• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 61
  • 30
  • 13
  • 8
  • 4
  • 3
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 155
  • 19
  • 17
  • 17
  • 17
  • 16
  • 16
  • 16
  • 15
  • 12
  • 11
  • 11
  • 10
  • 10
  • 10
  • 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.
31

Biotesting and Surface Science of Polyurethanes with Novel Soft Blocks

Kurt, Pinar 01 January 2007 (has links)
Contact antimicrobial coatings with poly-alkylammonium compositions have been a subject of increasing interest in part because of the contribution of biocide release coatings to antibiotic resistance. Herein, a concept for antimicrobial coatings is developed based on thermodynamically driven surface concentration of soft block side chains. The concept incorporates structural and compositional guidance from naturally occurring antimicrobial proteins and achieves compositional economy via a polymer surface modifier (PSM). For this purpose, polyurethanes having P[AB] co-polyoxetane soft blocks, where A is a surface active (fluorous) or PEG-like side chain and B represents a desired function (alkylammonium) were prepared. Specifically, poly(2,2-substituted-1,3-propylene oxide) ran-co-telechelics with bromobutoxymethyl (CH2O(CH2)4Br) and either trifluoroethoxymethyl (3FOx, -CH2OCH2CF3)) or PEG-like (2-(2-methoxyethoxy)ethoxy)methyl (ME2Ox, (-CH2(OCH2CH2) 2OCH3)) side chains were prepared via cationic ring opening polymerization. Characterization utilized 1H NMR spectroscopy, temperature modulated differential scanning calorimetry (MDSC) and thermogravimetric analysis (TGA). Molecular weights (Mn) by 1H NMR end group analysis were ~6000-8000g/mole. Bromobutoxymethyl groups were completely substituted with N,N-dimethylalkyl amines to obtain alkylammonium co-telechelics. Two alkyl ammonium chain lengths, six carbons (C6) and twelve carbons (C12) were used. Tgs of bromobutoxymethyl co-telechelics were -68 degrees C and -48 degrees C for ME2Ox and 3FOx, respectively. Tgs remained low after amine substitution. Alkylammonium co-telechelics decomposed at 220-230 degrees C regenerating amine. Telechelics were incorporated into polyurethanes (PUs) having 4,4'-(methylene bis (p-cyclohexyl isocyanate) (H12MDI) and butanediol (BD) as the hard block (30wt%). Characterization by 1H NMR, GPC, MDSC and TGA is described. From DSC data, using the Fox equation, the weight fraction of pure soft block in the soft block domain (w1) was very high (0.96-0.99) for polyurethanes with fluorous soft blocks, while soft blocks with PEG-like side chains were phase mixed (w1 = 0.73-0.75). To our knowledge, this is the first time that a polycationic telechelic has been incorporated into a polyurethane. By using X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared (ATR-IR) spectroscopy, dynamic contact angle (DCA) analysis, sessile drop measurement, and Tapping Mode Atomic Force Microscopy (TM-AFM), surface properties of polyurethanes were examined. These polyurethanes were co-processed with base polyurethanes to modify surfaces. Surface concentration of 2 wt % P[AB]-polyurethanes was studied by using the same surface characterization methods. Surface concentration of semifluorinated and alkylammonium side chains (C6 and C12) was observed. Miscibility of PEG-like side chains resulted in weak concentration of short alkyl ammonium side chains (C6). However, longer alkylammonium side chains (C12) can 'self-chaperone' and surface concentrate better compared to shorter side chain analogs. For biocidal testing, aerosol and touch tests were designed and implemented. Coatings were tested for zone of inhibition. The polyurethanes were first tested as 100 wt % coatings and found to be highly effective against both Gram(-) (Pseudomonas aeruginosa, Escherichia coli) and Gram(+) (Staphylococcus aureus) bacteria. Polyurethane modified surfaces (2 wt %) were tested against aerosol challenges of the same bacteria strains. The 2 wt % PSM with soft block containing trifluoroethoxy (A, 89 mol %) and C12 alkylammonium (B, 11mol %) side chains gave the highest biocidal effectiveness against all bacteria strains in 30 min (100% kill, 3.6-4.4 log reduction).
32

Estudo da tenacificação do PLA pela adição de elastômero termoplástico EMA-GMA. / Study of the toughening of PLA by adding thermoplastic elastomer EMA-GMA.

Silveira, Éder Baroni da 06 August 2015 (has links)
Neste trabalho foi estudado o processo de tenacificação do poli(ácido lático), PLA, através da produção de blenda com terpolímero randômico (etileno/éster acrílico/glicidil metacrilato), EMA-GMA, como modificador de impacto. Três composições foram estudadas, 90/10, 80/20 e 70/30% em massa, as misturas foram homogeneizadas em extrusora dupla-rosca (melt blending) e corpos de prova foram moldados por injeção. A avaliação do comportamento mecânico e da eficiência da tenacificação foi realizada através de ensaios mecânicos de tração (ATSM D638), resistência ao impacto Izod com entalhe (ASTM D256), flexão (ASTM D790) e dureza Shore D (ASTM 2240). A presença de umidade e a temperatura de degradação foram avaliadas por análise termogravimétrica (TGA), as temperaturas de transição vítrea (Tg), fusão cristalina (Tm) e grau de cristalinidade foram avaliadas por calorimetria exploratória diferencial (DSC) e a morfologia foi analisada por meio de micrografias obtidas por microscopia eletrônica de varredura (MEV). Os resultados dos ensaios mecânicos idicaram que todas as blendas possuem valores de tenacidade superiores ao do PLA. Entretanto, as blendas apresentaram como efeito colateral queda em módulo (obtidos por ensaios de resistência a tração e flexão), resistência a tração no ponto de escoamento e dureza, em função do aumento da concentração de EMA-GMA no PLA. Na composição com 20% de EMA-GMA a distribuição da dispersa ao longo da fase matriz está mais homogênea, e a composição com 30% de EMA-GMA resultou em um material super tenaz (com valores de resistência ao impacto Izod com entalhe acima de 500J/m). / In this work poly(lactic acid), PLA, was toughened by addition a thermoplastic elastomer, the random terpolymer (ethylene / acrylic ester / glycidyl methacrylate), EMA-GMA. Three= compositions were prepared: with concentrations of 10, 20 and 30 wt% of EMA-GMA into PLA. The blends were prepared in a twin-screw extruder and molded by injection molding. The samples were systematically characterized by tensile strength, notched Izod impact strength, flexural properties and Shore hardness (using Shore D scale). The presence of moisture and the degradation temperature of PLA were evaluated by thermogravimetric analysis (TGA), the glass transition temperature (Tg), crystalline melting (Tm) and crystallinity index of PLA and of the blend were evaluated by differential scanning calorimetry (DSC) and the blend morphology was analyzed by scanning electron microscopy (SEM). The results showed that all blends presented a dramatic increase in their toughness, when compared to PLA. However, the moduli (obtained by tensile and flexural tests), tensile strength at yield, and hardness decreased when the dispersed phase content increased. In the 80/20 PLA/EMA-GMA blend, the dispersed phase is more homogeneously dispersed within the matrix, and the composition with 30 wt% of EMA-GMA resulted in a super tough material (notched Izod impact strength exceeding 500 J/m).
33

