As tireoidites auto-imunes são afecções endocrinológicas relativamente comuns. Há uma noção entre os clínicos de que a incidência das mesmas tem aumentado nos últimos anos. Este aumento foi documentado em algumas regiões no mundo, mas ainda há controvérsias se o mesmo ocorre no nosso país. Apesar de ser alvo de intensos e exaustivos estudos, a fisiopatologia das tireoidites auto-imunes bem como a identidade do fator desencadeante inicial da auto-imunidade permanecem obscuros e fatores genéticos, ambientais, medicamentosos e nutricionais (por exemplo, iodo) têm sido responsabilizados como causas do incremento da freqüência da auto-imunidade tireoidiana. O Iodo tem sido implicado, como responsável pelo aumento de incidência em diferentes populações após sua introdução para prevenção de bócio endêmico. Na literatura as tireoidites são definidas e classificadas de diferentes formas e há diversidade de metodologias para avaliação de material cirúrgico e de necropsias o que dificulta o estudo comparativo em diferentes séries. Para verificar se houve incremento da freqüência de tireoidites em nossa área estudamos retrospectivamente os laudos de 5 anos de necropsias realizadas no SVO da FMUSP e comparamos com levantamento anterior realizado na mesma instituição. Os infiltrados linfocitários foram marcados para CD4, CD8, CD20 e CD68. A participação da apoptose foi analisada pela técnica do TUNEL e marcação de caspase 3. Camundongos NOD (Não Obesos Diabéticos) foram submetidos à sobrecarga oral de iodo por 60 e 90 dias com o objetivo de avaliar o papel do iodo nas alterações histolopatológicas da tireóide e para criar um modelo experimental para o estudo da fisiopatologia da tireoidite autoimune.. Resultados: A freqüência de tireoidite em nosso estudo de necropsias aumentou 58 vezes em relação ao estudo anterior (2,3% e 0,04%, respectivamente). À imunohistoquímica, os casos classificados inicialmente como tireoidite linfocítica e tireoidite de Hashimoto mostraram padrão semelhante de infiltrados sugerindo serem as duas condições estágios evolutivos da mesma doença. A apoptose foi marcante nos casos estudados demonstrando ter papel importante na fisiopatologia da tireoidite auto-imune. Nos camundongos NOD o iodo antecipou e aumentou a prevalência de tireoidites. Nas duas tireóides estudadas à microscopia eletrônica encontramos lesões mitocondriais e do retículo endoplasmático rugoso que não foram vistas em nossos controles. Conclusão: Temos um incremento real da prevalência de tireoidites em necropsias realizadas em nossa instituição. O padrão histopatológico das tireoidites auto-imunes estudadas sugere que a tireoidite dita linfocítica poderia corresponder à fase inicial do processo auto-imune que levaria à tireoidite de Hashimoto. O iodo foi o fator desencadeante e que aumentou e antecipou a incidência de tireoidite em nosso estudo experimental. / Autoimmune thyroiditis are relatively common endocrine diseases. There is a common perception among clinicians that its incidence has been increasing in recent years. Such an increase has been documented in a number of regions worldwide; it remains controversial, however, whether the frequency of thyroiditis is increasing in our country. Despite of being a subject of intense and exhaustive studies, the pathophysiology of auto-immune thyroiditis as well as the identity of the factor that triggers the initial autoimmunity have remained undetermined and genetics, environmental factors, drugs and, nutrition (e.g., iodine) have been implicated in the increase of frequency of thyroid autoimmunity. The iodine has been hold responsible for the increase in the incidence of autoimmune thyroiditis in different populations after its introduction in iodine-defficient regions as a prophylaxis for endemic goiter. There is a myriad of different definitions and classifications for thyroiditis. There is also a great diversity in methods used in the assessment of surgical specimens and necropsy materials. Such a diversity of classification systems and study protocols creates a barrier for comparison of data from different series/studies. In order to verify whether an increase in frequency of thyroids is occurring in our population we retrospectively analyzed the report of necropsies performed in a period of five years in the service of death verification of University of Sao Paulo School of Medicine and compared to a published study performed previously at the same institution. Lymphocytic infiltrations were labeled with antiserum against CD4, CD8, CD20 e CD68. The