Mostrando recursos 1 - 20 de 1.429

  1. Methanol extracts from Cystoseira tamariscifolia and Cystoseira nodicaulis are able to inhibit cholinesterases and protect a human dopaminergic cell line from hydrogen peroxide-induced cytotoxicity

    Custódio, Luísa; Silvestre, Laura; Rocha, Maria Isabel; Rodrigues, Maria João; Vizetto-Duarte, Catarina; Pereira, Hugo; Barreira, Luisa; Varela, J.
    Context Marine macroalgae contain several bioactive molecules that may be developed as functional foods, but information about their neuroprotective potential is scarce.Objective The objective of this study is to determine the in vitro antioxidant and neuroprotective features of marine algae from the southern coast of Portugal and to assess the total content of different types of bioactives.Materials and methods Methanol extracts from 21 macroalgal species from the southern Portugal were evaluated for in vitro antioxidant and acetylcholinesterase (AChE) inhibition. Active extracts were further evaluated for inhibitory activity against butyrylcholinesterase (BuChE) and tyrosinase (TYRO), and for their ability to attenuate hydrogen...

  2. Profiling of antioxidant potential and phytoconstituents of Plantago coronopus

    Pereira, C. G.; Custódio, L.; Rodrigues, M. J.; Neng, N. R.; Nogueira, J. M. F.; Carlier, J.; Costa, Maria Clara; Varela, J.; Barreira, Luísa
    The halophyte species Plantago coronopus has several described ethnomedicinal uses, but few reported biological activities. This work carried out for the first time a comparative analysis of P. coronopus organs in terms of phenolic composition and antioxidant activity of organic and water extracts from roots, leaves and flowers. The leaves contents in selected nutrients, namely amino acids and minerals, are also described. Roots (ethyl acetate and methanol extracts) had the highest radical scavenging activity (RSA) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, while leaves (hexane extract) had higher RSA on nitric oxide radical and iron chelating ability. High performance...

  3. Characterization and refinement of growth related quantitative trait loci in European sea bass (Dicentrarchus labrax) using a comparative approach

    Louro, Bruno; Kuhl, Heiner; Tine, Mbaye; de Koning, Dirk-Jan; Batargias, Costas; Volckaert, Filip A. M.; Reinhardt, Richard; Canário, Adelino V. M.; Power, Deborah
    The identification of genetic markers for traits of interest for aquaculture, such as growth, is an important step for the establishment of breeding programmes. As more genomic information becomes available the possibility of applying comparative genomics to identify and refine quantitative trait locus (QTLs) and potentially identify candidate genes responsible for the QTL effect may accelerate genetic improvement in established and new aquaculture species. Here we report such an approach on growth related traits in the European sea bass (Dicentrarchus labrax), an important species for European aquaculture. A genetic map was generated with markers targeted to previously identified QTL for...

  4. Practice of martial arts and bone mineral density in adolescents of both sexes

    Ito, Igor Hideki; Mantovani, Alessandra Madia; Agostinete, Ricardo Ribeiro; Costa Junior, Paulo; Zanuto, Edner Fernando; Christofaro, Diego Giulliano Destro; Ribeiro, Luís; Fernandes, Rômulo Araújo
    The purpose of this study was to analyze the relationship between martial arts practice (judo, karate and kung-fu) and bone mineral density in adolescents.METHODS: The study was composed of 138 (48 martial arts practitioners and 90 non-practitioners) adolescents of both sexes, with an average age of 12.6 years. Bone mineral density was measured using Dual-Energy X-ray Absorptiometry in arms, legs, spine, trunk, pelvis and total. Weekly training load and previous time of engagement in the sport modality were reported by the coach. Partial correlation tested the association between weekly training load and bone mineral density, controlled by sex, chronological age,...

  5. Numerical simulation of the application of solar radiant systems, internal airflow and occupants' presence in the improvement of comfort in winter conditions

    Conceição, E. Z. E.; Lúcio, M. Manuela J. R.
    In this work, the use of numerical simulation in the application of solar radiant systems, internal airflow and occupants' presence in the improvement of comfort in winter conditions is made. The thermal comfort, the local thermal discomfort and the air quality in an occupied chamber space are evaluated. In the experimental measurements, a wood chamber, a desk, two seats, two seated hygro-thermal manikins, a warm radiant floor, a solar radiation simulator and a water solar collector are used. The air velocity and the air temperature fluctuation are experimentally evaluated around 15 human body sections. The chamber surface temperature is experimentally...

