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1.
Dent Mater ; 37(12): 1751-1760, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34565584

RESUMO

OBJECTIVE: Synthesize novel epigallocatechin-gallate (EGCG) methacrylate monomers with the ability to copolymerize with dental methacrylate resins. METHODS: EGCG was reacted with 1/3 (E33), 2/3 (E67) and 1 (E100) molar equivalents of methacyloyl chloride introducing three degrees of polymerizablility. EGCG-methacrylates were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). E33, E67, E100 and neat EGCG were incorporated into TEGDMA at 0.5-20% ratios (m/m). Copolymers were tested for degree of conversion (%DC), EGCG release, gel content (%GC), degree of swelling (%DS), flexural properties and bacterial viability (Streptococcus mutans, baseline/30-days). Neat TEGDMA and TEGDMA passively loaded with EGCG (E0) were used as controls. Data were analysed by one-way ANOVA, Tukey, and Dunnett's method (α=5%). Two-way ANOVA and Bonferroni were used to investigate factor interaction. RESULTS: FTIR/NMR confirmed synthesis of desired compounds. All of E100 incorporated ratios had %DC similar to TEGDMA. Remaining groups had reduction in %DC at 2% in E0, 10% in E33 and 20% in E67 ratios. EGCG was stable within ECGC-methacrylate copolymers. Release of EGCG from E0 significantly increased with higher EGCG ratios. Except for E100, higher EGCG or EGCG-methacrylate ratios led to decreased %CG and %DS. At baseline, E0 had the lowest bacterial survival rates (1-10% survival) at all ratios compared to E33, E67, E100, and neat TEGDMA. However, E33, E67 and E100 still had statistically lower survival rates (7-53%) compared with neat TEGDMA. After 30-days, all compounds had similar survival rates for all ratios, which were lower than that of neat TEGDMA. SIGNIFICANCE: Demonstration of methacrylate functionalized EGCG- with inherited antibacterial activity for improved restoration longevity.


Assuntos
Polímeros , Streptococcus mutans , Catequina/análogos & derivados , Teste de Materiais , Polimerização
2.
Rev. peru. biol. (Impr.) ; 15(supl.1): 115-120, nov. 2008. ilus, tab
Artigo em Inglês | LIPECS | ID: biblio-1111266

RESUMO

En la Amazonía, el 30% de la población se encuentra representada por pequeños núcleos poblacionales aislados. Uno de los problemas más graves para el desarrollo de estas poblaciones es el relacionado con la disponibilidad de energía eléctrica, porque su ausencia o constante racionamiento no permiten la instalación de agro-industrias para el aprovechamiento de los recursos naturales, lo que podria proprocionar valor agregado de los productos regionales renovables. En consecuencia, la búsqueda por mejores condiciones socio-económicas tiene como única alternativa la extracción depredadora y rápida de las riquezas naturales, llevando a la destrucción acelerada de los ecosistemas. Las plantas oleaginosas, destinadas principalmente a la alimentación básica de la población, también pueden constituir la base de un modelo de desarrollo tecnológico industrial auto-sostenido, ya que presentan la ventaja de ser recursos en áreas antrópizadas de la Amazonia; y que posibilitan la retención del hombre en el campo y evitan con esto la degradación de los ecosistemas naturales. En el presente estudio se da a conocer el conjunto de actividades que facilitaron la determinación del potencial de biomasa del “huasaí” (Euterpe precatoria Mart.) y otras oleaginosas disponibles en comunidades ribereñas del Estado de Amazonas (Brasil); éstas actividades estuvieron asociadas a las posibilidades de sumanejo sostenido para la generación de energía eléctrica. De esta forma, se presentan datos que sugieren condiciones del uso sostenible de la oferta de biomasa como fuente energética alternativa para desarrollar un programa de universalización de la energía eléctrica en la Amazonia brasileña.


In the Amazon, approximately 30% of the population is agglomerated in small villages or isolated areas. One of the most serious problems is the lack of electricity, where reduced supply and frequent rationing reduce life quality and prevent the instalation of industries that could raise the value of renewable regional products. Consequently, the pursuit of better socioeconomic conditions promote the quick depletion of natural resources, which invariably results in the accelerated destruction of local ecosystems. Oil palms, that are mainly used forbasic nutrition of local populations, could also form the basis for models of self-sustained technological and industrial development. A quantitative survey of native species of oil palms offers an alternative for sustained development based on a technological and industrial model because this resource occurs in populated areas inthe Amazon, which facilitates retaining the people in the field, preventing the depletion of natural ecosystems.This study presents the activities that were used to identify the potential of biomass of Euterpe precatoria Martand other oil palms available in riverside communities in the state of Amazonas (Brazil). These activities are associated with the possibilities of using palm species for sustainable development of energy generation. It was possible to identify the conditions for a sustainable supply of biomass as an alternative energy source which contributes to the Energy Universalization Program in the Brazilian Amazon.