involvement of apoptosis was assessed by TUNEL and caspase 3 labeling. NOD (Non Obese Diabetic) mice were exposed with high dose oral iodine for 60 or 90 days in order to evaluate the role of iodine in the genesis of histopathological derangements of thyroid and to create an experimental model for the study of autoimmune thyroiditis. Results: In this study, we found a 58-fold increase in the frequency of thyroiditis in comparison to the study performed previously (2,3% e 0,04%, respectively). Cases categorized initially as lymphocytic thyroiditis showed a cell infiltrate that labeled by immunohistochemistry in a similar way as the infiltrates of cases classified as Hashimotos thyroiditis which suggests that these entities might be different stages of a same disease. All cases displayed strong labeling for apoptosis markers demonstrating its important role in the pathophysiology of autoimmune thyroiditis. Iodine anticipated and increased the frequency of thyroiditis in NOD mice. In both thyroids studied with electron microscopy, we found mitochondrial and rough endoplasmic reticulum lesions that were not seen on control thyroids. Conclusion: there is an actual increase in thyroiditis prevalence in necropsies performed at our institution. The histological pattern of autoimmune thyroiditis we studied suggests that the sol called lymphocytic thyroiditis might be the initial stage of an autoimmune process that would eventually lead to Hashimotos thyroiditis. The iodine was the triggering factor which increased and anticipated the incidence of thyroiditis in our experimental study.

Orientador : Ranulfo Monte Alegre / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T14:22:54Z (GMT). No. of bitstreams: 1 Alberte_TaniaMaria_D.pdf: 9835439 bytes, checksum: 74ab1a7efc7d568bc9c3b37f762f08ec (MD5) Previous issue date: 2003 / Resumo: Reatores "air-lift" são uma classe especial de coluna de bolhas, sendo recentemente utilizados em processos químicos, bioquímicos e em tratamento de águas residuárias. Neste trabalho, estudou-se o desempenho de um reator "air-lift" de tubos concêntricos no tratamento de água residuária sintética utilizando Iodo ativado. O reator construido de aço-inox, com tubos de aeração e reciclo de 1,2 e 1,5 m respectivamente, foi alimentado com água residuária sintética, sendo o Iodo separado em sedimentador na parte superior do reator e reciclado ao mesmo. A pressão manométrica no reator variou de O a 1,2 Kgf.cm-2, vazão de ar de 200 a 1600 mL.min-1 e vazão de substrato de 200 a 400 mL.h-1. Para cada taxa de alimentação, vazão de ar e pressão, o reator foi operado de forma contínua até que o estado estacionário hidráulico e microbiológico fossem atingidos. As amostras foram retiradas na altura média do reator e análises da Demanda Química de Oxigênio (DQO) e biomassa (quantificada como sólidos suspensos voláteis - SSV) foram feitas de acordo com métodos descritos pelo "Standard Methods for the Examination of Water and Wastewater" (1985). Os três parâmetros, vazão de alimentação, vazão de ar e pressão, variaram gradativamente, além da concentração de DQO do substrato (1100 a 8600 mgDQO.L-1), de forma que foi possível aumentar a concentração de Iodo no reator (SSV) de 1010 a 15000 mgSSV.L-1, sendo este último valor cerca de cinco vezes maior que os de processos convencionais de Iodo ativado, que é de 2000 a 3000 mgSSV.L -1 (Ramalho, 1983). Isto permitiu aumentar a eficiência de redução de DQO de 47 a 87%, respectivamente para reator operado a pressão ambiente e com variação de pressão. O coeficiente de transferência de oxigênio (K1a) aumentou com o aumento da vazão de ar até o limite de 1000 mL.min-1 (5,41 h-1), decrescendo para vazões superiores a esta, possivelmente devido à coalescência de bolhas. O coeficiente de retenção de gás (Eg) foi determinado e, para as vazões de ar testadas (200 a 1400 mL.min-1), variou de 2,08.10-3 a 12,95.10-3, proporcionalmente às vazões de ar utilizadas / Abstract: Air lift reaetors are a speeial elass of bubble eolumns and are been reeently used in ehemieal and bioehemical processes, as well as in wastewater treatment. In this work, it was studied the performanee of aeoneentrie tube air lift reaetor in the synthetie wastewater treatment by aetivated sludge. The reaetor was eonstrueted of stainless steel, 1.2 m high of riser and 1.5 m high of downeomer. It was fed with synthetie wastewater and the sludge was separeted in a sedimentator in the top of reaetor and reeyeled. The manometrie pressure varied from O to 1.2 kgf.em'2, the air