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Search Results: 1 - 10 of 494365 matches for " B. M. Vinagre "
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Ancient ceramic analysis by neutron activation in association with multivariate methods
Vinagre Filho, U. M.;Latini, R. M.;Bellido, A V. B.;Buarque, A.;Borges, A. M.;
Brazilian Journal of Physics , 2005, DOI: 10.1590/S0103-97332005000500015
Abstract: we report a comparative study of two archaeological sites, bela vista and serrano, located in the araruama region of the state of rio de janeiro, in brazil. the elemental geochemical compositions of the ceramics from both sites were determined by instrumental neutron activation analysis (inaa). a statistical treatment of the data, using cluster analysis and principal component analysis, indicates that there are no correlations between these sites.
Controller Design for A Stance-Control Knee-Ankle-Foot Orthosis Based on Optimization Techniques
S. H. HosseinNia,F. Romero,I. Tejado,F. J. Alonso,B. M. Vinagre
Physics , 2012,
Abstract: Design of active orthosis is a challenging problem from both the dynamic simulation and control points of view. The redundancy problem of the simultaneous human-orthosis actuation is an interesting exercise to solve concerning the analytical and computational cost effectiveness. The physiological static optimization approach tries to solve the actuation sharing problem. Its objective is to quantify the contributions of muscles and active orthosis to the net joint torques in order to select the proper actuator for the joint. Depending on the disability of each patient, different controllers can be designed. As a matter of fact, the duration of the gait cycle for each patient should be different. In this paper, a PI controller is designed whose parameters are tuned by optimizing a cost function which takes into account the patients muscle power and the error of the knee angle with the reference value. Moreover, the final time is obtained by minimizing the mean of integral squared errors. The performance of the method is shown by designing the controller for three types of patients, ordered from low to high disability. The objective of this work is to use optimal control techniques based on physiological static optimization approach to the design of active orthosis and its control.
The modelling and analysis of fractional-order control systems in frequency domain
I. Petras,L. Dorcak,P. O'Leary,B. M. Vinagre,I. Podlubny
Mathematics , 2000,
Abstract: This paper deals with fractional-order controlled systems and fractional-order controllers in the frequency domain. The mathematical description by fractional transfer functions and properties of these systems are presented. The new ways for modelling of fractional-order systems are illustrated with a numerical example and obtained results are discussed in conclusion.
Practical application of digital fractional-order controller to temperature control
Petrá? Ivo,Vinagre Blas M.
Acta Montanistica Slovaca , 2002,
Abstract: Príspevok sa zaoberá praktickym návrhom a aplikáciou èíslicového regulátora neceloèíselného rádu na riadenie teploty iarièa. V príspevku je alej uvedeny matematicky popis regulátorov a regulovanych sústav neceloèíselného rádu. Pre pou itie èíslicovych regulátorov neceloèíselného rádu je uvedeny príslu ny algoritmus. Vlastnosti regulaèného obvodu s regulátorom neceloèíselného rádu sú porovnané s regulaènym obvodom s klasickym regulátorom celoèíselného rádu a dosiahnuté vysledky sú uvedené a diskutované v závere príspevku.
Efecto de tratamientos termicos sobre las características químicas de carne de jaiba mora (Homalaspis plana)
Quitral Robles,Vilma; Abugoch J,Lilian; Vinagre L,Julia; Guarda M,Abel; Larraín B,Ma Angélica; Santana R,Gabriela;
Archivos Latinoamericanos de Nutrición , 2003,
Abstract: summary. marine species muscles present non-proteics nitrogenated compounds, used as quality index. they are total volatile basis (nbvt), trimethylamine oxide (tmao) and trimethylamine (tma). ph is considered too as a quality index .the aim of this work was to evaluate these parameters in a fresh and canned marine product from the v region, corresponding to mora crab (homalaspis plana). fresh pincer meat from mora crab was extracted and kept in ice until theits analysis and thermal process of the canned product. a 32 statistical design was applied, considering two variables with 3 levels; 15, 30 y 45 minutes time levels; 80o, 100o y 121oc temperature levels. nine conditions of time-temperature were obtained. the thermal treatment caused an increase in ph and bvt. the tma was increased since reduction of otma.
