The effect of superabsorbent polymers on mechanical characteristics and cracking susceptibility of alkali-activated mortars containing ground granulated blast-furnace slag and copper Slag

In an attempt to increase sustainability of construction materials, both ground granulated blast-furnace slag (GGBS) and, less popular, copper slag (CS) can be used in alkali-activated composites. However, such composites are often more susceptible to cracking, triggered by the self-desiccation processes. The addition of superabsorbent polymers (SAP) may enable internal curing of concrete and prevent excessive cracking. Thus, this paper aims to evaluate the effectiveness of SAP as an internal curing agent for alkali-activated slag mortars containing GGBS and CS. The samples were activated by sodium silicate using 6.5% Na2O by mass of precursor. The evaluation was based on the analysis of mechanical properties, autogenous shrinkage, and water absorption capacity of two types of SAPs. Depending on the type of polymer, a higher alkali concentration in SAP solutions speeds up early age reactions up to 7 days. After this period, SAP collapses and reactions follow at the same pace as the reference sample. In the presence of CS, SAP with higher absorption and smaller particles well-distributed in the mix leads to a higher extension of reactions, observed in higher values of autogenous shrinkage (AS). This results in increased compressive strength of GGBS-CS mortars, achieving values 8.8% greater than the reference sample (without SAP) at 6 months. Although its leads to higher cracking susceptibility, SAP can improve mechanical properties and promote new applications for sustainable material containing copper slag

Espumas cerâmicas como suportes catalíticos

Espumas reticulares de cordierite desenvolvidas por um método de polimerização “in situ” revelaram propriedades de elevado interesse para a aplicação como suportes catalíticos. Estas espumas são caracterizadas por possuírem porosidades superiores (>90%) às obtidas pelo método de replicação polimérica (70-85%). O desenvolvimento de um método de revestimento de espumas cerâmicas com catalisadores zeolíticos, e a optimização de parâmetros como teor de sólidos, ligante, surfactante ou pré-revestimento da espuma, tem estado a ser efectuado. As melhores características foram observadas para espumas com aproximadamente 17% (p/p) de revestimento obtidas a partir de suspensões com cerca de 16% de teor de sólidos. Espumas revestidas com zeólitos Pt/ZSM5 estão a ser utilizadas como catalisadores para a combustão catalítica de COVs, nomeadamente isopropanol e toluen

UV-Visible Spectroscopy Study of Oxidative Degradation of Sunflower Biodiesel

In this study, three antioxidants (blend (hydrogenated cardanol + 5-n-pentadecyl-2-tert-butylphenol), 5-n-pentadecyl-2-tert-butylphenol and ionol BF200) were evaluated for their potential to reduce the degree of oxidation of sunflower biodiesel under thermal stress condition. Each antioxidant was added at a concentration of 1000 ppm. The oxidative degradation was investigated by UV-visible spectroscopy and iodometry were used to monitor the changes using peroxide values. The results showed that, blend and 5-n-pentadecyl-2-tert-butylphenol possess significant potentiality when compared with ionol BF200. The blend and 5-n-pentadecyl-2-tert-butylphenol reduced the absorbance around 31%. The peroxide value showed that, the formulations: sunflower biodiesel/A2, sunflower biodiesel/A3 and sunflower biodiesel/AC showed better results when compared with sunflower biodiesel without antioxidant.Keywords: Antioxidants; Peroxide value; Accelerated oxidation tes

hybridModels: An R Package for the Stochastic Simulation of Disease Spreading in Dynamic Networks

Disease spreading simulations are traditionally performed using coupled differential equations. However, in the setting of metapopulations, most of the solutions provided by this method do not account for the dynamic topography of subpopulations. Conversely, the alternative approach of individual-based modeling (IBM) may add computational cost and complexity. Hybrid models allow for the study of disease spreading because they combine both aforementioned approaches by separating them across different scales: a local scale that addresses subpopulation dynamics using coupled differential equations and a global scale that addresses the contact between these subpopulations using IBM. We present a simple way of simulating the spread of disease in dynamic networks using the high-level statistical computational language R and the hybridModels package. We built four examples using disease spread models at the local scale in several different networks: an animal movement network; a three-node network, whose model solution using a stochastic simulation algorithm is compared with the ordinary differential equations approach; the commuting of individuals between patches, which we compare with the permanent migration of individuals; and the commuting of individuals within the metropolitan area of São Paulo

Contribution for the phytochemical studies of Ageratum fastigiatum

Organic extracts from leaves plus branches plus inflorescences of Ageratum fastigiatum (Gardner) R. M. King & H. Rob., Asteraceae, were fractionated through classic chromatography. The steroids stigmasterol, chondrillasterol and campesterol were isolated from hexane extract. The triterpenes lupeol, taraxasterol, α-amyrin, β-amyrin, pseudotaraxasterol, lupeol acetate and α-amyrin acetate were isolated from ethyl acetate extract. Steroids and triterpenes were identified by GC-MS. The coumarin ayapin was isolated from ethanol extract and identified by NMR. Essential oils of the fresh leaves and fresh inflorescences were obtained by hydrodistillation and analyzed for GC-MS. The main components in both essential oils were α-pinene, limonene and germacrene D.FAPEMI

