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No description available.

The biosynthesis of integral membrane proteins (IMPs) is an essential cellular process. IMPs comprise roughly 20-30% of the protein coding genes of all organisms, nearly all of which are inserted and assembled at the endoplasmic reticulum (ER). The defining structural feature of IMPs is one or more transmembrane domains (TMDs). TMDs are typically stretches of predominately hydrophobic amino acids that span the lipid bilayer of biological membranes as an alpha helix. TMDs are remarkably diverse in terms of their topological and biophysical properties. In order to accommodate this diversity, the cell has evolved different sets of machinery that cater to particular subsets of proteins. Our knowledge of how the TMDs of IMPs are selectively recognized, chaperoned into the lipid bilayer, and assembled remains incomplete. This thesis is broadly interested in investigating how TMDs are correctly inserted and assembled at the ER. To address this the biosynthesis of multi-pass IMPs was first considered. Multi-pass IMPs contain two to more than twenty TMDs, with TMDs that vary dramatically in terms of their biophysical properties such as hydrophobicity, length, and helical propensity. The beta-1 adrenergic receptor (β1-AR), a member of the G-protein-coupled receptor (GPCR) family was established as a model substrate in an in vitro system where the insertion and folding of its TMDs could be interrogated. Assembly of β1-AR is not a straightforward process, and current models of insertion fail to explain how the known translocation machinery correctly identifies, inserts, and assembles β1-AR TMDs. An in vivo screen in mammalian cells was therefore conducted to identify additional factors which may be important for multi-pass IMP assembly. The ER membrane protein complex (EMC), a well conserved ER-resident complex of unknown biochemical function, was identified as a promising hit potentially involved in this assembly process. The complexity of working with multi-pass IMPs in an in vitro system prompted the investigation of a simpler class of proteins. Tail-anchored proteins (TA) are characterized by a single C-terminal hydrophobic domain that anchors them into membranes. Though structurally simpler compared to multi-pass IMPs, the TMDs of TA proteins are similarly diverse. We found that known TA insertion pathways fail to engage low-to-moderately hydrophobic TMDs. Instead, these are chaperoned in the cytosol by calmodulin (CaM). Transient release from CaM allows substrates to sample the ER, where resident machinery mediates the insertion reaction. The EMC was shown to be necessary for the insertion of these substrates both in vivo and in vitro. Purified EMC in synthetic liposomes catalysed insertion of its TA substrates in a fully reconstituted system to near-native levels. Therefore, the EMC was rigorously established as a TMD insertase. This key functional insight may explain its critical role in the assembly of multi- pass IMPs – which is now amenable to biochemical dissection.

Mutations in the COL10A1 gene cause metaphyseal chondrodysplasia type Schmid (MCDS) by triggering ER stress and unfolded protein response (UPR). MCDS is characterised by a mild short-limb dwarfism accompanied by expansion of the cartilage growth plate hypertrophic zone (HZ) and altered differentiation of hypertrophic chondrocytes (HCs). ATF6 is one of the UPR mediators, which exists in two isoforms, ATF6α and ATF6β. Activation and up-regulation of ATF6α was a prominent biochemical sign of ER stress in a mouse model of MCDS, COL10a1 p.N617K. Although ATF6β is induced and activated in response to ER stress in a similar fashion to ATF6α, the role and significance of ATF6β in the pathology of many ER stress-associated diseases including MCDS is unknown. Here we utilized a combination of in vitro and in vivo approaches to define the precise role of each isoform of ATF6 in MCDS.To investigate the functions of ATF6α and ATF6β in vitro, we developed a MCDS cell model system (expressing either the wild type collagen X or one of the following MCDS-causing mutant forms of the protein: p.N617K, G618V, Y598D, and NC1del10) in which the expression of either ATF6α or ATF6β was efficiently silenced using siRNAs. ATF6α knockdown in HeLa cells expressing different MCDS-causing mutations suppressed the increased expression of UPR-associated genes such as BiP leading to an elevated ER stress, based on increased XBP1 splicing and/or ATF4 protein. In contrast, ATF6β knockdown did not significantly affect the mutant collagen X-induced increased expression of UPR-associated genes. Furthermore, the ER stress levels were significantly reduced in the ATF6β knockdown MCDS mutant cells based on the lower levels of XBP1 splicing and/or ATF4 protein detected. We then crossed the ATF6α/β knockout mice models with COL10a1 p.N617K mouse model of MCDS to investigate the function of ATF6α and ATF6β in vivo. Ablation of ATF6α in MCDS mice further- reduced the endochondral bone growth rate, further expanded the growth plate hypertrophic zone, and disrupted differentiation of HCs. Therefore, ATF6α appeared to play a chondroprotective role in MCDS as its deficiency caused an increase in the severity of the disease. Of particular note, the level of ER stress was further increased in the absence of ATF6α in MCDS, based on enhanced activities of PERK and IRE1 signalling pathways in compensation for the ATF6α loss. Paradoxically, ablation of ATF6β in MCDS mice reduced the intracellular retention of collagen X protein, and alleviated the ER stress as judged by the attenuated activities of PERK and IRE1 signalling pathways. The reduced ER stress resulting from deficiency for ATF6β in MCDS mice restored the expression of collagen X mRNA towards normal and improved the differentiation of HCs, causing a mark decrease in the expansion of HZ. The results presented within this thesis greatly increased our understanding of the function of ATF6α and ATF6β and their interplay in the pathogenesis of MCDS. We demonstrated an indispensable beneficiary role for ATF6α but a detrimental role for its closely related isoform, ATF6β, in pathology of MCDS. We also showed that the role of ATF6β should not be ignored. These findings may be used to develop a potential therapeutic strategy for MCDS through targeting and enhancing ATF6α-dependent and/or attenuating/blocking of ATF6β-dependent signalling pathways.

Distraction and cognitive reappraisal are two widely used types of emotional regulation strategies that are thought to be reliable when down-regulating our emotions to negative or unpleasant stimuli. Gross‘s process model of emotion generation (Gross, 1998) holds that they differ in the time they intervene in the emotiongenerative process and also how they impact emotional responses when they are used to regulate negative emotions. Distraction which involves attentional deployment is expected to operate earlier than reappraisal that entails meaning evaluation and reevaluation. Cognitive reappraisal encompasses various strategies that are used to regulate our emotions through reinterpretation. Self-focused and situation-focused reappraisal are two of them. The former is considered more efficient and thus would lead to a greater attenuation of the LPPthan the latter. To test this prediction, electrocortical responses to angry faces when using these strategies were measured using the late positive potential (LPP). Twenty four healthy participants were recruited for the study and were cued to down-regulate their emotions using these strategies while angry and neutral facial stimuli were seen on a computer screen. Contrary to prediction, distraction did not modulate the LPP earlier than reappraisal. However, supporting our hypothesis self-focused strategies largely modulated the LPP than situation-focused strategy. The pattern of result suggests that reappraisal might have an influence on the early neural processes of emotion generation and that the subcategories of cognitive reappraisal have a differential effect on emotional regulation.

