Submitted by Maria Eneide de Souza Araujo (mearaujo@ipen.br) on 2015-09-02T12:47:25Z No. of bitstreams: 0 / Made available in DSpace on 2015-09-02T12:47:25Z (GMT). No. of bitstreams: 0 / A Radioterapia em Arco Modulado Volumétrico (VMAT) é uma técnica avançada de Radioterapia de Intensidade Modulada (IMRT). Esse avanço na técnica é devido à rotação contínua do gantry juntamente com a modulação do feixe de radiação proporcionando um tempo menor no tratamento do paciente. O objetivo desse trabalho é a verificação de curvas de isodose em uma simulação de um tratamento de vértebra com proteção de medula espinhal utilizando as técnicas de dosimetria termoluminescente (TL) e luminescência opticamente estimulada (OSL) e os dosímetros de LiF:Mg,Ti (TLD-100), CaSO4:Dy e Al2O3:C e microdosímetros de LiF:Mg,Ti (TLD-100). Os dosímetros foram caracterizados com a utilização de placas de PMMA de 30x30 cm2 e diversas espessuras. Todas as irradiações foram feitas utilizando o acelerador linear Truebeam STx da Varian do Hospital Israelita Albert Einstein, com feixe de fótons de 6 MV. Após a caracterização dos dosímetros, os mesmos foram irradiados seguindo a simulação do planejamento escolhido e utilizando um objeto simulador de PMMA produzido para medidas de VMAT. Essa irradiação teve como finalidade verificar através das duas técnicas de dosimetria as curvas de isodose dessa simulação de tratamento. Todos os tipos de dosímetros apresentaram resultados satisfatórios na verificação das curvas de isodose utilizando ambas as técnicas de dosimetria. Porém, analisando a complexidade das curvas de isodose e a possibilidade das curvas estarem muito próximas, o microdosímetro de LiF:Mg,Ti se mostrou o mais apropriado para o uso devido à suas pequenas dimensões. Em relação à melhor técnica, como ambas apresentaram resultados satisfatórios, a técnica TL é a que apresenta menor complexidade em ser utilizada, pois a maioria dos Departamentos de Radioterapia já possuem um Laboratório para leitura TL. A técnica OSL exige mais cuidados e maior investimento do Departamento. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Orientadores: Fernando Aparecido Sigoli, André Luiz Barboza Formiga / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T19:44:19Z (GMT). No. of bitstreams: 1 Monteiro_JorgeHenriqueSantosKlier_D.pdf: 54893672 bytes, checksum: 68dcf83b484b6ed57a8eac7493d1ef01 (MD5) Previous issue date: 2014 / Resumo: Neste trabalho sintetizaram-se os ligantes 4-azidadipicolinato (dipicN3), 4-aminodipicolinato (dipicNH2) e 4-aminopiridina-bis(oxazolina) (pyboxNH2), bem como seus complexos com íons lantanídeos(III) solúveis em água. Sintetizaram-se também complexos insolúveis em água, contendo ligantes derivados dos ácidos benzóico, fenilselenínico e fenilfosfínico. A coordenação dos complexos foi verificada utilizando espectroscopia de absorção no infravermelho, enquanto que a estequiometria dos complexos foi confirmada utilizando análise elementar de carbono e hidrogênio, titulação complexométrica, espectrometria de massas e 1H-RMN. Também foram obtidas as estruturas de alguns complexos por difração de raios X de monocristal. Com os complexos análogos de gadolínio(III) foram obtidos os espectros de fosforescência do ligante a ?77 K com resolução temporal para determinação da energia do nível tripleto, a qual foi obtida pelo método da tangente ou da transição 0-0 fônon. Os complexos de európio(III) foram classificados, comparativamente, em função da simetria pontual, utilizando os espectros de emissão, parâmetros de intensidade de Judd-Ofelt e razão assimétrica, e também em função do grau de covalência da ligação Eu ¿ O, obtido pelo baricentro da transição 5D0 ? 