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The present work deals with the investigation of the site-selective symmetries in Eu3+-doped KY3F10 with different crystal phases. Employing time-resolved fluorescence line-narrowing (TRFLN), a study of the luminescent response of the dopant is reported in samples presenting a single δ-phase, a single α-phase, and a mixture of both δ and α. A new, simple, very low time-consuming and high-yield method was developed to obtain nanospheres of the δ-phase. For both crystal phases, the main site symmetry is spectrally corroborated with that expected by the crystallographic substitution position (C2v in δ, and C4v in α). In addition, the accuracy of the measurements also unveils the presence of significantly distorted Eu3+ ions in the surface of the nanoparticles in all the samples studied, a spectral behavior commonly found in glassy systems. All these findings contribute to the proper understanding of the optical response of luminescent dopants in this and related types of complex fluorides. It is worth highlighting the fact that the huge potential of the unexplored δ-phase is demonstrated, since the site-selective emission of the Eu3+-doped δ-phase is up to 20 times more intense than that of the α-phase. This work was supported financially by the Spanish MCIN (Grant PID2020-116149GB-I00 and PID2020-115419GB/C-22 funded by MCIN/AEI/10.13039/501100011033) and the University of the Basque Country (GIU21/006). P. Serna also thanks the Spanish MCIN for an FPU predoctoral contract (FPU18/04511 funded by MCIN/AEI /10.13039/501100011033 and by “ESF Investing in your future”).

Las hemorragias externas derivadas de los traumas ocasionados por conflictos armados, accidentes viales e incidentes cotidianos son “cada vez más frecuentes y representan el 9% de la mortalidad anual en el mundo, se considera que la hemorragia es responsable del 30 al 40% de estas muertes” (Mejia Mantilla, Puentes Manosalva, Ciro, & Morales , 2009). Lo anterior incentivó al grupo de investigadores a identificar los escenarios de uso y efectividad de agentes hemostáticos disponibles mediante una revisión literaria; Se tomaron en cuenta conceptos claves en inglés y en español para la búsqueda en las bases de datos, tales como Pubmed, Lilacs, Scopus y Science Direct, en los que se hallaron métodos, medicamentos, dispositivos y formas farmacéuticas que son empleados para el control de las hemorragias. En un conglomerado y procesamiento de la información se llevó a cabo una tabla de análisis en Microsoft Excel donde se incluyeron 64 documentos tanto nacionales como internacionales del uso de agente hemostáticos en el entorno civil y militar. Estos fueron clasificados de acuerdo con sus ingredientes activos, tecnología biomédica, mecanismos de acción, efectos hemostáticos, fuente de material, escenarios de uso y efectividad. Se concluyó que definir el ingrediente activo en base a la fuente del material, para un desarrollo futuro de un agente hemostático facilitará su disponibilidad y el acceso, por otra parte la formación y capacitación en el uso de los agentes hemostáticos y la implementación biotecnológica hemostática, podría influir en la facilidad y el acceso a los mismos, estos aspectos podrían contribuir a la reducción la morbimortalidad en pacientes con hemorragias externas

Environment-friendly pigments based on AFeO3 (A = La, Pr, Nd, Sm, Gd, Tb, Y or Yb) with high near-infrared (NIR) reflectance were synthesised by a coprecipitation method at 1200 °C. The Rietveld refinement analysis showed single-phase orthorhombic perovskite for all compositions. All pigments, which showed reddish hues, offered good colour stability after mixing these pigments in powder form with siloxane transparent paint and two different glazes. The powder–paint mixtures produced with GdFeO3, TbFeO3 and YFeO3 pigments have the highest NIR solar reflectance, reaching values of R = 50%. The temperature shielding studies conducted using TbFeO3 pigment–paint mixture for a roof coating yielded a reduction of 3.2 °C in comparison to a commercial pigment. Moreover, the glazes that were pigmented using GdFeO3, TbFeO3 and YFeO3 compositions also presented the most intense reddish colours. A study of the thermal and chemical stability of the pigment with the highest NIR solar reflectance showed good stability in both cases. The reddish pigments that were prepared can therefore be good candidates for use in different applications such as cool pigments or pigments for ceramic glazes at high temperatures.

This article presents and discusses the results of an educational innovation that seeks to introduce the world of molecular gastronomy in chemistry lessons as a means to review stoichiometry and offer an alternative way to learn. In the literature to date, there is no evidence of haute cuisine having been employed to contextualize stoichiometry problem statements with its everyday applications. The proposed novel strategy, called “MasterChemist”, involved the participation of Spanish first-year university students taking the subject General Chemistry in the Bachelor’s Degree in Chemical Engineering. A Game-Based Learning (GBL) approach was used to solve the exercises and make the activity more appealing and interesting by adding fun to the learning process. The problems were contextualized in the use of siphons, isomalt sugar, and the spherification technique. Furthermore, dividing students into groups also boosted their cooperative skills. The students’ answers to a final survey revealed that the general opinion regarding the activity was highly positive. The undergraduates reviewed some stoichiometry concepts which we had previously observed that they had problems understanding. In addition, the attractive theme of haute cuisine made the activity dynamic and enjoyable both for students and for the teacher. Funding for open access charge: CRUE-Universitat Jaume I

