L’objectif de notre étude était de montrer le rôle du métabolisme oxydatif et énergétique au cours du vieillissement cutané et dans les cancers cutanés UVB-induits. Dans une première partie, nous avons cherché à établir un lien entre l'instabilité génétique, la production de ROS et l’altération métabolique dans le processus de vieillissement. Les résultats obtenus sur le modèle de souris XPC KO ont démontré qu’un excès de stress oxydatif dû à une sur activation du NOX1, couplé à des altérations métaboliques, jouaient un rôle prépondérant dans le vieillissement prématuré. L’application topique de notre nouvel inhibiteur de NOX, induisant l’inhibition de la production de ROS et ainsi l’apparition d’altération métabolique, a permis d’empêcher le vieillissement cutané prématuré chez les souris XPC KO. Nos résultats suggèrent que l’InhNOX peut être considéré comme une cible prometteuse dans la prévention du vieillissement prématuré et les maladies liées à NOX. Très peu d'informations sont disponibles sur la contribution de la reprogrammation du métabolisme énergétique dans l'initiation et la progression du cancer. Dans la deuxième partie de ma thèse, nous avons utilisé un modèle multi-étapes de cancer de la peau UVB-induits, nous permettant ainsi d’évaluer le rôle de la reprogrammation métabolique dans les différentes étapes de la cancérogenèse. Nous avons ensuite démontré que l'irradiation chronique à UVB entraînait une diminution de l’activité de la glycolyse, du cycle TCA et de la β-oxydation des acides gras, tandis que la synthèse d'ATP mitochondriale et une partie de la chaîne de transport d'électrons (CTE) étaient up-régulés. Nous avons montré que l’augmentation accrue de CTE été liée à la sur-activation des dihyroorotate déshydrogénase (DHODH). Alors que la diminution de l'activité DHODH ou ETC (chimiquement ou génétiquement) a conduit à une hypersensibilité à l'irradiation UVB. Nos résultats indiquent que la voie DHODH par l’induction de la synthèse d'ATP et de CTE joue un rôle majeur entre l'efficacité de réparation d'ADN et la reprogrammation métabolique au cours de la carcinogenèse UVB-induits. / Objective of the present research study was investigating the role of oxidative and energy metabolism in skin aging and UVB-induced skin cancer. In the first part, we aimed to find the link between genetic instability, ROS generation and metabolism alteration in the process of aging. The obtained results on XPC KO mice model demonstrated that excess of oxidative stress in addition to alterations in energy metabolism due to over activation of NOX1 play a causative role in premature skin aging. Topical application of novel NOX inhibitor prevented the premature aging in XPC KO mice through inhibition of ROS generation and alteration of energy metabolism. Our results suggest that the InhNOX can be considered as a promising target in prevention of premature aging and NOX-associated diseases. Little information is available on the contribution of energy metabolism reprogramming in cancer initiation and promotion. To assess the role of metabolic reprogramming in different phases of carcinogenesis, in the second part of my thesis we employed a multistage model of ultraviolet B (UVB) radiation-induced skin cancer. We showed that chronic UVB irradiation results in decreased glycolysis, TCA cycle and fatty acid β-oxidation while at the same time mitochondrial ATP synthesis and a part of the electron transport chain (ETC) are upregulated. Increased ETC was further found to be related to the over-activation of dihyroorotate dehydrogenase (DHODH). Decreased activity of DHODH or ETC (chemically or genetically) led to hypersensitivity to UVB irradiation. Our results indicated that DHODH pathway through induction of ETC and ATP synthesis represents the relation between DNA repair efficiency and metabolism reprogramming during UVB-induced carcinogenesis.

