Electric Conductivity Study of Porous Polyvinyl Alcohol/Graphene/Clay Aerogels: Effect of Compression

In this work, poly(vinyl alcohol) (PVOH)/graphene (GN) oxide/clay aerogels were prepared using montmorillonite (MMT) and kaolinite (KLT) as fillers. This work paves the way for the development of aerogels filled with MMT or KLT with high conductivity. The mechanical properties of the polymer/clay aerogels are enhanced by incorporating GN into these systems. These composite materials have an enhanced thermal stability, and the combination of PVOH and GN leads to interconnected channels which favored the conductivity when a clay (MMT or KLT) is added to the mixed PVOH/GN matrix. However, after compressing the samples, the conductivities drastically decreased. These results show that the design of solid MMT/GN and KLT/GN composites as aerogels allows maximizing the space utilization of the electrode volume to achieve unhindered ion transport, which seems contrary to the general design principle of electrode materials where a suitable porous structure is desired, such as in our uncompressed samples. These findings also demonstrate the potential of these materials in electrodes, sensors, batteries, pressure-sensing applications, and supercapacitors.Financial support for this research from Ministerio de Economía y Competitividad (project AGL2015-63855-C2-2-R) (MINECO/FEDER) is gratefully acknowledged.The authors acknowledge the Servei Central d’Instrumentació Científica (SCIC-UJI) and Servei Central de Suport a la Investigació Experimental (SCSIE-UV) from Universitat Jaume I and Universitat de València, respectively, for the use of instruments and staff assistance. Authors would like to acknowledge José Ortega and Raquel Oliver for experimental support

Designing anisotropy with waveguide subwavelength structures

Silicon sub-wavelength structures have become a versatile design tool for practical, high-performance integrated optical devices, ranging from highly efficient grating couplers to ultra-broadband beam-splitters. Recently, some of the basic anisotropic properties of these structures have been proposed for advance device design. Here we explore these properties in detail, from the underlying physics to emerging applications in on-chip polarization management.Ministerio de Economía y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (cofinanciado FEDER), Proyectos TEC2016-80718-R, TEC2015-71127-C2-1-R (FPI scholarship BES-2016-077798), and IJCI-2016-30484, the Community of Madrid (S2013/MIT-2790), the Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, the EMPIR program (JRP-i22 14IND13 Photind), co-financed by the participating countries and the European Union’s 2020 research and innovation program, and the Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant No. 734331

Eventos adversos asociados a post-vacunas COVID 19 en pacientes de una Unidad de Medicina Familiar

The prompt response to having vaccines against COVID-19 has been essential for the control of the pandemic. Scientific evidence has reported adverse events after inmunization ranging from mild to very severe reactions. To analyze the association between adversen events and types of vaccines in patients who attended a Social Security Family Medicine Unit (umf) in Puebla for this reason. Data from 134 patients who attended the clinic between February 2021 and February 2022 for presenting signs and symptoms after immunization for COVID-19 were analyzed. Those who reprted symptoms of attack to the general state (ags) were classified as (G1), G2 with respiratory symptoms plus AGS, G3 with digestive symptoms plus AGS, and G4 with digestive and respiratory symptoms plus AGS. From G1 they were 35.8%, G2 28.4%, G3 23.9% and G4 11.9%. Vaccines are a positive option to avoid COVID 19. In this study, diarrea was highly significant in the association as an adverse effect after the applicaction of the Sputnik and Astral Zenecal vaccines.La pronta respuesta para contar con vacunas contra COVID 19 ha sido fundamental para el control de la pandemia. Evidencias científicas han reportado eventos adversos posteriores a la inmunización que van desde reacciones leves hasta muy graves. Objetivo: Analizar los eventos adversos asociados a post-vacunas COVID 19 en pacientes de una Unidad de Medicina Familiar. Material y métodos: Se realizó un estudio observacional, transversal con información retrolectiva. De la base de datos que registra eventos adversos a vacunas, se recabó información del total de pacientes (134) que acudieron a consulta externa por presentar síntomas y signos que asociaron a la aplicación de vacunas para COVID 19 durante febrero de 2021 a febrero de 2022 de una Unidad Médico Familiar de seguridad social de Puebla. Se conformaron cuatro grupos de acuerdo con la sintomatología. (G1) los que reportaron síntomas de ataque al estado general (AEG), G2 síntomas respiratorios más AEG, G3 síntomas digestivos más AEG y G4 síntomas digestivos, respiratorios más AEG. Las variables bajo estudio fueron edad, género, ocupación, antecedentes antes de la vacunación, sano, con VIH, alergias, dosis recibida, marca de la vacuna recibida. Se realizó un análisis descriptivo de las variables bajo estudio, para investigar asociaciones se realizó un análisis bivariado y mutivariado mediante una regresión logística para el cálculo de los ORs. Resultados: La edad promedio de los grupos fue de 35 años, en los grupos G2 y G3 predominó el sexo femenino, en su mayoría empleados para los cuatro grupos. Las vacunas más aplicadas de acuerdo con lo reportado fueron AstraZeneca 38.06% y Sputnik 35.07%. Los resultados de la regresión logística ajustada considerando como variable de referencia el grupo G4 fueron para la vacuna Sputnik OR9.39 (P 0.001) y para Astra Zeneca OR 6.72 (P0.00). Conclusión: Las vacunas son una opción positiva para evitar COVID 19. En este estudio las vacunas que resultaron con una asociación significativa para presentar síntomas respiratorios, digestivos y ataque al estado general fueron Sputnik y AztraZeneca

Excited-State Dynamics of Hybrid Multichromophoric Systems: Toward an Excitation Wavelength Control of the Charge Separation Pathways

