RESUMEN
Water electrolysis is increasingly considered a viable solution for meeting the world's growing energy demands and mitigating environmental issues. An inventive strategy to mitigate the energy requirements involves substituting the energy-intensive oxygen evolution reaction (OER) with biomass-derived glycerol electrooxidation. Nonetheless, the synthesis of electrocatalysts for controlling the selectivity towards added-value chemicals at the anode and efficient H2 generation at the cathode remains a critical bottleneck. Herein, we implemented a galvanostatic electroshock synthesis approach to control the reduction kinetics of Au(III) and Pt(IV) to grow ultra-low amount of gold-platinum alloys on a gas diffusion electrode (12-26 µgmetal cmâ2) for glycerol-fed hydroxide anion exchange membrane based electrolyzer. The symmetric GDE-Au100-xPtx||GDE-Au100-xPtx systems showed a notable improvement in electrolyzer performance (GDE-Au64Pt36 = 201 mA cm-2) as compared to monometallic versions (GDE-Au100Pt0 = 18 mA cm-2, GDE-Au0Pt100 = 81 mA cm-2). Chromatography (HPLC) analysis underscores the critical importance of bulk electrolysis methodology (galvanostatic vs potentiostatic) for the efficient conversion of glycerol into high-value-added products. Regarding the electrical energy required to produce 1 kg of H2 for such an electrolyzer fed at the anode with glycerol, our results confirm a drastic decrease by a factor of at least two compared with conventional water electrolysis.
RESUMEN
BACKGROUND: Staphylococcus aureus prosthetic valve endocarditis (SAPIE) is a serious disease. AIMS: Our objective was to study the clinical, echocardiographic and prognostic characteristics of left-sided SAPIE, and to compare these characteristics with those of left-sided non-S. aureus prosthetic infective endocarditis (NSAPIE) (i.e. left-sided prosthetic infective endocarditis caused by another germ). METHODS: This was a retrospective analysis of 35 cases of SAPIE among 247 cases of left-sided prosthetic valve endocarditis hospitalized at two university hospitals (Amiens and Marseille, France). RESULTS: SAPIE accounted for 14.1% of the cases of left-sided prosthetic valve endocarditis. SAPIE complications included heart failure (in 42.8% of cases), acute renal failure (in 51.4%), sepsis (in 51.4%), neurological events (in 31.4%), systemic embolic event (in 34.2%) and abscess (in 60.0%). In-hospital mortality occurred in 48.5% of SAPIE cases compared with 16% of NSAPIE cases. A comparison of the SAPIE and NSAPIE groups showed a significant difference in terms of 4-year survival (31.8±7.3% vs 60.1±4.1%; P=0.001). Severe sepsis was the only prognostic factor associated with in-hospital mortality (odds ratio 5.7; P=0.03) and long-term mortality (odds ratio 3.7; P=0.01) in cases of SAPIE. Sepsis-induced multiple organ dysfunction syndrome was the main cause of in-hospital mortality (70.5%). CONCLUSIONS: SAPIE is a very serious disease, with elevated in-hospital mortality resulting from sepsis-induced multiple organ dysfunction syndrome. Emergency surgery is recommended in these cases, when possible, before the occurrence of complications, especially severe sepsis.
Asunto(s)
Endocarditis Bacteriana/etiología , Prótesis Valvulares Cardíacas/efectos adversos , Infecciones Relacionadas con Prótesis/etiología , Infecciones Estafilocócicas/etiología , Staphylococcus aureus/aislamiento & purificación , Anciano , Ecocardiografía , Endocarditis Bacteriana/diagnóstico , Endocarditis Bacteriana/epidemiología , Femenino , Francia/epidemiología , Prótesis Valvulares Cardíacas/microbiología , Mortalidad Hospitalaria/tendencias , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pronóstico , Infecciones Relacionadas con Prótesis/diagnóstico , Infecciones Relacionadas con Prótesis/epidemiología , Estudios Retrospectivos , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/epidemiologíaRESUMEN
BACKGROUND: Staphylococcus aureus infective endocarditis (SAIE) is a serious and common disease. AIMS: To assess the clinical and echocardiographic characteristics and prognostic factors of left-sided native-valve SAIE, and to compare these characteristics between two periods (1990-2000 vs. 2001-2010). METHODS: This was a retrospective analysis of 162 cases of left-sided native-valve SAIE among 1254 patients hospitalized for infective endocarditis (IE) between 1990 and 2010. RESULTS: SAIE represented 18.1% of all cases of IE and 22.9% of cases of native-valve IE. Complications included heart failure in 44.7% of cases, acute renal failure in 23.3%, sepsis in 28.5%, neurological events in 35.8%, systemic embolic events in 54.9% and in-hospital mortality in 25.3%. Factors associated with in-hospital mortality were heart failure (odds ratio [OR] 2.5; P=0.04) and sepsis (OR 5.3; P=0.001). Long-term 5-year survival was 49.6±4.9%. Factors associated with long-term mortality were heart failure (OR 1.7; P=0.032), sepsis (OR 3; P=0.0001) and delayed surgery (OR 0.43; P=0.003). Comparison of the two periods revealed a significant increase in bivalvular involvement, valvular incompetence and acute renal failure from 2001 to 2010. No significant difference was observed in terms of in-hospital mortality rates (28.1% vs. 23.5%; P=0.58) and long-term 5-year survival (45.0±6.6% vs. 57.1±6.4%; P=0.33). CONCLUSION: Mortality as a result of left-sided native-valve SAIE remains high. Factors associated with in-hospital mortality are heart failure and sepsis. Factors associated with long-term mortality are heart failure, sepsis and delayed surgery. Despite progress in surgical techniques, in-hospital mortality and long-term mortality have not decreased significantly between the two periods.