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Sage, Elizabeth Ann. "The functional competence of animal cells in culture : the NSO cell proteome." Thesis, University of Kent, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399618.
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Duncan, Philippa Jane. "The effect of hyperosmotic conditions on growth and recombinant protein production by NSO myeloma cells in culture." Thesis, Liverpool John Moores University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403285.
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Osman, Jason John. "Response of GS-NSO mouse myeloma cells to pH fluctuations relevant to those found in large scale fermentation." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393530.
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Waskow, Claudia, Bonin Malte von, Martin Wermke, Cosgun Kadriye Nehir, Christian Thiede, Martin Bornhauser, and Gerard Wagemaker. "In Vivo Expansion of Co-Transplanted T Cells Impacts on Tumor Re-Initiating Activity of Human Acute Myeloid Leukemia in NSG Mice." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-191633.
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Human cells from acute myeloid leukemia (AML) patients are frequently transplanted into immune-compromised mouse strains to provide an in vivo environment for studies on the biology of the disease. Since frequencies of leukemia re-initiating cells are low and a unique cell surface phenotype that includes all tumor re-initiating activity remains unknown, the underlying mechanisms leading to limitations in the xenotransplantation assay need to be understood and overcome to obtain robust engraftment of AML-containing samples. We report here that in the NSG xenotransplantation assay, the large majority of mononucleated cells from patients with AML fail to establish a reproducible myeloid engraftment despite high donor chimerism. Instead, donor-derived cells mainly consist of polyclonal disease-unrelated expanded co-transplanted human T lymphocytes that induce xenogeneic graft versus host disease and mask the engraftment of human AML in mice. Engraftment of mainly myeloid cell types can be enforced by the prevention of T cell expansion through the depletion of lymphocytes from the graft prior transplantation.
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Yu, Yi-Hsin Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Role of the RNAi pathway in influenza a virus infected mammalian cells." Publisher:University of New South Wales. Biotechnology & Biomolecular Sciences, 2008. http://handle.unsw.edu.au/1959.4/41545.
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The interferon (lFN) signalling and RNA interference (RNAi) pathways are the major antiviral pathways in animals and plants, respectively. Although the mechanism of RNAi remains to be completely characterised, the genes that encode the proteins involved in this process have been identified in the plant, fungi and animal kingdoms (Fagard et al., 2000, Grishok et aI., 2000, Hall et al., 2003, Kanellopoulou et al., 2005, Kolb et al., 2005); with comparative analyses indicating that RNAi is an evolutionarily conserved mechanism. Several studies have identified RNAi suppressors encoded by animal viruses, suggesting an antiviral role for the RNAi pathway in animals as well as plants (Andersson et al., 2005, Bennasser et al., 2006, Garcia et al., 2006, Li et al., 2004, Lichner et al., 2003, Lingel et al., 2005, Lu & Cullen, 2004, Wang et al., 2006). However, most of these studies were performed in non-mammalian systems and as yet, there is no direct evidence indicating that the RNAi pathway plays a significant antiviral role during the infection of mammalian cells. Interestingly, several viruses have now been shown to express their own microRNA (miRNA) in infected cells (Grey et al., 2005, Pfeffer et al., 2005, Pfeffer et al., 2004, Samols et al., 2005, Sullivan et al., 2005). Further, in the case of hepatitis C virus (HCV), there is evidence that the virus usurps the host cell miRNAs to enhance viral replication (Jopling et al., 2005). The principal aim of this project was to investigate the role of RNAi in mammalian cells during viral infection, particularly infection with the influenza A virus. This thesis is divided into six major chapters followed by a brief general discussion. Chapter 1 contains a general introduction to the RNAi pathway. It describes the history of the discovery of RNAi and summarizes the known and proposed antiviral roles of the RNAi pathway in plants and mammalian cells. Chapter 2 describes the general materials and methods used for this project. There are four main result chapters, each dealing with a specific experimental system. Each chapter is divided into a brief introduction, specific materials and methods used, followed by presentation of the experimental results and a brief discussion. Chapter 3 describes the development of an in vitro Dicer activity assay to study the effect of viral proteins on the activity of the mammalian Dicer protein. It was demonstrated that crude cell lysates derived from influenza A virus infected cells impaired the activity of Dicer and this observation was not due to degradation of the Dicer protein by virally-induced proteases. Chapter 4 describes the use of a GFP reporter assay for screening potential RNAi suppressors. This assay is suitable for studying viral proteins in isolation. The effect of the influenza NS1 protein on the RNAi pathway in HEK293 cells was investigated and it was shown that NS1 could exert modest, but nevertheless significant, suppression of the RNAi pathway. Northern studies, performed to examine the processing of shRNA in the presence of NS1, demonstrated that NSI suppressed the RNAi mechanism through interfering with the maturation ofshRNA into siRNA. Chapter 5 describes the effect of over-expressing components of the RNAi pathway on influenza A virus infection. In these experiments, Exportin 5, which encodes a protein involved in the transport of pre-miRNA/shRNA into the cytoplasm, was over-expressed during influenza A virus infection. Reduced viral infection was observed in cells over-expressing Exportin 5, suggesting that this treatment protects cells from virus infection. Chapter 6 describes the expressed small RNA profile during influenza A virus infection in MDCK cells. Novel canine miRNA homologues were identified through cloning and sequencing. No definitive evidence for virally-derived siRNA/miRNA was found but a general reduction of endogenous miRNA expression was detected.
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Waskow, Claudia, Bonin Malte von, Martin Wermke, Cosgun Kadriye Nehir, Christian Thiede, Martin Bornhauser, and Gerard Wagemaker. "In Vivo Expansion of Co-Transplanted T Cells Impacts on Tumor Re-Initiating Activity of Human Acute Myeloid Leukemia in NSG Mice." Public Library of Science, 2013. https://tud.qucosa.de/id/qucosa%3A28097.
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Human cells from acute myeloid leukemia (AML) patients are frequently transplanted into immune-compromised mouse strains to provide an in vivo environment for studies on the biology of the disease. Since frequencies of leukemia re-initiating cells are low and a unique cell surface phenotype that includes all tumor re-initiating activity remains unknown, the underlying mechanisms leading to limitations in the xenotransplantation assay need to be understood and overcome to obtain robust engraftment of AML-containing samples. We report here that in the NSG xenotransplantation assay, the large majority of mononucleated cells from patients with AML fail to establish a reproducible myeloid engraftment despite high donor chimerism. Instead, donor-derived cells mainly consist of polyclonal disease-unrelated expanded co-transplanted human T lymphocytes that induce xenogeneic graft versus host disease and mask the engraftment of human AML in mice. Engraftment of mainly myeloid cell types can be enforced by the prevention of T cell expansion through the depletion of lymphocytes from the graft prior transplantation.
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Wu, Mon-Han. "The effect of osmotic pressure on GS-NSO antibody production cell line." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439532.
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Chen, Baiyu, and 陳白羽. "Suprachiasmatic nucleus projecting retinal ganglion cells in golden hamsters development, morphology and relationship with NOS expressingamacrine cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37238218.
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Long, Xiangtian. "Synthesis and Evaluation of Stimulatory Properties of Glycolipids for Natural Killer T Cells." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/2133.
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Natural killer T cells (NKT cells) are a subset of T cells. They regulate a wide range of diseases including infection, tumor growth, and autoimmune diseases, through recognizing glycolipid antigens in the context of CD1d. An understanding of the scope of glycolipid antigens would facilitate use of this cell type in controlling immune responses. Till today, a lysosomal glycolipid, isoglobotrihexosylceramide (iGb3), is the only natural glycolipid that has been found to be recognized by both human and mouse NKT cells. To elucidate the molecular basis of this specific recognition, iGb3 variants were designed and prepared: i) replacement of the C26 acyl chain with shortened acyl chains; ii) replacement of the distal galactose with glucose and mannose; iii) replacement of the intermediate galactose with glucose; iv) replacement of the proximal glucose with galactose. Among these glycolipids, the iGb3 variants with shortened acyl chains are potent stimulators of NKT cells. The iGb3 variant with intermediate glucose also showed the ability to stimulate NKT cells, but this finding needs to be verified. Our findings support the specific recognition of iGb3 by NKT cells. The search for other natural glycolipid antigens focuses on glycolipids that are isolated from bacteria and parasites. Recently, glycosphingolipids (GSL-1, -3, and -4) isolated from the sphingomonodaceae family of bacteria were characterized. GSL-1 has been shown to be a potent stimulator of NKT cells. Moreover, it has been reported that GSL-4 is a stimulator as well. To verify the structures and stimulatory properties of GSLs, GSL-1 to -4 were prepared and tested for their abilities to stimulate NKT cells. The result that only GSL-1 can stimulate NKT cells suggests that synthesis of these higher order GSLs would be an immune evasion mechanism. Neutral glycosphingolipids from sheep-derived F. hepatica liver flukes, a causative agent of fascioliasis, were isolated and characterized. Their structures are closely related to iGb3. Among these glycolipids, neo-iGb4s could be truncated to iGb3 in the lysosome and thus stimulate NKT cells. To test this hypothesis, these glycosphingolipids were prepared and tested. None of these synthetic glycolipids stimulates NKT cells, which suggests that the secretion of these glycolipids by F. hepatica could be the result of the parasite-immune-evasion mechanism.
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Chen, Baiyu. "Suprachiasmatic nucleus projecting retinal ganglion cells in golden hamsters development, morphology and relationship with NOS expressing amacrine cells." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37238218.
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Piedade, Nuno André Reis. "Transcriptional and redox changes in Huntington´s disease human stem cells." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23437.
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Mestrado em Biomedicina MolecularA doença de Huntington (HD, “Huntington’s disease”) é uma doença neurodegenerativa autossómica dominante, causada pela repetição de sequências CAG no gene HTT. As manifestações clínicas da doença incluem alterações motoras, cognitivas e psiquiátricas, e atualmente não existe cura para a HD. A utilização de células estaminais pluripotentes induzidas (iPSC, ”inducedpluripotent stem cells”) e células estaminais neurais (NSC, “neural stem cells”) fornecem um modelo adequado para o estudo dos eventos iniciais conducentes à neurodegenerescência na HD. Assim, este trabalho teve como objetivo analisar as alterações de transcrição que envolvem a biogénese mitocondrial e a resposta ao stresse oxidativo em células HD-iPSC e HD-NSC, comparativamente a células controlo.Foi avaliada a expressão de PGC-1α (“peroxisome proliferator-activated receptor gamma coactivator 1-alpha”), do fator de transcrição mitocondrial A (TFAM) e subunidades dos complexos da cadeia respiratória mitocondrial e de enzimas que regulam a atividade da piruvato desidrogenase (PDH) em HD-iPSC e HD-NSC. Os resultados mostraram uma diminuição dos níveis de mRNA de PGC-1α, TFAM e subunidades do complexo III (CYC1, MT-CYB e UQCR10), e um aumento de mRNA da subunidade ND1 do complexo I e da cinase1 da PDH (PDK1) em HDiPSCNas HD-NSC apenas se observou uma diminuição nos níveis de mRNA de PGC-1α. Em células HD-iPSC e HD–NSC detetaram-se também níveis aumentados de peróxido de hidrogénio, uma espécie reativa de oxigénio (ROS, “reactive oxygen species”), sem contudo ocorrerem alterações na acetilação no resíduo de lisina 68 da superóxido dismutase 2 (SOD2) nas HD-iPSC; curiosamente, observou-se uma diminuição significativa dos níveis de mRNA de UCP2 (”uncoupling protein 2”) em HD-iPSC e HD-NSC. De forma a avaliar a resposta antioxidante, analisámos ainda os níveis proteicos e de mRNA do Nrf2 (”nuclear factor erythroid 2–related factor 2”) e da subunidade catalítica da enzima gama-glutamilcisteína ligase (GCLc) e heme oxigenase 1 (HO-1). Não foram encontradas alterações nos níveis de mRNA ou proteicos de Nrf2, apesar de se ter verificado uma tendência para um aumento da sua fosforilação no resíduo de serina 40 (P(Ser40)-Nrf2) em células HD-iPSC, sugerindo uma resposta ao aumento de ROS. Verificou-se ainda um aumento da expressão de GCLc nas HD-iPSC. Os resultados demonstram que a alteração transcricional de proteínas envolvidas na biogénese mitocondrial e de subunidades de complexos mitocondriais, assim como elevados níveis de ROS, a que se associa um aumento de GCLc e uma redução de UCP2, constituem potenciais eventos iniciais envolvidos na patogénese da HD.
