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  • Author: Antonia Díaz x
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Abstract

In this paper we propose a theory to study how the aggregate demand of energy responds to energy prices and technical innovations that affect the price of energy services. In our theory, energy use is determined by the interaction of the choice of Energy Saving Technical Change with energy prices and Investment Specific Technical Change (ISTC). The key mechanism is that the energy saving technology is embodied in capital vintages as a requirement that determines their energy intensity. We show that higher ISTC that increases the quality of capital goods is an energy saving device and, therefore, a substitute for Energy Saving Technical Change (ESTC). However, higher ISTC that rises the efficiency in producing capital goods is energy consuming and fosters ESTC to compensate for the amount of energy required by the new investment. A higher price of energy also induces a higher level of ESTC, but the aggregate amount of energy used may not be affected as investment does not change. These effects are amplified with rising prices of energy. Thus, our theory can be used to test when and how we should see a rebound effect in energy use at the aggregate level and to evaluate the aggregate effect of any policy aiming to reduce energy use.

Abstract

In this work, the viscosity of soybean oil subjected to thermal degradation has been determined and related to the chemical composition of the oil. In particular, it is found a linear relationship between the viscosity value and the triglycerides content during the degradation process (an increase of the former is associated to a decrease of the latter). Thus, it is shown that viscosity provides us a reliable way of measuring oil degradation and, insofar as proportional to flow time, it allows for the design of simple devices to control the oil quality. Besides, the study of the viscosity behavior along with the changes in composition during the cooking time, i.e. the period of time that the oil is being heated, give us valuable information about the type of chemical reactions occurring within the oil.

Abstract

Quinoa (Chenopodium quinoa Willd.) has been nutritionally highlighted when compared to other grains. In recent years the research on this pseudocereal has increased. In this work, six quinoa samples were studied: three from Peru, one from Brazil and two commercial samples. The samples were physically and physicochemically characterized, including macro- and micronutrient analysis, phenolic compounds content and antioxidant activity. Black, red and white samples showed as main difference the size, weight, ashes and dietary fibre content. Black samples were the smallest and lightest and had the lowest starch content but presented the highest levels of ashes and dietary fibre. The protein content (16.9 %) in the white Brazilian variety was higher than the others. Red and black samples had the highest levels of most minerals analysed. The antioxidant capacity measured by the DPPH method was higher for black and red samples in comparison with the white ones. However, the white Brazilian variety showed a significantly higher antioxidant capacity measured by the ABTS assay. With regard to the phenolic content, a difference was found between the samples which ranged from 55.5 to 95.5 g GAE 100 g−1. The colour of the grain was found as not related to a higher content of phenolic compounds. Because their compositions are generally similar to light-coloured grains, and in some parameters such as dietary fibre and content of some micronutrients are superior, the grains of dark-coloured quinoa varieties (RPP, BCP) would have to be explored to develop foods that take advantage of this colour diversity.

Abstract

Two styrene-6.7 % divinylbenzene copolymers functionalized with aminophosphonate groups and phosphonic acid groups by means of “one-pot” reactions were evaluated for gaseous mercury removal. The results were compared with those obtained using a commercial activated carbon. These materials exhibit a significant capacity for mercury oxidation (13–25 %) with low mercury capture (9–30 μg g–1). The mercury retention capacity was observed to decrease when acid gases are present in the gas atmosphere. The highest retention capacity corresponded to the highest oxidation ratio and was obtained using the AMINOPHOS sample. These results suggest a mercury oxidation and a subsequent chemical adsorption mechanism in which the amino groups play a role in mercury capture.

Abstract

Background:

Caspase-cleaved cytokeratin (CCCK)-18 is a protein released into the blood during apoptosis. Higher circulating CCCK-18 concentrations have been found in non-survivor than in survivor septic patients at moment of sepsis diagnosis. The following questions arise now: (1) How are serum CCCK-18 levels during the first week of sepsis? (2) Is there an association between sepsis severity and mortality and serum CCCK-18 levels during the first week? The aims of this study were to answer these questions.

Methods:

Multicenter study with 321 severe septic patients from eight Spanish intensive care units. We determined serum concentration of CCCK-18, tumor necrosis factor (TNF)-α, and interleukin (IL)-10 during the first week. Our end-point study was 30-day mortality.

Results:

Non-survivor (n=108) compared to survivor patients (n=213) showed higher serum CCCK-18 levels at days 1, 4 and 8 (p<0.001). ROC curve analyses showed that serum CCCK-18 levels at days 1 (AUC=0.77; 95% CI=0.72–0.82), 4 (AUC=0.81; 95% CI=0.76–0.85) and 8 (AUC=0.83; 95% CI=0.78–0.88) could predict mortality at 30 days (p<0.001). Logistic regression analyses showed that serum CCCK-18 levels at days 1 (OR=4.367; 95% CI=2.491–7.659), 4 (OR=10.137; 95% CI=4.741–21.678) and 8 (OR=8.781; 95% CI=3.626–21.268) were associated with 30-day mortality (p<0.001). We found a positive correlation between CCCK-18, SOFA, and lactic acid at days 1, 4 and 8.

