SILVA, J. S. P. Estudo das caracter?sticas f?sico-qu?micas e biol?gicas pela ades?o de osteoblastos em superf?cies de tit?nio modificadas pela nitreta??o em plasma. 2008. 119 f. Tese (Doutorado) - Faculdade de Medicina, Universidade de S?o Paulo. S?o Paulo, 2008. / Submitted by CECILIA SANTOS (cecilia@bczm.ufrn.br) on 2010-09-29T13:32:45Z No. of bitstreams: 2 2008Tese_JSandroPS_Estudo.pdf: 2786183 bytes, checksum: a2ca1d8386a1a0d5d0c3befb46b1ed92 (MD5) license_rdf: 20464 bytes, checksum: d540d98f4c56c073d1d99228e27d53ca (MD5) / Approved for entry into archive by clediane guedes(clediane@bczm.ufrn.br) on 2010-09-29T18:15:54Z (GMT) No. of bitstreams: 2 2008Tese_JSandroPS_Estudo.pdf: 2786183 bytes, checksum: a2ca1d8386a1a0d5d0c3befb46b1ed92 (MD5) license_rdf: 20464 bytes, checksum: d540d98f4c56c073d1d99228e27d53ca (MD5) / Made available in DSpace on 2010-09-29T18:15:54Z (GMT). No. of bitstreams: 2 2008Tese_JSandroPS_Estudo.pdf: 2786183 bytes, checksum: a2ca1d8386a1a0d5d0c3befb46b1ed92 (MD5) license_rdf: 20464 bytes, checksum: d540d98f4c56c073d1d99228e27d53ca (MD5) / PURPOSE: The aim of this study was to evaluated the physico-chemical properties of different titanium surfaces modified by means of low temperature plasma nitridind on rat osteoblast cell adhesion and proliferation. METHODS: Pure Titanium discs grade II was submitted to three different surface preparations (polishing, glowglow discharge plasma nitriding in planar and cathodic cage configurations). Surface parameters as roughness, wettability and chemichal composition was determined to compare influency of gas mixture on the modified surface material properties. Cellular morphology was observed by scanning electron microscopy.To evaluate the effect of the surface on cellular response, osteoblast cells (MC3T3) adhesion and proliferation was quantified and data analised by Kruskal-Wallis and Friedman statistical tests. RESULTS: plasma nitriding discs shows rougher surfaces( p<0,02) in cathodic cage configuration andlower contact angle values. MC3T3 cells attached on rough surfaces produced by cathodic cage configuration was statistically significant p<0,05 compared to polished discs. CONCLUSIONS: Glow discharge plasma nitriding improve titanium surface roughness and wettability. MC3T3 cell adhesion behavior is related to substrate chemical composition and topography. Resumo: INTRODU??O: Superf?cies de tit?nio modificadas por diferentes m?todos foram estudadas com base nos par?metros f?sicos e qu?micos de caracteriza??o superficial e sua influ?ncia no comportamento de c?lulas pr?osteobl?sticas (MC3T3) in vitro. M?TODOS: Discos de tit?nio comercialmente puro grau II foram submetidos a tr?s m?todos de modifica??o de superf?cie (polimento, nitretados em plasma em configura??o planar e gaiola cat?dica). As diferentes superf?cies foram caracterizadas para observar o efeito do processamento na estrutura da camada superficial, na rugosidade e molhabilidade. Ensaios de ades?o e prolifera??o celular usando linhagens de c?lulas pr?-osteobl?sticas MC3T3 foram realizados para avaliar o efeito das novas superf?cies no comportamento celular in vitro. RESULTADOS: Os resultados demonstraram que a nitreta??o em plasma na configura??o de gaiola cat?dica produz superf?cies mais rugosas (p<0,02) e com menores ?ngulos de contato com a ?gua. CONCLUS?ES: A ades?o celular ? maior nas superf?cies mais rugosas do que nas superf?cies polidas (p<0,05) e reagem de modo diferente a composi??o qu?mica do substrato e ? topografia da superf?cie

In nature, environments are often variable and heterogeneous influencing ecological and evolutionary processes. This thesis focus on how animals interact with their environment and how that affects the reproductive decisions they make. Using empirical data collected from wild collared flycatcher populations, experiments and molecular approaches I try to unveil some of these relationships and the evolutionary, ecological and conservation implications of these findings are discussed. Firstly, collared flycatchers were shown to use breeding densities of their own and other species using similar resources when assessing costs and benefits associated to breeding in specific habitats. However, species will vary in how informative they are, and the worst competitor – with whom