New perspectives for the application of diatomaceous earth to the remediation of polluted waters and soils

Se realizaron investigaciones acerca de la remediación de aguas residuales para prevenir daños, tanto de las reservas de aguas subterráneas como superficiales. Con este propósito, las tierras de diatomeas, un barato, disponible y no contaminante material, fue ensayado para la retención de contaminantes persistentes, tales como los metales pesados (cadmio) y pesticidas (antracita y cloropirifos). Esto ha sido utilizado en la prevención de la contaminación de aguas subterráneas debido a su gran movilidad reportada y a la irrigación y limpieza de suelos destinados a la agricultura. Variables tales como profundidad, espesor, etc. de los suelos quedaron cuidadosamente establecidos para simular una explotación casi real de suelos potencialmente contaminados. Los resultados preliminares presentados aquí muestran porcentajes de retención de cadmio mayores del 75 % y del 50 % para la antracita. Estos enfatizan el potencial uso como limpiador y remediador de las tierras de diatomea para contaminantes persistentes, tales como los metales pesados y los pesticidas, en particular, los utilizados en este estudio. La adsorción por las tierras de diatomeas es válida para todos los suelos ensayados. Luego, existe la posibilidad de prevenir la contaminación por cadmio en aguas subterráneas por deposición de una capa de las tierras de diatomeas bajo la superficie de los suelo

Development of a method for assessing the accumulation and metabolization of antidepressant drugs in zebrafish (Danio rerio) eleutheroembryos

Antidepressant drugs are widely used for the treatment of common mental or other psychiatric disorders such as depression, which affect about 121 million people worldwide. This widespread use has contributed to the input of these pharmaceuticals and their metabolites into the environment. The aim of this work was to develop an analytical method to quantify the most widely used antidepressant drugs, selective serotonin reuptake inhibitors (SSRI), and their main metabolites in the environment. For this, a new and reliable miniaturized extraction method based on dispersive SPE cleanup procedure for extraction of SSRI followed by derivatization with n-heptafluorobutyrylimidazole, and detection by GC-MS was developed. The methodology, including a firstorder one-compartment model, was then applied to a bioconcentration study in zebrafish (Danio rerio) eleutheroembryos. The results showed low bioaccumulation of these compounds; however, a biotransformation evidence of the parent compounds into their metabolites was observed after 6 h of exposure. These results indicate the need to integrate metabolic transformation rates to fully model and understand the bioaccumulation patterns of SSRI and their metabolites

Aprendizaje-Servicio para trasladar los resultados desarrollo sostenible: del laboratorio a la sociedad

El objetivo general planteado en este proyecto ha sido comunicar y concienciar a los estudiantes de secundaria y bachillerato sobre la necesidad de un desarrollo sostenible, con el fin de que sean capaces de comprender e identificar las problemáticas asociadas a los objetivos planteados en la Agenda 2030 y asociarlas con actividades propias de la vida cotidiana. De esta manera, los alumnos podrán adquirir herramientas de gran utilidad para el desarrollo de su futura vida personal y profesional. Para lograr dichos objetivos se han llevado a cabo una serie de actividades (charlas de divulgación científica, debates, uso de la aplicación Kahoot) en diferentes centros educativos no universitarios, en concreto, en tres institutos de educación secundaria y bachillerato (IES) y en un centro de educación de personas adultas (CEPA). Los temas tratados se encuadran dentro de los Objetivos de Desarrollo Sostenible (ODS) de la Agenda 2030, concretamente los ODS 2, 3 y 12

