Gold nanoparticles as colorimetric sensors for the detection of DNA bases and related compounds

[Abstract] Results regarding interaction of colloidal gold solutions with nucleobases, including uracil (U), as well as its sulfur derivatives, 2-thiouracil (2TU) and 4-thiouracil (4TU), cytosine (C), adenine (A), and guanine (G), as well as urea and thiourea (TU), are reported. Anionic stabilized citrate gold nanoparticles (AuNPs) were synthesized by reducing the tetrachloroaurate (III) trihydrate with trisodium citrate. The surface plasmon resonance (SPR) band was used in the characterization of synthesized AuNPs, as well as transmission electron microscope (TEM) imaging, which was used in the characterization of dispersed and aggregated gold nanoparticles. Interactions of nucleobases with the gold surface was analyzed by following the plasmon absorbance band red shift of the AuNPs. The sulfur-containing compounds adsorbed to the nanoparticle surfaces by chemisorption-type interactions; with TU and 4TU, the process is accompanied by a sudden change in color; in contrast, 2TU forms stable functionalized gold nanoparticles. Urea and U do not adsorb to nanoparticle surfaces, but the other heterocyclic bases containing nitrogen interact effectively with the gold surface, causing the assembly of nanoparticles, even though the interparticle self-aggregation process was slower than that mediated by either TU or 4TU. The method is efficient in the colorimetric detection of nucleobases and derivatives at concentration levels on the order of 1 µM.Ministerio de Economía y Competitividad; CTQ2015-71238-

Economic growth and employment: regional disparities in the UE.

One of the main problems of the European countries is their small capacity to generate employment. This is an important point because of the social and human problems that it produces, which are more serious in the case of peripheral regions. In this paper, we make a comparative analysis of employment and economic growth among the main EU countries. We study the reason of the more reduced rates of employment in several EU countries. Then, we analyse the generation of employment in the European regions, especially in the peripheral ones which are the most affected by unemployment.

Economic growth and employment: Regional disparities in the EU

One of the main problems of the European countries is their small capacity to generate employment. This is an important point because of the social and human problems that it produces, which are more serious in the case of the peripheral regions. In this paper, we make a comparative analysis of employment and economic growth among the EU and the main OECD countries. We study the reasons of the more reduced rates of employment in several EU countries in relation to USA and Japan. Then, we analyze the generation of employment in the European regions, specially in the peripheral ones which are the most affected by unemployment.

Fluorescence study of tetracaine–cyclodextrin inclusion complexes

The steady-state fluorescence emission from the local anaesthetic tetracaine (TCA) in water-solvent mixtures and in the presence of α-, β- and γ-cyclodextrin (CD) was investigated at various pH values. Emission was observed from the locally and the intramolecular charge transfer excited states. The TCA-CD system was found to be characterised by 1:1 associate in every case. The association constants of each complex were determined.Ministerio de Educación y Ciencia; CTQ2005-07428/BQUMinisterio de Ciencia e Innovación; CTQ2008-04429/BQ

Reciclaje en Colombia: oportunidad para incursionar al mercado internacional

El manejo del reciclaje en el mundo se ha vuelto una de las actividades más importantes tanto a nivel social, como ambiental, por eso se ha tomado la decisión de realizar un análisis sobre las ventajas, desventajas y beneficios que brinda esta práctica, como implementarlo y llevarlo a escalas más importantes convirtiéndolo en un negocio formal, dándole la oportunidad a las personas de escasos recursos que se dedican a este negocio de manera informal que reciban reconocimiento alguno de lo que hacen diariamente en sus vidas, el cual es el sustento en sus familias, y darle a conocer al gobierno, entidades privada y publicas, la oportunidad que hay en el reciclaje, consiguiendo su apoyo para acabar con la pobreza y con la contaminación que afecta al país, por falta de conocimiento sobre el tema. Es tan importante el reciclaje que a nivel internacional esta actividad ha traído muchos ingresos al país y ha generado empleo, se ha notado el mejoramiento del medio ambiente, es mas muchos países importan estos desechos transformados y muy pronto los exportaran, porque no tomar estos países como modelo de referencia y realizar la mis practicas de mejoramiento en Colombia, es una propuesta que hay que pensar y analizarla, para hacerla realidad y sacarle provecho a nuestros propios residuos.The management of recycling in the world has become one of the most important activities both at the social level, as environmental, that has taken the decision to carry out an analysis of the advantages, disadvantages and benefits afforded by this practice, implement it and take it to scales most important making it a formal business, giving the opportunity to the poor people who are dedicated to this business in an informal way that receive no recognition of the that do daily in their lives, which is the lifeline in their families, and give it to the Government, private entities and public, the opportunity that is in recycling, getting their support to end poverty and pollution that affects the country, due to lack of knowledge on the subject. Recycling is so important that, at the international level, this activity has brought many income to the country and has generated employment, the improvement of the environment, we have seen, is many countries import these wastes processed and exported them soon, because not to take these countries as reference model and to perform the same improvement in Colombia, is a proposal that should think and analyze it, to make it reality and take advantage of our own waste

