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Radionuclides analysis is a key point for nuclear waste management and nuclear material control. Several steps of sample modification have to be carried out before measurements in order to avoid any interferences and improve measurement precision. However those different steps are long, irradiant and difficult to achieve in gloveboxes. Moreover they produce liquid and solid waste. The goal of the study is to offer a new alternative to the use of solid phase extraction column for radionuclides separation in hard nitric acid medium. The system will decrease the amount of nuclear waste due to the analysis and automatize the different steps of the analysis. A plastic device made of COC containing a micro solid phase extraction column is first designed. Stationary phase is a poly(AMA-co-EDMA) monolith synthetized in situ. Its structure is adjustable and its functionalization versatile with a high resistance to nitric acid medium. Exchange capacity is 150 mg/g of monolith for TBP and TBP/CMPO column and up to 280 mg/g of monolith in case of DAAP. Exchange coefficients are determined for U(VI), Th(IV), Eu(III) and Nd(III) for 3 different extractants (and Pu(IV) in case of TBP column). Monolith synthesis is transferred in centrifugal device and hydrodynamic behavior studied. U,Th/Eu separation was finally carried out in both classic and centrifugal microsystem on TBP column., L’analyse des radionucléides est une nécessité pour la gestion des matières et déchets radioactifs liée à l’industrie nucléaire. Pour éviter les interférences et améliorer la précision des mesures, les étapes de traitement de l’échantillon et de séparations restent aujourd’hui incontournables. Elles sont cependant longues, irradiantes, difficiles à mettre en œuvre en boite à gants et produisent un volume de déchets liquides et solides significatif. L’objectif de cette thèse est de proposer une alternative innovante à l’utilisation des colonnes d’extraction sur phase solide dans les protocoles de séparation des radionucléides en milieu nitrique concentré permettant de réduire ces déchets en fin de cycle analytique et d’automatiser ces étapes. Un premier microsystème jetable en plastique (COC) intégrant une micro-colonne séparative de chromatographie d’extraction a été conçu. La phase stationnaire est un monolithe poly(AMA-co-EDMA) synthétisé par photopolymérisation in situ à structure ajustable, fonctionnalisable à façon, résistant au milieu nitrique concentré. Les capacités d’échange obtenues sont de l’ordre de 150 mgU/g de monolithe pour le TBP et le mélange TBP/CMPO et 280 mgU/g de monolithe pour le DAAP. Les valeurs des coefficients de partage des monolithes imprégnés ont été déterminées pour U(VI), Th(IV), Eu(III) et Nd(III) pour les 3 extractants (ainsi que pour Pu(IV) dans le cas de monolithes imprégnés par le TBP). La synthèse du monolithe a été transférée en microsystème centrifuge et après étude hydrodynamique, la séparation U,Th/Eu en milieu nitrique a été réalisée sur colonne imprégnée TBP en microsystème classique puis transférée en microsystème centrifuge.

