Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Made available in DSpace on 2016-06-02T19:02:42Z (GMT). No. of bitstreams: 1 5642.pdf: 1776062 bytes, checksum: da09965abd9a6b2902c7875682004bd4 (MD5) Previous issue date: 2012-11-08 / Universidade Federal de Sao Carlos / Photodynamic Therapy (PDT) is known to be limited to applications in large volume tumours due to its limited penetration. Therefore, the PDT with the Luzitin® photossensitizer as well as a combination of PDT and laser surgery may constitute a potential to destroy bulk tumors. Thus, with the aim of proposing a minimally invasive treatment protocol involving the application of PDT for large tumors, the present study analyzed histomorphometrically necrosis resulting from both a combination of a laser ablation with PDT as PDT with the photosensitizer Luzitin® (a bacteriochloryn synthetic with greater potential for penetration into biological tissue) in livers of healthy rats. In the first study, 87 animals were divided into 2 groups: CO2 laser and diode laser. Each of these groups were subdivided into six subgroups: 1) only laser ablation, 2) administered the PS and ablated with laser, 3) only PDT (drug and ligth), 4) drug and light (PDT) followed by laser ablation, 5) ) laser ablation followed by a PDT and 6) drug, followed by laser ablation and ligth. For each subgroup, three types of photosensitization were used: topical 5- aminilevunic acid (ALA), intravenous ALA and intravenous Photogem®. Thirty hours after the different treatments, the animals were sacrificed and the livers removed for the histological and morphometric study of necrosis. The results showed that the effects of treatment were considerably improved when PDT was used in combination with laser ablation. For the group CO2 laser, the average depth of necrosis obtained showed a minimum difference between the studied conditions for the group photosensitized Photogem® and with an increased depth of necrosis after the combined procedures in comparison with the isolated techniques for the subgroups fotossensibilizados with ALA, especially treatment with PDT was performed before ablation by CO2 laser. In the diode laser group, subgroups with better performance were those in which the ablation was performed before PDT using intravenous photosensitizers and ALA topic. From these results, it is suggested that PDT and laser ablation can synergistically in the treatment of large tumors. In the second study, sixteen normal male rats were randomly divided into 4 groups with 4 animals each. Initially, all groups were intravenously photosensitizated with 2 mg/kg or 2.6 mg/kg of the drug and after 12 hours, a 1cm2 of area, in the right abdominal region, corresponding to the liver, was irradiated during 22 minutes and 13 seconds or16 minutes and 40 seconds. Groups are described following: 1) control group: photosensitized with 2mg/kg, but untreated, 2) treated group 1: irradiated with light dose of 100J/cm2 after photosensitization with 2mg/kg of 12hs and 3) treated group 2: irradiated with light dose of 70J/cm2 and photosensitized with 2mg/kg of Luzitin®, 4) treated group 3: photosensitized with 2.6 mg/kg of the drug and irradiated with light dose of 70J/cm2 Animals were sacrificed 30 hours after irradiation, except the control group, which were sacrificed 42hs after drug administration. Livers were removed and prepared for histological analysis. Moreover, macroscopic aspects of liver were observed. Results showed significantly more extensive necrosis and greater severity in treated group 1. Data suggested that, among the conditions studied, light dose suitable for PDT treatment of photosensitized tissue by Luzitin® is 100J/cm2 and that 30% of reduction in this value produces decay in PDT response, even with proportional increase of drug concentration in the organism. / A terapia fotodinâmica (TFD) é uma técnica conhecida