Journal of Biological Physics最新文献

Eyring-Powell nanofluids have great potential for use in biomedical engineering to create more effective medical procedures and treatments due to their special properties of fluidity, efficient heat transfer, and interaction with biological systems. This study investigates bioconvection flow and its heat transfer characteristics of the magnetohydrodynamic ternary hybrid nanofluid containing silver, copper, and aluminum nanoparticles with human blood. The forced convection in a porous media, radiation, and viscous dissipation have been considered. The governing equations are reduced to dimensionless partial differential equations and further simplified using the local non-similarity method to obtain ordinary differential equations, which were solved numerically using the BVP4C algorithm. The results indicate that the concentration profiles reduce with inertia coefficients and Schmidt numbers, while radiation parameters increase the surface temperature. A higher Lewis number accelerates thermal diffusion, in contrast to mass diffusion. Fast dissipation of temperature prevents microbial growth and is useful in applications dealing with medicine administration and wound healing. These results support existing research and provide recommendations for further improvement of industrial and biological processes. As the (M) rises from (0.1) to (1,) the Nusselt number declines as follows: for (Ag) by around (4.48%-2.82%), for (Ag+Cu) by (13.57%, -7.58%) and for (Ag+Cu+Al) by (17.21%-12.53%). The Nusselt number increases around (1.01%-1.64%) as (lambda) rises from (0.1) to (0.3) for (Ag), for (Ag+Cu) by the Nusselt number increases by (6.77%-13.80%) and for (Ag+Cu+Al) by (13.84%-15.10%). The article proposes non-similar transformations for solving complex problems on the movement of ternary nanofluids. This provides insight into medical applications such as drug delivery and diagnostic tools and advances nanofluidic dynamics in healthcare.

Cytomegalovirus (CMV) is a significant clinical pathogen posing risks, especially for immunocompromised individuals. This study investigates the transport dynamics of CMV within viscoelastic saliva, focusing on factors influencing viral mobility. We employed mathematical models, including the Basset-Boussinesq-Oseen (BBO) equation, to analyze how viral density, particle diameter, saliva viscosity, and external electric and magnetic fields affect CMV movement in the oesophagus. Novel insights include the discovery that smaller CMV particles move significantly faster compared to larger ones, highlighting a critical aspect of viral infectivity. Additionally, we found that increased peristaltic wave amplitudes in the oesophagus greatly enhance viral velocity. More notably, our investigation reveals that the application of external magnetic fields can manipulate CMV transport by exerting forces that reduce viral mobility, thus potentially lowering infection rates through electromagnetic interactions. These findings underscore the complex interplay between fluid rheology, particle shape, and external fields in viral dynamics, suggesting novel therapeutic interventions aimed at controlling CMV spread based on saliva viscosity and electromagnetic manipulation. Our research paves the way for innovative strategies in viral infection management and therapeutic development.

Bone-substituted composite material based on bioceramics and polymer has enhanced their biological performance with dynamic properties such as bioactivity, biocompatibility, osseointegration, and mechanical stability, which can be used in a controlled drug delivery system for avoiding infections as well as pain. Here in this study, we developed a new approach for inducing antibacterial and osteogenic responses on biomaterial substrates via surface polarisation. The hydroxyapatite- sodium alginate composite was negatively polarised using a corona poling setup and characterised using X-ray diffraction analysis. The thermally stimulated depolarization current study showed a maximum current of 4.74 nA/cm², observed at a temperature of 480 °C. The wettability of the specimen was measured using contact angle measurements, which demonstrated that the polarised composite specimen exhibited higher water retention ability. The bacterial cell viability test was measured using the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay, which revealed poor bacterial growth on polarised specimens as compared to their unpolarised counterparts. In addition, the osteogenic MG63 cell proliferation showed increased gene expression on polarised specimens. These findings showed that polarising hydroxyapatite- sodium alginate composite could be an excellent option to be used as an antibacterial bone filler matrix for faster healing as it showed both antibacterial and osteogenic activity.

The increasing prevalence of microplastics in water sources poses significant threats to both human health and environmental sustainability. Bisphenol A (BPA) and polyethylene terephthalate (PET), two hazardous microplastic contaminants, are known to cause endocrine disruption and other health risks. This study investigates the potential of graphene oxide (GO) as an efficient adsorbent for the removal of these contaminants through detailed molecular interaction analysis. The adsorption efficiencies of GO were quantitatively assessed, demonstrating strong binding affinities of ∆G = − 9.50 kcal/mol for BPA and ∆G = − 6.90 kcal/mol for PET. The adsorption process is primarily governed by π-π stacking interactions between the aromatic structure of the microplastics and the polycyclic surface of GO, with additional contributions from hydrogen bonding and van der Waals forces. Computational simulations revealed consistent binding across specific active sites on the GO surface, indicating minimal variation in adsorption performance. These findings highlight the potential of GO-based filtration systems for large-scale water treatment applications, offering a promising approach to mitigating microplastic contamination and ensuring safer water supplies. These findings highlight the potential of GO-based filtration systems for large-scale water treatment applications, offering a promising approach to mitigating microplastic contamination and ensuring safer water supplies. Future research should focus on optimizing GO-based filtration techniques and exploring their long-term environmental impact. 