Today the cosmetic market is one of the most popular in the world. French people use many these products everyday as for examples, creams or shampoos. In order to protect the cosmetic products, the manufacturers introduced during these last year additives or conservative agents in cosmetic products to increase the shelf life or avoid a microbial contamination after a direct contact with the skin of consumers. However, recent years have also revealed that the consumer mindsets evolve and now, they would like cosmetics more natural, without addition of additives. In this context, it was interesting to work on the cosmetics protection by other ways. Firstly, we think immediately to the protection by use of packaging. The objective is to modify the current packaging to bring an antimicrobial activity and protect the cosmetics. This work presents different technologies of fabrication and modification of polymers to get an antimicrobial activity. For this, two techniques were studied. A first technology has consisted to develop antimicrobial coating at low temperature. This way has demonstrated possibilities of creation by photo-polymerization under UV radiations. Initially, the antimicrobial agents were introduced in liquid monomers before the polymerization and the fabrication of polymer networks. The final coatings were finally destiny to be added on specific areas of packaging, generally in contact with the consumers and prevent all risks of microbial contaminations from the products. The second technology has studied a way of polymer fabrication more industrial at high temperature. The technique has consisted to create antimicrobial pellets by extrusion with introductions of different natures of additives. The obtain pellets were injected at the end to fabricate certain pieces of the final packaging. This work has allowed the realization of a large range of antimicrobial materials. All the studied solutions have been used to fabricate prototype packaging in collaboration with partner companies of the project. All these prototypes will be tested by antimicrobial tests in real conditions of uses. If these tests prove successful, it will be possible to envisage an industrialization step, Le marché de la cosmétique est l’un des marché les plus porteur actuellement dans le monde. La population française utilise énormément ces produits pour son hygiène quotidienne. Ce sont les shampoings ou autre crème de soins. Pour protéger ces produits, depuis maintenant de nombreuses années, les fabricants ajoutent des agents conservateurs pour augmenter la durée de conservation, ou encore éviter certaines contaminations microbiennes après les contacts avec la peau. Ces dernières années ont également vu les mentalités des consommateurs évoluer et actuellement, ces derniers souhaiteraient des produits cosmétiques le plus naturel possible, sans ajouts de conservateurs. Dans ce contexte, il semble intéressant de travailler sur la protection de ces produits par d’autres moyens. En premier lieu, nous vient immédiatement à l’esprit, la protection par l’emballage. L’idée est de modifier les emballages actuels pour leur conférer des activités antimicrobiennes et ainsi les rendre protecteurs. L’étude présentée s’intéresse à certaines possibilités de mises en oeuvre et modifications de polymères pour apporter une activité antimicrobienne. Deux voies de fabrications ont été étudiées dans cette thèse. Une première a consisté en la réalisation de revêtements antimicrobiens et protecteurs à basse température. Cette technique a montré la possibilité de créer des couches antimicrobiennes par photo-polymérisation à partir de monomères méthacrylates renfermant les agents antimicrobiens. C’est cette couche finale qui va venir s’ajouter à certaines zones spécifiques des emballages finaux pour assurer la protection antimicrobienne du contenu.La seconde voie d’action a étudié une fabrication plus industrielle à haute température. Cette technologie a permis de créer par extrusion des granulés antimicrobiens avec des introductions d’actifs de différentes natures. Ceux sont ces granulés qui sont par la suite injectés sous la forme d’emballages. Pour cette voie d’action, l’idée n’est plus de protéger l’emballage via une couche antimicrobienne, mais de substituer certaines pièces de l’emballage constituées de polymères naturellement antimicrobiens. Ces travaux ont permis la réalisation d’une large gamme de matériaux antimicrobiens. Les différentes solutions étudiées ont également permis de réaliser des prototypes d’emballages, ceci en collaboration avec certaines entreprises partenaires du projet. Tous ces prototypes seront prochainement testés en conditions réelles d’utilisations, c’est-à-dire par des essais de mises en contact avec le consommateur d’un système complet, à savoir le produit cosmétique conditionné dans des emballages protecteurs. Ces tests devront permettre de vérifier si les solutions proposées pourraient aboutir à une adaptation sur une chaine industrielle pour une utilisation à grande échelle

