1,004 results on '"Microscopia eletronica de varredura"'
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2. Nanostructural characterization of surfaces and interfaces of Portland cement mortars using high resolution microscopy.
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de Faria e Oliveira Barreto, Matheus, Fonseca Gontijo, Marcelo Robert, Parreiras Teles, Carolina, and Faria de Araújo, Fabiana
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Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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3. Can Scanning Electron Microscopy be used to quantitatively measure dentine roughness?
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Marchan, Shivaughn Maria, IVEY, Marsha, RAJHBEHARRYSINGH, Amrita, and BASCOMBE, Kelee
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SCANNING electron microscopy ,STROKE patients ,DENTIN ,TOOTH abrasion ,STATISTICAL correlation - Abstract
Copyright of Brazilian Dental Science is the property of Brazilian Dental Science Journal-ICT-UNESP and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2024
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4. Avaliação da limpeza e eficácia antimicrobiana da ablação a laser com verde de indocianina contra biofilme de Enterococcus faecalis em canais radiculares.
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de Toledo LEONARDO, Renato, Angelo CINTRA, Luciano Tavares, de Castilho JACINTO, Rogério, LOUREIRO, Caroline, Augusto BANCI, Henrique, Fernandes RIBEIRO, Ana Paula, Duarte FARIA, Flávio, JENSEN, Steve, LARSEN, Rob, and CAO, Densen
- Abstract
Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
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5. Analysis of biofilm formation by Candida albicans in different types of orthodontic fixed appliances and devices.
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FERNANDES, Ellen Eduarda, Fernandes Lobo Molica OLIVEIRA, Daniela, Pilli JÓIAS, Renata, DINIZ, Pamela Aparecida, Pimentel de BARROS, Patrícia, Olavo Cardoso JORGE, Antônio, de OLIVEIRA, Wagner, and de Mello RODE, Sigmar
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CANDIDA albicans ,ORTHODONTIC appliances ,BIOFILMS ,CERAMICS ,SCANNING electron microscopy - Abstract
Copyright of Brazilian Dental Science is the property of Brazilian Dental Science Journal-ICT-UNESP and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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6. Bonding strategy of a universal adhesive system containing chitosan: influence on dentin permeability, and effect on adhesive layer micromorphology.
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Bettiol, Henrique E. G., Vieira-Junior, Waldemir F., França, Fabiana M. G., Amaral, Flávia L. B., and Basting, Roberta T.
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DENTIN ,CHITOSAN ,PERMEABILITY ,ADHESIVES ,SCANNING electron microscopes - Abstract
Copyright of Acta Odontologica Latinoamericana: AOL is the property of Acta Odontologica Latinoamericana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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7. Macro, micromorphological and histological aspects of the intestine pirarucu Arapaima gigas (SCHINZ, 1822) (Osteoglossiformes: Arapaimidae).
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Silva Pinto, Keila, Félix de Melo, Luana, Bastos de Aquino, Julia, Dantas Filho, Jerônimo Vieira, de Vargas Schons, Sandro, Miglino, Maria Angelica, and Grassi Rici, Rose Eli
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INTESTINES ,ANATOMY ,FISH farming ,INTESTINAL mucosa ,DIGESTIVE organs - Abstract
Copyright of Acta Veterinaria Brasilica is the property of Acta Veterinaria Brasilica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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8. Ultraestructura en la etapa larval vitelina de Brycon moorei (Steindachner 1878) producida en un sistema con recirculación de agua.
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David-Ruales, Carlos, Meza-Terraza, Dayana, and Machado-Fracalossi, Débora
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SCANNING electron microscopy , *CELL anatomy , *ENDEMIC species , *PITUITARY hormones , *WATERSHEDS , *WATER quality , *LARVAL dispersal , *HAIR cells - Abstract
Introduction. Brycon moorei (Dorada) is an endemic species of the Magdalena River basin with strong commercial, sport and consumption fishing pressure. However, it is considered highly vulnerable due to the loss of its habitats. Objective. Observe and determine some structures of the larval stage using Scanning Electron Microscopy (SEM). Materials and methods. In a recirculating water system, larvae were obtained by semi-natural reproduction using carp pituitary hormone (CPH). For visualization in SEM, 10 larvae at different development times were fixed in Karnovsky solution, following the internal protocols of the Center for Advanced Microscopy (CAM) of the University of Antioquia. Results. Oocytes of 1110.7±97.3 µm in diameter were obtained from hormonal induction; the latency time was 6 hours at a temperature of 26°C; the total length and weight of the newly hatched larvae were 3.05±0.05 mm and 1.8±0.2 mg, respectively. SEM observations show pavement cells lining the body at hatching; neuromasts, the primordium of the branchial system, olfactory hair cells, and the cement gland. The recirculation system allowed to maintain water quality conditions within the comfort of the species, ensuring larval survival of 95%. Conclusions. The SEM microphotographs made it possible to determine structures such as specialized cells associated with their cannibalistic behavior (smell, wave detection) and others related to their habitat (cement gland). In turn, the recirculation system allowed an adequate environmental management of the larvae. [ABSTRACT FROM AUTHOR]
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- 2022
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9. Evaluación físico-química de compositos madera-plástico para el diseño de productos.
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Adriana Martel-Estrada, Santos, Jessica Morales-Rivera, Ana, Olivas-Armendáriz, Imelda, and Aguilar-Cera, Fátima
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FOURIER transform infrared spectroscopy ,COMPOSITE materials ,WOOD waste ,SCANNING electron microscopy ,ENGINEERED wood ,POLYCAPROLACTONE - Abstract
Copyright of Revista ION is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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10. Synthesis, characterization and protection effect of black rice anthocyanins nano-composite against hepatotoxicity induced by methotrexate in rats
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M. A. Sheikha, N. A. Soheir, and F. M. SyragEldin
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arroz preto ,hepatotoxicity ,black rice ,nanocompósito de antocianinas ,Oryza ,methotrexate ,Rats ,Anthocyanins ,Oxidative Stress ,Methotrexate ,anthocyanins nano-composite ,hepatotoxicidade ,metotrexato ,microscopia eletrônica de varredura ,Animals ,espectroscopia de infravermelho ,Chemical and Drug Induced Liver Injury ,General Agricultural and Biological Sciences ,infrared spectroscopy ,scanning electron microscopy - Abstract
The present study aimed to investigate the beneficial of prepared black rice anthocyanins nano-composite (An-AgNps) against hepatotoxicity induced by methotrexate (MTX) in rats. Anthocyanins nano-composite was prepared by silver as the metallic ion reduction and were characterized by IR and SEM. The rats in our experiment were divided into five groups. Serum lipid profile, serum transaminases (ALT and AST), ALP, LDH, TBA, GSH and SOD were examined. The results show that SEM of An-AgNps has average particle size from 70 to 130nm. In the group treated with MTX; TC, TG, LDL-c, ALT, AST, ALP, LDH and TBA levels were significantly (P≤0.05) increased than NC, while, HDL-c, SOD and GSH levels were significantly (P≤0.05) decreased. On the other hand, An-AgNps + MTX treated groups were reversed the levels of all biomarkers similar to NC. In conclusion, the results show that An-AgNps has a protective effect on MTX-induced hepatotoxicity and oxidative stress. Resumo O presente estudo teve como objetivo investigar o benefício de nanocompósito de antocianinas de arroz preto preparado (An-AgNps) contra a hepatotoxicidade induzida por metotrexato (MTX) em ratos. O nanocompósito de antocianinas foi preparado a partir da prata por meio da redução do íon metálico e caracterizado por IR e SEM. Os ratos em nosso experimento foram divididos em cinco grupos, e foram examinados o perfil lipídico sérico, as transaminases séricas (ALT e AST), ALP, LDH, TBA, GSH e SOD. Os resultados mostram que SEM de An-AgNps tem tamanho médio de partícula de 70 a 130 nm. No grupo tratado com MTX, os níveis de TC, TG, LDL-c, ALT, AST, ALP, LDH e TBA aumentaram significativamente (P ≤ 0,05) do que NC, enquanto os níveis de HDL-c, SOD e GSH diminuíram significativamente (P ≤ 0,05). Por outro lado, nos grupos tratados com An-AgNps + MTX, foram revertidos os níveis de todos os biomarcadores semelhantes ao NC. Em conclusão, os resultados mostram que o An-AgNps tem um efeito protetor contra a hepatotoxicidade induzida pelo MTX e o estresse oxidativo.
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- 2024
11. Análise da eficácia de diferentes protocolos clínicos para limpeza da parede dentinária intrarradicular previamente à cimentação de pinos.
