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In this paper, we are concerned with the following singular perturbation Kirchhoff equation − ( ε 2 a + ε b ∫ R 3 | ∇ u | 2 d y) Δ u + V (y) u = | u | p − 1 u , u ∈ H 1 (R 3) , where constants a , b , ε > 0 and 1

Abstract There are many areas in the world where ground water has been contaminated by arsenic. MnO2 is one of the most inexpensive materials which can both adsorb arsenic and oxide arsenite [As(III)] to arsenate [As(V)]. In this study, the Ultra-long α-MnO2 nanowires with the (1 1 0) surface are used to remove As(III) and As(V) from solutions under different conditions. The adsorption kinetics for both As(III) and As(V) fit well with the pseudo-second-order kinetic model. For example, the pseudo-second-order adsorption kinetic constants are 0.076 × 103 and 0.077 × 103 g μg−1 min−1 at pH 7 for As(III) and As(V), respectively. At the same time, compared to the Freundlich model the Langmuir model better describes the adsorption equilibrium isotherms. For example, the maximum adsorption capacity values of the α-MnO2 nanowires obtained from the Langmuir model are 1.012 × 103 and 1.158 × 103 μg g−1 at pH 7 for As(III) and As(V), respectively. The adsorption capacities of α-MnO2 nanowires are affected by the pH value and increase with the initial arsenic concentration. Furthermore, the As(III) oxidation rate can be denoted by the pseudo-zero-order kinetic model and is related to O2 concentration, the light source used, the initial concentration of As(III), and the pH value. For example, the pseudo-zero-order kinetic equation is y = −0.90x + 163.6 with 4 L min−1 of O2, dark condition, 0.2 × 103 μg L−1 of As(III) and at pH 7. Finally, the oxidation mechanism is investigated and the oxidant in this reaction should be related with O2 not Mn(II). Besides its special structure and easy separation ability, it is a promising material to remove arsenic from water. [ABSTRACT FROM AUTHOR]

TiO 2 is one of the most cheap materials which can both adsorb arsenic and oxidize arsenite [As(III)] to arsenate [As(V)]. In this study, anatase TiO 2 crystals with different main facets such as {101}, {001} and {100} are synthesized and used to investigate arsenic adsorption kinetics, adsorption isotherms, photocatalytic oxidation (PCO) process and the pH effects. The adsorption kinetics of arsenic on TiO 2 crystals can be described by the pseudo second-order kinetic model. For the adsorption isotherms, the Langmuir model is better than the Freundlich model for arsenic on these TiO 2 crystals. For the PCO process, the rate of As(III) oxidation can be denoted by the pseudo first-order kinetic model. It should be noted that at neutral condition the adsorption and PCO rates of the three kinds of TiO 2 crystals follow the order of {101} > {001} > {100}. The pH effect is above all important for both the arsenic adsorption and its PCO. The highest PCO speed appears at high pH values such as at pH 11 or 12., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Chronic cerebral hypoperfusion (CCH) is a basic pathological process that is comorbid with brain diseases, such as vascular Parkinsonism and Alzheimer's disease. Icariside II (ICS II), which is one of the main metabolites of icariin, has anti-inflammatory and antioxidant effects and protects against ischemic brain injury. This study aims to investigate the neuroprotective effects of ICS II on neuronal axon regeneration-related factors in a CCH rat model. Sprague-Dawley (SD) rats were divided into the following four groups: sham group, model group and 4 and 8 mg/kg/day ICS II administration groups. Learning and spatial memory functions were tested using a Morris water maze. Pathological changes were observed in the rat hippocampal tissue by hematoxylin and eosin (H&E) staining. Neuronal axon regeneration-related proteins (GAP-43, MAP-2 and Nogo-A) were observed by immunohistochemical staining and detected by the average optical density method. The results showed that 8 mg/kg/day of ICS II can effectively reduce the escape latency and prolong the target quadrant residence time at 12 weeks and that ICS II can improve the histopathological changes in the CA1 area of the rat hippocampus. Moreover, ICS II administration at 8 mg/kg/day significantly increased GAP-43 and MAP-2 expression and reduced Nogo-A expression in the CA1 area of the rat hippocampus at 12 weeks; however, significant differences were not observed at 4 and 8 weeks. Hence, ICS II at a dosage of 8 mg/kg/day could promote learning and memory abilities and improve histopathological changes in the rat hippocampus in a CCH rat model. These results may be related to the promotion of neuronal axon regeneration in the CA1 area of the hippocampus under increases in hippocampal GAP-43 and MAP-2 protein expression and decreased Nogo-A protein expression., Competing Interests: None., (IJCEP Copyright © 2019.)