Today the cosmetic market is one of the most popular in the world. French people use many these products everyday as for examples, creams or shampoos. In order to protect the cosmetic products, the manufacturers introduced during these last year additives or conservative agents in cosmetic products to increase the shelf life or avoid a microbial contamination after a direct contact with the skin of consumers. However, recent years have also revealed that the consumer mindsets evolve and now, they would like cosmetics more natural, without addition of additives. In this context, it was interesting to work on the cosmetics protection by other ways. Firstly, we think immediately to the protection by use of packaging. The objective is to modify the current packaging to bring an antimicrobial activity and protect the cosmetics. This work presents different technologies of fabrication and modification of polymers to get an antimicrobial activity. For this, two techniques were studied. A first technology has consisted to develop antimicrobial coating at low temperature. This way has demonstrated possibilities of creation by photo-polymerization under UV radiations. Initially, the antimicrobial agents were introduced in liquid monomers before the polymerization and the fabrication of polymer networks. The final coatings were finally destiny to be added on specific areas of packaging, generally in contact with the consumers and prevent all risks of microbial contaminations from the products. The second technology has studied a way of polymer fabrication more industrial at high temperature. The technique has consisted to create antimicrobial pellets by extrusion with introductions of different natures of additives. The obtain pellets were injected at the end to fabricate certain pieces of the final packaging. This work has allowed the realization of a large range of antimicrobial materials. All the studied solutions have been used to fabricate prototype packaging in collaboration with partner companies of the project. All these prototypes will be tested by antimicrobial tests in real conditions of uses. If these tests prove successful, it will be possible to envisage an industrialization step; Le marché de la cosmétique est l’un des marché les plus porteur actuellement dans le monde. La population française utilise énormément ces produits pour son hygiène quotidienne. Ce sont les shampoings ou autre crème de soins. Pour protéger ces produits, depuis maintenant de nombreuses années, les fabricants ajoutent des agents conservateurs pour augmenter la durée de conservation, ou encore éviter certaines contaminations microbiennes après les contacts avec la peau. Ces dernières années ont également vu les mentalités des consommateurs évoluer et actuellement, ces derniers souhaiteraient des produits cosmétiques le plus naturel possible, sans ajouts de conservateurs. Dans ce contexte, il semble intéressant de travailler sur la protection de ces produits par d’autres moyens. En premier lieu, nous vient immédiatement à l’esprit, la protection par l’emballage. L’idée est de modifier les emballages actuels pour leur conférer des activités antimicrobiennes et ainsi les rendre protecteurs. L’étude présentée s’intéresse à certaines possibilités de mises en oeuvre et modifications de polymères pour apporter une activité antimicrobienne. Deux voies de fabrications ont été étudiées dans cette thèse. Une première a consisté en la réalisation de revêtements antimicrobiens et protecteurs à basse température. Cette technique a montré la possibilité de créer des couches antimicrobiennes par photo-polymérisation à partir de monomères méthacrylates renfermant les agents antimicrobiens. C’est cette couche finale qui va venir s’ajouter à certaines zones spécifiques des emballages finaux pour assurer la protection antimicrobienne du contenu.La seconde voie d’action a étudié une fabrication plus industrielle à haute température. Cette technologie a permis de créer par extrusion des granulés antimicrobiens avec des introductions d’actifs de différentes natures. Ceux sont ces granulés qui sont par la suite injectés sous la forme d’emballages. Pour cette voie d’action, l’idée n’est plus de protéger l’emballage via une couche antimicrobienne, mais de substituer certaines pièces de l’emballage constituées de polymères naturellement antimicrobiens. Ces travaux ont permis la réalisation d’une large gamme de matériaux antimicrobiens. Les différentes solutions étudiées ont également permis de réaliser des prototypes d’emballages, ceci en collaboration avec certaines entreprises partenaires du projet. Tous ces prototypes seront prochainement testés en conditions réelles d’utilisations, c’est-à-dire par des essais de mises en contact avec le consommateur d’un système complet, à savoir le produit cosmétique conditionné dans des emballages protecteurs. Ces tests devront permettre de vérifier si les solutions proposées pourraient aboutir à une adaptation sur une chaine industrielle pour une utilisation à grande échelle

The evolution of laws on the use of biocide products makes it necessary to explore innovative methods of treating wood. In this context, the presented research focuses on a new alternative called a "non-biocide" treatment method involving the manufacture of solid wood-polymer composites obtained by impregnation of monomers and in situ polymerization caused by heating. Methyl methacrylate, four organic acrylates and three water-soluble acrylates, and furfuryl alcohol were tested. Composites manufactured were characterized: the polymer is present in the timber and may be resistant to leaching in water. Wood has been densified, while the composites are less hydrophilic and more dimensionally stable; the mechanical properties are improved. Treatment can induce high durability. Otherwise, an innovative method of impregnation was tested: axial impregnation. This process consists in the low-pressure impregnation of green wood ridges by treatment solution transiting via natural pathways of sap circulation. Ridges were impregnated with a copper solution, later determined to ensure good distribution of the product in the timber; this allowed the validation of the axial impregnation method for beech, hornbeam and birch. Finally, the composites were produced by axial impregnation of polymerizable aqueous solutions based on furfuryl alcohol; they are resistant to water leaching and less hydrophilic than the original wood. Their durability in the presence of wood-destroying fungi is improved, particularly in the case of the more concentrated treatment, L’évolution des lois relatives à l’utilisation de produits biocides impose d’étudier des méthodes innovantes de traitement du bois. Dans ce contexte, les travaux de recherche présentés s’intéressent à une nouvelle alternative dite « non-biocide » impliquant la fabrication de composites bois massif / polymères obtenus par imprégnation de monomères et polymérisation in situ provoquée par chauffage. Le méthacrylate de méthyle, quatre acrylates organiques et trois acrylates hydrosolubles, ainsi que l’alcool furfurylique ont été testés. Les composites fabriqués ont été caractérisés : le polymère est bien présent dans le bois et il peut être résistant au lessivage à l’eau. Le bois a été densifié, les composites sont alors moins hydrophiles et plus stables dimensionnellement ; les propriétés mécaniques sont améliorées. Le traitement peut induire une durabilité conférée élevée. Parallèlement, une méthode d’imprégnation innovante a été testée : l’imprégnation axiale. Ce procédé consiste en l’imprégnation basse pression de billons de bois vert par une solution de traitement transitant via les voies naturelles de circulation de la sève. Des billons ont été imprégnés avec une solution de cuivre, dosé ultérieurement afin de s’assurer de la bonne répartition du produit dans le bois ; cela a permis la validation du procédé d’imprégnation axiale pour le hêtre, le charme et le bouleau. Enfin, des composites ont été fabriqués par imprégnation axiale de solutions aqueuses polymérisables à base d’alcool furfurylique ; ils sont résistants à la lixiviation à l’eau et moins hydrophiles que le bois naturel. Leur durabilité face aux champignons lignivores est améliorée, particulièrement dans le cas du traitement le plus concentré

