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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Modificações superficiais em polímeros por feixes iônicos para estudo de biocompatibilidade / Surface modifications in polymers by ion beams for the study of biocompatibility

Trindade, Gustavo Ferraz 07 October 2013 (has links)
Nos dias atuais, grande parte das intervenções cirúrgicas inclui o implante de materiais. Os grandes obstáculos na implantação de próteses em organismos humanos são a coagulação sanguínea em contato com o material devido ao alto grau de ativação plaquetária e a compatibilidade dos tecidos biológicos ao material implantado. Agregando melhorias de propriedades mecânicas a superfícies biocompatíveis, materiais poliméricos apresentam grandes tendências a serem excelentes candidatos a biomateriais para tais aplicações. O objetivo deste trabalho foi realizar modificações superficiais em polímeros através do método de implantação por feixe iônico a fim de se investigar mudanças induzidas em suas propriedades superficiais e estudar possíveis mudanças em sua biocompatibilidade, em específico, sua hemocompatibilidade. Amostras de policarbonato foram irradiadas com feixes de íons de argônio com energia 23 keV e cinco diferentes doses. As superfícies das amostras foram analisadas com medidas de ângulo de contato, microscopia de força atômica, espectroscopia de massa de íons secundários, espectroscopia de fotoelétrons, espectroscopia de retroespalhamento Rutherford, deteção de recuo elástico, espectroscopia de raios-X induzidos por partículas e testes de adesão plaquetária. Os resultados das diferentes técnicas apontaram de forma consistente a uma série de alterações químicas e físicas induzidas nas superfícies das amostras, dentre elas: a perda significativa de hidrogênio nas amostras irradiadas, aumento do grau de reticulação entre as cadeias poliméricas que levou ao aumento de elétron deslocalizados e mudança de coloração, remoção de aditivos, migração à superfície de átomos de argônio implantados e alteração de hidrofilicidade. Ao confrontar todos os resultados obtidos com os resultados dos testes de adesão plaquetária, constatou-se que os efeitos observados aumentam o caráter trombogênico da superfície do policarbonato e que a remoção de aditivos com grupos sulfato e sulfonato após irradiação com argônio teve grande influência em tal aumento. / In the current days, a big part of the surgical interventions includes the implant of materials. The great obstacles for prosthesis implantation in living organisms are the blood clotting when in contact to the material due to a high level of platelet activation and the biological tissues compatibility to the implanted material. By joining improvements on mechanical properties to biocompatible surfaces, polymer materials present high tendencies to be excellent biomaterials candidates for such applications. The objective of this work was to perform surface modification in polymers through the ion beam implantation method in order to investigate changes induced in their surface properties and study possible biocompatibility changes. Samples of polycarbonate were irradiated with argon ion beam with 23 keV energy and different doses. The surfaces of the samples were analyzed by contact angle measurements, atomic force microscopy, secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, Rutherford backscattering spectroscopy, elastic recoil detection, particle induced x-ray spectroscopy and platelet adhesion tests. The results from the different techniques pointed consistently to a series of chemical and physical changes induced on the samples\' surfaces, such as: significant loss of hydrogen for the irradiated samples, increase of cross-linking between polymer chains which led to the increase of delocalized electrons and color change, removal of additives, migration of argon atoms to the surface and hydrophilicity changes. By comparing all the obtained results to the platelet adhesion tests results, it was found that the observed effects increase the thrombogenic characteristic of the polycarbonate surface and that the removal of additives with sulfate and sulfonate groups after the argon irradiation had great influence on such increase.
142

Modificações superficiais em polímeros por feixes iônicos para estudo de biocompatibilidade / Surface modifications in polymers by ion beams for the study of biocompatibility

Gustavo Ferraz Trindade 07 October 2013 (has links)
Nos dias atuais, grande parte das intervenções cirúrgicas inclui o implante de materiais. Os grandes obstáculos na implantação de próteses em organismos humanos são a coagulação sanguínea em contato com o material devido ao alto grau de ativação plaquetária e a compatibilidade dos tecidos biológicos ao material implantado. Agregando melhorias de propriedades mecânicas a superfícies biocompatíveis, materiais poliméricos apresentam grandes tendências a serem excelentes candidatos a biomateriais para tais aplicações. O objetivo deste trabalho foi realizar modificações superficiais em polímeros através do método de implantação por feixe iônico a fim de se investigar mudanças induzidas em suas propriedades superficiais e estudar possíveis mudanças em sua biocompatibilidade, em específico, sua hemocompatibilidade. Amostras de policarbonato foram irradiadas com feixes de íons de argônio com energia 23 keV e cinco diferentes doses. As superfícies das amostras foram analisadas com medidas de ângulo de contato, microscopia de força atômica, espectroscopia de massa de íons secundários, espectroscopia de fotoelétrons, espectroscopia de retroespalhamento Rutherford, deteção de recuo elástico, espectroscopia de raios-X induzidos por partículas e testes de adesão plaquetária. Os resultados das diferentes técnicas apontaram de forma consistente a uma série de alterações químicas e físicas induzidas nas superfícies das amostras, dentre elas: a perda significativa de hidrogênio nas amostras irradiadas, aumento do grau de reticulação entre as cadeias poliméricas que levou ao aumento de elétron deslocalizados e mudança de coloração, remoção de aditivos, migração à superfície de átomos de argônio implantados e alteração de hidrofilicidade. Ao confrontar todos os resultados obtidos com os resultados dos testes de adesão plaquetária, constatou-se que os efeitos observados aumentam o caráter trombogênico da superfície do policarbonato e que a remoção de aditivos com grupos sulfato e sulfonato após irradiação com argônio teve grande influência em tal aumento. / In the current days, a big part of the surgical interventions includes the implant of materials. The great obstacles for prosthesis implantation in living organisms are the blood clotting when in contact to the material due to a high level of platelet activation and the biological tissues compatibility to the implanted material. By joining improvements on mechanical properties to biocompatible surfaces, polymer materials present high tendencies to be excellent biomaterials candidates for such applications. The objective of this work was to perform surface modification in polymers through the ion beam implantation method in order to investigate changes induced in their surface properties and study possible biocompatibility changes. Samples of polycarbonate were irradiated with argon ion beam with 23 keV energy and different doses. The surfaces of the samples were analyzed by contact angle measurements, atomic force microscopy, secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, Rutherford backscattering spectroscopy, elastic recoil detection, particle induced x-ray spectroscopy and platelet adhesion tests. The results from the different techniques pointed consistently to a series of chemical and physical changes induced on the samples\' surfaces, such as: significant loss of hydrogen for the irradiated samples, increase of cross-linking between polymer chains which led to the increase of delocalized electrons and color change, removal of additives, migration of argon atoms to the surface and hydrophilicity changes. By comparing all the obtained results to the platelet adhesion tests results, it was found that the observed effects increase the thrombogenic characteristic of the polycarbonate surface and that the removal of additives with sulfate and sulfonate groups after the argon irradiation had great influence on such increase.
143

