Dyes adsorption from aqueous solutions by Chitosan

In this study the ability of chitosan to remove acid, basic, reactive and direct dyestuffs by adsorption was studied. The effect of several factors influencing dye adsorption such as dye concentration, grain size, pH and temperature were investigated. Desorption of dyes at different pH was also examined. It was shown that the adsorption capacities of chitosan were comparatively high for acid and direct dyes and that the adsorption was controlled by the acidity of the solution. The kinetics of adsorption were found to be of pseudo second order. Batch isotherm studies showed that adsorption of dyes from aqueous solution by chitosan was described by the Langmuir equation

Amino-functionalized poly(l-lactide) lamellar single crystals as a valuable substrate for delivery of HPV16-E7 tumor antigen in vaccine development

Background: Poly(L-lactide) (PLLA) is a biodegradable polymer currently used in many biomedical applications, including the production of resorbable surgical devices, porous scaffolds for tissue engineering, nanoparticles and microparticles for the controlled release of drugs or antigens. The surfaces of lamellar PLLA single crystals (PLLAsc) were provided with amino groups by reaction with a multifunctional amine and used to adsorb an Escherichia coli-produced human papillomavirus (HPV)16-E7 protein to evaluate its possible use in antigen delivery for vaccine development. Methods: PLLA single crystals were made to react with tetraethylenepentamine to obtain amino-functionalized PLLA single crystals (APLLAsc). Pristine and amino-functionalized PLLAsc showed a two-dimensional microsized and one-dimensional nanosized lamellar morphology, with a lateral dimension of about 15–20 µm, a thickness of about 12 nm, and a surface specific area of about 130 m2/g. Both particles were characterized and loaded with HPV16-E7 before being administered to C57BL/6 mice for immunogenicity studies. The E7-specific humoral-mediated and cell-mediated immune response as well as tumor protective immunity were analyzed in mice challenged with TC-1 cancer cells. Results: Pristine and amino-functionalized PLLAsc adsorbed similar amounts of E7 protein, but in protein-release experiments E7-PLLAsc released a higher amount of protein than E7-APLLAsc. When the complexes were dried for observation by scanning electron microscopy, both samples showed a compact layer, but E7-APLLAsc showed greater roughness than E7-PLLAsc. Immunization experiments in mice showed that E7-APLLAsc induced a stronger E7-specific immune response when compared with E7-PLLAsc. Immunoglobulin G isotyping and interferon gamma analysis suggested a mixed Th1/Th2 immune response in both E7-PLLAsc-immunized and E7-APLLAsc-immunized mice. However, only the mice receiving E7-APLLAsc were fully protected from TC-1 tumor growth after three doses of vaccine. Conclusion: Our results show that APLLA single crystals improve the immunogenicity of HPV16-E7 and indicate that E7-APLLAsc could be used for development of an HPV16 therapeutic vaccine against HPV16-related tumors

Intermolecular interaction and solid state characterization of abietic acid/chitosan solid dispersions possessing antimicrobial and antioxidant properties

The aim of this work was to prepare and characterize solid dispersions of abietic acid (AB) and chitosan (CS) to investigate how formulation of the mixture may help in the battle against microbial colonization in different areas, such as the biomedical field or the food industry. Solid dispersions were characterized by differential scanning calorimetry, infrared spectroscopy, Raman spectroscopy, polarized optical microscopy, zeta potential and size analysis. The data showed that the dispersion/solvent evaporation method formed solid dispersions in which abietic acid was molecularly dispersed in the carrier. A synergistic effect between the two components in terms of antioxidant and antimicrobial properties was found, especially in the formulations obtained with 1/1 AB/CS molar ratio. Interestingly, the aggregation state (amorphous/crystalline) of AB seemed to affect the antimicrobial activity of the formulation, suggesting increased bioactivity when the drug was in the amorphous state. These findings, together with the demonstrated biocompatibility of the formulations, seem to open promising perspectives for a successful application of the developed AB/CS formulations in the biomedical field or in the food industry

Epithelium-Off Corneal Collagen Cross-linking Versus Transepithelial Cross-linking for Pediatric Keratoconus.