Um estudo sobre os objetos cognatos e os adjetivos adverbiais no português do Brasil / A study about the cognate objects and adverbial adjectives in the Brazilian Portuguese

Leung, Renata Takllan Frauches 19 September 2007 (has links)
Neste trabalho, analiso o fenômeno conhecido como \"uso adverbial do adjetivo\" (ou \"adjetivos adverbiais\"). Tal fenômeno, comum no Português do Brasil (PB), ocorre em sentenças como A Maria falou claro (cf. A Maria falou claramente) e levanta a questão sobre o estatuto categorial do modificador, na medida em que este apresenta forma de adjetivo, mas comportamento de advérbio. Alguns autores afirmam que se trata, de fato, de advérbios: os adjetivos sofrem um processo morfológico chamado de derivação imprópria ou conversão, que consiste na \"transposição de uma palavra de uma classe gramatical para outra\" (Basílio, 2000: 60). Outros autores, como Carnie (2000) e Negrão, Scher e Viotti (2003), sugerem que adjetivos e advérbios constituem uma única categoria gramatical. Um dos argumentos usados pelos autores é o fato de adjetivos e advérbios desempenharem o mesmo papel na sentença: atribuem propriedades aos itens que eles modificam. Essas e outras propostas existentes na literatura têm bons argumentos a seu favor. Contudo, ao olharmos para os dados, todas essas propostas se tornam insatisfatórias, na medida em que nenhuma delas dá conta de explicar os seguintes fatos da língua: em alguns contextos, as formas adverbial e adjetival são possíveis (A Maria falou claro/claramente); em outros contextos, apenas a forma adjetival é possível (A Maria namora firme/*firmemente), e ainda em outros, apenas a forma adverbial (Os soldados resistiram heroicamente/*heróico). A partir de um modelo gerativista do estudo da linguagem, é pertinente investigar não apenas o estatuto categorial dos itens lexicais em questão, mas também o que há na estrutura subjacente dessas sentenças que determina o contexto em que esses itens podem ou não ser utilizados. Seguindo a proposta de Lobato (2005), proponho que os chamados adjetivos adverbiais são, de fato, adjetivos, na medida em que eles modificam um nome implícito na sentença nomeadamente, o objeto cognato relacionado ao verbo, ou um indivíduo denotado pela raiz do verbo, nos termos de Levinson (2006). De fato, os contextos de produtividade das construções com objetos cognatos eventivos (Leung, 2006) são os mesmos contextos de produtividade dos adjetivos adverbiais. Além disso, apesar das aparências, o comportamento dos itens lexicais em questão não é tão adverbial quanto parece: ao contrário dos advérbios, eles não flutuam na sentença, mas têm que ser, obrigatoriamente, adjacentes ao verbo. Outro fator é que, via de regra, eles não podem co-ocorrer com um objeto temático, o que deveria ser possível se esses itens fossem, de fato, adverbiais. / In this work, I analyze the phenomenon known as \"the adverbial use of adjective\" (or \"adverbial adjectives\"). Such phenomenon, common in Brazilian Portuguese (PB), occurs in sentences such as A Maria falou claro (cf. A Maria falou claramente) and raises a question about the categorial status of the modifier, since it presents adjective form, but behaves like an adverb. Some authors say that, in fact, they are adverbs: the adjectives undergo a morphological process called improper derivation or conversion, which consists of the \"shift of a word from a grammatical class to another\" (Basílio, 2006:60). Some other authors, such as Carnie (2000) and Negrão, Scher e Viotti (2003), suggest that adjectives and adverbs belong to an unique grammar category. One of the arguments used by the authors is the fact that adjectives and adverbs carry out the same role in sentence: they attribute properties to the items modified by them. These and other existing suggestions in literature have good arguments on their side. However, when we look at some language data, all these suggestions become unsatisfactory, since none of them can explain the following facts: in some contexts, both the adverbial and adjectival forms is possible (A Maria falou claro/claramente); in other contexts, only the adjectival form is possible (A Maria namora firme/*firmemente), and still in others contexts, only the adverbial form can appear in the sentence (Os soldados resistiram heroicamente/*heróico). Based on a generative model for grammar studies, it is necessary to investigate not only the categorial status of the lexical items in question, but also what there is in the subjacent structure of these sentences, that determines the context in which they can or cannot be used. In this work, I suggest that the adverbial adjectives are, in fact, adjectives, since they can modify either an implicit noun in the sentence, namely, the cognate object related to the verb, or, in Levinson (2006)\'s terms, an individual denoted by the same root as the verb\'s. In fact, the productivity contexts of these constructions with eventive cognate objects (Leung, 2006) are the same productivity contexts where one can find the adverbial adjectives. Besides, the behavior of the lexical items in question is not so adverbial as it looks: differenty from adverbs, they don\'t float in the sentence, but they are, obligatorily, adjacent to the verb. Another important factor is that, generally, they can\'t occur with a thematic object, what should be possible if these items were, in fact, adverbs.
34

