Estudio de mezclas polímero-cromóforo con orientación polar para dispositivos electroópticos

Este trabajo recoge una caracterización óptica detallada de películas delgadas de polímeros en los que se dispersan cromóforos con propiedades ópticas no lineales. El polímero utilizado es el polimetilmetacrilato (PMMA) en dos variantes distintas según su peso molecular. El cromóforo que se ha incorporado (en distinta concentración) a la matriz polimérica es el ``Disperse Red 1''. Las muestras se someten a una orientación polar, necesaria para que presenten propiedades no lineales de segundo orden a nivel macroscópico. Para ello, se utilizan dos métodos de orientación con campo eléctrico, uno basado en el efecto Corona y otro mediante electrodos. Se trabaja en todo momento con películas delgadas de espesores entre $1$ y $2\mu m$. Se detallan en este estudio las condiciones óptimas de preparación de muestras, el procedimiento de caracterización de las películas y los resultados obtenidos tanto antes como tras forzar la orientación polar, discutiendo en qué medida cambian las propiedades después de este proceso.<br /

Respuesta óptica no lineal de sistemas poliméricos para aplicaciones optoelectrónicas

El trabajo que se presenta se enmarca en el estudio de la respuesta óptica no lineal de segundo orden de materiales orgánicos. Se ha preparado y caracterizado una serie de películas poliméricas delgadas que contienen moléculas orgánicas dispersas. Se han analizado sus características ópticas y, tras ser sometidas a un proceso de orientación polar con campo eléctrico, se ha analizado su respuesta no lineal, determinando los valores de los coeficientes relevantes del tensor susceptibilidad de segundo orden.<br /

Novel push-pull chromophores to prepare electro-optic modulators

In recent years, a large number of push-pull organic molecules have been proposed as promising candidates for electronic and optical applications. Generally, the main effort has been focused on the design of chromophores with large first hyperpolarizability values (β); this would result in a wide variety of nonlinear optical (NLO) applications, such as modulators.[1,2] In this work, we report an experimental and theoretical investigation of the NLO properties of novel push-pull systems derived from the dicyanomethylene-4H-chromene (DCM) group. Particular attention will be paid to better understand the molecular and electronic properties of these systems by using vibrational spectroscopic techniques and electrochemistry. Furthermore, these materials have been tested in a silicon-organic hybrid modulator based on an integrated dual-mode interferometer.[3]Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Efecto del tamaño y concentración de nanopartículas plasmónicas en las propiedades de electrodos para celdas solares

En este trabajo final de máster se estudian las propiedades de electrodos y celdas solares sensibilizadas con colorante (DSSC) tras la incorporación de nanopartículas (NPs) plasmónicas de metales nobles como el oro. Se analiza el comportamiento final de la DSSC bajo ciertas variables, como pueden ser la concentración y diámetro de NPs, técnicas de incorporación y colorantes y electrolitos utilizados. Se caracterizan cada una de las componentes del sistema mediante técnicas de absorción y reflectancia óptica, perfilometría o microscopía electrónica de transmisión y barrido. <br /

Síntesis de sistemas anilina-π-aceptor para óptica no lineal: moléculas y películas poliméricas

Síntesis de sistemas D-π-A para su estudio de Óptica No Lineal y elaboración de películas con propiedades ópticas no lineales de segundo orden

D-π-A compounds with tunable intramolecular charge transfer achieved by incorporation of butenolide nitriles as acceptor moieties

Chromophores where a polyenic spacer separates a 4H-pyranylidene or benzothiazolylidene donor and three different butenolide nitriles have been synthesized and characterized. The role of 2(5H)-furanones as acceptor units on the polarization and the second-order nonlinear (NLO) properties has been studied. Thus, their incorporation gives rise to moderately polarized structures with NLO responses that compare favorably to those of related compounds featuring more efficient electron-withdrawing moieties. Derivatives of the proaromatic butenolide PhFu show the best nonlinearities. Benzothiazolylidene-containing chromophores present less alternated structures than their pyranylidene analogues, and, unlike most merocyanines, the degree of charge transfer does not decrease on lengthening the π-bridge.Financial support from MICINN-FEDER (CTQ2011-22727 and MAT2011-27978- C02-02), MINECO (CTQ2014-52331R), and Gobierno de Aragon-Fondo Social Europeo (E39 and E04) is gratefully acknowledged. Research at the Universidad de Malaga was supported by MINECO (CTQ2012-33733) and Junta de Andalucıa (P09-4708).Peer Reviewe

Push-pull thiophene chromophores for electro-optic applications: from 1D linear to beta-branched structures

