Trifluoroacetic Acid::Toxicity, Sources, Sinks and Future Prospects

Trifluoroacetic acid (TFA) is a known persistent pollutant in the environment. Although several direct anthropogenic sources exist, production from the atmospheric degradation of fluorocarbons such as some hydrofluorocarbons (HFCs) has been a known source for some time. The current transition from HFCs to HFOs (hydrofluoroolefins) is beneficial from a global warming viewpoint, because HFOs are much shorter-lived and pose a much smaller threat to warming, but the fraction of HFO conversion to TFA is higher than for the corresponding HFCs and the region over which the TFA is produced is close to the source. Therefore, it is timely to review the role of TFA in the Earth’s environment. This review considers its toxicity, sources and removal processes, measurements in a variety of environments and future prospects. New global model integrations quantify the impacts on TFA levels of uncertainties in the Henry’s Law constant for TFA and the range of gas-phase kinetic parameters determined for the reaction of OH radicals with a representative HFO (HFO-1234yf). Model runs suggest that TFA surface concentrations vary by up to 10% based on Henry’s Law data, but could be up to 25% smaller than previously modelled values depending on the kinetic analysis adopted. Therefore, future estimates of TFA surface concentrations based on HFO removal re-quire updating and the kinetic analysis of TFA production warrants further investigation. The toxicity of TFA appears to be low but further studies of a much wider range of animal and plant types are required

Human Recognition for~Resource-Constrained Mobile Robot Applied to~Covid-19 Disinfection

The global COVID-19 pandemic has stimulated the use of disinfection robots: in September 2021, following a European Commission's action, 200 disinfection robots were delivered to European Hospitals. UV-C light is a common disinfection method, however, direct exposure to UV-C radiation is harmful and disinfection can be operated only in areas strictly forbidden to human personnel. We believe more advanced safety mechanisms are needed to increase the operational flexibility and safety level. We propose a safety mechanism based on vision and artificial intelligence, optimised for execution on mobile robot platforms. It analyses in real-time four video streaming and disables UV-C lamps when needed. Concerning other detection methods, it has a relatively wider and deeper range, and the capability to operate in a dynamic environment. We present the development of the method with a performance comparison of different implementation solutions, and an on-field evaluation through integration on a mobile disinfection robot

Understanding the active role of water in laboratory chamber studies of reactions of the OH radical with alcohols of atmospheric relevance

International audienceA photoinduced reaction takes place between reactants co-adsorbed at the interface of a thin film of water formed on the Teflon walls of the reaction chamber at high humidity

Atmospheric chemistry of 3-methoxy-1-propanol and 3-methoxy-1-butanol: Kinetics with OH radicals and Cl atoms, identification of the end-products in the presence of NO, mechanisms and atmospheric implications

The rate coefficients for the reactions of OH radicals and Cl atoms with 3-methoxy-1-propanol (3-M-1-POL) and 3-methoxy-1-butanol (3-M-1-BOL) in the gas-phase have been measured at (298 ± 2) K and atmospheric pressure. A conventional relative-rate technique was used to determine the rate coefficients: k1 (OH + 3-M-1-POL)= (2.15 ± 0.28) x 10−11, k2 (OH + 3-M-1-BOL)= (2.38 ± 0.31) x 10−11, k3 (Cl + 3-M-1-POL)= (2.66 ± 0.23) x 10−10 and k4 (Cl + 3-M-1-BOL)= (2.95 ± 0.27) x 10−10, all in units of cm3 molecule−1s−1. The present work provides the first kinetic study of the reactions of Cl atoms with 3-M-1-POL and 3-M-1-BOL, and of the reaction of OH radicals with 3-M-1-POL. The kinetic results are presented and compared with those calculated (kSAR) using the structure-reactivity relationship (SAR) method, and reactivity trends are discussed. Additionally, products identification under atmospheric conditions was performed for the first time for the reactions cited above in the presence of NO, using two sampling methods and GC-MS-FID. 3-methoxypropanal, methyl formate and glycolaldehyde were identified from the 3-M-1-POL + OH/Cl reactions, while 3-methoxybutyraldehyde, methyl acetate and glycolaldehyde, were identified from the 3-M-1-BOL + OH/Cl reactions. From these identified products, a general scheme of the reaction mechanisms is proposed. Finally, based on the kinetic results and radiative efficiencies (REs) of the titled compounds, a discussion on the atmospheric implications due to its emissions into the troposphere is also presented.Fil: Barrera, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Garavagno, María de los A.. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Dalmasso, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Taccone, Raul Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Nacional de Córdoba; Argentin