Restrição de domínio, distributividade e a expressão kar em um dialeto de língua Kaingang / Domain restriction, distributivity and the expression kar in a dialect of the Kaingang language

Navarro, Michel Platiny Assis 25 May 2012 (has links)
Esta dissertação apresenta uma análise semântica, no paradigma da Semântica Formal, da (i) restrição de domínio no DP e da (ii) expressão kar, que veicula a ideia de totalidade, no dialeto paranaense da língua Kaingang, do tronco Macro-Jê, família Jê, falada nas regiões sul e sudeste do Brasil. Num primeiro momento, o artigo definido parece ter, no Kaingang Paranaense, uma distribuição não trivial: aplica-se primeiro a um determinante quantificacional e restringe, via essa combinação, o domínio do quantificador, tal como no Basco, Grego e Státimcets (Giannakidou 2003, Etxeberria 2005 e Etxeberria & Giannakidou 2009), línguas muito parecidas com o Kaingang no domínio nominal. Alguns dados, contudo, apontaram a análise em outra direção. Entendemos que certos padrões de comportamento semântico e sintático apresentado por kar nas sentenças, tal como sua neutralidade quanto à propriedade de distributividade e a possibilidade da conjunção de duas sequências de [NP+kar] sob um mesmo artigo definido (ao contrário do Basco, no qual a mesma estrutura é agramatical, sugerindo que os quantificadores universais em Basco criam um QP), são algumas das evidências que, no conjunto, dão suporte para a hipótese, defendida nesta dissertação, de que kar, no Kaingang Paranaense, parece ser um modificador - à la Lasersohn (1999) -, não tendo, por isso, uma força quantificacional própria. A função semântica de kar seria de controlar o quanto de desvio da verdade é pragmaticamente permissível. Como consequência desta análise, no Kaingang Paranaense o artigo definido não operaria sobre um determinante quantificacional, mas sim sobre um NP. O que aponta no sentido de que os artigos definidos ag/fag (os/as) no Kaingang Paranaense, em contextos em que eles co-ocorrem com kar, não perderiam a sua função max, i.e., de formadores de indivíduo a partir de um conjunto, para funcionar meramente como um operador preservador de tipo e restritor de domínio adjungido ao determinante quantificacional, como proposto por Giannakidou 2003, Etxeberria (2005) e Etxeberria & Giannakidou (2009) para o Basco e o Grego. Ag/fag continuariam sendo artigos definidos clássicos ocupando o núcleo de uma projeção DP e kar um modificador. Também discutimos brevemente algumas das vantagens e problemas de se tentar estender esta análise para o Basco, Grego e Státimcets. E, por último, investigamos o comportamento de kar na sentença, as possíveis leituras quando da sua interação com indefinidos, numerais, tipos de predicados e o operador distributivo introduzido via reduplicação verbal. Com base nos dados, nossa proposta é de que - em função de a leitura distributiva, na maioria dos exemplos, ser permitida pelos informantes somente quando houve reduplicação verbal - kar é neutro quanto à propriedade da distributividade e que o operador distributivo introduzido por reduplicação verbal tem escopo sobre todo o VP. / This dissertation presents, in the paradigm of formal semantics, a semantic analysis of both (i) the phenomenon of domain restriction in the DP and (ii) the expression kar, which conveys the idea of totality, in a dialect of the Kaingang language, a Brazilian language from the Macro-Jê Stock, Jê family, spoken in southern and southeastern Brazil. Although, at first, the definite article in Kaingang seems to have a non-trivial distribution: it applies first to a quantificational expression, and via such combination restricts the domain of quantifier, such as in Basque, Greek and Státimcets (Giannakidou 2003, Etxeberria 2005 and Etxeberria & Giannakidou 2009), some data pointed the analysis in another direction. Patterns of semantic and syntactic bevavior presented by kar in some sentences, such as its neutralite regarding the property of distributivity and the possibility of conjoining two [NP + kar] sequences under the same definite article (unlike Basque, which does not allow such structure, suggesting that in Basque the universal quantifier creats a QP), seem to be as a whole evidences for the hypothesis, advocated in this thesis, that the expression kar may be a modifier - à la Lasersohn (1999) - and as such would not have a quantificational force of its own. The semantic function of kar would be to control how much deviation from the truth conditions of the sentences is pragmatically allowed. As a result of this analysis, the definite articles ag/fag in Kaingang do not operate on a quantificational expression, as in Basque and Greek, but on the NP. Such fact suggests that the definite articles in Kaingang, in contexts they co-occur with kar, do not lose their max function in order to work merely as a type preserver and a domain restrictor combined with a quantificational expression, as proposed by Giannakidou 2003, Etxeberria (2005) e Etxeberria & Giannakidou (2009) for Basque and Greek. Ag/fag would still be a classical definite article occupying the head of a DP projection and kar a modifier, instead of a universal quantifier. We also discuss briefly some of the advantages and problems of trying to extend this analysis to the Basque, Greek and Státimcets languages. And lastly, we investigated the behavior of kar in the sentence, its interaction with indefinites, numerals, types of predicates and the distributive operator introduced via verbal reduplication. Based on such data, once distributive readings were permitted by the informants only via verbal reduplication, our proposal is that kar is neutral regarding the property of distributivity and that the distributive operator introduced via verbal reduplication has scope over the VP.
35

Efeito do tipo de óleo básico no desempenho tribológico de dialquilditiocarbamato de molibdênio como aditivo para lubrificantes automotivos. / Effect of the base oil on the tribological behaviour of molybdenum dialkyldithiocarbamate as automotive lubricants additive.

