Abstract Background: Snakebite envenoming can be a life-threatening condition, for which emergency care is essential. The Bothrops (lancehead) genus is responsible for most snakebite-related deaths and permanent loss of function in human victims in Latin America. Bothrops spp. venom is a complex mixture of different proteins that are known to cause local necrosis, coagulopathy, and acute kidney injury. However, the long-term effects of these viper envenomings have remained largely understudied. Case presentation: Here, we present a case report of a 46-years old female patient from Las Claritas, Venezuela, who was envenomed by a snake from the Bothrops genus. The patient was followed for a 10-year period, during which she presented oliguric renal failure, culminating in kidney failure 60 months after the envenoming. Conclusion: In Latin America, especially in Brazil, where there is a high prevalence of Bothrops envenoming, it may be relevant to establish long-term outpatient programs. This would reduce late adverse events, such as chronic kidney disease, and optimize public financial resources by avoiding hemodialysis and consequently kidney transplantation.

Abstract In the present study, hydrodynamics and gas to particle heat transfer in pseudo two dimensional spouted beds (2DSB) with and without draft plates were investigated using the Eulerian-Eulerian approach. The main objective of the study was to provide an understanding of effects of the presence of draft plates on the hydrodynamics and heat transfer behavior of solid particles in the spouted beds. To validate the model, the predicted mean particle vertical velocity at the bed axis, the lateral profiles of vertical particle velocity at different bed heights for both systems, and the particle velocity vector fields in the beds were compared with the experimental measurements. A close agreement between the CFD results and the experimental data was found for both systems. The simulation results showed that the particle volume fraction in the spout and fountain regions of the spouted bed with draft plates is considerably lower than that in a conventional spouted bed (without draft plates). Simulation results also showed significant differences between the temperature distributions of gas and solid phases in spouted beds with and without draft plates.

No presente artigo, o uso de pasta de eletrodo de carbono modificada por nanotubos de carbono e derivados de benzofurano (1-(4-(1,3-ditiolan-2-il)-6,7-dihidroxi-2-metil-6,7-dihidrobenzofuran-3-il) etanona) para a determinação de isoproterenol (IP) foi descrito. O coeficiente de transferência de carga, α, e a constante de transferência de carga, k s, para a transferência de elétrons entre o derivado de benzofurano e a pasta de eletrodo de carbono foram calculados como 0,52 e 1,04 s-1, respectivamente. O potencial anódico do IP diminui cerca de 256 mV com esse eletrodo modificado. Picos de corrente de voltametria de pulso diferencial (DPV) do IP, acetaminofeno (AC) e ácido fólico (FA) aumentam linearmente com concentrações na faixa de 0,05-2000 µmol L-1, 50,0-1200 µmol L-1 e 67,0-1600 µmol L-1, respectivamente e os limites de detecção para IP, AC e FA foram 0,020 µmol L-1, 0,385 µmol L-1 e 0,690 µmol L-1, respectivamente.

In the present paper, the use of carbon paste electrode modified by carbon nanotubes and benzofuran derivative (1-(4-(1,3-dithiolan-2-yl)-6,7-dihydroxy-2-methyl-6,7-dihydrobenzofuran-3-yl) ethanone) for the electrocatalytic determination of isoproterenol (IP) was described. The charge transfer coefficient, α, and the charge transfer rate constant, k s, for electron transfer between the benzofuran derivative and the carbon paste electrode were calculated as 0.52 and 1.04 s-1, respectively. The anodic overpotential of IP is decreased about 256 mV by this modified electrode. Differential pulse voltammetric (DPV) peak currents of IP, acetaminophen (AC) and folic acid (FA) increased linearly with their concentration in the ranges of 0.05-2000.0 µmol L-1, 50.0-1200.0 µmol L-1 and 67.0-1600.0 µmol L-1, respectively and the detection limits for IP, AC and FA were 0.020 µmol L-1, 0.385 µmol L-1 and 0.690 µmol L-1, respectively.

The adsorption characteristics of cadmium and nickel onto expanded perlite from aqueous solution have been investigated with respect to changes in pH of solution, adsorbent dosage, contact time and temperature of the solution. The maximum removal efficiency of Cd (II) is 88.8% at pH 6 and exposure to 10 g/L expanded perlite, while for Ni (II), it is 93.3% at the same pH and exposure to 8 g/L adsorbent. For the adsorption of both metals, the Freundlich isotherm model fitted the equilibrium data better than the Langmuir isotherm model. Experimental data are also evaluated in terms of kinetic characteristics of adsorption and it was found that the adsorption process for both metal ions follows well pseudo-second-order kinetics. Thermodynamic functions, the change of free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption are also calculated for each metal ion. The results show that the adsorption of these metal ions on expanded perlite is feasible and exothermic at 20-50°C.

A procedure for separation and preconcentration of trace amounts of Zn(II) from aqueous media is proposed. The procedure is based on the adsorption of Zn2+ on octadecyl bonded silica membrane disk modified with N,N'-disalicylidene-1,2-phenylendiamine at pH 7. The retained zinc ions were then stripped from the disk with a minimal amount of 1.5 mol L-1 hydrochloric acid solution as eluent, and determined by flame atomic absorption spectrometry. Maximum capacity of the membrane disk modified with 5 mg of the ligand was found to be 226 µg Zn2+. The relative standard deviation of zinc for ten replicate extraction of 10 µg zinc from 1000 mL samples was 1.2%. The limit of detection of the proposed method was 14 ng of Zn2+ per 1000 mL. The method was successfully applied to the determination of zinc in natural water samples and accuracy was examined by recovery experiments and independent analysis by graphite furnace atomic absorption spectrometry (GFAAS).