28 resultados para optimization of production processes
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Cancer remains as one of the top killing diseases in first world countries. It’s not a single, but a set of various diseases for which different treatment approaches have been taken over the years. Cancer immunotherapy comes as a “new” breath on cancer treatment, taking use of the patients’ immune system to induce anti-cancer responses. Dendritic Cell (DC) vaccines use the extraordinary capacity of DCs’ antigen presentation so that specific T cell responses may be generated against cancer. In this work, we report the ex vivo generation of DCs from precursors isolated from clinical-grade cryopreserved umbilical cord blood (UCB) samples. After the thawing protocol for cryopreserved samples was optimized, the generation of DCs from CD14+ monocytes, i.e., moDCs, or CD34+ hematopoietic stem cells (HSCs), i.e, CD34-derived DCs, was followed and their phenotype and function evaluated. Functional testing included the ability to respond to maturation stimuli (including enzymatic removal of surface sialic acids), Ovalbumin-FITC endocytic capacity, cytokine secretion and T cell priming ability. In order to evaluate the feasibility of using DCs derived from UCB precursors to induce immune responses, they were compared to peripheral blood (PB) moDCs. We observed an increased endocytosis capacity after moDCs were differentiated from monocyte precursors, but almost 10-fold lower than that of PB moDCs. Maturation markers were absent, low levels of inflammatory cytokines were seen and T cell stimulatory capacity was reduced. Sialidase enzymatic treatment was able to mature these cells, diminishing endocytosis and promoting higher T cell stimulation. CD34-derived DCs showed higher capacity for both maturation and endocytic capacity than moDCs. Although much more information was acquired from moDCs than from CD34-derived DCs, we conclude the last as probably the best suited for generating an immune response against cancer, but of course much more research has to be performed.
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Dissertation presented in partial fulfillment of the requirements for the degree of Master in Biotechnology
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Dissertation presented to obtain a Ph.D. degree in Engineering and Technology Sciences, Systems Biology at the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa
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Dissertação para obtenção do Grau de Mestre em Biotecnologia
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Polysaccharides are gaining increasing attention as potential environmental friendly and sustainable building blocks in many fields of the (bio)chemical industry. The microbial production of polysaccharides is envisioned as a promising path, since higher biomass growth rates are possible and therefore higher productivities may be achieved compared to vegetable or animal polysaccharides sources. This Ph.D. thesis focuses on the modeling and optimization of a particular microbial polysaccharide, namely the production of extracellular polysaccharides (EPS) by the bacterial strain Enterobacter A47. Enterobacter A47 was found to be a metabolically versatile organism in terms of its adaptability to complex media, notably capable of achieving high growth rates in media containing glycerol byproduct from the biodiesel industry. However, the industrial implementation of this production process is still hampered due to a largely unoptimized process. Kinetic rates from the bioreactor operation are heavily dependent on operational parameters such as temperature, pH, stirring and aeration rate. The increase of culture broth viscosity is a common feature of this culture and has a major impact on the overall performance. This fact complicates the mathematical modeling of the process, limiting the possibility to understand, control and optimize productivity. In order to tackle this difficulty, data-driven mathematical methodologies such as Artificial Neural Networks can be employed to incorporate additional process data to complement the known mathematical description of the fermentation kinetics. In this Ph.D. thesis, we have adopted such an hybrid modeling framework that enabled the incorporation of temperature, pH and viscosity effects on the fermentation kinetics in order to improve the dynamical modeling and optimization of the process. A model-based optimization method was implemented that enabled to design bioreactor optimal control strategies in the sense of EPS productivity maximization. It is also critical to understand EPS synthesis at the level of the bacterial metabolism, since the production of EPS is a tightly regulated process. Methods of pathway analysis provide a means to unravel the fundamental pathways and their controls in bioprocesses. In the present Ph.D. thesis, a novel methodology called Principal Elementary Mode Analysis (PEMA) was developed and implemented that enabled to identify which cellular fluxes are activated under different conditions of temperature and pH. It is shown that differences in these two parameters affect the chemical composition of EPS, hence they are critical for the regulation of the product synthesis. In future studies, the knowledge provided by PEMA could foster the development of metabolically meaningful control strategies that target the EPS sugar content and oder product quality parameters.
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With the final purpose of adding value to Amorim Turismo, several papers were analysed, key stakeholders were heard, competitors were studied and so was the market. After this evaluation, it was concluded that there is a chance to consolidate the quality of the service offered and it was with this goal in mind that several recommendations were given. However, such recommendations suffer a cost restriction, which was not neglected, and should be considered into further complementary research activity. Risk assessment was also conducted so that future issues can be anticipated and dealt with preventively.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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Dissertação para obtenção do Grau de Mestre em Engenharia Informática
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Field Lab of Entrepreneurial Innovative Ventures
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IEEE International Symposium on Circuits and Systems, pp. 724 – 727, Seattle, EUA
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Thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Electrical and Computer Engineering
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European Journal of Operational Research, nº 73 (1994)
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Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Química e Bioquímica pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia
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Dissertação para obtenção do Grau de Doutor em Engenharia Química, especialidade de Engenharia Bioquímica
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Dissertation presented to Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa for obtaining the master degree in Membrane Engineering