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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Effektivisering av intern logistik : Vargön Alloys AB / Rationalisation of internal logistics : Vargön Alloys AB

Berlin, Hanna, Herlogsson, Emma January 2009 (has links)
Med väl fungerande interna logistiska flöden kan hela produktionen effektiviseras samtidigt som man kan skapa mer bränsleeffektiva transporter. Ett företag som är intresserade av att både kunna arbeta mer effektivt med sina transporter och spara på bränsle både för miljön och för kostnadernas skull är Vargön Alloys AB i Vargön utanför Vänersborg.Vargön Alloys är en av Europas största tillverkare av olika Ferrolegeringar. Legeringar ger bl.a. stålet hårdhet och förhindrar korrosion. Företagets kunder är Europas ledande tillverkare av specialstål.Ett problem för Vargön Alloys har varit att man inte har någon dokumentation eller kartläggning över hur de interna transporterna sker idag. Syftet med detta examensarbete är därför att kartlägga hur Vargön Alloys interna transporter sker idag samt att ge förslag till effektivisering, både vad gäller arbetsmetoder och lagerplanering, som leder till minskad bränsleförbrukning samt mindre trafik på fabriksområdet.En kvalitativ undersökningsmetod har använts där observationer följts av intervjuer med personer med olika arbetsområden på företaget. Intervjuobjekten har till största del fått vara anonyma och intervjuerna har skett individuellt med öppna frågor. Användbara teorier studerades i lämpliga läroböcker.Observationer och intervjuer har resulterat i en värdefödeskarta över informationsflödena samt en spagettikarta över transportflödena. Efter analys av dessa har ett antal förbättringsförlag framkommit. Genom att använda nya moderna tekniker som hjälpmedel i arbetet skulle Vargön Alloys definitivt kunna effektivisera sina interna transporter till att bli mer bränsleeffektiva. Med hjälp av ett verktyg som t. ex. GPS timber skulle förtaget få ett system som innehåller både planeringssystem, lagerstyrning och ett GPS-system i fordonen.
272

Optimering av lageraktiviteter och transporter : Flügger AB / Optimization of warehouse activities and transports : Flügger AB

Algestam, Sara, Kılıçaslan, Ertuğrul January 2009 (has links)
Detta examensarbete har utförts under höstterminen 2008 på Högskolan i Borås på uppdrag av Flügger AB i Bollebygd. År 1994 köpte Flügger A/S upp HP Färg & Kemi och kedjan Flügger AB startades i Sverige. Idag har Flügger i Bollebygd 150 anställda, vilket gör dem till en av Bollebygds största arbetsgivare. Dagens fabrik i Bollebygd är uppdelad i fyra producerande enheter; Alkyd-, Latex-, Kemi- och Spackelfabrik. Fabrikerna rymmer produktion av vattenbaserad- och terpentinbaserad färg, träskydd, spackelprodukter, rengöringsmedel för industri och biltvättsanläggningar, samt målningsrelaterade rengöringsmedel. I Bollebygd finns även ett råvaru- och emballagelager som ansvarar för materialtillförsel till de fyra produktionsenheterna. Syftet med detta arbete är att hitta förbättringar och effektiviseringsförslag för nuvarande interna transporter från råvaru- och emballagelager. Målsättningen är även att hitta lösningar för mellanlagringsplatser, samt förslag till utformning av råvaru- och emballagelager. En ytterligare uppgift är att hitta ett tillvägagångssätt som förbättrar beställningsrutiner och returhantering. Behovssvängningar skall jämnas ut genom att sprida ut de interna beställningarna till råvaru- och emballagelagret. I och med att företaget är certifierat enligt ISO 14 001 skall ovanstående punkter utföras med hänsynstagande till miljön. Genom intervjuer med de anställda på Flügger har information erhållits om de problem som finns inom internlogistik och lagerhantering. Intervjuer har även gjorts för att ta vara på de eventuella förbättringsförslag de anställda besitter. För att få en sådan korrekt helhetsbild som möjligt har både lagerpersonal och fabrikspersonal intervjuats. Observationer har gjorts på lagret såväl som på produktionsenheterna. På lagret har även tidtagning av lageraktiviteter utförts. En klar bild av Flüggers interna logistik och lageraktiviteter har erhållits under arbetets gång. Utifrån den bilden dras slutsatsen att aktiviteterna kan effektiviseras och att Flügger med relativt små medel kan förändra bilden till det bättre. Ett antal förbättringsförslag har framtagits inom de olika problemområdena. Dessa innehåller bland annat en presentation av lagerutformning, beställningsrutin samt effektivisering av lageraktiviteter.
273

