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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.
1

Utredningsregeln i svensk skattelagstiftning : En studie av begreppet organisatoriskt nära beträffande näringsbetingade andelar / The investigation rule in Swedish tax law : A study of the term organizational close regarding business-related shares

Dahlberg, Josephine, Elander, Daniel January 2015 (has links)
I vår uppsats har vi tagit del av såväl den befintliga lagtexten som äldre lagtext, vilket rör beskattningsrätten för näringsbetingade andelar. Vi har granskat tillämpliga paragrafer i inkomstskattelagen, inhämtat praxis på området samt läst förarbeten till lagen. Dessutom har vi tagit kontakt med skatteverket och efterfrågat deras ställningstagande i frågan. Vi har även redogjort för och analyserat ett antal relevanta avgöranden inom området, däribland de två mest aktuella rättsfallen, RÅ 2005 ref 48 och RÅ 2008 ref 67. Uppsatsens grund har byggt på vår inhämtning av information från gällande lagar, praxis och förarbeten, vilket vi sedan redogjort och sammanställt, för att ge våra läsare en djupare förståelse inom ämnet.
2

Not for art's sake the story of Il Frontespizio.

Mazza, Maria Serafina, January 1948 (has links)
Thesis--Columbia University. / Pub. also without thesis statement. Vita. Bibliographical table": p. [203]-214. "Reference notes": p. [154]-176.
3

The censorship and fortuna of Platina's "Lives of the popes" in the sixteenth century /

Bauer, Stefan, January 2006 (has links)
Texte remanié de: PhD thesis--London--Warburg Institute, 2004. / Contient l'édition du texte latin des propositions de censure. Bibliogr. p. 323-372.
4

Padrão imuno-histoquímico da mucosa nasal de portadores de rinossinusite crônica com e sem exposição a fibras do algodão e controle / Immunohistochemical pattern of the nasal mucosa of patients with chronic rhinosinusitis with and without exposure to cotton fibers and control

Zappelini, Carlos Eduardo Monteiro 18 April 2019 (has links)
A rinossinusite crônica (RSC) é uma doença inflamatória da mucosa nasal, e pouco tem sido relacionada à exposição no ambiente de trabalho, em especial ao algodão. Atualmente, uma série de citocinas e quimiocinas tem sido estudada para elucidação das características imunológicas que levam ao desenvolvimento da doença. Objetivos: Caracterizar a exposição ao algodão como indutora de RSC e determinar o padrão de resposta inflamatória imuno-histoquímica da mucosa nasal de indivíduos expostos ou não ao algodão e que desenvolveram RSC. Casuística e Metodos: Por meio de questionário baseado no EPOS e SNOT-22 foi realizado diagnóstico clínico de RSC em indivíduos expostos ao algodão no ambiente de trabalho. Após a confirmação diagnóstica com tomografia computadorizada e nasofibroscopia flexível foi realizada biópsia na mucosa de concha média de pacientes com diagnóstico clínico de RSC para análise da expressão de IL-4, IL-5, IL-10, IL-17 e IL-33. A análise foi realizada também em grupo com RSC sem exposição ao algodão e controle sem RSC. Resultados: Todos os indivíduos expostos ao algodão com sintomatologia sugestiva de RSC apresentaram padrão histológico com aumento da expressão de IL-4, IL-5, IL-10, IL-17 e IL-33. Conclusões: O presente estudo comprovou a estreita relação entre a exposição ao algodão no ambiente de trabalho e o surgimento de uma resposta inflamatória com aumento da expressão das interleucinas estudadas. A possível instituição de terapias/medicamentos que inibissem a expressão dessas citocinas poderia auxiliar na diminuição do processo inflamatório presente na RSC e/ou no desencadeamento da doença / The chronic rhinusinusitis (CRS) is an inflammatory disease of the nasal mucosa, and has been little related to exposure in the work environment, especially to cotton. Currently, a number of cytokines and chemokines have been studied to elucidate the immunological characteristics that lead to the development of the disease. Objectives: To characterize exposure to cotton as an inducer of CRS and to determine the pattern of inflammatory immune-histochemical response of the nasal mucosa of individuals exposed or not to cotton and who developed CRS. Casuistic and Methods: Using a questionnaire based on EPOS and SNOT-22, a clinical diagnosis of CRS was performed in individuals exposed to cotton in the work environment. After diagnostic confirmation with computed tomography and flexible nasofibroscopy, biopsy was performed on the middle concha mucosa of patients with clinical diagnosis of CRS to analyze the expression of IL-4, IL-5, IL-10, IL-17 and IL- 33. The analysis was also performed in a group with CRS without exposure to cotton and control without CRS. Results: All individuals exposed to cotton with symptoms suggestive of CRS had a histological pattern with increased expression of IL-4, IL-5, IL-10, IL-17 and IL-33. Conclusions: This study confirms the close relationship between exposure to cotton in the workplace and the appearance of an inflammatory response with increased expression of interleukins studied. The possible institution of therapies / drugs that inhibit the expression of these cytokines could help in the reduction of the inflammatory process present in CRS and in the onset of the disease
5

