1,308 research outputs found

    Efeitos Da Clonidina E Da Rilmenidina Sobre Os Sistemas Cardiorrespiratório E Gastrointestinal De Equinos

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    Clonidine and rilmenidine are drugs used in human medicine as central acting antihypertensive agents due to their actions on the alpha2-adrenoceptor and I1 imidazoline receptors in the central nervous system. Currently, clonidine is also used as a pre-anesthetic medication and in spinal anesthesia, and rilmenidine, despite the lower selectivity for alpha2-adrenergic receptors than clonidine, has also shown antinociceptive potential in experimental pain models. In this study, six horses were submitted to four treatments: R1 group (0.014 mg/kg of rilmenidine); R2 group (0.021 mg/kg of rilmenidine); Clo group (0.002 mg/kg of clonidine), and a control group. The assessment comprehended their heart and respiratory rates, systolic blood pressure and intestinal motility at basal levels and, then, 60 and 120 minutes after the oral administration of the drugs. Rilmenidine decreased heart rate on the two tested doses, which did not occur in the Clonidine treatment; slight variations in systolic blood pressure in all treatments and respiratory rate reduction in treatments with rilmenidine at 0.021 mg/ kg and clonidine at 0.002 mg/kg were also observed. Further studies with different dosages and varied administration routes are still necessary in order to elucidate more effects of these drugs on horses. © 2016, Cienc. anim. bras., Goiânia. All rights reserved.17460861

    Application of catalysts developed from compost derived from municipal solid waste in the removal of caffeine by wet peroxide oxidation

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    Nowadays, waste management through mechanical biological treatment (MBT) consists on the use of the separated organic fraction of municipal solid waste (MSW) to feed anaerobic digestion processes, resulting therein a solid stream, further processed to compost, which can be used as fertilizer. Currently, the production of compost from MBT is higher than the existing demand, and the expected developments on up-coming directives ruling “End-of-waste” criteria are leading to barriers on the use of waste-derived fertilizers (European Commision, 2013). In this context, the current work proposes an alternative strategy to the valorisation of compost, through the production of low-cost materials to be applied in the catalytic wet peroxide oxidation (CWPO) of synthetic wastewater effluents contaminated with caffeine, used as a model pollutant of emerging concern. Caffeine is the most consumed psychoactive drug worldwide. It is one of the components of painkillers, medication against migraine, fatigue, drowsiness and breathing problems. Its consumption is also associated with an overall lower risk of malignant growth like hepatocellular, endometrial or colorectal cancer (Ganzenko et al., 2015). However, the effect of caffeine and its environmental degradation products on aquatic living species is not properly known. Caffeine, is a world wide consumed psychoactive drug, in a way that becomes a persistent compound and cannot be efficiently removed by municipal wastewater treatment facilities (Ganzenko et al., 2015). As a consequence, caffeine and its metabolites are present in the effluents of wastewater treatment plants (Gracia-Lor et al., 2017).This work was financially supported by project “VALORCOMP - Valorización de compost y otros desechos procedentes de la fracción orgánica de los residuos municipales”, 0119_VALORCOMP_2_P, and project “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, reference NORTE-01-0145-FEDER-000006, supported by NORTE 2020, under the Portugal 2020 Partnership Agreement, through FEDER, and Project Associate Laboratory LSRE-LCM - UID/EQU/50020/2019 - funded by national funds through FCT/MCTES (PIDDAC).info:eu-repo/semantics/publishedVersio

    Evaluation of Arenaria montana L. hydroethanolic extract as a chemopreventive food ingredient: A case study focusing a dairy product (yogurt)

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    Natural ingredients are valuable options to be exploited in the design of innovative food formulations with health benefits. Therefore, it was evaluated the potential use of Arenaria montana L. hydroethanolic extract (rich in apigenin derivatives) as a chemopreventive agent in functional foods. Apigenin is recognized as inhibiting VEGFR-2, which is the key receptor involved in angiogenesis. The obtained extract was also able to inhibit the VEGFR-2 phosphorylation through an enzymatic assay (IC 50 = ~63 µg/mL). Thereafter, free and microencapsulated forms were incorporated in yogurt. The obtained products maintained the nutritional value along the tested 3 days of storage, as also free sugars and fatty acids profiles, in comparison with the control samples. Nevertheless, the VEGFR-2 phosphorylation inhibition was not exhibited as intended. Even this behavior for the microencapsulated forms can be attributed to the protecting effect of the alginate matrix, further studies are required in order to better understand the shown performance.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER for CIMO (UID/AGR/00690/2013) financial support. To POCI-01-0145-FEDER-006984 (LA LSRE-LCM) funded by ERDF through POCI-COMPETE2020 and FCT. To NORTE-01-0145-FEDER-000006, funded by NORTE 2020, under PT2020 through ERDF. L. Barros, R.C. Calhelha and J.C.M. Barreira acknowledge the FCT for their post-doctoral grants (SFRH/BPD/107855/2015, SFRH/BPD/68344/2010 and SFRH/BPD/72802/2010, respectively). The authors also thank Ana Maria Carvalho for providing Arenaria montana L. samples.info:eu-repo/semantics/publishedVersio