The chemical analysis of spent nuclear fuels is essential to design future nuclear fuelscycle and reprocessing methods but also for waste management. The analysis cycle consistsof several chemical separation steps which are time consuming and difficult to implement dueto confinement in glove boxes. It is required that the separation steps be automated and thatthe volume of radioactive waste generated be reduced. The design of automated, miniaturizedand disposable analytical platforms should fulfill these requirements.This project aims to provide an alternative to the first analytical step of the spent fuelsanalysis: the chromatographic separation of Uranium and Plutonium from the minor actinidesand fission products.The goal is to design a miniaturized platform showing analytical performancesequivalent to the current process, and to reduce both the exposure of workers throughautomation, and the volume of waste produced at the end of the analysis cycle. Thus, theseparation has been implemented on a disposable plastic microsystem (COC), specificallydesigned for automation: a lab on a Compact Disk or lab-on-CD.The developed prototype incorporates an anion-exchange monolithic micro-columnwhose in-situ synthesis as well as surface functionalization have been optimized specificallyfor the desired separation. The development of an adapted separation protocol was carried outusing a simulation tool modeling the elution of the various elements of interest. This tool isable to predict the column geometry (length and cross section) suited to obtain pure fractionsof Uranium and Plutonium as a function of the sample composition.Finally, the prototype is able to automatically carry out four separationssimultaneously reducing the number of manipulations, the analysis time and reducing thevolume of liquid waste by a factor of 1000., L'analyse chimique est indispensable à de nombreuses étapes de la mise au point et dusuivi des procédés de retraitement des combustibles nucléaires usés, de la gestion des déchetsnucléaires, ou encore de l’optimisation des combustibles du futur. Le cycle global d’analysecomprend généralement plusieurs étapes de séparations chimiques longues, manuelles etdifficiles à mettre en oeuvre en raison de leur confinement en boite à gants. Il apparaîtaujourd’hui nécessaire de proposer des solutions innovantes et viables dans le butd’automatiser ces étapes mais aussi de réduire le volume de déchets radioactifs en fin de cycleanalytique. Une solution est alors la conception de plateformes analytiques miniaturiséesautomatisées et jetables.L’objectif de cette thèse est de concevoir un système miniaturisé alternatif à lapremière étape actuelle d’analyse des combustibles usés séparant, par chromatographied’échange d’ions, l’Uranium et le Plutonium des autres éléments constituant l’échantillon. Cesystème doit permettre à la fois de conserver les performances analytiques du processusactuel, de réduire drastiquement l’exposition des expérimentateurs par l’automatisation, ainsique le volume de déchets produits en fin de cycle analytique. Ainsi, la séparation a étéimplantée sur un microsystème jetable en plastique (COC), au design spécialement adapté àl’automatisation : un lab-on-CD.Le prototype développé intègre une micro-colonne séparative d’échange d’anionsremplie d’un polymère monolithique dont la synthèse in-situ ainsi que la fonctionnalisation desurface ont été optimisées spécifiquement pour la séparation voulue. Le développement duprotocole de séparation adapté à ces micro-colonnes a été réalisé à l’aide d’un outil desimulation de l’élution des différents éléments d’intérêts. Cet outil permet de prévoir lagéométrie de la colonne (section et longueur) afin d’obtenir, en fonction de l’échantillon, desfractions de collecte de l’Uranium et du Plutonium pures.Finalement, le prototype actuel est capable de conduire simultanément 4 séparationsde façon automatisée et permet de réduire à la fois le nombre de manipulations, le tempsd’analyse mais aussi de diviser approximativement par 1000 le volume des déchets liquidesgénérés.

