Repurposing existing medications for coronavirus disease 2019: protocol for a rapid and living systematic review

BACKGROUND Coronavirus disease 2019 (COVID-19) has no confirmed specific treatments. However, there might be in vitro and early clinical data as well as evidence from severe acute respiratory syndrome and Middle Eastern respiratory syndrome that could inform clinicians and researchers. This systematic review aims to create priorities for future research of drugs repurposed for COVID-19. METHODS This systematic review will include in vitro, animal, and clinical studies evaluating the efficacy of a list of 34 specific compounds and 4 groups of drugs identified in a previous scoping review. Studies will be identified both from traditional literature databases and pre-print servers. Outcomes assessed will include time to clinical improvement, time to viral clearance, mortality, length of hospital stay, and proportions transferred to the intensive care unit and intubated, respectively. We will use the GRADE methodology to assess the quality of the evidence. DISCUSSION The challenge posed by COVID-19 requires not just a rapid review of drugs that can be repurposed but also a sustained effort to integrate new evidence into a living systematic review. TRIAL REGISTRATION PROSPERO 2020 CRD42020175648

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Crystal structure of A-site deficient La0.2Sr0.2-xCaxTiO3 perovskite at ambient conditions and high temperatures : a neutron powder diffraction study

The authors thank the Government of the United Arab Emirates for sponsoring this project, the EPSRC for Platform grant support and the Royal Society for a Wolfson Research Merit Award.The crystal structures of several solid solutions of the perovskite La0.2Sr0.7-xCaxTiO3 were determined using the Rietveld analysis of neutron powder diffraction patterns collected at room temperature and at high temperatures. At room temperature, samples showed a tetragonal I4/mcm symmetry for compositions with 0.1 ≤ x ≤ 0.35 followed by a phase transition to orthorhombic Pbnm symmetry for compositions with 0.4 ≤ x ≤ 0.7. Samples with the orthorhombic symmetry showed two reversible phase transitions in the temperature range 20oC – 900oC. The first transition was a discontinuous Pbnm – I4/mcm around 300oC and the second was a continuous I4/mcm - Pm3 ̅m transition below 900oC. The lower symmetries resulted from very small distortions and changes in tilts of the BO6 octahedra of this perovskite; which was a direct result from the A-site ionic radius mismatch.Publisher PDFPeer reviewe

Development and characterisation of an A-site deficient perovskite as alternative anode material for solid oxide fuel cells

The research presented in this thesis is a collection of many different, yet connected, parts that stemmed from the development of a new alternative material intended to be utilised as anode material in solid oxide fuel cells. The main part is the research conducted in the development and characterisation of the novel A-site deficient La₀.2₂Sr₀.₇₋ₓCaₓTiO₃. Calcium introduction resulted in reducing this perovskite unit cell volume which, at the beginning, enhanced its electrical conductivity in reducing conditions. However, the ideal cubic symmetry coud not be maintained, as in the starting material LA₀.₂Sr₀.₇TiO₃, as a result of the increased A-site ionic radius mismatch and two lower symmetries were observed at room temperature. These were the tetragonal I4/mcm for 0.1 ≤ x ≤ 0.35 and orthorhombic Pbnm for 0.4 ≤ x ≤ 0.7. Higher temperature NPD data showed that the orthorhombic samples transformed into higher symmetries with Pbnm → I4/mcm → Pm3-m phase transitions. Detailed crystallographic analysis is discussed; where the different unit cells showed changes to the tilts of the BO₆ octahedra, along with distortions to these octahedra. DC conductivity measurements showed a high electrical conductivity of 27.5 S/cm for a pre-reduced composition La₀.₂Sr₀.₂₅Ca₀.₄₅TiO₃ at 900°C and pO₂ = 10⁻¹⁹ atm. This material showed very encouraging features; which makes it a very promising anode material for SOFCs. A study was also done which explores the best renewable energy options for the United Arab Emirates given its local climate and other aspects. The reliance on seawater desalination is argued to by unsustainable for different reasons. Thus, water security should be a main element in the planning process for adopting renewable energy technologies. A system that combines different technologies; with a focus on fuel cells technology; is outlined which is thought of to be a very promising basis for a broader system that will secure power and water in a very environment friendly way. Different compositions of the system La₀.₂Sr₀.₇₋ₓCaₓTiO₃ were also studied using AC impedance spectroscopy in order to establish whether or not this system can show a ferroelectric behaviour. Results showed a variation in the dielectric constant of different samples with temperature; however, no Curie point was observed. Nonetheless, the results did show that the different compositions were very homogeneous when fully oxygenated and there were some indications of possible symmetry changes at sub-ambient temperatures. The final part of this thesis outlined the work done towards the development of a new analytical instrument. An existing TGA instrument was altered in order to provide a simultaneous thermogravimetric analysis and DC conductivity measurement for solid solutions at controlled temperature and oxygen partial pressure. Results were obtained for different samples of the system La₀.₂Sr₀.₇₋ₓCaₓTiO₃ which showed a great dependence of the electrical conductivity on the oxygen stoichiometry in these oxides. Also, a direct method is possible with this instrument to estimate the oxygen chemical diffusion coefficient using the electrical conductivity relaxation method. This new setup will be very useful for different electrochemical and thermal studies which can broaden the understanding of the different mechanisms that affect the performance of different solid state materials

