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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avalia??o in vitro e in vivo da citotoxidade e da genotoxicidadde das soldagens a prata, a Tungsten Inert Gas (TIG) e a laser em ortodontia

Rinaldi, Mariana Roennau Lemos 19 January 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T14:39:33Z No. of bitstreams: 1 TES_MARIANA_ROENNAU_LEMOS_RINALDI_COMPLETO.pdf: 2232512 bytes, checksum: 72ea5572f7e50b32cdf95dc1dbfe7366 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T14:39:42Z (GMT) No. of bitstreams: 1 TES_MARIANA_ROENNAU_LEMOS_RINALDI_COMPLETO.pdf: 2232512 bytes, checksum: 72ea5572f7e50b32cdf95dc1dbfe7366 (MD5) / Made available in DSpace on 2017-06-30T14:39:51Z (GMT). No. of bitstreams: 1 TES_MARIANA_ROENNAU_LEMOS_RINALDI_COMPLETO.pdf: 2232512 bytes, checksum: 72ea5572f7e50b32cdf95dc1dbfe7366 (MD5) Previous issue date: 2017-01-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Soldered appliances are widely used in orthodontics and pediatric dentistry. The cytotoxicity and genotoxicity of silver solder and laser welding has already been tested in dentistry. However, little is known about the Tungsten Inert Gas (TIG) welding technique, which uses an electric arc between an electrode and the part to be welded. The aims of this study were to evaluate the cytotoxicity and genotoxicity of silver soldered (silver soldered bands - SSB), laser welded (laser welded bands - LWB), TIG welded (TIG welded bands ? TWB) joints and no soldered/welded bands (NS /WB) in vitro and in vivo. For that, MTT reduction assay was performed in HGF, HaCat, Vero and MRC-5 cell lines. The genotoxicity of the metallic eluates of the joints was determined by comet assay in HGF cells after 3-h treatment. The quantification of Ni, Fe, Cr, Cu, Ag, Zn Cd and Sn in the metallic eluates was performed with inductively coupled plasma mass spectrometry (ICP-MS). Cu, Zn and Ag were the most detected ions in SSB medium samples, and Fe, Cr and Ni in the samples of LWB and TWB. The SSB group induced strong cytotoxicity in all cell lines. NS/WB, LWB and TWB presented a weak cytotoxic induction. In comet assay, SSB group showed a higher damage index and more comets with damage class 3 and 4, compared to the other groups. In the in vivo study, the genotoxic effects on the buccal mucosa cells of children with lingual arches containing silver soldered joints, laser welded joints and without any appliance were accessed by buccal comet assay (BCA) and the buccal micronucleus cytome (BMCyt) assay. The urinary levels of Ni, Cr, Fe, Zn, Cu, Ag, Cd and Sn were investigated through urine samples analyzed by ICP-MS. The results of the study indicate that silver solder and laser welding did not cause genotoxicity in buccal mucosa cell during the period evaluated. The changes of the ions in the urinary contents cannot only be attributed to the appliances. TIG welding may be a promising technique to be applied in orthodontics and deserve be further investigated, as it presented in the in vitro and in vivo tests a low cytotoxic and genotoxic potential. / Aparelhos soldados s?o utilizados amplamente em Ortodontia e Odontopediatria. A citotoxicidade e a genotoxicidade da solda a prata e da soldagem a laser j? foram testadas em Odontologia. No entanto, pouco se sabe sobre a t?cnica de soldagem Tungsten Inert Gas (TIG), que utiliza um arco el?trico entre um eletrodo e a pe?a a ser soldada. Os objetivos deste estudo foram avaliar a citotoxicidade e a genotoxicidade de uni?es soldadas a prata (silver soldered band - SSB), soldadas a laser (laser welded band - LWB), soldadas a TIG (TIG welded band ? TWB) e de an?is n?o soldados (no soldered or welded bands ? NS / WB) in vitro e in vivo. Para isso, o ensaio de redu??o de MTT foi realizado nas linhagens celulares HGF, HaCat, Vero e MRC-5. A genotoxicidade dos eluatos met?licos das ?reas soldadas foi determinada atrav?s do ensaio de cometas em c?lulas HGF ap?s tratamento de 3 horas. A quantifica??o de Ni, Fe, Cr, Cu, Ag, Zn, Cd e Sn nos