990 resultados para Sequência de Bases


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Helicobacter pylori coloniza o estômago humano e está associada a várias gastropatologias. Este trabalho teve como objectivo o estudo de dois membros da família das OMP de H. pylori, o gene jhp870, possível marcador da úlcera péptica, e o seu homólogo jhp649. A prevalência destes genes, a variabilidade no número de cópias, a sua localização genómica e o estudo dos polimorfismos, ao nível da sequência de bases e respectivas proteínas, foram avaliados numa amostra de estirpes clínicas de H. pylori, isoladas de doentes de diferentes regiões geográficas, apresentando diversas gastropatologias. No geral, ambos os genes apresentam uma elevada similaridade quer ao nível de nucleótidos quer de aminoácidos, observando-se, no entanto, uma região média muito polimórfica. Nesta, foram identificadas seis variantes alélicas (alelo AI a AVI), com diferentes prevalências nos dois genes. O alelo AI é exclusivo e predominante do gene jhp870, e o AII predominante do gene jhp649. A observação da constância destes alelos em todas as estirpes, independentemente da sua origem geográfica, patologia, tipo de população, sugere a sua antiguidade, e evidencia a sua conservação ao longo da evolução. Mais, ao existir esta conservação numa região polimórfica, implica que estes alelos podem ter influência na função da proteína.

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Disease-causing alterations within the F8 gene were identified in 177 hemophilia A families of Portuguese origin. The spectrum of non-inversion F8 mutations in 101 families included 67 different alterations, namely: 36 missense, 8 nonsense and 4 splice site mutations, as well as 19 insertions/deletions. Thirty-four of these mutations are novel. Molecular modeling allowed prediction of the conformational changes introduced by selected amino acid substitutions and their correlation with the patients' phenotypes. The relatively frequent, population-specific, missense mutations together with de novo alterations can lead to significant differences in the spectrum of F8 mutations among different populations.

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A series of novel 1-(substituted phenyl)-3-(2-oxo-1,3,4-oxadiazol-5-yl) β-carbolines (4a-e) and the corresponding Mannich bases 5-9(a-c) were synthesized and evaluated for their in vitro antitumor activity against seven human cancer cell lines. Compounds of 4a-e series showed a broad spectrum of antitumor activity, with GI50 values lower than 15μM for five cell lines. The derivative 4b, having the N,N-dimethylaminophenyl group at C-1, displayed the highest activity with GI50 in the range of 0.67-3.20μM. A high selectivity and potent activity were observed for some Mannich bases, particularly towards resistant ovarian (NCI-ADR/RES) cell lines (5a, 5b, 6a, 6c and 9b), and ovarian (OVCAR-03) cell lines (5b, 6a, 6c, 9a, 9b and 9c). In addition, the interaction of compound 4b with DNA was investigated by using UV and fluorescence spectroscopic analysis. These studies indicated that 4b interact with ctDNA by intercalation binding.

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This article intends to answer the question: what is the best way to evaluate the strength of acids and bases? The meaning of the word strength, the main acid-base theories (ionotropic and electron pair), the neutralization reactions and the thermodynamical formalism are considered. Some cases are presented and discussed. In conclusion, evaluating acid-base strength is dependent on the theory (formalism) as well as on the system and measuring techniques.

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The main objective of this work is to discuss the notion of metalanguage concerning the use of thesaurus (symbols systems, functions indicators, descriptors) utilized by indexers for article representation in computerized bibliographical databases. Our corpus comprises article abstracts and bibliographical database descriptors LILACS (Literatura Latino-Americana em Ciências da Saúde) and SOCIOFILE Sociological Abstracts. We aim at clarifying the effects of subjectivity in the functioning of indexing taking account the grounds for interpretation that allow different meanings.

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This study examined the influence of three polymerization cycles (1: heat cure - long cycle; 2: heat cure - short cycle; and 3: microwave activation) on the linear dimensions of three denture base resins, immediately after deflasking, and 30 days after storage in distilled water at 37± 2ºC. The acrylic resins used were: Clássico, Lucitone 550 and Acron MC. The first two resins were submitted to all three polymerization cycles, and the Acron MC resin was cured by microwave activation only. The samples had three marks, and dimensions of 65 mm in length, 10 mm in width and 3 mm in thickness. Twenty-one test specimens were fabricated for each combination of resin and cure cycle, and they were submitted to three linear dimensional evaluations for two positions (A and B). The changes were evaluated using a microscope. The results indicated that all acrylic resins, regardless of the cure cycle, showed increased linear dimension after 30 days of storage in water. The composition of the acrylic resin affected the results more than the cure cycles, and the conventional acrylic resin (Lucitone 550 and Clássico) cured by microwave activation presented similar results when compared with the resin specific for microwave activation.

