Caracterización y propiedades catalíticas de clústeres cuánticos subnanométricos

El objetivo general de esta tesis es establecer la relación que existe entre la estructura y propiedades de clústeres metálicos subnamométricos y su actividad electrocatalítica en reacciones químicas de interés tecnológico. En este contexto se incluyen la caracterización de las propiedades fisicoquímicas de dichos clústeres, el diseño de nuevos protocolos para su purificación y la determinación de su actividad catalítica en reacciones seleccionadas por su interés en áreas de importancia actuales, como biomedicina y obtención energía

An Empirical Comparative Study of Prediction Methods for Estimating Multipath Due to Signal Scattering from Wind Turbines on Digital TV Services

[EN] Several authors have theoretically studied the effect of wind turbines on the propagation of electromagnetic waves in the UHF band. The International Telecommunication Union also proposes a simplified model to evaluate the impact caused to television reception by a wind turbine in the Recommendation ITU-R BT.805. This paper presents an empirical study of the above mentioned prediction methods for estimating signal scattering from wind turbines in the UHF band, comparing predicted values with empirical data obtained from a DTV measurement campaign carried out in Spain. As signal scattering is independent of the transmission standard or modulation, the results are applicable to any broadcasting and wireless communication signals in the UHF band that may be affected by the multipath interference caused by a wind farm.This work was supported in part by the Basque Government under both the SAIOTEK program and the program for the training of the researcher staff (BFI08.230)

In-Hospital Post-Operative Infection after Heart Transplantation: Epidemiology, Clinical Management, and Outcome

Observational study[Abstract] Background: Infection is a major cause of morbidity and mortality after heart transplantation (HT). Little information about its importance in the immediate post-operative period is available. The aim of this study was to analyze the characteristics, incidence, and outcomes of in-hospital post-operative infections after HT. Methods: We conducted an observational, single-center study based on 677 adults who underwent HT from 1991 to 2015 and who survived the surgical intervention. In-hospital post-operative infections were identified retrospectively according to the medical finding in the clinical records. Results: Over a mean hospital stay of 24.5 days, 239 patients (35.3%) developed 348 episodes of infection (2 episodes per 100 patient-days). The most common sources of infection were those related to invasive procedures (respiratory infections, 115 [33%]; urinary tract infections, 47 [13.5%]; bacteremia, 42 [12.1%]; surgical site infections, 25 [7.2%]), in addition to abdominal focus (33, 9.5%). Enterobacteriaceae (76, 21.8%) and gram-positive cocci (58, 16.7%) were the predominant germs, although opportunistic infections were not infrequent (69, 19.8%). Ninety-five septic episodes were detected with a mean Sequential Organ Failure Assessment Score of 9.5 ± 5.3 points, with hemodynamic failure being the most severe organ dysfunction and renal dysfunction the most frequent one. Management included broad-spectrum antibiotics in 48.8% of episodes and surgical management in 13.8%. The overall antimicrobial success rate was 96.3%. Higher in-hospital mortality was observed among infected patients (15.1% vs. 10.3%), but this difference was not statistically significant (p = 0.067). The one-year survival and events were not different between patients suffering from a post-operative infection and those who did not. Conclusions: In-hospital infections were frequent in the post-operative period after HT and were associated with a poor short-term outcome. Patients who survived sepsis had a similar one-year morbidity and mortality compared with patients who did not develop an infection

In-hospital postoperative infection after heart transplantation: risk factors and development of a novel predictive score

[Abstract] Introduction: Infection is one of the most significant complications following heart transplantation (HT). The aim of this study was to identify specific risk factors for early postoperative infections in HT recipients, and to develop a multivariable predictive model to identify HT recipients at high risk. Methods: A single-center, observational, and retrospective study was conducted. The dependent variable was in-hospital postoperative infection. We examined demographic and epidemiological data from donors and recipients, surgical features, and adverse postoperative events as independent variables. Backwards, stepwise multivariable logistic regression with a P-value < 0.05 was used to identify clinical factors independently associated with the risk of in-hospital postoperative infections following HT. Results: Six hundred seventy-seven patients were included in this study. During the in-hospital postoperative period, 348 episodes of infection were diagnosed in 239 (35.9%) patients. Seven variables were identified as independent clinical predictors of early postoperative infection after HT: history of diabetes mellitus, previous sternotomy, preoperative mechanical ventilation, primary graft failure, major surgical bleeding, use of mycophenolate mofetil, and use of itraconazole. Based on the results of multivariable models, we constructed a 7-variable (8-point) score to predict the risk of in-hospital postoperative infection in HT recipients, which showed a reasonable ability to predict the risk of in-hospital postoperative infection in this population. Prospective external validation of this new score is warranted to confirm its clinical applicability. Conclusions: In-hospital postoperative infection is a common complication after HT, affecting 35% of patients who underwent this procedure at our institution. Diabetes mellitus, previous sternotomy, preoperative mechanical ventilation, primary graft failure, major surgical bleeding, use of mycophenolate mofetil, and itraconazole were all independent clinical predictors of early postoperative infection after HT

