Rheology of Suspensions of TEMPO-Oxidised and Cationic Cellulose Nanofibrils-The Effect of Chemical Pre-Treatment.

Cellulose nanofibrils (CNFs) are particles with a high aspect ratio. Typically, chemically pre-treated CNFs (containing anionic or cationic charged groups) consist of long fibrils (up to 2 µm) with very low thickness (less than 10 nm). Derived from their high aspect ratio, CNFs form strong hydrogels with high elasticity at low concentrations. Thus, CNF suspensions appear as an interesting rheology modifier to be applied in cosmetics, paints, foods, and as a mineral suspending agent, among other applications. The high viscosity results from the strong 3D fibril network, which is related to the good fibrillation of the material, allowing the nanofibrils to overlap. The overlap concentration (c*) was found to vary from ca. 0.13 to ca. 0.60 wt.% depending on the type and intensity of the pre-treatment applied during the preparation of the CNFs. The results confirm the higher tendency for the fibres treated with (3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC) and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) to form a 3D network, resulting in the lowest c*. For the TEMPO-oxidised CNF suspensions, it was also found that aggregation is improved at acidic pH conditions due to lower charge repulsion among fibrils, leading to an increase in the suspension viscosity as well as higher apparent yield stresses. TEMPO CNF suspensions with a low content of carboxylic groups tend to precipitate at moderately acidic pH values.

Eco-Friendly Methods for Extraction and Modification of Cellulose: An Overview.

Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na2S, and water, to break loose fibers. In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose's use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.

Anionic bio-flocculants from sugarcane for purification of sucrose: An application of circular bioeconomy.

In sugar production, polyacrylamide-based anionic flocculants are added for juice treatment, the main objective being to remove impurities that affect the quality of the sugar. However, if they remain in the final product, those polymers can present carcinogenic and neurotoxic actions besides contaminating the soils where the waste is discharged. To overcome this problem, the present study proposes, for the first time, natural flocculants based on cellulose obtained from sugarcane bagasse (residue from sugarcane processing) as substitutes for the flocculants based on polyacrylamide, normally used in sugar cane juice purification. Additionally, cellulose-based flocculants obtained from Acacia wood, developed in a previous study, have also been tested for sugar juice treatment. Acacia wood and sugarcane bagasse were first treated with a choline chloride/levulinic acid solution in a molar ratio of 1:2, at 160 °C, for 4 h. Subsequently, the cellulose-rich samples were modified by a two-stage process (oxidation with sodium periodate followed by reaction with sodium metabisulfite), and polyelectrolytes with different characteristics were produced. The final products obtained were characterized, and their performance in the treatment of sugarcane juice, at different concentrations (10, 50, 100, 250, and 500 mg kg-1), was evaluated and compared to the synthetic commercial flocculant (Flonex, based on polyacrylamide) usually used by the sugarcane industry in Brazil. The substitution of petrol-based flocculants by natural-based ones, obtained from sugarcane residues, is presented for the first time in this study, with very relevant performance of the new flocculants. Overall, it was possible to produce anionic flocculants, modifying the cellulose obtained from different raw materials, which showed good results in the purification of sucrose, when compared with the commercial polyacrylamide normally used. It is also important to stress that, for the first time, a residue from sugarcane industry could be used with success in the purification of the sugar juice itself, which constitutes a major novelty.

Acacia Wood Fractionation Using Deep Eutectic Solvents: Extraction, Recovery, and Characterization of the Different Fractions.