Taking Root: Enduring Effect of Rhizosphere Bacterial Colonization in Mangroves

Mangrove forests are of global ecological and economic importance, but are also one of the world's most threatened ecosystems. Here we present a case study examining the influence of the rhizosphere on the structural composition and diversity of mangrove bacterial communities and the implications for mangrove reforestation approaches using nursery-raised plants.A barcoded pyrosequencing approach was used to assess bacterial diversity in the rhizosphere of plants in a nursery setting, nursery-raised transplants and native (non-transplanted) plants in the same mangrove habitat. In addition to this, we also assessed bacterial composition in the bulk sediment in order to ascertain if the roots of mangrove plants affect sediment bacterial composition. We found that mangrove roots appear to influence bacterial abundance and composition in the rhizosphere. Due to the sheer abundance of roots in mangrove habitat, such an effect can have an important impact on the maintenance of bacterial guilds involved in nutrient cycling and other key ecosystem functions. Surprisingly, we also noted a marked impact of initial nursery conditions on the rhizosphere bacterial composition of replanted mangrove trees. This result is intriguing because mangroves are periodically inundated with seawater and represent a highly dynamic environment compared to the more controlled nursery environment.In as far as microbial diversity and composition influences plant growth and health, this study indicates that nursery conditions and early microbial colonization patterns of the replants are key factors that should be considered during reforestation projects. In addition to this, our results provide information on the role of the mangrove rhizosphere as a habitat for bacteria from estuarine sediments

Tricritical Points in the Sherrington-Kirkpatrick Model in the Presence of Discrete Random Fields

The infinite-range-interaction Ising spin glass is considered in the presence of an external random magnetic field following a trimodal (three-peak) distribution. The model is studied through the replica method and phase diagrams are obtained within the replica-symmetry approximation. It is shown that the border of the ferromagnetic phase may present first-order phase transitions, as well as tricritical points at finite temperatures. Analogous to what happens for the Ising ferromagnet under a trimodal random field, it is verified that the first-order phase transitions are directly related to the dilution in the fields (represented by $p_{0}$). The ferromagnetic boundary at zero temperature also exhibits an interesting behavior: for $0<p_{0}<p_{0}^{*} \approx 0.30856$, a single tricritical point occurs, whereas if $p_{0}>p_{0}^{*}$ the critical frontier is completely continuous; however, for $p_{0}=p_{0}^{*}$, a fourth-order critical point appears. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified; in particular, the Almeida-Thouless line in the plane field versus temperature is shown to depend on the weight $p_{0}$.Comment: 23pages, 7 ps figure

Canalopatias em endocrinologia: achados genéticos recentes e fisiopatologia

Ion channels serve diverse cellular functions, mainly in cell signal transduction. In endocrine cells, these channels play a major role in hormonal secretion, Ca2+-mediated cell signaling, transepithelial transport, cell motility and growth, volume regulation and cellular ionic content and acidification of lysosomal compartments. Ion channel dysfunction can cause endocrine disorders or endocrine-related manifestations, such as pseudohypoaldosteronism type 1, Liddle syndrome, Bartter syndrome, persistent hyperinsulinemic hypoglycemia of infancy, neonatal diabetes mellitus, cystic fibrosis, Dent's disease, hypomagnesemia with secondary hipocalcemia, nephrogenic diabetes insipidus and, the most recently genetically identified channelopathy, thyrotoxic hypokalemic periodic paralysis. This review briefly recapitulates the membrane action potential in endocrine cells and offers a short overview of known endocrine channelopathies with focus on recent progress regarding the pathophysiological mechanisms and functional genetic defects.Canais iônicos auxiliam diferentes funções celulares, principalmente na transdução de sinal. Nas células endócrinas, esses canais têm funções importantes na secreção hormonal, sinalização do Ca2+, transporte transepitelial, regulação da motilidade, volume e conteúdo iônico celular e da acidificação do compartimento lisossomal (pH). Como esperado, as alterações nos canais iônicos podem causar distúrbios endocrinológicos, como pseudo-hipoaldosteronismo tipo 1, síndrome de Liddle, síndrome de Bartter, hipoglicemia hiperinsulinêmica da infância, diabetes melito neonatal, fibrose cística, doença de Dent, hipomagnesemia com hipocalcemia secundária, diabetes insípido nefrogênico e paralisia periódica tirotóxica hipocalêmica. Este artigo propõe uma breve revisão das canalopatias endócrinas conhecidas, com foco particular nos recentes progressos no conhecimento dos mecanismos fisiopatológicos adquirido a partir das alterações funcionais encontradas.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUNIFESP-EPM Departamento de BioquímicaUNIFESP, EPM, Depto. de MedicinaUNIFESP, EPM Depto. de BioquímicaSciEL

