Orientador: Frab Norberto Boscolo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-12T19:59:29Z (GMT). No. of bitstreams: 1 Cruz_AdrianaDiboda_D.pdf: 5672004 bytes, checksum: ac1f74246e4d3453193616e0b3d5a093 (MD5) Previous issue date: 2009 / Resumo: No presente estudo, materiais adesivos com diferentes modos de aplicação foram submetidos à ação de radiações ionizantes de diferentes energias com o objetivo de verificar a resistência adesiva após irradiação, por meio do ensaio de microcisalhamento, avaliando o padrão de fratura, considerando se as radiações utilizadas podem ser agentes externos capazes de causar degradação da união adesiva. Após aprovação do projeto pelo comitê de ética em pesquisa (protocolo:032/2007), 60 dentes humanos tiveram as coroas seccionadas no sentido mesiodistal, e incluídas em bloco de resina epóxi. As coroas foram lixadas para exposição da dentina média obtendo 120 corpos de provas. Os corpos de prova foram divididos em 3 grupos (n=40), de acordo com os sistemas adesivos usados: SB (Adper ¿ Single Bond Plus), CB (Clearfil¿ SE Bond) e AP (Adper¿ Prompt¿ Self-Etch). Os adesivos foram aplicados em dentina e fotoativados usando LED (Lec 1000, MMoptics, 1000mW/cm2). Sobre as áreas adesivas foram colocados moldes de elastômero (0,5mm de espessura por 1,2mm de diâmetro) com três orifícios que foram preenchidos com resina composta (Filtek¿ Z-250) fotoativada por 20s. Cada grupo foi subdividido em 4 (n=10): GC= grupo controle que não foi irradiado; UV= grupo irradiado com ultravioleta; RXD= grupo irradiado com raios-X de energia para o diagnóstico; e RXT= grupo irradiado com raios-X de energia para terapia. Após irradiação foram realizados testes de microcisalhamento (Instron Inc., modelo 4411) para a avaliação da resistência adesiva, e em seguida foram avaliados os modos da fratura das amostras, classificando-os com 5 escores: 1- fratura adesiva; 2- fratura mista com 75% de exposição dentinária, 3 -fratura mista com 50% de exposição dentinária, fratura mista com 25% de exposição dentinária, e fratura coesiva. Os resultados foram submetidos à ANOVA com os testes de Tukey, Dunnett, Kruskal-Wallis e Dunn ( =0,05). As diferentes radiações ionizantes não causaram alterações na resistência da união dos adesivos CB e AP; somente o adesivo SB exibiu aumento na resistência da união após a exposição com UV (p=0,0267). A UV também alterou os padrões de fratura do adesivo SB (p=0,0000). As alterações na resistência da união adesiva e no padrão de fratura não foram degradantes, mas dependeram tanto da energia das radiações ionizantes como do modo de aplicação dos adesivos. Assim as radiações ionizantes não podem ser consideradas como agentes externos capazes de causar degradação nos materiais adesivos estudados / Abstract: In the present study, adhesive materials with different application types were exposed to ionizing radiations of varying energy with the objective to verify by means of microshear and failure mode test the bond strength after irradiation trying to determine whether the used radiations could be external agents able to degrade the adhesive bond. After approbation of this project by the Ethical Committee for Human Research (protocol number 032/2007), 60 human teeth had its crowns sectioned mesio-distally and then were included into block of epoxy resin. The crowns were sanded to show the medium dentin and to obtain 120 specimens. The specimens were divided into 3 groups (n=40), according to the adhesive systems used: SB (Adper¿ Single Bond Plus), CB (Clearfil¿ SE Bond) and AP (Adper¿ Prompt¿ Self-Etch). The adhesives were applied on dentin and photo-activated using LED (Lec 1000, MMoptics, 1000mW/cm2). Onto the bonding areas were placed customized elastomer molds (0.5 mm-thickness by 1.2mm-diameter) with three orifices which were filled with composite resin (Filtek¿ Z-250) photoactivated during 20s. Each group was subdivided into 4 subgroups (n=10): GC=control group without irradiation; UV=group irradiated with ultraviolet radiation; RXD=group irradiated with diagnostic radiation-X; RXT=group irradiated with therapeutic radiation-X. After irradiation the microshear tests were carried out (Instron Inc., model 4411) to evaluate the adhesive bond, and afterwards the modes of failure of the specimens were evaluated and classified using 5 scores: 1=adhesive failure, 2=mixed failure with 75% dentin exposed; 3=mixed failure with 50% dentin exposed; 4=mixed failure with 25% dentin exposed; 5=cohesive failure. The results were submitted to ANOVA by the Tukey, Dunnett, Kruskal-Wallis and Dunn test ( =0.05). No changes in bond strength of CB and AP were observed after application of the different radiations; only SB showed an increase in bond strength after UV (p=0.0267) irradiation. UV also changed the failure patterns in SB (p=0.0000). The changes in the adhesive bond and in the mode of failure did not show degradation, but were dependent of both the energy of ionizing radiation and the way of adhesive application. Thus, the ionizing radiation cannot be considered an external agent able to cause degradation in the studied adhesive materials / Doutorado / Radiologia Odontologica / Doutor em Radiologia Odontológica

