Farah Maqsood

The present investigation examines the magnetohydrodynamic behavior of a SWCNT–MWCNT/water hybrid nanofluid flowing over porous configurations, specifically cones, wedges, and flat plates, in the presence of thermal radiation and microbial bioconvection incorporating coupled Soret–Dufour effects. The governing nonlinear partial differential equations are reduced to a system of ordinary differential equations through suitable similarity transformations and subsequently solved using a robust boundary value problem solver. The analysis demonstrates that an increase in magnetic field intensity and Forchheimer resistance substantially decelerates the fluid motion, leading to a velocity reduction of approximately 25%–30%, while concurrently intensifying thermal and concentration fields by nearly 15%–22% due to enhanced Lorentz force interactions. The combined influence of thermal radiation and the Dufour effect significantly promotes heat transport, resulting in a 10%–18% elevation in temperature, whereas porous medium characteristics further facilitate this enhancement. Conversely, elevated magnetic and thermal parameters contribute to a decline in nanoparticle concentration and micro‐organism density by about 12%–20%, indicating regulated particle dispersion and attenuation of bioconvective strength. Geometrical variations play a crucial role, with the flat plate exhibiting comparatively higher velocity profiles, while the cone geometry experiences greater resistance due to curvature effects. Furthermore, microbial dynamics are observed to considerably influence flow stability and mass transfer characteristics. Overall, the study elucidates the complex interplay among electromagnetic forces, thermal radiation, cross‐diffusion mechanisms, and microbial activity, offering valuable insights for the design and optimization of hybrid nanofluid systems in advanced thermal management, biomedical engineering, microfluidics, and environmental applications.

Introduction: Corneal biomechanics is a relatively new discipline of research that focuses on the physical and biological interactions in the anterior part of the eye. Corneal biomechanics is influenced by a wide range of variables, including environmental influences, hydration, and hormone changes. Central Corneal Thickness (CCT), Intraocular Pressure (IOP), and age are other variables that might impact the corneas. The biomechanical properties of the cornea, at any level of cell to tissue to the sub-organ, might cause serious corneal diseases. Aim: To measure the corneal biomechanial properties in healthy Saudi females. Materials and Methods: This cross-sectional study was conducted in the Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia on 53 right eyes of Saudi female participants from April 2021 to April 2022. The IOP, CCT, and the corneal biomechanical properties at the first applanation (timeT1, velocity-V1, length-L1, deformation amplitude-DA1), second applanation (time-T2, velocity-V2, length-L2, deformation amplitude-DA2), highest concavity (Highest Concavity Time-HCT, Highest Concavity Radius-HCR, Highest Concavity Deformation Amplitude-HCDA), and Peak Distance (PD) were evaluated by using Corneal Visualisation Scheimpflug Technology (CST) whereas, Ocular Response Analyser (ORA) was used for the comparison of biomechanical properties. The statistical analysis of the data was done by applying statistical package IBM Statistical Package for the Social Sciences (SPSS) (version 24) and conducting Analysis of Variance (ANOVA) tests. Results: The mean age of the participants was 20.74±1.89 years, mean Spherical Equivalent (SE) refraction was -1.41±1.97 Diopters (D), the mean IOP was 16.82±1.96 mmHg, and the mean CCT was 569.43±27.22 μm for the right eyes. The results showed that the two most affecting factors in the biomechanical parameters were IOP and CCT. A potential association was found between first applanation time (T1) and corneal speed during the first applanation (V1) for both IOP and CCT (p<0.001) in the linear regression analysis, while a significant difference was observed in V1 (p=0.029) in SE. In the second applanation, a significant association was found in T2 with IOP (p<0.001) and CCT, cord length of the second applanation (L2) with CCT, and V2 with SE, IOP, and CCT was observed. A significant association between time and SE (p=0.034) was notice in the highest concavity parameter. However, deformation amplitude exhibited the significant association between SE and IOP, radius with IOP and CCT, and the PD with SE, IOP, and CCT (p<0.001). Conclusion: Most of the corneal biomechanical parameters were affected with CCT and IOP. Thus, the biomechanical characteristics of the cornea can be used to compare normal eyes with pathological eyes.

