Desarrollo de membranas de doble capa y reciclaje de módulos de membrana de ósmosis inversa para tratamiento de aguas

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, leída el 10-12-2021Nowadays, water scarcity is a problem that important organizations such as the United Nations (UN) warn about, indicating that only less than two-thirds of the world's population has adequate access to safe and drinking water. Membrane technologies and mainly desalination by reverse osmosis (RO) process, are being applied worldwide as mechanisms to obtain drinking water. However, RO has still some problems that require an immediate solution, such as the treatment and management of the produced brines and wastes caused by discarded RO membrane modules. Other membrane processes of emerging interest such as forward osmosis (FO), pervaporation (PV) or membrane distillation (MD), also need focused efforts for their proper development and subsequent large scale application.The main objective of this PhD thesis is twofold. On one hand, dual-layer polymeric membranes (DLMs) are developed using different membrane preparation techniques in order to improve the performance of membrane separation processes of emerging interest such as PV and MD; and on other hand, attempts are made to recycle discarded RO modules in order to extend the useful life of their components making them suitable for water treatment by other membrane processes, contributing therefore to the circular economy of membrane science and protection of the environment...En la actualidad la escasez de agua es un problema del que alertan importantes organizaciones como la Organización de las Naciones Unidas (ONU), indicando que solo menos de dos tercios de la población mundial tiene acceso adecuado a agua potable y segura. Las tecnologías de membrana y principalmente la desalación mediante el proceso de separación ósmosis inversa (OI), están siendo aplicadas en todo el mundo como mecanismos para la obtención de agua potable. Sin embargo, la OI presenta algunos problemas que requieren una inmediata solución como el tratamiento y la gestión de las salmueras producidas y el adecuado manejo de los residuos ocasionados por los módulos de membrana desechados. Otros procesos de membrana de interés emergente como la osmosis directa (OD), la pervaporación (PV) o la destilación en membrana (DM), también necesitan la focalización de esfuerzos para su adecuado desarrollo y posterior aplicación a gran escala. El objetivo principal de esta tesis doctoral es doble. Por un lado se estudia el desarrollo de membranas poliméricas de doble capa (MDCs) aplicando diferentes técnicas de preparación de membranas, con el objeto de mejorar el rendimiento de procesos de separación por membranas emergentes como la PV y la DM; y por otro lado se reciclan módulos de OI descartados con el objeto de alargar la vida útil de sus componentes para aplicaciones en otros procesos de membrana para el tratamiento de aguas, contribuyendo en la economía circular de la ciencia de membranas y protección del medio ambiente...Fac. de Ciencias FísicasTRUEunpu

Estudios pioneros en torno al origen del lenguaje natural

It has being an ancient desire to ask apes what their natural lives are. De la Mettrie was the first to propose, in the 18th C., that the sign language of deaf adults could be used with them since they do not speak. We enhance here some of the pioneering projects of the two strategies for this endeavor: the use of ASL and the utilization of lexigrams and computers. Besides the ancient communicative quest with them, the evolutionist’s perspective has seen in these studies a way to find out how the natural language (NL) emerged in hominids. If it is clear that apes do no possess totally the NL, the linguistic turn in primatology has left way, as in philosophy, to more complex field and laboratory cognitive studies of less anthropocentric nature.Tratar de hablar con los simios y preguntarles cosas sobre su vida natural es un viejo deseo. De la Mettrie propone, en el s. XVIII, que se les enseñe el lenguaje de los sordos en vista de que no pueden hablar. Resaltamos aquí algunos estudios pioneros en relación con las dos estrategias llevadas a cabo para tratar de hablar con los simios: el uso del lenguaje americano de sordos (ASL) y el de los lexigramas y computadoras. Además del viejo interés interrogativo humano hacia ellos, la perspectiva evolucionista ha visto en estos estudios un medio de investigar cómo surgió el lenguaje natural (LN) en homínidos. Si queda claro que los simios no poseen totalmente el LN, el giro lingüistico en primatología ha cedido, como en filosofía, el paso a estudios cognitivos más complejos, de campo y de laboratorio, de orientación menos antropomórfica

Primer registro del zorrillo manchado del sur spilogale angustifrons howell 1902 para el estado de Campeche, México

We found two roadside-killed individuals of Southern Spotted Skunk Spilogale angustifrons in the Calakmul region Campeche, Mexico (one, on the road Dziblachén-Xpujil, and the other, on the road to Calakmul archeological site). This information represents the first record for this species in this Mexican state and the extension of its distributional range.We found two roadside-killed individuals of Southern Spotted Skunk Spilogale angustifrons in the Calakmul region Campeche, Mexico (one, on the road Dziblachén-Xpujil, and the other, on the road to Calakmul archeological site). This information represents the first record for this species in this Mexican state and the extension of its distributional range

