Preparation of modified clay with cetylpyridinium chloride and evaluation of their interaction with PVC [Preparação de argila modificada com cloreto de cetilpiridíneo e avaliação da interação desta com o PVC]
Resende D.K.,Federal University of Rio de Janeiro |
Dornelas C.B.,Federal University of Rio de Janeiro |
Tavares M.I.B.,Federal University of Rio de Janeiro |
Gomes A.S.,Federal University of Rio de Janeiro |
And 3 more authors.
Polimeros | Year: 2010
A modified silicate with cetylpyridinium was prepared from sodium clay with cation exchange in solution. The amount of modification agent for clay and the reaction time were evaluated. The materials produced were characterized using X ray diffraction (XRD), termogravimetric analysis (TGA) and low field nuclear magnetic resonance (NMR). The formation of new organic clay was confirmed, which was introduced in PVC for the formation of nanocomposites. The beginning of degradation of the new clay occurred at temperatures higher than commonly used in the processing of PVC. The nanocomposites were partially exfoliated and partially intercalated. Source
Batista M.C.P.,University of Brasilia |
de Fatima Duarte E.,HUB |
de Fatima Duarte E.,McGill University |
dos Reis Borba M.D.,University of Brasilia |
And 13 more authors.
Gene | Year: 2014
Introduction: Polycystic Ovary Syndrome (PCOS) is a complex endocrine disorder, of multifactorial etiology, which affects 6-10% of women of reproductive age. It is considered the leading cause of anovulatory infertility, menstrual disorders and hyperandrogenism in this population. The genetic basis of PCOS is still largely unknown despite significant family clustering; determining its mode of inheritance is particularly difficult given the heterogenic presentation of the disease. Materials and methods: 130 Brazilian women, aged 14-42. years, who met the 2003 Rotterdam criteria for PCOS diagnosis, were included, and 96 healthy women constituted the control group. Presence of hirsutism was classified using the modified Ferriman-Gallwey score (F-G score) as absent (≤. 7), mild (8-14), and severe (≥. 15). Blood levels of luteinizing hormone (LH), total testosterone (TT), dehydroepiandrosterone sulfate (DHEA-S) and androstenedione were determined. The coding region of the luteinizing hormone beta-subunit (LHB) gene was amplified and sequenced. Differences in allelic and genotypic frequency distribution of each polymorphism across controls and cases were estimated by the Mantel-Haenszel chi-square or Fisher's exact test (p. <. 0.05), and the probability of an association between the detection of a polymorphism and presence of a diagnosis of PCOS, by logistic regression. Result(s): Sequencing detected 8 polymorphisms in the LHB gene coding region. Two polymorphisms in linkage disequilibrium were significantly more prevalent in the presence of hyperandrogenemia: rs1800447/rs34349826 (Trp28Arg/Ile35Thr) (p. = 0.02). Conclusion(s): In this series, a modulatory effect of LHB polymorphisms on hyperandrogenemia phenotype of PCOS was observed; however, this finding needs to be replicated in other populations. © 2014 Elsevier B.V. Source
Barros C.D.,Federal University of Pernambuco |
Amato A.A.,Laboratorio Of Farmacologia Molecular |
Oliveira T.B.d.,Federal University of Pernambuco |
Iannini K.B.R.,Laboratorio Of Farmacologia Molecular |
And 8 more authors.
Bioorganic and Medicinal Chemistry | Year: 2010
Eight new 5-arylidene-3-benzyl-thiazolidine-2,4-diones with halide groups on their benzyl rings were synthesized and assayed in vivo to investigate their anti-inflammatory activities. These compounds showed considerable biological efficacy when compared to rosiglitazone, a potent and well-known agonist of PPARγ, which was used as a reference drug. This suggests that the substituted 5-arylidene and 3-benzylidene groups play important roles in the anti-inflammatory properties of this class of compounds. Docking studies with these compounds indicated that they exhibit specific interactions with key residues located in the site of the PPARγ structure, which corroborates the hypothesis that these molecules are potential ligands of PPARγ. In addition, competition binding assays showed that four of these compounds bound directly to the ligand-binding domain of PPARγ, with reduced affinity when compared to rosiglitazone. An important trend was observed between the docking scores and the anti-inflammatory activities of this set of molecules. The analysis of the docking results, which takes into account the hydrophilic and hydrophobic interactions between the ligands and the target, explained why the 3-(2-bromo-benzyl)-5-(4-methanesulfonyl-benzylidene)-thiazolidine-2,4-di one compound had the best activity and the best docking score. Almost all of the stronger hydrophilic interactions occurred between the substituted 5-arylidene group of this compound and the residues of the binding site. © 2010 Elsevier Ltd. All rights reserved. Source