Submitted by Fernanda Alves Feitosa null (fernanda.feitosa@fosjc.unesp.br) on 2016-06-07T14:46:57Z No. of bitstreams: 1 Tese ok - versão final com ficha catalografica certa.pdf: 3711607 bytes, checksum: d94558d40ddaabd3c84ddd7cdec2d8bb (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-08T13:34:17Z (GMT) No. of bitstreams: 1 feitosa_fa_dr_sjc.pdf: 3711607 bytes, checksum: d94558d40ddaabd3c84ddd7cdec2d8bb (MD5) / Made available in DSpace on 2016-06-08T13:34:17Z (GMT). No. of bitstreams: 1 feitosa_fa_dr_sjc.pdf: 3711607 bytes, checksum: d94558d40ddaabd3c84ddd7cdec2d8bb (MD5) Previous issue date: 2016-06-02 / O objetivo desse estudo foi avaliar a eficiência da irradiação com lasers de alta potência e a influência da aplicação do silano previa ou posteriormente à irradiação com os lasers na resistência de união entre cerâmica vítrea de dissilicato de lítio, cimento resinoso e dentina humana. Foram confeccionados 50 espécimes tronco-cônicos de cerâmica (n=10), divididos aleatoriamente em 5 grupos: 1- Controle- Condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano; 2- Er:YAG – irradiação com laser Er:YAG (200 mJ e 10 Hz), seguido do condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano; 3- Silano + Er:YAG – Condicionamento com ácido hidrofluorídrico 10% por 1 min, aplicação do silano e irradiação com laser Er:YAG nos mesmo parâmetros do grupo anterior; 4- Nd:YAG – irradiação com laser Nd:YAG (120 mJ e 10 Hz), seguido de condicionamento com ácido hidrofluorídrico 10% por 1 min e aplicação do silano, 5- Silano + Nd:YAG - Condicionamento com ácido hidrofluorídrico 10% por 1 min, aplicação do silano e irradiação com laser Nd:YAG nos mesmo parâmetros do grupo anterior. Após os tratamentos os espécimes cerâmicos foram cimentados com cimento resinoso de presa dual à superfície de dentina de 50 molares humanos incluídos em resina acrílica ativada quimicamente. Após armazenamento por 24 h foi realizado o ensaio de tração em máquina de ensaios universais com célula de carga de 10 KgF e velocidade constante de 1mm/min. Os dados obtidos foram submetidos à ANOVA 2-fatores e teste de Dunnet (α=5%). A análise dos padrões de fratura foram analisadas em estereomicroscopio. Adicionalmente foram confeccionados 15 espécimes em cerâmica no formato cilíndrico, submetidos aos mesmo tratamentos dos grupos anteriores (n=3) e utilizados para análise do ângulo de contato e análise em microscópio eletrônico de varredura. O teste de Dunnet mostrou diferenças significativas entre o grupo controle (9,42 ± 2,27 MPa) e os grupos Er (19,25 ± 3,7 MPa) e Sil+Er (14,11 ± 4,11 MPa). A análise de variância (p<5%) para os fatores Tipo de Laser (p<0,0001) e Técnica de Silanização (p=0,0002) mostraram diferenças significativas para os dois fatores, porém não para sua interação. Assim, a irradiação com Er:YAG (16,68 MPa) mostrou-se mais eficiente que a irradiação com Nd:YAG (8,19 MPa). A técnica de silanização posterior à irradiação com laser (14,46 MPa) também se mostrou superior à silanização previa (10,41 MPa). Quanto à análise de fraturas, o grupo Controle teve prevalência de falhas adesivas em dentina e em cerâmica; os grupos Nd, Sil + Nd e Sil + Er tiveram prevalência de falhas adesivas em cerâmica, e o grupo Er apresentou predominância de falhas coesivas no cimento. A análise do ângulo de contato foi submetida aos testes ANOVA 1-fator e Tukey, apresentando diferenças significativas entre os grupos (p<0,0001). Os grupos com silanização prévia (Sil + Er = 45,60b graus; Sil + Nd = 52,10b graus) apresentaram ângulos de contato superiores aos demais, e semelhantes entre si. As imagens de Microscopia Eletrônica de Varredura mostram a presença da camada de silano sobre a superfície cerâmica no grupo Sil + Nd, e uma aparente fundição à superfície cerâmica no grupo Sil + Er. Para os Grupos Er e Nd foi possível verificar modificações no padrão normal da estrutura da cerâmica, entremeadas por áreas semelhantes ao padrão convencional do grupo Controle após condicionamento com ácido hidrofluorídrico. Conclui-se que o tratamento com laser de Érbio associado ao condicionamento com ácido hidrofluorídrico a 10% por 1 min apresenta os melhores resultados de resistência de união e ângulo de contato. O tratamento com silano previamente à irradiação melhorou a resistência de união em relação ao grupo Controle apenas quando associado ao laser de Érbio. / The aim of this study was to evaluate the efficiency of irradiation with high-power lasers and the influence of silane application before or after irradiation with lasers on the bond strength between lithium disilicate glass-ceramic, resin cement and human dentin. Fifty truncated-cones