Chromatic universes for Chile’s heritage

[ES] Para el diseño de dos centros de interpretación en la Región de O´Higgins, Chile, destinados a la puesta en valor de sitios patrimoniales, se encargan estudios de color y la creación de paletas cromáticas con el objetivo de dar coherencia interna e identidad al proyecto general. Durante la investigación preliminar de cada proyecto, de enfoque cualitativo, un equipo interdisciplinario recogió información en terreno mediante entrevistas, relevamientos cromáticos, fotografías y otros. Se planteó ampliar el concepto paleta de color hacia un orden espacial conceptualmente coherente con el proyecto de arquitectura, llamado “universo cromático”, cuyo objetivo fue facilitar el uso de los colores durante el proceso de diseño. La utilización de estos universos fue disímil en ambos proyectos, sin embargo, se logró dar coherencia e identidad a ambos y también orientar el uso de sus colores. Los universos cromáticos podrían abrir posibilidades para el acompañamiento de otros proyectos de arquitectu[EN] Color studies and chromatic palettes were commissioned for the design of two interpretation centers aimed at enhancing and promoting heritage sites in the Region of O´Higgins, Chile. Their purpose was to provide overall consistency and identity to the overall project. During each project’s preliminary qualitative research, a transdisciplinary team collected information on the ground using interviews, chromatic surveys, photographs and others. The idea of expanding the color palette concept onto a spatial order that was conceptually consistent with the architectural project –called “chromatic universe”– was suggested, and its purpose was to facilitate the use of colors during the design process. While these universes were used differently in both projects, consistency and identity were achieved, as well as guidance on the use of colors. Chromatic universes are expected to open up possibilities for their use in other architecture and design projects.Cordero-Jahr, E. (2019). Universos cromáticos para el patrimonio de Chile. EGA Expresión Gráfica Arquitectónica. 24(37):204-213. https://doi.org/10.4995/ega.2019.11188OJS2042132437CASTRO, A., MUJICA, F., CUSSEN F., 2017. Chamantos y mantas corraleras de Doñihue: ascenso y consolidación de un textil con DO (1917-2016). RIVAR Vol. 4, Nº 11. Mayo 2017: 4-30FRIDELL ANTER, K., 2001. What Colour is the red house? Nordic Journal for Architectural Research. http://arkitekturforskning.net/na/article/view/358 (visto el 20 de mayo de 2019).INSTITUTO DE ARQUITECTURA Y URBANISMO, 2012. Proyecto de investigación y desarrollo Centro de Interpretación Chamantos de Doñihue. Edición interna, Universidad Austral de ChileINSTITUTO DE ARQUITECTURA Y URBANISMO, 2014. Proyecto de investigación y desarrollo Parque paleontológico Tagua Tagua. Edición interna, Universidad Austral de ChileJACKSON, D., ASPILLAGA, E., RODRÍGUEZ, X.P., JACKSON, D., SANTANA, F., MÉNDEZ, C., 2012. Las Ocupaciones Humanas del Sitio Arqueológico de Santa Inés, Laguna de Tagua Tagua, Chile Central. Revista de Antropología N° 26, 2do Semestre, 2012: 151-168 https://doi.org/10.5354/0719-1472.2012.26558LACOSTE, P., LACOSTE M., 2018. Chamantos, Ponchos y Balandres en Colchagua y Rancagua (siglos XVII-XIX). Revista Estudios Atacameños. Arqueología y Antropología Surandinas. Universidad Católica del Norte https://doi.org/10.4067/S0718-10432018005000701LYNCH, K., 2008. La imagen de la ciudad. Editorial Gustavo Gili, SL, Barcelona.MARTÍNEZ R., 2011. Los Jardines del cielo. Centro de Interpretación Chamantos de Doñihue. Revista AUS Nº 10, p. 22-25. https://doi.org/10.4206/aus.2011.n10-06SANZ, J., GALLEGO, R., 2001. Diccionario Akal del Color. Ediciones Akal, S.A., Madrid, EspañaSAUERBRUCH, M., HUTTON, L. 2012. Sauerbruch Hutton, Color in Architecture. Distanz Verlag GmbH, Berlin.SCHINDLER, V. 2004. Prefabricated rolls of oil paint: Le Corbusier's 1931 colour keyboards. AIC 2004 Color and Paints, Interim Meeting of the International Color Association, Proceedings.SCHINDLER, V., GRIBER, Y., 2017. Environmental Colour Design:Theory and Practice. Editorial de la Universidad Estatal de Smolensk, Rusia.SCHMUCK, F. 1999. Farbe und Architektur 2. Eine Farbenlehre für die Praxis. Verlag Georg D.W. Callwey GmbH & Co, München

