Impact of Oxy-Fuel Conditions on Elemental Mercury Re-Emission in Wet Flue Gas Desulfurization Systems.

This study evaluates some of the variables that may influence mercury retention in wet flue gas desulfurization (WFGD) plants, focusing on oxy-coal combustion processes and differences when compared with atmospheres enriched in N2. The main drawback of using WFGD for mercury capture is the possibility of unwanted reduction of dissolved Hg(2+), leading to the re-emission of insoluble elemental mercury (Hg(0)), which decreases efficiency. To acquire a better understanding of the mercury re-emission reactions in WFGD systems, this work analyses different variables that influence the behavior of mercury in slurries obtained from two limestones, under an oxy-combustion atmosphere. The O2 supplied to the reactor, the influence of the pH, the concentration of mercury in the gas phase, and the enhancement of mercury in the slurry were the variables considered. The study was performed at laboratory scale, where possible reactions between the components in the scrubber can be individually evaluated. It was found that in an oxy-combustion atmosphere (mostly CO2), the re-emission of Hg(0) is lower than under a N2-enriched atmosphere, and the mercury is mainly retained as Hg(2+) in the liquid phase.

Effect of oxy-combustion flue gas on mercury oxidation.

This study evaluates the effect of the gases present in a typical oxy-coal combustion atmosphere on mercury speciation and compares it with the mercury speciation produced in conventional air combustion atmospheres. The work was performed at laboratory scale at 150 °C. It was found that the minor constituents (SO2, NOx, and HCl) significantly modify the percentages of Hg(2+) in the gas. The influence of these species on mercury oxidation was demostrated when they were tested individually and also when they were blended in different gas compositions, although the effect was different to the sum of their individual effects. Of the minor constituents, NOx were the main species involved in oxidation of mercury. Moreover, it was found that a large concentration of H2O vapor also plays an important role in mercury oxidation. Around 50% of the total mercury was oxidized in atmospheres with H2O vapor concentrations typical of oxy-combustion conditions. When the atmospheres have similar concentrations of SO2, NO, NO2, HCl, and H2O, the proportion of Hg(0)/Hg(2+) is similar regardless of whether CO2 (oxy-fuel combustion) or N2 (air combustion) are the main components of the gas.

The application of regenerable sorbents for mercury capture in gas phase.

Mercury is a well-known toxic element, and flue gas streams emitted from coal-fired utilities are one of the largest anthropogenic sources of this element. This study briefly reviews the proposed technologies for reducing mercury emissions from coal combustion, focusing on an emerging process which involves the use of regenerable sorbents and especially those loaded with noble metals. Among the mercury species formed during coal combustion, elemental mercury is the most difficult to remove from the flue gases due to its low reactivity and insolubility in water. The widespread interest in using regenerable sorbents with metals is due to their ability to retain elemental mercury. With this technology, not only can efficiencies of 100 % be reached in the retention of elemental mercury but also a way to avoid the generation of new wastes loaded with mercury. This study considers the main aspects that must be taken into account when developing effective regenerable sorbents for mercury capture, with special attention to sorbents containing noble metals. The characteristics of this process are compared with those of other processes in a more advanced state of development.

[Ability to predict hospitalization and resource requirements: comparison of the 3M Triage Assistance system and the combined Spanish Triage System and Andorran Triage Model]. / Comparación de la capacidad de predecir hospitalización y consumo de recursos del Programa de Ayuda al Triaje 3M TAS y el Sistema Español de Triaje ­ Model Andorrà de Triaje (SET-MAT).

OBJECTIVES: To determine the validity of 2 triage systems: the 3M Triage Assistance System (3M-TAS) and the combined Spanish Triage System and Andorran Triage Model (SET-MAT) for predicting hospitalization and use of emergency resources; and to estimate the level of agreement between them. MATERIAL AND METHODS: Prospective observational study of consecutive cohorts classified with the studied triage systems in the emergency department (ED) of a secondary-level hospital between March 24 and April 30, 2014. Patients were classified blindly and simultaneously between 9 AM and 10 PM by a clinical nurse using the SET-MAT program and a researcher nurse using the 3M-TAS software. We collected patients' demographic details and assigned triage level, laboratory and imaging tests ordered, specialist consultations requested in the ED, length of stay until discharge from the department, and destination on discharge. Outcome variables were hospitalization and use of at least 1 resource in the ED. RESULTS: A total of 3379 emergencies were included. The conventionally weighted κ statistic for agreement between the 2 triage systems was 0.26, but the triage-weighted κ was 0.17. The 3M-TAS software was better able to predict hospitalization than the SET-MAT (P<.001); however, the 2 systems, predictions of resource usage were similar (P=.111). CONCLUSION: Agreement between the 3M-TAS and SET-MAT triage systems was poor, although they predicted similar use of resources in the ED. The 3M-TAS was better able to predict hospital admission than the SET-MAT.

