11 resultados para Temperature of animals.
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Filosofia
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Dissertation presented at Faculdade de Ciências e Tecnologia from Universidade Nova de Lisboa to obtain the degree of Master in Chemical and Biochemical Engineering
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Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente, perfil Engenharia Sanitária
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RESUMO: O uso de ratinhos transgénicos em neurociências aumentou consideravelmente nos últimos anos devido ao crescente interesse em compreender o cérebro e a necessidade de solucionar situações clínicas do foro neurológico e psiquiátrico. Para esse efeito, diferentes métodos de produção de animais transgénicos têm sido testados. O objectivo desta tese foi comparar métodos de integração aleatória de um transgene no genoma de ratinhos em termos de eficiência, estabilidade da integração do transgene, número de animais e de horas de trabalho necessárias para cada método. Assim, foi comparado o método mais utilizado - microinjecção pronuclear (PNMI) - com duas outras técnicas cujo desempenho foi considerado promissor – a transferência génica através dos testículos por electroporação e transfecção por lentivírus in vivo. As três técnicas foram realizadas usando um gene repórter sob o controlo de um promotor constitutivo, e depois reproduzidas usando um gene de interesse de modo a permitir obtenção de um animal capaz de ser usado em experimentação laboratorial. O transgene de interesse utilizado codifica uma proteína de fusão correspondendo a uma variante da rodopsina (channelrhodopsin) fundida à proteína enhanced yellow fluorescente protein ((EYFP) resultando num produto designado ChR2-EYFP. Este animal transgénico apresentaria expressão deste canal iónico apenas em células dopaminergicas, o que, com manipulação optogenética, tornaria possivel a activação especifica deste grupo de neurónios e, simultaneamente, a observação do impacto desta manipulação no comportamento num animal em livre movimento. Estas ferramentas são importantes na investigação básica em neurociências pois ajudam a esclarecer o papel de grupos específicos de neurónios e compreender doenças como a doença de Parkinson ou a esquizofrenia onde a função de certos tipos de neurónios de encontra alterada. Quando comparados os três métodos realizados verifica-se que usando um gene repórter PMNI resulta em 31,3% de, a de animais transgénicos obtidos, a electroporação de testículos em 0% e a injecção de lentivírus em 0%. Quando usado o gene de interesse, os resultados obtidos são, respectivamente, 18,8%, 63,9% e 0%.--------------ABSTRACT: The use of transgenic mice is increasing in all fields of research, particularly in neuroscience, due to the widespread need of animal models to solve neurological and psychiatric medical conditions. Different methodologies have been tested in the last decades in order to produce such transgenic animals. The ultimate goal of this thesis is to compare different methods of random integration of a transgene in the genome of mice in terms of efficiency, stability of the transgene integration, number of animals required and the labour intensity of each technique. We compared the most used method – pronuclear microinjection (PNMI) – with two other promising techniques – Testis Mediated Gene Transfer (TMGT) by electroporation and in vivo lentiviral transfection. The three techniques were performed using a reporter gene – green fluorescent protein (GFP), whose transcription was driven by the constitutive cytomegalovirus (CMV) promoter. These three techniques were later reproduced using the tyrosine hydroxylase promoter (TH) and the neuronal manipulator, channelrhodopsin-2 fused to the enhanced yellow fluorescent reporter protein (ChR2-EYFP). The transgenic animal we sough to produce would express the light driven channel only in dopaminergic cells, making possible to specifically activate this group of neurons, while simultaneously observe the behaviour in a freely moving animal. This is a very important tool in basic neuroscience research since it helps to clarify the role of specific groups of neurons, map circuits in the brain, and consequently understand neurological diseases such as Parkinson’s disease or schizophrenia, where the function of certain types of neurons is affected. When comparing the three methods, it was verified that using a reporter gene PNMI resulted in 31.3% of transgenic mice obtained, testis electroporation in 0% and lentiviral injection in 0%. When using the gene of interest, the results obtained were, respectively, 18.8%, 63.9% and 0%.
