Investigação de hemicelulose catiônica - sintetizada a partir do resíduo agroindustrial casca de amendoim - como coagulante natural no tratamento de efluente industrial de laticínio

Trabalho de Conclusão de Curso (Graduação)A produção agroindustrial destaca-se como uma das principais atividades econômicas do país por visar a produção de alimentos, fibras, entre outros produtos essenciais para a sociedade. Recentemente, uma das preocupações do setor é a geração de resíduos, no entanto, a maior parte dos seus resíduos é considerada um recurso para agregação de valor onde a biorrefinaria se estabelece. Neste contexto, o resíduo constituído de biomassa lignocelulósica (abundante no setor) é composto pelas principais frações poliméricas: lignina, hemicelulose e celulose. Dessa forma, o objetivo principal desta pesquisa foi a partir da casca de amendoim (resíduo agroindustrial) extrair e cationizar a hemicelulose para aplicação como coagulante natural no tratamento de efluente sintético de laticínio tendo como métodos de separação sólido-líquido comparativo a sedimentação e flotação por ar dissolvido (FAD). Ademais, foi confrontada a eficiência apresentada pela HC com um coagulante comercial estabelecido na literatura, o Tanfloc SG (TSG), um polímero composto por tanino catiônico adquirido da empresa TANAC Brasil S/A. Inicialmente foi realizado a síntese da HC, pela reação de eterificação em meio alcalino com cloreto de 2,3-epoxi-propil-trimetil-amônio (ETA). A caracterização do material obtido foi realizada por espectroscopia de infravermelho por transformada de Fourier (FTIR), análise elementar (AE) e grau de substituição (GS). Os coagulantes (TSG e HC) foram testados por meio ensaios de jar test, variando o pH de coagulação de 4 a 11 e em dosagens de 50 a 500 ppm. Os ensaios geraram diagramas de coagulação pelo método de interpolação espacial de modelo regressão Kringing. A análise da morfologia dos flocos foi realizada por meio da aplicação do método não intrusivo de captura de imagens e obtido a distribuição do tamanho de partículas (DTP) e dimensão fractal (Df). Quanto à caracterização da HC foi observado aumento da intensidade da banda de grupamentos metila (-CH3), em 1480 cm-1, um forte indicativo da cationização. A análise elementar resultou num GS de 0,38 (±0,05), próximo aos dados da literatura. A condição com melhor desempenho no tratamento físico-químico de efluente sintético de laticínio para a sedimentação, foi de 100 ppm para o TSG em pH 8, enquanto para a HC foi 50 ppm em pH 11, as eficiências de remoção de turbidez, cor verdadeira e demanda química de oxigênio, para o TSG/HC foram, respectivamente: 96.31% / 84.74%, 92.58% / 98.75% e 84.53% / 99.89%. Quanto a morfologia dos flocos, para a HC a alteração de dosagem pouco alterou a distribuição do tamanho de partículas, mantendo-se uniforme, enquanto para o TSG a variação das dosagens resultou em diferentes DTP. Em relação a Df, o TSG apresentou pequena variação entre as dosagens, de 1,72 a 1,86, enquanto para HC houve maior variação do Df entre as dosagens sendo de 1,58 a 1,83 quando comparado ao TSG, deste modo, comprovou-se a formação de flocos menores e menos densos para HC com diâmetros de 0,022mm 1,20 mm, justificando a sedimentação mais lenta e flocos em dispersão, enquanto para TSG obteve-se 0,022 a 3,28 mm mais propensos a sedimentação. A condição de melhor desempenho no tratamento físico-químico de efluente sintético de laticínio para flotação por ar dissolvido, permaneceu nas mesmas condições de dosagem e pH para ambos os coagulantes, assim como apresentado na sedimentação. As eficiências de remoção de turbidez, cor verdadeira e demanda química de oxigênio, para o TSG/HC foram, respectivamente: 98,69 / 87,48%, 98,75% / 99.37% e 87,46% / 93.38%, deste modo, sugere-se a aplicação da FAD como método de separação sólido-líquido por oferecer grandes vantagens operacionais como redução do tempo de operação e espaço na planta de tratamento de efluentes industriais