O hidrogênio molecular potencializa a hipotermia e previne a hipotensão e a febre durante a inflamação sistêmica induzida por LPS / Molecular hydrogen potentiates hypothermia and prevents hypotension and fever in LPS-induced systemic inflammation

Saramago, Eduardo Alves 29 November 2018 (has links)
O hidrogênio molecular (H2) exerce efeito antioxidante, anti-apoptótico e antiinflamatório. Nesse estudo testamos a hipótese que o H2 modula as mudanças cardiovasculares, inflamatórias e termorregulatórias na inflamação sistêmica (IS) induzida por lipopolissacarídeo (LPS) em diferentes doses (0,1 ou 1,5 mg/kg, intravenoso, induzindo IS moderada ou severa) em ratos machos Wistar (250-300 g). LPS ou salina foi injetada imediatamente antes do início dos 360 minutos de inalação do H2 (2% H2, 21% O2, balanceado com nitrogênio) ou ar ambiente (21% O2, balanceado com nitrogênio). A temperatura corporal (Tc) foi mensurada por datalogger pré-implantados na cavidade peritoneal. O H2 não causou mudança nos parâmetros cardiovasculares, inflamatórios e na Tc dos ratos controle (tratados com salina). Durante a IS moderada o H2 reduziu o surgimento das citocinas pró-inflamatórias no plasma (TNF-? e IL-6) enquanto causou um aumento da IL-10 plasmática (citocina anti-inflamatória) e preveniu a febre. Durante a IS severa o H2 potencializou a hipotermia e preveniu a febre e a hipotensão. Além disso, o H2 causou uma redução no surgimento das citocinas pró-inflamatórias (TNF-? e IL-1? do plasma) e prostaglandina E2 [(PGE2), no plasma e no hipotálamo], e um aumento da IL-10 plasmática. Esses dados são consistentes com o entendimento que o H2 atenua a febre na IS moderada e durante a IS severa potencializa a hipotermia, previne a hipotensão e exerce um efeito antiinflamatório forte o suficiente para prevenir a febre alterando a sinalização febrigênica e alterando a produção hipotalâmica de PGE2 / Molecular hydrogen (H2) exerts anti-oxidative, anti-apoptotic, and anti-inflammatory effects. Here we tested the hypothesis that H2 modulates cardiovascular, inflammatory, and thermoregulatory changes in systemic inflammation (SI) induced by lipopolysaccharide (LPS) at different doses (0.1 or 1.5 mg/kg, intravenously, to induce mild or severe SI) in male Wistar rats (250-300 g). LPS or saline was injected immediately before the beginning of 360- minute inhalation of H2 (2% H2, 21% O2, balanced with nitrogen) or room air (21% O2, balanced with nitrogen). Deep body temperature (Tb) was measured by dataloggers preimplanted in the peritoneal cavity. H2 caused no change in cardiovascular, inflammatory parameters, and Tb of control rats (treated with saline). During mild SI, H2 reduced plasma surges of proinflammatory cytokines (TNF-? and IL-6) while caused an increase in plasma IL-10 (anti-inflammatory cytokine) and prevented fever. During severe SI, H2 potentiated hypothermia, and prevented fever and hypotension. Moreover, H2 caused a reduction in surges of proinflammatory cytokines (plasma TNF-? and IL-1?) and prostaglandin E2 [(PGE2), in plasma and hypothalamus], and an increase in plasma IL-10. These data are consistent with the notion that H2 blunts fever in mild SI, and during severe SI potentiates hypothermia, prevents hypotension and exerts anti-inflammatory effects strong enough to prevent fever by altering febrigenic signaling and ultimately down-modulating hypothalamic PGE2 production
6