La Quebrada Santa Mónica es la fuente con el mayor aporte de agua al embalse la Nitrera, que abastece el consumo al municipio de Concordia, Antioquia; con el objetivo de conocer calidad de agua de la Quebrada y determinar si cumple con los criterios de calidad, se realizó la caracterización fisicoquímica y biológica empleando los macroinvertebrados acuáticos como bioindicadores. En tres estaciones de la quebrada, se tomaron muestras fisicoquímicas e hidrobiológicas durante tres campañas en el año 2017. Los resultados fisicoquímicos presentaron una variación espaciotemporal leve, se pudo determinar que el mes de noviembre se presentó el valor más alto de abundancia y riqueza de macroinvertebrados, siendo Phylloicus el taxa predominante. El índice BWWP/Col estuvo entre 52 y 119. La Quebrada Santa Mónica presenta una buena calidad de agua y la mayoría de los parámetros fisicoquímicos cumplen con la normatividad para ser fuente de abastecimiento de agua potable. The Santa Monica creek is the main source of the Nitrera reservoir, which supplies the drinking water to the municipality of Concordia. To determine the quality of the water in the Creek, and if it accomplish the standards, a physical-chemical and biological characterization was carried out using aquatic macroinvertebrates as bioindicators. Physical-chemical and hydro-biological samples were taken at three stations in the creek during three campaigns in 2017. The physicochemical results presented a slight spatial-temporal variation, and we determined that November presented the highest abundance and richness values of macroinvertebrates, being Phylloicus the predominant taxa. The BWWP/Col index values were between 52 and 119. Santa Mónica Creek has a good water quality, and most of the physical-chemical parameters accomplish the regulations to be a source for drinkable water supply.

Black pigments are very commonly used and arouse widespread interest in the ceramic industry. Nevertheless, these pigments contain toxic elements that are detrimental to human health. In view of this, the present work is focused on the development of sustainable black pigments prepared by a coprecipitation method at 1200 °C. Samples with the nominal formula (Gd1–xCax)(Fe0.95Zn0.05)O2.975–x/2 (x = 0.00, 0.05, 0.10) showed single-phase orthorhombic perovskite. The presence of dopants played an important role in the reduction of Fe3+ to Fe2+ and caused different local distortions in the structure which explained the final black colouration of these pigments in comparison with the red GdFeO3 sample. The loss of symmetry and the increase in the number of d-d transitions of iron may explain the aforementioned changes. Co-doped pigments reached low C* values, improving on the purest black colour obtained in a commercial black ceramic pigment, which contains toxic elements. In addition to presenting good NIR solar reflectance values of up to 8%, the final colours of these pigments were also stable after their application in a commercial transparent glaze at 1080 °C that could be used for tiles. Funding for open access charge: CRUE-Universitat Jaume I

RESUMEN El embalse La Nitrera se encuentra localizado a 2140 m.s.n.m. en el municipio de Concordia, departamento de Antioquia (Colombia) y es la única fuente de abastecimiento de agua del municipio. La operación de un embalse sobre un sistema lótico afecta la estructura y ensamblaje de sus ecosistemas acuáticos. Esta investigación tuvo como propósito analizar la distribución de la biomasa de los macroinvertebrados acuáticos antes y después del embalse, con el fin de determinar el impacto de este sobre las comunidades hidrobiológicas. Para tal fin, se analizaron las variables hidrobiológicas en época seca, de lluvia y en diferentes periodos de transición entre el año 2016 y 2017. Se investigaron cuatro estaciones de monitoreo, realizando la determinación, conteo y definiendo el rol trófico de los macroinvertebrados acuáticos, además de un análisis termogravimétrico (TGA) de la biomasa. Con la información obtenida, se construyó un modelo trófico y se calculó la pérdida de energía calórica disponible de la biomasa (TGA). Los resultados evidenciaron que las comunidades de macroinvertebrados acuáticos presentan una modularidad similar entre ellas en las estaciones antes del embalse, y una modularidad diferente en la estación después del embalse. A través del índice de modularidad (modelo Ghepi) y el análisis TGA, se logró establecer que el embalse altera la cadena trófica de las comunidades de macroinvertebrados acuáticos. ABSTRACT The reservoir La Nitrera is located at 2140 m.a.s.l. in Concordia's town, in the Antioquia's department (Colombia) and is the only source of water supply in the municipality. The operation of a reservoir on a lotic system generates affectations in the structure and assembly of aquatic ecosystems. The purpose of this research was to analyze the distribution of biomass of aquatic macroinvertebrates before and after of the reservoir to determine the impact of it on the hydrobiological communities. For this purpose, the hydrobiological variables were analyzed in dry season, rain season and in different periods of transition between 2016 and 2017 in four monitoring stations, making the determination, counting and defining the trophic role of aquatic macroinvertebrates, in addition to a thermogravimetric analysis (TGA) of the biomass. With the obtained information, a trophic model and an analysis of the loss of the available caloric energy of the biomass (TGA) was made. The results showed that the communities of aquatic macroinvertebrates had a similar modularity between them in the stations before the reservoir and different modularity in the station after the reservoir. Through the modularity index (Ghepi model) and the TGA analysis, it could be established that the reservoir generates an alteration in the trophic chain of aquatic macroinvertebrate communities.