Estudo analítico dos flavonoides dos frutos do maracujá (Passiflora edulis Sims f. flavicarpa Degener) / Analytical studies of the flavonoids in passion fruit (Passiflora edulis Sims f. flavicarpa Degener)

Zeraik, Maria Luiza 16 April 2010 (has links)
Atualmente tem-se dado grande ênfase aos alimentos funcionais, pois atuam na prevenção e auxiliam na recuperação de várias doenças, como doenças inflamatórias crônicas, cardiovasculares e câncer, por apresentarem principalmente flavonoides, que previnem lesões oxidativas, propiciando benefícios à saúde. O Brasil é o maior produtor mundial do maracujá, e em vista disto é de suma importância o desenvolvimento de métodos analíticos e estudos de atividade antioxidante e anti-inflamatória do fruto de maracujá, visando sua possível utilização como alimento funcional e produção de possíveis fármacos. Passiflora edulis Sims. f. flavicarpa Degener, conhecida como maracujá azedo ou amarelo é a espécie mais cultivada e comercializada no Brasil. Desta forma, os objetivos deste trabalho foram: desenvolver e validar um método analítico por CLAE-UV/DAD (cromatografia líquida de alta eficiência acoplada detector de arranjo de fotodiodos) para quantificação da flavona isoorientina, presente na polpa de P. edulis; quantificação dos flavonoides totais desta espécie, usando um padrão de baixo custo (rutina); comparar as técnicas CLAE e CCDAE (cromatografia em camada delgada de alta eficiência) e analisar a isoorientina nas cascas dos frutos de P. edulis infectada com o vírus PWV e cascas sadias por CCDAE; quantificar as proteínas totais e avaliar as atividades antioxidantes e anti-inflamatória dos extratos de cascas de P. edulis e da polpa dos frutos de P. edulis e P. alata, empregando-se o método do DPPH•, e os ensaios de QLluc (quimioluminescencia dependente de lucigenina), ELISA (Enzyme Linked Immunosorbent Assay), e SIEFED (Specific Immunologic Extraction Followed by Enzymatic Detection). Os resultados mostraram que o método desenvolvido por CLAE-UV/DAD foi adequado e eficiente para quantificação de isoorientina e de flavonoides totais na polpa de P. edulis, apresentando especificidade, linearidade, exatidão, precisão, dentro das faixas internacionalmente aceitas. Além disso, este método foi aplicado com sucesso nas análises de flavonoides em cascas de P. edulis e polpa de P. alata. O trabalho mostrou as vantagens da utilização da técnica CCDAE, como a realização de análises mais rápida e econômica, com baixo consumo de solvente e resíduos gerados frente à CLAE-UV/DAD. Por meio da técnica CL-EM/EM (cromatografia líquida acoplada à espectrometria de massas em tandem) foi possível identificar as flavonas isoorientina e isovitexina na polpa de P. edulis. Os extratos de cascas de P. edulis apresentaram maior capacidade redutora de radicais (método do DPPH•), seguido das polpas de P. edulis e P. alata, respectivamente. Os extratos de cascas também mostraram maior inibição da produção de EROs (espécies reativas de oxigênio) pelos neutrófilos ativados e da atividade da MPO (mieloperoxidase) isolada, porém verificou-se que todos os extratos testados não modificaram a desgranulação dos neutrófilos, não influenciando a liberação de MPO no plasma. Assim, concluiu-se que a atividade antioxidante pode estar diretamente relacionada com a concentração de isoorientina presente nos extratos. A grande quantidade de proteínas e isoorientina encontrada nas cascas de P. edulis, se comparada à polpa de P. edulis, aliada à elevada atividade antioxidante e anti-inflamatória, sugere o potencial das cascas de P. edulis como um alimento funcional, ou como possível fonte de flavonoides naturais para a produção de fármacos, sugerindo assim o aproveitamento deste grande resíduo industrial. / Functional foods have been the focus of many studies nowadays, because they act preventing and assisting in the recovery of several diseases, such as chronic inflammatory, cardiovascular and cancer, due to they have mainly flavonoids, which prevent oxidative damage, providing health benefits. Brazil is the largest producer of passion fruit; therefore, it is very important to develop analytical methods and studies of antioxidant and anti-inflammatory activities of passion fruit, intending to its use as a functional food and in the development of drugs. Passiflora edulis Sims. f. flavicarpa Degener, known as yellow passion fruit, is the most cultivated and marketed species in Brazil. Therefore, the objectives were: to develop and validate an analytical method by HPLC-UV/DAD (high-performance liquid chromatography with photo-diode array detection) for quantification of isoorientin present in the pulp of P. edulis and quantification of total flavonoids of this specie, using a low-cost standard (rutin); to compare HPLC and HPTLC (high-performance thin layer chromatographic) techniques and to analyze isoorientin in the peels of P. edulis fruits infected by PWV virus and healthy peels by HPTLC; to quantify the proteins and to evaluate the antioxidant and anti-inflammatory activities of the extracts of P. edulis peels and P. edulis and P. alata pulp, using the method of DPPH•, QLluc (chemiluminescence dependent of lucigenin), ELISA (enzyme linked immunosorbent assay), and SIEFED (specific immunologic extraction followed by enzymatic detection). The results showed that the HPLC-UV/DAD method was suitable and efficient for isoorientin quantification and total flavonoids in the P. edulis pulp, with specificity, linearity, accuracy, precision, within internationally acceptable limits. Moreover, this method was successfully applied to the analysis of flavonoids in the P. edulis peels and P. alata pulp. The study presented the advantages of using the HPTLC technique such as to perform faster and cheaper analysis, with low solvent consumption and waste generated compared to HPLC-UV/DAD. Using LC-MS/MS technique (liquid chromatography with tandem mass spectrometry detection) the flavones isoorientin and isovitexin were identified in the pulp of P. edulis. The extracts of peels of P. edulis showed the higher radical scavenging ability (DPPH• method), followed by P. edulis and P. alata pulps, respectively. The peels extracts also showed greater inhibition of ROS (reactive oxygen species) production by neutrophils activated and isolated MPO activity, but it was found that the extracts did not alter the neutrophils degranulation and does not influence the MPO release in the plasma. Therefore, it was concluded that the antioxidant activity might be directly related to the concentration of isoorientin present in the extracts. The high amount of protein and isoorientin found in the P. edulis fruit peels, compared with P. edulis pulp, and the high antioxidant and anti-inflammatory activities, suggests the potential of the P. edulis fruit peels as functional food or a possible source of natural flavonoids for drugs production, suggesting the use of this substantial industrial waste.
144

