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Search Results: 1 - 10 of 230100 matches for " C.;Patrício "
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Nuclear activity in Apis mellifera L. (Hymenoptera, Apidae) queen ovary cells demonstrated by silver nitrate impregnation and ultrastructure
Cruz-Landim, C.;Patrício, K.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000500023
Abstract: the present paper shows through conventional light microscopy, silver nitrate impregnation and transmission electron microscopy, the changes in nuclear activity that occurs in the ovary cells during vitellogenesis of apis mellifera (linnaeus, 1758). the material impregnated by silver nitrate was detected in nurse cells, oocyte germinal vesicle and follicular cells, whose amounts are greater in phases corresponding to ovarian cells more intense activity. the silver impregnation permitted to demonstrate that the oocyte germinal vesicle synthezises ribonucleoproteins (rnp) during the beginning of the vitellogenesis. the ultrastructure show nucleolar-like material corresponding to nuclear sites impregnated by silver.
Mating influence in the ovary differentiation in adult queens of Apis mellifera L. (Hymenoptera, Apidae)
PATRíCIO, K.;CRUZ-LANDIM, C.;
Brazilian Journal of Biology , 2002, DOI: 10.1590/S1519-69842002000400012
Abstract: the present results show that in the ovarioles of a newly emerged (0 day) queen of a. mellifera only two regions may be distinguished: a proximal, short germarium and a very long distal, terminal filament. as the queen matures and gets ready for the nupcial flight, the germarium increases in lenght, advancing towered the distal end, as the terminal filament shortens. the ovarioles of queens ready to mate (6 to 8 days old) have, already one or two ovarian follicles, i.e. a very short proximal vitellarium, but a real vitellogenesis only starts after the fecundation. if the queen does not mate the ovarioles structure is disrupted (12-16 days old). in mated queen eggs the ovarioles present three differentiated regions, from the apice to the basis: a short terminal filament, a medium size germarium, and a very long basal vitellarium. as the eggs are laid, the emptied follicle collapses, degenerates and produces a corpus luteum.
Ultrastructural aspects of the intercellular bridges between female bee germ cells
Patrício, K.;Cruz-Landim, C.;
Brazilian Journal of Biology , 2006, DOI: 10.1590/S1519-69842006000200013
Abstract: the germline cells in the ovary of the female bee are interconnected by intercellular bridges kept open by cytoskeletal reinforcements in the plasmic membrane. these bridges among the germline cells display a dynamic behavior and probably act in the determination of the oocyte among the cells of the clone formed by the premeiotic mitoses, subsequently forming a pathway that enables the products synthesized by the nurse cells to reach the oocyte during its maturation. the cytoskeletal elements in the intercellular bridges of bee gonads are basically microfilaments and microtubules, but another type of filament (thick, of non-defined nature, associated with elements of the endoplasmic reticulum) is present in the bridges between the premeiotic cystocytes. this filament crosses the bridge, using microfilaments to fasten itself to the plasmic membrane. these filaments appear to control the span of the bridge. upon completion of the proliferation phase the cystocytes take on a rosette shape, and a fusome formed by the convergence of the bridges appears at their center. the thick filaments are not present in this conformation. the differentiation of the oocyte and the nurse cells leads to a new change, in which the bridges are reoriented to convey the content of the future nurse cells to the oocyte.
Mating influence in the ovary differentiation in adult queens of Apis mellifera L. (Hymenoptera, Apidae)
PATRíCIO K.,CRUZ-LANDIM C.
Brazilian Journal of Biology , 2002,
Abstract: The present results show that in the ovarioles of a newly emerged (0 day) queen of A. mellifera only two regions may be distinguished: a proximal, short germarium and a very long distal, terminal filament. As the queen matures and gets ready for the nupcial flight, the germarium increases in lenght, advancing towered the distal end, as the terminal filament shortens. The ovarioles of queens ready to mate (6 to 8 days old) have, already one or two ovarian follicles, i.e. a very short proximal vitellarium, but a real vitellogenesis only starts after the fecundation. If the queen does not mate the ovarioles structure is disrupted (12-16 days old). In mated queen eggs the ovarioles present three differentiated regions, from the apice to the basis: a short terminal filament, a medium size germarium, and a very long basal vitellarium. As the eggs are laid, the emptied follicle collapses, degenerates and produces a corpus luteum.
