Le programme international Argo a révolutionné l'observation globale des océans. Une flotte de plus de 3000 instruments sous-marins autonomes est en place, programmés pour fournir des mesures globales de profils de température et de salinité sur les 2000 premiers mètres de l'océan. Ces mesures sont assimilées dans des modèles océaniques conjointement aux observations satellitaires afin de décrire et prévoir l'océan. Dans cette thèse nous proposons une analyse permettant de caractériser les erreurs d'un modèle global océanique par comparaison aux données du réseau Argo. Ces erreurs sont décrites via leurs amplitudes, leurs variations régionales et temporelles ainsi que via les échelles spatiales associées. Une caractérisation des échelles spatiales à la fois pour la variabilité océanique et pour les erreurs modèles est, en particulier, menée permettant de relier la structure des erreurs modèles à celle du signal. Enfin, des techniques basées sur le contenu en information sont testées afin de pouvoir à terme mieux quantifier l'impact des observations Argo sur les systèmes d'assimilation de Mercator Océan. / The international Argo program has revolutionized the observation of the global ocean. An array of more than 3000 profiling floats is in place and provides global measurements of temperature and salinity on the first 2000 meters of the ocean. These measurements are assimilated into ocean models together with satellite observations to describe and forecast the ocean state. We propose here to characterize model errors using Argo observations. Model errors are described through their amplitude, geographical and temporal variations as well as their spatial scales. Spatial scales of both model errors and ocean signals are, in particular, estimated. This allows a comparison of model errors and ocean variability structure. Finally, techniques based on information content are tested in the longer run quantifying the impact of Argo observations in the Mercator Ocean data assimilation systems.

LIRA, Cleomar Ferreira Santos. A Implementação de unidades de conservação de proteção integral: o caso do parque ecológico da lagoa da Maraponga/Ceará Fortaleza . 2006. 108 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Pró-Reitoria de Pesquisa e Pós-Graduação, Mestrado em Desenvolvimento e Meio Ambiente - PRODEMA, Fortaleza-CE, 2006. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-04-28T13:55:19Z No. of bitstreams: 1 2006_dis_cfslira.pdf: 5436489 bytes, checksum: 1b73091e4eb3df7061d4043c4a2713bf (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-04-28T13:59:53Z (GMT) No. of bitstreams: 1 2006_dis_cfslira.pdf: 5436489 bytes, checksum: 1b73091e4eb3df7061d4043c4a2713bf (MD5) / Made available in DSpace on 2016-04-28T13:59:53Z (GMT). No. of bitstreams: 1 2006_dis_cfslira.pdf: 5436489 bytes, checksum: 1b73091e4eb3df7061d4043c4a2713bf (MD5) Previous issue date: 2006 / A conservação in situ promovida através da criação de unidades de conservação tem sido um dos meios mais utilizados para a consecução de uma política de proteção da biodiversidade. A implementação dessas unidades, entretanto, afigura-se como um desafio constante do Poder Público, principalmente em relação às unidades de conservação de proteção integral, pois muitos são os problemas encontrados para alcançar uma total implementação, que causa inclusive críticas severas de autores nacionais que consideram um equívoco a adoção, na América Latina, do modelo norte-americano de criação de áreas protegidas. Com o objetivo de avaliar uma unidade de conservação de proteção integral denominada Parque Ecológico da Lagoa da Maraponga, localizada na cidade de Fortaleza-Ceará, cuja origem ocorreu de forma diferenciada através da participação decisiva da população e movimento ambientalista, concretizou-se o presente trabalho, utilizando levantamentos bibliográficos e cartográficos, aplicação de questionário ao gerente da unidade, visitas de campo e entrevista com os freqüentadores do Parque. Para análise dos dados lançou-se mão de dez critérios adaptados do método aplicado pela World Widelife Fund - WWF-Brasil, concluindo-se que o Parque Ecológico da Lagoa da Maraponga encontra-se precariamente implementado e, por isso, sugere-se uma ação urgente do Poder Público responsável, inclusive, no sentido de promover a necessária criação da unidade nos termos da Lei do Sistema Nacional de Unidades de Conservação da Natureza - SNUC.

