740 resultados para Variaçao sintática


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O provável fator de início de tradução 5A (eIF5A) é altamente conservado de arqueas a mamíferos e sofre uma modificação pós-traducional única e essencial chamada hipusinação. Este fator já foi relacionado ao transporte nucleocitoplasmático, à degradação de mRNA e à proliferação celular. Dados recentes restabelecem uma função para eIF5A na tradução e sugerem a sua atuação na etapa de elongação ao invés de início, como originalmente proposto. Uma vez que o envolvimento de eIF5A com a degradação de mRNA ainda não foi elucidado, tornou-se interessante estudar qual a natureza desta relação. O metabolismo de mRNA é um processo complexo que envolve as etapas da tradução, repressão da tradução e degradação de mRNA. Na primeira parte deste trabalho, foi avaliada a existência de interação genética sintética entre os mutantes tif51A-1 e tif51A-3 e mutantes de fatores envolvidos com a repressão da tradução e/ou degradação de mRNA. Foi revelada uma supressão parcial do fenótipo de termossensibilidade com nocautes dos genes SBP1, DHH1 e PAT1, que codificam fatores ativadores da remoção do capacete de metilguanosina e repressores da tradução. Por outro lado, uma interação sintético doente (“synthetic sick”) entre os mutantes tif51A-1 e xrn1Δ foi observada.Os dados obtidos reforçam o envolvimento de eIF5A com a elongação da tradução, mostram que o efeito de eIF5A na degradação de mRNA é secundário e sugerem uma função para eIF5A como ativador da tradução. Na segunda etapa são apresentados os resultados do rastreamento de supressores extragênicos do mutante tif51A-1 através de deleções genômicas induzidas por transposon. Foram rastreados aproximadamente 2,2x105 transformantes... (Resumo completo, clicar acesso eletrônico abaixo)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This paper, which examines restrictive and non-restrictive constructions in the Lusophone varieties, assumes that Portuguese has a set of relativization strategies that are recognized by typological linguistics as constructions that define related groups of languages. Thus, it is possible that these different strategies, when employed by the same linguistic system, not really constitute variants of the same syntactic variable but the speaker’s actual choices facing the necessity to perform different social and discursive functions.

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This work examines relative constructions in Portuguese varieties based on the principle that Portuguese has a set of relativization strategies that are recognized in typological linguistics as constructions that define related groups of languages. It is postulated that these different strategies, when employed by the same linguistic system, do not really constitute variants of the same syntactic variable, but they are the speaker’s actual choices facing the necessity to perform different social and discursive functions.

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In this paper we consider a broad conception of phraseology to propose a description and analysis of phraseological units of stemming diacritical Spanish / Portuguese bilingual dictionaries. The focus of the analysis seeks to show not only the organization of the macro-structure proposed by two different lexicographical works, but also to discuss the use of labels and equivalences presented. Phraseological units are understood here as diacritical phraseologisms containing unique lexias, lacking syntactic and semantic autonomy recognized by speaker only within fixed expressions.

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Pós-graduação em Engenharia Mecânica - FEG

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coumarin is a natural active compound that can be found in many plants. The coumarins have many properties such as bronchodilator, anti-inflammatory, antioxidant, anticoagulant, antibiotics, immunomodulatory, antimicrobial and antiviral, thus, they are widely used in medical applications. More recently the coumarin derivatives have attracted the interest of many research groups in the field of new materials, for example the possibility of their use as sensitizers in dye-sensitized solar cells (DSSC) and lasers. The MCRs are defined as a process in which three or more reactants are combined in the same reaction pot, resulting in products with good structural complexity a single step, in addition to economy of atoms and selectivity and is a very important feature in modern synthetic methodology. In this work we investigated the use of niobium pentachloride as catalyst of the multicomponent reactions between phenolic derivatives, various aromatic aldehydes and β-diester derivatives in the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives. The reactions were carried out at room temperature, under inert atmosphere (N2), using dichloromethane anhydrous (CH2 Cl2) as solvent, with a reaction time of most 120 hours. The products were isolated by column chromatography on silica gel and submitted to spectrometric and spectroscopic analysis. The results show that NbCl5 is an excellent agent for promoting the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives through multicomponent reactions, obtaining yields varying from 45 to 95%

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This paper examines the historical role that Tesnière’s theory on the centrality of the verb exerted on some theoretical branches that study the way utterances are built in language. The main goal of this paper is to evaluate the impact that such a proposal had in changing the view of the clause being purely logical (a proposition) or purely syntactic (abstractly equated) to a view that embodies semantics and pragmatics to the syntactic organization of the utterance. A close examination of research dedicated to the grammatical and lexicographic description of Portuguese helps to illustrate the here proposed assessment and contributes to support the claim of the influence of Tesnière on current linguistic analyses.

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Pós-graduação em Agronomia (Horticultura) - FCA