24 research outputs found

    Composição, distribuição e substratos da fauna de esponjas (Porifera: Demospongiae) no Parque Nacional de Anavilhanas

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    Freshwater sponges, being sessile animals, heavily depend upon a substrate on which their larvae or their gemmules will settle. It is expected different sponge species to exhibit preferences or adaptations to specific substrates and habitats. Studies targeted to evaluate the role substrates play in the distribution of freshwater sponge communities are rare. Here we evaluate the effect of different substrates and habitats in the distribution of freshwater sponge communities in the igapós of Anavilhanas, the world largest freshwater archipelago. Two surveys aiming to uncover the sponge fauna and corresponding substrates were performed in the Anavilhanas National Park at the low water period, when seasonally flooded surfaces are exposed. Two transects were carried out by boat along the margins of the River Negro and its canals among the islands or inside parts of the yet inundated forest. Also several higher parts of the islands at the time free of the flooding waters were crossed by foot. The sponge crusts were first visually searched for and next sampled, having its GPS taken and its environments and substrates shortly described. The association between the presence of nine sponge species, seven different environments and seven types of substrates detected were used in a Redundancy Analysis (RDA). The first two axes of RDA accounted for 45.9% of variation in the species data. The overall RDA was significant (P = 0.005; Number of permutations = 199). Substrates, especially trunks, branches, leaves and sand, were more important than environments to explain the variability in the distribution of sponge species.Key words: Continental sponges, substrates, shaded habitats, flooding pulses, Brazilian Amazonia. Sendo animais sésseis, as esponjas de água doce dependem de um substrato sobre o qual suas larvas ou suas gêmulas se fixarão. Espera-se que espécies diferentes mostrem preferências ou adaptações a substratos e habitats específicos. Estudos para avaliar o papel dos substratos na distribuição de comunidades dessas esponjas são raros. Aqui avaliamos o efeito de diferentes substratos e habitats na distribuição de comunidades dessas esponjas, nos igapós de Anavilhanas, o maior arquipélago de águas doces do mundo. Dois levantamentos destinados a detectar a fauna espongológica e os correspondentes substratos foram feitos no Parque Nacional de Anavilhanas, no período de águas baixas, quando as superfícies estacionalmente inundadas estão expostas. Dois transectos foram percorridos de barco, ao longo das margens do rio Negro e seus canais entre as ilhas ou dentro das porções de florestas ainda inundadas. Porções mais elevadas no interior das ilhas, nessas ocasiões, livres da inundação, foram percorridas a pé. As crostas das esponjas foram inicialmente buscadas a olho nu e, em seguida, amostradas, registrando-se seu posicionamento geográfico (GPS), substrato e ambiente. A associação entre nove espécies de esponjas, sete diferentes ambientes e sete distintos tipos de substratos identificados foi utilizada em Análise de Redundância (RDA). Os dois primeiros eixos da RDA responderam por 45.9% da variação nos dados das especies. O RDA geral foi significativo (P = 0.005; Número de permutas = 199). Substratos, especialmente troncos, galhos, folhas e areia foram mais importantes do que os ambientes para explicar a variabilidade na distribuição das espécies.Palavras-chave: esponjas continentais, substratos, habitats sombreados, pulsos de inundação, Amazônia Brasileira

    Antioxidantes Inorgânicos em Frutos Amazônicos / Inorganic Antioxidants in Amazonian Fruits

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    A região amazônica apresenta várias espécies frutíferas com potencial agronômico, tecnológico, nutricional e econômico. Existem poucas informações sobre a composição inorgânica de muitas destas matérias-primas. Este trabalho objetivou avaliar a concentração de elementos inorgânicos presentes em resíduos e/ou subpartes de dezoito espécies frutíferas nativas da região amazônica brasileira a partir do uso da técnica de “ED-X-ray fluorescence”. Os elementos minerais K, P, Si e Na apresentaram as maiores concentrações nas diversas frutíferas e suas subpartes estudadas exibiram, em menor concentração, os elementos Mg, Ca, S, Cl, Fe, Rb, Ba, Ti, Co, Al, Sr, Br e Ag. Tais resultados quantitativos encontrados aqui foram obtidos pela primeira vez, em se tratando de resíduos e/ou subpartes de frutíferas amazônicas. 