The chemical analysis of spent nuclear fuels is essential to design future nuclear fuelscycle and reprocessing methods but also for waste management. The analysis cycle consistsof several chemical separation steps which are time consuming and difficult to implement dueto confinement in glove boxes. It is required that the separation steps be automated and thatthe volume of radioactive waste generated be reduced. The design of automated, miniaturizedand disposable analytical platforms should fulfill these requirements.This project aims to provide an alternative to the first analytical step of the spent fuelsanalysis: the chromatographic separation of Uranium and Plutonium from the minor actinidesand fission products.The goal is to design a miniaturized platform showing analytical performancesequivalent to the current process, and to reduce both the exposure of workers throughautomation, and the volume of waste produced at the end of the analysis cycle. Thus, theseparation has been implemented on a disposable plastic microsystem (COC), specificallydesigned for automation: a lab on a Compact Disk or lab-on-CD.The developed prototype incorporates an anion-exchange monolithic micro-columnwhose in-situ synthesis as well as surface functionalization have been optimized specificallyfor the desired separation. The development of an adapted separation protocol was carried outusing a simulation tool modeling the elution of the various elements of interest. This tool isable to predict the column geometry (length and cross section) suited to obtain pure fractionsof Uranium and Plutonium as a function of the sample composition.Finally, the prototype is able to automatically carry out four separationssimultaneously reducing the number of manipulations, the analysis time and reducing thevolume of liquid waste by a factor of 1000.; L'analyse chimique est indispensable à de nombreuses étapes de la mise au point et dusuivi des procédés de retraitement des combustibles nucléaires usés, de la gestion des déchetsnucléaires, ou encore de l’optimisation des combustibles du futur. Le cycle global d’analysecomprend généralement plusieurs étapes de séparations chimiques longues, manuelles etdifficiles à mettre en oeuvre en raison de leur confinement en boite à gants. Il apparaîtaujourd’hui nécessaire de proposer des solutions innovantes et viables dans le butd’automatiser ces étapes mais aussi de réduire le volume de déchets radioactifs en fin de cycleanalytique. Une solution est alors la conception de plateformes analytiques miniaturiséesautomatisées et jetables.L’objectif de cette thèse est de concevoir un système miniaturisé alternatif à lapremière étape actuelle d’analyse des combustibles usés séparant, par chromatographied’échange d’ions, l’Uranium et le Plutonium des autres éléments constituant l’échantillon. Cesystème doit permettre à la fois de conserver les performances analytiques du processusactuel, de réduire drastiquement l’exposition des expérimentateurs par l’automatisation, ainsique le volume de déchets produits en fin de cycle analytique. Ainsi, la séparation a étéimplantée sur un microsystème jetable en plastique (COC), au design spécialement adapté àl’automatisation : un lab-on-CD.Le prototype développé intègre une micro-colonne séparative d’échange d’anionsremplie d’un polymère monolithique dont la synthèse in-situ ainsi que la fonctionnalisation desurface ont été optimisées spécifiquement pour la séparation voulue. Le développement duprotocole de séparation adapté à ces micro-colonnes a été réalisé à l’aide d’un outil desimulation de l’élution des différents éléments d’intérêts. Cet outil permet de prévoir lagéométrie de la colonne (section et longueur) afin d’obtenir, en fonction de l’échantillon, desfractions de collecte de l’Uranium et du Plutonium pures.Finalement, le prototype actuel est capable de conduire simultanément 4 séparationsde façon automatisée et permet de réduire à la fois le nombre de manipulations, le tempsd’analyse mais aussi de diviser approximativement par 1000 le volume des déchets liquidesgénérés.