Crystal structure of A-site deficient La_0.2Sr_0.2-xCa_xTiO₃ perovskite at ambient conditions and high temperatures:a neutron powder diffraction study

The crystal structures of several solid solutions of the perovskite La0.2Sr0.7-xCaxTiO3 were determined using the Rietveld analysis of neutron powder diffraction patterns collected at room temperature and at high temperatures. At room temperature, samples showed a tetragonal I4/mcm symmetry for compositions with 0.1 ≤ x ≤ 0.35 followed by a phase transition to orthorhombic Pbnm symmetry for compositions with 0.4 ≤ x ≤ 0.7. Samples with the orthorhombic symmetry showed two reversible phase transitions in the temperature range 20oC – 900oC. The first transition was a discontinuous Pbnm – I4/mcm around 300oC and the second was a continuous I4/mcm - Pm3 ̅m transition below 900oC. The lower symmetries resulted from very small distortions and changes in tilts of the BO6 octahedra of this perovskite; which was a direct result from the A-site ionic radius mismatch.</p

Ca-substituted, A-site deficient perovskite La_0.2Sr_0.7TiO₃ as a potential anode material for SOFCs

Samples from across the solid solution series La0.2Sr0.7-xCaxTiO3, were successfully synthesised by solid state reaction. Structural properties were determined at room temperature using X-ray powder diffraction and conductivity measurements were performed using the four probe DC and van der Pauw techniques at different temperatures and atmospheres. On increasing x, the perovskite phase lattice symmetry changes from cubic Pm (3) over barm to tetragonal I4/mcm at x = 0.05 and tetragonal to orthorhombic Pbnm at x = 0.425. The lattice also shrinks as x increases. Samples showed only a slight 0.3% increase in lattice volume after reduction at 900 degrees C in 5% H-2. On increasing calcium doping, conductivity in reduced samples and equilibrated at 900 degrees C in 5%H-2 increased markedly reaching 27.53 S cm(-1) at x = 0.45, but decreased as x increased further.</p

Bond load-slip behaviour of FRP bars in recycled-aggregate concrete

This study presents an experimental program conducted to investigate the bond strength of FRP bars in recycled-aggregate concrete compared to the one in normal-aggregate concrete for the improved evaluation of results. The experimental program contains thirty six specimens tested using direct pull-out test. In this study, glass, carbon and basalt FRP bars are used with 12 mm diameter and bar bond lengths of 5d, where d is the bar diameter. The FRP bars are casted in different recycled-aggregate concrete strengths of 30, 45 and 60 MPa. The behaviour of bars in normal-aggregate concrete strength of 30 MPa is used as a benchmark and its behaviour is compared with the ones in the recycled-aggregate concrete. The impact of the concrete strength considered is identified based on the gain in the bond behaviour. The experimental results demonstrate the prospect of the recycled aggregates applied as an alternative to normal aggregates in the FRP reinforced concrete. In addition, the use of the recycled aggregate increases the bearing friction behaviour between the FRP bars and concrete

Bond Behavior of Basalt Fiber Reinforced Polymer Bars in Recycled Coarse Aggregate Concrete

