Strategies to prevent the occurrence of resistance against antibiotics by using advanced materials

This is a post-peer-review, pre-copyedit version of an article published in Applied microbiology and biotechnology The final authenticated version is available online at: http://dx.doi.org/10.1007/s00253-018-8776-0Drug resistance occurrence is a global healthcare concern responsible for the increased morbidity and mortality in hospitals, time of hospitalisation and huge financial loss. The failure of the most antibiotics to kill Bsuperbugs^ poses the urgent need to develop innovative strategies aimed at not only controlling bacterial infection but also the spread of resistance. The prevention of pathogen host invasion by inhibiting bacterial virulence and biofilm formation, and the utilisation of bactericidal agents with different mode of action than classic antibiotics are the two most promising new alternative strategies to overcome antibiotic resistance. Based on these novel approaches, researchers are developing different advanced materials (nanoparticles, hydrogels and surface coatings) with novel antimicrobial properties. In this review, we summarise the recent advances in terms of engineered materials to prevent bacteria-resistant infections according to the antimicrobial strategies underlying their design.Peer ReviewedPostprint (author's final draft

Caracterización del fenómeno “Isla urbana de calor” en la zona central de la ciudad de Guayaquil

This paper deals with the determination of the physical conditions that cause the urban heat island phenomenon in the central zone of the city of Guayaquil, a place of which actual appearance has been replicated in every local process of urban regeneration. In order to achieve this, it was necessary to take in-situ thermal profiles of twenty three street intersections along a study transect, with the quantification of thermal masses in accordance with coverage materials and their underlying layers one foot depth down the finished floor elevation; besides worked with the estimated anthropogenic heat production after evaluate the built intensity and land use in the study zone, finally calculated sky view factors caused by buildings, vegetation and topography in general. With the results, the numeric model will be a starting point for future urban climate investigations that are intended to predict the effects of replication of these covers in other urban zones with similar urban geometry.El presente artículo tiene como finalidad la determinación de las condiciones físicas que ocasionan el fenómeno de la isla urbana de calor en el casco comercial de la ciudad de Guayaquil, un sector cuya apariencia actual ha sido imitada en todos los procesos de restauración urbana locales. Para ello se procedió a realizar el levantamiento in-situ de los perfiles térmicos de veinte y tres intersecciones viales a lo largo de un transecto de estudio, junto con la cuantificación de las masas térmicas intervinientes según los materiales de cobertura y sus capas subyacentes hasta una profundidad de sesenta y un centímetros bajo el nivel de piso terminado; además se estimó la producción de calor antropogénico al evaluar la intensidad de edificación y usos de suelo en la zona de estudio, y se computó los porcentajes de cielo visible respectivos en función de la geometría urbana que ocasionan los edificios, árboles y la topografía en general. Se espera que, con los resultados obtenidos, el modelo numérico generado sea un punto de partida para las futuras investigaciones del clima urbano que apunten a predecir los efectos derivados de la replicación de estas coberturas en sectores con similar grado de consolidación de geometría urbana

Isla de calor en expansión , el futuro térmico de la zona residencial en el desarrollo de la autopista Guayaquil-Salinas desde el Km10 hasta el km26

