A disposição de resíduos sólidos é um dos temas mais discutidos na atualidade. A queima controlada dos resíduos possibilita a redução do volume a ser depositado e a geração de energia. Este trabalho estudou o emprego de uma nova tecnologia no atual processo de queima de uma série de resíduos carbonosos. Um sistema de catálise foi utilizado para sintetizar nanotubos de carbono (CNTs) a partir dos gases gerados pela pirólise/combustão dos resíduos. Os CNTs são materiais com alto valor de mercado devido às suas excepcionais propriedades. Foram alvos de estudo os resíduos da indústria do etanol (bagaço da cana-de-açúcar e grãos secos de destilaria com solúveis - DDGS), borracha de pneus inservíveis e garrafas de poli(tereftalato de etileno) pós-consumo. Amostras dos resíduos foram incineradas em um forno de fluxo contínuo com atmosfera controlada através da injeção de N2 e temperaturas de 600-1000°C, sendo que jatos de O2 foram adicionados em alguns experimentos. O efluente gasoso da queima foi submetido a um filtro de SiC e repassado a um segundo forno com temperatura constante de 1000°C. Telas de aço inoxidável foram dispostas no forno secundário para atuarem como catalisador. A cromatografia gasosa foi utilizada para a comparação dos efluentes com e sem o uso do catalisador, sendo constatado que o emprego das telas ocasionou uma significativa redução na emissão de poluentes. Após os experimentos, foi verificada a formação de partículas de carbono sólido na superfície do catalisador. As partículas formadas foram submetidas a análises por MEV, MET, TG e Raman. Os resultados apontaram a formação de nanotubos de carbono de parede múltiplas com comprimentos de 20 a 50 µm e diâmetros entre 20 e 50 nm quando empregados pneus e bagaço da cana como matérias-primas. Experimentos que empregaram DDGS e garrafas PET produziram microfibras de carbono com comprimentos em torno de 40 µm e diâmetros entre 80 e 200 nm. / The disposal of solid wastes is one of the most discussed topics nowadays. Controlled burning allows the reduction of waste volumes to be deposited, and the energy generation. This study examined the use of a new technology in the current burn processes of several carbonaceous wastes. A catalyst system was used to synthesize carbon nanotubes (CNTs) from the gases generated by pyrolysis/combustion of wastes. CNTs are materials with high market value due to its exceptional properties. Residues of the ethanol industry (sugarcane bagasse and distillers dried grains with solubles - DDGS), scrap tire rubbers and post-consumer polyethylene terephthalate bottles were subject of study. Waste samples were incinerated in a laminar-flow furnace with controlled atmosphere by injection of N2, and temperatures of 600-1000°C, while jets of O2 were added in some experiments. The effluent gases were subjected to a SiC filter and channeled into the second furnace with constant temperature of 1000°C. Stainless steel meshes were placed in the second furnace in order to work as catalyst. Gas chromatography was used to compare the effluent with and without the catalyst use, wherein was showed that the use of meshes caused a significant reduction in the emissions. After the experiments, the formation of solid carbon particles was verified on the catalyst surface. The formed particles were analyzed by SEM, TEM, TG and Raman. Results showed the formation of multi-wall carbon nanotubes with lengths of 20-50 µm and diameters in the range of 20-50 nm when tires and sugarcane bagasse were used as raw materials. Experiments using DDGS and PET bottles produced carbon microfibers with lengths of about 40 µm and diameters of 80-200 nm.