Le déterminisme génétique du sexe nécessite souvent l’évolution d’une région non-recombinante (NR) formant ainsi paire de chromosomes sexuels. Bien que la reproduction sexuée ait une origine commune à tous les eucaryotes, l’évolution des chromosomes sexuels s’est quant à elle effectuée de manière répétée et indépendante. Les chromosomes du sexe ont été particulièrement étudiés dans les systèmes diploïdes (chromosomes sexuels XY et ZW) des plantes et animaux. Le récent séquençage du génome d’Ectocarpus, modèle d’étude des algues brunes, donne non seulement une chance unique d’analyser les chromosomes sexuels dans un groupe phylogénétiquement distant des opisthocontes et de la lignée verte ; mais il donne aussi l’opportunité d’examiner un système haploïde de chromosomes sexuels (système UV). Chez Ectocarpus l’expression du sexe a lieu pendant la phase haploïde du cycle de vie, avec les chromosomes U et V, respectivement spécifiques aux femelles et aux mâles. L’analyse des chromosomes sexuels chez Ectocarpus a montré que la taille de la région NR est restée modeste pour un système vieux de plus de 70 millions d’années. Une analyse des dimorphismes sexuels a été effectuée ainsi que l’étude comparative des transcriptomes mâle et femelle d’Ectocarpus. Le développement parthénogénétique est, dans certaines populations d’Ectocarpus, un dimorphisme sexuel. Le lien génétique entre parthénogenèse et sexe a été analysé et suggère qu’un locus contrôlant la parthénogenèse est localisé au niveau de la partie recombinante du chromosome sexuel d’Ectocarpus. De plus, une analyse de fitness indique que le locus de la parthénogenèse est soumis à une sélection antagoniste entre les deux sexes. / Genetic sex determination is usually controlled by sex chromosomes carrying a non-recombining sex-determining region (SDR). Despite the common origin of sex (meiosis) in Eukaryotes, the evolution of sex chromosomes has evolved repeatedly and independently. Our knowledge in sex chromosomes comes mainly from the analysis of diploid systems (XY and ZW sex chromosomes) in animals and land plants. However the recent genome sequencing of the brown alga Ectocarpus, not only opens up the possibility of studying sex chromosomes in a phylogenetic distant group but also of analysing a haploid sex chromosome system (UV sex chromosomes). Indeed in Ectocarpus sex is expressed during the haploid phase of the life cycle, where U and V sex chromosomes are restricted to female and male, respectively. The Ectocarpus sex chromosomes have some unusual evolutionary features such as the size of the non-recombining region, which is surprisingly small for a 70 million year old system. Also the evolutionary aspect of sexual dimorphism was studied by analyzing male and female transcriptomes and by identifying several subtle sexual dimorphic traits. Parthenogenetic capacity is a sexual dimorphic trait in some populations of Ectocarpus. The genetic link between parthenogenesis and sex was analysed and a locus that controls parthenogenetic was located to the Ectocarpus sex chromosome, in the recombining pseudoautosomal region. Fitness analysis strongly suggested that the parthenogenetic locus is a sexual antagonistic locus

A sepse é a maior causa de morbidade e mortalidade em pacientes queimados, uma vez que profundas alterações ocorrem na farmacocinética de agentes anti-infecciosos prescritos para o controle das infecções. Além disso, pacientes queimados podem apresentar quadro de infecção por germes da comunidade, numa fase precoce de internação na UTI, devendo receber antimicrobianos que diferem daqueles indicados na infecção sistêmica causada por germes hospitalares. Adicionalmente, na vigência de infecção fúngica, o quadro se torna ainda mais grave para os pacientes queimados de prolongada internação e imunocomprometimento. No presente trabalho deve como objetivo realizar o monitoramento plasmático de fluconazol prescrito aos pacientes com infecção sistêmica fúngica internados na UTI e investigar a farmacocinética para o ajuste do regime de dose no controle da infecção fúngica nos pacientes queimados. Investigaram-se 12 pacientes queimados internados na UTI/ Unidade de Queimados - Divisão de Cirurgia Plástica do HC FMUSP, portadores de infecção fúngica recebendo fluconazol através de infusão. Os pacientes receberam o antifúngico geralmente em associação a outros antimicrobianos para o controle das infecções seguindo a recomendação da CCIH do hospital relativa ao regime de dose empírica inicial do controle de infecção na UTI de Queimados. Realizou-se o monitoramento plasmático do fluconazol através da coleta de amostras sanguíneas de pico e vale. Complementarmente, a critério Clínico, foram colhidas amostras seriadas de sangue (pico, 1ª, 2ª, 4ª, 6ª e vale), totalizando seis coletas, para investigação da farmacocinética do agente que requereu ajuste de dose e individualização de terapia no paciente queimado. As coletas de sangue foram realizadas através de cateter venoso (2 mL/coleta em tubos contendo EDTA sódico) pelo médico intensivista de plantão na UTI; o plasma foi obtido pela centrifugação para análise do fármaco de interesse ou então armazenado no congelador (-80° C) até o ensaio. Previamente à realização da Etapa Clínica, foi realizado no Laboratório a validação do método bioanalítico para quantificação