Associação de heparina e antiveneno: eficácia da neutralização dos venenos de Bothrops atrox e Bothrops erythromelas

Heparin, in some regions of Brazil has been used in the treatment of bothropic accidents, but the data found in the literature are inconclusive about its effectiveness. The venoms of Bothrops atrox and of B. erythromelas were characterized according to their biological activities. The capacity of heparin in neutralizing these activities was tested with doses of 3 and 6 IU in isolated form and associated to Antibothropic Serum (ABS). It was verified that heparin, in doses of 3 and 6 IU, was not effective in neutralizing the desfibrinating and edema-forming activities of B. atrox venom and the hemorrhagic and coagulant actions of both venoms. Heparin diminished the effectiveness of the ABS in the neutralization of the hemorrhagic and edema-forming activities of the B. atrox venom. However, heparin in the 6 IU dose was capable of neutralize the edema-forming of the B. erythromelas and increase the effectiveness of the ABS. Heparin also neutralized the phospholipasic A2 activity of B. atrox (14.3%) and B. erythromelas (28.0%) venoms. For B. erythromelas venom, the associated treatment, heparin and ABS, was more effective in the neutralization of its lethal activity.A heparina tem sido utilizada no tratamento dos acidentes botrópicos em algumas regiões do Brasil, porém, os dados encontrados na literatura são inconclusivos sobre sua eficácia. Os venenos de Bothrops atrox e de B. erythromelas foram caracterizados segundo suas atividades biológicas. A capacidade da heparina em neutralizar estas atividades foi testada com as doses de 3 e 6UI de forma isolada e associada ao soro Antibotrópico (SAB). Verificou-se que a heparina nas doses de 3 e 6UI, não foi eficaz em neutralizar a atividade desfibrinante e edematogênica do veneno de B. atrox e as ações hemorrágica e coagulante dos dois venenos. A heparina diminuiu a eficácia do soro SAB na neutralização das atividades hemorrágica e edematogênica do veneno de B. atrox. Contudo, a heparina na dose de 6UI foi capaz de neutralizar a atividade edematogênica do veneno de B. erythromelas e aumentar a eficácia do soro SAB. A heparina neutralizou ainda a atividade fosfolipásica A2 dos venenos de B. atrox (14,3%) e de B. erythromelas (28,0%). Para o veneno de B. erythromelas, o tratamento associado de heparina e soro SAB, foi mais eficaz na neutralização da atividade letal

Numerical study and geometrical investigation of an onshore overtopping device wave energy converter with a seabed coupled structure

Studies regarding renewable energy sources have gained attention over recent years. One example is wave energy converters, which harvest energy from sea waves using different operational principles such as oscillating water columns, oscillating bodies, and overtopping devices. In the present paper, a numerical study is carried out, and a geometrical investigation of a fullscale overtopping device with a coupled structure mounted on the seabed is performed using the Constructal Design method. The main purpose is to investigate the influence of the design over the available power of the device. The areas of the overtopping ramp (Ar) and the trapezoidal seabed structure (At) are the problem constraints. Two degrees of freedom are studied, the ratio between the height and length of the ramp (H3/L3) and the ratio between the upper and lower basis of the trapezoidal obstacle (L1/L2). The device submersion is kept constant (H1 = 3.5 m). The equations of continuity, momentum, and the transport of volume fraction are solved with the Finite Volume Method, while the water–air mixture is treated with the multiphase model Volume of Fluid. Results showed that the ratio H3/L3 presented a higher sensibility than the ratio L1/L2 over the accumulated water in the reservoir. Despite that, the association of a structure coupled to the ramp of an overtopping device improved the performance of the converter by 30% compared to a conventional condition without the structure

Electrically conductive polyetheretherketone nanocomposite filaments: from production to fused deposition modeling

The present work reports the production and characterization of polyetheretherketone (PEEK) nanocomposite filaments incorporating carbon nanotubes (CNT) and graphite nanoplates (GnP), electrically conductive and suitable for fused deposition modeling (FDM) processing. The nanocomposites were manufactured by melt mixing and those presenting electrical conductivity near 10 S/m were selected for the production of filaments for FDM. The extruded filaments were characterized for mechanical and thermal conductivity, polymer crystallinity, thermal relaxation, nanoparticle dispersion, thermoelectric effect, and coefficient of friction. They presented electrical conductivity in the range of 1.5 to 13.1 S/m, as well as good mechanical performance and higher thermal conductivity compared to PEEK. The addition of GnP improved the composites’ melt processability, maintained the electrical conductivity at target level, and reduced the coefficient of friction by up to 60%. Finally, three-dimensional (3D) printed test specimens were produced, showing a Young’s modulus and ultimate tensile strength comparable to those of the filaments, but a lower strain at break and electrical conductivity. This was attributed to the presence of large voids in the part, revealing the need for 3D printing parameter optimization. Finally, filament production was up-scaled to kilogram scale maintaining the properties of the research-scale filaments.Most of this study was performed under ESA Contract Nr. 4000116010/15/NL/FE.info:eu-repo/semantics/publishedVersio