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Froehlich, Julia, Mallmann Weschenfelder, Vanessa, and Fontoura de Melo, Tiago André
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SALINE solutions ,SCANNING electron microscopes ,SALINE irrigation ,MEDICAL protocols ,DENTAL pulp cavities - Abstract
Copyright of RSBO: Revista Sul-Brasileira de Odontologia is the property of UNIVILLE and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
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12. Avaliação da interface entre o componente protético reto e a conexão interna tipo Cone Morse do implante dentário por meio da microscopia eletrônica de varredura
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Mariana Bispo COSTA, Lorena Fernandes FERREIRA, Wilton Mitsunari TAKESHITA, Antonio Carlos MARQUETI, and Cleverson Luciano TRENTO
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Implantes dentários ,pilares protéticos ,microscopia eletrônica de varredura ,Medicine ,Dentistry ,RK1-715 - Abstract
Resumo Introdução A interface implante-pilar protético e a formação dos seus microgaps são aspectos relevantes na transferência das cargas e na resposta biológica, estando ligadas ao sucesso da reabilitação. Objetivo Avaliar microgaps na interface entre a conexão interna do implante do tipo Cone Morse e a superfície do componente protético por meio da microscopia eletrônica de varredura (MEV). Material e método Foram utilizados 20 implantes dentários de tamanho 3,75 × 11,0mm do tipo Cone Morse com seus respectivos pilares protéticos da Singular® (Singular Implants, RN, Brasil). Os munhões retos foram acoplados aos implantes com torque de 32N/cm2 e o conjunto resultante foi emergido em base de Resina Epóxi ES260, para permitir secção longitudinal da amostra. As amostras foram analisadas e os microgaps mensurados no MEV (JEOL JCM-5700, MA, USA), e posteriormente os dados foram analisados. Resultado A média e o desvio padrão dos maiores microgaps foram observados na parte apical do implante nos lados direito e esquerdo, sendo 1,44±2,68 e 1,16±1,49 μm, respectivamente. Os menores microgaps foram na parte superior do implante nos lados direito e esquerdo, sendo 0,60±0,73 e 0,66±0,67 μm, respectivamente. Contudo, no teste de Kruskal-Wallis, não houve diferença estatisticamente significativa entre as regiões dos implantes, tanto para o lado esquerdo (p=0,692) como para o direito (p=0,865). No teste de Mann-Whitney, não houve diferenças estatisticamente significativas entre os lados para as diferentes regiões dos implantes. Conclusão Mesmo com a presença de microgaps na interface implante-pilar protético, estes apresentam tamanho inferior ao que causaria problemas biológicos e mecânicos. As amostras analisadas quanto à sua compatibilidade de encaixe foram satisfatórias.
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- 2020
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13. Eficácia de três protocolos de irrigação final para remoção de raspas dentinárias e material obturador em irregularidades simuladas.
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NASCIMENTO, Angela Longo do, MENDES, Aline Teixeira, TIETZ, Lilian, SILVA, Paula Barcellos, DUARTE, Pedro Henrique Marks, da ROSA, Ricardo Abreu, VILLA, Natália, and SÓ, Marcus Vinícius Reis
- Abstract
Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
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14. Avaliação em MEV da interface dente/restauração com preparo do cavo-superficial em 90 graus ou bisel e polimento em diferentes sentidos.
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Pedroso de Moraes, Fernanda, Ribeiro dos Santos, Everton, Reis Garcia, Filipe, and Duarte Irala, Luis Eduardo
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TEETH polishing ,INCISORS ,ELECTRON microscopy ,TEETH ,HOMOGENEITY - Abstract
Copyright of Stomatos is the property of Revista Stomatos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
15. Efeitos abrasivos produzidos por um dentifrício à base de carvão.
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Paula Losekann, Ana, Zimmer, Roberto, Afonso Klein-Junior, Celso, Galia Reston, Eduardo, and Rodrigues Macedo, Cármen Lúcia
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DENTAL enamel ,SCANNING electron microscopy ,DENTIFRICES ,ACTIVATED carbon ,TOOTHPASTE - Abstract
Copyright of Stomatos is the property of Revista Stomatos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
16. Avaliação da rugosidade promovida por diferentes concentrações e tempos de exposição ao ácido fluorídrico em superfícies de cerâmica reforçada por dissilicato de lítio.
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de Almeida Nunes, Ana Paula, Silva de Mello, Ana Paula, de França Leite, Karla Lorene, de Mello, Elson Braga, and de Azevedo Miranda, Diogo
- Abstract
Copyright of Journal of Clinical Dentistry & Research is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
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17. CARACTERIZAÇÃO DA SUPERFÍCIE DE PARTÍCULAS DE PRODUTOS LÁCTEOS DESIDRATADOS.
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de Melo Toledo, Paulo Henrique, Fortes Pereira, João Pablo, Tuler Perrone, Ítalo, Fernandes Carvalho, Antônio, Cappa Oliveira, Luiz Fernando, and Stephani, Rodrigo
- Abstract
Copyright of Revista do Instituto de Laticínios Cândido Tostes is the property of Revista do Instituto de Laticinios Candido Tostes and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
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18. Avaliação da interface entre o componente protético reto e a conexão interna tipo Cone Morse do implante dentário por meio da microscopia eletrônica de varredura.
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Bispo COSTA, Mariana, Fernandes FERREIRA, Lorena, Mitsunari TAKESHITA, Wilton, MARQUETI, Antonio Carlos, and Luciano TRENTO, Cleverson
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Copyright of Universidade Estadual Paulista. Revista de Odontologia is the property of Universidade Estadual Paulista. Revista de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
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19. Morphological and molecular characterization of Contracaecum australe (Nematoda: Anisakidae) parasitizing Phalacrocorax brasilianus (Aves: Phalacrocoracidae) on the north coast of Brazil
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Santana, Ricardo Luis Sousa, Carvalho, Elaine Lopes de, Sindeaux Neto, José Ledamir, Silva, Michele Velasco Oliveira da, Pinheiro, Raul Henrique da Silva, Gonçalves, Evonnildo Costa, and Giese, Elane Guerreiro
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Parasitos ,aves ,birds ,microscopia eletrônica de varredura ,DNA ribossomal nuclear ,Parasites ,internal transcribed spacers (ITS) ,espaçadores transcritos internos (ITS) ,nuclear ribosomal DNA ,scanning electron microscopy - Abstract
For the first time in Brazil, Contracaecum australe is recorded parasitizing Phalacrocorax brasilianus (Aves, Suliformes, Phalacrocoracidae) from the Marine Extractive Reserve of Soure on Marajó Island, Brazilian Amazon. Its morphology revealed a body with a transversally striated cuticle, smooth or slightly cleft interlabia, lips with auricles, labial papillae, and conspicuous amphids. In males, the presence of the median papilla on the upper lip of the cloaca and spicules that reach almost half of the body of the parasite. These morphological characters, added to the number and distribution of the pre- and postcloacal papillae of the male specimens, and supported by the molecular phylogeny from the analysis of the ITS-1, 5.8S and ITS-2 genes, allowed the identification of these parasites. Resumo Pela primeira vez no Brasil, Contracaecum australe é registrado parasitando Phalacrocorax brasilianus (Aves, Suliformes, Phalacrocoracidae) da Reserva Extrativista Marinha de Soure na Ilha de Marajó, Amazônia brasileira. Sua morfologia revelou corpo com cutícula estriada transversalmente, interlábios lisos ou levemente fendidos, lábios com aurículas, papilas labiais e anfídeos conspícuos. Nos machos, observa-se a presença da papila mediana no lábio superior da cloaca e espículos que atingem quase a metade do corpo do parasito. Esses caracteres morfológicos, somados ao número e distribuição das papilas pré e pós-cloacais dos espécimes machos, e apoiados pela filogenia molecular a partir da análise dos genes ITS-1, 5.8S e ITS-2, permitiram a identificação desses parasitos.
- Published
- 2023
20. Evaluation of the corneal epithelium of rabbits treated with preservative-free eye drops containing ketorolac tromethamine or diclofenac sodium
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Pereira, Fabiana Quartiero, Bender, Melina Barbara, Silva, Tanise Carboni da, Santos, Bruna Santos dos, Hünning, Paula Stieven, Faganello, Cláudia Skilhan, Pacheco, Maira Haase, Mello, João Roberto Braga de, Mello, Fernanda Bastos de, and Pigatto, João Antonio Tadeu
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nonsteroidal anti-inflammatory agent ,ophthalmic solutions ,cornea ,solução oftálmica ,microscopia eletrônica de varredura ,antiinflamatório não esteroidal ,córnea ,scanning electron microscopy - Abstract
This study aimed to evaluate the corneal epitheliotoxic effects of preservative-free ketorolac tromethamine 0.5% and diclofenac sodium 0.1% eye drops in rabbits. Seventeen New Zealand rabbits were randomly divided into three groups: the 0.5% ketorolac tromethamine group, the 0.1% diclofenac sodium group, and the control group (0.9% NaCl). For each rabbit, both eyes were treated three times daily according to their treatment group. The corneal epithelia were analyzed using scanning electron microscopy to observe the number of light, grey, and dark cells; the number of epithelial holes; and the loss of hexagonal shape. Both of the formulations administered caused changes in the healthy corneal epithelia of rabbits. Except for number of epithelial holes (p < 0.05), all the parameters showed a statistically significant difference between the groups. The number of dark cells was highest in the ketorolac tromethamine group (p
- Published
- 2023
21. AVALIAÇÃO POR MEIO DA MICROSCOPIA ELETRÔNICA DE VARREDURA DE ALTERAÇÕES SOFRIDAS EM PONTAS DIAMANTADAS –ESTUDO PILOTO
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IANA MARIA COSTA GONÇALVES, THACYANNA WANDERLEY JUCÁ, CAMILA HELENA MACHADO DA COSTA FIGUEIREDO, ELIZANDRA SILVA DA PENHA, MARCUS VINÍCIUS LIA FOOK, and LUANNA ABÍLIO DINIZ MELQUÍADES DE MEDEIROS
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esterilização ,microscopia eletrônica de varredura ,instrumentos odontológicos ,Science ,Social Sciences - Abstract
O uso de pontas diamantadas de forma descartável tem sido incentivado, porém a re-esterilização é uma prática habitual nos consultórios odontológicos. O objetivo deste estudo piloto é verificar, por meio da microscopia eletrônica de varredura (MEV), as alterações nas características superficiais de pontas diamantadas devido ao método de esterilização através do uso da autoclave (calor úmido). Foram utilizadas 3 pontas diamantadas 1014 da marca MICRODONT®, às quais foram submetidas a diferentes procedimentos, sendo P1 (Ponta 1) não submetida a nenhum ciclo de esterilização, sendo, portanto, o controle; P2 (Ponta 2) submetida a esterilização através do calor úmido em autoclave por 5 vezes consecutivas e P3 (Ponta 3) submetida por 10 vezes consecutivas à esterilização em autoclave. Posteriormente as pontas diamantadas foram analisadas por microscopia eletrônica de varredura (MEV), utilizando-se aumentos de 150x, 330x e 500x. Observou-se que as pontas utilizadas nesta pesquisa, às quais foram submetidas à esterilização, sofreram desgaste por corrosão, sendo que a ponta submetida a 10 ciclos consecutivos de esterilização apresentou um maior desgaste. É possível concluir que a corrosão sofrida pelas pontas devido ao processo de esterilização em autoclave ocasiona a perda de grãos de diamante o que pode acarretar em queda no seu desempenho de corte, prejudicando sua eficiência.