Potentiometric characterisation of cyclodextrin inclusion complexes of local anaesthetics

The complexation of several local anaesthetics by β and γ-cyclodextrins was studied by potentiometry with glass electrode. Tetracaine and dibucaine complexation constants were determined at 25°C in the presence of 0.1 M of NaCl. It was found that prilocaine and lidocaine complexes cannot be detected.Ministerio de Educacion y Ciencia; CTQ2005-07428/BQUMinisterio de Ciencia e Innovacion; CTQ2008-04429/BQ

Micellar effects on aromatic esters hydrolysis

The alkaline hydrolysis of two aromatic esters, 2-naphthyl acetate (2NA) and phenyl acetate (PhA) has been tackled in this work. The reaction has been followed in water and in the presence of cationic surfactants with different chain lengths: dodecyltrimethylammonium bromide (DTABr), tetradecyltrimethylammonium bromide (TTABr), and hexadecyltrimethylammonium bromide (CTABr) and the corresponding hydroxides (DTAOH, TTAOH and CTAOH) at 25. °C. The pseudo-first order rate constants increase with surfactant concentration in the presence of surfactants with reactive counter-ions, while a maximum is reached for bromide surfactants with a constant concentration of hydroxyl ion. Both, the association equilibrium constants of 2NA and PhA with micelles and the rate constant in this medium were determined. The degree of counter-ion association to micelles was considered as a variable parameter, using the adsorption equilibrium of bromide and hydroxide ions to the micelle.Ministerio de Educación y Ciencia; CTQ2005-07428/BQUMinisterio de Ciencia e Innovación; CTQ2008-04429/BQ

A further study of acetylacetone nitrosation

The nitrosation of acetylacetone (AcAc) has been revised in an aqueous acid medium of perchloric acid and buffers of mono-, di-, or tri-chloroacetic acid. The results show that in the presence of buffers, under conditions of [nit] ≪ [AcAc] (nit = sodium nitrite) the reaction cannot be studied by UV-Vis spectroscopy, contrary to the recently published paper by García-Rio et al. (J. Org. Chem., 2008, 73, 8198). The present study also corroborates the previously published mechanism of AcAc nitrosation, where no base-catalysis was observed. Contrarily, the low effect of buffers was attributed to the formation of nitrosyl chloro-, dichloro- or trichloro-acetate salts that are new nitrosating agents.Ministerio de Ciencia e Innovación; CTQ2008-04429/BQ

Un analisis econometrico de la concentracion industrial en las regiones españolas

En este trabajo se analiza la concentracion de la produccion en las regiones españolas a lo largo de los ultimos años. Para ello diferenciamos entre aquellos sectores que muestran una tendencia a la concentracion por encima de la media, de los que se comportan siguiendo una pauta intermedia y de los que tienden a la dispersion geografica. La convergencia real y la estabilidad en las regiones españolas, integradas en la UE, requieren la modificacion de los problemas creados por la excesiva concentracion. Nos proponemos elaborar un modelo econometrico para cuantificar y analizar la competitividad y los efectos de politica industrial sobre el crecimiento de las regiones.

Interactions between speaker’s speech rate, orality and emotional involvement, and perceptions of interpreting difficulty: a preliminary study

La elevada tasa de elocución se considera un indicador fiable de dificultad del input, y se asocia a la presentación leída. La velocidad, en palabras/sílabas por minuto, se emplea como criterio en la selección de la dificultad del material para la evaluación de intérpretes. Pero la velocidad se superpone a otros componentes prosódicos concomitantes a los varios modos de presentación del input, su grado de oralidad y a la implicación emocional del orador. En este estudio observacional de un subcorpus de discursos originales en inglés del Parlamento Europeo se ha estudiado si los discursos con elevada velocidad se percibieron muy difíciles y los input más lentos como menos difíciles. Las percepciones de 11 expertas muestran provisionalmente que la velocidad, en sí misma, no es un factor determinante en percepciones de dificultad, y que se debería analizar junto a otros factores prosódicos concurrentes. Los resultados podrían contribuir al debate sobre la selección de material de evaluación y certificación de intérpretes.High speech rate is regarded as a reliable indicator of input difficulty, and it is associated with read speeches. Input speech rate, measured in terms of words/syllables per minute, is used as a criterion measuring difficulty when selecting material for the assessment of interpreters. However, speech rate is a multifaceted perception phenomenon that hinges on concurrent prosodic features, which are concomitant to the various modes of speech presentation, their orality and speakers’ emotional involvement. This observational, corpus-based study of English inputs at the European Parliament analyses whether fast inputs are related to perceptions of more difficulty, and slower speeches to perceptions of less difficulty. The holistic perceptions of 11 experts tentatively show that speech rate, per se, does not impinge on perceptions of difficulty. Rather, speech rate should be measured as a cluster of concurrent prosodic features. The data could contribute to the debate about the criteria used when selecting interpreting material for assessment and certification