An imaging system was developed to visualize Drop-on-Demand (DOD) inkjet drop formation and impaction on substrate over drop sizes and impaction speeds of the magnitudes encountered in applications of inkjet printing. Using a pulsed laser, a low-speed charge-coupled-device (CCD) camera, and signal generators, the imaging system based on flash photography was used to capture sharp images with a temporal resolution of 200 ns and a spatial resolution of 0.81 micron/pixel. First, the dynamics of DOD drop formation was studied experimentally. The effects of the driving signal, which controls the piezoelectric transducer that produces the pressure pulse to drive the liquid from the reservoir through the orifice, have been examined along with those of liquid properties. The main stages of DOD drop formation, including ejection and stretching of liquid, pinch-off of liquid thread from the nozzle exit, contraction of liquid thread, breakup of liquid thread into primary drop and satellites, and recombination of primary drop and satellites, are analyzed. A necessary condition for the recombination of the primary drop and satellite and the limit for liquid thread length without breakup during contraction are proposed. Second, using the visualization system coupled with a motorized stage, micron-drop impaction on a smooth substrate was investigated over a regime of We and Oh typical for inkjet printing applications. The results indicate that scaling of micron-drop impaction from millimeter-drop impaction, based on dimensionless numbers (Oh, We and cos ), is valid. The predictions of maximum spreading ratio by six existing models agree well with experimental values for high-We impaction, but not for low-We and low-contact-angle impactions; however, the model of Park et al. predicts well for high- and low-We impaction due to its inclusion of spontaneous spreading dissipation. Fingering and splashing do not occur in the micron drop impaction on either dry solid substrates or a pre-existing liquid layer. The drying time of a micron drop deposited on a substrate is less than one second and increases as the contact angle of the drop on the substrate increases.

In this study a fiber optic interferometer (FOI) was designed and constructed to measure micron level clearances occurring in piston cylinder arrangements. A Cartesian model of the piston cylinder assembly is manufactured and lateral motion and vertical displacement are generated via a step motor, and micrometers, respectively. Clearance measurements are conducted in air and also in a lubricant. The range of vertical displacements is kept between 0-50 &amp / #956 / m, and the lateral motion is 13.5 mm. The effect of the step motor and lateral motion carriage on distance measurement is determined and this is used to correct displacement measurements.

The objectives of this study are to synthesize sub-micron sized zinc borate and to use them with other flame retardant additives in poly(ethylene terephthalate) (PET) based composites. The study can be divided into two parts. In the first part, it was aimed to synthesize sub-micron sized zinc borate (2ZnO.3B2O3.3.5H2O) with the reaction of zinc oxide and boric acid. For this purpose, low molecular weight additives or surfactants were used in the syntheses to prevent the agglomeration and to decrease particle size. Effect of type of surfactant and its concentration / effect of using nano-sized zinc oxide as reactant on the synthesis, properties and morphology of 2ZnO.3B2O3.3.5H2O were investigated. Synthesized zinc borates were characterized by X-Ray diffraction (XRD), Scanning Electron Microscope (SEM) and Thermogravimetric Analysis (TGA). The results were compared with a commercial zinc borate, Firebrake (FB). Characterization results showed that at least in one dimension sub-micron size was obtained and synthesized zinc borates did not lose their hydration water until the process temperature of the composites. In the second part of the study, PET based composites, which mainly included synthesized sub-micron sized zinc borates were prepared by using a co-rotating twin screw extruder and injection molding machine. Synergist materials such as boron phosphate (BP) and triphenyl phosphate (TPP) were also used in the composite preparation. The composites were characterized in terms of flammability and mechanical properties. Flammability of composites was determined by using a Limiting Oxygen Index (LOI) test. Mechanical properties such as tensile strength, elastic modulus, elongation at break and impact strength were also studied. According to LOI and impact tests, the composites containing 3 wt. % BP and 2 wt. % zinc borate which was modified with poly(styrene-co-maleic anhydride), 2PSMA05/3BP and 2PSMA1/3BP have higher LOI and impact values when compared to neat PET.

