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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.
91

Migração celular, viabilidade e reação tecidual de soluções irrigadoras à base de hipoclorito de cálcio : estudo in vitro e in vivo / Cell migration, viability and tissue reaction of calcium hypochlorite based‐solutions irrigants : an in vitro and in vivo study

Blattes, Gabriela Bess Ferraz January 2015 (has links)
Introdução: O objetivo do presente estudo foi analisar a citotoxicidade e biocompatibilidade de soluções de hipoclorito de cálcio (Ca(OCl)2) comparadas a soluções de hipoclorito de sódio (NaOCl) in vitro em cultura de fibroblastos 3T3 e in vivo em ratos. Metodologia: Culturas de fibroblastos 3T3 foram expostas a diferentes concentrações de hipoclorito de cálcio e sódio e foi realizado um ensaio de “scratch”. Além disso, a taxa de viabilidade foi analisada utilizando o teste Azul de Trypan. As soluções a 1 e 2,5% foram, também, injetadas no tecido conjuntivo de 18 ratos Wistar de 18 semanas de idade. A reação inflamatória tecidual foi avaliada em 2h, 24h e 14 dias após as injeções e as amostras foram qualitativamente analisadas em microscópio óptico. Análise estatística foi realizada utilizando teste ANOVA e post hoc de Tukey para testes in vitro e Kruskal‐Wallis e post hoc de Dunn para o teste in vivo (α=.05). Resultados: No ensaio de “scratch”, Ca(OCl)2 não apresentou diferença estatística em relação ao controle no período de 24h (p<0.05). NaOCl e Ca(OCl)2 a 0.0075% e 0.005% apresentaram resultados de viabilidade similar ao grupo controle positivo (p > 0.05) no ensaio Azul de Trypan. No teste in vivo, Ca(OCl)2 1% mostrou uma diminuição significativa de neutrófilos entre 2h e 24h (p=0.041) e entre 2h e 14d (p=0.017). Não houve diferença estatística entre os grupos para linfócitos/plasmócitos e macrófagos. Conclusão: Ca(OCl)2 mostrou resultados favoráveis de viabilidade e induziu um baixo nível de resposta inflamatória tecidual, apresentando, assim, citotoxicidade e biocompatibilidade aceitáveis para uma solução irrigadora. / Introduction: The aim of the present study was to analyze cytotoxicity in vitro on cultured 3T3 fibroblasts and inflammatory tissue reaction in vivo on rats to calcium hypochlorite (Ca(OCl)2) solutions compared with sodium hypochlorite (NaOCl) solutions. Methods: Cultured 3T3 fibroblasts were exposed to different concentrations of calcium and sodium hypochlorite and a scratch assay was performed. The viability rate was analyzed with Trypan Blue assay. A. The 1 and 2.5% solutions were still injected into the subcutaneous tissues of eighteen male Wistar rats aged 18 weeks. Inflammatory tissue reaction was evaluated at 2h, 24h and 14 days after the injections and the samples were qualitatively analyzed through a light microscope. Statistical analysis was assessed by ANOVA and Tukey post hoc test for in vitro assays and by Kruskal-­‐Wallis and Dunn post hoc test for in vivo assay (α=.05). Results: In scratch assay, Ca(OCl)2 showed no statistically significant difference to control group at 24h (p<0.05). 0.0075% and 0.005% NaOCl and Ca(OCl)2 presented results similar to positive control group (p > 0.05) on Trypan Blue assay. In in vivo assay, 1% calcium hypochlorite group showed a significant decrease of neutrophils at 2h and 24h (p=0.041) and 2h and 14d (p=0.017). There was no statistically significant difference for lymphocytes/plasmocytes and macrophages among groups. Conclusions: Ca(OCl)2 showed favorable results of viability and induced an low level of inflammatory response, thus presenting an acceptable cytotoxicity and biocompatibility for an irrigant solution.
92

Production and evaluation of electrospun polyaniline/biopolymer composite nanofibres for medical applications