MiniBacillus - the construction of a minimal organism

Klewing, Anika 23 March 2020 (has links)
No description available.
274

Caracterização estrutural e análises funcionais das proteínas periplasmáticas NrtT e PotF de transportadores do tipo ABC de Xanthomonas axonopodis pv. citri. / Structural characterization and functional analysis of the NrtT and PotF periplasmic proteins of Xanthomonas axonopodis pv. citri ABC transporter.

Pinto, Aline Sampaio 15 June 2015 (has links)
Xanthomonas citri (X. citri), causador do cancro cítrico, afeta muitas áreas de cultivo de citros com impacto comercial. Transportadores ABC foram relatados como essenciais para a patogênese de X. citri. O gene nrtT codifica a proteína periplasmática responsável pelo suposto transporte de nitrato/nitrito/taurina. Neste trabalho, mostramos que a deleção de nrtT não afeta o crescimento de X. citri, porém reduz e atrasa os sintomas do cancro durante a infecção em folhas de citros. Observamos redução na produção de goma xantana e capacidade de aderência na linhagem mutante. A proteína NrtT foi expressa monomérica e monodispersa. Foram observadas alterações na estrutura secundária e aumento da estabilidade térmica de NrtT na presença de MOPS, indicando ser este um possível ligante de NrtT. A proteína PotF descrita como ligadora de putrescina não sofre alteração significativa na estabilidade térmica na presença de putrescina, entretanto, dados de SAXS mostram alterações na estrutura possivelmente decorrentes da ligação com putrescina. / Xanthomonas citri (X. citri), which causes citrus canker, affects many citrus growing areas with commercial impact. ABC transporters have been reported as essential for the pathogenesis of X. citri. The nrtT gene encodes the periplasmic protein responsible for the alleged transport of nitrate/nitrite/taurine. In this work, we show that nrtT deletion does not affect the growth of X. citri, but delays and reduces the symptoms of cancer during infection of citrus leaves. We observed a reduction in the production of xanthan gum and adhesion capacity in the mutant strain. The NrtT protein was expressed monomeric and monodisperse. There were changes in the secondary structure and increased thermal stability NrtT in the presence of MOPS, indicating that this was a possible binder NrtT. The PotF protein described as putrescine-binding is not significantly altered thermal stability in the presence of putrescine, however, SAXS data shows changes in the structure possibly resulting from connection with putrescine.
275

Étude de la remobilisation des métaux au cours de la sénescence foliaire : évaluation de l’implication des NRAMP dans ce processus dans le cadre de la stratégie de phytoremédiation / Metal remobilization during leaf senescence : evaluation of the NRAMP involvement in this process in the context of the phytoremediation strategy