7F0. Foi também medido o tempo de vida de emissão e o rendimento quântico dos complexos contendo os íons európio(III) ou térbio(III). As geometrias do estado fundamental foram determinadas utilizando o método Sparkle/PM3, sendo assim possível explicar alguns dos resultados experimentais obtidos, tal como a alta eficiência de sensitização de alguns complexos. Os complexos de európio(III) e térbio(III) com os ligantes dipicN3, dipicNH2 e pyboxNH2 apresentaram luminescência em solução aquosa, tempo de vida > 1 ms e rendimento quântico na faixa 15 ¿ 40 %, qualificando-os como marcadores luminescentes em sistemas biológicos. Os ligantes e seus complexos tiveram suas citotoxicidades testadas contra células normais (NIH/3T3) e células neoplásicas (NG97, câncer de cérebro e PANC1, câncer de pâncreas). Somente os complexos apresentaram atividade citotóxica e esta é seletiva para células NG97 e PANC1. O complexo K3[Eu(dipicNH2)3] foi capaz de atravessar a barreira hemato-encefálica e foi utilizado como marcador luminescente para células NG97 e PANC1 / Abstract: Water-soluble lanthanide complexes with the ligands 4-azidodipicolinate (dipicN3), 4-aminodipicolinate (dipicNH2) and 4-aminopyridine bis-oxazoline (pyboxNH2) were synthesized, a long with water-insoluble lanthanide complexes with ligands derived from benzoic, phenylseleninic or phenylphosphinic acids. The coordination modes of the carboxylic ligands were verified by FT-IR. The stoichiometries of the complexes were confirmed by carbon and hydrogen elemental analysis, complexometric titration and mass spectrometry. The crystal structures of some complexes were determined by single crystal X-ray diffraction. The time-resolved phosphorescence spectra of the ligands were obtained at ?77 K using the gadolinium(III) analogs complexes in order to obtain the energies of triplet levels. The triplet energies were determined by the tangent method or the 0-0 phonon transition. The europium(III) complexes were classified, comparatively, as a function of the point symmetry, using the emission spectra, Judd-Ofelt intensity parameters and the asymmetric ratio, and as a function of the Eu ¿ O bond covalence degree, obtained from the centroid of the 5D0 ? 7F0 transition. The emission lifetimes and quantum yields for the europium(III) and terbium(III) complexes were also determined. The ground state geometries were calculated using the Sparkle/PM3 method and were used to explain some of the experimental results such as the high sensitization efficiency of some complexes. The europium(III) and terbium(III) complexes with the ligands dipicN3, dipicNH2 and pyboxNH2 showed luminescence in water, emission lifetimes > 1 ms and quantum yields in the range 15 ¿ 40 %, qualifying them as potential luminescent markers for biological systems. Cytotoxic assays using the ligands and their complexes against normal cells (NIH/3T3) and neoplastic cells (NG97, brain¿s cancer and PANC1, pancreatic cancer) were performed. Only the complexes showed selective cytotoxicity against NG97 and PANC1 cells. The complex K3[Eu(dipicNH2)3] was able to cross a simulated blood-brain barrier and was also used as a luminescent marker for NG97 and PANC1 cells / Doutorado / Quimica Inorganica / Doutor em Ciências

The high incidence rate of Nasopharyngeal Carcinoma (NPC) in southern China, including Hong Kong, has attracted worldwide attention. According to the Center for Health Protection in Hong Kong, there were 841 new cases of NPC, with 655 cases of males and 186 cases of females in 2013. The development of NPC is highly associated with the infection of one human herpes virus, the Epstein-Barr virus (EBV). Given that the homodimerization of one of the EBV endogenous protein-Epstein-Barr Nuclear Antigen 1 (EBNA1) is essential for both viral genome maintenance and infected-cell survival, thus the interference of EBNA1 homodimerization would be a novel strategy for the inhibition of EBV-positive tumours. In this thesis we devote to conjugate several kinds of organic fluorophores with various EBV-specific peptides in order to achieve the highly responsive and selective imaging, as well as the effective inhibition of EBV-positive tumours in vitro and in vivo. The first research focused on the conjugation of a styrene pyridine fluorophore with two EBNA1-specific peptides, aiming to develop a dual-probe for the imaging and inhibition of EBV-positive tumour cells. Then we tried to introduce a Nuclear Localization Sequence into the EBNA1-specific peptide, and used an Intra-molecular Charge Transfer characterized fluorophore for the following second research, it showed an impressively responsive signal when the probe binds with EBNA1 both in vitro and in vivo, more importantly, only 4 μg probe can inhibit 92.8% of growth inhibition of an EBV-positive tumour. Along this line, our last research centred on the further improvement of the imaging by taking advantage of lanthanide.