Trindade, Eduardo Dominguez 14 March 2014 (has links)
A otimização da formulação do óleo lubrificante empregado em motores de combustão interna é uma importante maneira de se reduzir o atrito e assim aumentar a eficiência energética. É também uma forma de assegurar proteção ao sistema, mantendo a taxa de desgaste em um nível adequado. O óleo de motor é uma mistura de óleos básicos selecionados com aditivos, entre os quais podem ser encontrados os modificadores de atrito, que são compostos com capacidade de aderir às superfícies metálicas, proporcionando melhoria da lubrificação em condições mista e limítrofe. O dialquilditiocarbamato de molibdênio (MoDTC) está entre os mais importantes redutores de atrito empregados em óleos lubrificantes. Ésteres sintéticos podem ser usados como óleos básicos em algumas formulações. Visto que ésteres são mais polares que hidrocarbonetos, essas moléculas podem atuar modificando propriedades do óleo na região próxima à superfície metálica. Podem também interferir com filmes adsorvidos, limitando sua efetividade. O objetivo do trabalho é a comparação dos efeitos do MoDTC em diferentes misturas contendo hidrocarboneto e éster. Para isso, formulações lubrificantes contendo uma polialfaolefina, um diéster e um aditivo à base de MoDTC foram preparadas, caracterizadas e ensaiadas em tribômetro oscilatório SRV usando configuração esfera-­disco. Foram empregadas esferas de aço AISI 52100 e discos de aço AISI H13. Foi estudada a influência da variação da temperatura e da força normal aplicada. Empregando-­se mistura de hidrocarboneto e éster como lubrificante, o aumento da temperatura causou leve aumento do coeficiente de atrito. Em ausência de MoDTC, a presença de éster aumentou a capacidade de suportação de carga das formulações. Os testes com óleos contendo MoDTC foram marcados pela ocorrência de dois fenômenos: ativação e depleção do aditivo. Estes fenômenos se mostraram dependentes da carga normal e da composição do óleo. O efeito de redução do atrito pelo MoDTC tende a ser menos duradouro com óleos mais ricos em éster e em condições de carregamento mais severo. O comportamento tribológico do éster em mistura com polialfaolefina, medido através do coeficiente de atrito, seguiu a isoterma de adsorção de Frumkin, com alguma atração entre as moléculas do éster, e energia livre da ordem de -­4 kJ/mol, típica de fisissorção. Óleos envelhecidos artificialmente foram testados e não apresentaram diferenças significativas com relação aos mesmos óleos novos. A adição de etanol aos óleos envelhecidos causou uma leve diminuição no coeficiente de atrito a 40 °C; tal efeito não foi perceptível em temperaturas mais altas, provavelmente devido à perda por evaporação do álcool. / The optimization of the lubricant oil formulation used in internal combustion engines is an important way of reducing friction, thus increasing energetic efficiency. It is also a way of protecting the system, maintaining wear rate in an adequate level. The engine oil is a blend of selected base oils with additives, amongst which are the friction modifiers substances able to adhere to the metal surfaces, thus providing better lubrication at the mixed and boundary regimes. Molybdenum dialkyldithiocarbamate (MoDTC) is amongst the most important friction reducers used in lubricant oils. Synthetic esters may be employed as base oils in some formulations as well. Given that esters are more polar than hydrocarbons, these molecules can actuate by modifying oil properties in the near-­surface region. They can also interfere with adsorbed films, preventing their effectiveness. The objective of this work is the comparison of the effects of MoDTC in different mixtures containing hydrocarbon and ester. With this aim, lubricating formulations containing a polyalphaolefin, a diester and a MoDTC-­based additive were prepared, characterized and tested in a reciprocating SRV tribometer using ball-­on-­disc configuration. AISI 52100 steel balls and AISI H13 steel discs were employed. The influences of the temperature and of the normal load were both studied. Employing a mixture of hydrocarbon and ester as lubricant, a higher temperature caused a slightly higher coefficient of friction in the lubricant free of additive. In the absence of MoDTC, the ester increased the load-­carrying capacity of the lubricant formulations. Tests with MoDTC-­containing oils were characterized by two phenomena: activation and depletion of the additive. These phenomena showed to be dependent on the normal load and on the oil composition. The MoDTC friction reducing effect tends to be less sustainable with higher ester concentrations and at higher loads. The tribological behavior of the ester in the presence of polyalphaolefin, as measured by the coefficient of friction, followed the Frumkin adsorption isotherm, with some attraction between ester molecules, and free energy in the order of -­4 kJ/mol, typical of physisorption. Artificially aged oils were tested and did not show differences when compared with the results of the fresh oils. Adding ethanol to the aged oils caused a slightly reduction in the coefficient of friction at 40 °C, but this effect was not observed at higher temperatures, probably due to evaporation loss of the alcohol.
36

Variabilidade fenotípica de um modelo murino para a Síndrome de Marfan - Triagem de genes modificadores do fenótipo / Phenotypic variability in a mouse model for Marfan Syndrome - Identification of phenotype modifier genes