elu?dos met?licos foi realizada com espectrometria de massa por plasma indutivamente acoplado (ICP-MS). Cu, Zn e Ag foram os ?ons mais detectados nas amostras de meio de bandas soldadas a prata, e Fe, Cr e Ni, nas amostras soldadas a laser e nas soldadas a TIG. O grupo SSB induziu forte citotoxicidade em todas as linhagens celulares. NS / WB, LWB e TWB apresentaram indu??o citot?xica fraca. No ensaio Cometa, o grupo SSB apresentou maior ?ndice de danos e mais cometas com classes de dano 3 e 4, em rela??o aos outros grupos. As uni?es soldadas a TIG, bem como uni?es soldadas a laser mostraram melhor biocompatibilidade. No estudo in vivo, genotoxicidade sobre as c?lulas da mucosa bucal dessas crian?as com arcos linguais contendo uni?es soldadas a prata, uni?es soldadas a laser, e sem qualquer aparelho foram avaliadas pelo ensaio de cometa bucal (BCA) e pelo ensaio de citometria bucal do micron?cleo (BMCyt). Os n?veis urin?rios de Ni, Cr, Fe, Zn, Cu, Ag, Cd e Sn foram investigados atrav?s de amostras de urina analisadas por ICP-MS. Os resultados do estudo indicam que a solda a prata e a soldagem a laser n?o causaram genotoxicidade na mucosa bucal durante o per?odo avaliado. As altera??es dos ?ons no conte?do urin?rio n?o puderam ser unicamente atribu?das aos aparelhos. A soldagem TIG parece ser t?cnica promissora a ser aplicada em ortodontia e merece ser mais investigada, uma vez que apresentou nos testes in vitro e in vivo um baixo potencial citot?xico e genot?xico.
2

Revitaliza??o do Rio Golandim (RN/Brasil) ap?s d?cadas de contamina??o por efluentes industriais e dom?sticos: este rio est? recuperado?

Costa, Aline Rocha de Paiva 31 May 2012 (has links)
Made available in DSpace on 2014-12-17T15:55:00Z (GMT). No. of bitstreams: 1 AlineRPC_DISSERT.pdf: 3018551 bytes, checksum: 17363a397c49ea615dc8b9fbdbe31f5c (MD5) Previous issue date: 2012-05-31 / Environmental pollution causes the loss of the quality of aquatic resources and also affects the health of human beings. The Golandim River is located in S?o Gon?alo do Amarante (RN Brazil) and had its water recovered seven years ago by measurements of parameters of the water s quality analyses physicochemistry, microbiological and heavy metals. However, it is not well established if this river is truly recovered, so this study provides a wide knowledge about the quality of these waters. Therefore, this investigation was accomplished by assays of ecotoxicology utilizing Ceriodaphnia dubia and of genotoxicity of the river s water using a biomarker Tradescantia Pallida (Trad-MCN). In set, it carried through a study of environmental perception through questionnaires that approached questions related to the profile of the interviewed one, knowledge on the environment and of the river Golandim with the community that lives in the neighborhoods of the river to diagnosis as they perceive the environment where live and its problems. The assays of the water had been carried out by collecting samples in three different sites of the Golandim River. They were collected between the periods of December 2010 (dry season in the northeast of Brazil) and July 2011 (rainy season in the northeast of). The analysis of the data allowed observing that the majority of the inhabitants are adult and presents a global vision of what it is part of the environment, the majority mentions the pollution of the river as one of the problems of the city, considering it serious. The ecotoxicology assay showed that there was not acute toxicity in all three samples collected. Meanwhile, all these three samples demonstrated significant chronic toxicity. The results from the Trad-MCN assay presented an increase in the frequency of micronucleus in one of the sites analyzed (S3) (p<0.01), in both seasons collected. On the other hand, the sites S1 and S2 did not presented a significant increase of micronucleus using this bioassay. The analyses of chemicals detected an increase in the levels of some metals, in different seasons and samples, which can be associates with some compounds