Made available in DSpace on 2014-12-17T15:55:01Z (GMT). No. of bitstreams: 1 AnuskaCFSG_DISSERT.pdf: 2730570 bytes, checksum: 99e9352dede08f56c7542f82fe889d15 (MD5) Previous issue date: 2011-02-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The water quality of many reservoirs in the world has been reduced due to percolation of contaminants to water, which can have natural or anthropogenic origin, increasing the level of genotoxic compounds in aquatic ecosystems. This fact has contributed to the reduction of environmental quality, and commitment the health of living beings that inhabit these ecosystems, including the human population. In this backdrop of reduced water quality, is the Lucrecia dam, which is a major surface water reservoirs by volume of semi-arid region of Rio Grande do Norte, and that has shown contamination by heavy metals, cyanobacteria toxic and the natural presence of Radon. The population that use this source has been showing high rates of cancer, popularly associated with the consumption of this water, with a prevalence about three times higher compared to the whole state of Rio Grande do Norte. Based on this, the present study aimed to evaluate the mutagenic potencial of surface water from the Lucrecia dam, using the Micronucleus Test in Tradescantia pallida (Trad-MN) and in human peripheral blood lymphocytes (CBMN) assay, as well as identify the concentrations of some heavy metals in this water. Water samples were collected on a dry season and a rainy season, in two distinct points. Moreover, in order to bring a completely view about the relationship of man-health-environment in this local, through the knowledge of knowing / acting environmental from residents of Lucrecia, and the use and perceptions they have about the dam of your city, a study of Environmental Perception was carried out with local residents. The results obtained for the both micronucleus test, showed significant results for the three points analyzed. The strongest mutagenic effect was observed in the dry season for both assays. Chemical analyses detected an increase of heavy metal levels in different points and season above the maximum allowed by legislation. Regarding the study of Environmental Perception with local residents, it was observed the knowledge of the environment that the residents have, as well as the strong ties and perceptions with the dam of the city. Thus, the combination of these two aspects (the genetic toxicity tests conducted in the dam together with analysis of environmental perception with the residents of Lucrecia) allowed to draw a more complete diagnosis on the local situation / A qualidade h?drica de diversos mananciais tem sido reduzida devido ? percola??o de contaminantes, seja de origem antr?pica ou natural, aumentando consideravelmente o n?vel de compostos genot?xicos nos ecossistemas aqu?ticos. Tal fato vem contribuindo para a redu??o da qualidade ambiental, bem como para o comprometimento da sa?de dos seres vivos que habitam esses ecossistemas, inclusive o homem. Diante deste cen?rio, est? o a?ude de Lucr?cia, que ? um dos principais reservat?rios h?dricos superficiais, da regi?o Semi-?rida do Estado do RN, e que tem demonstrado contamina??o por metais pesados, cianobact?rias t?xicas e a presen?a natural do Rad?nio. Aliado a esses problemas, a popula??o deste munic?pio vem apresentando elevada incid?ncia de c?ncer associada popularmente ao consumo dessa ?gua, sendo a preval?ncia cerca de tr?s vezes maior, quando comparada a todo o Estado do Rio Grande do Norte. Visto isso, o presente estudo teve como objetivo avaliar o potencial mutag?nico da ?gua superficial do a?ude de Lucr?cia por meio do teste de micron?cleo em Tradescantia pallida e em cultura de Linf?citos Humanos, assim como identificar as concentra??es de metais pesados presentes nesta ?gua. A coleta de ?gua foi realizada em dois pontos amostrais, no per?odo de seca e no per?odo chuvoso. Ademais, com o intuito de trazer um panorama mais completo da rela??o homem-sa?de-ambiente nesta localidade, atrav?s do conhecimento do saber/agir ambiental dos moradores de Lucr?cia, assim como o uso e percep??es estes t?m sobre o a?ude do seu munic?pio, foi realizado um estudo de