1,721,026 research outputs found
Biochar as support in catalytic CO2 methanation: Enhancing effect of CeO2 addition
No full textActivated biochar obtained through slow pyrolysis and subsequent activation with CO2 was chosen as support in the synthesis of low Ni-content catalysts to be employed in CO2 methanation process. The main aim of this work was to obtain a more sustainable catalytic formulation compared to those proposed in literature. Biochar-supported catalyst resulted to be efficient in CO2 methanation, but with a relatively low selectivity toward methane. Support doping with CeO2 led to a remarkable increase in methane yield and in stability overtime. A maximum CH4 production was achieved with a CeO2 loading of 30 wt.%. Nevertheless, the lowest deactivation rate was observed for a support loaded with 50 wt.% of CeO2 Ceria promotes a faster activation of the CO2 molecule and a strengthens the Ni/support interactions, resulting in reduced active phase mobility and moderate sintering phenomena. The outcomes of this work were attractive for further studies related to the improvements in the catalyst stability
Selective embolization with an adhesive fluid of complicated aneurysms of the hepatic artery: 3 cases.
No full textIncidence and predictive factors for complications after uterine leiomyoma embolization
No full textSTUDY QUESTION What is the risk of complications after uterine leiomyoma embolization and what are the factors associated with complications? SUMMARY ANSWER The cumulative risk of complications after embolization is relatively low even in the long term, but submucosal leiomyoma location may increase the risk. WHAT IS KNOWN ALREADY A broad spectrum of complications after leiomyoma embolization have been described with widely varying rates. There is uncertainty over the actual risk of complications and the factors associated with this risk. STUDY DESIGN, SIZE, DURATION This was a prospective cohort study of 288 consecutive women undergoing leiomyoma embolization in the general gynaecology clinic of a university teaching hospital between January 2001 and December 2010. PARTICIPANTS/MATERIALS, SETTING, METHODS Complications occurring after embolization were categorized as major or minor according to the severity of their impact on health, the level of care required and the outcome. Cumulative complication rates were estimated by survival analysis and log-rank tests according to baseline variables. Multivariable Cox proportional hazards analysis was performed to adjust for confounders. MAIN RESULTS AND THE ROLE OF CHANCE There were 48 patients who experienced a complication at a median of 5 months (95% confidence interval, 4.1-11.4) after embolization. Complications were minor in 38 patients and major in 10 patients. The cumulative overall complication rate was 13% (95% CI, 9.0-17.0) at 6 months, 16% (95% CI, 11.0-20.0) at 1 year, 17% (95% CI, 12.0-22.0) at 3 years and 18% (95% CI, 12.9-22.8) at 5 years. The most frequent complication (19/48, 39.6%) was leiomyoma expulsion, which occurred spontaneously in 13 (68.4%) of these cases and required assistance in 6 (31.6%) cases. Eight (2.8%) patients underwent re-intervention, including six hysteroscopic myomectomies, one laparoscopic myomectomy and one hysteroscopic adhesiolysis, as a result of a complication. Submucosal leiomyoma location was the only baseline variable associated with an increased risk for complications [Hazard ratio (HR), 2.28, 95% CI, 1.24-4.18, P = 0.008]. LIMITATIONS, REASONS FOR CAUTION Our population did not include women of African descent, who have been reported to be at higher risk of post-procedural complications compared with Causcasian women. If such women were involved in the study, higher morbidity rates might have been observed. WIDER IMPLICATIONS OF THE FINDINGS Women with submucosal leiomyomas at the time of embolization are more likely to have post-procedural complications. This is important new information for counselling patients contemplating this therapeutic approach. STUDY FUNDING/COMPETING INTEREST(S) The authors have no competing interests to declare. The study was not supported by any external grant. © 2014 The Author
- …