do fluconazol no plasma com base na legislação nacional e boas práticas de laboratório, empregando a cromatografia líquida de alta eficiência (CLAE) com detector ultravioleta. A estatística foi realizada pelo tratamento estatístico com utilização do software GraphPad Instat 4.0., GraphPad Prism 4.0, pela utilização de testes não paramétricos. A modelagem farmacocinética foi realizada através da aplicação do software NonCompartmental Analysis, PK Solutions 2.0, aos pares de dados (C vs T) para o agente antifúngico investigado. Os pacientes queimados incluídos no protocolo eram adultos de ambos os sexos 8M/4F, 46,8 ± 20,6 anos, 69,9 ± 11,5 kg, 38,8 ± 24,0% de superfície corporal queimada, e os agentes da queimadura foram para 10 pacientes/ térmico-fogo e para dois pacientes/trauma elétrico; a lesão inalatória foi registrada em 50% pacientes com queimadura pelo fogo. Foram realizados 31 seguimentos farmacoterapêuticos com a emissão de laudos de resultado de exame para o fluconazol. Registrou-se alta variabilidade na farmacocinética para todos os parâmetros investigados. Adicionalmente, registrou-se alteração significativa na farmacocinética do fluconazol nos diversos seguimentos realizados nos pacientes queimados com disfunção renal dialítica quando comparados aqueles em que se registrou função renal preservada. O método bioanalítico mostrou-se adequado ao monitoramento das concentrações plasmáticas do fluconazol através cromatografia líquida de alta eficiência com detecção UV. Registrou-se alta variabilidade na farmacocinética desse agente que justificou em parte a substituição da terapia empírica inicial pela dose ajustada para garantia de terapia eficaz ao paciente queimado. / The sepsis is a main cause of morbidity and mortality in burn patients, once pharmacokinetics of anti-infective drugs prescribed for the control of systemic infections are significantly altered in those patients. In addition, burn patients in the ICU, initially can present infections by community microbial and must receive different antimicrobials than those prescribed for sepsis. On the other hand, burn immunocompromized patients with prolonged staying in the ICU, re-incidence of sepsis and fungal infection requires an effective antifungal agent that must be associated to the antimicrobials prescription. The objective of the study was to therapeutic plasma monitoring of fluconazole largely prescribed to burn patients from the ICU with fungal infection, Pharmacokinetic modeling for dose adjustment and for the control of infection. Twelve burn inpatients with systemic fungal infections from the ICU Burns- Division of Plastic Surgery of Clinics Hospital Medical School University of Sao Paulo received systemically antimicrobials/ antifungal agents. In general burn patients received several antimicrobial agents as recommended by the Control of Hospital Infection Committee as empirical dose at the beginning of therapy and also afterwards in the ICU. The control of infections by community microbial or yet by hospital microbial, and also for fungal infection, was performed by drug plasma after blood sample collection at the peak and at the trough. Complementary, usually by clinical criteria, six blood sample collections were performed at time dose interval (end of drug infusion 1st, 2nd, 4th, 6th and at the trough) for pharmacokinetic purposes, dose adjustment and individualization of drug therapy for burn patients. Blood sample collection was done by the physician from the ICU by venous catheter (2mL/each into blood collection tubes sodium EDTA); plasma obtained by centrifugation of blood tubes were analyzed in the same day or in a deep freezer to storage (-80° C) until assay. Bioanalytical method reported previously was re-validated as recommended by good laboratory practices (GLP). Parameters as linearity, sensitivity, precision and accuracy, recovery and stability, specificity and selectivity were determined for all drugs investigated to guaranteed drug plasma measurements during the pharmacotherapeutic follow up in the ICU. Descriptive statistics was performed by applying the software GraphPad Instat 4.0., GraphPad Prism 4.0 non parametric tests. Pharmacokinetics was estimated by applying the software NonCompartmental Analysis, PK Solutions 2.0, to data (C vs T) for each antimicrobial agent. Burn patients included in the protocol were of both genders 8M/4F, 46.8+/- 20.6 yrs, 69.9+/- 11.5 kg, 38.8+/-24.0% TBSA; agents of the accident were fire/ alcohol for 10 patients and electrical trauma for two patients; inhalation injury were described for 50% of patients with fire. High pharmacokinetic variability was registered for the antifungal agent investigated. In addition, significant changes on pharmacokinetic parameters were described for fluconazole for burn patients with dialytic renal dysfunction compared to those with renal function preserved. Bioanalytical methods validated with basis on good laboratory practices (GLP), recommended by the national and international guidelines were adequate for drug plasma monitoring by liquid chromatography, UV detection. High pharmacokinetic variability was obtained for fluconazol. In conclusion, it was demonstrated that PK modeling of antimicrobial is an important tool for the control of severe systemic fungal infection in burn patients.

