RESUMEN
Thousands of tons of residual lignocellulosic biomass are produced and discarded by agroindustries in the Amazon. These biomasses could be harnessed and used in the preparation of activated carbon, in view of the growing demand for this product with high added value, however, little is known about their characteristics, in addition to their potential as precursors of activated carbon. Therefore, the aim of this work was to evaluate the potential of four different biomasses in the preparation and quality of activated carbon. Residues from the processing of the fruits of acai, babassu, Brazil nut, and oil palm were collected, characterized, carbonized, physically activated with CO2, and characterized. The contents of the total extractives, insoluble lignin, minerals, holocellulose, and elemental (CHNS-O) were analyzed. The surface area and surface morphology were determined from the AC produced, and adsorption tests for methylene blue and phenol were performed. The four biomasses showed potential for use in the preparation of CA; the residues presented high contents of lignin (21.83-55.76%) and carbon (46.49-53.79%). AC were predominantly microporous, although small mesopores could be observed. The AC had a surface area of 569.65-1101.26 m2 g-1, a high methylene blue (93-390 mg g-1), and phenol (159-595 mg g-1) adsorption capacities. Babassu-AC stood out compared to the AC of the other analyzed biomasses, reaching the best results.
RESUMEN
The specificity of activated carbon (AC) can be targeted by pretreatment of the precursors and/or activation conditions. Piassava (Leopoldinia piassaba and Attalea funifera Martius) are fibrous palms used to make brushes, and other products. Consolidated harvest and production residues provide economic feasibility for producing AC, a value-added product from forest and industrial residues. Corona electrical discharge and extraction pretreatments prior to AC activation were investigated to determine benefits from residue pretreatment. The resulting AC samples were characterized using elemental analyses and FTIR and tested for efficacy using methylene blue and phenol. All resulting AC had good adsorbent properties. Extraction as a pretreatment improved functionality in AC properties over Corona electrical discharge pretreatment. Due to higher lignin content, AC from L. piassaba had better properties than that from A. funifera.
RESUMEN
This paper provides proof of concept that activated carbon (AC) may be readily produced using limited conversion methods and resources from sawdust of massaranduba (Manilkara huberi) wood, thereby obtaining value-added products. Sawdust was sieved and heat-treated in an oxygen-free muffle furnace at 500 °C to produce charcoal. The charcoal was activated in a tubular electric furnace at 850 °C while being purged with CO2 gas. Microstructural, thermal and physical properties of the three components: sawdust, charcoal and AC were compared by means of field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), density and water adsorption/desorption measurements. The resulting AC had a large surface area as measured by Brunauer-Emmett-Teller (BET) comparable to other such values found in the literature. The large surface area was due to pore development at the microstructural level as shown by FESEM. XRD illustrated that sawdust had a semi-crystalline structure whereas charcoal and AC evidenced mostly amorphous structures. TGA and DSC showed that AC had high reactivity to moisture compared to sawdust and charcoal.
RESUMEN
o Transtorno do espectro do autismo (TEA) é marcado por prejuízos nas áreas de interação social, comunicação, comportamento e processamento sensorial. Aspectos relacionados a prejuízos no repertório de interação social, bem como estratégias para torná-la mais adequada têm sido amplamente estudados. Dentre estas estratégias, as que utilizam música têm recebido atenção. O presente estudo tem como objetivo investigar os benefícios da educação musical ao desenvolvimento da interação social de crianças com seus pares, focando-se na qualidade e na frequência da apresentação de tais comportamentos. Participaram duas crianças com TEA, com idades de cinco e seis anos, em aulas de percussão em grupo. Os instrumentos utilizados foram a Ficha de dados sociodemográficos e de desenvolvimento, para traçar os perfis dos participantes; e o Protocolo de observação de comportamentos de crianças com TEA com seus pares, para a análise comportamental, durante oito aulas/percussão (240 minutos). Os resultados sugerem que ambos apresentaram tendência ao aumento de iniciativas e respostas espontâneas e à diminuição de comportamentos não funcionais. Verificou-se a ocorrência do uso de estereotipias para tentativas de/e interações, embora esporadicamente. Destacaram-se os papéis do contexto, dos perfis das crianças, e do manejo comportamental por adultos, na promoção de interações.
The Autism Spectrum Disorder (ASD) is characterized by impairments in the areas of social interaction, communication, behavior and sensory processing. Aspects related to difficulties in social interaction repertoire, as well as strategies to help them behave more adequately have been widely studied. Among these strategies, those using music have received attention. The present study aims to investigate the benefits of music education to the social interaction of children with ASD, with their peers, focusing on both the quality and frequency of these behaviors. Two ASD children, aged 5 and 6 years respectively, who attended a percussion class group, participated in the study. The Demographics and Development information enabled the children´s profiles to be drawn. The social interaction behaviors were coded using a Behavioral Observation Protocol during 8 sessions (240 minutes). The results suggest that both tended to increase initiatives and spontaneous responses and to decrease non-functional behaviors as the sessions progressed. It was found that stereotypies were used by the ASD children when attempting to interact with others, albeit sporadically. The role of context, of the children's profile and of adult behavioral management of children in promoting interactions was highlighted.
RESUMEN
The apparently dormant breast cancer micrometastases in haemopoietic marrow are correlated with distant metastatic carcinoma dissemination. We studied in vitro interactions of carcinoma cells with adjacent stromata, using connective tissue cell cultures from breast and bone marrow samples of normal donors, comparing them to the pericancerous breast tissue and bone marrows of 12 selected patients with invasive breast carcinomas. Cancer cells were detected by immunocytochemistry and RT-PCR in all the bone marrows and in most blood samples of the studied patients. We monitored the growth and interaction of carcinoma MCF-7 cells with the stromata. The normal breast stroma sustained typical massive cancer growth. The pericancerous breast stroma induced the invasive mesenchymal pattern of growth. Normal bone marrow stroma induced the same conversion and was highly adhesive, retaining the cells in the stroma, but carcinoma patients' bone marrow stromata underwent low adhesive interactions with cancer cells, releasing them potentially into the circulation. The semi-quantitative RT-PCR indicated an enhanced expression of the hepatocyte growth factor and its receptor c-met in breast and bone marrow stromata of cancer patients. The input of cancer cells into the normal bone marrow may induce modifications of the local microenvironment, favourable for growth and release of carcinoma cells into the systemic circulation, which correlate with the poor prognosis of patients with bone marrow micrometastases.