19 research outputs found

    Design, Fabrication and Properties of Rib Poly(methylmethacrylimide) Optical Waveguides

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    We report about design, fabrication and properties of the polymer optical waveguides deposited on silica-on-silicon substrate. The design of the waveguides is based on a concept that geometric dimensions of the single mode polymer waveguide are determined by geometrical parameters of the silica layer. The design of the waveguides was schemed for 650 nm, 850 nm, 1310 nm and 1550 nm wavelength. The design of the presented planar waveguides was realized on the bases of modified dispersion equation while the ridge waveguides design was proposed following the Fischbeck concept. Both designs were refined applying RSoft software using beam propagation method. Proposed shapes of the waveguides were etched by standard photolithography process into the silica layers and polymer waveguide layers were subsequently deposited into the treated substrate by spin coating. Poly(methylmethacrylimide) was used as the waveguide core material and polymethylmethacrylate was used as a cover protection layer. Propagation optical loss measurements were done by using the cut-back method and the best samples had optical losses lower than 0.6 dB/cm at 650 nm, 1310 nm and 1550 nm

    THE RAMAN SPECTROSCOPY USE FOR MONITORING OF CHANGES IN THE GLASS STRUCTURE OF THE THIN LAYERS CAUSED BY ION IMPLANTATION

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    In this paper, we have demonstrated the utility of Raman spectroscopy as a technique for the characterisation of changes in the glass structure of the thin layers caused by ion implantation. Various types of silicate glasses were implanted by Au+ ions with energy of 1.7 MeV and a fluence of 1 x 1016 ions.cm-2 to create gold nanoparticles in thin sub-surface layer of the glass. It was proved that the structure of the glass has an indisputable impact on the extent of depolymerisation of the glass network after implantation. It was shown that the degree of glass matrix depolymerisation can be described using the evaluation of Qn factors in the implanted layers from different depths. After analysis of Raman spectra, the relation between nucleation and the resulting parameters of the gold nanoparticles was put into connection with the feasibility of the glass to recover its structure during post-implantation annealing. Also the creation of new bonds in the glass network was discussed

    Real-World Six- and Twelve-Month Drug Retention, Remission, and Response Rates of Secukinumab in 2,017 Patients With Psoriatic Arthritis in Thirteen European Countries

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    Objective There is a lack of real-life studies on interleukin-17 (IL-17) inhibition in psoriatic arthritis (PsA). We assessed real-life 6- and 12-month effectiveness (i.e., retention, remission, low disease activity [LDA], and response rates) of the IL-17 inhibitor secukinumab in PsA patients overall and across 1) number of prior biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs), 2) years since diagnosis, and 3) European registries. Methods Thirteen quality registries in rheumatology participating in the European Spondyloarthritis Research Collaboration Network provided longitudinal, observational data collected as part of routine care for secondary use. Data were pooled and analyzed with Kaplan-Meier plots, log rank tests, Cox regression, and multiple linear and logistic regression analyses. Results A total of 2,017 PsA patients started treatment with secukinumab between 2015 and 2018. Overall secukinumab retention rates were 86% and 76% after 6 and 12 months, respectively. Crude (LUNDEX adjusted) 6-month remission/LDA (LDA including remission) rates for the 28-joint Disease Activity Index for Psoriatic Arthritis, the Disease Activity Score in 28 joints using the C-reactive protein level, and the Simplified Disease Activity Index (SDAI) were 13%/46% (11%/39%), 36%/55% (30%/46%), and 13%/56% (11%/47%), and 12-month rates were 11%/46% (7%/31%), 39%/56% (26%/38%), and 16%/62% (10%/41%), respectively. Clinical Disease Activity Index remission/LDA rates were similar to the SDAI rates. Six-month American College of Rheumatology 20%/50%/70% improvement criteria responses were 34%/19%/11% (29%/16%/9%); 12-month rates were 37%/21%/11% (24%/14%/7%). Secukinumab effectiveness was significantly better for b/tsDMARD-naive patients, similar across time since diagnosis (4 years), and varied significantly across the European registries. Conclusion In this large real-world study on secukinumab treatment in PsA, 6- and 12-month effectiveness was comparable to that in previous observational studies of tumor necrosis factor inhibitors. Retention, remission, LDA, and response rates were significantly better for b/tsDMARD-naive patients, were independent of time since diagnosis, and varied significantly across the European countries.Peer reviewe

    Thermal stability and photoluminescence properties of RE-doped (RE = Ho, Er, Tm) alumina nanoparticles in bulk and fiber-optic silica glass