Silver clusters of five atoms as highly selective antitumoral agents through irreversible oxidation of thiols

Low atomicity clusters present properties dependent on the size, due to the quantum confinement, with well-defined electronic structures and high stability. Here it is shown that Ag5 clusters catalyze the complete oxidation of sulfur to S+6. Ag5 catalytic activity increases with different oxidant species in the order O2 ≪ H2O2 < OH•. Selective oxidation of thiols on the cysteine residues of glutathione and thioredoxin is the primary mechanism human cells have to maintain redox homeostasis. Contingent upon oxidant concentration, Ag5 catalyzes the irreversible oxidation of glutathione and thioredoxin, triggering apoptosis. Modification of the intracellular environment to a more oxidized state to mimic conditions within cancer cells through the expression of an activated oncogene (HRASG12V) or through ARID1A mutation, sensitizes cells to Ag5 mediated apoptosis. While cancers evolve to evade treatments designed to target pathways or genetic mutations that drive them, they cannot evade a treatment that takes advantage of aberrant redox homeostasis, which is essential for tumor progression and metastasis. Ag5 has antitumor activity in mice with orthotopic lung tumors reducing primary tumor size, and the burden of affected lymphatic nodes. The findings suggest the unique intracellular redox chemistry of Ag5 may lead to new redox-based approaches to cancer therapyThis research was partially supported by 1) “la Caixa” Foundation, Ref. LCF/PR/PR12/11070003 to F.D. and M.A.L.Q.; 2) Ministerio de Ciencia, Innovación y Universidades (MAT2017-89678-R, AEI/FEDER, UE) to F.D. and A.V.; 3) the Consellería de Educación (Xunta de Galicia), Grants No. Grupos Ref. Comp. ED431C 2017/22, ED431C 2019/13 and AEMAT-ED431E2018/08 to M.A.L.Q.; and ED431C 2019/13 to A.V. This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme (Bac-To-Fuel) under Grant Agreement No. 825999 (M.A.L.Q.). J.C.H. acknowledge financial support from European Union's Horizon 2020 research and innovation programme under grant agreement no. 823717-ESTEEM3, and the MICIIN (projects PID2019-107578GA-100 and PID-110018GA-100). J.M.D, L.J.G., and F.G.R. thank to the ANPCyT (PICT 2015-2285 and 2017-3944), UNLP (Project 11/X790) and the partial support by the Laboratório Nacional de Luz Síncrotron (LNLS, Brazil) under proposal SXS-20180280. G.B. acknowledges the CINECA Award N. IsC51, year 2017, under the ISCRA initiative, for the availability of high-performance computing resources and support. D.B. expresses gratitude for a postdoctoral grant from Xunta de Galicia, Spain (POS-A/2013/018). B.D. expresses gratitude for a predoctoral grant from MICINN, Spain (BES-2016-076765). F.D. and A.V. also acknowledged Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2019-2022 ref ED431G 2019/02) and the European Union (European Regional Development Fund – ERDF). Work in M.P.M.'s lab was supported by the Medical Research Council UK (MC_U105663142). T.G.C. gratefully acknowledges the technical assistance of María José Otero-Fraga (FIDIS)S

Understanding the metal distribution in core-shell nanoparticles prepared in micellar media

The factors that govern the reaction rate of Au/Pt bimetallic nanoparticles prepared in microemulsions by a one-pot method are examined in the light of a simulation model. Kinetic analysis proves that the intermicellar exchange has a strong effect on the reaction rates of the metal precursors. Relating to Au, reaction rate is controlled by the intermicellar exchange rate whenever concentration is high enough. With respect to Pt, the combination of a slower reduction rate and the confinement of the reactants inside micelles gives rise to an increase of local Pt salt concentration. Two main consequences must be emphasized: On one hand, Pt reduction may continue independently whether or not a new intermicellar exchange takes place. On the other hand, the accumulation of Pt reactants accelerates the reaction. As the reactant accumulation is larger when the exchange rate is faster, the resulting Pt rate increases. This results in a minor difference in the reduction rate of both metals. This difference is reflected in the metal distribution of the bimetallic nanoparticle, which shows a greater degree of mixture as the intermicellar exchange rate is faster.Works were supported by Ministerio de Ciencia e Innovación, Spain (MAT2012-36754-C02-01), and Xunta de Galicia (GRC2013-044, FEDER Funds, REDES 2014/019)S