No presente trabalho modificou-se o polímero polipropileno por meio de radiação por feixes de elétrons com dose de 20, 40, 60, 100, 200 e 300kGy. Foram estudados os efeitos das doses de radiação nas propriedades físicas e químicas do polímero e a possível existência de uma correlação entre os resultados da indentação instrumentada e as demais propriedades físico-químicas do polímero, assim como ocorre com os metais. O polímero foi submetido aos ensaios de tração, indentação instrumentada, difração de raios-X (DRX), espectroscopia de elétrons na região do ultravioleta próximo e visível (UV VIS), espectroscopia vibracional no infravermelho com transformada de Fourier (FTIR), índice de fluidez, fração gel e análise térmica. Sobre as propriedades químicas do polímero observa-se que em doses de esterilização (até 20kGy) o mesmo não sofre oxidação radiolítica. A partir de doses superiores a 40kGy o polímero apresentou modificação permanente de cor (amarelecimento). Esta formação da cor mostrou ser ocasionada pela presença crescente do grupo cromóforo -C=O, fato este confirmado pelos resultados de espectroscopia UV-VIS. O resultado não pode ser comprovado no espectro de FTIR, porém observou-se que o método de preparação das amostras afetou o resultado deste ensaio lançando dúvidas sobre sua representatividade. A falha em identificar a presença crescente de grupos carbonila por FTIR, portanto, não invalida esta conclusão. Sobre as propriedades físicas do polímero comprovou-se com o ensaio de DRX que o aumento da dose de radiação não alterou a estrutura cristalina do polímero e não houve mudança significativa nos parâmetros de rede da célula monoclínica. Observou-se, entretanto, a diminuição da cristalinidade do polímero irradiado com doses de radiação até 60kGy. Para doses maiores observou-se novamente o aumento de fração cristalina, ou seja, a amostra sofreu recristalização induzida por irradiação. O polímero apresentou um aumento da resistência à degradação térmica com doses até 60kGy, permanecendo constante para doses maiores. Os resultados obtidos no ensaio de tração mostraram que o polímero irradiado com doses até 40kGy, não apresentaram alteração do limite de escoamento, porém para doses de radiação maiores houve decréscimo desta propriedade. Finalmente observou-se ensaio de indentação instrumentada não é sensível o suficiente para reproduzir as significativas alterações de propriedades mecânicas produzidas no polímero aqui estudado em função da irradiação por feixe de elétrons, porém observa-se uma queda acentuada do módulo de rigidez estimado no ensaio a partir do material irradiado com uma dose de 100kGy, que correlaciona com a recuperação da cristalinidade observada. / A polypropylene resin was modified in the present work by submitting standard tensile specimens to electron beam irradiation, with doses corresponding to 20, 40, 60, 100, 200 and 300kGy. The effect of this irradiation upon the polymer\'s chemical and physical properties was investigated, in particular seeking a possible correlation between these properties and instrumented indentation results, as it is common usage in the case of metals and alloys. The polymer was submitted to tensile, instrumented indentation, X-ray diffraction (DRX), electron spectroscopy (UV-VIS), vibrational infrared spectroscopy (FTIR), melt-flow index, gel fraction and thermal analysis tests. Concerning the chemical properties, it was observed that up to 20kGy dose there is no evidence of radiolytic oxidation in the polymer. Above 40kGy dose it was observed the irreversible yellowing of the samples, indicating the growing presence of chromophore groups (e.g. -C=O), which was confirmed by the UV-VIS results. The FTIR data could not confirm this hypothesis, but it was observed that the sample preparation method severely affected the FTIR spectra, casting doubt about its representativity. This failure of the FTIR data to identify the growing presence of carbonyl groups does not invalidate the previous results. Concerning the physical properties, X-ray diffraction showed that irradiation did not change the crystal structure of the polymer and no significant changes in lattice parameters could be identified either. The samples crystallinity, however, shows a remarkable reduction up to 60kGy dose. At the 100kGy sample, however, it was observed a recover of the crystallinity, which was attributed to radiation induced recrystallization. The thermal degradation resistance of the polymer enhanced up to 60kGy dose and remained approximately constant for higher doses. The yield strength of the samples kept approximately constant up to 60kGy dose, but decreased after that. Finally the instrumented indentation results where not sensible enough to detects the macroscopic mechanical properties, but the estimated Young\'s modulus shows a remarkable reduction for radiation doses equal or higher than 100kGy, which correlated well with the other chemical and physical properties.