Introduction: Analysis of functional feeding groups (FFG) in aquatic macroinvertebrates is important in understanding the structure, function, and dynamics of ecological processes in ecosystems. Modularity refers to the degree of compartmentalization of food webs and varies between -1 and 1. A network with a modularity value close to 1 is resilient to disturbances and can be interpreted as an indicating factor for the stability of communities. Objective: In this study, we analyzed the trophic structure of benthic macroinvertebrates in La Nitrera stream, the San Juan River, and the Cauca River in the Colombian Andes. Methods: The study was supported by ecological networking techniques using Gephi software. We studied nine sites in dry, rainy, and transition seasons in 2017 and 2018, monitoring changes in the altitude gradient. At each of the sites, the organisms were captured and determined, and physicochemical and hydraulic information was obtained. Results: The variance component analysis allowed to explain the variability of the data by relating the following environmental variables: FFG, diversity, richness, modularity, season, and time. Simple multifactorial ANOVA indicated that significant changes in FFG were associated with altitude, and modularity to time. The allocation of the FFG was done by stomach analysis and secondary information. Conclusion: The transition season had the highest modularity, possibly due to the recolonization of some biotopes caused by the decrease in the velocity of water currents. La Nitrera and San Juan presented higher values than the Cauca, which may indicate that the altitudinal change and velocity of water currents affects the compartmentalization of the network. Resumen Introducción: El análisis de grupos funcionales de alimentación (GFA) en macroinvertebrados acuáticos es importante para comprender la estructura, función y dinámica de los ecosistemas de procesos ecológicos. La modularidad se refiere al grado de compartimentación de las redes alimentarias y varía entre -1 y 1. Una red con un valor de modularidad cercano a 1 es resistente a las alteraciones y puede interpretarse como un factor indicativo para la estabilidad de las comunidades. Objetivo: En este estudio se analizó la estructura trófica de los macroinvertebrados bentónicos, un elemento importante en la calidad ambiental, en el arroyo La Nitrera, el río San Juan y el río Cauca. Métodos: El estudio contó con el apoyo de técnicas de redes ecológicas utilizando el software Gephi. En 2017 y 2018, estudiamos nueve sitios en estaciones secas, lluviosas y de transición, monitoreando cambios en el gradiente de altitud. En cada uno de los sitios se capturaron y determinaron los organismos y se recogió información fisicoquímica e hidráulica. Resultados: El análisis de componentes de varianza permitió explicar la variabilidad de los datos relacionando las siguientes variables ambientales: GFA, diversidad, riqueza, modularidad, estación y tiempo. La ANOVA simple multifactorial indicó que existen cambios significativos en los GFA en relación con la altitud, y la modularidad con el tiempo. La asignación de los GFA se realizó mediante análisis estomacal e información secundaria. Conclusión: La temporada de transición tuvo la mayor modularidad, posiblemente debido a la recolonización de algunos biotopos provocada por la disminución de la velocidad del cauce. La Nitrera y San Juan presentaron valores superiores a los del Cauca, lo que puede indicar que el cambio altitudinal y la velocidad de las corrientes de agua influyen en la compartimentación de la red.

We developed a three-component model to evaluate the present and future hydrological behavior of Ayapel Cienaga under different scenarios of climate variability and human intervention associated with fishing and mining activities and the maintenance of levees. We calibrated the water balance with historical information on hydrological variables, water levels, stream discharges, fishing activities and gold mining records in the period 1985-2015. We use autoregressive statistical models to project climate scenarios that consider extreme variations in mean monthly rainfall, ENSO activity, temperature increases of 2°C, and levee breaks along the Cauca River. In addition, we incorporated two dynamic of systems models of bocachico fish population and mercury accumulation in the Cienaga. The simulations indicate that the Cienaga levels can be affected by extreme changes in rainfall associated with ENSO. The model estimates the fraction of water that could enter from the Cauca River due to levee breaks. Furthermore, using a fish dynamic population we could project the population and catch of bocachico. Finally, the mercury balance model due to mining in the region help to estimate mercury concentrations in water, fish and aquatic macrophytes matrices. This model offers a tool for management and decision-making in ecohydrological aspects of the Cienaga under different climate change scenarios. RESUMEN : Desarrollamos un modelo con tres componentes para evaluar el comportamiento hidrológico presente y futuro de La Ciénaga de Ayapel bajo diferentes escenarios de variabilidad climática e intervención humana asociada con pesca y minería y el mantenimiento de diques. Calibramos el balance hídrico con información histórica sobre variables hidrológicas, niveles de agua, descargas de arroyos, actividades de pesca y registros de extracción de oro en el período 1985-2015. Utilizamos modelos estadísticos autorregresivos para proyectar escenarios climáticos que consideran variaciones extremas en la precipitación media mensual, la actividad de ENSO, un aumento de temperatura de 2 °C y la ruptura de diques en el río Cauca. Además, incorporamos dos modelos de dinámica de sistemas de la población de peces bocachico y la acumulación de mercurio en la Ciénaga. Las simulaciones indican que el nivel de Ciénaga puede verse afectado por cambios extremos en las precipitaciones asociadas con ENSO. El modelo estima la fracción de agua que podría ingresar desde el río Cauca por las rupturas del dique. Además, utilizando una población dinámica de peces podríamos proyectar la población y la captura de bocachico. El modelo de balance de mercurio debido a la minería ayuda a estimar las concentraciones de mercurio en el agua, los peces y las macrófitas. Este modelo ofrece una herramienta para la gestión y la toma de decisiones en aspectos ecohidrológicos de Ciénaga bajo diferentes escenarios de cambio climático. COL0009832