por sua limitada aplicação em tumores volumosos, devido a sua restrita penetração. Portanto, a TFD com o fotossensibilizador (FS) Luzitin®, bem como a combinação da TFD com a cirurgia a laser possuem potencial destrutivo para tumores volumosos. Assim, com o intuito de propor um protocolo de tratamento minimamente invasivo envolvendo a TFD para aplicação em tumores volumosos, o presente estudo analisou histomorfometricamente a necrose resultante tanto da combinação de lasers ablativos com a TFD, quanto da TFD com o fotossensibilizador Luzitin® (uma bacterioclorina sintética com maior potencial para penetração nos tecidos biológicos) em fígados de ratos saudáveis. No primeiro estudo, 87 animais foram divididos em 2 grupos: grupo laser de CO2 e grupo laser de Diodo. Cada um desses grupos foram subdivididos em 6 subgrupos: 1) subgrupo ablação a laser, 2) subgrupo fotossensibilização seguida de ablação a laser, 3) subgrupo TFD, 4) subgrupo fotossensibilização e luz seguido pela ablação a laser, 5) subgrupo laser seguido de fotossensibilização e luz, e 6) subgrupo fotossensibilização seguida da ablação a laser e luz. Para cada subgrupo, três condições de fotossensibilização foram utilizadas: ácido 5-aminolevulínico (ALA) tópico, ALA endovenoso e Photogem® endovenoso. Trinta horas após o tratamento, os animais foram eutanasiados e os fígados removidos para estudo histológico e morfométrico da necrose. Os resultados mostram que os efeitos do tratamento com TFD foram consideravelmente melhorados quando combinada com a ablação a laser. Para o grupo laser de CO2, a profundidade de necrose média obtida mostrou uma mínima diferença entre as condições estudadas para o grupo fotossensibilizado com o Photogem® e um aumento da profundidade de necrose após os procedimentos combinados em comparação com as técnicas isoladas para os subgrupos fotossensibilizados com o ALA, especialmente qunado o tratamento com a TFD foi realizado antes da ablação pelo laser de CO2. No grupo laser de Diodo, os subgrupos com melhor desempenho foram aqueles em que a ablação foi realizada antes da TFD para os fotossensibilizadores intravenosos e o subgrupo fotossensibilizado com ALA tópico, ablacionado e iluminado. A partir desses resultados, sugere-se que a TFD e a ablação a laser podem atuar de forma sinérgica no tratamento de tumores volumosos. No segundo estudo, dezesseis ratos machos normais foram randomicamente divididos em 4 grupos, com 4 animais cada. Inicialmente foi realizada a fotossensibilização por meio da administração intravenosa de 2mg/kg ou 2,6mg/kg da droga e após 12 horas, uma área de 1cm2 na região abdominal direita correspondente ao fígado foi irradiada durante 22 minutos e 13 segundo ou 16 minutos e 40 segundos. Os grupos estão descritos a seguir: 1) grupos controle: fotossensibilizado com 2mg/kg, porém não tratado; 2) grupo tratado 1: irradiado com intensidade de 100J/cm2 após 12hs da fotossensibilização com 2mg/kg; 3) grupo tratado 2: irradiado com intensidade de 70J/cm2 e fotossensibilizados com 2mg/kg de Luzitin®, 4) grupo tratado 3: fotossensibilizado com 2,6mg/kg da droga e irradiado com intensidade de 70J/cm2 Os animais foram eutanasiados após 30 horas da irradiação, exceto o grupo controle, que foram aguardadas 42hs após a administração do composto. Os fígados dos animais foram removidos e preparados para a análise histológica. Além disso, foram observados aspectos macroscópicos do fígado. A análise dos resultados mostrou uma necrose significativamente mais extensa e com maior grau de severidade para o grupo tratado 1. Com base nos dados observados, sugere-se que, dentre as condições estudadas, a dose mais adequada para o tratamento com TFD do tecido fotossensibilizado com Luzitin® seja de 100J/cm2 e que uma redução de 30% desse valor provoca um decaimento na resposta da TFD, mesmo com aumento proporcional da concentração da droga no organismo.