A indústria de plástico tem reconhecido que novos materiais podem ser produzidos por meio da mistura de polímeros dando origem às chamadas blendas poliméricas. Estes materiais, em geral, apresentam uma melhoria das propriedades em relação às dos polímeros que formam a blenda. Freqüentemente, as blendas são produzidas a partir de polímeros imiscíveis, os quais apresentam fases, microestruturas ou morfologias diferentes. A melhoria da miscibilidade entre os componentes da blenda, o que leva a um melhor desempenho, denomina-se compatibilização. Esta compatibilização pode ser feita por meio de processos químicos ou utilizando radiação ionizante. O presente trabalho tem como objetivo central o estudo do efeito da radiação ionizante de feixe de elétrons na blenda polimérica formada por poliamida PA 6,6 e polietileno de baixa densidade PEBD na proporção, respectivamente, de 75%/25% em peso, quando esta é submetida a diferentes doses de radiação no intervalo entre 50 kGy e 250 kGy. O efeito da compatibilização, induzida pela radiação ionizante, foi avaliado por meio de ensaios mecânicos que mostraram uma melhoria nas suas propriedades de tração e dureza e pela diminuição da resistência ao impacto das amostras irradiadas. Este comportamento mecânico pode ser atribuído à ação combinada da reticulação induzida na estrutura molecular dos polímeros que formam a blenda e ao aumento da miscibilidade destes componentes na blenda irradiada. O grau de compatibilização induzido pela radiação ionizante foi avaliado determinando-se as temperaturas de transição vítrea (Tg) dos componentes da blenda por meio de análise dinâmico mecânica (DMA). Dos resultados obtidos constatou-se que os valores de Tg dos polímeros PA 6,6 e PEBD se aproximaram em 8ºC, indicando que a radiação ionizante produziu efeito de compatibilização na blenda irradiada. / The plastic industry has recognized that mixture of polymers, called polymeric blends, yields new materials with improve properties and better features of those of the polymer blended. In most of the cases, blends are formed by immiscible components presenting separated phases, micro-structures or morphologies. One of the main factors for good mechanical performance is the interfacial adhesion of the blend components. The improvement of miscibility between the polymer components and the enhancement of blend performance is denominated of compatibilization. This compatibilization can be achieved by chemical methods or using ionizing radiation. The present work has as a main objective the study of the effect of the ionizing radiation from electron beam in the compatibilization of the polyamide (PA) 6.6 and low density polyethylene (LDPE) 75%/25% wt blend, in the range of applied doses from 50 to 250 kGy. The compatibilization effect was evaluated by mechanical test, which has shown improvement in the tensile strength and hardness properties and a reduction of the impact resistant. This mechanical behavior can be considered as a combination effect of the cross-linking, induced in the molecular structure on the polymers, and the increase of the miscibility of the blend components. The degree of compatibilization was evaluated by the behavior of the glass transition temperatures (Tg) for the blend components obtained by dynamic mechanical analysis (DMA) measurements. The results have shown that the values of Tg for PA 6.6 and LDPE get near by 8oC, showing that the ionizing radiation have promoted a compatibilization effect on the irradiated blend.