Huntington´s disease (HD) is an autosomal dominant neurodegenerative disorder caused by an abnormal expansion of CAG repeats in the HTT gene. Clinical manifestations of the disease include motor, cognitive and psychiatric changes, and currently there is no cure for HD. The use of induced-pluripotent stem cell (iPSC) and neural stem cell (NSC) provide reliable models to study early events involved in HD neurodegeneration.Thus, in this study we aimed to determine changes in transcripts related with mitochondrial biogenesis and the response to oxidative events in HD-iPSC and HD-NSC, when compared with the respective control cells. We investigated the expression of the transcription factor peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and its downstream targets, namely TFAM (mitochondrial transcriptional factor A) and subunits of mitochondrial complexes, and enzymes that regulate the activity of pyruvate dehydrogenase (PDH) in both HD-iPSC and HD-NSC. Our analysis revealed reduced mRNA levels of PGC-1α, TFAM and mitochondrial and nuclear-encoded complex III subunits (CYC1, MT-CYB and UQCR10) and enhanced mRNA levels of ND1 subunit of complex I and PDH kinase 1 (PDK1) in HD-iPSC. Interestingly, apart from PGC-1α, unchanged mRNA levels of other targets were observed in HD-NSC. In both HD-iPSC and HD-NSC we observed increased levels of hydrogen peroxide, a reactive oxygen species (ROS), but unchanged acetylation at Lys68 of superoxide dismutase 2 (SOD2 or Mn-SOD); nevertheless, we observed a significant reduction in the expression of uncoupling protein 2 (UCP2) in HD-iPSC and HD-NSC. To evaluate the antioxidant response, we further measured protein and mRNA levels of nuclear factor erythroid 2–related factor 2 (Nrf2) and two of its downstream targets, namely γ- glutamylcysteine ligase catalytic subunit (GCLc) and heme oxygenase 1 (HO-1). We did not find changes in mRNA expression nor protein levels of Nrf2, but we observed a tendency for increased Nrf2 phosphorylation at Ser40 (p-Nrf2) in HDiPSC, suggesting a slight response to ROS. Concomitantly, we found an increase in GCLc expression in HD-iPSC. Our results evidence reduced transcriptional changes associated with decreased mitochondrial biogenesis and complexes subunits, as well as enhanced ROS levels linked to increased GCLc and reduced UCP2 as potential early events in HD pathogenesis.
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Ribeiro, Rodrigo Alves. "Avalia??o in vitro da ades?o e prolifera??o de c?lulas mesenquimais do ligamento periodontal humano em diferentes superf?cies de tit?nio." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17065.
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Previous issue date: 2011-02-04In the last years, many scientific researches in implantology have been focused on alternatives that would provide higher speed and quality in the process of osseointegration. Different treatment methods can be used to modify the topographic and chemical properties of titanium surface in order to optimize the tissue-implant reactions by a positive tissue response. This study aimed to evaluate the adhesion and proliferation of mesenchymal cells from human periodontal ligament on two different titanium surfaces, using cell culture techniques. Grade II titanium discs received different surface treatments, forming two distinct groups: polished and cathodic cage plasma nitriding. Human periodontal ligament mesenchymal cells were cultured on titanium discs in 24-well cell culture plates, at a density of 2 x 104 cells per well, including wells with no discs as positive control. Data obtained by counting the cells that adhered to the titanium surfaces (polished group and cathodic cage group) and to the plastic surface (control group), in the 24, 48 and 72-hour periods after plating, were used to analyze cell adhesion and proliferation and to obtain the cell growing curve in the different groups. The data were submitted to nonparametric analysis and the differences between groups were compared by Kruskal-Wallis and Friedman statistical tests. No statistically significant differences were found in the cells counts between the groups (p>0.05). It was concluded that both treatments produced surfaces compatible with the adhesion and proliferation of human periodontal ligament mesenchymal cells
Nos ?ltimos anos, v?rias pesquisas cient?ficas em Implantodontia t?m buscado alternativas que proporcionem maior rapidez e qualidade no processo de osseointegra??o. Diferentes m?todos de tratamento podem ser utilizados para modificar as propriedades topogr?ficas e qu?micas da sua superf?cie do tit?nio, a fim de otimizar as rea??es tecido-implante atrav?s de uma resposta tecidual favor?vel. O presente trabalho teve como objetivo analisar a ades?o e prolifera??o de c?lulas mesenquimais de ligamento periodontal humano a diferentes superf?cies de tit?nio, atrav?s de t?cnicas de cultivo celular. Discos de tit?nio grau II receberam diferentes tratamentos de superf?cie, constituindo dois grupos distintos: polido e nitretado a plasma na configura??o de gaiola cat?dica. C?lulas mesenquimais obtidas do ligamento periodontal de dentes humanos h?gidos foram cultivadas sobre os discos de tit?nio em placas de cultivo de 24 po?os, na densidade de 2 x 104 c?lulas/po?o, incluindo po?os sem discos como controle positivo. Os dados obtidos das contagens das c?lulas aderidas ?s superf?cies de tit?nio (grupo polido e grupo gaiola cat?dica) e ? superf?cie pl?stica (grupo controle), nos intervalos de 24, 48 e 72 horas ap?s o plaqueamento, foram utilizados para analisar a ades?o e prolifera??o celular e obter a curva de crescimento celular nos diferentes grupos. Os dados foram submetidos a an?lises n?o param?tricas e as diferen?as entre os grupos foram comparadas pelos testes estat?sticos Kruskal-Wallis e Friedman. N?o foram encontradas diferen?as estat?sticas significativas nas contagens celulares entre os grupos estudados (p>0,05). Conclui-se que ambos os tratamentos produziram superf?cies compat?veis com ades?o e prolifera??o de c?lulas mesenquimais do ligamento periodontal humano
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Schneider, Júlia. "Efeito do sulfato de dehidroepiandrosterona (SDHEA) sobre células foliculares nos estágios antral inicial e pré-ovulatório." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/157962.
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O folículo ovariano é composto pelo oócito (gameta feminino) e por várias camadas de células foliculares somáticas, sendo que destas, as mais intimamente associadas com o oócito são as células do cumulus oophorus (CCs), as quais estão em contato direto com o gameta feminino e formam o complexo cumulus-oócito (CCO), e as células murais da granulosa (CGs), que revestem a parede do folículo ovariano. Visto que estas CGs e CCs são facilmente acessadas durante tratamentos de reprodução assistida (RA), que podem ser coletadas sem comprometimento do oócito e que são descartadas após a recuperação do oócito é possível que elas sejam utilizadas em pesquisas que visam elucidar a fisiologia ovariana. No entanto, quando recuperadas, nos ciclos de reprodução assistida, estas células se encontram em um estado luteinizado, devido ao tratamento hormonal que as pacientes realizam. Sabe-se que o uso de CGs luteinizadas em cultura celular para o estudo do processo molecular ovulatório é limitado visto esta prévia exposição celular às gonadotrofinas e ao seu estado luteinizado. Porém, foi demonstrado que CGs luteinizadas podem readquirir sua capacidade de resposta à estimulação por gonadotrofinas, recuperando características semelhantes às daquelas de folículos não luteinizados nos estágios iniciais de diferenciação (early antral não luteinizado). A estimulação destas células com FSH causa aumento na expressão de genes que caracterizam CGs típicas de folículos pré-ovulatórios (pré-ovulatório não luteinizado). Ainda, outra questão importante com relação ao folículo ovariano diz respeito à ação dos androgênios nesta estrutura ovariana, sendo que já se sabe que a ativação do receptor de androgênio, localizado nas células foliculares, é capaz de modular a expressão e a atividade de genes importantes para a manutenção do desenvolvimento do folículo ovariano. Desta forma, sugere-se que o efeito reprodutivo do tratamento com dehidroepiandrosterona (DHEA) e seu sulfato (SDHEA), importantes androgênios, pode ser devido às suas ações justamente no microambiente folicular. Portanto, o objetivo deste trabalho foi analisar a exposição de células foliculares desluteinizadas (estágios early antral e pré-ovulatório) ao SDHEA. Para isto, células da granulosa e do cumulus foram obtidas de pacientes submetidas à fertilização in vitro e foram cultivas separadamente. Inicialmente, fez-se a determinação do melhor tempo de cultivo deste modelo celular proposto, dentre 6, 8 ou 10 dias de cultivo. As análises de viabilidade celular realizadas mostraram que o melhor tempo para o cultivo primário folicular, para as próximas etapas do trabalho, seria de oito dias. Após, também por análises de viabilidade celular, a melhor dose de SDHEA para exposição às células foliculares foi determinada dentre cinco doses testadas em comparação a um controle sem exposição hormonal. As análises mostraram que a dose mais adequada a ser utilizada era a dose de 0,08 μM de SDHEA. Posteriormente, tendo definido o melhor tempo de cultivo e a dose ideal de exposição das células em questão ao SDHEA, os experimentos foram realizados com dois grupos experimentais distintos: células early antral não luteinizadas e células pré-ovulatórias não luteinizadas – expostas ao FSH. Ambos os grupos foram divididos em dois subgrupos: grupo controle (sem exposição hormonal) e grupo SDHEA (com exposição ao SDHEA). Foram feitas dosagens hormonais de SDHEA, de estradiol e de progesterona nos dias 1, 4, 6 e 8 do sobrenadante do cultivo celular. A análise ao longo do tempo mostrou que os valores das dosagens de SDHEA se mantiveram constantes no grupo controle durante todo o período de cultivo celular, não havendo diferença estatística entre as quatro dosagens hormonais feitas neste grupo. Por outro lado, no grupo tratado houve diferença nos valores deste hormônio nos dias 6 e 8, em comparação aos dias 1 e 4, devido justamente ao tratamento com SDHEA realizado neste grupo experimental. Com relação ao estradiol, independente do tipo celular e do estágio de desenvolvimento, foi possível ver que a sua secreção era elevada no primeiro dia de cultivo, diminuindo nos outros dias devido às condições e ao tempo de cultivo do protocolo de desluteinização celular. Além disso, as células tratadas com SDHEA apresentaram uma secreção de estradiol superior àquelas não tratadas. Por fim, as dosagens de progesterona revelaram que o tratamento com SDHEA não alterou a secreção deste hormônio pelas células, em nenhum dos dois estágios de desenvolvimento. Ainda, as células apresentaram uma secreção aumentada de progesterona no sexto dia de cultivo celular em comparação ao primeiro e ao quarto dia; porém, esta secreção começou a diminuir quando do oitavo dia de cultivo. Tendo em vista os resultados obtidos, podemos concluir que o tratamento com SDHEA é capaz de aumentar a secreção de estradiol de células foliculares não luteinizadas, não alterando a secreção de progesterona dessas mesmas células. Mais estudos são necessários para um melhor entendimento dos efeitos do SDHEA nos processos que compõem a foliculogênese.Ovarian follicle is formed by the oocyte (female gamete) and somatic follicular cells. Those closer to the oocyte are cumulus oophorus cells (CCs), which are in direct contact with the female gamete, and the granulosa mural cells (GCs), which form the wall of the ovarian follicle. As GCs and CCs are easily accessed during assisted reproduction procedures and are discarded after oocyte retrieval, they can be used in research aimed at elucidating ovarian physiology. However, when recovered in assisted reproduction cycles, these cells are in a luteinized state due patient hormonal treatment. It is known that the use of luteinized GCs to study the molecular ovulatory process is limited due to this prior cellular exposure to gonadotrophins and their luteinized state. However, luteinized CGs have been shown to reacquire similar characteristics to those of non-luteinized follicles in early stages of differentiation (non-luteinized early antral). Stimulation of these cells with follicle stimulating hormone (FSH) increases expression of genes that characterize CGs typical of pre ovulatory follicles (non-luteinized pre ovulatory). Another important question regarding the ovarian follicle relates to androgens action in this ovarian structure. As it is known, androgen receptor activation, located in follicular cells, is able to modulate expression and activity of important genes for the maintenance of ovarian follicle development. Thus, authors suggest that the reproductive effect of dehydroepiandrosterone (DHEA) and their sulfate (SDHEA) treatment, important androgens, may be due their actions precisely in the follicular microenvironment. Consequently, the aim of this work was to analyze the exposure to SDHEA of non-luteinized follicular cells (early antral and pre-ovulatory stages). Granulosa and cumulus cells were obtained from patients submitted to in vitro fertilization and were separately cultivated. Initially, the best culture time of this proposed cellular model was determined among 6, 8 or 10 days of culture. Cellular viability analysis showed that primary follicular culture for the next steps of the study would be of 8 days. Thereafter, cellular viability assays were used to determine the best SDHEA dose among 5 doses to follicular cells exposure in comparison to a control without hormonal exposure. The analysis showed that the best dose to use was 0,08 μM of SDHEA. Subsequently, after defined the best culture time and the ideal exposure dose of the cells to SDHEA, experiments were performed with two different experimental groups: non-luteinized early antral cells and non-luteinized pre ovulatory cells – exposed to FSH. Both groups were divided in two subgroups: control group (no hormonal exposure) and SDHEA group (with SDHEA exposure). SDHEA, estradiol and progesterone hormonal dosages of the cell culture supernatant were done on days 1, 4, 6 and 8. Over time analysis revealed that SDHEA values were constant in control group during all the cell culture period, without statistical difference between the four hormonal dosages performed in this group. However, treated group showed a difference in the values of this hormone on days 6 and 8, compared to days 1 and 4, due to treatment with SDHEA of these experimental group . Regarding estradiol, independent of cell type and stage of development, it was possible to see that its secretion was high on the first day of culture, decreasing in others due to conditions and time of culture of the non-luteinized cells protocol. In addition, the SDHEA treated cells presented higher estradiol secretion than those not treated. Finally, progesterone dosages revealed that treatment with SDHEA did not alter this hormone secretion from the cells in either of the two development stages. Besides that, the cells had an increased progesterone secretion on the sixth cell culture day compared to first and fourth day; however, this secretion began to decrease on the eight day of culture. In conclusion, SDHEA treatment is able to increases the non-luteinized follicular cells secretion of estradiol, but it is not able to modify the progesterone secretion of the same cells. More studies are needed to better understand the effects of SDHEA on the process that make part of folliculogenesis.