OBJETIVO: Determinar el grado de concordancia y validez, a la hora de predecir la hospitalización y el consumo de recursos en urgencias, del Sistema de Ayuda al Triaje 3M TAS y su comparación con el Sistema Español de Triaje - Model Andorrà de Triatge (SET-MAT). METODO: Estudio observacional de cohortes prospectivo que incluyó de forma consecutiva los episodios filiados de 9 a 22 horas en un servicio de urgencias de un hospital secundario entre el 24 de marzo y el 30 de abril de 2014. Los pacientes se clasificaron de forma enmascarada y simultánea por una enfermera asistencial mediante el programa de ayuda al triaje SET-MAT y por una enfermera de investigación mediante el 3M TAS. Se recogieron variables demográficas, de gravedad, las pruebas de laboratorio, radiológicas e interconsulta a especialistas realizadas en urgencias, el tiempo de estancia y el destino final. Las variables de resultado fueron la hospitalización y el consumo de al menos un recurso en urgencias. RESULTADOS: Se incluyeron 3.379 episodios. El índice de concordancia mediante el kappa ponderado cuadrático entre los sistemas de triaje fue de 0,26 y el kappa triaje de 0,17. El sistema 3M TAS presentó una mayor capacidad predictiva de hospitalización en comparación con el SET-MAT (p < 0,001), no siendo así en lo que respecta al consumo de recursos en urgencias (p = 0,111). CONCLUSIONES: La concordancia entre los sistemas de triaje 3M TAS y SET-MAT fue baja, sin diferencias para predecir el consumo de recursos en urgencias, aunque el 3M TAS predijo mejor ingreso hospitalario que el SET-MAT.

Fibrodisplasia Osificante Progresiva: Reporte De Casos / Progressive Ossifying Fibrodysplasia: Case Reports

Resumen Presentamos 2 casos con diagnóstico de fibrodisplasia osificante progresiva (FOP) en el Hospital de Especialidades "Eugenio Espejo". La FOP es una enfermedad rara de transmisión autosómica dominante. En la mayoría de pacientes se debe a una mutación nueva en familias no afectadas previamente. Se caracteriza por osificación heterotópica progresiva del tejido conectivo, aponeurosis, fascia, ligamentos, tendones y músculo esquelético. El diagnóstico precoz mejora el pronóstico y la calidad de vida.

Abstract. We report two cases with diagnosis of progressive ossifying fibrodysplasia (FOP) at the "Eugenio Espejo" Specialty Hospital. The FOP is a rare autosomal dominant disease. In most of the patients is due to a mutation in families not affected previously. It's characterized by progressive ossification of connective tissue, aponeurosis, fascia, ligaments, tendons and skeletal muscle. The early diagnosis improves the prognosis and the quality of life.

Mitral valve repair in a patient with mitral regurgitation and osteogenesis imperfecta tarda.

We present the case of a 62-year-old female with a diagnosis of osteogenesis imperfecta and mitral valve regurgitation. The patient underwent a mitral valve repair without complications. We describe the case and our surgical technique.

Spontaneous closure of pseudoaneurysm after transapical aortic valve implantation.

Transcatheter aortic valve implantation by an apical approach has been developed as an alternative to conventional aortic valve replacement. Complications with these relatively new procedures are being reported. We report a case of transapical transcatheter aortic valve implantation, in which a pseudoaneurysm at the apex of the left ventricle as a complication of the procedure developed in the patient and was treated without surgery. The defect spontaneously closed.

Video-assisted cardioscopy for removal of primary left ventricular fibroma.

We present a case of a cardiac fibroma affecting the base of the anterior papillary muscle resected under cardiopulmonary bypass with cardioscopy and video-assisted thoracic surgery (VATS) instruments through the mitral valve. The surgical approach and instrumentation of previous case reports are reviewed.

Mitroaortic valve replacement after aortic transapical approach failure in a patient with essential thrombocytosis.

There is a lack of published information about intraoperative and postoperative course of cardiac surgery in patients with essential thrombocytosis using cardiopulmonary bypass. Both risks of intraoperative thrombosis of extracorporeal conduits or uncontrolled postoperative bleeding are present, but its incidence and treatment are not well known. Here, we present a rare case of a patient with essential thrombocytosis, moderate mitral regurgitation and severe aortic stenosis who had a transapical aortic valve implantation with short-term severe periprosthetic regurgitation, who needed a mitroaortic replacement on cardiopulmonary bypass with no complications.