Rate coefficient and mechanism of the OH-initiated degradation of cyclobutanol: A combined experimental and theoretical study

International audienc

TB and COVID-19 co-infection: rationale and aims of a global study

International audienc

Long-term outcomes of the global tuberculosis and COVID-19 co-infection cohort.

Longitudinal cohort data of patients with tuberculosis (TB) and coronavirus disease 2019 (COVID-19) are lacking. In our global study, we describe long-term outcomes of patients affected by TB and COVID-19. We collected data from 174 centres in 31 countries on all patients affected by COVID-19 and TB between 1 March 2020 and 30 September 2022. Patients were followed-up until cure, death or end of cohort time. All patients had TB and COVID-19; for analysis purposes, deaths were attributed to TB, COVID-19 or both. Survival analysis was performed using Cox proportional risk-regression models, and the log-rank test was used to compare survival and mortality attributed to TB, COVID-19 or both. Overall, 788 patients with COVID-19 and TB (active or sequelae) were recruited from 31 countries, and 10.8% (n=85) died during the observation period. Survival was significantly lower among patients whose death was attributed to TB and COVID-19 versus those dying because of either TB or COVID-19 alone (p<0.001). Significant adjusted risk factors for TB mortality were higher age (hazard ratio (HR) 1.05, 95% CI 1.03-1.07), HIV infection (HR 2.29, 95% CI 1.02-5.16) and invasive ventilation (HR 4.28, 95% CI 2.34-7.83). For COVID-19 mortality, the adjusted risks were higher age (HR 1.03, 95% CI 1.02-1.04), male sex (HR 2.21, 95% CI 1.24-3.91), oxygen requirement (HR 7.93, 95% CI 3.44-18.26) and invasive ventilation (HR 2.19, 95% CI 1.36-3.53). In our global cohort, death was the outcome in >10% of patients with TB and COVID-19. A range of demographic and clinical predictors are associated with adverse outcomes

Tuberculosis and COVID-19 co-infection: description of the global cohort

Background Information on tuberculosis (TB) and coronavirus disease 2019 (COVID-19) is still limited. The aim of this study was to describe the features of the TB/COVID-19 co-infected individuals from a prospective, anonymised, multicountry register-based cohort with special focus on the determinants of mortality and other outcomes. Methods We enrolled all patients of any age with either active TB or previous TB and COVID-19. 172 centres from 34 countries provided individual data on 767 TB-COVID-19 co-infected patients, (>50% population-based). Results Of 767 patients, 553 (74.0%) out of 747 had TB before COVID-19 (including 234 out of 747 with previous TB), 71 (9.5%) out of 747 had COVID-19 first and 123 (16.5%) out of 747 had both diseases diagnosed within the same week (n=35 (4.6%) on the same day). 85 (11.08%) out of 767 patients died (41 (14.2%) out of 289 in Europe and 44 (9.2%) out of 478 outside Europe; p=0.03): 42 (49.4%) from COVID-19, 31 (36.5%) from COVID-19 and TB, one (1.2%) from TB and 11 from other causes. In the univariate analysis on mortality the following variables reached statistical significance: age, male gender, having more than one comorbidity, diabetes mellitus, cardiovascular disease, chronic respiratory disease, chronic renal disease, presence of key symptoms, invasive ventilation and hospitalisation due to COVID-19. The final multivariable logistic regression model included age, male gender and invasive ventilation as independent contributors to mortality. Conclusion The data suggest that TB and COVID-19 are a “cursed duet” and need immediate attention. TB should be considered a risk factor for severe COVID disease and patients with TB should be prioritised for COVID-19 preventative efforts, including vaccination