Fernandes, Gustavo Ribeiro 06 February 2013 (has links)
A Síndrome de Marfan (SMF) (OMIM# 154700) é a mais comum das doenças genéticas do tecido conjuntivo Herdada de forma autossômica dominante, ela apresenta incidência de 1 em cada 5.000 indivíduos. Apesar de apresentar grande variabilidade clínica inter e intrafamiliar, o fenótipo da SMF possui penetrância completa, e suas manifestações clínicas afetam primariamente os sistemas esquelético, ocular e cardiovascular. Afim de estudar os mecanismos patogênicos da SMF foi desenvolvido um modelo murino, mgΔneoLoxP, que reproduz as manifestações ósseas, cardiovasculares e pulmonares da síndrome. O modelo foi estabelecido nas linhagens isogênicas 129/Sv e C57BL/6, que apresentam diferenças tanto quanto a idade de acometimento quanto a gravidade das alterações, é possível que as diferenças alélicas existentes entre essas linhagens alterem a manifestação fenotípica, ou seja, que existam genes modificadores para a SMF. Assim, objetivo deste projeto é utilizar este modelo experimental para identificar genes modificadores do fenótipo da SMF e tentar entender melhor a arquitetura genética da síndrome. Ao todo foram gerados 82 animais 129xB6 F2 heterozigotos para o alelo mgΔneoLoxP, a analise de ligação utilizando microssatélites e SNPs nos animais com fenótipos mais extremos mostraram ligação sugestiva do fenótipo ósseo com as regiões compreendidas entre as posições 56 cM e 68 cM do cromossomo 3; e 2 cM e 20 cM do cromossomo X; ligação significativa entre as posições 41cM e 49 cM do cromossomo 6; além de mostrar ligação sugestiva do fenótipo cardiovascular do 66 cM ao 70 cM do cromossomo 4; e do 44 cM ao 52 cM do cromossomo 13. Além da variabilidade entre linhagens, os animais 129 apresentam uma grande variabilidade fenotípica interna, o que por se tratar de animais isogênicos causada por fatores aleatórios ou devido a modificações epigenéticas que alterem o nível de expressão de alguns genes e assim o fenótipo. A comparação entre animais 129 leves e graves levou a identificação de 25 genes diferencialmente expressos dos quais 11 apresentavam funções relevantes para a SMF, entretanto foram aferidos os níveis de expressão de 2 destes que não validaram os resultados obtidos devido a uma grande variação observada entre os animais de todos as classes fenotípicas. Também foram identificadas 46 vias que se apresentavam mais frequentes nos conjuntos de genes obtidos entre as duas classes fenotípica de animais heterozigotos contra os animais selvagens. Tanto as vias, quanto os genes identificados através de ligação quanto diferença de expressão mostram uma convergência para as funções dos genes de interesse, sendo que entre eles existem genes já associados com a SMF, controle de ativação de TGF-B e da biogênese das microfibras da matriz extracelular, quanto genes que ainda não foram associados mas são possíveis modificadores do fenótipo, tais como genes envolvidos nos processos de enovelamento e degradação protéico e nos processos de endocitose e exocitose de vesículas, que podem alterar a quantidade de fibrilina-1 truncada disponível e assim o fenótipo / The Marfan syndrome (MFS) (OMIM # 154700) is the most common genetic disorder of the connective tissue and is inherited in a autosomal dominant fashion, it has an incidence of 1 in 5,000 individuals. Despite a great clinical variability being one of the \"trademarks\" of the syndrome, the phenotype of the MFS has complete penetrance and its clinical manifestations primarily affect the skeletal, ocular and cardiovascular systems. In order to study the pathogenic mechanisms of MFS was developed a mouse model, named mgΔneoLoxP, which reproduces the skeletal, cardiovascular and pulmonary manifestations of the syndrome. The model was established in inbred mouse strains 129/Sv and C57BL / 6, which phenotypes differ as to age of onset and severity of manifestation. It is possible that allelic differences between these inbred strains alter the phenotyic manifestation of disease, leading to the conclusion that may exist modifier genes involved in the for MFS. This study inteds to use this experimental model to identify phenotype modifier genes of MFS so a better understand the genetic architecture of the syndrome. Altogether, 82 129xB6 F2 heterozygous animals were generated so that a linkage analysis using microsatellite and SNP could be conducted. The linkage analysis using a selective genotyping procedure showed a suggestive linkage of the skeletal phenotype with regions included between positions 56 cM and 68 cM on chromosome 3, and 2 cM and 20 cM on chromosome X; and a significant linkage between positions 41cM and 49 cM on chromosome 6; also showing suggestive linkage of the cardiovascular phenotype from 66 cM to 70 cM on chromosome 4, and 44 cM to 52 cM on chromosome 13. Besides the variability between strains, 129 animals have a wide inner strain phenotypic variability, which in the case of isogenic animals should be caused by random factors or due to epigenetic modifications that may alter the expression level some genes and thus the phenotype. The comparison between animals of the 129 strain with mild and severe alterations led to the identification of 25 differentially expressed genes of which 11 showed relevant functions to the MFS, however it was only possible to measure the expression levels of two genes using real-time PCR, although those did not validate the results obtained from the expression microarray due to a large expression variation in all phenotypic classes. It was also identified 46 pathways that were more frequent in the gene lists obtained from the comparison between the two phenotypic classes of heterozygous animals against 129 wildtype animals. There is a similarity in the function of genes or pathways of interest found in pathways analysis and genes identified, either by differential expression or linkage analisys, and among them there genes already associated with the MFS, such as in the control activity of TGF-B and biogenesis of microfibers in the extracellular matrix, as also genes that were not associated with MFS but are possible phenotype modifier genes, such as genes involved in protein folding and degradation processes and of endocytosis and exocytosis processes of vesicle, which can change the amount of truncated fibrillin-1 available and thus the phenotype
37

Molecular characterization and functional analysis of posttranslational modification at lysine 343 of type 2 angiotensin receptor.

