Absence of quantum-confined Stark effect in GaN quantum disks embedded in (Al,Ga)N nanowires grown by molecular beam epitaxy

Several of the key issues of planar (Al,Ga)N-based deep-ultraviolet light emitting diodes could potentially be overcome by utilizing nanowire heterostructures, exhibiting high structural perfection and improved light extraction. Here, we study the spontaneous emission of GaN/(Al,Ga)N nanowire ensembles grown on Si(111) by plasma-assisted molecular beam epitaxy. The nanowires contain single GaN quantum disks embedded in long (Al,Ga)N nanowire segments essential for efficient light extraction. These quantum disks are found to exhibit intense emission at unexpectedly high energies, namely, significantly above the GaN bandgap, and almost independent of the disk thickness. An in-depth investigation of the actual structure and composition of the nanowires reveals a spontaneously formed Al gradient both along and across the nanowire, resulting in a complex core/shell structure with an Al deficient core and an Al rich shell with continuously varying Al content along the entire length of the (Al,Ga)N segment. This compositional change along the nanowire growth axis induces a polarization doping of the shell that results in a degenerate electron gas in the disk, thus screening the built-in electric fields. The high carrier density not only results in the unexpectedly high transition energies, but also in radiative lifetimes depending only weakly on temperature, leading to a comparatively high internal quantum efficiency of the GaN quantum disks up to room temperature.Comment: This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Nano Letters (2019), copyright (C) American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/acs.nanolett.9b01521, the supporting information is available (free of charge) under the same lin

Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet

In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.The present study has been supported by grants from Instituto de Salud Carlos III (ISCIII) (contract numbers: PID2022–140169OB-C21; PI21/01248; PI19/00883) and from Consejería de Salud de Andalucía (contract number: PEMP-0127–2020, Spain), cofounded by the European Union. This research was funded by HORIZON-HLTH-2022-STAYHLTH-02, grant number 101095679. Funded by the European Union. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them. MK was partially supported by Grant UID/BIM/0009/2020 of the Portuguese Fundação para a Ciência e a Tecnologia (FCT). MVP and IAA hold Sara Borrell research contracts from ISCIII (CD21/00198 and CD20/00083, respectively). This research was supported by CIBERehd – Consorcio Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea – European Regional Development Fund. JIG and GPA are supported by NIHR Nottingham Biomedical Research Centre [NIHR203310]. The views expressed are those of the authors and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health. This publication is based upon work from COST Action “CA17112—Prospective European Drug-Induced Liver Injury Network” supported by COST (European Cooperation in Science and Technology); www.cost.eu.Peer reviewe