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Bond, Jennifer Emma. "Investigation of the dynamic relationship between extracellular and intracellular pH in GS-NSO cell culture." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415045.
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Mocherla, Supriya. "Inhibitory Effects of Growth Factors on Proliferation of Porcine Smooth Muscle Cells in the Direct Co-culture System." VCU Scholars Compass, 2007. http://scholarscompass.vcu.edu/etd_retro/142.
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Intimal hyperplasia (IH) is defined as the abnormal migration and proliferation of smooth muscle cells with associated deposition of extracellular matrix in the intimal layer. It is a natural response to endovascular injury induced by procedures such as angioplasty, stent implantation, or atherectomy. Research on the molecular pathways and mediators has led to the discovery of a variety of substances aimed to interrupt or attenuate IH. Heparin, low-molecular-weight heparin, aspirin, corticoids, angiotensin-converting enzyme inhibitors, cyclosporin, vascular endothelial growth factor (VEGF) and other agents have been investigated. However, none of these agents has been used with marked success at the clinical level. Therapeutic angiogenesis studies have demonstrated the potential of heparin binding angiogenic growth factors such as VEGF and basic fibroblast growth factor (bFGF/FGF-2) to treat ischemic heart diseases. Studies on endothelial nitric oxide synthase (eNOS) gene transfer in vivo showed attenuated IH caused by constitutive generation of nitric oxide (NO) via the NOS pathway. FGF-2 increased VEGF mRNA levels in single-cultures of rabbit smooth muscle cells (SMC) and also promoted NO production from endothelial cells (EC). Therefore, we hypothesize that FGF-2 mediates SMC inhibition through the NOS pathway. In order to elucidate the influence of these growth factors, we employed an appropriate SMC-EC co-culture system.Studies on SMC-EC interactions have been established in various in vitro co-culture systems. However, there exist only few co-culture systems in which the structure of a vessel wall is imitated. A direct co-culture model was used in this study to determine the effect of growth factors on the SMC and EC proliferation. In the following study we investigate the effects of VEGF, FGF-2 and FGF-2+VEGF on porcine aorta smooth muscle and endothelial cells. Addition of the higher concentrations (>10 ng/ml) of FGF-2 to the SMC-EC direct co-culture greatly reduced smooth muscle cell numbers and cell cycle S-phase, as judged by propidium iodide DNA analysis using flow cytometry. We also observed that coadministration of FGF-2 with VEGF did not show any difference on SMC proliferation compared to control. These data demonstrate the potent regulatory capabilities of FGF-2 on smooth muscle cell inhibition. Nitric oxide which is generated by the enzyme NOS is hindered by the addition of NOS inhibitor, NG-Methyl-L-arginine acetate (L-NMMA). Utilizing L-NMMA we found that FGF-2 mediated smooth muscle cell inhibition does not follow the NOS pathway. This study is intended to understand the interactions of combination of therapeutic growth factors on vascular cells. The current study is a first step towards an overall goal of setting up an in vivo porcine model for clinical treatment of IH using FGF-2.
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Khoo, Soo Hean Gary. "Molecular profiling of the increased antibody productivity in a proliferation arrested NSO mouse myeloma cell line." Thesis, University of Birmingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521990.
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Chapman, Laurie A. "Interactions of nutrients on methyl mercury toxicity in neuron X spinal chord hybrid cells (NSC-34) and human oligodendrocyte X rhabdomyosarcoma cells (MO3.13)." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36888.
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Exposure to methyl mercury (MeHg) is a global concern. Increased chronic exposure to MeHg among fish and marine mammal consuming populations will increase the risk of prenatal exposure and as a result, the risk of infant brain damage and neurotoxcity. It is therefore important to understand the role of environmental factors, such as nutrition, in determining susceptibility to MeHg toxicity. Three nutrients (selenium (Se), vitamin C and vitamin E) were selected for examination of their interactions with the mechanisms of McHg cytotoxicity in vitro. Two hybrid neural cell lines (M03.13 and NSC-34) were evaluated for their usefulness in the study of MeHg cytotoxicity. Sixteen toxic endpoints were selected for investigation of growth, viability, structure and biochemistry. Both cell lines responded to MeHg exposure in a dose dependent manner for the majority of endpoints suggesting that both MO3.13 and NSC-34 cells undergo structural and biochemical changes during exposure to McHg, but that MO3.13 cells are more sensitive to DNA, mitochondria) membrane damage and glutathione (GSH) depletion and that NSC-34 cells are more sensitive to protein damage and apoptosis. Se exposure lessened the MeHg-induced decrease in DNA and GSH concentrations in both cell lines. In NSC-34 cells, Se also increased F-actin concentrations and prevented an increase in caspase-3 activity. Se may alter the mechanism of cell death by preventing McHg disruption of DNA replication thus maintaining the production and function of peptides (GSH) and protein (polymerized actin) that aid in MeHg detoxification and neural function. In NSC-34 cells, vitamin C prevented the induction of caspase-3 activity and lessened DNA damage and GSH depletion. Vitamin E lessened GSH depletion and lessened G-actin depletion. Both vitamin C and E improved GSH status, but vitamin C also delayed McHg damage of DNA and prevented early signs of apoptosis suggesting these two vitamins interfere with MeHg metabolism by diffe
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Vasou, Andri. "Development of a novel cell-based screening platform to identify inhibitors of viral interferon antagonists from clinically important viruses." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/8266.
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All viruses encode for at least one viral interferon (IFN) antagonist, which is used to subvert the cellular IFN response, a powerful antiviral innate immune response. Numerous in vitro and in vivo studies have demonstrated that IFN antagonism is crucial for virus survival, suggesting that viral IFN antagonists could represent promising therapeutic targets. This study focuses on Respiratory Syncytial Virus (RSV), an important human pathogen for which there is no vaccine or virus-specific antiviral drug. RSV encodes two IFN antagonists NS1 and NS2, which play a critical role in RSV replication and pathogenicity. We developed a high-throughput screening (HTS) assay to target NS2 via our A549.pr(ISRE)GFP-RSV/NS2 cell-line, which contains a GFP gene under the control of an IFN-stimulated response element (ISRE) to monitor IFN- signalling pathway. NS2 inhibits the IFN-signalling pathway and hence GFP expression in the A549.pr(ISRE)GFP-RSV/NS2 cell-line by mediating STAT2 degradation. Using a HTS approach, we screened 16,000 compounds to identify small molecules that inhibit NS2 function and therefore relinquish the NS2 imposed block to IFN-signalling, leading to restoration of GFP expression. A total of twenty-eight hits were identified; elimination of false positives left eight hits, four of which (AV-14, -16, -18, -19) are the most promising. These four hit compounds have EC₅₀ values in the single μM range and three of them (AV-14, -16, -18) represent a chemically related series with an indole structure. We demonstrated that the hit compounds specifically inhibit the STAT2 degradation function of NS2, not the function of NS1 or unrelated viral IFN antagonists. At the current time, compounds do not restrict RSV replication in vitro, hence hit optimization is required to improve their potency. Nonetheless, these compounds could be used as chemical tools to determine the unknown mechanism by which NS2 mediates STAT2 degradation and tackle fundamental questions about RSV biology.
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Ferreira, Luciana Corrêa [UNESP]. "Efeitos do LPS bacteriano nos processos funcionais e de diferenciação de células progenitoras da polpa dentária." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/127660.
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000844099.pdf: 1423355 bytes, checksum: 8649e82cdb205c9cea62cc32e42d5564 (MD5)Os processos de reparo da polpa dentária frente a procedimentos conservadores passam, em geral, pelo confronto entre possíveis microrganismos presentes na área da exposição e as células responsáveis pela diferenciação e produção de tecido mineralizado. Entretanto, a literatura ainda necessita de informações sobre o efeito direto de produtos bacterianos sobre este processo. O objetivo deste estudo foi avaliar os efeitos do lipopolissacarídeo (LPS) bacteriano (E. coli) sobre células progenitoras da polpa dental, utilizando-se condições basais e com mineralização préinduzida por meio osteogênico. Para isso, células progenitoras caracterizadas foram submetidas a diferentes concentrações de LPS bacteriano (com ou sem indutor da mineralização [lM]), para observação da atividade de fosfatase alcalina (ALP). A concentração mínima de 200 ng/ml, para se verificar alteração de atividade enzimática de ALP, foi usada para se observar os efeitos funcionais de mineralização (pelo alizarin vermelho - ARS), expressão das citocinas IL-1β e TNF-α, além da expressão dos genes DSPP e DMP-1. Os dados quantitativos foram analisados por ANOVA e teste de Tukey. As células em meio osteogênico com as diferentes concentrações de LPS apresentaram baixa atividade da ALP no curto prazo, comparadas às tratadas com meio α-MEM. Estas apresentaram alta atividade, comparadas ao controle. 200 ng/ml do LPS afetaram o processo de mineralização ao longo do tempo, reduzindo a ação de mineralização dos grupos que o associaram ao indutor de mineralização. Houve expressão de IL-1β e TNF-α para todos os grupos em todos os tempos, além disso, para a IL-1β, o grupo que associou os 200ng/ml de LPS com o meio indutor após 7 dias apresentou maior expressão. Houve expressão do gene DMP-1 e não expressão de DSPP e ocorreu uma maior expressão gênica nos grupos tratados com meio indutor da mineralização no gene DMP-1 . Esses achados
Dental pulp repair processes due to conservative procedures are, in general, affected by the conflicts between possible microorganisms at the area of exposure and cells responsible for differentiation and production of mineralized tissue. However, the literature still lacks information on how bacterial products affect these processes directly. The purpose of this study was to evaluate the bacterial lipopolysaccharide (E. coli LPS) effects on dental pulp progenitor cells, regarding the expression of differentiation genes and function of mineralization, using basal conditions and pre-induced mineralization by osteogenic media. Characterized progenitor cells was initially submitted to different LPS concentrations (with or without osteogenic medium [lM]), to observe alkaline phosphatase activity (ALP). The minimal concentration (200 ng/ml) to observe phosphatase enzymatic activity was used to assess the functional mineralization effects (by alizarin red staining - ARS), cytokine production (IL-1β e TNF-α), besides the gene expression for odontoblast differentiation markers (DSPP and DMP-1). Quantitative data will be statistically analyzed by ANOVA and Tukey's test. Cells in osteogenic medium with different concentrations of LPS showed low ALP activity shortterm compared to those treated with α-MEM. These showed high activity, compared to control. 200 ng/ml of LPS did affect the mineralization process over time, reducing the action of mineralization of the groups that have associated LPS with the IM. There was expression of IL-1β and TNF-α for all groups at all times, additionally, IL-1β for the group that has associated 200 ng/ml of LPS with osteogenic media after 7 days showed higher expression. There was expression of DMP-1 and DSPP genes and the expression in groups treated with IM was greater in DMP-1. These findings suggest that the inflammatory potential of LPS on the pulp progenitor cells contribute to an early mineralization ...
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Ferreira, Luciana Corrêa. "Efeitos do LPS bacteriano nos processos funcionais e de diferenciação de células progenitoras da polpa dentária /." São José dos Campos, 2014. http://hdl.handle.net/11449/127660.