I.amAble: la ciencia (química) al alcance de toda la sociedad

En este proyecto de innovación, que nace con vocación de continuar en años sucesivos, se persigue mejorar la calidad de la formación de los estudiantes de la Facultad de Ciencias Químicas (F. CC.QQ.) en el ámbito de la docencia teórico-práctica y de la divulgación científica. El trabajo ha consistido en la preparación de unos experimentos prácticos para llevarlos a cabo en centros educativos no universitarios en los que se ha tenido en cuenta la participación conjunta de personas con y sin diversidad funcional, desde una perspectiva inclusiva colaborativa. Estas actividades las han realizado los estudiantes bajo la supervisión de profesores (PDI) y personal de administración y servicios (PAS). Los experimentos se han recogido en fichas didácticas para facilitar su desarrollo y aplicación por parte de otros usuarios. En estas fichas se explica detalladamente cómo realizar las experiencias en formato de taller. Las fichas de los talleres realizados están disponibles en una página web vinculada a la Universidad Complutense bajo el título I.amAble (iamable.ucm.es). Está página ha sido construida por un estudiante de la Facultad de Informática , bajo la supervisión de profesionales, tanto de esa facultad como del Instituto de Tecnología del Conocimiento, y está abierta a contribuciones similares de otras facultades y otras instituciones. La página web está diseñada de manera que resulte lo más intuitiva y accesible posible para todo tipo de público. Entre todos los experimentos se han elegido cuatro para llevarlos a la práctica en centros educativos como actividades inclusivas en las que han participado conjuntamente personas con y sin discapacidad. Con este proyecto se pretende mejorar la calidad docente al ofrecer a los estudiantes la posibilidad de aprender enseñando mediante una actividad semipresencial. El desarrollo por parte de los estudiantes de competencias transversales en educación y en divulgación de la ciencia facilitarán algunas salidas profesionales en el ámbito educativo formal (centros de enseñanza) o informal (museos, animación sociocultural). Otro aspecto importante a resaltar es la potenciación de la colaboración entre todos los miembros de la institución universitaria. Este proyecto pretende contribuir a la mejora de la cultura científica, así como al establecimiento de puentes entre la UCM y la sociedad a la que debe servir. Finalmente, es importante subrayar que incidirá en la inclusión de las personas con discapacidad como parte de la sociedad, a través del acercamiento compartido a la ciencia (Dimensiones de inclusión social y derechos de Schalock; NAVAS MACHO, P. y otros, 2012. Derechos de las personas con discapacidad intelectual: implicaciones de la Convención de Naciones Unidas. Siglo Cero. 43 (243): 7-28.)

SILAC-based quantitative proteomics identifies size-dependent molecular mechanisms involved in silver nanoparticles-induced toxicity

Silver nanoparticles are currently one of the most widely used metallic nanoparticles. Due to their antibacterial properties, they are applied in textiles, house-holds items, and medical devices, among many other products. Understanding the potential toxicity associated with silver nanoparticles and the differential effect that nanoparticles of different size might induce is crucial, due to the increasing human and environmental exposure to this type of nanoparticles. In this work, we explored the different biomolecular mechanisms underlying the toxicity of silver nanoparticles in a size-dependent manner. Quantitative proteomic analysis of hepatic cells exposed to 10 and 60 nm silver nanoparticles demonstrated the alteration of a different set of proteins depending on the particle size. We demonstrated that while 10 nm silver nanoparticles induce nucleolar stress and ribosome biogenesis halt, both types of nanoparticles induce DNA damage and oxidative stress but through different pathways. In addition, both types of nanoparticles also affected cell proliferation, disrupted the cell cycle and ultimately, induced apoptosis. The alteration of different cellular mechanisms in a size-dependent manner, have relevant implications not only from a toxicity point of view, but also for the potential applications of silver nanoparticles.Ministerio de Economía y Competitividad (España)Comunidad Autónoma de MadridEuropean CommissionDepto. de Química AnalíticaFac. de Ciencias QuímicasTRUEpu

Cold vapour atomic fluorescence spectrometry and gas chromatography-pyrolysis-atomic fluorescence spectrometry for routine determination of total and organometallic mercury in food samples. Analyst 2002