Orientador: Maria Isabel Felisberti / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-16T00:31:14Z (GMT). No. of bitstreams: 1 Carvalho_FabianaPiresde_D.pdf: 10993804 bytes, checksum: d95821798b6ae5ce1dd39dc3037a996e (MD5) Previous issue date: 2010 / Resumo:Neste trabalho foram preparadas e caracterizadas blendas de poli(metacrilato de metila), PMMA e poli[acrilonitrila-g-(etileno-co-propileno-co-dieno)-g-estireno], AES. O AES é um polímero amorfo e um material complexo, composto de uma mistura de poli(etileno-co-propileno-co-2-etilideno-5-norboneno) (EPDM), poli(estireno-coacrilonitrila) (SAN), e copolímero de enxertia EPDM-g-SAN. As blendas PMMA-AES foram obtidas por polimerização in situ, tendo-se como variáveis o solvente, agitação e atmosfera inerte, a fim de avaliar a influência destas sobre as propriedades estruturais e morfológicas das blendas. As blendas foram caracterizadas por espectroscopia infravermelho (IV), ressonância magnética nuclear de C (RMN de C), microscopia eletrônica de varredura (SEM), microscopia eletrônica de transmissão (TEM), análise dinâmico-mecânica (DMA) e resistência ao impacto. Os resultados mostraram que as blendas são imiscíveis apresentando uma morfologia complexa de domínios elastoméricos dispersos em uma matriz vítrea, dependente das condições de polimerização. Em algumas blendas, uma fração de PMMA encontra-se incluso na fase elastómerica, sugerindo uma morfologia tipo core shell ou tipo salame. Porém, essa morfologia complexa é afetada após o processo de injeção, devido ao efeito de temperatura e de cisalhamento. Extração seletiva e análise por espectroscopia infravermelho dos componentes das blendas mostraram que ocorre enxertia e/ou reticulação durante a polimerização. A sindiotaticidade do PMMA obtido em presença de AES aumenta com a quantidade de AES na blenda, devido às possíveis interações entre os grupos carbonilas do PMMA e os grupos nitrilas e fenilas da fase SAN. As blendas PMMA-AES apresentam propriedades mecânicas dependentes do teor de AES, sendo a resistência ao impacto das blendas superiores a do PMMA puro. Ensaios de envelhecimento fotoquímico acelerado mostraram que as blendas PMMA-AES apresentam queda na resistência ao impacto após envelhecimento / Abstract: In this work, blends of the poly(methyl methacrylate), PMMA, and the poly[acrylonitrile-g-(ethylene-co-propylene-co-diene)-g-styrene], AES, were prepared. AES is a complex mixture of poly(styrene-co-acrylonitrile), SAN, and poly(ethylene-copropylene-co-diene), EPDM, and the graft copolymer EPDM-g-SAN. Blends PMMA-AES were obtained by polymerization in situ, varying the solvent, the agitation and the inert atmosphere in order to evaluate their influence on the morphological and structural properties of the blends. The blends were characterized by infrared spectroscopy (FTIR), carbon-13 nuclear magnetic resonance (C NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic mechanical analysis (DMA) and Izod impact resistance test. The results showed that the PMMA-AES blends are immiscible and present a complex morphology. The morphology of some PMMA-AES blends is made up of an elastomeric dispersed phase in the glassy matrix, with inclusion of the matrix in the EPDM domains, suggesting core shell or salami morphology. However, this morphology is affected by the moulding injection process, due the temperature and shear effects. The selective extraction of the blends¿ components and the infrared spectroscopy showed that crosslinked and/or grafting reactions occur on EPDM chains during MMA polymerization. The syndiotactic PMMA obtained in the presence of AES increases with the amount of AES, due to the possible interaction among the carbonyl groups of PMMA and the nitrile or phenyl groups of SAN copolymer. The mechanical properties of the blends were influenced by the composition of the blend and the impact strength of the blends is superior to near PMMA. Photochemical aging tests showed that PMMA-AES blends presented decrease in the impact strength after aging / Doutorado / Físico-Química / Doutor em Ciências