Analyse par ToF-SIMS de matériaux fragiles pour les micro/nanotechnologies : évaluation et amplification de l'information chimique / ToF-SIMS characterisation of fragile materials used in microelectronic and microsystem devices : validation and enhancement of the chemical information

Scarazzini, Riccardo 04 July 2016 (has links)
Aujourd’hui, une grande variété de matériaux dit « fragiles » sont intégrés dans des dispositifs micro ou nanotechnologiques. Ces matériaux sont définissables comme « fragiles » en raison de leur forme, de leur dimension ou encore de leur densité. Dans ce travail, trois catégories de matériaux, de différents niveaux de maturités industrielle et technologique, ont été étudiés par spectrométrie de masse des ions secondaires à temps du vol (ToF-SIMS). Ces matériaux sont: du silicium méso-poreux, des polyméthacrylates déposés en couches très minces par voie chimique en phase vapeur initiée (iCVD) et des matériaux organosilicates (SiOCH) à basse constante diélectrique (low-k). L’objectif de ce travail est de vérifier et de valider la méthode ToF-SIMS comme une technique fiable pour répondre aux besoins de caractérisation chimique rencontrés pas ces matériaux Il s’agit également d’établir la cohérence de l’information chimique produite par l’interprétation de l’interaction ion/matière se déroulant lors de l’analyse. Pour le silicium méso-poreux, les échantillons ont été pulvérisés par différentes sources primaires d’ions (Césium, Xénon, Oxygène) et l’information secondaire générée comme, par exemple, les différences d’ionisation entre la couche poreuse et le matériau dense ont été analysées, notamment vis de l’énergie du faisceau de pulvérisation mais aussi du taux de porosité du matériau cible. Des modifications morphologiques significativement différentes selon la source d’ions ont également été observées et ont été corrélées à différents types de régime de pulvérisation, principalement induits par le taux de porosité de la cible.Concernant la caractérisation de polymères en couches minces, des conditions d’abrasion très peu agressives, notamment l’usage d’ions d’argon en cluster polyatomiques, ont été appliquées avec l’intention d’obtenir une information chimique secondaire riche en hautes masses moléculaires. La discrimination de films de polyméthacrylate avec une structure chimique quasi-identique a pu être obtenue et un protocole de quantification de copolymères proposé. De plus, par l’utilisation de la méthode d’analyse de données en composantes principales (PCA) appliquée aux spectres,une corrélation claire a été établie entre les composantes principales et la masse moléculaire des films de polymères.Enfin l’impact de traitements d’intégration tels que de la gravure ou du nettoyage chimique, nécessaires à la mise en œuvre industrielle des matériaux low-k, mais défavorables à leurs propriétés diélectriques, a été étudié. Pour obtenir une information chimique résolue en profondeur, l’abrasion par césium à basse énergie a été identifiée comme la stratégie la plus sensible et la plus adaptée. De même, la PCA a permis d’amplifier significativement les différences chimiques entre échantillons, permettant de rapprocher les variations de constante diélectrique aux compositions chimiques / Nowadays, the micro and nanotechnology field integrates a wide range of materials that can be defined as “fragile” because of their shape, dimension or density. In this work, three materials of this kind, at different level of technological and industrial maturity are studied by time of flight secondary ion mass spectrometry (ToF-SIMS). These materials are: mesoporous silicon, thin polymethacrylate films deposited by initiated Chemical Vapour Deposition (i-CVD)and hybrid organosilicate (SiOCH) dielectric materials (low-k). The objective is to verify and validate the ToF-SIMS as a reliable characterisation technique for describing the chemical properties of these materials. Indeed, because of this intrinsic ‘fragility’ the consistency of the chemical information is connected to an appropriate interpretation of the specific ion/matter interactions taking place.For mesoporous silicon, a systematic analysis is carried out considering various sputtering ion sources (Caesium, Xenon and Oxygen); both sputtering and ionisation behaviours are examined relatively to the nonporous silicon, taking into account energy of the sputtering beam and porosity rate of the target material.Concerning nanometric thick polymer films, low damaging analysis conditions are applied by the use of argon cluster primary ion sources in order to obtain a significant molecular secondary ion information. In these conditions, a discrimination of quasi-identical nanometre thick structures is made possible and a quantification method for copolymers is then proposed. In addition, with the supplement of data principal component analysis (PCA) an innovative and significant correlation is obtained between main Principal Component and sample molecular weights.Finally, the effect of several industrial integration processes (such as etching or wet cleaning) applied on low-k materials are studied in order to understand their detrimental impact on low-k insulating properties. To achieve a depth-resolved chemical information, low energy caesium sputterings are shown to be the most adapted and sensitive strategy. In addition, PCA is shown to be almost essential to amplify differences between samples significantly. This approach allowed combining the variation of physical properties (dielectric constant) with the chemical ones.
145