Receptores para o peptídeo liberador de gastrina (GRPr) são super expressos em vários tipos de células cancerígenas, incluindo câncer de mama e próstata. A Bombesina é um análogo do peptídeo GRP de mamíferos que se liga com alta especificidade e afinidade aos receptores do peptídeo liberador de gastrina (GRPr). Significantes pesquisas têm sido realizadas para desenvolver e radiomarcar um análogo da bombesina para diagnóstico de tumores de próstata e mama, utilizando-se técnicas de SPECT e PET, com radionuclídeos como 111In e 68Ga. O objetivo deste trabalho foi estudar a marcação com 111In de uma série inédita de peptídeos derivados de bombesina e determinar o potencial de aplicação no diagnóstico de tumores de próstata em modelos animais. Vários estudos foram realizados para padronizar o procedimento de marcação, variando-se temperatura, tempo de marcação, massa do peptídeo e atividade do radionuclídeo. Os resultados demonstraram que os análogos da bombesina estudados podem ser marcados com índio-111 com alto rendimento de marcação e alta atividade específica. Os estudos de biodistribuição em animais normais demonstraram que o derivado de BBN com espaçador aminoacídico Gly5 apresentou captação pancreática e intestinal expressiva, sugerindo ser o melhor derivado. Dois derivados DOTA- conjugados, com espaçador Gly5 foram radiomarcados com gálio-68 e investigados em modelo animal com tumor de próstata humano, indicando o potencial para aplicação do peptídeo radiomarcado no diagnóstico por PET. / Gastrin releasing peptide receptors (GRPRs) are over expressed in various types of cancer cells including prostate and breast cancer. Bombesin is an analogue of the mammalian GRP that binds with high specificity and affinity to GRPRs. Significant research efforts have been devoted to the design and radiolabel bombesin peptides for the diagnostic of prostatic and breast cancer using SPECT e PET, with radionuclides like 111In e 68Ga. The objective of this work was to study the labeling with 111In of a new bombesin series and evaluate the potential for diagnostic application using animal model. Several studies were evaluated to optimize the labelling conditions of BBN derivatives with 111In using different temperature, time, mass of peptide and radionuclide activity. High radiochemical purity and high specific activity were obtained for all the peptides labeled with 111-indium. Biodistribution studies in normal mices showed that the BBN derivative with Gly5 as aminoacidic spacer presented high uptake on pancreas and intestines that suggests that is the best peptide. Two DOTA-derivatives with Gly5 as spacer were radiolabelled with 68-gallium and evaluated in tumor model animals of human prostatic cancer and showed high potential for clinical application in diagnostic procedures with PET.

Os estudos de Avaliação do Ciclo de Vida (ACV) aplicados ao setor têxtil tiveram inicio na década de 1990, sendo realizados principalmente nos Estados Unidos e na Europa. No Brasil, os estudos de ACV aplicados a produtos têxteis utilizando dados nacionais iniciaram nos últimos dois anos. As normas ISO 14040 e 14044 fornecem a estrutura indispensável para a ACV, no entanto, ainda que balizadas por recomendações, certas escolhas metodológicas são realizadas pelo executor do estudo. Na maioria dos ciclos de vida do produto, há pelo menos um processo que tem mais de um produto como saída, e para o qual não é possível coletar dados em separado, sendo necessário aplicar um procedimento de alocação. O presente trabalho teve como objetivo avaliar a influência da aplicação de diferentes procedimentos de alocação no resultado final de um estudo de ACV aplicado à produção de fibras têxteis, através da análise de estudos publicados e da realização de estudo de caso. A revisão dos estudos publicados na literatura baseou-se no método de revisão bibliográfica sistemática. Dentre as publicações que apresentaram o procedimento de alocação selecionado, o que representa apenas 34% dos estudos, a alocação econômica foi realizada em sete estudos, seguido da alocação baseada em critérios físicos (massa) em cinco estudos. No estudo de caso realizado para a produção de 1 tonelada de fibra de algodão no Brasil, a alocação de todo o impacto para a fibra de algodão resultou em 4120kg/CO2 equivalente, enquanto alocando por massa e critério econômico, respectivamente, obteve-se 1627kg/CO2 equivalente e 3419kg/CO2 equivalente. Para a fibra de politereftalato de etileno (PET), observou-se que o método de alocação selecionado altera a fronteira do estudo, que por sua vez impacta no resultado final. Os resultados encontrados no presente estudo reforçam a necessidade de reportar explicitamente as escolhas metodológicas e realizar análise de sensibilidade. / Life Cycle Assessment (LCA) studies applied to the textile sector started in the 1990s, being conducted primarily in the United States and Europe. In Brazil, the LCA studies applied to textiles using national data began in the last two years. The ISO standards 14040 and 14044 provide the necessary structure to the LCA, however, certain methodological choices even that oriented, are made by the analyst. In most product life cycles, there is at least one process that has more than one product as output, and for which it is not possible to collect separate data, being necessary to apply an allocation procedure. This study has aimed to evaluate the influence of applying different allocation procedures in the results of an LCA study applied to textile fibers, through the analysis of published studies and conducting a case study. The review of published studies was performed based on the systematic review method. Among the publications that have presented the allocation procedure selected, which represents only 34% of the studies, economic allocation was performed in seven studies, followed by allocation based on physical criteria (mass) in five studies. In the case study for the production of one ton of cotton fibers in Brazil, allocating the full impact for cotton fiber resulted in 4120kg/CO2 equivalent, while allocating according to mass and economic criteria, respectively, resulted in 1627kg/CO2 equivalent and 3419kg/CO2 equivalent. For the PET fiber, it was observed that the allocation procedure changes the system boundary, and hence the results. The results of this study emphasize the need to explicitly communicate the methodological choices and perform sensitivity analysis on LCA results.

A medicina nuclear é a área da ciência médica que usa radiofármacos, isto é um radionuclídeo ligado a uma molécula de interesse biomédico, para estudar o funcionamento do organismo. Com isso, essa ciência pode realizar diagnósticos de patologias ou tratamento oncológico. Os estudos pré-clínicos, estudo com pequenos animais, são requisitos de suma importância para o desenvolvimento dessa área. São esses estudos que permitem os testes de novos radiofármacos que possivelmente serão usados em humanos. Quando se trata de pequenos animais, os órgãos de estudo são muito pequenos, portanto é vital que o equipamento tenha uma ótima resolução espacial e boa sensibilidade. Na medicina nuclear, a tomografia por emissão de pósitron (Positron Emission Tomography, PET) tem as características necessárias para desenvolver esses estudos com pequenos animais. Os animais mais usados são ratos e camundongos, e como nem sempre esses animais representam modelo humano seria interessante ter um equipamento que também funcionasse em outros animais. Sendo esse tomógrafo caro, não é viável ter um equipamento para cada tipo de animal. O presente trabalho propõe justamente um único tomógrafo que possa ser usado em diferentes animais ou eventualmente em dois animais simultaneamente. Isso será alcançado variando o anel de detecção usado nesse tipo de tomógrafos. Isso é alcançado mais facilmente em geometrias retangulares, pois com apenas 4 hastes se consegue variar a distância máxima entre os detectores preservando a forma da geometria. O custo envolvido na construção física desse tomógrafo é elevado, consequentemente é interessante ter um teste preliminar que forneça dados que possam sustentar essa ideia. A melhor alternativa para esse teste é o uso de simulação computacional. GATE (Geant4 Application for Tomographic Emission) foi o programa escolhido para essa simulação, porque já é um software validado, isto quer dizer que é compatível com experimentos reais. Assim sendo, quatro simulações foram montadas, duas para geometrias circulares com diâmetros diferentes, e analogamente, duas quadradas. Para verificar qual das geometrias tem melhor performance, foram usados os métodos sugeridos pela norma NEMA NU 4-2008. Efetuados esses testes, pode-se observar que as geometrias quadradas tem resolução semelhante às circulares. A sensibilidade e a relação sinal-ruído são maiores nas geometrias quadradas. Portanto, conclui-se que no geral, as geometrias retangulares simuladas são melhores que