Processos de fragmentação são ferramentas fundamentais no estudo de íons por espectrometria de massas, pois permitem a obtenção de informação sobre a estrutura e termoquímica destes íons . Desenvolvemos uma técnica de dissociação de íons baseada na ativação destes através da absorção multifotônica sequencial de radiação infravermelha de um filamento incandescente. Nesta técnica, íons aprisionados na cela de um espectrômetro de massas por transformada de Fourier são submetidos a radiação do filamento por intervalos de tempo relativamente longos (da ordem de segundos), e passam por um processo de multíplos eventos de absorção e emissão de radiação, até a energia interna dos íons atingir um nível suficiente para a fragmentação. A partir deste modelo para o processo foram implementados métodos computacionais que permitem a simulação da dissociação. A realização destas simulações exige o conhecimento do espectro vibracional do íon, que normalmente tem que ser obtido por algum método teórico de cálculo, como foi feito neste trabalho paro o caso de alguns dos íons estudados. O método de dissociação unimolecular induzida por absorção de radiação infravermelha foi aplicado na determinação das energias de ativação e de dissociação dos íons moleculares de acetofenona, p-cimeno e cumeno. Este método também mostrou-se capaz de diferenciar diferentes estruturas isomericas, e foi com esta finalidade aplicado no estudo da isomerização ceto-enol do íon molecular de acetofenona. Demonstrou-se também a capacidade do método dissociar os íons moleculares de n-butilbenzeno e brometo de alila. / Fragmentation processes are fundamental tools for the mass spectrometric study of ions because they provide information on structure and termochemistry of these ions. We have developed a dissociation technique that is based on the multiphoton activation of trapped ions by infrared radiation emitted by an incandescent filament. In this technique, ions trapped in the cell of a Fourier Transform mass spectrometer are exposed to the filament radiation for long time periods (seconds), and a process of multiple absorption and emition events occurs, until the internal energy of the ions is high enough for fragmentation. Computational methods have been implemented from this model allowing for simulation of the dissociation process. For this simulation the ion vibrational spectra, that normally must be obtained from theoretical calculations, is also required, as has been done in this work for some of the studied ions. The method of unimolecular dissociation induced by infrared radiation was applied to the determination of activation and dissociation energies of the molecular ions of acetophenone, p-cymene and cumene. This method also proved to be capable in the differentiation of isomeric structures, and was so applied in the study for the keto-enol isomerization of the acetophenone molecular ion. It was also shown that the method can dissociate the molecular ions of n-butylbenzene an allyl bromide.

No description available.

Le but de cette thèse est de sonder la flexibilité de NCp7 et de Δ(-)PBS, deux bio-molécules impliquées dans le second saut de brin de la transcription inverse du VIH. Deux stratégies expérimentales ont été mises en place. Un nouveau montage de spectroscopie ultra-rapide de fluorescence par down-conversion a été construit. Les dynamiques de quenching de la 2-aminopurine (2Ap), insérée en position 6, 8 et 10 de la boucle Δ(-)PBS ont pu être entièrement résolues à une résolution sub-ps. Pour chaque position, 4 temps de vie ont été révélés. Des mesures d'anisotropie confirment que les deux composantes < 5 ps sont liées à un empilement de la 2Ap avec les Guanines avoisinantes. Cet empilement est site-spécifique, prouvé par l'augmentation significative de leurs amplitudes lorsque la 2Ap est située près de la tige (position 10). La faible proportion de conformations reliées à un quenching collisionnel est significative de la faible exposition des 2Ap au solvant et de l'encombrement général de la boucle. La seconde approche avait pour but d'étudier l'effet du repliement du squelette protéique de [35-50] NCp7 autour de son atome de zinc par CID et par LID. Les spectres CID de la protéine nue sont expliqués par le modèle du proton mobile et une description détaillée d'un schéma de fragmentation spécifique autour du Tryptophane (Trp) a été soulignée, attribué une Lysine voisine. Un seul fragment issu de l'excitation à 266 nm a été identifié, son apparition entre en compétition avec les fragments CID du Trp. L'effet général du repliement autour du Zinc se traduit par une augmentation du taux de fragmentation autour du Trp et par une perte de spécificité pour le reste du spectre.Les flexibilités de Δ(-)PBS et NCp7 ont été respectivement évaluées par spectroscopie ultra-rapide de type down-conversion et par spectrométrie en phase gazeuse. La première méthode nécessite l'utilisation d'une sonde fluorescente non invasive, la 2-aminopurine (2Ap), placée en position 6, 8 et 10 de la boucle Δ(-)PBS. Notre résolution temporelle permet de résoudre entièrement les dynamiques locales de quenching et d'anisotropie de la 2Ap. Les composantes liées au quenching statique et quenching collisionnel ont été discriminées et révèlent les degrés d'empilement / encombrement locaux de la boucle. L'effet du repliement de [35-50] NCp7 autour de son atome de zinc a été étudié par CID et par LID à 266 nm. La protéine nue présente un interessant shéma de fragmentation autour du Tryptophane (Trp), exalté par la complexation avec le zinc, au prix une perte de spécificité pour le reste du spectre. Un seul fragment LID a été identifié, un mécanisme de sa formation est proposé. / This thesis aims to probe the flexibility of NCp7 and Δ(-)PBS, two biomolecules involved in the second strand transfer of the HIV's reverse transcription. We brought to the front two original experimental methods. A new ultrafast fluorescence down-conversion setup has been built, suitable for biological chromophore investigations. The quenching dynamics of 2-aminopurine (2Ap), site-mutated at the positions 6, 8 and 10 of Δ(-)PBS loop, were completely resolved under a ps scale. For each location, 4 decay times, were highlighted. Further anisotropy measurements confirmed that the two < 5 ps components correspond to stacking interactions of 2Ap with neighbouring Guanines. The site-specific aspect of the stacking were supported by a significant increase of their relative amplitudes when 2Ap were cloesly located to the stem (position 10). The minor portion of conformations involved with ps to ns collisional quenching suggests a low exposure of 2Ap towards the solvent as well as a general restriction of the loop. The second method planned to investigate the effet of the zinc-folding on [35-50] NCp7's peptidic backbone, thanks to CID and LID. The CID-generated spectra of the bare peptide were explained by the mobile proton model, and an exhaustive tryptophan (Trp) fragmentation pattern was described, mainly due to a neighbouring Lysin effects. Only one LID-fragment has been identified upon 266 nm excitation, probably created through a pathway competing with the generation of Trp fragments by CID. The main aspects related to zinc-folding are a general enhancement of the fragmentation ratios related to Trp and a loss of specificity for the remaining mass spectra parts.Δ(-)PBS et NCp7 has been respectively investigated by ultrafast down-conversion spectroscopy and gas-phase spectrometry. The first method implies the use of a non invasive fluorescent probe, named 2 aminopurine (2Ap), site mutated in position 6, 8 et 10 of the Δ(-)PBS loop. Our time resolution allows to fully depict the local quenching dynamics and anisotropy decays. The component related to static and collisional has been solved, thus describing different stacking degrees as well as local restrictions. The effect of [35-50] NCp7 folding around its zinc atom has been studied by CID and 266 nm LID. The bare protein displays an interesting fragmentation pathway around its Tryptophan (Trp), enhanced with zinc complexation, at the cost of a loss of specificity for the remaining mass spectra parts. Only one LID fragment has been identified, its occurence has been interpreted.