Bonding is a major component of our therapeutic arsenal. We routinely bond attachments to enamel as well as to other surfaces including dentin, ceramic, acrylic, steel, amalgam, and gold, especially for adult patients. This procedure poses certain technical problems for which adapted and specific technical protocols can provide solutions.

The bonding procedures used in the Incognito system are now well known. Practitioners can work with either a protocol for Maximum-cure which utilizes a hydrophobic and chemo-polymerizable adhesive or an adhesive that is dual and hydrophilic, the association Nexus 3/Excite. Clinically the two protocols provide equivalent results in the quality of the bonding seal for attachments. They are simple to use, but in applying them practitioners must scrupulously follow the manufacturer's recommended stages of procedure.

The indirect bonding technique is pivotal for success in lingual orthodontics. There are different laboratory techniques available for indirect positioning and bonding of lingual brackets. Different approaches are presented and described to perform a clinical application.

Dental amalgam containing mercury has been condemned because of its toxicity and hence to be damaging of harmful to the general health. It must be clear that many sensational, confusing and misleading reports have been published. Today there is evidence that dental amalgam in the oral cavity does not harm anyone's health. For those who are condemning amalgam there an abundant number of alarming reports taking into consideration the biologic effects of resin composites: methacrylate allergy for dentists and dental technicians, the three-finger-syndrome due to contact with liquid resin, allergic reactions at the level of the airways and breathing problems caused by dust particles (esp. composite particles after polishing procedures) have been described. It can be concluded that dental amalgam is not more toxic than resin composite in light of both patients' and dental care providers' health. Recent investigations demonstrated higher than expected health risks with resin composites.

In Côte-d'Ivoire, banana leaf surfaces are attacked by Mycosphaerella fijiensis var. difformis, Cladosporium musae, and Deigthonielle torulosa. Control is based on fungicides recommanded for Mycosphaerella fijiensis. Fungicides belonging to triazoles and strobilurines types were added, at different concentrations, to the PDA medium, using this PDA medium containing no fungicide as the control. Mycelium disc and spores of Cladosporium musae, Mycosphaerella fijiensis and Deightoniella torulosa were put on the different media. Total inhibition of mycelium growth of every fungus on the PDA amended with propiconazole was observed. The fungicides used show different activities according to their concentration and their mode of action. The application of a fungicide should talke into account the pathogenic fungus involved in the leaf attacked. Against Mycosphaerella fijiensis var. difformis, the Ci(50) are different according to the concentrations (0.44 to 1.06 ppm). Correlations ranked from 0.71 to 0.91 are also different according to fungicide used. The Ci(50) of Cladosporium musae (0.10 to 2.44 ppm) and Deightoniella torulosa (0.26 to 0.52 ppm) are different and their correlations are respectively 0.78 to 0.99 and 0.86 to 0.95. An assessment of the sensitivity of parasitic fungi of banana can be made by mycelium growth measurement of fungi isolated from resistance zones.

A new type of composite materials, referred to as low viscosity composites, has been introduced onto the dental market. Little has been published yet concerning the biological and mechanical properties of these new materials, and the practitioner has to rely on the information, provided by the manufacturer. The low viscosity composites are hybrid composites, with a decreased amount of filler particles. This results in a lower viscosity, which makes these materials more appropriate in certain situations. Since the filler loading of these materials is decreased, one could expect inferior mechanical properties, compared to the conventional and hybrid composites. Therefore, the indications for using low viscosity composites are limited. In this article we propose to use low viscosity composites for the bonding of lingual retainers and implant-borne transpalatal arches. The explicit feature of flow, is very attractive for these indications, because a minimum of finishing is needed, when a low viscosity composite is used in these situations. Since there is no direct occlusal bite force put on the composite, the fact that the mechanical properties of a low viscosity composite could be inferior to those of a conventional composite, can be disregarded. A protocol for fixing lingual retainers and implant-borne transpalatal arches is proposed in the article, with other tips, concerning the fabrication of the retainers themselves.