ceramic specimens (n=10) were randomly divided into 5 groups: Control- etching with hydrofluoric acid 10% for 1 min and application of silane; 2- Er - Er:YAG laser irradiation (200 mJ and 10 Hz), followed by etching with hydrofluoric acid 10% for 1 min and application of silane; 3- Sil + Er - etching with hydrofluoric acid 10% for 1 min, silane application and irradiation with Er: YAG laser in the same parameters as the previous group; 4- Nd:YAG laser - irradiation with Nd: YAG laser (120 mJ and 10 Hz), followed by etching with hydrofluoric acid 10% for 1 min and application of the silane, 5- Sil + Nd- Etching with hydrofluoric acid 10% for 1 min, silane application and irradiation with Nd: YAG laser on the same parameters as the previous group. After treatment, the ceramic specimens were cemented with dual cure resin cement to the dentin of 50 human molars included in acrylic resin. After storage for 24 h it was submitted to tensile test in a universal testing machine with 10 kgf load cell and constant speed of 1 mm/min. Data were submitted to ANOVA 2-way and Dunnet test (α = 5%). The analysis of fracture patterns were analyzed in stereomicroscope. In addition were made 15 ceramic specimens in cylindrical shape, subjected to the same treatment of the above groups (n = 3) and used for analysis of the contact angle analysis and scanning electron microscope. The Dunnet test showed significant differences between Control group (9.42 ± 2.27 MPa) and Er group (19.25 ± 3.7 MPa) and Sil + Er (14.11 ± 4.11 MPa). ANOVA 2-way (p <5%) for Laser Type (p <0.0001) and Technical of Silanization (p = 0.0002) showed significant differences for both factors, but not for their interaction. Thus, the irradiation with Er:YAG laser (16,68 MPa) was more effective than irradiation with Nd:YAG laser (8,19 MPa). The technique of silanization after laser irradiation was more effective (14,46 MPa) than the previous silanization (10,41 MPa). The analysis of fractures showed a prevalence of adhesive failures on dentin and ceramic for the Control group; Nd, Sil + Nd e Sil + Er had a prevalence of adhesive failures in ceramics, and Er group presented predominance of cohesive failures in cement. The analysis of contact angle was submitted to ANOVA 1-way and Tukey test, with significant differences between the groups (p <0.0001). Groups with silanization previous to laser irradiation (Sil + Er = 45,60b degrees; Sil + Nd = 52,10b degrees) had contact angles greater than the other groups. The Scanning Electron Microscopy images showed the presence of a silane layer on the ceramic surface in Sil + Nd group, and an apparent casting of the ceramic surface in Sil + Er group. For Er and Nd Groups was possible to see changes in the normal pattern of ceramic structure, interspersed with areas similar to conventional standard control group after etching with hydrofluoric acid. It is concluded that treatment with Er:YAG laser associated with etching with hydrofluoric acid at 10% for 1 min gives the highest bond strength results and the lower contact angle, resulting in a recommended treatment. Treatment with silane previously to laser irradiation improved bond strength only when associated with the Er:YAG laser, which probably occurred by the efficiency of Er: YAG laser irradiation, and not due to the silanization technique.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:17:38Z No. of bitstreams: 1 MarcelaRibeiro_DISSERT.pdf: 946035 bytes, checksum: 921123383ebaeec86fe2de48dfe8f68e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-06T23:21:21Z (GMT) No. of bitstreams: 1 MarcelaRibeiro_DISSERT.pdf: 946035 bytes, checksum: 921123383ebaeec86fe2de48dfe8f68e (MD5) / Made available in DSpace on 2016-06-06T23:21:21Z (GMT). No. of bitstreams: 1 MarcelaRibeiro_DISSERT.pdf: 946035 bytes, checksum: 921123383ebaeec86fe2de48dfe8f68e (MD5) Previous issue date: 2015-06-17 / A presente pesquisa tem como proposta geral a delimita??o do espa?o er?tico no papel impresso, em meio ao texto po?tico. Para tanto, prop?e-se comparar duas escritas de car?ter transgressor, fazendo a uni?o da portuguesa Maria Teresa Horta e do brasileiro Carlos Drummond de Andrade pela trama er?tica, pelo discurso at?pico e marginal do erotismo para o qual os dois produziram livros, que s?o, respectivamente, Educa??o sentimental (1975) e O amor natural (1992). Tem-se o erotismo como a soma das vozes masculina e feminina na rela??o heterossexual e pretende-se esquadrinhar como o universo da literatura representa o homem e a mulher e se essa representa??o na verdade ? imposta socialmente ou se traz ? luz algo de novo. Se cada ponto de vista ? a vista de um ponto, cada autor