Em nossa dissertação, preocupamo-nos em analisar, à luz dos Estudos de Gênero e através do Método Comparativo em História, como foram construídas as masculinidades no medievo ibérico. Não objetivamos estudar as masculinidades na Península Ibérica como um todo, mas sim, casos específicos de Castela no século XIII, a partir da análise dos discursos de duas obras selecionadas, o Poema de Mio Cid e a Vida de Santo Domingo de Silos. Tratam-se de textos contemporâneos, escritos no século XIII pelos clérigos poetas Per Abbat e Gonzalo de Berceo, respectivamente. A partir da análise comparativa dos protagonistas, Cid e Domingo, e de demais personagens selecionados nos dois documentos, defendemos que, ao caracterizarem seus protagonistas, as obras apresentam um mesmo ideal de masculinidade, comum a leigos e religiosos, construído mediante qualificações positivas como coragem, bondade, fidelidade, compromisso com a fé cristã, etc., e em seu relacionamento com outros homens e mulheres. Ao mesmo tempo, observamos, nas narrativas, diversos graus de masculinidade, representados por demais personagens das obras, cujas construções se aproximam ou se afastam da masculinidade dita ideal. Estas gradações ligadas à masculinidade relacionam-se às idéias, que circulavam no medievo, de que as diferenças sexuais eram de grau e não de natureza. Partindo do ideal, o homem próximo a Deus, em graus descentes, chegava-se às mulheres pecadoras._________________________________________________________________________________________ RÉSUMÉ: Dans notre dissertation, on s´est occupée en analyser, selon les Etudes de Genre et par moyen de la Méthode Comparative en Histoire, comment se sont construites les masculinités dans le Moyen-Âge ibérique. On ne veut pas étudier les masculinités dans la Peninsule Ibérique comme un tout, mais des cas spécifiques de Castela, dans le XIIIe siècle, à partir de l´analyse du discours de deux oeuvres sélectionnées, le Poème de Mio Cid et la Vie de Saint Domingo de Silos. Il s´agit de textes modernes, écrits au XIIIe siècle par les clériques poètes Per Abbat et Gonzalo de Berceo, respectivement. À partir de l´analyse comparative des protagonistes, Cid et Domingo, et des autres personnages sélectionnés dans les deux documents, on pense que, au moment où on caractérise les protagonistes, les oeuvres présentent le même idéal de masculinité, commun à des laïques et à des réligieux, construit selon des qualifications positives comme le courage, la bonté la fidélité, le compromis avec la foi chrétienne, etc. et dans son rapport avec d´autres hommes et femmes. En même temps, on a observé, dans les récits, plusieurs dégrés de masculinité, representes par d´autres personnages des oeuvres, dont les constructions s´approchent ou s´éloignent de la masculinité dite idéale. Ces gradations liées à la masculinité se rapportent aux idées qui étaient présents dans le Moyen Age, dont les différences sexuelles étaient de dégré et non de nature. En partant de l´idéal, l´homme proche de Dieu, en dégrés descendants, s´approchait des femmes pêcheuses.

Processos de fragmentação são ferramentas fundamentais no estudo de íons por espectrometria de massas, pois permitem a obtenção de informação sobre a estrutura e termoquímica destes íons . Desenvolvemos uma técnica de dissociação de íons baseada na ativação destes através da absorção multifotônica sequencial de radiação infravermelha de um filamento incandescente. Nesta técnica, íons aprisionados na cela de um espectrômetro de massas por transformada de Fourier são submetidos a radiação do filamento por intervalos de tempo relativamente longos (da ordem de segundos), e passam por um processo de multíplos eventos de absorção e emissão de radiação, até a energia interna dos íons atingir um nível suficiente para a fragmentação. A partir deste modelo para o processo foram implementados métodos computacionais que permitem a simulação da dissociação. A realização destas simulações exige o conhecimento do espectro vibracional do íon, que normalmente tem que ser obtido por algum método teórico de cálculo, como foi feito neste trabalho paro o caso de alguns dos íons estudados. O método de dissociação unimolecular induzida por absorção de radiação infravermelha foi aplicado na determinação das energias de ativação e de dissociação dos íons moleculares de acetofenona, p-cimeno e cumeno. Este método também mostrou-se capaz de diferenciar diferentes estruturas isomericas, e foi com esta finalidade aplicado no estudo da isomerização ceto-enol do íon molecular de acetofenona. Demonstrou-se também a capacidade do método dissociar os íons moleculares de n-butilbenzeno e brometo de alila. / Fragmentation processes are fundamental tools for the mass spectrometric study of ions because they provide information on structure and termochemistry of these ions. We have developed a dissociation technique that is based on the multiphoton activation of trapped ions by infrared radiation emitted by an incandescent filament. In this technique, ions trapped in the cell of a Fourier Transform mass spectrometer are exposed to the filament radiation for long time periods (seconds), and a process of multiple absorption and emition events occurs, until the internal energy of the ions is high enough for fragmentation. Computational methods have been implemented from this model allowing for simulation of the dissociation process. For this simulation the ion vibrational spectra, that normally must be obtained from theoretical calculations, is also required, as has been done in this work for some of the studied ions. The method of unimolecular dissociation induced by infrared radiation was applied to the determination of activation and dissociation energies of the molecular ions of acetophenone, p-cymene and cumene. This method also proved to be capable in the differentiation of isomeric structures, and was so applied in the study for the keto-enol isomerization of the acetophenone molecular ion. It was also shown that the method can dissociate the molecular ions of n-butylbenzene an allyl bromide.