- Published
- 2017
22. EX VIVO MODEL OF RABBIT INTESTINAL EPITHELIUM APPLIED TO THE STUDY OF COLONIZATION BY ENTEROAGGREGATIVE ESCHERICHIA COLI
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Ricardo Luís Lopes BRAGA, Ana Claudia Machado PEREIRA, Paula Azevedo dos SANTOS, Angela Corrêa FREITAS-ALMEIDA, and Ana Cláudia de Paula ROSA
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Escherichia coli ,Mucosa intestinal ,ultraestrutura ,Técnicas de cultura de órgãos ,Coelhos ,Microscopia eletrônica de varredura ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
ABSTRACT BACKGROUND The diarrheal syndrome is considered a serious public health problem all over the world and is considered a major cause of morbidity and mortality in developing countries. The high incidence of enteroaggregative Escherichia coli in diarrheal syndromes classified as an emerging pathogen of gastrointestinal infections. After decades of study, your pathogenesis remains uncertain and has been investigated mainly using in vitro models of adhesion in cellular lines. OBJECTIVE The present study investigated the interaction of enteroaggregative Escherichia coli strains isolated from childhood diarrhea with rabbit ileal and colonic mucosa ex vivo, using the in vitro organ culture model. METHODS The in vitro adhesion assays using cultured tissue were performed with the strains co-incubated with intestinal fragments of ileum and colon over a period of 6 hours. Each strain was tested with three intestinal fragments for each region. The fragments were analysed by scanning electron microscopy. RESULTS Through scanning electron microscopy we observed that all strains adhered to rabbit ileal and colonic mucosa, with the typical aggregative adherence pattern of “stacked bricks” on the epithelium. However, the highest degree of adherence was observed on colonic mucosa. Threadlike structures were found in greater numbers in the ileum compared to the colon. CONCLUSION These data showed that enteroaggregative Escherichia coli may have a high tropism for the human colon, which was ratified by the higher degree of adherence on the rabbit colonic mucosa. Finally, data indicated that in vitro organ culture of intestinal mucosa from rabbit may be used to elucidate the enteroaggregative Escherichia coli pathogenesis.
- Published
- 2017
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23. Análise da composição química dos cimentos MTA Angelus® branco, cinza e HP Repair® através de Microscopia Eletrônica de Varredura (MEV) acoplada a Espectrômetro de Energia Dispersiva (EDS)
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Gabriela Duarte Rocha SARZEDA, Marcelo Santos BAHIA, Paulo Victor Teixeira DORIGUÊTTO, Karina Lopes DEVITO, and Anamaria Pessoa Pereira LEITE
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Microscopia eletrônica de varredura ,materiais dentários ,endodontia ,Medicine ,Dentistry ,RK1-715 - Abstract
Resumo Introdução Devido às suas propriedades biológicas e físico-químicas, o MTA tem sido indicado para diferentes situações clínicas na Endodontia. Objetivo O objetivo foi analisar a composição química dos cimentos MTA Angelus branco, cinza, e Repair HP. Material e método Foram confeccionados cinco corpos de prova de cada tipo de cimento estudado, com diâmetro de 4 mm e altura de 1 mm, utilizando fita condutora de carbono dupla face. Em seguida, as amostras foram analisadas com auxílio de um microscópio eletrônico de varredura acoplado ao aparelho de espectrometria de energia dispersiva. Posteriormente, foram submetidos ao teste estatístico Kolmogorov-Smirnov para verificar a normalidade. Os elementos químicos que apresentaram distribuição normal (média de 5%) foram submetidos ao teste ANOVA e o teste Kruskal-Wallis foi aplicado naqueles com distribuição assimétrica. Resultado Após a análise dos elementos químicos, foram observados para o MTA branco: O, Na, K, Mg, Al, Si, Ca e Bi; para o MTA cinza: O, Mg, Al, Si, Ca, Bi, Fe e S, e para o Repair HP: O, Al, Mg, Si, Ca, Fe, Sr, C, Rb e W. Foram identificados 14 elementos químicos nas amostras analisadas (O, Na, Al, Mg, Si, S, K, Ca, Fe, Sr, Bi, C, Rb e W). Destes, cinco foram encontrados em todos os cimentos estudados: O, Al, Mg, Si e Ca. Conclusão Os elementos Rb, W e C foram encontrados somente na nova formulação de MTA da Angelus, o Repair HP. Nas amostras analisadas, o Ca e o O foram os que se apresentaram em maior quantidade.
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- 2019
- Full Text
- View/download PDF
24. Morfologia e morfometria de Paratanaisia bragai () Freitas, 1959 (Digenea, Eucotylidae) através da microscopia de luz e microscopiaeletrônica de varredura
- Author
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V. B. Xavier, A. Oliveira-Menezes, F. A. O. Adnet, V. Sant’Anna, W. Souza, R. A. DaMatta, J. Pinheiro, and S. V. P. B. Brandolini
- Subjects
morfologia ,Paratanaisia bragai ,morphology ,morfometria ,microscopia eletrônica de varredura ,microscopia de luz ,General Agricultural and Biological Sciences ,morphometry ,scanning electron microscopy ,light microscopy - Abstract
Paratanaisia bragai is a digenetic trematode that reaches sexual maturity in the kidney collecting ducts of domestic and wild birds, while the snails Subulina octona and Leptinaria unilamellata serve as its intermediate hosts in Brazil. The present study analyzed the morphology and morphometry of P. bragai. Adult specimens of the parasite were collected from naturally infected Columba livia kidneys, fixed and prepared for observation via bright field and differential interference contrast light microscopy and scanning electron microscopy. The parasite has an elongated and flattened body, with a subterminal oral sucker located at the anterior end of the body, as observed by all techniques used. Staining the parasite with hematoxylin-eosin enabled observation of the pharynx, located posteriorly to the oral sucker, the vitelline glands, which are extra-cecal and extend anteriorly to the pre-ovarian region and later to the median region of the body, and intestinal caeca parallel to the vitelline glands. The presence and functionality of the acetabulum are controversial points in the literature, but it was observed in all specimens analyzed by scanning electron microscopy, with a major diameter of 38.36 ± 6.96 (28.77 – 45.39) and minor diameter of 31.59 ± 7.04 (21.75 - 38.16). Close to the acetabulum, scales were observed in the integument of the parasite. Scales with (1 - 5) blade divisions were identified. In the genital pore, it was possible to see the everted cirrus with rosette shape. The excretory pore (first morphometric record) is dorsal and subterminal, with major diameter of 12.27 ± 9.16 (5.79 - 18.75) and minor diameter of 3.95 ± 1.49 (2.89 - 5.00). Resumo Paratanaisia bragai é um trematódeo digenético que atinge a maturidade sexual nos ductos coletores de aves domésticas e silvestres, enquanto os moluscos Subulina octona e Leptinaria unilamellata atuam como seus hospedeiros intermediários no Brasil. O presente estudo analisou a morfologia e morfometria de P. bragai. Amostras adultas do parasito foram coletadas de rins de Columba livia naturalmente infectada, fixadas e preparadas para observação na microscopia de campo claro e microscopia de luz de contraste de interferência diferencial e microscopia eletrônica de varredura. O parasite possui corpo alongado e achatado, com uma ventosa oral subterminal localizada na extremidade anterior do corpo, conforme observado por todas as técnicas utilizadas. A coloração do parasito com hematoxilina-eosina permitiu observar a faringe, localizada posteriormente à ventosa oral, as glândulas vitelogênicas, que são extracecais e estendem-se anteriormente à região pré-ovariana e posteriormente à região mediana do corpo, e os cecos intestinais paralelos às glândulas vitelinas. A presença e funcionalidade do acetábulo são pontos controversos na literatura, mas foi observado em todos os espécimes analisados por microscopia eletrônica de varredura, com diâmetro maior de 38.36 ± 6.96 (28.77 – 45.39) e diâmetro menor de 31.59 ± 7,04 (21.75 – 38.16). Próximo ao acetábulo foram observadas escamas no tegumento do parasito. Escamas com (1 - 5) divisões de lâmina foram identificadas. No poro genital, foi possível visualizar o cirro evertido com formato de roseta. O poro excretor (primeiro registro morfométrico) é dorsal e subterminal, com diâmetro maior de 12.27 ± 9.16 (5.79 – 18.75) e diâmetro menor de 3.95 ± 1.49 (2.89 – 5.00).