From normative imaginary reality of the Network of Emergency Care

Modelo do estudo: estudo de caso. Objetivo: analisar a Rede de Atenção às Urgências sob a ótica do Serviço de Atendimento Móvel de Urgência (SAMU) Metropolitano do Recife. Material e Método: estudo de caso com múltiplas unidades de análise. O caso foi o SAMU Metropolitano do Recife e as unidades de análise foram os componentes: promoção, prevenção à saúde e vigilância; organização e governança da rede. Optou-se pela triangulação de métodos e de fontes, utilizando entrevista semiestruturada com 57 profissionais que atuavam nesse serviço; observação direta e documentos oficiais (banco de dados, portarias e relatórios). Para a análise dos dados qualitativos utilizou-se a técnica de condensação de significados e para os quantitativos, a frequência média dos eventos. Resultados: O perfil dos profissionais entrevistados mostra que 53% era do sexo masculino, 65% graduados há menos de 12 anos, um pouco mais da metade atuava no SAMU há menos de 2 anos e 77% tinham vínculo empregatício temporários por meio de contratos com as prefeituras. Segundo os entrevistados há estratégias de promoção e prevenção, mas, não conseguem visualizar mudanças no perfil epidemiológico e demográfico como resultado da implantação dessas estratégias. Existe uma distribuição inadequada dos equipamentos de saúde; baixa cobertura populacional dos pontos de atenção à saúde (50% de cobertura de PSF/ESF e déficit de 3.089 leitos hospitalares do SUS) e, falta de coordenação do comitê gestor estadual regional do sistema de atenção as urgências pela Secretaria do Estado de Pernambuco. Conclusão: A falta de gestão de informação dos atendimentos na área de urgência e das estratégias de promoção e prevenção gera descontinuidade no processo de vigilância, corroborada pelas falhas de comunicação em toda a rede de assistência do SAMU, gerando déficit de cobertura populacional e inadequação dos pontos de saúde frente à legislação vigente. A falta de integração dos serviços, a dificuldade de acesso e de continuidade ao tratamento demonstra a inadequada governança da rede de assistência às urgênciasStudy design: a case study. Objective: To analyze the Emergency Care Network from the perspective of the Mobile Emergency Care Service of the Metropolitan Recife (SAMU). Material and Method: a case study with multiple units of analysis. The object of the study was the SAMU and the units of analysis were the components: promotion, prevention and health surveillance; organization and governance of the network. We opted for the triangulation of methods and sources, using semistructured interviews with 57 professionals working in this service; direct observation and official documents (database, ordinances and reports). For the analysis of qualitative data we used the technique of condensing meanings and quantitative, the average frequency of events. Results: The profile of the professionals interviewed shows that 53% were male, 65%, had graduated less than 12 years, a little more than half worked in the SAMU for less than 2 years and 77% had temporary employment through contracts with the municipalities. According to the interviewees there are strategies of promotion and prevention, but one cannot see changes in the epidemiological and demographic profile as a result of the implementation of these strategies. There is an inadequate distribution of health equipment; low health coverage of the population (50% of PSF coverage / ESF and deficit of 3,089 hospital beds) and lack of coordination between the state regional steering committee of the care system emergencies.Conclusion: The lack of information on care management in the emergency area, promotion and prevention strategies generates discontinuity in the process of surveillance, added by communication failures across the SAMU service network. Therefore, there is a deficit and inadequacy of health coverage. The lack of integration between services, the difficulty of access and the patient continuity on the treatment demonstrates the inadequate governance of the service network to the emergency roo

Avaliação química e da atividade antidiarréica das folhas de Byrsonima cinera DC. (Malpighiaceae)

Folhas e cascas de algumas especies do gênero Byrsonima (Malpighiaceae) são empregadas popularmente contra diarréia. Contudo, não existem dados na literatura à respeito de investigacões químicas ou farmacológicas dos extratos de B. cinera. Neste estudo, nós avaliamos a atividade antidiarreica dos extratos metanólico e hidrometanólico das folhas de B. cinera em ratos Swiss. Os resultados mostraram que ambos os extratos reduziram signitivamente a motilidade intestinal. Investigacão fitoquímica do extrato metanólico levou ao isolamento e identificacão da (+)-catequina e da quercetina-3-O-a-L-arabinopiranosídeo. A atividade observada pode estar correlacaionada com a presença dessas substâncias nos extratos.Leaves and bark of some Byrsonima species (Malpighiaceae) are popularly employed against diarrhoeal diseases. However, no data were reported in the literature about the chemisty and pharmacology of extracts from B. cinera leaves. In the present study we evaluated the anti-diarrhoeal activity of methanolic and hydromethanolic extracts obtained from the leaves of B. cinera in Swiss mice. Results showed that both extracts reduced significantly the gastrintestinal motility. Phytochemical evaluation of the methanolic extract led to the isolation and identification of (+)-catechin and quercetin-3-O-a-L-arabinopyranoside. The observed activity may be correlated to the presence of these compounds in the extract