Assuntos
Arecaceae/classificação , Conservação dos Recursos Naturais , Ecossistema Amazônico
3.
Acta amaz ; Acta amaz;32(2)2002.
Artigo em Português | LILACS-Express | LILACS, VETINDEX | ID: biblio-1454881

RESUMO

The pollen grains collected by Melipona seminigra merrillae, Melipona compressipes manaosensis, Melipona seminigra seminigra, Frieseomelitta sp. and Scaptotrigona sp. were obtained directly from the corbiculae of the worker bees during one year. Identification of the pollen grains showed that Scaptotrigona sp. was the most generalist bee, followed by Frieseomelitta sp., which together collected more pollen taxa than the three species of Melipona. Pollen from three plant species: Miconia myrianthera, Myrcia amazonica e Tapirira guianensis -were collected by this five bee species. Regarding pollen morphology, no significant correlations were found that could indicate a preference for certain pollen grain forms, external structures or sizes of grains. All five meliponids collected pollen of several forms and sizes. It is indicative that the bees collected pollen in accordance to protoplasmic nutrients. Biochemical analyses of some pollen types carried on the corbiculae of the bees showed a high concentration of total soluble sugars, reductive sugars and starch.


Durante um ano, o pólen transportado por Melipona compressipes manaosensis, Melipona seminigra merrillae, Melipona seminigra seminigra, Frieseomelitta sp. e Scaptotrigona sp. foi coletado diretamente das corbículas das operárias. Feita a identificação dos grãos de pólen constatou-se que a abelha mais generalista foi Scaptotrigona sp., seguida de Frieseomelitta sp., as quais juntas coletaram mais tipos polínicos que as três espécies de meliponas. Duas espécies de plantas: Miconia myrianthera e Myrcia amazonica, tiveram seu pólen coletado pelas cinco espécies de meliponíneos durante o ano todo. Quanto à morfologia do pólen, não houve correlação significativa que comprovasse que as abelhas coletassem o pólen de acordo com a forma, ornamentação e o tamanho dos grãos. As cinco espécies de meliponíneos coletaram pólen de diversas formas e tamanhos. Tudo indica que as abelhas coletam o pólen de acordo com os nutrientes contidos no seu protoplasma. Análises bioquímicas de alguns tipos polínicos encontrados nas corbículas das abelhas apresentaram alto teor de açúcares solúveis totais, açúcares redutores e amido.

4.
Acta amaz. ; 32(2)2002.
Artigo em Português | VETINDEX | ID: vti-449916

RESUMO

The pollen grains collected by Melipona seminigra merrillae, Melipona compressipes manaosensis, Melipona seminigra seminigra, Frieseomelitta sp. and Scaptotrigona sp. were obtained directly from the corbiculae of the worker bees during one year. Identification of the pollen grains showed that Scaptotrigona sp. was the most generalist bee, followed by Frieseomelitta sp., which together collected more pollen taxa than the three species of Melipona. Pollen from three plant species: Miconia myrianthera, Myrcia amazonica e Tapirira guianensis -were collected by this five bee species. Regarding pollen morphology, no significant correlations were found that could indicate a preference for certain pollen grain forms, external structures or sizes of grains. All five meliponids collected pollen of several forms and sizes. It is indicative that the bees collected pollen in accordance to protoplasmic nutrients. Biochemical analyses of some pollen types carried on the corbiculae of the bees showed a high concentration of total soluble sugars, reductive sugars and starch.


Durante um ano, o pólen transportado por Melipona compressipes manaosensis, Melipona seminigra merrillae, Melipona seminigra seminigra, Frieseomelitta sp. e Scaptotrigona sp. foi coletado diretamente das corbículas das operárias. Feita a identificação dos grãos de pólen constatou-se que a abelha mais generalista foi Scaptotrigona sp., seguida de Frieseomelitta sp., as quais juntas coletaram mais tipos polínicos que as três espécies de meliponas. Duas espécies de plantas: Miconia myrianthera e Myrcia amazonica, tiveram seu pólen coletado pelas cinco espécies de meliponíneos durante o ano todo. Quanto à morfologia do pólen, não houve correlação significativa que comprovasse que as abelhas coletassem o pólen de acordo com a forma, ornamentação e o tamanho dos grãos. As cinco espécies de meliponíneos coletaram pólen de diversas formas e tamanhos. Tudo indica que as abelhas coletam o pólen de acordo com os nutrientes contidos no seu protoplasma. Análises bioquímicas de alguns tipos polínicos encontrados nas corbículas das abelhas apresentaram alto teor de açúcares solúveis totais, açúcares redutores e amido.

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