Determination of sildenafil citrate and tadalafil by ultra. performance liquid chromatography with diode-array detection (UPLC-DAD) [DeTERMINAÇÃO de citrato de sildenafila e de tadalafila por cromatografia liquida de ultraeficiência com dETECÇão por arranjo de diodos (CLUE-DAD)]
Ortiz R.S.,Federal University of Rio Grande do Sul |
Antunes M.V.,Centro Universitario Feevale |
Linden R.,Centro Universitario Feevale
Quimica Nova | Year: 2010
A simple ultra-performance liquid chromatographic method for the simultaneous determination of sildenafil citrate and tadalafll was developed and validated. Sample preparation was dissolution in methanol, followed by centrifugation and dilution (1:10) with methanol. Analysis was performed in an Acquity® UPLC system, with Acquity®BEH C18 column (2.1 × 50 mm, with 1.7 μm particles). The elution was isocratic with phosphate buffer pH 2.3 and acetonitrile (65:35, v/v) at a flow rate of 0.7 mL/min. The method, presented adequate specificity, linearity, precision and accuracy and allowed, the determination of the drugs in seized, forensic samples.
De Andrade F.M.,Centro Universitario Feevale |
Maluf S.W.,Medical Genetics Service |
Schuch J.B.,Centro Universitario Feevale |
Voigt F.,Centro Universitario Feevale |
And 3 more authors.
Nutrition, Metabolism and Cardiovascular Diseases | Year: 2011
Background and aims: Hypertriglyceridemia is an important independent risk factor for coronary artery diseases and is determined by a wide range of factors, both genetic and exogenous. The A5 apolipoprotein, which is associated with the synthesis and removal of triglycerides (TG), is encoded by the APOA5 gene. One of the polymorphisms of this gene that has been the focus of a large number of studies, and which appears to be associated with increased TG, is S19W (rs 3135506). In this study, we examined the influence of this single nucleotide polymorphism (SNP) on TG levels of a sample of southern Brazilians. Methods and results: Samples obtained from 567 people of European descent were genotyped; interactions between this variant and anthropometric variables were analyzed, and the effects of lifestyle, sex, menopause, and variations of the APOE gene were evaluated. We found that the 19W allele is associated with increased TG (p = 0.025) and that this influence was modulated by sex (p = 0.003), menopause (p = 0.022) and the presence of the E*4 allele (p = 0.027). Conclusion: Our data showed, for the first time, the importance and magnitude of the influence of the S19W variant in a southern Brazilian population. © 2010 Elsevier B.V.
Effects of 2,4-D on the germination of megaspores and initial development of Regnellidium diphyllum Lindman (Monilophyta, Marsileaceae) [Efeitos do 2,4-D sobre a germinação de megásporos e o desenvolvimento inicial de Regnellidium diphyllum Lindman (Monilophyta, Marsileaceae)]
Cassanego M.B.B.,University of the Rio dos Sinos Valley |
Droste A.,Centro Universitario Feevale |
Windisch P.G.,Federal University of Rio Grande do Sul
Brazilian Journal of Biology | Year: 2010
Regnellidium diphyllum is considered as endangered, occurring in the State of Rio Grande do Sul, Brazil, and a few adjoining localities in Uruguay, Argentina and the State of Santa Catarina. It grows in wetlands frequently altered for agricultural activities. Herbicides based on 2,4-dichlorophenoxyacetic acid (2,4-D) are widely used in these fields. The effects of 2,4-D on the germination of megaspores and initial sporophytic development of R. diphyllum were investigated. Six concentrations of 2,4-D (0.32; 0.64; 1.92; 4.80; 9.60 and 19.20 mg.L-1), and the control (0.00 mg.L-1), were tested in vitro, using Meyer's medium. Cultures were maintained in a growth chamber at 24 ± 1 °C, under artificial light with nominal irradiance of 110 μmol.m-2/s and 16 hours photoperiod. Megaspore germination was lower at 9.60 and 19.20 mg.L-1 of 2,4-D (56 and 48%, respectively), compared with the control (68%). Herbicide concentrations of up to 1.92 mg.L-1 did not significantly decrease the number of sporophytes formed. At 19.20 mg.L-1, no sporophytes were formed. The lengths of the primary root, primary and secondary leaves were greater at concentrations of 0.32 and 0.64 mg.L-1 of 2,4-D. Low concentrations of 2,4-D do not affect germination rates and initial development of R. diphyllum in a significant way. However, higher concentrations (9.60 and 19.20 mg.L-1) affect substantially the germination of the megaspores and interfere with the establishment of the species.
Barcellos L.J.G.,University Of Passo Fundo |
Marqueze A.,Unilassale Centro Universitario Lassalle |
Trapp M.,Centro Universitario Feevale |
Quevedo R.M.,University Of Passo Fundo |
Ferreira D.,Federal University of Santa Maria
Aquaculture | Year: 2010
Both in nature and in aquaculture, fishes could experience periods of food deprivation or starvation. The hormonal regulation of metabolism in fishes is a complex process that involves several factors, including cortisol. Data about the effects of fasting on cortisol level were inconsistent, from no effect of starvation to a decrease or increase in cortisol level in fasted fish. Because of these highly variable results, it is not safe to speculate about the effects of fasting on cortisol levels in Rhamdia quelen. Thus, the present work aimed to elucidate the role of cortisol in controlling metabolism during fasting periods. Jundiás were distributed in five experimental groups. The first group was considered as the control and was fed normally. Jundiás of the second group were fasted for a 1-day period and then re-fed and those in the third group were fasted for 7 days and then re-fed. The fourth group was fasted for a 14-day period and then re-fed. The fifth batch was fasted for 21 days and then re-fed. Fasting periods of 7, 14, and 21 days significantly increased plasma cortisol levels compared with the control, with a return to basal level after 4 days of re-feeding. Blood glucose values remained unchanged during fasting with a low nonsignificant variation. At the end of the 7-, 14-, and 21-day fasting period, liver glycogen content was depleted, but 2 days after re-feeding, liver glycogen increased with values ranging from 1.1 to 3.5 times those of control concentrations. In contrast, no starvation effect was verified in the muscle glycogen. In conclusion, the variation in cortisol levels within treatment is suggestive of a functional role in control of intermediary metabolism during fasting in R. quelen. The early and large depletion of liver glycogen in fasted fish also suggests that this is a primary energy source in periods of food restriction. © 2010 Elsevier B.V. All rights reserved.
Molina G.C.,University of Santiago de Chile |
Cayo C.H.,University of Santiago de Chile |
Cayo C.H.,Federal University of Rio Grande do Sul |
Rodrigues M.A.S.,Centro Universitario Feevale |
Bernardes A.M.,Federal University of Rio Grande do Sul
Minerals Engineering | Year: 2013
This paper presents the results obtained by different oxidative processes when an aqueous solution containing sodium isopropyl xanthate is treated; this reagent is used in the flotation of copper minerals. The advanced oxidation processes used are UV photolysis, direct electrolysis and photoelectrooxidation. The solutions used containing sodium isopropyl xanthate were adjusted to the following concentrations: 6, 8, 10, 25 and 40 mg L-1. The results show that the three oxidation processes proved to be suitable for the destruction of xanthate, with the following maximum destruction efficiencies: 76% for electrolysis, 95% for UV photolysis and 99% for photoelectrooxidation. © 2012 Elsevier Ltd. All rights reserved.