Free Radical Copolymerization of 2,2,2-Trifluoroethyl a-Fluoroacrylate and tert-Butyl a-Trifluoromethylacrylate: Thermal and Optical Properties of the Copolymers

International audienceThe radical copolymerization of 2,2,2-trifluoroethyl a-fluoroacrylate (FATRIFE) with tert-butyl a-trifluoromethylacrylate (MAF-TBE) initiated by tertbutyl 2,2-dimethylperoxypropanoate was investigated in acetonitrile solution. A series of poly(FATRIFE-co-MAF-TBE) copolymers were synthesized with MAF-TBE compositions, determined by 19F NMR, ranging from 12 to 44 mol %. MAF-TBE incorporation was less than 50 mol % as this monomer underwent no radical homopolymerization. The obtained copolymers exhibited number-average molecular weights and polydispersity indexes ranging from 1.5 3 104 to 9.6 3 104 g/mol and from 1.5 to 3.1, respectively. The reactivity ratios were determined by the Kelen-Tu¨ dos method (rFATRIFE ¼ 1.71 6 0.01 and rMAF-TBE ¼ 0 at 74 8C) leading to random copolymers and alternating copolymers when the MAF-TBE molar ratio in copolymer is close to 50 mol %. Thermal and optical properties of the resulting polymers were examined. Glass transition temperatures of copolymers were varying from 89 to 108 8C. Modifying the compositions of these copolymers allowed a precise control over the refractive index measured at 633, 1320, and 1550 n

Synthèse et caractérisation de (co)polymères halogénés pour l optique linéaire (application à la réalisation d un guide d onde)

Les polymères halogénés constituent une classe de polymères particulièrement intéressante pour des applications en tant que guide d'onde en raison des propriétés remarquables qu'ils possèdent. Dans le cadre des travaux de cette thèse, nous nous sommes plus particulièrement intéressés à la synthèse et la caractérisation de (co)polymères acryliques halogénés, de type poly(alpha-fluoroacrylate)s, poly(alpha,beta-difluoroacrylate)s ainsi que poly(alpha-trifluorométhacrylate)s. De nouveaux monomères acryliques, l'acide alpha, beta-difluoroacrylique et l' alpha-fluoroacrylate d'hexachloroisopropyle, ont été synthétisés, puis leur polymèrisation a été étudiée. D'autre part, plusieurs séries de copolymères ont été synthétisées à partir d' alpha-fluoroacrylates, d' alpha-trifluorométhacrylates et d'un éther vinylique fluoré afin d'obtenir des matériaux possédant une haute Tg (> 110 C), une bonne stabilité thermique (Td > 300 C) et une large gamme d'indices de réfraction, compatibles avec l'application visée. Finalement, un guide d'onde en poly(alpha-fluoroacrylate de trichloroéthyle) a été réalisé et ses propriétés en termes d'atténuation optique et de mise en oeuvre ont été étudiées.There is a great potential for the use of polymeric materials for communication systems and considerable interest has been focused on polymer waveguides because of their fabrication process at low temperature, their tunable optical and mechanical properties, and mass production possibility. Among the polymeric materials developed as potential waveguides, fluorinated polymers are of particular interest because of their unique properties. This work reports the synthesis and the characterization of halogenated acrylic (co)polymers. New acrylic monomers, alpha, beta-difluoroacrylic acid and hexachloroisopropyl alpha-fluoroacrylate, have been synthesized and their polymerization has been studied. Several series of copolymers have been obtained from alpha-fluoroacrylates, alpha-trifluoromethacrylates and a fluorinated vinyl ether leading to materials with an high Tg (> 110 C), a good thermal stability (Td > 300 C) and a broad range of refractive indices, in agreement with the aimed application. Finally, a poly(2,2,2-trichloroethyl alpha-fluoroacrylate) waveguide has been realized and its properties in terms of optical absorption and process have been studied.LE MANS-BU Sciences (721812109) / SudocSudocFranceF

Free-radical copolymerization of 2,2,2-trifluoroethyl methacrylate and 2,2,2-trichloroethyl alpha-fluoroacrylate: Synthesis, kinetics of copolymerization and characterization

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Synthesis and characterization of poly(fluorinated vinyl ether-alt-tert-butyl alpha-trifluoromethacrylate) copolymers

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[Evolution of the satisfaction of subjects enrolled in clinical studies]

Within the context of a quality initiative for a clinical research unit, participants' opinions relative to participation conditions allows the identification and quantification of certain dysfunctions in the unit or more widely of the site. An initial satisfaction survey of users of the Grenoble Clinical Research Center showed that the management of volunteers by a staff dedicated to, and in an environment adapted to, clinical research protocols is associated with elevated participant satisfaction. Corrective action has been taken relative to points of dissatisfaction. We conducted a second participant survey from June 1st, 2004, to May 31st, 2005, to measure the impact of our corrective actions. Eighty five percent of the persons contacted responded, and 90.4% of completed questionnaires were valid. The global satisfaction level on a scale of ten was 8.53 +/- 1.16 in 2005 (n = 292) versus 8.61 +/- 1.16 in 2004 (n = 144) (Not Significant = NS). Scores for each dimension of care (comprising 1-6 questions each) were not statistically different between the two years. An improvement was noted for the frequency of physician visits, the communication of results, and the explication of aftercare. On the other hand, there was a moderate decline of the satisfaction score relative to concern for personal needs, the swiftness of check in at arrival and the unit's peace and quiet. Globally, the participation of a subject in clinical research in the context of a Clinical Research Center is associated with a high satisfaction score. Nevertheless, the practice of annual satisfaction surveys permits the sensitisation of staff to certain specifics points, and to observe the effect of corrective action. It serves as an important element in the context of a quality initiative

Plasma levels of high-density lipoprotein cholesterol are not associated with survival in pulmonary arterial hypertension.