found in urban and industrial areas. On the other hand, the physicochemistries parameters demonstrated that the Golandim River is recouped, when compared with the values presented at the CONAMA s legislation. However, these results indicate the presence of compounds capable of inducing chromosomal mutation in plants. On the other hand, the parameters physicistchemistries demonstrate that the river Golandim is if recouping, since when compares the values observed with the legislation of the CONAMA. All these results point to the fact that the Trad-MCN assay was sensitive and efficient biomarker for chromosomal instability and the C. dubia ecotoxicology assay was as though an efficient biomarker of toxicity of water s quality. The results from Trad-MCN associated with the ecotoxicology demonstrates that these analyses are important for environmental monitoring, once the first bioassay described above indicates alterations at the standards of cells and the other one indicates alterations at the standards of organisms. This study alerts for the necessity to carry out biological assays for the analyses of the water s quality / A ?gua ? essencial para a manuten??o da vida, entretanto, a polui??o ambiental vem causando a perda da qualidade dos recursos h?dricos, afetando assim a sa?de humana. Este estudo avaliou a qualidade da ?gua do Rio Golandim no munic?pio de S?o Gon?alo do Amarante/RN/Brasil ap?s a realiza??o do plano de recupera??o atrav?s de medi??es de par?metros de qualidade de ?gua - an?lises f?sico-qu?micas, de metais pesados e microbiol?gicos al?m de incluir ensaio de ecotoxicidade com Daphnia dubia e teste que detecta a presen?a de compostos mutag?nicos em Tradescantia pallida (Trad-MCN). Em conjunto, foi realizado um estudo de percep??o ambiental atrav?s de question?rios que abordou quest?es relacionadas ao perfil do entrevistado, conhecimentos sobre o meio ambiente e do rio Golandim, com a comunidade que vive nas proximidades deste rio para diagnosticar como eles percebem o ambiente em que vivem e seus problemas. Os experimentos foram realizados a partir de amostras de ?gua coletadas em dezembro de 2010 (esta??o do ano seca) e em julho de 2011 (esta??o das chuvas) em tr?s pontos diferentes do rio Golandim. A an?lise dos dados de percep??o ambiental permitiu observar que a maioria dos moradores s?o adultos e apresentam uma vis?o global do que ? meio ambiente e a maioria menciona a polui??o do rio como um dos problemas do munic?pio, considerando-o grave. Os dados resultantes do ensaio ecotoxicol?gico n?o indicou efeito de toxicidade aguda, entretanto demonstrou toxicidade cr?nica para a m?dia de reprodu??o dos clad?ceros nas esta??es do ano seca e chuvosa, em todos os pontos amostrados, os resultados provenientes do ensaio Trad-MCN para a ?gua bruta mostrou resposta positiva, representada pelo aumento na frequ?ncia de micron?cleos, para um dos pontos analisados (P3) em ambas as esta??es de coleta. As an?lises qu?micas detectaram um aumento nos n?veis de alguns metais nos diferentes per?odos e amostras, que podem estar associados ainda ? presen?a de compostos de origem urbana e industrial. Contudo, os par?metros f?sico-qu?micos demonstram que o rio Golandim est? se recuperando, j? que quando se compara os valores observados com a legisla??o brasileira do CONAMA. Nossos resultados apontam para a presen?a na ?gua de compostos capazes de induzir muta??es, podendo gerar s?rios agraves ? sa?de da popula??o que utiliza e reside nas proximidades do Golandim, a qual ainda se sente insegura quanto a utiliza??o do mesmo. Desta forma, este estudo alerta para a necessidade de realizar ensaios biol?gicos al?m de empregar apenas as an?lises provenientes das medi??es f?sico-qu?micas para atestar a qualidade de um corpo d ?gua, como tamb?m da realiza??o de trabalhos de educa??o ambiental com a comunidade ribeirinha
3

An?lise da genotoxicidade das ?guas da Lagoa da Extremoz - RN

Barbosa, Jefferson da Silva 10 March 2008 (has links)
