Growth and reductive transformation of a gold shell around pyramidal cadmium selenide nanocrystals

We report the growth of an unstable shell-like gold structure around dihexagonal pyramidal CdSe nanocrystals in organic solution and the structural transformation to spherical domains by two means: i) electron beam irradiation (in situ) and (ii) addition of a strong reducing agent during synthesis. By varying the conditions of gold deposition, such as ligands present or the geometry of the CdSe nanocrystals, we were able to tune the gold domain size between 1.4 nm to 3.9 nm and gain important information on the role of surface chemistry in hetero nanoparticle synthesis and seed reactivity, both of which are crucial points regarding the chemical design of new materials for photocatalysis and optoelectronic applications.Comment: 5 pages, 4 figure

Photoluminescence Activation of Organic Dyes via Optically Trapped Quantum Dots

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © American Chemical Society after peer review and technical editing by the publisher.[EN] Laser tweezers afford quantum dot (QD) manipulation for use as localized emitters. Here, we demonstrate fluorescence by radiative energy transfer from optically trapped colloidal QDs (donors) to fluorescent dyes (acceptors). To this end, we synthesized silica-coated QDs of different compositions and triggered their luminescence by simultaneous trapping and two-photon excitation in a microfluidic chamber filled with dyes. This strategy produces a near-field light source with great spatial maneuverability, which can be exploited to scan nanostructures. In this regard, we demonstrate induced photoluminescence of dye-labeled cells via optically trapped silica-coated colloidal QDs placed at their vicinity. Allocating nanoscale donors at controlled distances from a cell is an attractive concept in fluorescence microscopy because it dramatically reduces the number of excited dyes, which improves resolution by preventing interferences from the whole sample, while prolonging dye luminescence lifetime due to the lower power absorbed from the QDs.H.R.-R. is supported by an FPI-UAM 2015 fellowship (BES-2009-027909). Authors acknowledge funding from the Spanish Ministry of Economy and Competitiveness through MAT2017-85617-R and MAT2015-71806-R. B.H.J. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the Maria de Maeztu (IFIMAC) and Severo Ochoa (IMDEA Nanoscience) Programmes for Units of Excellence in R&D.Rodríguez-Rodríguez, H.; Acebrón, M.; Iborra, F.; Arias-Gonzalez, JR.; Juárez, B. (2019). Photoluminescence Activation of Organic Dyes via Optically Trapped Quantum Dots. ACS Nano. 13(6):7223-7230. https://doi.org/10.1021/acsnano.9b02835S7223723013

Unexpected Optical Blue Shift in Large Colloidal Quantum Dots by Anionic Migration and Exchange

Compositional changes taking place during the synthesis of alloyed CdSeZnS nanocrystals (NCs) allow shifting of the optical features to higher energy as the NCs grow. Under certain synthetic conditions, the effect of those changes on the surface/interface chemistry competes with and dominates over the conventional quantum confinement effect in growing NCs. These changes, identified by means of complementary advanced spectroscopic techniques such as XPS (X-ray photoelectron spectroscopy) and XAS (X-ray absorption spectroscopy), are understood in the frame of an ion migration and exchange mechanism taking place during the synthesis. Control over the synthetic routes during NC growth represents an alternative tool to tune the optical properties of colloidal quantum dots, broadening the versatility of the wet chemical methods.Fil: Acebrón, María. IMDEA Nanociencia; EspañaFil: Galisteo López, Juan F.. Universidad de Sevilla. Consejo Superior de Investigaciones Cientificas. Instituto de Ciencia de Materiales de Sevilla; EspañaFil: López, Cefe. Instituto de Ciencia de Materiales de Madrid; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Herrera, Facundo Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Mizrahi, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Requejo, Felix Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Palomares, F. Javier. Consejo Superior de Investigaciones Científicas; España. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Juárez, Beatriz H.. Universidad Autónoma de Madrid; España. IMDEA Nanoscience; Españ

Association between Life Skills and Academic Performance in Adolescents in the Autonomous Community of Aragon (Spain)

Background: Learning and socio-emotional development is promoted through the creation and nurturing of an optimal school climate. This study aims to analyze the relationship between life skills and academic performance in a large sample of adolescents from the autonomous community of Aragón (Spain). Methods: A cross-sectional study was conducted on the life skills and academic performance of a sample of 7th and 8th grade middle school students during the academic year 2018–2019. A sample of 43 middle schools were randomly selected; the final sample comprised 1745 students. The following data were collected through an anonymized, previously validated questionnaire: sociodemographic variables, social skills, self-efficacy, affective balance, and academic performance. Results: We found a statistically significant association between life skills and academic performance (p < 0.001) in our sample. We also observed significant gender differences in life skills, with boys obtaining higher scores in cognitive skills and affective balance, and with girls achieving higher scores in social skills. Conclusion: We argue that life skills should be integrated into educational policies in order to improve the academic performance and health outcomes of students

3D characterization of CdSe nanoparticles attached to carbon nanotubes

The crystallographic structure of CdSe nanoparticles attached to carbon nanotubes has been elucidated by means of high resolution transmission electron microscopy and high angle annular dark field scanning transmission electron microscopy tomography. CdSe rod-like nanoparticles, grown in solution together with carbon nanotubes, undergo a morphological transformation and become attached to the carbon surface. Electron tomography reveals that the nanoparticles are hexagonal-based with the (001) planes epitaxially matched to the outer graphene layer.Comment: 7 pages, 8 figure