Com o aumento na prevalência das lesões de erosão, medidas preventivas e de controle das mesmas vêm sendo propostas. Dentre elas, encontram-se os produtos fluoretados e, mais recentemente, os compostos contendo cátions metálicos polivalentes, como o tetrafluoreto de titânio (TiF4). Este estudo in situ visou avaliar os efeitos do gel de TiF4 na inibição da progressão da erosão em dentina humana erodida e abrasionada. Para tanto, foram obtidas oitenta e quatro amostras de dentina (3 x 3 x 1 mm) a partir de terceiros molares humanos hígidos. Setenta e duas amostras foram erodidas in vitro previamente a etapa in situ e divididas aleatoriamente em 6 grupos (n=12) de acordo com o tratamento e com o número de ciclos erosivos/abrasivos a serem executados durante a etapa in situ. Os grupos controle foram submetidos a apenas 1 (C1), 2 (C2) e 3 (C3) ciclos erosivos/abrasivos. Já os grupos experimentais receberam 1 (TiF4 1), 2 (TiF4 2) e 3 (TiF4 3) aplicações de gel de TiF4 (4%) seguidos de 1, 2 e 3 ciclos erosivos/abrasivos, respectivamente. Um sétimo grupo controle (n=12) foi incluído, sendo que amostras sem erosão in vitro foram submetidas a 3 ciclos erosivos/abrasivos. Cada ciclo erosivo/abrasivo correspondeu a 2 dias de desafios erosivos (ácido cítrico 0,5%, pH 2,6, 6x/dia) e abrasivos (1x/dia). Para realização da etapa in situ, as amostras foram posicionadas em dispositivos intra-orais removíveis utilizados por 12 voluntários. Os espécimes foram avaliados em perfilometria (n=12), microscopia eletrônica de varredura ambiental (MEV ambiental) (n=12) e microscopia de força atômica (AFM) (n=3) para avaliar as alterações causadas pelo fluoreto sobre a superfície da dentina. A ANOVA a dois critérios para medidas repetidas mostrou que o desgaste superficial foi afetado pelos tratamentos avaliados (p<0,001). O teste de Tukey demonstrou que o grupo TiF4 2, que não diferiu dos grupos TiF4 1 e TiF4 3, apresentou redução significativa no desgaste quando comparado aos grupos C1, C2, C3 e controle sem erosão in vitro. Os grupos TiF4 1 e TiF4 3 não revelaram diferença significativa em relação ao grupo C1, porém ambos os grupos de tratamento demonstraram desgaste significativamente menor que C2 e C3. Os maiores desgastes foram verificados para C3 e controle sem erosão in vitro. As micrografias obtidas em MEV ambiental e AFM sugeriram a manutenção do glaze sobre a superfície da dentina tratada com o gel de TiF4, mesmo após os desafios ácidos. A superfície passou a apresentar um aspecto mais liso que as amostras dos grupos controles, com redução dos diâmetros dos lúmens dos túbulos dentinários, justificando o efeito protetor do TiF4. Portanto, o TiF4 demonstrou potencial em reduzir a progressão das lesões de erosão in situ, independente do número de aplicações avaliado. / With the increase in the prevalence of erosion lesions, preventive and control measures for them have been proposed. Among them are the fluoride products and, more recently, compounds containing polyvalent metal ions such as titanium tetrafluoride (TiF4). This in situ study aimed to evaluate the effects of the TiF4 gel on the erosion progression inhibition in human eroded and abraded dentin. For this purpose, eighty-four dentin samples (3 x 3 x 1 mm) were prepared from undamaged human third molars. Seventy-two samples of previously eroded dentin in vitro were allocated into 6 groups (n=12) according to the treatment to be received during the in situ phase and the number of erosive/abrasive cycles. Control groups were subjected to 1 (C1), 2 (C2) and 3 (C3) erosive/abrasive cycles only. Experimental groups had TiF4 gel (4%) applied once (TiF41), twice (TiF42) or three times (TiF43) followed by 1, 2 and 3 erosive/abrasive cycles, respectively. A seventh group (n=12) comprised in vitro uneroded samples that were subjected to 3 erosive/abrasive cycles. Each cycle corresponded to 2 days of erosive (citric acid 0.5%, pH 2,6, 6x/day) and abrasive (1x/day) challenges. To perform the in situ stage, the samples were placed in removable intra-oral devices used by 12 volunteers Specimens were evaluated in profilometry (n=12), environmental scanning electron microscopy (ESEM) (n=12) and atomic force microscopy (AFM) (n=3) to evaluate the changes caused by fluoride on the surface of the dentin. The two-factor ANOVA for repeated measures showed that, after profilometric analysis, the surface loss was affected by the treatments evaluated (p<0.001). Tukeys test showed that TiF4 2 group, which did not differ from TiF4 1 and TiF4 3 groups showed a significant reduction in surface loss compared to C1, C2, C3 and in vitro-uneroded control. The TiF4 1 and TiF4 3 groups showed no significant difference from C1, but both treatment groups demonstrated significantly smaller surface loss than C2 and C3. The greatest losses were observed for C3 and in vitro-uneroded control. The micrographs by ESEM and AFM suggested the maintenance of the glaze on the dentin surface treated with the TiF4 gel, even after acid challenge. The surface started to show a smoother appearance than samples from control groups, with reduced diameters of the dentinal tubules lumens, explaining the protective effect of TiF4. Therefore, the TiF4 demonstrated potential to reduce the progression of erosion lesions, regardless of the number of applications evaluated.