As radiações ionizantes (RI) são amplamente utilizadas na área médica, principalmente para diagnóstico e terapia. Uma vez que a exposição às radiações implica em sérias complicações para a saúde humana e para o meio ambiente, torna-se relevante a compreensão dos mecanismos moleculares que coordenam as respostas em diferentes tipos celulares, especialmente em células normais. A taxa de dose (TD) é um importante fator a ser considerado em radiobiologia, com base em alguns estudos sobre a sua influência nas respostas celulares. Nesse contexto, duas TD distintas (0,5 e 2,0Gy/min) foram testadas para verificar a influência da TD na expressão gênica e protéica em fibroblastos e linfócitos humanos. Fibroblastos primários em estado de confluência foram irradiados com 4Gy e linfócitos com 2 Gy, sob as TDs de 0,5 e 2,0 Gy/min. Em fibroblastos, o RNA foi coletado 6 h após a irradiação, tempo em que foram analisados os níveis de expressão gênica pelo método de microarranjos de cDNA e, para alguns genes de reparo do DNA e algumas proteínas (H2AX, PCNA e FEN1) a expressão foi analisada por qPCR e Western blot, respectivamente, em ambos os tipos celulares, 2 e 6 h após a irradiação. A análise de expressão gênica por microarranjos de cDNA efetuada pelo programa SAM revelou 94 genes (FDR < 0.05) induzidos sob a TD de 0,5 Gy/min. Os principais processos biológicos associados aos genes modulados foram metabolismo, reparo do DNA, apoptose e resposta ao estresse. Por outro lado, 34 genes foram modulados nas células irradiadas sob a taxa de dose de 2,0 Gy/min. Nesta TD, os processos biológicos de maior importância foram: metabolismo, reparo do DNA, replicação, resposta ao estresse e apoptose. Na análise por qPCR, alguns genes de reparo (ERCC1, ERCC3 (ou XPB), XPF, XPA, FEN1) e ATM (sensor de dano) apresentaram uma ampla diferença na modulação gênica detectada em resposta à variação na TD, principalmente nos fibroblastos analisados 2 h após a irradiação. Entretanto, essa diferença foi menor nos linfócitos. Em linfócitos houve um maior número de genes do NER reprimidos relativamente aos fibroblastos, principalmente quando se consideram as células analisadas 2 h após a irradiação, sugerindo que em linfócitos irradiados sob a menor TD, outras vias alternativas de reparo do DNA podem ter ocorrido, possivelmente para lesões do tipo quebra dupla, que são eficientemente induzidas por 2 Gy. A análise protéica de expressão da proteína PCNA indicou que esta se mostrou reprimida nos fibroblastos irradiados com a maior TD, enquanto que a expressão de H2AX nos linfócitos diminuiu 6 h após a irradiação. A proteína PCNA apresentou potencial como um bom indicador dos efeitos de diferentes TDs em fibroblastos irradiados. Em conjunto, os resultados do presente trabalho mostraram uma ampla variedade de processos biológicos envolvidos na resposta ao estresse gerado pela irradiação sob duas diferentes TDs em células humanas (linfócitos e fibroblastos) demonstrando que a TD realmente é capaz de influenciar as respostas celulares em nível transcricional e protéico, o que ainda não foi descrito na literatura. Assim, os resultados constituem informações relevantes que podem contribuir para o esclarecimento das respostas moleculares e vias de sinalização em células normais irradiadas. / Ionizing radiation (IR) has been widely applied in medicine, mainly in diagnosis and therapy purposes. Considering that the exposure to radiation lead to serious complications to human health and environment, it has been relevant to study molecular mechanisms underlying cell responses to gamma-rays in different cell types, especially in normal cells. In radiobiology, dose rate (DR) is an important factor to be taken in account, on the basis of previous results in the literature. In this context, two distinct DR (0.5 and 2.0Gy/min.) were tested aiming to verify the influence of DR on profiles of gene and protein expression displayed by human fibroblasts and lymphocytes. Confluent primary fibroblasts were irradiated with 4Gy and lymphocytes with 2 Gy of -rays, doses delivered at 0.5 and 2.0 Gy/min. RNA was extracted at 6 h post-irradiation for the expression analysis by the cDNA array method in fibroblasts. Few DNA repair genes and proteins (H2AX, PCNA and FEN1) were analyzed by qPCR and Western blot, respectively, in both cell types, at two time-points (2 and 6 h post-irradiation). Results on gene expression were analyzed by the SAM method, which indicated 94 up-regulated genes (False discovery rate < 0.05) at 0.5 Gy/min. The most significant biological processes associated with modulated genes were metabolism, DNA repair, apoptosis signaling and stress response. On the other hand, 34 genes were modulated in cells irradiated at 2.0 Gy/min. (4 up-regulated and 30 down-regulated genes). For such DR, the major biological processes were metabolism, DNA repair, replication, stress response and apoptosis. By using qPCR method, some DNA repair genes (ERCC1, ERCC3 (or XPB), XPF, XPA, FEN1) and ATM (damage sensor) were studied. A wide difference in gene modulation was detected in response to different DR, mainly for fibroblasts analyzed at 2 h post-irradiation. However, this difference was slight in lymphocytes, suggesting that other alternative repair pathways could occurr in irradiated lymphocytes under low TD, possibly in consequence of DNA lesions such as double strand breaks, which are efficiently induced by 2 Gy. Interestingly, the expression of PCNA was down-regulated in fibroblasts irradiated at 2.0 Gy/min, while the expression of H2AX in lymphocytes decreased at both DR 6 h post-irradiation, These findings indicated several biological processes involved in stress responses generated by irradiation at two different DR in human cells. Actually, DR influenced cellular responses at transcriptional and protein levels. These data obtained at molecular level provide relevant information towards clarifying the mechanisms underlying cellular responses displayed by irradiated- normal cells.