as circulares. Esse resultado é motivador para dar início à construção física do tomógrafo, pois o mesmo permite desenvolver novos produtos de modo mais eficiente e com menos custo / Nuclear medicine is an area of medical science that uses radiopharmaceutical (a radionuclide bounded to a molecule of biomedical interest) to study human physiology by images. Thus, this science can perform diagnostics of diseases and eventually, in specific cases, cancer treatment. Before using a new radiopharmaceutical in humans it is necessary to test it in small animals. The organs in these animals are very small, consequently it is vital that the equipment has a great spatial resolution and high sensitivity. In nuclear medicine Positron Emission Tomography (PET) has this requirement. The most animal used to develop this kind of studies are rats and mice. However, they are not always representing human animal model, so equipment that works to other animals also it would be interesting. But it is not feasible to have equipment for each animal, because it will be very expensive. Therefore, the aim of this work is test one scanner that can be used in different animals or possibly in two animals at the same time. This will be achieved by varying the detection ring used in this type of scanners (PET). To do it, it is easier using rectangular geometries because moving only four stalks the distance between the detectors can be varied preserving the shape of the geometry. The cost involved in physical construction of this kind of tomograph is too high, therefore it is interesting have a preliminary test that provides some data which supports this idea. Computer simulation is a cheap alternative for this test and it is able to provide a reliable data. The software used to do the simulations was GATE (Geant4 Application for Tomographic Emission) because it has already validated, what means it is compatible with real experiments. Thus, four simulations were builded, two for circular geometries with different diameters and two for rectangular geometries. To check which kind of geometry has better performance, it used the methods suggested by NEMA NU 4-2008. At end of these tests, it is possible to observe that the spatial resolution in square geometries is similar to circular. The sensitivity and signal to noise ratio are higher in the square geometries. So, in general, it is concluded that the simulated rectangular geometries are better than circular certainly, this result can be motivating to begin physical construction of the scanner, as it allows developing new products more efficiently and with less cost.

Introduction. Fused Positron Emission Tomography and Computed Tomography (PET/CT) is an emerging investigative tool in cardiovascular disease that provides an imaging-based quantification of pathophysiological processes of interest. The purpose of this thesis was to study the application of PET to identify fundamental pathophysiological processes driving 3 forms of cardiovascular disease: aortic stenosis, myocardial infarction, and atherosclerosis. Methods. Aortic Stenosis. Patients with a spectrum of calcific aortic valve disease (n=121) who underwent PET-CT imaging for the identification of valvular calcification (18Ffluoride) and inflammation (18F-fluorodeoxyglucose, 18F-FDG) underwent serial imaging and clinical follow-up over 2 years. Baseline imaging findings were compared with echocardiographic and CT markers of disease progression and clinical outcome. Myocardial Infarction. Patients underwent PET-CT imaging with 18F-fluciclatide (a novel αvβ3-selective radiotracer highlighting active angiogenesis, inflammation and fibrosis) after ST-segment elevation MI (n=21), alongside stable patients with chronic total occlusion (CTO) of a major coronary vessel (n=7), and healthy volunteers (n=9). Myocardial radiotracer uptake was compared with clinical and cardiac magnetic resonance imaging (CMR) markers of infarction and remodeling. Atherosclerosis. Patients with a spectrum of atherosclerotic disease categorized as stable or unstable (recent MI) underwent PET/CT imaging with 18F-fluciclatide (n=46). Thoracic aortic 18F-fluciclatide uptake was compared with aortic atherosclerotic burden quantified by CT plaque thickness, plaque volume and calcium scoring. Histological validation. Tissue from the aortic valve, myocardium and carotid arteries of study subjects was acquired and examined ex vivo using histology and autoradiography. Results. Aortic Stenosis. Baseline valvular 18F-fluoride uptake correlated strongly with the rate of progression in AVC (r=0.80, p < 0.001) and with haemodynamic progression (mean aortic valve gradient r=0.32, p=0.001). It emerged as independently associated with clinical outcome after age and sex-adjustment (HR 1.55 [1.33-1.81], p < 0.001). 