Depresión post ictus: una actualización

Resumen: Introducción: La depresión post ictus (DPI) es el trastorno afectivo más frecuente tras un ictus y el principal factor que limita la recuperación y rehabilitación de los pacientes, además de poder incrementar su mortalidad hasta 10 veces. Desarrollo: La DPI se presenta en uno de cada 3 pacientes con ictus y en más de la mitad de los casos no se diagnostica ni se trata. En su etiopatogenia son varios los mecanismos implicados: biológicos, conductuales y sociales.Los síntomas suelen aparecer en los primeros 3 meses tras el ictus (DPI «precoz») y menos frecuentemente más tarde (DPI «tardía»). Los síntomas son similares a los de otras depresiones, aunque con algunas diferencias, como presentar más trastornos del sueño, síntomas vegetativos e introversión para las relaciones sociales.Para su diagnóstico se recomienda mantener una actitud vigilante y emplear herramientas diagnósticas específicas, como el Patient Health Questionaire-2 (PHQ-2).Finalmente, el tratamiento de elección son los inhibidores selectivos de la recaptación de serotonina (ISRS). No obstante, aún son muchas las cuestiones por resolver en el tratamiento de la DPI, como cuándo es el mejor momento para iniciar el tratamiento o el efecto de los antidepresivos sobre la cognición y la función motora, entre otros. Conclusiones: Los neurólogos desempeñan un papel fundamental en la recuperación de los enfermos con ictus. Es necesario que estén familiarizados con la detección temprana y el tratamiento de la DPI, para así facilitar la recuperación funcional del paciente, su reinserción social y la mejora en la calidad de vida del enfermo y su familia. Abstract: Introduction: Post-stroke depression (PSD) is the most common mood disorder following a stroke, and also the main factor limiting recovery and rehabilitation in stroke patients. In addition, it may increase mortality by up to ten times. Development: PSD occurs in 1 in 3 stroke patients and more than half of all cases are neither diagnosed nor treated. Several mechanisms, including biological, behavioral, and social factors, are involved in its pathogenesis. Symptoms usually occur within the first three months after stroke (early onset PSD), and less frequently at a later time (late onset PSD). Symptoms resemble those of other types of depression, although there are some differences: PSD patients experience more sleep disturbances, vegetative symptoms, and social withdrawal.For PSD diagnosis, we recommended vigilance and use of specific diagnostic tools such as the Patient Health Questionnaire-2 (PHQ-2). The treatments of choice are selective serotonin reuptake inhibitors (SSRI). However, there are still many unanswered questions in the treatment of PSD, such as the best time to start treatment or the effects of antidepressants on cognition and motor function, among others. Conclusions: Neurologists play a pivotal role in the care and management of patients recovering from stroke. They must be familiar with methods for early detection and treatment of PSD, as this can facilitate a patient's functional recovery and social reintegration, and improve quality of life for patients and their families. Palabras clave: Antidepresivos, Depresión post ictus, Enfermedad cerebrovascular, Ictus, Inhibidores selectivos de la recaptación de serotonina, Keywords: Antidepressants, Post-stroke depression, Cerebrovascular disease, Stroke, Selective serotonin reuptake inhibitor

Post-stroke depression: an update

Introduction: Post-stroke depression (PSD) is the most common mood disorder following a stroke, and also the main factor limiting recovery and rehabilitation in stroke patients. In addition, it may increase mortality by up to ten times. Development: PSD occurs in 1 in 3 stroke patients and more than half of all cases are neither diagnosed nor treated. Several mechanisms, including biological, behavioural, and social factors, are involved in its pathogenesis. Symptoms usually occur within the first three months after stroke (early onset PSD), and less frequently at a later time (late onset PSD). Symptoms resemble those of other types of depression, although there are some differences; PSD patients experience more sleep disturbances, vegetative symptoms, and social withdrawal. For PSD diagnosis, we recommended vigilance and use of specific diagnostic tools such as the Patient Health Questionnaire-2 (PHQ-2). The treatments of choice are selective serotonin reuptake inhibitors (SSRI). However, there are still many unanswered questions in the treatment of PSD, such as the best time to start treatment or the effects of antidepressants on cognition and motor function, among others. Conclusions: Neurologists play a pivotal role in the care and management of patients recovering from stroke. They must be familiar with methods for early detection and treatment of PSD, as this can facilitate a patient's functional recovery and social reintegration, and improve quality of life for patients and their families. Resumen: Introducción: La depresión post ictus (DPI) es el trastorno afectivo más frecuente tras un ictus y el principal factor que limita la recuperación y rehabilitación de los pacientes, además de poder incrementar su mortalidad hasta 10 veces. Desarrollo: La DPI se presenta en uno de cada 3 pacientes con ictus y en más de la mitad de los casos no se diagnostica ni se trata. En su etiopatogenia son varios los mecanismos implicados: biológicos, conductuales y sociales. Los síntomas suelen aparecer en los primeros 3 meses tras el ictus (DPI «precoz») y menos frecuentemente más tarde (DPI «tardía»). Los síntomas son similares a los de otras depresiones, aunque con algunas diferencias, como presentar más trastornos del suẽno, síntomas vegetativos e introversión para las relaciones sociales. Para su diagnóstico se recomienda mantener una actitud vigilante y emplear herramientas diagnósticas específicas, como el Patient Health Questionaire-2 (PHQ-2). Finalmente, el tratamiento de elección son los inhibidores selectivos de la recaptación de serotonina (ISRS). No obstante, aún son muchas las cuestiones por resolver en el tratamiento de la DPI, como cuándo es el mejor momento para iniciar el tratamiento o el efecto de los antidepresivos sobre la cognición y la función motora, entre otros. Conclusiones: Los neurólogos desempẽnan un papel fundamental en la recuperación de los enfermos con ictus. Es necesario que estén familiarizados con la detección temprana y el trata-miento de la DPI, para así facilitar la recuperación funcional del paciente, su reinserción social y la mejora en la calidad de vida del enfermo y su familia. Keywords: Antidepressants, Post-stroke depression, Cerebrovascular disease, Stroke, Selective serotonin reuptake inhibitors, Palabras clave: Antidepresivos, Depresión post ictus, Enfermedad cerebrovascular, Ictus, Inhibidores selectivos de la recaptación de serotonin

