Development of a piezoelectric sensor for the detection of methamphetamine.

A computationally designed molecularly imprinted polymer (MIP) specific for methamphetamine was used as a synthetic receptor for the development of a piezoelectric sensor. Several different protocols were tested for the immobilisation of the MIP onto the gold sensor surface. The developed MIP sensor had a detection limit for methamphetamine as low as 1 microg mL(-1). The effect of the addition of poly(vinyl acetate) (PVA) on the pre-polymerisation mixtures, which increases the porosity of the polymer layer, was also studied using an Atomic Force Microscope (AFM). PVA seemed to affect both the porosity and the binding kinetics of the polymers prepared in dimethylformamide (DMF). However, no clear effect on porosity and binding kinetics was observed when polymers were prepared in diglyme. Moreover, PVA did not appear to improve the amplitude of the sensor response. In conclusion, because of its excellent recognition ability in aqueous solutions, the sensor described in this work could be an ideal starting point for the development of a commercial device for fast, on-site or road-side testing of drugs of abuse in body fluids such as saliva.

Design of molecular imprinted polymers compatible with aqueous environment.

The main problem of poor water compatibility of molecularly imprinted polymers (MIPs) was addressed in examples describing design of synthetic receptors with high affinity for drugs of abuse. An extensive potentiometric titration of 10 popular functional monomers and corresponding imprinted and blank polymers was conducted in order to evaluate the subtleties of functional groups ionisation under aqueous conditions. It was found that polymers prepared using 2-trifluoromethacrylic acid (TFMAA) in combination with toluene as porogen possess superior properties which make them suitable for effective template recognition in water. The potential impact of phase separation during polymerisation on formation of high quality imprints has been discussed. Three drugs of abuse such as cocaine, deoxyephedrine and methadone were used as template models in polymer preparation for the practical validation of obtained results. The polymer testing showed that synthesized molecularly imprinted polymers have high affinity and selectivity for corresponding templates in aqueous environment, with imprinting factors of 2.6 for cocaine and 1.4 for methadone and deoxyephedrine. Corresponding blank polymers were unable to differentiate between analytes, suggesting that imprinting phenomenon was responsible for the recognition properties.

Influencias del desarrollo de las habilidades visuales en el rendimiento deportivo en deportistas élite de raquetball / Effect of the development of visual skills on the performance of racketball elite athletes

La información visual juega un papel extremadamente importante en el deportista porque alrededor del 85 por ciento de la información que requiere proviene del sistema visual; por eso el entrenamiento y desarrollo de las habilidades visuales se relacione con el rendimiento deportivo. Por ese motivo, nos propusimos como objetivos: determinar cómo influye el desarrollo de las habilidades visuales en el rendimiento deportivo de los jugadores de raquetball, evaluar el desarrollo de las habilidades visuales, definir cuáles son las más desarrolladas, compararlas por sexo, relacionarlas con el resultado deportivo y con patologías oculares o sistémicas. Se obtuvo como principal resultado que todos tenían desarrollada la binocularidad. Concluimos que hubo una mayor cantidad de atletas de raquetball con habilidades visuales desarrolladas; las más desarrolladas fueron: la binocularidad, la agudeza visual (estática y dinámica) y la visualización. En el sexo femenino las más desarrolladas fueron: la agudeza visual (estática y dinámica), la acomodación-convergencia, la binocularidad y la visualización mientras que en el masculino fueron: la binocularidad, la agudeza visual (estática y dinámica) y la visualización. En el caso del equipo femenino no hubo correspondencia entre la atleta con mayor desarrollo de las habilidades visuales y el mejor resultado deportivo; pero en el masculino sí se correspondió. No se encontraron patologías oculares o sistémicas asociadas a las habilidades visuales estudiadas. Recomendamos realizar este estudio a todos los atletas en su iniciación deportiva; y crear una consulta oftalmológica especializada dedicada al control de su visión, al entrenamiento visual para potenciar las habilidades visuales menos desarrolladas en los deportistas y examinarlos periódicamente.

Visual information plays a very important role in an athlete since roughly 85 percent of required information comes from the visual system; therefore training and development of visual skills are related to sport performance. The objectives of this paper were to determine how the development of visual skills affects the sports performance of racketball players, to evaluate the development of these skills, to define the most developed ones, to compare them by sex and associate them with the sports achievements and with ocular and/ or systemic pathologies. Binocularity was the most developed skill. It was concluded that there was a higher number of racketball athletes presenting with developed visual skills, particularly binocularity, visual acuity (statics and dynamics) and visualization. The most developed skills in females were visual acuity (statics and dynamics), accommodation-convergence, binocularity and visualization whereas males showed binocularity, visual acuity (statics and dynamics) and visualization. In the case of the female racketball team, the highest development of visual skills was not associated with the best sport achievements, but in the case of the male team, this association did exist. No ocular or systemic pathologies related to the studied visual skills were found. It was recommended to perform this study in all the athletes at the beginning of their sports life, and also to set up a specialized ophthalmologic service for vision control, visual training to potentate the less developed skills in athletes and for regular check-ups.