Luminescent transition metal complexes have arisen as viable alternatives to organic dyes for sensory applications due to their notable advantages. This thesis aimed to synthesize different kinds of iridium(III) complexes as chemosensors and G-quadruplex probes for the detection of metal ions, small molecules, proteins and DNA to demonstrate the versatility of iridium(III) complex in luminescence sensing. Iridium(III) complex chemosensors were synthesized and developed for the detection of Cu2+ and cysteine. The iridium(III) complex plays the role of the "signaling unit", which transduces the analyte binding event into an optical (luminescent) signal and the "receptor unit" attached to the metal complex selectively binds the analyte of interest. Meanwhile, a series of iridium(III) complexes incorporating a variety of C^N and N^N donor ligands were synthesized and were shown to exhibit G-quadruplex-selective binding properties via emission titration, fluorescence resonance energy transfer melting and G-quadruplex fluorescent intercalator displacement experiments. These G-quadruplex-selective Ir(III) complexes were utilized as signal transducers to monitor the conformational changes of oligonucleotides in label-free oligonucleotide-based luminescent detection platforms for metal ion (Ag+), small molecules (cocaine), protein (insulin and AGR2) and gene deletion.

Depuis quelques années, les matériaux luminescents mécanochromiques présentant un changement réversible de leur longueur d'onde d'émission en réponse à un stimulus mécanique externe, suscitent un grand intérêt en raison de leurs applications potentielles pour les mémoires optiques ou les capteurs de pression par exemple. En effet, au cours des cinq dernières années, le nombre de composés luminescents sensibles à la pression rapportés dans la littérature a explosé avec des exemples basés principalement sur des molécules organiques. Comparativement, l’étude de complexes de métaux de transition reste relativement limitée et sont majoritairement des complexes d'or et de platine. Les travaux de recherches menés concernent l’étude des propriétés de mécanochromisme de luminescence de clusters moléculaires d'iodure de cuivre. Après broyage mécanique, leurs propriétés de photoémission sont grandement modifiées. De plus, ces composés ont la particularité de présenter à la fois des propriétés de mécanochromisme et de thermochromisme de luminescence. / In the last years, mechanochromic luminescent materials which exhibit reversible modification of the emission wavelength in response to external mechanical stimuli have attracted great attention because of their potential applications in optical memory devices, pressure sensing systems, for instance. Indeed, due to their promising development, the number of reported pressure sensitive luminescent compounds has exploded in the five last years with examples based mainly on organic dyes. Examples of transition-metal complexes are comparatively limited and essentially based on gold and platinum metals. The developed research concern the study of the mechanochromic luminescent properties of molecular copper iodide clusters. Upon mechanical grinding, their photoemission properties are greatly modified. These compounds have the particularity of exhibiting both mechanochromic and thermochromic luminescence properties.

The general theme of this dissertation concerns how the locality of an anionic moiety, be it a weakly coordinating anion or an anionic ligand, affect the spectroscopic and structural properties of organotransition metal complexes. Probing the columbic interactions between traditional and novel weakly coordinating anions with transition metal complexes, enables synthetic chemists to select anions that can improve catalytic transformations, impart stability of reactive intermediates, or develop new mechanistic insights. Additionally, presented herein is the manifestation of a new class of luminescent copper complexes which bear a weakly coordinating anionic N-heterocyclic carbene ligand.Firstly, a qualitative scale of coordinating ability is prepared by pairing traditional anions and weakly-coordinating anions with [Pd(IPr)(C(O)C9H6N)]+. NMR, IR, Computation, %Vbur, and X-ray crystallographic techniques are used to study the solution and solid-state interactions of these salts. During this study, a novel anion, denoted IMP- is prepared where two B(C6F5) groups are bridged by a phenyl imidazole core. Ultimately, it was found that sterics dictate coordinating ability observed by NMR and %Vbur, while IR and computation show the electronic effects of anion coordination. Continuing our understanding of the interplay between cation and anion, anionic Au(I) complexes are synthesized and paired with the same palladium cation in our first investigation. The framework of these Au(I) anions features a weakly coordinating N-heterocyclic carbene ligand that bears a borate moiety of the NHC backbone. Facile dissociation of a dimethyl sulfide ligand with metal alkoxide/phenoxides/thiophenoxides affords sodium or potassium salts. With these anions in hand, ion pairs are isolated in polar solvents and in the solid state. Au anions reside in the outer sphere of the palladium cation; like that of weakly coordinating