falar? do alto de seu ponto de observa??o e experimenta??o, o mais confort?vel para si. Para tanto, busca-se investigar o erotismo em si e sua rela??o com a vida cotidiana, delimitando tamb?m o que o afasta - ou aproxima - da pornografia e da obscenidade. / This research has the delimitation of erotic space on printed paper as a general proposition, amidst the poetic text, and therefore the real world. To do so, it proposes the comparison of two transgressor writing styles, putting together the Portuguese writer Maria Teresa Horta and the Brazilian writer Carlos Drummond de Andrade by an erotic plot, by an atopic and declassed speech to which both of them produced works, respectively, Educa??o Sentimental (1975) and O amor natural (1992). Has the eroticism as a combination of the masculine and feminine voices in a heterosexual relationship. It is intended to probe how the literary universe represents man and woman, and if this representation is actually socially imposed or brings to light something new. If each point of view is the view of a point, each author will talk from the top of its point of observation and experimentation, the most comfortable for itself. Therefore, it seeks to investigate eroticism itself and its relationship to everyday life, also delimiting it from what separates ? or near ? it from pornography and obscenity.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-02T19:08:12Z No. of bitstreams: 1 FrancisliCostaGaldino_DISSERT.pdf: 2173203 bytes, checksum: 4174d964da89b665dc24976efd66f741 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-05T19:09:22Z (GMT) No. of bitstreams: 1 FrancisliCostaGaldino_DISSERT.pdf: 2173203 bytes, checksum: 4174d964da89b665dc24976efd66f741 (MD5) / Made available in DSpace on 2017-06-05T19:09:22Z (GMT). No. of bitstreams: 1 FrancisliCostaGaldino_DISSERT.pdf: 2173203 bytes, checksum: 4174d964da89b665dc24976efd66f741 (MD5) Previous issue date: 2015-05-25 / O objetivo desta pesquisa ? apresentar um estudo cr?tico sobre como se d?o as representa??es do feminino nos poemas er?ticos de John Donne (15721631), acreditando assim possibilitar uma melhor vis?o de como o feminino era visto pela sociedade Inglesa dos s?culos XV e XVI por meio das an?lises dos poemas e de suas representa??es. Neste sentido, essa pesquisa, de car?ter bibliogr?fico, anal?tico e interpretativo, se encontra justificada na relev?ncia que se d? a contextualiza??o do lugar e do espa?o do feminino em uma sociedade de uma ?poca de transforma??es e turbul?ncias sociais (fim do Renascimento, da Idade M?dia e contra-reforma religiosa). Tendo como cerne os estudos sobre no lugar do feminino na sociedade ocidental al?m de direcionar suas an?lises ao estudo dos poemas er?ticos, uma vez que as representa??es do feminino possuem tra?os mais marcantes nesse espa?o, tendo em vista toda a obra po?tica de Donne. Para isso, a pesquisa teve como orienta??o te?rica, prioritariamente, os estudos cr?ticos de Campus (1988), Eliot (1941), Erickson (2010), sobre quest?es que envolvem a po?tica Donniana; Bataille (1988) e Beauvoir (1980), nos questionamentos a respeito do erotismo e sexualidade; Grolli (2004) e Macedo (2002), quanto ao feminino e seu lugar no espa?o. / The objective of this research is to present a critical study on how the feminine representations happens in the erotic poems of John Donne (15721631), believing thus allow a better view of how the female was seen by English society of the fifteenth and sixteenth centuries by the analysis of the poems and their representations. The objectives are directed from the critical reading and interpretative analysis of the poems, both concerning understanding of social historical aspects as the identification of feminine places with regard its manifestations in Donneana poetry. In this sense, this research, bibliographic, analytical and interpretative character, is justified in the importance that is given to contextualization of the place and the feminine space in a society of a time of changes and social upheavals (end of the Renaissance, Middle Ages and religious reformulation). With the core studies on the place of women in Western society as well as direct their analysis to the study of erotic poems, since the feminine representations have most striking features in this space, considering all the work poetry of Donne. For this, the research was theoretical guidance, primarily, critical studies of Campus (1988), Eliot (1941), Erickson (2010), on issues surrounding the poetic Donneana; Bataille (1988) and Beauvoir (1980), the questions about the eroticism and sexuality; Grolli (2004) and Macedo (2002), about the women and their place in space.