O Brasil atualmente ocupa a nona posição entre os maiores produtores de tomate (Solanum lycopersicum L.) do mundo. O desenvolvimento das plantas e a produção dos tomateiros, no entanto, podem ser afetados por diversos problemas fitossanitários, entre os quais aqueles causados por vírus. Atualmente, entre as viroses que mais tem se destacado estão aquelas causadas por espécies dos gêneros Begomovirus, Crinivirus e Tospovirus. Entre os begomovirus, especial atenção tem sido dada ao Tomato severe rugose virus (ToSRV), pois tem sido a espécie prevalente na maioria das regiões produtoras de tomate no país. Esse begomovirus, que até o momento foi relatado somente no Brasil, é transmitido pelo aleirodídeo (\"mosca branca\") Bemisia tabaci biótipo B, numa relação persistente circulativa. 8Estudos da relação do ToSRV com esse aleirodídeo indicaram períodos mínimos de acesso à aquisição e inoculação de 5 minutos. Esse trabalho teve como objetivos: a) identificar o menor tempo de alimentação da B. tabaci biótipo B para a aquisição do ToSRV em tomateiros e b) identificar possíveis sítios de aquisição do ToSRV em tecido foliar de tomateiro via microscopia de luz de epifluorescência por hibridização in situ. Insetos livres de vírus foram confinados em folha de tomateiro infectado com o ToSRV durante 1, 3 e 5 minutos e 24 h (controle) para a aquisição do vírus. Parte dos insetos foi utilizada para a detecção do vírus no vetor, enquanto a outra parte foi usada em testes de transmissão do ToSRV para tomateiros. A detecção do vírus no inseto e nos tomateiros foi feita por PCR. B. tabaci biótipo B foi capaz de adquirir o ToSRV nos diferentes tempos de alimentação. Os insetos foram capazes de transmitir o vírus para tomateiros, com eficiência de 33% a 100%. Análises de cortes histológicos longitudinais na região das nervuras de folhas de tomateiro infectados com o ToSRV, em microscopia de luz de epifluorescência por hibridização in situ, revelaram vários pontos de fluorescência localizados nas células do parênquima do floema, incluindo as células companheiras e nas células da epiderme. Essa fluorescência não foi constatada em tecido sadio. A localização do ToSRV em células do parênquima foliar do tomateiro, associada ao conhecimento de que esse aleirodídeo efetua picadas de prova intracelulares, de curta duração, durante o processo de penetração intercelular do estilete, podem explicar a aquisição deste begomovirus durante curtíssimos períodos de alimentação. / Brazil currently ranks ninth position among the largest tomato (Solanum lycopersicum L.) producers in the world. Several diseases, including those caused by virus, however, can affect plant growth and yield of tomatoes. Currently, among the most important virus diseases are those caused by species of the Genus Begomovirus, Crinivirus and Tospovirus. Among the begomoviruses, especial attention has been given to Tomato severe rugose virus (ToSRV), because it has been the prevalent species in most of the tomato producing regions of the country. This begomovirus, which so far has only been reported in Brazil, is transmitted by the whitefly Bemisia tabaci biotype B, in a persistent circulative relationship. Studies on the virus-vector relationship indicated five minutes as the minimum period of access for virus acquisition and inoculation by the vector. This study aimed to: a) identify the shortest feeding period of B. tabaci biotype B for acquisition of ToSRV in tomato plants, and b) identify possible ToSRV acquisition sites in infected leaf tissue via epifluorescence light microscopy by in situ hybridization. Virus free insects were confined in tomato leaf infected with ToSRV during 1, 3 and 5 minutes and 24 hours (control) for virus acquisition. Part of the insects was used for virus detection in the vector, while the other part was used on ToSRV transmission tests for tomato plants. Virus detection in both, insect tomato plants, was carried out by PCR. B. tabaci biotype B was capable to acquire the ToSRV on the different feeding times. The insects were capable to transmit the virus to the tomato plants, with efficiency of 33% to 100%. Analysis of longitudinal histological cuts of ToSRV infected leaves, in epifluorescence light microscopy by in situ hybridization, revealed several fluorescence spots located in phloem parenchyma cells, including the companion and the epidermal cells. Fluorescence was not verified on healthy tissue. The location of ToSRV in parenchyma cells of tomato leaf, associated with the knowledge that this insect performs very short intracellular feeding probes, during the process of intercellular penetration of the stylet, may explain the acquisition of this begomovirus during very short feeding periods.