18F-FDG demonstrated moderate correlations with disease progression as assessed by CT (r=0.43, p=0.001) and echocardiography (18F-FDG r=0.30, p=0.001), and was associated with clinical outcomes independent of age and sex (HR 1.35 [1.16-1.58], p < 0.001). Valvular 18F-fluoride uptake correlated with immunohistochemical markers of calcification activity. There was no correlation between 18F-FDG uptake and inflammation. Myocardial Infarction. 18F-Fluciclatide binding was demonstrated in ex vivo peri-infarct myocardium and uptake was increased in vivo at sites of acute infarction compared to remote myocardium (tissue-to-background ratio (TBRmean) 1.34±0.22 vs 0.85±0.17 respectively, p < 0.001) and myocardium of healthy volunteers (TBRmean 1.34±0.22 vs 0.70±0.03; p < 0.001). There was no 18F-fluciclatide uptake at sites of established prior infarction in patients with CTO, with myocardial activity similar to healthy volunteers (TBRmean 0.71±0.06 vs. 0.70±0.03,p=0.83). 18F-Fluciclatide uptake occurred at sites of regional wall hypokinesia (wall motion index ≥1 vs 0; TBRmean 0.93±0.31 vs 0.80±0.26 respectively, p < 0.001), was increased in segments displaying functional recovery (TBRmean 0.95±0.33 vs 0.81±0.27, p=0.002) and associated with increase in probability of regional recovery. Atherosclerosis. 18F-Fluciclatide vascular binding ex vivo co-localised with regions of increased αvβ3 integrin expression, and markers of inflammation and angiogenesis. 18F-Fluciclatide uptake in vivo correlated with measures of aortic atherosclerotic burden: plaque thickness (r=0.57, p=0.001), total plaque volume (r=0.56, p=0.001) and the CT aortic calcium score (r=0.37, p=0.01). Patients with recent MI had greater aortic 18F-fluciclatide uptake than those with stable disease (TBRmax 1.33 vs 1.21, p=0.01). Conclusions. In a range of cardiovascular diseases, PET-CT can provide insights into key pathophysiological processes, guide patient risk stratification and prognosis, and identify important biomarkers of disease activity that can be used for the development of future therapeutic interventions.

Os materiais plásticos possuem papel importante na transformação do estilo de vida das pessoas e é cada vez mais utilizado na produção e consumo pela população mundial. O material plástico tornou possível o fenômeno do crescimento de produtos descartáveis. Como conseqüência desta conjuntura, a reciclagem desses materiais torna-se opção obrigatória da sociedade moderna. A economia proporcionada pela reutilização dos materiais reciclados é vantajosa não apenas em consideração à reutilização dos recursos naturais envolvidos nestes produtos, mas principalmente pelo beneficio proporcionado no que tange a preservação das questões ambientais. Dentro do grande universo dos plásticos e embalagens plásticas disponíveis no mercado atual, no decorrer deste trabalho, foi realizada a reciclagem mecânica das embalagens pós-consumo, produzidas a partir do polímero PET, e mais especificamente às garrafas utilizadas na embalagem de bebidas em geral como, por exemplo, bebidas carbonatadas, água mineral, isotônicos e similares. Portanto, o objetivo deste trabalho foi estudar a reciclagem do PET de origem pós-consumo, e avaliar os efeitos provocados pela ação de diferentes doses de radiação ionizante, nas propriedades deste polímero reciclado, tendo como referência o PET virgem. Com base nos resultados obtidos, concluiu-se que os efeitos provocados pela ação da radiação ionizante a partir de feixe de elétrons proveniente de aceleradores de elétrons e, raios gama emitidos por fonte de 60Co, promoveram a predominância das reações de cisão aleatória da cadeia principal do PET, com conseqüente queda da massa molar do polímero. Fato este comprovado pelos ensaios de índice de fluidez e viscosidade intrínseca. Também foi realizada a análise térmica por calorimetria exploratória diferencial (DSC) comprovando a diminuição da massa molar do PET irradiado. / The plastic materials have an important role in the life style changing, in the lives of the people and it is more and more utilized in the production and consumption by the world population. By the