Effect of Environmental Conditioning on the Properties of Thermosetting and Thermoplastic-Matrix Composite Materials by Resin Infusion for Marine Applications (PREPRINT)

Glass-fibre reinforced polymer (GFRP) laminates were manufactured using Vacuum assisted Resin Transfer Moulding (VaRTM) with a range of thermosetting resins and a novel infusible thermoplastic resin as part of a comprehensive down-selection to identify suitable commercially available resin systems for the manufacture of marine vessels greater than 50 m in length. The effect of immersion in deionised water and in an organic liquid (diesel) on the interlaminar shear strength (ILSS) and glass transition temperature (Tg) was determined. The thermoplastic had the highest Tg of all materials tested and comparable ILSS properties to the epoxy. Immersion in water, however, caused larger reductions in ILSS properties of the thermoplastic compared to the other systems. SEM showed a transition from matrix-dominated failure in the dry condition to failure at the fibre-matrix interface in the wet and organic-wet specimens. The overall performance of the infusible thermoplastic is good when compared to well-established marine resin systems; however, the environmental performance could be improved if the thermoplastic resin is used in conjunction with a fibre sizing that is tailored for use with acrylic-based resin systems

Fluticasone Propionate Orally Disintegrating Tablet (APT-1011) for Eosinophilic Esophagitis: Randomized Controlled Trial.

Topical steroids are effective treatments for eosinophilic esophagitis (EoE). The FLUTE (Fluticasone in EoE) trial evaluated safety and efficacy of APT-1011 (fluticasone propionate oral disintegrating tablet) vs placebo for treatment of EoE. In this randomized, double-blind, placebo-controlled, dose-finding, phase 2b trial, 106 adults with EoE received 1 of 4 APT-1011 doses or placebo for a 12-week induction period and 40 weeks of maintenance. Primary outcome was histologic response (≤6 eosinophils per high-power field) at Week 12. Secondary outcomes included endoscopic features and dysphagia frequency. Histologic response rates were 0% for placebo, 80% for APT-1011 3 mg twice daily (BID), 67% for 3 mg at bedtime (HS), 86% for 1.5 mg BID, 48% for 1.5 mg HS (P < .001 for all groups vs placebo). At Week 12, mean Edema/Rings/Exudates/Furrows/Strictures (EoE Endoscopic Reference Score) total score (max, 9.0) improved from 4.5 to 2.3 for 3 mg BID, 5.3 to 2.1 for 3 mg HS, 4.6 to 1.7 for 1.5 mg BID, 5.3 to 2.9 for 1.5 mg HS vs 5.2 to 4.5 for placebo. Mean dysphagia frequency over 14 days improved from baseline to Week 12 with all active groups improving more than placebo. Improvements were sustained to Week 52. APT-1011 was safe and well-tolerated, with higher incidence of candidiasis noted at the higher twice daily doses. APT-1011 dosing regimens were superior for histologic and endoscopic responses, and for reduction in dysphagia frequency vs placebo. Based on the symptom improvement and assessment of adverse events together with the histologic response rate, 3 mg once daily at bedtime dose showed the most favorable risk-benefit profile. gov, Number: NCT03191864

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Composite repair in wind turbine blades: an overview

Renewable energy sources such as wind energy—together with energy-efficient technologies—are essential to meet global energy demands and address climate change. Fiber-reinforced polymer composites, with their superior structural properties (e.g., high stiffness-to-weight) that allow lightweight and robust designs, play a significant part in the design and manufacture of modern wind turbines, especially turbine blades, for demanding service conditions. However, with the current global growth in onshore/offshore wind farm installations (with total global capacity of ∼282 GW by the end of 2012) and trend in wind turbine design (∼7–8 MW turbine capacity with ∼70–80 m blade length for offshore installations), one of the challenges that the wind energy industry faces with composite turbine blades is the aspect of structural maintenance and repair. Although wind turbines are typically designed for a service life of about 20 years, robust structural maintenance and repair procedures are essential to ensure the structural integrity of wind turbines and prevent catastrophic failures. Wind blades are damaged due to demanding mechanical loads (e.g., static and fatigue), environmental conditions (e.g., temperature and humidity) and also manufacturing defects. If material damage is not extensive, structural repair is the only viable option to restore strength since replacing the entire blade is not cost-effective, especially for larger blades. Composite repairs (e.g., external and scarf patches) can be used to restore damaged laminate/sandwich regions in wind blades. With composite materials in the spar (∼30–80 mm thick glass/carbon fiber laminates) and aerodynamic shells (sandwich sections with thin glass fiber skins and thick foam/wood as core), it is important to have reliable and cost-effective structural repair procedures to restore damaged wind blades. However, compared to aerospace bonded repairs, structural repair procedures in wind blades are not as well developed and thus face several challenges. In this regard, the area of composite repair in wind blades is broadly reviewed to provide an overview as well as identify associated challenges

Flexural properties and failure mechanisms of infusible thermoplastic-and thermosetting based composite materials for marine applications

This study aims to evaluate the flexural properties and associated failure mechanisms of a reactive thermoplastic relative to traditional thermosetting resin systems (polyester, vinylester, epoxy) for potential application in marine vessels over 50 m in length, as part of the H2020 FIBRESHIP project. All resin systems are compatible with the vacuum assisted liquid resin infusion manufacturing technique commonly used in small/medium size shipyards. Glass fibre reinforced polymer (GFRP) laminates were manufactured, test samples extracted, immersed in deionised water or an organic liquid (diesel) and mechanically tested to evaluate the flexural strength and modulus. Failure mechanisms are analysed by scanning electron microscope (SEM). In terms of flexural strength, the reactive thermoplastic based laminate performed similar to the epoxy in terms of retained strength in both deionised water and diesel. The governing failure mode of fibre buckling and kink band formation coupled with interlaminar cracking was identified for both the epoxy and the thermoplastic. The vinylester laminate retained equivalent strength in all three environments while polyester showed the greatest reduction in water due to extensive interlaminar cracking. Overall, the flexural properties of the reactive thermoplastic are shown to be competitive with traditional candidate resin systems for marine structures. The strength reduction and failure modes in the dry, wet and diesel condition were similar to the epoxy while the reduction of modulus was negligible in water and less than 10% in diesel