pdfEn temas de clima urbano, el estudio del fenómeno de la isla de calor es uno de los que más importancia tiene a nivel mundial pues, toda ciudad presenta microclimas de diferentes comportamientos térmicos que siempre resultan mucho más calurosos que su entorno rural inmediato. De momento en Guayaquil no se monitorea tales microclimas, pero esta investigación emprendió la toma manual de temperaturas en varios transectos para compararlos con los registros meteorológicos en tiempo real publicados en línea de la estación Simón Bolívar del actual aeropuerto; aunque ubicada dentro de la misma ciudad, de allí se confirmó que existe más de una isla de calor y que la de mayor intensidad se encuentra a lo largo del Blvd. 9 de Octubre con un pico de 5.3°C de diferencia media. Como es de esperar, una estación móvil de toma manual de datos supone ciertas limitantes debido a la no simultaneidad de las lecturas de temperatura, por lo que se adoptó márgenes de tolerancia para los tiempos según estándares internacionales; caso similar ocurrió con los flujos de calor antropogénico que, en vista de que tampoco existen registros en Guayaquil, hubo que importar datos típicos de otras ciudades en función de la similitud en intensidad de edificación. Los resultados obtenidos en este trabajo están presentados con un lenguaje universal para proyectistas, constructores, planificadores urbanos e interesados en el clima de la ciudad y van desde el hallazgo de la identidad térmica de sesenta y ocho intersecciones viales, modelos numéricos predictivos de respuesta calórica, diagramas psicrométricos de confort higrotérmico exclusivos de Guayaquil, construcción de criterios de diseño sustentable de coberturas, geometría urbana y reducción de calor antropogénico hasta la elaboración de una propuesta de modificación a la actual normativa urbana que carece de políticas de prevención de islas de calor para el sector de expansión planificada en la vía a la costa desde la ciudadela Puerto Azul hasta el peaje del km26.In urban climate concerns, the study of urban heat island phenomenon is one of the most attended in the world, because of every city shows different thermal behaviors in each micro-climate that always are heater than the nearest rural environment. Currently, in Guayaquil there are not monitoring of such micro-climates, but this research has applied the transects method in order to take temperatures and then compare them with on-line published meteorological registers of Simon Bolivar station that reports to the actual airport, even though it is in the middle of the mere city, data confirmed that it do exists more than one heat island and the most intense is located through Blvd. 9 de Octubre with a peak value of 5.3°C of average difference. As everyone should expect, a mobile meteorological station is quite limited due to the impossibility in getting simultaneous data, so the author had to use tolerance ranges for the timing based on international standards; a similar case occurred in anthropogenic heat fluxes, author had to import typical data from other cities with similar characteristics on building intensity. The results on this work are shown with a universal language that project designers, civil builders, urban planners and urban climate researchers could find suitable. Findings contains the providing of thermal identity of sixty eight street intersections, numeric models that predicts thermal response, psychrometric charts of hygrothermal comfort for Guayaquil, construction of sustainable design patterns for surface coverage management, urban geometry, reduction of anthropogenic heat and a proposal of an actual urban normative modification due to the lack of urban heat islands prevention policies in planned expansion sector placed on “Vía a la Costa” road from Puerto Azul housing to the tollbooth at km26

The zinc binding receptor GPR39 interacts with 5-HT1A and GalR(1) to form dynamic heteroreceptor complexes with signaling diversity

GPR39 is a class A G protein-coupled receptor involved in zinc binding and glucose homeostasis regulation, among other physiological processes. GPR39 was originally thought to be the receptor for obestatin peptide but this view has been challenged. However, activation of this receptor by zinc has been clearly established. Recent studies suggest that low GPR39 expression, due to deficient zinc levels, is involved in major depressive disorder. We have previously reported that zinc can alter receptor-receptor interactions and favor specific receptor interactions. In order to unravel the effect of zinc on specific G protein-coupled receptor association processes, we have performed FRET and co-immunopurification studies with GPR39 and 5-HT1A and GalR(1) which have been shown to dimerize. Our results suggest that zinc can modulate the formation of specific 5-HT1A-GPR39 and GalR(1)-5-HT1A-GPR39 heteroreceptor complexes under our experimental conditions.; We have analyzed the differences in signaling between the mono-homomeric receptors 5-HT1A, GalR(1) and GPR39 and the heteroreceptor complexes between them Our results show that the GPR39-5-HT1A heterocomplex has additive functionalities when compared to the monomeric-homomeric receptors upon receptor activation. In addition, the heterocomplex including also GalR(1) shows a different behavior, upon exposure to the same agonists. Furthermore, these processes appear to be regulated by zinc. These findings provide a rationale for the antidepressive effect widely described for zinc because pro-depressive heterocomplexes are predominant at low zinc concentration levels. (C) 2015 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author's final draft

Effect of trace metal Ions on the conformational stability of the visual photoreceptor rhodopsin