Avaliação da qualidade das águas de poços em comunidades e assentamentos rurais Mossoró-RN

As águas subterrâneas são apontadas como uma alternativa viável para garantir o acesso das comunidades rurais do nordeste à água, a partir de investimentos públicos na perfuração de poços tubulares. Muitas comunidades rurais de Mossoró, RN, são abastecidas com água proveniente do aquífero Jandaíra, de elevada concentração de sais, sendo utilizada na irrigação de culturas sem o manejo adequado para o seu uso sustentável, o que pode acarretar em problemas de salinização. Devido aos impactos causados pelo uso de águas salobras na irrigação, para viabilizar a sua utilização deve-se adotar práticas de manejo da água e solo para o controle da salinidade. Desta forma de faz necessário caracterizar essas águas, para que seja possível estabelecer um manejo do sistema solo-água-planta da área irrigada. Assim, o presente trabalho objetivou avaliar a qualidade da água para fins de irrigação de comunidades rurais de Mossoró, abastecidas com águas salobras provenientes de poços tubulares, fornecendo estas informações como uma ferramenta de auxílio para o manejo adequado da utilização destas águas na irrigação. As análises dos resultados indicaram que as águas de poços de todas as comunidades apresentaram alto grau de restrição de uso para a irrigação quanto aos riscos de salinização, sodicidade e toxicidade de íons cloreto, necessitando de práticas de manejo

Determinant Factors of Dividend Payments in Brazil

This study identifies factors that shaped cash disbursement distribution policies employed by Brazilian public companies listed on the Brazilian Securities, Commodities and Futures Exchange (BM&FBOVESPA) from 1995 to 2011. Relationships between Dividends/Total Assets and potential determinants discussed in the literature, including firm size, corporate governance, profitability, leverage, market to book, liquidity, investment, risk, profit growth, information asymmetry and agency conflict, are examined. The following econometric methods are employed: (1) Tobit, given the nature of the dividend data, and (2) the Generalized Method of Moments (GMM) to control for endogenous regressors. Significant positive variables found include size, return on assets (ROA), market to book, liquidity and profit growth. It can thus be inferred that larger firm size, profitability, market value, liquidity and profit growth correlate with greater firm pro pensity to distribute money to shareholders, thus supporting the theory of corporate finance. Significant negative variables found include leverage, liquidity squared, capex, beta and tag along 100%. It is thus inferred that more significantly leveraged companies that invest more heavily in fixed assets and that exhibit high liquidity, higher risk and less conflict between controlling and minority shareholders will be less likely to pay dividends to shareholders.</p

Incidence and outcome of invasive candidiasis in intensive care units (ICUs) in Europe: results of the EUCANDICU project

BACKGROUND: The objective of this study was to assess the cumulative incidence of invasive candidiasis (IC) in intensive care units (ICUs) in Europe. METHODS: A multinational, multicenter, retrospective study was conducted in 23 ICUs in 9 European countries, representing the first phase of the candidemia/intra-abdominal candidiasis in European ICU project (EUCANDICU). RESULTS: During the study period, 570 episodes of ICU-acquired IC were observed, with a cumulative incidence of 7.07 episodes per 1000 ICU admissions, with important between-center variability. Separated, non-mutually exclusive cumulative incidences of candidemia and IAC were 5.52 and 1.84 episodes per 1000 ICU admissions, respectively. Crude 30-day mortality was 42%. Age (odds ratio [OR] 1.04 per year, 95% CI 1.02-1.06, p&nbsp;&lt; 0.001), severe hepatic failure (OR 3.25, 95% 1.31-8.08, p 0.011), SOFA score at the onset of IC (OR 1.11 per point, 95% CI 1.04-1.17, p 0.001), and septic shock (OR 2.12, 95% CI 1.24-3.63, p 0.006) were associated with increased 30-day mortality in a secondary, exploratory analysis. CONCLUSIONS: The cumulative incidence of IC in 23 European ICUs was 7.07 episodes per 1000 ICU admissions. Future in-depth analyses will allow explaining part of the observed between-center variability, with the ultimate aim of helping to improve local infection control and antifungal stewardship projects and interventions