Influence of the Microstructural Texture of Cast Superalloys on their High-Temperature Oxidation Behaviour

International audienceThe high-temperature oxidation behaviours of Ni base and Co base cast superalloys were studied to determine the effect of different grain sizes and different surface dendritic orientations. These microstructural characteristics were obtained by varying solidification rate and cutting orientation with regard to the external surface. Thermogravimetry tests were run at 1000 and 1100°C and parabolic oxidation constants were considered. It appears that oxidation is faster for fine microstructures than for coarser ones for Ni or Co alloys including tungsten in their chemical composition, while it is the contrary when W is not present. When the sample surface is mainly parallel to the dendritic network, the oxidation rate is greater than for a surface perpendicular to dendrites, for the studied Ni alloy. The same phenomenon is observed for the studied Co base alloy at 1100°C but the order is inverted at 1000°C. These different behaviours can be explained by the grain boundary densities and orientations obtained on surface, since they can influence the diffusion of species involved in the oxidation phenomena. It is also possible that the characteristics of the chromia scale, such as grain size and general quality, depend on the microstructural texture of the alloy

Effect of Revascularization on Intramuscular Vascular Endothelial Growth Factor Levels in Peripheral Arterial Disease

Vascular endothelial growth factor (VEGF) is a potent driver of angiogenesis, which may help to relieve ischemia in peripheral arterial disease (PAD). We aimed to investigate the role of intramuscular VEGF in ischemic and non-ischemic skeletal muscle in PAD patients before and after surgical or endovascular revascularization and different stages of PAD. Biopsies of the gastrocnemius and vastus muscles from twenty PAD patients with stenosis or occlusion of the superficial femoral artery were obtained both during revascularization and 8 weeks postoperatively. The gastrocnemius muscle was considered ischemic, while vastus muscle biopsies served as intraindividual controls. The levels of vascular endothelial growth factor in muscle lysates were then determined by ELISA. Preoperative VEGF levels were significantly higher in ischemic muscles compared to the controls (98.07 ± 61.96 pg/mL vs. 55.50 ± 27.33 pg/mL, p = 0.004). Postoperative values decreased significantly (p = 0.010) to 54.83 ± 49.60 pg/mL in gastrocnemius biopsies. No significant change was observed in vastus muscle biopsies, with mean postoperative VEGF values found at 54.16 ± 40.66 pg/mL. Since all patients still had indications for revascularization, impairment of angiogenesis mechanisms can be assumed. More research about angiogenesis in PAD is needed with the ultimate goal to improve conservative treatment

Predicting the Lay Preventive Strategies in Response to Avian Influenza from Perceptions of the Threat

Background: The identification of patterns of behaviors that lay people would engage in to protect themselves from the risk of infection in the case of avian influenza outbreak, as well as the lay perceptions of the threat that underlie these risk reduction strategies. Methodology/Principal Findings: A population-based survey (N = 1003) was conducted in 2008 to understand and describe how the French public might respond to a possible outbreak. Factor analyses highlighted three main categories of risk reduction strategies consisting of food quality assurance, food avoidance, and animal avoidance. In combination with the fear of contracting avian influenza, mental representations associated with the manifestation and/or transmission of the disease were found to significantly and systematically shape the behavioral responses to the perceived threat. Conclusions/Significance: This survey provides insight into the nature and predictors of the protective patterns that might be expected from the general public during a novel domestic outbreak of avian influenza

Determinants of Non-Vaccination against Pandemic 2009 H1N1 Influenza in Pregnant Women: A Prospective Cohort Study

