Polarity-Dependent Adsorption of Inverse Micelles.

The adsorption of charged inverse micelles at the electrode-liquid interface has an important effect on field screening and on the voltage drop over diffuse double layers. Recently, we analyzed the behavior of inverse micelles in a nonpolar liquid close to this electrode-liquid interface. For the fluorocarbon/surfactant system under study, we are in the limit of slow adsorption and negligible desorption of inverse micelles on the electrodes. Upon applying a voltage step, this results in a measurable Stern layer buildup in the time range of hours clearly distinguishable from the diffuse double layer buildup, which happens in less than 1 s. This Stern layer buildup manifests itself by a shift in the voltage drop from the diffuse double layer to the Stern layer until the voltage drop over the Stern layers reaches the applied voltage, leaving a zero bulk field without the diffuse double layer. New measurements of the transients of Stern layer buildup show that the buildup of charges in the Stern layer is more complex. We explain the observed transient behavior by introducing an asymmetry in the adsorption rate of charged inverse micelles. We provide an equivalent electrical network, an analytical solution to explain the behavior in more detail, and simulations within the diffuse double layer limit for a range of adsorption rates.

Sustained low rotavirus activity and hospitalisation rates in the post-vaccination era in Belgium, 2007 to 2014.

In 2006, Belgium was the first country in the European Union to recommend rotavirus vaccination in the routine infant vaccination schedule and rapidly achieved high vaccine uptake (86-89% in 2007). We used regional and national data sources up to 7 years post-vaccination to study the impact of vaccination on laboratory-confirmed rotavirus cases and rotavirus-related hospitalisations and deaths. We showed that (i) from 2007 until 2013, vaccination coverage remained at 79-88% for a complete course, (ii) in children 0-2 years, rotavirus cases decreased by 79% (95% confidence intervals (CI): 68--89%) in 2008-2014 compared to the pre-vaccination period (1999--2006) and by 50% (95% CI: 14-82%) in the age group ≥ 10 years, (iii) hospitalisations for rotavirus gastroenteritis decreased by 87% (95% CI: 84-90%) in 2008--2012 compared to the pre-vaccination period (2002--2006), (iv) median age of rotavirus cases increased from 12 months to 17 months and (v) the rotavirus seasonal peak was reduced and delayed in all post-vaccination years. The substantial decline in rotavirus gastroenteritis requiring hospitalisations and in rotavirus activity following introduction of rotavirus vaccination is sustained over time and more pronounced in the target age group, but with evidence of herd immunity.

Anisotropic materials in OLEDs for high outcoupling efficiency.

We present the results of an optical study in which we evaluate the effect of anisotropic electron transport layers (ETL) and anisotropic hole transport layers (HTL) on the outcoupling efficiency of bottom emitting organic light emitting diodes (OLEDs). We demonstrate that optical anisotropy can have a profound influence on the outcoupling efficiency and introduce a number of design rules which ensure that light extraction is enhanced by anisotropic layers.

RCWA and FDTD modeling of light emission from internally structured OLEDs.

We report on the fabrication and simulation of a green OLED with an Internal Light Extraction (ILE) layer. The optical behavior of these devices is simulated using both Rigorous Coupled Wave Analysis (RCWA) and Finite Difference Time-Domain (FDTD) methods. Results obtained using these two different techniques show excellent agreement and predict the experimental results with good precision. By verifying the validity of both simulation methods on the internal light extraction structure we pave the way to optimization of ILE layers using either of these methods.

Healthcare costs of post-traumatic trigeminal neuropathy in Belgium - A retrospective analysis.

The present aim was to estimate direct health care costs of patients suffering from post-traumatic trigeminal neuropathy (PTTN) and to compare the use of health care services, medications, and costs between temporary and persistent (>3 months) PTTN cohorts. A pre-existing clinical dataset of PTTN patients visiting a tertiary orofacial pain clinic in Belgium was utilized, including symptoms and quality of life measurements. Cost and resource utilization data were obtained by Belgium's largest health insurance provider for a period of 5 years after onset. Data from 158 patients was analyzed. The average cost per patient in the first year after injury was €2353 (IQR 1426-4499) with an out-of-pocket expense of 25% of the total cost. Hospitalization and technical interventions were the main drivers of cumulative costs, followed by consultation costs. For each cost category, expenditure was significantly higher in patients with persistent PTTN than in those with temporary PTTN (median 5-year total costs in persistent PTTN patients yielded €8866 (IQR 4368-18191) versus €4432 (IQR 2156-9032) in temporary PTTN, p <0.001) PTTN patients received repeated and frequent head and neck imaging (mean number of imaging investigations per patient was 10 ± 12). Medication consumption was high, with an unwarranted higher use of opioids and antibiotics in persistent PTTN patients. Within the limitations of this study, it seems there is a need for informing patients in detail on the inherent risks of nerve damage during dental and oromaxillofacial procedures. Every surgery should be preceded by a risk-benefit assessment in order to avoid unnecessary nerve damage.

Tuning charge carrier transport and optical birefringence in liquid-crystalline thin films: A new design space for organic light-emitting diodes.

Liquid-crystalline organic semiconductors exhibit unique properties that make them highly interesting for organic optoelectronic applications. Their optical and electrical anisotropies and the possibility to control the alignment of the liquid-crystalline semiconductor allow not only to optimize charge carrier transport, but to tune the optical property of organic thin-film devices as well. In this study, the molecular orientation in a liquid-crystalline semiconductor film is tuned by a novel blading process as well as by different annealing protocols. The altered alignment is verified by cross-polarized optical microscopy and spectroscopic ellipsometry. It is shown that a change in alignment of the liquid-crystalline semiconductor improves charge transport in single charge carrier devices profoundly. Comparing the current-voltage characteristics of single charge carrier devices with simulations shows an excellent agreement and from this an in-depth understanding of single charge carrier transport in two-terminal devices is obtained. Finally, p-i-n type organic light-emitting diodes (OLEDs) compatible with vacuum processing techniques used in state-of-the-art OLEDs are demonstrated employing liquid-crystalline host matrix in the emission layer.

Mortality in Individuals Treated With Glucose-Lowering Agents: A Large, Controlled Cohort Study.

CONTEXT: Several observational studies and meta-analyses have reported increased mortality of patients taking sulfonylurea and insulin. The impact of patient profiles and concomitant therapies often remains unclear. OBJECTIVE: The objective of the study was to quantify survival of patients after starting glucose-lowering agents (GLAs) and compare it with control subjects, matched for risk profiles and concomitant therapies. DESIGN: This was a retrospective, controlled, cohort study. SETTING: The study is based on health expenditure records of the largest Belgian health mutual insurer, covering more than 4.4 million people. PATIENTS: A total of 115 896 patients starting metformin, sulfonylurea, or insulin (alone or in combination) between January 2003 and December 2007 participated in the study. Control subjects without GLA therapy were matched for age, gender, history of cardiovascular events, and therapy with antihypertensives, statins and blood platelet aggregation inhibitors. INTERVENTION(S): There were no interventions. MAIN OUTCOME MEASURE: Five-year survival after the start of GLA was measured. RESULTS: Profiles of patients using different GLAs varied, with patients on sulfonylurea being oldest and patients on insulin having more frequently a history of cardiovascular disease. Excess mortality differed across GLA therapies compared with matched controls without GLAs, even after adjusting for observable characteristics. Only metformin monotherapy was not associated with an increased 5-year mortality compared with matched controls, whereas individuals on a combination of sulfonylurea and insulin had the highest mortality risks. Age and concomitant use of statins strongly affect survival. CONCLUSIONS: Differences exist in 5-year survival of patients on GLA, at least partly driven by the risk profile of the individuals themselves. Metformin use was associated with lowest 5-year mortality risk and statins dramatically lowered 5-year mortality throughout all cohorts.