Abstract PURPOSE:: To compare efficiency and safety of epithelium-off corneal cross-linking (CXL) and transepithelial cross-linking (TE-CXL) in pediatric patients with progressive keratoconus. METHODS:: Uncorrected and corrected visual acuity, corneal topography and pachymetry (Pentacam; Oculus Pentacam), and in vivo confocal microscopy (HRT II, Rostock Cornea Module, Heidelberg Engineering, Heidelberg, Germany) were evaluated at baseline and at 3, 6, and 12 months. RESULTS:: In the epithelium-off CXL group (19 patients, 23 eyes; mean age, 14.75 ± 2.1 years), a significant improvement at month 12 was present for Kmax [-1.11 diopters (D), P = 0.01], Kmin (-3.2 D, P = 0.001), mean K (-1.47 D, P = 0.01), surface asymmetry index (-0.64 D, P = 0.001), inferior-superior symmetry index (-0.54 D, P = 0.01), index of height asymmetry (-2.97, P = 0.03), and anterior elevation at the thinnest location (-2.82 D, P = 0.01) and at the apex (-2.27 D, P = 0.01). Postoperative corneal edema lasted 3 months in 16 eyes (69.5%) and more than 6 months in 2 eyes (8.7%). In the TE-CXL group (10 patients, 14 eyes; mean age, 15 ± 4.2 years), a significant improvement at month 12 was present for Kmax (-1.14 D, P = 0.02), Kmin (-2.04 D, P = 0.01), mean K (-1.63 D, P = 0.01), surface asymmetry index (-0.86 D, P = 0.001), inferior-superior symmetry index (-0.55 D, P = 0.001), index of height asymmetry (-2.95, P = 0.01), and anterior elevation at the thinnest location (-2.96 D, P = 0.01) and at the apex (-2.19 D, P = 0.01). No postoperative corneal edema after TE-CXL was observed. Changes at month 12 from baseline were not significantly different between the 2 groups (P > 0.05). TE-CXE was significantly less painful than epithelium-off CXL. CONCLUSIONS:: In pediatric patients with progressive keratoconus, TE-CXL was less painful, provided similar effectiveness and fewer complications than epithelium-off CXL at 12-month follow-up

The analysis of European lacquer : optimization of thermochemolysis temperature of natural resins

In order to optimize chromatographic analysis of European lacquer, thermochemolysis temperature was evaluated for the analysis of natural resins. Five main ingredients of lacquer were studied: sandarac, mastic, colophony, Manila copal and Congo copal. For each, five temperature programs were tested: four fixed temperatures (350, 480, 550, 650 degrees C) and one ultrafast thermal desorption (UFD), in which the temperature rises from 350 to 660 degrees C in 1 min. In total, the integrated signals of 27 molecules, partially characterizing the five resins, were monitored to compare the different methods. A compromise between detection of compounds released at low temperatures and compounds formed at high temperatures was searched. 650 degrees C is too high for both groups, 350 degrees C is best for the first, and 550 degrees C for the second. Fixed temperatures of 480 degrees C or UFD proved to be a consensus in order to detect most marker molecules. UFD was slightly better for the molecules released at low temperatures, while 480 degrees C showed best compounds formed at high temperatures

o estranho caso do "Cidadão Quinlan"

Em "Touch of Evil", Orson Welles, diretor e ator, dá vida a um personagem e a um enredo onde elementos de crítica social se entrelaçam em busca de respostas para o enigma de vidas "marcadas pela maldade". A trama, aparentemente apenas mais um exemplo do duelo mortal entre "bandido e mocinho", tão recorrente na cinematografia hollywoodiana, desenvolve-se numa atmosfera estranha e misteriosa, onde situações improváveis e personagens inusitados compõem imagens, ora grotescas, ora dramáticas, da condição humana degradada. O espectador encontra aí a mesma intrigante ambigüidade presente em outros fUmes de Welles, como "Cidadão Kane" (1941) e "Grilhões do passado" (1955), onde o abuso do poder e da riqueza associa-se a um destino trágico de solidão e de morte. O cineasta parece oscilar permanentemente entre a vontade política e pedagógica de denunciar e "punir" os maus e o impulso irresistível de desvendar a história íntima dos personagens, trazendo à tona o segredo de suas vidas. Sob este aspecto, a história é para o espectador um "fio de Ariadne", chamando-o a penetrar, atrás da divisão estereotipada entre bem e mal, os motivos ocultos que levam indivíduos sensíveis e íntegros ao crime e à corrupção. A tensão entre estes dois enfoques contribui para criar efeitos desconcertantes na obra de Welles, onde múltiplos sentidos se cruzam impossibilitando qualquer leitura linear. Em "Touch of Evil", o bom e o mau, empenhados num combate sem trégua, são construídos por um contraste berrante na caracterização visual, na ação, no discurso; no entanto, além deste contraste, responsável pela dinâmica da história, pode-se perceber um lastro comum entre eles, a ponto de um parecer apenas a imagem antitética do outro, como Dorian Gray e seu retrato

Rousseau And Condorcet: Public Education Versus State Education

O artigo buscou explorar as ideias de pensadores iluministas - sobretudo Condorcet e Rousseau - no que diz respeito às relações entre processo civilizatório, liberdade, igualdade e democratização do saber. Na elaboração de Condorcet, o papel social e político da educação é iluminado pelo nexo estabelecido por esses pensadores entre a realização da "comunidade dos livres e iguais" e a apropriação universal do conhecimento. Daí sua preocupação em criar condições para que a instrução seja instrumento de democratização do poder, evitando o monopólio do recrutamento, responsável pela ossificação de correntes doutrinárias e pela estratificação de privilégios corporativos. O pensamento de Rousseau, com seus elementos passadistas e pessimistas, é sublinhado para mostrar outro lado dessa questão. E talvez nos ajude a pensar esses temas em nossos tempos, em que se pode observar "a derrota e o progressivo desaparecimento de modelos societários mais cooperativos em favor da consolidação de agregados conflitivos, em que os indivíduos mais fortes organizam o todo de forma vantajosa para si".3713533734

From necessity to freedom: a note on Diderot and Condorcet's proposals for higher education

Along the XVIIIth century prompted by their quest for a fairer, freer and more egalitarian society, the men of the Enlightenment got involved in spreading scientific and cultivated knowledge among the masses. They thought these, once enlightened about their own capacities and interests, could autonomously partake in the economical, political and social life of their nations. Focusing on the relationships between the highest and lowest degrees of education, this paper explores the proposals Diderot, then director of the Encyclopedia, and Condorcet, then a member of the Legislative Assembly of the Revolutionary France, respectively elaborated for a universal, free public education. The renewal of the traditional contents to privilege the studies of arts and sciences, which may be applied to practical life, and the implementation of didactics that, albeit simplifying its language, would preserve the rigor the theoretical knowledge both reveal the range and limits of this universal access formally guaranteed to common men. Scrutinizing the educational ideas that stake out the course of public education shows a gap between the liberal conceptualization of promotion through merit and the democratizing vocation, which aims at a social coexistence built upon the free intertwining of people's talents, knowledge and tastes.Movidos pela busca de uma sociedade mais justa, livre e igualitária, os homens das Luzes, ao longo do século XVIII, engajaram-se em alastrar o saber científico e cultivado entre as massas populares, para que estas, esclarecidas a respeito de suas próprias capacidades e interesses, pudessem participar, com autonomia, da vida econômica, política e cultural das nações. Este artigo examina as propostas para uma educação pública, gratuita e universal, elaboradas respectivamente por Diderot, diretor da Enciclopédia, e Condorcet, membro da Assembléia legislativa na França revolucionária, focalizando as relações entre os degraus superiores e mais elementares do ensino. A renovação dos conteúdos tradicionais, privilegiando o estudo das ciências e artes, aplicáveis à vida prática, e a implementação de uma didática que preserva o rigor do saber teórico simplificando sua linguagem, evidencia os alcances e limites do acesso universal formalmente garantido aos homens comuns. O exame dos ideais educacionais que norteiam o percurso da instrução pública indica um descompasso entre a conceituação liberal da ascensão pelo mérito e a vocação democratizante, que tem em perspectiva uma convivência social erguida sobre o livre entrelaçamento entre talentos, saberes, gostos dos indivíduos.65567

Rousseau E Condorcet: Educação Pública Versus Educação Estatal

This paper explores the ideas of Enlightenment thinkers — especially Condorcet and Rousseau — as to relations between the civilizing process, freedom, equality and democratization of knowledge. According to Condorcet, the social and political role of education is lead by the link established by these thinkers between the realization of the “community of the free and equal” and universal appropriation of knowledge. Hence his concern to create conditions to make instruction a tool for power democratization, avoiding the monopoly of recruitment, which is responsible for the fossilization of doctrinal currents and stratification of corporate privileges. The thought of Rousseau, his “passive” and pessimistic elements are emphasized to show the other side of this issue. And maybe help us think about these matters in our times, when one can observe “the defeat and gradual disappearance of more cooperative corporate models in favor of the consolidation of conflictive aggregates where the strongest individuals organize everything as best suit them”. © 2016, Centro de Estudos Educacao e Sociedade - CEDES. All rights reserved.3713533734

Robert Owen em New Lanark: Umlaboratório do futuro?

Este artigo examina a proposta pedagógica implementada por Robert Owen em New Lanark, a partir das concepções antropológicas e da filosofia da história a ela subjacentes, tendo como fonte os textos onde o famoso "socialista utópico" trata dos meios e formas de transição para uma sociedade racional e cooperativa. Tal análise tem por objetivo mostrar que o entrelaçamento entre uma visão antropológica otimista e um diagnóstico sombrio do processo civilizatório constitui a base para a ênfase na necessidade de uma "revolução das mentes", a ser operada por um programa educativo integral iniciado nos primeiríssimos anos de vida. Nesta perspectiva, a autora identifica na educação o principal instrumento - alternativo à luta social- para a construção da utopia oweniana.Abstract:This article looks into a pedagogic proposal implemented by Robert Owen in New Lanark, from the under1ying anthropologic conceptions to philosophy of history taking as a source texts in which the famous "utopic socialist" treats the means and patterns of transition to a rational and cooperative society. The goal of this analysis is to show that the intertwining of an optimistic anthropologic view with a gloomy diagnosis of the civilization process makes up the basis to the emphasis in the necessity of a "minds revolution", to be performed by an integrated educational program started in the very ear1y years of life. Through this perspective , the author identifies in education the main instrument- alternative to the social struggle - to the construction of the Owenian utopia.Decriptors: Order. Nature. History. Education. Science. Cooperatio