Assessment of Antiviral and Photodynamic Inactivation Activity of Different Compounds Against Hepatitis A Virus

Food contamination from hepatitis A virus (HAV) is a great concern to food producers worldwide. Finding an innovative approach to inactivate HAV on food contact surfaces and on different produce remains a challenge. Using chemical disinfectants (e.g. chlorine) is an effective way to inactivate HAV on fomites, but it maybe unfavorable for food products. While heat inactivation of HAV remains the most efficient way to inactivate HAV when present in foods, most foodborne outbreaks of HAV are related to ready-to-eat (RTE) foods including produce which do not undergo further heating. Therefore, finding compounds with effective anti-HAV activities will be of great benefit to the food sector. In our study, oleanolic acid (OA) and ursolic acid (UA) have been investigated for their anti-HAV properties. OA at 600 μg/ml and UA at 360 μg/ml showed 2.27±0.67 and 1.33±0.35 log PFU/ml reduction after a 1 h treatment, respectively. Furthermore, to increase virus inactivation, photodynamic inactivation (PDI) was applied, which uses oxygen, light and a photosensitizer to produce reactive oxygen species (ROS). Grape seed extract (GSE) and oleanolic acid with known antiviral properties were tested as photosensitizers. Conditions using UV light at 254 nm with a distance of 72 cm and doses (energy density) of 0.012±0.000, 0.020±0.001, 0.040±0.001, 0.061±0.002, 0.081±0.002 and 0.121±0.003 J/cm2 for 3, 5, 10, 15, 20 and 30 min exposure times, respectively were applied for the PDI experiments. However, the acquired viral reductions by GSE and OA mediated PDI were attributed to UV light more than ROS production. Future work may include the use of different light sources for illumination, and the use of UA as a potential photosensitizer compound

A Mathematical Study of the (3+1)-D Variable Coefficients Generalized Shallow Water Wave Equation with Its Application in the Interaction between the Lump and Soliton Solutions

In this paper, the Hirota bilinear method, which is an important scheme, is used. The equation of the shallow water wave in oceanography and atmospheric science is extended to (3+1) dimensions, which is a well-known equation. A lot of classes of rational solutions by selecting the interaction between a lump and one- or two-soliton solutions are obtained. The bilinear form is considered in terms of Hirota derivatives. Accordingly, the logarithm algorithm to obtain the exact solutions of a (3+1)-dimensional variable-coefficient (VC) generalized shallow water wave equation is utilized. The analytical treatment of extended homoclinic breather wave solutions is studied and plotted in three forms 3D, 2D, and density plots. Using suitable mathematical assumptions, the established solutions are included in view of a combination of two periodic and two solitons in terms of two trigonometric and two hyperbolic functions for the governing equation. Maple software for computing the complicated calculations of nonlinear algebra equations is used. The effect of the free parameters on the behavior of acquired figures to a few obtained solutions for two nonlinear rational exact cases was also discussed