    Entanglement and Quantum Phase Transitions via Adiabatic Quantum Computation

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    For a finite XY chain and a finite two-dimensional Ising lattice, it is shown that the paramagnetic ground state is adiabatically transformed to the GHZ state in the ferromagnetic phase by slowly turning on the magnetic field. The fidelity between the GHZ state and an adiabatically evolved state shows a feature of the quantum phase transition.Comment: Revise

    Acetonitrile as adjuvant to tune polyethylene glycol + K3PO4 aqueous two-phase systems and its effect on phenolic compounds partition

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    Aqueous two-phase systems (ATPS) have been proposed as platforms for the purification of biomolecules, and the application of adjuvants to tune the properties of ATPS phases and their ability to extract and separate biological products investigated. This work addresses, for the first time, the use of acetonitrile (ACN) as adjuvant in ATPS composed of polyethylene glycol (PEG) of different molecular weights (from 400 to 20,000 g·mol−1) and potassium phosphate. The effect of ACN concentration (at 0.25, 2.5, 5 and 7.5 wt%) in the liquid-liquid equilibrium is here studied by measuring the phase diagrams, the composition of the phases in equilibrium and their Kamlet-Taft parameters. The results obtained demonstrate that the ACN presence increases the biphasic region of PEG-K3PO4 ATPS and its distribution between the coexisting phases is dependent on its concentration and ATPS composition. The difference in the dipolarity/polarizability of the coexisting phases is significantly affected by the presence of ACN in the ternary mixture. The partition of two phenolic compounds – protocatechuic acid and gallic acid – was studied, showing that ACN improves the partition of these molecules to the salt-rich phase, and that the system selectivity can be significantly improved by changing the concentration of the phase forming compounds.publishe

    Nanodispersions of beta-carotene: effects on antioxidant enzymes and cytotoxic properties

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    Beta-carotene is a carotenoid precursor of vitamin A, known for its biological activities. Due to its high hydrophobicity, nanonization processes, i.e. the transformation into nanoparticles, can improve its water affinity, and therefore the activity in aqueous systems. The objective of this study was to produce beta-carotene nanoparticles by the solid dispersion method and to evaluate their effects on the activity of glutathione-S-transferase and acetylcholinesterase enzymes using Drosophila melanogaster (DM) homogenate, the superoxide dismutase- and catalase-like activities under in vitro conditions, and their cytotoxic properties against tumor and non-tumor cells. The formed nanometric beta-carotene particles resulted in stable colloids, readily dispersed in water, able to modulate acetylcholinesterase (AChE) activity, and presenting high potential to control the cholinergic system. Beta-carotene nanoparticles, at concentrations much lower than the pure pristine beta-carotene, presented in vitro mimetic activity to superoxide dismutase and altered glutathione-S-transferase activity in DM tissue. The content of hydrogen peroxide was neither affected by the nanoparticles (in aqueous solution) nor by pristine beta-carotene (in DMSO). In the cytotoxic assays, beta-carotene nanoparticles dispersed in water showed activity against four different tumor cell lines. Overall, beta-carotene nanoparticles presented significant bioactivity in aqueous medium surpassing their high hydrophobicity constraint.The authors thank CNPq, CAPES and Fundação Araucária for the support. The authors are also grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (strategic project UID/AGR/00690/2013) and R. Calhelha contract, and to the project POCI-01-0145- FEDER-006984 – Associate Laboratory LSRE-LCM funded by the FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT. This work was also funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and Project Mobilizador ValorNatural®.info:eu-repo/semantics/publishedVersio

    Magnetoresistance of Three-Constituent Composites: Percolation Near a Critical Line

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    Scaling theory, duality symmetry, and numerical simulations of a random network model are used to study the magnetoresistance of a metal/insulator/perfect conductor composite with a disordered columnar microstructure. The phase diagram is found to have a critical line which separates regions of saturating and non-saturating magnetoresistance. The percolation problem which describes this line is a generalization of anisotropic percolation. We locate the percolation threshold and determine the t = s = 1.30 +- 0.02, nu = 4/3 +- 0.02, which are the same as in two-constituent 2D isotropic percolation. We also determine the exponents which characterize the critical dependence on magnetic field, and confirm numerically that nu is independent of anisotropy. We propose and test a complete scaling description of the magnetoresistance in the vicinity of the critical line.Comment: Substantially revised version; description of behavior in finite magnetic fields added. 7 pages, 7 figures, submitted to PR
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