The effects of graded levels of calorie restriction : I. impact of short term calorie and protein restriction on body composition in the C57BL/6 mouse

We acknowledge the BSU staff for their invaluable help with caring for the animals and anonymous referees for their inputs. The work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) of the UK (Standard grant BB/G009953/1 and China partnering award BB/JO20028/1). The authors declare no competing interests.Peer reviewedPublisher PD

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Phénoménologie et calculs numériques de la propagation d'une flamme prémélangée hydrogène-air pauvre dans un milieu turbulent

Ce travail de doctorat a pour objet l'étude de la propagation d'une zone de combustion dans un milieu turbulent constitué d'un mélange pauvre hydrogène-air. Le but est de préciser les caractéristiques d'une telle propagation ainsi que les modèles de combustion et de turbulence nécessaires à l'étude numérique de celle-ci, compte-tenu des spécificités introduites par la nature des mélanges combustibles et les caractéristiques du confinement dans lequel s'effectue la propagation. Le champ d'application d'une telle étude est la prévention des accidents et la maîtrise du risque hydrogène dans les enceintes de réacteurs nucléaires.This thesis concerns the study of flame propagation in a turbulent flow of lean hydrogen-air mixtures. The aim is to precise the characteristics of propagation as well as combustion and turbulence models able to take into account the pecularities of these mixtures. This research work is related to the prevention of firehazards associated with accidental release of hydrogen within the reactor of a nuclear power plant. In a first part, the scales (the flame velocity and thickness) associated with the laminar flame propagation in hydrogen-air mixtures are studied. A specific attention is devoted to the intrinsic instability properties of such flames. Then, the turbulence scales potentially present within a reactor are estimated in order to allow for the determination of the regimes of combustion that might be present within the reactor and among which the flamelet regime appears to be conceivable. In a second part, starting with the analysis of the propagation properties of a mean reaction zone calculated with a flamelet model, we show that, with an adequate tuning of the parameter appearing in the mean reaction rate expression, it is possible to predict numerically the turbulent flame speeds available with the litterature.POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Adoption of a multicomponent intervention to improve HPV vaccination in France: a mixed methods study

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Psychological antecedents of HPV vaccination among French adolescents and their parents

International audienceDespite proven efficacy against cervical cancer, the HPV vaccination coverage in France – since 2019 recommended to 11- to 14-year-old girls and boys – is low with 32.7 % of 16-year-old girls fully vaccinated (2020). Based on an integrative model to understand vaccination behaviour, we aimed at understanding which psychological antecedents explain HPV vaccine acceptance among adolescents of both genders and their parents, and how the parental and child attitudes influence each other within families.This study includes the baseline data of a multi-component, multi-centre interventional research project in 64 middle schools in France (PrevHPV). Using an internet-based questionnaire and a confidential linkage code, the data are collected during December 2021-March 2022 among approximately 15 000 12- to 15-year-old adolescents (in classroom) and their parents (at home).In addition to socio-demographic data, the questionnaire includes information on: - Antecedents of vaccine hesitancy (VH) with both knowledge and attitude items based on a 7C-model;- Personal attitude and perception of attitudes in the participants’ environment (friends, family) about vaccination in general and vaccination against HPV in particular;- Vaccination status against HPV, intention to get vaccinated (based on the Prochaska et Di Clemente behaviour-change theory).Data collection is still ongoing and will end in March 2022. Results expected in June 2022 are as follows: - Attitudes mediate between knowledge and vaccine intention in adolescents and their parents;- Adolescents’ vaccine antecedents and intention are positively correlated with parental antecedents and intention