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- 2023
25. 'Revisitando o passado': uma redescrição de Physaloptera retusa (Nemata, Physalopteridae) a partir de material depositado em museus e novo material de lagartos amazônicos
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Lílian Cristina Macedo, Yuri Willkens, Leandro Maurício Oliveira Silva, Scott Lyell Gardner, Francisco Tiago de Vasconcelos Melo, and Jeannie Nascimento dos Santos
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Helmintos de répteis ,Amazônia ,morfologia ,General Veterinary ,morphology ,identificação taxonômica ,microscopia eletrônica de varredura ,Parasitology ,Amazon ,scanning electron microscopy ,Helminths of reptiles ,taxonomical identification - Abstract
Physaloptera Rudolphi, 1819 is a genus of nematodes that includes approximately 100 species parasitic in vertebrates around the world. From these, approximately 30 occur in the Neotropical region, with nine reported from neotropical reptiles. Physaloptera spp. are recognized by their distinct morphology of the apical end and characters of the reproductive system. However, despite the fact that the morphological characters for species diagnosis have been firmly established, we frequently find identification problems regarding poorly detailed descriptions and poorly preserved specimens. These may lead to taxonomic incongruencies. Physaloptera retusa (Rudolphi, 1819) is the most common species of the genus and has been reported from several species of neotropical reptiles. Based on our reexaminations of nematode specimens identified as P. retusa from different museum collections, we provide a detailed redescription including the type material, voucher specimens and new specimens recovered currently and showed in this study with new morphological data obtained using light and scanning electron microscopy tools. Resumo Physaloptera Rudolphi, 1819 é um gênero de nematódeos que inclui aproximadamente 100 espécies parasitárias em vertebrados em todo o mundo. Destes, aproximadamente 30 ocorrem na região Neotropical, e nove foram reportados para répteis neotropicais. Physaloptera spp. são reconhecidas por sua morfologia distinta na extremidade apical e por caracteres do sistema reprodutivo, especialmente nos machos. No entanto, embora os caracteres morfológicos para o diagnóstico de espécies tenham sido estabelecidos, frequentemente são encontrados problemas de identificação em relação a descrições pouco detalhadas e espécimes mal preservados. Isto pode levar a incongruências taxonômicas e erros de identificação. Physaloptera retusa (Rudolphi, 1819) é a espécie mais comum do gênero e tem sido reportada para várias espécies de répteis neotropicais. Com base nos estudos das revisões de espécimes de nematódeos, identificados como P. retusa de diferentes coleções de museus, foi providenciada uma redescrição detalhada, incluindo-se o material-tipo, espécimes "voucher" e novos espécimes obtidos neste estudo com novos dados morfológicos, obtidos a partir de microscopia eletrônica de luz e varredura.
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- 2023
26. Efeito de nanotubos de carbono em matrizes de cimento Portland
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Marcelo Henrique Farias de Medeiros and Thiago Melanda Mendes
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rheological properties ,x-ray diffraction ,desempenho mecânico ,comportamento reológico ,microscopia eletrônica de varredura ,General Medicine ,difração de raios-X ,mechanical properties ,thermo-gravimetry ,scanning electron microscopy ,análise termogravimétrica - Abstract
This study evaluates the effects of three carbon nanotubes with different geometric characteristics on the rheological behaviour and mechanical performance, as well as on the microstructure of mortars and cement pastes. For nanotube content ranging from 0.025 to 0.2 wt%, the yield stress and viscosity were determined by rotational rheometry, and mechanical performance was evaluated by flexural strength and dynamic modulus of elasticity. The microstructural analysis was performed by X-ray diffraction, thermo-gravimetric analysis and scanning electron microscopy (SEM). The obtained results showed that the yield stress presents a considerable increase as the carbon nanotube content increases. The viscosity was also influenced by the presence of carbon nanotubes. The flexural strength of mortars increases for different amounts of carbon nanotubes, and depending on the geometric characteristics of the carbon nanotubes, the material behaves like a composite. The microstructural analysis showed the nucleation of hydration products on the surface of the carbon nanotubes, and that the better mechanical performance of matrices containing carbon nanotubes is not related to the increase in hydration products. resumo: este estudo avaliou os efeitos de três nanotubos de carbono com diferentes características geométricas no comportamento reológico e desempenho mecânico, assim como na microestrutura de argamassas e pastas de cimento. Para teores de nanotubos de carbono variando de 0.025 a 0.2%, a tensão de escoamento e a viscosidade foram determinadas por meio de reometria rotacional, e o desempenho mecânico foi avaliado através da resistência a flexão e módulo de elasticidade dinâmico. A análise microestrutural foi conduzida através da difração de raios-X, análise termogravimétrica, e microscopia eletrônica de varredura. Os resultados obtidos mostram que a tensão de escoamento apresenta um aumento considerável com o aumento no teor de nanotubos. E a viscosidade também é influenciada pela presença dos nanotubos de carbono. A resistência à flexão das argamassas aumenta para os diferentes teores de nanotubos de carbono. E dependendo das características geométricas dos nanotubos, o material se comporta como um compósito. A análise microestrutural mostrou a nucleação de produtos de hidratação sobre a superfície dos nanotubos de carbono, e que o melhor desempenho mecânico das matrizes contendo nanotubos de carbono não está relacionada com o aumento dos produtos de hidratação.
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- 2023
27. Microhardness, Color Stability and Microstructural Analysis of Prefabricated Composite Resin Veneers.
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de Albuquerque, Pedro Paulo Albuquerque Cavalcanti, Moreno, Marina Barreto Pereira, Nishida, Alexander Cassandri, Rodrigues Júnior, Ezequias Costa, and Francci, Carlos Eduardo
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COLOR , *DENTAL equipment , *DENTAL materials , *DENTAL veneers , *MATERIALS testing , *SPECTROPHOTOMETERS , *STATISTICS , *DATA analysis , *DESCRIPTIVE statistics , *IN vitro studies , *ONE-way analysis of variance - Abstract
The aim of the work was to determine Knoop microhardness (KH), color stability (ΔE00) and microstructure of prefabricated composite resin veneers (PCRVs). Two PCRVs systems (Componeer Brilliant New Generation, Coltene, Altstätten, Switzerland; and Direct Veneer, Edelweiss, Wolfurt, Austria) were tested. KH was measured at the buccal surface of the PCRVs. Color analyze was evaluated by a spectrophotometer and ΔE00 calculated using CIEDE2000 formula. Microstructure of the PCRVs was characterized using scanning electron microscopy (SEM). Data of KH and ΔE00 were subjected to One-way ANOVA followed by Tukey post hoc test (a=0.05). Componeer (KH = 46) and Edelweiss (KH = 43) presented statistical similar hardness results (p>0.05). Componeer (ΔE00water= 0.1 and ΔE00coffee= 13.4) showed lower ΔE00 than Edelweiss (ΔE00water= 0.5 and ΔE00coffee= 18.7). SEM-images indicated similar microstructures of the PCRVs tested. Although PCRVs present similar microhardness and microstructure, Componeer showed higher color stability and lower extrinsic pigmentation to coffee in comparison to Edelweiss. Direct composite resin veneer treatment might be simplified with PCRVs. However, the high pigmentation observed in the PCRVs could generate aesthetic failures over the time. [ABSTRACT FROM AUTHOR]
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- 2019
- Full Text
- View/download PDF
28. Efeito de diferentes protocolos de irrigação final na remoção da smear layer.
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de LIMA, Carolina Oliveira, Fonseca de CARVALHO, Fernanda Leal, Rivera FIDEL, Sandra, Neiva CAMPOS, Celso, de Carvalho MARION, Jefferson José, Sergio FIDEL, Rivail Antônio, and do PRADO, Maíra
- Abstract
Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
29. Avaliação de rugosidade, dureza e superfície dos cimentos de ionômero de vidro após diferentes sistemas de acabamento e polimento
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Jéssika Raíssa Medeiros de ALMEIDA, Thiago Clístines de MEDEIROS, Diana Ferreira Gadelha de ARAÚJO, Sergei Godeiro Fernandes Rabelo CALDAS, and Marília Regalado GALVÃO
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Cimentos de ionômero de vidro ,microscopia eletrônica de varredura ,testes de dureza ,propriedades de superfície ,Medicine ,Dentistry ,RK1-715 - Abstract
Resumo Introdução A rugosidade de superfície é uma limitação que interfere nos desempenhos mecânico e estético do cimento de ionômero de vidro (CIV), sendo necessária a utilização de procedimentos para acabamento e polimento adequados às propriedades desse material. Objetivo Avaliar o efeito de diferentes sistemas de acabamento e polimento na rugosidade, dureza e superfície de restaurações realizadas com dois tipos de CIV. Material e método Foram utilizados 100 corpos de prova (CP), divididos em 10 grupos, de acordo com o tipo de CIV (convencional e modificado por resina) e o sistema de acabamento e polimento empregado [C-tira de poliéster (controle); PD-ponta diamantada; DA-discos abrasivos; PE-ponta Enhance; BM-broca multilaminada]. Após sete dias em água destilada, os CP foram avaliados em Microscópio Eletrônico de Varredura (MEV) e submetidos aos testes de rugosidade de superfície e microdureza Vickers. A análise estatística foi realizada com ANOVA dois fatores e pós-Teste de Tukey. Resultado A análise por MEV indicou superfície mais lisa no grupo BM em ambos os tipos de CIV. Quanto à rugosidade, observou-se diferença estatisticamente significante (p
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- 2017
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30. Biological development, direct and indirect damages of the pink sugarcane mealybug Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Pseudococcidae) in the state of São Paulo : biosystematic of the pink sugarcane mealybug
- Author
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Monteiro, Gabriel Gonçalves [UNESP], Universidade Estadual Paulista (Unesp), Martinelli, Nilza Maria, and Peronti, Ana Lúcia Benfatti Gonzalez
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Microscopia eletrônica de varredura ,Life table ,Cochonilha ,Red rot ,Tabela de vida ,Podridão vermelha ,Cana-de-açúcar - Abstract