Electrospun Nanostructured Membrane Engineering Using Reverse Osmosis Recycled Modules: Membrane Distillation Application

As a consequence of the increase in reverse osmosis (RO) desalination plants, the number of discarded RO modules for 2020 was estimated to be 14.8 million annually. Currently, these discarded modules are disposed of in nearby landfills generating high volumes of waste. In order to extend their useful life, in this research study, we propose recycling and reusing the internal components of the discarded RO modules, membranes and spacers, in membrane engineering for membrane distillation (MD) technology. After passive cleaning with a sodium hypochlorite aqueous solution, these recycled components were reused as support for polyvinylidene fluoride nanofibrous membranes prepared by electrospinning technique. The prepared membranes were characterized by different techniques and, finally, tested in desalination of high saline solutions (brines) by direct contact membrane distillation (DCMD). The effect of the electrospinning time, which is the same as the thickness of the nanofibrous layer, was studied in order to optimize the permeate flux together with the salt rejection factor and to obtain robust membranes with stable DCMD desalination performance. When the recycled RO membrane or the permeate spacer were used as supports with 60 min electrospinning time, good permeate fluxes were achieved, 43.2 and 18.1 kg m(-2) h(-1), respectively; with very high salt rejection factors, greater than 99.99%. These results are reasonably competitive compared to other supported and unsupported MD nanofibrous membranes. In contrast, when using the feed spacer as support, inhomogeneous structures were observed on the electrospun nanofibrous layer due to the special characteristics of this spacer resulting in low salt rejection factors and mechanical properties of the electrospun nanofibrous membrane

Desarrollo a distancia de la maestría en docencia para la educación media superior (MADEMS) de la Univesidad Nacional Autónoma de México (UNAM)

The general characteristics of the Master’s degree program MADEMS and the strategic actions required to organize the distance education program are described. The possibilities for generalization and collaboration with high schools and colleges in Mexico and in other countries are examined. Furthermore, the implications of this program in the context of educational spaces in which our institution is involved are also considered. This is done by taking into account that this program provides a multidisciplinary model with a multiplicative effect and that it is also a project which contributes to education, training, innovation, cooperation and development.Describimos las características generales de la MADEMS y las acciones estratégicas necesarias para impartir la modalidad a distancia. También comentamos sus posibilidades de generalización y colaboración con centros de educación media y superior en México y en otros países, así como las implicaciones que tiene este posgrado en el marco de los espacios educativos en los cuales participa la institución, en tanto modelo de programa multidisciplinario, experiencia de efecto multiplicador y proyecto donde convergen aportaciones a la educación, la capacitación, la innovación, la cooperación y el desarrollo

Thy-1 (CD90)-Induced Metastatic Cancer Cell Migration and Invasion Are β3 Integrin-Dependent and Involve a Ca2+/P2X7 Receptor Signaling Axis

Cancer cell adhesion to the vascular endothelium is an important step in tumor metastasis. Thy-1 (CD90), a cell adhesion molecule expressed in activated endothelial cells, has been implicated in melanoma metastasis by binding to integrins present in cancer cells. However, the signaling pathway(s) triggered by this Thy-1-Integrin interaction in cancer cells remains to be defined. Our previously reported data indicate that Ca2+-dependent hemichannel opening, as well as the P2X7 receptor, are key players in Thy-1-αVβ3 Integrin-induced migration of reactive astrocytes. Thus, we investigated whether this signaling pathway is activated in MDA-MB-231 breast cancer cells and in B16F10 melanoma cells when stimulated with Thy-1. In both cancer cell types, Thy-1 induced a rapid increase in intracellular Ca2+, ATP release, as well as cell migration and invasion. Connexin and Pannexin inhibitors decreased cell migration, implicating a requirement for hemichannel opening in Thy-1-induced cell migration. In addition, cell migration and invasion were precluded when the P2X7 receptor was pharmacologically blocked. Moreover, the ability of breast cancer and melanoma cells to transmigrate through an activated endothelial monolayer was significantly decreased when the β3 Integrin was silenced in these cancer cells. Importantly, melanoma cells with silenced β3 Integrin were unable to metastasize to the lung in a preclinical mouse model. Thus, our results suggest that the Ca2+/hemichannel/ATP/P2X7 receptor-signaling axis triggered by the Thy-1-αVβ3 Integrin interaction is important for cancer cell migration, invasion and transvasation. These findings open up the possibility of therapeutically targeting the Thy-1-Integrin signaling pathway to prevent metastasis