Pottier, Mathieu 13 March 2014 (has links)
Depuis le début des années 1990, différentes stratégies de phytoremédiation ont été proposées pour réhabiliter les zones polluées par des éléments traces métalliques (ETM). Parmi ces stratégies, la phytoextraction consiste en l’absorption et l’accumulation par les plantes des ETM présents dans les sols. Afin de mettre en place cette stratégie, il a été proposé d’utiliser le peuplier en raison de sa croissance rapide, de son importante biomasse et de ses débouchés énergétiques. Cependant une proportion considérable des métaux absorbés par cet arbre est accumulée dans les feuilles alors que celles-ci chutent à l’automne. Ainsi, l’efficacité de phytoextraction du peuplier peut se trouver limitée si aucun mécanisme de remobilisation des ETM n’est mis en place au cours de la sénescence automnale. Dans ce contexte, une partie des travaux de cette thèse a été réalisée sur la parcelle expérimentale de Pierrelaye polluée suite à l’épandage d’eaux usées de la ville de Paris. Nous avons recherché parmi les 14 génotypes de peuplier présents sur le site, ceux qui sont les plus efficaces pour remobiliser les métaux des feuilles vers les parties pérennes. Des mesures de contenu en métaux, d’expression de gènes et des analyses corrélatives ont ouvert de nouvelles pistes concernant la gestion des métaux foliaires. Parce que la vacuole constitue le principal lieu de stockage des métaux de la cellule, les protéines d’efflux vacuolaire NRAMP (Natural Resistance-Associated Macrophage Protein) précédemment identifiées chez Arabidopsis thaliana, représentent de bons candidats pour stimuler la remobilisation des métaux foliaires. La caractérisation de leurs homologues chez le peuplier a donc été entreprise par expression chez la levure et chez A. thaliana. Afin de contrôler indépendamment le transport des métaux essentiels et non-essentiels chez les NRAMP, une étude visant à identifier les déterminants structuraux impliqués dans leur sélectivité a été réalisée. La caractérisation des mutants NRAMP affectés dans leur sélectivité par expression chez A. thaliana a mis en lumière leur impact sur l’accumulation et la tolérance aux métaux. Dans le but d’étudier l’implication de mécanismes plus généraux de recyclage des nutriments dans la remobilisation des métaux au cours de la sénescence foliaire, le rôle de l’autophagie a été testé chez A. thaliana. L’étude de plantes déficientes pour l’autophagie a montré l’implication de ce mécanisme dans l’efficacité d’utilisation des métaux et probablement dans leur remobilisation au cours de la sénescence. En combinant des études en champ sur le peuplier et de génétique moléculaire chez Arabidopsis, ce travail permet de proposer différentes pistes pour diminuer spécifiquement l’accumulation des ETM dans les feuilles de peuplier. / Since the early 1990s, various strategies have been proposed to rehabilitate trace element (TE) polluted areas by phytoremediation. Among these strategies, phytoextraction consists in TE uptake from soil and accumulation by plants. To implement this strategy, it has been proposed to use poplar due to its fast growth, its large biomass and its use in energy production. However, a substantial proportion of absorbed metals is accumulated in poplar leaves which fall in autumn. Thus, poplar phytoextraction efficiency may be limited if TE are not re-mobilized during autumn senescence. In this context, part of this thesis work has been carried out on the experimental field of Pierrelaye which was polluted by the spreading of sewage water from Paris. Among the 14 poplar genotypes growing on the field, we tried to identify those that efficiently remobilize leaf metals to perennial organs. Metal content, gene expression and correlative analyses have been undertaken, providing new insight in the management of metals in leaves. Because the vacuole is the main metal storage compartment in the cell, NRAMP (Natural Resistance-Associated Macrophage Protein) vacuolar efflux proteins previously identified in Arabidopsis thaliana are good candidates to enhance leaf metal remobilization. Characterization of their homologues in poplar was therefore undertaken by expression in yeast and in A. thaliana. In order to independently control the transport of essential and non-essential metals by NRAMP, a study aiming to identify the structural determinants involved in selectivity was undertaken. Expression of NRAMP mutants affected in their selectivity in A. thaliana highlighted their impact on metal accumulation and tolerance. To study the involvement of more general nutrient recycling mechanisms in metal remobilization during leaf senescence, the involvement of autophagy was tested in A. thaliana. Physiological characterization of autophagy deficient plants indicated that this mechanism plays a role in metal use efficiency and probably in metal remobilization during senescence. By combining a field approach on poplar and molecular genetics in Arabidopsis, this work opens multiple perspectives to specifically reduce the accumulation of TE in poplar leaves.
276

Expression, purification and characterisation of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) in Saccharomyces cerevisiae

