Designing micro- and mesoporous carbon networks by chemical activation of organic resins.

Carbon xerogels with ultrahigh micro- and mesopore volumes were synthesized from the activation of polymeric resins prepared by sol-gel polycondensation of resorcinol/formaldehyde mixtures in basic medium and subcritical drying. Various activating conditions (e.g., agent, temperature, impregnation conditions) were used and it was found that the textural features of the resulting carbon xerogels are linked to the experimental procedure of the activation reaction to promote the porosity development. The shrinkage and structural collapse of the fragile resins typically obtained upon annealing at high temperatures (during carbonization and/or physical activation) is suppressed when the impregnation of the chemical activating agent is performed under controlled conditions. If the alkaline reagent (either KOH or K2CO3) is put in contact with the resin by wet impregnation (liquid/solid); under such conditions, the intimate contact between both compounds allows the formation of microporosity during the activation along with the enlargement and/or preservation of the mesoporosity of the pristine resin. Furthermore, the chemical activation via wet impregnation allows the combination of high surface areas and the preservation (even higher development) of the mesoporosity created during the synthesis of the resin. The effect of the impregnation method was found highly dependent of the reagent and activation temperature, highlighting the possibility to design micro-mesoporous carbon xerogels at low temperatures with a subtle control of the activation conditions.

Enzymatic amplification-free nucleic acid hybridisation sensing on nanostructured thick-film electrodes by using covalently attached methylene blue.

Amplification-free (referring to enzymatic amplification step) detection methodologies are increasing in biosensor development due to the need of faster and simpler protocols. However, for maintaining sensitivity without this step, highly detectable molecules or very sensitive detection techniques are required. The nanostructuration of transducer surfaces with carbon nanotubes (CNTs), gold nanoparticles (AuNPs) or both in nanohybrid configurations has been employed in this work for DNA hybridisation sensing purposes. Methylene blue (MB), covalently attached to single stranded DNA, (ssDNA) was incubated with a complementary sequence immobilized on nanostructured screen-printed electrodes (AuSPEs). Although CNTs can increase notoriously the signal of the marker, adsorptive properties should also be considered when bioassays are performed because non-specific adsorption (NSA) phenomena are magnified. In this work, strategies for decreasing NSA were thoroughly evaluated for the detection of Mycoplasma pneumoniae (MP) on CNTs-nanostructured screen-printed electrodes. Among them, the employ of UV-radiation or long incubation times (72h) allowed obtaining higher signals for the complementary strand with respect to the non-complementary one. The use of CNTs/AuNPs nanohybrids, together with the use of streptavidin-biotin (ST-B) interaction allows the higher differentiation (with a 3.5 ratio) in the genosensing of M. pneumoniae.

Methylene blue covalently attached to single stranded DNA as electroactive label for potential bioassays.

Methylene blue is an electroactive molecule that has been employed for the detection of the DNA hybridization event in electrochemical sensors. However, its use as a covalent label is very scarce and in most of the cases, non-covalent interactions (hydrophobic, electrostatic) are employed. Although it has advantages as simplicity and fewer number of procedure steps, the covalent attachment is less exploited in the development of these sensors. In this article, the electrochemical behavior of methylene blue attached to different DNA-strands is studied. Several lengths (15- and 30-mer) and different degree of DNA modification (MB-DNA, MB-DNA-MB and MB-DNA-SH) have been studied. The highest signals were obtained for longer strands with two MB molecules. In all the cases the signal is enhanced by CNT-nanostructuration of the electrode. Adsorption on these modified screen-printed electrodes allowed the amplification by employing an accumulation time. In this way, a sensitivity of -0.2864 µA µM-1 and a limit of detection of 800 nM for a 120 s accumulation time were obtained.

Nafion® modified-screen printed gold electrodes and their carbon nanostructuration for electrochemical sensors applications.