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies
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Dissertação para obtenção do Grau de Doutor em Engenharia Química e 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
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Dissertation presented in partial fulfilment of the Requirements for the Degree of Master in Biotechnology
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Salmonella enterica serovars are Gram-negative facultative intracellular bacterial pathogens that infect a wide variety of animals. Salmonella infections are common in humans, causing usually typhoid fever and gastrointestinal diseases. Salmonella enterica serovar Typhimurium (S. Typhimurium), which is a leading cause of human gastroenteritis, has been extensively used to study the molecular pathogenesis of Salmonella, because of the availability of sophisticated genetic tools, and of suitable animal and tissue culture models mimicking different aspects of Salmonella infections.(...)
Valorization of olive pomace through combination of biocatalysis with supercritical fluid technology
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A supercritical carbon dioxide (scCO2) based oil extraction method was implemented on olive pomace (alperujo), and an oil yield of 25,5 +/- 0,8% (goil/gdry residue) was obtained. By Soxhlet extraction with hexane, an oil extraction yield of 28,9 +/- 0,8 % was obtained, which corresponds to an efficiency of 88,4 +/- 4,8 % for the supercritical method. The scCO2 extraction process was optimized for operating conditions of 50 MPa and 348,15 K, for which an oil loading of 32,60 g oil/kg CO2 was calculated. As a proof of concept, olive pomace was used as feedstock for biodiesel production, in a process combining the use of lipase as a catalyst with the use of scCO2 as a solvent, and integrating the steps of oil extraction, oil to biodiesel transesterification and subsequent separation of the latter. In the conducted experiments, FAME (fatty acid methyl ester) purities of 90% were obtained, with the following operating parameters: an oil:methanol molar ratio of 1:24; a residence time of 7,33 and 11,6 mins; a pressure of 40 MPa; a temperature of 313,15 K; and Lipozyme (Mucor miehei; Sigma-Aldritch) as an enzyme. However, oscillations of FAME purity were registered throughout the experiments, which could possibly be due to methanol accumulation in the enzymatic reactor. Finally, the phenolic content of olive pomace, and the effect of the drying process – oven or freeze-drying – and the extraction methods – hydro-alcoholic method and supercritical method – on the phenolic content were analysed. It was verified that the oven-drying process on the olive pomace preserved 90,1 +/- 3,6 % of the total phenolic content. About 62,3 +/- 5,53% of the oven-dried pomace phenolic content was extracted using scCO2 at 60 MPa and 323,15 K. Seven individual phenols – hydroxytyrosol, tyrosol, oleuropein, quercetin, caffeic acid, ferulic acid and p-coumaric acid – were identified and quantified by HPLC.
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Mycobacterium avium Complex (MAC) comprises microorganisms that affect a wide range of animals including humans. The most relevant are Mycobacterium avium subspecies hominissuis (Mah) with a high impact on public health affecting mainly immunocompromised individuals and Mycobacterium avium subspecies paratuberculosis (Map) causing paratuberculosis in animals with a high economic impact worldwide. In this work, we characterized 28 human and 67 porcine Mah isolates and evaluated the relationship among them by Multiple-Locus Variable number tandem repeat Analysis (MLVA). We concluded that Mah population presented a high genetic diversity and no correlations were inferred based on geographical origin, host or biological sample. For the first time in Portugal Map strains, from asymptomatic bovine faecal samples were isolated highlighting the need of more reliable and rapid diagnostic methods for Map direct detection. Therefore, we developed an IS900 nested real time PCR with high sensitivity and specificity associated with optimized DNA extraction methodologies for faecal and milk samples. We detected 83% of 155 faecal samples from goats, cattle and sheep, and 26% of 98 milk samples from cattle, positive for Map IS900 nested real time PCR. A novel SNPs (single nucleotide polymorphisms) assay to Map characterization based on a Whole Genome Sequencing analysis was developed to elucidate the genetic relationship between strains. Based on sequential detection of 14 SNPs and on a decision tree we were able to differentiate 14 phylogenetic groups with a higher discriminatory power compared to other typing methods. A pigmented Map strain was isolated and characterized evidencing for the first time to our knowledge the existence of pigmented Type C strains. With this work, we intended to improve the ante mortem direct molecular detection of Map, to conscientiously aware for the existence of Map animal infections widespread in Portugal and to contribute to the improvement of Map and Mah epidemiological studies.