Phenylpyrazolone derivatives inhibit gastric emptying in rats by a capsaicin-sensitive afferent pathway
Vinagre, A.M.;Collares, E.F.;
Brazilian Journal of Medical and Biological Research , 2009, DOI: 10.1590/S0100-879X2009001100014
Abstract: dipyrone (dp), 4-aminoantipyrine (aa) and antipyrine (at) administered iv and dp administered icv delay gastric emptying (ge) in rats. the participation of capsaicin (cps)-sensitive afferent fibers in this phenomenon was evaluated. male wistar rats were pretreated sc with cps (50 mg/kg) or vehicle between the first and second day of life and both groups were submitted to the eye-wiping test. ge was determined in these animals at the age of 8/9 weeks (weight: 200-300 g). ten minutes before the study, the animals of both groups were treated iv with dp, aa or at (240 μmol/kg), or saline; or treated icv with dp (4 μmol/animal) or saline. ge was determined 10 min after treatment by measuring % gastric retention (gr) of saline labeled with phenol red 10 min after orogastric administration. percent gr (mean ± sem, n = 8) in animals pretreated with cps and treated with dp, aa or at (35.8 ± 3.2, 35.4 ± 2.2, and 35.6 ± 2%, respectively) did not differ from the gr of saline-treated animals pretreated with vehicle (36.8 ± 2.8%) and was significantly lower than in animals pretreated with vehicle and treated with the drugs (52.1 ± 2.8, 66.2 ± 4, and 55.8 ± 3%, respectively). the effect of icv administration of dp (n = 6) was not modified by pretreatment with cps (63.3 ± 5.7%) compared to dp-treated animals pretreated with vehicle (62.3 ± 2.4%). the results suggest the participation of capsaicin-sensitive afferent fibers in the delayed ge induced by iv administration of dp, aa and at, but not of icv dp.
Effect of 4-aminoantipyrine on gastric compliance and liquid emptying in rats
Vinagre, A.M.;Collares, E.F.;
Brazilian Journal of Medical and Biological Research , 2007, DOI: 10.1590/S0100-879X2006005000119
Abstract: dipyrone (dp) delays gastric emptying (ge) in rats. there is no information about whether 4-aminoantipyrine (aa), one of its metabolites, has the same effect. the objectives of the present study were to assess the effects of aa and dp on ge when administered intravenously (iv) and intracerebroventricularly (icv) (240 μmol/kg and 4 μmol/animal, respectively) and on gastric compliance when administered iv (240 μmol/kg). ge was determined in male wistar rats weighing 250-300 g (5-10 per group) after icv or iv injection of the drug by measuring percent gastric retention (gr) of a saline meal labeled with phenol red 10 min after administration by gavage. gastric compliance was estimated in anesthetized rats (10-11 per group), with the construction of volume-pressure curves during intragastric infusion of a saline meal. compliance was significantly greater in animals receiving dp (mean ± sem = 0.26 ± 0.009 ml/mmhg) and aa (0.24 ± 0.012 ml/mmhg) than in controls (0.19 ± 0.009 ml/mmhg). aa and dp administered iv significantly increased gr (64.4 ± 2.5 and 54.3 ± 3.8%, respectively) compared to control (34 ± 2.2%), a phenomenon observed only with dp after icv administration. subdiaphragmatic vagotomy reduced the effect of aa (gr = 31.4 ± 1.5%) compared to sham-treated animals. baclofen, a gabab receptor agonist, administered icv significantly reduced the effect of aa (gr = 28.1 ± 1.3%). we conclude that dp and aa increased gastric compliance and aa delayed ge, with the participation of the vagus nerve, through a pathway that does not involve a direct action of the drug on the central nervous system.
Effect of the GABA B agonist baclofen on dipyrone-induced delayed gastric emptying in rats
Collares, E.F.;Vinagre, A.M.;
Brazilian Journal of Medical and Biological Research , 2005, DOI: 10.1590/S0100-879X2005000100015
Abstract: dipyrone administered intravenously (iv) or intracerebroventricularly (icv) delays gastric emptying (ge) in rats. gamma-aminobutyric acid (gaba) is the most potent inhibitory neurotransmitter of the central nervous system. the objective of the present study was to determine the effect of icv baclofen, a gabab receptor agonist, on delayed ge induced by dipyrone. adult male wistar rats received a saline test meal containing phenol red as a marker. ge was indirectly evaluated by determining the percent of gastric retention (%gr) of the meal 10 min after orogastric administration. in the first experiment, the animals were injected iv with vehicle (civ) or 80 mg/kg (240 μmol/kg) dipyrone (dpiv), followed by icv injection of 10 μl vehicle (bac0), or 0.5 (bac0.5), 1 (bac1) or 2 μg (bac2) baclofen. in the second experiment, the animals were injected icv with 5 μl vehicle (cicv) or an equal volume of a solution containing 4 μmol (1333.2 μg) dipyrone (dpicv), followed by 5 μl vehicle (bac0) or 1 μg baclofen (bac1). ge was determined 10 min after icv injection. there was no significant difference between control animals from one experiment to another concerning gr values. baclofen at the doses of 1 and 2 μg significantly reduced mean %gr induced by iv dipyrone (dpivbac1 = 35.9% and dpivbac2 = 26.9% vs dpivbac0 = 51.8%). similarly, baclofen significantly reduced the effect of dipyrone injected icv (mean %gr: dpicvbac1 = 30.4% vs dpicvbac0 = 54.2%). the present results suggest that dipyrone induces delayed ge through a route in the central nervous system that is blocked by the activation of gabab receptors.
Evidence of the effect of dipyrone on the central nervous system as a determinant of delayed gastric emptying observed in rats after its administration
Collares, E.F.;Vinagre, A.M.;
Brazilian Journal of Medical and Biological Research , 2003, DOI: 10.1590/S0100-879X2003001000014
Abstract: dipyrone administered intravenously (iv) delays gastric emptying (ge) in rats. the objectives of the present study were to assess: 1) the effect of the dose of dipyrone and time after its iv administration on ge in rats, 2) the effect of subdiaphragmatic vagotomy (vgx) and bilateral electrolytic lesion of the paraventricular nucleus (pvnx) on the delayed ge induced by the drug, and 3) the intracerebroventricular (icv) action of dipyrone and of one of its metabolites, 4-aminoantipyrine on ge. male wistar rats received saline labeled with phenol red intragastrically as a test meal. ge was indirectly assessed by the determination of percent gastric retention (gr) of the test meal 10 min after administration by gavage. dipyrone delays ge in a dose- and time-dependent manner. thirty minutes after the iv administration of 80 mg/kg dipyrone, the animals showed significantly higher gr (mean = 62.6%) compared to those receiving vehicle (31.5%). vgx and pvnx significantly reduced the iv effect of 80 mg/kg dipyrone (mean %gr: vgx = 28.3 vs sham = 55.5 and pvnx = 34.5 vs sham = 52.2). icv administration of 4 μmol dipyrone caused a significant increase in gr (54.1%) of the test meal 10 min later, whereas administration of 4 μmol 4-aminoantipyrine had no effect (34.4%). although the dipyrone dose administered icv was 16 times lower than that applied iv, for the same time of action (10 min), the gr of animals that received the drug icv (54.1%) or iv (54.5%) did not differ significantly. in conclusion, the present results suggest that the effect of dipyrone in delaying ge is due to the action of the drug on the central nervous system, with the participation of the pvn and of the vagus nerve.
Uso antenatal do corticosteroide e hemorragia peri-intraventricular
Vinagre, Luis Eduardo de F.;Marba, Sérgio Tadeu M.;
Revista Paulista de Pediatria , 2010, DOI: 10.1590/S0103-05822010000300014
Abstract: objective: to conduct a literature review on the use of antenatal corticosteroids for the prevention of peri-intraventricular hemorrhage. data source: bibliography search in pubmed and scielo databases covering the past 20 years using the following key-words: "cerebral hemorrhage", "steroids" and "newborn infant". data synthesis: the peri-intraventricular hemorrhage is an important disease of preterm infants, especially those with less than 34 weeks, due to its serious neurological sequelae. once the bleeding occurs, there is no specific treatment. thus, prevention becomes the main goal of the research. meta-analysis of randomized studies showed that antenatal corticosteroids reduce mortality and the incidence of hyaline membrane disease and peri-intraventricular hemorrhage. the physiologic basis for this protective effect in reducing the risk of peri-intraventricular hemorrhage is not completely clear. besides accelerating lung maturity, antenatal steroids stimulate the maturation of the microvasculature of the germinal matrix, promote the thickening of the basement membrane, accelerate the formation of protein in tight functions and stabilize the cerebral blood flow. they also improve the birth conditions of preterm babies. conclusions: the use of antenatal corticosteroids associated with implementing best practices to assist preterm infants reduces the frequency of peri-intraventricular hemorrhage. despite its proven efficacy and safety, it is not widely used. measures should be taken to encourage its use as a routine practice in the care of pregnant women at risk of premature birth.
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