The appearance of secondary cataract constitutes the most common complication of cataract surgery since the advent of phacoemulsification. Prevention is today one of the most crucial challenges of research in ophthalmology. We have developed a drug-sustained capsular ring releasing 5-fluorouracil (5-FU). This system aims to combine mechanical and pharmacological properties with the ability to interfere on the lens epithelial cellular processes of secondary cataract. This first article will report on the in vitro evaluation of this system.Development of a hydrogel that can serve as a mechanical support and as a release of an active agent requires a comparative trial of multiple hydrophobic products providing rigidity to the ring and of hydrophilic products providing the ability to release a drug. The choice of 5-FU as a non-proliferate agent was based on its well-known pharmacological properties and its wide use in ophthalmology. Evaluation comprised adjustment of the adequate copolymer, then of the loading phase, and finally assessment of 5-FU release. The mechanical characteristics and cytocompatibility of the ring were also assessed.The characteristics of drug release differed depending on the water content and resulting volume of the copolymer. The pharmaceutical and mechanical testing led to selecting the HPMA-MMA combination (75:25). However, a burst effect within the first 2 hours was observed in all cases. That limit was eliminated by creating a biodegradable surface coating of Poly Lactid-co-Glycolid (PLG 50:50) that could provide a positive barrier effect against migration and a controlled continual release of 0.25 microg/h extended to 9 days. Mechanical tests of tension, compression, and traction showed the crucial influence of the ring's hydration state. The cytocompatibility study showed no evidence of cellular toxicity.The synthesized copolymer is able to release a constant, regular and safe rate of 5-FU, higher than CI50 over a period of 9 days for a cell proliferation phase of 3-5 days. We adjusted the ring associating the mechanical properties and the ability to release 5-FU, allowing further evaluation on animal models, the subject of the second part of this report.

The actual restorative dentistry need to bond material which are under the constraint of saliva likely, as all liquid, to enter inside the product with time and to modify its characteristics. In this study, we compare the behaviour of five materials opposite water absorption, in vitro, until one year: two composite resins (Tetric et Pertac II), two ceromer (ceromer (Tetric ceram et Tetric flow) and one compomer (Hytac(r)). Each pastille weight is expressed in percentage of initial weight. All materials loose weight in the first hours except Tetric ceram which stay stable. At 48 h, all materials except Pertac II get back their initial weight. At long-term, all the materials are stable with a profit of 1% for Hytac, 0.5% for Tetric, Tetric ceram et Tetric flow and a loss of à 0.3% for Pertac II. As a result of this study, we understand why the clinical used of Hytac must be done following strict conditions.

Many chemical products are known to induce depigmentation. This phenomenon was never reported with methacrylates which are components of acrylic resine.A female patient with artificial nails developed contact dermatitis. Localized depigmentation at the site of positive patch tests to methacrylates derivatives was observed.The chemical substance could have a direct influence either by its toxic effect or by the induced inflammatory reaction.

This article gives the results of contact allergic reactions to cosmetics seen between 1985 and 1990 (462 patients investigated) and between 1991 and 1996 (486 patients investigated). Perfume components remain the most frequently occurring allergens in cosmetics. They are followed by preservative agents, a class within which important shifts have occurred over time (e.g. as with the isothiazolinone mixture). Excipients and certainly emulsifiers (e.g. cocamidopropylbetaine) are potentially not only irritants but also allergens. Among the "active" or category-specific ingredients, oxidative hair dyes, based on paraphenylenediamine and derivatives, and nail care products, based on (meth)acrylates are particularly apt to cause professional dermatoses. Finally, the share of sunscreens as cosmetic allergens remains limited, which may well be because a contact or photocontactallergy is often not recognized since the differential diagnosis with a primary sun intolerance is not always obvious.

This study attempts to measure the adhesive resistance between VitreBond and P-50 composite resin when the VitreBond surface is submitted to grinding and to the application of Scotchprep. The results indicate that this adhesion is superior to the cohesive resistance of VitreBond independently from grinding and from the application of Scotchprep.

IgE mediated type 1 hypersensitivity induces an immediate phase, during the minutes that follow contact with the allergen and is very often associated with a late phase that occurs during the hours that follow contact. The late phase of asthma induced by an IgE--dependent mechanism is linked with a cellular activation (lymphocytes, eosinophils) and release of different mediators (Paf Acether, LTB4, ECFA, MBP, EcP) from those of the immediate phase. Corticosteroids are well known as inhibitors of the late phase. Like cromoglycate, AZELASTINE inhibits both the immediate and late phases.