L’origine et l’évolution des différentes structures qui peuplent l’au-delà de la photosphère du Soleil, ainsi que les processus qui interviennent dans la dynamique et le chauffage de sa couronne demeurent de nos jours assez peu compris. L’inextricable complexité inhérente aux phénomènes physiques qui gouvernent l’atmosphère externe solaire s’accompagne de l’absence de données adaptées au besoin scientifique. En effet, l’interprétation et la modélisation des « mécanismes » qui raccordent les échanges entre la chromosphère et la couronne dépendent de paramètres d’observation critiques. Il est par exemple essentiel de pouvoir mesurer de larges bandes de températures et densités verticales s’adaptant aux multiples échelles spatiales et temporelles caractéristiques des différents évènements qui se déroulent dans le Soleil. La compréhension de la dynamique des plasmas repose aussi sur l’analyse Doppler de la scène observée. Ceci implique notamment la capacité de combiner des techniques de spectroscopie et d’imagerie simultanément dans le temps. Pour la couronne, le passage à l’UV spatial est incontournable, et relève d’un véritable défi technique. Malgré les excellents progrès technologiques, l’étude UV du Soleil est une science relativement récente, et aucune mission spatiale solaire n’a pu fournir jusqu’à présent une spectro-imagerie combinée et simultanée dans le domaine spectral qui nous intéresse. C’est pour répondre à cette attente que l’étude d’un nouveau dispositif appelé IFTSUV (abréviation de Imaging Fourier Transform Spectrometer working in the far UV), est présentée dans cette recherche. Malgré l’absence de missions d’opportunité dans l’horizon proche, les travaux de thèse se sont déroulés suivant le plan de l’action R&T du CNES R-S11/OT-0004-040, concernant la définition d’un spectro-imageur à transformée de Fourier dans l’UV lointain, et la réalisation en laboratoire d’un démonstrateur de métrologie dédié, pierre angulaire de la faisabilité technique de l’instrument. Ainsi, partant de la détermination du besoin scientifique et de la justification du choix technique, le premier objectif de cette étude est de concevoir un modèle instrumental préliminaire complet de l’IFTSUV. La spécification technique est fondée sur le calcul de dimensionnement et l’évaluation théorique des spécifications en termes de précision spectrale, qualité de l’image et rapport signal sur bruit. A travers l’identification des points durs, la réalisation d’une métrologie d’asservissement du miroir d’échantillonnage apparait tout naturellement, comme un besoin intrinsèque de la validation du concept. En effet, l’acquisition de l’interférogramme doit se faire de manière rigoureusement constante et le pas d’échantillonnage doit être connu avec une grande exactitude, car il fixe les nombres d’onde pour lesquels les spectres bruts sont calculés. Le maquettage d’une solution métrologique constitue donc le deuxième objectif de ce travail. L’architecture optique mise en place a été choisie afin de satisfaire les besoins de stabilité angulaire (< 2.5 μrad) et de précision linéaire (< 8 nm) discernés, et testée en laboratoire. Les résultats sur la maquette valident le concept, même si ses performances s’éloignent des prédictions théoriques. L’évaluation expérimentale des performances permet d’établir des solutions aux problèmes rencontrés qui convergent vers l’optimisation et le prototypage d’un système pouvant être intégré dans une application spatiale. / The origin and evolution of the different structures that inhabit beyond the Sun’s photosphere, as well as the processes involved in the dynamics and the heating of the corona remain quite unknown. The inextricable complexity of the physical phenomena that govern the solar outer atmosphere is accompanied by the lack of suitable data adapted to the scientific need. Indeed, the interpretation and the models of the mechanisms that connect the exchanges between the chromosphere and the corona depend on critical observational parameters. It is for example essential to measure broad bands of vertical temperature and density ranges that fit the multiple spatial and temporal scales that are characteristic of the different events that take place in the Sun. The understanding of the dynamics of the plasma must be also based on the Doppler analysis of the observed scene. That implies the ability to combine time resolved spectroscopic and imaging technologies. Moreover, space is the place to observe the far UV corona and that implies a real technical challenge. Despite excellent advances in technology and instrumentation, the study of the Sun in the far UV is a fairly recent. To date, no solar space mission could provide a combined and simultaneous diagnostic of both observable in the spectral range of interest. It is because of these expectations that the study of a new device called IFTSUV (the acronym of Imaging Fourier Transform Spectrometer working in the far UV) is presented in this research. Despite the lack of opportunity missions on the near horizon, these thesis works have been conducted thanks to the R&D funding R-S11/OT-0004-040 from the CNES, concerning either the definition of an imaging Fourier transform spectrometer in the far UV, or the realization of a laboratory metrology demonstrator that is the cornerstone of the instrument’s feasibility. Thus, starting from the definition of the scientific requirements that lead to the technical choice, the first objective of this study is to develop a preliminary instrumental model of the IFTSUV. The overall technical and design specifications are based in theoreticalcalculations that have been expressed in terms of spectral accuracy, image quality and signal to noise ratio. Throughout the identification of difficult points, the realization of a servo-metrology system dedicated to the sampling mirror appears naturally as an intrinsic need of proof of concept. Indeed, the wavenumbers from the raw spectra are set by the interferogram. That implies that acquisition must be rigorously constant and that the sampling steps must be known with high accuracy. The mockup of a metrological solution is therefore the second objective of this work. The optical breadboard architecture under test has been chosen to meet the needs of angular stability (< 2.5 μrad) and linear accuracy (< 8 nm). The results on the demonstrator validate the concept even if its performances are away from the theoretical predictions. The experimental performance evaluation is used to establish solutions to the instrumental problems encountered. That converge to the optimization and prototyping of a system that could be integrated in a space based application.