In this study Eu

We obtain eigenstates of interacting disorder Hamiltonians using unitary displacement transformations that rotate the state of the system. The method generates excited states if the strength of these transformations is chosen to optimize the energy, while decreasing the energy variance. We apply the method to analyse the localization properties of one-dimensional spinless fermions with short range interactions, reaching relatively large system sizes. We quantify the degree of localization through the evolution of the inverse participation ratio as a function of the energy variance.

This article describes a new, simple, and high-yield method based on a sonochemical process for obtaining the δ-KY3F10·xH2O compound with a ‘super-diamond’ structure, a material that has been completely neglected in the literature since it was first discovered. We explore the mechanism underlying the formation of the synthesized nanomaterials and show their connection with the pH of the medium. Additionally, we demonstrate for the first time the adequacy of the δ-phase of KY3F10 for optical applications through the novel Eu3+-doped nanoplates, which exhibit long lifetimes and high quantum efficiencies. The results reveal that this material, which also has zeolitic characteristics, can have a strong impact on future photonic and associated applications.

International audience; The simplest topologically ordered phase in 2+1D is the deconfined phase of Z2 gauge theory (realized in the toric code, for example). This phase permits a duality that exchanges electric and magnetic excitations (“e” and “m” particles). The phase transition where one of these particles condenses, while the other remains gapped, has 3D Ising exponents. But the transition out of the deconfined phase when self-duality symmetry is preserved is more mysterious. It has so far been unclear whether this transition is continuous, but if continuous, it may be the simplest critical point for which a useful continuum Lagrangian is still lacking. These questions are relevant to soft matter, too, since the gauge theory also describes classical membranes in 3D. Here, we study the self-dual transition with Monte Carlo simulations of the Z2 gauge-Higgs model on cubic lattices of linear size L≤96. Our results indicate a continuous transition, for example via a striking parameter-free scaling collapse. We use duality symmetry to distinguish the leading duality-odd and duality-even scaling operators A and S. We explain why standard techniques for locating the critical point are ineffective, and we develop an alternative using “renormalization group trajectories” of cumulants. We check that two- and three-point functions are scale invariant, with scaling dimensions xA and xS (autocorrelations in the Monte Carlo dynamics also yield a dynamical exponent z). Separately, we propose a general picture for emergent 1-form symmetries, in terms of “patching” of membranes or world surfaces. We relate this to the percolation of anyon worldlines in spacetime. The latter yields a fourth exponent for the self-dual transition. We propose variations of the model for further investigation.

Pyramidal neurons are covered by thousands of dendritic spines receiving excitatory synaptic inputs. The ultrastructure of dendritic spines shapes signal compartmentalization but ultrastructural diversity is rarely taken into account in computational models of synaptic integration. Here, we developed a 3D correlative light-electron microscopy (3D-CLEM) approach allowing the analysis of specific populations of synapses in genetically defined neuronal types in intact brain circuits. We used it to reconstruct segments of basal dendrites of layer 2/3 pyramidal neurons of adult mouse somatosensory cortex and quantify spine ultrastructural diversity. We found that 10% of spines were dually-innervated and 38% of inhibitory synapses localized to spines. Using our morphometric data to constrain a model of synaptic signal compartmentalization, we assessed the impact of spinous versus dendritic shaft inhibition. Our results indicate that spinous inhibition is locally more efficient than shaft inhibition and that it can decouple voltage and calcium signaling, potentially impacting synaptic plasticity.