Moutsatsou, Panagiota January 2017 (has links)
The aim of this study is the production of a nanofibrous electroactive mat and the investigation of its potential use in tissue engineering, and more specifically for wound dressing purposes. The limitations regarding electrospinnability of the conducting polymer will be identified and addressed and the factors related to its biological properties will be evaluated. To this end, conducting polymer, polyaniline (PANI) was chosen as the electroactive component and blend electrospinning was identified as the most suitable method to produce continuous nanofibres containing PANI. Various biocompatible polymers and solvent systems were investigated for their suitability to assist in electrospinning and PEO (polyethylene oxide) and CH (chitosan) were chosen as carrier polymers for blend electrospinning of PANI. Consequently, CSA (Camphor-10-sulfonic acid (β)) doped PANI/PEO and CSA doped PANI/CH conducting nanofibrous mats were produced by electrospinning. The electrospinning windows for both blends were determined by using full factorial experimental designs. The combined effects of the humidity, voltage and flow rate on the fibre morphology and diameter were examined for both blends, demonstrating that the ambient humidity is the critical factor affecting the electrospinning process and determining the electrospinning window for a conducting polymer. Low humidity favors the formation of defect free fibres while high humidity either hinders fibre formation or causes the formation of defects on the fibres. In the case of PANI/PEO blends, different levels of PANI doping were investigated, and high level of doping with CSA was found to lead to the formation of crystalline structures. Data fitting was used to explore the behavior of conducting polymers using the case of PANI/PEO electrospinning and very good agreement between experimental and theoretical predictions was obtained for only a limited range of experimental conditions, whereas deviation was observed for all other sets of conditions. In the case of PANI/CH, the effect of different ratios of conducting polymer in the blend (0:1, 1:3, 3:5 and 1:1) was examined, as for the electrospinnability, resulting 3 nanofibrous morphology, mat contact angle, electrical conductivity, antibacterial activity and cellular biocompatibility. The incorporation of PANI in the electrospinning blend, affected the electrospinnability of the solution, making it more susceptible to RH deviations, and contributed to the decrease of nanofibre diameter. Higher PANI content was found to result in more hydrophobic and more conducting mats. The method that was used to stabilize the PANI/CH mats was also found to affect antibacterial activity and conductivity. The produced blend mats, exhibited antibacterial activity which was higher against Gram positive B. subtilis and lower against gram negative E. coli. The cellular biocompatibility was assessed with human osteoblasts and fibroblasts, in terms of cell proliferation rate as well as cell attachment and morphology. Cells of both cell lines adhered well and showed good growth rates on nanofibrous substrates of all blend ratios when compared to standard tissue culture plastic. Finally, amongst the PANI containing mats, the one of 1:3 PANI:CH ratio, was identified as the best to support osteoblast and fibroblast cell proliferation when compared to the pure chitosan.
93

Avaliação do comportamento biológico do cimento endodôntico MTA Fillapex em tecido ósseo de ratos / Evaluation of rat bone tissue response to MTA Fillapex

Assmann, Eloísa January 2013 (has links)
Introdução: A biocompatibilidade é uma propriedade importante e necessária a um cimento endodôntico. O objetivo do presente estudo foi fazer uma análise microscópica das reações do tecido ósseo do fêmur de ratos da linhagem Wistar frente ao cimento MTA Fillapex, comparando-as ao cimento AH Plus e ao grupo controle (cavidade vazia), nos períodos de 7, 30 e 90 dias. Materiais e Métodos: Foram utilizados 18 animais, divididos em 3 grupos, de acordo com o período experimental (n=6). Três cavidades foram preparadas no fêmur da pata traseira direita de cada animal, sendo que uma foi preenchida com AH Plus, a outra com MTA Fillapex e a última permaneceu vazia (controle negativo). Decorridos os períodos experimentais, os ratos foram mortos e as patas removidas, dissecadas e preparadas para análise histológica. Os cortes foram analisados em microscópico óptico. O infiltrado inflamatório e as zonas de calcificação foram avaliados de forma dicotômica (presente ou ausente). A formação de barreira óssea foi classificada como ausente, parcial ou completa. Testes estatísticos não-paramétricos foram utilizados para a comparação dos dados (p<0,05). Resultados: As comparações entre os períodos experimentais mostraram que aos 7 dias todos os grupos apresentaram menor formação de barreira óssea e que o MTA Fillapex apresentou mais áreas de calcificação em relação aos demais períodos. Nos grupos do AH Plus e do MTA Fillapex, o infiltrado inflamatório reduziu significativamente aos 90 dias. As comparações entre os grupos mostraram mais áreas de calcificação no grupo do AH Plus aos 30 e 90 dias. O grupo controle apresentou menos infiltrado inflamatório aos 30 dias. Não houve diferença significativa entre os grupos na formação de barreira óssea. Conclusões: O cimento endodôntico MTA Fillapex apresentou comportamento biológico satisfatório em contato direto com tecido ósseo de rato. As características do reparo foram semelhantes às do cimento AH Plus, porém o MTA Fillapex não induziu a formação de áreas de calcificação na medula óssea. / Introduction: Biocompatibility is an important property required for a endodontic sealer. This study aimed to analyze bone tissue reactions to MTA Fillapex compared to an epoxy resin-based material in the femur of Wistar rats. Methods: Bone tissue reactions were evaluated in 18 animals after 7, 30 and 90 days (n=6 per period). Three surgical cavities were prepared on femur and filled with 0.1 mL of AH Plus, MTA Fillapex or no sealer (negative control). By the end of each experimental period, six animals were randomly euthanized, the femur was dissected and the surgical cavities separated. The samples were histologically processed and analyzed by light microscope. Inflammatory infiltrate and the calcification zones were evaluated dichotomously; hard tissue barrier was classified as absent, partial or full. Results: Comparison among periods showed that at 7 days all groups presented less hard tissue barrier and MTA Fillapex showed more calcification zones than in other periods. The inflammatory infiltrate significantly reduced at 90 days in AH Plus and MTA Fillapex groups. Comparisons among the groups presented more calcification zones for AH Plus than for the other groups at 30 and 90 days. Control group showed less inflammatory infiltrate at 30 days. There were no singificant diferences to hard tissue barrier among the groups. Data were analyzed by non-parameric tests. Significance level was preset in 0.05. Conclusions: MTA Fillapex presented satisfactory biological behaviour when in direct contact with rat bone tissue. The repair characteristics were similar to those produced by AH Plus, but MTA Fillapex doesn’t induce mineralization in the bone marrow.
94