La socialisation du joueur-adolescent : son voyage identitaire avec Les Sims® / The video-ludological socialization of teenager-gamers : their voyage of identity with The Sims®

Lorentz, Pascaline 18 October 2012 (has links)
Ce travail doctoral se propose de prendre pour objet un jeu vidéo très connu du grand public paradoxalement ignoré par la communauté scientifique alors que son premier opus fut distribué dès l’an 2000. Alors que les études précédemment réalisées sur les jeux vidéo portent principalement sur une pratique en ligne, nous avons voulu nous consacrer à un jeu hors-ligne afin de nous questionner sur la relation que le joueur entretient avec ses avatars dans cette configuration. En effet, quelle est la nature de cette relation entre le joueur et ses personnages ? Que se passe-t-il durant le jeu ? Que font les joueurs et pourquoi ? En étudiant les joueurs de Les Sims ainsi que leurs pratiques, nous avons pu mettre en évidence la présence d’une socialisation spécifique, la socialisation vidéo-ludique, via un processus particulier comportant différentes étapes. L’adolescence nous est apparue comme un moment de la vie à la charnière entre des temporalités socialisatrices favorisant la richesse de l’expérience de simulation et un âge de la vie où le jeu est encore socialement permis et même encouragé. Dans le but d’améliorer notre interprétation, nous avons dessiné un modèle théorique prenant la forme d’un voyage que le joueur effectue durant son activité. Ce voyage identitaire véhicule le processus de socialisation vidéo-ludique advenant au cours de la pratique de simulation de vie. En prenant du recul, et en ajoutant les résultats d’une enquête menée en parallèle de la recherche doctorale, nous avons complété notre modèle avec des explications relevant d’un niveau macro social. Notre objectif a été d’inscrire la pratique vidéo-ludique dans la globalité de la vie sociale du joueur. / In many books, articles, conferences, we can read, hear, notice that gaming is helping the socialization process, that games are socializing tools and that is the reason why video games could be “good” for individuals (Greenfield, 1994 ; Taylor, 2002 ; Gee, 2003). But what is that socialization? What does this specific socialization is bringing to the overall understanding of the evolution of individuals in our societies? In one word: what is the video-ludological socialization? The concept of socialization is widely used by many disciplines such as Sociology, Social Psychology, Communication Sciences, Media Studies, Game Studies and Educational Studies and so forth. Socialization, which is the social process that makes a subject become a social being, is a key concept for understanding society and its functioning. That is why I scrutinize video-ludological socialization in this dissertation. To cast light on benefits of this specific socialization, no game is better than one simulating life which is also very popular: The Sims. For my research I overlooked praxis of teenagers gaming and how they utilize the gameplay to experiment social behaviours. In this thesis, I propose to explain what video gaming is bringing more than usual play by presenting findings of this study carried out in two steps with 180 teenagers from 12 to 16 years old.This video-ludological socialization, befalling through interacting, is part of the main socialization process which lasts during all the lifespan of individuals (Berger & Luckmann, 1966). In my research, I demonstrated that gaming with The Sims channels the video-ludological socialization process and that gaming plays an active role in gamers’ social lives.
146

Jogos de simulação de vida e subjetividade: a experiência de poder/controle entre jovens jogadores de The Sims.