In vitro Activity of Pentamidine Alone and in Combination With Aminoglycosides, Tigecycline, Rifampicin, and Doripenem Against Clinical Strains of Carbapenemase-Producing and/or Colistin-Resistant Enterobacteriaceae

Enterobacteriaceae cause different types of community- and hospital-acquired infections. Moreover, the spread of multidrug-resistant Enterobacteriaceae is a public health problem and the World Health Organization pointed them among the pathogens in which the search of new antibiotics is critical. The objective of this study was to analyze the in vitro activity of pentamidine alone and in combination with gentamicin, tobramycin, amikacin, tigecycline, rifampicin, or doripenem against eight clinical strains of carbapenemase-producing and/or colistin-resistant Enterobacteriaceae: five carbapenemase-producing Klebsiella pneumoniae, one carbapenemase-producing Escherichia coli, and two colistin-resistant Enterobacter cloacae. MIC and MBC were determined following standard protocols. MIC results were interpreted for all the antibiotics according to the EUCAST breakpoints but for rifampicin in which the French FSM breakpoint was used. Bactericidal and synergistic activity of pentamidine alone and in combination with antibiotics at concentrations of 1xMIC was measured by time-kill curves. For one selected strain, K. pneumoniae OXA-48/CTX-M-15 time-kill curves were performed also at 1/2xMIC of pentamidine. All studies were performed in triplicate. Pentamidine MIC range was 200-800 μg/mL. The 50, 12.5, 62.5, 87.5, and 62.5% of the strains were susceptible to gentamicin, tobramycin, amikacin, tigecycline, and doripenem, respectively. Only the two E. cloacae strains were susceptible to rifampicin. Pentamidine alone at 1xMIC showed bactericidal activity against all strains, except for the E. cloacae 32 strain. The bactericidal activity of pentamidine alone was also observed in combination. The combinations of pentamidine were synergistic against E. cloacae 32 with amikacin and tobramycin at 24 h and with tigecycline at 8 h. Pentamidine plus rifampicin was the combination that showed synergistic activity against more strains (five out of eight). Pentamidine plus doripenem did not show synergy against any strain. At 1/2xMIC, pentamidine was synergistic with all the studied combinations against the K. pneumoniae OXA-48/CTX-M-15 strain. In summary, pentamidine alone and in combination shows in vitro activity against carbapenemase-producing and/or colistin-resistant Enterobacteriaceae. Pentamidine appears to be a promising option to treat infections caused by these pathogens.Plan Nacional de I+D+I 2013-2016 REIPI RD16/0016/0009Instituto de Salud Carlos III. Subdirección General de Redes y Centros de Investigación Cooperativa REIPI RD16/0016/0009Ministerio de Economía, Industria y Competitividad REIPI RD16/0016/0009Spanish Network for Research in Infectious Diseases REIPI RD16/0016/0009European Development Regional Fun

Synthesis and characterization of a new nanosorbent based on functionalized magnetic nanoparticles and its use in the determination of mercury by FI-CV-ETAAS

