Broadband plasmonic nanoantennas for multi-color nanoscale dynamics in living cells

Recently, the implementation of plasmonic nanoantennas has opened new possibilities to investigate the nanoscale dynamics of individual biomolecules in living cell. However, studies have yet been restricted to single molecular species as the narrow wavelength resonance of gold-based nanostructures precludes the simultaneous interrogation of different fluorescently labeled molecules. Here we exploited broadband aluminum-based nanoantennas carved at the apex of near-field probes to resolve nanoscale-dynamic molecular interactions on intact living cell membranes. Through multicolor excitation, we simultaneously recorded fluorescence fluctuations of dual-color labeled transmembrane receptors known to form nanoclusters in living cells. Fluorescence cross-correlation studies revealed transient interactions between individual receptors in regions of ~60 nm. Moreover, the high signal-to-background ratio provided by the antenna illumination allowed us to directly detect fluorescent bursts arising from the passage of individual receptors underneath the antenna. Remarkably, by reducing the illumination volume below the characteristic receptor nanocluster sizes, we resolved molecular diffusion within nanoclusters and distinguished it from nanocluster diffusion. Spatiotemporal characterization of transient interactions between molecules is crucial to understand how they communicate with each other to regulate cell function. Our work demonstrates the potential of broadband photonic antennas to study multi-molecular events and interactions in living cell membranes with unprecedented spatiotemporal resolution

Enhancing Magnetic Light Emission with All-Dielectric Optical Nanoantennas

Electric and magnetic optical fields carry the same amount of energy. Nevertheless, the efficiency with which matter interacts with electric optical fields is commonly accepted to be at least 4 orders of magnitude higher than with magnetic optical fields. Here, we experimentally demonstrate that properly designed photonic nanoantennas can selectively manipulate the magnetic versus electric emission of luminescent nanocrystals. In particular, we show selective enhancement of magnetic emission from trivalent europium-doped nanoparticles in the vicinity of a nanoantenna tailored to exhibit a magnetic resonance. Specifically, by controlling the spatial coupling between emitters and an individual nanoresonator located at the edge of a near field optical scanning tip, we record with nanoscale precision local distributions of both magnetic and electric radiative local densities of states (LDOS). The map of the radiative LDOS reveals the modification of both the magnetic and electric quantum environments induced by the presence of the nanoantenna. This manipulation and enhancement of magnetic light-matter interaction by means of nanoantennas opens up new possibilities for the research fields of opto-electronics, chiral optics, nonlinear&nano-optics, spintronics and metamaterials, amongst others.Peer ReviewedPostprint (author's final draft

Participación del alumnado de Grado en Educación Social en los procesos de evaluación formativa de las asignaturas

[SPA] La evaluación es uno de los elementos clave en el nuevo modelo educativo de formación por competencias, si bien, la modalidad que mayor importancia alcanza en estos momentos de transformación universitaria es la evaluación formativa, principalmente por su potencial adquirido para mejorar los procesos de enseñanza y de aprendizaje. Esta modalidad de evaluación se optimiza cuando en ella se otorga una participación activa al alumnado. Por ello, el objetivo de este estudio fue mejorar los procesos educativos en el aula mediante un sistema de evaluación formativa y participativa. En la investigación participaron 40 estudiantes de segundo curso de Grado de Educación Social de la Universidad de Murcia, aplicándose para la recogida de información dos técnicas: un cuestionario a cumplimentar por parejas consensuadamente, y un grupo de discusión. Como resultado de dicha evaluación se obtuvo una valoración global del desarrollo de las asignaturas únicamente de aceptable, lo que conllevó una serie de propuestas de mejora que comenzaron a aplicarse en el primer cuatrimestre y continuarán implementándose a lo largo del segundo cuatrimestre.[ENG] Evaluation is one of the key elements in the new educational model of skills training, although and mode of formative assessment that it has more importance now, in these times of transformation mainly for its ability to improve teaching and learning. This type of evaluation is better when the students is actively involved. Therefore, the aim of this study was to improve the educational process in the classroom through a system of formative and participatory evaluation. Participated in the research were 40 sophomores of Social Education Degree from the University of Murcia. For data collection a questionnaire, which was to be completed by couples consensual and a discussion group was applied. As a result of this evaluation was obtained an overall assessment of the development of the subjects acceptable only, which involves a series of improvement proposals that have already begun to be implemented in the first semester and continue to be implemented during the second semester

