Nanotecnología y sus potenciales aplicaciones en microbiología

Tanto la nanotecnología como la nanociencia tratan sobre el estudio de materiales y objetos a escala nanométrica. Los nanoobjetos y nanomateriales están constituidos por nanopartículas (NPs). Las NPs son aquella parte diminuta de la materia que presentan una o más dimensiones externas en el intervalo de tamaños comprendido entre 1 nm y 100 nm. La síntesis de NPs se puede llevar a cabo mediante métodos físicos, químicos o biológicos. Estos últimos son respetuosos con el medio ambiente y evitan la producción de químicos tóxicos que en la mayoría de los casos resultan perjudiciales para la salud. Además los métodos biológicos son ventajosos en cuanto a su rentabilidad y bajo consumo energético. Las NPs pueden ser sintetizadas por distintos tipos de microorganismos incluyendo bacterias, levaduras, hongos y virus. Los microorganismos son capaces de sintetizar NPs metálicas, NPs compuestas por óxidos, y NPs con propiedades semiconductoras. En el ámbito de la microbiología, las NPs presentan aplicaciones en áreas muy diversas tales como el tratamiento de aguas (inhibiendo el crecimiento de microorganismos y la formación de biofilms), la microbiología alimentaria (evitando el desarrollo de microorganismos causantes de contaminación alimentaria), la detección de microorganismos (a través de ensayos inmunológicos basados en reacciones especificas antígeno-anticuerpo se puede detectar la presencia de microorganismos en distintas muestras de analito), entre otras. Las NPs se emplean también en el campo clínico como antimicrobianos y para combatir la resistencia a antibióticos debido a su mecanismo de acción particular que difiere de los antibióticos convencionales. Los mecanismos de acción a través de los cuales las NPs actúan como antimicrobianos son muy variadosUniversidad de Sevilla. Grado en Farmaci

Ecotoxicity of Ionic Liquids Towards Vibrio fischeri: Experimental and QSAR Studies

Ionic liquids (ILs) have gained significant attention within the academic and industrial circle owing to their attractive and unique characters. However, the usual green image of the ionic liquids mainly associated with their low vapour pressure has become increasingly doubtful. Several recent studies have highlighted the underestimated ILs toxicity which has not been adequately addressed. Therefore, improving the understanding of the ionic liquids toxicity towards aquatic organisms will undoubtedly lead to formulation of right solutions to address the toxicity problem hence contributing towards the development of green and sustainable ILs‐based technology. The chapter provides a collective review of studies conducted on the effect of ILs structure on toxicity, specifically focussing on the various types of cations and anions, and the length of the alkyl chain attached. Based on the qualitative outcome from the review, a discussion on the development of statistical modelling on the impact of ILs structural features towards the overall toxicity is presented. The application of quantitative structure activity relationship (QSAR) for developing the predictive model for toxicity is highlighted

Phytochemical Screening and Antioxidant Activities of Different Organic Extracts of Three Algerian Plants

We compared the phytochemical constituents and antioxidant activities of three important species of Lamiaceae in Algeria (Mentha spicata, Ocimum basilicum and Thymus algeriensis). We noticed that the M. spicata species contains the largest fraction of phenolic and flavonoid products (231 and 22 mg / g) than the other two species studied. Other hand we founded that the two species M. spicata and T. algeriensis show excellent antioxidant activity in the ethanolic extract according to the two tests (DPPH and ABTS) compared to the ascorbic acid of reference. But the specie O. basilicum has good antioxidant activity in aqueous extraction. This Lamiaceae family takes an important place in the lives of Algerians citizens, so this species are very good source of natural antioxidant compounds in algerian traditional medicine. Keywords: Antioxidant activity, Lamiaceae, Mentha spicata, Ocimum basilicum and Thymus algeriensis, DPPH

Datation des changements structurels au sein d’une chronique : le cas des séries macroéconomiques marocaines

Over the past four decades, many events and economic and extra-economic changes questioned the relevance and validity of structural econometric models. Currently, all models are developed for a stationary process. However, this hypothesis is not usually verified. This article attempts to implement some unit root tests both in classical and modern ways. In particular, we will base our application on the tests with structural breaks time. Our investigation sample is composed about several Moroccan macroeconomic variables, namely real GDP, inflation rate, etc. Most of results of these implementation tests reveal us that all the series have undergone at least two breaks (two structural changes) at the time. The stationary is confirmed around a segmented trend, in case when that makes the reviewing the all standard stationary tests findings

Datation des changements structurels au sein d’une chronique : le cas des séries macroéconomiques marocaines

Over the past four decades, many events and economic and extra-economic changes questioned the relevance and validity of structural econometric models. Currently, all models are developed for a stationary process. However, this hypothesis is not usually verified. This article attempts to implement some unit root tests both in classical and modern ways. In particular, we will base our application on the tests with structural breaks time. Our investigation sample is composed about several Moroccan macroeconomic variables, namely real GDP, inflation rate, etc. Most of results of these implementation tests reveal us that all the series have undergone at least two breaks (two structural changes) at the time. The stationary is confirmed around a segmented trend, in case when that makes the reviewing the all standard stationary tests findings