BMJ Open

INTRODUCTION: Sarcomas are rare tumours of connective tissue. The exact overall incidence of sarcomas is unknown due to diagnostic difficulties and the various histological subtypes (over 80 subtypes). However, the apparent increasing incidence of sarcomas suggests environmental causes such as pesticides. Except for some specific factors (ie, ionising radiation, vinyl chloride, dioxin and genetic predispositions) the scientific knowledge on the aetiology of sarcomas is sparse and inconsistent. France is a particularly appropriate country to set up a study investigating the causes of sarcoma occurrence due to the French organisation in treatment and care of sarcoma patients, which is highly structured and revolved around national expert networks. The main objective of the ETIOlogy of SARcomas (ETIOSARC) project is to study the role of lifestyle, environmental and occupational factors in the occurrence of sarcomas among adults from a multicentric population-based case-control study. METHODS AND ANALYSIS: Cases will be all incident patients (older than 18 years) prospectively identified in 15 districts of France covered by a general population-based cancer registry and/or a reference centre in sarcoma's patient care over a 3-year period with an inclusion start date ranging from February 2019 to January 2020 and histologically confirmed by a second review of the diagnosis. Two controls will be individually matched by sex, age (5 years group) and districts of residence and randomly selected from electoral rolls. A standardised questionnaire will be administered by a trained interviewer in order to gather information about occupational and residential history, demographic and socioeconomic characteristics and lifestyle factors. At the end of the interview, a saliva sample will be systematically proposed. This study will permit to validate or identify already suspected risk factors for sarcomas such as phenoxyherbicides, chlorophenol and to generate new hypothesis to increase our understanding about the genetic and environmental contributions in the carcinogenicity process. ETHICS AND DISSEMINATION: The present study is promoted by the French National Institute of Health and Medical Research (identification number C17-03). This study received National French Ethic committee (CPP Sud Mediterrannee I) approval (identification number 18-31) and French Data Protection Authority (CNIL) approval (identification number 918171). Results of this study will be published in international peer-reviewed journals. Technical appendix, statistical code and dataset will be available in the Dryad repository when collection data are completed. TRIAL REGISTRATION NUMBER: NCT03670927

Attributable risk in men in two French case-control studies on mesothelioma and asbestos

International audiencePleural mesothelioma is a primary tumor of the pleura that is mainly due to asbestos exposure. To study the relationship between mesothelioma and occupational asbestos exposure in France, two case-control studies (A and B) were conducted. A substantial difference in the attributable risk in the population (AR) was observed among men: 44.5% (95% CI: [32.6-56.4]) in study A and 83.2% (95% CI: [76.8-89.6]) in study B. As different exposure assessment expert methods were used, the main objective of this work was to re-estimate the AR men in two case-control studies according to a common standardized exposure assessment by using a Job Exposure Matrix (JEM) and to assess the role of subjects' selection. The initial observed AR difference was maintained: 36.3% (95% CI: [24.3-50.3]) in study A and 69.7% (95% CI: [51.7-83.2]) in study B. Further investigations highlighted the potential selection bias introduced in both studies, especially among controls. The AR could be underestimated in study A and overestimated in study B. After weighting subjects according to distribution of socio-economic status in the general population for controls and according to distribution of socio-economic status of cases registered by the French National Mesothelioma Surveillance Program, re-estimated AR values were 52.4% in study A and 70.2% in study B. These results provide additional information to describe the relationship between pleural mesothelioma and occupational asbestos exposure, but also confirm the importance of subjects' recruitment in case control studies, particularly control selection

Développements récents de l'étude en temps réel par diffraction des rayons X couplée à une thermographie infrarouge : application au suivi de la réaction MASHS dans les systèmes FeAl, et MoSi2

La formation au cours d'une réaction de combustion autoentretenue et mécaniquement activée (MASHS) d'intermétalliques nanométrique, tels que les composés FeAl et MoSi2, a pu être observée in-situ et en temps réel en couplant la diffraction des rayons X, produit par rayonnement synchrotron, et une thermographie infrarouge. La mise en oeuvre d'une telle expérience est indispensable en raison de la vitesse importante (10 mm/s) de propagation du front de combustion. Des développements récents réalisés au niveau des systèmes de détections permettent d'obtenir des temps d'acquisition très courts (quelques dizaines de millisecondes) et de révéler des étapes intermédiaires au cours de la transformation. De plus, ces expériences apportent une information importante sur le rôle de l'activation mécanique dans les procédés SHS classiquesThe mechanical Activation Self-propagating High-temperature Synthesis (MASHS) processing is a new way to produce nanocrystalline iron aluminide or molybdenum disilicide compounds. This kind of reaction has been investigated in situ using the Time Resolved X-Ray Diffraction (TRXDR), with an X-ray synchrotron beam, coupled to an infrared thermography to follow in resolved time structure transformation and temperature evolution. With short acquisition times, it has been possible to observe several steps before obtaining compound and to reveal the mechanical activation effect versus a classical SHS process

Contactless investigation on laser-heated oxides by synchrotron radiation

International audienc

Characterisation of uranium vacancies in hyper stoichiometric uranium dioxide

An experimental method, based on measurements of the expansion of a single crystal as a function of the p(O-2) was used to determine the concentration of uranium vacancies in hyperstoichiometric Uranium dioxide. The results are consistent with the concentration of electrical carriers measured in the same conditions, they are also in qualitative agreement with a theoretical modelling proposed in the literature. However, an improved interpretation would require to take into account the clusters of oxygen interstitials and vacancies

Contactless investigation on laser-heated oxides by synchrotron radiation

Aerodynamic levitation associated with $\rm CO_2$ laser heating was used to carefully characterize a series of rare-earth and others refractory oxides in the solid and the liquid state. The differences and the similarities between the structure on both sides of the liquid-crystalline solid phase transition are discussed. The temperature dependence of the structural parameters has been studied by performing, for the first time, in situ combined XAS and XRD experiments up to $\rm 2800\ {}^\circ C$