ABSTRACT
A mixed metal oxide W-TiO2 nanopowder photocatalyst was prepared by using the sol-gel method with a broad range of elemental compositions x = CW/(CW + CTi), including TiO2 and WO3. The material was structurally characterized and evaluated in adsorption and photocatalytic processes by testing its removal capacity of a representative pollutant methylene blue (MB) in aqueous solutions and under UV-A and sunlight illuminations. The nanopowders appeared to be more effective adsorbents than pure TiO2 and WO3 materials, showing a maximum at 15 mol% W, which was set as the tungsten solubility limit in anatase titania. At the same time, the photocatalytic decomposition of MB peaked at 2 mol% W. The examination of different compositions showed that the most effective MB removal took place at 15 mol% W, which was attributed to the combined action of adsorption and heterogeneous photocatalysis. Moreover, MB decomposition under sunlight was stronger than under UV-A, suggesting photocatalyst activation by visible light. The pollutant removal efficiency of the material with 15 mol% W was enhanced by a factor of ~10 compared to pure TiO2 at the beginning of the process, which shows its high potential for use in depollution processes in emergency cases of a great pollutant leak. As a result, a Wx=0.15-TiO2 catalyst could be of high interest for wastewater purification in industrial plants.
ABSTRACT
BackgroundCoronavirus disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is estimated to have caused more than 18 million deaths worldwide as of end-May 2022. MethodsCOVIDENCE UK is a longitudinal population-based study that investigates risk factors for, and impacts of, COVID-19 in UK residents aged [≥]16 years. A unique feature is the capacity to support trial-within-cohort studies to evaluate interventions for prevention of COVID-19 and other acute respiratory illnesses. Participants complete a detailed online baseline questionnaire capturing self-reported information relating to their socio-demographic characteristics, occupation, lifestyle, quality of life, weight, height, longstanding medical conditions, medication use, vaccination status, diet and supplemental micronutrient intake. Follow-up on-line questionnaires capturing incident symptoms of COVID-19 and other acute respiratory infections, incident swab test-confirmed COVID-19, doses of SARS-CoV-2 vaccine received, and quality of life are completed at monthly intervals. ResultsThe study was launched on 1st May 2020 and closed to recruitment on 6th October 2021. A total of 19,981 participants enrolled and consented to 5-year follow-up with medical record linkage. Their mean age was 59.1 years (range 16.0 to 94.4 years), 70.2% were female, and 93.7% identified their ethnic origin as White. Analyses conducted to date have provided key insights into risk factors for SARS-CoV-2 infection and COVID-19 disease, determinants of SARS-CoV-2 vaccine immunogenicity and efficacy, and impacts of COVID-19 on health economic outcomes. The cohort has also supported conduct of a Phase 3 randomised trial-within-cohort study (CORONAVIT) evaluating implementation of a test-and-treat approach to correcting sub-optimal vitamin D status on incidence and severity of acute respiratory infections, including COVID-19. ConclusionsThe COVIDENCE UK dataset represents a valuable resource containing granular information on factors influencing susceptibility to, and impacts of, COVID-19 in UK adults. Researchers wishing to access anonymised participant-level data should contacting the corresponding author for further information.
ABSTRACT
OBJECTIVESTo determine whether population-level implementation of a test-and- treat approach to correction of sub-optimal vitamin D status (25-hydroxyvitamin D [25(OH)D] <75 nmol/L) influences risk of all-cause acute respiratory infection (ARI) or coronavirus disease 2019 (COVID-19). DESIGNPhase 3 open-label randomised controlled trial (CORONAVIT) utilising trials-within-cohorts (TwiCs) methodology. SETTINGUnited Kingdom. PARTICIPANTS6200 adults aged 16 years or older, who were not already taking vitamin D supplements at baseline. INTERVENTIONSOffer of a postal finger-prick test of blood 25(OH)D concentration with provision of a 6-month supply of higher-dose vitamin D (3200 IU/day, n=1550) or lower-dose vitamin D (800 IU/day, n=1550) to those with blood 25(OH)D concentration <75 nmol/L, vs. no offer of testing or supplementation (n=3100). Follow-up was from 17th December 2020 to 16th June 2021. MAIN OUTCOME MEASURESThe primary outcome was the proportion of participants experiencing at least one doctor- or swab test-confirmed ARI of any cause. Secondary outcomes included the proportion of participants developing swab test-confirmed COVID-19. Logistic regression was used to calculate odds ratios and associated 95% confidence intervals. RESULTSOf 3100 participants offered 25(OH)D testing, 2958 (95.4%) accepted, and 2690 (86.8%) had 25(OH)D <75 nmol/L and were sent vitamin D supplements (1356 higher-dose, 1334 lower-dose). 76 (5.0%) vs. 87 (5.7%) vs. 136 (4.6%) participants in higher-dose vs. lower-dose vs. no offer groups experienced at least one ARI of any cause (odds ratio [OR] for higher-dose vs. no offer 1.09, 95% CI 0.82-1.46; lower-dose vs. no offer 1.26, 0.96-1.66). 45 (3.0%) vs. 55 (3.6%) vs. 78 (2.6%) participants in higher-dose vs. lower-dose vs. no offer groups developed COVID-19 (OR for higher-dose vs. no offer 1.13, 0.78-1.63; lower-dose vs. no offer 1.39, 0.98-1.97). CONCLUSIONSAmong adults with a high baseline prevalence of sub-optimal vitamin D status, implementation of a population-level test-and-treat approach to vitamin D replacement did not reduce risk of all-cause ARI or COVID-19. TRIAL REGISTRATIONClinicalTrials.gov no. NCT04579640 SUMMARY BOXO_ST_ABSWhat is already known on this topic?C_ST_ABSVitamin D metabolites support innate immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Sub-optimal vitamin D status (25-hydroxyvitamin D <75 nmol/L) associates with increased susceptibility to all-cause acute respiratory infections (ARI) and coronavirus disease 2019 (COVID-19). Phase 3 randomised controlled trials of vitamin D to prevent COVID-19 have not yet reported. What this study addsThis phase 3 randomised controlled trial, including 6200 participants, shows that implementation of a population-level test-and-treat approach to oral vitamin D replacement at a dose of 800 IU or 3200 IU per day did not reduce risk of all-cause ARI or COVID-19 among adults with a high baseline prevalence of sub-optimal vitamin D status.