A adaptação dos cimentos endodônticos, Ketac-Endo, AH Plus e Endomethásone, à dentina radicular submetida à ação prévia dos agentes de limpeza final laser de Er:YAG, EDTA a 17% e Solução Salina Fisiológica a 0,9% foi estudada pelas microscopias óptica e eletrônica de varredura. Foram empregados 90 caninos humanos extraídos, que após instrumentação pela técnica escalonada de memória e irrigação com hipoclorito de sódio a 1%, foram divididos em três grupos de 30, de acordo com o agente de limpeza final empregado. No grupo A, empregou-se o laser de Er:YAG intracanal, com parâmetros de 100mJ (energia real de 44mJ), 10pps, durante dez segundos, sob refrigeração a ar, com movimentos circulares no sentido apicocoronário, seguido de irrigação com 20ml de solução salina fisiológica a 0,9%. No grupo B, empregaram-se 5ml de EDTA a 17% durante cinco minutos, seguido de irrigação com solução salina fisiolólgica a 0,9%. No grupo C, empregaram-se 20ml de Solução Salina Fisiológica a 0,9%. Após secagem, os canais radiculares foram armazenados em solução salina fisiológica a 0,9% durante 48 horas. Cada grupo foi então dividido em três subgrupos de dez,de acordo com o cimento endodôntico. Os 90 canais radiculares foram obturados pela técnica clássica, seguida da condensação lateral ativa da guta-percha. Após comprovação radiográfica da obturação os canais foram vedados com Cimpat no terço cervical e forame apical, e as raízes armazenadas em solução salina fisiológica a 0,9% em umidade de 100% a 37oC, durante 30 dias. Em seguida, foram seccionadas transversalmente a 5mm do ápice radicular, fotografadas com aumento de quatro vezes e submetidas à análise em microscopia óptica. Para a análise em microscopia eletrônica de varredura, as secções apicais foram moldadas em silicona Aquasil e os moldes obtidos foram metalizados e fotografados em aumentos que variaram de 50 a 200 vezes. As fotos obtidas pelas microscopias foram escaneadas e transferidas para um programa de medida de área (SigmaScan) para mensuração das áreas preenchidas pelos materiais obturadores e das possíveis fendas entre material obturador e parede do canal radicular. Diante dos resultados obtidos com a metodologia empregada e da discussão apresentada pudemos concluir que: 1- Os agentes de limpeza final empregados exerceram efeito diferenciado na adaptação dos cimentos testados. O laser de Er:YAG interferiu na adaptação de todos os cimentos, o EDTA melhorou a adaptação do Endomethásone e do AH Plus em relação ao laser de Er:YAG e à solução salina fisiológica a 0,9% e a solução salina fisiológica melhorou a adaptação do Ketac-Endo, em ambas microscopias empregadas. 2- O Endomethásone apresentou a pior adaptação entre os cimentos e o AH Plus apresentou a melhor adaptação com EDTA na microscopia eletrônica de varredura. 3- A associação das microscopias óptica e eletrônica de varredura mostrou ser um método confiável na detecção das fendas, sendo que a microscopia eletrônica de varredura propiciou melhor visualização. 4- Todos os cimentos testados apresentaram alteração dimensional, verificando-se contração para o Ketac-Endo, expansão para o Endomethásone e AH-Plus, sendo que o AH Plus mostrou-se mais próximo da estabilidade dimensional. / The adaptation of endodontic sealers, Ketac-Endo, AH Plus and Endomethásone to dentinal root submitted to the previous action of final Er:YAG laser cleaning agents, EDTA at 17% and a saline solution at 0.9% was studied by Optical and Scanning Electron Microscopy. Ninety extracted human canines were employed, and following the step back technique preparation and irrigation with sodium hypochlorite solution they were divided into three groups with thirty teeth each, according to the final cleaning agent used. In group A, Er:YAG laser was used intracanal, with