January 2007 (has links)
Teng, Man Kuen. / Thesis submitted in: November 2006. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 160-169). / Abstracts in English and Chinese. / Thesis Committee --- p.i / Declaration --- p.ii / Acknowledgments --- p.iii / Abstract --- p.iv / 摘要 --- p.vi / List of Abbreviation --- p.viii / Table of Contents --- p.x / List of Figures --- p.xiv / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Biochemistry of the Renin-Angiotensin System --- p.2 / Chapter 1.2 --- Physiological Roles of Angiotensin II --- p.7 / Chapter 1.3 --- Physiological Roles of Angiotensin Receptors --- p.9 / Chapter 1.4 --- Characterization of Type 2 Angiotensin Receptor --- p.12 / Chapter 1.5 --- Trafficking of Type 2 Angiotensin Receptor --- p.16 / Chapter 1.6 --- SUMO and protein SUMOylation --- p.19 / Chapter 1.7 --- Aims of Study --- p.21 / Chapter Chapter 2 --- Preparation of EGFP-and FLAG tagged wild-type AT2 and K343R-AT2 mutant constructs / Chapter 2.1 --- Introduction --- p.26 / Chapter 2.2 --- Materials --- p.27 / Chapter 2.2.1 --- Chemicals --- p.27 / Chapter 2.2.2 --- Enzymes --- p.27 / Chapter 2.2.3 --- DNA Purification Kit --- p.27 / Chapter 2.3 --- Methods --- p.28 / Chapter 2.3.1 --- Preparation of pEGFP/AT2 Construct --- p.28 / Chapter 2.3.1.1 --- PCR amplification --- p.30 / Chapter 2.3.1.2 --- Agarose gel electrophoresis --- p.30 / Chapter 2.3.1.3 --- Restriction enzyme digestion --- p.31 / Chapter 2.3.1.4 --- Purification of DNA fragment by ethanol precipitation --- p.31 / Chapter 2.3.1.5 --- Ligation --- p.32 / Chapter 2.3.1.6 --- Preparation of competent cells --- p.33 / Chapter 2.3.1.7 --- Bacterial transformation --- p.33 / Chapter 2.3.1.8 --- Minipreparation of plasmid DNA --- p.34 / Chapter 2.3.1.9 --- Quantitation of DNA --- p.35 / Chapter 2.3.1.10 --- DNA sequencing --- p.36 / Chapter 2.3.2 --- Preparation of pEGFP/AT2-01igo Construct --- p.36 / Chapter 2.3.2.1 --- PCR amplification of AT2-oligo --- p.39 / Chapter 2.3.2.2 --- PCR amplification of oligo-GFP --- p.39 / Chapter 2.3.2.3 --- Overlapping PCR amplification --- p.40 / Chapter 2.3.2.4 --- Gel extraction of DNA fragment --- p.41 / Chapter 2.3.2.5 --- Restriction enzyme digestion --- p.41 / Chapter 2.3.2.6 --- Ligation and transformation --- p.42 / Chapter 2.3.2.7 --- Construction of pEGFP/oligo --- p.42 / Chapter 2.3.3 --- Preparation of pCMV/AT2 Construct --- p.43 / Chapter 2.3.3.1 --- PCR amplification --- p.45 / Chapter 2.3.3.2 --- Restriction enzyme digestion --- p.45 / Chapter 2.3.3.3 --- Ligation and transformation --- p.45 / Chapter 2.3.4 --- Preparation of mutants --- p.46 / Chapter 2.3.4.1 --- Site directed mutagenesis at SUMOylation site --- p.46 / Chapter 2.3.4.2 --- Transformation of mutants --- p.47 / Chapter 2.4 --- Results --- p.48 / Chapter 2.4.1 --- Preparation of pEGFP/AT2 Construct --- p.48 / Chapter 2.4.2 --- Preparation of pEGFP/AT2-oligo Construct --- p.50 / Chapter 2.4.3 --- Preparation of pCMV/AT2 Construct --- p.53 / Chapter 2.4.4 --- Preparation of Mutants --- p.55 / Chapter 2.5 --- Discussion --- p.57 / Chapter Chapter 3 --- Transient Expression of AT2 and K343R mutants in CHO-K1 and HEK-293 cells / Chapter 3.1 --- Introduction --- p.61 / Chapter 3.2 --- Materials --- p.64 / Chapter 3.2.1 --- Chemicals --- p.64 / Chapter 3.2.2 --- Antibodies --- p.64 / Chapter 3.2.3 --- Protein Concentration Measurement Kit --- p.65 / Chapter 3.3 --- Methods --- p.66 / Chapter 3.3.1 --- Expression of AT2 in Mammalian Cells --- p.66 / Chapter 3.3.1.1 --- Cell culture --- p.66 / Chapter 3.3.1.2 --- Counting cells --- p.67 / Chapter 3.3.1.3 --- Transient transfection --- p.67 / Chapter 3.3.2 --- Western Blot Analysis --- p.68 / Chapter 3.3.2.1 --- Preparation of protein sample from total lysate --- p.68 / Chapter 3.3.2.2 --- Protein sample derived from immunoprecipitation --- p.69 / Chapter 3.3.2.3 --- SDS PAGE and Western blot analysis --- p.70 / Chapter 3.3.3 --- Confocal microscopy --- p.71 / Chapter 3.4 --- Results --- p.73 / Chapter 3.4.1 --- Expression Analysis of GFP-tagged AT2 --- p.73 / Chapter 3.4.1.1 --- Western blot analysis with anti-GFP antibody --- p.73 / Chapter 3.4.1.2 --- Western blot analysis with anti-AT2 antibody --- p.79 / Chapter 3.4.1.3 --- Confocal microscopy --- p.81 / Chapter 3.4.2 --- Western Blot Analysis of FLAG-tagged AT2 --- p.90 / Chapter 3.5 --- Discussion --- p.92 / Chapter Chapter 4 --- Stable Expression of AT2 and K343R mutants in CHO-K1 cells / Chapter 4.1 --- Introduction --- p.97 / Chapter 4.2 --- Materials --- p.99 / Chapter 4.2.1 --- Chemicals --- p.99 / Chapter 4.2.2 --- Enzymes --- p.99 / Chapter 4.2.3 --- Antibodies --- p.99 / Chapter 4.2.4 --- Protein Concentration Measurement Kit --- p.100 / Chapter 4.3 --- Methods --- p.101 / Chapter 4.3.1 --- Linearization of Vector --- p.101 / Chapter 4.3.2 --- Transfection by Lipofectamine 2000 --- p.101 / Chapter 4.3.3 --- Screening for the Stably Transfected Cells --- p.101 / Chapter 4.3.4 --- Western Blot Analysis --- p.103 / Chapter 4.3.5 --- Confocal Microscopy --- p.103 / Chapter 4.4 --- Results --- p.104 / Chapter 4.4.1 --- Stable expression of wild type and mutant AT2-GFP in CHO-K1 --- p.104 / Chapter 4.4.2 --- Stable expression of wild type and mutant AT2-Gly10Ser5-GFP in CHO-K1 --- p.115 / Chapter 4.4.3 --- Stable expression of wild type and mutant AT2-FL AG in CHO-K1 --- p.123 / Chapter 4.5 --- Discussion --- p.125 / Chapter Chapter 5 --- Co-immunoprecipitation Analysis of CHO-K1 stably expressing wild type and mutant AT2-Gly10Ser5-GFP / Chapter 5.1 --- Introduction --- p.129 / Chapter 5.2 --- Materials --- p.129 / Chapter 5.2.1 --- Chemicals --- p.130 / Chapter 5.2.2 --- Antibodies --- p.130 / Chapter 5.2.3 --- Protein Concentration Measurement Kit --- p.130 / Chapter 5.3 --- Methods --- p.131 / Chapter 5.3.1 --- Transfection by Lipofectaime 2000 --- p.131 / Chapter 5.3.2 --- Western Blot Analysis --- p.131 / Chapter 5.4 --- Results --- p.132 / Chapter 5.4.1 --- Western blot analysis of SUMO 1 transfected stable cell lines --- p.132 / Chapter 5.4.2 --- Western blot analysis of SUM03 transfected stable cell lines --- p.136 / Chapter 5.5 --- Discussion --- p.143 / Chapter Chapter 6 --- General Discussion / Chapter 6.1 --- Investigation of AT2 trafficking in mammalian cells --- p.147 / Chapter 6.2 --- Future Aspects --- p.153 / Appendix I Buffer composition --- p.155 / Appendix II Sequence of Primers --- p.156 / Appendix III Sequencing Results --- p.157 / References --- p.160
38