O hidrogênio molecular potencializa a hipotermia e previne a hipotensão e a febre durante a inflamação sistêmica induzida por LPS / Molecular hydrogen potentiates hypothermia and prevents hypotension and fever in LPS-induced systemic inflammation

Eduardo Alves Saramago 29 November 2018 (has links)
O hidrogênio molecular (H2) exerce efeito antioxidante, anti-apoptótico e antiinflamatório. Nesse estudo testamos a hipótese que o H2 modula as mudanças cardiovasculares, inflamatórias e termorregulatórias na inflamação sistêmica (IS) induzida por lipopolissacarídeo (LPS) em diferentes doses (0,1 ou 1,5 mg/kg, intravenoso, induzindo IS moderada ou severa) em ratos machos Wistar (250-300 g). LPS ou salina foi injetada imediatamente antes do início dos 360 minutos de inalação do H2 (2% H2, 21% O2, balanceado com nitrogênio) ou ar ambiente (21% O2, balanceado com nitrogênio). A temperatura corporal (Tc) foi mensurada por datalogger pré-implantados na cavidade peritoneal. O H2 não causou mudança nos parâmetros cardiovasculares, inflamatórios e na Tc dos ratos controle (tratados com salina). Durante a IS moderada o H2 reduziu o surgimento das citocinas pró-inflamatórias no plasma (TNF-? e IL-6) enquanto causou um aumento da IL-10 plasmática (citocina anti-inflamatória) e preveniu a febre. Durante a IS severa o H2 potencializou a hipotermia e preveniu a febre e a hipotensão. Além disso, o H2 causou uma redução no surgimento das citocinas pró-inflamatórias (TNF-? e IL-1? do plasma) e prostaglandina E2 [(PGE2), no plasma e no hipotálamo], e um aumento da IL-10 plasmática. Esses dados são consistentes com o entendimento que o H2 atenua a febre na IS moderada e durante a IS severa potencializa a hipotermia, previne a hipotensão e exerce um efeito antiinflamatório forte o suficiente para prevenir a febre alterando a sinalização febrigênica e alterando a produção hipotalâmica de PGE2 / Molecular hydrogen (H2) exerts anti-oxidative, anti-apoptotic, and anti-inflammatory effects. Here we tested the hypothesis that H2 modulates cardiovascular, inflammatory, and thermoregulatory changes in systemic inflammation (SI) induced by lipopolysaccharide (LPS) at different doses (0.1 or 1.5 mg/kg, intravenously, to induce mild or severe SI) in male Wistar rats (250-300 g). LPS or saline was injected immediately before the beginning of 360- minute inhalation of H2 (2% H2, 21% O2, balanced with nitrogen) or room air (21% O2, balanced with nitrogen). Deep body temperature (Tb) was measured by dataloggers preimplanted in the peritoneal cavity. H2 caused no change in cardiovascular, inflammatory parameters, and Tb of control rats (treated with saline). During mild SI, H2 reduced plasma surges of proinflammatory cytokines (TNF-? and IL-6) while caused an increase in plasma IL-10 (anti-inflammatory cytokine) and prevented fever. During severe SI, H2 potentiated hypothermia, and prevented fever and hypotension. Moreover, H2 caused a reduction in surges of proinflammatory cytokines (plasma TNF-? and IL-1?) and prostaglandin E2 [(PGE2), in plasma and hypothalamus], and an increase in plasma IL-10. These data are consistent with the notion that H2 blunts fever in mild SI, and during severe SI potentiates hypothermia, prevents hypotension and exerts anti-inflammatory effects strong enough to prevent fever by altering febrigenic signaling and ultimately down-modulating hypothalamic PGE2 production
7