the following parameters: 100mJ (real energy 44mJ), 10pps, for 10 seconds under air cooling with circular movements in apicocervical direction and the canals were irrigated with 20ml saline solution at 0.9%. In group B, 5ml of EDTA at 17% irrigated the root canals for 5 minutes, followed by a saline solution at 0.9%. In group C, a saline solution at 0.9% was employed to irrigate the root canals. After drying, the roots were stored in a saline solution at 0.9% for 48 hours. Each group was divided into three subgroups of ten, according to the selected endodontic sealer. The ninety root canals were filled through standard technique, followed by gutta-percha lateral condensation. Following radiographic filling proof, the root canals were sealed with Cimpat in the cervical third and at the apical foramen, and the roots stored in a 0.9% saline solution at 37oC and 100% humidity for 30 days. Afterwards, they were transversally secctioned at 5mm to the root apex, and photographed with a 4x magnification, and submitted to optical microscopic analysis. Before the Scanning Electron Microscopic analysis, the apical root sections were molded with Aquasil and the obtained replicas metallized and photographed with 50x and 200x magnifications. The resulting images, in both microscopies, were scanned and transferred to the area measurement software program (SigmaScan) to measure the areas filled by endodontic materials and the failed areas between the endodontic material and the root canal walls. Through the results with the selected methodology and by means of the presented discussion, we could conclude that: 1- The final cleaning agents employed in the root canals presented different effects in the adaptation of the endodontic sealers. The Er:YAG laser was harmful to the adaptation of all the endodontic sealers; the EDTA improved the adaptation of Endomethásone and AH Plus and the 0.9% saline solution improved the adaptation of Ketac-Endo in both microscopies. 2- Endomethásone presented the worst adaptation compared to the other sealers and AH Plus presented the best adaptation with EDTA by Scanning Electron Microscopic analysis. 3- The Optical Microscopy associated with the Scanning Electron Microscopy proved to be a safe method in detecting filling failures, being, the Scanning Electron Microscopy the best. 4- All endodontic sealers presented dimensional alterations, Ketac-Endo presented contraction, Endomethásone and AH Plus presented expansion, being, AH Plus closer to dimensional stability.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / The overlay welding is a way for manufacture of materials that need specific properties on the surface. Typically, a low level of dilution is required to minimize the chemical changes that modify the overlay properties. The standard ISO 10423 establishes means for assessing the quality for the alloy AWS ER NiCrMo-3, that set a suitable overlay to severe conditions of corrosion those clads that have until 5% wt of iron content in the fusion zone, while for applications of moderate corrosion the criteria is required iron content until 10% wt. However, it is not known what quality criteria should be applied for coatings using noble alloys such as alloy AWS ER NiCrMo-14. The aim of this study was evaluate the effect of dilution on the microstructure, microsegregation and corrosion resistance of AWS ER NiCrMo-14 alloy overlay welded by GTAW cold wire feed process. Each clad was welded on ASTM A36 steel by GTAW process with the addition of a single cold wire layer of alloy AWS ER NiCrMo-14. The microstructure was characterized by scanning electron microscopy (SEM) and have not identified significant changes to the variation of dilution. It was observed on all overlays a &#947;-CFC matrix with dispersed