was found that the surface area of the nanocast perovskites can be tuned（80–190 m2/g）by varying the aging temperature of the SBA-15 template.Nanocast LaMnO3 catalysts showed high conversion efficiencies for the total oxidation of methanol under steady state conditions,the one with the highest value of surface area being the best catalysts,as expected.Kinetic studies were performed for all of the synthesized catalysts.Rate constants were found to vary in accordance with the specific surface area of the nanocast catalyst which depends on the aging temperature of the parent template.From the rate constants obtained from experimental conversions at various space velocities（19500 to 78200 h〈sup〉–1）,values of activation energy and pre-exponential factor for the three nanocast LaMnO3 catalysts were determined by the linear regression of the Arrhenius plot.It is observed that the activation energy for all the catalysts remain constant irrespective of the variation in specific surface area.Further,a linear relationship was found to exist between the pre-exponential factor and specific surface areas of the catalysts indicating that the rates per unit surface area remains the same for all the catalysts.展开更多
AIM： To evaluate long-term follow-up of minimum-sized hepatocellular carcinoma （HCC） treated with percutaneous ethanol injection （PEI）. METHODS： PEI was applied to 42 lesions in 31 patients （23 male and eight f...AIM： To evaluate long-term follow-up of minimum-sized hepatocellular carcinoma （HCC） treated with percutaneous ethanol injection （PEI）. METHODS： PEI was applied to 42 lesions in 31 patients （23 male and eight female） with HCC 〈 15 mm in diameter, over the past 15 years. RESULTS： Overall survival rate was 74.1% at 3 years, 49.9% at 5 years, 27.2% at 7 years and 14.5% at 10 years. These results are superior to, or at least the same as those for hepatic resection and radiofrequency ablation. Survival was affected only by liver function, but not by sex, age, etiology of Hepatitis B virus or Hepatitis C virus, α-fetoprotein levels, arterial and portal blood flow, histological characteristics, and tumor multiplicity or size. Patients in Chiid-Pugh class A and B had 5-, 7- and 10-years survival rates of 76.0%, 42.2% and 15.8%, and 17.1%, 8.6% and 0%, respectively （P = 0.025）. CONCLUSION： Treatment with PEI is best indicated for patients with HCC 〈 15 mm in Child-Pugh class A.展开更多
AIM: To summarize the effects of laparoscopic ethanol injection and radiofrequency ablation (L-EI-RFA), thora- coscopic (T-EI-RFA) and open-surgery assisted EI-RFA (O-EI-RFA) under general anesthesia for the treatment...AIM: To summarize the effects of laparoscopic ethanol injection and radiofrequency ablation (L-EI-RFA), thora- coscopic (T-EI-RFA) and open-surgery assisted EI-RFA (O-EI-RFA) under general anesthesia for the treatment of hepatocellular carcinoma (HCC). METHODS: Time-lag performance of RFA after ethanol injection (Time-lag PEI-RFA) was performed in all cases. The volume of coagulated necrosis and the applied en- ergy for total and per unit volume coagulated necrosis were examined in the groups treated under general (group G) or local anesthesia (group L). RESULTS: The results showed that the total applied energy and the applied energy per unit volume of whole and marginal, coagulated necrosis were significantly larger in group G than those in the group L, resulting in a larger volume of coagulated necrosis in the group G. The rate of local tumor recurrence within one year was extremely low in group G. CONCLUSION: These results suggest that EI-RFA, un- der general anesthesia, may be effective for the treat- ment of HCC because a larger quantity of ethanol and energy could be applied during treatment under pain- free condition for the patients.展开更多
基金supported by the the National Science and Engineering Research Council(Canada)the Fonds Québécois de la Recherche sur la Nature et les Technologies(Province of Quebec)
文摘Mesoporous LaMnO3 perovskite catalysts with high surface area were synthesized by using the recently developed hard templating method designated as ＂nanocasting＂.Ordered mesoporous silica designated as SBA-15 was used as the hard template.It was found that the surface area of the nanocast perovskites can be tuned（80–190 m2/g）by varying the aging temperature of the SBA-15 template.Nanocast LaMnO3 catalysts showed high conversion efficiencies for the total oxidation of methanol under steady state conditions,the one with the highest value of surface area being the best catalysts,as expected.Kinetic studies were performed for all of the synthesized catalysts.Rate constants were found to vary in accordance with the specific surface area of the nanocast catalyst which depends on the aging temperature of the parent template.From the rate constants obtained from experimental conversions at various space velocities（19500 to 78200 h〈sup〉–1）,values of activation energy and pre-exponential factor for the three nanocast LaMnO3 catalysts were determined by the linear regression of the Arrhenius plot.It is observed that the activation energy for all the catalysts remain constant irrespective of the variation in specific surface area.Further,a linear relationship was found to exist between the pre-exponential factor and specific surface areas of the catalysts indicating that the rates per unit surface area remains the same for all the catalysts.
文摘AIM： To evaluate long-term follow-up of minimum-sized hepatocellular carcinoma （HCC） treated with percutaneous ethanol injection （PEI）. METHODS： PEI was applied to 42 lesions in 31 patients （23 male and eight female） with HCC 〈 15 mm in diameter, over the past 15 years. RESULTS： Overall survival rate was 74.1% at 3 years, 49.9% at 5 years, 27.2% at 7 years and 14.5% at 10 years. These results are superior to, or at least the same as those for hepatic resection and radiofrequency ablation. Survival was affected only by liver function, but not by sex, age, etiology of Hepatitis B virus or Hepatitis C virus, α-fetoprotein levels, arterial and portal blood flow, histological characteristics, and tumor multiplicity or size. Patients in Chiid-Pugh class A and B had 5-, 7- and 10-years survival rates of 76.0%, 42.2% and 15.8%, and 17.1%, 8.6% and 0%, respectively （P = 0.025）. CONCLUSION： Treatment with PEI is best indicated for patients with HCC 〈 15 mm in Child-Pugh class A.
文摘AIM: To summarize the effects of laparoscopic ethanol injection and radiofrequency ablation (L-EI-RFA), thora- coscopic (T-EI-RFA) and open-surgery assisted EI-RFA (O-EI-RFA) under general anesthesia for the treatment of hepatocellular carcinoma (HCC). METHODS: Time-lag performance of RFA after ethanol injection (Time-lag PEI-RFA) was performed in all cases. The volume of coagulated necrosis and the applied en- ergy for total and per unit volume coagulated necrosis were examined in the groups treated under general (group G) or local anesthesia (group L). RESULTS: The results showed that the total applied energy and the applied energy per unit volume of whole and marginal, coagulated necrosis were significantly larger in group G than those in the group L, resulting in a larger volume of coagulated necrosis in the group G. The rate of local tumor recurrence within one year was extremely low in group G. CONCLUSION: These results suggest that EI-RFA, un- der general anesthesia, may be effective for the treat- ment of HCC because a larger quantity of ethanol and energy could be applied during treatment under pain- free condition for the patients.