plastic utilization, it became possible the growth phenomenon of disposable products. As a consequence of this conjecture, the recycling of these materials becomes an obliging option of the modern society. The economy provided by the reutilization of the recycling materials is advantageous not only in consideration to the reutilization of the natural resources involved in these products, but specially for its benefit provided in which concern to the preservation of the environmental matters. Within the big universe of the plastics and plastic packaging materials, available in the current market, it was carried out, during this work, the mechanical recycling of the packagings postconsumption, produced from PET polymer and more specifically, the bottles used in packagings for beverages as a whole; such as carbonated beverages, mineral water, isotonics, and so on. Thus, the aim of this work was to recycle the PET post-consumption and evaluate the effects provoked by the action of different ionizing radiation doses, in the properties of this recycled polymer, based on virgin PET. Based on the conclusive results, it was taken for granted that the effects provoked by the action of the ionizing radiation from the electron beam by electron accelerators and gamma rays emitted by 60Co source in the virgin and recycled PET polymer promoted the predominance of the scission reactions at random of the main chain, with consequent decrease of the polymer molecular weight. Such fact was corroborated by the flow index essay and intrinsic viscosity. It was also carried out, thermal analysis by Differential Scanning Calorimetry (DSC) proving the decreasing of molecular weight in the irradiated PET samples.

El presente trabajo tiene como objetivo investigar acerca de la disposición a reciclar botellas de plástico PET en la generación de los Millennials, considerando algunas variables externas como agentes influenciadores de esta disposición. Dichos factores externos, para esta tesis, son los hábitos en el hogar, en el centro de trabajo y las redes sociales. La muestra con la que se ha trabajado es de 364 personas del rango de edad de 18 a 37 años, considerados dentro de la generación Millennials, de diferentes distritos de Lima Metropolitana y Callao y además que se encuentren laborando en la actualidad. Estos filtros fueron necesarios considerarlos para poder validar las variables externas seleccionadas en este estudio. Algunos aspectos demográficos como la edad, el distrito de residencia, el nivel de estudios alcanzando, entre otros, también han sido considerados, ya que pueden influir en la disposición de reciclar botellas de plástico PET en la generación ya mencionada. Todos los aspectos que se han mencionado anteriormente, han sido desarrollados en la presente tesis. La finalidad de este trabajo es promover una cultura de reciclaje, la cual es fundamental para mitigar los impactos negativos que genera el plástico en el medio ambiente. Este estudio, se ha centrado en el reciclaje de botellas de plástico PET, el motivo principal es que existe un incremento considerable en el consumo de productos envasados en PET, lo cual se ha generado porque las empresas del rubro alimenticio y de bebidas, principalmente, ha optado por usar PET para sus envasar sus productos. Las características de este insumo como la alta maleavilidad, transparencia y alta resistencia a la corrosión y desgaste han hecho que sea calificado como el más apto para envasar alimentos y bebidas destinados al consumo humano (Cisneros & Sánchez, 2014). Asimismo este trabajo se ha enfocado en un segmento específico de personas, la generación Millennials, ya que tiene más poder de difusión debido al fácil acceso que tienen en las redes sociales, un medio de comunicación, cada vez, más masivo. / The objective of this paper is to investigate the disposition to recycle plastic PET bottles in the generation of Millennials, considering some external variables as agents influencing this provision. These external factors, for this thesis, are the habits in the home, in the workplace and social networks. The sample with which we have worked is of 364 people from the age range of 18 to 37 years old, considered within the Millennials generation, from different districts of Metropolitan Lima and Callao and also who are currently working. These filters were necessary to consider them in order to validate the external variables selected in this study. Some demographic aspects such as age, district