Low-temperature titania-graphene quantum dots paste for flexible dye-sensitised solar cell applications

Graphene possesses excellent mechanical strength and chemical inertness with high intrinsic carrier mobility and superior flexibility making them exceptional candidates for optoelectronic applications. Graphene quantum dots (GQDs) derived from graphene domains have been widely explored to study their photoluminescence properties which can be tuned by size. GQDs are biocompatible, low cytotoxic, strongly luminescent and disperse well in polar and non-polar solvents showing bright promise for the integration into devices for bioimaging, light emitting and photovoltaic applications. In the present study, graphene quantum dots were synthesized by an electrochemical cyclic voltammetry technique using reduced graphene oxide (rGO). GQDs have been incorporated into binder free TiO2 paste and studied as a photoelectrode material fabricated on ITO/PEN substrates for flexible dye sensitized solar cells (DSSCs). DSSC based on GQDs-TiO2 exhibited open circuit output potential difference (Voc) of 0.73 V, and short circuit current density (Jsc) of 11.54 mA cm-2 with an increment in power conversion efficiency by 5.48 %, when compared with those with DSSC build with just a TiO2 photoanode (open-circuit output potential difference (Voc) of 0.68 V and short circuit density (Jsc) of 10.67 mA cm-2). The results have been understood in terms of increased charge extraction and reduced recombination losses upon GQDs incorporation

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Innovación docente para convencidos : VI Jornadas de Innovación Educativa de la Universidad de La Laguna

Las VI Jornadas de Innovación Educativa representan la continuidad del esfuerzo de la Universidad de La Laguna en su apuesta por la Innovación en el ámbito de la docencia. El profesorado actual debe formarse en los distintos procesos de diseño, puesta en práctica, evaluación y reflexión necesarios para el desempeño docente, así como adquirir competencias pedagógicas diferentes, adaptadas al entorno social y a un alumnado que demanda nuevos modelos de aprendizaje en la universidad. Esta edición de las Jornadas de Innovación se ha centrado en la idea del docente como un profesional convencido y reflexivo, que conoce y valora la importancia de la innovación en la docencia universitaria como medio para alcanzar unos fines que van más allá de transmitir el conocimiento de un repertorio técnico, por más denso y extenso que éste pueda ser, despreciando la posibilidad de enseñar a preguntar más que a responder. La mejora de la calidad educativa está directamente vinculada a un profesorado que aspira a convertirse en un especialista en enfrentarse a situaciones problemáticas de distinta naturaleza, a través de una actividad reflexiva que no se agota en la búsqueda de los medios idóneos para unos fines ya definidos, sino que trasciende hasta la indagación sobre los propios fines