Vidros dopados com íons terras-raras trivalentes TR3+, são materiais importantes devido a suas potenciais aplicações tecnológicas como em dispositivos luminescentes e lasers de estado sólido. Os TR3+ possuem níveis de energia eletrônicos que permitem obter emissões desde o ultravioleta até o infravermelho próximo. A classe de vidros tungstênio fosfatos tem sido amplamente estudada devido as suas propriedades incomuns aos vidros fosfato clássicos como, por exemplo, alta estabilidade térmica contra devitrificarão, absorção óptica não linear e efeitos fotocrômicos mediante irradiação. Neste trabalho, foram estudados vidros tungstênio fosfato dopados com os íons Nd3+, Tb3+ e co-dopados com os íons Er3+ e Yb3+, no sistema composicional 90NaPO3-10WO3 + x%Nd2O3 (x = 0,25; 0,5; 1; 3 e 5% em peso em excesso) 90NaPO3 &#8211; 10WO3 + y%TbF3 (y = 0,1; 0,5; 1; 3 e 5 em peso em excesso) (90-z-k)NaPO3 &#8211; 10WO3 + z%Er2O3 + k%Yb2O3 (z = 0,25; 0,5; e 1 mol%; k = 0 e 2 mol%). As amostras foram obtidas pelo método convencional de fusão e resfriamento e foram caracterizadas por absorção UV-VIS-NIR, fotoluminescência (emissão e excitação), e tempos de vida de estado excitado. Para as amostras dopadas com Nd3+ foram observadas emissões intensas em 1060 nm, os tempos de vida do nível emissor 4F3/2 foram medidos e a eficiência quântica do sistema foi estimada. As amostras dopadas com Tb3+ apresentaram o pico de emissão de maior intensidade em 542 nm, porém para os vidros com baixa concentração de íon dopante, duas transições com intensidades relativas da mesma ordem da transição do verde, correspondentes a emissões em 415 nm e 435 nm, foram observadas e o tempo de vida para estado emissor 5D4 também foi medido. Os vidros co-dopados com Er3+/Yb3+ apresentaram emissões intensas em 522 nm, 545 nm e 658 nm em um processo de conversão ascendente de energia (upconversion) que envolve dois fótons. Os tempos de vida do estado emissor 4I13/2 do Er3+ dessa amostra também foram mensurados. / Glasses and glass-ceramics doped with trivalent earth-rare ions TR3+, are important materials due to their potential technological applications, such as in luminescent devices and solid-state lasers. These ions have electronic energy levels that allow emissions from ultraviolet to infrared. The tungsten phosphate glass class has been extensively studied due to its unusual properties when compared to the classical phosphate glasses, such as high thermal stability against devitrification, nonlinear optical absorption, photochromic effects under visible irradiation, and efficient emission properties of earth-rare ions. In this work, tungsten phosphate glasses doped with Nd3+ and Tb3+ ions. and co-doped with Er3+ and Yb3+ ions, were studied in the compositional system 90NaPO3-10WO3 + x%Nd2O3 (x = 0.25; 0.5; 1; 3 e 5% by weight in excess) 90NaPO3 &#8211; 10WO3 + y%TbF3 (y = 0.1; 0.5; 1; 3 e 5 by weight in excess) (90-z-k)NaPO3 &#8211; 10WO3 + z%Er2O3 + k%Yb2O3 (z = 0.25; 0.5; e 1 mol%; k = 0 e 2 mol%). The samples were obtained by the conventional melt quenching technique and were characterized by UV-VIS-NIR absorption, photoluminescence (emission and excitation), and excited state lifetime values. For samples doped with Nd3+ intense emissions were observed at 1060 nm, the lifetimes of the 4F3/2 emitting level were measured and the quantum efficiency of the system was estimated. The Tb3+ doped samples presented the highest intensity emission peak at 542 nm, but for the glasses with low dopant ion concentration, two transitions with relative intensities of the same order of the green transition, corresponding to emissions at 415 nm and 435 nm were detected. The lifetime value of the 5D4 emitting state was also measured. The Er3+/Yb3+ co-doped glasses exhibited intense emission at 522 nm, 545 nm and 658 nm in an upconversion process involving two photons, the lifetime of the emitting state 4I13/2 of Er3+ were also measured for these samples.