Orientador: Maria Isabel Felisberti / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química. / Made available in DSpace on 2018-08-19T11:49:08Z (GMT). No. of bitstreams: 1 Cocco_DanielRotella_M.pdf: 5124890 bytes, checksum: 11103bdc5dccd20252a90d83a5a6ba95 (MD5) Previous issue date: 2011 / Resumo: Neste trabalho foram preparadas e caracterizadas blendas de poli(metacrilato de metila), PMMA, e poli[acrilonitrila-co-acrilato de butila], ASA. O ASA é um polímero amorfo e constituído de uma mistura de poli(acrilato de butila) (PBA) e poli(estireno-co-acrilonitrila) (SAN). As blendas PMMA-ASA foram obtidas por polimerização in situ, tendo sido estudada a influência do agente de transferência de cadeia, da agitação e da atmosfera inerte sobre as propriedades estruturais e morfológicas das blendas. As blendas foram caracterizadas por cromatografia de permeação em gel (GPC), espectroscopia infravermelho (IV), análise termogravimétrica (TGA), ressonância magnética nuclear de C (RMN de C), análise dinâmico-mecânica (DMA), microscopia eletrônica de varredura (SEM), microscopia eletrônica de transmissão (TEM), e resistência ao impacto e tração. Os resultados mostraram que as blendas são imiscíveis apresentando uma morfologia complexa de domínios elastoméricos dispersos em uma matriz vítrea, dependente das condições de polimerização. Em algumas blendas, uma fração de PMMA encontra-se possivelmente inclusa na fase elastómerica, sugerindo uma morfologia tipo core shell ou tipo salame. Porém, essa morfologia complexa é afetada após o processo de injeção para algumas blendas, devido ao efeito de temperatura e de cisalhamento. Extração seletiva e análise por espectroscopia infravermelho dos componentes das blendas mostraram que ocorre enxertia e/ou reticulação durante a polimerização. A sindiotaticidade do PMMA obtido em presença de ASA aumenta com a quantidade de ASA na blenda, devido às possíveis interações entre os grupos carbonilas do PMMA e os grupos nitrilas e fenilas da fase SAN. As blendas PMMA-ASA apresentam propriedades mecânicas dependentes do teor de ASA e das condições de preparo, sendo a resistência ao impacto das blendas superiores à do PMMA puro / Abstract: In this work, blends of the poly(methyl methacrylate), PMMA, and the poly[acrylonitrile-co-styrene-co-butyl acrylate], ASA, were prepared. ASA is a complex mixture of poly(styrene-co-acrylonitrile), SAN, and poly(butyl acrylate), PBA. Blends PMMA-ASA were obtained by polymerization in situ, and the influence of a chain transfer agent, stirring and the inert atmosphere on the morphological and structural properties of the blends was studied. The blends were characterized by gel permeation chromatography (GPC), infrared spectroscopy (FTIR), C nuclear magnetic resonance ( C NMR), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), lzod impact resistance test and tensile tests. The results showed that the PMMA-ASA blends are immiscible and present a complex morphology. The morphology of some PMMA-ASA blends is made up of an elastomeric dispersed phase in the glassy matrix, with a possible inclusion of the matrix in the elastomeric domains, suggesting core shell or salami morphology. However, this morphology is affected by the moulding injection process, for some blend compositions, due the temperature and shear effects. The selective extraction of the blends components and the infrared spectroscopy showed that crosslinked and/or grafting reactions occur on ASA chains during MMA polymerization. The syndiotacticity of PMMA obtained in the presence of ASA increases with the amount of ASA, due to the possible interaction among the carbonyl groups of PMMA and the nitrile or phenyl groups of SAN copolymer. The mechanical properties of the blends were influenced by the composition of the blend and conditions of polymerization, and the impact strength of the blends is superior to neat PMMA / Mestrado / Físico-Química / Mestre em Química