Study of Rheological Behaviour of Coating Paste containing conductive polymer complex

IQBAL, KASHIF January 2010 (has links)
Conducting polymer coating is the new developing area in the field of advanced textiles. In this project the rheological behaviour of paste containing conducting polymer was studied during formulation to coating application. The literature study is done by keeping all the contents of project in mind and a wide area of conductive polymer, coating methods, binder system and rheology modifier is covered. The rheological behaviour of different fluid containing newtanion and non-newtanion behaviour is discussed for better understanding of the project working. Polyester fabric was coated by knife coating method. In paste formulation, the chemicals used were polyurethane binder with two HEUR based rheology modifiers. A lot of experiments were performed to determine the right amount of rheology modifier alone or in combination for paste formulation and coating application and interesting findings were observed during the experimental work which had been justified in results and analysis. After application, the coated fabric was checked for resistivity. / Program: Magisterutbildning i textilteknologi
39

Restrição de domínio, distributividade e a expressão kar em um dialeto de língua Kaingang / Domain restriction, distributivity and the expression kar in a dialect of the Kaingang language

Michel Platiny Assis Navarro 25 May 2012 (has links)
Esta dissertação apresenta uma análise semântica, no paradigma da Semântica Formal, da (i) restrição de domínio no DP e da (ii) expressão kar, que veicula a ideia de totalidade, no dialeto paranaense da língua Kaingang, do tronco Macro-Jê, família Jê, falada nas regiões sul e sudeste do Brasil. Num primeiro momento, o artigo definido parece ter, no Kaingang Paranaense, uma distribuição não trivial: aplica-se primeiro a um determinante quantificacional e restringe, via essa combinação, o domínio do quantificador, tal como no Basco, Grego e Státimcets (Giannakidou 2003, Etxeberria 2005 e Etxeberria & Giannakidou 2009), línguas muito parecidas com o Kaingang no domínio nominal. Alguns dados, contudo, apontaram a análise em outra direção. Entendemos que certos padrões de comportamento semântico e sintático apresentado por kar nas sentenças, tal como sua neutralidade quanto à propriedade de distributividade e a possibilidade da conjunção de duas sequências de [NP+kar] sob um mesmo artigo definido (ao contrário do Basco, no qual a mesma estrutura é agramatical, sugerindo que os quantificadores universais em Basco criam um QP), são algumas das evidências que, no conjunto, dão suporte para a hipótese, defendida nesta dissertação, de que kar, no Kaingang Paranaense, parece ser um modificador - à la Lasersohn (1999) -, não tendo, por isso, uma força quantificacional própria. A função semântica de kar seria de controlar o quanto de desvio da verdade é pragmaticamente permissível. Como consequência desta análise, no Kaingang Paranaense o artigo definido não operaria sobre um determinante quantificacional, mas sim sobre um NP. O que aponta no sentido de que os artigos definidos ag/fag (os/as) no Kaingang Paranaense, em contextos em que eles co-ocorrem com kar, não perderiam a sua função max, i.e., de formadores de indivíduo a partir de um conjunto, para funcionar meramente como um operador preservador de tipo e restritor de domínio adjungido ao determinante quantificacional, como proposto por Giannakidou 2003, Etxeberria (2005) e Etxeberria & Giannakidou (2009) para o Basco e o Grego. Ag/fag continuariam sendo artigos definidos clássicos ocupando o núcleo de uma projeção DP e kar um modificador. Também discutimos brevemente algumas das vantagens e problemas de se tentar estender esta análise para o Basco, Grego e Státimcets. E, por último, investigamos o comportamento de kar na sentença, as possíveis leituras quando da sua interação com indefinidos, numerais, tipos de predicados e o operador distributivo introduzido via reduplicação verbal. Com base nos dados, nossa proposta é de que - em função de a leitura distributiva, na maioria dos exemplos, ser permitida pelos informantes somente quando houve reduplicação verbal - kar é neutro quanto à propriedade da distributividade e que o operador distributivo introduzido por reduplicação verbal tem escopo sobre todo o VP. / This dissertation presents, in the paradigm of formal semantics, a semantic analysis of both (i) the phenomenon of domain restriction in the DP and (ii) the expression kar, which conveys the idea of totality, in a dialect of the Kaingang language, a Brazilian language from the Macro-Jê Stock, Jê family, spoken in southern and southeastern Brazil. Although, at first, the definite article in Kaingang seems to have a non-trivial distribution: it applies first to a quantificational expression, and via such combination restricts the domain of quantifier, such as in Basque, Greek and Státimcets (Giannakidou 2003, Etxeberria 2005 and Etxeberria & Giannakidou 2009), some data pointed the analysis in another direction. Patterns of semantic and syntactic bevavior presented by kar in some sentences, such as its neutralite regarding the property of distributivity and the possibility of conjoining two [NP + kar] sequences under the same definite article (unlike Basque, which does not allow such structure, suggesting that in Basque the universal quantifier creats a QP), seem to be as a whole evidences for the hypothesis, advocated in this thesis, that the expression kar may be a modifier - à la Lasersohn (1999) - and as such would not have a quantificational force of its own. The semantic function of kar would be to control how much deviation from the truth conditions of the sentences is pragmatically allowed. As a result of this analysis, the definite articles ag/fag in Kaingang do not operate on a quantificational expression, as in Basque and Greek, but on the NP. Such fact suggests that the definite articles in Kaingang, in contexts they co-occur with kar, do not lose their max function in order to work merely as a type preserver and a domain restrictor combined with a quantificational expression, as proposed by Giannakidou 2003, Etxeberria (2005) e Etxeberria & Giannakidou (2009) for Basque and Greek. Ag/fag would still be a classical definite article occupying the head of a DP projection and kar a modifier, instead of a universal quantifier. We also discuss briefly some of the advantages and problems of trying to extend this analysis to the Basque, Greek and Státimcets languages. And lastly, we investigated the behavior of kar in the sentence, its interaction with indefinites, numerals, types of predicates and the distributive operator introduced via verbal reduplication. Based on such data, once distributive readings were permitted by the informants only via verbal reduplication, our proposal is that kar is neutral regarding the property of distributivity and that the distributive operator introduced via verbal reduplication has scope over the VP.
40