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Orientador: Bruno Das Neves CavalcantiBanca: Cláudio Antonio Talge Carvalho
Banca: Aletéia Massula de Melo Fernandes
Resumo: Os processos de reparo da polpa dentária frente a procedimentos conservadores passam, em geral, pelo confronto entre possíveis microrganismos presentes na área da exposição e as células responsáveis pela diferenciação e produção de tecido mineralizado. Entretanto, a literatura ainda necessita de informações sobre o efeito direto de produtos bacterianos sobre este processo. O objetivo deste estudo foi avaliar os efeitos do lipopolissacarídeo (LPS) bacteriano (E. coli) sobre células progenitoras da polpa dental, utilizando-se condições basais e com mineralização préinduzida por meio osteogênico. Para isso, células progenitoras caracterizadas foram submetidas a diferentes concentrações de LPS bacteriano (com ou sem indutor da mineralização [lM]), para observação da atividade de fosfatase alcalina (ALP). A concentração mínima de 200 ng/ml, para se verificar alteração de atividade enzimática de ALP, foi usada para se observar os efeitos funcionais de mineralização (pelo alizarin vermelho - ARS), expressão das citocinas IL-1β e TNF-α, além da expressão dos genes DSPP e DMP-1. Os dados quantitativos foram analisados por ANOVA e teste de Tukey. As células em meio osteogênico com as diferentes concentrações de LPS apresentaram baixa atividade da ALP no curto prazo, comparadas às tratadas com meio α-MEM. Estas apresentaram alta atividade, comparadas ao controle. 200 ng/ml do LPS afetaram o processo de mineralização ao longo do tempo, reduzindo a ação de mineralização dos grupos que o associaram ao indutor de mineralização. Houve expressão de IL-1β e TNF-α para todos os grupos em todos os tempos, além disso, para a IL-1β, o grupo que associou os 200ng/ml de LPS com o meio indutor após 7 dias apresentou maior expressão. Houve expressão do gene DMP-1 e não expressão de DSPP e ocorreu uma maior expressão gênica nos grupos tratados com meio indutor da mineralização no gene DMP-1 . Esses achados
Abstract: Dental pulp repair processes due to conservative procedures are, in general, affected by the conflicts between possible microorganisms at the area of exposure and cells responsible for differentiation and production of mineralized tissue. However, the literature still lacks information on how bacterial products affect these processes directly. The purpose of this study was to evaluate the bacterial lipopolysaccharide (E. coli LPS) effects on dental pulp progenitor cells, regarding the expression of differentiation genes and function of mineralization, using basal conditions and pre-induced mineralization by osteogenic media. Characterized progenitor cells was initially submitted to different LPS concentrations (with or without osteogenic medium [lM]), to observe alkaline phosphatase activity (ALP). The minimal concentration (200 ng/ml) to observe phosphatase enzymatic activity was used to assess the functional mineralization effects (by alizarin red staining - ARS), cytokine production (IL-1β e TNF-α), besides the gene expression for odontoblast differentiation markers (DSPP and DMP-1). Quantitative data will be statistically analyzed by ANOVA and Tukey's test. Cells in osteogenic medium with different concentrations of LPS showed low ALP activity shortterm compared to those treated with α-MEM. These showed high activity, compared to control. 200 ng/ml of LPS did affect the mineralization process over time, reducing the action of mineralization of the groups that have associated LPS with the IM. There was expression of IL-1β and TNF-α for all groups at all times, additionally, IL-1β for the group that has associated 200 ng/ml of LPS with osteogenic media after 7 days showed higher expression. There was expression of DMP-1 and DSPP genes and the expression in groups treated with IM was greater in DMP-1. These findings suggest that the inflammatory potential of LPS on the pulp progenitor cells contribute to an early mineralization ...
Mestre
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Startzman, Ashley N. "Inhibition of stat3 protein as an approach to sensitizing ovarian cancer cells to cisplatin." Honors in the Major Thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1143.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Medicine
Molecular Biology and Microbiology
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Matusica, Dusan, and matu0012@flinders edu au. "Regulation of p75NTR Trafficking by Neurotrophins in the NSC-34 Motor Neuron Cell Line." Flinders University. School Of Medicine, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20080808.115027.
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Neurotrophins are a family of growth factors necessary for the development and maintenance of the nervous system. They produce their effects through receptor mediated signaling mechanisms that are highly regulated by sophisticated intracellular transport networks. The impairment of intracellular trafficking of neurotrophins in motor neurons has been identified as one possible factor in the development of motor neuron diseases, but remains inadequately studied. Aided by advances in imaging technology and the development of more powerful and sensitive detection tools for in-vitro studies, the dynamics of intracellular transport of neurotrophins are beginning to be unraveled. However, a primary limiting factor in the study of neurotrophin-transport dynamics in motor neurons has been the lack of alternative and easily available in-vitro systems able to substitute the often difficult and costly primary motor neuron cultures.
The aim of this project was to develop a suitable motor neuron model using the NSC-34 cell line for the study of receptor mediated trafficking events through endosomal transport pathways. Successful evaluation and characterization of NSC-34 cells for motor neuron specific markers would result in the investigation of the p75 neurotrophin receptor (p75NTR) trafficking pathways in the presence of exogenous neurotrophins, with a variety of confocal imaging techniques.
Chapter 3 describes the optimisation of NSC-34 cell culture conditions through media modification and the development of a suitable growth substrate matrix, which significantly improved cell adhesion, differentiation and the ability to culture the cells for extended time periods in serum free conditions. Quantitative measurements of cell proliferation, culture viability, cell-body size and neurite length are described to highlight the increased value of the cell line for long-term culture and experiments examining a broad range of issues relevant to motor neurons.
In Chapter 4, multiple experimental approaches were used to extensively screen the NSC-34 cell line for the presence of motor neuron-specific markers, neurotrophin receptors and proteins involved in regulation of endosomal transport. This characterization established the presence of a developing motor neuron-like neurotrophin receptor profile (p75NTR, TrkB and TrkC), a genetic marker of developing motor neurons, cholinergic markers, proteins regulating transport within the endosomal pathway, and additional proteins previously shown to directly interact with neurotrophin receptors, including sortilin, and the lipid raft associated ganglioside GT1b. Furthermore, evidence is provided that NSC-34 cells undergo apoptosis in response to exogenous nerve growth factor (NGF) or neurotrophin-3 (NT-3), but not brain derived neurotrophic factor (BDNF) or neurotrophin-4 (NT-4). In addition characterization of mouse specific p75NTR antibodies is presented to establish their suitability for internalization studies without altering the binding of exogenous neurotrophins to the receptor.
Subsequent confocal microscopy examination focusing on p75NTR trafficking in Chapter 5 revealed that internalization and intracellular transport of this receptor is regulated by exogenous neurotrophins at the cell surface where ligand binding and internalization occur, and in endosomal compartments where the bulk of receptors and ligands are targeted to their specific destinations. Evidence is provided showing that p75NTR internalization is altered in the presence of NGF, NT-3, or NT-4, but not BDNF, and the receptor is diverted into non-clathrin mediated endosomal pathways in response to NGF but not BDNF. Immunofluorescence confocal microscopy suggests that p75NTR recycles to the plasma membrane in a Rab4 GTPase dependent manner in the absence of neurotrophins. Addition of neurotrophins diverted p75NTR from the recycling Rab4 positive pathway, into EEA-1 positive sorting endosomes in the presence of NGF or NT-3, or lysosomal degradation in the presence of BDNF or NT-4.
This study clearly demonstrates the suitability of the NSC-34 cell line as an alternate in-vitro system for the study of motor neuron biology, particularly the study of neurotrophin receptor trafficking. Taken together the results represented in this study suggest for the first time, that the fate of the p75NTR receptor depends on which neurotrophin is bound. These findings have important implications for understanding the dynamic mechanisms of action of p75NTR in normal neuronal function, and may also offer further insight into the potential role of neurotrophins in the treatment of neurodegenerative diseases.
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Watatani, Yosaku. "Molecular heterogeneity in peripheral T-cell lymphoma, not otherwise specified revealed by comprehensive genetic profiling." Kyoto University, 2020. http://hdl.handle.net/2433/253204.
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Gianfrancesco, Anthony Giacomo. "Multi-wavelength characterization of cadmium telluride solar cell: Development of Q-EBIC and NSOM measurement techniques." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-theses/213.
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Thin-film inorganic solar cells, such as CdTe, have demonstrated the most promise to date for a viable low-cost renewable energy resource. Their current performance, however, is far from the theoretical limit suffering from significant charge recombination losses due to grain boundaries and point defects. It is likely that the microscopic compositions of grain bulk and grain boundaries are significantly different and not optimal for the overall device performance. Good understanding of charge transport along and across the grain boundaries and other microscopic interfaces is lacking, preventing the development of reliable and predictive device models. The insufficient microscopic understanding hinders efficient characterization of photovoltaic materials and also holds back the development of process control techniques. We first show preliminary results for a novel technique, quantum-dot electron-beam induced current to characterize semiconductors in the near-field. We also propose the use of near-field optical scanning microscopy for high precision optical excitation and for local, high-resolution characterization. These imaging techniques are examined with the goal of synthesizing information obtained by both methods, of material phenomena at the relevant length scales, to other measurement methods. The most important nanoscale phenomena being the separation of compositional and electrical effects.
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Shyu, Duan-Liang. "Rescue of host innate immunity in pigs infected with Nsp1ß mutant PRRSV." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437049612.
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Zhang, Lei. "Exploring Electron Transfer Dynamics of Novel Dye Sensitized Photocathodes : Towards Solar Cells and Solar Fuels." Doctoral thesis, Uppsala universitet, Fysikalisk kemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-302263.
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The design of dyes for NiO-based dye-sensitized solar cells (DSSCs) has drawn attention owing to their potential applications in photocatalysis and because they are indispensable for the development of tandem dye-sensitized solar cells. The understanding of the electron transfer mechanisms and dynamics is beneficial to guide further dye design and further improve the performance of photocathode in solar cells and solar fuel devices. Time-resolved spectroscopy techniques, especially femtosecond and nanosecond transient absorption spectroscopy, supply sufficient resolution to get insights into the charge transfer processes in p-type dye sensitized solar cell and solar fuel devices. In paper I-V, several kinds of novel organic “push-pull” and inorganic charge transfer dyes for sensitization of p-type NiO, were systematically investigated by time-resolved spectroscopy, and photo-induced charge transfer dynamics of the organic/inorganic dyes were summarized. The excited state and reduced state intermediates were investigated in solution phase as references to confirm the charge injection and recombination on the NiO surface. The charge recombination kinetics is remarkably heterogeneous in some cases occurring on time scales spanning at least six orders of magnitude even for the same dye. In this thesis, we also proposed a novel concept of solid state p-type dye sensitized solar cells (p-ssDSSCs) for the first time (paper VI), using an organic dye P1 as sensitizer on mesoporous NiO and phenyl-C61-butyric acid methyl ester (PCBM) as electron conductor. Femtosecond and nanosecond transient absorption spectroscopy gave evidence for sub-ps hole injection from excited P1 to NiO, followed by electron transfer from P1●- to PCBM. The p-ssDSSCs device showed an impressive 620 mV open circuit photovoltage. Chapter 6 (paper VII) covers the study of electron transfer mechanisms in a covalently linked dye-catalyst (PB-2) sensitized NiO photocathode, towards hydrogen producing solar fuel devices. Hole injection from excited dye (PB-2*) into NiO VB takes place on dual time scales, and the reduced PB-2 (PB-2●-) formed then donates an electron to the catalyst unit. The subsequent regeneration efficiency of PB-2 by the catalyst unit (the efficiency of catalyst reduction) is determined to ca. 70%.
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Oscarsson, Johan. "Towards Mixed Molecular Layers for Dye-Sensitized Solar Cells : A Photoelectron Spectroscopy Study." Doctoral thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-301164.
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The increasing demand for renewable energy has led to substantial research on different solar cell technologies. The dye-sensitized solar cell (DSC) is a technology utilizing dye molecules for light absorption. Dye molecules are adsorbed to a mesoporous semiconductor surface and after light absorption in the dye, charge separation occurs at this interface. Traditionally, DSCs have used layers of single dye species, but in recent efforts to enhance power conversion efficiency, more complex molecular layers have been designed to increase the light absorption. For example, the most efficient DSCs use a combination of two dye molecules, and such dye co-adsorption is studied in this thesis. A key to highly efficient DSCs is to understand the dye/semiconductor interface from a molecular perspective. One way of gaining this understanding is by using an element specific, surface sensitive technique, such as photoelectron spectroscopy (PES). In this thesis, PES is used to understand new complex dye/semiconductor interfaces. Dyes adsorbed to semiconductor surfaces are analyzed using PES in terms of geometric and electronic surface structure. The investigations ultimately target the effects of co-adsorbing dyes with other dyes or co-adsorbents. PES shows that Ru dyes can adsorb in mixed configurations to TiO2. Co-adsorption with an organic dye affects the configuration of the Ru dyes. As a consequence, shifts in energy level alignment and increased dye coverage are observed. The dyes are affected at a molecular level in ways beneficial for solar cell performance. This is called collaborative sensitization and is also observed in todays most efficient DSC. Dye molecules are generally sensitive to high temperatures and the substantial decrease in power conversion efficiency after heat-treatment can be understood using PES. Furthermore, comparing two mesoscopic TiO2 morphologies used in DSCs show differences in trap state density in the band gap, explaining the photovoltage difference in DSCs comprising these morphologies. Using mixed molecular layers on NiO results in significant improvements of p-type DSC power conversion efficiency. PES shows that changed adsorption configuration contribute to this effect. This thesis shows that PES studies can be used to obtain insight into functional properties of complex DSC interfaces at a molecular level.
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Philip, Diana Liz. "The Influence of Synthetic Microenvironments in Determining Stem Cell Fate." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1627669247178055.
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Spens, Erika. "Development of a protein-free fed-batch process for NS0 cells: studies on regulation of proliferation." Doctoral thesis, Stockholm : Department of Bioprocess Technology, School of Biotechnology, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4162.
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Rutherford, Claire. "The role of platelet derived growth factor-BB and basic fibroblast growth factor in neo-intimal and fatty streak formation in models of experimental atherosclerosis." Thesis, Queen Mary, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313562.
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Borba, Claudio Carneiro. "Fatores que influenciaram nos resultados das coletas de células progenitoras hematopoéticas em crianças portadoras de neuroblastoma avançado." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/5/5141/tde-08082016-083044/.