anions such as BArF4-. Lastly, Luminescent group 11 organometallic complexes featuring N-heterocyclic carbene (NHC) ligands offer a swath of applications; catalytic transformations in organic chemistry to inorganic material uses in light emitting technologies. Conventional complexes are of the type NHC-M-X, where M is Cu, Ag, or Au and X represents anionic ligands that are often prone to hydrolysis. In this dissertation, Cu(I) complexes featuring this N- heterocyclic carbene ligand bearing a weakly coordinating anionic substituent (WCA-NHC) are prepared. (WCA-NHC)-M-L are air and moisture stable and differ from conventional NHC-M-X in that the metal can be supported by 2 datively-bound ligands. Initial computation reveals a change in dipole of (WCA-NHC)-Cu-PR3 charge transfer compared to that of reported NHC-M-X. By exchanging triphenylphosphine for diphenyl-2-pyridyl phosphine, we can change the emission wavelength by about 200 nm. / Chemistry

X-ray imaging scintillators and detectors play a critical role in numerous everyday life applications, including medical radiography, high-energy physics research, and security inspections. Despite its importance, current X-ray imaging technologies are not fully equipped to meet the growing demands for flexible, cost-efficient, and environment-friendly solutions. To overcome the limitations associated with traditional imaging scintillators, recent research efforts have focused on developing lead-free luminescent materials. Of particular interest are Cu(I) complexes, which exhibit excellent photoluminescence behavior, a facile synthesis process, and a high atomic number, making them an ideal candidate for X-ray imaging applications. Our work focuses on developing a low-dimensional Cu(I) organometallic halide and utilizing it as an imaging scintillator for real-life X-ray imaging. By utilizing the 0D Cu(I)-based imaging scintillators, we successfully obtained detailed images of both biological and non-biological objects, with a low detection limit of 458.3 nGy/s and high resolution of 16.8 lp/mm. This study not only provides a design roadmap for Cu(I) luminescent materials, but also highlights their potential for high-impact real-life X-ray imaging applications. Overall, our findings represent a significant step forward for X-ray imaging technology and its widespread applications in fields such as medicine and security.

Luminescent materials can be found in a broad range of everyday applications. While in the seventies and eighties, the field of luminescent materials seemed to be fairly well covered, research in nineties has been revitalized both in industry and academia. Improvements over the last three decades have led to phosphor materials that operate close to their physical limits. It cannot be expected that properties such as quantum yield and spectral energy distribution will be significantly improved or that distinctly better materials will be found in the near future. Recently, there is a considerable research activity in the field of luminescent materials for lighting and displays to improve the chemical stability and to adopt the materials to the production technology. Ongoing miniaturization, lifetime improvement and spectral stability of fluorescent lamps on the one hand and brightness and contrast improvement in imaging systems on the other hand demand luminescent materials with very high stability that is invariable to operating conditions. All of the today's efficient lighting sources are based on either direct or indirect light emission from plasma discharges. During the pioneering stage, fluorescent lamp industries predominantly used mixtures of two photo luminescent materials: (Zn,Be)2SiO4.'Mn2+ having two emission maxima at 520 and 600 nm and MgW04 with 480 nm emission. The emission from these two phosphors covers the major portion of the visible spectrum. However, the compound (Zn,Be)2Si04 is hazardous to health because of its beryllium content. In 1942, Jenkins showed that Ca5(PO4)3(F,Cl):Sb,Mn was a very efficient emitter. The halophosphates emit both in the blue (Sb3+) as well as in the orange (Mn2+) spectral region, thus in addition yield white light. By carefully adjusting the ratio of Sb3+ and Mn2+ ion concentrations, a white light emitting phosphor was obtained with color temperatures ranging between 6500 and 2700K. However, the drawback of the halophosphate lamps is that it is impossible to have simultaneously high brightness and high color rendering; if the brightness is high (efficacy -80 lm W"1), the color rendering index (CRI) is of the order of 60, the CRI value can be improved up to 90, but then brightness decreases (-50 lm W"1). In 1974, another important breakthrough came in the form of compact fluorescent lamp, based on the trichromatic phosphor blend which resulted color rending values of 80-85 (color 80 lamps) at high efficiencies of 100 lm W"1. The fluorescent lamps with very high color rendering and efficiency can be obtained if three narrow band emitters with emission maxima at 450, 540 and 610 nm are employed. A typical trichromatic lamp phosphor blend comprises of (i) Sr5(PO4)3Cl:Eu2\ BaMgAl1()O,7:Eu2' as blue component, (ii) Ce0.67Tbo.33MgAl,,0,9, LaPO4,Le3\Tb3+ as green component and (iii)Y2C>3:Eiru as