Percep??o Ambiental com os moradores locais. Os resultados obtidos para o teste de Micron?cleo, para ambos os modelos utilizados, mostraram resultados significantes para os pontos coletados. O per?odo de seca apresentou uma m?dia maior de micron?cleos quando comparado ao per?odo chuvoso. Foi observado tamb?m concentra??es acima do permitido pela legisla??o brasileira de alguns metais pesados. Com rela??o ao estudo de Percep??o Ambiental com os moradores locais, a an?lise dos dados permitiu observar os conhecimentos sobre meio ambiente que os moradores possuem, assim como a forte liga??o e as concep??es que os mesmos possuem com o a?ude do munic?pio. Assim, a jun??o dessas duas vertentes (os testes de toxicidade gen?tica realizados no a?ude desta cidade aliado a an?lise de percep??o ambiental com os moradores de Lucr?cia) permitiu tra?ar um diagn?stico mais completo sobre a situa??o local

Orientador: Marizilda dos Santos Menezes / Banca: José Carlos Plácido da Silva / Banca: Rosane Fonseca Martins / Resumo: O presente estudo tem como objetivo apresentar as contribuições da gestão de design como ferramenta estratégica para micro e pequenas empresas do vestuário de moda. Para tanto, foi elaborado um referencial teórico que procurou mostrar as transformações ocorridas no decorrer da história da gestão empresarial e a importância que a inovação e a qualidade assumiram no contexto das organizações contemporâneas. Abordou-se, também, os conceitos e bases teóricas sobre a gestão do design, que permitiram compreender a importância de os elementos da gestão estarem aliados à dimensão do design nas organizações. Outro ponto importante esteve relacionado às peculiaridades inerentes aos produtos de moda e ao contexto das Micro e Pequenas Empresas - MPEs, marcado pelo uso diversificado de estratégias empresariais, com implicações de diferentes perspectivas. De acordo com os procedimentos metodológicos adotados para o trabalho, realizou-se um estudo de caso múltiplo entre duas empresas de confecção do vestuário de moda feminina, sendo que numa das empresas tivesse a gestão do design implementada e na outra não a utilizasse e/ou desconhecesse tal ferramenta. Os dados foram analisados pelo método indutivo, por comparação entre os resultados obtidos no estudo de caso múltiplo, confrontando os aspectos teóricos com os práticos em relação aos elementos estudados. Concluiu-se que a utilização da gestão do design como elemento de articulação estratégica e operacional pelas micro e pequenas empresas do vestuário de moda substitui o empirismo e a improvisão até então dominante. / Abstract: The present study has as objective to present contributions of the design management as a strategical tool for the micron and small enterprise of fashion clothes. For in such a way, was elaborated a theoretical referencial that it looked to show the occurred transformations in history elapsing of the enterprise management and the importance that the innovation and the quality had assumed in the context of the organizations contemporaries. It was also approached the concepts and theoretical bases on the design management, that had allowed to understand the importance of the elements of the management to be allies to the design dimension in the organizations. Another important point was related to the inherent peculiarities to the fashion products and the context of the micron and small enterprise - MPEs, maked for the diversified use of enterprise stategies, with implications of different perspectives. In accordance with the adopted methodological procedures for the work, a study of multiple case was become fulfilled between two feminine fashion clothes confection enterprise, being that in one for the enterprises it had the design management implemented and in the other did not use it and/or was unaware of such tool. The data had been analyzed by inductive method, by comparison between the gotten results in a multiple case study, collating the theoretical aspects with the practical ones in relation to the studied elements. The use of the design management was concluded that as element of strategically and operational articulation for the micron and small enterprise of fashion clothes substitutes the empiric and the improvisation until then dominant. / Mestre

