Turbidity patterns in the Albufera lake, Spain, and their relation to irrigation cycles

[EN] The Albufera Natural Park (Valencia, Spain) is one of the most representative coastal wetlands in the Mediterranean basin. It holds several protection designations at national and international level, such as Spanish Natural Park, Special Protection Areas (SPAs) for birds, Sites of Community Importance (SCIs) and Ramsar Site. Both the park and its main lake, Albufera¿s lake, face several environmental problems. One of them is reduced transparency and lake clogging. The lake is highly dependent on the rice cycle and on irrigation returns, mainly from the Acequia Real. In this study, we analyse the monthly transparency and turbidity patterns during year 2018, and we relate them to irrigation cycles. We used Sentinel 2A satellite images from the European Space Agency, which have an atmospheric correction. Remote sensing results were compared with in situ data from the monitoring program of the Environment General Subdivision of the regional government. This monitoring program samples five points on a monthly basis, and analyses Secchi disk depth, suspended solids and chlorophyll a. Our results show the temporal and spatial pattern of turbidity in the Albufera lake which offers relevant information for water resources management.María-Teresa Sebastiá-Frasquet was beneficiary of the CAS18/00107 post-doctoral research grant, supported by the Spanish Ministry of Education Culture and Sports during her stay at the Universidad Autónoma de Baja California (Mexico), image processing was partially developed during the staySebastiá-Frasquet, M.; Aguilar-Maldonado, JA.; Santamaría-Del-Ángel, E.; Altur Grau, VJ. (2019). Turbidity patterns in the Albufera lake, Spain, and their relation to irrigation cycles. WIT Transactions on Ecology and the Environment (Online). 239:173-180. https://doi.org/10.2495/WS190151S17318023

Gold-Based Nanoparticles on Amino-Functionalized Mesoporous Silica Supports as Nanozymes for Glucose Oxidation

The transformation of glucose represents a topic of great interest at different levels. In the first place, glucose is currently conceived as a green feedstock for the sustainable production of chemicals. Secondly, the depletion of glucose at the cellular level is currently envisioned as a promising strategy to treat and alter the erratic metabolism of tumoral cells. The use of natural enzymes offers multiple advantages in terms of specificity towards the glucose substrate but may lack sufficient robustness and recyclability beyond the optimal operating conditions of these natural systems. In the present work, we have evaluated the potential use of an inorganic based nanohybrid containing gold nanoparticles supported onto ordered mesoporous supports. We have performed different assays that corroborate the enzyme-mimicking response of these inorganic surrogates towards the selective conversion of glucose into gluconic acid and hydrogen peroxide. Moreover, we conclude that these enzyme-like mimicking surrogates can operate at different pH ranges and under mild reaction conditions, can be recycled multiple times and maintain excellent catalytic response in comparison with other gold-based catalysts

Relación de la estructura con las propiedades eléctricas en solución sólida La2/3-xLi3xTiO3 (0.03 x 0.167)

En este trabajo se investigó la solución sólida La2/3-xLi3xTiO3 (0.03<x<0.167) por las técnicas de difracción de rayos-X en polvos (DRX), espectroscopía de impedancias (EI) y resonancia magnética nuclear (RMN) de 7Li. En estas muestras se observó un cambio en la simetría de tetragonal a ortorrómbica cuando disminuye el contenido de litio por debajo de x=0.06. Hallamos que las modificaciones estructurales producidas se deben principalmente al ordenamiento de las vacancias a lo largo del eje c. Estas modificaciones disminuyen gradualmente al incrementarse el contenido de litio en la solución sólida. Se detectaron dos señales de litio con diferente constante cuadrupolar para el espectro de RMN del 7Li en las perovskitas ortorrómbicas/tetragonales, las cuales asociamos con dos sitios cristalográficos para el litio dentro de la estructura. Para la perovskita de composición La0.5Li0.5TiO3, se realizó un experimento enfriándola rápidamente desde 1300° C en nitrógeno líquido. En ésta se detectó una elevada movili- dad del litio en el espectro de RMN del 7Li. Para las perovskitas analizadas, la dependencia de la conductividad eléctrica con el contenido de litio no sigue el comportamiento esperado, basado en la teoría de una distribución aleatoria de los átomos de La y Li sobre los sitios A. La conductividad DC aumenta rápidamente con el contenido de litio en las muestras ortorrómbicas, aunque el cambio es mucho más gradual en las tetragonales, donde la distribución de las vacancias se desordena progresivamente. En todas las perovskitas analizadas, la dependencia de la conductividad dc con la temperatura muestra un comportamiento no-Arrhenius con energías de activación de 0.39±0.02 eV y 0.29±0.02 eV en los rangos de temperatura de 160 – 250 y 250 – 360 K, respectivamente

Polymer functionalized gold nanoparticles as non-viral gene delivery reagents.