Rimington, Tracy L. January 2014 (has links)
Mutations in the eukaryotic integral membrane protein Cystic Fibrosis Transmembrane conductance Regulator (CFTR) cause the hereditary disease cystic fibrosis (CF). CFTR functions as an ion channel at the surface of epithelial cells and regulates the movement of chloride ions and water across the plasma membrane. CFTR is difficult to express and purify in heterologous systems due to its propensity to form insoluble aggregates and its susceptibility to degradation. Obtaining good yields of highly purified CFTR has proven problematic and contributes to our limited understanding of the structure and function of the protein. The most prevalent disease causing mutation, F508del, results in misfolded CFTR which is particularly unstable and is quickly targeted for degradation by the host system and is prevented from being trafficked to the plasma membrane. There are limited treatment options for patients with the F508del mutation and it is therefore of significant interest within CF research. New methods and assays are required to identify potential compounds which could correct the F508del mutation. This thesis investigates the use of Saccharomyces cerevisiae to express and purify codon optimised recombinant CFTR. The use of a green fluorescent protein (GFP) tag enabled quick and simple detection of CFTR in whole cells and after extraction from the plasma membrane. By optimising the culture conditions for CFTR expression and detergent solubilisation conditions, relatively high yields of full-length protein were obtained. When used as a chemical chaperone at the time of inducing CFTR expression, glycerol increased yields of full-length protein. Degradation of CFTR could be limited by inducing expression at an optimal cell density and by harvesting cells within a specific time window. CFTR was extracted by solubilisation in the mild detergent dodecyl-β-D-maltopyranoside (DDM) in the presence of up to 1 M NaCl with up to ~87% efficiency in some cases. Using a gene optimisation strategy in which additional purification tags and a yeast Kozak-like sequence were added, the human CFTR (hCFTR) protein was expressed and purified. Fluorescence microscopy revealed CFTR localisation at the periphery of yeast cells. Immunoaffinity chromatography facilitated by the GFP tag at the C terminus of CFTR produced protein of up to 95% purity. An assessment of the thermal stability of this highly purified CFTR using a fluorescent probe binding assay revealed a denaturation midpoint (Tm) of ~43 degC. The ability of this assay to determine the stability of CFTR is encouraging and there is the potential to further develop it in a high-throughput manner to identify compounds which stabilise the F508del protein and which may hold the key to developing new treatments for CF.
277

Framtida förbättringsförslag för kombi- och omlastningsterminal : En fallstudie på Alvestas kombi- och omlastningsterminal / Future possible improvements for intermodal terminals : A case study at Alvestas intermodal terminal

Delius, Hanna, Svensson, Matilda January 2017 (has links)
Kurs: Examensarbete i Logistik, 30 hp Författare: Matilda Svensson och Hanna Delius Handledare:Petra Andersson Examinator: Helena Forslund Titel: Framtida förbättringsmöjligheter för kombi- och omlastningsterminaler - En fallstudie på Alvestas kombi- och omlastningsterminal Nyckelord: Kombi- och omlastningsterminaler, intermodala transporter, utnyttjandegrad, interna och externa faktorer   Arbetets syfte är att identifiera och analysera interna och externa faktorer som uppstår på kombi- och omlastningsterminaler samt att analysera hur utbudet på kombi- och omlastningsterminaler kan utvecklas för att möjliggöra ökad utnyttjandegrad.   Arbetet har besvarat tre frågeställningar: <ol type="1">Vilka interna och externa faktorer har lett till att kombi- och omlastningsterminalen i Alvesta inte når önskad utnyttjandegrad?    Interna faktorer: kompetens, typ av gods, lagring, hantering av gods/ej synkroniserat, ej elektrifierade spår, informationshantering, typ av utrustning, ej kontinuerligt flöde, utrymme och markunderlag. Externa faktorer: Lagar, dieselskatt, vägslitageskatt, konjunktur, befolkningsmängd, buller, nya innovationer, IT-system, infrastruktur, Andra kombi- och omlastningsterminaler, leverantörer, kund och lastbil.   <ol type="1">Hur kan kombi- och omlastningsterminaler i Sverige möta externa faktorer i framtiden? I utförandeplanen kom författarna fram till att det är viktigt för kombi- och omlastningsterminaler att inte bara fokusera på intermodal verksamhet. Det är även viktigt att ha ett effektivt IT-system som kan användas och hantera många och komplexa flöden. Järnvägen är lönsam med gods som är tungt och som kan fraktas långa sträckor därför borde kombi- och omlastningsterminaler kolla på möjligheten att transportera gods till andra länder och inte bara inom Sverige. Sedan borde kombi- och omlastningsterminaler kolla på möjligheten att förlänga spåren som finns på terminalen för att kunna hantera längre tåg. Den sista förbättringslaget är att kombi- och omlastningsterminaler borde kolla på att automatisera hanteringen.   Hur kan kombi- och omlastningsterminalen i Alvesta utvecklas, genom att möta identifierade interna faktorer, för att möjliggöra för ökad utnyttjandegrad?   För att öka utnyttjandegraden har författarna till arbetet kommit fram till att Alvestas kombi- och omlastningsterminal borde ha flera transportoperatörer, förbättrad lagerhantering, stuffa containrar, hantera virkespaket, använda cross-docking, hantera farligt gods, utökade öppettider, bättre markunderlag, elektrifierade spår, hantera timmer, implementera ett intermodalt transportsystem, investera i ett lagringstält, automatisering kring hantering och omlastning.
278

