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Amyloid fibril formation is associated with an array of degenerative diseases. While no real cure is currently available, evidence suggests that suppression of amyloid fibrillogenesis is an effective strategy toward combating these diseases. Brilliant blue R (BBR), a disulfonated triphenylmethane compound, has been shown to interact with fibril-forming proteins but exert different effects on amyloid fibrillogenesis. These inconsistent findings prompted us to further evaluate BBR’s effect on the inhibition/suppresion of protein fibrillogenesis. Using 129-residue hen lysozyme, which shares high sequence homology to human lysozyme associated with hereditary non-neuropathic systemic amyloidosis, as a model, this study is aimed at thoroughly examining the influence of BBR on the in vitroprotein fibrillogenesis. We first showed that BBR dose-dependently attenuated lysozyme fibril formation probably by affecting the fibril growth rate, with the value of IC50determined to be ~4.39 μM. Next, we employed tryptophan fluorescence quenching method to determine the binding constant and number of binding site(s) associated with BBR-lysozyme binding. In addition, we further conducted molecular docking studies to gain a better understanding of the possible binding site(s) and interaction(s) between lysozyme and BBR. We believe some of the information and/or knowledge concerning the structure–function relationship associated with BBR’s suppressing activity obtained here can be applied for the future work in the subject matter related with the therapeutic strategies for amyloid diseases.

This study applied response surface methodology to investigate chemical oxygen demand (COD) removal from dyeing wastewater by coupling anodic chlorination using Ti/Pt anode and cathodic electro-Fenton oxidation using activated carbon fiber cathode. The COD was removed by electrogenerated HOCl in the anodic compartment, while in the cathodic compartment the COD was removed by OH' produced by combing the cathodically generated H2O2with Fe2+. A face-centered central composite experimental design was used to obtain the main variables, such as current density, initial chloride concentration, Fe2+concentration and solution pH, on the individual response surface for anodic chlorination and cathodic electro-Fenton COD removal efficiencies. Two mathematical models that can describe the individual COD removal response were obtained. Analysis of variance showed a high coefficient of determination value (R2) and insignificant lack of fit for both anodic and cathodic quadratic response surface models. The Pareto analysis gave the percentage effect of each variable on the response. For the anodic chlorination, the current density and the added chloride concentration were the most important two factors. On the other hand, the solution pH played the most important part for cathodic electro-Fenton oxidation.

AbstractThis study investigated the electrogeneration of Ce(IV) and its application on the destruction of polyvinyl alcohol (PVA) in an undivided electrochemical cell. The effects of electric current, concentration of nitric acid, and temperature on PVA destruction efficiency were investigated and the corresponding specific energy consumptions (SEC) were also evaluated. The experimental results indicate that the PVA destruction increased with increasing the applied current, the concentration of nitric acid, and decreasing the temperature. When considering the PVA destruction efficiency and the corresponding SEC simultaneously, the best operating condition was found by 92% at the optimal applied current 0.1 A, concentration of nitric acid 0.5 M, and temperature 323 K, respectively. A pseudo-first-order kinetic model provided a good fit to the experimental results at various temperatures. The activation energy was calculated to be 78.27 kJ mol−1, based on pseudo-first-order rate constants from the Arrhenius equation.

This study investigated the electrogeneration of Ce(IV) and its application on the destruction of polyvinyl alcohol (PVA) in an undivided electrochemical cell. The effects of electric current, concentration of nitric acid, and temperature on PVA destruction efficiency were investigated and the corresponding specific energy consumptions (SEC) were also evaluated. The experimental results indicate that the PVA destruction increased with increasing the applied current, the concentration of nitric acid, and decreasing the temperature. When considering the PVA destruction efficiency and the corresponding SEC simultaneously, the best operating condition was found by 92% at the optimal applied current 0.1 A, concentration of nitric acid 0.5 M, and temperature 323 K, respectively. A pseudo-first-order kinetic model provided a good fit to the experimental results at various temperatures. The activation energy was calculated to be 78.27 kJ mol−1, based on pseudo-first-order rate constants from the Arrhenius equation.

The transdermal drug delivery of iontophoresis provides a noninvasive method for the administration of effective drugs. The enhanced iontophoretic transport of thyrotropin-releasing hormone (TRH), a tripeptide with molecular weight of 362 and a pKa of 6.2, through an excised rabbit skin has been achieved by in vitro iontophoresis. The results indicate that the steady-state flux of TRH in a diffusion cell is proportional to the current density. In addition, the electrochemical properties of rabbit skin were studied with impedance spectroscopy, and it was found that the skin impedance decreased to a low and stable value with respect to its initial skin impedance while a current was applied through the rabbit skin. This is in good agreement with our experimental results on iontophoretic transport. As compared to passive diffusion, the iontophoresis dramatically increased the transport fluxes of TRH, and ethanol pretreatment further enhanced its iontophoretic transport. A practical implication of these results is that iontophoresis with a chemical permeation enhancer (ethanol pretreatment) can be applied to enhance and control the transdermal delivery of peptides.