MEDEIROS, Márcia Duarte January 2006 (has links)
MEDEIROS , Macia Duarte. Jogos de simulação de vida e subjetividade: a experiência de poder/controle entre jovens jogadores de The Sims. 2006. 102 f. Dissertação (Mestrado em Psicologia) – Universidade Federal do Ceará, Departamento de Psicologia, Programa de Pós-Graduação em Psicologia, Fortaleza-CE, 2006. / Submitted by moises gomes (celtinha_malvado@hotmail.com) on 2012-03-28T18:13:10Z No. of bitstreams: 1 2006_dis_MDMedeiros.PDF: 849608 bytes, checksum: 8b3b245a66725319f5562166c7e74516 (MD5) / Approved for entry into archive by Maria Josineide Góis(josineide@ufc.br) on 2012-03-29T16:58:28Z (GMT) No. of bitstreams: 1 2006_dis_MDMedeiros.PDF: 849608 bytes, checksum: 8b3b245a66725319f5562166c7e74516 (MD5) / Made available in DSpace on 2012-03-29T16:58:28Z (GMT). No. of bitstreams: 1 2006_dis_MDMedeiros.PDF: 849608 bytes, checksum: 8b3b245a66725319f5562166c7e74516 (MD5) Previous issue date: 2006 / At the present time, great part of our actions and relationships are mediated by electronic objects. In a special way, children and adolescents begin in the "technological adventure" saw electronic games, which start to intervene directly in the production in new ways of subjectivities. The high investments in the industry of electronic games show that, far away from an idiom, that is an activity that settled down in practically everyone, what allows us and he/she demands to think her as a relevant subject for the Humanities and, especially, for the Social Psychology. This research is accomplished with intention of contemplating concerning the uses of the new technologies in the production of the contemporary subjectivity, investigating, especially, the expressions of power raised by the game of life simulation "The Sims" and other implications for their users’ sociability. He/she intends to examine, through interviews on line and personal, that it forms the feelings of power, possibly raised by the referred game, they affect the adolescents’ relationships with their pairs, as well as their perceptions and capacity of discernment concerning the virtual world and of the real world. This use the theoretical-critical referencial of the School of Frankfurt and contemporary authors, to example of Turkle, Lasch and Severiano. The methodological strategies used in the empiric research involved three stages, to know: collects of initials data in forums on the game; application of questionnaires, sent by e-mail to the users, and accomplishment of interviews on line. The data were analyzed initially quantitatively, with the software EPInfo, and later we proceeded to a qualitative analysis of the most relevant positionings, in articulation with the first ones. Our data confirm attributable elements to the that Lasch (1983) denominated of "Culture of the narcissism", in the measure in that the category "power/control" received a strong adhesion of the researched youths. They also reveal nuances different from this culture type, especially in what it concerns to the category "sociability", once those young ones still demonstrate the need of the other in his/her concrete reality, preferring it to those of the virtual world. / Na atualidade, grande parte de nossas ações e relações é mediada por objetos eletrônicos. De modo especial, crianças e adolescentes se iniciam na “aventura tecnológica” via jogos eletrônicos, os quais passam a intervir diretamente na produção de novas formas de subjetividades. Os altos investimentos na indústria de jogos eletrônicos mostram que, longe de um modismo, essa é uma atividade que se estabeleceu em praticamente todo o mundo, o que nos permite e exige pensá-la como uma questão relevante para as Ciências Humanas e, em especial, para a Psicologia Social. Esta pesquisa foi realizada com intuito de refletir acerca dos usos das novas tecnologias na produção da subjetividade contemporânea, investigando, em especial, as expressões de poder/controle suscitadas pelo jogo de simulação de vida The Sims e demais implicações para a sociabilidade de seus usuários. Parte do referencial teórico-crítico da Escola de Frankfurt e de autores contemporâneos, a exemplo de Turkle, Lasch e Severiano. As estratégias metodológicas utilizadas na pesquisa empírica envolveram três etapas, a saber: coleta de dados iniciais em fóruns sobre o jogo; aplicação de questionários, enviados por e-mail aos usuários, e realização de entrevistas on line. Os dados foram analisados inicialmente quantitativamente, com auxilio do software EPInfo, e posteriormente procedeu-se a uma análise qualitativa dos posicionamentos mais relevantes, em articulação com os primeiros. Nossos dados confirmam elementos atribuíveis ao que Lasch (1983) denominou de “Cultura do narcisismo”, na medida em que a categoria “poder/controle” recebeu uma forte adesão dos jovens pesquisados. Revelam também nuanças distintas deste tipo de cultura, especialmente no que concerne à categoria “sociabilidade”, uma vez que esses jovens ainda demonstram a necessidade do outro em sua realidade concreta, preferindo-o àqueles do mundo virtual.
147

Seleção em famílias de irmãos completos de maracujazeiro amarelo (Passiflora edulis Sims f. flavicarpa Deg.) no segundo ano de produção / Selection of families of whole brothers of the yellow passion flower plant (Passiflora edulis Sims f. flavicarpa Deg.) in the second year of production