Comunicació presentada a EDULEARN2020, 12th International Conference on Education and New Learning Technologies (Online, July 6-7, 2020). The design of undergraduate laboratory sessions that provide meaningful research-based experiences enhances undergraduate curricula and prepares future graduate students for research careers. Solid-State Chemistry has attracted the attention of many fields due to its wealthy chemistry as well as the versatility of its applications. Among the wide fields in this area, the study of an inorganic ceramic pigment has been selected in this experience. A pigment can be defined as a colored organic or inorganic solid (black, white or fluorescent) normally insoluble and practically unaffected neither chemically nor physically by the vehicle or substrate in which it is incorporated. From a structural point of view, a ceramic pigment is formed by a host network where the chromophore component, usually transition ions, generates the color without producing a change in the structure. A suitable host network must have, in addition to a high chemical resistance against oxidation and reduction and a high melting point, energy differences between favorable bands to allow the chromophore to produce colors in the region of the visible spectrum. A teaching strategy has been proposed for undergraduate chemistry students, introducing them to the solid-solid reaction by the synthesis of a pink ceramic pigment based on chromium-doped ZnAl2O4 with the spinel structure. The as-prepared pigment has been characterized by two different techniques, such as X-Ray Diffraction and UV-Vis spectroscopy, commonly used in Solid-State Chemistry. In this way, students have a first approach to the basic concepts of the Solid-State Chemistry through simple laboratory sessions. Due to the easy strategy used in this study, students will be able to participate in an active way, fulfilling the pedagogical character demanded by a Problem-Based Learning (PBL).

The aquatic macroinvertebrate community reflects the ecological status of a river. Typically, some extraction methods have been implemented, but the capture and preservation of organisms are necessary. The techniques of digital image processing applied to ecology have become innovative tools for the characterization of aquatic macroinvertebrates. This research implements a methodology for the processing and classification of four aquatic macroinvertebrates genera Thraulodes, Traverella (Ephemeroptera), Anacroneuria (Plecoptera), and Smicridea (Trichoptera) present in three rivers in Antioquia (Colombia), which includes two phases. The first of these was the collection and capture of organisms to obtain a database of the most abundant genera, at laboratory scale. The second was the use of simulations that allow the classification of data through a process of selection and extraction of characteristics using the bag of visual words technique. Of all the classifiers tested, Gaussian vector support machines obtained a percentage of success in the recognition up method of four organisms to the genus level of 97.1 %. The training and computational processing for classification enabled the standardization of an appropriate methodology that will serve as a starting point for aquatic biomonitoring and inventory in Colombia and internationally.

Background There is no proven specific pharmacological treatment for patients with the acute respiratory distress syndrome (ARDS). The efficacy of corticosteroids in ARDS remains controversial. We aimed to assess the effects of dexamethasone in ARDS, which might change pulmonary and systemic inflammation and result in a decrease in duration of mechanical ventilation and mortality. Methods We did a multicentre, randomised controlled trial in a network of 17 intensive care units (ICUs) in teaching hospitals across Spain in patients with established moderate-to-severe ARDS (defined by a ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen of 200 mm Hg or less assessed with a positive end-expiratory pressure of 10 cm H2O or more and FiO(2) of 0.5 or more at 24 h after ARDS onset). Patients with brain death, terminal-stage disease, or receiving corticosteroids or immunosuppressive drugs were excluded. Eligible patients were randomly assigned based on balanced treatment assignments with a computerised randomisation allocation sequence using blocks of 10 opaque, sealed envelopes to receive immediate treatment with dexamethasone or continued routine intensive care (control group). Patients in the dexamethasone group received an intravenous dose of 20 mg once daily from day 1 to day 5, which was reduced to 10 mg once daily from day 6 to day 10. Patients in both groups were ventilated with lung-protective mechanical ventilation. Allocation concealment was maintained at all sites during the trial. Primary outcome was the number of ventilator-free days at 28 days, defined as the number of days alive and free from mechanical ventilation from day of randomisation to day 28. Secondary outcome was all-cause mortality 60 days after randomisation. All analyses were done according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov, NCT01731795. Findings Between March 28, 2013, and Dec 31, 2018, we enrolled 277 patients and randomly assigned 139 patients to the dexamethasone group and 138 to the control group. The trial was stopped by the data safety monitoring board due to low enrolment rate after enrolling more than 88% (277/314) of the planned sample size. The mean number of ventilator-free days was higher in the dexamethasone group than in the control group (between-group difference 4.8 days [95% CI 2.57 to 7.03]; p

In the past decade, optical imaging methods have significantly improved our understanding of the information processing principles in the brain. Although many promising tools have been designed, se...

Eu-Doped BaTiO ceramics with dopant contents between 0 and 10 mol% were prepared by sol-gel synthesis based on the nominal compositions (BaEu)TiO and Ba(TiEu)O, where two possible substitution mechanisms are addressed. By means of optical spectroscopy, our study gives a plausible elucidation of Eu site occupation in micron-sized BaTiO particles. Time-resolved fluorescence line narrowing (TRFLN) shows the presence of five different crystal field sites for europium ions and possible symmetries are inferred for each one. The solubility limit of the lanthanide ion was found to be about 3 mol%. The experimental results are consistent with the preference of Eu to occupy Ba sites regardless of the nominal compositions and target substitution mechanism. However, TRFLN results showed that the dopant could also occupy Ti sites, highlighting the amphoteric character of Eu. The existence of anti-Stokes and Stokes vibronic sidebands in the D → F transitions of Eu ions is confirmed. This can explain the lack of resolution found in room temperature spectra of these transitions due to vibronic mixing of the excited levels. The existence of non-equivalent europium sites with different spectroscopic properties could have an impact on the optical properties of doped-BaTiO ceramics and associated applications., P. S.-G., H. B.-M. and E. C. thank the Universidad Jaume I (Project UJI-B2016-38) and Ministerio de Economía y Empresa (Project MAT2016-80410-P) for financial support. P. S.-G. also thanks Universidad Jaume I for a fellowship. R. B. and J. F. acknowledge financial support from MINECO under Project MAT2017-87035-C2-2-P (AEI/FEDER, UE), Basque Country University PPG17/07 and GIU17/014, and Eusko Jaurlaritza PIBA2018-24.

