1,752 research outputs found

    Particle size distribution and specific surface area of SCM's compared through experimental techniques

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    Supplementary cementitious materials (SCMs) are mainly used to produce a green concrete. To reach that goal effectively, it is highly important to adequately characterize the SCMs. It is well known that particle size distribution (PSD) and fineness of SCMs have a great influence on concrete properties. Traditionally, cement fineness has been assessed by the specific surface area (SSA) through the Blaine method (BM). However, the BM has the simplification of considering ideal spherical shape particles. The BET theory has also been used to calculate SSA, however, also some assumptions may lead to inaccuracy in the calculations. Both PSD and SSA can be evaluated through Laser Diffractometry (LD), but this technique also considers ideal spherical particles as a simplification. Regardless of the mentioned drawbacks, these techniques provide useful information to characterize SCMs provided that the limitations are considered. In this paper, Ground Granulated Blast Furnace Slag (GGBFS), Natural Pozzolan (NP) and Limestone Powder (LP) are tested using the BM, LD, and nitrogen adsorption. Particle texture and shape are assessed through petrography and scanning electron microscope (SEM). Results from BM, BET and LD are compared, analysing the possible effects of particle shape and texture

    Síndrome metabólica em adolescentes obesos: comparação entre três diferentes critérios diagnósticos

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    Objective: To investigate the difference in the proportion of adolescents with metabolic syndrome diagnosed based on three different criteria, as well as the use of insulin resistance instead of fasting glucose.Methods: Cross-sectional study with 121 obese adolescents, between 10 and 14 years old, from public schools of the city of Porto Alegre, Brazil, in 2011. Anthropometric, blood pressure, and biochemical variables were assessed. Metabolic syndrome was defined using three different diagnostic criteria: the International Diabetes Federation (IDF), Cook and de Ferranti. All of them include five components: waist circumference, blood pressure, high-density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose, and there should be at least three abnormal results for the diagnosis of the syndrome. the Homeostasis Model Assessment - Insuline Resistance (HOMA-IR) was used for the characterization of insulin resistance. the analysis of agreement among the criteria was performed using Kappa statistics.Results: Metabolic syndrome Was diagnosed in 39.7, 51.2, and 74.4% of adolescents, according to the IDF, Cook and de Ferranti criteria, respectively. There was agreement for the three diagnostic criteria in 60.3% of the sample. Waist circumference was the most prevalent component (81.0, 81.0, and 96.7%), whereas high fasting glucose was the least prevalent (7.4, 1.7, and 1.7%). the use of HOMA-IR significantly increased the proportion of positive diagnoses for the syndrome.Conclusion: the results showed significant differences between the three diagnostic criteria. While there is no consensus on the diagnostic criteria for metabolic syndrome, differences in the prevalence of the disease in pediatric population will be frequent.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundo de Incentivo a Pesquisa e Eventos (FIPE), Hospital de Clinicas de Porto Alegre (HCPA)Research and Events Incentive Fund - FIPE of Hospital de Clinicas de Porto Alegre - HCPAUniversidade Federal de São Paulo UNIFESP, São Paulo, BrazilUniv Fed Rio Grande do Sul, Escola Educ Fis ESEF, Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, ESEF, Porto Alegre, RS, BrazilUniv London, Inst Child Hlth, London WC1N 1EH, EnglandUniv Fed Rio Grande do Sul, Fac Med, Dept Pediat, Porto Alegre, RS, BrazilHCPA, Serv Pediat, Porto Alegre, RS, BrazilUniv Fed Santa Maria, Santa Maria, RS, BrazilUniversidade Federal de São Paulo UNIFESP, São Paulo, BrazilCNPq: 159754/2010-0Web of Scienc

    An orally active formulation of angiotensin-(1-7) produces an antithrombotic effect

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    INTRODUCTION AND OBJECTIVE: The heptapeptide angiotensin-(1-7) is a component of the renin-angiotensin system, which promotes many beneficial cardiovascular effects, including antithrombotic activity. We have recently shown that the antithrombotic effect of angiotensin-(1-7) involves receptor Mas-mediated NO-release from platelets. Here, we describe an orally active formulation based on angiotensin-(1-7) inclusion in cyclodextrin [Ang-(1-7)- CyD] as an antithrombotic agent. Cyclodextrins are pharmaceutical tools that are used to enhance drug stability, absorption across biological barriers and gastric protection. METHOD: To test the antithrombotic effect of Ang-(1-7)-CyD, thrombus formation was induced in the abdominal vena cava of spontaneously hypertensive rats that were pretreated either acutely or chronically with Ang-(1-7)-CyD. Male Mas-knockout and wild-type mice were used to verify the role of the Mas receptor on the effect of Ang-(1-7)-CyD. RESULTS: Acute or chronic oral treatment with Ang-(1-7)-CyD promoted an antithrombotic effect (measured by thrombus weight; all values are, respectively, untreated vs. treated animals) in spontaneously hypertensive rats (acute: 2.86 + 0.43 mg vs. 1.14 + 0.40 mg; chronic: 4.27 + 1.03 mg vs. 1.39 + 0.68 mg). This effect was abolished in Mas-knockout mice (thrombus weight in Mas wild-type: 0.76 + 0.10 mg vs. 0.37 + 0.02 mg; thrombus weight in Mas-knockout: 0.96 + 0.11 mg vs. 0.87 + 0.14 mg). Furthermore, the antithrombotic effect of Ang-(1-7)-CyD was associated with an increase in the plasma level of Angiotensin-(1-7). CONCLUSION: These results show for the first time that the oral formulation Ang-(1-7)-CyD has biological activity and produces a Mas-dependent antithrombotic effect