Under de senaste åren har olika former av kognitiv distraktion, till exempel att tala i mobiltelefon med handsfree, relaterats till en betydande mängd olyckor i trafiken. Av den anledning finns det ett stort intresse i att ta fram olika tekniska system för att upptäcka förare som är distraherade. Målet med denna studie var att ta ett steg tillbaka och undersöka människors förmåga och metoder för att avgöra distraktion hos andra. Då det saknas tidigare forskning är upplägget en explorativ förstudie bestående av två delar. Under den första delen samlades material in på distraherade bilförare i simulerad förarmiljö. Distraktionen bestod av olika uppgifter designade för att skapa kognitiv distraktion. Förarnas arbetsbelastning mättes med Peripheral Detection Task (PDT). Resultaten visar att de mer komplexa kognitiva uppgifterna försämrar prestationen på PDT, men ingen skillnad dem sinsemellan observerades. I den andra delen testades hur ett antal bedömares uppskattning av distraktion hos förarna stämde överens med prestationen på PDT. Resultaten kan inte påvisa en förmåga att upptäcka distraktion hos andra, men ett antal svagheter i metoden diskuteras vilket kan ge vägledning för metoddesign i framtida studier.

Aim of this thesis is to implement system for translation words from source language into the target language with pair input texts. There are descriptions  of terms and methods used in machine translation and machine build dictionary. The thesis also contains a concept and specification of each part created system including final evaluation. There is analysed options which make extension of existing dictionatry.

The goal of the project was to simulate a typical silicon detectorresponse in an experiment made at the Tandem lab in Uppsala. The plasma delay time was analyzed by simulating the experiment. Three different models of the plasma delay time were introduced and their effects on time of flight measurements were studied. A continuation of the main goal was to see if the inserted PDT models could be extracted from the simulations when being treated as a pseudo experiment, to see theoverall effectiveness of the experiment. When comparing the final simulations with actual measurements, it was concluded that the main properties of the detector response had been featured and that the simulations were successful. The successful extraction of the inserted plasma delay times and their dependencies on energy also proved that the experiment was a good one. The result of the project was that one of the models seemed to have a strong mass dependence, however with no clear dependence on the energy. The other two models showed a somewhat similar dependence on energy. One of the two models also showed a relatively weak mass dependence.

No description available.

Designing new materials for CO₂ capture and utilization is one of the most challenging research topics. Metal-organic frameworks (MOFs) are one of the most efficient CO₂ adsorbents, as well as an emerging class of heterogeneous catalysts for CO₂ chemical transformations. Highlighted by their high content of active centers, large internal surface areas, tunable pore size, and versatile chemical functionalities, MOFs can serve as highly stable and reusable heterogeneous catalysts and provide a great platform to explore the structure-function relationships for transforming CO₂ into useful chemicals. In this dissertation, we aim to develop a new class of metal-cyclam based robust MOFs as porous materials for CO₂ uptake as well as efficient catalysts for CO₂ chemical transformations, including CO₂ chemical fixation, CO₂ photo- and electroreduction. Chapter 1 introduces the concept and main challenges of CO₂ capture and conversion. The potential of metal-cyclam complexes as molecular catalysts for CO₂ conversion is also mentioned. The current state of the art in designing stable MOFs and azamacrocyclic-based MOFs is briefly discussed. Finally, the strategies, challenges and future outlook of using MOF as catalysts in CO₂ chemical transformation are summarized. Metal-organic frameworks (MOFs) as highly ordered, tunable hybrid materials have shown great promise in photon collection, energy transfer and photocatalytic reactions. In Chapter 2, the fundamental principles of energy transfer in the condensed phase are summarized, and a series of studies in light-harvesting, excited state quenching and photo-excited reactivity occurring within ruthenium-polypyridyl-doped zirconium MOFs are reviewed. The application of MOFs in energy conversion devices such as dye-sensitized solar cells (DSSC) is also discussed. Chapter 3 reports two new robust 3D porous metal-cyclam based Zr-MOFs, VPI-100 (Cu) and VPI-100 (Ni) with potential as heterogeneous catalysts for CO2 chemical fixation. The frameworks are prepared by a modulated synthetic strategy and the structure highlighted