Identification of non-small cell lung cancer biomarkers using mass spectrometry

Comunicaciones a congreso

Characterization of the rat Na+/nucleoside cotransporter 2 and transport of nucleoside-derived drugs using electrophysiological methods.

The Na(+)-dependent nucleoside transporter 2 (CNT2) mediates active transport of purine nucleosides and uridine as well as therapeutic nucleoside analogs. We used the two-electrode voltage-clamp technique to investigate rat CNT2 (rCNT2) transport mechanism and study the interaction of nucleoside-derived drugs with the transporter expressed in Xenopus laevis oocytes. The kinetic parameters for sodium, natural nucleosides, and nucleoside derivatives were obtained as a function of membrane potential. For natural substrates, apparent affinity (K(0.5)) was in the low micromolar range (12-34) and was voltage independent for hyperpolarizing membrane potentials, whereas maximal current (I(max)) was voltage dependent. Uridine and 2'-deoxyuridine analogs modified at the 5-position were substrates of rCNT2. Lack of the 2'-hydroxyl group decreased affinity but increased I(max). Increase in the size and decrease in the electronegativity of the residue at the 5-position affected the interaction with the transporter by decreasing both affinity and I(max). Fludarabine and formycin B were also transported with higher I(max) than uridine and moderate affinity (102 +/- 10 and 66 +/- 6 microM, respectively). Analysis of the pre-steady-state currents revealed a half-maximal activation voltage of about -39 mV and a valence of about -0.8. K(0.5) for Na(+) was 2.3 mM at -50 mV and decreased at hyperpolarizing membrane potentials. The Hill coefficient was 1 at all voltages. Direct measurements of radiolabeled nucleoside fluxes with the charge associated showed a ratio of two positive inward charges per nucleoside, suggesting a stoichiometry of two Na(+) per nucleoside. This discrepancy in the number of Na(+) molecules that bind rCNT2 may indicate a low degree of cooperativity between the Na(+) binding sites

Superior Performance of Ablative Glass Coatings Containing Graphene Nanosheets

Glass compositions in the Y₂O₃-Al₂O₃-SiO₂ (YAS) system are envisaged as promising coatings for high‐temperature protection, in particular for the thermal protection systems (TPS) looked for aerospace applications. Recently, thermally sprayed YAS hybrid coatings containing a small amount of graphene nanoplateletes (GNPs) showed enhanced performance as compared to the blank YAS coating, demonstrated by the occurrence of unusual electrical conductivity for these glasses and the development of better mechanical compliance, both phenomena associated with the presence of GNPs. Nevertheless, a crucial issue is to demonstrate if these kinds of coatings would also have superior behavior under ablation conditions, particularly regarding the mentioned TPS applications. This work goes far beyond, exploring the ablative behavior of new YAS/GNPs coatings flame sprayed over SiC substrates. These essential tests were carried out under laboratory conditions, reaching limit temperatures of 1350°C while blowing gas. Results evidence that hybrid coatings having just 1.05 vol% GNPs show enhanced ablation resistance, actually withstanding up to 30 thermal cycles (between 200°C and 1350°C) without apparent damage. This satisfactory performance is linked to the benefits of the GNP additions, and fundamentally to the higher emissivity and the directional thermal conduction characteristics of the hybrid coatings—produced by the formation of a GNP network with a preferential surface parallel arrangement—that preclude the creation of hot spots and also hinder heat propagation toward the substrate; accordingly, coating degradation is constrained to the uppermost layer of these coatings

The effect of graphene nanoplatelets on the thermal and electrical properties of aluminum nitride ceramics

The thermal conductivity (κ) of AlN (2.9 wt.% of Y_{2}O_{3}) is studied as a function of the addition of multilayer graphene (from 0 to 10 vol.%). The κ values of these composites, fabricated by spark plasma sintering (SPS), are independently analyzed for the two characteristic directions defined by the GNPs orientation within the ceramic matrix; that is to say, perpendicular and parallel to the SPS pressing axis. Conversely to other ceramic/graphene systems, AlN composites experience a reduction of κ with the graphene addition for both orientations; actually the decrease of κ for the in-plane graphene orientation results rather unusual. This behavior is conveniently reproduced when an interface thermal resistance is introduced in effective media thermal conductivity models. Also remarkable is the change in the electrical properties of AlN becoming an electrical conductor (200 S m⁻¹) for graphene contents above 5 vol.%

Attitudes of Germans towards distributive issues in the German health system

Social health care systems are inevitably confronted with the scarcity of resources and the resulting distributional challenges. Since prioritization implies distributional effects, decisions on respective rules should take citizens’ preferences into account. Thus, knowledge about citizens’ attitudes and preferences regarding different distributional issues implied by the type of financing health care is necessary to judge the public acceptance of a health system. In this study we concentrate on two distributive issues in the German health system: First, we analyse the acceptance of prioritizing decisions concerning the treatment of certain patient groups, in this case patients who all need a heart operation. Here we focus on the fact that a patient is strong smoker or a non-smoker, the criteria of age or the fact that a patient has or does not have young children. Second, we investigate Germans’ opinions towards income dependent health services. The results reveal strong effects of individuals’ attitudes regarding general aspects of the health system on priorities, e.g. that individuals behaving health demanding should not be preferred. In addition, experiences of limited access to health services are found to have a strong influence on citizens’ attitudes, too. Finally, decisions about different prioritization criteria are found to be not independent.

