Simultaneous quantification of lycopene, β-carotene, retinol and α -tocopherol in plasma after a simple extraction procedure: stability study and application to human volunteers

A method for the simultaneous quantification of lycopene, β-carotene, retinol and α-tocopherol by high-performance liquid chromatography (HPLC) with Vis/fluorescence detection with isocratic elution was optimized and validated. The method consists of a rapid and simple liquid-liquid extraction procedure and a posterior quantification of extracted supernatants by HPLC. Aliquots of plasma were stored at -20°C for three months for stability study. The methodology was applied to samples from painters and individuals not exposed to paints (n = 75). The assay was linear for all vitamins (r > 0.99). Intra- and inter-run precisions were obtained with coefficient of variation smaller than 5%. The accuracies ranged from 0.29 to -5.80% and recoveries between 92.73 and 101.97%. Plasma samples and extracted supernatants were stable for 60 days at -20°C. A significant decrease of lycopene, β-carotene and retinol concentrations in plasma from exposed individuals compared to non-exposed individuals (p < 0.05) was observed. The method is simple, reproducible, precise, accurate and sensitive, and can be routinely utilized in clinical laboratories.

A simple method to evaluate, correlate and predict boiling and flash points of alkynes

Boiling points (T B) of acyclic alkynes are predicted from their boiling point numbers (Y BP) with the relationship T B(K) = -16.802Y BP2/3 + 337.377Y BP1/3 - 437.883. In turn, Y BP values are calculated from structure using the equation Y BP = 1.726 + Ai + 2.779C + 1.716M3 + 1.564M + 4.204E3 + 3.905E + 5.007P - 0.329D + 0.241G + 0.479V + 0.967T + 0.574S. Here Ai depends on the substitution pattern of the alkyne and the remainder of the equation is the same as that reported earlier for alkanes. For a data set consisting of 76 acyclic alkynes, the correlation of predicted and literature T B values had an average absolute deviation of 1.46 K, and the R² of the correlation was 0.999. In addition, the calculated Y BP values can be used to predict the flash points of alkynes.

A simple-versatile approach to achieve all-Si-based optical micro-cavities

At present, solid thin films are recognized by their well established and mature processing technology that is able to produce components which, depending on their main characteristics, can perform either passive or active functions. Additionally, Si-based materials in the form of thin films perfectly match the concept of miniaturized and low-consumption devices-as required in various modern technological applications. Part of these aspects was considered in the present work that was concerned with the study of optical micro-cavities entirely based on silicon and silicon nitride thin films. The structures were prepared by the sputtering deposition method which, due to the adopted conditions (atmosphere and deposition rate) and arrangement of layers, provided cavities operating either in the visible (at ~ 670 nm) or in the near-infrared (at ~ 1560 nm) wavelength ranges. The main differential of the work relies on the construction of optical microcavities with a reduced number of periods whose main properties can be changed by thermal annealing treatments. The work also discusses the angle-dependent behavior of the optical transmission profiles as well as the use of the COMSOL software package to simulate the microcavities.

Simulación de una columna de destilación simple para una mezcla binaria de compuestos utilizados como biodiesel. Comparación entre un nuevo modelo propuesto y simuladores comerciales de ingeniería química.

Máster Universitario en Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería (SIANI)

A simple model to estimate active flux in relation to zooplankton lunar cycles in subtropical waters

Máster en Oceanografía. Programa de Doctorado en Oceanografía

Simulations of glacial/interglacial cycles with simple box-models. The ocean CO2 source during deglaciations

Máster en Oceanografía

Desarrollo de videojuegos en 2D usando Simple DirectMedia

[ES]Los Indie games, o videojuegos independientes, son aplicaciones creadas por individuos o pequeños grupos sin apoyo financiero de distribuidores. A menudo se centran en la innovación, y se basan en la distribución digital. En los últimos años han visto un gran aumento principalmente debido a; nuevos métodos de distribución en línea (Steam Greenlight1, Xbox Live2, Playstation Store3, Android Market, Apple Store), nuevas formas de financiación como Kickstarter4 y potentes herramientas gratuitas para el desarrollo. Este proyecto se puede considerar como uno de los primeros pasos en el desarrollo de videojuegos independientes o Indie. Usando SDL como base se pretende diseñar y desarrollar dos prototipos de videojuego, el primero será un clon del conocido Tetris, aprovechando la poca complejidad de las mecánicas del juego para tener un primer contacto con las herramientas. El segundo, de mayor complejidad, se centrará en desarrollar las principales características de un juego tipo plataformas en 2D, del estilo Super Mario, Sonic o los anteriormente mencionados Super Meat Boy y Braid. La Simple DirectMedia Layer (SDL) es un conjunto de bibliotecas desarrolladas en el lenguaje de programación C, que proporcionan funciones básicas para realizar operaciones de dibujo en dos dimensiones, gestión de efectos de sonido y música, además de carga y gestión de imágenes. Fueron desarrolladas inicialmente por Sam Lantinga en 1998, en este proyecto se ha usado la versión 1.2.15 y se espera que este año se termine la versión 2.0, el uno de Junio de este año ha alcanzado el estado Release Candidate.