Background: In this study we investigated the ability of PEG functionalized gold nanoparticles as non-viral vectors in the transfection of different cell lines, comparing them with commercial lipoplexes. Methods: Positively charged gold nanoparticles were synthesized using PEI as reducing and stabilizer agent and its cytotoxicity reduced by its functionalization with PEG. We bound the nanoparticles to three plasmids with different sizes (4-40 kpb). The vector internalization was evaluated by confocal and electronic microscopy. Its transfection efficacy was studied by fluorescence microscopy and flow cytometry. The application of the resulting vector in gene therapy was indirectly evaluated using ganciclovir in HeLa cells transfected to express the herpes virus thymidine kinase. Results: An appropriate ratio between the nitrogen from the PEI and the phosphorous from the phosphate groups of the DNA together with a reduced size and an elevated electrokinetic potential are responsible for an increased nanoparticle internalization and enhanced protein expression when carrying plasmids of up to 40kbp (plasmid size close to the limit of the DNA carrying capacity of viral vectors). Compared to a commercial transfection reagent, an equal or even higher expression of reporter genes (on HeLa and HEK 293T) and suicide effect on HeLa cells transfected with the herpes virus thymidine kinase gene were observed when using this novel nanoparticulated vector. Conclusions: Non-viral vectors based on gold nanoparticles covalently coupled with polyethylene glycol (PEG) and Polyethylenimine (PEI) can be used as efficient transfection reagents showing expression levels same or greater than the ones obtained with commercially available lipoplexes.pre-print3905 K

Influencia del enfriamiento en las propiedades de titanatos de lantano y litio

Se ha estudiado el efecto de los tratamientos a alta temperatura sobre la estructura y la movilidad del litio para la solución sÛlida Li3xLa2/3-xTiO3 (0.03<x<0.167) con difracciÛn de rayos X a alta temperatura (DRXAT), espectroscopia Raman, RMN y de impedancias. Los patrones de difracción de rayos X (DRX) a temperatura ambiente de muestras enfriadas lentamente muestran una estructura tipo perovskita doblada en el eje c con simetrÌas tetragonales u ortorrómbicas, mientras que las muestras con un enfriamiento r·pido muestran una estructura tipo perovskita c ̇bica simple. Sin embargo, el espectro Raman de las muestras analizadas se interpreta, en todos los casos, con una simetrÌa tetragonal en la que el desorden catiónico se incrementa con el contenido de litio y el tratamiento de enfriamiento. La existencia de microdominios de maclado, orientados a lo largo de las tres direcciones de la perovski- ta, favorece la detecciÛn de la fase c ̇bica en los patrones de DRX. A partir de la espectroscopia de RMN del 7Li, se ha detectado un movimiento bidi- mensional del litio en las muestras ordenadas, el cual se convierte progresivamente en un movimiento tridimensional conforme se incrementa el desorden catiÛnico. Asimismo, la presencia de microdominios hace disminuir la conductividad dc de muestras con contenidos bajos de litio

Polyoxometalates as alternative Mo precursors for methane dehydroaromatization on Mo/zsm-5 and Mo/mcm-22 catalysts

The conversion of methane into higher molecular weight hydrocarbons of greater added value has emerged as one of the grand challenges of the 21st century. The non-oxidative methane dehydroaromatization (hereafter MDA) reaction is a promising methane valorisation reaction since it transforms methane into added-value aromatics and olefins, namely benzene, naphthalene and ethylene. Molybdenum-promoted ZSM-5 zeolite has proven to be one of the most effective catalysts for MDA providing a shape-selective environment for the conversion of methane into benzene. However, one of the principle disadvantages of using aluminosilicates in the presence of methane is that the catalyst suffers from rapid deactivation induced by coke formation, which ultimately leads to a decrease in activity and aromatics selectivity, making the process unsuitable for large-scale industrial applications. Better control of the metal dispersion on the surface of the aluminosilicate supports represents a crucial factor to partially suppress catalyst coking and improve stability. Here we show how different molecular polyoxomolybdate (POM) anions can be used as alternative Mo precursors to conventional Mo salts for the preparation of catalysts for the MDA reaction. Molecular dynamics simulations and experimental testing were conducted to characterize the interphase interactions between polyoxomolybdates and zeolite surfaces at the atomistic level and to evaluate the MDA performance of different POM-based catalysts supported on ZSM-5 and MCM-22, respectively. The catalysts prepared using hexamolybdate anions, [Mo6O19]2-, were found to be more active and selective towards benzene than those employing the commercial heptamolybdate, [Mo7O24]6-. The Mo loading and dispersion of MoOx species were found to be the key factors leading to enhanced catalytic stability on ZSM-5 and MCM-22-based supports for MDA where the 5% Mo6/MCM-22 catalyst provided a constant aromatics yield above 7% for more than 18 hours time-on stream operating at 700 °C with a diluted methane flow under atmospheric pressure. The zeolitic catalysts prepared with the Mo6 precursor were found to be amongst the most promising MDA catalysts in the literature and the results of this study pave the way for the selection and use of different POMs as innovative metal precursors to formulate new catalysts and further improve the MDA reaction process