    Produção de biomassa e rendimento de óleo essencial de folhas, galhos finos e rebrotas utilizando poda da copa de Aniba canelilla (H.B.K.) (Lauraceae) na Amazônia Central

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    Aniba canelilla (H.B.K.) Mez. is a tree species from Amazon that produces essential oil. The oil extraction from its leaves and stems can be an alternative way to avoid the tree cutting for production of essential oil. The aim of this study was to analyse factors that may influence the essential oil production and the biomass of resprouts after pruning the leaves and stems of A. canelilla trees. The tree crowns were pruned in the wet season and after nine months the leaves and stems of the remaining crown and the resprouts were collected, in the dry season. The results showed that the essential oil yield and chemical composition differed among the stems, leaves and resprouts. The stems' essential oil production differed between the seasons and had a higher production in the resprouting stems than the old stems of the remaining crown. The production of essential oil and leaf biomass of resprouts were differently related to the canopy openness, indicating that light increases the production of the essential oil and decreases the biomass of resprouting leaves. This study revealed that plant organs differ in their essential oil production and that the canopy openness must be taken into account when pruning the A. canelilla tree crown in order to achieve higher oil productivity.Aniba canelilla (H.B.K.) Mez. é uma espécie arbórea da Amazônia que produz óleo essencial. A extração do óleo de suas folhas e galhos pode ser uma forma alternativa de evitar a derrubada do tronco para sua produção de óleo essencial. O objetivo deste estudo foi analisar os fatores que podem influenciar a produção de óleo essencial e sua biomassa da rebrota após a poda de folhas e galhos das árvores de A. canelilla. As copas das árvores foram podadas na estação chuvosa e, após nove meses, as folhas e os galhos da copa remanescente e da rebrota foram coletadas na estação seca. Os resultados mostraram que o rendimento e a composição química de óleo essencial diferiram entre os galhos finos, as folhas e as rebrotas. A produção de óleo essencial de galhos diferiu entre as estações e teve maior produção nos galhos da rebrota do que nos galhos velhos da copa remanescente. A produção de óleo essencial e de biomassa das folhas da rebrota foram diferentemente relacionadas com a abertura de dossel, indicando que a luz aumenta a produção de óleo essencial e diminui a de biomassa nas folhas da rebrota. Este estudo revelou que as diferenças entre os órgãos da planta na produção de óleo essencial e a abertura de dossel devem ser levadas em consideração para podar a copa da árvore da A. canelilla e alcançar maior produtividade de óleo

    Piper aduncum Essential Oil Rich in Dillapiole: Development of Hydrogel-Thickened Nanoemulsion and Nanostructured Lipid Carrier Intended for Skin Delivery

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    The essential oil extracted from the leaves of Piper aduncum, an aromatic plant from the Amazon region, is rich in dillapiole and presents anti-inflammatory activity. In this study, nanoemulsions (NE) and nanostructured lipid carriers (NLC), which are biocompatible nanostructured systems of a lipid nature, were prepared by high-pressure homogenization for the yet unexplored skin delivery of dillapiole. The addition of hydroxyethylcellulose produced hydrogel-thickened NE or NLC in view to improving the viscosity and skin adherence of the nanoformulations. Formulations were characterized with respect to dillapiole content, droplet size, polydispersity index, zeta potential, morphology, rheological behavior, bioadhesion, skin permeation profile, and in vitro irritancy (HET-CAM). The formulations developed presented spherical, homogeneous nanometric particle size (around 130 nm), narrow polydispersity index (<0.3), and negative zeta potential (around −40 mV). Dillapiole content was slightly lower in NLC compared to NE since the production process involves heating. The hydrogels containing nanocarriers showed pseudoplastic behavior with bioadhesive characteristics. The developed formulations exhibited a controlled release profile, dillapiole delivery up to the dermis, the layer of interest for anti-inflammatory potential, and low irritant potential in the chorioallantoic membrane (HET-CAM). Both hydrogels-thickened NE and NLC seemed to be promising formulations for skin delivery of Piper aduncum essential oil

    Comparative analysis of the effects of Copaifera multijuga oil-resin and nitrofurazona in the cutaneous wound healing process

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    ABSTRACT Objectives: to evaluate, histologically and macroscopically, the influence of Copaifera multijuga (Copaíba) oil-resin on the healing process of cutaneous wounds, comparing it with nitrofurazone. Methods: we divided 36 rats into three groups of 12 animals, according to the treatment to be administered. Group SL (control) received saline on the lesion; the Group OIL received topical treatment with Copaíba oil; and the Group NITRO was treated with Nitrofurazone. We inflicted a circular wound of 8mm in diameter on the back of each animal. We subdivided each of the three groups of 12 animals into three subgroups, according to treatment time and euthanasia (7, 14 and 21 days). All animals received the proposed treatment daily. We photographed the lesions for area measurement, as well as for evaluation of macroscopic aspects. We resected and stained the scars to quantify and qualify elastic fibers, collagen, degree of epithelization, neovascularization and inflammation. Results: although the saline solution provided a faster wound closure in its initial phase, after 14 days the wound size of the three groups tested was the same. Levels of inflammation and neovascularization were similar in all three groups. The amount of collagen and elastic fibers was higher in the Nitrofurazone and Copaíba oil groups. Conclusion: in male Wistar rats, Copaifera multijuga oil-resin positively influences the healing process, but it is less effective than nitrofurazone in healing by secondary intention
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