Made available in DSpace on 2014-06-11T19:24:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-20Bitstream added on 2014-06-13T19:07:25Z : No. of bitstreams: 1 emidio_lfb_me_bauru.pdf: 687772 bytes, checksum: 55198c5fb471b87b21bc8cd2c2030b3e (MD5) / O presente estudo tem como objetivo apresentar as contribuições da gestão de design como ferramenta estratégica para micro e pequenas empresas do vestuário de moda. Para tanto, foi elaborado um referencial teórico que procurou mostrar as transformações ocorridas no decorrer da história da gestão empresarial e a importância que a inovação e a qualidade assumiram no contexto das organizações contemporâneas. Abordou-se, também, os conceitos e bases teóricas sobre a gestão do design, que permitiram compreender a importância de os elementos da gestão estarem aliados à dimensão do design nas organizações. Outro ponto importante esteve relacionado às peculiaridades inerentes aos produtos de moda e ao contexto das Micro e Pequenas Empresas - MPEs, marcado pelo uso diversificado de estratégias empresariais, com implicações de diferentes perspectivas. De acordo com os procedimentos metodológicos adotados para o trabalho, realizou-se um estudo de caso múltiplo entre duas empresas de confecção do vestuário de moda feminina, sendo que numa das empresas tivesse a gestão do design implementada e na outra não a utilizasse e/ou desconhecesse tal ferramenta. Os dados foram analisados pelo método indutivo, por comparação entre os resultados obtidos no estudo de caso múltiplo, confrontando os aspectos teóricos com os práticos em relação aos elementos estudados. Concluiu-se que a utilização da gestão do design como elemento de articulação estratégica e operacional pelas micro e pequenas empresas do vestuário de moda substitui o empirismo e a improvisão até então dominante. / The present study has as objective to present contributions of the design management as a strategical tool for the micron and small enterprise of fashion clothes. For in such a way, was elaborated a theoretical referencial that it looked to show the occurred transformations in history elapsing of the enterprise management and the importance that the innovation and the quality had assumed in the context of the organizations contemporaries. It was also approached the concepts and theoretical bases on the design management, that had allowed to understand the importance of the elements of the management to be allies to the design dimension in the organizations. Another important point was related to the inherent peculiarities to the fashion products and the context of the micron and small enterprise - MPEs, maked for the diversified use of enterprise stategies, with implications of different perspectives. In accordance with the adopted methodological procedures for the work, a study of multiple case was become fulfilled between two feminine fashion clothes confection enterprise, being that in one for the enterprises it had the design management implemented and in the other did not use it and/or was unaware of such tool. The data had been analyzed by inductive method, by comparison between the gotten results in a multiple case study, collating the theoretical aspects with the practical ones in relation to the studied elements. The use of the design management was concluded that as element of strategically and operational articulation for the micron and small enterprise of fashion clothes substitutes the empiric and the improvisation until then dominant.

Made available in DSpace on 2014-12-17T14:05:20Z (GMT). No. of bitstreams: 1 DeborahAC_TESE.pdf: 2567069 bytes, checksum: 17be3c292d241e19b0a9d1323613899f (MD5) Previous issue date: 2012-04-13 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Human multipotent mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells, have become an important and attractive therapeutic tool since they are easily isolated and cultured, have in vitro expansion potential, substantial plasticity and secrete bioactive molecules that exert trophic effects. The human umbilical cord as a cell source for cell therapy will help to avoid several ethical, political, religious