Caracterización termodinámica de mezclas acuosas de aminas

El importante crecimiento económico en nuestra sociedad desde mediados del siglo pasado ha estado asociado a un notable aumento del consumo energético, basado en un modelo energético centrado en el uso de combustibles fósiles , lo que ha conllevado un aumento de las emisiones de gases de efecto invernadero. La problemática generada como consecuencia del aumento del CO2, principal gas causante del efecto invernadero, ha obligado a tomar iniciativas que traten de reducir o evitar que el CO2 de las emisiones, principalmente de la industria alcance la atmósfera. Los sistemas de absorción química basados en disoluciones acuosas de aminas han sido utilizados durante años, especialmente para la eliminación de gases ácidos del gas natural. En la captura de CO2 pueden utilizarse aminas primarias, secundarias y terciarias, y cada una tiene sus ventajas y desventajas. Propiedades como la densidad, viscosidad y capacidad calorífica de dichas mezclas intervienen por ejemplo, en el modelado de la tasa de transferencia de masa, dimensionamiento de tuberías y el diseño de bombas e intercambiadores de calor. Es por esta razón que conocer dichas propiedades termofísicas es de vital importancia para que el proceso de captura sea llevado de forma eficiente. Conscientes de esta problemática el Grupo de Investigación de Excelencia TERMOCAL (Laboratorio de Metrología y Calibración de la Universidad de Valladolid) y con la financiación de la Junta de Castilla y León desarrollan el proyecto: Biogás renovable y procesos de captura del CO2 de combustión asociados como base a la sostenibilidad energética ambiental: Investigación Termodinámica Experimental. Dicho proyecto en el cual se enmarca este trabajo tiene entre las sus líneas de desarrollo la investigación de propiedades termodinámicas de las aminas involucradas en el proceso de captura de CO2 proveniente de gases de postcombustión.Departamento de Ingeniería Energética y FluidomecánicaDoctorado en Investigación en Ingeniería Termodinámica de Fluido

Viscosity and density measurements of aqueous amines at high pressures: MDEA-water and MEA-water mixtures for CO2 capture

Producción CientíficaViscosity and density are thermophysical properties crucial to characterizing any kind of fluid such as aqueous amines. These blends are becoming more and more relevant for their CO2 capture potential, such that having accurate viscosity and density measurements would prove useful. Densities and viscosities of these mixtures at atmospheric pressure may be found in the literature although it is more difficult to find values at high pressures, these potentially proving interesting when seeking to provide a full description of these fluids. Viscosity and density measurements at high pressures (up to 120 MPa) and at temperatures between 293.15 and 353.15 K of MDEA + water and MEA + water mixtures (both from 10 % to 40 % amine mass fraction) are presented in this work. Density measurements were performed with an Anton Paar DMA HPM densimeter with an expanded uncertainty (k = 2) less than ± 0.7 kg·m-3. A falling body technique was used to measure viscosities at high pressures due to its sturdiness in terms of corrosion. Details of this latter equipment are presented, including calibration using n-dodecane and uncertainty calculations, which give a relative expanded uncertainty (k = 2) of less than ± 2.4 % for the highest viscosity and ± 2.9 % for the lowest.2018-03-15Education Ministry (Spanish Government) through a FPU scholarshipProject for European Latin American Cooperation and Exchange (PEACE)Regional Government of Castilla y León through the Project VA295U1

Density and viscosity measurements of aqueous amines at high pressures: DEA-water, DMAE-water and TEA-water mixtures

Producción CientíficaIn this paper, density and viscosity measurements at pressures up to 140 MPa are presented in a temperatura range from (293.15 to 393.15) K for diethanolamine (DEA) + water, triethanolamine (TEA) + wáter and 2-dimethylaminoethanol (DMAE) + water in amine weight concentrations from 10% to 40%. Densities were measured using a vibrating tube densimeter (Anton Paar DMA HPM) with an expanded uncertainty (k = 2) less than ±0.7 kg m 3. Viscosity measurements were obtained using a falling body viscometer which was calibrated with water and dodecane. The viscosity expanded uncertainty (k = 2) ranges from ±2.5% for the highest viscosity to ±3.2% for the lowest.2019/05/05Regional Government of Castilla y León through the Project VA295U1

Density and viscosity measurements of (piperazine + water) and (piperazine + 2-dimethylaminoethanol + water) at high pressures

