Enhanced efficiency of multilayer organic light-emitting diodes with a low-refractive index hole-transport layer: An effect of improved outcoupling?

The authors report on an internal device modification for multilayerorganic light-emitting diodes(OLEDs) with enhanced efficiency that promises high compatibility with conventional manufacturing processes. By copolymerization of a hole-conducting monomer with a compound possessing a lower refractive index, a hole-transport layer with reduced optical density but slightly reduced hole-transport properties is formed. MultilayerOLEDs based on this reduced-index layer show a 25% increased efficiency compared to reference devices. The results are compared to optical simulations of the dipole emission from thin organic films. It is found that the efficiency improvement is only to some extent due to enhanced outcoupling resulting directly from the reduced refractive index but primarily due to a change of the width of the emission zone

Positive affect, anhedonia, and compliance with self-care in patients with chronic heart failure

Objective Optimal self-care is crucial in patients with chronic heart failure (HF). While the focus of research has been on negative mood states, adequate psychological resources may be required to successfully engage in HF self-care. Therefore, the longitudinal associations of multiple positive affect measures in explaining HF self-care including consulting behavior were examined while adjusting for depressive symptoms and potential covariates (e.g., disease severity). Methods In this prospective cohort study, 238 patients (mean age: 66.9 ± 8.6 years, 78% men), with chronic HF completed questionnaires at baseline and 1-year follow-up. Positive affect was assessed with the Positive and Negative Affect Schedule (PANAS) and the Global Mood Scale (GMS). Anhedonia, i.e. diminished interest or pleasure, was assessed with a subscale of the Hospital Anxiety and Depression Scale (HADS). The 9-item European Heart Failure Self-care Behaviour scale was completed to assess HF self-care including consultation behavior. Results Linear mixed modeling results showed that anhedonia was most strongly associated with both poor self-care (estimate = − .72, P < .001) and consulting behavior (estimate = − .44, P < .001) over time, after adjustment for covariates and depressive symptoms. GMS positive affect was related to better HF self-care adjusting for standard depressive symptoms but not when adjusting for anhedonia. PANAS positive affect was not independently related to self-care. Conclusion Anhedonia was associated with worse compliance with self-care among chronic HF patients over time, irrespective of disease severity and depression. Associations between positive affect and self-care were dependent on the measures used in multivariable analyses.Keywords: Positive affect, Anhedonia, Depression, Compliance, Self-care, Heart failur