The solar radiation in general and UV radiation in particular has been recognized to stimulate plant litter decomposition through photochemical mineralization of photosensitive organic molecules, such as lignin, facilitating microbial decomposition, with great relevance role in dryland ecosystems where microbial activity is low, however little is known about how photodegradation could influence other ecosystems without moisture limitations and under what conditions may be favored, therefore the mechanisms has not yet been established. Decomposition in tropical ecosystem is a complex process and can be induced by a number of environmental factors with certain differences when compared to arid and semi-arid ecosystems. To assess the mechanisms underlying UV-B photodegradation, we designed a 300 days field experiment at a tropical ecosystem with high levels of annual precipitation and exposure litter to three levels of radiation combined with a biocide treatment. Results show that the removal of UV-B radiation decelerated plant litter decomposition during the later stage compared to litter exposure to full sun, however shaded litter had similar mass loss compared to litter exposed to full sun. Furthermore, differences in the decay constant among radiation treatments due to UV-B effect is independent of lignin loss. Overall, our study suggest that UV-B contributes to the plant litter decomposition through carbon losses, however, had no effect on nitrogen, neither lignin nor cellulose loss. However, more studies are needed in order to investigate the positive and negative effects of UV exposure on microbial activity in tropical ecosystems. / A radiação solar em geral e a radiação ultravioleta (UV) em particular têm sido reconhecida por estimular a decomposição da serapilheira através da mineralização fotoquímica de moléculas fotossensíveis, como a lignina, facilitando a decomposição microbiana, com um papel de grande relevância em ecossistemas áridos onde a atividade microbiana é baixa, no entanto pouco se sabe como a fotodegradação pode influenciar outros ecossistemas como por exemplo os mais úmidos e sob quais condições a fotodegradação é favorecida, portanto os mecanismos ainda não foram estabelecidos. Decomposição em ecossistemas tropicais é um processo complexo e pode ser influenciado por vários fatores ambientais e com certas diferenças quando comparada com ecossistemas áridos e semiáridos. Para avaliar os mecanismos subjacentes à fotodegradação via radiação UV-B, um experimento de campo de 300 dias foi estabelecido em um ecossistema tropical com alto índice de precipitação anual onde a serapilheira foi exposta a três níveis de radiações diferentes, combinada com um tratamento com biocida. Resultados mostram que a remoção da radiação UV-B desacelerou a decomposição da serapilheira durante o último estágio do experimento comparado com a serapilheira exposta a radiação ambiente, no entanto a serapilheira quando sombreada teve perda de massa similar à exposta a radiação ambiente. Além disso, diferenças na taxa de decaimento entre os tratamentos de radiação devido ao efeito da radiação UV-B foram independentes da perda de lignina. No geral, nosso estudo sugere que a radiação UV-B contribui com a decomposição da serapilheira através da perda de carbono, no entanto não teve efeito na perda de massa de nitrogênio, lignina e celulose. Portanto, mais estudos são necessários para investigar o efeito positivo e negativo da exposição à radiação UV-B na atividade microbiana e na decomposição da serapilheira em ecossistemas tropicais.

Submitted by Diego da Silva Manoel null (diegosma@rc.unesp.br) on 2017-02-05T16:40:20Z No. of bitstreams: 1 Dissertação Diego.pdf: 1793320 bytes, checksum: ba0a17055ebb3486b214146535165ef9 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-02-06T18:25:08Z (GMT) No. of bitstreams: 1 manoel_ds_me_rcla.pdf: 1793320 bytes, checksum: ba0a17055ebb3486b214146535165ef9 (MD5) / Made available in DSpace on 2017-02-06T18:25:08Z (GMT). No. of bitstreams: 1 manoel_ds_me_rcla.pdf: 1793320 bytes, checksum: ba0a17055ebb3486b214146535165ef9 (MD5) Previous issue date: 2017-01-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O processo sol-gel permite a produção de materiais Híbridos Orgânicos/Inorgânicos para aplicações em óptica e fotônica. Materiais Híbridos de Sílica/orgânico unem propriedades da Sílica e dos polímeros orgânicos e permitem a incorporação de diversas moléculas orgânicas na matriz, possibilitando a obtenção de materiais fotoativos avançados. Destas moléculas destacam-se os corantes lasers, como a Rodamina-B, que possui comprimento de onda de emissão bem definido e alta eficiência quântica. Neste trabalho preparamos materiais híbridos de sílica/orgânico via processo sol-gel utilizando como precursores os alcóxidos de silício 3-glicidoxipropiltrimetoxisilano (GPTS) e tetraetilortosilicato (TEOS). Amostras