The prevalence and risk factors of myopia among school children in Africa: a structured literature review

Aim: This review aims to provide current evidence on the prevalence and risk factors of Myopia among school children in Africa.Background: Myopia has emerged the most prevalent and major cause of visual distress which may result in poor academic performance among school children compared to other refractive error conditions. Whereas the importance of optimal vision for competence in academic achievement has been emphasised. Hence, the association of increase in myopia prevalence with increase in age coupled with its projected critical rise to 26.9% in Africa by 2050 is worrisome.Methodology: This review was conducted using the population, intervention, comparison, outcome (PICO) framework guidelines and PRISMA 2020 Flow Diagram for New systematic Reviews. Also, four digital databases; MEDLINE, CINAHL, PROQUEST, WEB OF SCIENCE and a Web Search Engine (Google scholar) were searched for studies on Prevalence and Risk factors of myopia among school children in Africa from January 2012 to March 2023. Studies were appraised for quality using Joanna Briggs Appraisal tool for prevalence studies. Data were analysed based on age, gender, and risk factors of myopia, while the myopia was defined as SE ≥-0.50D.Results: Data from 10,031 school children and 6 quality appraised studies were included in this review. Overall, the prevalence of myopia ranged from 2.7% to 16.05% among school children in Africa. The prevalence of myopia was significantly higher among the older children (10–18-yearolds), while Age at school start, Level of education, family history of myopia, working distance atnear, prolonged near work per day, private school of learning, time spent on mobile exposure, and presence of ocular abnormality were significantly associated with myopia.Conclusion: Prevalence of myopia among school children is generally low in Africa but the retrieved studies offered geographical variations with outlying higher prevalence in some regions

SYNTHESIS, MODIFICATION, AND CHARACTERISATION OF FUNCTIONAL POLYURETHANE COATING SYSTEMS FROM CASTOR OIL

Environmental challenges have driven production science towards using biodegradable and sustainable feedstocks for product development. Developing sustainable and high-performance coating materials to address the environmental concerns and technical demands of modern industries has become so critical that plant seed oils are considered viable renewable feedstocks capable of substituting petrochemical-based materials in polymeric material preparation. This study reports the synthesis and characterisation of functional organic polyurethane coatings from castor bean seed oil (CSO) (Ricinus communis seed oil). Graphene nanoparticles were modified into graphene oxide and incorporated within the polyurethane polymer matrix in a one-pot synthesis. Also, aminopropyltrimethoxysilane (APTMS) was used to alter silica nanoparticles and was incorporated into the polyurethane system. Bisphenol A and trimethylolpropane (TMP) were used as extenders, and their influences on the coating properties were also examined in the urethane systems. Physicochemical analysis of the feedstock and prepared coating formulations was conducted. Structural evaluation of synthesised materials was performed using proton nuclear magnetic resonance (1H NMR) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Synthesised urethane coatings were cured on silicon resin mould and mild steel. Thermal stability and crystallinity of pristine and composite films were studied using thermogravimetric analysis (TGA) and X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to analyse surface morphology. Water contact angle analysis revealed the hydrophobicity of the synthesised urethane films. Solubility, anticorrosive, and antimicrobial properties of prepared materials were evaluated. Spectroscopic analysis confirmed the structure of modified nanomaterials, pristine, and composite films. Surface morphology and photographic images showed successful incorporation of nanomaterials (graphene oxide and hybrid APTMSmodified silica) within the polymer matrix. Thermal stability, anti-corrosive, and antimicrobial properties of the coating films were enhanced with increasing percentages of nanomaterials in the polyurethane systems. Coating films exhibited improved hydrophobicity with rising percentages of modified nanoparticles. Film photographic retention tests showed no particle agglomeration and high transparency at 0.5% graphene oxide composition (0.5% PU-GO). It also shows that the polymer with 0.5% PU-GO is the most thermally stable. Similarly, composite films of modified silica in CSO showed enhanced thermal stability, hydrophobicity, antimicrobial activity, and corrosion resistance. The polymer with 5% PU-SNP was the most thermally stable at high temperatures. It also has the highest water contact angle and lowest corrosion rate, hence the most hydrophobic and corrosion resistant. In conclusion, the 0.5% loading of modified graphene oxide (0.5% PU-GO) nanoparticles is the optimum loading in applications requiring low and high temperatures. At the same time, 5% loading is the optimum loading of APTMS-modified silica (5% PU-SNP) in applications that require high temperature. These results present a viable, sustainable alternative for various industrial applications

The Effects of Rabbit Compost Tea and NPK Fertilizer on the Growth Parameters of Maize (Zea mays L.)