by eight-connected Zr₆ clusters and metallocyclams as organic linkers. The VPI-100 MOFs exhibit excellent chemical stability in various organic and aqueous solvents over a wide pH range and show high CO₂ uptake capacity (up to ∼9.83 wt% adsorption at 273 K under 1 atm). Moreover, VPI-100 MOFs demonstrate some of the highest reported catalytic activity values (turnover frequency and conversion efficiency) among Zr-based MOFs for the chemical fixation of CO₂ with epoxides. The MOFs, which bear dual catalytic sites (Zr and Cu/Ni), enable chemistry not possible with the cyclam ligand under the same conditions and can be used as recoverable stable heterogeneous catalysts without losing performance. A follow-up study of CO₂ chemical fixation using Hf analogs of VPI-100 is presented in Chapter 4. Structural characterization and catalytic performance of Hf-VPI-100 are summarized. Moreover, a detailed comparison of VPI-100 and Hf-VPI-100 is made. In situ powder X-ray diffraction (PXRD), quartz crystal microbalance (QCM) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) have been used to probe the interaction between the guest molecules (CO₂/epoxide) and Hf-VPI-100. For CO₂, no specific chemical binding sites in MOFs has been observed and the uptake of CO₂ does not change the crystal structure of Hf-VPI-100. Both QCM and DRIFTs revealed the irreversible binding between the framework and 1,2-epoxybutane. The epoxide uptake per unit cell of VPI-100 MOFs and diffusion coefficients have been calculated by QCM analysis. Transition metal complexes capable of visible light-triggered cytotoxicity are appealing potential candidates for photodynamic therapy (PDT) of cancer. In Chapter 5, two monometallic polyazine complexes, [(Ph₂phen)₂Ru(dpp)]²⁺ and [(Ph₂phen)₂Os(dpp)]⁺ (Ph₂phen = 4,7-diphenyl-1,10-phenanthroline; dpp =2,3-bis(2-pyridyl)pyrazine), were synthesized, characterized and studied as light activated drugs to kill rat malignant glioma F98 cells. Both compounds display strong absorption in visible spectrum, oxygen-mediated DNA and BSA photocleavage and significant photocytotoxicity under blue light irradiation along with negligible activity in the dark. The compounds show approximately five-fold higher cytotoxicity compared the traditional chemotherapeutic drug, cisplatin. Furthermore, [(Ph₂phen)₂Os(dpp)]⁺ shows promising photocytotoxicity in F98 rat malignant glioma cells within the phototherapeutic window with an IC50 value of (86.07±8.48) µM under red light (625 nm) irradiation. In Chapter 6, the mixed-metal supramolecular complex, [(Ph₂phen)₂Ru-(dpp)PtCl₂]²⁺, was found to display significant DNA modification, cell growth inhibition, and toxicity towards F98 malignant glioma cells following visible light irradiation. The design of this complex has a significantly higher potential for membrane permeability than three other FDA-approved anti-cancer agents, including cisplatin, and exhibited a dramatic ten-fold higher uptake by F98 cells than cisplatin in a two-hour window. Based on studies with a rat glioma cell line, the compound has very low cytotoxicity in the dark, but results in substantial cell death upon light treatment. The complex is thus among the first to exhibit all the hallmarks of a very promising new class of PDT agents. / Ph. D. / Increased carbon dioxide (CO₂) emissions have triggered a series of environmental effects, including global warming and ocean acidification. Scientists are trying to develop new materials to capture and convert CO₂ into useful chemical products. However, the main challenge is that CO₂, the gas generated upon burning fossil fuels, has strong C=O bonds that are hard to break. In other words, it is too stable to be easily changed into other compounds. A class of highly porous materials known as metal-organic frameworks (MOFs) possess significant potential for CO₂ adsorption uptake and chemical fixation. MOFs are metal ions or clusters held together by organic linkers to make highly ordered, crystalline 3D structures with tunable porosity and functionality. The design and synthesis of MOFs is similar to playing with Legos at the molecular level; you need to pick the right pieces (metal nodes and linkers) to get your desired structure. In this dissertation, we aim to develop a new class of macrocycle complexes based stable MOFs as porous materials for CO₂ uptake as well as efficient catalysts for CO₂ chemical transformations. We have developed two new stable three dimensional porous frameworks, VPI-100 (Cu) and VPI-100 (Ni) as catalysts for CO₂ chemical fixation. The new 3D robust MOFs named VPI-100 (VPI = Virginia Polytechnic Institute) are assembled by the reaction of zirconium oxo clusters and linkers bearing metal complexes. Using the metal complexes as the linker provides additional metal active sites in the framework that can act as accessible catalytic centers for