Conjugate coupling induced symmetry breaking and quenched oscillations

Spontaneous symmetry breaking (SSB) is essential and plays a vital role many natural phenomena, including the formation of Turing pattern in organisms and complex patterns in brain dynamics. In this work, we investigate whether a set of coupled Stuart-Landau oscillators can exhibit spontaneous symmetry breaking when the oscillators are interacting through dissimilar variables or conjugate coupling. We find the emergence of SSB state with coexisting distinct dynamical states in the parametric space and show how the system transits from symmetry breaking state to out-of-phase synchronized (OPS) state while admitting multistabilities among the dynamical states. Further, we also investigate the effect of feedback factor on SSB as well as oscillation quenching states and we point out that the decreasing feedback factor completely suppresses SSB and oscillation death states. Interestingly, we also find the feedback factor completely diminishes only symmetry breaking oscillation and oscillation death (OD) states but it does not affect the nontrivial amplitude death (NAD) state. Finally, we have deduced the analytical stability conditions for in-phase and out-of-phase oscillations, as well as amplitude and oscillation death states.Comment: Accepted for publication in Europhysics Letter

Aging transition under weighted conjugate coupling

We investigate the effect of symmetry breaking couplings on the macroscopic dynamical behavior of an ensemble of globally coupled active and inactive oscillators. Conjugate coupling among the ensemble and the weighted coupling within the active and inactive groups introduces the asymmetry. Large values of the global coupling strength facilitate the onset of the phenomenon of aging transition, thereby deteriorating the macroscopic oscillatory behavior. We find that the natural frequency of oscillation favors the onset of the aging transition even in the presence of a large proportion of the active oscillators because of the broken symmetry. Further the ratio of the intra-group (weighted) couplings plays a nontrivial role in determining the dynamical behaviors and their transitions. It is also observed that even a feeble change in the simple feedback factor in the coupling facilitates the counterintuitive effect of preserving the macroscopic oscillatory nature of the ensemble, comprising completely inactive oscillators, in the entire parameter space where the ensemble suffered the aging transition

Fast Dissolving Electrospun Nanofibers Fabricated from Jelly Fig Polysaccharide/Pullulan for Drug Delivery Applications

The fast-dissolving drug delivery systems (FDDDSs) are developed as nanofibers using food-grade water-soluble hydrophilic biopolymers that can disintegrate fast in the oral cavity and deliver drugs. Jelly fig polysaccharide (JFP) and pullulan were blended to prepare fast-dissolving nanofiber by electrospinning. The continuous and uniform nanofibers were produced from the solution of 1% (w/w) JFP, 12% (w/w) pullulan, and 1 wt% Triton X-305. The SEM images confirmed that the prepared nanofibers exhibited uniform morphology with an average diameter of 144 ± 19 nm. The inclusion of JFP in pullulan was confirmed by TGA and FTIR studies. XRD analysis revealed that the increased crystallinity of JFP/pullulan nanofiber was observed due to the formation of intermolecular hydrogen bonds. The tensile strength and water vapor permeability of the JFP/pullulan nanofiber membrane were also enhanced considerably compared to pullulan nanofiber. The JFP/pullulan nanofibers loaded with hydrophobic model drugs like ampicillin and dexamethasone were rapidly dissolved in water within 60 s and release the encapsulants dispersive into the surrounding. The antibacterial activity, fast disintegration properties of the JFP/pullulan nanofiber were also confirmed by the zone of inhibition and UV spectrum studies. Hence, JFP/pullulan nanofibers could be a promising carrier to encapsulate hydrophobic drugs for fast-dissolving/disintegrating delivery applications

Fast Dissolving Electrospun Nanofibers Fabricated from Jelly Fig Polysaccharide/Pullulan for Drug Delivery Applications

The fast-dissolving drug delivery systems (FDDDSs) are developed as nanofibers using food-grade water-soluble hydrophilic biopolymers that can disintegrate fast in the oral cavity and deliver drugs. Jelly fig polysaccharide (JFP) and pullulan were blended to prepare fast-dissolving nanofiber by electrospinning. The continuous and uniform nanofibers were produced from the solution of 1% (w/w) JFP, 12% (w/w) pullulan, and 1 wt% Triton X-305. The SEM images confirmed that the prepared nanofibers exhibited uniform morphology with an average diameter of 144 ± 19 nm. The inclusion of JFP in pullulan was confirmed by TGA and FTIR studies. XRD analysis revealed that the increased crystallinity of JFP/pullulan nanofiber was observed due to the formation of intermolecular hydrogen bonds. The tensile strength and water vapor permeability of the JFP/pullulan nanofiber membrane were also enhanced considerably compared to pullulan nanofiber. The JFP/pullulan nanofibers loaded with hydrophobic model drugs like ampicillin and dexamethasone were rapidly dissolved in water within 60 s and release the encapsulants dispersive into the surrounding. The antibacterial activity, fast disintegration properties of the JFP/pullulan nanofiber were also confirmed by the zone of inhibition and UV spectrum studies. Hence, JFP/pullulan nanofibers could be a promising carrier to encapsulate hydrophobic drugs for fast-dissolving/disintegrating delivery applications

Natural biocompatible polymer-based polyherbal compound gel for rapid wound contraction and promote re-epithelialization: An in vivo study

Polyherbal biocompatible natural polymer gel was prepared to study the wound healing properties in skin tissue engineering. The natural biopolymer-based polyherbal gel mimicked the extracellular matrix (ECM) properties and had a strong antioxidant and anti-inflammatory properties. In vitro cell viability was examined using male foreskin fibroblasts (HS68) and the results revealed that the polyherbal compound gel was biocompatible and nontoxic and could improve the cell viability significantly. In vivo wound healing results showed faster, significant wound contraction (p < 0.001), and reduced re-epithelialization (p < 0.001) in polyherbal gel treatment compared to the control. Hence, the polyherbal gel developed in this study could be a promising material for wound healing applications

Raw data for the figures in the manuscript from Reduced graphene oxide-loaded nanocomposite scaffolds for enhancing angiogenesis in tissue engineering applications

MS-Excel file with the raw data for all the figures in the manuscrip