Submitted by Gabriel Gonçalves Monteiro (gabrielmonteiro7777@hotmail.com) on 2022-10-18T00:52:58Z No. of bitstreams: 1 Tese_GabrielMonteiro.pdf: 2450261 bytes, checksum: dce8d61c1026ac2c62b4530fa5ea568a (MD5) Approved for entry into archive by Laudicélia Martins Arantes (lm.arantes@unesp.br) on 2022-10-18T11:38:36Z (GMT) No. of bitstreams: 1 monteiro_gg_dr_jabo.pdf: 2450261 bytes, checksum: dce8d61c1026ac2c62b4530fa5ea568a (MD5) Made available in DSpace on 2022-10-18T11:38:36Z (GMT). No. of bitstreams: 1 monteiro_gg_dr_jabo.pdf: 2450261 bytes, checksum: dce8d61c1026ac2c62b4530fa5ea568a (MD5) Previous issue date: 2022-09-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) O cultivo de cana-de-açúcar Saccharum spp. (Poales: Poaceae) faz do Brasil o maior produtor mundial. Apesar de estratégias agronômicas empregadas, problemas fitossanitários como insetos-praga e doenças fitopatogênicas se destacam. A cochonilha-rosada-da-cana-de-açúcar Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Pseudococcidae) e o fungo da podridão vermelha Colletotrichum falcatum Went, são comumente encontrados na canavicultura. Para compreender a atuação de um inseto-praga, relacionado ou não com um agente fitopatogênico, necessita-se estudar seu desenvolvimento biológico e os danos diretos e indiretos que ele pode ocasionar. Este trabalho objetivou avaliar o desenvolvimento biológico de S. sacchari em diferentes temperaturas, analisar as características biométricas e tecnológicas dos diferentes estádios fenológicos de plantas de cana-de-açúcar, infestadas pela cochonilha, estimar o número de perfurações ocasionadas pelo pseudococcídeo através de diferentes números do inseto e confirmar por Microscopia Eletrônica de Varredura (MEV) o complexo cochonilha-podridão. Para a análise do desenvolvimento biológico, foram coletadas fêmeas oviplenas e colmos de cana-de-açúcar. Os colmos foram infestados com cochonilhas, individualizados em placas de Petri e mantidos em duas BODs (23 °C ± 2 °C e 28 °C ± 2 °C). Diariamente registrou-se o número de ovos, ovos viáveis e inviáveis, tempo de incubação, duração da última oviposição, eclosão de ninfas, duração de cada ínstar, mortalidade de ninfas, tempo de emergência e longevidade do adulto. O pseudococcídeo se reproduz por partenogênese telítoca. Em condições laboratoriais, o aumento da temperatura favorece a longevidade do inseto com três fases de crescimento. No estudo dos danos diretos, plantas de cana-de-açúcar foram infestadas, em cada estádio fenológico, por cochonilhas oviplenas. As plantas foram submetidas à biometria externa, e, no estádio de maturação, se obteve os dados tecnológicos. Obteve-se que as infestações do inseto em todos estádios fenológicos reduzem as características físicas das plantas, mas não as químicas tecnológicas qualitativas. Para o estudo das perfurações e do complexo cochonilha-podridão, colmos fragmentados foram infestados com diferentes números do pseudococcídeo por progressão geométrica, e colmos infestados pelo pseudococcídeo e infectados por C. falcatum foram coletados. Os colmos de cada tratamento foram imergidos em solução de fucsina ácida 1% e realizada a contagem de perfurações. Amostras isoladas da cochonilha-rosada-da-cana-de-açúcar, do pseudococcídeo com o aparelho bucal nas plantas, do fungo da podridão-vermelha, e do complexo cochonilha-podridão foram observadas sob Microscopia Eletrônica de Varredura (MEV). Verificou-se que as perfurações ocasionadas por S. sacchari variaram entre 5,3 e 30,3, sendo dependente das perfurações de prova, do número de indivíduos, da área disponível para a alimentação e da sobrevivência das ninfas de primeiro, segundo e terceiro ínstares que conseguiram atingir até a fase adulta. Confirma-se a veracidade da hipótese do complexo cochonilha-podridão em plantas de cana-de-açúcar. The sugarcane crop Saccharum spp. (Poales: Poaceae) makes Brazil the world's largest producer. Despite of agronomic strategies used, phytosanitary issues such as insect pests and phytopathogenic diseases stand out. The pink sugarcane mealybug Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Pseudococcidae) and the red rot fungus Colletotrichum falcatum Went are commonly found in sugarcane crops. In order to understand the performance of the insect pest, related or not to a phytopathogenic agent, it is necessary to study its biological development and the direct and indirect damages that it can cause. This study aimed to evaluate the biological development of S. sacchari under different temperatures, to analyze the biometric and technological characteristics in different phenological stages of sugarcane plants, infested by the mealybug, and to estimate the perforations caused by the pseudococcid through different numbers of the insect and to confirm by Scanning Electron Microscopy (SEM) the mealybug-rot complex. For the analysis of the biological development, gravid females and sugarcane stalks were collected. The stalks were infested with mealybugs, individualized in Petri dishes and kept in two BODs (23 °C ± 2 °C and 28 °C ± 2 °C). The number of eggs, viable and nonviable eggs, incubation time, timing of the last oviposition, nymph hatching, timing of each instar, mortality of nymphs, emergence time and adult longevity were recorded daily. Pseudococcids reproduce by thelytocal parthenogenesis. Under laboratory conditions, the increase in temperature favors the longevity of the insect with three phases of growth. In the study of direct damage, sugarcane plants were infested, at each phenological stage, by gravid mealybugs. The plants were submitted to external biometrics, and in the ripening stage, the technological data were obtained. It was found that the insect infestations at all phenological stages reduce the physical characteristics of the plants, but not the qualitative technological chemistry. To accomplish the last objective, fragmented stems were infested with different numbers of the pseudococcid by geometric progression, and stems infested by the pseudococcid and infected by C. falcatum were collected. The stalks from each treatment were immersed in 1% acid fuchsin solution and the holes were counted. Isolated samples of the pink sugarcane mealybug, the pseudococcid with the mouthparts in plants, the red rot fungus and the mealybug-rot complex were observed under Scanning Electron Microscopy (SEM). It was obtained that the number of holes caused by S. sacchari ranged between 5.3 and 30.3, being dependent on the proof perforations, number of individuals, the area available for feeding and on the survival of the first, second and third instar nymphs that reached the adult stage. The veracity of the hypothesis of the mealybug-rot complex in sugarcane plants is confirmed.
- Published
- 2022
31. Comparing the egg ultrastructure of three Psorophora ferox (Diptera: Culicidae) populations.
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Mello, C. F., Santos-Mallet, J. R., Tátila-Ferreira, A., and Alencar, J.
- Subjects
PSOROPHORA ,MORPHOMETRICS ,ARBOVIRUSES ,PHYLOGENY ,SCANNING electron microscopy - Abstract
Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
32. MORFOLOGIA E CINÉTICA DA DISSOLUÇÃO DE CERA DE PETRÓLEO EM SISTEMAS DE HIDROCARBONETOS.
- Author
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IVANOVA, Izabella Karlovna, DIAKONOV, Afanasii Alekseevich, SEMENOV, Matthew Egorovich, and KORYAKINA, Vladilina Vladimirovna
- Subjects
- *
GAS condensate reservoirs , *TORSION balances , *ACTIVATION energy - Abstract
This paper studies the effect of solvent chemical nature on the kinetic parameters of dissolution and the morphology of the petroleum waxes. The kinetics of the petroleum wax dissolution in gas condensate and the hexane-cyclohexane-benzene mixture was examined on the torsion balance within the temperature range from 10 to 40°C. The process was described using the Erofeev-Kolmogorov equation. The following kinetic parameters were calculated: reaction rate, the order of reactions and effective energy for activation the wax dissolution in the studied solvents. It was found that the wax dissolution rate in the ternary composite is an order of magnitude greater and the activation energy is three times less in comparison with the process of wax dissolution in the gas condensate. The morphological features of the wax samples, treated by these solvents, were examined by means of scanning electron microscopy. It was found that in the ternary composite, wax has a porous structure and in the gas condensate, it is compressed. Thus, the identified kinetic and morphological behavior of petroleum waxes indicates the influence of the chemical nature of the solvent. The findings of this study can be useful when choosing a solvent for the paraffin deposits removal. [ABSTRACT FROM AUTHOR]
- Published
- 2018
33. Descontaminação de canais radiculares infectados com instrumentos reciprocantes, hipoclorito de sódio a 2,5% e vinagre de maçã.
- Author
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OLIVEIRA, Helder Fernandes, ALENCAR, Ana Helena Gonçalves, de Araújo ESTRELA, Cyntia Rodrigues, DECURCIO, Daniel Almeida, SILVA, Julio Almeida, SOUSA, Vinícius Caixeta, and ESTRELA, Carlos
- Abstract
Copyright of Dental Press Endodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
34. Characterization of the nucleus, cutting edge and failure detection in NiTi instruments for endodontic retreatment.
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de Almeida Decurcio, Daniel, Almeida Silva, Julio, Gehrke Barbosa, Mateus, Silva Chavesa, Lucas, Zaiden Loureiro, Marco Antônio, and Estrela, Carlos
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ROOT canal treatment ,DENTAL equipment ,SCANNING electron microscopy ,MEDICAL equipment reliability ,MEDICAL equipment reuse ,EQUIPMENT & supplies - Abstract
Copyright of Revista Odonto Ciencia is the property of EDIPUCRS - Editora Universitaria da PUCRS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2017
- Full Text
- View/download PDF
35. Determination of chemical species of fluoride during uptake mechanism of glass-ionomer cements with NMR spectroscopy
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Ana Flávia Sanches Borges, John W. Nicholson, Sharanbir K. Sidhu, Maria Fidela de Lima Navarro, Lígia Bueno, and Robert G. Hill
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Magnetic Resonance Spectroscopy ,Materials science ,Energy-dispersive X-ray spectroscopy ,Glass ionomer cement ,Dental Cements ,chemistry.chemical_element ,02 engineering and technology ,Fluorides ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Aluminium ,Materials Testing ,General Materials Science ,General Dentistry ,Fluoride selective electrode ,Cement ,Aqueous solution ,Water ,MICROSCOPIA ELETRÔNICA DE VARREDURA ,030206 dentistry ,021001 nanoscience & nanotechnology ,chemistry ,Glass Ionomer Cements ,Mechanics of Materials ,Fluorine ,0210 nano-technology ,Fluoride ,Nuclear chemistry - Abstract
Objective The aim of the present study was to determine the chemical species formed inside glass-ionomer cements after fluoride uptake and to investigate the depth of penetration of fluoride ions within the cement matrix. Methods An experimental fluoride-free glass with composition 2SiO2–AlO3–CaO was produced. The glass powder was mixed with aqueous poly(acrylic acid) (PAA), and allowed to set. The resulting specimens were stored in 20 ml KF solution with 1000 ppm fluorine for 24 h and then placed into the same amount of water as for 24 h. A fluoride selective electrode was used to give the F concentration of the respective solutions. 19F MAS-NMR spectra were recorded on powdered cement specimens using a Bruker AVANCE-NEO 600 spectrometer. In addition, SEM observation and EDX chemical analysis were conducted on the cross-section of a carefully fractured specimen. Results Fluoride was shown to be mainly present in the surface layers of the specimen after placement in the KF solution, and only a small fraction was re-released into water. 19F NMR spectroscopy showed that AlF complexes were formed within the cement. Significance The fluoride taken up by a free-fluoride glass ionomer cement mostly occupies surface layers and is retained because it bonds to aluminum within the matrix. This finding explains why the majority of fluoride taken up by conventional glass ionomer cements is retained.