Genomic history of coastal societies from eastern South America

Sambaqui (shellmound) societies are among the most intriguing archaeological phenomena in pre-colonial South America, extending from approximately 8,000 to 1,000 years before present (yr bp) across 3,000 km on the Atlantic coast. However, little is known about their connection to early Holocene hunter-gatherers, how this may have contributed to different historical pathways and the processes through which late Holocene ceramists came to rule the coast shortly before European contact. To contribute to our understanding of the population history of indigenous societies on the eastern coast of South America, we produced genome-wide data from 34 ancient individuals as early as 10,000 yr bp from four different regions in Brazil. Early Holocene hunter-gatherers were found to lack shared genetic drift among themselves and with later populations from eastern South America, suggesting that they derived from a common radiation and did not contribute substantially to later coastal groups. Our analyses show genetic heterogeneity among contemporaneous Sambaqui groups from the southeastern and southern Brazilian coast, contrary to the similarity expressed in the archaeological record. The complex history of intercultural contact between inland horticulturists and coastal populations becomes genetically evident during the final horizon of Sambaqui societies, from around 2,200 yr bp, corroborating evidence of cultural change

Streptococcus pyogenes Causing Skin and Soft Tissue Infections Are Enriched in the Recently Emerged emm89 Clade 3 and Are Not Associated With Abrogation of CovRS

Although skin and soft tissue infections (SSTI) are the most common focal infections associated with invasive disease caused by Streptococcus pyogenes (Lancefield Group A streptococci - GAS), there is scarce information on the characteristics of isolates recovered from SSTI in temperate-climate regions. In this study, 320 GAS isolated from SSTI in Portugal were characterized by multiple typing methods and tested for antimicrobial susceptibility and SpeB activity. The covRS and ropB genes of isolates with no detectable SpeB activity were sequenced. The antimicrobial susceptibility profile was similar to that of previously characterized isolates from invasive infections (iGAS), presenting a decreasing trend in macrolide resistance. However, the clonal composition of SSTI between 2005 and 2009 was significantly different from that of contemporary iGAS. Overall, iGAS were associated with emm1 and emm3, while SSTI were associated with emm89, the dominant emm type among SSTI (19%). Within emm89, SSTI were only significantly associated with isolates lacking the hasABC locus, suggesting that the recently emerged emm89 clade 3 may have an increased potential to cause SSTI. Reflecting these associations between emm type and disease presentation, there were also differences in the distribution of emm clusters, sequence types, and superantigen gene profiles between SSTI and iGAS. According to the predicted ability of each emm cluster to interact with host proteins, iGAS were associated with the ability to bind fibrinogen and albumin, whereas SSTI isolates were associated with the ability to bind C4BP, IgA, and IgG. SpeB activity was absent in 79 isolates (25%), in line with the proportion previously observed among iGAS. Null covS and ropB alleles (predicted to eliminate protein function) were detected in 10 (3%) and 12 (4%) isolates, corresponding to an underrepresentation of mutations impairing CovRS function in SSTI relative to iGAS. Overall, these results indicate that the isolates responsible for SSTI are genetically distinct from those recovered from normally sterile sites, supporting a role for mutations impairing CovRS activity specifically in invasive infection and suggesting that this role relies on a differential regulation of other virulence factors besides SpeB

Divulgação científica e o projeto momento ciência

O projeto Momento Ciência tem como propósito tornar o conhecimento cientifico acessível, promovendo a divulgação científica através do contato direto de alunos de ensino médio de escolas públicas do Distrito Federal e alunos recém aprovados, calouros, nos cursos de Ciências Biológicas e de Biotecnologia na Universidade de Brasília (UnB). Esse contato com a comunidade científica ocorre por meio de visitas aos laboratórios acadêmicos do Instituto de Ciências Biológicas (IB) da Universidade de Brasília. O projeto obteve resultados positivos e esperados ao longo da sua execução

Streptococcus canis Are a Single Population Infecting Multiple Animal Hosts Despite the Diversity of the Universally Present M-Like Protein SCM