the red component. The color 80 lamps employ line emitters that generated light in discrete wavelength intervals. Colored objects that absorb outside these spectral regions appear with a slightly different body color when illuminated with these lamps rather than with a black body radiator such as the light bulb. For these purposes, color 90 or Deluxe lamps have been developed. The emission maximum of the blue phosphor can be shifted towards longer Wavelength by substituting BaMgAli0Oi7:Eu2+ with Sr4Ali4025:Eu2+. The red and green line emitters can be substituted by broad band emitters covering the whole spectral range. For this concept, (Ce,Gd,Tb)MgB5Oi0:Mn has been developed as a red emitter in which energy transfer from Ce3+ via Gd3+ to Mn2+ gives rise to an additional broad band at 630 nm. On the other hand, (Ba,Sr,Ca)2Si04:Eu has been developed as an alternative green-band emitter in which depending on the exact composition, the phosphor emits between 550 and 580 nm with a high quantum yield. Unfortunately, the host lattice is not stable in water, which prevents its deposition on the lamp bulb from aqueous suspensions and for environmental reasons more and more lamps producers use water as the suspending solvent in production instead of butyl acetate. Therefore, it is necessary to develop a new full color emitting phosphors, which has both thermal and chemical stability for application in luminescent lighting. The classical cathode ray tube (CRT) invented as the brown tube more than 100 years ago has developed into a remarkably mature product considering the complexity of its manufacturing process. Cathode rays are a beam of fast electrons, the accelerating voltage in a television picture tube is high (>10 kV). Basic requirements of display phosphors are stability (2000 hr operation) and emission color purity according to the standards set by the European Broadcasting Union (EBU). The blue and green phosphors are still the very cheep ZnS based materials, essentially the same ever since color-TV was introduced in fifties. On the other hand, (Zn,Cd)S, Ag+,C1" was originally used as the red phosphor however, the broad emission centered at 650 nm due to intrinsic donor-acceptor transition leads to rather low lumen equivalent as large fraction of the emission integral lies outside the eye sensitivity curve. For this and the environmental reasons, it has been replaced by the much more expensive Y2O2S:Eu with main emission lines at 612 and 628 nm. Recently, the big electronic companies are trying to enforce flat panel displays e.g. PDPs (plasma display panels) and FEDs (field emission displays). This is because of the fact that when compared to the CRT screen pigments, FED phosphors are required to operate at lower voltages and higher current densities. Although the voltages used in FEDs are only 0.1 to < 2 kV, the high-energy surface excitation on the phosphor particles causes degradation of sulfides, leaving the oxide hosts as the only favorable choice. The phosphor blends used are mixtures of SrTiO3:Pr3+ (red), Y2Si05:Tb (green) and Y2Si05:Ce (blue). However, the white light generation efficiency is very low (-5 lm W"1) and required improvement of phosphor efficacy because of its distinct advantages such as a very wide range of operational temperatures, stability under rugged conditions and wide viewing angle of emission. Similarly, in PDPs blue emitting BaMgAlioOniEu, green emitting Z^SiO^Mn and red emitting (Y,Gd)BO3:Eu are mostly used which shows a screen efficiency of about 1.5 lm W"1, just only half that of a CRT used in today's TV sets. However, the advantages of PDPs over CRTs are that it is not sensitive towards the display manufacturing process, which includes high temperature annealing up to about 600°C and it is stable under the harsh conditions of a Ne/Xe plasma used in PDPs (ion bombardment, VUV radiation). This puts pressure on the development of phosphor for maximum brightness and high stability to replace completely the classical CRTs. On the other hand, the invention of the blue-light emitting diode (LED) based on GaN can be regarded as a triumph of materials chemistry. In principle, it is possible to vary the emission wavelength of blue GaN-based LEDs between 370 nm (band-gap of pure GaN) and 470 nm by increasing the indium (In) content in InGaN devices. Assuming a conversion from the incident light by a phosphor material emitting at 555 nm, InGaN is coated with (Yi.xGdx)3(Ali-yGay)5Oi2:Ce (YAG:Ce) which has broad yellow band varying between 510 and 580 nm. This allows the adjustment of white color temperature from 8000 down to 3000 K. Recently, S^SiCU and S^SiOs have attracted current interest due to their potential applications in developing white light-emitting-diodes (LEDs) because GaN (400 nm chip)-coated with Sr2Si04:Eu2+ or Sr3SiC>5;Eu2+ exhibits better luminous efficiency than that of the industrially available product such as InGaN (460 nm chip)-coated with YAG:Ce. However, the major drawback of this combination is the strongly decreasing overall efficiency upon lowering the color temperature. This can be solved by using a phosphor material that has sufficient absorption at the emission wavelength of the blue diode, the quantum yield should be high under UV/Vis