In the last decade, optical imaging methods have significantly improved our understanding of the information processing principles in the brain. Although many promising tools have been designed, sensors of membrane potential are lagging behind the rest. Semiconductor nanoparticles are an attractive alternative to classical voltage indicators, such as voltage-sensitive dyes and proteins. Such nanoparticles exhibit high sensitivity to external electric fields via the quantum-confined Stark effect. Here we report the development of lipid-coated semiconductor voltage-sensitive nanorods (vsNRs) that self-insert into the neuronal membrane. We describe a workflow to detect and process the photoluminescent signal of vsNRs after wide-field time-lapse recordings. We also present data indicating that vsNRs are feasible for sensing membrane potential in neurons at a single-particle level. This shows the potential of vsNRs for detection of neuronal activity with unprecedentedly high spatial and temporal resolution.

Eu3+-doped YF3 and KY3F10 phosphors have been prepared hydrothermally in a wide range of pH values without the use of surface chelators and adding oxalic or tartaric acid. We have proved, for the first time, the usefulness of dicarboxylic acids to modulate the evolution of the surface and crystal phases in the KF-YF3 system. The morphologies and crystal structures of the materials displayed a critical dependence on the pH and the chelator employed, and a plausible mechanism to explain the differences among the distinct series of samples is proposed. As a result, the fluorides exhibited outstanding and tunable photoluminescence, with extremely high quantum efficiencies and very long lifetimes. The asymmetry ratio and Judd-Ofelt parameters calculations allowed us to establish a relationship between the optical performance of the compounds and their physicochemical properties. We feel that this study can arouse widespread interest within the materials engineering community, since similar procedures could be implemented to the extended family of complex yttrium/lanthanide fluorides for advanced applications in important fields such as bioanalytics, biomedics, or photonics. Indeed, the materials in the present work, with orangish-yellow colored emissions, could be very interesting for application in white light emitting diodes through their combination with blue chips.

Comunicació presentada a EDULEARN2019, 11th International Conference on Education and New Learning Technologies (July 1-3, 2019, Palma, Mallorca, Spain). Nowadays, it is undeniable that the amount of technological devices is having a sharp increase all around us, with important benefits and repercussions for the society. Despite this, students are not used to knowing the basic principles of its operations. Hence, it is of utmost importance to approach undergraduate students to a practical example of a device they can find in their daily life. It is a fact that science is interconnected with multiple disciplines, such as Physics and Solid State Chemistry, Materials Science and Engineering. A good example of it is a smoke detector because it combines both optical and electrical behaviour. Such a device contains a chamber inside which there is an infrared LED (light-emitting diode) and a photodiode (light detector). When the path of light is interrupted by the smoke, according to the principle of light scattering, the smoke will scatter a fraction of light into the photodiode, activating the detector. Thus, detecting low levels of smoke is vital for preventing the fire expansion and occupants can get more time to escape from the premises. The main purpose of this work is to help students to understand the work mechanism of the LED and photodiode in basis of their material composition. In order to do that, a smoke detector is disassembled and its different parts are observed. After that, the microstructure and composition of them are fully analysed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques. With these experiments, students have gained knowledge about semiconductors materials and got a more accurate understanding of their role in these devices. All in all, this experience has allowed them to keep in contact during the whole study with three main concepts of Materials Science: composition, structure and properties. This fact make the work interesting not only from the point of view of students, but also for teachers of Inorganic Chemistry and Materials Science owing to its pedagogical character employing a Problem Based Learning.

An unusual phenomenology is uncovered in a class of (2+1)-dimensional phase transitions. An accurate, yet not exact O(4) symmetry, relating distinct order parameters, emerges at intermediate length scales. At longer scales it becomes apparent that the transition is weakly first order. However, O(4) persists as a symmetry relating the coexisting ground states, implying very unconventional scaling properties. The transition studied is from N\'eel order to a twofold degenerate valence-bond solid. Via dualities, the results have implications for other deconfined critical points with four soft-order parameter components and for two-flavor QED${}_{3}$.