Estudo da imunoexpressão dos transportadores de glicose 1 e 3 e do índice angiogênico em tumores odontológicos ceratocísticos isolados e associados à Síndrome de Gorlin

Leite, Rafaella Bastos 30 July 2014 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-03-15T13:08:48Z No. of bitstreams: 1 PDF - Rafaella Bastos Leite.pdf: 1326501 bytes, checksum: 57e6fffb3bbe74433cba4f469a5b6545 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-07-21T21:05:02Z (GMT) No. of bitstreams: 1 PDF - Rafaella Bastos Leite.pdf: 1326501 bytes, checksum: 57e6fffb3bbe74433cba4f469a5b6545 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-07-21T21:05:12Z (GMT) No. of bitstreams: 1 PDF - Rafaella Bastos Leite.pdf: 1326501 bytes, checksum: 57e6fffb3bbe74433cba4f469a5b6545 (MD5) / Made available in DSpace on 2016-07-21T21:05:12Z (GMT). No. of bitstreams: 1 PDF - Rafaella Bastos Leite.pdf: 1326501 bytes, checksum: 57e6fffb3bbe74433cba4f469a5b6545 (MD5) Previous issue date: 2014-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The keratocystic odontogenic tumor (KOT) stands out among the other odontogenic lesions in view of the potentially aggressive biological behavior and its association in some cases, with the Gorlin syndrome. Some studies have suggested a more aggressive biological behavior for KOTs associated with Gorlin syndrome, compared to isolated KOTs, characterized by greater growth capacity and bone infiltration and higher tendency to recur. The present study aimed to evaluate, descriptively and comparatively, by means of immunohistochemistry, the expression of glucose transporter-1 (GLUT-1) and -3 (GLUT-3) and the angiogenic index (CD34) in isolated primary and recurrent KOTs and in KOTs associated with Gorlin syndrome. The sample was composed by 21 isolated KOTs (14 primary and 7 recurrent) and 14 KOTs associated with Gorlin syndrome. The expression of GLUTs was evaluated in the epithelial component of the lesions, establishing the percentage of immunopositive cells, according to the scores: score 0 (negative), score 1 (≤ 25% of positive cells), score 2 (26% - 50% of positive cells), score 3 (51% - 75% of positive cells), and score 4 (≥ 76% positive cells). For the angiogenic index, the microvessel count (MVC) technique was applied, quantifying the microvessels immunoreactive to anti-CD34 antibody. Regarding the median scores for immunopositivity for GLUT-1 and the angiogenic index, comparisons between groups were performed using the nonparametric Kruskal-Wallis test. For GLUT-3, the data obtained from the evaluation of epithelial expression of this protein were submitted to descriptive statistical analysis. Possible correlations between the scores of immunopositivity for GLUT-1 and angiogenic index in the lesions were evaluated using the Spearman correlation test. The level of significance was set at 5% (p <0.05). The analysis of epithelial GLUT-1 immunoreactivity revealed predominance of score 4 in isolated primary KOTs (n = 9, 64.3%) and in KOTs associated with Gorlin syndrome (n = 8; 57.1%). In isolated recurrent KOTs, it was identified a slightly higher frequency of cases with scores 4 (n = 3; 42.9%) and 2 (n = 2; 28.6%). The nonparametric Kruskal-Wallis test showed no statistically significant difference between groups (p = 0.406). Regarding the GLUT-3, all groups showed higher frequency of negative cases. The few KOTs positive for GLUT-3 were classified as score 1 (≤ 25% of positive cells), showing a low expression of this protein in the epithelial component. The mean number of microvessels was 63.80 in isolated primary KOTs, 61.11 in KOTs associated with the Gorlin syndrome, and 65.88 in isolated recurrent