150 research outputs found

    Experimental validation of opto-thermo-elastic modeling in OOFELIE Multiphysics

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    The objective of this work is to demonstrate the correlation between a simple laboratory test bench case and the predictions of the Oofelie MultiPhysics software in order to deduce modelling guidelines and improvements. For that purpose two optical systems have been analysed. The first one is a spherical lens fixed in an aluminium barrel, which is the simplest structure found in an optomechanical system. In this study, material characteristics are assumed to be well known: BK7 and aluminium have been retained. Temperature variations between 0 and +60°C from ambient have been applied to the samples. The second system is a YAG laser bar heated by means of a dedicated oven. For the two test benches thermo-elastic distortions have been measured using a Fizeau interferometer. This sensor measures wavefront error in the range of 20 nm to 1 μm without physical contact with the optomechanical system. For the YAG bar birefringence and polarization measurements have also been performed using a polarimetric bench. The tests results have been compared to the predictions obtained by Oofelie MultiPhysics which is a multiphysics toolkit treating coupled problems of optics, mechanics, thermal physics, electricity, electromagnetism, acoustics and hydrodynamics. From this comparison modelling guidelines have been issued with the aim of improving the accuracy of computed thermo-elastic distortions and their impact on the optical performances

    It starts at home? Climate policies targeting household consumption and behavioral decisions are key to low-carbon futures

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    Through their consumption behavior, households are responsible for 72% of global greenhouse gas emissions. Thus, they are key actors in reaching the 1.5 °C goal under the Paris Agreement. However, the possible contribution and position of households in climate policies is neither well understood, nor do households receive sufficiently high priority in current climate policy strategies. This paper investigates how behavioral change can achieve a substantial reduction in greenhouse gas emissions in European high-income countries. It uses theoretical thinking and some core results from the HOPE research project, which investigated household preferences for reducing emissions in four European cities in France, Germany, Norway and Sweden. The paper makes five major points: First, car and plane mobility, meat and dairy consumption, as well as heating are the most dominant components of household footprints. Second, household living situations (demographics, size of home) greatly influence the household potential to reduce their footprint, even more than country or city location. Third, household decisions can be sequential and temporally dynamic, shifting through different phases such as childhood, adulthood, and illness. Fourth, short term voluntary efforts will not be sufficient by themselves to reach the drastic reductions needed to achieve the 1.5 °C goal; instead, households need a regulatory framework supporting their behavioral changes. Fifth, there is a mismatch between the roles and responsibilities conveyed by current climate policies and household perceptions of responsibility. We then conclude with further recommendations for research and policy

    Time to treatment with bridging intravenous alteplase before endovascular treatment:subanalysis of the randomized controlled SWIFT-DIRECT trial.

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    BACKGROUND We hypothesized that treatment delays might be an effect modifier regarding risks and benefits of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT). METHODS We used the dataset of the SWIFT-DIRECT trial, which randomized 408 patients to IVT+MT or MT alone. Potential interactions between assignment to IVT+MT and expected time from onset-to-needle (OTN) as well as expected time from door-to-needle (DTN) were included in regression models. The primary outcome was functional independence (modified Rankin Scale (mRS) 0-2) at 3 months. Secondary outcomes included mRS shift, mortality, recanalization rates, and (symptomatic) intracranial hemorrhage at 24 hours. RESULTS We included 408 patients (IVT+MT 207, MT 201, median age 72 years (IQR 64-81), 209 (51.2%) female). The expected median OTN and DTN were 142 min and 54 min in the IVT+MT group and 129 min and 51 min in the MT alone group. Overall, there was no significant interaction between OTN and bridging IVT assignment regarding either the functional (adjusted OR (aOR) 0.76, 95% CI 0.45 to 1.30) and safety outcomes or the recanalization rates. Analysis of in-hospital delays showed no significant interaction between DTN and bridging IVT assignment regarding the dichotomized functional outcome (aOR 0.48, 95% CI 0.14 to 1.62), but the shift and mortality analyses suggested a greater benefit of IVT when in-hospital delays were short. CONCLUSIONS We found no evidence that the effect of bridging IVT on functional independence is modified by overall or in-hospital treatment delays. Considering its low power, this subgroup analysis could have missed a clinically important effect, and exploratory analysis of secondary clinical outcomes indicated a potentially favorable effect of IVT with shorter in-hospital delays. Heterogeneity of the IVT effect size before MT should be further analyzed in individual patient meta-analysis of comparable trials. TRIAL REGISTRATION NUMBER URL: https://www. CLINICALTRIALS gov ; Unique identifier: NCT03192332