    Angiotensin-(1–7)/Mas axis integrity is required for the expression of object recognition memory

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    AbstractIt has been shown that the brain has its own intrinsic renin–angiotensin system (RAS) and angiotensin-(1–7) (Ang-(1–7)) is particularly interesting, because it appears to counterbalance most of the Ang II effects. Ang-(1–7) exerts its biological function through activation of the G-protein-coupled receptor Mas. Interestingly, hippocampus is one of the regions with higher expression of Mas. However, the role of Ang-(1–7)/Mas axis in hippocampus-dependent memories is still poorly understood. Here we demonstrated that Mas ablation, as well as the blockade of Mas in the CA1-hippocampus, impaired object recognition memory (ORM). We also demonstrated that the blockade of Ang II receptors AT1, but not AT2, recovers ORM impairment of Mas-deficient mice. Considering that high concentrations of Ang-(1–7) may activate AT1 receptors, nonspecifically, we evaluate the levels of Ang-(1–7) and its main precursors Ang I and Ang II in the hippocampus of Mas-deficient mice. The Ang I and Ang II levels are unaltered in the whole hipocampus of MasKo. However, Ang-(1–7) concentration is increased in the whole hippocampus of MasKo mice, as well as in the CA1 area. Taken together, our findings suggest that the functionality of the Ang-(1–7)/Mas axis is essential for normal ORM processing

    Methicillin-resistant Staphylococcus epidermidis carrying biofilm formation genes: detection of clinical isolates by multiplex PCR

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    Staphylococcus epidermidis is the most prevalent coagulase-negative Staphylococcus (CNS) and is a major cause of hospital bacteremia. Based on 18 reference strains and 149 Staphylococcus clinical strains, used in a novel multiplex PCR method, the aim of this study was to identify S. epidermidis with respect to the sequence of three genes: recN, which encodes a recombination/repair protein, mecA (methicillin resistance), and icaAB, which is involved in biofilm formation. Amplicons of 219 bp (S. epidermidis-recN gene), 154 bp (mecA gene), and 546 bp (icaAB genes) were obtained. Reliableresults were achieved for 100% of the evaluated strains, suggesting that this new multiplex-PCR approach could be useful forthe accurate identification of methicillin-resistant S. epidermidis with the potential to produce biofilm. [Int Microbiol 2011;14(1):13-17

    A localized outbreak of Chikungunya virus in Salvador, Bahia, Brazil

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    A localized Chikungunya virus (CHIKV; East/Central/South African genotype) outbreak (50 cases, 70% laboratory-confirmed; attack rate: 5.3 confirmed cases/100 people) occurred in a Salvador, Brazil neighborhood, between Apr-Jun/2017. Highly clustered cases in space and time, mostly along a single street, highlight an increased risk of CHIKV transmission among pockets of susceptible populations. This finding underscores the need for ongoing local level surveillance for arboviral outbreaks.Fil: Tauro, Laura Beatriz. Fundación Oswaldo Cruz; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Cardoso, Cristiane W.. Secretaria Municipal da Saúde de Salvador; BrasilFil: Souza, Raquel L.. Fundación Oswaldo Cruz; BrasilFil: Nascimento, Leile Cj. Fundación Oswaldo Cruz; BrasilFil: Santos, Daniela R Dos. Secretaria Municipal da Saúde de Salvador; BrasilFil: Campos, Gubio S.. Universidade Federal da Bahia; BrasilFil: Ferro Sardi, Silvia Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidade Federal da Bahia; BrasilFil: Reis, Olivete B Dos. Secretaria Municipal da Saúde de Salvador; BrasilFil: Reis, Mitermayer G.. Fundación Oswaldo Cruz; Brasil. Universidade Federal da Bahia; Brasil. University of Yale; Estados UnidosFil: Kitron, Uriel D.. Fundación Oswaldo Cruz; Brasil. University of Emory; Estados UnidosFil: Ribeiro, Guilherme S.. Universidade Federal da Bahia; Brasil. Fundación Oswaldo Cruz; Brasi

    Crise sócioeconômica e processo de trabalho : à busca de uma relação teórica

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    Acesso ao livro na íntegra no endereço: http://acesso.mte.gov.br/data/files/8A7C816A2E7311D1012FEAA3403E09B2/TrabalhonaCapital.pdf.Este capítulo propõe-se a explorar questões como estas e suscitar hipóteses sobre a relação teórica das crises capitalistas com mudanças na organização do processo de trabalho, entendidas como tentativas de reorganizar o trabalho em função da crise, estratégias que permitam ao capital contornar a crise e voltar a trilhar os caminhos da acumulação, conduzindo possivelmente a novas formas de exploração do trabalho e de produção da mais-valia absoluta e relativa
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