The selective extraction and recovery of different lignocellulosic molecules of interest from forestry residues is increasing every day not only to satisfy the needs of driving a society toward more sustainable approaches and materials (rethinking waste as a valuable resource) but also because lignocellulosic molecules have several applications. For this purpose, the development of new sustainable and ecologically benign extraction approaches has grown significantly. Deep eutectic solvents (DESs) appear as a promising alternative for the processing and manipulation of biomass. In the present study, a DES formed using choline chloride and levulinic acid (ChCl:LA) was studied to fractionate lignocellulosic residues of acacia wood (Acacia dealbata Link), an invasive species in Portugal. Different parameters, such as temperature and extraction time, were optimized to enhance the yield and purity of recovered cellulose and lignin fractions. DESs containing LA were found to be promising solvent systems, as the hydrogen bond donor was considered relevant in relation to lignin extraction and cellulose concentration. On the other hand, the increase in temperature and extraction time increases the amount of extracted material from biomass but affects the purity of lignin. The most promising DES system, ChCl:LA in a ratio of 1:3, was found to not significantly depolymerize the extracted lignin, which presented a similar molecular weight to a kraft lignin. Additionally, the 31P NMR results revealed that the extracted lignin has a high content of phenolic OH groups, which favor its reactivity. A mixture of ChCl:LA may be considered a fully renewable solvent, and the formed DES presents good potential to fractionate wood residues.

Extraction and Characterization of Microplastics from Portuguese Industrial Effluents.

Microplastics (MPs) are contaminants present in the environment. The current study evaluates the contribution of different well-established industrial sectors in Portugal regarding their release of MPs and potential contamination of the aquifers. For each type of industry, samples were collected from wastewater treatment plants (WWTP), and different parameters were evaluated, such as the potential contamination sources, the concentration, and the composition of the MPs, in both the incoming and outcoming effluents. The procedures to extract and identify MPs in the streams entering or leaving the WWTPs were optimized. All industrial effluents analysed were found to contribute to the increase of MPs in the environment. However, the paint and pharmaceutical activities were the ones showing higher impact. Contrary to many reports, the textile industry contribution to aquifers contamination was not found to be particularly relevant. Its main impact is suggested to come from the numerous washing cycles that textiles suffer during their lifetime, which is expected to strongly contribute to a continuous release of MPs. The predominant chemical composition of the isolated MPs was found to be polyethylene terephthalate (PET). In 2020, the global need for PET was 27 million tons and by 2030, global PET demand is expected to be 42 million tons. Awareness campaigns are recommended to mitigate MPs release to the environment and its potential negative impact on ecosystems and biodiversity.

Lignin Extraction from Waste Pine Sawdust Using a Biomass Derived Binary Solvent System.

Lignocellulosic biomass fractionation is typically performed using methods that are somehow harsh to the environment, such as in the case of kraft pulping. In recent years, the development of new sustainable and environmentally friendly alternatives has grown significantly. Among the developed systems, bio-based solvents emerge as promising alternatives for biomass processing. Therefore, in the present work, the bio-based and renewable chemicals, levulinic acid (LA) and formic acid (FA), were combined to fractionate lignocellulosic waste (i.e., maritime pine sawdust) and isolate lignin. Different parameters, such as LA:FA ratio, temperature, and extraction time, were optimized to boost the yield and purity of extracted lignin. The LA:FA ratio was found to be crucial regarding the superior lignin extraction from the waste biomass. Moreover, the increase in temperature and extraction time enhances the amount of extracted residue but compromises the lignin purity and reduces its molecular weight. The electron microscopy images revealed that biomass samples suffer significant structural and morphological changes, which further suggests the suitability of the newly developed bio-fractionation process. The same was concluded by the FTIR analysis, in which no remaining lignin was detected in the cellulose-rich fraction. Overall, the novel combination of bio-sourced FA and LA has shown to be a very promising system for lignin extraction with high purity from biomass waste, thus contributing to extend the opportunities of lignin manipulation and valorization into novel added-value biomaterials.

New deep eutectic solvent assisted extraction of highly pure lignin from maritime pine sawdust (Pinus pinaster Ait.).

Lignocellulosic biomass is a renewable and sustainable feedstock, mainly composed of cellulose, hemicellulose, and lignin. Lignin, as the most abundant natural aromatic polymer occurring on Earth, has great potential to produce value-added products. However, the isolation of highly pure lignin from biomass requires the use of efficient methods during lignocellulose fractionation. Therefore, in this work, novel acidic deep eutectic solvents (DESs) were prepared, characterized and screened for lignin extraction from maritime pine wood (Pinus pinaster Ait.) sawdust. The use of cosolvents and the development of new DES were also evaluated regarding their extraction and selectivity performance. The results show that an 1 h extraction process at 175 °C, using a novel DES composed of lactic acid, tartaric acid and choline chloride, named Lact:Tart:ChCl, in a molar ratio of 4:1:1, allows the recovery of 95 wt% of the total lignin present in pine biomass with a purity of 89 wt%. Such superior extraction of lignin with remarkable purity using a "green" solvent system makes this process highly appealing for future large-scale applications.

Microplastics in Ecosystems: From Current Trends to Bio-Based Removal Strategies.

Plastics are widely used due to their excellent properties, inexpensiveness and versatility leading to an exponential consumption growth during the last decades. However, most plastic does not biodegrade in any meaningful sense; it can exist for hundreds of years. Only a small percentage of plastic waste is recycled, the rest being dumped in landfills, incinerated or simply not collected. Waste-water treatment plants can only minimize the problem by trapping plastic particles of larger size and some smaller ones remain within oxidation ponds or sewage sludge, but a large amount of microplastics still contaminate water streams and marine systems. Thus, it is clear that in order to tackle this potential ecological disaster, new strategies are necessary. This review aims at briefly introducing the microplastics threat and critically discusses emerging technologies, which are capable to efficiently clean aqueous media. Special focus is given to novel greener approaches based on lignocellulose flocculants and other biomaterials. In the final part of the present review, it was given a proof of concept, using a bioflocculant to remove micronized plastic from aqueous medium. The obtained results demonstrate the huge potential of these biopolymers to clean waters from the microplastics threat, using flocculants with appropriate structure.

Brief Overview on Bio-Based Adhesives and Sealants.

Adhesives and sealants (AS) are materials with excellent properties, versatility, and simple curing mechanisms, being widely used in different areas ranging from the construction to the medical sectors. Due to the fast-growing demand for petroleum-based products and the consequent negative environmental impact, there is an increasing need to develop novel and more sustainable sources to obtain raw materials (monomers). This reality is particularly relevant for AS industries, which are generally dependent on non-sustainable fossil raw materials. In this respect, biopolymers, such as cellulose, starch, lignin, or proteins, emerge as important alternatives. Nevertheless, substantial improvements and developments are still required in order to simplify the synthetic routes, as well as to improve the biopolymer stability and performance of these new bio-based AS formulations. This environmentally friendly strategy will hopefully lead to the future partial or even total replacement of non-renewable petroleum-based feedstock. In this brief overview, the general features of typical AS are reviewed and critically discussed regarding their drawbacks and advantages. Moreover, the challenges faced by novel and more ecological alternatives, in particular lignocellulose-based solutions, are highlighted.

Educação em Enfermagem: conceituando projeto pedagógico na visão de professores / Nursing Education: conceptualizing a pedagogical project from the view of professors

Resumo Objetivo Apreender o conceito de Projeto Pedagógico dos professores da Escola Paulista de Enfermagem e identificar os desafios e os limites enfrentados por eles durante sua elaboração. Métodos Estudo qualitativo, na modalidade História Oral Temática. Por meio de entrevistas semiestruturadas obtiveram-se as narrativas de seis professores que participaram de, no mínimo, metade dos encontros para essa construção. Os depoimentos foram gravados, transcritos, transcriados e analisados, respeitando-se as etapas do método e os preceitos éticos. Foi utilizada a Teoria de Mundo Social de Pierre Bourdieu como referencial de análise. Resultados O conceito de Projeto Pedagógico ficou circunscrito à grade curricular e a formação docente é a principal dificuldade para a mudança de paradigma na ação do planejamento. Conclusão Os docentes valorizam a elaboração do Projeto Pedagógico, mas não avançam na proposição porque estão fixados em modelos anteriores que privilegiam a carga horária e a organização por disciplinas.

Abstract Objective To understand the pedagogical project concept of the professors of the Paulista School of Nursing, and to identify the challenges and the limits faced by them during its development. Methods Qualitative study, in the oral history thematic modality. Using semi-structured interviews, the narratives of six professors who participated in, at least, half of the meetings for the pedagogical development were obtained. The statements were recorded, interpreted text transcribed, recreated and analyzed, respecting the methodological steps and ethical precepts. The Social World Theory of Pierre Bourdieu was used as a reference for analysis. Results The concept of the pedagogical project was limited to the curriculum frameworks; training of the professors is the main difficulty for the planning phase of the paradigmatic change. Conclusion Professors value the pedagogical project development, but do not advance the proposition because they are steeped in previous models that support workload and organization according to specialty.

Effect of ethyleneoxide groups of anionic surfactants on lipase activity.

The use of enzymes in laundry and dish detergent products is growing. Such tendency implies dedicated studies to understand surfactant-enzyme interactions. The interactions between surfactants and enzymes and their impact on the catalytic efficiency represent a central problem and were here evaluated using circular dichroism, dynamic light scattering, and enzyme activity determinations. This work focuses on this key issue by evaluating the role of the ethyleneoxide (EO) groups of anionic surfactants on the structure and activity of a commercial lipase, and by focusing on the protein/surfactant interactions at a molecular level. The conformational changes and enzymatic activity of the protein were evaluated in the presence of sodium dodecyl sulfate (SDS also denoted as SLE0 S) and of sodium lauryl ether sulfate with two EO units (SLE2 S). The results strongly suggest that the presence of EO units in the surfactant polar headgroup determines the stability and the activity of the enzyme. While SDS promotes enzyme denaturation and consequent loss of activity, SLE2 S preserves the enzyme structure and activity. The data further highlights that the electrostatic interactions among the protein groups are changed by the presence of the adsorbed anionic surfactants being such absorption mainly driven by hydrophobic interactions. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1276-1282, 2016.

Imagem / Imagem

Bombeiro, 31 anos, relata ter calçado bota pela manhã e trabalhado por aproximadamente 12 horas seguidas. Ao final desse período, começou a sentir dor progressivamente mais forte, em queimação, no pé direito. Ao retirar a bota e a meia, observou a lesão mostrada na imagem.

Percepção de graduandos de enfermagem sobre sua qualidade de vida / Perceptions of nursing students on their quality of life

OBJETIVO: Conhecer a percepção de graduandos de Enfermagem sobre sua qualidade de vida. MÉTODOS: Estudo transversal realizado na Escola Paulista de Enfermagem da Universidade Federal do Estado de São Paulo/Brasil. Amostra constituída de 178 graduandos. Para a obtenção dos dados, utilizou-se o instrumento genérico WHOQOL-bref. Os grupos de interesse foram submetidos aos testes de normalidade de Kolmogorov-Smirnov e o t de Students. RESULTADOS: Os graduandos consideravam sua qualidade de vida boa e estavam satisfeitos com sua saúde. Na análise, o escore médio encontrou resultado maior para o domínio das relações sociais e o menor para o físico. Os alunos da primeira série, apresentou qualidade de vida menor do que os da segunda em todos os domínios e estes maior do que os da terceira no domínio físico e maior que a quarta no domínio meio ambiente. CONCLUSÃO: os graduandos merecem atenção nos aspectos da qualidade de vida sobretudo nos aspectos físicos e os alunos da primeira série devem ser acompanhados.

OBJECTIVE: To know the perception of nursing students on their quality of life. METHODS: A cross-sectional study in São Paulo School of Nursing, Federal University of São Paulo / Brazil. The sample consisted of 178 undergraduates. To obtain the data, we used the generic instrument WHOQOL-brief. Interest groups were tested for normality using Kolmogorov-Smirnov and student t-test. RESULTS: The students considered their quality of life good and were satisfied with their health. The analysis found the highest average score occurred in the domain of social relationships and the lowest was in the physical domain. The students in their first year of courses had a lower quality of life than those in their second, across all domains; they were higher in the physical domain than those in their third year; and were higher than those in their fourth year in terms of the environmental domain. CONCLUSION: the students deserve attention on aspects of quality of life, especially on the physical aspects and students in their first courses must be followed.

OBJETIVO: Conocer la percepción de graduandos de Enfermería sobre su calidad de vida. MÉTODOS: Estudio transversal realizado en la Escuela Paulista de Enfermería de la Universidad Federal del Estado de Sao Paulo/Brasil. Muestra constituída por 178 graduandos. Para la obtención de los datos, se utilizó el instrumento genérico WHOQOL-bref. Los grupos de interés fueron sometidos a los test de normalidad de Kolmogorov-Smirnov y el t de Students. RESULTADOS: Los graduandos consideraban su calidad de vida bueno y estaban satisfechos con su salud. En el análisis, el escor medio encontró el mayor resultado para el dominio de las relaciones sociales y el menor para el físico. Los alumnos de la primera serie, presentaron calidad de vida menor que los de la segunda en todos los dominios y éstos mayor que los de la tercera en el dominio físico y mayor que la cuarta en el dominio medio ambiente. CONCLUSIÓN: los graduandos merecen atención en los aspectos de la calidad de vida sobre todo en los aspectos físicos y los alumnos de la primera serie deben ser acompañados.

Do topo da montanha temos um ótimo ângulo de visão das coisas... mas será que podemos ver tudo? Uma visão sobre as políticas públicas para educação da infância / From the top of a moutain we can see things from a great angle, but we can see everything? A reflection on public policies for children education

O atendimento à criança de 0 a 6 anos, no Brasil, existe há mais de um século e com ele acompanharam-se as transformações do conceito de infância, instituídas pelos discursos científicos e institucionais, que acabaram por transformar a criança em um sujeito/objeto cultural, inserido em um amplo projeto de constituição do sujeito moderno. Compreender as políticas públicas para a educação da infância implica refletir sobre o que é ser criança, hoje, em nossa sociedade, e ver o modo como as alterações nesse conceito passam a definir, orientar e ressignificar práticas de atenção, criação, socialização e educação, para que aquela corresponda ao desenvolvimento do projeto da sociedade moderna. Com essa análise tentamos clarear as intenções que nortearam as tomadas de decisões em relação à educação infantil, destacando sobretudo a perspectiva neoliberal, discernindo a lógica, a dinâmica viva e até contraditória das políticas públicas para a educação da infância brasileira (AU)

Brazilian government has provided assistance for children of 0 to 6 years of age for over one hundred years now – this happened alongside many changes in the concept of childhood. Scientific and institutional thoughts and mass means of communication to transform childhood into a cultural subject/object of modernity have influenced such changes. To comprehend public policies is also to reflect on “what it is to be a child” today in our society, and how changes in the concept of childhood have defined educational practices as well as socialization of children for modern society. Through this analysis we have tried to clarify some of the intentions that influenced children education – especially neo-liberal thoughts. We have also proposed to discern the logic, living dynamic and even the contradiction of public policies of the education of the Brazilian childhood. (AU)

Do topo da montanha temos um ótimo ângulo de visão das coisas... mas será que podemos ver tudo? Uma visão sobre as políticas públicas para educação da infância / From the top of a moutain we can see things from a great angle, but we can see everything? A reflection on public policies for children education

O atendimento à criança de 0 a 6 anos, no Brasil, existe há mais de um século e com ele acompanharam-se as transformações do conceito de infância, instituídas pelos discursos científicos e institucionais, que acabaram por transformar a criança em um sujeito/objeto cultural, inserido em um amplo projeto de constituição do sujeito moderno. Compreender as políticas públicas para a educação da infância implica refletir sobre o que é ser criança, hoje, em nossa sociedade, e ver o modo como as alterações nesse conceito passam a definir, orientar e ressignificar práticas de atenção, criação, socialização e educação, para que aquela corresponda ao desenvolvimento do projeto da sociedade moderna. Com essa análise tentamos clarear as intenções que nortearam as tomadas de decisões em relação à educação infantil, destacando sobretudo a perspectiva neoliberal, discernindo a lógica, a dinâmica viva e até contraditória das políticas públicas para a educação da infância brasileira.

Método dialético: uma construção possível na pesquisa em educação na infância? / Dialetic method: a possible construction for research into education in the childhood

Este trabalho objetiva enunciar algumas reflexões pontuais no campo da pesquisa sobre as práticas educativas utilizadas na educação da infância, enfatizando questões pertinentes ao método de pesquisa. Toma, então, como objeto de sua análise, estudos e investigações já concluídos ou em andamento procurando apreender a constituição de possibilidades de orientação dialética. Têm-se em vista a construção de novos olhares sobre o processo investigativo, a partir dos quais seja possível redimensionar não somente as análises como os próprios objetos pesquisados. Considera-se que a reflexão metodológica é uma condição necessária para a (re)criação de paradigmas teórico-epistemológicos que possibilitem interpretar o dinamismo do movimento e das interconexões que compõem aqueles objetos. A superação da pesquisa assentada em processos fossilizados que não consegue apreender a inversão da realidade – estabelecida no processo de representação sobre as relações de produção, as relações sociais e o próprio conhecimento – apresenta-se como um grande desafio para que a educação da infância seja, cada vez mais, objeto de múltiplos olhares, configurando um trabalho em zonas fronteiriças do conhecimento. Tal perspectiva é uma exigência do próprio método dialético(AU)

The current work intends to enunciate some valuable reflections concerning researches into educational practices used in the education in the childhood, emphasizing research method issues. It takes ongoing or concluded studies and investigations as the object of analysis for new possibilities of dialect orientation. It looks for a renew in the investigative process to redefine not only the analysis, but also the subjects of research. It is considered that methodologic reflections are essential to re(create) theorical epistemological paradigms that make possible the understanding of the dinamic of movments and interconections that compose that object. The challenge is now to overcome researches which were set in fossilized process that can’t apprehend reverse reality – established in the process of representation over productionrelations, social relation and knowledge itself – and this is in order to bring multiple sights onto education in the childhood, and then comprise a work made in frontiers of knowledge. Such a perspective is a requirement of the dialect method itself. (AU)

Método dialético: uma construção possível na pesquisa em educação da infância? / Dialetic method: a possible construction for research into education in the childhood

Este trabalho objetiva enunciar algumas reflexões pontuais no campo da pesquisa sobre as práticas educativas utilizadas na educação da infância, enfatizando questões pertinentes ao método de pesquisa. Toma, então, como objeto de sua análise, estudos e investigações já concluídos ou em andamento procurando apreender a constituição de possibilidades de orientação dialética. Têm-se em vista a construção de novos olhares sobre o processo investigativo, a partir dos quais seja possível redimensionar não somente as análises como os próprios objetos pesquisados. Considera-se que a reflexão metodológica é uma condição necessária para a (re)criação de paradigmas teórico-epistemológicos que possibilitem interpretar o dinamismo do movimento e das interconexões que compõem aqueles objetos. A superação da pesquisa assentada em processos fossilizados que não consegue apreender a inversão da realidade – estabelecida no processo de representação sobre as relações de produção, as relações sociais e o próprio conhecimento – apresenta-se como um grande desafio para que a educação da infância seja, cada vez mais, objeto de múltiplos olhares, configurando um trabalho em zonas fronteiriças do conhecimento. Tal perspectiva é uma exigência do próprio método dialético.