of residence, level of studies reaching, among others, have also been considered, as they can influence the disposition to recycle PET plastic bottles in the aforementioned generation. All the aspects mentioned above have been developed in this thesis. The purpose of this work is to promote a culture of recycling, which is fundamental to mitigate the negative impacts generated by plastics in the environment. This study has focused on the recycling of PET plastic bottles, the main reason is that there is a considerable increase in the consumption of products packed in PET, which has been generated because the companies of food and beverages, mainly, has chosen to use PET to package their products. The characteristics of this input such as high malleability, transparency and high resistance to corrosion and wear have made it qualified as the most suitable for packaging food and beverages intended for human consumption (Cisneros & Sánchez, 2014). Likewise, this work has focused on a specific segment of people, the Millennials generation, since it has more diffusion power due to the easy access they have in social networks, a means of communication, each time, more massive. / Tesis

Reconstructed tomographic image resolution of small animal PET imaging systems is improving with advances in radiation detector development. However the trend towards higher resolution systems has come with an increase in price and system complexity. Recent developments in the area of solid-state photomultiplication devices like silicon photomultiplier arrays (SPMA) are creating opportunities for new high performance tools for PET scanner design. Imaging of excised small animal organs and tissues has been used as part of post-mortem studies in order to gain detailed, high-resolution anatomical information on sacrificed animals. However, this kind of ex-vivo specimen imaging has largely been limited to ultra-high resolution μCT. The inherent limitations to PET resolution have, to date, excluded PET imaging from these ex-vivo imaging studies. In this work, we leverage the diminishing physical size of current generation SPMA designs to create a very small, simple, and high-resolution prototype detector system targeting ex-vivo tomographic imaging of small animal organs and tissues. We investigate sensitivity, spatial resolution, and the reconstructed image quality of a prototype small animal PET scanner designed specifically for imaging of excised murine tissue and organs. We aim to demonstrate that a cost-effective silicon photomultiplier (SiPM) array based design with thin crystals (2 mm) to minimize depth of interaction errors might be able to achieve sub-millimeter resolution. We hypothesize that the substantial decrease in sensitivity associated with the thin crystals can be compensated for with increased solid angle detection, longer acquisitions, higher activity and wider acceptance energy windows (due to minimal scatter from excised organs). The constructed system has a functional field of view (FoV) of 40 mm diameter, which is adequate for most small animal specimen studies. We perform both analytical (3D-FBP) and iterative (ML-EM) methods in order to reconstruct tomographic images. Results demonstrate good agreement between the simulation and the prototype. Our detector system with pixelated crystals is able to separate small objects as close as 1.25 mm apart, whereas spatial resolution converges to the theoretical limit of 1.6 mm (half the size of the smallest detecting element), which is to comparable to the spatial resolution of the existing commercial small animal PET systems. Better system spatial resolution is achievable with new generation SiPM detector boards with 1 mm x 1 mm cell dimensions. We demonstrate through Monte Carlo simulations that it is possible to achieve sub-millimeter spatial image resolution (0.7 mm for our scanner) in complex objects using monolithic crystals and exploiting the light-sharing mechanism among the neighboring detector cells. Results also suggest that scanner (or object) rotation minimizes artifacts arising from poor angular sampling, which is even more significant in smaller PET designs as the gaps between the sensitive regions of the detector have a more exaggerated effect on the overall reconstructed image quality when the design is more compact. Sensitivity of the system, on the other hand, can be doubled by adding two additional detector heads resulting in a, fully closed, 4π geometry.