The photophysical properties of two hybrid multichromophoric systems consisting of an oligophenylethynyl (OPE) scaffold decorated by 10 red or blue naphthalene diimides (NDIs) have been investigated using femtosecond spectroscopy. Ultrafast charge separation was observed with both red and blue systems. However, the nature of the charge-separated state and its lifetime were found to differ substantially. For the red system, electron transfer occurs from the OPE scaffold to an NDI unit, independently of whether the OPE or an NDI is initially excited. However, charge separation upon OPE excitation is about 10 times faster, and takes place with a 100 fs time constant. The average lifetime of the ensuing charge-separated state amounts to about 650 ps. Charge separation in the blue system depends on which of the OPE scaffold or an NDI is excited. In the first case, an electron is transferred from the OPE to an NDI and the hole subsequently shifts to another NDI unit, whereas in the second case symmetry-breaking charge separation between two NDI units occurs. Although the charges are located on two NDIs in both cases, different recombination dynamics are observed. This is explained by the location of the ionic NDI moieties that depends on the charge separation pathway, hence on the excitation wavelength. The very different dynamics observed with red and blue systems can be accounted for by the oxidation potentials of the respective NDIs that are higher and lower than that of the OPE scaffold. Because of this, the relative energies of the two charge-separated states (hole on the OPE or an NDI) are inverted

High performance silicon photonic devices based on practical metamaterials

Robert Halir, et al., "High performance silicon photonic devices based on practical metamaterials," OECC/PSC, 7-12 July 2019, Fukuoka (Japan)Subwavelength grating metamaterials are enabling a new generation of high-performance silicon photonic devices. Here we discuss the fundamental physics along with some of the latest advances in this rapidly expanding field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad, Programa Estatal de Investigación Orientada a los Retos de la Sociedad (cofinanciado FEDER) – TEC2016-80718-R, TEC2015-71127-C2-1-R (FPI BES-2016-077798) and IJCI-2016-30484; Community of Madrid – S2018/NMT-4326, Marie Sklodowska-Curie –734331, Czech Science Foundation – 1900062

Silicon high performance devices using subwavelength structures

Ministerio de Economía y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (cofinanciado FEDER), Proyecto TEC2016-80718-R Universidad de MälagaSilicon photonics is poised to solve challenges in areas such as datacom, environmental monitoring and diagnostics, by leveraging the economies of scale afforded by CMOS manufacturing. This requires a wide variety of integrated silicon devices, including fiber-to-chip couplers, polarization splitters and waveguide couplers, operating both in the near-infrared and the mid-infrared wavelength range. However, the reduced set of materials available in this platform can often limit the performance of these devices. Subwavelength structures enable the synthesis of optical metamaterials, with properties than can be tuned to enhance device performance, by using fully etched silicon structures with a periodicity smaller than the wavelength of light. Here we review the basic operating principles of these structures, discuss how to efficiently model them, and report on the latest advances in this rapidly growing field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

AOLI: Near-diffraction limited imaging in the visible on large ground -based telescopes

The combination of Lucky Imaging with a low order adaptive optics system was demonstrated very successfully on the Palomar 5m telescope nearly 10 years ago. It is still the only system to give such high-resolution images in the visible or near infrared on ground-based telescope of faint astronomical targets. The development of AOLI for deployment initially on the WHT 4.2 m telescope in La Palma, Canary Islands, will be described in this paper. In particular, we will look at the design and status of our low order curvature wavefront sensor which has been somewhat simplified to make it more efficient, ensuring coverage over much of the sky with natural guide stars as reference object. AOLI uses optically butted electron multiplying CCDs to give an imaging array of 2000 x 2000 pixels.Science and Technology Facilities CouncilThis is the author accepted manuscript. The final version is available from SPIE via http://dx.doi.org/10.1117/12.223090

Artificial tongues and leaves

The objective with synthetic multifunctional nanoarchitecture is to create large suprastructures with interesting functions. For this purpose, lipid bilayer membranes or conducting surfaces have been used as platforms and rigid-rod molecules as shape-persistent scaffolds. Examples for functions obtained by this approach include pores that can act as multicomponent sensors in complex matrices or rigid-rod π-stack architecture for artificial photosynthesis and photovoltaic

Subwavelength metamaterial for communications and sensing

Silicon photonics is considered a breakthrough technology with strong impact in areas as diverse as data center interconnection, high performance computing, the deployment of 5G future communication systems or lab-on-a-chip sensors. The emergence of sub-wavelength grating waveguides (SWG) has been fundamental to achieve advanced devices with unprecedented performance in integrated optics. In this talk we will focus on our recent progress in designing sub-wavelength engineered devices like ultra-broadband mode (de)multiplexers and converters [1], ultra-narrowband Bragg filters [2], sensing waveguides with enhanced sensitivity [3], or suspended silicon mid-infrared waveguides capable of covering the full transparency window of silicon [4], among other. This work was supported by the Ministerio de Economía y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (Proyecto TEC2016-80718-R), and the Universidad de Málaga (Campus de Excelencia Internacional Andalucía Tech).Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

Subwavelength metamaterial structures for silicon photonics

Sub-wavelength periodic metamaterial structures are enabling the design of silicon photonic devices with unprecedented performance in the near infrared band. However, for applications in the promising mid-infrared band it is expected that they acquire even more prominence because for longer wavelengths it is far easier to fabricate structures with a sub- wavelength pitch. Here we report our recent progress in the electromagnetic modeling of sub-wavelength structures, and we will review some of our latest advances in the development of sub-wavelength based devices operating both at near and mid- infrared wavelengths.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech