Inverse problems with hybrid lenses

We design lenses composed of a combination of standard freeform refracting surface and flat metasurface refracting an arbitrary incident field into a collimated beam with a fixed direction. In the near-field case, we study the existence of such lenses refracting a bright object into a predefined image at the target

Occurrence and risk factors of relapse activity after vaccination against COVID-19 in people with multiple sclerosis: 1-year follow-up results from a nationwide longitudinal observational study

Several studies reported post-SARS-CoV-2-vaccination (PV) symptoms. Even people with multiple sclerosis (PwMS) have concerns about disease activity following the SARS-CoV-2 vaccination. We aimed to determine the proportion of PwMS with PV relapses, the PV annualized relapse rate (ARR), the time from vaccination to subsequent relapses, and identify sociodemographic/clinical risk factors for PV relapses. PwMS were surveyed several times at baseline and four follow-ups as part of a longitudinal observational study regarding the safety and tolerability of the SARS-CoV-2 vaccination. The inclusion criteria for this analysis were age ≥18 years, ≥1 SARS-CoV-2 vaccination, and ≥1-year observation period since initial vaccination. Of 2466 PwMS, 13.8% reported PV relapses (mostly after second [N = 147] or booster vaccination [N = 145]) at a median of 8.0 (first/third quantile: 3.55/18.1) weeks PV, with the shortest period following initial vaccination (3.95 weeks). The ARR was 0.153 (95% confidence interval: 0.138-0.168), with a median observation period since initial vaccination of 1.2 years. Risk factors for PV relapses were younger age, female gender, moderate-severe disability levels, concurrent autoimmune diseases, relapsing-remitting MS courses, no DMT, and relapses within the year prior to the first vaccination. Patients' health conditions before/during initial vaccination may play a more important role in PV relapse occurrence than vaccination per se

Frequency and predictors of relapses following SARS-CoV-2 vaccination in patients with multiple sclerosis: interim results from a longitudinal observational study

Despite protection from severe COVID-19 courses through vaccinations, some people with multiple sclerosis (PwMS) are vaccination-hesitant due to fear of post-vaccination side effects/increased disease activity. The aim was to reveal the frequency and predictors of post-SARS-CoV-2-vaccination relapses in PwMS. This prospective, observational study was conducted as a longitudinal Germany-wide online survey (baseline survey and two follow-ups). Inclusion criteria were age ≥18 years, MS diagnosis, and ≥1 SARS-CoV-2 vaccination. Patient-reported data included socio-demographics, MS-related data, and post-vaccination phenomena. Annualized relapse rates (ARRs) of the study cohort and reference cohorts from the German MS Registry were compared pre- and post-vaccination. Post-vaccination relapses were reported by 9.3% PwMS (247/2661). The study cohort’s post-vaccination ARR was 0.189 (95% CI: 0.167–0.213). The ARR of a matched unvaccinated reference group from 2020 was 0.147 (0.129–0.167). Another reference cohort of vaccinated PwMS showed no indication of increased post-vaccination relapse activity (0.116; 0.088–0.151) compared to pre-vaccination (0.109; 0.084–0.138). Predictors of post-vaccination relapses (study cohort) were missing immunotherapy (OR = 2.09; 1.55–2.79; p < 0.001) and shorter time from the last pre-vaccination relapse to the first vaccination (OR = 0.87; 0.83–0.91; p < 0.001). Data on disease activity of the study cohort in the temporal context are expected for the third follow-up

Therapy switches in fingolimod-treated patients with multiple sclerosis: long-term experience from the German MS Registry

INTRODUCTIONS: Therapy switches in patients with multiple sclerosis (MS) receiving treatment with fingolimod occur frequently in clinical practice but are not well represented in real-world data. The aim of this study was to identify and characterize treatment switches and reveal sociodemographic/clinical changes over time in fingolimod-treated people with MS (PwMS). METHODS: Data on 2536 fingolimod-treated PwMS extracted from the German MS Registry during different time periods were analyzed (2010-2019). RESULTS: Overall, 28.3% of PwMS were treatment-naïve before fingolimod initiation. Interferon beta (30.7%) was the most common pre-fingolimod treatment. Ocrelizumab (19.8%) was the most frequent subsequent treatment in the 944 patients on fingolimod who switched. Between 2010 and 2019, median disease duration at fingolimod initiation decreased from 8.5 to 7.1 years (p < 0.001), and patients taking fingolimod for ≥ 1 year after treatment initiation decreased from 89.6 to 80.5% (p < 0.001). Females (p < 0.001) and young patients (p = 0.003) showed a shorter time on fingolimod. The most frequent reason for switching was disease activity (relapse/MRI) despite treatment. The annualized relapse rate increased from 0.37 in patients on fingolimod to 0.47 after treatment cessation, decreasing to 0.19 after treatment with a subsequent disease-modifying drug (DMD) was initiated. CONCLUSION: Treatment switches from fingolimod to subsequent DMDs currently occur after shorter treatment durations than 10 years ago, possibly due to the growing treatment spectrum. Planning adequate washout periods is essential and should be done on an individualized basis

Ultra Broadband Curved Pyramidal Absorber Metamaterial in the UHF/SHF Region

International audienceA microwave ultra-broadband polarization independent metamaterial absorber in the UHF/SHF frequency bands is presented. As a first task, we enhanced the relative absorptive bandwidth of the conventional pyramidal absorber making the altitude curved. Such modification increased the Relative Absorptive Bandwidth (RAB) from 36% to 70.45% with an absorptive level greater than 90%. In addition, we focused on another task by which we aimed to have an ultra-broadband of absorption in UHF/SHF region. In this manner, we present the new metamaterial absorber prototype, with a total thickness of (12.7) cm, consisting of 35 curved resonant layers of different sizes. Numerical simulations show an enhanced design with an absorption band from 0.3 GHz to 30 GHz. Both prototypes are tested using the numerical simulator High Frequency Structure Simulator (HFSS)