Eu3+-doped KY3F10 materials with a dopant content between 0 and 5 mol% were prepared based on the nominal composition K(Y3-xEux)F10 using different synthetic routes. The reaction conditions have been proven to be critical factors for the characteristics of the final products: morphology, size and crystallinity. As a result, noticeable changes in their photoluminescence spectra and lifetimes were observed. Quantum cutting processes or similar energy transfers between Eu3+ ions allowed obtaining high quantum efficiencies, while the analysis of the Ω 2 Judd-Ofelt parameter suggested that the crystal field of Eu3+ was very similar in all the compositions. A well-designed synthesis of Ln3+-doped fluorides can provide a full range of opportunities to explore new phenomena. Thus, this study highlights the complexity of the fluoride-based systems, which are exceptional candidates for doping with luminescent lanthanide ions and have very important characteristics for their future application in bioanalytics, biomedics or photonics. Indeed, the color-tunable emissions of the phosphors, which vary from orangish to yellow, could be interesting for their application in white light-emitting diodes through their combination with blue chips.

Proceeding of 10th International Conference on Education and New Learning Technologies (EDULEARN2018), 2nd-4th July 2018, Palma, Mallorca, Spain Solid state chemistry has attracted the attention of many fields due to its wealthy chemistry as well as the versatility of its applications. Among the wide fields in this area, the light interaction with a solid has been selected in this experience to understand the phosphorescence process in a material. This experience will allow students to understand an amazing phenomena which occurs in our quotidian life as the light emission of fireflies, stickers or fireworks. A teaching strategy has been proposed for undergraduate chemistry students, introducing them to the concepts of phosphorescence as well as different techniques of characterization through a simple laboratory session based in the synthesis of a phosphor material. Nowadays, it is a challenge to encourage students to properly understand chemistry and materials science due to the importance that represents in our society. Luminescence is a spontaneous light emission coming from excited electronic states after the absorption of UV/visible light. These processes include triboluminescence, fluorescence, phosphorescence, chemiluminescence and bioluminescence. In particular, phosphorescence visible light on slow (minute to hour) time scales after the excitation source has been removed. Lanthanidedoped strontium aluminate (Eu:SrAl2O4) is one of the most widely used phosphor owing to its green environmental properties and their excellent features, like their long-lasting phosphorescence or their potential applications in optoelectronic devices. The aim of this work is showing an example to understand this energetic concept from the preparation of a phosphorescent material based on the strontium aluminate structure. A new methodology of synthesis derived of the Pechini’s method has been introduced to the students. The importance of lanthanides ions has also been highlighted. Two common characterization techniques in Solid State Chemistry are presented to the students: X-Ray Diffraction and Electron Microscopy. Finally, phosphorescence properties have been studied in order to bring them closer in the complete preparation of a material. It has allowed them to keep in contact during the whole experiment with the three main concepts of Materials Science: synthesis, structure and properties. This fact makes the work interesting not only from the point of view of students, also for teachers of inorganic chemistry and material science and undergraduate students owing to its pedagogical character employing a Problem Based Learning.

We find the complete phase diagram of a generalised XY model that includes half-vortices. The model possesses superfluid, pair-superfluid and disordered phases, separated by Kosterlitz-Thouless (KT) transitions for both the half-vortices and ordinary vortices, as well as an Ising-type transition. There also occurs an unusual deconfining phase transition, where the disordered to superfluid transition is of Ising rather than KT type. We show by analytical arguments and extensive numerical simulations that there is a point in the phase diagram where the KT transition line meets the deconfining Ising phase transition. We find that the latter extends into the disordered phase not as a phase transition, but rather solely as a deconfinement transition. It is best understood in the dual height model, where on one side of the transition height steps are bound into pairs while on the other they are unbound. We also extend the phase diagram of the dual model, finding both O(2) loop model and antiferromagnetic Ising transitions., Comment: 19 pages. v2: references added and minor changes. Appears in "John Cardy's scale-invariant journey in low dimensions: a special issue for his 70th birthday"