flow rate from 200 to 1,600 mL.min-1 and the feed solution from 200 to 400 mL.h -1. To eaeh feed solution of synthetie wastewater rate, air flow rate and pressure, the reaetor was operated in eontinuous form until the hidraulie and mierobiologieal steady-state was reaehed. The samples were eolleeted in the half of the reaetor. Chemieal oxygen demand (COO) and volatils solids eoneentration (VSS) was determinated aceording to ín Standard Methods for the Examínation of Water and Wastewater (1985). Feed solution rate, air flow rate and pressure rangedgradually, as well as eoneentration of feed synthetie wastewater (1,100 of 8,600 mgCOO.L- / Doutorado / Doutor em Engenharia de Alimentos

Orientadores: Marcio Zaffalon Casati, Sergio de Toledo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T05:05:03Z (GMT). No. of bitstreams: 1 Ribeiro_EricaDelPeloso_M.pdf: 1796294 bytes, checksum: 9bd1ed49b1a4f14b073dca3cf4bbb7e2 (MD5) Previous issue date: 2005 / Resumo: O objetivo do presente estudo foi avaliar a ação de uma solução de iodo povidine (PVP-I), associada à raspagem e alisamento radicular, no tratamento de lesões de bifurcação. Foram selecionados 44 pacientes com pelo menos um molar com lesão de bifurcação classe II, em face livre, profundidade de sondagem ³ 5 mm e sangramento à sondagem. Os pacientes foram divididos aleatoriamente em 2 grupos: grupo controle - raspagem e alisamento radicular com ultra-som e água destilada como solução refrigerante; grupo teste - raspagem e alisamento radicular com ultra-som e PVP-I 10% como solução refrigerante. Foram avaliados os seguintes parâmetros clínicos: índice de placa (IP), sangramento à sondagem (SS), posição da margem gengival (PMG), nível clínico de inserção relativo (NICr), profundidade de sondagem (PS) e nível clínico de inserção horizontal relativo (NICHr). A avaliação bioquímica da atividade de enzimas tipo tripsina no biofilme subgengival foi feita pelo teste BAPNA. Os parâmetros descritos acima foram avaliados antes do tratamento, 1, 3 e 6 meses após. Ambos os grupos apresentaram médias semelhantes de redução da PS, ganho de NICr e de NICHr. Aos 6 meses, esses valores foram, respectivamente, 2,31 mm, 1,17 mm e 1,00 mm no grupo controle e 2,31 mm, 1,23 mm e 1,02 mm no grupo teste (p>0,05). Diferença estatisticamente significante também não foi observada entre os grupos quanto ao número de sítios que ganharam 2 mm ou mais de inserção. Aos 6 meses, os grupos controle e teste apresentaram, respectivamente, 45,16% e 30,77% das áreas com ganho de inserção = 2 mm. Na comparação entre os grupos quanto ao SS das lesões de bifurcação aos 6 meses e à quantidade de áreas que exigiram retratamento no 3° mês foi encontrado p=0,06, favorecendo o grupo teste. O teste BAPNA não detectou diferença entre os grupos, entretanto, foi observada diferença intra-grupo, indicando redução na atividade de enzimas do tipo tripsina. Pôde-se concluir que o PVP-I, usado como adjunto da instrumentação periodontal traz benefícios clinicamente significantes ao tratamento de lesões de bifurcação classe II, em faces livres / Abstract: The aim of this randomized single-blind controlled clinical trial was to evaluate the effect of topically applied povidone-iodine (PVP-I), used as an adjunct to non-surgical therapy of furcation involvements. Forty-four patients presenting at least one class II furcation involvement that bled on probing, in bucal or lingual surfaces, with probing pocket depth ³ 5 mm were recruited. Patients were stratified into 2 treatment groups: subgingival instrumentation by an ultrasonic device using PVP-I (10%) as the cooling liquid (test group); identical treatment using distilled water as the cooling liquid (control group). The following clinical outcomes were evaluated: plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), probing pocket depth (PPD) and relative horizontal attachment level (RHAL). BAPNA test was used to analysis the trypsin-like activity in dental biofilm. The clinical and biochemical parameters were evaluated at baseline and 1, 3 and 6 months after therapy. Both groups had similar means of PPD reduction and RAL and RHAL gain. At 6 months, these variables were, respectively, 2.31 mm, 1.17 mm and 1.00 mm in the control group and 2.31 mm, 1.23 mm and 1.02 mm in the test group (p<0.05). No differences were observed in terms of the frequency distribution of sites demonstrating RAL gain ³ 2 mm. The comparison between groups on BOP of the furcation sites, at 6 months and on the number of sites referred for re-treatment at 3 months showed better values in the test group (p=0.06). The results of BAPNA test failed to demonstrate significant differences between groups. The use of topically applied PVP-I with subgingival instrumentation may provide additional clinical significant benefits to the treatment of class II furcation involvements / Mestrado / Periodontia / Mestre em Clínica Odontológica