- Published
- 2021
36. Comparing the egg ultrastructure of three Psorophora ferox (Diptera: Culicidae) populations
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C. F. Mello, J. R. Santos-Mallet, A. Tátila-Ferreira, and J. Alencar
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microscopia eletrônica de varredura ,mosquitos ,Aedini ,morfometria ,ovo ,Science ,Biology (General) ,QH301-705.5 ,Zoology ,QL1-991 ,Botany ,QK1-989 - Abstract
Abstract Characterising the external morphology of mosquito eggs is important, since it facilitates the identification of material from breeding sites and contributes to the understanding of species biology and group systematics. Therefore, was to compare eggs from different Psorophora ferox populations using scanning electron microscopy (SEM). Eggs were obtained from adult female of Ps. ferox collected in the Poços das Antas Biological Reserve (Reserva Biológica de Poços das Antas, Rio de Janeiro, Brazil). From each female, one portion of eggs (n = 5) was reared for identification purposes, and the second portion (n = 10) was examined using SEM for morphometric analysis. The egg morphology was then compared to that of eggs from Ps. ferox populations in Florida (USA) and Arena (Trinidad). The exochorion ornamentation of the populations differs considerably in the morphology of the tubercles of the chorionic cells, external chorionic reticulum, micropylar collar, and micropyle.
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- 2017
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37. Avaliação físico-química de compósitos madeira-plástico aplicados ao design de produtos
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Martel-Estrada, Santos Adriana, Morales-Rivera, Ana Jessica, Olivas-Armendáriz, Imelda, and Aguilar-Cera, Fátima
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Compósito madeira-plástico ,Microscopía electrónica ,General Medicine ,Resíduos de madeira ,Álamo ,Polycaprolactone ,Microscopia eletrônica de varredura ,Espectroscopia infravermelha ,Wood waste ,Wood-plastic composite ,Policaprolactona ,Compositos madera-plástico ,Popplar ,Espectroscopía de infrarrojo ,Scanning electron microscopy ,Infrared spectroscopy ,Residuos de madera - Abstract
Resumen Los residuos de madera son tratados comúnmente como desecho y existe un problema para su disposición. Actualmente, las fibras son utilizadas para producir papel, material de construcción y bioplásticos; aunque han sido desarrollados previamente materiales compuestos madera-plástico, no hay reportes de uno con matriz de policaprolactona. Durante la investigación se desarrollaron materiales compuestos policaprolactona-harina de madera de álamo que fueron caracterizados por medio de microscopía electrónica de barrido, espectroscopía infrarrojo por transformada de Fourier, biodegradación, prueba de captación de agua, propiedades mecánicas de flexión a tres puntos y barrido de temperatura. Las imágenes de microscopía electrónica de barrido mostraron materiales compuestos con uniformidad en la matriz, la espectroscopía evidenció interacción del grupo carbonilo de la policaprolactona y el enlace de estiramiento O-C-O con los grupos OH de la madera. Los materiales compuestos son resistentes a la degradación hidrolítica aún bajo los efectos de los rayos UV. De acuerdo con los resultados, se obtuvo un material apropiado para su uso en diseño de productos, por lo que finalmente fue generada una propuesta de diseño del mismo. Abstract Wood waste is commonly treated as waste, and there is a problem for its disposal. Currently, fibers are used to produce paper, building material, and bioplastics, although wood-plastic composite materials have previously been developed, there are no reports of one with a polycaprolactone matrix. During this research, polycaprolactone-poplar wood composite materials were developed that were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, biodegradation, water uptake test, three-point bending mechanical properties, and temperature sweeping. Scanning electron microscopy images showed composite materials in a uniform matrix, spectroscopy showed the interaction of the carbonyl group of polycaprolactone and the stretch bond O-C-O with the OH groups of wood. Composite materials are resistant to hydrolytic degradation even under the effects of UV rays. According to the results, an appropriate material was obtained for product design, so a design proposal for it was eventually generated. Resumo A eliminação de resíduos de madeira, comumente tratados como desperdício, ocasiona problemas em seu processo de descarte. Atualmente, as fibras são utilizadas na produção de papel, material de construção e bioplásticos; embora materiais compostos de madeira-plástico tenham sido desenvolvidos anteriormente, não há relatos de algum com matriz de policaprolactona. Durante a presente pesquisa, foram desenvolvidos materiais compósitos de policaprolactona-farinha de madeira de choupo que foram caracterizados por meio de microscopia eletrônica de varredura, espectroscopia de infravermelho por transformada de Fourier, biodegradação, teste de absorção de água, propriedades mecânicas de flexão em três pontos e varredura de temperatura. Imagens de microscopia eletrônica mostraram materiais compostos com uniformidade na matriz, a espectroscopia mostrou interação do grupo carbonil de policaprolactona e da ligação elástica O-C-O com os grupos de madeira OH. Os materiais compostos são resistentes à degradação hidrolítica mesmo sob os efeitos dos raios UV. De acordo com os resultados alcançados, foi obtido um material adequado para uso em projeto de produto, para o qual foi finalmente gerada uma proposta formal de design.
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- 2022
38. Hancornia speciosa Gomes Latex Increases Bone Mineralization in Rats: A Preclinical Study
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Felipetti, Francielly Andressa, Costa, Victor Seabra Lima Prado, Neves, Juliana dos Santos, Sousa, Ingrid Grazielle, Piedade, Sônia Maria De Stefano, and Novaes, Pedro Duarte
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histology ,complementary therapies ,histologia ,hidroxiapatitas ,hydroxyapatites ,microscopia eletrônica de varredura ,apocynaceae ,terapias complementares ,scanning electron microscopy - Abstract
Objective To evaluate the systemic effect of Hancornia speciosa latex on bone neoformation and mineralization in rats. Methods For that, the latex was first collected, and its composition was analyzed. A total of 30 male Wistar rats were used, which were simultaneously submitted to two surgical procedures: extraction of an incisor and creation of a defect with 2 mm in diameter in the parietal bone. The rats were divided into two groups: systemic control (SC) systemic latex (SX) which were administered, orally and daily, 1.5 mL of water or a solution containing 50% of water and 50% of latex by gavage, respectively. After 15 days of the treatment, the animals were euthanized and their samples were collected. Results The results were statistically analyzed, and the level of significance was set at 0.05. We showed that H. speciosa latex contained calcium. The oral and daily administration of the latex for 15 days increased the contents of calcium and phosphorus in the basal bone and newly-formed bone in the mandibular alveolus of rats. Conclusion The present was a pioneer study demonstrating the potential of H. speciosa latex in increasing bone mineralization. Our results may aid in the conception and development of a natural drug. Resumo Objetivo Avaliar o efeito sistêmico do látex de Hancornia especiosa na neoformação óssea e mineralização em ratos. Métodos Para isso, primeiro o látex foi coletado, e sua composição foi analisada. No estudo, foram utilizados 30 ratos Wistar machos submetidos simultaneamente a dois procedimentos cirúrgicos: extração de incisivo e criação de um defeito de 2 mm de diâmetro no osso parietal. Os ratos foram divididos em dois grupos: controle sistêmico (CS) e látex sistêmico (XS), aos quais foi administrado, oral e diariamente, 1,5 mL de água ou uma solução contendo 50% de água e 50% de látex por gavagem, respectivamente. Após 15 dias do tratamento, os animais foram eutanizados, e suas amostras, coletadas. Resultados Os resultados foram analisados estatisticamente, e o nível de significância foi fixado em 0,05. Mostramos que o látex de H. speciosa continha cálcio. A administração oral e diária deste látex por 15 dias aumentou o conteúdo de cálcio e fósforo de osso basal e de osso recém-formado no alvéolo mandibular de ratos. Conclusão Este foi um estudo pioneiro, que demonstrou o potencial do látex de H. speciosa no aumento da mineralização óssea. Nossos resultados podem ajudar na concepção e no desenvolvimento de uma droga natural.