Incidência de recessão gengival e fatores de risco e de prognóstico associados : estudo longitudinal prospectivo de base populacional

Rios, Fernando Silva January 2017 (has links)
Este estudo teve como objetivo avaliar a citotoxicidade, biocompatibilidade e perfil osteoindutor de um novo material a base de MTA (MTA Flow) comparado ao AH plus e MTA fillapex. A viabilidade celular foi avaliada em células-tronco do ligamento periodontal pelo teste MTT. A resposta inflamatória e o perfil osteoindutor foram avaliados em tecido conjuntivo de 24 ratos machos (Rattus norvegicus albinus, Rodentia, Mammalia da linhagem Wistar), pesando entre 300 e 350g. Os animais foram divididos em 4 grupos experimentais. Foram implantados 4 tubos de polietileno no dorso de cada animal, sendo um vazio e outros três preenchidos com um dos materiais. Após 7, 30 e 60 dias, 8 animais foram mortos com anestésico inalatório. O tubo e o tecido subcutâneo adjacente foram removidos e fixados em solução de formalina a 10%. O material foi analisado histológicamente quanto ao processo inflamatório, condensação fibrosa e presença de abscesso. Posteriormente, realizou-se a análise imunoistoquímica para identificação de colágeno I, osteopontina, sialoproteina óssea e proteína morfogentica óssea-4 (BMP-4). Os dados foram analisados estatisticamente pela ANOVA, complementado pelo teste de Tukey usando SPSS 15.0. O MTA Flow mostrou não ser citotóxico e ter excelente biocompatibilidade com menor reação inflamatória no tecido subcutâneo de ratos em comparação com AH Plus e MTA Fillapex. Além disso, o MTA Flow mostrou ser capaz de estimular o processo mineralização, sendo uma vantagem em relação aos outros materiais testados. / This study aimed to evaluate the cytotoxicity, biocompatibility and osteoinductive profile of a new MTA based material (MTA Flow) compared to AH plus and MTA fillapex. Cell viability was evaluated in periodontal ligament stem cells by the MTT test. The inflammatory response and the osteoinductive profile were evaluated in the connective tissue of 24 male rats (Rattus norvegicus albinus, Rodentia, Mammalia of the Wistar line) weighing between 300 and 350g. The animals were divided into 4 experimental groups. Four polyethylene tubes were implanted on the back of each animal, one empty and another three filled with one of the materials. After 7, 30 and 60 days, 8 animals were killed with inhaled anesthetic. The tube and adjacent subcutaneous tissue were removed and fixed in 10% formalin solution. The material was analyzed histologically for the inflammatory process, fibrous condensation and presence of abscess. Subsequently, the immunohistochemical analysis was performed to identify collagen I, osteopontin, bone sialoprotein and bone morphogenetic protein-4 (BMP-4). Data were analyzed statistically by ANOVA, complemented by the Tukey test using SPSS 15.0. MTA Flow was shown to be non-cytotoxic and to have excellent biocompatibility with lower inflammatory reaction in rat subcutaneous tissue compared to AH Plus and MTA Fillapex. In addition, the MTA Flow showed to be able to stimulate the mineralization process, being an advantage over the other materials tested.
95

Modificação de superfície empregando-se laser e recobrimento de implantes dentários de titânio com apatitas

BRAGA, FRANCISCO J.C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:53:13Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:37Z (GMT). No. of bitstreams: 1 11663.pdf: 10292078 bytes, checksum: 0f5eba7b9211550254ba580ec5d5f63d (MD5) / Tese (Doutoramento) / IPEN/T / Universidade Estadual Paulista, Instituto de Quimica, Campus de Araraquara
96