Iodine is necessary for thyroid hormones synthesis which in turn are essential for brain development during fetal and early postnatal life. In these critical periods, severe iodine deficiency can induce irreversible brain damage in the fetus and the infant, resulting in retarded cognitive and/or psychomotor development. Despite the introduction of salt iodization programs such as national measures to control iodine deficiency, some European countries, including Belgium, are still affected by Mild Iodine Deficiency (MID) and MID during pregnancy may affect neurodevelopment of the offspring. Elevated thyroid stimulating hormone (TSH) concentration (>5mU/l) at birth has been used as an indicator of iodine deficiency during late pregnancy and at the population level. This doctoral research aimed to investigate the association between neonatal TSH level, used as a surrogate marker of MID during late pregnancy, and cognitive, psychomotor and psychosocial development of preschool children. It was hypothesized that elevation of TSH at birth is associated with impaired intellectual and psychomotor development and with behavioral problems at 4-5 years. As the use of TSH as an indicator of iodine deficiency has been criticized, we have also set out to assess the potential factors influencing neonatal TSH level measured through neonatal screening using a representative sample of TSH values between 0 and 15 mIU/L. Additionally, we aimed to reevaluate the neonatal TSH cut-off (5mIU/L) used to monitor iodine status in the population. The objective was to evaluate the cut-off point from which we can observe the impairment of children’s neurodevelopment. We hypothesized that this is a good way to establish the best cut-off value for identifying iodine deficiency.The study included 315 Belgian preschool children with a TSH concentration between 0 and 15 mU/L at screening. For each sex and TSH-interval (0-1 mU/L, 1-2 mU/L, 2-3 mU/L, 3-4 mU/L, 4-5 mU/L, 5-6 mU/L, 6-7 mU/L, 7-8 mU/L, 8-9 mU/L, 9-15 mU/L) 19 newborns were randomly selected after excluding infants with congenital hypothyroidism, low birth weight and premature infants. Neonatal TSH was measured in dried blood spots collected by heel stick 3 to 5 days after birth using the Autodelphia method. Cognitive abilities and psychomotor development were assessed using respectively the Wechsler Preschool and Primary Scale of Intelligence-III and the Charlop-Atwell scale of motor coordination. Psychosocial development was measured using the Child Behavior Check List for ages 1½-5 years. In addition, the mothers completed a self-administered questionnaire in order to account for confounding factors. No association between neonatal TSH within the range of 0 to 15 mIU/L - a surrogate marker for mild iodine deficiency during pregnancy and neurocognitive development was present in Belgian preschool children. The current level of iodine deficiency in Belgium is probably not severe enough to affect the neurodevelopment of children. In this study, we were able to identify several maternal and pregnancy related determinants of neonatal TSH levels. Higher TSH levels were associated with a lifetime (up to child birth) smoking behavior in the mother, a lower weight gain during pregnancy, a longer pregnancy duration. Higher TSH levels were found in spring and winter compared to summer and autumn. It is not advised to use elevated neonatal TSH levels at birth as an indicator of iodine deficiency during late pregnancy without taking potential covariates into account. Given the fact that no association was found between TSH and developmental scores in the children, we cannot evaluate the cut-off point from which we can observe the impairment of children’s neurodevelopment. / Doctorat en Sciences psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished

Ce manuscrit présente le développement de nouvelles réactivités mettant en jeu des sources d’halogène électrophile et leur application dans les réactions de carbocyclisation de substrats possédant des fonctions carbonées insaturées. Le concept d’activation par une base de Lewis de l’agent d’halogénation a été étudié dans ce type de réactions, d’abord en version racémique, puis en version énantiosélective. L’efficacité des chalcogénures de phosphines et de phosphites a en particulier été démontrée dans les réactions d’iocarbocyclisation d’énynes-1,5 et d’iodoarylation d’oléfines. De nouveaux organocatalyseurs chiraux ont par la suite été synthétisés par analogie aux bases de Lewis achirales utilisées. Des molécules chirales de types chalcogénures de phosphoramidites et de phosphites ont ainsi été préparées et leur activité a par la suite été évaluée dans la perspective du développement d’une version asymétrique des réactions d’iodocarbocyclisation étudiées précédemment. En parallèle, de nouvelles méthodologies impliquant des substrats possédant une fonction allène ont été développées. En particulier, la réaction d’iodocarbocyclisation d’arylallènes a permis d’accéder à des 2-iodoindènes polysubstitués selon un procédé 5-endo avec des rendements allant jusqu’à 95%. / This manuscrit concerns the development of new reactivities, involving electrophilic halogen sources and their application in carbocyclization reactions of substrates bearing unsaturated carbon functions. The concept of Lewis base activation of the halogenation reagent was assessed in this type of reaction, first in a racemic version, then in an enantioselective fashion. In particular, the efficiency of phosphine and phosphite chalcogenides has been demonstrated in iodocarbocyclization reactions of 1,5-enynes and iodoarylation reactions of olefins. New chiral organocatalysts were afterwards synthesized by analogy with achiral Lewis bases previously employed. Thus, chiral molecules such as phosphoramidite and phosphite chalcogenides were prepared and their activity has been evaluated in the perspective of the development of an asymmetric version of these reactions. In parallel, new methodologies involving substrates bearing an allene function were developed. In particular, the iodocarbocyclization reaction of arylallenes was exploited to access polysubstituted 2-iodoindenes following a 5-endo process with yields up to 95%.

Mineral supplementation of is a well-known factor contributing to productivity in sheep or cattle herds. However, little is known about mineral interactions in these species. The objective of the present work was to evaluate the inter-relation of iodine (I) and fluoride (F) in young ovine metabolism and the thyroid gland. Two experiments were conducted; first it was analyzed the dynamics of urinary I excretion in sheep. Five lambs were used in a repeated measurement protocol. After a 15-day adaptation period urine samples were collected (control group), then animals received 3 different 15-day treatments (0,05; 0,42; and 0,8 mg of I/kg DM) consecutively. Punctual (8 hour interval) and 24 hour total urine samples were collected. No differences in I excretion among treatments or collection time. Also, there were no differences in urinary creatinine levels among treatments or collection time, except between 16:00 and 24:00 hours in the medium dose. No significant correlation was found between urinary I and creatinine. In a second experiment, it was evaluated the effect of chronic fluoride administration in thyroid function and histology in sheep. Twelve ram lambs were allocated into 2 groups: Control which received 5g NaCl + 0,2 mg of I/Kg DM and treated group which received the same treatment plus sodium fluoride (4,7 mg F/ Kg BW) daily for 150 days. Blood samples were collected at 60, 90, 120, and 150 days for determination of F, I T3 and T4. At the same time points, total 24-hour urine production was collected for measurement of F and I. After euthanasia, at 150 days of treatment, thyroid gland was removed for histopathological and morphometrical analyses. No differences were found between or within groups for urinary I. Also no differences were found for T3 and T4 nor serum I between groups or among time points. No histological alterations were found in the thyroid. In conclusion, urinary I excretion is not a reliable parameter to access I status in animals with supplementation within the recommended levels. Additionally, data related to Iodine-fluoride interactions cannot be used across species, since the effect of fluoride on the thyroid appears to have specie dependant intensity / A suplementação mineral dos rebanhos é um fator que influi de forma relevante no índice de produtividade, porém, há carência de novos estudos relacionados à situação e interação dos elementos minerais nos rebanhos e nisso está alicerçado o objetivo do presente