The occurrence of vibrational resonance (VR) in a modulated spatially varying periodic system is investigated in this study. A modulation profile possessing a harmonic order is exerted on a spatially periodic function to yield a modulated landscape. The dual-frequency driven modulated system is subsequently treated within the separation of motion scheme, to yield a quantifier for VR in the form of response amplitude. Applying a linearly damped regime, within the domain of the fast field drive and for different values of the harmonic order, multiple resonances were detected in the response profile for particular values of the weak excitation frequency component. All analytical deductions were confirmed through numerical simulations, which demonstrated a reasonable level of agreement. Comparisons with related studies reveal the distinctive influence of harmonic order modulation in enhancing and transforming VR responses for specific operating values of field parameters. The impact of the modulating function in transforming features of the forced system, viz., effective potential and resonant frequency under VR analysis, provides avenues of active enrichment of the output signal at the low frequency. These unique characteristics may provide pertinent prospects for dynamical systems that adopt spatially periodic states.
This study developed whey protein concentrate (WPC)-polysaccharide (arabinoxylan and carboxymethyl chitosan) conjugates via high-pressure homogenization (HPH)-assisted enzymatic glycosylation for stabilizing oil-in-water high internal phase emulsions (HIPEs). Optimal conjugation at 30 MPa significantly enhanced the functional properties of WPC, including solubility, emulsifying, and foaming activities, while reducing its particle size and increasing absolute zeta potential. Meanwhile, structural analysis indicated protein unfolding, evidenced by a decrease in ordered secondary structures (α-helix, β-sheet, β-turn) and an increase in random coils, which facilitated the adsorption of the conjugation at the oil-water interface. Compared with the control group, the HIPEs stabilized by the conjugates exhibited smaller droplet size, higher absolute zeta potential, uniform microstructure, significantly improved oxidative stability, elasticity-dominated characteristics with a significant increase in apparent viscosity, and excellent storage stability during the storage period.
In this study, ternary complexes were constructed using whey protein concentrate (WPC), sodium caseinate (SC), arabinoxylan (AX), and quercetin (Q), named WPC-AX-Q and SC-AX-Q, respectively, and their structural and functional properties were systematically characterized and compared with individual protein, protein/AX mixture and protein-AX binary conjugate. High internal phase emulsions (HIPEs) were also prepared to investigate their effects on the stability and fat digestion in the HIPEs. Results from fluorescence spectroscopy and Fourier transform infrared spectroscopy (FTIR) revealed notable alterations in the structure of milk proteins, suggesting interactions among milk proteins, AX and Q. Dynamic investigation into interfacial characteristics revealed that, in comparison to proteins alone, the ternary complexes exhibited lower interfacial tension and greater adsorption ability at the oil-water interface. Additionally, the ternary complexes showed a marked decrease in surface hydrophobicity and a notable increase in solubility, along with the most powerful foaming, emulsifying, and antioxidant capabilities compared with protein, protein/AX mixture and protein-AX binary conjugate. The stability of HIPEs stabilized by the ternary complexes was confirmed through rheological and microstructure studies. HIPEs stabilized by the ternary complexes exhibit superior environmental and in vitro digestive stability, and can mitigate the extent of lipid oxidation, delay and reduce the release of free fatty acids. This research offers theoretical backing for how the combined effect of polysaccharides and polyphenols impacts protein structure and properties, as well as the enhancement of fat digestion traits in HIPEs.
Patients with fractures require internal fixations, since treatment options are limited to metallic implants and autologous bone grafts. These limitations include chances of infection transference, quantity restrictions and the need for additional surgery. Bone tissue engineering seeks to address these limitations through the development of biocompatible bone scaffolds. This study fabricated a PLA based scaffold that sought to address some of the challenges associated with currently available treatment options. The methodology involved acquiring raw eggshells, which were rinsed with water and calcined with concentrated H3PO4. Hitherto, HAp powder was extracted from eggshells, and its presence was confirmed using color test. PLA (60,000 molecular weight) was procured from Sigma Aldrich, which was used with HAp powder, to form the composite, employing sol gel technique. SEM morphology established PLA, which has polymeric binding properties, as the 3D scaffold with the highest Ct (PLA/HAp (45/55 wt.%). It had a more consistent crystal and pore formation and weaker grain boundaries. FTIR analysis showed PLA characterizing peaks, and that functional groups present in 3D scaffold are not toxic to the body. X-RD spectra confirmed PLA and HAp presence in 3D scaffolds. However, peaks intensities decreased with lower Ct of HAp, and those of PLA increased in the 3D scaffold. This indicates that PLA and HAp particles have semi-crystalline and crystalline structures, respectively. Thus, 3D scaffolds can be tailored for many biomedical applications.
In the present study, ultrasonication combined with enzymatic covalent bonding with arabinoxylan (AX) induced by laccase were used to modify the conformational and functional properties of whey protein concentrate (WPC), and the effects on high internal phase emulsions (HIPEs) were also investigated. The results showed that the optimal covalent reaction mass ratio of AX to WPC was 3:2 through characterization, and 10 min ultrasonication-pretreatment of WPC facilitated the formation of WPC-AX conjugates and improvement of solubility and emulsifying property. The WPC-AX conjugates can quickly adhere to the oil-water interface and form a more compact three-dimensional network structure. The formation of this structure can slow down the oxidation rate of the encapsulated oil droplets. The HIPEs formed by WPC-AX conjugates exhibited smaller droplet size, uniform microstructure, elasticity-dominated characteristics with a significant increase in apparent viscosity and better stability during the process of gastric digestion.
