Chemical desorption and diffusive dust chemistry

In molecular clouds, gaseous species can accrete efficiently on the cold surfaces of dust grains. As for radical-radical reactions, the surface of the grains acts as a third body, and changes dramatically the efficiency of the reactions (i.e., H2 formation), or lowers considerably the barrier to formation (i.e., H2O synthesis) in comparison with gas phase reaction processes. These properties make dust grains efficient catalytic templates. However, the chemical role of dust grains depends on the diffusive properties of the reactive partners. Over the last years, we have developed experimental tools and methods to explore the chemistry occurring on cold (6-50K) surfaces. We have obtained some hints about the diffusivity of H on amorphous ice, and studied in detail the diffusion of O atoms. The latter species appears to have a hopping rate in the range 0.01-100 hops/sec. The diffusion rate of O atoms is dependent on the surface morphology and on the surface temperature. The diffusion law is compatible with a diffusion dominated by quantum tunnelling rather than classical thermal hopping. Using H, O, N atoms and, indirectly, OH and HCO radicals, we have begun to explore many chemical reactive networks. In this presentation, I will focus on the formation of H2O and CO2, and will propose many possible formation routes to obtain these chemical traps. The molecules formed on surfaces have a certain probability of desorbing upon their formation. This non-thermal desorption mechanism, or chemical desorption, has been proposed to explain why some molecules can be detected in the gas phase of those region where they were believed to be part of the icy mantles covering dust grains. We have shown that this process can be very efficient, but is very sensitive to the substrate and the surroundings of the reaction site, is dependent on the kind of molecule formed and its chemical pathway. In my presentation I will present how the surface coverage and the type of reaction can play a major role in the chemical desorption process. I will discuss of possible key parameters that rule this process

Pilot scale investigation of DBD-Plasma photocatalysis for industrial application in livestock building air: Elimination of chemical pollutants and odors

International audiencePhotocatalysis and Plasma are widely considered as efficient and eco-friendly methods for the air treatment at domestic and industrial scales. In fact, the respective application of titanium dioxide (TiO2) and Dielectric-Barrier-Discharge(DBD) drew increasing attention in the last decades for their, flexible, non-selective and high efficiencies for the mineralization and the degradation of large selection of molecules. Nevertheless, the application of these techniques in separate conditions might generate undesired by-products that might hinder their treatment efficiencies. In this study, the effect of combining photocatalysis and Dielectric-Barrier-Discharge (DBD)techniques was investigated for the treatment of livestock building air at laboratory and industrial scale.. of Experiments were conducted in separate (i.e., Photocatalysis or plasma) and combined (i.e., Photocatalysis and plasma) systems to assess the degradation efficiency of two molecules, namely (NH3) and Propionaldehyde (ProPA) under various operating conditions. Studies onducted on laboratory scale showed a interesting level of treatment when applying either photocatalysis or plasma, with degradation yields reaching 29 and 36% for NH3 and 37 and 42% for ProPA, respectively. These degradation efficiencies were further enhanced when combining the processes, thus reaching 72 and 83% for NH3and ProPA, respectively. Moreover, investigations conducted on the generation of ozone during photocatalysis / Plasma treatment showed a decrease in the O3 concentration when compared to separate Plasma treatment. The photocatalytic degradation of ozone under UV radiation and in presence of TiO2 led to Low concentrations of ozone were detected at joint processas a consequence ofits catalytic decomposition under UV-light into HO2°, OH°,O2°-radicals at high humid conditions. The synergetic effect during the pollutant degradation was explained by the association of discharge plasma, presence of O3, UV-light and TiO2..Additionally,The implementation of the photocatalytic-plasma discharge reactor was performed to treat livestock sector air effluent loaded with ammonia.The effect of airflow and relative himidity were assessed. Results showed a significant NH3 removal efficiency in real conditions where it varied between59 and 75% for a flowrate of 2 m2/h and a relative humidity of 100%. Additonnlay, chemical and olfactometric studies were conducted to assess the performance of cimined sytem with real efflluent of livestock building air

The neurodevelopmental and facial phenotype in individuals with a TRIP12 variant

Haploinsufficiency of TRIP12 causes a neurodevelopmental disorder characterized by intellectual disability associated with epilepsy, autism spectrum disorder and dysmorphic features, also named Clark-Baraitser syndrome. Only a limited number of cases have been reported to date. We aimed to further delineate the TRIP12-associated phenotype and objectify characteristic facial traits through GestaltMatcher image analysis based on deep-learning algorithms in order to establish a TRIP12 gestalt. 38 individuals between 3 and 66 years (F = 20, M = 18) - 1 previously published and 37 novel individuals - were recruited through an ERN ITHACA call for collaboration. 35 TRIP12 variants were identified, including frameshift (n = 15) and nonsense (n = 6) variants, as well as missense (n = 5) and splice (n = 3) variants, intragenic deletions (n = 4) and two multigene deletions disrupting TRIP12. Though variable in severity, global developmental delay was noted in all individuals, with language deficit most pronounced. About half showed autistic features and susceptibility to obesity seemed inherent to this disorder. A more severe expression was noted in individuals with a missense variant. Facial analysis showed a clear gestalt including deep-set eyes with narrow palpebral fissures and fullness of the upper eyelids, downturned corners of the mouth and large, often low-set ears with prominent earlobes. We report the largest cohort to date of individuals with TRIP12 variants, further delineating the associated phenotype and introducing a facial gestalt. These findings will improve future counseling and patient guidance

Type 1 Diabetes in People Hospitalized for COVID-19: New Insights From the CORONADO Study

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The association between macrovascular complications and intensive care admission, invasive mechanical ventilation, and mortality in people with diabetes hospitalized for coronavirus disease-2019 (COVID-19)

International audienceAbstract Background It is not clear whether pre-existing macrovascular complications (ischemic heart disease, stroke or peripheral artery disease) are associated with health outcomes in people with diabetes mellitus hospitalized for COVID-19. Methods We conducted cohort studies of adults with pre-existing diabetes hospitalized for COVID-19 infection in the UK, France, and Spain during the early phase of the pandemic (between March 2020—October 2020). Logistic regression models adjusted for demographic factors and other comorbidities were used to determine associations between previous macrovascular disease and relevant clinical outcomes: mortality, intensive care unit (ICU) admission and use of invasive mechanical ventilation (IMV) during the hospitalization. Output from individual logistic regression models for each cohort was combined in a meta-analysis. Results Complete data were available for 4,106 (60.4%) individuals. Of these, 1,652 (40.2%) had any prior macrovascular disease of whom 28.5% of patients died. Mortality was higher for people with compared to those without previous macrovascular disease (37.7% vs 22.4%). The combined crude odds ratio (OR) for previous macrovascular disease and mortality for all four cohorts was 2.12 (95% CI 1.83–2.45 with an I 2 of 60%, reduced after adjustments for age, sex, type of diabetes, hypertension, microvascular disease, ethnicity, and BMI to adjusted OR 1.53 [95% CI 1.29–1.81]) for the three cohorts. Further analysis revealed that ischemic heart disease and cerebrovascular disease were the main contributors of adverse outcomes. However, proportions of people admitted to ICU (adjOR 0.48 [95% CI 0.31–0.75], I 2 60%) and the use of IMV during hospitalization (adjOR 0.52 [95% CI 0.40–0.68], I 2 37%) were significantly lower for people with previous macrovascular disease. Conclusions This large multinational study of people with diabetes mellitus hospitalized for COVID-19 demonstrates that previous macrovascular disease is associated with higher mortality and lower proportions admitted to ICU and treated with IMV during hospitalization suggesting selective admission criteria. Our findings highlight the importance correctly assess the prognosis and intensive monitoring in this high-risk group of patients and emphasize the need to design specific public health programs aimed to prevent SARS-CoV-2 infection in this subgroup