CO₂ conversion. The VPI-100 MOFs are not only able to convert CO₂ to cyclic carbonates (important industrial chemicals) in high efficiency (~ 98%), but also can be reused for multiple cycles. The heterogeneous catalyst can be easily recovered from the reaction mixture by centrifugation and the active metal centers are earth-abundant transition metals (Cu and Ni), which are cost effective. Additionally, VPI-100 MOFs also show high CO₂ uptake capacity (up to ~10 wt%) at ambient pressure. Since the MOFs can enhance the local concentration of CO₂ around the active catalytic centers located inside the pores of the framework, these materials could be used as catalysts for flow chemistry, which is widely used in industry. We further investigated the CO₂ chemical fixation using Hf analogs of VPI-100. Structural characterization and catalytic performance of Hf-VPI-100 are summarized. Moreover, a detailed comparison of VPI-100 and Hf-VPI-100 is made. Different analytical techniques have been used to further understand the reaction mechanism as well as the interaction between the CO₂/epoxide and the frameworks. These insights would help us to design new MOFs as better catalysts for practical applications.

A terapia fotodinâmica (PDT) é uma alternativa promissora de tratamento para lesões pré-cancerosas e para câncer de pele não-melanoma, como o carcinoma espinocelular, agressivo e potencialmente metastático. Visando melhorar a eficiência da terapia fotodinâmica de carcinoma espinocelular de pele, este estudo otimizou o tempo para início da terapia, avaliou a eficácia dos fotossensibilizadores ácido aminolevulínico (ALA- 20%) e o metil-ester aminolevulínico (MEALA-10%) e verificou o coeficiente de atenuação relativo à pele normal dos grupos experimentais, por meio de Tomografia por Coerência Óptica. Para a indução do tumor foi realizada a carcinogênese química (DMBA/TPA) por um período de 28 semanas. A espectroscopia de fluorescência foi utilizada para monitoração da emissão da molécula de protoporfirina IX, induzida pelo ALA e MEALA. A aquisição de dados a cada 30 minutos totalizando um período de 360 minutos, permitiu verificar a máxima incorporação de ALA e MEALA em 300 e 330 minutos após a aplicação, respectivamente. Após a otimização foi realizada a PDT, avaliação clínica, histopatológica e análise por OCT dos grupos experimentais, por meio das quais verificou-se maior eficiência do grupo tratado com MEALA. No período de 20 dias, o percentual de lesões com redução de área maior que 50%, foi de 33% na PDT com ALA e 83% para o MEALA. Os coeficientes de atenuação ópticos para os grupos com neoplasia foram maiores do que os do grupo controle. Os grupos tratados com PDT apresentaram valores de coeficiente de atenuação que se aproximam dos valores obtidos para a pele sadia, evidenciando a resposta ao tratamento. Entretanto para ambos os fotossensibilizadores utilizados, a PDT mostrou-se eficaz quando iniciada nos tempos determinados neste estudo, e a técnica de OCT mostrou-se uma potencial ferramenta na avaliação deste tratamento. / Photodynamic therapy (PDT) is a promising alternative for pre-cancerous lesions and non-melanoma skin cancer treatment as squamous cells carcinoma, which is aggressive and potentially metastatic. Aiming the improvement of photodynamic therapy efficiency for skin squamous cells carcinoma, this study has optimized the time to start the therapy, it also evaluated the effectiveness of the aminolevulinic acid (ALA-20%) and methyl-ester aminolevulinic (MEALA-10%) as photosensitizers as well as verified the optical attenuation coefficient relative to normal skin of the experimental groups by optical coherence tomography (OCT). A chemical carcinogenesis was performed (DMBA/TPA), by a period of 28 days. Fluorescence Spectroscopy was used to monitor the emission of protoporphyrin IX induced by ALA and MEALA. Signal acquisition was performed every 30 minutes for a total period of 360 minutes, showing a maximum incorporation of ALA and MEALA, 300 and 330 minutes after the application. PDT was conducted after the optimization of the irradiation time. Clinical and histopathologic evaluation and OCT analysis of the experimental groups showed higher efficiency of the MEALA-treated group. After 20 days of treatment, the percentage of lesions with area reduction greater than 50%, was 33% for the ALA group and 83% for the MEALA group. The optical attenuation coefficients for groups with cancer were higher than those in the control group. The groups treated with PDT presented attenuation coefficient values that are close to the values obtained for healthy skin, showing the positive response to the treatment. This study showed that PDT was effective for both photosensitizers when initiated at the times determined in this study, and OCT technique proved to be a potential tool in the assessment of this treatment.