Trace metals are essential elements that play key roles in a number of biochemical processes governing human visual physiology in health and disease. Several trace metals, such as zinc, have been shown to play important roles in the visual phototransduction process. In spite of this, there has been little research conducted on the direct effect of trace metal elements on the visual photoreceptor rhodopsin. In the current study, we have determined the effect of several metal ions, such as iron, copper, chromium, manganese, and nickel, on the conformational stability of rhodopsin. To this aim, we analyzed, by means of UV-visible and fluorescence spectroscopic methods, the effects of these trace elements on the thermal stability of dark rhodopsin, the stability of its active Metarhodopsin II conformation, and its chromophore regeneration. Our results show that copper prevented rhodopsin regeneration and slowed down the retinal release process after illumination. In turn, Fe3+, but not Fe2+, increased the thermal stability of the dark inactive conformation of rhodopsin, whereas copper ions markedly decreased it. These findings stress the important role of trace metals in retinal physiology at the photoreceptor level and may be useful for the development of novel therapeutic strategies to treat retinal disease.This research was funded by grants from Ministry of Science and Innovation, Spain (PID2019-104817GB-I00), and from the Government of Catalonia to Research Consolidated Groups (2021 SGR 00342) to P.G. F.W. is the recipient of a predoctoral grant from the Secretariat for Universities and Research of the Ministry of Business and Knowledge of the Government of Catalonia and the European Social Fund (2021 FI_B 00228).Peer ReviewedPostprint (published version

Human blue cone opsin regeneration involves secondary retinal binding with analog specificity

Human color vision is mediated by the red, green, and blue cone visual pigments. Cone opsins are G-protein-coupled receptors consisting of an opsin apoprotein covalently linked to the 11-cis-retinal chromophore. All visual pigments share a common evolutionary origin, and red and green cone opsins exhibit a higher homology, whereas blue cone opsin shows more resemblance to the dim light receptor rhodopsin. Here we show that chromophore regeneration in photoactivated blue cone opsin exhibits intermediate transient conformations and a secondary retinoid binding event with slower binding kinetics. We also detected a fine-tuning of the conformational change in the photoactivated blue cone opsin binding site that alters the retinal isomer binding specificity. Furthermore, the molecular models of active and inactive blue cone opsins show specific molecular interactions in the retinal binding site that are not present in other opsins. These findings highlight the differential conformational versatility of human cone opsin pigments in the chromophore regeneration process, particularly compared to rhodopsin, and point to relevant functional, unexpected roles other than spectral tuning for the cone visual pigmentsPeer ReviewedPostprint (author's final draft

Flavonoid allosteric modulation of mutated visual rhodopsin associated with retinitis pigmentosa

Dietary flavonoids exhibit many biologically-relevant functions and can potentially have beneficial effects in the treatment of pathological conditions. In spite of its well known antioxidant properties, scarce structural information is available on the interaction of flavonoids with membrane receptors. Advances in the structural biology of a specific class of membrane receptors, the G protein-coupled receptors, have significantly increased our understanding of drug action and paved the way for developing improved therapeutic approaches. We have analyzed the effect of the flavonoid quercetin on the conformation, stability and function of the G protein-coupled receptor rhodopsin, and the G90V mutant associated with the retinal degenerative disease retinitis pigmentosa. By using a combination of experimental and computational methods, we suggest that quercetin can act as an allosteric modulator of opsin regenerated with 9-cis-retinal and more importantly, that this binding has a positive effect on the stability and conformational properties of the G90V mutant associated with retinitis pigmentosa. These results open new possibilities to use quercetin and other flavonoids, in combination with specific retinoids like 9-cis-retinal, for the treatment of retinal degeneration associated with retinitis pigmentosa. Moreover, the use of flavonoids as allosteric modulators may also be applicable to other members of the G protein-coupled receptors superfamily.Peer ReviewedPostprint (author's final draft

Influencia del neuromarketing en la percepción de carteles publicitarios

El neuromarketing pretende ahondar en la mente del consumidor. El objetivo de esta investigación es determinar la fiabilidad y precisión del neuromarketing para realizar campañas y valorar emociones. Metodológicamente, se utiliza Gazerecorder, que permite conocer los movimientos oculares al ver unas imágenes. Se analizan carteles publicitarios reales siguiendo un grupo de variables. Se concluye que la novedad es el principal elemento de atención al ver anuncios publicitarios, no así el color, y que existe un sesgo entre los elementos de llamamiento de atención valorados a priori y los realmente tenidos en cuenta al evaluar un anuncio