you overlap most in resources needs – also provides the best source of information. Collared flycatcher parents will also benefit differentially from investments in sons and daughters due to habitat characteristics and dispersal differences between the sexes. Here, I show that they will produce more of the sex that will give the highest expected fitness return given the environment they are in. These results also provide a reciprocal scenario to Clark's (1978) classical study of sex ratio adjustment in relation to local resource competition (LRC), as more of the natal philopatric sex is produced when LRC is low. Secondly, the effect of elaborated ornaments on paternity in the socially monogamous collared flycatcher was shown to be of more importance in areas where the intensity of intra- and intersexual conflicts are expected to be elevated. Hence, ornamentation by environmental interactions determines paternity, illustrating that sexual selection through extra-pair paternity is context dependent. Finally, even though the collared flycatcher populations that this thesis is based on have been studied on their breeding grounds for more then 25 years, we know little of where they are when they are not breeding. Here, stable isotope signatures in winter-grown feathers suggests that they may spend their winter with their breeding ground neighbours and do so repeatedly over years. Differences between breeding populations at this small scale should have many impactions for evolutionary and ecological processes as it will, for example, determine with whom individuals interact throughout their life.

By warning signalling prey advertises its unpalatability to the predators. Typical examples are true bugs (Heteroptera) combining optical and chemical signals. The aim of this study was to find out the effectiveness of chemical defence against wild-caught adults of great tits (Parus major) and blue tits (Cyanistes caeruleus) and towards hand-reared juveniles of great tits. The tested prey were adults and larvae of two invasive species of genus Oxycarenus (Heteroptera: Oxycarenidae) (aposematic O. lavaterae, non-aposematic O. hyalinipennis), adults of Horvathiolus superbus (Heteroptera: Lygaeidae) and crickets (Gryllus assimilis) as a control prey. We were focusing on the influence of seed bugs to the initial reaction, the learning process and to the displays of discomfort behaviour in tits. Reactions affected by the tit species, age and sex were compared in adults. Juveniles were divided into two independent experimental groups, one group was offered adults of genus Oxycarenus, the second was offered sunflower (Helianthus sp.) or Digitalis sp. seed fed adults of H. superbus. The first bug offered did not elicit an initial aversive reaction in tits, but birds reacted aversively to the bugs after having further handling experience. All juveniles, contrary to the adult tits, attacked at least one bug...

Understanding the genetic basis of fitness differences has been a major goal for evolutionary biologists over the last two decades. Although there are many studies investigating how natural selection can promote local adaptation, few have succeeded to find the link between genotype and fitness of the phenotype. Polymorphic genes of the major histocompatibility complex (Mhc) are excellent candidates for such associations as they are a central component of the vertebrate immune system, playing an important role in parasite resistance, and hence can have direct effects on survival of their bearers. Although associations between Mhc and disease resistance are frequently documented, the epidemiological basis of the host-parasite interaction is often lacking and few studies have investigated the role that Mhc genes play in individual variation in fitness; thus comparatively little is known about the fitness consequences of Mhc in wild populations. Furthermore, the majority of work to date has involved testing associations between Mhc genotypes and disease. However, the mechanism by which any direct selection on the Mhc acts, depends on how genotypes map to the functional properties of Mhc molecules. The aim of this thesis was to characterize Mhc alleles in terms of their predicted functional properties and to investigate whether and how selection operates on