Cancer-derived exosomes loaded with ultrathin palladium nanosheets for targeted bioorthogonal catalysis

The transformational impact of bioorthogonal chemistries has inspired new strategies for the in vivo synthesis of bioactive agents through non-natural means. Among these, Pd catalysts have played a prominent role in the growing subfield of bioorthogonal catalysis by producing xenobiotics and uncaging biomolecules in living systems. However, delivering catalysts selectively to specific cell types still lags behind catalyst development. Here, we have developed a bioartificial device comprising cancer-derived exosomes that are loaded with Pd catalysts by a method that enables the controlled assembly of Pd nanosheets directly inside the vesicles. This hybrid system mediates Pd-triggered dealkylation reactions in vitro and inside cells, and displays preferential tropism for their progenitor cells. The use of Trojan exosomes to deliver abiotic catalysts into designated cancer cells creates the opportunity for a new targeted therapy modality; that is, exosome-directed catalyst prodrug therapy, whose first steps are presented herein with the cell-specific release of the anticancer drug panobinostat

The effect of hollow gold nanoparticles on stem cell migration. Potencial application in tissue regeneration.

Every year trauma together with bone, joints and cartilage-associated diseases usually involve structural damage, resulting in a severe pain and disability for millions of people worldwide[1]. In regenerative medicine, cellular, tissue and organ-based approaches are developed to restore biological functions that have been lost[2],[3]. Therefore, tissue repair and regenerative medicine have attracted the interest of the scientific community, providing promising results in preclinical models and clinical pilot studies.pre-print3341 K

Recensiones [Revista de Historia Económica Año XII Primavera-Verano 1994 n. 2 pp. 437-472]

Editada en la Universidad Carlos IIIRobert C. Allen. Enclosure and the Yeoman. The Agricultural Development of the SouthMidlands 1410-1850 (Por Gaspar Feliú).-- Ruggiero Romano. Conjonctures opposées. La «crise» du XVII siècle: en Europe et en Amérique ibérique (Por Gaspar Feliú).-- Simposio de Historia de las Mentalidades. Instituto Nacional de Antropología e Historia, México. Familia y poder en Nueva España (Por Juan Carlos Sola Corbacho).-- Leandro Prados de la Escosura y Samuel Amaral (Eds.). La independencia americana: consecuencias económicas (Por Javier Cuenca).-- M.ª Cruz Romeo Mateo. Entre el orden y la revolución. La formación de la burguesía liberal en la crisis de la monarquía absoluta (1814-1833) (Por Ricardo Robledo).-- José G. Cayuela Fernández. Bahía de ultramar. España y Cuba en el siglo XIX. El control de las relaciones coloniales (Por Candelaria Sáiz Pastor).-- José Manuel Pose Antelo. La economía y la sociedad compostelanas a finales del siglo XIX (Por Carlos Larrinaga Rodríguez).-- Frank Broeze. Mr Brooks and the Australian Trade. Imperial Business in the Nineteenth Century (Por Jesús M.ª Valdaliso).-- Robert H. Bremner. Desde lo más bajo. El descubrimiento de la pobreza en Estados Unidos / James T. Patterson. La lucha contra la pobreza en los Estados Unidos de América, 1900-1985 (Por Nuria Puig).-- Justo Navarro Clari. Curso de Historia Económica (Por Antonio Santamaría)Publicad

Bioorthogonal uncaging of cytotoxic paclitaxel through Pd nanosheet-hydrogel frameworks

The promising potential of bioorthogonal catalysis in biomedicine is inspiring incremental efforts to design strategies that regulate drug activity in living systems. To achieve this, it is not only essential to develop customized inactive prodrugs and biocompatible metal catalysts but also the right physical environment for them to interact and enable drug production under spatial and/or temporal control. Toward this goal, here, we report the first inactive precursor of the potent broad-spectrum anticancer drug paclitaxel (a.k.a. Taxol) that is stable in cell culture and labile to Pd catalysts. This new prodrug is effectively uncaged in cancer cell culture by Pd nanosheets captured within agarose and alginate hydrogels, providing a biodegradable catalytic framework to achieve controlled release of one of the most important chemotherapy drugs in medical practice. The compatibility of bioorthogonal catalysis and physical hydrogels opens up new opportunities to administer and modulate the mobility of transition metal catalysts in living environs