excitation and the FWHM of the emission band should be as small as possible in order to achieve high luminous output. The search for stable inorganic rare-earths phosphors with high absoiption in the near UV/blue spectral region is therefore an attractive research work. Since luminescence materials are a key component for lighting and display concept, research in the field of rare-earths doped oxide phosphors is carried out. Although state-of-the-art materials fulfill most requirements, improvements are still necessary to further boost the efficiency of the phosphor materials. Since it is not expected that materials will be found that perform better than the already established phosphor, the present work concentrates on the improvements of the phosphor by modifying the chemical and niicrostructurai features as well as the crystal structure. Chapter I gives a brief introduction to luminescence in solids, physical aspects and applications. Chapter II describes the synthesis and various experimental techniques employed in the investigation. Chapter III deals with photoluminescence and energy transfer involving charge transfer states in Sr2-xLnxCe04+x/2 (Ln = Eu and Sm) leading to an efficient full color emitting phosphor for luminescent lighting. Chapter IV and V describe charge transfer transition involving interface states associated with transitional nanophaseprecipitates leading to photoluminescence enhancement of SrTiO3:Pr3+,Al3+ and SrAli2Oi9:Pr3+,Ti4\ The light induced charge transfer leading to changing oxidation state of Eu in Sr2Si04 involving transient crystal structure results an efficient material for optical storage is presented in Chapter VI.Photoluminescence due to efficient energy transfer from Ce3+ to Tb3+ and Mn2t in SnAlioSi02o leading to an efficient phosphor for FEDs is presented in Chapter VII. Chapter VIII describes charge transfer transition involving trap states leading to long phosphorescence in SrAl2-xBxO4 (0<x<0.2) and Sr4Al14.xBxO25 (0.1<x<0.4) co-doped with Eu2+ and Dy3+. Chapter IX presents the role of particle size on the charge transfer associated luminescence of GdVO4:Ln3+ (Ln = Eu and Sm). A summary of the important findings and the conclusions arrived on the basis of results from these investigations are presented at the end of the thesis.

Ce travail est consacré à l’étude du comportement photochimique d’un encapsulant multifonctionnel de cellules photovoltaïques organiques (CPO) dont la finalité est d’augmenter à la fois la durée de vie et le rendement de conversion des cellules. L’étude rapportée dans ce manuscrit porte sur le développement d’un revêtement permettant la conversion lumineuse du rayonnement UV solaire, ce dernier étant un facteur important de dégradation des CPO à base de P3HT et ne contribuant que faiblement à la conversion photovoltaïque. Dans un premier temps cette étude a porté sur l’élaboration d’une couche de conversion à partir d’une matrice polymère en EVA et d’une charge luminescente inorganique (SrAl2O4 : Eu2+, Dy3+). Dans un second temps, l’évolution des propriétés physiques et chimiques de cette couche de conversion sous irradiation à des longueurs d’onde supérieures à 300 nm a été étudiée. La présence des charges s’est révélée être un facteur pro-dégradant des films composites, sans pour autant que le mécanisme de dégradation du polymère ne soit affecté. L’étude des conditions de propagation de la lumière dans les films diffusants par l’application de la théorie de Mie a mis en évidence une possible augmentation du trajet optique des photons dans certains films composites. Ce phénomène pourrait contribuer à expliquer l’origine du comportement photochimique particulier des films étudiés. C’est finalement une preuve de concept qui a été recherchée pour l’utilisation d’un revêtement multifonctionnel pour l’amélioration et la conservation des propriétés de conversion d’une CPO à base de P3HT. / This work is devoted to the study of the photochemical behavior of a multifunctional coating dedicated to the encapsulation of organic solar cells (OSC), elaborated with the aim of improving both the lifetime of the cells and their efficiency. The study reported in this manuscript focuses on the development of a coating allowing the conversion of UV sunlight, this last greatly damaging P3HT based OSC and poorly contributing to the photovoltaic conversion. A composite film was then elaborated by incorporating an inorganic luminescent filler (SrAl2O4 : Eu2+, Dy3+) in Ethyl Vinyl Acetate copolymer (EVA). The modifications of chemical and physical properties of these films were investigated upon irradiation using wavelengths beyond 300 nm. The presence of fillers was revealed to be a pro-degrading factor of the composite films, without existence of any change of the degradation mechanism of the polymer. The propagation of light within these films was carefully investigated by applying Mie theory. The results highlight a possible increase of the light optical path in composite films due to scattering. This phenomenon might contribute to explain the photochemical behavior of the studied films. At last, a proof of concept was searched for the design of multifunctional coatings able to increase and preserve the conversion properties of a P3HT based OSC.