International audienceBACKGROUND: In October 2009, the French government organized a national-wide, free of charge vaccination campaign against pandemic H1N1 influenza virus, especially targeting pregnant women, a high risk group for severe illness. The study objective was to evaluate pandemic flu vaccine uptake and factors associated with non-vaccination in a population of pregnant women. METHODOLOGY/PRINCIPAL FINDINGS: In a prospective cohort conducted in 3 maternity hospitals in Paris, 882 pregnant women were randomly included between October 12, 2009 and February 3, 2010, with the aim to study characteristics of pandemic influenza during pregnancy. At inclusion, socio-demographic, medical, obstetrical factors and those associated with a higher risk of flu exposition and disease-spreading were systematically collected. Pandemic flu vaccine uptake was checked until delivery. 555 (62.9%) women did not get vaccinated. Determinants associated with non-vaccination in a multivariate logistic regression were: geographic origin (Sub-Saharan African origin, adjusted Odd Ratio aOR = 5.4[2.3-12.7], North African origin, aOR = 2.5[1.3-4.7] and Asian origin, aOR = 2.1[1.7-2.6] compared to French and European origin) and socio-professional categories (farmers, craftsmen and tradesmen, aOR = 2.3[2.0-2.6], intermediate professionals, aOR = 1.3[1.0-1.6], employees and manual workers, aOR = 2.5[1.4-4.4] compared to managers and intellectual professionals). The probability of not receiving pandemic flu vaccine was lower among women vaccinated against seasonal flu in the previous 5 years (aOR = 0.6[0.4-0.8]) and among those who stopped smoking before or early during pregnancy (aOR = 0.6[0.4-0.8]). Number of children less than 18 years old living at home, work in contact with children or in healthcare area, or professional contact with the public, were not associated with a higher vaccine uptake. CONCLUSIONS/SIGNIFICANCE: In this cohort of pregnant women, vaccine coverage against pandemic 2009 A/H1N1 flu was low, particularly in immigrant women and those having a low socio-economic status. To improve its effectiveness, future vaccination campaign for pregnant women should be more specifically tailored for these populations

Social sciences research in neglected tropical diseases 2: A bibliographic analysis

The official published version of the article can be found at the link below.Background There are strong arguments for social science and interdisciplinary research in the neglected tropical diseases. These diseases represent a rich and dynamic interplay between vector, host, and pathogen which occurs within social, physical and biological contexts. The overwhelming sense, however, is that neglected tropical diseases research is a biomedical endeavour largely excluding the social sciences. The purpose of this review is to provide a baseline for discussing the quantum and nature of the science that is being conducted, and the extent to which the social sciences are a part of that. Methods A bibliographic analysis was conducted of neglected tropical diseases related research papers published over the past 10 years in biomedical and social sciences. The analysis had textual and bibliometric facets, and focussed on chikungunya, dengue, visceral leishmaniasis, and onchocerciasis. Results There is substantial variation in the number of publications associated with each disease. The proportion of the research that is social science based appears remarkably consistent (<4%). A textual analysis, however, reveals a degree of misclassification by the abstracting service where a surprising proportion of the "social sciences" research was pure clinical research. Much of the social sciences research also tends to be "hand maiden" research focused on the implementation of biomedical solutions. Conclusion There is little evidence that scientists pay any attention to the complex social, cultural, biological, and environmental dynamic involved in human pathogenesis. There is little investigator driven social science and a poor presence of interdisciplinary science. The research needs more sophisticated funders and priority setters who are not beguiled by uncritical biomedical promises

AVIS de l'ANSES relatif à " l'évaluation du rapport bénéfice risque des pratiques de lutte anti-vectorielle habituellement mises en oeuvre pour lutter contre la dengue, dans le contexte actuel de confinement global "

Dans le contexte de la gestion de crise liée à l'épidémie de Covid-19 en France, l'Anses a été saisie en urgence le 14 avril 2020 par la Direction Générale de la Santé pour réaliser l'expertise suivante : " Évaluation du rapport bénéfice-risque des pratiques de lutte anti-vectorielle habituellement mises en oeuvre pour lutter contre la dengue, dans le contexte actuel de confinement global "

Avoidance behaviors and negative psychological responses in the general population in the initial stage of the H1N1 pandemic in Hong Kong

<p>Abstract</p> <p>Background</p> <p>During the SARS pandemic in Hong Kong, panic and worry were prevalent in the community and the general public avoided staying in public areas. Such avoidance behaviors could greatly impact daily routines of the community and the local economy. This study examined the prevalence of the avoidance behaviors (i.e. avoiding going out, visiting crowded places and visiting hospitals) and negative psychological responses of the general population in Hong Kong at the initial stage of the H1N1 epidemic.</p> <p>Methods</p> <p>A sample of 999 respondents was recruited in a population-based survey. Using random telephone numbers, respondents completed a structured questionnaire by telephone interviews at the 'pre-community spread phase' of the H1N1 epidemic in Hong Kong.</p> <p>Results</p> <p>This study found that 76.5% of the respondents currently avoided going out or visiting crowded places or hospitals, whilst 15% felt much worried about contracting H1N1 and 6% showed signs of emotional distress. Females, older respondents, those having unconfirmed beliefs about modes of transmissions, and those feeling worried and emotionally distressed due to H1N1 outbreak were more likely than others to adopt some avoidance behaviors. Those who perceived high severity and susceptibility of getting H1N1 and doubted the adequacy of governmental preparedness were more likely than others to feel emotionally distressed.</p> <p>Conclusions</p> <p>The prevalence of avoidance behaviors was very high. Cognitions, including unconfirmed beliefs about modes of transmission, perceived severity and susceptibility were associated with some of the avoidance behaviors and emotional distress variables. Public health education should therefore provide clear messages to rectify relevant perceptions.</p