La Forma Espacial de la Isla de Calor en la Ciudad de Guayaquil

Uno de los impactos ambientales de importancia macro-escalar quele conciernen a la ciudad de Guayaquil es el de la presencia delfenómeno “Isla de calor”, como consecuencia de la configuracióngeométrica de su casco empresarial que marca un pico de +5,32°Ccon respecto a los registros meteorológicos locales y que ha llegadoa comprometer la calidad del aire a nivel del suelo y los patrones detransferencia térmica con el que se encuentra inmediatamente sobrela cubierta de los edificios. El presente estudio confirma la existenciadel fenómeno con evidencia empírica y pretende ilustrar suaspecto espacial basado en la medición de variables geométricasque denotan una elevada intensidad de usos de suelo en callesdemasiado angostas en relación a la altura de las edificaciones quelas flanquean

El fenómeno blog en España : análisis sectorial de hipertextualidad, multimedia e interactividad

El uso de internet y de las redes sociales influye en las decisiones de los turistas a la hora de consumir cualquier tipo de producto o servicio. De hecho, una estrategia eficiente en herramientas de marketing digital por parte de las empresas turísticas y los destinos aumenta su visibilidad de cara a la audiencia y, por tanto, sus ventas. Esta investigación pretende analizar algunos de los blogs más conocidos en lengua española mediante el análisis de contenido de sus webs. Así, se utiliza una metodología cualitativa (entrevistas en profundidad con profesionales del marketing y con lectores y creadores de blogs) y cuantitativa (una encuesta al público en general para valorar el perfil de los visitantes de los blogs, lo que capta más la atención de estas páginas web). Se establece una ficha técnica de cada blog que agrupa 22 variables que analizan cuatro partes principales (la cabecera como puerta de entrada, el artículo, la barra lateral y el pie de página). Se concluye que los blogs de viajes y sus redes sociales son herramientas de marketing muy relevantes en la actualidad y que la mayor parte de los mileniales los usan como primera opción a la hora de buscar información para viajar.L'ús d'internet i de les xarxes socials influeix en les decisions dels turistes a l'hora de consumir qualsevol tipus de producte o servei. De fet, una estratègia eficient en eines de màrqueting digital per part de les empreses turístiques i les destinacions augmenta la seva visibilitat de cara a l'audiència i, per tant, les seves vendes. Aquesta recerca pretén analitzar alguns dels blogs més coneguts en llengua espanyola mitjançant l'anàlisi de contingut dels seus webs. Així, s'utilitza una metodologia qualitativa (entrevistes en profunditat amb professionals del màrqueting i amb lectors i creadors de blogs) i quantitativa (una enquesta al públic en general per valorar el perfil dels visitants dels blogs, la qual cosa capta més l'atenció d'aquestes pàgines web). S'estableix una fitxa tècnica de cada blog que agrupa 22 variables que analitzen quatre parts principals (la capçalera com a porta d'entrada, l'article, la barra lateral i el peu de pàgina). Es conclou que els blogs de viatges i les seves xarxes socials són eines de màrqueting molt rellevants en l'actualitat i que la major part dels mil·lennistes els utilitzen com a primera opció a l'hora de buscar informació per viatjar.The use of the internet and social networks influences the decisions of tourists when it comes to consuming any type of tourist product or service. In fact, an efficient strategy in digital marketing tools by tourism companies and destinations increases their visibility to the audience and, therefore, their sales. This research aims to analyse some of the bestknown blogs in the Spanish language through content analysis of their websites. Both qualitative methodology (in-depth interviews with marketing professionals, blog readers and blog creators) and quantitative methodology (a survey of the general public to assess the profile of blog visitors; what attracts most attention on these web pages) are used. A technical sheet is established, which uses 22 variables to analyse four main sections of each blog (the header as entry point, the post, the sidebar and the footer). The study concludes that travel blogs and their social networks are very important marketing tools today, and that most millennials use travel blogs as the first option when looking for information for travel