Effectiveness of a School- and Primary Care–Based HPV Vaccination Intervention

International audienceImportance - The human papillomavirus (HPV) vaccine is safe and effective, yet vaccination coverage remains below public health objectives in many countries. Objective - To examine the effectiveness of a 3-component intervention on HPV vaccination coverage among adolescents aged 11 to 14 years 2 months after the intervention ended, each component being applied alone or in combination. Design, Setting, and Participants - A cluster randomized trial with incomplete factorial design (PrevHPV) was conducted between July 1, 2021, and April 30, 2022, in French municipalities receiving 0, 1, 2, or 3 components of the intervention. Randomization was stratified by school district and municipalities’ socioeconomic level. Analyses were carried out on 11- to 14-year-old adolescents living in all participating municipalities, regardless of what had been implemented. Intervention - The PrevHPV intervention had 3 components: (1) educating and motivating 11- to 14-year-old adolescents in middle schools, along with their parents; (2) training general practitioners (GPs) on up-to-date HPV information and motivational interviewing techniques; and (3) free HPV vaccination at school. Main Outcomes and Measures - The primary outcome was HPV vaccination coverage (≥1 dose) 2 months after the intervention ended among 11- to 14-year-old adolescents living in participating municipalities, based on the French national reimbursement database and data collected during the trial in groups randomized to implement at-school vaccination. Results - A total of 91 municipalities comprising 30 739 adolescents aged 11 to 14 years (15 876 boys and 14 863 girls) were included and analyzed. Half the municipalities were in the 2 lowest socioeconomic quintiles and access to GPs was poor in more than two-thirds of the municipalities. Thirty-eight of 61 schools (62.3%) implemented actions and 26 of 45 municipalities (57.8%) had at least 1 trained GP. The median vaccination coverage increased by 4.0 percentage points (IQR, 2.0-7.3 percentage points) to 14.2 percentage points (IQR, 9.1-17.3 percentage points) at 2 months. At-school vaccination significantly increased vaccination coverage (5.50 percentage points [95% CI, 3.13-7.88 percentage points]) while no effect was observed for adolescents’ education and motivation (−0.08 percentage points [95% CI, −2.54 to 2.39 percentage points]) and GPs’ training (−1.46 percentage points [95% CI, −3.44 to 0.53 percentage points]). Subgroup analyses found a significant interaction between at-school vaccination and access to GPs, with a higher effect when access was poor (8.62 percentage points [95% CI, 5.37-11.86 percentage points] vs 2.13 percentage points [95% CI, −1.25 to 5.50 percentage points]; P = .007 for interaction). Conclusions and Relevance - In this cluster randomized trial, within the context of the late COVID-19 pandemic period and limited school and GP participation, at-school HPV vaccination significantly increased vaccination coverage. The trial did not show a significant effect for training GPs and education and motivation, although it may be observed after more time has elapsed after the intervention

Psychometric validation of a 7C-model of antecedents of vaccine acceptance among healthcare workers, parents and adolescents in France

Support for vaccine decision-making requires a tailored approach taking into account psychological antecedents of vaccine acceptance. We aimed at validating an extended 7C-model of antecedents in three different target population groups (healthcare workers [n = 3870], parents [n = 2002] and adolescents [n = 7118]) and two vaccinations (COVID-19, HPV) in France. We performed a secondary analysis of questionnaires collecting sociodemographic characteristics, attitudes and knowledge on vaccination, and vaccine status and intention. We used standard psychometric techniques to validate a first and second order latent structure, and evaluated their association with vaccine intentionality in three levels (refusal, indecision, acceptance). In all populations, the 7C-model yielded a very good model fit (CFI and TLI > 0.90) and, in comparison with non-nested and nested 5C-models, significantly improved the model performance (Ω 2 , p < 0.05; Wald’s test, p < 0.05). The resulting vaccine readiness score was strongly associated with vaccine intentionality (acceptance vs. indecision: β HCW = 2.93, β Parents = 2.41, β Adolescents = 1.34; refusal vs. indecision: β HCW = − 1.68, β Parents = − 0.16, β Adolescents = − 0.89.). The addition of confidence in the system and social conformism among antecedents of vaccine acceptance allowed a finer understanding of the continuum moving from refusal to indecision and acceptance. To work with these antecedents in interventional research, appropriate questionnaire items should be developed for various vaccines and target populations