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    We present the thermal stability and the photoluminescence properties of RE-doped (RE = Ho, Er, Tm) alumina nanoparticles in the phase system Al2O3-SiO2 with respect to the chemical composition and the thermal processing conditions applied in the fiber-optic technology. The alumina and silica soot reacted together to form mullite when the Al2O3 concentration was higher than 5 mol. %. We have demonstrated that the solubility limits of RE ions in the mullite nanocrystals are strongly limited. The RE ions preferentially occupy highly disordered positions on the nanoparticle surface or in the amorphous Al3+-enriched shell around the nanoparticles, exhibiting maximal lifetime of approx. 1.2 ms, 10.0 ms and 0.6 ms in the Ho-, Er- and Tm-doped samples. Rapid cooling of the samples with stoichiometric composition 3Al2O3.2SiO2 managed to prepare highly defective mullite nanocrystals with embedded RE ions, exhibiting promising photoluminescence lifetimes of 5.6 ms and 2.4 ms in the case of Ho3+ and Tm3+ ions, respectively. In optical fibers with 5 mol. % Al2O3, the formation of amorphous Al3+-enriched nanoparticles was observed and the photoluminescence lifetime was in a good agreement with corresponding bulk samples. Exploitation of the RE-doped stoichiometric mullite in the fiberoptic technology may be a perspective way to improve the photoluminescence efficiency of active optical fibers for high-power applications

    Effectiveness and treatment retention of TNF inhibitors when used as monotherapy versus comedication with csDMARDs in 15 332 patients with psoriatic arthritis. Data from the EuroSpA collaboration

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    Background Comedication with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) during treatment with tumour necrosis factor inhibitors (TNFi) is extensively used in psoriatic arthritis (PsA), although the additive benefit remains unclear. We aimed to compare treatment outcomes in patients with PsA treated with TNFi and csDMARD comedication versus TNFi monotherapy. Methods Patients with PsA from 13 European countries who initiated a first TNFi in 2006-2017 were included. Country-specific comparisons of 1 year TNFi retention were performed by csDMARD comedication status, together with HRs for TNFi discontinuation (comedication vs monotherapy), adjusted for age, sex, calendar year, disease duration and Disease Activity Score with 28 joints (DAS28). Adjusted ORs of clinical remission (based on DAS28) at 12 months were calculated. Between-country heterogeneity was assessed using random-effect meta-analyses, combined results were presented when heterogeneity was not significant. Secondary analyses stratified according to TNFi subtype (adalimumab/infliximab/etanercept) and restricted to methotrexate as comedication were performed. Results In total, 15 332 patients were included (62% comedication, 38% monotherapy). TNFi retention varied across countries, with significant heterogeneity precluding a combined estimate. Comedication was associated with better remission rates, pooled OR 1.25 (1.12-1.41). Methotrexate comedication was associated with improved remission for adalimumab (OR 1.45 (1.23-1.72)) and infliximab (OR 1.55 (1.21-1.98)) and improved retention for infliximab. No effect of comedication was demonstrated for etanercept. Conclusion This large observational study suggests that, as used in clinical practice, csDMARD and TNFi comedication are associated with improved remission rates, and specifically, comedication with methotrexate increases remission rates for both adalimumab and infliximab.Peer reviewe

    The impact of a csDMARD in combination with a TNF inhibitor on drug retention and clinical remission in axial spondyloarthritis

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    Objectives: Many axial spondylarthritis (axSpA) patients receive a conventional synthetic DMARD (csDMARD) in combination with a TNF inhibitor (TNFi). However, the value of this co-therapy remains unclear. The objectives were to describe the characteristics of axSpA patients initiating a first TNFi as monotherapy compared with co-therapy with csDMARD, to compare one-year TNFi retention and remission rates, and to explore the impact of peripheral arthritis. Methods: Data was collected from 13 European registries. One-year outcomes included TNFi retention and hazard ratios (HR) for discontinuation with 95% CIs. Logistic regression was performed with adjusted odds ratios (OR) of achieving remission (Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP < 1.3 and/or BASDAI < 2) and stratified by treatment. Inter-registry heterogeneity was assessed using random-effect meta-analyses, combined results were presented when heterogeneity was not significant. Peripheral arthritis was defined as ≥1 swollen joint at baseline (=TNFi start). Results: Amongst 24 171 axSpA patients, 32% received csDMARD co-therapy (range across countries: 13.5% to 71.2%). The co-therapy group had more baseline peripheral arthritis and higher CRP than the monotherapy group. One-year TNFi-retention rates (95% CI): 79% (78, 79%) for TNFi monotherapy vs 82% (81, 83%) with co-therapy (P < 0.001). Remission was obtained in 20% on monotherapy and 22% on co-therapy (P < 0.001); adjusted OR of 1.16 (1.07, 1.25). Remission rates at 12 months were similar in patients with/without peripheral arthritis. Conclusion: This large European study of axial SpA patients showed similar one-year treatment outcomes for TNFi monotherapy and csDMARD co-therapy, although considerable heterogeneity across countries limited the identification of certain subgroups (e.g. peripheral arthritis) that may benefit from co-therapy
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