ainda na fase de sol foram dopadas com Rodamina-B em concentrações variando de 0,01 a 5 mmol/L. A fluorescência das amostras foi caracterizada mostrando dependência entre as características da emissão e a concentração de dopante. Os espectros de fluorescência sofrem um deslocamento para a região do vermelho com o aumento da concentração do dopante, enquanto a intensidade de emissão apresenta maior valor para a amostra com concentração de 0,5 mmol/L. Também foram determinados os coeficientes de absorção óptica, que apresentaram comportamento linear com a concentração. A partir das amostras (sol) foram produzidos xerogéis com concentrações de Rodamina-B de 0,0386 a 19,3 mmol/L. Os espectros de fluorescência destes xerogéis também apresentaram deslocamento para a região do vermelho para maiores concentrações de dopante, a intensidade de emissão é máxima para o xerogel com concentração de 6,56 mmol/L. Os coeficientes de absorção óptica dos xerogéis apresentaram um comportamento linear com a concentração de dopante. O xerogel com concentração de 19,3 mmol/L de Rodamina-B apresentou emissão de laser randômico quando excitado com laser pulsado (532 nm, 8ns), fenômeno caracterizado por um estreitamento da banda de emissão devido a dímeros da Rodamina-B em 630 nm. Microscopia eletrônica de transmissão revelou a formação de partículas de Sílica com diâmetro médio de 6,3 nm distribuídas na matriz sólida. Estes resultados são de grande interesse para aplicações em fotônica. / Organic-Inorganic Hybrid Materials prepared by sol-gel process have applications in different areas such as optics and photonics. Silica/organic hybrid materials combine the properties from the silica and the organic polymers and can be doped with organic molecules with different optical properties, allowing preparation of advanced photoactive materials. In the wide range of photoactive organic materials one of interest is the Rhodamine-B, a laser dye which presents tunable emission and high quantum yield. In this work we have produced hybrid silica/organic samples derived from 3-glycidoxypropyltrimethoxysilane (GPTS) and tetraethylorthosilicate (TEOS) by sol-gel process. Silica/organic sols were doped with Rhodamine-B concentrations ranging from 0.01 to 5 mmol/L. The fluorescence spectra of the samples were characterized and a relationship between emission characteristics and dopant concentration has been observed. A red shift in the wavelength emission was observed, as the dopant concentration increased and the maximum emission intensity was achieved for the sample with concentration of 0.5mmol/L. Were determined the optical absorption coefficients that showed a linear relation with the concentration. The sol samples were dried and xerogels were obtained and the new concentrations of Rhodamine-B in the solid matrix were determined, ranging from 0.0386 to 19.3 mmol/L. The fluorescence spectra of the xerogels were characterized, showing a red shift as the dopant concentration increased and the maximum emission intensity was achieved for the xerogel with concentration of 6.56 mmol/L. The optical absorption coefficients of these xerogels showed a linear behavior with the dopant concentration. Random laser action for the xerogel with concentration of 19.3 mmol/L was measured using an pulsed laser (532 nm, 8ns), and characterized by a narrowing emission of the Rhodamine-B dimmers emission at 630 nm. Transmission electron microscopy revealed silica particles with 6.3 nm average diameter in the solid matrix. These results are very important for applications in photonics.

The goal of the diploma thesis was to prepare a spectrum of electron-rich macrocyclic derivatives of tetrathiafulvalene (TTF), which should serve as electron donors in interactions with electron-deficient acceptor molecules. A two-step synthesis was used for their preparation. First, a non-cyclic three-segment precursor was prepared by a reaction of a thiolate TTF construction block with a bis(bromomethyl)aromate. Then, a reaction of this precursor with another molecule of bis(bromomethyl)derivative closed the macrocycle. The latter reaction produced mainly [2+2] macrocycles containing two TTF and two aromatic units. In most cases, larger [4+4] macrocycles were also isolated from the reaction mixture. Besides thiolate TTF unit two other thiolate units, one with extended TTF core and other with smaller trithiafulvene ring, were used analogically in synthesis. By a combination of three thiolate blocks and five bis(bromomethyl)aromates 11 three-segment components were prepared and these were converted to 11 structural types of macrocycles with [2+2] and 7 macrocycles with [4+4] stoichiometry. The resulting macrocycles were characterized by 1 H a 13 C NMR spectroscopy and analyzed by a gel permeation chromatography. Their structures were also confirmed by high-resolution mass spectroscopy. Interaction...