Ces travaux visaient à développer de nouveaux implants biodégradables se formant in situ pour le traitement des parodontites, les infections les plus fréquentes au monde. Ces implants permettront de délivrer localement le principe actif et de contrôler sa libération. L’un des pré-requis pour ces nouveaux systèmes est de présenter une bonne bioadhésion et des propriétés mécaniques permettant d’éviter une expulsion prématurée hors de la poche parodontale.Tout d’abord, de nouveaux implants se formant in situ avec un potentiel prometteur pour surmonter l'un des inconvénients majeurs liés au traitement local de la parodontite: l’adhérence limitée aux tissus environnants ont été développés. L'addition de diverses concentrations de différents types de plastifiants (l’acetyltributyl citrate, ATBC et le dibutyl sebacate, DBS) et de polymères adhésifs (l'hydroxypropyl méthylcellulose, HPMC) ont permis d’obtenir une augmentation significative de l’adhésion des implants à base de l’acide poly(lactique-co-glycolique) (PLGA). Ces systèmes sont formés in situ à partir des formulations liquides de N-méthyl-2-pyrrolidone (NMP). Dans le même temps, une bonne aptitude à la déformation plastique des implants a été obtenue et les cinétiques de libération du principe actif souhaitées ont pu être affinées à l'aide de plusieurs outils de formulation. L'activité antimicrobienne de ce nouveau type d'implants se formant in situ, chargés à l’hyclate de doxycycline, a été démontrée en utilisant la méthode de diffusion en gélose sur plusieurs souches de Streptococcus isolées à partir de la microflore buccale des patients souffrant de parodontite.Ensuite, une meilleure compréhension des mécanismes de formation in situ des implants a été suivi en utilisant de différentes techniques tels que: la résonance paramagnétique électronique (EPR), la résonance magnétique nucléaire (1H NMR), le suivi de l’évolution de la masse et la cinétique de libération du principe actif dans différentes conditions, la microscopie optique, la chromatographie d'exclusion stérique (SEC). Des implants se formant in situ à base de PLGA, d’ATBC, de chlorhydrate de minocycline, de NMP et d’HPMC, ont été préparés et caractérisés en détail in vitro. Ces résultats ont révélé une vision approfondie sur les phénomènes physico-chimiques impliqués dans la formation de l'implant et sur le contrôle de la libération du principe actif. Par exemple, les effets de l'ajout d’HPMC dans la formulation, qui améliore l'adhérence de l'implant et réduit le gonflement, ont pu être expliqués. De manière importante, les implants se formant in situ ont efficacement empêché la croissance bactérienne dans les poches parodontales des patients. Enfin, l’impact de la composition des implants sur la performance des systèmes a été étudié. Afin d’élucider ces relations, des techniques de caractérisation de pointe, telles que l'analyse EPR ont été utilisées. Il est intéressant de noter que l’ajout d’HPMC et de PLGA de plus faible poids moléculaire a légèrement diminué la libération du principe actif, alors que dans le cas de PLGA de poids moléculaire plus élevé, la vitesse de libération a substantiellement augmenté. Ces tendances peuvent être expliquées en se basant sur la cinétique du transport de masse au cours de la formation de l'implant et des structures internes des systèmes. En outre, l'activité antimicrobienne des implants contre les micro-organismes présents dans les poches parodontales de patients atteints de parodontite a été évaluée. Ces systèmes gênent plus efficacement la croissance des bactéries pathogènes que celle des micro-organismes physiologiques. Ainsi, une recolonisation de la flore saine dans les poches des patients peut être envisagée in vivo. / This work aimed to develop new biodegradable in situ forming implants for the treatment of periodontitis, the most common infections in the world. These implants would locally deliver the active ingredient and control its release. One of the prerequisites for these new systems is to provide a good bioadhesion and mechanical properties to prevent premature expulsion from the periodontal pocket. Firstly, new in situ forming implants with promising potential to overcome one of the major drawbacks for the local treatment of periodontitis: limited adhesion to the surrounding tissue were developed. The addition of various concentrations of different types of plasticizers (acetyltributyl citrate, ATBC and dibutyl sebacate, DBS) and adhesive polymers (hydroxypropyl methylcellulose, HPMC) resulted in a significant increase in the adhesion of poly(lactic-co-glycolic acid) (PLGA)-based implants. The systems are formed in situ from N-methyl pyrrolidone (NMP)-based liquid formulations. Importantly, at