IL-27 Enhances LPS-Induced Proinflammatory Responses in Human Monocytes: Augmented Inflammasome Activity and IL-23 Expression

WYNICK, CHRISTOPHER 27 June 2014 (has links)
Inflammation plays an important role in responding to injury and combating infections. In this thesis, I examine how inflammation is regulated by cytokines responsible for driving initial immune responses to combat infections. Toll-Like receptor (TLR)-mediated activation of monocytes, macrophages and dendritic cells can lead to the co-expression of proinflammatory cytokines including IL-1β, IL-23, and IL-27. IL-23 and IL-27 belong to the IL-12 cytokine family yet have distinct functions; IL-23, along with IL-1β, regulates TH17 cell differentiation, while IL-27 supports TH1 proliferation and inhibits TH17 differentiation. Our lab has previously demonstrated that IL-27 can modulate inflammasome activation, the multi-protein regulatory complex that produces bioactive IL-1β; however, the mechanism behind this is poorly understood. Similarly, the effect of IL-27 on IL-23 expression has not been well described. Using the CD14+ THP-1 monocytic cell line as a model system, I investigated the role of IL-27 on LPS-mediated inflammasome activation and IL-23 expression. To induce inflammasome activation, CD14+ THP-1 cells were treated with LPS and/or IL-27, followed by treatment with ATP. I demonstrated that IL-27-enhanced inflammasome activation, which is associated with increased surface expression of LPS and ATP receptors: TLR4 and P2X7 respectively. Furthermore, costimulation resulted in increased secretion of ATP from CD14+ THP-1 cells. Inhibition of ATP signaling and inflammasome activation significantly decreased secreted IL-1β, suggesting that an ATP autocrine feedback loop is driving IL-1β secretion. Moreover, LPS and IL-27 costimulation increased IL-23 expression concurrent with that of IL-1β and ATP secretion. Furthermore I showed that IL-23 secretion is dependent on inflammasome activation and IL-1β, and ATP signaling following IL-27 and LPS priming. My data point to a novel mechanism of IL-27 enhanced LPS-induced IL-1β and IL-23 secretion from CD14+ THP-1 cells through an ATP autocrine feedback loop. / Thesis (Master, Microbiology & Immunology) -- Queen's University, 2014-06-26 15:18:20.124
8

Pollution à l'ozone : maintien de la barrière pulmonaire via l'IL-33, implication des autres membres de la famille IL-1 et régulation cytokinique via AhR / Ozone pollution : pulmonary barrier maintenance via IL-33, involvement of IL-1 family members and AhR-dependent cytokine regulation