Screen printed electrodes are frequently used in electroanalytical applications because of their properties such as small size, low detection limit, fast response time, high reproducibility and disposable nature. On the other hand, since the discovery of carbon nanotubes there has been enormous interest in exploring and exploiting their properties, especially for their use in chemical (bio)sensors and nanoscale electronic devices. This paper reports the characterization of gold screen printed electrodes, modified with Nafion(®) and nanostructured with carbon nanotubes and carbon nanofibers dispersed on Nafion(®). The dispersing agent and the nanostructure have a marked effect on the analytical signal that, in turn depends on the intrinsic characteristics of the analyte. Several model analytes have been employed in this study. Anionic, cationic and neutral species such as methylene blue, dopamine, iron (III) sulfate, potassium ferrycianide and urea were considered. The importance for the development of nanostructured sensors relies on the fact that depending on these factors the situation may vary from a notorious enhancement of the signal to a blocking or even decrease.

Signos de alerta de Cáncer en el adulto mayor / Alert signs of cancer in elderly patients

Se realizó un estudio observacional descriptivo en el área de salud Guillermo Tejas, con el objetivo de identificar los signos de alerta de cáncer en el adulto mayor, en el periodo comprendido entre los años 2002 y 2006; el universo de trabajo estuvo representado por 144 fallecidos por neoplasia maligna, la obtención de la información se llevó a cabo a través de la revisión de las historias clínicas y certificados de defunción de los fallecidos, se utilizaron algunas variables de interés, tales como: signos de alerta de cáncer, antecedentes patológicos familiares de neoplasias malignas, antecedentes patológicos de otras enfermedades. Las conclusiones fundamentales del trabajo fueron: como antecedentes patológicos personales más frecuentes se encontraron la bronquitis crónica, la displasia de mama y la Inflamación Pélvica Crónica (IPC), y los Antecedentes Patológicos Familiares (APF) de neoplasia fueron significativos. Los signos de alerta tales como: tos o ronquera persistente, cambios en el funcionamiento del intestino o vejiga y la dureza o abultamiento de una mama o en otra parte, fueron los más definidos. Además se logró comprobar la hipótesis planteada (AU)

An observational descriptive research was carried out from 2002 to 2006 at the Guillermo Tejas health area to identify the alert signs of cancer in elderly patients. The universe was represented by 144 people who died of malignant neoplasm. The data was collected from the health histories and death certificates and analyzed using variables of interest like: alert signs of cancer, familial pathological antecedents of malignant neoplasm and other illnesses. The fundamental results achieved were: chronic bronchitis, breast dysplasia and Chronic Pelvic Inflammation (CPI) were among the personal pathological antecedents found, and the Familial Pathological Antecedents of malignant neoplasm (FPA) were very significant. The alert signs mostly defined were: cough or persistent hoarseness, changes in the intestinal or bladder function and nodule or bulges in the breasts or in any other body parts. All these results corroborated the hypothesis presented (AU)

Evaluación en programas de prevención de recaída: adaptación española del Inventario de Habilidades de Afrontamiento (CBI) de Litman en dependientes de alcohol / Assesment at relapse prevention programs: spanish adaptation of the doping behaviour inventory (CBI) in alcohol depedence patients

La evaluación de las habilidades de afrontamiento se enmarca en las intervenciones de prevención de recaídas desarrolladas desde la psicología cognitivo conductual. Se presentan los resultados de fiabilidad y validez de la versión española del Inventario de Habilidades de Afrontamiento, CBI, en una muestra de 151 pacientes dependientes de alcohol. Mediante este instrumento, que consta de 36 ítems, se identifican aquellas habilidades de afrontamiento que el dependiente del alcohol emplea para no consumir cuando experimenta deseos de bebida. La consistencia interna del instrumento es adecuada en esta muestra (alpha= 0.90). El análisis factorial presenta 4 factores (pensamiento positivo, pensamiento negativo, distracción y evitación) que explican el 44.39 por ciento de la varianza y que coinciden en gran medida con los de estudios previos en muestras no españolas. La alta fiabilidad y validez de constructo de la versión española del CBI hace recomendable su utilización con fines de evaluación y clínicos (AU)