The Epstein-Barr virus affects more than 90% of the world population and, consequently, is a virus whose infection dynamics should not be overlooked. It can cause the disease infectious mononucleosis and comes with other virus-associated diseases and conditions ranging from certain cancers to episodes of fatigue and depression. While previous epidemiological and virological modeling studies have worked out the details of possible infection dynamics scenarios, the current study takes a different approach. Using a nonlinear physics perspective and a fairly general epidemiological model, we identify the essential EBV infection dynamics along its so-called infection order parameter. We demonstrate that the essential dynamics describes the initial path that EBV infections take in the multi-dimensional model space. In particular, we show that the essential dynamics predicts the initial dynamics of the relevant subpopulations and describes how the subpopulations involved in an EBV infection outbreak organize themselves during the outbreak. Intervention and prevention measures are discussed in the context of the nonlinear physics perspective. An adverse synergy effect between two infection rate parameters is identified. An early warning system based on the so-called critical slowing down phenomenon is proposed for EBV infection waves in college and university student populations, which are populations particularly vulnerable to EBV infections.

Magnesium-based implants are highly valued in the biomedical field for biocompatibility and biodegradability, though their inherent low strength in body fluids is a limitation. This study addresses this by alloying magnesium with zinc and titanium to enhance its properties. Mechanical alloying was used to synthesize binary (Mg-Zn, Mg-Ti) and ternary (Mg-Zn-Ti) alloys, which were then compacted and sintered. The alloy powders, composed of 10 wt% Zn and 5 wt% Ti, were milled at 360 rpm for 10 h. Microstructural analysis revealed uniformly dispersed particles, with SEM confirming spherical and fine particles alongside laminates. XRD identified intermetallic compound formation. The ternary alloy demonstrated superior micro-hardness and Young’s modulus similar to human bone, making it particularly promising for biomedical applications. Incorporating zinc and titanium into the magnesium matrix resulted in a ternary alloy that outperformed its binary counterparts.

This study evaluates the unsteady laminar flow and heat and mass transfer of a nanofluid in the appearance of gyrotactic microorganisms. In this analysis, using the Darcy–Forchheimer flow inside the vicinity of a nonlinearly stretched surface with Brownian motion and thermophoresis impacts. Similarity conversion is familiar with reduced governing models into dimensionless variables, and “bvp4c,” a MATLAB solver, is employed to find the computational outputs of this analysis. This analysis reports that the use of nanofluids provides better thermal characteristics which are helpful to enhance the heat transfer coefficient. Graphs for this analysis are created for distinct values of non-dimensionless parameters, whereas the coefficient of surface drag, heat flux, mass flux, and rate of microorganism density are all interpreted numerically and graphically. The high level of resistance provided by velocity slip and Forchheimer parameters leads to a decrease in velocity curves while an increment is seen in the temperature profile. It is also remarked that bioconvection Peclet number induces a decrement in the density distribution of motile microorganisms. In addition, it has been observed that the Nusselt number for a nonlinear stretching sheet is better as compared to a linear stretching sheet.

Conventional kinesin protein is a prototypical biological molecular motor that can step processively on microtubules towards the plus end by hydrolyzing ATP molecules, performing the biological function of intracellular transports. An important characteristic of the kinesin is the load dependence of its velocity, which is usually measured by using the single molecule optical trapping method with a large-sized bead attached to the motor stalk. Puzzlingly, even for the same kinesin, some experiments showed that the velocity is nearly independent of the forward load whereas others showed that the velocity decreases evidently with the increase in the magnitude of the forward load. Here, a theoretical explanation is provided of why different experiments give different dependencies of the velocity on the forward load. It is shown that both the stalk orientation and bead size play a critical role in the different dependencies. Additionally, the reason why the optical trapping experiments with the movable trap usually gave a sigmoid form of the velocity versus backward load whereas with the fixed trap gave a nearly linear form is also explained theoretically. The study is not only critical to the understanding of the response of the motor to the load but also provides strong insights into the coupling mechanism of the motor.

Graphical Abstract

The present article focuses on the analysis of the two-phase flow of blood via a stenosed artery under the influence of a pulsatile pressure gradient. The core and plasma regions of flow are modeled using the constitutive relations of Herschel-Bulkley and the Newtonian fluids, respectively. The problem is modeled in a cylindrical coordinate system. A modest stenosis assumption is used to simplify the non-dimensional governing equations of the flow issue. An explicit finite difference approach is used to solve the resultant nonlinear system of differential equations while accounting for the provided boundary conditions. After the necessary adjustments have been made to the crucial non-dimensional parameters, an analysis of the data behind the huge image, such as axial velocity, temperature field, concentration wall shear stress, flow rate, and flow impedance, is conducted. The current study shows that the curvature of blood vessels plays a significant role in influencing blood velocity. Specifically, a unit increase in the curvature radius results in a 24% rise in blood velocity.