Michaudel, Chloé 25 October 2017 (has links)
L’ozone est un des polluants présents dans l’air que nous respirons. Les pics de ce polluant entrainent une augmentation des hospitalisations et des cas d’exacerbations d’asthme allergique. L’objectif de ce travail est d’étudier plus en détails les mécanismes inflammatoires mis en place après exposition à l’ozone. Cette étude s’est déroulée en trois axes, les deux premiers traitant du rôle de deux alarmines, l’IL-33 et l’IL-1α et le troisième se focalisant sur AhR, un récepteur impliqué dans la réponse à de nombreux polluants. Pour ce faire, des souris ont été exposées à l’ozone selon deux modèles, l’un aigu et l’autre chronique, puis les paramètres inflammatoires, le dommage tissulaire et les difficultés respiratoires ont été évalués. Nous montrons ici qu’une exposition aigüe à l’ozone induit la libération de molécules comme l’IL-33 et l’IL-1α. L’IL-33 agit au niveau de la barrière épithéliale, où elle permet l’expression et le maintien des jonctions serrées, qui sont augmentées en réponse à la pollution à l’ozone. L’IL-33 régule également l’infiltration des neutrophiles, alors que l’IL-1α l’induit. Ensuite nous avons montré que le récepteur AhR est activé après exposition chronique à l’ozone. AhR semble réguler la production de cytokines telles que l’IL-17A et l’IL-22 et ainsi protège d’une trop forte réponse inflammatoire. Pour conclure, nous avons montré que la production d’IL-33 et l’activation du récepteur AhR étaient nécessaires pour contrôler l’inflammation induite par l’ozone, alors que la production d’IL-1α l’induisait. Cette étude aura permis de mettre en évidence de potentielles cibles thérapeutiques pour soulager les maux provoqués par la pollution. / Ozone is a common ambient air polluant. Ozone peaks induce increase of asthma exacerbation, respiratory distress, emergencies and hospital admissions. The aim of this thesis project is to dissect inflammatory mechanisms induced after ozone exposure. This study is conducted according three axes, the first two dealing with the roles of two alarmines, IL-1α and IL-33 and the third is focused on the role of aryl hydrocarbon receptor (AhR), a receptor involved in several pollutant responses. Acute and chronic experimental models of ozone exposure were used to evaluate inflammatory parameters in lung, tissue damage and airway hyperresponsiveness. Here we show that acute ozone exposure induces IL-1α and IL-33 release. IL-33 acts on lung epithelial barrier, allowing the expression and maintenance of tight junctions induced after ozone exposure. Moreover, IL-33 represses neutrophils infiltration while IL-1α induces it. Furthermore we show that AhR is activated after chronic ozone exposure. AhR regulates cytokines production such as IL-17A and IL-22 and plays a protective role against higher inflammation. Overall, IL-33 production and AhR activation are necessary to control ozone-induced inflammation, in contrast to IL-1α. These findings highlight potential therapeutic targets for the treatment of lung inflammation following ozone exposure.
9

Les effets synergiques des cytokines pro-inflammatoires et des cytokines impliquées dans l’homéostasie sur les réponses des lymphocytes T CD8 aux antigènes / Increased antigen responsiveness of CD8 T cells after cytokine primings