KOTs, without significant differences between groups (p = 0.965). The results of this study suggest that the differences in biological behavior of isolated KOTs and KOTs associated with Gorlin syndrome may not be related to the expression of GLUTs-1 and -3, or to the angiogenic index in the lesions. The high expression of GLUT-1 in KOTs suggests an important role for this protein in glucose uptake by the epithelial cells of these tumors. / O tumor odontogênico ceratocístico (TOC) se destaca entre as demais lesões odontogênicas em virtude do comportamento biológico potencialmente agressivo e por sua associação, em alguns casos, à síndrome de Gorlin. Pesquisas tem sugerido um comportamento biológico mais agressivo para os TOCs associados à síndrome de Gorlin, em comparação aos TOCs isolados, caracterizado por maior capacidade de crescimento e infiltração óssea e maior tendência a recorrência. O presente estudo se propôs a avaliar, descritiva e comparativamente, a imunoexpressão dos transportadores de glicose-1 (GLUT-1) e -3 (GLUT-3) e o índice angiogênico (CD34) em TOCs isolados primários e recorrentes e TOCs associados à síndrome de Gorlin. A amostra foi composta por 21 TOCs isolados (14 primários e 7 recorrentes) e 14 TOCs associados à síndrome de Gorlin. A expressão dos GLUTs foi avaliada no componente epitelial das lesões, estabelecendo-se o percentual de células imunopositivas, de acordo com os escores: escore 0 (negativo), escore 1 (≤ 25% das células positivas), escore 2 (26% - 50% das células positivas), escore 3 (51% - 75% das células positivas) e escore 4 (≥76% das células positivas). Para o índice angiogênico, foi empregada a técnica da contagem microvascular (MVC), quantificando-se os microvasos imunomarcados pelo anticorpo anti-CD34. Em relação às medianas para os escores de imunopositividade para GLUT-1 e para o índice angiogênico, as comparações entre os grupos foram realizadas por meio do teste não paramétrico de Kruskal-Wallis. Para o GLUT-3, os dados obtidos com a avaliação da expressão epitelial desta proteína foram submetidos apenas à análise estatística descritiva. Possíveis correlações entre os escores de imunopositividade para GLUT-1 e o índice angiogênico nas lesões foram avaliadas por meio do teste de correlação de Spearman. O nível de significância foi estabelecido em 5% (p < 0,05). A análise da imunoexpressão epitelial de GLUT-1 revelou predomínio de casos com escore 4 nos TOCs isolados primários (n = 9; 64,3%) e nos TOCs associados à síndrome de Gorlin (n = 8; 57,1%). Nos TOCs isolados recorrentes, foi identificada frequência discretamente maior para os casos com escores 4 (n = 3; 42,9%) e 2 (n = 2; 28,6%). O teste não paramétrico de Kruskal-Wallis revelou ausência de diferença estatisticamente significativa entre os grupos (p = 0,406). Em relação ao GLUT-3, todos os grupos estudados revelaram maior frequência de casos negativos. Os poucos TOCs positivos para GLUT-3 foram classificados como escore 1 (≤ 25% das células positivas), revelando uma baixa expressão desta proteína no componente epitelial. O número médio de microvasos foi de 63,80 nos TOCs isolados primários, 61,11 nos TOCs associados a síndrome de Gorlin e 65,88 nos TOCs isolados recorrentes, sem diferenças significativas entre os grupos (p = 0,965). Os resultados do presente estudo sugerem que as diferenças no comportamento biológico de TOCs isolados e TOCs associados à síndrome de Gorlin não foram relacionadas com a expressão de GLUTs-1 e -3 ou com o índice angiogênico (CD34) nas lesões. A alta expressão de GLUT-1 em TOCs sugere um importante papel para esta proteína na captação de glicose pelas células epiteliais destes tumores.
279

