"Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 \ub1 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

Coupled plasmonic modes in organic planar microcavities

We report on the nature of the resonant modes in organic planar microcavities featuring semi-transparent metallic layers. We theoretically demonstrate that symmetric microcavities support a total of four modes originating from the coupling of surface plasmon polaritons. For red top-emitting organic light-emitting diodes with one semi-transparent metallic electrode, we identify three coupled plasmonic modes and calculate a light outcoupling efficiency close to 34% when assuming emitters with isotropic transition dipole moment. This value is estimated to increase to 50% in the case the dipole moment is purely horizontal. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729820]</p

Influence of ion-induced secondary electron emission parameters in PICMC plasma simulations with experimental validation in DC cylindrical diode and magnetron discharges

Niobium thin lms are used at CERN (European Organization for Nuclear Research) for coatings of superconducting radio-frequency (SRF) accelerating cavities. Numerical simulations can help to better understand the physical processes involved in such coatings and provide predictions of thin lm properties. In this article, Particle-in-Cell Monte Carlo (PICMC) 3D plasma simulations are validated against experimental data in a coaxial cylindrical system allowing both DC diode and DC magnetron operation. A proper choice of ion induced secondary electron emission (IISEE) parameters enables to match experimental and simulated discharge currents and voltages, with argon as the process gas and niobium as the target element. Langmuir probe measurements are presented to further support simulation results. The choice of argon gas with a niobium target is driven by CERN applications, but the methodology described in this paper is applicable to other discharge gases and target elements. Validation of plasma simulations is the rst step towards developing an accurate methodology for predicting thin lm coatings characteristics in complex objects such as SRF cavities

Investigation of Triplet Harvesting and Outcoupling Efficiency in Highly Efficient Two-Color Hybrid White Organic Light-Emitting Diodes

We investigate singlet and triplet transfer processes in white triplet harvesting (TH) organic light-emitting diodes (OLEDs), comprising fluorescent and phosphorescent emitter molecules. By analyzing electroluminescence spectra and performing time-resolved measurements, we prove direct TH from the blue fluorescent emitter N,N′-di-1-naphthalenyl-N,N′-diphenyl-[1,1′:4′,1″:4″,1′′′-quaterphenyl]-4,4′′′-diamine (4P-NPD) to the yellow phosphorescent emitter bis(2-(9,9-dihexyluorenyl)-1-pyridine)(acetylacetonate)iridium(III) (Ir(dhfpy)2(acac)). Singlet transfer is identified as a second exciton transfer mechanism in the TH OLEDs under investigation. The CIE coordinates of these devices can be adjusted over a wide range by varying the distance between exciton generation and TH zone. For an OLED with CIE color coordinates of (0.42/0.40), close to the warm white color point A, we obtain nearly perfect Lambertian emission characteristics. This device achieves an external quantum efficiency (EQE) of 9.4% and a luminous efficacy (LE) of 27.1 lm W−1 (at 1000 cd m−2) which can be further increased to 46 lm W−1 using outcoupling enhancement techniques. Optical modeling of the electromagnetic field inside the TH OLED and a comparison to the position of the emitters within the device confirms that the devices operate close to the optical optimum and yields an estimated internal quantum efficiency (IQE) of 48.7% and a singlet/(harvested) triplet ratio of 0.28/0.72 = 0.39

Analysis of the external and internal quantum efficiency of multi-emitter, white organic light emitting diodes

We report on a theoretical framework for the efficiency analysis of complex, multi-emitter organic light emitting diodes (OLEDs). The calculation approach makes use of electromagnetic modeling to quantify the overall OLED photon outcoupling efficiency and a phenomenological description for electrical and excitonic processes. From the comparison of optical modeling results and measurements of the total external quantum efficiency, we obtain reliable estimates of internal quantum yield. As application of the model, we analyze high-efficiency stacked white OLEDs and comment on the various efficiency loss channels present in the devices. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4757610]</p