Background. Magnesium oxide nanoparticles (MgONPs) have been fabricated by several approaches, including green chemistry approach due to diverse application and versatile features. Objectives. The current study aimed to prepare a convenient, biocompatible, and economically viable MgONPs using waste citron peel extract (CP‐MgONPs) to evaluate their biological applications. Methods. The CP‐MgONPs were synthesized by a sustainable approach from extract of waste citron peel both as capping and reducing agents without use of any hazardous material. The physicochemical features of formed CP‐MgONPs were determined by sophisticated analytical and microscopic techniques. The biogenic CP‐MgONPs were examined for their antibacterial, anticarcinogenic, and photocatalytic attributes. Results. A prominent absorption peak in the UV‐Vis spectra at 284 nm was the distinguishing characteristic of the CP‐MgONPs. The scanning electron microscopy (SEM) reveals polyhedral morphology of nanoparticles with slight agglomeration of CP‐MgONPs. The CP‐MgONPs exerted excellent antibacterial potencies against six bacterial strains. The CP‐MgONPs displayed significant susceptibility towards E. coli (20.72 ± 0.33 mm) and S. aureus (19.52 ± 0.05 mm) with the highest inhibition zones. The anticancer effect of CP‐MgONPs was evaluated against HepG2 (IC₅₀ : 15.3 μg·mL⁻¹) cancer cells and exhibited potential anticancer activity. A prompt inversion of cellular injury manifested as impairment of the integrity of the cell membrane, apoptosis, and oxidative stress was observed in treated cells with CP‐MgONPs. The biosynthesized CP‐MgONPs also conducted successful photocatalytic potential as much as MgO powder under the UV‐light using acid orange 8 (AO‐8) dye. The degradation performance of CP‐MgONPs showed over 94% photocatalytic degradation efficiency of acid orange 8 (AO‐8) dyes within a short time.​ Conclusions. Outcomes of this research signify that biogenic CP‐MgONPs may be advantageous at low concentrations, with positive environmental impacts.

Introduction: A non contact specular microscope has been used to acquire the morphology of the corneal endothelial cell layer. This analysis provides measurements of the Coefficient of Variation (CV), the hexagonal appearance of the cells, and the mean corneal Endothelial Cell Density (ECD). These parameters are used to assess the function of the corneal endothelial layer. Aim: To evaluate the average corneal ECD, Hexagonality (HEX), CV, and their relationship with myopia in young females. Materials and Methods: The present cross-sectional study was conducted over a period of five months, from November 2016 to March 2017 at the clinics of the Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia and involved 107 eyes of healthy subjects aged 18-25 years. The participants’ refraction was estimated using an automatic refractor. Non contact specular microscopy was performed on emmetropic and myopic subjects. The average of three successive estimations of ECD, hexagonal appearance, and CV in cell size were recorded. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) program (version 22.0), and the independent student’s t-test was used to compare the means of various variables between low and moderate myopia. Results: The study included the right eyes of 107 healthy Saudi female subjects aged 18-25 years, who were divided into three groups based on their refractive errors. Non contact specular microscopy was performed on emmetropic (n=36, 20.58±1.20 years and mean Spherical Equivalent (SE) of -0.01±0.23 D), low myopic (n=49, 20.63±1.51 years and SE of -1.19±0.68 D), and moderate myopic (n=22, 20.64±1.26 years with mean SE of -4.15±0.90 D) subjects. The mean ECD in low myopic eyes was 2799.59±184.39 per square millimetre, the mean CV was 26.67±4.03 percent, and the mean hexagonal appearance of the cells was 67.69±4.82%. The average ECD, mean CV, and hexagonal appearance in moderate myopic eyes were found to be 2722.36±143/mm2 , 26.68±3.57%, and 68.73±5.87%, respectively. The results showed no statistically significant differences in ECD (p>0.05) and hexagonal appearance (p>0.05) in the cells of moderate and low myopic eyes. Conclusion: The present study found no significant relationship between corneal endothelial parameters and mild to moderate myopic eyes.

Aluminum oxide nanoparticles (Al₂O₃ NPs) were synthesized using a simple, eco-friendly green synthesis approach in an alkaline medium from the extract of grapefruit peel waste. The pre-synthesized, nano-crystalline Al₂O₃ NPs were characterized by using spectroscopic (UV–vis, FTIR, XRD, and EDX) and microscopic (SEM and TEM) techniques. The formed Al₂O₃ NPs exhibited a pronounced absorption peak at 278 nm in the UV–vis spectrum. The average particle size of the as-prepared Al₂O₃ NPs was evaluated to be 57.34 nm, and the atomic percentages of O and Al were found to be 54.58 and 45.54, respectively. The fabricated Al₂O₃ NPs were evaluated for antioxidant, anti-inflammatory, and immunomodulatory properties. The Al₂O₃ NPs showed strong antioxidant potential towards all the four tested assays. The anti-inflammatory and immunomodulatory potential of Al₂O₃ NPs was investigated by measuring the production of nitric oxide and superoxide anion (O₂^•−), as well as proinflammatory cytokines tumour necrosis factor (TNF-α, IL-6) and inhibition of nuclear factor kappa B (NF- κB). The results revealed that Al₂O₃ NPs inhibited the production of O₂^•− (99.4%) at 100 μg mL⁻¹ concentrations and intracellular NO^•− (55%), proinflammatory cytokines IL-6 (83.3%), and TNF-α (87.9%) at 50 μg mL⁻¹ concentrations, respectively. Additionally, the Al₂O₃ NPs inhibited 41.8% of nuclear factor kappa B at 20 μg mL⁻¹ concentrations. Overall, the outcomes of current research studies indicated that Al₂O₃ NPs possess anti-inflammatory and immunomodulatory properties and could be used to treat chronic and acute anti-inflammatory conditions.