This study is an experimental investigation of the bond stress–slip behavior of BFRP bars in recycled coarse aggregate concrete using the pull-out experiment. The experimental program contains twenty-three BFRP specimens and twelve specimens with GFRP bars. The pull-out test results of the BFRP and GFRP specimens in recycled coarse aggregate concrete are balanced to those of normal coarse aggregate concrete, which are used as a benchmark. In this study, the influence of major parameters on the BFRP bond performance are investigated: concrete strengths (30, 45, and 60 MPa), bar diameter (8, 10, and 12 mm), and bar bond length (5, 10, and 15d, where d is the diameter of the bar). The effect of the parameters considered is determined on the basis of the increase in the bond resistance. The test findings showed that the bond resistance of BFRP bars in recycled coarse aggregate concrete is highly comparable to that of normal aggregate concrete. In addition, the BFRP bar pull-out failure is not governing when a bar bond length of 10 or 15d, or high concrete strength of 45 or 60 MPa, is utilized. Theoretical equations from the literature that predict the bond resistance and bond stress–slip performance for FRP reinforced concrete are compared to the experimental results of this study. It is found that the equation described by Orangun and colleagues can accurately predict the bond resistance for BFRP bars in recycled coarse aggregate concrete with an average of 86% compared to the experimental results

Experimental Study of Produced Water Treatment Using Activated Carbon with Aluminum Oxide Nanoparticles, Nanofiltration and Reverse Osmosis Membranes

This work inspected the produced water discharged from the Amara oil field in (Misan-Iraq) to improve the quality of water before reuse and reinjection or disposal. The process of treatment included a pretreatment step using activated carbon and post-treatment using flat polymeric nanofiltration membrane (NF) (1.0 nm) and reverse osmosis membrane (RO) (0.3nm), respectively. Therefore, activated carbon without aluminum oxide (Al2O3) nanoparticles and with (Al2O3) nanoparticles (20 nm) was used to examine the removal efficiency of the total organic compound (TOC). The height of the fixed bed of activated carbon and its diameter were 35 cm and 2.5 cm, respectively. The volumetric flow rates of the produced water flowing through the activated carbon column were taken as (25, 20, 15, 10 and 5)×10-4 m3/h respectively, at transmembrane pressure (TMP) of 1.0 bar, pH equals 6, and the temperature of 25 oC. The TOC removal efficiencies attained using activated carbon without Al2O3 nanoparticles were (52, 64, 77, 83 and 87%), respectively, and (65, 72.7, 83.4, 92.5 and 95.2%) with the use of Al2O3 nanoparticles, respectively. Produced water effluent from the activated carbon column was treated by flat NF and RO membranes to reduce the total dissolved solids (TDS). The cross-flow rates through NF and RO membranes were 0.1 and 0.25 m3/h, TMP (1-12 bar) and 60 bar, respectively. The removal efficiency of TDS was enhanced up to 40% and 99.67%, respectively. In addition, the TOC removal efficiency was 100% in the effluent of the RO membrane

Energy Efficiency and Thermal Characterization of Eco-Friendly Wood Fiber Masonry Blocks

A pressing need exists to produce masonry blocks that are more sustainable and energy efficient since the concrete industry is responsible for more than 5% of the worldwide carbon dioxide emissions. Producing masonry blocks that have a higher thermal insulation capacity can reduce energy consumption. In this study, an experimental investigation was conducted to explore the energy efficiency and thermal characterization of a new alternative masonry unit that were manufactured using waste (wood fiber) and by-product (fly ash) materials. Two different tests were performed, according to both ASTM standards C1363-11 and D5334-14, to determine the thermal conductivity factor, energy saving, and thermal insulation for the entire masonry unit and the new alternative material itself. A guarded hot box was fabricated to simulate a real insulation case. The results indicated that producing masonry units using fly ash and wood fiber instead of the conventional materials clearly influenced the energy consumption. Specimens produced out of fly ash and wood fiber reduced the energy consumption by 64% compared to a conventional masonry unit. A modified thermal needle probe procedure was used to find the thermal conductivity of the fly ash-wood fiber as a material, not a unit. The new material exhibited a clear reduction in thermal conductivity compared to many commonly used standard construction materials. The mechanical characterization and dimension requirements were reported to show that the new ecofriendly masonry units met the ASTM requirements for non-load-bearing concrete masonry units