Mhc class I functional variation using the great tit (Parus major) population at Wytham Woods as a model host species. Through a comprehensive characterization effort and the use of 454 pyrosequencing platform, I performed a detailed analysis of genetic variation at Mhc class I exon 3 and grouped alleles with similar antigen-binding affinities into supertypes to classify functionally distinct Mhc types. There was extreme complexity at the Mhc class I of the great tit both in terms of allelic diversity and gene number. A total of 862 alleles were detected from 857 individuals; the highest number yet characterized in a wild bird species. The functional alleles were clustered into 17 supertypes; there was clear evidence that functional alleles were under strong balancing selection. To understand the role of Mhc in disease resistance, I examined the linkage between Mhc supertypes, Plasmodium infection and great tit survival, and showed that certain functional variants of Mhc confer resistance to two divergent Plasmodium parasite species that are common in the environment. I further investigated the fitness consequences of functional variation at Mhc, using mark-recapture methods and long-term breeding data; and tested the hypotheses that selection: (i) maximizes Mhc diversity; (ii) optimizes Mhc diversity, or (iii) favours specific functional variants. I found that the presence of three different supertypes was associated with three different components of individual fitness: adult survival, annual recruitment probabilities and lifetime reproductive success. In contrast, there was no evidence for a selective advantage of Mhc functional diversity, either in terms of maximal or optimal supertype diversity. Finally, I explored the role that Mhc plays in female mate choice decisions and examined the reproductive fitness consequences of Mhc-dependent mating patterns. There was little evidence to suggest that functional dissimilarity at Mhc has any influence on female mate choice decisions or that dissimilarity at Mhc affects the reproductive output of the social pair. Overall, this thesis provides strong support for the suggestion that selection favours specific functional variants of Mhc, possibly as a result of supertype-specific resistance or susceptibility to parasites that exert strong selective pressures on their hosts; whereas there is no support for selection favouring maximal or optimal Mhc diversity. More importantly it demonstrates that functional variants of Mhc class I loci are an important determinant of individual fitness in natural populations.

Made available in DSpace on 2015-04-14T13:58:44Z (GMT). No. of bitstreams: 1 434834.pdf: 2467680 bytes, checksum: d94eca86dabe6ec28377349c07e8a880 (MD5) Previous issue date: 2011-08-31 / O comportamento passivante da camada formada de ?xido de tit?nio ? uma caracter?stica relevante para a aplica??o biom?dica. As intera??es com o meio biol?gico ap?s a implanta??o de uma pr?tese est?o diretamente ligadas, entre outros fatores, com as propriedades f?sico-qu?micas da superf?cie do material implantado. As superf?cies de tit?nio que s?o tratadas qu?mica ou eletroquimicamente tendem a desenvolver camadas espec?ficas com composi??o qu?mica e porosidade que promovem a osseointegra??o. O objetivo deste trabalho ? estudar o processo de anodiza??o para desenvolver o crescimento de nanotubos de TiO2 em substrato de tit?nio comercialmente puro. Foram utilizadas solu??es eletrol?ticas de 1M H3PO4 e 0,2 % de HF variando a tens?o aplicada e alterando o distanciamento entre os eletrodos. Ap?s o processo an?dico as esp?cimes foram tratadas termicamente nas temperaturas de 500, 600, 700, 800 e 900?C. Os film es formados e tratados termicamente foram analisados por microscopia eletr?nica de varredura (MEV), espectroscopia por energia dispersiva (EDS) e difratometria de raios X (DRX). Os resultados indicaram a forma??o de nanotubos nos filmes de ?xidos de tit?nio tratados anodicamente em toda extens?o da superf?cie, al?m de boa uniformidade da camada de ?xido e regularidade do di?metro dos nanotubos de 171nm. As an?lises da composi??o qu?mica indicaram a presen?a de f?sforo, oriundos das condi??es do experimento. A estrutura cristalogr?fica verificada foi hexagonal, a qual corresponde ? estrutura do tit?nio.