  6. The status of Ischnura senegalensis (Odonata: Coenagrionidae) in Cape Verde

    Loureiro, Nuno de Santos; Martins, S.
    The first record of a zygopteran breeding population in the Cape Verde archipelago is presented. A small population of Ischnura senegalensis (Rambur, 1842) was found living in the lagoon 'Lagoinha', Santiago island, where the species was observed in all seven surveys conducted between May 2014 and June 2015. Reproductive behaviour was repeatedly observed and exuviae were found and collected.

  7. Can macroalgae provide promising anti-tumoral compounds? A closer look at Cystoseira tamariscifolia as a source for antioxidant and anti-hepatocarcinoma compounds

    Vizetto-Duarte, Catarina; Custódio, Luísa; Acosta, Gerardo; Lago, João H. G.; Morais, Thiago R.; de Sousa, Carolina Bruno; Gangadhar, Katkam N.; Rodrigues, Maria João; Pereira, Hugo; Lima, Raquel T.; Helena Vasconcelos, M.; Barreiro, Luísa; Rauter, Amélia P.; Albericioi, Fernando; Varela, J.
    Marine organisms are a prolific source of drug leads in a variety of therapeutic areas. In the last few years, biomedical, pharmaceutical and nutraceutical industries have shown growing interest in novel compounds from marine organisms, including macroalgae. Cystoseira is a genus of Phaeophyceae (Fucales) macroalgae known to contain bioactive compounds. Organic extracts (hexane, diethyl ether, ethyl acetate and methanol extracts) from three Cystoseira species (C. humilis, C. tamariscifolia and C. usneoides) were evaluated for their total phenolic content, radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, and antiproliferative activity against a human hepatocarcinoma cell line...

  8. Estimation of gillnet and hook selectivity for Carangoides fulvoguttatus (Forsskal, 1775) captured off Kanyakumari coast of India

    Balasubramanian, A.; Meenakumari, B.; Pravin, P.; Dhanapal, K.; Boopendranath, M. R.; Erzini, Karim
    Selectivity and fishing powers of multi-mesh gillnets with mesh sizes of 13.5, 14, 14.5 and 15 cm and hooks No. 5, 6, 7 and 8 were studied using the experimental catch data of the carangid Carangoides fulvoguttatus (Forsskal, 1775). The selectivity curves, parameters and residual plots for different models viz., normal scale, normal location, log-normal, gamma and bi-normal models were produced applying the SELECT (Share Each Length Class Total) methodology which has been incorporated in the software GILLNET (Generalised Including Log-Linear N Estimation Technique). The models were evaluated using the statistical tools viz., model deviance, dispersion parameter and residual plots...

  9. Decavanadate Toxicology and Pharmacological Activities: V-10 or V-1, Both or None?

    Aureliano, M.
    This review covers recent advances in the understanding of decavanadate toxicology and pharmacological applications. Toxicological in vivo studies point out that V-10 induces several changes in several oxidative stress parameters, different from the ones observed for vanadate (V-1). In in vitro studies with mitochondria, a particularly potent V-10 effect, in comparison with V-1, was observed in the mitochondrial depolarization (IC50 = 40 nM) and oxygen consumption (99 nM). It is suggested that mitochondrial membrane depolarization is a key event in decavanadate induction of necrotic cardiomyocytes death. Furthermore, only decavanadate species and not V-1 potently inhibited myosin ATPase activity stimulated by...

  10. Evolution problems of Navier-Stokes type with anisotropic diffusion

    Antontsev, S. N.; de Oliveira, H. B.
    In this work, we consider the evolutive problem for the incompressible Navier-Stokes equations with a general diffusion which can be fully anisotropic. The existence of weak solutions is proved for the associated initial problem supplemented with no-slip boundary conditions. We prove also the properties of extinction in a finite time, exponential time decay and power time decay. With this respect, we consider the important case of a forces fields with possible different behavior in distinct directions. Perturbations of the asymptotically stable equilibrium are established as well.

