Ab initio studies of ethanol dehydrogenation at binary AuPd nanocatalysts

Producción CientíficaDensity Functional Theory (DFT) simulations have been performed to study ethanol anaerobic oxidation at 10-atom binary gold–palladium clusters with varying compositions, ranging from 0% to 100% gold content. For each case, we have studied the loss of two hydrogen atoms, the desorption of acetaldehyde, and recombination of hydrogen into gas-phase H2. The results show that alloying produces sizable changes in the reaction barriers and in the stability of the intermediate species, which are related to different intrinsic reactivities of palladium and gold.Ministerio de Economía, Industria y Competitividad (Project MAT2014-54378-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. A050U14

Au-Cu/SBA(Ti) based catalysts for photocatalytic applications

Comunicación a congresoIn this work, it has been synthesized several Au and Au-Cu alloy photocatalysts supported on two different mesoporous supports: a non-commercial SBA-15 and a post-synthesis TiO2 modified SBA-15 (TiSBA-15), with which a high dispersion of TiO2 species have been achieved maintaining the SBA-15 structure. In addition, it has also been obtained highly dispersed Au nanoparticles confined in SBA-15 pore channels, as can be observed in Figure 1. The photocatalysts have been preliminary tested in the preferential CO oxidation in a H2-rich stream (CO-PROX) at room temperature and atmospheric pressure under simulated solar light irradiation. In spite of the very low gold and copper loading (1.5 wt% and 0.5wt% respectively), the catalysts resulted active and selective in the low temperature photo-CO-PROX.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

Identificando actividades de matematización horizontal y vertical en un proceso de clasificación

La noción de matematización progresiva se expresa través de una secuencia generada por dos tipos de actividad matemática relacionadas reflexivamente: la matematización horizontal y la vertical (Treffers, 1987). Aunque, frecuentemente, la matematización horizontal se describe a través de la transformación de una situación problemática en un problema matemático propiamente dicho, en nuestro trabajo utilizaremos este concepto en un sentido más amplio que nos permitirá incluir situaciones de partida que sean de naturaleza ya matemática (Rasmussen, Zandieh, King & Teppo, 2005). Las actividades que pueden ser identificadas cuando se produce la matematización horizontal y la matematización vertical han sido descritas por Üzel y Mert Uyangör (2006)

Early evidence of bone marrow dysfunction in children with indeterminate fulminant hepatic failure who ultimately develop aplastic anemia.

In children, aplastic anemia (AA) is a common complication associated with fulminant hepatic failure (FHF). The objective of this study was to determine whether specific pretransplantation clinical and laboratory characteristics can be used to distinguish between patients with FHF who are at higher risk of developing AA. We performed a retrospective case-control study to evaluate the clinical and laboratory characteristics of those patients who presented with evidence of FHF and eventually developed aplastic anemia. We identified nine patients with AA, and all had the indeterminate form of FHF and underwent liver transplantation (LTx). The AA patients were compared with a control group of 47 patients with indeterminate FHF that underwent transplantation and did not develop AA. We found that males were over-represented in the group of patients that developed AA (p = 0.01). Furthermore, during the pretransplant period, the AA group had a significantly lower white count (p = 0.005), absolute lymphocyte count (p = 0.004), and platelet count (p = 0.019) when compared with controls. We conclude that evidence of early bone marrow dysfunction is apparent before liver transplantation and the development of AA in a subset of patients with the indeterminate form of FHF

Predictors of clinical outcome in children undergoing orthotopic liver transplantation for acute and chronic liver disease.

The current United Network for Organ Sharing (UNOS) policy is to allocate liver grafts to pediatric patients with chronic liver disease based on the pediatric end-stage liver disease (PELD) scoring system, while children with fulminant hepatic failure may be urgently listed as Status 1a. The objective of this study was to identify pre-transplant variables that influence patient and graft survival in those children undergoing LTx (liver transplantion) for FHF (fulminant hepatic failure) compared to those patients transplanted for extrahepatic biliary atresia (EHBA), a chronic form of liver disease. The UNOS Liver Transplant Registry was examined for pediatric liver transplants performed for FHF and EHBA from 1987 to 2002. Variables that influenced patient and graft survival were assessed using univariate and multivariate analysis. Kaplan-Meier analysis of FHF and EHBA groups revealed that 5 year patient and graft survival were both significantly worse (P < 0.0001) in those patients who underwent transplantation for FHF. Multivariate analysis of 29 variables subsequently revealed distinct sets of factors that influenced patient and graft survival for both FHF and EHBA. These results confirm that separate prioritizing systems for LTx are needed for children with chronic liver disease and FHF; additionally, our findings illustrate that there are unique sets of variables which predict survival following LTx for these two groups