trabalho: avaliar a inter-relação do iodo (I) e do flúor (F) no metabolismo de ovinos jovens, através da avaliação do efeito do F sobre a glândula tireóide. Para tanto, foram realizados dois experimentos. O primeiro teve o objetivo de analisar a dinâmica da excreção urinária de I em ovinos. Assim, utilizaram-se cinco animais. Antes de iniciar o tratamento com I, coletou-se amostras de urina (grupo controle), posteriormente, os animais passaram a receber três diferentes tratamentos (0,05; 0,42 e 0,8 mg de iodo/kg de matéria seca), consecutivamente. Cada tratamento teve duração de 15 dias. Foram coletadas amostras de urina equivalente às 24 horas e amostras pontuais (intervalo de oito horas). Não houve diferença na excreção urinária de I entre tratamentos e entre horários de coleta. Os valores urinários de creatinina não diferiram entre os horários de coleta dentro de cada tratamento, exceto entre as 16:00 e às 24:00 horas, na dose média. A relação iodo/creatinina não demonstrou correlação. No segundo experimento, o objetivo foi avaliar o efeito da administração crônica de fluoreto de sódio na função e histologia da glândula tireóide de ovinos. Foram utilizados doze ovinos, os quais foram divididos em dois grupos: Controle, o qual recebeu somente sal iodado (5g NaCl/animal+0,2mg de iodo/kg MS) e o grupo Tratado, que recebeu sal iodado (5g NaCl/animal+0,2mg de iodo/kg MS) adicionado de fluoreto de sódio (4,7mg F/kg de peso corporal), durante um período de 150 dias. Amostras de sangue foram coletadas aos 60, 90, 120 e 150 dias de tratamento para análise sérica de I e F, Triiodotironina (T3) e Tetraiodotironina (T4). Ainda, nesse mesmo intervalo de tempo, coletou-se a urina, correspondente às 24 horas, para análise da excreção urinária de I e F. Após o sacrifício dos animais, a glândula tireóide foi removida para posterior exame histopatológico e morfométrico. Quanto ao I urinário, não foi observada diferença estatística entre os grupos controle e tratado e dentro de cada grupo, entre os períodos. As concentrações de T3 e T4 não diferiram estatisticamente entre ambos os grupos e dentro de cada grupo, nos diferentes tempos de tratamento. Assim como, também não houve diferença estatística nos teores de I sérico. Quanto à avaliação histopatológica da glândula tireóide, não foram observadas alterações. De um modo geral, é possível concluir que a excreção urinária de iodo, quando utilizada como estimativa do status nutricional deste elemento, deve ser considerada com parcimônia, principalmente se forem utilizadas doses dentro do intervalo de recomendação requerido para a espécie. Outrossim, conclui-se que dados referentes a inter-relação do iodo e flúor não podem ser aplicados de uma espécie para outra, pois o efeito do flúor sobre a glândula tireóide não ocorre na mesma forma e intensidade

Masters of Science / Invasive pneumococcal disease (IPD), which includes potentially fatal conditions such as meningitis, septicaemia and pneumonia poses a threat in children aged <5 years, pneumonia being the leading cause of child mortality worldwide. Even though capsular polysaccharides are the main antigens involved in the immunity to encapsulated bacteria, it was found that in children in that age group, the immune system was unresponsive. Conjugate vaccines however induce immunologic memory and provide long-term protective immunity. Therefore the aim of this project was to develop novel conjugation strategies towards a pneumococcal conjugate vaccines and focuses mainly on the serotypes that are a burden to the African continent. The chemistry involved in developing a conjugate vaccine is of importance beacuse while some polysaccharides contain chemical grouping which can be conveniently utilized for conjugation, many medically important ones require derivatization before they can be coupled to protein. Derivatization of which can be achieved through various strategies, important to note is through hypervalent iodine oxidants. Two hypervalent iodine reagents, O-Methyl substituted-1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide (Me-IBX)and modified 1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide (mIBX)were successfully synthesized in preparation for the use in polysaccharide, polyribitol phosphate, (PRP) oxidation. The polysaccharide to be oxidised was first size reduced by microfluidisation to allow maximum oxidation. However, the extent to which oxidisation was achieved was not enough to conjugate the polysaccharide to the protein of preference, Bovine Serum Albumin, (BSA).

