Search results for "emitting"

Rock-salt CdZnO as a transparent conductive oxide

2018

Transparent conducting oxides (TCOs) are widely used in applications from solar cells to light emitting diodes. Here, we show that the metal organic chemical vapor deposition (MOCVD)-grown, rock-salt CdZnO ternary, has excellent potential as a TCO. To assess this compound, we use a combination of infrared reflectance and ultraviolet-visible absorption spectroscopies, together with Hall effect, to determine its optical and electrical transport characteristics. It is found that the incorporation of Zn produces an increment of the electron concentration and mobility, yielding lower resistivities than those of CdO, with a minimum of 1.96 × 10 − 4 Ω · cm for a Zn content of 10%. Moreover, due to…

Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes

2019

We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (~1- $\mu \text{m}$ thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, ${L}_{h}$ , coming from the p-contact…

Intrathecal B-cell accumulation and axonal damage distinguish MRI-based benign from aggressive onset in MS.

2019

ObjectiveWe explored the incremental value of adding multiple disease activity biomarkers in CSF and serum for distinguishing MRI-based benign from aggressive MS in early disease course.MethodsNinety-three patients diagnosed with clinically isolated syndrome (CIS) or early MS were divided into 3 nonoverlapping severity groups defined by objective MRI criteria. Ninety-seven patients with noninflammatory neurologic disorders and 48 patients with other inflammatory neurologic diseases served as controls. Leukocyte subsets in the CSF were analyzed by flow cytometry. CSF neurofilament light chain (NfL) and chitinase-3-like protein 1 (CHI3L1) levels were measured by ELISA. Serum NfL levels were e…

Ocrelizumab Extended Interval Dosing in Multiple Sclerosis in Times of COVID-19.

2021

ObjectiveTo evaluate the clinical consequences of extended interval dosing (EID) of ocrelizumab in relapsing-remitting multiple sclerosis (RRMS) during the coronavirus disease 2019 (COVID-19) pandemic.MethodsIn our retrospective, multicenter cohort study, we compared patients with RRMS on EID (defined as ≥4-week delay of dose interval) with a control group on standard interval dosing (SID) at the same period (January to December 2020).ResultsThree hundred eighteen patients with RRMS were longitudinally evaluated in 5 German centers. One hundred sixteen patients received ocrelizumab on EID (median delay [interquartile range 8.68 [5.09–13.07] weeks). Three months after the last ocrelizumab in…

Clinical implications of serum neurofilament in newly diagnosed MS patients: a longitudinal multicentre cohort study

2020

Abstract Background We aim to evaluate serum neurofilament light chain (sNfL), indicating neuroaxonal damage, as a biomarker at diagnosis in a large cohort of early multiple sclerosis (MS) patients. Methods In a multicentre prospective longitudinal observational cohort, patients with newly diagnosed relapsing-remitting MS (RRMS) or clinically isolated syndrome (CIS) were recruited between August 2010 and November 2015 in 22 centers. Clinical parameters, MRI, and sNfL levels (measured by single molecule array) were assessed at baseline and up to four-year follow-up. Findings Of 814 patients, 54.7% (445) were diagnosed with RRMS and 45.3% (369) with CIS when applying 2010 McDonald criteria (R…

2019

Background: Network science provides powerful access to essential organizational principles of the brain. The aim of this study was to investigate longitudinal evolution of gray matter networks in early relapsing–remitting MS (RRMS) compared with healthy controls (HCs) and contrast network dynamics with conventional atrophy measurements. Methods: For our longitudinal study, we investigated structural cortical networks over 1 year derived from 3T MRI in 203 individuals (92 early RRMS patients with mean disease duration of 12.1 ± 14.5 months and 101 HCs). Brain networks were computed based on cortical thickness inter-regional correlations and fed into graph theoretical analysis. Network conne…

Hybrid perovskites for light-emitting and photovoltaic devices

2017

El objetivo de esta tesis es el desarrollo de métodos y materiales apropiados para la preparación de capas delgadas de perovskitas híbridas, y su implementación en dispositivos optoelectrónicos. Se dedicará particular atención a las relaciones entre la naturaleza del material, el método de deposición y las propiedades optoelectrónicas. El trabajo está organizado como sigue: - Células solares de perovskitas preparadas por evaporación flash. Se desarrolla un simple método de evaporación por la preparación de células solares. - Dispositivos de perovskita con alta eficiencia fotovoltaica y electroluminiscente. En este capítulo se presentan dispositivos optoelectrónicos de perovskitas preparados…

Stable and efficient Light-Emitting Electrochemical Cells

2014

La evolución de la tecnología exige el diseño de nuevas pantallas y sis-temas de iluminación. En este marco se necesitan rendimientos mejores y diseños avanzados y novedosos de productos. Los diodos orgánicos emisores de luz (OLEDs) son una alternativa factible a los sistemas inorgánicos debido a sus propiedades físicas únicas. Se pueden preparar dispositivos muy finos que pueden ser procesados a temperatura ambiente en sustratos grandes y flexibles. Además, sus propiedades se pueden ajustar fácilmente modificando la estructura química de las moléculas emisoras. Los rendimientos de los OLEDs están ya muy cercanos a los obtenidos utilizando las tecnologías clá-sicas inorgánicas. Sin embargo,…

Cognitive dysfunction in patients with relapsing-remitting multiple sclerosis

2006

Cognitive dysfunction is considered one of the clinical markers of multiple sclerosis (MS). However, in the literature there are inconsistent reports on the prevalence of cognitive dysfunction, and separate data for the relapsing-remitting (RR) type of the disease are not always presented. In this study, we submitted 461 RRMS patients to a battery of neuropsychological tests to investigate their impairment in various cognitive domains. As a consequence of the exclusion criteria, the sample is not fully representative of the entire population of RRMS patients. In this selected sample, when only the eight scores of a core battery (Mental Deterioration Battery) were considered (with respectiv…

Dimethyl fumarate treatment restrains the antioxidative capacity of T cells to control autoimmunity

2021

Abstract Dimethyl fumarate, an approved treatment for relapsing-remitting multiple sclerosis, exerts pleiotropic effects on immune cells as well as CNS resident cells. Here, we show that dimethyl fumarate exerts a profound alteration of the metabolic profile of human CD4+ as well as CD8+ T cells and restricts their antioxidative capacities by decreasing intracellular levels of the reactive oxygen species scavenger glutathione. This causes an increase in mitochondrial reactive oxygen species levels accompanied by an enhanced mitochondrial stress response, ultimately leading to impaired mitochondrial function. Enhanced mitochondrial reactive oxygen species levels not only result in enhanced T…