Streptococcus canis is an animal pathogen which occasionally causes infections in humans. The S. canis M-like protein (SCM) encoded by the scm gene, is its best characterized virulence factor but previous studies suggested it could be absent in a substantial fraction of isolates. We studied the distribution and variability of the scm gene in 188 S. canis isolates recovered from companion animals (n = 152), wild animal species (n = 20), and humans (n = 14). Multilocus sequence typing, including the first characterization of wildlife isolates, showed that the same lineages are present in all animal hosts, raising the possibility of extensive circulation between species. Whole-genome analysis revealed that emm-like genes found previously in S. canis correspond to divergent scm genes, indicating that what was previously believed to correspond to two genes is in fact the same scm locus. We designed primers allowing for the first time the successful amplification of the scm gene in all isolates. Analysis of the scm sequences identified 12 distinct types, which could be divided into two clusters: group I (76%, n = 142) and group II (24%, n = 46) sharing little sequence similarity. The predicted group I SCM showed extensive similarity with each other outside of the N-terminal hypervariable region and a conserved IgG binding domain. This domain was absent from group II SCM variants found in isolates previously thought to lack the scm gene, which also showed greater amino acid variability. Further studies are necessary to elucidate the possible host interacting partners of the group II SCM variants and their role in virulence

Investigation of new natural coagulant - cationic hemicellulose associated with cationic tannin - for coagulation/dissolved air flotation (C/DAF) in the treatment of industrial effluent

The use of plant-based coagulants (natural coagulants) in wastewater treatments has potential advantages over the inorganic coagulants used commercially. This study evaluated organic coagulants cationic hemicelluloses (CH) synthesized from peanut shell and associated with commercial cationic tannin (TSG) for use as the primary coagulation/flocculation treatment, followed by solid-liquid separation via sedimentation/flotation by dissolved air (DAF). The assay was carried out in a jar test on effluent from a multinational industry in the grain processing sector, located in the city of Uberlândia-MG. Coagulation diagrams were determined using the data spatial interpolation method of the Kringing regression model and the Tukey test was used to assess the difference in the results obtained. The optimum removal points of turbidity removal efficiency (TRE), greater than 98%, were achieved for the TSG/CH association with 200 mg L-1 (pH 10.72), 350 mg L-1 (pH 9.72), 500 mg L-1 (pH 9.56) in sedimentation. For the separation by DAF, the association of TSG/CH resulted in TRE values greater than 95% at dosages of 350 mg L-1 (pH 9.59) and 500 mg L-1 (pH 7.92). Furthermore, the results indicate that the associated use of TSG/CH, a coagulation aid, favored the coupling of the DAF bubble-particle, resulting in a smaller volume of sludge. In addition, CH expanded the action of TSG to the basic region

The striatum drives the ergogenic effects of caffeine

Caffeine is one of the main ergogenic resources used in exercise and sports. Previously, we reported the ergogenic mechanism of caffeine through neuronal A2AR antagonism in the central nervous system [1]. We now demonstrate that the striatum rules the ergogenic effects of caffeine through neuroplasticity changes. Thirty-four Swiss (8-10 weeks, 47 ± 1.5 g) and twenty-four C57BL/6J (8-10 weeks, 23.9 ± 0.4 g) adult male mice were studied behaviorly and electrophysiologically using caffeine and energy metabolism was studied in SH-SY5Y cells. Systemic (15 mg/kg, i.p.) or striatal (bilateral, 15 μg) caffeine was psychostimulant in the open field (p < 0.05) and increased grip efficiency (p < 0.05). Caffeine also shifted long-term depression (LTD) to potentiation (LTP) in striatal slices and increased the mitochondrial mass (p < 0.05) and membrane potential (p < 0.05) in SH-SY5Y dopaminergic cells. Our results demonstrate the role of the striatum in the ergogenic effects of caffeine, with changes in neuroplasticity and mitochondrial metabolism

Divulgação científica e o projeto momento ciência

O projeto Momento Ciência tem como propósito tornar o conhecimento cientifico acessível, promovendo a divulgação científica através do contato direto de alunos de ensino médio de escolas públicas do Distrito Federal e alunos recém aprovados, calouros, nos cursos de Ciências Biológicas e de Biotecnologia na Universidade de Brasília (UnB). Esse contato com a comunidade científica ocorre por meio de visitas aos laboratórios acadêmicos do Instituto de Ciências Biológicas (IB) da Universidade de Brasília. O projeto obteve resultados positivos e esperados ao longo da sua execução

Resumos concluídos - Saúde Coletiva

Resumos concluídos - Saúde Coletiv

Resumos concluídos - Saúde Coletiva

Resumos concluídos - Saúde Coletiv