Monitoring the level of government trust, risk perception and intention of the general public to adopt protective measures during the influenza A (H1N1) pandemic in the Netherlands

<p>Abstract</p> <p>Background</p> <p>During the course of an influenza pandemic, governments know relatively little about the possibly changing influence of government trust, risk perception, and receipt of information on the public's intention to adopt protective measures or on the acceptance of vaccination. This study aims to identify and describe possible changes in and factors associated with public's intentions during the 2009 influenza A (H1N1) pandemic in the Netherlands.</p> <p>Methods</p> <p>Sixteen cross-sectional telephone surveys were conducted (N = 8060) between April - November 2009. From these repeated measurements three consecutive periods were categorized based on crucial events during the influenza A (H1N1) pandemic. Time trends in government trust, risk perception, intention to adopt protective measures, and the acceptance of vaccination were analysed. Factors associated with an intention to adopt protective measures or vaccination were identified.</p> <p>Results</p> <p>Trust in the government was high, but decreased over time. During the course of the pandemic, perceived vulnerability and an intention to adopt protective measures increased. Trust and vulnerability were associated with an intention to adopt protective measures in general only during period one. Higher levels of intention to receive vaccination were associated with increased government trust, fear/worry, and perceived vulnerability. In periods two and three receipt of information was positively associated with an intention to adopt protective measures. Most respondents wanted to receive information about infection prevention from municipal health services, health care providers, and the media.</p> <p>Conclusions</p> <p>The Dutch response to the H1N1 virus was relatively muted. Higher levels of trust in the government, fear/worry, and perceived vulnerability were all positively related to an intention to accept vaccination. Only fear/worry was positively linked to an intention to adopt protective measures during the entire pandemic. Risk and crisis communication by the government should focus on building and maintaining trust by providing information about preventing infection in close collaboration with municipal health services, health care providers, and the media.</p

Perceived risk, anxiety, and behavioural responses of the general public during the early phase of the Influenza A (H1N1) pandemic in the Netherlands: Results of three consecutive online surveys

Background: Research into risk perception and behavioural responses in case of emerging infectious diseases is still relatively new. The aim of this study was to examine perceptions and behaviours of the general public during the early phase of the Influenza A (H1N1) pandemic in the Netherlands. Methods. Two cross-sectional and one follow-up online survey (survey 1, 30 April-4 May; survey 2, 15-19 June; survey 3, 11-20 August 2009). Adults aged 18 years and above participating in a representative Internet panel were invited (survey 1, n = 456; survey 2, n = 478; follow-up survey 3, n = 934). Main outcome measures were 1) time trends in risk perception, feelings of anxiety, and behavioural responses (survey 1-3) and 2) factors associated with taking preventive measures and strong intention to comply with government-advised preventive measures in the future (survey 3). Results. Between May and August 2009, the level of knowledge regarding Influenza A (H1N1) increased, while perceived severity of the new flu, perceived self-efficacy, and intention to comply with preventive measures decreased. The perceived reliability of information from the government decreased from May to August (62% versus 45%). Feelings of anxiety decreased from May to June, and remained stable afterwards. From June to August 2009, perceived vulnerability increased and more respondents took preventive measures (14% versus 38%). Taking preventive measures was associated with no children in the household, high anxiety, high self-efficacy, more agreement with statements on avoidance, and paying much attention to media information regarding Influenza A (H1N1). Having a strong intention to comply with government-advised preventive measures in the future was associated with higher age, high perceived severity, high anxiety, high perceived efficacy of measures, high self-efficacy, and finding governmental information to be reliable. Conclusions. Decreasing tren