Infrared-Emitting Multimodal Nanostructures for Controlled In Vivo Magnetic Hyperthermia

Deliberate and local increase of the temperature within solid tumors represents an effective therapeutic approach. Thermal therapies embrace this concept leveraging the capability of some species to convert the absorbed energy into heat. To that end, magnetic hyperthermia (MHT) uses magnetic nanoparticles (MNPs) that can effectively dissipate the energy absorbed under alternating magnetic fields. However, MNPs fail to provide real-time thermal feedback with the risk of unwanted overheating and impeding on-the-fly adjustment of the therapeutic parameters. Localization of MNPs within a tissue in an accurate, rapid, and cost-effective way represents another challenge for increasing the efficacy of MHT. In this work, MNPs are combined with state-of-the-art infrared luminescent nanothermometers (LNTh; Ag2S nanoparticles) in a nanocapsule that simultaneously overcomes these limitations. The novel optomagnetic nanocapsule acts as multimodal contrast agents for different imaging techniques (magnetic resonance, photoacoustic and near-infrared fluorescence imaging, optical and X-ray computed tomography). Most crucially, these nanocapsules provide accurate (0.2 degrees C resolution) and real-time subcutaneous thermal feedback during in vivo MHT, also enabling the attainment of thermal maps of the area of interest. These findings are a milestone on the road toward controlled magnetothermal therapies with minimal side effects.E.X. and R.M. contributed equally to this work. Work partially supported by the Ministerio de Ciencia, Innovación y Universidades (PID2019-106301RB-I00 and PID2019-105195RA-I00), by the Spanish Ministry of Economy and Competitiveness (MAT2017-85617-R, SEV-2016-0686), by the Comunidad de Madrid (RENIM-CM, B2017/BMD-3867, co-financed by the European Structural and Investment Fund; NANOMAGCOST-CM P2018/NMT-4321), by the European COST Actions CA17115 (MyWave) and CA17140 (Nano2Clinic), by the Spanish Scientific Network HiperNano (RED2018-102626-T) and by the European Commission Horizon 2020 project NanoTBTech (Grant Number: 801305). D.G.-C. acknowledges CAM for funding PEJ-2018-AI/IND-11245. A.B. acknowledges funding from Comunidad de Madrid through TALENTO grant ref. 2019-T1/IND-14014. E.X. is grateful for a Juan de la Cierva Formación scholarship (FJC2018-036734-I). R.M. acknowledges the support of the European Commission through the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant agreement N 797945 (LANTERNS). A. E. acknowledges the support from Comunidad de Madrid (Talento project 2018-T1/IND-1005) and from AECC (Ideas Semilla 2019 project). P.R.S. is grateful for a Juan de la Cierva Incorporación scholarship (IJC2019-041915-I). Procedures involving animal experiments were approved by the regional authority for animal experimentation of the Comunidad de Madrid and were conducted in agreement with the Universidad Autónoma de Madrid Ethics Committee, in compliance with the European Union directives 63/2010UE and Spanish regulation RD 53/2013

Factores de riesgo psicosociales y ambientales asociados a trastornos mentales

In Colombia, there are few studies on the association of psychosocial and environmental factors with the most prevalent mental disorders; such studies are important due to the context of violence, social insecurity, and job and economic instability in the country. The objective of this study was to identify the psychosocial and environmental risk factors for mental disorders, in users of psychological services in Colombia. The Mini International Neuropsychiatric Interview and a Questionnaire to evaluate the Axis-IV of the DSM-IV-TR were applied to 490 participants. The analysis comprised descriptive statistics and risk factors. As risk factors for depression, there were identified housing problems, access to health care services, problems related to the primary group, economics, problems of the social environment, and labor. For generalized anxiety, there were identified economic and education issues. For panic disorders, the risk factors were related to social environment, and for social phobia, the risk factors were problems in education, work and social environment.En Colombia, son escasos los estudios sobre la asociaci&oacute;n de los factores psicosociales y medioambientales con trastornos mentales de mayor prevalencia; tales estudios son necesarios debido al contexto de violencia, inseguridad social e inestabilidad laboral y econ&oacute;mica del pa&iacute;s. El objetivo de este estudio fue identificar los factores de riesgo psicosociales y ambientales de los trastornos mentales, en los usuarios de servicios de psicolog&iacute;a de Colombia. Para ello, se aplicaron el MiniInternational Neuropsychiatric Interview y un cuestionario de evaluaci&oacute;n del Eje IV del DSM-IV-TR, a 490 participantes. Se utilizaron an&aacute;lisis descriptivos y de factores de riesgo. Como factor de riesgo para la depresi&oacute;n, se identificaron los problemas de vivienda, acceso a los servicios de asistencia sanitaria, los relativos al grupo primario, los econ&oacute;micos, del ambiente social y los problemas laborales. Para la ansiedad generalizada se identificaron los problemas econ&oacute;micos y los relativos a la ense&ntilde;anza. Para los trastornos de p&aacute;nico, fueron relevantes los problemas relacionados con el ambiente social, y para la fobia social, los problemas de ense&ntilde;anza, los laborales y el ambiente social

una mirada desde las Ciencias de la Conducta

Este libro es el resultado de los trabajos presentados en el 1er Congreso Internacional "Convivencia y bienestar con sentido humanista para una cultura de paz"