Estudo da homeostase de zinco no fungo patogênico Histoplasma capsulatum var. capsulatum: Abordagens proteômica e funcional / Study of zinc homeostasis in the pathogenic fungus Histoplasma capsulatum var. capsulatum: Proteomic and functional approaches

Siqueira, Janaina Gomes de 30 November 2016 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-09T12:02:26Z No. of bitstreams: 2 Dissertação - Janaina Gomes de Siqueira - 2016.pdf: 2965200 bytes, checksum: 015ab0c28746d09363a65c8817dd4068 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-09T12:03:04Z (GMT) No. of bitstreams: 2 Dissertação - Janaina Gomes de Siqueira - 2016.pdf: 2965200 bytes, checksum: 015ab0c28746d09363a65c8817dd4068 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-09T12:03:04Z (GMT). No. of bitstreams: 2 Dissertação - Janaina Gomes de Siqueira - 2016.pdf: 2965200 bytes, checksum: 015ab0c28746d09363a65c8817dd4068 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-11-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Histoplasma capsulatum var. capsulatum is a pathogenic fungus that causes the systemic disease known as histoplasmosis. This mycosis presents endemicity in the regions of the Mississippi and Ohio rivers in the United States, also found in several countries of South America. In Brazil, the number of people infected by this fungus has been growing in recent years, especially in immunocompromised people. H. capsulatum is a thermodymorphic microorganism, found in two morphotypes: mycelium at 25ºC and yeast at 37ºC. During the infection process the pathogenic microorganism needs to obtain nutrients so that it grows and develops within the tissue of the host. Among the essential nutrients, zinc is an essential metal ion, used in the maintenance of numerous metabolic pathways. Zinc is used as catalytic and structural cofactor of numerous metalloproteins. Zinc uptake is characterized as a virulence factor in H. capsulatum. In order to study the molecular mechanisms of zinc homeostasis in H. capsulatum, the in silico analysis of zinc homeostasis related proteins. The ZafA transcription factor, which acts on the regulation of genes in response to the zinc level in the medium and the transcription factor PacC that regulates genes in response to pH, were also found. ZrfA and ZrfC membrane transporters were also found ZrfF, ZrcA and ZrcC vacuolar transporters. The transcriptional profile analysis of these genes was measured by RT-PCR in infected macrophages and in vitro. During the infection the ZafA and ZrfA genes were induced, suggesting that these genes were expressed in order to supply the fungal cell with zinc, due to the metal deficiency caused by the infection. In vitro, ZafA, ZrfC, ZrfF, ZrcA and ZrcC were induced at zinc deprivation condition, compared with control condition. According with proteomic data of fungus under conditions of zinc deprivation, it was suggested the induction of proteins related to rescue, defense and virulence, related mainly to oxidative stress, besides other metabolic pathways such as gluconeogenesis. These data suggest that the fungus undergoes a metabolic remodeling in response to the oxidative stress caused by zinc deprivation. / Histoplasma capsulatum var. capsulatum é um fungo patogênico causador da doença sistêmica conhecida como histoplasmose. Essa micose apresenta endemicidade nas regiões do rio Mississipi e Ohio nos Estados Unidos, encontrado também em vários países da América do Sul. No Brasil, o número de pessoas infectadas por este fungo vem crescendo nos últimos anos, principalmente em pessoas imunocomprometidas. H. capsulatum é um micro-organismo termodimórfico, encontrado em dois morfotipos: micélio a 25ºC e levedura a 37ºC. Durante o processo de infecção o micro-organismo patogênico necessita obter nutrientes para que cresça e se desenvolva dentro do tecido do hospedeiro. Dentre os nutrientes essenciais, o zinco é um íon metal essencial, utilizado na manutenção de inúmeras vias metabólicas. O zinco é utilizado como cofator catalítico e ou estrutural de inúmeras metaloproteínas. A captação de zinco é caracterizada como um fator de virulência em H. capsulatum. Com o objetivo de estudar os mecanismos moleculares da homeostase de zinco em H. capsulatum, foi realizada primeiramente a análise in silico das proteínas relacionadas a homeostase de zinco. Foram encontrados o fator de transcrição ZafA que atua na regulação de genes em resposta ao nível de zinco no meio e o fator de transcrição PacC que atua na regulação de genes em resposta ao pH, adicionalmente foram encontrados transportadores de membrana ZrfA e ZrfC, além dos transportadores vacuolares ZrfF, ZrcA e ZrcC. A análise do perfil transcricional destes genes foi mensurada por RT-PCR em macrófagos infectados e in vitro. Durante a infecção os genes ZafA e ZrfA foram induzidos, sugerindo que estes genes foram expressos a fim de suprir a célula fúngica com zinco, devido a deficiência do metal causada pela infecção. In vitro, ZafA, ZrfC, ZrfF, ZrcA e ZrcC foram induzidos na condição de privação de zinco, comparado com a condição controle. De acordo com os dados proteômicos do fungo em condições de privação zinco, foi sugerido a indução de proteínas relacionadas ao resgate, defesa e virulência, relacionadas principalmente ao estresse oxidativo, além de outras vias metabólicas como gliconeogênese. Estes dados sugerem que o fungo sofre um remodelamento metabólico em resposta ao estresse oxidativo causado pela privação de zinco.
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Metabolização de açúcares em linhagens de Saccharomyces cerevisiae com e sem transportador de sacarose e diferentes atividades de invertase / Sugar metabolization of Saccharomyces cerevisiae with transporter of sucrose and different invertase activity