  11. Simple and effective chitosan based films for the removal of Hg from waters: Equilibrium, kinetic and ionic competition

    Rocha, Luciana S.; Almeida, Ângela; Nunes, Cláudia; Henriques, Bruno; Coimbra, Manuel A.; Lopes, Cláudia B.; Silva, Carlos M.; Duarte, Armando C.; Pereira, Eduarda
    The efficiency of chitosan cross-linked with genipin (Chg) and cross-linked with genipin and grafted with caffeic acid (Ch(g+car)) to remove Hg(II) from waters was investigated. An optimal dose of 50 mg L-1 for both chitosan films was selected based on the equilibrium removal percentage and on the contact time required to attain the equilibrium. The sorption extent was dependent on the initial Hg(II) concentration (C-Hg,C-0), with removal efficiencies varying between 79% and 82% for C-Hg,C-0 = 0.05 mg L-1 and between 89% and 94% for C-Hg,C-0 = 0.50 mg L-1. Under ion competition, the Ch(g) and Ch(g+caf) films showed to...

  12. Electromechanical actuators based on poly(vinylidene fluoride) with [N-1 (1) (1) (2(OH))][NTf2] and [C(2)mim] [C2SO4]

    Dias, J. C.; Martins, M. S.; Ribeiro, S.; Silva, M. M.; Esperança, J. M. S. S.; Ribeiro, C.; Botelho, G.; Costa, C. M.; Lanceros-Mendez, S.
    Actuators based on electroactive polymers are increasingly used in applications including microelectronic devices and artificial muscles, demanding low voltage operation and controllable switching response. This work reports on the preparation of electroactive actuators based on poly(vinylidene fluoride) (PVDF) composites with 10, 25, and 40 wt% N,N,N-trimethyl-N-(2-hydroxyethyl) ammonium bis(trifluoromethylsulfonyl)imide ([N-1 1 1 2(OH)][NTf2]) and 1-Ethyl-3-methylimidazolium Ethylsulfate ([C(2)mim][C2SO4]) ionic liquids (ILs) prepared by solvent casting. Independent of the IL type, its presence leads to the crystallization of PVDF in the piezoelectric beta-phase. The degree of crystallinity and electrical conductivity of the samples strongly depends on ILs type and content. The highest electrical...

  13. Time series analysis of data for sea surface temperature and upwelling components from the southwest coast of Portugal

    Costa Goela, Priscila; Cordeiro, Clara; Danchenko, Sergei; Icely, John; Cristina, Sónia; Newton, Alice
    This study relates sea surface temperature (SST) to the upwelling conditions off the southwest coast of Portugal using statistical analyses of publically available data. Optimum Interpolation (OI) of daily SST data were extracted from the United States (US) National Oceanic and Atmospheric Administration (NOAA) and data for wind speed and direction were from the US National Climatic Data Center. Time series were extracted at a daily frequency for a time horizon of 26 years. Upwelling indices were estimated using westerly (Q(x)) and southerly (Q(y)) Ekman transport components.In the first part of the study, time series were inspected for trend and...

  14. Standard and regional bio-optical algorithms for chlorophyll a estimates in the Atlantic off the southwestern Iberian Peninsula

    Cristina, Sónia; D'Alimonte, Davide; Goela, Priscila Costa; Kajiyama, Tamito; Icely, John; Moore, Gerald; Fragoso, Bruno; Newton, Alice
    This study investigates standard and regional algal pigment index 1 (API1) estimates in the Atlantic off the southwestern Iberian Peninsula. Standard API1 data are those delivered by the Medium Resolution Imaging Spectrometer (MERIS) orbiting sensor. Equivalent quantities are computed by applying a regional inversion scheme using as input both MERIS and in situ remote sensing reflectances (R-rs). Reference data for the development of the regional algorithm and for the analysis of tested products include field measurements of total concentration of chlorophyll a (TChla) and coincident R-rs values collected at different distances from the coast. Validation results, based on matchup analysis,...