Effect of school-based HPV vaccine campaigns on inequalities in uptake in France: the PrevHPV trial

International audienc

Co‐development of a school‐based and primary care‐based multicomponent intervention to improve HPV vaccine coverage amongst French adolescents (the PrevHPV Study)

International audienceIntroduction: Despite various efforts to improve human papillomavirus (HPV) vaccine coverage in France, it has always been lower than in most other high-income countries. The health authorities launched in 2018 the national PrevHPV research programme to (1) co-develop with stakeholders and (2) evaluate the impact of a multicomponent complex intervention aimed at improving HPV vaccine coverage amongst French adolescents.Objective: To describe the development process of the PrevHPV intervention using the GUIDance for rEporting of intervention Development framework as a guide.Methods: To develop the intervention, we used findings from (1) published evidence on effective strategies to improve vaccination uptake and on theoretical frameworks of health behaviour change; (2) primary data on target populations' knowledge, beliefs, attitudes, preferences, behaviours and practices as well as the facilitators and barriers to HPV vaccination collected as part of the PrevHPV Programme and (3) the advice of working groups involving stakeholders in a participatory approach. We paid attention to developing an intervention that would maximise reach, adoption, implementation and maintenance in real-world contexts.Results: We co-developed three components: (1) adolescents' and parents' education and motivation using eHealth tools (web conferences, videos, and a serious video game) and participatory learning at school; (2) general practitioners' e-learning training on HPV using motivational interviewing techniques and provision of a decision aid tool and (3) easier access to vaccination through vaccination days organised on participating middle schools' premises to propose free of charge initiation of the HPV vaccination.Conclusion: We co-developed a multicomponent intervention that addresses a range of barriers and enablers of HPV vaccination. The next step is to build on the results of its evaluation to refine it before scaling it up if proven efficient. If so, it will add to the small number of multicomponent interventions aimed at improving HPV vaccination worldwide.Patient or Public Contribution: The public (adolescents, their parents, school staff and health professionals) participated in the needs assessment using a mixed methods approach. The public was also involved in the components' development process to generate ideas about potential activities/tools, critically revise the successive versions of the tools and provide advice about the intervention practicalities, feasibility and maintenance

How can we improve the acceptability of vaccination against Human Papillomavirus (HPV) in France? An original qualitative study with focus groups comprising parents and school staff, interviewed separately

International audienceBackground: It has been proven that vaccination is effective against Human Papillomavirus (HPV) infections, genital warts, and pre-cancerous and cancerous cervical lesions. Nevertheless, the HPV vaccine coverage of 37.4% in 2021 in France is one of the lowest in Europe. To explore and understand the reason why French population is so late compared to its neighbours, we carried out focus groups with mothers and with National Education school staff. We aimed to identify knowledge and perceptions of HPV in both study populations, as well as factors influencing HPV vaccination.Methods: Between January 2020 and March 2021, we performed a qualitative study using an inductive approach with a thematic content analysis (TCA). We conducted semi-structured focus groups with 29 people including 15 mothers of adolescents in middle schools and 14 school staff from the national education system.Results: Different factors influenced the decision-making process of parents and school staff: knowledge and perceptions of HPV and its vaccine, sources of information about HPV and vaccination. Mothers' discourses differed from those of school staff. They mentioned the importance of gynaecological monitoring and the negative image of pharmaceutical companies, and questioned internet as a reliable source of information. For their part, school staff mentioned cultural and/or religious affiliation, municipalities’ role to inform the population, and ethical dilemma or logistical challenges regarding HPV vaccination in schools.Conclusion: The results of these focus groups provided information on which elements may harm or help HPV vaccination. Identified perceptions, beliefs, knowledge, barriers, and facilitators will help us to build an intervention program focus on general practitioners (GP), school staff, parents, and adolescents