Phenolic Compounds Influence Seed Dormancy of Palicourea rigida H.B.K. (Rubiaceae), a Medicinal Plant of the Brazilian Savannah  [PDF]
Marielle C. Inácio, Rita Maria Moraes, Patrícia C. Mendon?a, Lucas J. F. Morel, Suzelei C. Fran?a, Bianca W. Bertoni, Ana M. S. Pereira
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.41017
Abstract: Palicourea rigida H.B.K. (Rubiaceae), a medicinal species commonly known as douradinha, has wide distribution across ecosystems in Central and South America. This species exhibits seed dormancy delaying germination until optimal conditions for seedling growth and development are in place. While dormancy ensures species survival, it also presents a technical problem for developing P. rigidas plant production program. Thus, the objective of this study was to investigate if secondary metabolites present in seeds influence the seed dormancy of P. rigida. Mature fruits were harvested from the native habitat, in the savanna region of the State of Minas Gerais during February 2009, 2010 and 2011. The content of phenolic compounds in the seed of P. rigida was measured, and the allelopathic effects were assessed using the germination of lettuces as model to detect phytotoxicity. The P. rigida seeds geminated at rates varying between 7% and 31% with a Seed Germination Index (SGI) of 0.09. Data suggest that the phenolic compounds present in the seeds may be
Effect of tungsten doping on catalytic properties of niobium oxide
Cardoso, Franciane P.;Nogueira, Andre E.;Patrício, Patrícia S. O.;Oliveira, Luiz C. A.;
Journal of the Brazilian Chemical Society , 2012, DOI: 10.1590/S0103-50532012000400016
Abstract: a novel material based on niobia (nb2o5) was synthesized to oxidize an organic compound in aqueous medium in the presence of h2o2 after chemical modifications. niobia was modified by doping with tungsten and also treating with h2o2 in order to maximize the oxidative properties of this oxide. the analysis of the products from methylene blue dye oxidation with electrospray ionization mass spectrometry (esi-ms) showed that the dye was successively oxidized to different intermediate compounds. the successive hydroxylation during this oxidation strongly suggests that highly reactive hydroxyl radicals are generated involving h2o2 on the w-doped niobia grain surface. these results strongly suggest that the h2o2 can regenerate in situ the peroxo group remaining active the system.
Ciprofibrate increases cholesteryl ester transfer protein gene expression and the indirect reverse cholesterol transport to the liver
Eliete JB Bighetti, Patrícia R Patrício, Andrea C Casquero, Jairo A Berti, Helena CF Oliveira
Lipids in Health and Disease , 2009, DOI: 10.1186/1476-511x-8-50
Abstract: Mice expressing apo CIII and/or CETP and non-transgenic littermates (CIII, CIII/CETP, CETP, non-Tg) were treated with ciprofibrate during 3 weeks. Drug treatment reduced plasma triglycerides (30-43%) and non-esterified fatty acids (19-47%) levels. Cholesterol (chol) distribution in plasma lipoprotein responses to ciprofibrate treatment was dependent on the genotypes. Treated CIII expressing mice presented elevation in VLDL-chol and reduction in HDL-chol. Treated CETP expressing mice responded with reduction in LDL-chol whereas in non-Tg mice the LDL-chol increased. In addition, ciprofibrate increased plasma post heparin lipoprotein lipase activity (1.3-2.1 fold) in all groups but hepatic lipase activity decreased in treated CETP and non-Tg mice. Plasma CETP activity and liver CETP mRNA levels were significantly increased in treated CIII/CETP and CETP mice (30-100%). Kinetic studies with 3H-cholesteryl ether (CEt) labelled HDL showed a 50% reduction in the 3H-CEt found in the LDL fraction in ciprofibrate treated compared to non-treated CETP mice. This means that 3H-CEt transferred from HDL to LDL was more efficiently removed from the plasma in the fibrate treated mice. Accordingly, the amount of 3H-CEt recovered in the liver 6 hours after HDL injection was increased by 35%.Together these data showed that the PPARα agonist ciprofibrate stimulates CETP gene expression and changes the cholesterol flow through the reverse cholesterol transport, increasing plasma cholesterol removal through LDL.Apolipoproteins (apo) CIII are small proteins mainly found on the surface of apoB containing lipoproteins (including VLDL, IDL and LDL), which strongly affect their metabolism. They inhibit catabolism of these lipoproteins by lipoprotein-lipase (LPL) and retard their clearance from plasma by decreasing their affinity for hepatic lipoprotein receptors [1-3]. The ability of apo CIII in inducing hypertriglyceridemia was directly demonstrated in transgenic mice over-expressing this pro