Conclusions:

Non-survivor septic patients showed persistently during the first week higher serum CCCK-18 levels than survivor patients, and there is an association between sepsis severity and mortality and serum CCCK-18 levels during the first week.

Abstract

Objetivos

El objetivo de este estudio es conocer la evolución de la prestación analítica de los laboratorios participantes en los programas EQA de la SEQCML durante los 30 años de funcionamiento y compararla con la prestación obtenida en otros programas EQA para saber si los resultados son similares.

Métodos

Se evalúan los resultados obtenidos durante este periodo, aplicando las especificaciones de la calidad derivadas de la VB y del estado del arte. Además, se realiza una comparación con los resultados obtenidos por otras organizaciones de programas EQA.

Resultados

Se observa que los laboratorios participantes en los programas EQA-SEQCML han mejorado su prestación durante los 30 años de experiencia y que las especificaciones derivadas de la variación biológica son alcanzables. La comparación entre programas EQA es difícil, debido a: la falta de accesibilidad y a las diferencias en el diseño de estos programas (materiales control, cálculos empleados y especificaciones analíticas establecidas).

Conclusiones

Los datos de este estudio ponen de manifiesto que para algunas magnitudes biológicas los resultados obtenidos en los programas todavía no están armonizados, aunque se estan realizando esfuerzos para alcanzar la armonización. Los organizadores de programas EQA deberían sumarse al esfuerzo de armonización, facilitando la información sobre sus resultados para permitir su comparación.

Abstract

The purpose of this study is to understand the evolution of the analytical performance of the laboratories participating in the Spanish society of laboratory medicine (SEQCML) external quality assurance (EQA) programmes during its 30 years of operation and to compare it with the performance of other EQA programmes to establish whether the results are similar. The results obtained during this period are evaluated by applying the biological variability (BV) and state of the art-derived quality specifications. In addition, the results are compared with those obtained by other EQA programme organisations. It is noted that the laboratories participating in the EQA–SEQCML programmes have improved their performance over 30 years of experience and that the specifications derived from biological variation are achievable. It is difficult to compare EQA programmes, due to lack of accessibility and the differences in the design of these programmes (control materials, calculations used and analytical specifications established). The data from this study show that for some biological magnitudes the results obtained by the programmes are not yet harmonised, although efforts are being made to achieve this. Organisers of EQA programmes should also join the harmonisation effort by providing information on their results to enable comparison.

Resumen

Introducción

El objetivo de este estudio es comprobar la evolución de las especificaciones de la prestación analítica (EPA) utilizadas en programas de garantía externa de la calidad (EQA) y el papel de un programa de categoría 1 en la vigilancia de la estandarización de la prestación de los laboratorios clínicos en España.

Métodos

Se ha revisado la bibliografía sobre tipos de especificaciones de la calidad usados en programas de otros países y se ha comprobado su evolución; se ha comparado el posible impacto de distintas EPA empleadas en ocho países en la toma de decisiones clínicas con tres ejemplos de magnitudes: sodio, tirotropina (TSH) y tiempo de tromboplastina parcial activado (TTPA).

Resultados

Se ha evidenciado la estandarización entre métodos analíticos comprobando si los resultados medios se desvían respecto al valor de referencia certificado del control dentro de las EPA derivadas de la variación biológica (VB). Las EPA usadas en EQA han evolucionado desde el estado del arte hacia la VB. Si se aplican los resultados que se aceptarían con algunas EPA se podrían producir decisiones clínicas erróneas.

Conclusiónes

En España, solo 2 de las 18 magnitudes biológicas estudiadas se pueden considerar bien estandarizadas. Sería necesaria una colaboración más estrecha entre los laboratorios y proveedores de sistemas analíticos para resolver las discrepancias.

Abstract

Background

The objective of the present study was to examine the evolution of the analytical performance specifications (APS) used in External Quality Assurance (EQA) schemes, as well as the efficacy of a category 1 EQA scheme in monitoring the harmonization of clinical laboratory results in Spain.

Methods

A review of the literature on the types of quality specifications used in schemes in other countries and their evolution was performed. In addition, a comparative analysis of the potential impact that different APS from eight countries had on clinical decision-making was made based on three measurands: sodium, thyroid-stimulating hormone (TSH), and activated partial thromboplastin time (aPTT).

Results

Harmonization of analytical methods was demonstrated by assessing whether average results deviated from the certified reference value of control materials within the APS derived from biological variation (BV). The APS used in EQA have evolved from state-of-the-art models to BV. Poor clinical decision-making would occur if the results accepted by some APS were applied.

Conclusions

In Spain, only 2 of the 18 measurands studied are considered to be well harmonized. Closer collaboration between laboratories and analytical system providers would be required to resolve discrepancies.