Linhales, Heloisa 13 July 2007 (has links)
Made available in DSpace on 2015-03-26T13:40:07Z (GMT). No. of bitstreams: 1 texto completo.pdf: 372745 bytes, checksum: 6f1e60efc5a019ffb5aabeff2579b6ad (MD5) Previous issue date: 2007-07-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to select superior genotypes of the yellow passion flower related to productivity and quality of the fruits. A population of 26 families of whole brothers was evaluated in the second year of production, in a design of random plots, with three repetitions, starting with four plants per plot. The experiment was carried out in the experimental area of Fruitculture in the Departamento de Fitotecnia of the Universidade Federal de Viçosa, in Viçosa, Minas Gerais State, Brazil. In the selection among and within the families, the efficiency of the direct and indirect selection as well as that based on the classical index was verified. The selection strategies among and within, combined, massal and stratified massal were compared. The results found by the selection among and within were compared with those obtained from the selection made in this same population in the first year of production. The characteristics measured were number of fruits per plant, estimated production per plant, length of the fruit, diameter of the fruit, weight of the fruit, weight of the peel, thickness of the peel, weight of the pulp, color of the pulp, percentage of the pulp, total content of soluble solids, titrable total acidity and the rate between the total soluble solids/titrable total acidity. Samples of 10 fruits of each plant were obtained to evaluate the qualitative characteristics of the fruits. The collection of the fruits for the analyses was made as they became yellowishgreen, during the second year of production, from January to July 2006. All the statistical analyses were made with the genetics and statistics software GENES. The selection gains were estimated based on a percentage of 24% among families and of 25% within families for all the characteristics measured. The selection criterium adopted for all the characteristics was the increase in peel their original mediuns, except for the weight and thickness of the peel for which a decrease was desired. For the characteristics choice that were part of the classic index of selection, the multicolinearity diagnosis was carried out, using the autovalues and the autovectors analyses. The selected characteristics to make up the index were estimated production per plant, diameter of the fruit, pulp percentage, pulp color and total titrable acidity. The use of the strategy of simultaneous selection of characters, based on the classic index showed estimations of gains greater than those of the other methodologies, in estimated production per plant and pulp percentage. In the direct selection, the estimations of gains were greater in pulp color and total titrable acidity. The combined selection, when compared to the among and within selection massal and stratified massal, provided the greatest estimations of gains in 11 out of 13 characteristics evaluated, except length and weight of the fruit, thus being the most suitable strategy for the breeding of the population studied. The evaluations made in the first year of production generated satisfactory results, which practically were reproduced in the second year, and therefore can be recommended, because of costs and time reduction of the selection cycle. / Com o objetivo de selecionar genótipos de maracujazeiro amarelo superiores quanto à produtividade e qualidade dos frutos, uma população constituída de 26 famílias de irmãos completos foi avaliada no segundo ano de produção, em delineamento de blocos casualizados, com três repetições e originalmente com quatro plantas por parcela. O trabalho foi realizado na área experimental de Fruticultura do Departamento de Fitotecnia da Universidade Federal de Viçosa, em Viçosa, MG. Verificou-se, na seleção entre e dentro de famílias, a eficiência da seleção direta, indireta e com base em índice clássico. Compararam-se as estratégias de seleção entre e dentro, combinada, massal e massal estratificada. Os resultados encontrados pela seleção entre e dentro foram confrontados com os obtidos em seleção realizada, nessa mesma população, no primeiro ano de produção. As características mensuradas foram número de frutos por planta, produção estimada por planta, comprimento do fruto, diâmetro do fruto, massa do fruto, massa da casca, espessura da casca, massa da polpa, coloração da polpa, porcentagem de polpa, teor de sólidos solúveis totais, acidez total titulável e relação entre teor de sólidos solúveis totais/acidez total titulável. Foi obtida amostra de 10 frutos de cada planta, para avaliação das características qualitativas dos frutos. A colheita dos frutos foi feita de forma parcelada durante o segundo ano de produção, de janeiro a julho de 2006. Os frutos destinados à análise foram colhidos a partir do estádio verde-amarelo . Todas as análises estatísticas foram realizadas com o aplicativo computacional em genética e estatística (GENES). Foram estimados os ganhos de seleção em função de uma porcentagem de seleção de 24% entre famílias e 25% dentro de famílias para todas as características mensuradas. O critério de seleção adotado para todas as características foi o acréscimo em suas médias originais, exceto em massa e espessura da casca, em que se buscou o decréscimo. Para escolha das características que fizeram parte do índice clássico de seleção, foi realizado o diagnóstico de multicolinearidade, empregando para isso a análise dos autovalores e autovetores. As características selecionadas para compor o índice foram produção estimada por planta, diâmetro do fruto, porcentagem de polpa, coloração da polpa e acidez total titulável. A utilização da estratégia de seleção simultânea de caracteres, com base no índice clássico apresentou estimativas de ganhos superiores às das outras metodologias em produção estimada por planta e porcentagem de polpa. Na seleção direta, as estimativas de ganhos foram superiores em coloração de polpa e acidez total titulável. A seleção combinada, quando comparada à seleção entre e dentro, massal e massal estratificada, proporcionou as maiores estimativas de ganhos em 11 das 13 características avaliadas, exceto comprimento e massa do fruto, sendo, assim, a estratégia mais apropriada para o melhoramento genético da população estudada. A realização das avaliações no primeiro ano de produção gera resultados satisfatórios, os quais praticamente, se reproduzem no segundo ano, podendo ser recomendada, por reduzir o custo e o tempo de realização do ciclo de seleção.
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Estudo analítico dos flavonoides dos frutos do maracujá (Passiflora edulis Sims f. flavicarpa Degener) / Analytical studies of the flavonoids in passion fruit (Passiflora edulis Sims f. flavicarpa Degener)