Blogfolio. Aprendiendo a través de la evaluación

One of the most innovating tools used in web 2.0 is the blogfolio. This research, of evaluational nature, has the aim of determining the advantages and limitations of said tool in the educational field. For that purpose, a group of Pre-school Education degree students from the University of Murcia were asked about their opinion on a blogfolio that they had been using throughout the course of one of their subjects. An ad hoc questionnaire, validated by inter-judge reliability, was used for that matter. The results show that, in general, the blogfolio is suitable as an instrument for the students’ learning process and as a form of evaluation, as well as a way of encouraging collaborative work among them. While meaningful differences have been found regarding the students’ perception of the portfolio depending on the group they belonged to, no significant differences based on previous knowledge about blogs (either by having followed one or having created one) have been noticed.Una de las herramientas más innovadoras utilizadas en la web 2.0 es el denominado blogfolio. Con el fin de determinar las ventajas y limitaciones de dicha herramienta en el ámbito educativo, en esta investigación, de carácter evaluativo, se ha querido conocer la opinión de un grupo de estudiantes del Grado en Educación Infantil de la Universidad de Murcia, sobre un blogfolio que los mismos estaban utilizando durante el transcurso de una de las asignaturas. Para ello, se ha empleado un cuestionario ad hoc, validado mediante el procedimiento interjueces. Los resultados indican que, en general, el blogfolio es adecuado como instrumento para el aprendizaje y la evaluación de los estudiantes, así como para fomentar el trabajo colaborativo entre los mismos. Si bien se han hallado diferencias significativas en lo que respecta a la percepción que tienen los alumnos y alumnas sobre la utilización del portafolios en función del grupo al que éstos pertenecen, no ha sido así considerando el conocimiento previo que los estudiantes tenían sobre los blogs, ni en función de que hubiesen creado antes otros blogs, ni tampoco según hiciesen seguimiento o no de algún blog

Evaluación de la pertinencia de las competencias de cuarto curso del Grado en Pedagogía de la Universidad de Murcia

[SPA] En el actual modelo educativo universitario de formación por competencias, éstas constituyen el núcleo principal de los procesos de enseñanza y aprendizaje. Al ser los estudiantes los verdaderos protagonistas de su desarrollo educativo, la perspectiva que éstos aportan en relación a la planificación, desarrollo y evaluación de las competencias transversales y específicas contempladas en las guías docentes de las asignaturas ha de ser tenida en cuenta por el profesorado. Comenzando por la planificación de dichas competencias, en esta investigación se analiza la pertinencia de las mismas teniendo en cuenta su claridad, relevancia, evaluabilidad y exclusividad, desde la perspectiva del alumnado. Para ello se ha aplicado un cuestionario a una muestra de 30 estudiantes de último curso de Grado en Pedagogía de la Universidad de Murcia. Las competencias evaluadas han sido las de las asignaturas impartidas en dicho curso durante el primer cuatrimestre. Los resultados indican que, en general, dichas competencias han de ser modificadas en relación a los cuatro criterios considerados, especialmente en lo que respecta a su evaluabilidad y exclusividad.[ENG] In the current model of university education competencies training, these competencias are the core of the teaching and learning. Students are the true protagonists of their educational development and its perspective in relation to the planning, development and evaluation of the transversal and specific competencies covered in the guides teachers of the subjects, must be taken into account by teachers. Beginning with the planning of these competencies, in this research the relevance of competencies is analyzed, taking into account its clarity, relevance, evaluability and exclusivity, from the perspective of students. This questionnaire has been applied to 30 students in their final year of Degree in Pedagogy at the University of Murcia. We evaluated the competencies of the subjects taught in this course during the first semester. The results indicate that, in general, those competencies must be modified in relation to the four criteria considered, especially in regard to its evaluability and exclusivity.BELMONTE ALMAGRO, María Luisa, GARCÍA SANZ, María Paz y GALIÁN NICOLÁS, Begoña