Um estudo sobre os objetos cognatos e os adjetivos adverbiais no português do Brasil / A study about the cognate objects and adverbial adjectives in the Brazilian Portuguese

Renata Takllan Frauches Leung 19 September 2007 (has links)
Neste trabalho, analiso o fenômeno conhecido como \"uso adverbial do adjetivo\" (ou \"adjetivos adverbiais\"). Tal fenômeno, comum no Português do Brasil (PB), ocorre em sentenças como A Maria falou claro (cf. A Maria falou claramente) e levanta a questão sobre o estatuto categorial do modificador, na medida em que este apresenta forma de adjetivo, mas comportamento de advérbio. Alguns autores afirmam que se trata, de fato, de advérbios: os adjetivos sofrem um processo morfológico chamado de derivação imprópria ou conversão, que consiste na \"transposição de uma palavra de uma classe gramatical para outra\" (Basílio, 2000: 60). Outros autores, como Carnie (2000) e Negrão, Scher e Viotti (2003), sugerem que adjetivos e advérbios constituem uma única categoria gramatical. Um dos argumentos usados pelos autores é o fato de adjetivos e advérbios desempenharem o mesmo papel na sentença: atribuem propriedades aos itens que eles modificam. Essas e outras propostas existentes na literatura têm bons argumentos a seu favor. Contudo, ao olharmos para os dados, todas essas propostas se tornam insatisfatórias, na medida em que nenhuma delas dá conta de explicar os seguintes fatos da língua: em alguns contextos, as formas adverbial e adjetival são possíveis (A Maria falou claro/claramente); em outros contextos, apenas a forma adjetival é possível (A Maria namora firme/*firmemente), e ainda em outros, apenas a forma adverbial (Os soldados resistiram heroicamente/*heróico). A partir de um modelo gerativista do estudo da linguagem, é pertinente investigar não apenas o estatuto categorial dos itens lexicais em questão, mas também o que há na estrutura subjacente dessas sentenças que determina o contexto em que esses itens podem ou não ser utilizados. Seguindo a proposta de Lobato (2005), proponho que os chamados adjetivos adverbiais são, de fato, adjetivos, na medida em que eles modificam um nome implícito na sentença nomeadamente, o objeto cognato relacionado ao verbo, ou um indivíduo denotado pela raiz do verbo, nos termos de Levinson (2006). De fato, os contextos de produtividade das construções com objetos cognatos eventivos (Leung, 2006) são os mesmos contextos de produtividade dos adjetivos adverbiais. Além disso, apesar das aparências, o comportamento dos itens lexicais em questão não é tão adverbial quanto parece: ao contrário dos advérbios, eles não flutuam na sentença, mas têm que ser, obrigatoriamente, adjacentes ao verbo. Outro fator é que, via de regra, eles não podem co-ocorrer com um objeto temático, o que deveria ser possível se esses itens fossem, de fato, adverbiais. / In this work, I analyze the phenomenon known as \"the adverbial use of adjective\" (or \"adverbial adjectives\"). Such phenomenon, common in Brazilian Portuguese (PB), occurs in sentences such as A Maria falou claro (cf. A Maria falou claramente) and raises a question about the categorial status of the modifier, since it presents adjective form, but behaves like an adverb. Some authors say that, in fact, they are adverbs: the adjectives undergo a morphological process called improper derivation or conversion, which consists of the \"shift of a word from a grammatical class to another\" (Basílio, 2006:60). Some other authors, such as Carnie (2000) and Negrão, Scher e Viotti (2003), suggest that adjectives and adverbs belong to an unique grammar category. One of the arguments used by the authors is the fact that adjectives and adverbs carry out the same role in sentence: they attribute properties to the items modified by them. These and other existing suggestions in literature have good arguments on their side. However, when we look at some language data, all these suggestions become unsatisfactory, since none of them can explain the following facts: in some contexts, both the adverbial and adjectival forms is possible (A Maria falou claro/claramente); in other contexts, only the adjectival form is possible (A Maria namora firme/*firmemente), and still in others contexts, only the adverbial form can appear in the sentence (Os soldados resistiram heroicamente/*heróico). Based on a generative model for grammar studies, it is necessary to investigate not only the categorial status of the lexical items in question, but also what there is in the subjacent structure of these sentences, that determines the context in which they can or cannot be used. In this work, I suggest that the adverbial adjectives are, in fact, adjectives, since they can modify either an implicit noun in the sentence, namely, the cognate object related to the verb, or, in Levinson (2006)\'s terms, an individual denoted by the same root as the verb\'s. In fact, the productivity contexts of these constructions with eventive cognate objects (Leung, 2006) are the same productivity contexts where one can find the adverbial adjectives. Besides, the behavior of the lexical items in question is not so adverbial as it looks: differenty from adverbs, they don\'t float in the sentence, but they are, obligatorily, adjacent to the verb. Another important factor is that, generally, they can\'t occur with a thematic object, what should be possible if these items were, in fact, adverbs.

Page generated in 0.0383 seconds