Maria Luiza Zeraik 16 April 2010 (has links)
Atualmente tem-se dado grande ênfase aos alimentos funcionais, pois atuam na prevenção e auxiliam na recuperação de várias doenças, como doenças inflamatórias crônicas, cardiovasculares e câncer, por apresentarem principalmente flavonoides, que previnem lesões oxidativas, propiciando benefícios à saúde. O Brasil é o maior produtor mundial do maracujá, e em vista disto é de suma importância o desenvolvimento de métodos analíticos e estudos de atividade antioxidante e anti-inflamatória do fruto de maracujá, visando sua possível utilização como alimento funcional e produção de possíveis fármacos. Passiflora edulis Sims. f. flavicarpa Degener, conhecida como maracujá azedo ou amarelo é a espécie mais cultivada e comercializada no Brasil. Desta forma, os objetivos deste trabalho foram: desenvolver e validar um método analítico por CLAE-UV/DAD (cromatografia líquida de alta eficiência acoplada detector de arranjo de fotodiodos) para quantificação da flavona isoorientina, presente na polpa de P. edulis; quantificação dos flavonoides totais desta espécie, usando um padrão de baixo custo (rutina); comparar as técnicas CLAE e CCDAE (cromatografia em camada delgada de alta eficiência) e analisar a isoorientina nas cascas dos frutos de P. edulis infectada com o vírus PWV e cascas sadias por CCDAE; quantificar as proteínas totais e avaliar as atividades antioxidantes e anti-inflamatória dos extratos de cascas de P. edulis e da polpa dos frutos de P. edulis e P. alata, empregando-se o método do DPPH•, e os ensaios de QLluc (quimioluminescencia dependente de lucigenina), ELISA (Enzyme Linked Immunosorbent Assay), e SIEFED (Specific Immunologic Extraction Followed by Enzymatic Detection). Os resultados mostraram que o método desenvolvido por CLAE-UV/DAD foi adequado e eficiente para quantificação de isoorientina e de flavonoides totais na polpa de P. edulis, apresentando especificidade, linearidade, exatidão, precisão, dentro das faixas internacionalmente aceitas. Além disso, este método foi aplicado com sucesso nas análises de flavonoides em cascas de P. edulis e polpa de P. alata. O trabalho mostrou as vantagens da utilização da técnica CCDAE, como a realização de análises mais rápida e econômica, com baixo consumo de solvente e resíduos gerados frente à CLAE-UV/DAD. Por meio da técnica CL-EM/EM (cromatografia líquida acoplada à espectrometria de massas em tandem) foi possível identificar as flavonas isoorientina e isovitexina na polpa de P. edulis. Os extratos de cascas de P. edulis apresentaram maior capacidade redutora de radicais (método do DPPH•), seguido das polpas de P. edulis e P. alata, respectivamente. Os extratos de cascas também mostraram maior inibição da produção de EROs (espécies reativas de oxigênio) pelos neutrófilos ativados e da atividade da MPO (mieloperoxidase) isolada, porém verificou-se que todos os extratos testados não modificaram a desgranulação dos neutrófilos, não influenciando a liberação de MPO no plasma. Assim, concluiu-se que a atividade antioxidante pode estar diretamente relacionada com a concentração de isoorientina presente nos extratos. A grande quantidade de proteínas e isoorientina encontrada nas cascas de P. edulis, se comparada à polpa de P. edulis, aliada à elevada atividade antioxidante e anti-inflamatória, sugere o potencial das cascas de P. edulis como um alimento funcional, ou como possível fonte de flavonoides naturais para a produção de fármacos, sugerindo assim o aproveitamento deste grande resíduo industrial. / Functional foods have been the focus of many studies nowadays, because they act preventing and assisting in the recovery of several diseases, such as chronic inflammatory, cardiovascular and cancer, due to they have mainly flavonoids, which prevent oxidative damage, providing health benefits. Brazil is the largest producer of passion fruit; therefore, it is very important to develop analytical methods and studies of antioxidant and anti-inflammatory activities of passion fruit, intending to its use as a functional food and in the development of drugs. Passiflora edulis Sims. f. flavicarpa Degener, known as yellow passion fruit, is the most cultivated and marketed species in Brazil. Therefore, the objectives were: to develop and validate an analytical method by HPLC-UV/DAD (high-performance liquid chromatography with photo-diode array detection) for quantification of isoorientin present in the pulp of P. edulis and quantification of total flavonoids of this specie, using a low-cost standard (rutin); to compare HPLC and HPTLC (high-performance thin layer chromatographic) techniques and to analyze isoorientin in the peels of P. edulis fruits infected by PWV virus and healthy peels by HPTLC; to quantify the proteins and to evaluate the antioxidant and anti-inflammatory activities of the extracts of P. edulis peels and P. edulis and P. alata pulp, using the method of DPPH•, QLluc (chemiluminescence dependent of lucigenin), ELISA (enzyme linked immunosorbent assay), and SIEFED (specific immunologic extraction followed by enzymatic detection). The results showed that the HPLC-UV/DAD method was suitable and efficient for isoorientin quantification and total flavonoids in the P. edulis pulp, with specificity, linearity, accuracy, precision, within internationally acceptable limits. Moreover, this method was successfully applied to the analysis of flavonoids in the P. edulis peels and P. alata pulp. The study presented the advantages of using the HPTLC technique such as to perform faster and cheaper analysis, with low solvent consumption and waste generated compared to HPLC-UV/DAD. Using LC-MS/MS technique (liquid chromatography with tandem mass spectrometry detection) the flavones isoorientin and isovitexin were identified in the pulp of P. edulis. The extracts of peels of P. edulis showed the higher radical scavenging ability (DPPH• method), followed by P. edulis and P. alata pulps, respectively. The peels extracts also showed greater inhibition of ROS (reactive oxygen species) production by neutrophils activated and isolated MPO activity, but it was found that the extracts did not alter the neutrophils degranulation and does not influence the MPO release in the plasma. Therefore, it was concluded that the antioxidant activity might be directly related to the concentration of isoorientin present in the extracts. The high amount of protein and isoorientin found in the P. edulis fruit peels, compared with P. edulis pulp, and the high antioxidant and anti-inflammatory activities, suggests the potential of the P. edulis fruit peels as functional food or a possible source of natural flavonoids for drugs production, suggesting the use of this substantial industrial waste.
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Les séries radioactives de l'uranium dans les sédiments de la Gandak (Himalaya) : de la roche total aux analyses in situ sur les minéraux séparés / The Uranium decay series in the Gandak river sediments (Himalaya) : from the bulk sediments to the in situ analysis of the mineral grains

