Isotope Labelling for Reaction Mechanism Analysis in DBD Plasma Processes

Dielectric barrier discharge (DBD) plasmas and plasma catalysis are becoming an alternative procedure to activate various gas phase reactions. A low-temperature and normal operating pressure are the main advantages of these processes, but a limited energy efficiency and little selectivity control hinder their practical implementation. In this work, we propose the use of isotope labelling to retrieve information about the intermediate reactions that may intervene during the DBD processes contributing to a decrease in their energy efficiency. The results are shown for the wet reforming reaction of methane, using D2O instead of H2O as reactant, and for the ammonia synthesis, using NH3/D2/N2 mixtures. In the two cases, it was found that a significant amount of outlet gas molecules, either reactants or products, have deuterium in their structure (e.g., HD for hydrogen, CDxHy for methane, or NDxHy for ammonia). From the analysis of the evolution of the labelled molecules as a function of power, useful information has been obtained about the exchange events of H by D atoms (or vice versa) between the plasma intermediate species. An evaluation of the number of these events revealed a significant progression with the plasma power, a tendency that is recognized to be detrimental for the energy efficiency of reactant to product transformation. The labelling technique is proposed as a useful approach for the analysis of plasma reaction mechanisms

Diseño y Simulación de Sistemas de Colas con e-Motions

Este trabajo propone el uso de un lenguaje de dominio espec í co de alto nivel y ejecutable para analizar el rendimiento de un sistema de colas implementado mediante diferentes estrategias. En concreto se utiliza un enfoque basado en el Desarrollo del Software Dirigido por Modelos (DSDM) para modelar el comportamiento del sistema de facturación de una aerolínea y obtener datos relativos a su rendimiento en cuanto a costes y tiempos de espera, dependiendo de la estrategia utilizada. Para lograr ese propósito se utiliza e-Motions, una herramienta que permite al usuario modelar y analizar sistemas en tiempo real de forma grá ca

Using alignment with corporate strategy for the selection of a project portfolio based on ANP

Trabajo presentado al 14th International Symposium on the Analytic Hierarchy Process celebrado en Washington (US) del 29 de junio al 2 de julio de 2014.In this paper a new approach to prioritize project portfolio in an efficient and reliable way is presented. The research methodology is based on a combination of a synthesis of the literature across the diverse fields of project management, project alignment, multicriteria decision methods and a parallel analysis of an industrial case study. The paper introduces a rigorous methodology with acceptable complexity which seeks to assist managers of the National Electricity Corporation of Venezuela (Corpoelec) in their yearly resources' assignment on their projects portfolio. The aim being to determine the degree of alignment of each project to corporate strategy based on the judgments of a group of experts on the expected contribution of the projects to the business strategic objectives. The model presented can be used both as a descriptive and a prescriptive model. The approach presented uses project prioritization based on the multi-criteria decisionmaking technique called Analytic Network Process. Thus the corporate strategic objectives will be used as prioritization criteria to obtain the Relative Alignment Index (RAI).Peer Reviewe

Análisis y distribución de hidrocarburos policíclicos aromáticos (PAH's) en suelos y aguas de escombreras en Puertollano (Ciudad Real)

The aim of this study was to examine if the soils and waters of Puertollano area are affected by pollution of polycyclic aromatic hydrocarbons (PAHs) and their quantification. The results show that PAHs concentrations are higher in all samples than the reference levels gathered in the Spanish legislation. The possible actions for the coal waste remediation (re-wash of waste dumps, photodegradation and biorremediation) seems to be unviable in this case because of the large volume of materials affected, the slowness of these processes, and the geomorphological characteristics of the carboniferous Puertollano basin. During the spatial regional planning, maps showing the concentration of PAHs should be made to adapt the soil for its corresponding use. It is proposed to consider as contaminants more PAHs, such as naftalene or fluorantene in waters, and phenanthrene and benzo[ghi] perilene in soils

Stochastic green functions in dissipative and non dissipative closed chaotic devices

In this communication we will introduce a new set of Green Functions for closed cavities. Closed cavities are, in general, chaotic, which implies that tiny changes in the configuration (among others, wave frequency, small geometry perturbations, permittivity or permeability alterations due to temperature or pressure fluctuations) cause large electromagnetic field fluctuations. Stochastic models are the most suitable way for addressing this chaotic behaviour. We demonstrate that the Green functions in chaotic environments can be modelled by a random variable (Stochastic Green Function) that can be obtained in closed forms for non dissipative and low dissipative cavities. This closed form corresponds to alphastable distributions whose parameters depends mainly of frequency and distance (between source and observation) and in a lesser extent of volume of the cavity and are independent of the shape of the cavity

Haemoglobin interference and increased sensitivity of fluorimetric assays for quantification of low-parasitaemia Plasmodium infected erythrocytes