La frecuencia respiratoria de Phragmites australis en presencia de agua residual sintética (ARS) y clorotalonilo (CLT) se evaluó utilizando un respirómetro. El estudio se dividió en dos fases, con los siguientes tratamientos: fase I con a) agua de grifo, b) agua de grifo + P. australis, c) ARS; fase II con a) ARS + CLT (0,29 mg L-1), b) ARS + CLT (2,18 mg L-1), c) CLT (0,29 mg L-1), d) CLT (2,18 mg L-1). Cada experimento se realizó por duplicado. Se analizó la influencia de las variables humedad relativa (HR), radiación solar (Rs), temperatura ambiente (T), presión barométrica (PB), evaporación y la evapotranspiración potencial (ETo) sobre la frecuencia de respiración de P. australis. No se encontraron diferencias significativas de la frecuencia respiratoria de P. australis (p < 0,05) con agua de grifo y ARS durante los experimentos de la fase I; lo mismo se encontró para todos los experimentos de la fase II. Las variables climatológicas afectaron la frecuencia respiratoria en todos los tratamientos. ETo, T y R mostraron una correlación positiva significativa con la frecuencia respiratoria; y la HR y la PB, una correlación negativa.A frequência respiratória de Phragmites australis em presença de água residual sintética (ARS) e clorotalonilo (CLT) avaliou-se utilizando um respirómetro. O estudo dividiu-se em duas fases, com os seguintes tratamentos: fase I com a) água de grifo, b) água de grifo + P. australis, c) ARS; fase II com a) ARS + CLT (0,29 mg L-1), b) ARS + CLT (2,18 mg L-1), c) CLT (0,29 mg L-1), d) CLT (2,18 mg L-1). A cada experimento realizou-se por duplicado. Analisou-se a influência das variáveis umidade relativa (HR), radiação solar (Rs), temperatura ambiente (T), pressão barométrica (PB), evaporação e a evapotranspiração potencial (ETo) sobre a frequência de respiração de P. australis. Não se encontraram diferenças significativas da frequência respiratória de P. australis (p < 0,05) com água de grifo e ARS durante os experimentos da fase I; o mesmo encontrou-se para todos os experimentos da fase II. As variáveis climatológicas afetaram a frequência respiratória em todos os tratamentos. ETo, T e R mostraram uma correlação positiva significativa com a frequência respiratória, e a HR e a PB, uma correlação negativa.The respiratory rate of Phragmites australis exposed to synthetic sewage water (SSW) and chlorothalonil (CLT) was evaluated using a respirometer. The study was divided into two phases with the following treatments: phase I with a) tap water, b) tap water + P. australis, c) ARS; phase II with a) SWW+ CLT (0,29 mg L-1), b) SWW + CLT (2,18 mg L-1), c) CLT (0,29 mg L-1), d) CLT (2,18 mg L-1). Each experiment was done by replicate. The influence of relative humidity (RH), solar radiation (SR), air temperature (T), barometric pressure (BP), evaporation and potential evapotranspiration (ETo) on P. australis respiration rate was analyzed. No significant differences were found on the respiratory rate of P. australis (p < 0.05) using tap water and SWW during phase I experiments; the same finding was seen for all phase II experiments. Meteorological variables affected the respiratory rate in all treatments. ETo, T and SR showed significant positive correlation with respiratory rate; RH and BP, a negative correlation.

Many statistical mechanics problems can be framed in terms of random curves; we consider a class of three-dimensional loop models that are prototypes for such ensembles. The models show transitions between phases with infinite loops and short-loop phases. We map them to $CP^{n-1}$ sigma models, where $n$ is the loop fugacity. Using Monte Carlo simulations, we find continuous transitions for $n=1,2,3$, and first order transitions for $n\geq 5$. The results are relevant to line defects in random media, as well as to Anderson localization and $(2+1)$-dimensional quantum magnets., Published version

Impact of the Interchannel Interference in a gridless scenario based on Nyquist-WDM is evaluated under variation of power and spectral channel spacing. Backpropagation reduces the power penalty, but the overlapping effects induce a higher BER-penalty.

We show numerically that the `deconfined' quantum critical point between the N\'eel antiferromagnet and the columnar valence-bond-solid, for a square lattice of spin-1/2s, has an emergent $SO(5)$ symmetry. This symmetry allows the N\'eel vector and the valence-bond-solid order parameter to be rotated into each other. It is a remarkable 2+1-dimensional analogue of the $SO(4)= [SU(2)\times SU(2)]/Z_2$ symmetry that appears in the scaling limit for the spin-1/2 Heisenberg chain. The emergent $SO(5)$ is strong evidence that the phase transition in the 2+1D system is truly continuous, despite the violations of finite-size scaling observed previously in this problem. It also implies surprising relations between correlation functions at the transition. The symmetry enhancement is expected to apply generally to the critical two-component Abelian Higgs model (non-compact $CP^1$ model). The result indicates that in three dimensions there is an $SO(5)$-symmetric conformal field theory which has no relevant singlet operators, so is radically different to conventional Wilson-Fisher-type conformal field theories., Comment: 4+epsilon pages, 6 figures

Polymers in a melt may be subject to topological constraints, as in the example of unlinked polymer rings. How to do statistical mechanics in the presence of such constraints remains a fundamental open problem. We study the effect of topological constraints on a melt of directed polymers, using simulations of a simple quasi-2D model. We find that fixing the global topology of the melt to be trivial changes the polymer conformations drastically. Polymers of length $L$ wander in the transverse direction only by a distance of order $(\ln L)^\zeta$ with $\zeta \simeq 1.5$. This is strongly suppressed in comparison with the Brownian $L^{1/2}$ scaling which holds in the absence of the topological constraint. It is also much smaller than the predictions of standard heuristic approaches - in particular the $L^{1/4}$ of a mean-field-like `array of obstacles' model - so our results present a sharp challenge to theory. Dynamics are also strongly affected by the constraints, and a tagged monomer in an infinite system performs logarithmically slow subdiffusion in the transverse direction. To cast light on the suppression of the strands' wandering, we analyse the topological complexity of subregions of the melt: the complexity is also logarithmically small, and is related to the wandering by a power law. We comment on insights the results give for 3D melts, directed and non-directed., Comment: 4 pages + appendices, 11 figures. Published version