Bosia, Clio 02 May 2016 (has links)
L’analyse de sédiments totaux et de fractions granulométriques de la rivière Gandak (Himalaya) a montré que la variabilité des séries de l’uranium observée pour les sédiments himalayens est contrôlée par leur évolution minéralogique et granulométrique plutôt que par le mécanisme d’altération. Cette conclusion questionne les travaux antérieurs et souligne la nécessité d’étudier la mobilité des radionucléides à échelle minérale. A cette fin, une approche sur fractions minérales a mis en évidence des processus d’échange entre les minéraux, avec une mobilité significative de 230Th, fortement appauvri dans les zircons, et 226Ra, enrichis en particulier dans la fraction argileuse. Les déséquilibres observés semblent induits par un processus d’altération récent, de quelque ka.Ces résultats sont confirmés par l’analyse des déséquilibres 238U-234U-230Th dans des minéraux par SIMS, qui montre un enrichissement en 230Th à la surface des monazites et une perte de Th (232, 230) dans les zircons. / The analysis of total sediments and grain-size fractions from the Gandak river (Himalaya) showed that the Uranium series variability observed for the Himalayan sediments is controlled by their mineralogical and grain-size evolution, rather than by the weathering process.This conclusion called into question the transfer timescale in Himalayan plains estimated by previous works and highlighted the need to explore radionuclide mobility at the mineral scale. For this purpose, an approach on pure mineral fractions pointed out exchange processes between the mineral phases, with a significant mobility of 230Th, strongly depleted in zircon, and 226Ra, particularly enriched in the clay fraction. The observed disequilibria are attributed to a recent weathering process of a few ky. Those observations are confirmed by the SIMS analysis of 238U-234U-230Th disequilibria on mineral grains, which show a 230Th enrichment at the grain surface in monazites and a loss of Th, 230 and 232, in zircons.
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Développement de méthodes de caractérisation chimiques de surface en support à l’amélioration des procédés de la microélectronique avancée / Development of surface analysis chemical characterization methods making possible to improve processes in advanced microelectronics

James, Anthony 09 July 2015 (has links)
L'objectif principal de ce travail de thèse a été de développer des méthodologies d'analyse de surface fiables pour caractériser divers nouveaux matériaux intégrés dans des structures de très faibles dimensions caractéristiques des développements actuels de la microélectronique. Un intérêt particulier a été porté sur l'utilisation combinée de plusieurs techniques complémentaires. Une première étude a porté sur les artefacts de caractérisation de couches isolantes (dioxyde de silicium et dioxyde de silicium dopé au fluor – FTEOS) situées entre les niveaux de métallisation des puces. Une étude systématique des effets de la dose électronique liée à une analyse AES a été réalisée en utilisant la complémentarité des techniques AES/XPS. Les résultats ont révélé des changements chimiques en extrême surface (sous-oxydes) dépendant de la nature du matériau. La seconde étude a porté sur la mise en oeuvre d'une méthodologie analytique pour la caractérisation de la couche de passivation formée sur les flancs de gravure après deux gravures plasma successives sur des structures de très faibles dimensions (lignes de 300 nm et tranchées de 200 nm). Cette méthodologie a été basée sur l'utilisation de l'effet de charge différentiel, observé lors d‘analyses simultanées de deux matériaux de propriétés électriques différentes, ainsi que sur la complémentarité des caractérisations par XPS et ToF-SIMS y compris des analyses XPS résolues en angles (AR-XPS). La composition chimique de l'extrême surface de la couche de passivation a ainsi pu être déterminée sur des parois verticales. La surface de cette couche a révélé être composée principalement par de l'oxygène ayant réagi avec le silicium pour former des sous-oxydes de silicium de différentes stoechiométries / The main goal of this thesis was to develop reliable surface analysis methods to characterize various new materials used in very small size structures typical of current developments in microelectronics applications. A particular interest has been taken in combining several complementary techniques. The first study was focused on potential artifacts when characterizing insulating layers (silicon dioxide and fluorine doped silicon dioxide – FTEOS) which are used between metal layers in chips. A comprehensive study of the electron dose effects in AES was performed using complementary AES and XPS techniques. The results revealed chemical changes in the outermost surface (suboxides) that depend on the nature of the material. The second study was focused on the development of an analytical methodology to characterize the passivation layer on the etch sidewalls after two successive plasma etching processes applied onto very small size structures (300 nm lines and 200 nm trenches). This methodology was based on the use of the differential charging effect that takes place when analyzing simultaneously two materials exhibiting different electrical properties and on the complementarity of ToF-SIMS and XPS characterizations including angular resolved XPS (AR-XPS). The chemical composition of the outermost surface of the sidewall passivation layer could then be determined. The surface of that layer was found to be consisting mostly from oxygen than reacted with silicon to form silicon suboxides with various stoichiometries

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