This study is divided into three parts. Part I deals with the mechanism of the self-initiated polymerization (or thermal polymerization) of styrene in the gas phase. In this work, we present the first direct evidence for the thermally self-initiated polymerization of styrene in the gas phase. Our approach is based on on-line analysis of the gas phase Oligomers by mass-selected ion mobility. The mobility measurements provide structural information on the ionized oligomers based on their collision cross-sections (Ω) which depend on the geometric shapes of the ions. Theoretical calculations of possible structural candidates of the Oligomers ions are then used to compute angle averaged Ω for comparison with the measured ones. The agreement between the measured and calculated Ω of the candidate structures provides reliable assignments to the structures of the oligomers. Furthermore, collisional-induced dissociations of the mass-selected oligomer ions provide further support for the structures obtained from the mobility measurements. Our results indicate that the gas phase polymerization of styrene proceeds via essentially the same initiation mechanism (the Mayo mechanism) as in condensed phase polymerization. The structural evidence, the mechanism of formation and the observed fragmentation pathway of the growing dimers and trimers in the gas phase are presentedIn Part II the solvation of a variety of metal cations by benzene clusters have been studied using laser vaporization, cluster beam and time-of-flight mass spectrometry techniques. In this work strong magic numbers were observed for clusters containing 10, 13 and 14 benzene molecules depending on the nature of the metal cation involved. The metal cations exhibiting preference solvation by 14 benzene molecules show a strong tendency to form sandwich structures with two benzene molecules. The interpretation of these results in view of the proposed structures and the growth patterns of the clusters are presented. In Part III, the work is focused on the investigation of the intracluster ion molecule reactions following the generation of Mg+ within the polar clusters (water, methanol, ether and acetonitrile).

Informe de Seminario para optar al grado de Licenciado en Lengua y Literatura Hispánica mención Literatura. / Seminario de grado: Desde la escritura: imágenes y representaciones del Islam y los musulmanes / El Poema de Fernán González y El Cantar de Roldán: La ‘mala imagen’ del moro en la épica española y francesa, consiste en la revisión de dos famosos poemas épicos: El Cantar de Roldán y el Poema de Fernán González, textos canónicos de la literatura medieval. Esta investigación se centrará en el estudio de la manera en que los personajes ‘moros’ o ‘sarracenos’ son representados en estas obras, tomando en cuenta tanto sus características físicas como morales y sicológicas. Asimismo, se tendrá en especial consideración la caracterización de su religión.

