Michael Okpara University of Agriculture

Abstract The accelerated growth of population and the rise in the number of vehicle owners are expected to create a sharp demand in the global market for brake pads, which will exert an acute demand to substitute asbestos-containing materials. Asbestos, which was previously employed in friction composites, is dangerous and does not withstand hot climates; hence, substitutes with safer ones are required. This paper explores the utilization of doum palm shell (DPS) as an agro-waste that contains silica as a reinforcement in asbestos-free brake pads manufactured using phenolic (PR) and epoxy (EP) binders. DPS is biodegradable, economical, and locally available, and it helps in valorizing waste and recovering resources that are sustainable. Graphite, glass fibre, aluminium oxide, and alkali-treated DPS were used to create brake pads. FTIR analysis showed better bonding, and TGA showed better thermal stability in EP and more char yield with better flame resistance in PR. Compressive strengths of EP samples of 47–77 MPa and impact energies of 4.27–7.09 J/m² were obtained in mechanical tests, compared to 70.12–80.20 MPa and 8.75 J/m² in PR samples. Hardness peaked at 95.6 Hv in S1PR. The tribological analysis showed that PR composites had lower wear levels and increased friction coefficients, while EP had high thermal resistance and lower water absorption (0.098%). The best performance was recorded in S2PR with 20 g DPS and 15 g glass fibre, which had a balance between strength and friction. Phenolic binders outperformed epoxy in tribological criteria, while epoxy had greater heat stability. The results reveal that DPS is a potential reinforcement in the manufacturing process of sustainable brake pads. Future research ought to address fade and recovery behaviour, thermo-mechanical coupling, and long-term durability. Graphical Abstract

The current therapeutic agents for diabetes provide glycemic control but not without adverse effects, necessitating the investigation of safe and effective alternatives. This research investigated the potential of a flavonoid-rich extract of Pteridium aquilinum (PAFRE) in the treatment of diabetes, employing an integrated in silico, in vitro, and in vivo approach. The DPP4 inhibitory potential of PAFRE was studied using an in vitro and in silico model, while the antihyperglycemic effect of PAFRE was studied in an alloxan-induced diabetic rat model. Thirty albino rats randomly assigned to five groups were used and given different treatments: Group 1, normal control; Group 2, diabetes control; Groups 3 and 4, diabetic rats treated with 100 mg/kg b.w. and 200 mg/kg b.w. of PAFRE, respectively; Group 5, diabetic rats treated with glibenclamide (5 mg/kg b.w.) for 14 days. The compounds of PAFRE identified by GC-MS were docked for inhibitory potential against DPP-4 using AutoDock in PyRx and Discovery Studio. In vitro assays revealed that PAFRE possesses potent inhibitory activity against DPPH and DPP-4. The in silico molecular docking supported these findings, showing high binding affinity of identified phytocompounds to the active site of DPP-4, comparable to that of a standard inhibitor (Alogliptin). An in vivo study showed that PAFRE administration significantly (p < 0.05) reduced fasting blood glucose, modulated antioxidant enzyme activities (SOD, CAT, GPx), and suppressed lipid peroxidation (MDA), thereby mitigating oxidative stress while attenuating dyslipidemia, liver enzyme dysfunction, and renal damage. These findings suggest that PAFRE exhibits antidiabetic effects by attenuating oxidative stress and inhibiting DPP-4 activity, highlighting P. aquilinum flavonoids as promising candidates for the development of natural therapeutics for managing diabetes mellitus.

The application of artificial intelligence (AI) based model like ResNet50 has been examined for crop disease detection through computer vision algorithms, which has potential integration into remote sensing systems. Detecting diseases early is beneficial to decrease crop damage and for optimized usage of pesticides in precision agriculture. We used a dataset of more than 20,000 crop images labelled. Further, we selected 5650 samples for the model training and testing after preprocessing and augmentation. The accuracy, precision, recall, and F1-score were used to evaluate the models. ResNet50 produced the best performance with an accuracy of 91.3

This study employs a combined Density Functional Theory (DFT) and Molecular Dynamics (MD) approach to elucidate the corrosion inhibition mechanism of daidzein on the Al(AA7075) surface in a NaCl environment. DFT results reveal that the neutral daidzein molecule (DZIN) possesses favorable electronic characteristics for adsorption, including a relatively small HOMO-LUMO energy gap of 4.398 eV, an ionization potential of 6.101 eV, and a high electrophilicity index of 3.462 eV, indicating strong electron-donation and acceptance capabilities. The fractional electron transfer (ΔN = 0.231) confirms efficient charge exchange with aluminum, supported by a low chemical hardness (η = 2.199 eV) and high softness (σ = 0.455), which collectively enhance its surface reactivity. Molecular Electrostatic Potential (MEP) and Mulliken charge analyses further identify carbonyl and hydroxyl oxygen atoms as dominant adsorption centers due to their highly negative potentials. Complementary MD simulations demonstrate that neutral daidzein exhibits a remarkably strong interaction energy of -130.23 kcal mol-1, significantly outperforming its protonated form (-35.55 kcal mol-1), enabling it to form a compact, adherent protective film through π-metal interactions and van der Waals stabilization. The combined DFT-MD findings confirm that the superior inhibition performance of daidzein arises from its strong electron-donating functional groups, favorable charge-transfer characteristics, and highly stable adsorption configuration on aluminum, making it a highly efficient, bio-derived corrosion inhibitor for mitigating chloride-induced degradation of Al(AA7075) surfaces.

As the population ages, cognitive decline and neurodegenerative diseases have become major public health concerns. The human gut microbiota plays a major role in regulating neurodevelopment, neuroinflammation, and cognitive decline through the gut-brain axis. Emerging evidence reveals a possible association between alterations in gut microbial diversity and age-related neurological disorders, including Alzheimer’s disease and neurodegeneration. Regional and dietary differences shape the gut microbiome. These variations may, in turn, be associated with differences in brain aging across populations. Several cross-sectional studies indicate that rural African communities consuming predominantly fiber-rich diets exhibit distinct gut microbiota profiles characterized by increased abundance of genera, including Prevotella, Faecalibacterium, and Ruminococcus. These microbial configurations have been associated with improved gut barrier integrity, reduced systemic inflammation, and enhanced production of short-chain fatty acids in some preclinical and human studies. All these factors have been studied as potential mechanisms linked to delayed brain aging. Furthermore, epidemiological reports suggest lower prevalence rates of dementia and other neurodegenerative disorders in these populations, although such comparisons may be influenced by differences in study design, diagnosis, and case ascertainment across regions. This narrative review synthesized current understanding of the gut microbiota’s role in brain aging, summarized available data on gut microbiota composition in African versus Western populations, and explored the pathways by which traditional African diets may contribute to neuroprotection. By critically examining this evidence and highlighting major research gaps, the review advocates for region-specific investigations and future longitudinal studies to validate causal links.