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- 2022
39. Microscopic study of edema in hydatidiform mole
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Olivar C. Castejón, Aury Caraballo, Oliver Castejón, and Elizabeth Cedeño
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Mola hidatiforme ,Edema ,Microscopia ,Microscopia eletrônica de varredura ,Gynecology and obstetrics ,RG1-991 - Abstract
Objectives: the purpose of this study is to use light microscopy and scanning electron microscopy to determine the effect of edema on the structure of the molar vesicle. Methods: samples were taken from the complete hydatidiform mole and processed using conventional light and scanning electron microscopy techniques and an observation protocol that identified four variables: factors underlying the development of edema; the condition of the trophoblast basement membrane, development of the villi, accumulation and degeneration of sulphated mucosubstances at stromal level. Results: light microscopy showed a permeable trophoblastic basement membrane, a swollen syncytium, edematous regions disorganizating the stromal region and causing ischemic necrosis of cells. Using scanning electron microscopy, the basement membrane was found to be distended and thickened, with large irregular holes for the entry and movement of liquid, leaving a wide range of fluids during the influx process and depriving stromal cells of nutrition. Conclusions: a new three-dimensional view of the changes brought about by the entry of fluids into the stroma of molar hydropic vesicles was provided by scanning electron microscopy and confirmed by light microscopy, thereby explaining the changes occurring at the level of the stroma as an effect of the edema.
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- 2014
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40. Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment. Part 2: Microscopic surface appraisal and metallurgical characteristics
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Marco Abdo Gravina, Cristiane Canavarro, Carlos Nelson Elias, Maria das Graças Afonso Miranda Chaves, Ione Helena Vieira Portella Brunharo, and Cátia Cardoso Abdo Quintão
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Propriedades físicas ,Fios ortodônticos ,Microscopia eletrônica de varredura ,Níquel ,Titânio ,Cobre ,Dentistry ,RK1-715 - Abstract
OBJECTIVE: This research aimed at comparing the qualitative chemical compositions and the surface morphology of fracture regions of eight types of Nickel (Ni) Titanium (Ti) conventional wires, superelastic and heat-activated (GAC, TP, Ormco, Masel, Morelli and Unitek), to the wires with addition of copper (CuNiTi 27oC and 35oC, Ormco) after traction test. METHODS: The analyses were performed in a scanning electronic microscope (JEOL, model JSM-5800 LV) with EDS system of microanalysis (energy dispersive spectroscopy). RESULTS : The results showed that NiTi wires presented Ni and Ti as the main elements of the alloy with minimum differences in their composition. The CuNiTi wires, however, presented Ni and Ti with a significant percentage of copper (Cu). As for surface morphology, the wires that presented the lowest wire-surface roughness were the superelastic ones by Masel and Morelli, while those that presented the greatest wire-surface roughness were the CuNiTi 27oC and 35oC ones by Ormco, due to presence of microcavity formed as a result of pulling out some particles, possibly of NiTi. 4 The fracture surfaces presented characteristics of ductile fracture, with presence of microcavities. The superelastic wires by GAC and the CuNiTi 27oC and the heat-activated ones by Unitek presented the smallest microcavities and the lowest wire-surface roughness with regard to fracture, while the CuNiTi 35oC wires presented inadequate wire-surface roughness in the fracture region. CONCLUSION: CuNiTi 35oC wires did not present better morphologic characteristics in comparison to the other wires with regard to surfaces and fracture region.
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- 2014
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41. Shear bond resistance and enamel surface comparison after the bonding and debonding of ceramic and metallic brackets
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José Maurício da Rocha, Marco Abdo Gravina, Marcio José da Silva Campos, Cátia Cardoso Abdo Quintão, Carlos Nelson Elias, and Robert Willer Farinazzo Vitral
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Resistência ao cisalhamento ,Esmalte dentário ,Braquetes ortodônticos ,Microscopia eletrônica de varredura ,Dentistry ,RK1-715 - Abstract
OBJECTIVE: To evaluate, in vitro, the shear bond strength presented by three brands of polycrystalline ceramic brackets and one brand of metallic bracket; verify the adhesive remnant index (ARI) after the tests, and analyze, through scanning electron microscopy (SEM) the enamel surface topography after debonding, detecting the release of mineral particles. METHODS: Sixty bovine lower incisors were used. Three ceramic brackets (Allure(r), InVu(r), and Clarity(r)) and one metallic bracket (Geneus(r)) were bonded with Transbond XT(r). Kruskal-Wallis's test (significance level set at 5%) was applied to the results of share bond and ARI. Mann Whitney's test was performed to compare the pairs of brackets in relation to their ARI. Brown-Forsythe's test (significance level set at 5%) was applied to the results of enamel chemical composition. Comparisons between groups were made with Games-Howell's and the Post-hoc tests. RESULTS: No statistically significant difference was observed in relation to the shear bond strength loads. Clarity(r) brackets were the most affected in relation to the surface topography and to the release of mineral particles of enamel (calcium ions). CONCLUSION: With regard to the ARI, there was a prevalence of score 4 (40.4%). As for enamel surface topography, the Geneus(r) bracket was the only one which did not show superficial tissue loss. The InVu(r) and Clarity(r) ones showed cohesive fractures in 33.3% and the Allure(r) in 50%, the latter being the one that presented most fractures during removal.
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- 2014
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42. Surface morphology changes of acrylic resins during finishing and polishing phases
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Glaucio Serra, Liliane Siqueira de Morais, and Carlos Nelson Elias
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Resinas acrílicas ,Microscopia eletrônica de varredura ,Propriedades de superfície ,Dentistry ,RK1-715 - Abstract
INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length) were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.
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- 2013
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43. Ultraestrutura comparativa da língua do sagui-de-tufo-preto (Callithrix penicillata) e do bugio-preto (Alouatta caraya) em diferentes faixas etárias
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Cayo Y. Nitta, Luana C.S. Silva, Maria A. Miglino, Carlos E. Ambrosio, Pedro P. Bombonato, and Rose E.G. Rici
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Papilas linguais ,microscopia eletrônica de varredura ,Callithrix penicillata ,Alouatta caraya ,Veterinary medicine ,SF600-1100 - Abstract
Para a análise e descrição comparativa da morfologia da língua e de suas papilas, bem como a distribuição destas, foram utilizados três animais de faixas etárias distintas (filhote, jovem, adulto), de duas espécies de primatas, Callithrix penicillata (sagui-de-tufo-preto) e Alouatta caraya (bugio-preto), ambas sendo observadas através da microscopia eletrônica de varredura. Os animais da espécie Callithrix penicillata eram procedentes de um criadouro comercial de animais selvagens em Atibaia/SP e vieram a óbito por causas naturais, e os da espécie Alouatta caraya eram provenientes do acervo do Laboratório de Anatomia Macroscópica da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (FMVZ-USP). Com o material analisado e a técnica empregada pôde-se constatar que as línguas dos saguis-de-tufo-preto e dos bugios-pretos analisadas apresentavam papilas linguais similares às descritas para outras espécies de primatas. As línguas possuíam diferenças morfológicas, principalmente para alguns tipos de papilas linguais, em detrimento do avançar da idade dos animais. De forma geral, foram observados quatro tipos de papilas linguais, sendo estas: filiforme, fungiforme, valada e folhada. As línguas dos bugio-pretos apresentavam características de animais com dietas herbívoras. Possuindo desta forma papilas filiformes com formatos variados (coroa, lança, multifilamentar), de acordo com as regiões da língua, e também robustas papilas, principalmente na proeminência lingual. Já as línguas dos saguis-de-tufo-preto possuíam características de animais onívoros. Com papilas filiformes em formato de coroa, grandes quantidades de papilas fungiformes e desenvolvidas papilas folhadas. Observou-se que as modificações das papilas linguais que ocorrem nos animais após o nascimento apresentaram correlação com a mudança nos tipos de alimentos consumidos. Sendo presumível então concluir que as dietas possuem relação direta para com as alterações morfológicas e estruturais das papilas linguais nos animais ora aqui analisados.
