Wesley B. Cardoso

West Nile virus (WNV) is a neurotropic flavivirus lacking approved antiviral therapies. Here, we evaluated the repurposing potential of ten HIV protease inhibitors as inhibitors of the WNV NS2B–NS3 protease using molecular docking followed by molecular dynamics simulations. Structural, energetic, and interaction analyses revealed substantial differences in binding stability under dynamic conditions. Indinavir and Atazanavir consistently showed strong and stable interactions, low structural and positional fluctuations, persistent hydrogen bonding, and favorable binding free energies. In contrast, several inhibitors displayed transient binding despite favorable docking scores. These findings emphasize the importance of molecular dynamics in drug repurposing studies and identify Indinavir and Atazanavir as promising candidates for further experimental evaluation against WNV.

We study stationary, spatially localized modes in linearly coupled optical waveguides governed by coupled nonlinear Schrödinger equations with asymmetric defocusing Kerr nonlinearities. A waveguide with spatially inhomogeneous nonlinearity supports self-trapped states, whereas a homogeneous defocusing waveguide cannot localize on its own. We show that linear coupling induces localization in the nonlocalizing guide. Fundamental and excited stationary modes are computed, and their existence, power asymmetry, and stability are analyzed as functions of the coupling strength and nonlinearity. Dynamical simulations reveal stable ground and first excited states, whereas higher-order modes are unstable. These results demonstrate coupling-induced spatial localization in defocusing nonlinear waveguide systems.

The Oropouche virus (OROV), an emerging arbovirus from the Peribunyaviridae family, represents a growing public health concern in Latin America, particularly due to its rapid urban spread and lack of specific treatments. In this study, we employed an integrated computational strategy combining molecular docking and molecular dynamics (MD) simulations to evaluate the potential of HIV protease inhibitors as candidates for repurposing against the Gc glycoprotein of OROV, a critical component in viral fusion and host cell entry. While docking initially ranked Saquinavir as the top binder, subsequent MD simulations revealed that nelfinavir and indinavir exhibited superior performance across multiple criteria, including binding energy, structural stability, center-of-mass distance maintenance, and consistent hydrogen bonding. These findings emphasize the limitations of docking-only approaches and highlight the importance of dynamic and energetic analyses for accurate inhibitor selection. The proposed computational pipeline demonstrates its value in identifying stable, high-affinity ligands and offers a promising route for accelerating drug discovery against neglected viral diseases such as OROV.

We introduce a model of an optical cavity based on the one-dimensional Lugiato-Lefever (LL) equation, which includes the pump represented by a symmetric pair of tightly localized "hot spots" (HSs) with phase shift χ between them, and self-focusing or defocusing cubic nonlinearity. Families of bound states, pinned to the double HS, are found in the system's parameter space. They feature the effect of the symmetry breaking (SB) between peaks pinned to individual HSs, provided that the phase shift takes values 0<χ<π, and the LL equation includes the loss term. The SB, which is explained analytically, takes place in the full LL model and its linearized version alike. The same phenomenology is also explored in the framework of the LL equation with the double HS and quintic self-focusing. In that case, there are stable symmetric and asymmetric bound states, in spite of the presence of the background instability driven by the critical collapse.