This study evaluates the effects of rabbit compost tea and NPK (15-15-15) fertilizer on the growth parameters of maize (Zea mays L.) at the Teaching and Research Farm of Ekiti State Polytechnic, Isan-Ekiti. The treatments were laid out in a randomized complete block design (RCBD) with three replicates. Each replicate consisted of four (4) treatments. Total land area measured 88 m2 (11 m by 8 m) with 12 plots, and each plot size measured 3 m by 2 m (6 m2) with 1 m alleyways between plots and replicates. The treatments and application rate were the control, rabbit compost tea at 400 l ha-1, a combination of NPK at 100 kg ha-1 and rabbit compost tea at 200 l ha-1, and the application of NPK (15-15-15) fertilizer at the rate of 200 kg ha-1, which was incorporated as the experiment's standard treatment. In the experiment, growth parameters of maize (Zea mays L.) were monitored and evaluated. Findings showed that the application of rabbit compost tea and NPK (15-15-15) fertilizer significantly (p < 0.05) increased the plant height, stem girth, number of leaves, and leaf area when compared with the control, especially when combined. According to this study, rabbit compost tea is an effective and sustainable organic amendment that smallholder maize farmers should consider using to improve growth and output

Attenuation of Vanadium-Induced Neurotoxicity in Rat Hippocampal Slices (In Vitro) and Mice (In Vivo) by ZA-II-05, a Novel NMDA-Receptor Antagonist

Exposure to heavy metals, such as vanadium, poses an ongoing environmental and health threat, heightening the risk of neurodegenerative disorders. While several compounds have shown promise in mitigating vanadium toxicity, their efficacy is limited. Effective strategies involve targeting specific subunits of the NMDA receptor, a glutamate receptor linked to neurodegenerative conditions. The potential neuroprotective effects of ZA-II-05, an NMDA receptor antagonist, against vanadium-induced neurotoxicity were explored in this study. Organotypic rat hippocampal slices, and live mice, were used as models to comprehensively evaluate the compound’s impact. Targeted in vivo fluorescence analyses of the hippocampal slices using propidium iodide as a marker for cell death was utilized. The in vivo study involved five dams, each with eight pups, which were randomly assigned to five experimental groups (n = 8 pups). After administering treatments intraperitoneally over six months, various brain regions were assessed for neuropathologies using different immunohistochemical markers. High fluorescence intensity was observed in the hippocampal slices treated with vanadium, signifying cell death. Vanadium-exposed mice exhibited demyelination, microgliosis, and neuronal cell loss. Significantly, treatment with ZA-II-05 resulted in reduced cellular death in the rat hippocampal slices and preserved cellular integrity and morphological architecture in different anatomical regions, suggesting its potential in countering vanadium-induced neurotoxicity

Development of functional graphene oxide-urethane coating systems from Ricinus communis seed oil

The surface-modified graphene oxide (GO) nanoparticles and their blending with a fixed percentage of trimethylopropane (TMP) in Ricinus communis seed oil were successfully prepared in a one-pot urethane reaction using 4,4′-diisocyanato dicyclohexylmethane (H12MDI) and methyl isobutyl ketone (MIBK) as the reaction solvent. The structural elucidation and surface morphology of pristine and hybrid composites of the polyurethane coating films were investigated with the aid of Fourier transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), Proton nuclear magnetic resonance (1H NMR), X-ray diffraction (XRD), and Scanning electron microscope (SEM). The presence of FT-IR absorption peaks at 790 cm−1 to 870 cm−1, 990 cm−1, and 1017 cm−1 confirms the following functional groups phenyl -CH bend, stretching phenolic -CO, and epoxyl -C-O-C, respectively in modified graphene oxide. An evaluation of the thermal stability of the coating films that were synthesised was carried out with the use of a thermogravimetric analyzer (TGA). It was seen that as the amount of modified graphene oxide in the urethane films increased, so did the water contact angle from 0% to 0.5%. Antimicrobial and anticorrosive properties of the materials were also evaluated

Sapium ellipticum (Hochst) Pax ethanol leaf extract modulates glucokinase and glucose-6-phosphatase activities in streptozotocin induced diabetic rats