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- 2013
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44. Chemical and mineralogical characterization of samples of the majority mineral bodies from an underground gold ore mine and its influence on the recovery of the precious metal
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Istelamares Alvarenga de Barros, Paulo Roberto Gomes Brandão, Daniel Majuste, and Itamar Daniel Delbem
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Microscopia eletrônica de varredura ,Microanálise química ,Minério de ouro ,Beneficiamento de minério ,Tecnologia mineral ,Geometalurgia ,Caracterização ,Engenharia de minas ,Geologia ,Beneficiamento metalúrgico ,Microquímica - Abstract
O processamento de minérios de ouro tem se tornado cada vez mais desafiador em virtude da exaustão dos depósitos de maiores teores e elevação da complexidade da recuperação do metal. Neste contexto, a caracterização é uma etapa fundamental dentro da abordagem da geometalurgia, pois fornece os subsídios mineralógicos necessários à correta definição de rotas de processo e possibilita a otimização do rendimento global de uma planta. O objetivo deste trabalho foi caracterizar os três corpos de minério majoritários (BF, BF2 e LPA) da mina de Pilar, da Jaguar Mining Inc., empresa brasileira de capital estrangeiro, que produz ouro no Quadrilátero Ferrífero. A metodologia envolveu a integração de informações fornecidas pelas análises químicas, caracterização mineral por MEV-EDS/MLA (Mineral Liberation Analyser) e difratometria de raios X, e ensaios laboratoriais de concentração metalúrgica (gravimetria, flotação e lixiviação), a fim de determinar as associações mineralógicas e compreender o comportamento de cada um destes corpos no processo hidrometalúrgico. Os resultados de caracterização apontaram que há diferença de composição de fases minerais nestes corpos, sendo o quartzo um dos minerais de maior expressão e comum a todos; os outros minerais diferem quanto à concentração nos corpos: para BF os principais são clorita, muscovita e ankerita; para BF2, siderita e estilpnomelano; e para LPA, siderita e arsenopirita. A concentração de sulfetos não excede a 16,00 %, e os majoritários são arsenopirita e pirrotita. Os grãos de ouro identificados foram na maioria ouro nativo, inclusos na arsenopirita e com diâmetro médio inferior a 0,010 mm. Os ensaios metalúrgicos de bancada indicaram que nenhum dos corpos é considerado refratário. Apresentam mais de 70,00 % de ouro gravítico e recuperação por cianetação direta seguida de adsorção acima de 91,00 % na granulometria 80,00 % passante em 0,075 mm. Na etapa de flotação, as recuperações e teores de rejeitos foram bastante diferentes entre as condições aplicadas e corpos, sendo o corpo BF com o pior desempenho. A combinação de reagentes a base de ditiofosfatos e xantatos promoveu melhor desempenho na recuperação de ouro na flotação, mas a inclusão da etapa de flotação para o rejeito da gravimetria, seguida de cianetação/adsorção do concentrado de flotação, resultou em redução da recuperação global de ouro em até 8,88 % em relação à recuperação por cianetação direta. O circuito com melhores resultados de recuperação metalúrgica para todos os corpos foi gravimetria e cianetação do rejeito gravítico. Os resultados indicaram que o conhecimento das particularidades mineralógicas de cada corpo, associado a condições específicas de processo para gravimetria, flotação e lixiviação, pode elevar a eficiência de extração do ouro e minimizar perdas. Gold ore processing has become increasingly challenging due to the exhaustion of higher grade deposits and increasing complexity of metal recovery. In this context, characterization is a fundamental step within the geometallurgy approach, as it provides the mineralogical knowledge necessary for the correct definition of process routes and allows the optimization of the overall yield of a metallurgical plant. The objective of this research was to characterize the three major ore bodies (BF, BF2 and LPA) of the Pilar mine of Jaguar Mining Inc., a Brazilian company with foreign capital, which produces gold in the Iron Quadrangle. The methodology involved the integration of information provided by chemical analyses, mineral characterization by SEM-EDS/MLA (Mineral Liberation Analyser) and X-ray diffractometry, and laboratory tests of metallurgical concentration (gravimetry, flotation and leaching), in order to determine the mineralogical associations and to understand the behavior of each one of these bodies in the hydrometallurgical process. The characterization results showed that there is a difference in the composition of mineral phases in these bodies, with quartz being one of the most abundant mineral and common to all; the other minerals differ in terms of concentration in the bodies, the main ones for BF being chlorite, muscovite and ankerite; for BF2, siderite and stilpnomelane; and for LPA, siderite and arsenopyrite. The concentration of sulfides does not exceed 16.00 %, and the majority are arsenopyrite and pyrrhotite. The gold grains identified were mostly native gold, included in arsenopyrite and with an average diameter of less than 0.010 mm. The metallurgical tests indicated that none ore body was considered refractory. The yield was more than 70.00 % of gravity gold and recovery by direct cyanidation followed by adsorption above 91.00 % in the granulometry of 80.00 % of particles below 0.075 mm. In the flotation stage, the recoveries and tailings contents were quite different between the applied conditions and bodies, with the BF body having the worst performance. The combination of reagents based on dithiophosphates and xanthates has promoted better performance in the gold recovery in flotation, but the inclusion of the flotation step for the gravity tailings, followed by cyanidation/adsorption of the flotation concentrate, resulted in a reduction in the global recovery of gold by up to 8.88% compared to direct cyanidation recovery. The circuit with the best metallurgical recovery results for all ore bodies was gravity and cyanidation of the gravitational tailings. The results indicated that the knowledge of the mineralogical characteristics of each ore body, associated with specific process conditions for gravity, flotation and leaching, can increase the gold extraction efficiency and minimize losses.
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- 2022
45. AVALIAÇÃO POR MEIO DA MICROSCOPIA ELETRÔNICA DE VARREDURA DE ALTERAÇÕES SOFRIDAS EM PONTAS DIAMANTADAS -- ESTUDO PILOTO.
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COSTA GONÇALVES, IANA MARIA, WANDERLEY JUCÁ, THACYANNA, MACHADO DA COSTA FIGUEIREDO, CAMILA HELENA, SILVA DA PENHA, ELIZANDRA, LIA FOOK, MARCUS VINÍCIUS, and DINIZ MELQUÍADES DE MEDEIROS, LUANNA ABÍLIO
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- 2017
46. Avaliação da adaptação cervical do componente UCLA calcinável utilizado em prótese fixa do tipo protocolo: estudo comparativo com microscopia eletrônica de varredura.
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Andrade Oliva, Marcos, Barbosa Bezerra, Fábio José, Pereira Ramos, Maria Emília Santos, Ghiraldini, Bruna, and Goes Neto, Aristóteles
- Abstract
Copyright of Journal of Clinical Dentistry & Research is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2017
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47. Efeito da nanotecnologia em sistemas adesivos autocondicionantes na resistência ao cisalhamento da colagem em braquetes ortodônticos de aço inoxidável.
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Hammad, Shaza M., El-Wassefy, Noha, Maher, Ahmed, and Fawakerji, Shafik M.
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Copyright of Dental Press Journal of Orthodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2017
- Full Text
- View/download PDF
48. Qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem
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Rodrigo de Góes Esperon Reis, Renato Mendes Guimarães, Diego de Sousa Pereira, Matheus Bornelli de Castro, Antônio Rodrigues Vieira, and Maria Laene Moreira de Carvalho
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Solanum melongena ,atividade enzimática ,condicionamento fisiológico ,microscopia eletrônica de varredura ,Agriculture (General) ,S1-972 - Abstract
O objetivo deste trabalho foi avaliar a qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem. Utilizaram-se sementes de berinjela, cultivar Embu, condicionadas em solução aerada de KNO3 (-0,8 MPa), a 25ºC, por 48 horas. As sementes foram submetidas aos seguintes procedimentos: redução do teor de água inicial (r), choque térmico (CT) e secagem lenta (SL) ou rápida (SR) por 48 horas. As combinações desses procedimentos constituíram os tratamentos: sementes condicionadas e sem secagem, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL e rCTSR, além da testemunha (sementes sem condicionamento). As sementes condicionadas e as secas lentamente expressaram maior percentagem de germinação. Não houve diferença entre os tratamentos quanto à percentagem de emergência de plântulas. A testemunha levou mais tempo para alcançar a máxima emergência do que os demais tratamentos. As sementes submetidas ao choque térmico apresentaram maiores valores de condutividade elétrica do que as que não passaram por esse tratamento. A qualidade fisiológica das sementes de berinjela obtida com o condicionamento é mantida após a secagem. A secagem de sementes de berinjela condicionadas deve ser realizada preferencialmente de forma lenta, com ou sem redução do teor de água inicial.
- Published
- 2013
- Full Text
- View/download PDF
49. Essential oils and whole milk in the control of soybean powdery mildew
- Author
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Fabiano José Perina, Eduardo Alves, Ricardo Borges Pereira, Gilvaine Ciavareli Lucas, Claudia Regina Gontijo Labory, and Hilário Antonio de Castro
- Subjects
Erysiphe diffusa ,Glycine max ,controle biológico ,microscopia eletrônica de varredura ,concentrações efetivas ,Agriculture ,Agriculture (General) ,S1-972 - Abstract
This research aimed to evaluate the potential of essential oils (EOs) and cow's whole milk (CWM) in order to control soybean powdery mildew and to estimate the most effective concentrations of these natural products in reducing the disease severity on soybean plants. Three experiments were carried out: The first experiment evaluated and selected the most effective treatments to reduce the severity of soybean powdery mildew under greenhouse conditions; the second experiment evaluated the effect of CWM and EOs of citronella, lemongrass, eucalyptus, cinnamon and tea tree on the pathogen through the ultrastructure analysis of soybean leaflets infected by Erysiphe diffusa using the scanning electron microscope (SEM) and light microscope (LM) technology. In the third experiment, the most effective products were tested at several concentrations in order to define the most effective concentrations to reduce disease severity under greenhouse conditions. The treatments CWM (100mL L-1) and EOs of citronella, lemongrass and eucalyptus (1.0mL L-1), reduced the disease severity from 67 to 74%. Direct effects from all natural products tested on the structures of E. diffusa were demonstrated through the SEM and LM analysis. Concentrations at 1.5mL L-1 for EOs of citronella, lemongrass and eucalyptus and also at 180mL L-1 for the treatment CWM were the most effective against E. diffusa on soybean.
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- 2013
- Full Text
- View/download PDF
50. The physical, chemical and functional characterization of starches from Andean tubers: oca (Oxalis tuberosa Molina), olluco (Ullucus tuberosus Caldas) and mashua (Tropaeolum tuberosum Ruiz & Pavón)
- Author
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Beatriz Valcárcel-Yamani, Gerby Giovanna Rondán-Sanabria, and Flavio Finardi-Filho
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Tuberosas andinas ,Amidos de tuberosas ,Microscopia eletrônica de varredura ,Pharmacy and materia medica ,RS1-441 - Abstract
The physical, chemical, and functional properties of starches isolated from the Andean tubers oca (Oxalis tuberosa M.), olluco (Ullucus tuberosus C.) and mashua (Tropaeolum tuberosum R. & P.) were studied. The tubers were obtained from a local grocery. The morphology of the starch granules (size and shape) was studied with scanning electron microscopy (SEM), which revealed ellipsoid, oval, conical, pear-shaped and prismatic forms: ellipsoids and oval granules with lengths up to 54.30 µm in oca; with lengths up to 32.09 µm for olluco starch granules; and with predominantly truncated spherical or oval forms and smaller dimensions (up to 16.29 um) for mashua starch granules. Amylose contents were similar among the samples: 27.60% (oca), 26.49% (olluco) and 27.44% (mashua). Olluco starch had less swelling power, forming opaque, less firm gels. All three starch gels showed the same stability on refrigeration and presented high syneresis under freezing temperatures, with a variation of 40.28 to 74.42% for olluco starch. The starches cooked easily, with high peak viscosity. The low gelatinization temperatures and high stability during cooling make these starches suitable feedstock for use in formulations that require milder processing temperatures and dispense freezing storage.
- Published
- 2013
- Full Text
- View/download PDF
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