Made available in DSpace on 2015-04-14T14:50:47Z (GMT). No. of bitstreams: 1 399015.pdf: 142110 bytes, checksum: c5ffb33c81a7c9cbade03c8428376c8e (MD5) Previous issue date: 2007-12-05 / Uma conex?o est?vel entre a superf?cie de tit?nio e os tecidos a sua volta ? um dos mais importantes pr?-requisitos para o sucesso a longo prazo dos implantes. Para isso, uma forte e efetiva ades?o das c?lulas na superf?cie do biomaterial ? requerida. O objetivo desse estudo foi o de avaliar a ades?o de fibroblastos estimulados por Fator de Crescimento de Fibroblastos b?sico (bFGF) em discos de tit?nio. Para esse estudo foram produzidos 30 discos de tit?nio com superf?cie lisa. Esses discos foram colocados em placas de cultura e sobre eles foi inserido meio com fibroblastos NIH3T3, estimulados por bFGF, no grupo teste e sem este fator de crescimento no controle. As amostras foram obtidas em 3 horas, 24 horas e 48 horas. Foram feitas 10 imagens com Microsc?pio Eletr?nico de Varredura em cada disco, totalizando 300 micrografias. Como resultado foi encontrado que existe uma diferen?a significativa no crescimento de fibroblastos nos tr?s tempos deste experimento, do grupo onde o bFGF foi administrado.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-12-08T16:24:06Z No. of bitstreams: 1 476571 - Texto Completo.pdf: 1876137 bytes, checksum: 9fe390eadadb7a4c4bb1e5c4f411b37c (MD5) / Made available in DSpace on 2015-12-08T16:24:07Z (GMT). No. of bitstreams: 1 476571 - Texto Completo.pdf: 1876137 bytes, checksum: 9fe390eadadb7a4c4bb1e5c4f411b37c (MD5) Previous issue date: 2015-03-13 / This study evaluates the electrochemical anodization process parameters in the formation of titanium nanotubes on titanium sheets in order to determine their implications on the morphology of the tubes and the film/substrate adhesion. The evaluated parameters were the anodization time, applied potential, water content in the electrolyte and the electrolyte stirring (ultrasound bath and magnetic agitation) in an ethylene glycol electrolyte with addition of ammonium fluoride. The obtained results were compared to those obtained from the anodization in an aqueous acid electrolyte (mixed solution of hydrofluoric and phosphoric acid). Analyzes using scanning and transmission electron microscopy were performed for the morphological characterization of the samples. Rutherford backscattering spectrometry was used to determine the composition and density profile of the different oxide layers formed. Tensile tests (pull out) were used in order to determine the adhesion of the titanium nanotubes to the substrate. The results showed that it is possible to form titanium nanotubes with various morphologies by changing the parameters of the electrolytic process. The average adhesive tension of nanotubes ranged from 2,82 ? 0,27 Mpa to 5,18 ? 3,61 MPa, however, it was not possible to observe a direct relationship between the morphologies formed and the obtained adhesive tension values. / No presente trabalho, foram estudados os par?metros do processo de anodiza??o eletroqu?mica para forma??o de nanotubos de tit?nio (NTT) sobre chapas de tit?nio a fim de determinar suas implica??es na morfologia dos tubos e na ades?o NTT/substrato. Os par?metros avaliados foram o tempo de anodiza??o, a tens?o de trabalho, o teor de ?gua no eletr?lito e o tipo de agita??o do eletr?lito (banho de ultrassom e magn?tica) usando um eletr?lito org?nico de etilenoglicol com adi??o de fluoreto de am?nia. Os resultados obtidos foram comparados com os de anodiza??es feitas em eletr?lito aquoso ?cido (mistura de ?cido fluor?drico com ?cido fosf?rico). Para a caracteriza??o morfol?gica das amostras, foram realizadas an?lises de microscopia eletr?nica de varredura (FEGMEV) e de transmiss?o (MET). Para a determina??o de um perfil de composi??o e densidade das diferentes camadas ?xidas formadas foi utilizada espectrometria de retroespalhamento Rutheford (RBS). Para determinar a ades?o dos NTT ao substrato de tit?nio foram utilizados testes de tra??o (pull out). Os resultados mostraram que ? poss?vel crescer NTT com diversas morfologias a partir das altera??es dos par?metros do processo eletrol?tico. As m?dias da tens?o adesiva dos NTT ao Ti apresentaram valores variando entre 2,82 ? 