525 research outputs found
Origin of the Exclusive Ternary Electroluminescent Behavior of BN‐Doped Nanographenes in Efficient Single‐Component White Light‐Emitting Electrochemical Cells
White-light-emitting electrochemical cells (WLECs) still represent a significant milestone, since only a few examples with moderate performances have been reported. Particularly, multiemissive white emitters are highly desired, as a paradigm to circumvent phase separation and voltage-dependent emission color issues that are encountered following host:guest and multilayered approaches. Herein, the origin of the exclusive white ternary electroluminescent behavior of BN-doped nanographenes with a B3N3 doping pattern (hexa-perihexabenzoborazinocoronene) is rationalized, leading to one of the most efficient (approximate to 3 cd A(-1)) and stable-over-days single-component and single-layered WLECs. To date, BN-doped nanographenes have featured blue thermally activated delayed fluorescence (TADF). This doping pattern provides, however, white electroluminescence spanning the whole visible range (x/y CIE coordinates of 0.29-31/0.31-38 and average color rendering index (CRI) of 87) through a ternary emission involving fluorescence and thermally activated dual phosphorescence. This temperature-dependent multiemissive mechanism is operative for both photo- and electroluminescence processes and holds over the device lifespan, regardless of the device architecture, active layer composition, and operating conditions. As such, this work represents a new stepping-stone toward designing a new family of multiemissive white emitters based on BN-doped nanographenes that realizes one of the best-performing single-component white-emitting devices compared to the prior-art
Actitudes del profesional de enfermería frente al cuidado enfermero basado en la evidencia en el servicio de neonatología. hospital provincial docente Belén de Lambayeque. 2016.
La Enfermería Basada en la Evidencia, es una metodología que requiere tomar decisiones clínicas basándose en la investigación, por ello las actitudes juegan un rol importante y tienen una gran relevancia en su aplicación dentro del campo enfermero. Este estudio tuvo como objetivo describir y caracterizar las actitudes del profesional de enfermería frente al cuidado enfermero basado en la evidencia en el servicio de neonatología del Hospital Provincial Docente Belén de Lambayeque en enero de 2016. Con enfoque cualitativo y abordaje de estudio de caso, mediante la técnica de saturación se obtuvo una muestra de seis enfermeras, a quienes se les aplicó una entrevista semiestructurada. Se utilizó el análisis de contenido para procesar la información, obteniéndose cuatro categorías: “Aplicando la evidencia científica en el cuidado del neonato”, “Limitaciones para aplicar la evidencia científica en el cuidado enfermero”, “Sentimientos positivos que experimenta el profesional enfermero al aplicar cuidados basados en evidencia científica”, “Caracterizando las actitudes del profesional de enfermería frente a la EBE”. Los profesionales de enfermería, han dejado de realizar algunas prácticas rutinarias para introducir cambios basados en investigaciones.Tesi
Subpicosecond photoinduced Stark spectroscopy in fullerene-based devices
Published versio
Metallic objects among Guaraní groups of Parana Delta. Late Holocene, Buenos Aires – Argentina
Hacia finales del Holoceno tardío, el delta del Paraná estuvohabitado por diferentes grupos poblacionales, entre ellos los conocidos como“Guaraníes”. En los diversos contextos arqueológicos del área raramente serecuperan objetos metálicos; por lo que estudiar los casos en los que estánpresentes permite discutir procesos de poblamiento y ocupación del área. Estetrabajo se ocupa particularmente del análisis de las piezas recuperadas en elsitio Arroyo Fredes, datado entre 1262 y 1642 AD. Nuestro objetivo es evaluara través del análisis morfológico y composicional de las piezas su posible vinculacióncon dos centros metalúrgicos que habrían estado disponibles al momentode ocupación del sitio: la esfera hispánica y el Noroeste argentino. En doscasos, la lámina y el disco, la composición de cobre puro permite establecer unaconexión con las poblaciones locales. En el tercero, el alfiler o topu, los resultadosno son concluyentes. Los datos, en definitiva, muestran la complejidad delproceso de ocupación del área momentos antes de la ocupación europea.Hacia finales del Holoceno tardío, el delta del Paraná estuvo habitado por diferentes grupos poblacionales, entre ellos los conocidos como “Guaraníes”. En los diversos contextos arqueológicos del área raramente se recuperan objetos metálicos; por lo que estudiar los casos en los que están presentes permite discutir procesos de poblamiento y ocupación del área. Este trabajo se ocupa particularmente del análisis de las piezas recuperadas en el sitio Arroyo Fredes, datado entre 1262 y 1642 AD. Nuestro objetivo es evaluar a través del análisis morfológico y composicional de las piezas su posible vinculación con dos centros metalúrgicos que habrían estado disponibles al momento de ocupación del sitio: la esfera hispánica y el Noroeste argentino. En dos casos, la lámina y el disco, la composición de cobre puro permite establecer una conexión con las poblaciones locales. En el tercero, el alfiler o topu, los resultados no son concluyentes. Los datos, en definitiva, muestran la complejidad del proceso de ocupación del área momentos antes de la ocupación europea