  15. Relationships between broodstock condition, oocyte quality, and 24h D-larval survival during the spawning season of the pullet carpet shell Venerupis corrugata (Gmelin, 1791)

    Joaquim, Sandra; Matias, Domitília; Matias, Ana Margarete; Gonçalves, Rui; Vera, Cátia; Chícharo, Luís; Gaspar, Miguel B.
    Venerupis corrugata is commercially exploited in Europe. Over-fishing and recruitment failure is causing the decline of its populations and stock sustainability. Knowledge of this species reproduction is paramount to establish hatchery production of juveniles for restoring natural beds. This work aimed to find a relationship between broodstock condition, oocyte quality, and viability of 24h D-larvae. Adult specimens were induced to spawn by thermal stimulation. From each female, oocytes were taken for biochemical analyses (proteins, total lipids, and carbohydrates), and the remaining oocytes were fertilized. The 24h D-larval yield was calculated after embryo incubation. Spawning in the hatchery with 'wild' broodstock...

  16. Larval hatching and development of the wedge shell (Donax trunculus L.) under increased CO2 in southern Portugal

    Pereira, Alexandre Miguel; Range, Pedro; Campoy, Ana; Oliveira, Ana Paula; Joaquim, Sandra; Matias, Domitília; Chícharo, Luís; Gaspar, Miguel Baptista
    Noticeable changes in global temperatures, climate and ocean carbon chemistry are the result of carbon dioxide increase in the atmosphere. This increase has been mitigated by the oceans capacity to absorb one-fourth of the carbon dioxide in the atmosphere, although this CO2 intake affects oceans carbonate chemistry [i.e., ocean acidification-(OA)]. The detrimental effect of OA in the development and shell formation has been studied in several species of bivalves, although no information is available on the wedge shell Donax trunculus, a gastronomically appreciated species and an important economical resource in several southern European countries. We evaluated the effect of pCO(2)...

  17. Sustainable approach for recycling seafood wastes for the removal of priority hazardous substances (Hg and Cd) from water

    Monteiro, Rui J. R.; Lopes, Cláudia B.; Rocha, Luciana S.; Coelho, João P.; Duarte, Armando C.; Pereira, E.
    Mercury and cadmium are considered by the water framework directive priority hazardous substances. In this work, the capacity of crab carapace and clam shell wastes to remove mercury and cadmium from water was evaluated under batch conditions, for realistic contamination scenarios in monometallic and binary solutions. The results evidenced that in monometallic solutions and under studied operational conditions, both biosorbents can achieve Hg2+ removal efficiencies higher than 80% and the kinetic process is well described by two of the most widely used equations, the pseudo-second order and the Elovich model. In terms of biosorption equilibrium, crab carapace and clam shell...

  18. Effect of monomer organization on the behavior of PSS-PS micelles

    Alves, Nuno G.; Rocha, Luciana S.; Moreira, José A.; Rosa da Costa, Ana M.; Pinheiro, José Paulo
    Six copolymers of styrenesulfonate-styrene (SS-S) of varying molecular weights were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization and proven to give rise to micelles in aqueous solution. Three are diblock copolymers (PSS-b-PS), while the other three have a random distribution of the two monomers, probably forming a gradient (PSS-co-PS). The latter ones form micelles of smaller sizes and present lower critical micellar concentrations (CMC) than the former. The morphologic and dimensional features of the micelles were obtained by TEM analysis and their CMC were determined by fluorescence spectroscopy.The trace metal ion removal ability of these micelles was tested. Thus...

  19. Sustainability of future coasts and estuaries: a synthesis

    Newton, Alice; Harff, Jan; You, Zai-Jin; Zhang, Hua; Wolanski, Eric

  20. The role of environmental and fisheries multi-controls in white seabream (Diplodus sargus) artisanal fisheries in Portuguese coast

    Leitão, Francisco; Baptista, Vania; Teodósio, Maria A.; Hughes, Samantha Jane; Vieira, Vasco; Chícharo, Luís
    Evaluating the effects of fishing and environmental factors on fish populations are fundamental tenets of fisheries science. In this study, we assess associations between environmental variables (sea surface temperature; North Atlantic Oscillation index; upwelling; wind magnitude; westerly winds; northerly winds; river discharge) and fishing variables (fishing effort) in Diplodus sagus catch rates accounting for regional analyses (northwest coast; southwest coast and Algarve-Algarve south coast). Different time series models for data fitting (multi-model approach) were used. The models were lagged, according to species fishing recruitment age based on the hypothesis that fisheries catches depend on larvae recruitment and survivorship. D. sargus...

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