Tilapia culture in Indonesia was started with the Mozambique Tilapia (Oreochromis mossambicus) in the 1930’s, and the Nile Tilapia (Oreochromis niloticus) the 1960’s. The genetic improvement program of the Nile Tilapia, has led Indonesia to be one of the main tilapia producers in the world. On the other hand, shrimp aquaculture in the country was not started until the 1960’s, it became more popular after the eye ablation technology for broodstock maturation was developed in the early 1980’s. The first experimental study was conducted to investigate the feasibility of low salinity shrimp farming in a polyculture system with tilapia. Polyculture increased the survival for shrimp (77% compared to 62%), but at the same time decreased the survival of tilapia (87% compared to 97%). Together, the data on survival, specific growth rates, and feed conversion ratios showed that the shrimp performed well at low salinity. The second experimental study investigated the feasibility of brackishwater shrimp farming in a polyculture system with tilapia. Polyculture increased the survival for shrimp (82% compared to 65%), and had higher survival for the tilapia (60% compared to 43%). The Red hybrid Tilapia strain used in the study experienced mortalities after one month, suggesting the need for a salt tolerant strain. The presence of tilapia stimulated the growth of microalgae (Chlorella dominance), promoted higher numbers of heterotrophic bacteria in the water, and had lower presumptive vibrios on TCBS agar. A challenge study was conducted by mixing pathogenic luminescent Vibrio harveyi UAZ-651 into shrimp and tilapia feed. The survival of shrimp in monoculture were significantly lower (20%) compared to in polyculture systems (75 - 95%). Mortality was not found in tilapia. Based on 16S rRNA gene sequence, shrimp monoculture water was dominated by marine Vibrio spp., while the polyculture system had Bacillus spp. and Vibrio spp. with high homology to V. cholerae. The presence of Bacillus spp. which produce a lactonase enzyme AiiA, seems to inhibit vibrio growth. While providing advantages, shrimp-tilapia polyculture might also contribute to streptococcosis transmission. Injecting shrimp with Streptococcus iniae and S. agalactiae resulted in mortalities. S. iniae caused higher mortality in the shrimp cultured in 20 ppt (40%) compared to 10 ppt (20%), and no mortality in 5 ppt. S. agalactiae caused higher mortality in 5 ppt (40%) compared to 10 ppt (20%) and 20 ppt (20%). Quorum sensing (QS) is a density dependent cell to cell communication process in bacteria. Based on challenge studies in shrimp, the luminescent Vibrio harveyi BB120 wild-type strain caused 75-90 % mortality through injection of 106 CFU/shrimp. The mortality patterns in the QS mutants suggest that QS defined, when specific virulence genes were expressed or repressed. As QS in V. harveyi consists of three different circuits, further experiments deployed six mutants lacking either a synthase or a receptor for each circuit. The highest survival in the CqsS (a receptor for CAI-1 circuit) mutant group indicates that the CAI-1 circuit is the most crucial for virulence, followed by the AI-2 and HAI-1 cascades. Chitin acquisition and oxygen scavenging may be two reasons for luminescence in V. harveyi evolution and why they infect shrimp.