We report the synthesis and characterization of a novel series of push-pull chromophores bearing 1D linear and beta-branched thiophenes as pi-conjugated spacers between a 2, 2, 4, 7-tetramethyl-1, 2, 3, 4-tetrahydroquinoline electron donor unit and dicyano- and tricyanovinylene electron acceptor groups. The effect of the introduction of beta-thiophenes on the linear and nonlinear (NLO) optical properties as well as electrochemical and thermal data is studied in detail by performing a comparative study between the branched and 1D linear systems. In addition, a parallel DFT computational study is used to evaluate structure-property relationships. The non-linear optical behavior of the molecules both in solution and in solid state as electro-optic (EO) films using a guest-host approach shows very promising performance for electro-optic applications with high molecular first hyperpolarizabilities (mu beta) of 4840 x 10(-48) esu and electro-optic coefficients r(33) reaching 650 pm V-1. One highlight is that the electro-optic films of the beta-branched chromophores are superior in terms of thermal stability in device operation as measured by a transmissive modified reflective Teng-Man method. This work provides guidelines for the design of improved electro-optic materials including beta-branched chromophores which could be useful for practical EO applications, where both enhanced beta and r(33) values together with chemical and thermal stability are necessary

Characterization of Nematic Liquid Crystal at Microwave Frequencies Using Split-Cylinder Resonator Method

[EN] Liquid crystal (LC) is an anisotropic liquid material, which flows like a liquid, but at the same time, its molecules have an orientational order like in the solid state. Thus, LC is a promising dielectric material for designing reconfigurable devices at microwave frequencies. In order to optimize the design of reconfigurable microwave devices, accurate values of the dielectric permittivity and the loss tangent of LCs are needed. However, new LCs are not well characterized at these frequencies because of its recent use for microwave applications. Therefore, the characterization in this frequency range is required for its practical use within microwave components and devices. In this paper, a split-cylinder resonator method is used for the characterization of four different nematic LCs at two frequency points, i. e., 5 and 11 GHz. This characterization includes the extraction of their complex dielectric permittivity values at these frequencies. The employed method allows to obtain the two extreme permittivity values without applying any external electric or magnetic field to polarize the LC molecules. Two different approaches, a modal analysis method and a full-wave numerical technique, have been used for determining the LC parameters obtaining similar results in both cases.This work was supported in part by the Generalitat Valenciana Research under Project PROMETEOII/2015/005, in part by the Ministerio de Educacion, Cultura y Deporte, Spain, through the Fellowship Program for Training University Professors under Grant FPU14/00150, in part by the Ministerio de Economia y Competitividad, Spain through Research and Development Projects under Grant TEC2016-75934-C4-R-1, and in part by the Gobierno de Aragon-Fondo Europeo de Desarrollo Regional (FEDER)-Fondo Social Europeo 2017-2019 under Reference E14-7R.Sánchez-Marín, JR.; Nova-Giménez, V.; Bachiller Martin, MC.; Villacampa, B.; De La Rua, A.; Kronberger, R.; Penaranda-Foix, FL.... (2019). Characterization of Nematic Liquid Crystal at Microwave Frequencies Using Split-Cylinder Resonator Method. IEEE Transactions on Microwave Theory and Techniques. 67(7):2812-2820. https://doi.org/10.1109/TMTT.2019.2916790S2812282067

V-shaped pyranylidene/triphenylamine-based chromophores with enhanced photophysical, electrochemical and nonlinear optical properties

We report the synthesis and comprehensive study of two chromophores based on 4H-pyranylidene moiety as a part of the π-conjugated spacer. Triphenylamine (TPA) acts as donor and tricarbonitrile-based electron-accepting groups complete these V-shaped D–A–D architectures (A, acceptor; D, donor). Their electrochemical, photophysical and nonlinear optical properties are analyzed in detail by using a joint experimental and theoretical approach. The two chromophores exhibit near-infrared fluorescence, large Stokes shift, enhanced emission in tetrahydrofuran/water mixtures and good photostability. Additionally, the dimerization of triphenylamine groups to tetraphenylbenzidine (TPB) takes place upon electrochemical and chemical oxidation showing their peculiar electrochemical behavior and film formation capabilities. Interestingly, high molecular first hyperpolarizabilities and two-photon absorption cross-sections were found, highlighting their potential applications in electro-optical devices. Overall, our work demonstrates that these near-infrared (NIR) fluorescent chromophores are versatile materials with a myriad of applications ranging from optoelectronics to biological applications.The work at the University of Málaga was funded by the MICINN (PID2019-110305GB-I00, PID2019-104293GB-I00, RTI2018-095410-B-I00, EuroNanoMed 2019 PCI2019-111825-2), the Institute of Health Carlos III (ISCIII) RETIC ARADYAL (RD16/0006/0012) and by the Junta de Andalucıa (P09-FQM-4708, UMA18-FEDERJA-080, UMA18-FEDERJA-007, PIER-0084-2019). The work at the University of Zaragoza was funded by the MICINN (PID2019-104307GB-I00/AEI/10.13039/501100011033) and Gobierno de Aragón (E47_20R). The work at the University of Stuttgart was funded by the German Science Foundation (DFG) through the project “LU 1445/7-1, project number 416982273” on electrooptical hybrid modulators, C. Malacrida is acknowledged for discussions. S. G.-V. thanks the MINECO for a FPU predoctoral fellowship (FPU17/04908) and CB-M for FPU fellowship (FPU16/02516). Computer resources, technical expertise and assistance provided by the SCBI (Supercomputing and Bioinformatics) centre of the University of Málaga are gratefully acknowledged. We thank the Vibrational spectroscopy lab (EVI) of the Research Central Services (SCAI) of the University of Málaga and John Pearson (BIONAND) for help with laser confocal microscopy analysis. We gratefully acknowledge the ICTS “NANBIOSIS” facilities, more specifically the U28 Unit of the Andalusian Centre for Nanomedicine & Biotechnology (BIONAND), for their help with the 2PA characterization and the microscopy studies.Peer reviewe