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Objetivos: Avaliar os resultados das coletas de células hematopoéticas CD34+, por aférese, em crianças portadoras de neuroblastoma tratadas no Serviço de Oncologia e Hematologia do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo; estudar os fatores (idade, peso, estimulação com quimioterapia, dose do G-CSF, uso terapêutico de 131I-MIBG e tempo entre exposição à quimioterapia prévia) que influenciaram na mobilização e no rendimento da coleta de células CD34+ no sangue periférico e associar a quantidade de células CD34+ obtidas com a evolução clínica do paciente. Métodos: Trata-se de um estudo retrospectivo de pacientes com neuroblastoma submetidos à coleta de células-tronco hematopoéticas entre janeiro de1989 e junho 2012. Resultados: Avaliados 45 prontuários de crianças com idade mediana de 3,1 anos (0-12 anos), 26 (57%) apresentavam metástase em medula óssea ao diagnóstico. O tempo entre diagnóstico e o início da mobilização foi em média 19,7 ± 12 meses (mediana de 15,8 meses). Dos pacientes estudados, 11/45 (24,4%) receberam 131I-MIBG terapêutico antes da mobilização. Somente cinco pacientes (11,1%) receberam quimioterapia associada ao G-CSF para mobilização; as demais 40 crianças (88,9%) receberam exclusivamente G-CSF na dose média 26,5 ± 5,3 ug/kg/dia (mediana 28 ug/kg/dia). Não houve correlação entre o número máximo de células CD34+ no sangue periférico com a idade (p=0,9), com o peso (p=0,63), com a dose do G-CSF (p=0,46) ou com o intervalo entre o diagnóstico e o início da mobilização (p=0,09). A mediana da quantificação de células CD34+/uL no sangue periférico foi de 36,6 células, média de 45,2 ± 42,6 (mínimo 1,7 e máximo 236,3). Pacientes que haviam recebido 131I-MIBG previamente à mobilização apresentaram menor número de células CD34+/uL no sangue periférico (p=0,04). Em 26 pacientes (57,8%) foi possível coletar mais de 2,0x106 células CD34+/Kg na primeira coleta e em 19 pacientes (42,2%) foram necessárias mais de uma coleta, sendo que, oito pacientes (17,8%) apresentaram falha de mobilização. Os pacientes que apresentaram menor quantidade de células CD34+/uL no sangue periférico (<= 12) não conseguiram número maior ou igual a 2,0x106 células CD34+/Kg em 81,8% das coletas. O número mediano de células infundidas foi de 2,66 x106 células CD34+/Kg (média 3,38 ±1,6; mínimo 1,8; máximo 8,74 x106 CD34+/Kg). Os pacientes apresentaram contagem de leucócitos maior que 1000/mm3 e de plaquetas maior 50000/mm3 por dois dias consecutivos em média, no dia 13 ± 10 e no dia 46 ± 33, respectivamente, após infusão. Conclusões: A coleta de células-tronco hematopoéticas por aférese foi factível em todos os pacientes do estudo. Não houve influência significativa da idade, do peso, da dose do G-CSF e do tempo entre diagnóstico e inicio da mobilização, no número máximo de células. O uso prévio à coleta de 131I-MIBG terapêutico parece influenciar negativamente no pico de células CD34+ no sangue periférico (p=0,04). A contagem de células CD34+ no sangue periférico é importante fator preditivo do resultado das coletas de células progenitoras hematopoéticas CD34+ por aféreseObjectives: To evaluate the results of peripheral hematopoietic CD34+ stem cells harvesting in children with neuroblastoma treated at Serviço de Oncologia e Hematologia do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo; regarding age, weight, stimulation with chemotherapy, G-CSF dose, time between diagnosis and the mobilization beginning and therapeutic 131I-MIBG use and the influence in mobilization and peripheral harvesting of autologous hematopoietic stem cells and to associate the amount of CD34+ cells obtained with the patient\'s clinical evolution. Methods: Between January 1989 and June 2012, children with neuroblastoma underwent to mobilization and peripheral hematopoietic stem cell harvesting and were retrospectively analyzed. Results: The charts of 45 children were reviewed. Median age was 3.1 years (0-12years), and 26 (57%) had metastases in bone marrow at diagnosis. Average time between diagnosis and mobilization was 19.7 ± 12 months (median, 15.8 months). 11/45 (24.4%) received therapeutic 131I-MIBG prior to mobilization. The average G-CSF dose was 26.5 ± 5.3mg/kg/day (mean 28mg/kg/day). There was no correlation between the absolute number of peripheral CD34+ cells and age (p=0.9), weight (p=0.63), G-CSF dose (p=0.46) or the range between diagnosis and early mobilization (p=0.09). The median quantification of CD34+ cells/uL in peripheral blood was 36.6, average 45.2 ±42.6 (minimum 1.7 and maximum 236.3 CD34+ cells/uL). Patients who had received therapeutic 131I-MIBG prior to mobilization, showed fewer absolute amount of CD34+/uL cells in peripheral blood (p=0.04). In 26 patients (57.8%) it was possible to harvest more than 2.0 x106 CD34+ cells/kg at first apheresis and in 19 patients (42.2%) more than one collection were necessary, and eight patients (17.8 %) failure to mobilize. Patients presenting less than 12 CD34+ cells/uL in peripheral blood on the harvesting day failed to reach more then 2.0x106 cells CD34+/kg in 81.8% of the apheresis procedures. It was infused a median number of 2.66 x106 CD34+ cells/kg (mean 1.6 ± 3.38; min 1.8; max 8.74 x106 CD34+ cells/kg). After the stem cells infusion, patients had white blood cells count greater than 1000/mm3 and platelet greater than 50,000/mm3 for two consecutive days on average after 13 ±10 and 46 ± 33 days, respectively. Conclusions: The hematopoietic stem cells harvesting was feasible in all patients included in this report. The G-CSF dose, age, weight and the period between harvesting and diagnosis showed no influence in mobilization and harvesting of autologous hematopoietic stem cells, however the absolute number of peripheral blood CD34+ cells/uL is an important predictive factor for the harvesting outcome. Additionally our findings support for the first time the notion that the use of therapeutic 131I-MIBG could have a negative impact in mobilization of peripheral blood stem cells in children with neuroblastoma
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Santos, Pedro Paulo de Andrade. "Express?o imuno-histoqu?mica da triptase em mast?citos nos fibromas de c?lulas gigantes e hiperplasias fibrosas de mucosa oral." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17103.
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Previous issue date: 2008-02-27Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The giant cell fibroma is a benign neoplasm characterized by the presence of mono, bi or multinucleate cells, which can have a connection to the presence of mast cells. This research aims to analyze, descriptively and comparatively, the immunohystochemistry expression of the tryptase in mast cells of the giant cell f ibroma, f ibrous hyperplasia and samples of the normal oral mucosa. Thirty cases of giant cell fibroma, ten cases of fibrous hyperplasia and ten cases of normal oral mucosa were selected for the analysis of the immunohistochemistry expression, determination of the number of present mast cells, as well as their location and shape. It could be stated that there was a statistically signif icant difference (p<0,001) in relation to the quantity of mast cells among other samples analyzed where the giant cell f ibroma presented lesser quantity of mast cell and the hyperplasia showed higher concentration of this cellular type. Although the oral mucosa has presented a higher quantity of mast cells when compared to the giant cells fibroma, these were found in usual locations in the connective tissue in normal tissues. There could be noticed a statistically significant difference in relation to the number of non-granulated mast cells (p<0,001). On the areas of fibrosis, we could observe a statistically signif icant difference (p<0,006) among the samples. In relation to the present mast cells in perivascular location, no statistically signif icant difference was found. On the morphological analysis there was a predominance of oval mast cells. It was concluded that despite of the fact there was a lesser quantity of mast cells present in cases of giant cell f ibroma, they appeared to have a stronger relation to the present giant fibroblasts in this lesions, around 59,62%, being also evidenced a strong relation between these cells and the fibrosis areas in both cases of giant cell f ibroma and f ibrous hyperplasias and samples of normal oral mucosa, used as control group in our study, confirming, this way, the role of the mast cells as fibrinogenous inductor
O fibroma de c?lulas gigantes constitui-se de uma neoplasia benigna, caracterizada pela presen?a de c?lulas gigantes, mono, bi ou multinucleadas, c?lulas estas que podem guardar rela??o com a presen?a de mast?citos. O prop?sito desta pesquisa consistiu em analisar descritiva e comparativamente a express?o imuno-histoqu?mica da triptase em mast?citos de fibroma de c?lulas gigantes, hiperplasia fibrosa e esp?cimes de mucosa oral normal. Foram selecionados 30 casos de fibroma de c?lulas gigantes, 10 casos de hiperplasia fibrosa e 10 casos de mucosa oral normal, para a an?lise da express?o imuno-histoqu?mica, determina??o do n?mero de mast?citos presentes, bem como a sua forma e localiza??o. Constatou-se diferen?a estatisticamente significativa (p<0,001) em rela??o a quantidade de mast?citos entre os esp?cimes analisados, onde o fibroma de c?lulas gigantes apresentou a menor quantidade de mast?citos e a hiperplasia exibiu a maior concentra??o deste tipo celular. Embora a mucosa oral tenha apresentado uma maior quantidade de mast?citos quando comparado com os casos de f ibroma de c?lulas gigantes, estes se encontravam em localiza??es usuais no tecido conjuntivo em tecidos normais. Verif icou-se, diferen?a estatisticamente significativa, no que diz respeito ao n?mero de mast?citos n?o degranulados (p<0,001). Nas ?reas de fibrose, observamos diferen?a estatisticamente signif icativa (p<0,006) entre os esp?cimes. Com rela??o aos mast?citos presentes em localiza??o perivascular n?o se observou diferen?a estatisticamente significativa. Na an?lise morfol?gica verif icou-se uma predomin?ncia de mast?citos ovais. Concluiu-se que embora uma menor quantidade de mast?citos estivesse presente nos casos de fibroma de c?lulas gigantes, estes exibiam maior rela??o com os fibroblastos gigantes presentes nestas les?es em torno de 59,62%, sendo evidenciada tamb?m uma forte rela??o entre estas c?lulas e ?reas de fibrose tanto nos casos de fibroma de c?lulas gigantes como de hiperplasias fibrosas e esp?cimes de mucosa oral normal, utilizados como controle em nosso estudo, confirmando desta forma, o papel dos mast?citos como indutor fibrinog?nico
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Freitas, Adriana Regina de Oliveira. "Caracterização das vias de sinalização desencadeadas pelas interações PrPc-p66 e PrPc-laminina e sua relevância nos processos de morte celular programada e consolidação da memória." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-20072018-181445/.
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PrPc é uma glicoproteína de 35 KDa, bastante conservada entre as espécies e essencial no processo de transmissão e patogênese de várias doenças neurodegenerativas como a encefalopatia espongiforme bovina e a doença de Creutzfeldt-Jacob (PRUSINER, 1991). Embora sua função fisiológica ainda seja desconhecida, sabe-se que a patogênese das doenças priônicas requer a sua expressão e é freqüentemente acompanhada do acúmulo no cérebro de uma isoforma anormal de PrPc, designada PrPsc (GABIZON e cols., 1997). Interessado nos possíveis papéis fisiológicos da proteína PrPc, nosso grupo tem se dedicado a estudar as interações que PrPc realiza com outras moléculas. Identificamos e caracterizamos duas interações nas quais PrPc está envolvido: com uma proteína ligante de 66 KDa, recém-identificada como sendo a proteína STI1 (ZANATA e cols., 2002) e com a principal proteína não colagênica da matriz extracelular, a laminina (GRANER e cols., 2000). No presente trabalho, procuramos investigar as vias de sinalização deflagradas por cada uma dessas interações, como também o seu papel nos mecanismos de morte celular programada e memória. Os resultados apresentados nesse trabalho demonstram que a interação PrPc-p66 desencadeia uma resposta neuroprotetora na camada neuroblástica da retina de roedores em desenvolvimento via cAMP/PKA. Além disso, verificamos que a interação PrPc-laminina desempenha um importante papel na formação da memória de curta duração através da ativação da via cAMP-PKA-MAPK, e na memória de longa duração ativando somente a via cAMP/PKA.PrPc is an extremely conserved 35 KDa glycoprotein which seems to be essential during the transmission and pathogenesis of several neurodegenerative diseases like bovine spongiform encephalopathy or Creutzfeldt-Jacob disease (PRUSINER, 1991). Although the physiological function of this protein remains unclear, it is well established that prion diseases require PrPc expression and are often characterized by deposition of an abnormal PrPc isoform, named PrPsc (GABIZON et. al., 1997). Interested in the normal fuction of PrPc, our group has been dedicated to study the interations that PrPc could entertain with other molecules. We have identified and characterized two interactions in which PrPc is involved: with a 66 KDa ligand protein, recently identified as the STI1 protein (ZANATA et. al., 2002) and with laminin (GRANER et. al., 2000). In this work, we have investigated the signaling pathways triggered by these interactions, as well as their relevance in programmed cell death and memory formation mechanisms. We show in this work that PrPc-p66 interaction transduces neuroprotective signals through a cAMP/PKA-dependent pathway in the neuroblastic layer of rodents\' retina. Moreover, we demonstrated that PrPc-laminin interaction has an important role for short-term memory formation through the activation of cAMP-PKA-MAPK pathways and for long-term memory with the activation of the cAMP/PKA pathway only.
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Yoshito, Walter Kenji. "Estudo de rotas de síntese e processamento cerâmico do compósito NiO-YSZ para aplicação como anodo em células a combustível do tipo óxido sólido." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-01062011-154148/.