Reliability and validity results of the Coping Behaviour Inventory, CBI, are presented in a sample of 151 alcohol dependents. This instrument is frequently used in relapse prevention treatment as a tool for therapeutic purpose. This 36 item questionnaire evaluates those coping behaviours that the alcohol dependent patients use to avoid a relapse. The internal reliability is satisfactory (alpha = 0.90). Factorial analysis showed four emergent factors (positive thinking, negative thinking, distraction, and avoidance) accounting for 44.39 of the variance, which are similar, to a large extent, with those found in non-Spanish studies. The satisfactory reliability and construct validity of the Spanish version of the CBI confirms that it is adequate for assessment and clinical purposes (AU)

Adaptación española del inventario de situaciones precipitantes de recaída (RPI) en dependientes del alcohol / Spanish adaptation of the relapse precipitant inventory (RPI) with alcohol dependence patients

Se presentan los resultados de fiabilidad y validez del 'Inventario de Situaciones Precipitantes de Recaída' (Relapse Precipitant Inventory, RPI; Litman et al., 1983) en una muestra de 201 pacientes dependientes de alcohol que reciben tratamiento en el Centro de Salud Mental de Retiro (Madrid). En estudios previos se ha mostrado la capacidad de este instrumento para discriminar entre aquellos pacientes con recaídas y aquellos que se mantienen abstinentes. Por otra parte, el inventario es utilizado con frecuencia dentro de los programas de intervención orientados a la prevención de recaídas como herramienta terapéutica. Mediante este instrumento, que consta de 25 ítems, se identifican aquellas situaciones que el bebedor podría percibir como peligrosas o de alto riesgo.El análisis factorial presenta 4 factores que explican el 53,7 por ciento de la varianza y que coinciden en gran medida con los de estudios previos en muestras no españolas: 1) estados de humor desagradables, 2) vigilancia cognitiva reducida, 3) situaciones interpersonales y/o de diversión y 4) acontecimientos externos. Otras cualidades psicométricas del inventario en la muestra comentada son asimismo presentadas (AU)

Estudio de los accidentes en instituciones educacionales seleccionadas del municipio especial Isla de la Juventud / Study of accidents in educational institutions selected at the Isle of the Youth special municipality

Los accidentes constituyen la primera causa de muerte de 1 a 49 años, tanto a nivel mundial como en Cuba. Esto motivó a realizar un estudio para conocer características de los accidentes ocurridos a 208 niños y adolescentes, en 6 instituciones educacionales de diferentes niveles de enseñanza, del municipio especial Isla de la Juventud, durante el curso escolar de 1986 a 1987. Los datos fueron recogidos mediante encuestas confeccionadas al efecto y se empleó el porcentaje como medida de frecuencia relativa. Los accidentes constituyeron causa de morbilidad y mortalidad en los educandos y fueron más frecuentes en el sexo masculino y en los grupos de adolescentes. Hubo mayor número de heridas e hincadas, así como accidentes moderados. La práctica de deportes fue la actividad más relacionada con la producción de accidentes y éstos ocasionaron ausencias a actividades docentes y laborales

Estudio de los accidentes en instituciones educacionales seleccionadas del municipio especial Isla de la Juventud / Study of accidents in educational institutions selected at the Isle of the Youth special municipality

Los accidentes constituyen la primera causa de muerte de 1 a 49 años, tanto a nivel mundial como en Cuba. Esto motivó a realizar un estudio para conocer características de los accidentes ocurridos a 208 niños y adolescentes, en 6 instituciones educacionales de diferentes niveles de enseñanza, del municipio especial Isla de la Juventud, durante el curso escolar de 1986 a 1987. Los datos fueron recogidos mediante encuestas confeccionadas al efecto y se empleó el porcentaje como medida de frecuencia relativa. Los accidentes constituyeron causa de morbilidad y mortalidad en los educandos y fueron más frecuentes en el sexo masculino y en los grupos de adolescentes. Hubo mayor número de heridas e hincadas, así como accidentes moderados. La práctica de deportes fue la actividad más relacionada con la producción de accidentes y éstos ocasionaron ausencias a actividades docentes y laborales