and technical issues. One of the main issues with SC lines from different sources, mainly those of embryonic origin, is the possibility of chromosomal alterations and genomic instability during in vitro expansion. Cells isolated from one umbilical cord exhibited a rare balanced paracentric inversion, likely a cytogenetic constitutional alteration, karyotype: 46,XY,inv(3)(p13p25~26). Important genes related to cancer predisposition and others involved in DNA repair are located in 3p25~26. Titanium is an excellent biomaterial for bone-implant integration; however, the use can result in the generation of particulate debris that can accumulate in the tissues adjacent to the prosthesis, in the local bone marrow, in the lymph nodes, liver and spleen. Subsequently may elicit important biological responses that aren?t well studied. In this work, we have studied the genetic stability of MSC isolated from the umbilical cord vein during in vitro expansion, after the cryopreservation, and under different concentrations and time of exposition to titanium microparticles. Cells were isolated, in vitro expanded, demonstrated capacity for osteogenic, adipogenic and chondrogenic differentiation and were evaluated using flow cytometry, so they met the minimum requirements for characterization as MSCs. The cells were expanded under different concentrations and time of exposition to titanium microparticles. The genetic stability of MSCs was assessed by cytogenetic analysis, fluorescence in situ hybridization (FISH) and analysis of micronucleus and other nuclear alterations (CBMN). The cells were able to internalize the titanium microparticles, but MSCs preserve their morphology, differentiation capacity and surface marker expression profiles. Furthermore, there was an increase in the genomic instability after long time of in vitro expansion, and this instability was greater when cells were exposed to high doses of titanium microparticles that induced oxidative stress. It is necessary always assess the risks/ benefits of using titanium in tissue therapy involving MSCs, considering the biosafety of the use of bone regeneration using titanium and MSCs. Even without using titanium, it is important that the therapeutic use of such cells is based on analyzes that ensure quality, security and cellular stability, with the standardization of quality control programs appropriate. In conclusion, it is suggested that cytogenetic analysis, FISH analysis and the micronucleus and other nuclear alterations are carried out in CTMH before implanting in a patient / C?lulas mesenquimais estromais multipotentes, tamb?m conhecidas como c?lulas-tronco mesenquimais humanas (CTMH), s?o c?lulas multipotentes utilizadas em v?rias pesquisas de terapia celular, pois apresentam a capacidade de se diferenciar em m?ltiplas e diferentes linhagens, t?m grande capacidade de autorrenova??o e de expans?o in vitro, excelentes propriedades imunossupressoras e s?o capazes de secretar mol?culas bioativas que exercem efeitos tr?ficos. O cord?o umbilical ? uma fonte de CTMH cuja extra??o n?o necessita de um procedimento invasivo, al?m de n?o envolver controv?rsias ?ticas, pol?ticas e religiosas. Um dos problemas que envolvem linhagens de CTMH de diferentes fontes ? a possibilidade de ocorr?ncia de altera??es cromoss?micas e instabilidade gen?tica, que podem aparecer durante a expans?o in vitro. Al?m disso, as CTMH de um dos cord?es apresentaram uma altera??o cromoss?mica constitucional: invers?o parac?ntrica no bra?o curto do cromossomo 3, cari?tipo: 46,XY,inv(3)(p13p25~26). Em 3p25-26, est?o localizados v?rios genes de grande import?ncia biol?gica, como genes envolvidos com o reparo de DNA e outros respons?veis pelo desenvolvimento de tumores. O tit?nio ? um dos materiais mais utilizado para fabrica??o de implantes ortop?dicos e dent?rios, e ? considerado um excelente biomaterial, entretanto, as part?culas derivadas de pr?teses acumulam-se nos tecidos periprost?ticos e na medula ?ssea local, disseminam-se para linfonodos, f?gado e ba?o. As implica??es biol?gicas em longo prazo da dissemina??o sist?mica de part?culas de metais e seus efeitos cito e genot?xicos n?o est?o bem caracterizados. Neste trabalho investigamos a