    AGuIX® from bench to bedside-Transfer of an ultrasmall theranostic gadolinium-based nanoparticle to clinical medicine

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    International audienceAGuIX® are sub-5 nm nanoparticles made of a polysiloxane matrix and gadolinium chelates. This nanoparticle has been recently accepted in clinical trials in association with radiotherapy. This review will summarize the principal preclinical results that have led to first in man administration. No evidence of toxicity has been observed during regulatory toxicity tests on two animal species (rodents and monkeys). Biodistributions on different animal models have shown passive uptake in tumours due to enhanced permeability and retention effect combined with renal elimination of the nanoparticles after intravenous administration. High radiosensitizing effect has been observed with different types of irradiations in vitro and in vivo on a large number of cancer types (brain, lung, melanoma, head and neck…). The review concludes with the second generation of AGuIX nanoparticles and the first preliminary results on human

    Innovation et développement dans les systèmes agricoles et alimentaires

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    L’innovation est souvent présentée comme l’un des principaux leviers pour promouvoir un développement plus durable et plus inclusif. Dans les domaines de l’agriculture et de l’alimentation, l’innovation est marquée par des spécificités liées à sa relation à la nature, mais aussi à la grande diversité d’acteurs concernés, depuis les agriculteurs jusqu’aux consommateurs, en passant par les services de recherche et de développement. L’innovation émerge des interactions entre ces acteurs, qui mobilisent des ressources et produisent des connaissances dans des dispositifs collaboratifs, afin de générer des changements. Elle recouvre des domaines aussi variés que les pratiques de production, l’organisation des marchés, ou les pratiques alimentaires. L’innovation est reliée aux grands enjeux de développement : innovation agro-écologique, innovation sociale, innovation territoriale, etc. Cet ouvrage porte un regard sur l’innovation dans les systèmes agricoles et alimentaires. Il met un accent particulier sur l’accompagnement de l’innovation, en interrogeant les méthodes et les organisations, et sur l’évaluation de l’innovation au regard de différents critères. Il s’appuie sur des réflexions portées par différentes disciplines scientifiques, sur des travaux de terrain conduits tant en France que dans de nombreux pays du Sud, et enfin sur les expériences acquises en accompagnant des acteurs qui innovent. Il combine des synthèses sur l’innovation et des études de cas emblématiques pour illustrer les propos. L’ouvrage est destiné aux enseignants, professionnels, étudiants et chercheurs

    Prospective functional analysis of trapeziectomy combined with intermetacarpal tendon stabilisation in trapeziometacarpal arthritis.

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    We conducted a prospective study to evaluate the functional status of patients surgically treated by trapeziectomy with intermetacarpal tendon stabilisation. Pain relief, the height of the trapezial cavity, hand impairment, and manual ability were measured in a group of 18 patients at a mean of 2.3 years after surgery. Complete relief of pain was achieved in 89% of our patients. The height of the trapezial cavity was significantly reduced. Hand strength and digital dexterity were not impaired after the operation. Manual ability was significantly improved by the trapeziectomy as demonstrated by the median VAS values of 53.5 before and 95.5 after surgery. The ABILHAND questionnaire revealed that most of the patients were satisfied with the functional results of the trapeziectomy. Based on our findings in this prospective study, it appears that trapeziectomy with intermetacarpal tendon stabilisation relieved pain in almost 90% of patients suffering from trapeziometacarpal osteoarthritis, at no functional cost

    Simuler et appréhender les modes de vie bas carbone des ménages : le cas du programme de recherche HOPE

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    International audienceÀ la suite de la COP21, le travail introspectif sur les modes de vie des ménages et leurs émissions de gaz à effet de serre a été accéléré. Dans le cadre du projet européen HOPE, des ménages de la région aixoise ont été approchés afin d’évaluer leur empreinte carbone et les incidences monétaires et sanitaires de choix d’actions vers un mode de vie bas carbone. Libre à eux de choisir l’ensemble d’actions leur correspondant le mieux, en piochant dans diverses catégories, du logement à la mobilité. Reposant sur un recrutement délicat des ménages, en considérant les exigences d’un protocole d’enquête lourd et ambitieux, le projet visait à étudier les choix d’actions et mieux comprendre les raisons derrière ces choix. Les premiers résultats montrent une diversité de profils qui se reflète dans la diversité des choix d’actions, mais aussi des différences de choix selon l’absence de contraintes ou la présence d’un objectif chiffré et forcé (ici 50 % de réduction des émissions). Des entretiens complémentaires laissent apparaître certains éléments de compréhension sur les leviers et les obstacles comme la perception de barrières structurelles pour se projeter vers les actions les plus porteuses de potentiel de réduction d’émissions
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