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Universidade Estadual de Campinas. Faculdade de Educação Física

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A adoção de novos processos seletivos para o acesso de alunos às universidades só foi possível com a promulgação da Lei de Diretrizes e Bases da Educação Nacional n. 9.394/96. O vestibular seriado é uma dessas propostas alternativas, que prevê uma avaliação sistemática dos alunos ao término de cada ano do ensino médio. O propósito deste estudo foi caracterizar o vestibular seriado, hoje presente em 22 instituições públicas, quanto ao seu objetivo, estilos de avaliação e conteúdos da disciplina de Biologia distribuídos nos módulos referentes às três séries do ensino médio. Averiguamos que os diferentes programas analisados não apresentam uniformidade em diversos aspectos, tais como número de vagas, estrutura de avaliação e conteúdo programático. Verificamos, ainda, a ausência de consenso sobre a sequência a ser adotada para o ensino de Biologia e a resultante restrição para que o aluno possa preparar-se para as provas seriadas em mais de uma instituição.

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The Steady-State Free Precession (SSFP) sequence has been widely used in low-field and low-resolution imaging NMR experiments to increase the signal-to-noise ratio (s/n) of the signals. Here, we analyzed the Scrambled Steady State - SSS and Unscrambled Steady State - USS sequences to suppress phase anomalies and sidebands of the 13C NMR spectrum acquired in the SSFP regime. The results showed that the application of the USS sequence allowed a uniform distribution of the time interval between pulses (Tp), in the established time range, allowing a greater suppression of phase anomalies and sidebands, when compared with the SSS sequence.

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Syrups with high sugar content and dehydrated fruits in its composition can be added to chocolate fillings to reduce the need of artificial flavor and dyes attributing a natural appeal to the product. Fruit bases were produced with lyophilized strawberry, passion fruit, and sliced orange peel. Rheological dynamic oscillatory tests were applied to determine the products stability and tendency of shelf life. Values of G´< G´´ were observed for strawberry and passion fruit flavor, whereas values of G´ > G´´ were found for orange flavor during the 90 days of storage. It was observed that shear stress values did not vary significantly suggesting product stability during the studied period. For all fillings, it was found a behavior similar to the fruit base indicating that it has great influence on the filling behavior and its stability. The use of a sugar matrix in fillings provided good shelf life for the fruit base, which could be kept under room temperature conditions for a period as long as one year. The good stability and storage conditions allow the use of fruit base for handmade products as well as for industrialized products.

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Several numerical methods for boundary value problems use integral and differential operational matrices, expressed in polynomial bases in a Hilbert space of functions. This work presents a sequence of matrix operations allowing a direct computation of operational matrices for polynomial bases, orthogonal or not, starting with any previously known reference matrix. Furthermore, it shows how to obtain the reference matrix for a chosen polynomial base. The results presented here can be applied not only for integration and differentiation, but also for any linear operation.

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Grobner bases have been generalised to polynomials over a commutative ring A in several ways. Here we focus on strong Grobner bases, also known as D-bases. Several authors have shown that strong Grobner bases can be effectively constructed over a principal ideal domain. We show that this extends to any principal ideal ring. We characterise Grobner bases and strong Grobner bases when A is a principal ideal ring. We also give algorithms for computing Grobner bases and strong Grobner bases which generalise known algorithms to principal ideal rings. In particular, we give an algorithm for computing a strong Grobner basis over a finite-chain ring, for example a Galois ring.

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In a previous study (Jones and Smith, 1999) we established that much the same core pattern of national identity characterizes many developed countries. Using the national identity module from the 1995 International Social Survey Programme, we identified two dimensions of national identity: an ascriptive dimension resembling the concept of ethnic identity described in the historical and theoretical literature, and a voluntarist dimension closer to the notion of civic identity. Some writers view these dimensions in terms of a historical sequence but we find that both constructs coexist in the minds of individual respondents in the nations we examine (we exclude Bulgaria and the Philippines from the present but not the earlier analysis). The dataset used for the multilevel analyses reported here consists of 28 589 respondents in the remaining 21 countries included in the national identity database for the 1995 round of surveys. The macrosociological literature on national identity does not offer well-defined predictions about what precise patterns of national identification we might expect to find among the masses of the developed countries. There are, however, recurring themes from which one can construct plausible hypotheses about how countries might differ according to their level of development, broadly conceived. Thus, we hypothesize that forces such as post-industrialism and globalization tend to favour the more open voluntaristic form of national identity over the more restrictive ascribed form. We develop different multi-level models in order to evaluate specific hypotheses pertaining to such issues, by simultaneously relating individual and societal characteristics to the relative strength of individual commitment to these different types of national identity.