In this work, a new chelating sorbent which employs 1,5-bis(di-2-pyridil)methylene thiocarbohydrazide as the functional group and magnetic nanoparticles (MNPs) as its support (DPTH-MNP) was synthetized and characterized. The MNPs were prepared by coprecipitation of Fe+2 and Fe+3 with NH3 and then coated with silica in order to easily bind the support and the functionalizing molecule. The aim of the synthesis of this material is applying it as a solid-phase extracting agent and evaluating its potential for the extraction and pre-concentration of trace amounts of analytes present in biological and environmental samples with on-line methods. The MNPs’ magnetic core would allow overcoming the usual backpressure problems that happen in solid-phase extraction methods thanks to the possibility of immobilizing the MNPs by applying an external magnetic field. From the study of its adsorption capacity toward metal ions, mercury and antimony were the most retained. Thus, a flow injection solid phase extraction and cold vapor generation method for mercury determination based on the use of this new chelating nanosorbent was optimized. The greatest efforts were put into the reactor design to minimize compaction and loss of nanosorbent. The knotted reactor shown in Figure 1 was chosen as the best. Then, chemical and flow variables were optimized by Central composite designs (CCDs). The method developed has showed to be useful for the automatic pre-concentration and determination of mercury in environmental and biological samples. The determination was performed using electrothermal atomic absorption spectrometry (ETAAS). Under the optimum conditions, pH 5 and 120 s preconcentration time, the enrichment factor was 5.33; the detection limit (3σ) was 7.8 ng L-1; the determination limit (10σ) was 99 ng L-1; and the precisions (calculated for 10 replicate determinations at a 1 and 5 µg L-1 standards) were 1.7 and 1.9 % (RSD), respectively. Two linear calibration graphs were obtained, from the determination limits to 10 µg L-1 and from 10 to at least 50 µg L-1. From the comparison with other similar methods found in the bibliography, the detection limit and precisions calculated with our method were better. In order to evaluate the accurate and applicability of the method, the analysis of five certified samples LGC 6016 estuarine water, TMDA 54.4 fortified lake water, SRM 2976 mussel tissue, TORT-1 lobster hepatopancreas and DOLT-1 dogfish liver by standard addition and external calibration, were addressed. The results showed good agreement between the certified values, or added amounts of mercury, and the found concentrations. The method was successfully applied to the determination of mercury in sea-water samples collected in the Málaga Bay.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Methanol dehydration on carbon-based acid catalysts

Methanol dehydration to produce dimethyl ether (DME) is an interesting process for the chemical industry since DME is an important intermediate and a promising clean alternative fuel for diesel engines. Pure or modified γ-aluminas (γ-Al2O3) and zeolites are often used as catalysts for this reaction. However, these materials usually yield non desirable hydrocarbons and undergo fast deactivation. In this work, we study the catalytic conversion of methanol over an acid carbon catalyst obtained by chemical activation of olive stone with H3PO4. A significant amount of phosphorus remains over the catalyst surface after the activation process, mostly in form of C-O-PO3 and C-PO3 groups, which provide the carbon a relatively high surface acidity and oxidation resistance. Methanol decomposition on this catalyst yields selectivities to DME higher than 82% at 623K and methanol conversion of 34%, under the operating conditions studied. The activated carbon catalytic activity and stability, under inert and oxidant atmospheres, as well as different regeneration procedures, were studied. In the absence of oxygen, the catalyst suffers a progressive deactivation by coke deposition on the active acid sites (Fig. 1). The presence of oxygen modifies the carbon surface chemistry, probably through oxygen spillover on the catalyst surface, where the availability of labile oxygen avoids catalyst deactivation. A reaction mechanism has been proposed where methanol dehydration seems to proceed through an Eley-Rideal mechanism, which assumes the adsorption of water and oxygen spillover on the acid active sites, avoiding coke deposition

Elastic and dielectric measurements of the structural transformations in the ferroelectric perovskite (Na1/2Bi1/2)1-xBaxTiO3

NBT is a perovskite undergoing a series of structural and polar transitions starting from the high temperature paraelectric phase: tetragonal antiferroelectric, rhombohedral and finally ferroelectric. In solid solution with BaTiO3 the ferroelectric phase changes from rhombohedral to tetragonal, at the so-called morphotropic phase boundary, and the phases at higher temperature become ill-defined, also because of the large lattice disorder induced by the coexistence of differently charged cations in the same sublattice. Combined dielectric and anelastic spectroscopy measurements are presented, which clarify some issues related to the phase transitions in NBT-BT. The influence of Ba substitution on the tetragonal antiferroelectric phase is determined for the first time, and the possibility that a monoclinic phase, although with very short coherence length, exists near the morphotropic phase boundary is discussed in view of a large maximum of the elastic complianc

¿Qué pasa cuando se duerme?