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[Evolution of the satisfaction of subjects enrolled in clinical studies]

Within the context of a quality initiative for a clinical research unit, participants' opinions relative to participation conditions allows the identification and quantification of certain dysfunctions in the unit or more widely of the site. An initial satisfaction survey of users of the Grenoble Clinical Research Center showed that the management of volunteers by a staff dedicated to, and in an environment adapted to, clinical research protocols is associated with elevated participant satisfaction. Corrective action has been taken relative to points of dissatisfaction. We conducted a second participant survey from June 1st, 2004, to May 31st, 2005, to measure the impact of our corrective actions. Eighty five percent of the persons contacted responded, and 90.4% of completed questionnaires were valid. The global satisfaction level on a scale of ten was 8.53 +/- 1.16 in 2005 (n = 292) versus 8.61 +/- 1.16 in 2004 (n = 144) (Not Significant = NS). Scores for each dimension of care (comprising 1-6 questions each) were not statistically different between the two years. An improvement was noted for the frequency of physician visits, the communication of results, and the explication of aftercare. On the other hand, there was a moderate decline of the satisfaction score relative to concern for personal needs, the swiftness of check in at arrival and the unit's peace and quiet. Globally, the participation of a subject in clinical research in the context of a Clinical Research Center is associated with a high satisfaction score. Nevertheless, the practice of annual satisfaction surveys permits the sensitisation of staff to certain specifics points, and to observe the effect of corrective action. It serves as an important element in the context of a quality initiative

Évaluation de la satisfaction des participants à une recherche biomédicale

Objectif : Le centre d'investigation clinique (CIC) de Grenoble a mené une enquête de satisfaction auprès des personnes ayant participé à une étude de recherche biomédicale dans ses locaux. Matériels et méthodes : Un questionnaire a été envoyé à 198 sujets. Il comportait 24 items regroupés en 5 dimensions, sur lesquelles étaient calculés des scores moyens. Résultats : Le taux de participation de l'enquête était de 82,6 %. Au total, 94,4 % des sujets seraient d'accord pour participer à une nouvelle étude si nous les sollicitions, et 72,2 % étaient satisfaits ou très satisfaits de leur séjour, 24 % étant sans opinion. Le score moyen de satisfaction globale noté sur 10 était de 8,6 (intervalle de confiance [IC] à 95 % : 7,6–9,6). Conclusion : Cette enquête montre que la prise en charge des sujets par du personnel spécifique et dans un lieu adapté, dans le cadre d'un protocole de recherche clinique, est associée à une satisfaction élevée des volontaires participants. Cependant, des efforts restent à fournir en particulier en ce qui concerne la transmission des informations et résultats d'étude

Évolution de la satisfaction des usagers du CIC de Grenoble

Dans le cadre de la démarche qualité d'une unité de recherche clinique, l'avis des participants quant aux conditions de participation permet de soulever et quantifier certains dysfonctionnements de l'unité ou plus largement du site. Une première enquête de satisfaction des usagers du Centre d'Investigation Clinique (CIC) de Grenoble avait montré que la prise en charge des sujets par du personnel spécifique et dans un lieu adapté, dans le cadre de protocoles de recherche clinique, était associée à une satisfaction élevée des participants. Des mesures correctives avaient été mises en place concernant les points négatifs. Nous avons réalisé une seconde enquête pour les participants inclus entre le 1$^{\text{er}}$ juin 2004 et le 31 mai 2005, afin de mesurer l'impact des mesures mises en œuvre. Quatre-vingt cinq pour cent des personnes contactées ont répondu à notre enquête et 90,4 % de ces questionnaires étaient exploitables. Le score global, côté sur 10, était de 8,53 ±1,16 en 2005 (n = 292) versus 8,61 ± 1,16 en 2004 (n = 144) [Non Significatif = NS]. Les scores calculés pour les différentes dimensions de soin n'étaient pas non plus statistiquement différents entre les deux années. Une amélioration a été notée pour la fréquence des visites des médecins, la communication des résultats et l'explication du suivi médical. Par contre, une baisse modérée du score de satisfaction concernant le souci des besoins personnels, la rapidité de prise en charge à l'arrivée et le calme du service a été mise en évidence. Globalement, la participation d'un sujet à une recherche biomédicale dans le cadre d'un CIC est associée à un taux de satisfaction élevée. Cependant, la pratique d'enquêtes de satisfaction annuelles permet de sensibiliser le personnel sur certains points spécifiques et d'observer l'effet de la mise en œuvre de mesures correctrices. Elle se révèle un élément important dans le cadre d'une démarche qualité

[Satisfaction of subjects enrolled in clinical studies]

OBJECTIVE: The Grenoble clinical research centre carried out a prospective satisfaction survey of subjects taking part in clinical studies undertaken in its buildings. MATERIALS AND METHODS: A questionnaire adapted from Grenoble teaching hospital's inpatient satisfaction survey was sent to 198 subjects. It comprised 24 items pooled in categories on which were calculated average scores. The participation rate of the survey was 82.6%. On the whole, 94.4% of the questioned subjects would accept to take part in a new study if we requested them, and 72.2% were satisfied or very satisfied with their stay; 24% had no opinion. The mean overall satisfaction score was 8.6 (95% confidence interval: 7.6-9.6) out of 10. CONCLUSION: This investigation shows that the assumption of responsibility of the subjects by specific personnel and in an adapted place, within the framework of clinical protocol of research, is associated with a high satisfaction of the subjects. However, we still have to improve the transmission of the clinical study results to the patients