Absence of quantum-confined Stark effect in GaN quantum disks embedded in (Al,Ga)N nanowires grown by molecular beam epitaxy

\u3cp\u3eSeveral of the key issues of planar (Al,Ga)N-based deep-ultraviolet light-emitting diodes could potentially be overcome by utilizing nanowire heterostructures, exhibiting high structural perfection, and improved light extraction. Here, we study the spontaneous emission of GaN/(Al,Ga)N nanowire ensembles grown on Si(111) by plasma-assisted molecular beam epitaxy. The nanowires contain single GaN quantum disks embedded in long (Al,Ga)N nanowire segments essential for efficient light extraction. These quantum disks are found to exhibit intense light emission at unexpectedly high energies, namely, significantly above the GaN bandgap, and almost independent of the disk thickness. An in-depth investigation of the actual structure and composition of the nanowires reveals a spontaneously formed Al gradient both along and across the nanowire, resulting in a complex core/shell structure with an Al-deficient core and an Al-rich shell with continuously varying Al content along the entire length of the (Al,Ga)N segment. This compositional change along the nanowire growth axis induces a polarization doping of the shell that results in a degenerate electron gas in the disk, thus screening the built-in electric fields. The high carrier density not only results in the unexpectedly high transition energies but also in radiative lifetimes depending only weakly on temperature, leading to a comparatively high internal quantum efficiency of the GaN quantum disks up to room temperature.\u3c/p\u3

Prevalencia de infección por coronavirus SARS-CoV-2 en pacientes y profesionales de un hospital de media y larga estancia en España

Background and goals: The aim of the study is to know the prevalence of SARS-CoV-2 infection in patients and professional staff of a medium or long-stay hospital during the peak period of the pandemic in Spain, spring 2020. Material and methods: At the end of February 2020, we developed at the hospital a strategy to diagnose the SARS-CoV-2 infection consisting of complementing the realization of PCR tests at real time with a quick technique of lateral flow immunochromatography to detect IgG and IgM antibodies against the virus. We also developed a protocol to realize those diagnostic tests and considered an infection (current or past) a positive result in any of the above tests. We included 524 participants in the study (230 patients and 294 hospital staff), and divided them into hospital patients and Hemodialysis outpatients. Furthermore, we divided the hospital staff into healthcare and non-healthcare staff. The documented period was from March, 20th to April, 21st, 2020. Results: 26 out of 230 patients tested positive in any of the diagnostic techniques (PCR, antibodies IgG, IgM) with a 11.30% prevalence. According to patients groups, we got a 14.38% prevalence in hospital patients vs. 5.95% in outpatients, with a significantly higher risk in admitted patients after adjustment for age and gender (OR=3, 309, 95%CI: 1, 154-9, 495). 24 out of 294 hospital staff tested positive in any of the diagnostic techniques, with a 8.16% prevalence. According to the groups, we got a 8.91% prevalence in healthcare staff vs. 4.26% in non-healthcare staff. Thus, we do not see any statistically significant differences between hospital staff and patients as far as prevalence is concerned (P=0, 391), (OR=2, 200, 95%CI: 0, 500-9, 689). Conclusions: The result of the study was a quite low prevalence rate of SARS-CoV-2 infection, in both patients and hospital staff, being the hospital patients’ prevalence rate higher than the outpatients’, and the healthcare staff higher than the non-healthcare''s. Combining PCR tests (gold standard) with antibodies tests proved useful as a diagnostic strategy