Desenvolvimento, caracterização e estudo pré-clínico de dispositivos implantáveis biocompatíveis baseados no polímero poli(?-caprolactona) / Development, characterization and preclinical evaluation of the implantable biocompatible prototypes based on poli(?-caprolactona)

SILVA, FABIANA M. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:59Z (GMT). No. of bitstreams: 1 16497.pdf: 92708 bytes, checksum: 7ccf16810b03dfc8aa4c309390f8b21a (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
97

Pesquisa e desenvolvimento de biomateriais: estudo das inter-relações científicas, tecnológicas e normativas / Research and development of biomaterials: study of scientific, tecnological and regulatory inter relationship

BORELLI, VANESSA 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:34Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
98

Processamento e caracterizacao de ceramicas a base de hidroxiapatita e fosfato-tricalcico

RIBEIRO, CHRISTIANE 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:47:37Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:38Z (GMT). No. of bitstreams: 1 09244.pdf: 6936918 bytes, checksum: f617a299a215c92962967e2aa68b85f0 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:00/11693-7
99

Obtenção de pós nanométricos de hidroxiapatita sintetizados com magnésio utilizando ultra-som / Obtention of hydroxyapatite nanometric powders synthesized with magnesium using ultrasound

GOUVEIA, DEIBY S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:27Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:22Z (GMT). No. of bitstreams: 1 12759.pdf: 23849900 bytes, checksum: e0631f64bab4ba1dda3b9a8d5760ae19 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP
100

Biocompatibilidade de resinas acrílicas para base e reembasamento de próteses após períodos de imersão em soluções desinfetantes : análise do metabolismo celular /

Masetti, Paula. January 2016 (has links)
Orientador: Janaina Habib Jorge / Banca: Ana Carolina Pero Vizoto / Banca: Claudia Helena Lovato da Silva / Resumo: O objetivo deste estudo foi avaliar o efeito cumulativo das soluções desinfetantes na citotoxicidade de resinas acrílicas para base (Vipi Wave) e reembasamento (Tokuyama Rebase II) de próteses. Corpos de prova com 14 mm de diâmetro e 1,2 mm de espessura foram distribuídos em grupos (n=3) de acordo com o tipo de solução: água destilada, digluconato de clorexidina a 2%, perborato de sódio a 3,8%, hipoclorito de sódio a 0,5% e vinagre de maçã, e de acordo com o tempo de imersão: 0, 1, 3 e 6 meses. Os corpos de prova, tanto de base quanto de reembasamento, ficaram 8 horas imersos nas soluções e 16 horas em água destilada, simulando desinfecção noturna das próteses. As soluções foram trocadas diariamente. Após os diferentes períodos de imersão, as amostras foram colocadas em meio de cultura por 24 horas para obtenção de extratos para análise da citotoxicidade sobre queratinócitos humanos (HaCaT: 0341). O metabolismo celular foi avaliado pelo teste Alamar Blue ®. Empregou-se análise de variância (ANOVA) e teste de Tukey, com significância de 5%. Os resultados demonstraram que o tipo de resina não teve influência sobre o metabolismo celular. Além disso, a imersão das amostras de resina acrílica para base e reembasamento de próteses em água destilada, perborato de sódio a 3,8% e hipoclorito de sódio a 0,5% não influenciou o metabolismo celular dos queratinócitos, independentemente do tempo de imersão. Os extratos obtidos a partir da imersão das amostras em digluconato de clorexidina ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the cumulative effect of disinfectant solutions in cytotoxicity base acrylic resins (Vipi Wave) and reline (Tokuyama Rebase II) of dentures. Samples of 14 mm diameter and 1.2 mm thick were distributed in groups (n = 3) according to the type of disinfectant solution: distilled water, 2% chlorhexidine digluconate, 3.8 % sodium perborate, 0.5% sodium hypochlorite and apple vinegar and in accordance with the immersion time: 0, 1, 3 and 6 months. The samples of both base and of reline, eight hours were immersed in solutions and 16 hours in distilled water, simulating night disinfection of prostheses. The solutions were changed daily. After different periods of immersion, the samples were placed in culture medium for 24 hours to obtain extracts for analysis of cytotoxicity on human keratinocyte (HaCaT: 0341). The cellular metabolism was assessed by Alamar Blue ® test. It used analysis of variance (ANOVA) and Tukey test, with 5% significance. The results demonstrated that the resin type had no influence on cellular metabolism. Furthermore, the immersion of the samples in acrylic resin base and reline dentures in distilled water, 3.8% sodium perborate and 0.5% sodium hypochlorite did not influence the cellular metabolism of keratinocytes, regardless of the time of immersion. The extracts obtained from immersing the samples 2% chlorhexidine digluconate or apple vinegar for 3 and 6 months were considered strongly cytotoxic. It was concluded t... (Complete abstract click electronic access below) / Mestre

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