estabilidade gen?tica de CTMH isoladas da veia do cord?o umbilical durante a expans?o in vitro, ap?s a criopreserva??o, e em diferentes condi??es de cultivo, na presen?a e na aus?ncia de tit?nio, antes e ap?s o aparecimento de c?lulas senescentes no cultivo. As c?lulas foram isoladas, expandidas, diferenciadas em osteoblastos, adip?citos e condroblastos e analisadas com citometria de fluxo para comprovar que s?o c?lulas-tronco mesenquimais. As CTMH foram tratadas com diferentes doses/ tempo de exposi??o ? micropart?culas de tit?nio. A avalia??o da estabilidade gen?tica das CTMH foi realizada atrav?s da an?lise do cari?tipo, de hibrida??o in situ por fluoresc?ncia (FISH) e da an?lise do micron?cleo e outras altera??es nucleares (CBMN). Ficou estabelecido que as CTMH foram capazes de internalizar as micropart?culas de tit?nio, mas as c?lulas mant?m sua capacidade de prolifera??o, diferencia??o e preservam os mesmos marcadores de membrana. Al?m disso, demonstrou-se que existe um aumento na instabilidade gen?tica com o decorrer do tempo de expans?o in vitro, e esta instabilidade foi maior na presen?a de grande concentra??o de micropart?culas de tit?nio que induzem estresse oxidativo. ? necess?rio sempre avaliar os riscos/ benef?cios da utiliza??o do tit?nio na terapia tecidual envolvendo CTMH, considerando a biosseguran?a da utiliza??o da regenera??o ?ssea guiada que utiliza CTMH e tit?nio. Mesmo n?o se utilizando o tit?nio, ? importante que o uso terap?utico de tais c?lulas seja baseado em an?lises que garantam a qualidade, seguran?a e estabilidade celular, com a padroniza??o de programas de controle de qualidade adequados. Como conclus?o, sugere-se que a an?lise citogen?tica, FISH e a an?lise do micron?cleo e outras altera??es nucleares sejam realizadas nas CTMH antes de implantar num paciente, sejam elas cultivadas por longo tempo ou n?o

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-26T19:16:13Z No. of bitstreams: 1 LuizaAraujoDaCostaXavier_DISSERT.pdf: 2033184 bytes, checksum: 2e016a1123ca6a8907a0176e6866a4a7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-28T22:16:51Z (GMT) No. of bitstreams: 1 LuizaAraujoDaCostaXavier_DISSERT.pdf: 2033184 bytes, checksum: 2e016a1123ca6a8907a0176e6866a4a7 (MD5) / Made available in DSpace on 2016-04-28T22:16:51Z (GMT). No. of bitstreams: 1 LuizaAraujoDaCostaXavier_DISSERT.pdf: 2033184 bytes, checksum: 2e016a1123ca6a8907a0176e6866a4a7 (MD5) Previous issue date: 2015-07-31 / As fendas labiopalatinas n?o-sindr?micas (FL/PNS) s?o defeitos cong?nitos comuns em humanos, caracterizadas pelo desenvolvimento incompleto de estruturas que separam a cavidade nasal da cavidade oral, e s?o causadas devido a uma intera??o entre fatores gen?ticos e ambientais. Dados obtidos de estudos de caso-controle e interven??o diet?tica indicam que a suplementa??o materna com multivitaminas contendo ?cido f?lico previne o surgimento das fissuras orais. ? conhecido que o ?cido f?lico participa de fun??es celulares essenciais, como a s?ntese de nucleot?deos para o reparo do DNA, as quais contribuem para a prote??o da integridade do genoma contra eventos de danos gerados por fatores end?genos e/ou ex?genos. Inclusive, estudos revelam que a defici?ncia desta vitamina aumenta a forma??o de micron?cleos, estruturas citogen?ticas indicadoras de danos no DNA. Al?m disso, esta defici?ncia ? modulada pelos polimorfismos gen?ticos associados ao metabolismo do ?cido f?lico, comprometendo o desempenho das fun??es de estabilidade do genoma e, portanto, est?o sendo associados com o desenvolvimento de v?rios dist?rbios, dentre eles as fissuras orais. A partir deste contexto, foi conduzido um estudo transversal do tipo caso-controle n?o pareado com o objetivo de avaliar a frequ?ncia de biomarcadores de instabilidade gen?mica, sua rela??o com polimorfismos gen?ticos do metabolismo do folato, e se essas vari?veis est?o associadas com o desenvolvimento das FL/PNS em crian?as do Rio Grande do Norte, Brasil. Foram recrutados 48 pacientes fissurados e 18 crian?as controles, respectivamente, no Hospital de Pediatria Professor Heriberto Ferreira Bezerra (HOSPED)/UFRN e em escolas estaduais da cidade de Natal, RN. Com o devido consentimento dos participantes, realizou-se