Metastable VO2 complexes in silicon: experimental and theoretical modeling studies

We report on a combined experimental and theoretical study of the metastable form of the vacancy-dioxygen defect in Si labeled VO2*. Important new experimental observations are the 2 detection of mixed local vibrational modes of VO*(2) in O-16, O-18 co-doped samples, the determination of the position of LVM bands for the negatively charged defect, and an assignment of an acceptor level at about E-c - 0.05 eV. Defect energetics, electrical levels and LVM frequencies of the VO*(2) complex are also investigated by ab-initio density-functional modeling. We find it to be a bistable defect which accounts well for the experimental data. The metastable form produces an acceptor state at similar to 0.05 eV below E-c, and can be thought of as a VO defect perturbed by interstitial oxygen

Electronic properties and structure of a complex incorporating a self-interstitial and two oxygen atoms in silicon

The electronic properties and structure of a complex incorporating a self-interstitial (i) and two oxygen atoms are presented by a combination of deep level transient spectroscopy (DLTS), infrared absorption spectroscopy and ab-initio modeling studies. It is argued that the IO2 complex in Si can exist in four charge states (IO2-, IO20, IO2+, and IO2++). The first and the second donor levels of the IO2 complex show an inverted location order in the gap, leading to a E(0/+ +) occupancy level at E-V + 0.255 eV. Activation energies for hole emission, transformation barriers between different structures, and positions of LVM lines for different configurations and charge states have been determined. These observables were calculated by density-functional calculations, which show that they are accounted for if we consider at least two charge-dependent defect structures

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

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

Drug effectiveness of 2nd and 3rd TNF inhibitors in psoriatic arthritis - relationship with the reason for withdrawal from the previous treatment

Objective: To investigate real-world retention and remission rates in PsA patients initiating a 2nd or 3rd TNFi and the association with reason for discontinuation from the previous TNFi-treatment. Methods: Prospectively collected routine care data from 12 European registries were pooled. Retention rates (Kaplan-Meier estimation) and crude/LUNDEX-adjusted rates of Disease Activity Score 28 and Disease Activity index for PSoriatic Arthritis (DAS28 and DAPSA28) remission were calculated and compared with adjusted Cox regression analyses and Chi-squared test, respectively). Results: We included 5233 (2nd TNFi) and 1906 (3rd TNFi) patients. Twelve-month retention rates for the 2nd and 3rd TNFi were 68% (95%CI: 67-70%) and 66% (64-68%), respectively. Patients who stopped the previous TNFi due to AE/LOE had 12-month retention rates of 66%/65% (2nd TNFi), and 65%/63% (3rd TNFi), respectively. Patients who stopped the previous TNFi due to LOE after less vs more than 24 weeks had 12-month retention rates of 54%/69% (2nd TNFi), and 58%/65% (3rd TNFi). Six-month crude/LUNDEX-adjusted DAS28 remission rates were 48%/35% and 38%/27%, and DAPSA28 remission rates were 19%/14% and 14%/10%, for the 2nd and 3rd TNFi. Conclusion: Two-thirds of patients remained on TNFi at 12months for both the 2nd and 3rd TNFi, while one-third and one-quarter of patients were in DAS28 remission after 6months on the 2nd and 3rd TNFi. While drug effectiveness was similar in patients who stopped the previous TNFi due to AE compared to overall LOE, drug effectiveness was better in patients who had stopped the previous TNF due to secondary LOE compared to primary LOE.This work was supported by Novartis. Novartis had no influence on the data collection, statistical analyses, manuscript preparation or decision to submit.S