The thesis describes the development of new and improved methods for analyzing degradation markers from organophosphorus Chemical Warfare Agents (CWAs). Paper I and II describes an innovative and significantly improved method for the enrichment, derivatization (trimethysilylation) and GC-MS analysis of a broad range of organophosphorus CWAs degradation markers, namely the alkylphosphonic acids and a zwitterionic compound. That was achieved using solid phase disc extraction in combination with solid phase derivatization. The new method overcomes most limitations observed with existing techniques: it offers almost 100 % recoveries, requires no elution or evaporation steps, facilitates miniaturization of the solid sorbent and reagent, is compatible with in-vial derivatization, and minimizes the chromatographic background due to the use of a highly selective anion exchange sorbent disc. Paper III describes the development of new fluorinated diazomethane derivatization reagents and their evaluation for rapid and high sensitivity screening and identification of nerve agent degradation markers. The reagents are water-tolerant to some extent, which simplifies the derivatization step. The best reagent identified was 3,5-bis(trifluoromethyl)benzyl diazomethane, which outperformed the other reagent isomers tested and also the established commercial alternative, pentafluorobenzylbromide, allowing for the rapid (5 min) and direct derivatization of a 25 μL aqueous sample in acetonitrile. The spectra of the formed derivatives (high-energy collision induced fragmentation MS/MS) were used to construct a database (Paper IV) that proved to be superior in terms of match factor and probability compared to EI data gathered for trimethylsilyl derivatives. The study also focused on efforts towards achieving detailed structure information on the alkyl chains of the compounds in question using diagnostic ion interpretation. The final paper (paper V) describes the first rapid direct derivatization method for analyzing nerve agent metabolites in urine at trace levels. The method is based on the derivative from the paper III and the unambiguous identification was proven using a combination of low resolution and high resolution negative ion chemical ionization selected ion monitoring techniques. Novel results presented in these papers include: the first in-situ derivatization of alkylphosphonic acids on an SPE disc; the first direct derivatization of nerve agent markers in water and biomedical samples; the first high sensitivity GC-MS screening for these markers; and the first highly reproducible high-energy isomer specific CID MS/MS library. Overall, the results presented in this thesis represent significant contributions to the analysis of nerve agent degradation products.

El objeto de estudio de la presente investigación lo constituye la obra narrativa del escritor chileno Vicente Huidobro (1893-1948), específicamente aquella referida a sus novelas, a las que dedicó parte importante de su labor creativa, especialmente entre 1929 y 1939, década en la que fue publicada la totalidad de ellas. Si bien lo que se pretende es estudiar el proceso evolutivo que sigue esta producción novelística y establecer los puntos de conexión que mantiene con el sistema poético huidobriano en su generalidad, además de los vínculos que pudiesen existir con otros modelos o tendencias literarias, será necesario focalizar este estudio y delimitar el corpus de trabajo centrando el análisis en sólo dos de las seis novelas existentes. Por tanto, se ha optado por la primera, Mío Cid Campeador, hazaña (1929), en cuanto manifiesta el ideario estético de Huidobro, su espíritu vanguardista e iconoclasta y su convicción de que la obra literaria debe ser un objeto creado en todo el amplio sentido de la palabra, es decir, una expresión del creacionismo; y por Sátiro o el poder de las palabras (1939), la última novela de Vicente Huidobro, que cierra el ciclo narrativo con una serie de cambios notorios de estilo y de óptica frente al quehacer literario.