uma entrevista com os respons?veis para obten??o de dados epidemiol?gicos, como tamb?m procedeu-se a coleta sangu?nea das crian?as para a realiza??o dos testes. Foi executado o ensaio do micron?cleo com bloqueio da citocinese para calcular a frequ?ncia de micron?cleos (MN), pontes nucleoplasm?ticas (PN) e brotos nucleares (BN). A partir da extra??o do DNA gen?mico, avaliou-se os polimorfismos da metilenotetrahidrofolato redutase C677T e A1298C, metionina sintase A2756G, metionina sintase redutase A66G e do receptor de folato reduzido A80G pela t?cnica de rea??o em cadeia da polimerase associada ao polimorfismo de tamanho do fragmento de restri??o (PCR-RFLP). As crian?as com FL/PNS apresentaram maior frequ?ncia basal de MN, PN e BN que o grupo de crian?as controle (p < 0,001), e nenhum dos polimorfismos avaliados modificaram significativamente a frequ?ncia destes biomarcadores. Al?m disso, crian?as com FL/PNS apresentaram 2,3 vezes mais risco de exibir altas frequ?ncias de MN (p = 0,043) segundo modelo de regress?o log?stica bin?ria. A alta instabilidade do genoma nas crian?as com fissuras orais sugere que os eventos genot?xicos, em particular os que promovem quebras na dupla fita do DNA e n?o s?o devidamente reparados formando micron?cleos, representam fatores relevantes no desenvolvimento das fendas labiopalatinas n?o-sindr?micas. / The non-syndromic clefts of the lip and/or palate (NSCL/P) are common birth defects in humans characterized by an incomplete development of cellular structures that separate the nasal cavity from the oral cavity, and they are caused due to an interaction between genetic and environmental factors. Data from case-control and dietary intervention studies indicates that maternal supplementation with multivitamins containing folic acid prevents the formation of oral clefts. It is known that folic acid plays a role in essential cellular functions, such as nucleotides synthesis for DNA repair, which contribute to the protection of genome integrity from damage events generated by endogenous and/or exogenous factors. In fact, studies show that a deficiency in this vitamin increases micronuclei formation, a cytogenetic structure that indicates misrepair of damaged DNA. Furthermore, this deficiency is modulated by genetic polymorphisms associated with folic acid metabolism, affecting the performance of genome stability functions and therefore, it has been associated with the development of various disorders, including oral clefts. From this context, it was planned a unpaired case-control cross-sectional study in order to assess the frequency of genome instability biomarkers, their relationship with genetic polymorphisms in folate metabolism, and if these variables are associated with the development of NSCL/P in children from a Northeast region at Brazil. For this research, it was recruited 48 NSCL/P patients and 18 control children, respectively, at the Pediatric Hospital Professor Heriberto Ferreira Bezerra (HOSPED)/ UFRN and at schools in Natal city. With the participants consent, they were interviewed with a standard questionnaire to obtain epidemiological data, and the children underwent a blood sampling for the tests. It was performed the cytokinesis-block micronucleus assay to estimate the frequency of micronuclei (MN), nucleoplasmic bridges (NPB) and nuclear buds (NB). Also, from the genomic DNA extraction, it was evaluated by PCR-RFLP the polymorphisms of methylenetetrahydrofolate reductase C677T and A1298C, methionine synthase A2756G, methionine synthase reductase A66G and reduced folate carrier A80G. Children with NSCL/P had higher baseline frequency of MN, NPB and NB than the control group (p < 0.001), and none of the evaluated polymorphisms significantly modified the frequency of these biomarkers. In addition, children with clefts had 2.3 times more risk of displaying high frequency of MN (p = 0.043) according to the binary logistic regression model. The high genomic instability in children with oral clefts suggests that genotoxic events that promote double strand breaks on DNA and are not properly repaired, thus originating micronuclei, represent significant factors in the development of non-syndromic cleft lip/ palate.