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Este estudo visa a definição de condições de síntese e processamento cerâmico que possibilitem a obtenção do componente anódico com características adequadas para a operação de uma SOFC (Solid Oxide Fuel Cell), ou seja, boa distribuição microestrutural do NiO na matriz de YSZ e porosidade cerca de 30% após redução de NiO. As rotas de síntese selecionadas englobaram a coprecipitação em meio amoniacal, mistura mecânica dos pós e combustão a partir de sais de nitrato. As técnicas de caracterização de pós empregadas incluíram a difração de raios X, microscopia eletrônica de varredura, microscopia eletrônica de transmissão, difração a laser, adsorção gasosa (BET) e picnometria de hélio. Os resultados obtidos indicaram que empregando-se a técnica de coprecipitação, a perda de Ni2+, na forma de complexo [Ni(NH3)n]2+, pode ser minimizada pelo controle do pH em 9,3, mantendo-se a concentração de Ni2+ na solução inicial em 0,1M. No método de mistura mecânica a melhor condição de dispersão dos pós, sem a sedimentação diferencial, foi obtida para valores de potencial zeta em pH 8,0, fixando-se a concentração de dispersante em 0,8% em massa. Na síntese por combustão observou-se que para composições pobres em combustível, os produtos finais apresentaram-se amorfos e com alta área superficial (120,2 m2.g-1). Para as composições ricas em combustível, uréia, os pós obtidos apresentaram-se cristalinos sendo que a intensidade das reflexões do padrão de DRX aumenta com o aumento do excesso de combustível, devido ao aumento da temperatura de reação. No estudo de sinterabilidade dos compactados preparados a partir de pós preparados pelos três métodos determinou-se a temperatura ao redor de 1300 ºC para máxima taxa de densificação e porosidade entre 6,0 e 14%. Os resultados da redução em atmosfera de H2 dos compósitos confirmam que a cinética de reação ocorre em duas etapas, sendo que a primeira etapa com comportamento linear é controlada por reação química na superfície. Na segunda etapa a redução passa a ser controlada pela difusão do gás nos micros poros, gerados pela redução do NiO, diminuindo a taxa de redução.This study aim the definition of synthesis and ceramic processing conditions of the anodic component suitable for operation of SOFC, i.e, homogeneous distribution of NiO in YSZ matrix and porosity after reduction above 30%. The selected synthesis routes included the co-precipitation in ammonia media, mechanical mixing of powders and combustion reaction from nitrate salts. The characterization techniques of powders included the X-ray diffraction, scanning and transmission electron microscopy, laser diffraction, nitrogen gas adsorption technique (BET) and Helium pycnometry. The obtained results indicated that the loss of Ni2+ in co-precipitation process, due to the formation of complex [Ni(NH3)n]2+, can be minimized by controlling the pH around 9.3, keeping the concentration of nickel cation in the solution to be precipitated around 0.1M. In the mechanical mixing method the best condition of powder dispersion, without differential sedimentation, was obtained for zeta potential values at pH around 8.0, fixing the dispersant concentration at 0.8%. For the combustion synthesis it was observed that when stoichiometric and twofold stoichiometric urea was used, amorphous phase was formed and a higher surface area was attained in the final products. Employing the fuel-rich solution condition, crystallization of the powder was observed and the relative intensity of reflections of XRD patterns increased with excess of fuel, due to increasing the reaction temperature. Sinterability studies of pellets prepared from powder synthesized by the three routes described above showed the temperature around 1300 º C for maximum rate densification and porosity between 6.0 and 14%. Reduction results of the composites confirmed that the reduction kinetics occurs in two steps. The first one with a linear behavior and controlled by chemical reaction on the surface. The second reduction step is the reduction that is controlled by gas diffusion in micro pores, generated by reduction of nickel oxide, decreasing the rate of reduction.
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Najima, Yuho. "Induction of WT1 specific human CD8+ T cells from human HSCs in HLA class I Tg NOD/SCID/Il2rgKO mice." Kyoto University, 2016. http://hdl.handle.net/2433/215440.
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Final publication is available at http://www.bloodjournal.org/Kyoto University (京都大学)
0048
新制・課程博士
博士(医学)
甲第19614号
医博第4121号
新制||医||1015(附属図書館)
32650
京都大学大学院医学研究科医学専攻
(主査)教授 髙折 晃史, 教授 山田 亮, 教授 三森 経世
学位規則第4条第1項該当
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Andrade, Mariana Macedo Costa de. "O efeito da tolerância à endotoxina nos linfócitos T regulatórios e Th 17." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/5/5164/tde-20092016-155050/.
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O controle de respostas imunes patológicas (autoimunidade, alergia, rejeição de transplantes) tem sido um dos principais objetivos dos imunologistas. Apesar dos avanços recentes, a maioria dos tratamentos atuais ainda procura diminuir a imunidade e inflamação em vez de restabelecer o estado saudável da tolerância imunológica. Sepse é uma doença desencadeada pela presença de bactérias e/ou produtos bacterianos como lipopolissacarídeos (LPS), componente principal da membrana externa de bactérias gram-negativas, ativando a resposta imune do hospedeiro. A caracterização do perfil de linfócitos na resposta à tolerância ao LPS são de extrema importância para a contribuição do estudo da imunodepressão na sepse. O objetivo deste estudo foi investigar se a comprovada redução de mortalidade previamente vista em modelo de sepse animal através tolerância ao LPS, pode ser associada com o aumento da população de linfócitos T CD4+ regulatórios e Th17. Camundongos machos C57/6, receberam por via subcutânea ( s.c.) injecções de LPS ( 1mg/kg ) durante 5 dias , seguido por perfuração e ligadura cecal (CLP ) . Citocinas e linfócitos marcados foram medidos durante, após a tolerância e o desafio CLP. Ambos os subtipos de células T analisados Treg e Th17 , mostrou aumento destas células no baço durante e após a tolerância. Este estudo demonstrou que a mortalidade reduzida depois de tolerância previamente constatada pode ser associada com o aumento da população de células T regulatórias e Th17 devido a imunorregulação do hiperinflamação e recrutamento de neutrófilosThe control of pathological immune responses (autoimmunity, allergy, transplant rejection) has been a major goal of immunologists. Despite recent advances, most current treatments still seeks to reduce immunity and inflammation rather than restore the healthy state of immune tolerance. Sepsis is a disease triggered by the presence of bacteria and / or bacterial products like lipopolysaccharide (LPS), the main component of the outer membrane of gram-negative bacteria, activating the immune response of the host. The characterization of lymphocyte profile in response to LPS tolerance is extremely important for the study of immunosuppression in sepsis contribution. The aim of this study was to investigate whether the proven reduction in mortality seen previously in animal sepsis model by tolerance to LPS, can be associated with the increase in population of CD4 + regulatory and Th17. Mice C57 / 6 mice received subcutaneous (s.c.) injection of LPS (1mg / kg) for 5 days, followed by cecal ligation and puncture (CLP). Cytokines and marked lymphocytes were measured during after tolerance and CLP challenge. Both subtypes of T cells Treg and Th17 analyzed showed an increase of these cells in the spleen during and after tolerance. This study demonstrated that reduced mortality after previously seen tolerance may be associated with increasing the population of regulatory T cells and Th17 because immunoregulation of the hiperinflamação and neutrophil recruitment
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SKODA, SANDRO. "Hidrodinâmica do escoamento nos canais catódicos de um célula a combustível de membrana polimérica condutora de prótons." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11813.
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Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Brown, Jennifer L. "A molecular and immunological investigation of cellular responses to dengue virus identification of potentially upregulated host genes and the constructionof a vaccinia virus expressing the dengue 1 Hawaii NS3 protein." Link to electronic version, 2000. http://www.wpi.edu/Pubs/ETD/Available/etd-0330100-124248/.
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Baptistella, Jamila Cristina [UNESP]. "Caracterização das células-tronco oriundas da geléia de Wharton do cordão umbilical de bovinos nos três trimestres de gestação (Bos indicus)." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143804.
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A possibilidade para o isolamento de células mesenquimais multipotentes de anexo fetal bovino é uma perspectiva interessante devido potencial para utilização destas células em aplicações biotecnológicas. No entanto, ainda há pouco conhecimento disponível sobre as características destas células progenitoras na espécie bovina. Proliferando a morfologia das células, a partir de três fases da gestação, tipicamente apareceu forma de fuso do tipo fibroblastos, apresentando o mesmo número e viabilidade. Além disso, a capacidade proliferativa das células T em resposta a um estímulo mitogénico foi suprimida quando as células da geléia de Wharton foram incluídas na cultura. Multilinhagens foram confirmadas pela sua capacidade adipogênica, condrogénica e diferenciação neurogênica. O presente estudo demonstrou que células tronco mesenquimais colhidas a partir da geléia de Wharton do cordão umbilical de bovino em todas as fases da gestação mostraram capacidade proliferativa, potencial privilegiado e imunológico.
The possibility for isolating bovine mesenchymal multipotent stromal cells from fetal adnexa is interesting prospect because of the potential for these cells to be used for biotechnological applications. However, little knowledge is available about the characteristics of these progenitor cells in the bovine species. Proliferating cell morphology, from three stages of pregnancy, typically appeared fibroblast-like spindle shape, presenting the same viability and number. Moreover, the proliferative capacity of T cells in response to a mitogen stimulus was suppressed when Wharton’s jelly mesenchymal stem cells were included in the culture. Multilineage properties were confirmed by their ability to undergo adipogenic, chondrogenic and neurogenic differentiation. The study demonstrated that Wharton’s jelly mesenchymal stem cells harvested from bovine umbilical all pregnancy stages showed proliferative capacity, privileged and stem ness potential.
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Baptistella, Jamila Cristina. "Caracterização das células-tronco oriundas da geléia de Wharton do cordão umbilical de bovinos nos três trimestres de gestação (Bos indicus) /." Araçatuba, 2016. http://hdl.handle.net/11449/143804.
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Orientador: Tereza Cristina CardosoBanca:Marcos Antonio Maioli
Banca:Roberto Gameiro de Carvalho
Banca:Marcos Roberto Bonuti
Banca:Luiz Eduardo Correa Fonseca
Resumo: A possibilidade para o isolamento de células mesenquimais multipotentes de anexo fetal bovino é uma perspectiva interessante devido potencial para utilização destas células em aplicações biotecnológicas. No entanto, ainda há pouco conhecimento disponível sobre as características destas células progenitoras na espécie bovina. Proliferando a morfologia das células, a partir de três fases da gestação, tipicamente apareceu forma de fuso do tipo fibroblastos, apresentando o mesmo número e viabilidade. Além disso, a capacidade proliferativa das células T em resposta a um estímulo mitogénico foi suprimida quando as células da geléia de Wharton foram incluídas na cultura. Multilinhagens foram confirmadas pela sua capacidade adipogênica, condrogénica e diferenciação neurogênica. O presente estudo demonstrou que células tronco mesenquimais colhidas a partir da geléia de Wharton do cordão umbilical de bovino em todas as fases da gestação mostraram capacidade proliferativa, potencial privilegiado e imunológico.
Abstract: The possibility for isolating bovine mesenchymal multipotent stromal cells from fetal adnexa is interesting prospect because of the potential for these cells to be used for biotechnological applications. However, little knowledge is available about the characteristics of these progenitor cells in the bovine species. Proliferating cell morphology, from three stages of pregnancy, typically appeared fibroblast-like spindle shape, presenting the same viability and number. Moreover, the proliferative capacity of T cells in response to a mitogen stimulus was suppressed when Wharton's jelly mesenchymal stem cells were included in the culture. Multilineage properties were confirmed by their ability to undergo adipogenic, chondrogenic and neurogenic differentiation. The study demonstrated that Wharton's jelly mesenchymal stem cells harvested from bovine umbilical all pregnancy stages showed proliferative capacity, privileged and stem ness potential.
Doutor
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Riehs, Daniel. "Make Your Data Work for You: True Stories of People and Technology." Thesis, Boston College, 2006. http://hdl.handle.net/2345/422.
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Thesis advisor: Alan LawsonTechnology should enhance the human experience. Instead, it often alienates people from aspects of life that are considered most important. Artists are separated from their works, friends are separated from each other, and human ingenuity is filtered though computers before it can impact the world. These five short stories focus mainly on alienations inherent to communications and media technology, but also touch on database management and copyright concerns. Some take place in the present day; others present views of the future. All five stories use fiction to explore the truth of humanity's absurd relationship to technology
Thesis (BA) — Boston College, 2006
Submitted to: Boston College. College of Arts and Sciences
Discipline: College Honors Program
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Nihei, Jorge Sadao. "Participação das células T de memória e linfócitos CD4.CD25+Foxp3 (reguladores) nos mecanismos de resistência à infecção experimental pelo trypanosoma cruzi." Universidade Federal da Bahia, 2013. https://www.arca.fiocruz.br/handle/icict/7129.