the same time, good plastic deformability of the implants could be provided and desired drug release patterns could be fine-tuned using several formulation tools. The antimicrobial activity of this new type of in situ forming implants, loaded with doxycycline hyclate, was demonstrated using the agar well diffusion method and multiple Streptococcus strains isolated from the oral microflora of patients suffering from periodontitis.Secondly, a better understanding of the mechanisms of the in situ implant formation was followed using different techniques such as electron paramagnetic resonance (EPR), nuclear magnetic resonance (1H NMR), mass change and drug release measurements under different conditions, optical microscopy, size exclusion chromatography (SEC). The in situ forming implants containing PLGA, ATBC, minocycline hydrochloride, HPMC and NMP were prepared and characterized in detail in vitro. Based on these results, deeper insight into the physico-chemical phenomena involved in implant formation and the control of drug release could be gained. For instance, the effects of adding HPMC to the formulations, resulting in improved implant adherence and reduced swelling, could be explained. Importantly, the in situ formed implants effectively hindered the growth of bacteria present in the patients’ periodontal pockets.Finally, the impact of the composition of the implants on system performance was investigated using advanced characterization techniques, such as EPR analysis. Interestingly, HPMC addition to shorter chain PLGA slightly decreased drug release, whereas in the case of longer chain PLGA the release rate substantially increased. These tendencies could be explained based on the mass transport kinetics during implant formation and the systems’ inner structures. Furthermore, the implants’ antimicrobial activity against microorganisms present in the periodontal pockets of patients suffering from periodontitis was evaluated. Interestingly, these systems more effectively hinder the growth of pathogenic bacteria than of physiological microorganisms. Thus, a re-colonization of the patients’ pockets with healthy flora can be expected to be favored in vivo.

Ces travaux, effectués dans le cadre de la 4e année polaire internationale et à partir des mesures in-situ obtenues durant le projet POLARCAT-France, ont pour objectifs de fournir, dans un premier temps, une climatologie des panaches de pollution transportés depuis les continents sources (Amérique du Nord, Europe et Asie) vers l’Arctique. La climatologie contient des informations sur les propriétés physique, chimique et optique des particules d’aérosols, l’origine des panaches ayant été déterminée à l’aide du modèle lagrangien de rétro-trajectoire FLEXPART. Dans un second temps, les processus qui influent sur les propriétés des particules de pollution durant leur transport vers l’Arctique ont été étudiés. Si au cours de la campagne d’été au Groenland, il a été montré que la totalité des panaches rencontrés ont subit un processus de dépôt humide durant leur transport vers l’Arctique, la campagne de printemps au nord de la Suède a permis de mettre en avant l’évolution d’un même panache échantillonné lors de 3 vols consécutifs ainsi que des propriétés de mélange entre les contributions anthropiques et naturelles de deux panaches asiatiques. / The aims of this thesis were, in a first step, to build a climatology of pollution plumes transported from source continents to the Arctic as measured during the POLARCAT-France campaigns performed in spring and summer 2008, in the frame of the 4th International Polar Year. The climatology is including informations on aerosol particle physical, chemical and optical properties and is organized as a function of pollution plume origins (determined with the Lagrangian transport model FLEXPART). In a second step, aerosol processes which influenced aerosol properties during transport to the Arctic were studied. During the summer campaign, the whole plumes encounter experienced wet scavenging processes on their pathway to Groenland. In spring, a plume was sampled during three consecutive days and thus, its ageing was characterised. Finally, two Asian plumes allowed us to highlight the external mixing between anthropogenic and biomass burning contributions transported to northern scandinavia.