Made available in DSpace on 2014-12-17T15:18:07Z (GMT). No. of bitstreams: 1 JoanaCMT.pdf: 30865 bytes, checksum: 27f51c3cbcadb5a4ec7e07d9182ea1aa (MD5) Previous issue date: 2008-03-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / O Tit?nio (Ti) ? atualmente o material mais utilizado para fabrica??o de implantes ortop?dicos e dentais. Altera??es na superf?cie de tit?nio comercial puro (TiCP) podem determinar a reposta funcional das c?lulas, sendo um fator cr?tico para o sucesso do implante. Entretanto, a genotoxicidade de superf?cies de tit?nio tem sido pouco estudada. Deste modo, o objetivo deste trabalho foi avaliar o potencial genot?xico de uma nova superf?cie de tit?nio porosa desenvolvida por plasma comparada com uma superf?cie somente polida. Para tanto, foram realizados os ensaios cometa, aberra??es cromoss?micas (CAs) e micron?cleo (MN), utilizando c?lulas CHO-K1 (c?lulas do ov?rio de hamster Chin?s). Nossos resultados revelaram que a superf?cie de tit?nio polida foi capaz de induzir um aumento significativo dos danos no DNA, no n?mero das CAs, na tetraploidia e na freq??ncia de micron?cleos comparada ao controle. A superf?cie tratada por plasma, n?o promoveu efeito genot?xico significativo para todos os ensaios realizados. Estes resultados sugerem que a nova superf?cie de tit?nio tratada por plasma pode ser um material biologicamente seguro para sua utiliza??o em implantes ou futura aplica??o na terapia de regenera??o ?ssea-guiada, ao menos no que se refere ? sua genotoxicidade

Land-based turbine engines are currently used to burn heavy fuel oil (HFO), which is a lower cost fuel. HFO contains inorganic material that forms deposits on turbine blades reducing output and efficiency. Magnesium based additives are used to inhibit vanadium pentoxide deposition and reduce the corrosive nature of the gas and deposits in the hot gas path of the gas turbine. The focus of this study was to determine particle morphology and elemental composition of ash when firing HFO in an atmospheric combustor at various fuel injector atomization pressures. Prior to firing, the HFO was washed with water to remove sodium and potassium. A commercially available magnesium based additive was used to inhibit the vanadium in the HFO. Fuel was injected using an air-blast atomizer at air blast atomization gage pressures of 117, 186, and 255 kPa. Ash was collected from three locations downstream of combustion: immediately following combustion (pre-cyclone), from a cyclone separator (cyclone), and finally from a position located after the cyclone separator (post-cyclone). A Philips XL30 Scanning Electron Microscope (SEM) provided images, weight percent of elements of the ash, and element maps. Images taken from the SEM clearly show two particle types: 1) hollow spherical particles, or cenospheres, and 2) submicron agglomerated spherical particles. The cenospheres contained high carbon concentrations and were found primarily in the cyclone and probe bag filter. Element maps show that cenospheres, regardless of size, predominately contain carbon, oxygen, and sulfur with lesser amounts of sodium, magnesium, aluminum, and silicon. Particles collected downstream of the cyclone were primarily sub-micron in size and inorganic in composition. It is postulated that the cenospheres are the result of incomplete combustion of fuel oil droplets while the submicron spheres are nucleated inorganic material that initially evaporated from the liquid droplets. Particle size analysis was performed for each sample location. As the injection pressure was increased; the pre-cyclone and cyclone locations had similar number mean diameters that would decrease with increasing pressure. The diameter of the post-cyclone location did not change significantly with increasing air atomization. While increasing atomization pressure decreased the carbon content of the ash at all measurement locations, the atomization had little influence on the inorganic composition of the particles. The fine condensed phase particles and the larger cenosphere particles both produced similar compositions of inorganic material.