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Universidade Federal da Bahia. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
A infecção pelo Trypanosoma cruzi (T. cruzi) resulta em uma resposta imune que controla a predominância do parasito, mas é incapaz de eliminá-lo completamente, levando a persistência do parasito. A gravidade da doença de Chagas está correlacionada com a persistência do parasito nos tecidos musculares, neurais e intestinais. A função imunorregulatória das células T reguladoras em limitar a resposta imune poderia ser explorada no sentido de erificar a sua quantidade e qualidade no modelo experimental de infecção por T. cruzi. O principal objetivo deste projeto foi estudar a participação e influência dos linfócitos Treg sobre os mecanismos de resistência a infecção por T. cruzi, principalmente sobre a geração/manutenção de células T CD4+ e CD8+ memória efetora e central. Para tal, foi realizado um estudo comparativo da importância dos linfócitos T, e alterações das células Treg na infecção experimental por T. cruzi, de animais susceptíveis (C57Bl/6) e resistentes (BALB/c) nos dias 10, 20 e 30 apos a infecção. Adicionalmente, com o objetivo de investigar o papel das células T reguladoras, foi realizada a neutralização da citocina IL-2, com o tratamento in vivo com anti-IL-2 monoclonal (clone JES6-1A12), em animais C57Bl/6, durante a infecção com a cepa Tulahuen de T. cruzi. A análise da cinética de infecção (10, 20 e 30 dias) revelou que os animais resistentes (BALB/c) apresentaram maior expansão de células T efetoras CD4+ e CD8+ no baço e no tecido muscular esquelético. Os dados coletados demonstram que o tratamento com anti-IL-2 resultou em diminuição significativa da população de células T CD4+CD25+Foxp3+ nos animais infectados, comparado ao grupo infectado e tratado com imunoglobulina de rato. A diminuição das células Treg nestes animais resultou em alterações importantes nos mecanismos efetores como, por exemplo: o aumento da expansão das células T CD4+ e CD8+ efetoras e a produção de citocinas pró-inflamatórias e anti-inflamatórias no baço e tecido muscular esquelético. O reflexo destas alterações foi relacionado à diminuição da parasitemia e da mortalidade dos animais. Desta forma, as células Treg parecem exercer um controle da resposta imune efetora ao T. cruzi no sentido de tentar controlar a disseminação do patógeno e, ao mesmo tempo, impedir a destruição tecidual decorrente de uma exacerbação da resposta imune. Portanto, sugere-se que as células Treg estariam participando da resposta imune ao T. cruzi no sentido de modular a resposta imune efetora.
The Trypanosoma cruzi (T. cruzi) infection results in an immune response that controls the parasite prevalence, but is unable to eliminate it completely, leading to infection persistence. The severity of Chagas’ disease is correlated with the parasite persistence in the muscle, neural and bowel tissues. The immunorregulatory function of regulatory T cells in limiting the immune response could be exploited in order to verify its quantity and functional activities in an experimental model of T. cruzi infection. The main objective of this project was to study the participation and influence of Treg lymphocytes on the mechanisms of resistance to T. cruzi infection, mainly on generation and maintenance of central/effector memory T cells. In the first step, it was conducted a comparative study of the importance of T lymphocytes and alterations of Treg cells in experimental T. cruzi infection in susceptible (C57BL/6) and resistant (BALB/c) animals for 10, 20 and 30 days of infection. Additionally, in order to investigate the role of regulatory T cells, it was performed the neutralization of the cytokine IL-2, with the in vivo treatment with anti-IL-2 monoclonal antibody (clone JES6-1A12) of C57Bl/6 animals during infection with Tulahuen strain of T. cruzi. The analysis of the kinetics of infection (10, 20 and 30 days) revealed that the resistant animals (BALB/c) showed greater expansion and effector activity of the CD4+ and CD8+ splenic T cells and skeletal muscle tissue. The collected data demonstrate that the treatment with anti-IL-2 resulted in significant reduction of CD4+CD25+Foxp3+ T cells population in infected animals, compared to those infected and untreated. The decrease of Treg cells in those animals resulted in significant changes in the effector mechanisms such as: an increase in expansion of CD4+ and CD8+ T effector cells, and production of pro-inflammatory and anti-inflammatory cytokines in the spleen and skeletal muscle tissue. The reflection of these changes was verified by the decrease in parasitemia and mortality of the animals. Thus, Treg cells seem to have control of the effector immune response to T. cruzi in trying to control the spread of the pathogen and, at the same time, preventing tissue destruction due to an exacerbation of the immune response. Therefore, it is suggested that Treg cells would be participating in the immune response to T. cruzi by modulating the effector immune response.
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Bureš, František. "Nové laboratorní úlohy v prostředí NS3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-361719.
Full textAbstract:
Cílem bylo navrhnout dva simulační scénáře v prostředí NS-3. První scénář obsahuje ARQ (Automatic Repeat Request) metody v TCP (Transmission Control Protocol). Je v něm porovnání Stop-and-Wait, Go-Back-N a Selective-Repeat metod. Teoretická část obsahuje TCP a ARQ. Druhý scénář je o způsobech přenosu zpráv. Vytvořený scénář převážně s komutací paketů a buněk a teoretické základy jsou obsaženy v práci. Je v něm porovnání metod komutací s různou velikostí paketu/buňky, počtem uzlů a důsledek zpoždění v každé metodě. Scénáře jsou ve formě laboratorní úlohy s instrukcemi k vypracování.
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Almeida, Monique Rocha. "Desenvolvimento de um dispositivo fotoeletroqu?mico a base de g-C3N4, Cu2O e CuO para clivagem da ?gua em H2 e O2." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1311.
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Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM)
A convers?o de energia solar em energia qu?mica usando c?lulas fotoeletroqu?micas ? uma estrat?gia interessante para armazenar energia. C?lulas fotoeletroqu?micas s?o dispositivos constitu?dos de fotoeletrodos semicondutores que absorvem luz com energia maior ou igual a energia de bandgap do semicondutor e geram cargas reativas (el?trons e buracos) na superf?cie dos fotoeletrodos capazes de promover a redu??o e oxida??o da ?gua em H2 e O2, respectivamente. Nesta disserta??o, quatro fotoeletrodos de g-C3N4, g-C3N4/Cu1%, g- C3N4/Cu5% e Cu2O/CuO foram preparados com o objetivo de desenvolver uma c?lula fotoeletroqu?mica para clivagem da ?gua em H2 e O2 de forma espont?nea. As medidas de difratometria de raios X confirmaram a presen?a das fases g-C3N4 e Cu2O/CuO nos fotoeletrodos. As imagens de MEV mostraram que os materiais ? base de g-C3N4 possuem morfologia do tipo esponja, enquanto a heterojun??o Cu2O/CuO ? formada por nanopart?culas de forma indefinida. Medidas de reflect?ncia difusa mostraram que o acoplamento do g-C3N4 e Cu2O/CuO resulta em uma melhora significativa na absor??o ?ptica dos fotoeletrodos. Medidas de ?rea espec?fica indicaram que os nanomateriais ? base de g-C3N4 tem alta ?rea superficial (?100 m2 g?1), enquanto a ?rea espec?fica da heterojun??o Cu2O/CuO foi de 17 m2 g?1. Os resultados de redu??o ? temperatura programada evidenciaram a forma??o das heterojun??es. Os testes fotoeletroqu?micos de produ??o de O2 a partir da ?gua usando luz vis?vel indicaram que em potenciais an?dicos, apenas o fotoanodo de g-C3N4 foi est?vel apresentando uma densidade de fotocorrente de 16 ?A cm?2 que corresponde a uma efici?ncia de convers?o de luz de 0,014%. Em potenciais cat?dicos, a maior densidade de fotocorrente (60 ?A cm?2) foi obtida para o fotoeletrodo Cu2O/CuO. A efici?ncia de convers?o de luz do fotocatodo de Cu2O/CuO foi de 0,029%. Com base nos dados obtidos, uma c?lula fotoeletroqu?mica p-n foi constru?da usando a heterojun??o Cu2O/CuO como fotocatodo e g- C3N4 como fotoanodo. Esta c?lula gerou uma densidade de fotocorrente in operando de 0,62 ?A cm?2 e uma fotovoltagem de 0,62 V. A efici?ncia de convers?o solar da fotoc?lula foi de 0,004% sob irradia??o de luz vis?vel. Apesar da baixa efici?ncia obtida, espera-se que esta disserta??o possa servir de inspira??o para o desenvolvimento de novos dispositivos fotoeletroqu?micos para clivagem da ?gua em H2 e O2, usando luz vis?vel.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.
The conversion of solar energy into chemical energy using photoelectrochemical cells is an interesting strategy to store energy. Photoelectrochemical cells are made up of semiconductor photoelectrodes that absorb light with energy equal or higher than the bandgap energy of the semiconductor to generate reactive charges (electrons and holes) on the surface of the photoelectrodes, which can promote the oxidation and reduction reactions of water to form H2 and O2, respectively. In this dissertation, four photoelectrodes of g-C3N4, g-C3N4/Cu1%, g- C3N4/Cu5%, and Cu2O/CuO were prepared in order to develop a photoelectrochemical cell for spontaneous water splitting into H2 and O2. The X-ray diffraction patterns confirmed the presence of g-C3N4 and Cu2O/CuO phases in the photoelectrodes. The SEM images showed that the materials based on g-C3N4 have sponge-like morphology, whereas the Cu2O/CuO heterojunction is formed by nanoparticles with undefined shapes. Diffuse reflectance measurements showed that coupling g-C3N4 and Cu2O/CuO results in a significant improvement in optical absorption of the photoelectrodes. Surface area measurements indicated that the nanomaterials based on g-C3N4 have high surface areas (?100 m2 g?1), while the specific area for the Cu2O/CuO heterojunction was 17 m2 g?1. The temperature programmed reduction results evidenced the formation of the heterojunctions. The photoelectrochemical assays of O2 production from water using visible light indicated that at anodic potentials, only the photoanode g-C3N4 was stable showing a photocurrent density of 16 ?A cm?2, which corresponds to a light conversion efficiency of 0.014%. At cathodic potentials, the higher photocurrent density (60 ?A cm?2) was obtained for the Cu2O/CuO photoelectrode. The light conversion efficiency of the Cu2O/CuO photocathode was 0.029%. Based on the obtained data, a p-n photoelectrochemical cell was constructed using the Cu2O/CuO heterojunction as the photocathode and g-C3N4 as the photoanode. This photocell generated a photocurrent density in operando of 0.62 ?A cm?2 and photovoltage of 0.62 V. The light conversion efficiency of the photocell was 0.004% under visible light irradiation. Despite the low efficiency obtained for the p-n photocell, it is expected that this dissertation may serve of inspiration for the development of new photoelectrochemical devices for water splitting into H2 and O2 using visible light.
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Schade-Weskott, Mathilde L. "Interaction of the African horsesickness virus NS3 protein with selected cellular proteins and its importance in viral egress from mammalian cells." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/65853.
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African horsesickness virus (AHSV) is a member of the Orbivirus genus within the Reoviridae family and causes an acute disease in horses. AHSV encodes four non-structural proteins (NS1, NS2, NS3/NS3A), whose functions in the viral life cycle are not fully understood. Amongst these, NS3 is believed to mediate virus release from infected cells. Data for bluetongue virus (BTV), the prototype orbivirus, has indicated that NS3 recruits cellular proteins to aid in the non-lytic release of virus particles. By making use of yeast two-hybrid screens, it was shown previously that the AHSV NS3 protein interacts with three insect cell proteins, namely Smad Anchor for Receptor Activation (SARA) protein, heat shock protein 70 (Hsp70) and ubiquitin (UB). Based on the involvement of host cell proteins in NS3-mediated non-lytic virus release, the aims of this study were thus to confirm the interactions between AHSV NS3 and the insect cell proteins in vitro and to determine whether these proteins may aid virus release from infected mammalian cells. To confirm the interaction of the AHSV NS3 protein with the insect cell proteins, the SARA, Hsp70 and UB peptides were expressed as glutathione S-transferase (GST)-tagged fusion proteins in E. coli. These GST fusion proteins were subsequently used in pull-down assays with E. coli lysates containing a truncated AHSV NS3 protein. No interaction between the virus and insect cell proteins could be demonstrated with this assay. To determine whether the SARA, Hsp70 and UB proteins may have biological relevance in the non-lytic release of AHSV from infected cells, a RNA interference (RNAi)-based approach was used. Pre-designed small interfering RNAs (siRNAs) that have been validated for silencing SARA, Hsp70 and UB gene expression in mice were evaluated for their ability to knockdown expression of their target genes in BHK-21 cells. The results indicated that mSARA-siRNA and mUB-siRNA down-regulated transcription of the SARA and UB genes by 63% and 56%, respectively, whereas the mHsp70-siRNA suppressed Hsp70 gene expression by only 3%. BHK-21 cells were subsequently transfected with the respective siRNAs in separate experiments followed by virus infection. Exposure of BHK-21 cells to these siRNAs did not result in a reduction in extracellular virus titres when compared to control cells. Although it is tempting to conclude that the SARA and UB proteins are not functionally relevant with regards to a role in AHSV egress, it is, however, also plausible that these results were due to the inability to reduce the level of target mRNA transcripts to such an extent that it would result in a loss of gene function. During the course of this study, various parameters that may have potentially influenced the results were identified. Further experiments are thus required before definitive conclusions can be drawn as to whether or not AHSV NS3 interacts with the respective insect cell proteins and, if so, what the relevance of these interactions might be with regards to virus release.Dissertation (MSc)--University of Pretoria, 2018.