Dynamic growth pattern of chinchilla (<i>Chinchilla lanigera</i>) kits during lactation

Se evaluó la aptitud de la función lineal y de la función exponencial creciente para describir el comportamiento dinámico del peso corporal de gazapos de chinchilla durante la lactancia. Los valores observados de las variancias residuales y de los coeficientes de determinación asignaron una leve ventaja al modelo lineal. La función lineal subestimó el peso al nacimiento mientras que la función exponencial lo sobreestimó sin diferenciarse en la magnitud de las diferencias de uno u otro signo entre los valores estimados y observados. La utilización del modelo lineal para caracterizar el crecimiento de gazapos machos proveniente de camadas con uno, dos o tres crías, entre el nacimiento y el destete a los 43 días de edad, permitió constatar que el aumento del tamaño de la camada de uno a dos gazapos, si bien disminuye ligeramente el peso inicial y la tasa de crecimiento predestete, no presenta un efecto detrimental de trascendencia sobre el crecimiento en dicha etapa. Por el contrario, la presencia de un tercer gazapo reduce de manera notoria tanto el peso inicial de los miembros de la camada como su aumento medio diario de peso hasta el destete. De acuerdo con lo relevado en este estudio resultaría más conveniente plantear como objetivo aumentar el número de pariciones por año, por ejemplo mediante un manejo adecuado del fotoperíodo, que aumentar el tamaño de la camada al parto por encima de dos gazapos.The ability of linear and exponential functions to describe the dynamic behavior of body weight of chinchilla kits during lactation was evaluated. Residual variance and coefficient of determination average values derived from each model assigned to linear function a slight advantage. While the linear function underestimated birth weight the exponential model overestimated it showing both models differences of similar magnitude between estimated and observed values. The use of the linear model to characterize the dynamic growth of male kits belonging to litters with one, two or three pups, between birth and weaning at 43 days of age, allowed to confirm that increasing litter size from one to two pups slightly decreases their initial body weight and their growth rate during lactation, without a detrimental effect on overall pre-weaning growth. By contrast, the presence of a third kit in the litter markedly reduces both initial body weight and daily body weight gain from birth to weaning. According to data surveyed in this study increasing the number of parturitions per female per year, for example through an appropriate management of photoperiod, would be more useful than increasing litter size at birth above two kits to increase the overall efficiency of the system.Facultad de Ciencias Veterinaria

The Decisive Role Played by Graphene Nanoplatelets on Improving the Tribological Performance of Y2o3-al2o3-sio2 Glass Coatings

Graphene nanoplatelets (GNPs) have proved to be effective fillers for enhancing the mechanical and tribological properties of bulk ceramics and glasses, also with the added benefit of developing electrical and thermal functionalities. Similarly, enhanced transport performance has recently been shown for glass-ceramics coatings of the Y2O3-Al2O3-SiO2 (YAS) system containing a small amount of GNP fillers, intended for applications in the aerospace industry. In the present work, the wear and friction behaviour of GNP/YAS coatings –containing 0, 1.2 and 2.3 wt.% GNPs- on silicon carbide substrates is evaluated. The flame spraying process used for coating fabrication induces a structure of splats oriented parallel to the substrate with GNPs located at the inter-splat boundaries forming a connected network of platelets mainly oriented parallel to the surface as well. Unlubricated ball–on-plate reciprocating wear tests show that both the friction coefficient and the wear rate decreased by 35% and 65%, respectively, for 2.3 wt.% of GNPs. A wear mechanism for GNP/YAS coatings based on both the progressive exfoliation of the graphene sheets and the effect of the GNPs on preventing crack propagation within the coating is proposed

Dynamic growth pattern of chinchilla (<i>Chinchilla lanigera</i>) kits during lactation