precipitates in interdendritic regions. The microsegregation of the overlays was measured by energy dispersive of X-ray spectroscopy (EDS) chemical composition analysis, which showed that the Fe incorporation potential into the solid (k > 1) increased for increments in dilution. The Mo showed a high potential to segregate to liquid and your coefficient k increased with increments in dilution. The Cr and W showed a small drop in k partition coefficient with increases in the dilution. The precipitates were characterized by X-ray diffraction (XRD), EDS analysis using the transmission electron microscopy (TEM) and SEM and electron diffraction analysis. It were identified the phases &#963;, &#956; and P. The overlays were subjected to the corrosion test according to ASTM G48 C method to obtaining the critical pitting temperature (TCP) of each clad. The overlay with dilution of about 6% supported the maximum temperatures stipulated by the standard, 85 ÂC. While clads with dilutions of about 12% and 13% showed 55ÂC and 50ÂC TCP, respectively. Other overlays with dilutions over 20% failed in 45 ÂC. The corrosion mechanism apparently was initiated along solidification grain boundaries and/or in the interface between the precipitates and the matrix. / A soldagem de revestimentos à uma alternativa para a fabricaÃÃo de materiais que necessitam de propriedades especificas em sua superfÃcie. Normalmente, busca-se um baixo nÃvel de diluiÃÃo para minimizar as variaÃÃes quÃmicas que alteram as propriedades do revestimento. A norma ISO 10423, estabelece um critÃrio de qualidade para a liga AWS ER NiCrMo-3, que define um revestimento apto a condiÃÃes de corrosÃo severas aqueles com uma concentraÃÃo de atà 5% de Fe na zona fundida, jà para aplicaÃÃes de corrosÃo mais branda à recomendado um teor de ferro de atà 10%. No entanto, nÃo hà critÃrios de qualidade para revestimentos de ligas mais nobres como a liga AWS ER NiCrMo-14. O objetivo do presente estudo foi avaliar o efeito da diluiÃÃo sobre a microestrutura, a microssegregaÃÃo e a resistÃncia a corrosÃo dos revestimentos da liga AWS ER NiCrMo-14 depositados pelo processo TIG com a adiÃÃo de arame frio. Os revestimentos foram depositados sobre um substrato de aÃo ASTM A36 com uma Ãnica de liga AWS ER NiCrMo-14. A microestrutura foi caracterizada por microscopia eletrÃnica de varredura (MEV) e nÃo foram identificadas alteraÃÃes significativas com a variaÃÃo da diluiÃÃo. Foram observados em todos os revestimentos uma matriz &#947;-CFC com precipitados dispersos nas regiÃes interdendrÃticas. A microssegregaÃÃo foi avaliada por medidas de composiÃÃo quÃmica de energia dispersiva de raios X (EDS), que revelaram um aumento no potencial de incorporaÃÃo ao sÃlido (k > 1) com o acrÃscimo da diluiÃÃo para o Fe. Jà o Mo segregou para o lÃquido (k < 1) em nÃveis maiores com o aumento da diluiÃÃo. O Cr e o W apresentaram uma pequena queda no coeficiente de partiÃÃo k com o aumento da diluiÃÃo. Os precipitados foram caracterizados por difraÃÃo de raios X, anÃlises quÃmica de EDS utilizando a microscopia eletrÃnica de transmissÃo (MET) e MEV e por difraÃÃo de elÃtrons (MET). Foram identificadas fases &#963;, &#956; e P. Os revestimentos foram submetidos ao ensaio de corrosÃo segundo o mÃtodo C da norma ASTM G48 para a obtenÃÃo da temperatura crÃtica de pites (TCP) de cada revestimento. O revestimento com diluiÃÃo de aproximadamente 6% suportou a temperatura mÃxima estipulada pela norma, 85ÂC. Jà os revestimentos com diluiÃÃes de aproximadamente 12% e 13% apresentaram TCP de 55 e 50ÂC, respectivamente. Os demais revestimentos com diluiÃÃes acima de 20% falharam na temperatura de 45ÂC. O mecanismo de corrosÃo aparentemente deu inÃcio pelos contornos de grÃos de solidificaÃÃo e/ou na interface matriz/precipitados.