Microbiology and Plant Pathology
MSc
Unrestricted
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Melo, Edilailsa Janu?rio de. "Hematitas nanoparticuladas como fotocatalisadores potenciais para degrada??o qu?mica de contaminantes org?nicos em meio aquoso e a produ??o de hidrog?nio por fragmenta??o molecular da ?gua e da am?nia." UFVJM, 2017. http://acervo.ufvjm.edu.br/jspui/handle/1/1371.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
O desenvolvimento de novos semicondutores fotocatalisadores, em particular os ativos na produ??o de hidrog?nio por fragmenta??o molecular da ?gua e da am?nia (presente no lixiviado de biodigestores ou de aterros sanit?rios e em efluentes industriais), tem dominado a ordem priorit?ria de interesse nas tecnologias avan?adas para a gera??o de energia limpa. Este trabalho teve como objetivo principal avaliar a produ??o fotocatalisada de hidrog?nio gasoso, a partir da fragmenta??o molecular da ?gua ou da am?nia, por uso da hematita pura ou da hematita dopada com os c?tions met?licos cobalto, n?quel, cobre e zinco como materiais semicondutores. Os materiais preparados por coprecipita??o foram caracterizados pelas t?cnicas de EDX, MEV, DRX, espectroscopia M?ssbauer, FTIR, BET e XPS. A taxa da produ??o de hidrog?nio foi avaliada por medidas de densidade da corrente gerada pelo H2(g) evolu?do da fragmenta??o molecular da ?gua ou da am?nia, em c?lula fotoeletroqu?mica (PEC). Foram tamb?m realizados testes fotocatal?ticos, sob luz vis?vel, com as hematitas, pura e com dopantes, como fotocatalisadores para degrada??o do corante ?ndigo de carmim, utilizado como mol?cula modelo, simulando a decomposi??o de substrato org?nico poluente em ?gua presente em efluentes industriais. Os resultados dos testes de degrada??o do corante mostraram que as hematitas dopadas com cobre e zinco tiveram relativamente alta atividade na degrada??o do corante; os melhores resultados foram obtidos com a hematita com zinco. Na evolu??o do hidrog?nio da fotocat?lise da ?gua, a dopagem com c?tions met?licos n?o alterou significativamente a atividade fotoeletroqu?mica da hematita. Ainda assim, a amostra de hematita dopada com n?quel foi a que apresentou um discreto aumento da densidade de corrente, maior propor??o de hidrog?nio gasoso produzido, sob radia??o com comprimento de onda maior do que 450 nm. A densidade de corrente gerada da degrada??o da am?nia foi maior, se comparada ? fragmenta??o da ?gua. No entanto, a dopagem tamb?m n?o alterou de forma significativa a atividade PEC dos materiais. Das amostras de hematitas dopadas, a com cobre foi a que apresentou os melhores resultados fotoeletroqu?micos, ainda que abaixo da efici?ncia fotoeletroqu?mica da hematita pura.
Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017.
Technological developments of semiconductors to be used as photocatalysts for hydrogen production and for the degradation of organic pollutants in water in different circumstances, such as ammonia sluggishness from biodigesters and organic residues from industrial effluents, are strongly challenging the interest of the scientific community. The main objective of this work was to evaluate the molecular hydrogen production from the molecular fragmentation of water and ammonia using pure hematite and cobalt, nickel copper and zinc dopant prepared as co-precipitators as semiconductor materials. The materials prepared were characterized by EDX, MEV, XRD, M?ssbauer, FTIR, BET and XPS spectroscopy. The evaluation of the hydrogen production was carried out through measurements of current densities generated by the decomposition of water and ammonia in a photoelectrochemical cell (PEC). Photocatalytic tests were also carried out under visible light using pure hematite and with dopants as photocatalysts for the degradation of carmine indigo dye used as a model molecule. The results of the dye degradation tests showed that copper and zinc doped hematite increased dye degradation, and the best results were obtained for zinc hematite. In the evolution of hydrogen from water, the doping with metallic cations did not significantly alter photoelectrochemical activity of hematite, the hematite with nickel was the sample that presented a small increase in current density when in the presence of light. The current density generated by the ammonia degradation and consequent hydrogen production was higher when compared to water, however, doping also did not significantly alter the PEC activity of the materials, comparing the materials, the hematite with copper was the sample that presented the best results.
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Barbosa, Tercio Augusto Penteado 1979. "Historicidade e atualidade do estudo da célula nos livros didáticos de ciências do ensino fundamental." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/253957.
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Orientador: Eduardo GalembeckDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação
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Resumo: Considerando a importância das células como unidades fundamentais da vida, estas se tornam uma questão central no ensino de ciências, sendo um dos conceitos mais complexos para o aluno de ensino fundamental ao se iniciar o estudo dos seres vivos. A dificuldade de abstração dos estudantes para compreendê-las e contextualizá-las se torna frequentemente um problema, pois estes estão acostumados ao que é concreto em seu cotidiano, mas as células, pelo seu tamanho, somente são vistas com auxílio de microscópios. Portanto, é necessária uma ruptura com as ordens de grandeza e o senso comum dos estudantes, sendo essencial que entendam a importância das células para os seres vivos também através de uma perspectiva histórica. Para que isso ocorra, os estudantes devem substituir sua visão da ciência como uma coleção de fatos e teorias estagnadas pela compreensão de que o conhecimento científico é passível de contínua correção temporal. Atualmente diversas pesquisas mencionam a importância e a relevância da história da ciência nas salas de aula, nos diversos níveis de ensino, podendo esta ser um instrumento importante ao professor que, utilizando-se de fontes adequadas e atualizadas, pode promover aos seus alunos uma visão mais crítica em relação à ciência e a construção do conhecimento científico. Constatamos, nesta investigação, que ainda é pequena a presença desses conteúdos nas escolas. Isto se deve, principalmente, à escassez de material disponível, tanto ao professor quanto às escolas. Buscando superar esse hiato, realizamos uma extensa pesquisa bibliográfica da história do descobrimento das células, suas estruturas e funções, estabelecendo uma linha do tempo com diversos episódios históricos que permitiram o avanço do conhecimento sobre as células, evitando um recorte histórico comparativo entre os episódios. Em seguida, fizemos uma análise do conteúdo das coleções didáticas de ciências melhor avaliadas pelo PNLD do período 2011/2013, objetivando descrever a estrutura e o padrão de distribuição do conteúdo sobre células, destacando suas características e propriedades. Além disso, buscamos descrever as unidades e/ou capítulos específicos dessas obras didáticas que tratem a história do descobrimento e desenvolvimento dos estudos sobre células, buscando identificar o tipo de abordagem histórica (internalista ou externalista) presente nessas unidades e/ou capítulos, quando houve. Em nossa avaliação dos livros didáticos verificamos que há uma grande deficiência de conteúdos contextualizados sobre as células e sua historicidade. Acreditamos que uma abordagem que considere uma perspectiva histórica, e que relacione descobertas importantes com tecnologias presentes em nosso cotidiano, poderia contribuir de forma significativa com a compreensão dos conceitos fundamentais relacionados à biologia da célula compatíveis com o currículo de ciências do Ensino Fundamental
Abstract: Considering the importance of cells as the fundamental units of life, they become a central issue in science education, being one of the more complex concepts for student teaching in the beginning of living things study. The student's abstraction difficulty in understanding and contextualizing cells often becomes a problem, because they are accustomed to what is concrete in their daily lives, and cells, because of their size, are only seen with the aid of microscopes. Therefore, to break these orders of magnitude and common sense, it is essential that students understand the importance of the cells also through a historical perspective. Thus, it must be avoided the exclusive study of cell structures and teaching just the scientific results. For this to occur, students must replace their vision of science as a collection of facts and stagnant theories by a comprehension that scientific knowledge is subject to continuous temporal correctness. Currently, several studies mention the relevance and importance of science history in the classroom in various levels of education, which may be an important tool to the teacher that, using updated and appropriate sources, can promote in the students a more critical vision of science and the construction of scientific knowledge. We noticed, in this research, that such contents are poorly present in schools. This is mainly due to the scarcity of available material, both to teachers and schools. In order to overcome this gap, we conducted an extensive literature review of the history of cells discovery, their internal structures and functions, establishing a timeline with several historical episodes that allowed the advancement of knowledge about cells, avoiding a comparative historical view. Then we did a content analysis of the school textbooks best evaluated by the brazilian government PNLD science program (2011/2013), aiming to describe the structure and pattern of distribution of content over cells, highlighting its characteristics and properties. In addition, we seek to describe the units and/or chapter specific to those textbooks that address the history of the discovery and development of studies on cell, seeking to identify the type of historical approach (internalist or externalist) present in these units and/or chapters, when there. In our review of the textbooks we find that there is a great deficiency of contextualized content on cells and its historicity. We believe that an approach that considers a historical perspective, and linking major breakthroughs with technologies present in our daily lives, could contribute significantly to the understanding of the fundamental concepts related to cell biology compatible with the curriculum of elementary school science
Mestrado
Ensino de Ciencias e Matematica
Mestre em Multiunidades em Ensino de Ciências e Matemática
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SILVEIRA, LIVIO de B. "Verificacao do comportamento de mastocitos na parede nao mineralizada da bolsa periodontal supra-ossea submetida a radiacao laser de baixa intensidade (Estudo in anima nobile)." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10864.
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Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia)
IPEN/D-MPLO
Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo
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Wijayasinghe, Athula. "Development and Characterisation of Cathode Materials for the Molten Carbonate Fuel Cell." Doctoral thesis, KTH, Materials Science and Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3811.
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Among the obstacles for the commercialization of the MoltenCarbonate Fuel Cell (MCFC), the dissolution of thestate-of-the-art lithiated NiO cathode is considered as aprimary lifetime limiting constraint. Development ofalternative cathode materials is considered as a main strategyfor solving the cathode dissolution problem. LiFeO2and LiCoO2had earlier been reported as the most promisingalternative materials; however, they could not satisfactorilysubstitute the lithiated NiO. On the other hand, ternarycompositions of LiFeO2, LiCoO2and NiO are expected to combine some desirableproperties of each component. The aim of this work was todevelop alternative cathode materials for MCFC in the LiFeO2-LiCoO2-NiO ternary system. It was carried out byinvestigating electronic conductivity of the materials, firstin the form of bulk pellets and then in ex-situ sinteredporous-gas-diffusion cathodes, and evaluating theirelectrochemical performance by short-time laboratory-scale celloperations.
Materials in the LiFeO2-NiO binary system and five ternary sub-systems,each with a constant molar ratio of LiFeO2:NiO while varying LiCoO2content, were studied. Powders withcharacteristics appropriate for MCFC cathode fabrication couldbe obtained by the Pechini method. The particle size of LiFeO2-LiCoO2-NiO powders considerably depends on thecalcination temperature and the material composition. Theelectrical conductivity study reveals the ability of preparingLiFeO2-LiCoO2-NiO materials with adequate electricalconductivity for MCFC cathode application.
A bimodal pore structure, appropriate for the MCFC cathode,could be achieved in sintered cathodes prepared usingporeformers and sub-micron size powder. Further, this studyindicates the nature of the compromise to be made between theelectrical conductivity, phase purity, pore structure andporosity in optimization of cathodes for MCFC application. Cellperformance comparable to that expected for the cathode in acommercial MCFC could be achieved with cathodes prepared from20 mole% LiFeO2- 20 mole% LiCoO2- 60 mole% NiO ternary composition. It shows aniR-corrected polarization of 62 mV and a iR-drop of 46 mV at acurrent density of 160 mAcm-2at 650 °C. Altogether, this study revealsthe possibility of preparing LiFeO2-LiCoO2-NiO cathode materials suitable for MCFCapplication.
Keywords: molten carbonate fuel cell (MCFC), MCFC cathode,LiFeO2-LiCoO2-NiO ternary compositions, electrical conductivity,porous gas diffusion electrodes, polarization, electrochemicalperformance, post-cell characterization.
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Brown, Jennifer L. "A Molecular and Immunological Investigation of Cellular Responses to Dengue Virus: Identification of Potentially Upregulated Host Genes and the Construction of a Vaccinia Virus Expressing the Dengue 1 Hawaii NS3 Protein." Digital WPI, 2000. https://digitalcommons.wpi.edu/etd-theses/187.
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The purpose of this thesis for the degree of Master of Science was to use molecular and immunological techniques to study cellular responses to dengue virus infection. In the initial study, Differential Display was used to compare mRNA expression in dengue-infected K562 cells and mock-infected cells. Cloning and sequencing were then used to identify cellular genes that were potentially up-regulated in response to Dengue virus infection. These genes included bleomycin hydrolase and a dystrophin homologue. The goal of the later part of this research was to construct a recombinant vaccinia virus expressing the dengue 1 Hawaii NS3 protein. Cytotoxic T-lymphocyte assays and protein gel electrophoresis showed that the NS3 protein was being expressed. This construct was then used to study the cytotoxic T-cell response of a dengue 1 vaccine recipient. The results of this study showed that this individual has dengue 1 NS3 specific T-cells and also that this vaccinia virus can be used for subsequent T-cell studies.