0,27 MPa e 5,18 ? 3,61 MPa, contudo n?o foi poss?vel observar uma rela??o direta entre as morfologias formadas e os valores de tens?o de ades?o obtidos.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-04-06T11:40:47Z No. of bitstreams: 1 DIS_MARCEL_FERREIRA_KUNRATH_COMPLETO.pdf: 1943048 bytes, checksum: f2472fa9da9d6ca1d610f11f2d69bc64 (MD5) / Made available in DSpace on 2016-04-06T11:40:47Z (GMT). No. of bitstreams: 1 DIS_MARCEL_FERREIRA_KUNRATH_COMPLETO.pdf: 1943048 bytes, checksum: f2472fa9da9d6ca1d610f11f2d69bc64 (MD5) Previous issue date: 2016-01-12 / With the growing expansion of implant surfaces and the need for greater speed of osseointegration, methods of analysis of bone tissue and implant surface as well as the quality of the bone implant contact (BIC), they are increasingly being explored by researchers. The aim of this study is to show detail and describe a bone preservation protocol for making implants samples with and without implants without any harm or damage, or the bone tissue or the properties of the metal, preserving the BIC. In a second step, the samples prepared by the protocol preservation were compared with those made by histological analysis method for staining for HE, considered the gold standard for living tissue. Eight samples were used for bone tissue with implants in rabbit tibia and more four fragments of jaws without implants of the same rabbits. Samples with and without implants were made by the two protocols, after preparation of the test specimens, analysis by optical microscopy of transmission and reflection through scanned images were made. Each protocol had advantages when the results were analyzed individually in the implants without samples, becoming further analysis. However, for samples with implants, analysis only by histological method cannot bring good results, while the bone preservation method showed excellent results for osseointegration analysis, bone formation and bone implant interface. It follows that the bone preservation protocol is an excellent method for analyzing samples with implants, and can be complementary to histology, in analysis bone samples without implants. The histological method is not sufficient for analysis of bone formation and bone implant interface. / Com a crescente expans?o de superf?cies de implantes e a necessidade de maior velocidade de osseointegra??o, m?todos de an?lise do tecido ?sseo, an?lises da superf?cie de implantes e a qualidade do contato osso-implante (BIC) est?o cada vez mais sendo explorados pelos pesquisadores. O objetivo do presente estudo foi descrever detalhadamente um protocolo de preserva??o ?ssea para confec??o de amostras com e sem implantes, sem causar danos ou avarias nem ao tecido ?sseo nem ?s propriedades do metal, preservando o BIC. Em uma segunda etapa, as amostras confeccionadas pelo protocolo de preserva??o ?ssea foram comparadas com as amostras preparadas pelo m?todo de an?lise histol?gica por colora??o por Hematoxilina-Eosina, considerado padr?o ouro para tecidos vivos. Foram utilizadas oito amostras de tecido ?sseo com implantes de t?bias de coelhos e, mais quatro fragmentos de mand?bulas sem implantes, dos mesmos coelhos. As amostras com e sem implantes foram confeccionadas pelos dois protocolos e, ap?s a prepara??o dos corpos de prova, foram feitas as an?lises por microscopia ?ptica de transmiss?o e reflex?o atrav?s de imagens digitalizadas. Cada protocolo apresentou vantagens quando os resultados foram analisados individualmente nas amostras sem implantes. Por?m, para as amostras com implantes, a an?lise apenas pelo m?todo histol?gico n?o conseguiu apresentar bons resultados, enquanto que o m?todo de preserva??o ?ssea mostrou excelentes resultados para an?lise de osseointegra??o, neoforma??o ?ssea e interface osso-implante. Conclui-se que o protocolo de preserva??o ?ssea desenvolvido mostrou-se um excelente m?todo para an?lise de amostras com implantes, e que pode ser complementar ? histologia, em an?lises de tecido ?sseo sem implantes. O m?todo histol?gico n?o mostrou-se suficiente para an?lise de neoforma??o ?ssea e interface osso-implante.