L'efficacité de la thérapie photodynamique (PDT) est confrontée à plusieurs verrous : les photosensibilisateurs (PSs) utilisés en clinique ne sont pas adaptés à la fenêtre thérapeutique, ils subissent un photoblanchiment lors du traitement, et leur nature organique pose des problèmes de solubilité en milieu biologique. Ils présentent également une faible sélectivité envers les tissus tumoraux à traiter. Dans le cadre de cette thèse, trois approches visant une amélioration de la PDT appliquée à la cancérologie ont été développées : la vectorisation, l'adressage, et l'optimisation de nouveaux PSs. La synthèse de structure PS/vecteur a permis d'élaborer des structures hydrophiles capables de vectoriser des PSs hydrophobes. Des porphyrines ont ainsi été greffées sur des dendrimères polyamidoamine (PAMAM) dissymétriques. La conservation des propriétés photophysiques des PSs après leur couplage au dendrimère a été mise en évidence. Des quantum dots (QDs), grâce à la modularité de leurs propriétés photophysiques et leur capacité à résister au photoblanchiment, ont été synthétisés et utilisés comme nouvelle classe d'agents photosensibilisants. Ces QDs ont été préparés afin d?être hydrophiles et utilisables dans la fenêtre thérapeutique de la PDT. Une étude in vitro des QDs couplés à l'acide folique a mis en évidence leur activité photodynamique. Des études réalisées par une approche de plans d'expérience a permis de hiérarchiser les facteurs expérimentaux en fonction de leurs impacts sur l'activité photodynamique. Nous avons en particulier montré une amélioration de la sélectivité des conjugués envers les cellules surexprimant le récepteur à l'acide folique. / Photodynamic therapy (PDT) efficiency is confronted to various barriers, such as photosensitizers (PSs) which are not optimized to the therapeutic window and endure photobleaching during treatment, moreover their organic nature can also lead to solubility problems for biological uses. Usual PSs show also a lack of selectivity toward tumor tissues to treat. In order to improve PDT treatment, three approaches were studied: delivery, targeting and use of a new class of photosensitizing agents.Synthesis of PS/delivery vehicle structure enabled to developed hydrophilic structure able to deliver hydrophobic PSs. Porphyrins were linked to dissymmetric polyamidoamine dendrimers. Conservation of the photophysical properties of PSs after linkage to the dendrimer was then highlighted.Due to the modularity of their photophysical properties and their capacity to resist to photobleaching, hydrodispersable Quantum dots (QDs) were synthesized to match the therapeutic window of PDT.In vitro studies of these QDs linked to folic acid showed their ability to induce a photodynamic activity. We used an experimental design approach to distinguish the impact of each experimental factor on the photodynamic activity of these QD-folic acid conjugates. We showed in particular an increase of the selectivity of the folic acid-linked QDs towards cell line overexpressing the folate receptor