Microorganisms control many processes pertinent to the stability of radwaste inventories in nuclear storage and disposal facilities. Furthermore, numerous subsurface bacteria, such as Shewanella spp. have the ability to couple the oxidation of organic matter to the reduction of a range of metals, anions and radionuclides, thus providing the potential for the use of such versatile species in the bioremediation of radionuclide contaminated land. However, the organisms promoting these processes will likely be subject to significant radiation doses. Hence, the impact of acute doses of ionizing radiation on the physiological status of a key Fe(III)-reducing organism, Shewanella oneidensis, was assessed. FT-IR spectroscopy and MALDI-TOF-MS suggested that the metabolic response to radiation is underpinned by alterations to proteins and lipids. Multivariate statistical analysis indicated that the phenotypic response was somewhat predictable although dependent upon radiation dose and stage of recovery. In addition to the cellular environment, the impact of radiation on the extracellular environment was also assessed. Gamma radiation activated ferrihydrite and the usually recalcitrant hematite for reduction by S. oneidensis. TEM, SAED and Mössbauer spectroscopy revealed that this was a result of radiation induced changes to crystallinity. Despite these observations, environments exposed to radiation fluxes will be much more complex, with a range of electron acceptors, electron donors and a diverse microbial community. In addition, environmental dose rates will be much lower than those used in previous experiments. Sediment microcosms irradiated over a two month period at chronic dose rates exhibited enhanced Fe(III)-reduction despite receiving potentially lethal doses. The microbial ecology was probed throughout irradiations using pyrosequencing to reveal significant shifts in the microbial communities, dependent on dose and availability of organic electron donors. The radiation tolerance of an algal contaminant of a spent nuclear fuel pond was also assessed. FT-IR spectroscopy revealed a resistant phenotype of Haematococcus pluvialis, whose metabolism may be protected by the radiation induced production of an astaxanthin carotenoid. The experiments of this thesis provide evidence for a range of impacts of ionizing radiation on microorganisms, including the potential for radiation to provide the basis for novel ecosystems. These results have important implications to the long-term storage of nuclear waste and the geomicrobiology of nuclear environments.