Se evaluó la aptitud de la función lineal y de la función exponencial creciente para describir el comportamiento dinámico del peso corporal de gazapos de chinchilla durante la lactancia. Los valores observados de las variancias residuales y de los coeficientes de determinación asignaron una leve ventaja al modelo lineal. La función lineal subestimó el peso al nacimiento mientras que la función exponencial lo sobreestimó sin diferenciarse en la magnitud de las diferencias de uno u otro signo entre los valores estimados y observados. La utilización del modelo lineal para caracterizar el crecimiento de gazapos machos proveniente de camadas con uno, dos o tres crías, entre el nacimiento y el destete a los 43 días de edad, permitió constatar que el aumento del tamaño de la camada de uno a dos gazapos, si bien disminuye ligeramente el peso inicial y la tasa de crecimiento predestete, no presenta un efecto detrimental de trascendencia sobre el crecimiento en dicha etapa. Por el contrario, la presencia de un tercer gazapo reduce de manera notoria tanto el peso inicial de los miembros de la camada como su aumento medio diario de peso hasta el destete. De acuerdo con lo relevado en este estudio resultaría más conveniente plantear como objetivo aumentar el número de pariciones por año, por ejemplo mediante un manejo adecuado del fotoperíodo, que aumentar el tamaño de la camada al parto por encima de dos gazapos.The ability of linear and exponential functions to describe the dynamic behavior of body weight of chinchilla kits during lactation was evaluated. Residual variance and coefficient of determination average values derived from each model assigned to linear function a slight advantage. While the linear function underestimated birth weight the exponential model overestimated it showing both models differences of similar magnitude between estimated and observed values. The use of the linear model to characterize the dynamic growth of male kits belonging to litters with one, two or three pups, between birth and weaning at 43 days of age, allowed to confirm that increasing litter size from one to two pups slightly decreases their initial body weight and their growth rate during lactation, without a detrimental effect on overall pre-weaning growth. By contrast, the presence of a third kit in the litter markedly reduces both initial body weight and daily body weight gain from birth to weaning. According to data surveyed in this study increasing the number of parturitions per female per year, for example through an appropriate management of photoperiod, would be more useful than increasing litter size at birth above two kits to increase the overall efficiency of the system.Facultad de Ciencias Veterinaria

Dynamic growth pattern of chinchilla (<i>Chinchilla lanigera</i>) kits during lactation

Se evaluó la aptitud de la función lineal y de la función exponencial creciente para describir el comportamiento dinámico del peso corporal de gazapos de chinchilla durante la lactancia. Los valores observados de las variancias residuales y de los coeficientes de determinación asignaron una leve ventaja al modelo lineal. La función lineal subestimó el peso al nacimiento mientras que la función exponencial lo sobreestimó sin diferenciarse en la magnitud de las diferencias de uno u otro signo entre los valores estimados y observados. La utilización del modelo lineal para caracterizar el crecimiento de gazapos machos proveniente de camadas con uno, dos o tres crías, entre el nacimiento y el destete a los 43 días de edad, permitió constatar que el aumento del tamaño de la camada de uno a dos gazapos, si bien disminuye ligeramente el peso inicial y la tasa de crecimiento predestete, no presenta un efecto detrimental de trascendencia sobre el crecimiento en dicha etapa. Por el contrario, la presencia de un tercer gazapo reduce de manera notoria tanto el peso inicial de los miembros de la camada como su aumento medio diario de peso hasta el destete. De acuerdo con lo relevado en este estudio resultaría más conveniente plantear como objetivo aumentar el número de pariciones por año, por ejemplo mediante un manejo adecuado del fotoperíodo, que aumentar el tamaño de la camada al parto por encima de dos gazapos.The ability of linear and exponential functions to describe the dynamic behavior of body weight of chinchilla kits during lactation was evaluated. Residual variance and coefficient of determination average values derived from each model assigned to linear function a slight advantage. While the linear function underestimated birth weight the exponential model overestimated it showing both models differences of similar magnitude between estimated and observed values. The use of the linear model to characterize the dynamic growth of male kits belonging to litters with one, two or three pups, between birth and weaning at 43 days of age, allowed to confirm that increasing litter size from one to two pups slightly decreases their initial body weight and their growth rate during lactation, without a detrimental effect on overall pre-weaning growth. By contrast, the presence of a third kit in the litter markedly reduces both initial body weight and daily body weight gain from birth to weaning. According to data surveyed in this study increasing the number of parturitions per female per year, for example through an appropriate management of photoperiod, would be more useful than increasing litter size at birth above two kits to increase the overall efficiency of the system.Facultad de Ciencias Veterinaria

Análisis de la adhesión de recubrimientos del sistema Y2O3-Al2O3-SiO2 sobre sustratos de interés para la industria aeroespacial

En la industria aeroespacial se necesitan materiales ligeros que tengan unas altas prestaciones mecánicas combinadas con una baja densidad. El carburo de silicio, el carbono reforzado con fibra de carbono y el carburo de silicio reforzado con fibra de carbono son materiales que cumplen con estos requisitos, pero a altas temperaturas presentan problemas de oxidación. Una de las formas más efectivas de prevenir este fenómeno es la utilización de recubrimientos cerámicos, cuya correcta adhesión sobre los distintos sustratos es fundamental para garantizar su funcionamiento. En el caso del presente trabajo, se analiza la adhesión de recubrimientos vítreos del sistema Y2O3-Al2O3-SiO2 obtenidos mediante proyección térmica por llama oxiacetilénica. Para ello, se realizan ensayos de rayado a carga creciente analizando el tipo y la carga de fallo y su relación con las propiedades elásticas y mecánicas de los recubrimientos. Los resultados indican que la adhesión sobre los sustratos carburo de silicio y carburo de silicio reforzado con fibra de carbono es buena, mientras que el carbono reforzado con fibra de carbono no es un material adecuado para recubrir