Gagnon, Julien January 2016 (has links)
Résumé : L’IL-7 et l’IL-15 sont des cytokines impliquées dans l’homéostasie des lymphocytes T CD8 naïfs et mémoires respectivement. Lors d’une réponse immunitaire, certaines cytokines pro-inflammatoires, comme l’IL-6 et l’IL-21, sont produites par les cellules du système immunitaire inné. Nous avons observé que certaines cytokines de ces deux groupes (homéostasie et pro-inflammatoires), peuvent avoir un effet synergique sur la fonction des lymphocytes T CD8. Spécifiquement, l’incubation des lymphocytes T CD8 naïfs avec l’IL-6 ou l’IL-21, en présence d’IL-7 ou d’IL-15 cause une forte prolifération qui est indépendante de l’antigène. De plus, la combinaison d’IL-15 avec l’IL-6 ou l’IL-21 entraîne une prolifération préférentielle des lymphocytes T mémoires, tandis que la combinaison avec l’IL-7 entraîne une prolifération des lymphocytes T naïfs. La stimulation des lymphocytes T CD8 avec l’IL-6 ou l’IL-21, en présence d’IL-7 ou d’IL-15, entraîne une augmentation de la phosphorylation en tyrosine de STAT5 ainsi qu’une augmentation de liaison à l’ADN. Nous avons étudié l’effet d’une pré-stimulation des cellules T CD8 naïves par les cytokines synergiques sur leur réponse subséquente à un antigène. Nous avons observé qu’une pré-stimulation avec l’IL-6 ou l’IL-21, en présence d’IL-7 ou d’IL-15, même pour une courte durée de 24 heures, augmente leur sensibilité aux antigènes, entraînant une robuste prolifération et une forte augmentation de cytotoxité spécifique à l’antigène gp33. Nous avons observé que les cytokines pro-inflammatoires en combinaison avec l’IL-7 induisent une augmentation accrue de la prolifération chez les lymphocytes T CD8 exprimant un TCR transgénique de forte affinité (P14), ainsi que les cellules exprimant un TCR de faible affinité (H-Y). De plus, la combinaison synergique de cytokines entraîne une forte expression du récepteur de l’IL-2R[gamma] (CD132), ainsi qu’une augmentation de la production d’IL-2 après stimulation antigénique. Une forte augmentation de l’expression de CD8 et de CD45, ainsi qu’une diminution drastique de l’expression de CD5 peut expliquer l’augmentation de l’avidité fonctionnelle du TCR suite à une stimulation avec les combinaisons de cytokines synergiques. La stimulation des lymphocytes T CD8 avec les combinaisons de cytokines, induit une augmentation de la phosphorylation de LAT ainsi qu‘AKT. Cependant, la stimulation subséquente du CD3 n’entraîne pas d’augmentation de la phosphorylation de LAT ainsi qu’AKT chez les lymphocytes T CD8 pré-stimulés avec les combinaisons de cytokines. Nous avons aussi observé que les lymphocytes T CD8 stimulés avec les combinaisons de cytokines augmentent l’expression de CD62L, ce qui peut favoriser leur migration vers les ganglions lymphatiques. En conclusion, la production de cytokines pro-inflammatoires (IL-6, IL-15, IL-21) par les cellules du système immunitaire inné lors d’une infection ou d’une inflammation, ainsi que la présence constitutive d’IL-7, peuvent stimuler la prolifération et l’activation des lymphocytes T CD8 de façon non spécifique à l’antigène. Cette stimulation entraîne une augmentation de l’avidité fonctionnelle de leur TCR causant ainsi une forte prolifération ainsi que l’acquisition de fonctions effectrices spécifiques. Cette liaison entre le système immunitaire inné et adaptatif, médiée par les cytokines pro-inflammatoires et les cytokines homéostatiques joue un rôle très important dans l’élimination des pathogènes ainsi que dans le développement de maladies auto-immunitaires. / Abstract : Homeostasis of naive and memory CD8[superscript +] T lymphocytes is dependent on two cytokines IL-7 and IL-15, respectively. During an immune response to an infection, cells of the innate immune system produce several pro-inflammatory cytokines. We have observed that these two groups of cytokines, namely proinflammatory and homeostatic, can have a synergistic effect on CD8 T lymphocytes. Specifically, incubation of naive CD8 T cells with IL-6 or IL-21 in the presence of IL-7 or IL-15 induced strong proliferation in an antigen independent manner. While the combination of IL-6 or IL-21 with IL-15 induced strong proliferation of memory CD8 T cells, naïve CD8 T cells responded better to the combination with IL-7. These stimulatory cytokine combinations elicited strong STAT5 phosphorylation and it’s binding to DNA in CD8 T cells. We investigated the effect of priming CD8 T cells with the synergistic combination of IL-6 or IL-21 and IL-7 on their subsequent response to antigen. We observed that cytokine priming for only 24 hours enhanced their sensitivity to antigen, resulting in strong proliferation, effectors functions and cytotoxicity. These effects were observed with CD8 T cells expressing transgenic TCR with strong (P14) or weak (H-Y) affinity towards cognate peptide antigens. Priming CD8 T cells with the synergistic combination of cytokines increased the expression of IL-2 receptor gamma (CD132) and augmented the production of IL-2 when stimulated with antigen. These cells also expressed elevated levels of CD8 and CD45, as well as down modulate CD5, and these events may underlie the increased TCR avidity. Stimulation of CD8 T cells with the synergistic combination of cytokines induced phosphorylation of LAT and AKT. However, subsequent TCR stimulation did not further increase these phosphorylation events. We have observed that C D8 T cells primed with the synergistic combinations of cytokines up regulated CD62L, which could promote their migration through lymph nodes. In conclusion, inflammatory cytokines such as (IL-6, IL-15, IL-21) secreted by cells of the innate immune system during an infection or non-infectious inflammation, and basal levels of the homeostatic cytokine IL-7 can act in synergy with inflammatory cytokines to activate CD8 T lymphocytes in an antigen independent manner. This stimulation also results in an increase in the functional avidity of their TCR, as indicated by strong antigen responsiveness with increased proliferation and display of effectors functions. This connection between the innate and adaptive system mediated by inflammatory cytokines may play an important role in pathogen clearance and possibly in the development of autoimmune diseases.
10