La pregunta sobre qué pasa cuando se duerme y muchas otras interrogantes relacionadas con el sueño han ido surgiendo con el paso del tiempo, así como también las investigaciones para obtener las respuestas. En este artículo se explicará qué es el sueño, cuáles son sus etapas, por qué y cómo se producen los sueños, y qué podrían significar o provocar. Con esta investigación se busca aprender e informar sobre los sueños y lo que sucede mientras se duerme. El significado de los sueños ha tenido diferentes interpretaciones a través de los años; por ejemplo, para algunos filósofos como Sócrates y Platón los sueños son deseos contenidos que salen a la luz mientras se duerme. Las investigaciones relacionadas con el sueño muestran que mientras se duerme, el cerebro se encuentra en actividad y se dan algunos cambios en el organismo. Al momento de dormir se experimenta un ciclo que está formado por cinco fases que se repiten, las cuales se explicarán más adelante

Rapid Magnetic Dispersive solid phase extraction to preconcentration/determination of Cd and Pb in aqueous samples

A new magnetic dispersive solid phase extraction (MDSPE) method and graphite furnace atomic absorption spectrometry (GFAAS) have been combined for the analysis of Cd and Pb in environmental samples. For the preconcentration, a shell structured Fe3O4@graphene oxide nanospheres was synthetized and characterized. The material was suspended in the ionic liquid 1-n-butyl-3-metilimidazolium tetrafluoroborate [BMIM][BF4], the obtained stable colloidal suspension is named ferrofluid. GO presents excellent adsorbent properties for organic species due to the presence of the electronic π system. For this reason, the organic ligand [1,5-bis-(2-dipyridyl) methylene] thiocarbonohydrazide (DPTH) was used in order to form organic complexes of Cd and Pb. Once the DPTH ligand has been added to sample, the ferrofluid was injected and finely dispersed in the sample solution in order to extract the formed chelates. The complete adsorption of the chelates took place within few seconds then, the solid was separated from the solution with the aid of a strong magnet. Cd and Pb ions were desorbed from the material with 1 mL of acid nitric 5% solution and quantified by GFAAS. All experimental and instrumental variables were optimized. The analytical performances of the optimized method were: EF (Enrichment factor): 200 with LODs (detection limit): 0.005 and 0.004 µg L-1 and LOQs (determination limit): 0.017 and 0.013 µg L-1, for Cd and Pb, respectively. The reliability of the developed procedure was tested by relative standard deviation (% RSD), which was found to be < 5%. The accuracy of the proposed method was verified using certified reference materials (SLRS-5, SPS-SW2, and BCR-723) and by determining the analyte content in spiked aqueous samples. Sea waters and tap water samples collected from Málaga (Spain) were also analysed. The determined values were in good agreement with the certified values and the recoveries for the spiked samples were around 100% in all cases.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Cold vapour generation electrothermal atomic absorption spectrometry and solid phase extraction based on a new nanosorbent for sensitive HG determination in environmental samples (sea water and river water)