DNA origami assembled nanoantennas for manipulating single-molecule spectral emission

Optical nanoantennas can affect the decay rates of nearby emitters by modifying the local density of photonic states around them. In the weak-coupling limit, and according to the Fermi's Golden Rule, the emission spectrum of a dye is given by the energy of all the possible radiative transitions weighted by the probability of each of them to occur. By engineering the resonance of a nanoantenna, one can selectively enhance specific vibronic transitions of a dye molecule, thus shaping its emission spectrum. Since interactions between emitters and nanoantennas are known to be position dependent, we make here use of DNA origami to precisely place an individual dye at different positions around a gold nanorod. We show how this relative position between the nanorod and the emitter affects the emission spectrum of the latter. In particular, we observe the appearance of a second fluorescence peak whose wavelength and intensity are correlated with the fundamental plasmonic resonance of the nanorod, which we extract from its photoluminescence spectrum. This second peak results from the selective enhancement of transitions to different vibrational levels of the excitonic ground state, whose energies are in resonance with the plasmonic one. Furthermore, we argue that the drastic alteration of the fluorescence spectrum in some of our samples cannot be accounted for with Kasha's rule, which indicates that radiative and vibrational relaxation dye lifetimes can become comparable through the coupling to the gold nanorods

Anticoagulation

This chapter aims to summarize the most relevant aspects of anticoagulants. Initially, a brief review of the physiology is given in order to understand at which step of coagulation each anticoagulant acts. Later, the main indications and contraindications will be discussed, as well as the considerations that should be taken into account before starting treatment. Finally, the specific characteristics of each type of anticoagulant are developed, starting with vitamin K agonists and continuing with each of the direct oral anticoagulants

A cluster-randomized trial of hydroxychloroquine for prevention of Covid-19

Background: current strategies for preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are limited to nonpharmacologic interventions. Hydroxychloroquine has been proposed as a postexposure therapy to prevent coronavirus disease 2019 (Covid-19), but definitive evidence is lacking. Methods: we conducted an open-label, cluster-randomized trial involving asymptomatic contacts of patients with polymerase-chain-reaction (PCR)-confirmed Covid-19 in Catalonia, Spain. We randomly assigned clusters of contacts to the hydroxychloroquine group (which received the drug at a dose of 800 mg once, followed by 400 mg daily for 6 days) or to the usual-care group (which received no specific therapy). The primary outcome was PCR-confirmed, symptomatic Covid-19 within 14 days. The secondary outcome was SARS-CoV-2 infection, defined by symptoms compatible with Covid-19 or a positive PCR test regardless of symptoms. Adverse events were assessed for up to 28 days. Results: the analysis included 2314 healthy contacts of 672 index case patients with Covid-19 who were identified between March 17 and April 28, 2020. A total of 1116 contacts were randomly assigned to receive hydroxychloroquine and 1198 to receive usual care. Results were similar in the hydroxychloroquine and usual-care groups with respect to the incidence of PCR-confirmed, symptomatic Covid-19 (5.7% and 6.2%, respectively; risk ratio, 0.86 [95% confidence interval, 0.52 to 1.42]). In addition, hydroxychloroquine was not associated with a lower incidence of SARS-CoV-2 transmission than usual care (18.7% and 17.8%, respectively). The incidence of adverse events was higher in the hydroxychloroquine group than in the usual-care group (56.1% vs. 5.9%), but no treatment-related serious adverse events were reported. Conclusions: postexposure therapy with hydroxychloroquine did not prevent SARS-CoV-2 infection or symptomatic Covid-19 in healthy persons exposed to a PCR-positive case patient. (Funded by the crowdfunding campaign YoMeCorono and others; BCN-PEP-CoV2 ClinicalTrials.gov number, NCT04304053.)