Espalhamento de raios-X a baixo ângulo aplicado ao estudo estrutural de proteínas / Small Angle X ray Scattering applied to protein characterization studies

Oliveira Neto, Mario de 26 September 2008 (has links)
O espalhamento de raios X a baixo ângulo tem se mostrado uma poderosa ferramenta na ánalise estrutural de proteínas em solução. Estudos em condições próximas ao estado nativo podem ser realizados, permitindo a visualização tridimensional de proteínas ou complexos formados. A tese apresentada aborda a teoria envolvida para utilização desta ferramenta. Uma nova metodologia foi proposta para a determinação da massa molecular de proteínas em solução, utilizando apenas uma curva de SAXS em unidades arbitrárias, visto que até o momento, este procedimento era realizado em comparação com outra proteína padrão de peso molecular conhecido. Com relação à instrumentação científica, um equipamento de SAXS foi desenvolvido no Instituto de Física de São Carlos, permitindo agora que medidas de SAXS em proteínas em solução sejam realizadas no instituto. Clonagem, expressão e purificação foram realizadas para o domínio de ligação ao DNA da isoforma do receptor tireoideano humano, a caracterização experimental desta proteína foi realizada por anisotropia de fluorescência, crosslink e SAXS. Após formação do complexo DNA-proteína, F2-DBD hTR, o mesmo foi submetido a cristalização, os cristais obtidos para o complexo não apresentaram padrão de difração e modelos de baixa resolução foram gerados utilizando SAXS. Além disso, estudos de baixo ângulo foram realizados linha de SAXS do LNLS para a enzima ferredoxina redutase de leptospira interrogans e para o complexo formado por interleucina-22 e pelo receptor interleucina-22, sendo seus modelos tridimensionais resolvidos. / Small angle X-ray scattering has been proven to be a powerful tool in the structural analysis of proteins in solution. This technique permits the three-dimensional visualization of native proteins envelop at the level of nanometers. In this study we discuss the small angle X-ray scattering theory and we proposed a new methodology to determine the molecular weight of proteins in solution, using only SAXS curve in arbitrary units. Prior the development of this method, the proteins molecular weighs were calculated by comparison with another of known size, usually bovine serum albumin. We also assembled SAXS equipment at the Physics Institute of São Carlos, which will permits in house measurements; as well as the cloning, expression and purification of DBD hTR, followed by the characterization of this protein by fluorescence anisotropy, crosslink and SAXS. The DNA-protein complex, F2-DBD hTR, was subjected to crystallization assays. Although, the crystals obtained for the complex showed no pattern of diffraction we were able to generate low-resolution models for the F2-DBD hTR using SAXS analysis. Moreover, the studies of the protein LepFNR and the complex IL-22/IL-22R1 by small angle X-ray scattering were performed in the line of SAXS of the LNLS, and their threedimensional models were resolved

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