El presente estudio es de tipo cuantitativo, no experimental de diseño descriptivo correlacional y de corte transversal; el objetivo del presente estudio consistió en conocer la relación entre el autoconcepto y el vínculo que existe entre el niño (a) y su mascota en un grupo de 181 niños de ambos sexos (51.9% hombres, 48.1% mujeres) que pertenecieron al tercer (n = 64) , cuarto (n = 58) y quinto grado de primaria (n = 59) provenientes de dos colegios privados de Lima. Los participantes tenían edades de entre 7 y 13 años (M = 9.7, DE = 1.01) de los cuales 152 tenían un perro como mascota. Los integrantes respondieron al Cuestionario de Autoconcepto para Niños (Váldez-Medina, González, López, & Reusche, 2001) y la Escala de Vínculo con la Mascota (Schencke & Farkas, 2012). Con relación a las variables psicológicas, se encontró que el autoconcepto positivo y el vínculo con la mascota presenta una correlación positiva y no significativa (r = .13). En cuanto al autoconcepto negativo y el vínculo con la mascota presenta una correlación negativa y no significativa (r = -.10). Se discuten los resultados en función a la correlación entre los ítems con las dimensiones de Autoconcepto Positivo y Autoconcepto Negativo, en donde se encontró que existe una relación positiva entre el autoconcepto positivo y las conductas asociadas al cuidado de la mascota, así como también entre el autoconcepto positivo y la frecuencia con la que el niño le hace cariño a su mascota. Por último, se encontró una relación positiva y significativa entre el autoconcepto negativo y el número de hermanos que posee el niño. / The present research is a quantitative, non-experimental study of descriptive correlational and cross-sectional design, which objective is to explore the relationship between self-concept and the bond between the child and his/her pet in a group of 181 children of both sexes (51.9% male, 48.1% female) that belonged to the third (n = 64) , fourth (n = 58) and fifth grade (n = 59) from two private schools in Lima. The participants were between the ages of 7 and 13 years old (M = 9.7, DE = 1.01) of which 152 had a dog as a pet. Participants responded to the Self-concept Questionnaire for Children (Váldez-Medina, González, López, & Reusche, 2001) and the Companion Animal Bonding Scale (Schencke & Farkas, 2012). Regarding the psychological variables, it shows that positive self-concept and pet bonding have a positive but not significant correlation (r = .13). As for the negative self-concept and pet bonding, it was found that it has a negative but not significant correlation (r = -.10). The results are discussed according to the correlation between the items and the positive and negative self-concept dimensions, where it was found that there is a positive relationship between the positive self-concept and the behaviors associated with pet care, as well as between the positive self-concept and the frequency with which the child cares for his pet. Finally, a positive and significant relationship was also found between the negative self-concept and the number of siblings the child possesses. / Tesis

ABSTRACT Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor, which plays a pivotal part in the development of the central nervous system. Aberrant expression of full-length ALK occurs in neuroblastoma and chromosomal translocation or inversion of the ALK gene can generate novel fusion-ALK proteins that possess constitutive kinase activity and contribute to oncogenic processes. One of the well-studied fusion proteins is nucleophosmin (NPM-ALK), which draws a lot of attention for medicinal chemists to design small molecules as kinase inhibitors for this target. In this dissertation, [1, 2, 4]-Dihydrotriazine dimers as competitors of the lead compound NVP-TAE684 targeting NPM-ALK have been designed and synthesized. Molecular modelling studies show that those dihydrotriazine dimers have a great potential to be better kinase inhibitors. Chapter two describes imaging in the drug discovery and development arena. One of important imaging techniques is positron emission tomography (PET). PET is a radionuclide based molecular imaging technique, which can be used for early detection, characterization, "real time" monitoring of diseases, and investigation of the efficacy of drugs. Fluorine-18 (18F) based molecular probes for PET imaging still remain big challenging to prepare but have gained increased interest by radiochemists in the past two decades. In this study, a novel approach to introduce fluorine into a molecular probe has been discovered based on boron chemistry. A few novel fluorine capture reagents have been synthesized and described in this Chapter.