<p>Abstract</p> <p>Background</p> <p>Improvements on malarial diagnostic methods are currently needed for the correct detection in low-density <it>Plasmodium falciparum </it>infections. Microfluorimetric DNA-based assays have been previously used for evaluation of anti-malarial drug efficacy on <it>Plasmodium </it>infected erythrocytes. Several factors affecting the sensitivity of these methods have been evaluated, and tested for the detection and quantification of the parasite in low parasitaemia conditions.</p> <p>Methods</p> <p>Parasitaemia was assessed by measuring SYBRGreen I^®(SGI) and PicoGreen^®(PG) fluorescence of <it>P. falciparum </it>Dd2 cultures on human red blood cells. Different modifications of standard methods were tested to improve the detection sensitivity. Calculation of IC₅₀for chloroquine was used to validate the method.</p> <p>Results</p> <p>Removal of haemoglobin from infected red-blood cells culture (IRBC) increased considerably the fluorescent signal obtained from both SGI and PG. Detergents used for cell lysis also showed to have an effect on the fluorescent signal. Upon depletion of haemoglobin and detergents the fluorescence emission of SGI and PG increased, respectively, 10- and 60-fold, extending notably the dynamic range of the assay. Under these conditions, a 20-fold higher PG vs. SGI fluorescent signal was observed. The estimated limits of detection and quantification for the PG haemoglobin/detergent-depleted method were 0.2% and 0.7% parasitaemia, respectively, which allow the detection of ~10 parasites per microliter. The method was validated on whole blood-infected samples, displaying similar results as those obtained using IRBC. Removal of white-blood cells prior to the assay allowed to increase the accuracy of the measurement, by reducing the relative uncertainty at the limit of detection from 0.5 to 0.1.</p> <p>Conclusion</p> <p>The use of PG microassays on detergent-free, haemoglobin-depleted samples appears as the best choice both for the detection of <it>Plasmodium </it>in low-density infections and anti-malarial drugs tests.</p

Parasitostatic effect of maslinic acid. II. Survival increase and immune protection in lethal Plasmodium yoelii-infected mice

<p>Abstract</p> <p>Background</p> <p>The anti-malarial activity of maslinic acid (MA), a natural triterpene which has been previously shown to exert a parasitostatic action on <it>Plasmodium falciparum </it>cultures, was analysed <it>in vivo </it>by using the <it>Plasmodium yoelii </it>17XL murine model.</p> <p>Methods</p> <p>ICR mice were infected with <it>P. yoelii </it>and treated with a single dose of MA by a intraperitoneal injection of MA (40 mg kg^-1day^-1) followed by identical dose administration for the following three days. Parasitaemia and accumulation of intraerythrocytic stages was monitored microscopically. To assess protective immunity, cured mice were challenged with the same dose of parasites 40 days after recovery from the primary infection and parasitaemia was further monitored for 30 days. Humoral response was tested by ELISA and visualization of specific anti-<it>P. yoelii </it>antibodies was performed by Western-blotting.</p> <p>Results</p> <p>ICR mice treated with MA increased the survival rate from 20% to 80%, showing an arrest of parasite maturation from day 3 to 7 after infection and leading to synchronization of the intraerythrocytic cycle and accumulation of schizonts by day 6, proving that MA also behaves as a parasitostatic agent <it>in vivo</it>. Mice which survived the primary infection displayed lower rates of parasitic growth, showing a decline of parasitaemia after day 15, and complete clearance at day 20. These mice remained immunoprotected, showing not malaria symptoms or detectable parasitaemia after rechallenge with the same lethal strain. The analysis of specific antibodies against <it>P. yoelii</it>, present in mice which survived the infection, showed a significant increase in the number and intensity of immunoreactive proteins, suggesting that the protected mice may trigger a strong humoral response.</p> <p>Conclusion</p> <p>The survival increase observed in MA-treated mice can be explained considering that the parasitostatic effect exerted by this compound during the first days of infection increases the chances to develop effective innate and/or acquired immune responses. MA may represent a new class of anti-malarial compounds which, as a consequence of its parasitostatic action, favours the development of more effective sterilizing immune responses.</p

Deficiencias en piruvato quinasa y anemias hemolíticas

The enzyme pyruvate kinase (PK) catalyses the transformation of phosphoenolpyruvate and ADP to pyruvate and ATP. The activity of this ubiquitous enzyme is essential for the central carbohydrate metabolism. Deficiency in PK activity causes non-espherocitic haemolytic anaemia, due to alterations in the metabolism of erythrocytes. The red cell lacks alternate metabolic pathways for pyruvate, and can not cope with the enzymatic fault by increasing the synthesis of the protein. Clinical symptoms in patients harbouring a PK deficiency with anaemia, which may lead to death. Several difficulties appear in the biochemistry caracterization of the enzyme, which led to the application of molecular biology tools. The present work was performed on 10 PK deficient patients. By means of molecular analysis, we have found 11 different mutations in the 17 alleles analysed, three of which, G694A, A1150G y G1154A, have not been previously reported. Changes in the protein structure caused by mutations which introduce steric hindrance or substitutions in charged residues, analised by molecular modeling, showed a clear correlation with the reduction in PK activity in the patients studied.La piruvato quinasa cataliza la transformación de fosfoenolpiruvato y ADP en piruvato y ATP. La enzima, que aparece en toda las células vivas, es clave en la ruta central del metabolismo de carbohidratos. La deficiencia en piruvato quinasa, debida a una mutación en el gen PK-LR, origina alteraciones únicamente, en los eritrocitos, porque estas células no son capaces de compensar el defecto enzimático. Por ello, la deficiencia de esta enzima es causa principal de la anemia hemolítica no esferocítica que puede provocar incluso la muerte de los pacientes. Las dificultades en la caracterización bioquímica de la PK nos ha llevado a estudiar la enzimopatia mediante técnicas de Biología Molecular. El trabajo se realizó sobre 10 pacientes con deficiencia en piruvato quinasa eritrocitaria. Mediante análisis molecular se han encontrado 11 mutaciones diferentes en los 17 alelos mutados: tres de estas mutaciones, G694A, A1150G y G1154A, no habían sido previamente descritas. A las mutaciones que originan fuertes modificaciones en la estructura local de la molécula, observadas mediante estudios de modelización molecular, como consecuencia de un desajuste en el balance de las cargas eléctricas o por impedimento estérico, corresponden valores disminuidos de la actividad de la enzima en aquellos pacientes portadores de dichas mutaciones