Antioxidant, cytotoxic and UVB-absorbing activity of Maytenus guyanensis Klotzch. (Celastraceae) bark extracts
Macari, Patrícia de Almeida Telles;Portela, Cíntia Nicácio;Pohlit, Adrian Martin;
Acta Amazonica , 2006, DOI: 10.1590/S0044-59672006000400012
Abstract: maytenus guyanensis klotzch. is an amazonian medicinal tree species known in brazil by the common name chichuá and in peru and colombia by the name chuchuhuasi. it is used in traditional medicine as stimulant, tonic, and muscle relaxant, for the relief of arthritis, rheumatism, hemorrhoids, swollen kidney, skin eruptions, and skin cancer prevention, among others. initially, different extraction solvents and methods were applied to dried, ground bark which made possible the preparation of extracts having both significant lethality to brine shrimp larvae (artemia franciscana leach) as well as antioxidant activity in vitro based on tests involving reactions with 2,2,-diphenyl-1-picrylhydrazyl (dpph). analysis of fractions from serial extractions with solvents of increasing polarity supports the notion that antioxidant activity is associated with compounds of intermediate polarity and cytotoxicity is associated with compounds of low to intermediate polarity. variation of extraction time and conditions revealed that hot, continuous ethanol extraction provided good yields of bark extract in several hours. hot extraction also provided ethanol extracts having greater lethality to brine shrimp and antioxidant activity (compared to the flavonoid rutin in semi-quantitative methods based on dpph) than extracts obtained from maceration at room temperature. freeze-dried ethanol extracts were prepared by: 1) maceration at room temperature and 2) hot extraction (eight hours) on several hundred gram scales and the latter extract was shown to have partial screening effects on uvb light. in this work, cytotoxic, antioxidant and potential sun-screening activity are shown for the first time in m. guyanensis.
Fortran subroutines for network flow optimization using an interior point algorithm
Portugal, L. F.;Resende, M. G. C.;Veiga, G.;Patrício, J.;Júdice, J. J.;
Pesquisa Operacional , 2008, DOI: 10.1590/S0101-74382008000200005
Abstract: we describe fortran subroutines for network flow optimization using an interior point network flow algorithm, that, together with a fortran language driver, make up pdnet. the algorithm is described in detail and its implementation is outlined. usage of the package is described and some computational experiments are reported. source code for the software can be downloaded at http://www.research.att.com/~mgcr/pdnet.
Fenologia reprodutiva e produ??o de sementes em Araucaria angustifolia (Bert.) O. Kuntze
Mantovani, Adelar;Morellato, L. Patrícia C.;Reis, Maurício S. dos;
Brazilian Journal of Botany , 2004, DOI: 10.1590/S0100-84042004000400017
Abstract: the knowledge about the reproductive phenology of araucaria angustifolia has applications to the seed harvest for "ex situ" conservation, for commercial use of the seeds and to understand the dynamic and regeneration of its natural populations. the reproductive phenology and seed production of a. angustifolia were evaluated for a natural population occurring at parque estadual campos de jord?o, s?o paulo state, brazil. the present study investigates: (i) how is the reproductive cycle and the phenological pattern of araucaria? (ii) how is the potential of seed production and its variability? sixty adult plants (30 males and 30 females) were marked for phenological observations. seed production was estimated based on the number of female plants in a 10 ha area, number of cones per plant, number of seeds per cone and seed weight. the reproductive cycle of a. angustifolia extended for 20 to 24 months, from the observation of the first cone to seed fall. the pollination occurred between september and october and seed maturation and seed fall from march to june. seed production was significantly different between years (117 kg.ha-1 in 2001 e 160 kg.ha-1 in 2002). the duration of ripe seed offer was also different between years. the variation observed in the amount and availability of seeds suggests that the observation of reproductive phenology and estimation of seed production are important to guide strategies for conservation and management of this resource.
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