Le xénon est utilisé par la plupart des systèmes de propulsion électrique à grilles. Cependant sa rareté, son coût de production important ainsi que son usage dans de nombreuses applications industrielles font apparaître la nécessité de trouver une alternative à ce propergol. Il est apparu que l'iode était un candidat potentiel pour cela, étant beaucoup moins cher à produire et beaucoup moins rare. Il se présente sous forme de cristaux violacés dans les conditions standards de pression et de température et possède une pression de vaporisation peu élevée ainsi qu'un potentiel d'ionisation plus bas que celui du xénon. Un modèle global d'un plasma d'iode dans un propulseur électrique à grilles a donc été développé afin d'étudier le comportement et les performances d'un tel dispositif. Ces résultats de l'iode sont comparés à ceux du même dispositif obtenus par l'utilisation du xénon, les conditions d'opération étant bien évidemment similaires. Le modèle prédit une efficacité globale du propulseur 15% plus grande pour l'iode. Les résultats du modèle global en iode sont également comparés avec des résultats expérimentaux obtenus dans un propulseur électrique à grilles, sous des conditions d'opération et paramètres d'entrée similaires. Un band d'essai expérimental entièrement dédié à l'étude de l'iode comme nouveau propergol pour la propulsion à grilles a en effet été assemblé avec toutes les précautions nécessaires, l'iode étant un élément corrosif et chimiquement actif avec certains matériaux. Le banc d'essai en iode fut également utilisé pour effectuer la preuve de concept en iode du propulseur PEGASES. / Most state-of-the-art electric space propulsion systems such as gridded and Hall thrusters use xenon as the propellant gas. However, xenon is rare, expensive to produce and used in a number of competing industrial applications. Alternatives to xenon are currently being investigated, and iodine has emerged as a potential candidate. Its lower cost, larger availability, its solid state at standard temperature and pressure, its low vapour pressure and its low ionization potential makes it an attractive option. A global model of iodine plasma inside an ion gridded thruster has therefore been developed to study behaviour and performances of this propellant. We compared the iodine results with ones obtained in xenon under otherwise similar conditions. The model predicts a thruster efficiency 15% higher for iodine compared to xenon. Results of the iodine global model were compared with experimental data obtained under similar operating conditions and input parameters in a gridded ion thruster. An experimental test bench dedicated to iodine plasma study, inside a classic ion gridded thruster and PEGASES thruster, has been assembled with all precautions needed. Iodine is a corrosive gas and chemically active with certain metals and the right choice of materials is therefore important. The positive ion and electron densities obtained by the model and in experiments appeared to show close values, indicating that the iodine chemistry and reaction set used in the global model seem relevant to a first order approximation.

No description available.

La famille des composés halogènes et inter-halogènes représentent des solides moléculaires adoptant des phases denses communes avec des solides moléculaires diatomiques comme l’azote et l’hydrogène. Parmi les transformations structurales et électroniques induites sous haute pression et observées dans ces solides, on note, entre autres, la dissociation moléculaire et la métallisation. De plus, l’étude des phases denses de l’iode a permis récemment l’observation d’une structure cristalline possédant une modulation dite incommensurable, c’est-à-dire une modulation possédant une périodicité différente de celle de la structure cristalline, jetant ainsi une lumière nouvelle sur le processus de dissociation moléculaire dans les solides halogènes. Dans ce mémoire, on propose d’étudier les changements structuraux dans monobromure d’iode (IBr), un composé inter-halogène possédant des propriétés structurales semblables à celles de deux composés halogènes, soit l’iode (I2) et le brome (Br2) sous leur forme solide. Des expériences de diffraction des rayons X de poudres en utilisant un rayonnement synchrotron ont été réalisées à température ambiante sur l’IBr en variant la pression jusqu’aux environs de 60 GPa. La nature chimique particulière du composé IBr a nécessité la mise au point de techniques de chargement d’échantillon destinées à préserver l’intégrité chimique de la substance utilisée. On rapporte également l’observation d’une phase de l’IBr présentant une modulation incommensurable. Les phases observées dans l’IBr permettent d’établir des parallèles avec les phases denses rapportées dans I2 et Br2 par le biais d’un modèle phénoménologique décrivant la séquence structurale des solides halogènes sous forme condensée.