Made available in DSpace on 2014-12-17T15:18:09Z (GMT). No. of bitstreams: 1 JeffersonSB.pdf: 95921 bytes, checksum: fc181517bec40efa1a2dbb0343c7987a (MD5) Previous issue date: 2008-03-10 / The contamination of the waters resources for wastewater from industrial, agricultural, and domestic sources is a serious environment problem, compromising its use for human consumption and agriculture. The Extremoz-RN Lake is an important freshwater source for the supply of the city of Natal, supplying a population of approximately 160,000 habitants. This aquatic body is located near an industrial pole which can be a serious risk factor for quality of its waters. The objectives of this study were examined the genotoxicity of Extremoz Lake between September of 2006 and January of 2008, by a combination of the Allium micronucleus test, piscine micronucleus test and the comet assay in erythrocytes from peripheral blood of Oreochromis niloticus. Additionally, the level of eight different heavy metals was quantified through spectrometry of atomic absorption of flame. The Allium test did not detect increase in the frequencies of micronucleus in none of the analyzed periods, however a strong cytotoxic activity was demonstrated for decrease in mitotic index in the analyses carried in April and July of 2007. Negative results had been detected in the frequencies of micronucleus in O. niloticus. A statistic significant increase was observed in the levels of DNA damage in comet assay carried in July of 2007. The results of the chemical analysis had detected increase in the levels of cadmium, chromium, copper, nickel, lead and zinc in different periods. These results demonstrated an alteration of the water s quality of the Extremoz Lake caused for the contamination for heavy metals and increase of DNA strand breaks. The use of biomonitoring program of the heavy metal and other pollutants with genotoxic potential combinated with genotoxicity assays is recommends. / A contamina??o dos recursos h?dricos, por efluentes de origem dom?stica e industrial, ? um s?rio problema ambiental, que compromete o uso de suas ?guas tanto para o consumo humano quanto para a agricultura. A Lagoa de Extremoz-RN ? uma importante fonte de ?gua para o abastecimento da cidade do Natal, suprindo uma popula??o de aproximadamente 160.000 habitantes. Esse corpo aqu?tico est? localizado pr?ximo a um p?lo industrial o qual pode ser um fator de risco a qualidade de suas ?guas. O presente estudo teve como objetivo analisar o potencial genot?xico das ?guas da lagoa de Extremoz entre os meses de setembro de 2006 e janeiro de 2008, pelo uso combinado do teste Allium cepa, teste micron?cleo e ensaio cometa em eritr?citos do sangue perif?rico de Oreochromis niloticus. Adicionalmente foram quantificados os n?veis de sete diferentes metais pesados pela da t?cnica de espectrometria de absor??o at?mica de chama. O teste A. cepa n?o detectou aumento nas freq??ncias de micron?cleos em nenhum dos per?odos analisados, por?m um forte efeito citot?xico, demonstrado pela diminui??o no ?ndice mit?tico, foi observado nas an?lises realizadas em abril e julho de 2007. Resultados negativos tamb?m foram encontrados nas freq??ncias de micron?cleos em O. niloticus. Uma altera??o estatisticamente significativa foi observada nos n?veis de quebra no DNA pelo teste cometa. Nos resultados da an?lise qu?mica, foi observado aumento nos n?veis de c?dmio, cromo, cobre, n?quel, chumbo e zinco em diferentes per?odos amostrais, acima dos permitidos pela legisla??o brasileira. Em conjunto, esses resultados demonstraram uma altera??o da qualidade das ?guas da Lagoa de Extremoz causada pela contamina??o por metais pesados. Estes metais parecem estar interagindo com o material gen?tico, visto o aumento nos n?veis de quebras no DNA, identificados no teste Cometa. Contudo, os danos n?o est?o sendo fixados pela c?lula. Diante disso, ? importante recomendar um programa de monitoramento da presen?a de metais pesados, bem como de outros poluentes com potencial genot?xico, nessa ?rea de estudo.

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