Osmar Parazzi Júnior 22 September 2006 (has links)
O presente trabalho teve por objetivo avaliar o perfil metabólico da utilização dos açúcares por diferentes leveduras (BG-1, CAT-1, FLEISCHMANN, PE-2, 1403-7A e LCM001) em diferentes meios de crescimento e também analisar o comportamento e a atividade de invertase destas leveduras durante um processo fermentativo com reciclos de células, semelhantemente ao processo industrial, levando em consideração os parâmetros: produção de etanol, formação de biomassa, produção de trealose, glicogênio, glicerol, rendimento e eficiência fermentativa. Os experimentos foram divididos em três partes: a 1a foi a quantificação da atividade de invertase das diferentes leveduras, em mosto de fermentação à base de mel e água (13% ART), a 2a analisouse o perfil de metabolização em diferentes meios de crescimento à base de YEP com 2% de açúcares (glicose, sacarose, ou glicose + sacarose), e a 3a foi a realização de uma fermentação alcoólica com 4 reciclos de células, com mosto de mel (13% ART), sendo os três primeiros utilizados para a avaliação do rendimento fermentativo, bem como seus indicadores (trealose, glicogênio, viabilidade, entre outros) e o último, destinado ao perfil de metabolização de açúcares em condições de fermentação. Os resultados mostram que as leveduras possuem diferentes atividades de invertase (BG-1 = 7,34; FLEISCHMANN = 5,75; CAT-1 = 3,76; PE-2 = 2,39 gART.h-1.gbiomassa; 1403-7A e LCM001, não possuem atividade), apresentam diferentes velocidades de hidrólise da sacarose, tanto em meios de crescimento como mostos (BG-1 e FLEISCHMANN = 2 h; CAT-1 = 3h; PE-2 = 4h; 1403-7A = 24 h e LCM001 = >24 h), assim como a velocidade de metabolização dos açúcares presentes nestes. Conclui-se que a atividade de invertase é dependente da linhagem de levedura, assim como a velocidade de metabolização dos açúcares em meios de crescimento e mosto. A análise do perfil de metabolização de açúcares não permite identificar a presença de transportador de sacarose. No geral, as leveduras selecionadas apresentam melhor desempenho fermentativo. Por outro lado, verificou-se que as linhagens com transportador de sacarose apesar da menor produção de álcool, apresentaram uma boa eficiência fermentativa. O maior problema por parte destas últimas, é o alto tempo de fermentação e a baixa taxa de multiplicação, com conseqüente queda na viabilidade celular. / The aim of this work was to evaluate the metabolic profile in the utilization of sugars, using different yeast strains (BG-1, CAT-1, FLEISHMANN, PE-2, 1403-7A and LCM001) with different growth medium and also to analyze behavior and the invertase activities of these yeast strains during fermentative process with recycling, similar to the industrial process. The following parameters were used: ethanol production, biomass formation, trealose production, glycogen, glycerol, ethanol yield and fermentation efficiency. The trials were divided into three parts: First was activity quantification of invertase using different yeast strains, with a mix of molasses and water (13% ART), the second was analyzed the metabolization profile with different growth medium using YEP added 2% of sugars (glucose, sucrose, or glucose + sucrose), and the third it was the alcoholic fermentation with 4 yeast cell recycles, using wort of molasses and juice ( 13 % ART), The first three were utilized to evaluate the fermentation yield and also theirs indicatives (trealose, glycogen, viability within others) and, the last one was performed to study the profile of sugars metabolization in fermentation conditions. The results showed that those yeasts produced different invertase activities (BG-1 = 7,34; FLEISCHMANN = 5,75; CAT-1 = 3,76; PE-2 = 2,39 gART.h-1.gbiomass; 1403-7A and LCM001 did not have invertase activity), different velocity of sucrose hydrolysis, as much as medium growth as worts (BG-1 and FLEISCHANN = 2 h; CAT-1 = 3h; PE-2 = 4h; 1403-7A = 24 h and LCM001 = >24 h), also as the velocity of sugars metabolization present on this medium. It can be concluded that the invertase activity is dependent of yeast strain, as the velocity of sugars metabolization in growth medium and wort. The profile analysis of metabolization of sugars did not allow to identify the presence of sucrose transporter. In general, the selected yeasts present the best fermentation performance. On the other hand, it was observed the strains with sucrose transportation did not show stress. The major problem of these yeasts were the high fermentation time and low propagation rate, and a decrease of the viability.

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