Acrylates and methacrylates are industrial chemicals with insufficiently known irritating and allergic effects. After considering simples monoacrylates and monomethacrylates, this paper deals with the n-ethyleneglycol acrylates and methacrylates and some polyol polyacrylates and polymethacrylates. All of the diacrylates tested are irritants for humans at 3 p. 100 in olive oil but there is no irritation at 0,1 p. 100. Monomethacrylate and dimethacrylate are not irritants at 3 p. 100 in olive oil. Studies with animals confirm that diacrylates are more irritating than dimethacrylates and the Magnusson and Kligman method shows that the substances induce delayed hypersensitivity. Cross reactions were observed in homogeneous series (diacrylates or dimethacrylates) but not between series. These results are in good agreement with clinical observations. The irritating power of 5 polyacrylates and polymethacrylates of other polyols were tested in animals. For some of them, clinical observations indicate an allergic potential.

Acrylates and methacrylates are industrial chemicals with insufficiently known irritating and allergenic effects. In this paper, the simple monoacrylates and monomethacrylates are considered. Methyl acrylate is an irritant, giving a reaction in 10 out of 30 patients, when tested at 20 p. 100 in olive oil. It is also an allergen (2 out of 22 cases). Because of its irritating properties, the concentration of 2 p. 100 is proposed for allergeric investigations. Methyl methacrylate, at 20 p. 100 in olive oil, is not an irritant for humans, although we have observed a sensitization rate of about 15 p. 100 with an undiluted product. In animal studies (technic of Kligman and Magnusson), 10 p. 100 of the subjects reacted to a working concentration of 1 p. 100 in petrolatum (allergenicity degree II). A risk of sensitization due to test repetition exists, about 9 p. 100 and 15 p. 100 for methyl acrylate (20 p. 100) and undiluted methyl methacrylate, respectively. For the latter, sensitization appears around the 16 th-18th day and may be preceeded by an irritation (1 out of 3 cases). Allyl acrylate and allyl methacrylate are irritants which should be studied at a concentration of about 0,1 p. 100. A 5 p. 100 concentration in olive oil seems appropriate for studying allergies to the following monoacrylates and monomethacrylates: acrylamide and acrylonitrile, n-butyl, cyclohexyl, ethyl, ethyl-2-hexyl, ethoxy-2-ethyl, phenyl acrylates, cyclohexyl dodecyl, ethyl-2-hexyl, ethoxy-2-ethyl, methyl methacrylates.

Four embedding media were compared: paraffin, the mixing "paraplast-piccolyte", Technovit 7100, and JB 4. Each material embedding technic is described. Comparison criteria are: easiness in the technic and method, cutting and trimming qualities, staining, anatomy connections conservation. Results are compacted in a diagram and illustrated by microphotographs. Methacrylate resins, and particularly JB 4, gave us best results.

The authors describe a method for isolation of Toxoplasma gondii antigenic membrane components. Technical work is described into four points: 1) specific labelling of membrane proteins was realised by DD125ISA; 2) methacrylate microspheres were bound to unbroken toxoplasma membranes by the mean of an indirect technic with antibody molecules (double sandwich); these microspheres were used to modify the membrane density; 3) toxoplasmas bound to microspheres were broken by sonication; 4) microspheres fixed to membrane components were isolated by isopycnic ultracentrifugation on continuous sucrose gradient.

An experimental study has been made to explore the possibility of using plaster or surgical cement as a vehicle for the diffusion of local chemotherapeutic agents in osteosarcoma. In vitro, leeching out of methotrexate from plaster or acrylic cement occurred with a peak during the first few hours followed by a decreasing curve lasting for an average of two weeks. In dogs suffering from a spontaneous osteosarcoma, the loss of substance produced by excision was filled with cement to which methotrexate had been added extemporaneously. This method of administration produced a general diffusion of methotrexate whose blood levels were measured for three to five days. In laboratory rats into which osteosarcomata had been grafted, tablets of plaster containing antimitotic drug were implanted into the tumour, which was left in situ. This made it possible to show that the local chemotherapy was having a true effect, particularly when the antimitotic used was cisplatinum. In patients who had acrylic cement containing methotrexate inserted during operation, local diffusion resulted in very high concentrations, evidenced by the concentration found in fluid obtained from suction drains during the early days after operation.