Feasibility of Noninvasive Positive Pressure Ventilation in the Treatment of Oxygen-Dependent COVID-19 Patients in Peru
Intensive care is expensive, and availability is limited. Low- and middle-income countries in particular have struggled to cope with the large influx of critically ill patients during the COVID-19 pandemic. Noninvasive respiratory support devices delivering continuous positive airways pressure (CPAP) require less resource and staff expertise compared with invasive mechanical ventilators and can be routinely used outside of intensive care units. This study assessed the use of the UCL-Ventura Wayrachi CPAP device in hospitalized patients with COVID-19 in Peru. A secondary analysis of data collected for a feasibility study commissioned by the Peruvian Ministry of Health was conducted. Data were collected from three hospitals, including patient demographics, clinical data, and outcomes. Forty-five patients were enrolled from July 16 to September 1, 2020. Eight patients (18%) were intolerant of the CPAP mask. Of the remainder, 18 (48.7%) improved and were discharged from hospital after 6 days. Eight (21.6%) died while on CPAP and 11 (29.7%) were eventually intubated, of whom two died. In total, 27 (60%) survived to hospital discharge. Participating physicians noted the device was easy to use and provided patient benefit, though voiced concerns about the strain on hospital oxygen supplies. In conclusion, the UCL Ventura Wayrachi CPAP device proved feasible in COVID-19 patients in Peru, and offered a bridging therapy for patients who required a ventilator when none were available
Cove-Edged Hexa-peri-hexabenzo-bis-peri-octacene: Molecular Conformations and Amplified Spontaneous Emission
Microscopic spheroidal particles obtained by laser cutting
In this work we study the characteristics of the particles ejected from the cutting zone of a SAE 1010 steel while using a CO2 gaseous laser with the purpose of determining the feasibility to use this technique in the production of microscopic particles for nuclear applications [2] as well as for other scientific and technological uses [1].Instituto de Física La Plat
Highly enantioselective access to diketopiperazines via cinchona alkaloid catalyzed Michael additions
Alkaloid catalysed additions to triketopiperazines gives products in high yield and er (88 : 12 to 99 : 1), including bridged hydroxy-DKPs via Michael-addition–ring closure.</p
Photoinduced transient stark spectroscopy in organic semiconductors: a method for charge mobility determination in the picosecond regime.
Published versio
Origin of the exclusive ternary electroluminescent behavior of BN-doped nanographenes in efficient single-component white light-emitting electrochemical cells
White‐light‐emitting electrochemical cells (WLECs) still represent a significant milestone, since only a few examples with moderate performances have been reported. Particularly, multiemissive white emitters are highly desired, as a paradigm to circumvent phase separation and voltage‐dependent emission color issues that are encountered following host:guest and multilayered approaches. Herein, the origin of the exclusive white ternary electroluminescent behavior of BN‐doped nanographenes with a B3N3 doping pattern (hexa‐perihexabenzoborazinocoronene) is rationalized, leading to one of the most efficient (≈3 cd A−1) and stable‐over‐days single‐component and single‐layered WLECs. To date, BN‐doped nanographenes have featured blue thermally activated delayed fluorescence (TADF). This doping pattern provides, however, white electroluminescence spanning the whole visible range (x/y CIE coordinates of 0.29–31/0.31–38 and average color rendering index (CRI) of 87) through a ternary emission involving fluorescence and thermally activated dual phosphorescence. This temperature‐dependent multiemissive mechanism is operative for both photo‐ and electroluminescence processes and holds over the device lifespan, regardless of the device architecture, active layer composition, and operating conditions. As such, this work represents a new stepping‐stone toward designing a new family of multiemissive white emitters based on BN‐doped nanographenes that realizes one of the best‐performing single‐component white‐emitting devices compared to the prior‐art
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