Preparação de catalisadores para reações de esterificação do ácido oleico baseados em matrizes polímericas sulfonadas POLI(1- FENILETILENO) (PS) e POLI(1-CLOROETILENO) (PVC)

Chemical modification of polymer matrices is an alternative way to change its surface properties. The introduction of sulfonic acid groups in polymer matrices alter properties such as adhesion, wettability, biocampatibility, catalytic activity, among others. This paper describes the preparation of polymeric solid acid based on the chemical modification of poly (1-fenietileno) (PS) and Poly (1-chloroethylene) (PVC) by the introduction of sulfonic acid groups and the application of these polymers as catalysts in the esterification reaction of oleic acid with methanol. The modified materials were characterized by Infrared Spectroscopy, Elemental Analysis and titration acid-base of the acid groups. All techniques confirmed the chemical changes and the presence of sulfur associated with sulfonic acid groups or sulfates. The modified polymers excellent performance in the esterification reaction of oleic acid with methanol a degree of conversion higher than 90% for all investigated polymers (modified PS and PVC (5% w / w)), with a mass ratio of oleic acid: methanol 1:10 to 100 ° C. The best performance was observed for the modified PVC catalyst (PVCS) which showed low degree of swelling during the reactions is recovered by filtration different from that observed for polystyrene sulfonate (PSS). Given these facts, the PVCS was employed as a catalyst in the esterification reaction of oleic acid in different times and different temperatures to obtain the kinetic parameters of the reaction. Experimental data show a great fit for pseudo-homogeneous model of second order and activation energy value of 41.12 kJ mol -1, below that found in the literature for the uncatalyzed reaction, 68.65 kJ mol -1 .The PVCS exhibits good catalytic activity for 3 times of reuse, with a slight decrease in the third cycle, but with a conversion of about 78%. The results show that solid polymeric acid has good chemical stability for the application in esterification reaction of commercial importance with possible application in the biodiesel production. The advantages in use of this system are the increased reaction rate at about 150 times, at these test conditions, the replacement of sulfuric acid as a catalyst for this being the most corrosive and the possibility of reuse of the polymer for several cycles.

Tratamento tópico para xerostomia pós-radioterapia para câncer de cabeça e pescoço – Revisão Sistemática

The purpose of this systematic review was to compare the effectiveness of topical treatments to minimize post-radiotherapy xerostomia. PubMed, Cochrane Library (CENTRAL) and LILACS databases were searched without restriction on date or language until the 6thAugust, 2015. Key-wordsused for searching were radiotherapy, xerostomia and saliva. Two independent reviewers screened titles and abstracts, carried out data extraction and assessed risk of bias. The first search identified 429 articles. From these, 117 studies were selected for full-text reading, from which 18 were included in the qualitative synthesis. From the eighteen articles included, seven were non- controlled clinical trial, one article was controlled clinical trial and ten studies were randomized clinical trials (three clinical trials were placebo controlled and seven were crossover). By the assessment of the quality of the studies included, ten showed high risk of bias, four showed moderate risk of bias and four presented low risk of bias. All interventions were considered effective in treating xerostomia (mucin, polysaccharides, aloe vera, rape oil, linseed oil, carboxymethylcellulose, polyethylene oxide, pilocarpine and systems of care for xerostomia - gel, paste and mouthwash). Meta-analysis could not be performed due to heterogeneity between thestudiesand interventions. This systematic review showed that a single and general protocol for topical treatment of xerostomia post-radiotherapy does not exist and that follow-up visits should be performed to validate the individualized treatment plan.

Uma leitura de gênero nos contos "Prelúdio", "Na baía" e "A casa de bonecas", de Katherine Mansfield

This work aims to analyze the short stories “Prelude”, “At the Bay” and “The Doll’s House”, by Katherine Mansfield under the prism of the gender studies (mainly on the works of Joan Scott and Elisabeth Badinter). To reach such objective, and based on the feminist criticism works (especially those of Elaine Showalter and Toril Moi), we analyzed the three stories, which are from the writer’s so-called “family phase”. The present work contains a bibliographical contextualization of Mansfield’s modernist work under three main aspects: modernism, the short story and women’s writing/writings on women. From the analysis of the three short stories, we observed that questions of gender, representation and identity were depicted by means of the preponderance of female characters from all ages, marital statuses and classes. At the end it was possible to verify how Mansfield works contributed to a reflection about places and roles occupied by women in turn of the XIX and XX Centuries, whereas how this author was also in search for her own identity as a woman and as a writer, exactly in a context when women writers and women’s writings started to become more visible face to a predominantly masculine literary canon.

História, literatura e cinema: um debate sobre a historicidade das imagens dos piratas e da pirataria

We seek, through this work, to understand the construction of the pirates’ images from the Golden Age of Piracy (late seventeenth through early eighteenth century) through the observation of the circulation of these images, which are not limited to one field of knowledge. We take into account the importance of the book “A General History of the robberies and murders of the most notorious pirates...” written by Charles Johnson for these constructions, not only literary, but also historiographical provided that the stories of pirates and piracy gained ground in historiography from the twentieth century on. We also seek to show that this historiographical space arises opposed to an apparent historiographical silence about these stories that lasts for about two centuries, related to a new way of writing history in the aesthetic regime, where it arises as a science through a poetics of knowledge, of which the philosopher Jacques Rancière helps us reflect. Lastly, reflecting upon how these images of pirates circulate nowadays, we seek to understand the historicity of the pirates’ images within that aesthetic regime based on some scenes of the film series Pirates of the Caribbean by Disney™.