Objective: To examine the effects of Sapium ellipticum (SE) leaf extract on the hepatic activities of glucokinase and glucose-6-phosphatase in streptozotocin-induced diabetic Wistar rats. Methods: STZ-induced diabetic Wistar rats (four groups, n = 8) were used in this study. SE was assessed at two different doses, 400 and 800 mg/kg BW, in comparison with metformin (METF) (12 mg/kg BW) as a reference antidiabetic drug. All treatments were done orally (p.o), twice daily at 8 h interval for a period of 21 days. Glucokinase and glucose-6-phosphatase activities were respectively determined using standard protocols. Hepatic and muscle glycogen contents were estimated as well. Results: STZ caused significant decrease in glucose-6-phosphatase activity and concomitant increase in glucokinase activity. SE extract especially at 400 mg dosage significantly reversed the alterations by increasing glucokinase activity by 40.31% and inhibiting glucose-6-phosphatase activity by 37.29% compared to diabetic control animals. However, the effects were significantly lower than that of METF which enhanced glucokinase activity by 94.76% and simultaneously inhibited glucose-6-phosphatase activity by 49.15%. The extract also improved hepatic glycogen level by 32.37 and 27.06% at 400 and 800 mg dosage respectively. HPLC-MS analysis of some SE fractions in dynamic MRM mode (using the optimized compound-specific parameters) revealed among other active compounds, the presence of amentoflavone, which has been associated with antidiabetic function. Conclusions: The ability of SE extract to concurrently inhibit glucose-6-phosphatase and activate glucokinase in this study suggests that it may be a treatment option for type 2 diabetes patients, and the presence of amentoflavone in the plant extract may account for its anti-diabetic potential

Fractionation and identification of bioactive constituents from Sapium ellipticum (Hochst) leaf extract

In view of antidiabetic and antioxidant properties observed in a previous study, crudeethanol leaf extract of Sapium ellipticum (SE) was fractionated using Silica gel F254column chromatography to yield 164 fractions. Pooling together of fractions with similarthin layer chromatographic (TLC) mobility profile afforded five major fractions withmasses ranging from 0.06 to 2.09 g, and retention factor (RF) ranging from 0.59 to 0.87.Bioactivity of the fractions obtained was evaluated against streptozotocin-inducedoxidative stress and diabetes in adult Wistar rats. HPLC-MS analysis of active fractions indynamic MRM mode using compound-specific parameters revealed the presence oflupeol, luteolin-7-O-glucosides, amentoflavone and α-tocopherol in S. ellipticum leafextract. This array of phytochemicals present in the plant extract is arguably responsiblefor its pharmacological and medicinal properties.Keywords: Sapium ellipticum, Bioactive constituents, Fractionation, Chromatograph

FT-IR analysis of Sapium ellipticum (Hochst) pax ethanol leaf extract and its inhibitory effects on pancreatic α-amylase and intestinal α-glucosidase activities in vitro

AbstractThis study investigated the inhibitory effects of Sapium ellipticum (SE) (Hochst) Pax leaf extract on some carbohydrate metabolizing enzymes, pancreatic α-amylase and intestinal α-glucosidase activities in vitro. The inhibitory potential of SE extract was measured against Quercetin. SE extract in a dose dependent pattern significantly inhibited the activity of pancreatic α-amylase by 67.2% at 10 mg/mL. This effect was comparable to that of quercetin which offered 82.6% α-amylase inhibition. In terms of intestinal α-glucosidase activity, the inhibitory effect of the extract was significantly lower than that of quercetin at all investigated concentrations. At 10 mg mL−1 (maximum tested concentration), SE extract exhibited 35.8% inhibitory activity on α-intestinal glucosidase compared to the 74.3% exhibited by Quercetin at the same concentration. Phytochemical analysis results showed that SE contained 74 ± 3.12 milligram Gallic acid equivalents of total phenols and 67.2 ± 2.04 milligram Quercetin equivalents of flavonoids per gram of extract. Fourier Transformed Infra red spectroscopy (FT-IR) of SE extract revealed the presence of active functional groups reminiscence of polyphenols. Alpha amylase and α-glucosidase activities (in vivo) greatly contribute to postprandial hyperglycemia which is a great risk factor for type 2 diabetes mellitus. The inhibitory potential of SE extract on these enzymes as observed in this study suggests a positive and probable role of the extract in the management and treatment of diabetes mellitus, particularly, type 2