Os efluentes corados ainda são um problema em estações de tratamento de esgoto. Os corantes normalmente apresentam estruturas complexas e difíceis de serem degradadas por processos convencionais, entrando no meio ambiente aquático e causando impacto visual, mudanças nas características físico-químicas da água, prejudicam a fotossíntese do meio e podem apresentar efeitos ecotóxicos. Para o tratamento de vários tipos de efluentes, os Processos Oxidativos Avançados (POAs) são eficientes, rápidos e promovem uma oxidação não seletiva. Os POAs podem se tornar mais eficazes com o acoplamento de outras tecnologias, como as micro-ondas. As micro-ondas não possuem energia suficiente para quebrar as ligações intermoleculares, mas quando somadas ao processo UV/H2O2 pode haver um efeito sinérgico melhorando o desempenho do POA. Neste trabalho, buscou-se a otimização do processo UV/H2O2 acoplado às micro-ondas utilizando-se uma lâmpada de descarga sem eletrodo (LDE) de Hg e Fe. Utilizou-se um planejamento experimental para estudar a degradação de uma mistura de três corantes ácidos de classes diferentes: Acid Blue 9 (C.I. 42090, triarilmetano), Acid Red 92 (C.I. 45410, xanteno) e Acid Yellow 23 (C.I. 19140, monoazo). A variável-resposta observada foi a concentração residual dos corantes medida por CLAE. As condições ótimas para o tratamento foram: concentração inicial de peróxido de hidrogênio = 125 mg L-1, pH= 6,2 e vazão = 800 mL min-1. Em 180 min de tratamento, correspondente a 45 min de irradiação alcançou-se uma degradação de 23, 20 e 98% para AB9, AR92 e AY23 respectivamente. O modelo cinético foi de pseudo 1ª ordem para o AY23, com k = (1,7 &#177;0,041) × 10-2 min-1 e R² = 0,990. Não foi possível determinar a cinética de degradação do AB9 e do AR92 por causa da baixa degradação alcançada (aproximadamente uma ordem de grandeza menor). A partir das análises de espectrometria de massas, observou-se um único produto de degradação: o AY23 monohidroxilado. Esse produto não apresentou ecotoxicidade para o organismo-teste L. sativa. No entanto, ele foi tóxico para o organismo D. similis, imobilizando os microcrustáceos em todas as diluições testadas. / Colored effluents are still a problem in wastewater treatment plants. Dyes usually have complex structures that are difficult to be degraded by conventional processes, thus entering into the aquatic environment and causing visual impact, changes in the water physicochemical characteristics, impairing photosynthesis, and posing ecotoxic effects. For the treatment of various types of wastewater, the Advanced Oxidation Processes (AOP) are efficient, fast and promote non-selective oxidation. AOPs can become more effective by coupling them to other technologies, such as microwaves. Microwaves do not have enough energy to break intermolecular bonds, but when coupled to the UV/H2O2 process, there may be a synergistic effect improving the AOP performance. In this study, the UV/H2O2 process coupled to microwaves, using an Hg and Fe electrodeless discharge lamp (EDL), was optimized. An experimental design was performed to study the degradation of a mixture of three acid dyes of different classes: Acid Blue 9 (C.I. 42090 , triarylmethane), Acid Red 92 (C.I. 45410, xanthene), and Acid Yellow 23 (C.I. 19140, monoazo). The observed response variable was the residual concentration of the dyes measured by HPLC. The optimum conditions for the treatment were: initial hydrogen peroxide concentration = 125 mg L- 1, pH = 6.2, and flow rate = 800 mL min-1. In 180 min of treatment, corresponding to 45 min of irradiation, it was achieved a degradation of 23, 20, and 98% for AB9, AR92, and AY23 respectively. The AY23 degradation followed a pseudo-first-order kinetic model, with k = (1.7 &#177;0,041) × 10-2 min-1 and R² = 0.990. It was not possible to determine the degradation kinetics of AB9 and AR92 due to the low degradation achieved (approximately one order of magnitude lower). From mass espectrometry analyses, only one degradation product was observed: monohydroxilated AY23. That product showed no ecotoxicity towards the test-organism L. sativa. However, it was toxic towards the test-organism D. similis, immobilizing the microcrustaceans in all tested dilutions.

Nesse trabalho foi estudada uma técnica para a detecção de OHTC na água salina. Descobriu-se que certos complexos de rutênio em determinados valores de pH reagem com a molécula de OHTC e isto é detectável por espectrofotometria UV-Vis. Foram estudados os complexos fac-[RuCl2(S-DMSO)3(O-DMSO)] (complexo 1), {[(DMSO)2H][trans-RuCl4(DMSO)2]} (complexo 2) e cis-[RuCl2(bpy)2].2H2O (complexo 3). O complexo 1 possui um dos ligante (O-DMSO) que pode ser substituído pelo OHTC. Já o complexo 2 possui um dos ligantes (S-DMSO) na posição trans um ao outro, e o complexo 3 possui os 2 íons Cl- para tal finalidade. Determinou-se que o complexo 1 é viável, mesmo em presença de sais presentes na água do mar. Assim a reação foi realizada em função do tempo, variação do pH, temperatura e concentração de OHTC. Nos outros dois complexos os estudos foram realizados sem a variação da temperatura e concentração de OHTC. / p>In this work we studied a technique for detection of OHTC in water. It was discovered that complexes involving ruthenium, on determined pH values, react with the OHTC molecule and this is detectable by UV-VIS spectroscopy. The complexes fac-[RuCl2(S-dmso)3(O-dmso)] (complex 1), {[(DMSO)2H][trans-Ru(DMSO)2Cl4]} (complex 2), and cis-[RuCl2(bpy)2].2H2O (complex 3) were studied. The complex 1 present one position ( O - DMSO) which can be substituted by the OHTC. Additionally, the complex 2 present two ligands ( S- DMSO) trans between each other, and the complex 3 present two chloride ions for the same porpose of complex 1 respectively. It was determined that the complex 1 was able to react with OHTC even in presence of the salts present in sea water. Thereby, the reaction involving complex 1 and OHTC was monitored in function of the time, pH, temperature, and finally concentration of OHTC. On the other two complexes, the reaction was studied without variation of temperature and concentration of OHTC.