Made available in DSpace on 2015-04-14T13:29:36Z (GMT). No. of bitstreams: 1 422228.pdf: 2027786 bytes, checksum: fc45ed715786efb01f83f7fff755ceef (MD5) Previous issue date: 2010-01-14 / Atualmente, o foco de muitas pesquisas cient?ficas em Implantodontia est? voltado para a modifica??o da superf?cie do tit?nio na busca de alternativas que proporcionem maior rapidez e qualidade no processo de osseointegra??o. A osseointegra??o ? um fen?meno que acontece fundamentalmente atrav?s da resposta interfacial das c?lulas ?sseas em contato com a superf?cie do tit?nio. Diferentes m?todos de tratamento podem ser utilizados para modificar as propriedades topogr?ficas e qu?micas da superf?cie do tit?nio a fim de otimizar as rea??es tecido-implante. Neste estudo foi avaliada a influ?ncia de diferentes tratamentos de superf?cie do tit?nio na ades?o e prolifera??o de osteoblastos humanos, atrav?s da an?lise quantitativa do n?mero de c?lulas aderidas em diferentes per?odos de cultura celular. Para isso, 40 discos de tit?nio grau II, comercialmente puro, de 15mm de di?metro e 1mm de espessura, foram divididos em quatro grupos conforme a caracteriza??o de sua superf?cie: G1. maquinada; G2. ?cido-condicionada; G3. com cobertura de hidroxiapatita; e G4. com bisfosfonato imobilizado na cobertura de hidroxiapatita. C?lulas osteobl?sticas derivadas de osteossarcoma humano (SaOS-2) foram cultivadas sobre os discos e a contagem celular foi realizada em 3, 7 e 14 dias. Para determina??o do n?mero de c?lulas, um processo de colora??o dos n?cleos com Iodeto de Prop?dio foi realizado, e os discos foram analisados em microsc?pio ?ptico sob luz ultravioleta. As contagens celulares nos diferentes grupos experimentais e per?odos de cultura foram comparadas por meio de ANOVA, complementado pelo teste de Tukey. Os resultados da an?lise estat?stica permitem concluir que: (1) a superf?cie do tit?nio e o per?odo de cultura celular, bem como a intera??o de ambos, significativamente afetam o crescimento celular; (2) a modifica??o na superf?cie do tit?nio atrav?s de condicionamento ?cido favorece, in vitro, a ades?o e prolifera??o de osteoblastos humanos. Mais pesquisas s?o necess?rias para elucidar a influ?ncia do bisfosfonato imobilizado na superf?cie do tit?nio nos eventos iniciais da osteog?nese.

Made available in DSpace on 2015-04-14T13:29:42Z (GMT). No. of bitstreams: 1 417773.pdf: 1138982 bytes, checksum: 03423e2cddaa5a43349be69c0853e615 (MD5) Previous issue date: 2009-08-31 / Os implantes osseointegrados, em sua maioria, possuem algum tipo de condicionamento da sua superf?cie que visa melhorar a osseointegra??o. O mecanismo de diferencia??o celular in vitro de c?lulas mesenquimais em osteoblastos j? ? bastante conhecido e serve para avalia??o das propriedades de osteoindu??o e osteocondu??o de biomateriais. O presente estudo tem por objetivo avaliar a ades?o, prolifera??o e diferencia??o das c?lulas da medula ?ssea humana em superf?cies de implantes de tit?nio com e sem deposi??o discreta de fosfato de c?lcio. As c?lulas foram obtidas a partir da medula ?ssea de um doador humano. Foram selecionados 12 discos de tit?nio do tipo Bonelike? (Biomet 3I, Brasil) com superf?cie tratada por duplo ataque ?cido; Osseotite (Biomet 3I, USA) com superf?cie tratada por duplo ataque ?cido e Nanotite (Biomet 3I, USA). Ap?s 14 e 21 dias de cultura foi realizado PCR em tempo real para avalia??o da diferencia??o celular e microscopia eletr?nica de varredura para avalia??o da prolifera??o e ades?o celular aos discos de tit?nio. Os resultados indicaram que a rugosidade da superf?cie dos discos de tit?nio possibilita a ades?o, diferencia??o e prolifera??o celular, que a s?ntese de ALP ? maior na superf?cie Bonelike e que as part?culas de fosfato de c?lcio demonstraram maior grau de s?ntese de BGLAP e prolifera??o celular.