126 resultados para CROTON ELEGANS


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O termo câncer refere-se a um conjunto de doenças que atingem e matam milhões de pessoas em todo o mundo. Esta doença é caracterizada pela proliferação descontrolada de células que não respondem mais aos estímulos externos e internos que controlam a proliferação, diferenciação e morte celular. O aumento da expectativa de vida da população é um dos fatores que contribuem para a crescente incidência de câncer no mundo já que o desenvolvimento desta doença está relacionado com o envelhecimento do organismo. O câncer é a segunda maior causa de morte na população mundial e diante de tal índice, fica clara a necessidade de desenvolvimento de novos quimioterápicos. Cerca de 60% das drogas anticâncer são derivadas de produtos naturais, demonstrando assim o grande potencial destes produtos no desenvolvimento de novas drogas anticâncer. Este projeto teve como objetivo avaliar a atividade anticâncer dos extratos brutos e frações obtidas da espécie vegetal Croton urucurana Bailon. Os extratos brutos diclorometânico (EBD) e etanólico (EBE) foram avaliados em ensaio de citotoxicidade in vitro em cultura de células tumorais humanas. Os dois extratos apresentaram atividade in vitro, porém somente o EBD foi submetido ao processo cromatográfico de fracionamento, sendo as frações obtidas deste processo submetidas ao teste antiproliferativo in vitro. O EBD também foi utilizado para avaliar sua atividade em modelo de tumor sólido de Ehrlich. Neste teste, esse extrato apresentou inibição do crescimento tumoral apenas com a menor dose. Como o EBE também apresentou atividade antiproliferativa in vitro, é importante dar continuidade aos estudos com este extrato, com o objetivo de avaliar sua atividade em modelos experimentais in vivo

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Agronomia (Horticultura) - FCA

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Nematophagous fungi have been studied as a promising alternative for the management of nematodes of citrus. This study had the objective of documenting by scanning electron microscopy the outslading morphological structures for the identification of the main species of nematophagous fungi involved in the study and proving the pathogenicity of the isolated ones associated with T. semipenetrans and P. jaehni, Isolated came from in citrus orchards, mainly in São Paulo State, were studied in the Laboratory of Scanning Electron Microscopy of FCAV/UNESP - Campus de Jaboticabal-SP. The data obtained in this study have confirmed that the scanning electron microscopy is an effective tool to assist in the understanding of way of action of the nematophagous fungi: Arthrobotrys oligospora, A. conoides, A. robusta, A. musiformis, Dactylella leptospora, Monacrosporium eudermatum and M. elegans and to reveal details of their reproductive structures and the capture, to confirm the pathogenicity of the isolated to T. semipenetrans and P. jaehni, as well as to confirm the identification of some isolated.

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As part of a larger study evaluating several silvicultural techniques for restoring tropical moist forests on abandoned agricultural lands in southeastern Brazil, direct seeding with five early-successional Atlantic forest species was tested at three degraded sites, characterized by different soil types and land-use histories, within the Environmental Protection Area at Botucatu, SP. The species used in this study were Chorisia speciosa, Croton floribundus, Enterolobium contorstisiliquum, Mimosa scabrella, and Schizolobium parahyba. Scarified seeds of each of these species were sown in prepared seed spots in replicated, 0.25 ha mixed-species plots at an initial espacement of 1 m x 1 m at each site. of the five species planted, only two, Enterolobium and Schizolobium, showed good seed germination, seedling survival, and early growth rates, averaging 4.1-4.6 cm stem diameter and 1.5-1.7 m height growth during the first 2 years after sowing. These two species constituted 88-100% of the total stand density, which ranged from 1050 to 1790 stems ha(-1) at 2 years. Despite the poor performance of the other species tested, we observed that the natural regeneration of native forest species originating from remnant forests in the general vicinity of our study sites was significantly greater within the direct-seeded plots than in unplanted control plots that were protected from fire and other disturbances. Published by Elsevier B.V. B.V.

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The objective was to determine the distribution in pea seedling of GA (by thin layer chromatography) and IAA (by HPLC). Three samples of 30 7/day-old seedlings were sectioned into: apical meristem + plumular hook; stem elongation zone; stem non-elongation zone; cotyledons; root non-elongation zone; root tip. The material was frozen in liquid N and stored at -80 degrees C. The stem elongation zone, the apical meristem+plumular hook and the root tip had low IAA, whereas the stem non-elongation zone and root non-elongation zone had high IAA content. The stem elongation zone and apical meristem plumular hook had high GA, while root non-elongation zone had the lowest GA content.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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SDS electrophoresis of midgut proteins from two Trigonini species with different feeding habits shows many similarities and the absence of unique protein in the necrophagous stingless bee Trigona hypogea, suggesting that biochemical adaptation to necrophagy, in this bee, occurs more in the qualitative than in quantitative level. Workers of different ages display some variations in the midgut protein pattern, suggesting that it is important to know the age in studies regarding to bee digestion.

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The flowering, sex ratio, and spatial distribution of four dioecious species of Trichilia (Meliaceae) were studied in a semi-deciduous forest in southeastern Brazil. All reproductive trees (T. clausseni, T. pallida and T. catigua) with dbh greater than or equal to5 cm within a 1-ha plot were collected, sexed, mapped and, for individuals of each species, the distances to the nearest neighbour of the same and opposite sex were measured. For the shrub species T elegans (dbh <5 cm), all reproductive individuals were sampled randomly in 10 samples of 10 x 10 m. The reproductive phenology was observed at weekly to monthly intervals from May 1988 to January 1990. The species are strictly dioecious, did not present any sex-mixed trees or sex switching during the study, and sex ratio did not differ significantly from 1:1. The size distributions and the relative size variation were not significantly different. between sexes. There was no significant segregation or clumping between individuals of either sex and no fruit production without pollination. Onset of flowering and flowering peak were synchronous between male and female plants for all species studied. Flower synchrony was related to outcrossing and pollinator attraction rather than climatic factors.

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In tropical forests, rodents exert a prominent role as post-dispersal seed predators, while other vertebrates apparently have a minor effect on seed predation. In some forest fragments in southeast Brazil, however, the density of rodents is unusually low, whereas terrestrial granivorous birds are abundant. In this study, we used seeds of a second-growth tree (Croton priscus, Euphorbiaceae) to investigate experimentally the relative importance of rodents and birds as seed predators in a forest fragment. We also estimated the density of terrestrial granivorous birds and trapped small mammals. Results indicate that, as a consequence of decreased rodent population and increased bird abundance, the latter are at least as important as the former as the main post-dispersal seed predators of C priscus. We interpret such apparent imbalance in the interaction between C priscus and their seed predators as a possible consequence of forest fragmentation.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)