Two procedures have been investigated for the quantification of the different forms of mercury in food. A two-stage procedure has been developed to determine firstly total inorganic and organometallic species, and then the full separation of all organomercury species. The procedure involves solubilisation of the samples using alkaline extractions or enzymolysis, followed by the extraction of organic mercury in an organic solvent, preferably a mixture of dichloromethane and hexane (3+2). For the total organic mercury determination, the organic extract is analysed for "total" mercury after nitric acid/peroxide digestion, evaporation of the solvent and detection by cold vapour-atomic fluorescence spectrometry. Full organomercury speciation requires a clean-up step before analysis of the final extract in dichloromethane by gas chromatography coupled to a pyrolyser and an atomic fluorescence detector (GC-pyro-AFS). A detection limit of 6 ng l 21 , and reproducibility of 2% was achieved for the CV-AFS method; GC-pyro-AFS yielded 200 ng l 21 and 5% for detection limit and coefficient of variation, respectively. Both procedures were validated with the use of various certified reference materials over a wide range of mercury concentrations, and by spiking experiments. The validated methods were tested successfully on a wide range of commercially available food samples

Response to Arsenate treatment in Schizosaccharomyces pombe and the role of its Arsenate reductase activity

Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the MAPK Spc1/Sty1 in response to arsenate. This activation is dependent on Wis1 activation and Pyp2 phosphatase inactivation. Using arsenic speciation analysis we have also demonstrated the previously unknown capacity of S. pombe cells to reduce As (V) to As (III). Genetic analysis of several fission yeast mutants point towards the cell cycle phosphatase Cdc25 as a possible candidate to carry out this arsenate reductase activity. We propose that arsenate reduction and intracellular accumulation of arsenite are the key mechanisms of arsenate tolerance in fission yeast.Spanish Science and Innovation Ministry (CTQ2008-01031/BQU, BFU2006/01767, BFU2009/09116)Peer Reviewe

Bioaccumulation of ionic titanium and titanium dioxide nanoparticles in zebrafish eleutheroembryos

<div><p></p><p>The production of titanium dioxide nanoparticles (TiO₂ NPs) for commercial applications has greatly increased over the last years and consequently the potential risk for human health. There is a growing awareness of the need to understand the behavior and influence these nanoparticles exert on the environment. Bioaccumulation serves as a good integrator to assess chemical exposure in aquatic systems and is dependent on factors, such as the exposure routes, diet and the aqueous medium. We analyzed the experimental bioaccumulation capability of ionic titanium and TiO₂ NPs by zebrafish (<i>Danio rerio</i>) eleutheroembryos through bioconcentration factors (BCFs), after 48 or 72 h of exposure. The stability of both chemical forms in an aquatic medium was fully characterized for further bioaccumulation studies. Several stabilizing agents (humic acids, soluble starch, polyethylene glycol, Na₄P₂O₇ and Na₂HPO₄) for anatase and rutile, the two allotrophs of TiO₂ NPs, were evaluated to check the evolution of the aggregation process. Around 60% of TiO₂ NPs remained disaggregated under simulated environmental conditions with the addition of 50 mg L⁻¹ of humic acids. However, the presence of eleutheroembryos in the exposure medium increased TiO₂ NPs aggregation in the experimental tests. The BCFs values obtained in all cases were <100, which classifies ionic titanium and TiO₂ NPs as non-bioaccumulative substances, under the REACH regulations.</p></div

Response to arsenate treatment in Schizosaccharomyces pombe and the role of its arsenate reductase activity.

Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the MAPK Spc1/Sty1 in response to arsenate. This activation is dependent on Wis1 activation and Pyp2 phosphatase inactivation. Using arsenic speciation analysis we have also demonstrated the previously unknown capacity of S. pombe cells to reduce As (V) to As (III). Genetic analysis of several fission yeast mutants point towards the cell cycle phosphatase Cdc25 as a possible candidate to carry out this arsenate reductase activity. We propose that arsenate reduction and intracellular accumulation of arsenite are the key mechanisms of arsenate tolerance in fission yeast