Producción CientíficaThe purpose of this paper is broadening the understanding of amine solution behaviour through the experimental measurements of density (up to 140 MPa) and viscosity (up to 100 MPa) in a temperature range from (293.15 to 393.15) K. The two selected blends are Piperazine (PZ) + Water (10% amine weight concentration) and Piperazine (PZ) + 2-Dimethylaminoethanol (DMAE) + Water (10% and 30% amine weight concentration, respectively). Densities were measured using a vibrating tube densimeter (Anton Paar DMA HPM) with an expanded uncertainty (k = 2) less than 0.7 kg·m-3. Viscosities were obtained using a falling body viscometer which was calibrated with water and dodecane. The viscosity expanded uncertainty (k = 2) ranges from 2.5% for the highest viscosity to 3.2% for the lowest one. Experimental data were fitted to modified Tamman-Tait equation for densities and modified VFT model for viscosities, obtaining good results for both equations.Junta de Castilla y León VA280P18Ministerio de Economía, Industria y Competitividad RTI2018-097456-B-I0

Comprensión conceptual de estadística y métodos de decisión utilizando herramientas de gamificación para la adquisición de competencias en los grados de ciencias económicas y empresariales

El objetivo general del proyecto es mejorar la motivación y la actitud de los alumnos de los grados de ciencias sociales hacia las materias cuantitativas, así como su participación activa en el proceso de enseñanza-aprendizaje, individual y en grupo, con la finalidad última de incrementar su nivel de competencias y rendimiento

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

Effectiveness of Fosfomycin for the Treatment of Multidrug-Resistant Escherichia coli Bacteremic Urinary Tract Infections

IMPORTANCE The consumption of broad-spectrum drugs has increased as a consequence of the spread of multidrug-resistant (MDR) Escherichia coli. Finding alternatives for these infections is critical, for which some neglected drugs may be an option. OBJECTIVE To determine whether fosfomycin is noninferior to ceftriaxone or meropenem in the targeted treatment of bacteremic urinary tract infections (bUTIs) due to MDR E coli. DESIGN, SETTING, AND PARTICIPANTS This multicenter, randomized, pragmatic, open clinical trial was conducted at 22 Spanish hospitals from June 2014 to December 2018. Eligible participants were adult patients with bacteremic urinary tract infections due to MDR E coli; 161 of 1578 screened patients were randomized and followed up for 60 days. Data were analyzed in May 2021. INTERVENTIONS Patients were randomized 1 to 1 to receive intravenous fosfomycin disodium at 4 g every 6 hours (70 participants) or a comparator (ceftriaxone or meropenem if resistant; 73 participants) with the option to switch to oral fosfomycin trometamol for the fosfomycin group or an active oral drug or pa renteral ertapenem for the comparator group after 4 days. MAIN OUTCOMES AND MEASURES The primary outcome was clinical and microbiological cure (CMC) 5 to 7 days after finalization of treatment; a noninferiority margin of 7% was considered. RESULTS Among 143 patients in the modified intention-to-treat population (median [IQR] age, 72 [62-81] years; 73 [51.0%] women), 48 of 70 patients (68.6%) treated with fosfomycin and 57 of 73 patients (78.1%) treated with comparators reached CMC (risk difference, -9.4 percentage points; 1-sided 95% CI, -21.5 to infinity percentage points; P = .10). While clinical or microbiological failure occurred among 10 patients (14.3%) treated with fosfomycin and 14 patients (19.7%) treated with comparators (risk difference, -5.4 percentage points; 1-sided 95% CI. -infinity to 4.9; percentage points; P = .19), an increased rate of adverse event-related discontinuations occurred with fosfomycin vs comparators (6 discontinuations [8.5%] vs 0 discontinuations; P = .006). In an exploratory analysis among a subset of 38 patients who underwent rectal colonization studies, patients treated with fosfomycin acquired a new ceftriaxone-resistant or meropenem-resistant gram-negative bacteria at a decreased rate compared with patients treated with comparators (0 of 21 patients vs 4 of 17 patients [23.5%]; 1-sided P = .01). CONCLUSIONS AND RELEVANCE This study found that fosfomycin did not demonstrate noninferiority to comparators as targeted treatment of bUTI from MDR E coli; this was due to an increased rate of adverse event-related discontinuations. This finding suggests that fosfomycin may be considered for selected patients with these infections

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 17

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 17 de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada, de acceso abierto a todas las áreas del conocimiento, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico. Con esta colección, se aspira contribuir con el cultivo, la comprensión, la recopilación y la apropiación social del conocimiento en cuanto a patrimonio intangible de la humanidad, con el propósito de hacer aportes con la transformación de las relaciones socioculturales que sustentan la construcción social de los saberes y su reconocimiento como bien público

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p &lt; 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics