Un modèle de lubrification en régime mixte du laminage : Frottement et lubrification en mise en forme = A mixed lubrication model of the cold strip rolling process

Free access articleInternational audienceLe régime de lubrification mixte est le plus fréquemment rencontré en laminage à froid. Sa modélisation est le but de cet article. La lubrification, phénomène interfacial, est fortement couplée à la mécanique de l'opération de laminage. C'est pourquoi le modèle présenté assemble un modèle macroscopique de laminage (méthode des tranches élasto-plastique) et un modèle microscopique de lubrification en régime mixte, lui-même composé d'une équation de Reynolds entre surfaces rugueuses (formation du film lubrifiant) et d'une équation d'évolution de la rugosité, par conformation de la tôle au cylindre. Les principes du modèle sont présentés, comparés à ceux de la bibliographie, ses hypothèses et ses résultats sont discutés, et quelques applications sont évoquées = The mixed regime of lubrication is most frequently encountered in cold strip rolling processes. A model is presented hereafter. The lubrication at the interface is closely coupled with the mechanics of the rolling process. Therefore, the proposed model combines a macroscopic model of rolling (elastic-plastic slab method) with a microscopic mixed lubrication model, consisting of a Reynolds equation for rough surfaces (describing the formation of the lubricant film) and an equation for the evolution of roughness, describing the conformation of the strip surface to the roll. The bases of the model are presented and compared to models in the literature; its hypotheses and results are discussed, a few applications are given

Compréhension et modélisation du régime mixte : synthèse des avancées et perspectives d'applications industrielles : Frottement et lubrification en mise en forme = Understanding and modelling the mixed lubrication regime: summary of achievements and perspectives of industrial applications

Free access articleInternational audienceL'ensemble des travaux décrits précédemment, et résumés ici, a d'ores et déjà fait l'objet de mises en application diverses, qui sont décrites dans cette courte conclusion: explication d'observations sur sites de production, modèles de connaissance, nouvelles idées de formulation de lubrifiants, qui ne demandent qu'à être testées. Bien sûr, l'ensemble des besoins de connaissances et de nouveaux outils n'a pas été satisfait, et quelques pistes de travaux futurs sont dégagées = The works described previously, and summarized here, have already been applied under various forms, to be described hereafter: explanation of industrial observations, knowledge models, new ideas for lubricant formulation, which now have to be tested. Of course, not all the needs of industry have been fulfilled, so that perspectives for further research are highlighted

Nasopharyngeal microbiota profiling of pregnant women with SARS-CoV-2 infection.

We aimed to analyze the nasopharyngeal microbiota profles in pregnant women with and without SARS-CoV-2 infection, considered a vulnerable population during COVID-19 pandemic. Pregnant women were enrolled from a multicenter prospective population-based cohort during the frst SARS-CoV-2 wave in Spain (March-June 2020 in Barcelona, Spain) in which the status of SARSCoV-2 infection was determined by nasopharyngeal RT–PCR and antibodies in peripheral blood. Women were randomly selected for this cross-sectional study on microbiota. DNA was extracted from nasopharyngeal swab samples, and the V3-V4 region of the 16S rRNA of bacteria was amplifed using region-specifc primers. The diferential abundance of taxa was tested, and alpha/beta diversity was evaluated. Among 76 women, 38 were classifed as positive and 38 as negative for SARS-CoV-2 infection. All positive women were diagnosed by SARS-CoV-2 IgG and IgM/IgA antibodies, and 14 (37%) also had a positive RT–PCR. The overall composition of the nasopharyngeal microbiota difer in pregnant women with SARS-CoV-2 infection (positive SARS-CoV-2 antibodies), compared to those without the infection (negative SARS-CoV-2 antibodies) (p = 0.001), with a higher relative abundance of the Tenericutes and Bacteroidetes phyla and a higher abundance of the Prevotellaceae family. Infected women presented a diferent pattern of microbiota profling due to beta diversity and higher richness (observed ASV< 0.001) and evenness (Shannon index < 0.001) at alpha diversity. These changes were also present in women after acute infection, as revealed by negative RT–PCR but positive SARS-CoV-2 antibodies, suggesting a potential association between SARS-CoV-2 infection and long-lasting shift in the nasopharyngeal microbiota. No signifcant diferences were reported inmild vs. severe cases. This is the frst study on nasopharyngeal microbiota during pregnancy. Pregnant women with SARS-CoV-2 infection had a diferent nasopharyngeal microbiota profle compared to negative cases

Un probleme de deformation couplee: modelisation elastoplastique par elements finis du laminage a froid de bande mince

INIST T 76800 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Maternal Stress, Anxiety, Well-Being, and Sleep Quality in Pregnant Women throughout Gestation

This study was partially funded by the "LaCaixa" Foundation under grant agreements LCF/PR/GN14/10270005 and LCF/PR/GN18/10310003, the CEREBRA Foundation for the Brain Injured Child (Carmarthen, Wales, UK) and the Departament de Recerca i Universitats de la Generalitat de Catalunya 2021-SGR-01422. LB and FC have received funding from the Instituto de Salud Carlos III (ISCIII) through the projects CM21/00058 and INT21/00027 which are co-funded by the European Union. Funders played no role in the study's design, data collection, data analysis, data interpretation, or the writing of the manuscript.Background: Maternal stress, anxiety, well-being, and sleep quality during pregnancy have been described as influencing factors during pregnancy. Aim: We aimed to describe maternal stress, anxiety, well-being, and sleep quality in pregnant women throughout gestation and their related factors. Methods: A prospective study including pregnant women attending BCNatal, in Barcelona, Spain (n = 630). Maternal stress and anxiety were assessed by the Perceived Stress Scale (PSS) and State-Trait Anxiety Inventory (STAI)-validated questionnaires. Maternal well-being was assessed using the World Health Organization Well-Being Index Questionnaire (WHO-5), and sleep quality was assessed using the Pittsburgh Sleep Quality Index Questionnaire (PSQI). All questionnaires were obtained twice during the second and third trimester of pregnancy. A multivariate analysis was conducted to assess factors related to higher maternal stress and anxiety and worse well-being and sleep quality. Results: High levels of maternal stress were reported in 23.1% of participants at the end of pregnancy, with maternal age <40 years (OR 2.02; 95% CI 1.08-3.81, p = 0.03), non-white ethnicity (OR 2.09; 95% CI 1.19-4.02, p = 0.01), and non-university studies (OR 1.86; 95% CI 1.08-3.19, p = 0.02) being the parameters mostly associated with it. A total of 20.7% of women had high levels of anxiety in the third trimester and the presence of psychiatric disorders (OR 3.62; 95% CI 1.34-9.78, p = 0.01) and non-university studies (OR 1.70; 95% CI 1.11-2.59, p = 0.01) provided a significant contribution to high anxiety at multivariate analysis. Poor maternal well-being was observed in 26.5% of women and a significant contribution was provided by the presence of psychiatric disorders (OR 2.96; 95% CI 1.07-8.25, p = 0.04) and non-university studies (OR 1.74; 95% CI 1.10-2.74, p = 0.02). Finally, less sleep quality was observed at the end of pregnancy (p < 0.001), with 81.1% of women reporting poor sleep quality. Conclusion: Maternal stress and anxiety, compromised maternal well-being, and sleep quality disturbances are prevalent throughout pregnancy. Anxiety and compromised sleep quality may increase over gestation. The screening of these conditions at different stages of pregnancy and awareness of the associated risk factors can help to identify women at potential risk

Effects of a Mediterranean Diet Intervention on Maternal Stress, Well-Being, and Sleep Quality throughout Gestation-The IMPACT-BCN Trial

Stress and anxiety are frequent occurrences among pregnant women. We aimed to evaluate the effects of a Mediterranean diet intervention during pregnancy on maternal stress, well-being, and sleep quality throughout gestation. In a randomized clinical trial, 1221 high-risk pregnant women were randomly allocated into three groups at 19-23 weeks' gestation: a Mediterranean diet intervention, a Mindfulness-Based Stress Reduction program, or usual care. All women who provided self-reported life-style questionnaires to measure their anxiety (State Trait Anxiety Inventory (STAI), Perceived Stress Scale (PSS)), well-being (WHO Five Well Being Index (WHO-5)), and sleep quality (Pittsburgh sleep quality index (PSQI)) at enrollment and at the end of the intervention (34-36 weeks) were included. In a random subgroup of 106 women, the levels of cortisol and related metabolites were also measured. At the end of the intervention (34-36 weeks), participants in the Mediterranean diet group had significantly lower perceived stress and anxiety scores (PSS mean (SE) 15.9 (0.4) vs. 17.0 (0.4), p = 0.035; STAI-anxiety mean (SE) 13.6 (0.4) vs. 15.8 (0.5), p = 0.004) and better sleep quality (PSQI mean 7.0 ± 0.2 SE vs. 7.9 ± 0.2 SE, p = 0.001) compared to usual care. As compared to usual care, women in the Mediterranean diet group also had a more significant increase in their 24 h urinary cortisone/cortisol ratio during gestation (mean 1.7 ± SE 0.1 vs. 1.3 ± SE 0.1, p < 0.001). A Mediterranean diet intervention during pregnancy is associated with a significant reduction in maternal anxiety and stress, and improvements in sleep quality throughout gestation

Impact of the COVID-19 Pandemic on Maternal Well-Being during Pregnancy

The outbreak of a pandemic has negative psychological effects. We aimed to determine the impact of the SARS-CoV-2 pandemic during pregnancy and identify the risk factors for maternal well-being. A multicenter, prospective, population-based study was carried out that included women (n = 1320) who were pregnant during the SARS-CoV-2 pandemic in Barcelona (Spain) compared against a pre-pandemic cohort (n = 345). Maternal well-being was assessed using the validated World Health Organization Well-Being Index Questionnaire (WHO-5 Index). Pregnant women attended during the COVID-19 pandemic showed worst WHO-5 well-being scores (median (IQR) of 56 (36-72) for the pandemic cohort vs. 64 (52-76) for the pre-pandemic cohort p < 0.001), with 42.8% of women presenting a poor well-being score vs. 28% for the pre-pandemic cohort (p < 0.001). Presence of a previous psychiatric disorder (OR 7.1; 95% CI 2.6-19, p < 0.001), being in the third trimester of pregnancy (OR 1.7; 95% CI 1.5-2, p < 0.001), or requiring hospital admission for COVID-19 (OR 4.7; 95% CI 1.4-16.7, p = 0.014), significantly contributed to low maternal well-being during the COVID-19 pandemic (multivariate analysis). Being infected by SARS-CoV-2 was not associated with a lower well-being score. We conclude that, during the COVID-19 pandemic, there were higher rates of poor maternal well-being; the infection of SARS-CoV-2 itself did not worsen maternal well-being, but other factors as psychiatric disorders, being in the third trimester of pregnancy or hospital admission for COVID-19 disease did

Impact of the COVID-19 Pandemic on Maternal Well-Being during Pregnancy

Altres ajuts: KidsCorona Child and Mother COVID-19 OpenData; Biobank Initiative from Hospital Sant Joan de Déu (Stavros Niarchos Foundation, Santander Foundation and others); Fundació "LaCaixa"; Institut de Recerca Sant Pau; ISGlobal; AXA; Fundació Privada Daniel Bravo Andreu.The outbreak of a pandemic has negative psychological effects. We aimed to determine the impact of the SARS-CoV-2 pandemic during pregnancy and identify the risk factors for maternal well-being. A multicenter, prospective, population-based study was carried out that included women (n = 1320) who were pregnant during the SARS-CoV-2 pandemic in Barcelona (Spain) compared against a pre-pandemic cohort (n = 345). Maternal well-being was assessed using the validated World Health Organization Well-Being Index Questionnaire (WHO-5 Index). Pregnant women attended during the COVID-19 pandemic showed worst WHO-5 well-being scores (median (IQR) of 56 (36-72) for the pandemic cohort vs. 64 (52-76) for the pre-pandemic cohort p < 0.001), with 42.8% of women presenting a poor well-being score vs. 28% for the pre-pandemic cohort (p < 0.001). Presence of a previous psychiatric disorder (OR 7.1; 95% CI 2.6-19, p < 0.001), being in the third trimester of pregnancy (OR 1.7; 95% CI 1.5-2, p < 0.001), or requiring hospital admission for COVID-19 (OR 4.7; 95% CI 1.4-16.7, p = 0.014), significantly contributed to low maternal well-being during the COVID-19 pandemic (multivariate analysis). Being infected by SARS-CoV-2 was not associated with a lower well-being score. We conclude that, during the COVID-19 pandemic, there were higher rates of poor maternal well-being; the infection of SARS-CoV-2 itself did not worsen maternal well-being, but other factors as psychiatric disorders, being in the third trimester of pregnancy or hospital admission for COVID-19 disease did