Per- och polyfluoroalkylämnen (PFAS) är i enkla termer fluorerade kolväten som har använts i ett flertal produkter på grund av deras unika förmåga att vara vatten- och smutsavstötande, värmetåliga samt skiktbildande. PFAS har släppts ut i naturen på flera olika sätt. En stor bov till det är brandskum beståendes av vattenhaltigt filmbildande skum (AFFF), vilket innehåller PFAS. Stora volymer brandskum har släppts ut vid bränder eller brandövningsplatser. PFAS är mycket svårnedbrytbara och bioackumulerande, vilket betyder att de stannar kvar i miljön lång tid framöver. Eftersom de även har bevisats vara hälsofarliga vid små mycket mängder, har många varianter av PFAS blivit bannlysta, samt att rening av PFAS blivit centralt. Det har gjorts väldigt mycket forskning kring hur man renar PFAS från vatten vid dricksvattenproduktion, men inte lika mycket på hur man sanerar PFAS från mark och grundvatten in situ (på plats), främst eftersom det är svårt på grund av PFAS-kemikaliernas egenskaper. Det är en viktig del för att kunna ta bort PFAS ur naturen, då en stor del av den PFAS som blivit utsläppt, vid exempelvis brandövningsplatser, skapat plymer i jord och grundvatten som fortsätter vara spridningspunkter. Syftet med litteraturstudien är att sammanställa och jämföra utvecklande metoder inom området in situ sanering av PFAS för att se vilka metoder som har potential att stoppa spridningen. / Per- and polyfluoroalkyl substances (PFAS) are, in simple terms, fluorinated hydrocarbons that have been used in many products because of their unique ability to be water- and dirt-repellent, heat-resistant, and film forming. PFAS has been released into the environment in several ways. A major culprit is firefighting foam consisting of aqueous film-forming foam (AFFF), which contains PFAS. Large volumes of firefighting foam have been released during fires or firefighting exercises. PFAS are very persistent and bioaccumulative, meaning they stay in the environment for a long time. Since they have also been proven to be harmful to health at very low concentrations, several varieties of PFAS have been banned, and cleaning up PFAS has become a central issue. There has been a lot of research on how to clean PFAS from water during drinking water production, but not as much on how to remediate PFAS from soil and groundwater in situ (on-site), mainly because it is difficult due to the properties of the PFAS chemicals. This is an important part of removing PFAS from the environment since a large part of the PFAS that has been released, for example at firefighting sites, has created plumes in soil and groundwater that continue to be points of spread. The purpose of the literature study is to compile and compare developing methods in the field of in situ remediation of PFAS to see which methods have the potential to stop the spread.

Die mechanischen Eigenschaften eines Materials spielen eine entscheidende Rolle für mögliche Anwendungen. Für nanoskalige Metalle ist lange bekannt, dass sich deren mechanischen Eigenschaften von ihren bulk-Gegenstücken stark unterscheiden. In bulk-Metallen wird die Verformung durch die Wechselwirkung vorhandener Versetzungen kontrolliert. Dies erweist sich scheinbar auf der Nanoebene als weniger zutreffend, da nur wenige oder keine Versetzungen in nanoskaligen Proben vorhanden sind und diese einfach aus der Probe herauslaufen können, ohne dass es vorher zu einer Wechselwirkung kommt. Die Verformung wird dann bestimmt durch die Nukleation neuer Versetzungen. In dieser Arbeit wurde die Verformung von Gold-Nanodrähten mit einem Durchmesser zwischen 50 und 150nm, die entweder einkristallin oder entlang ihrer Länge verzwillingt waren, untersucht. Auf der einen Seite erfolgte die Durchführung der Versuche in-situ im Transmissionselektronenmikroskop, um die Entwicklung der Defektmorphologie direkt beobachten zu können. Auf der anderen Seite wurden ebenfalls Tests in-situ im Rasterelektronenmikroskop mit einem neu entwickelten Aufbau durchgeführt und dabei das Spannungs-Dehnungs-Verhalten der Nanodrähte analysiert. Sämtliche Nanodrähte zeigten anfänglich ein elastisches Verhalten mit einem Elastizitätsmodul, das größenunabhängig war und nahe an dem entsprechenden Wert für Bulk-Gold lag. Mit Beginn der plastischen Verformung entstehen planare Defekte homogen verteilt entlang der Drähte, sowohl bei einkristallinen als auch verzwillingten Drähten. Zusammen mit der gemessenen Nukleationsspannung zeigte dies eine gute Übereinstimmung mit existierenden Modellen für die Oberflächennukleation von leading-Partialversetzungen, die auf klassischer Nukleationstheorie basieren. Mit weiterer Verformung kommt es ebenfalls zur Nukleation von trailing-Partialversetzungen, wodurch bereits entstandene planare Defekte wieder verschwinden und im Fall von verzwillingten Drähten volle Versetzungen gespeichert werden. Da die Nukleation von trailing-Partialversetzungen durch die existierenden Modelle nicht vorhergesagt wird, öffnet diese Beobachtung neue Fragen, ob klassische Nukleationstheorie in der Lage ist, die Nukleation von Versetzungen korrekt darzustellen.