RNF43 mutations predict response to anti-BRAF/EGFR combinatory therapies in BRAFV600E metastatic colorectal cancer

Colorectal cancer; Predictive markers; Tumour biomarkersCáncer colorrectal; Marcadores predictivos; Biomarcadores tumoralesCàncer colorrectal; Marcadors predictius; Biomarcadors tumoralsAnti-BRAF/EGFR therapy was recently approved for the treatment of metastatic BRAFV600E colorectal cancer (mCRCBRAF-V600E). However, a large fraction of patients do not respond, underscoring the need to identify molecular determinants of treatment response. Using whole-exome sequencing in a discovery cohort of patients with mCRCBRAF-V600E treated with anti-BRAF/EGFR therapy, we found that inactivating mutations in RNF43, a negative regulator of WNT, predict improved response rates and survival outcomes in patients with microsatellite-stable (MSS) tumors. Analysis of an independent validation cohort confirmed the relevance of RNF43 mutations to predicting clinical benefit (72.7% versus 30.8%; P = 0.03), as well as longer progression-free survival (hazard ratio (HR), 0.30; 95% confidence interval (CI), 0.12–0.75; P = 0.01) and overall survival (HR, 0.26; 95% CI, 0.10–0.71; P = 0.008), in patients with MSS-RNF43mutated versus MSS-RNF43wild-type tumors. Microsatellite-instable tumors invariably carried a wild-type-like RNF43 genotype encoding p.G659fs and presented an intermediate response profile. We found no association of RNF43 mutations with patient outcomes in a control cohort of patients with MSS-mCRCBRAF-V600E tumors not exposed to anti-BRAF targeted therapies. Overall, our findings suggest a cross-talk between the MAPK and WNT pathways that may modulate the antitumor activity of anti-BRAF/EGFR therapy and uncover predictive biomarkers to optimize the clinical management of these patients.VHIO would like to acknowledge the Cellex Foundation for providing research facilities and equipment, the FERO Foundation for their funding support, the Consorcio Centro de Investigación Biomédica en Red de Cáncer (CIBERONC, CB16/12/00259) from the Institute of Health Carlos III (ISCIII), Ministry of Science and Innovation, and the Department of Health (Generalitat de Catalunya, SLT008/18/00198 and SLT008/18/00205) for their support on this research. Authors acknowledge financial support from the State Agency for Research (Agencia Estatal de Investigación) (CEX2020-001024-S / AEI / 10.13039 /501100011033). This research is funded by the SCITRON program; Novartis funded the genomics characterization by WES of samples from 28 patients from the discovery cohort and had no influence on data analysis/interpretation or writing of the paper (3003145512 to R.A.T.). S.Li. is financially supported by a Chinese Scholarship Council PhD fellowship (201909370083 to S. Li). R.P.-L. is supported by a CRIS Foundation Talent Award (TALENT19-05), the FERO Foundation, the Instituto de Salud Carlos III-Investigación en Salud (PI18/01395 and PI21/01019 to R.P.-L.) and the Prostate Cancer Foundation (Young Investigator Award). This work was supported by the Miguel Servet-I Research Award from ISCIII of the Ministry of Economy (CP17/00199 to R.A.T.), the Olga Torres Foundation Award to emerging researchers (2601 to R.A.T.), the ISCIII-FEDER (PI17/00947 and PI20/00968 to E.E.), and the Fundación AECC (CLSEN19001ELEZ to E.E.) and Ministry of Science and Innovation (Europa Redes y Gestores, ECT2020-000827 to E.E.)