Chinese hamster V79-171B cells grown for about 24 hours in suspension culture display increased resistance to cell killing by ionizing radiation compared with cells grown as monolayers, an observation originally termed the "contact effect". More recently, development of that resistance was shown to be accompanied by changes in the conformation of the DNA which reduce its denaturation rate in high salt/weak alkali. These changes in DNA conformation, mediated by the cellular micro-environment, appear to be responsible for the contact effect. The conditions necessary for the development of the effect are not, however, completely understood. In particular, when cells grown as monolayers on petri plates are suspended in spinner culture flasks, their growth characteristics change in three distinct ways. First, cells in suspension no longer have a solid substrate, so they remain round. Second, after several hours, they begin to aggregate to form "spheroids", so that three-dimensional intercellular cell contact develops. Third, cells in the stirred suspension cultures are not subjected to high local concentrations of metabolic by-products or surrounded by a zone depleted of nutrients, as are cells in monolayer culture. The studies described here were designed to determine how each of these factors influence changes in DNA conformation, as assayed using the alkali unwinding technique. Our results indicated that a round shape may not be an essential requirement, since cells spread out on the surface of cytodex beads in suspension culture, and sparsely-seeded cells in monolayer culture demonstrated at least a partial contact effect. Three-dimensional intercellular contact does not always seem necessary for the development of the contact effect. Cells grown in a methyl cellulose matrix developed radioresistance, even though the cells formed only small clusters of less than five cells. Similarly, suspension culture cells which were prevented from aggregating by frequent exposure to trypsin, also developed the contact effect. There was no evidence that nutrient depletion plays a role in the failure of cells grown as monolayers to develop a contact effect. However, cells grown as spheroids in the presence of monolayer cells, or in monolayer cell-conditioned medium, did not display a full contact effect. This indicates a role for monolayer cell-produced factors (possibly extracellular matrix proteins) in preventing the development of the contact effect. We conclude that changes in DNA conformation and the increase in radiation resistance, seen in V79-171b cells grown as spheroids, are not the result of intercellular contact or round shape of the cells. This radioresistance appears to be the result of an absence of monolayer cell-produced factors which could control both cell shape and DNA conformation. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Magister Scientiae Dentium - MSc(Dent) / The level of knowledge and the attitude of dentists regarding radiation safety will have a direct impact on patient exposure to radiation. Aim: The aim of the present study was to evaluate the knowledge and attitude of dentists regarding radiation safety in government dental clinics in Khartoum, Sudan. Materials and Methods: A cross-sectional study using an administered structured questionnaire was carried out. The questionnaire consisted of 13 questions that included the demographic data of dentists, basic knowledge regarding radiation safety, knowledge of methods of dose reduction and the attitude of dentists regarding radiation safety. One hundred and sixty seven dental practitioners participated in the study. Results: The response rate was 90%. The majority were female, 59%, in the age group younger than 29 years with clinical experience less than 10 years. Only fifteen of the respondents identified themselves as specialist. Half of the respondents did not know that the thyroid gland is the most radiosensitive organ in the head and neck region. Forty four percent believed that the dose for panoramic radiography was higher than that for full mouth periapical radiographs. Forty percent had no idea that a relationship exists between the length of the x-ray cone and the amount of the dose and 44% who knew that the relationship existed, failed to explain that the long cone is more effective for reducing the patient dose. Forty seven percent of the respondents had no idea that there is a relationship between the speed of the film and the amount of dose and 44% who knew that the relationship existed, failed to explain that the fast film is more effective for reducing the patient dose. Sixty six percent had no idea that a relationship exists between collimation of the x-ray tube and patient dose. Forty six percent who knew the relationship existed, failed to explain that rectangular collimation is more effective for dose reduction. Seventy two percent of the dentists did not know what a safe distance from the radiation source was. Forty seven percent did not use film holders when taking periapical radiographs. Conclusions: This study clearly illustrates that there is a lack of knowledge regarding radiation safety in dentists in the government dental clinics in Khartoum, Sudan. Therefore there is a need to increase their knowledge regarding methods of radiation dose reduction (to patient) as well as improving their attitude regarding the radiation safety.

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22730号 / 医博第4648号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 遊佐 宏介, 教授 溝脇 尚志, 教授 篠原 隆司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 新制・課程博士 / 博士(医科学) / 甲第23114号 / 医科博第125号 / 新制||医科||8(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 斎藤 通紀, 教授 篠原 隆司, 教授 滝田 順子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Cílem této práce je seznámení se s problematikou detekce ionizujícího záření a jeho detekcí zejména pomocí proporcionálních detektorů a navrhnutí algoritmu pro jejich klasifikaci a jeho následná implementace do FPGA. V první části práce je obecně popsáno, jak jednotlivé typy plynem plněných detektorů fungují. V druhé části je věnován prostor algoritmům pro klasifikaci pulzů, které se objevují v literatuře. Následuje návrh vlastního algoritmu, jeho rozbor a rozebrání výsledků. Ve třetí části následuje popis samotné realizace navrhnutého řešení na platformě RedPitaya. Je zde rozebrána celková architektura navrhnutého systému, detailně popsány jak jednotlivé bloky v logice FPGA, tak i ostatní skripty zajišťující zpracování naměřených výsledků a jejich vizualizaci.