Tese (doutorado)—Universidade de Brasília, Centro de Estudos Avançados Multidisciplinares, Pós-Graduação em Desenvolvimento, Sociedade e Cooperação Internacional, 2017. / Submitted by Raquel Almeida (raquel.df13@gmail.com) on 2017-07-20T16:38:38Z No. of bitstreams: 1 2017_MariadoCarmoReboucasdaCruzFerreiradosSantos.pdf: 2708851 bytes, checksum: fcb7fe5bff127077081a2a910d7ffc98 (MD5) / Approved for entry into archive by Raquel Viana (raquelviana@bce.unb.br) on 2017-09-12T16:36:43Z (GMT) No. of bitstreams: 1 2017_MariadoCarmoReboucasdaCruzFerreiradosSantos.pdf: 2708851 bytes, checksum: fcb7fe5bff127077081a2a910d7ffc98 (MD5) / Made available in DSpace on 2017-09-12T16:36:43Z (GMT). No. of bitstreams: 1 2017_MariadoCarmoReboucasdaCruzFerreiradosSantos.pdf: 2708851 bytes, checksum: fcb7fe5bff127077081a2a910d7ffc98 (MD5) Previous issue date: 2017-09-12 / Configura-se como objetivo geral da tese analisar e discutir quais são as premissas da Cooperação Sul-Sul (CSS) que quando verificáveis na sua concretude rompem com os pressupostos de um modelo hegemônico de desenvolvimento e se a sua prática seria válida para a reorientação de práticas e imaginários do desenvolvimento. Com a finalidade de ilustrar o trabalho, analisamos a cooperação técnica brasileira com Guiné-Bissau no período de 2003 a 2014. A pesquisa tem um caráter interdisciplinar no sentido de buscar a interação e articulação de diversas disciplinas e saberes que foram mobilizados na investigação para auxiliar na compreensão e explicação do problema de pesquisa. Para a tese realizamos uma pesquisa bibliográfica, documental e entrevistas semiestruturadas, assim como criamos um marco analítico com vistas a orientar a verificação dos princípios da CSS nos projetos de cooperação técnica entre o Brasil e a Guiné-Bissau. Construímos um alicerce epistêmico com referência e inspiração em autores do Sul, sem prejuízo da mobilização de pensadores do Norte. Não obstante a promessa e o potencial de ser um âmbito de autossuficiência coletiva e melhor colaboração, o modelo atual de CSS está comprometido pelos interesses de ganhos nacionais e geopolítico das potências emergentes, muitas vezes em detrimento dos interesses dos países mais pobres. Na nossa avaliação, somente quando inspirada em seus postulados fundacionais, a CSS pode ser um mecanismo difusor de outros modelos de desenvolvimento que reoriente para novas práticas e novos imaginários, que possam ser emancipadores e nos conduzam a sociedades mais equitativas. O estudo empírico demonstrou que na relação bilateral com Guiné- Bissau, os princípios da CSS brasileira se manifestaram na prática, não ficaram somente no campo político discursivo da diplomacia. Contudo, fatores como dependência financeira de Guiné-Bissau da Cooperação Norte-Sul (CNS) também surgiram como limitadores da apropriação e mesmo como um constrangimento para a cooperação brasileira como um todo com o país africano. / It is a general objective of the thesis to analyze and discuss what are the premises of SouthSouth Cooperation (SSC) that, when verifiable in its concreteness, break with the assumptions of a hegemonic model of development and if its practice would be valid for the reorientation of practical and imaginary aspects of development. With the purpose of illustrating the work, we analyzed the Brazilian technical cooperation with Guinea-Bissau from 2003 to 2014. The research has an interdisciplinary character in the sense of seeking the interaction and articulation of diverse disciplines and knowledge that were mobilized in the investigation to assist in the understanding and explanation of the research problem. For the thesis, we carried out a bibliographical, documentary and semi structured research, as well as creating an analytical framework to guide the verification of SSC principles in the technical cooperation projects between Brazil and Guinea-Bissau. We construct an epistemic foundation with reference and inspiration in authors from the South, without prejudice to the mobilization of thinkers from the North. Notwithstanding the promise and potential of being a collective self-reliance and better collaboration framework, the current SSC model is compromised by the interests of national and geopolitical gains of emerging powers, often in detriment of the interests of the poorest countries. In our evaluation, only when inspired by its foundational postulates, SSC can be a mechanism for diffusing other development models that reorient to new practices and new imaginaries, which can be emancipatory and lead to more equitable societies. The empirical study showed that in the bilateral relationship with Guinea-Bissau, the principles of the Brazilian SSC were manifested in practice, they were not only in the discursive political field of diplomacy. However, factors such as Guinea-Bissau's dependence on North-South Cooperation (NSC) have also emerged as limiting appropriation and even as a constraint on Brazilian cooperation as a whole with the African country.