Reunión bianual del Grupo Regional Andaluz de la Sociedad Española de Química AnalíticaMercury is not an essential element for plant or animal life and it is a potential environmental toxic because of its tendency to form covalent bonds with organic molecules and the high stability of the Hg-C bond. Reports estimate a total mercury concentration in natural waters ranging from 0.2 to 100 ng L-1. Due to this fact, highly sensitive methods are required for direct determination of such extremely low levels. In this work, a rapid and simple method was developed for separation and preconcentration of mercury by flow injection solid phase extraction coupled with on-line chemical vapour generation electrothermal atomic absorption spectrometry. The system is based on chelating retention of the analyte onto the mini column filled with a mesoporous silica functionalized with 1,5 bis (di-2-pyridyl) methylene thiocarbohydrazide. The main aim of this work was to develop a precise and accurate method for the determination of the Hg. Under the optima conditions and 120 s preconcentration time, the detection limit obtained was 0.009 μg L-1, with RSDs 3.7 % for 0.2 μg L-1, 4.8 % for 1 μg L-1 and enrichment factor 4, Furthermore, the method proposed has permitted the determination of Hg with a reduction in the analysis time, the sample throughput was about 18 h-1, low consumption of reagents and sample volume. The method was applied to the determination of Hg in sea water and river water. For the quality control of the analytical performance and the validation of the newly developed method, the analysis of two certified samples, TMDA 54.4 Fortified Lake, and LGC6187 River sediment was addressed. The results showed good agreement with the certified values.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Determination of Pb using F3eO4 GO join to DPTH for ferrofluid based dispersive solid phase extraction

In this work has been described a green and rapid method the synthesis of Fe3O4@GO nanospheres via chemical covalent bonding method. The Fe3O4@GO DPTH was applied to ferrofluid based dispersive solid phase extraction of lead as a model analyte using an ionic liquid carrier. The ferro fluid allows the rapid extraction of lead ions using a low amount of sorbent material. Besides, the magnetic separation greatly improved the separation rate. The presented method is highly time saving due to the high dispersion of the sorbent in the aqueous phase and also there is no need to shake the sample solution. The other benefits of the proposed methods are simplicity of operation, low cost, high sorption capacity, high recovery and high preconcentration. In order to optimize the method the following parameters were studied: sample solution pH, concentration of DPTH, extraction time, amount of sorbent, desorption conditions, influence of ionic strength, and tolerance of potentially interfering ions. The sample or standard solution containing Pb(II), DPTH (0.05% ethanol w/v), NaCl (0.5 %, w/v) and buffer (pH = 5.6) was poured into high volume. Then 240 µL of ferrofluid was injected rapidly into the sample solution through a syringe. Thereupon, a dark cloudy suspension was formed, ferrofluid was dispersed thoroughly in solution and the complex of Pb-DPTH was extracted in a few seconds. Subsequently, a strong magnet was placed at the bottom of the tube to let the extractant settle. After about 3 min, the solution became clear and the supernatant was discarded simply by decanting it. Afterwards, the magnet was removed and 1 mL of nitric acid (2.0 mol L−1) was introduced to the vial to desorb the Pb by sonication. Finally, the sorbent was separated by positioning the magnet to the outside of the tube and the concentration of Pb in acidic aqueous phase was determined by ETAAS.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Magnetic dispersive solid phase microextraction coupled with on-line chemical vapor generation method to extraction/preconcentration of mercury from environmental samples and determination by graphite furnace atomic absorption spectrometry.

Mercury (Hg) is classified as priority hazardous substances. Concentrations found in the aquatic environment are at trace levels as result of natural processes, such as erosion and volcanism, and anthropogenic discharges related mainly to industrial and mining activities. Mercury is one of the most potent neurotoxins known, showing a high number of adverse health effects in animals and humans. For this reason, a simple and rapid method for the determination and preconcentration of mercury in environmental waters is proposed. This work is based on magnetic dispersive solid phase microextraction (MDSPME) coupled with on-line chemical vapour generation (CVG). Graphite furnace atomic absorption spectrometry (GFAAS) was employed for the quantification of Hg. In the preconcentration step, a shell structured Fe3O4@graphene oxide was suspended in the ionic liquid carrier (1-n-butyl-3-metilimidazolium tetrafluoroborate [BMIM][BF4]), obtaining a stable colloidal suspension called ferrofluid. This sorbent possesses as large contact surface area and a high density of polar groups on its surface. The nanoparticles, when finely dispersed in the sample solution, result in almost complete extraction of Hg within a few seconds. All experimental and instrumental variables were optimized and the method was adequately validated by the analysis of certified reference materials of environmental waters. Acknowledgements The authors would like to thank Plan Propio “Proyecto Puente” de la Universidad de Málaga for financial support of this work.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec