515 research outputs found
Como as crianças estão se apropriando das Tecnologias Digitais na Primeira Infância?
O avanço tecnológico e o impulsionamento de ferramentas como a internet móvel, touchscreen, wireless, a facilidade de acesso e manipulação tem possibilitado que o manuseio o com auxÃlio destes dispositivos seja cada vez mais fácil e intuitivo. Diante deste novo paradigma, estar atento à forma com que as tecnologias estão sendo utilizadas pelas crianças, e como elas vêm percebendo este mundo digital se faz necessário. Nesse contexto, o presente artigo descreve um pesquisa de tese que foi realizada junto ao Programa de Pós Graduação em Informática na Educação, na Universidade Federal do Rio Grande do Sul que buscou investigar como as crianças de 7 meses a 7 anos de idade estão se apropriando das tecnologias digitais, bem como percebem os atrativos oferecidos por elas. Apresenta uma introdução, contextualização sobre o uso das tecnologias digitais por crianças na primeira infância, a metodologia utilizada para o desenvolvimento da pesquisa, as observações e interações realizadas com os sujeitos da pesquisa e por fim, os resultados obtidos
A construção do pensamento formal pelo adolescente em Ambiente Virtual
O presente artigo trata do desenvolvimento da lógica e da construção do pensamento formal pelo adolescente em Ambiente Virtual. Neste sentido, são apresentadas caracterÃsticas inerentes ao desenvolvimento da lógica e do pensamento formal pelo adolescente diante do contexto do mundo real e do uso de materiais concretos, posteriormente é realizada uma explanação de como o pensamento formal pode ser promovido em Ambientes Virtuais com a exploração de jogos, softwares, aplicativos e realidade aumentada. Para finalizar, é apresentado um estudo de caso em que uma mesa de bilhar digital é explorada visando constatar a aquisição da noção da igualdade dos ângulos pelo adolescente, como estes conceitos são percebidos e as considerações finais
A review on the valorization of lignin from sugarcane by-products: from extraction to application
The sugarcane industry generates several by-products including the harvest residue (straw) and the fibrous fraction following juice extraction (bagasse). The conversion of sugarcane industry by-products into value-added products is of paramount importance from a sustainable circular economy perspective. Also, the increase of second-generation bioethanol production has triggered the development of approaches to convert residues into functional bioproducts thus increasing the overall sustainability of the process. Lignin is the major biopolymer in nature, and one of the three main components of sugarcane bagasse (SCB) and straw (SCS) biomasses. Due to the potential of lignin as natural antioxidant, antimicrobial, and ultraviolet protector, lignin-based research and new product development have significantly increased. Therefore, this review aims at updating the progress on the valorization of SCS and SCB, and emphasizing their main potential bioactivities and applications, thus serving as a valuable reference material for the academy and industry. A brief introduction of the sugarcane and sugar industry in terms of by-products generation and current end-uses is presented. Recent research studies on SCB and SCS delignification techniques, lignin purification/separation and the main physical-chemical differences between SCS and SCB are covered. The most reported biological activities for sugarcane lignin and their potential applications in the cosmetic and materials fields are also detailed in this review.info:eu-repo/semantics/publishedVersio
Sugarcane bagasse as source of bioactive lignin: influence of pretreatment on the antioxidant and antibacterial activities
Sugarcane industry generates several by-products of particular interest in the context of a circular economy, due to their potential as a source of value-added ingredients. Bagasse is one of the main by-products, consisting of a fibrous fraction obtained after juice extraction. Sugarcane bagasse is composed of cellulose, hemicellulose, and lignin, with lower amounts of extractives and ash (del RÃo et al., 2015). Lignin is one of the most abundant renewable resources on earth and recognized as a profitable source of high value compounds. The main functions attributed to lignin in the plant are elasticity and mechanical strength. It is a complex aromatic macromolecule formed by the dehydrogenative polymerization of three phenylpropanoid monomers coniferyl, synapyl, and p-coumaryl alcohols. The antimicrobial activity of lignin is related to plant sources and attributed to the phenolic components, particularly the side-chain structure and its functional groups (Chauhan, 2020). The antioxidant activity of lignin is mainly attributed to the scavenging action of their phenolic structures on oxygen-containing reactive free radicals. For the antioxidant activity of the lignin, free phenolic hydroxyl groups and ortho-methoxy substitution in aromatic rings are essential. The structural characteristics of lignin depend on several factors including the botanical origin, and environmental growth and extraction conditions. The main objective of this work was to study the potential of lignin from sugarcane bagasse as antimicrobial and antioxidant agent and assess the influence of two different pretreatments - deep eutectic solvents and organosolv – on the biological potential.info:eu-repo/semantics/publishedVersio
Interplay between the salience and the default mode network in a social-cognitive task toward a close other
Social cognition relies on two main subsystems to construct the understanding of others, which are sustained by different social brain networks. One of these social networks is the default mode network (DMN) associated with the socio-cognitive subsystem (i.e., mentalizing), and the other is the salience network (SN) associated with the socio-affective route (i.e., empathy). The DMN and the SN are well-known resting state networks that seem to constitute a baseline for the performance of social tasks. We aimed to investigate both networks' functional connectivity (FC) pattern in the transition from resting state to social task performance. A sample of 38 participants involved in a monogamous romantic relationship completed a questionnaire of dyadic empathy and underwent an fMRI protocol that included a resting state acquisition followed by a task in which subjects watched emotional videos of their romantic partner and elaborated on their partner's (Other condition) or on their own experience (Self condition). Independent component and ROI-to-ROI correlation analysis were used to assess alterations in task-independent (Rest condition) and task-dependent (Self and Other conditions) FC. We found that the spatial FC maps of the DMN and SN evidenced the traditional regions associated with these networks in the three conditions. Anterior and posterior DMN regions exhibited increased FC during the social task performance compared to resting state. The Other condition revealed a more limited SN's connectivity in comparison to the Self and Rest conditions. The results revealed an interplay between the main nodes of the DMN and the core regions of the SN, particularly evident in the Self and Other conditions.info:eu-repo/semantics/publishedVersio
Valorization of lignin from sugarcane by-products: review
The valorization of sugarcane industry by-products is fundamental to increase competitiveness on a circular economy point of view. Straw and bagasse are by-products with huge potential as source of added value ingredients. Lignin is an abundant component found in these by-products with proved biological activity, particularly antimicrobial, antioxidant and UV protection. Additionally, recent applications on materials have been reported for lignin-based products.info:eu-repo/semantics/publishedVersio
High value-added lignin extracts from sugarcane by-products
This study evaluates the production of lignin bioactive extracts from sugarcane bagasse (SCB) and straw (SCS) alkaline black liquors using greener precipitating agents (methane sulfonic acid (MSA), formic acid (FA) and lactic acid (LA)) as replacers of sulfuric acid (SA), the most common one used in industry. Results showed that the highest precipitation yield was achieved by LA when applied to SCB (14.5 g extract/g SCB). Lignin SCB extracts were similar in composition in terms of total carbohydrates (61–70 %), lignin (22–30 %) and inorganics (1.6–2.6 %). Regarding the SCS extracts, similar yields were obtained among all extracts, however; differences in composition were observed between SA and greener precipitating agents, particularly in terms of sugar content. All extracts exhibited radical scavenging activity; overall the extracts were more effective in the scavenging of ABTS radical. FA was the most promising alternative to SA to recover lignin bioactive extracts. This work suggests organic acids as good candidates for obtaining valuable extracts from alkaline pulping of SCB and SCS instead of the conventional sulfuric acid, thus suggesting a green solution for this biomass valorization.info:eu-repo/semantics/publishedVersio
Effect of chitosan and Aloe Vera extract concentrations on the physicochemical properties of chitosan biofilms
Chitosan films have been extensively studied as dressings in formulations for the treatment of chronic wounds. The incorporation of aloe vera (Aloe barbadensis Miller) into chitosan dressings could potentialize the healing process since aloe vera shows several pharmacological activities. This work aimed to evaluate the effect of aloe vera and chitosan concentrations on the physicochemical properties of the developed films. The films were obtained by casting technique and characterized with respect to their color parameters, morphology, barrier and mechanical properties, and thermal analysis. Results showed that the presence of aloe vera modified the films color parameters, changed barrier properties, increased fluid handling capacity (FHC), and decreased water-vapor permeability (WVP). The reduced elongation at break resulted in more rigid films. Aloe vera concentration did not significantly change film properties, but the presence of this gel increased the films stability at temperatures below 200 °C, showing similar behavior as chitosan films above 400 °C. The results suggest a crosslinking/complexation between chitosan and aloe vera, which combine appropriate physicochemical properties for application as wound dressing materials.This work was supported by São Paulo Research Foundation (FAPESP) (2010/17.721-4), Portuguese Science and Technology Foundation (FCT) through the projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund) funded by national funds, and co-financed Education (FCT/MEC) from national funds and FEDER, under the Partnership Agreement PT202info:eu-repo/semantics/publishedVersio
Genotoxicity assessment of metal-based nanocomposites applied in drug delivery
Nanocomposites as drug delivery systems (e.g., metal nanoparticles) are being exploited for several applications in the biomedical field, from therapeutics to diagnostics. Green nanocomposites stand for nanoparticles of biocompatible, biodegradable and non-toxic profiles. When using metal nanoparticles for drug delivery, the question of how hazardous these virus-sized particles can be is posed, due to their nanometer size range with enhanced reactivity compared to their respective bulk counterparts. These structures exhibit a high risk of being internalized by cells and interacting with the genetic material, with the possibility of inducing DNA damage. The Comet Assay, or Single-Cell Gel Electrophoresis (SCGE), stands out for its capacity to detect DNA strand breaks in eukaryotic cells. It has huge potential in the genotoxicity assessment of nanoparticles and respective cells interactions. In this review, the Comet assay is described, discussing several examples of its application in the genotoxicity evaluation of nanoparticles commonly administered in a set of routes (oral, skin, inhaled, ocular and parenteral administration). In the nanoparticles boom era, where guidelines for their evaluation are still very limited, it is urgent to ensure their safety, alongside their quality and efficacy. Comet assay or SCGE can be considered an essential tool and a reliable source to achieve a better nanotoxicology assessment of metal nanoparticles used in drug delivery.This work was funded by the Portuguese Science and Technology Foundation (FCT) from
the Ministry of Science and Technology (MCTES), through the projects UIDB/04469/2020 (CEB
strategic fund) and UIDB/04033/2020 (CITAB), co-funded by European Funds
(PRODER/COMPETE) and FEDER, under the Partnership Agreement PT2020. The work was also
supported by the National Science Centre within the MINIATURA 4 for single research activity
(grant No: 2020/04/X/ST5/00789) and by the START 2021 Program of the Foundation for Polish
Science (FNP) granted to Dr. Aleksandra Zielińskainfo:eu-repo/semantics/publishedVersio
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