Journal of Mathematical and Fundamental Sciences

Molecular Docking and In Vitro Studies of Synthesized Oxadiazole Derivatives as Urease Inhibitors

2025-07-15T06:51:01+07:00

A novel sequence of 1,3,4-oxadiazoles (7a–h) was synthesized. The compounds were characterized by IR, ¹H NMR, and MS analyses. They were also examined to determine whether they could prevent urease from functioning. Molecular docking was done with AutoDock Vina, and the findings were visualized in Discovery Studio. The H NMR spectra showed peaks at δ 10.20 to 10.69 ppm for NH protons, δ 7.16 to 8.01 ppm for aromatic protons, and δ 4.21 to 4.37 ppm for 2H and CH₂ groups, confirming the structural details. The EI-MS spectra showed molecular ion peaks at 337 m/z with an intensity of 14-67%. Among the bioactivity-tested compounds, 7d resulted in robust activity with IC₅₀ values of 161.6 ± 5.8 µM; compound 7e exhibited the weakest activity, at 453.6 ± 5.8 µM; and no inhibition was discovered by the 7a, 7f, and 7h compounds when compared to the Thiourea, at 21.8 ± 1.51 µM. Molecular dockings confirmed compound 7d as the best-docked complex, with a minimum energy of -7.4 kcal/mol, an RMSD value of 1.573 Å, and hydrogen interactions at His593 with the active site residue, confirming the experimental results. It was determined that 1,3,4-oxadiazoles can be employed as urease inhibitors.

Forecasting Climate-driven Dengue Incidence in Penang, Malaysia

2025-08-24T21:00:57+07:00

Dengue continues to pose a major public health challenge in Malaysia, with no definitive cure currently available. Although the Ministry of Health of Malaysia has implemented various measures to control outbreaks, the number of cases keeps rising and is likely to worsen due to the impacts of climate change. Hence, early detection and prediction of dengue outbreaks are vital for the implementation of risk mitigation measures. This study applied and assessed the performance of a coupled ARIMAX and SI-SIR model for forecasting dengue incidence in Penang, Malaysia. Data from 2014 to 2020, including reported dengue cases and climate variables (rainfall and average temperature), were used. Previous research has demonstrated a strong correlation between climate factors and dengue transmission. Granger causality tests also indicated that the time series of rainfall and average temperature are significant predictors of the mosquito biting rate, which is closely linked to dengue transmission. Therefore, these climate variables were incorporated into the coupled model to enhance its forecasting performance. Through multiple simulation rounds with a four-week forecasting period, the coupled model achieved an average forecasting accuracy of around 80% in predicting dengue cases in Penang.

Bauxitization and REE Redistribution in Weathered I-type Granite Profile of Gunung Kijang, Bintan Island

2025-08-09T23:44:34+07:00

Weathering is often linked to economic mineral enrichment, including nickel, bauxite, and rare earth elements (REE). The exposed granitic rocks on Bintan Island, Riau Islands Province, belong to the Southeastern Asian Eastern Granite Province. This study examines the bauxitization process and REE distribution across weathered granite horizons in the Gunung Kijang area. Major oxides were analyzed using X-ray fluorescence, while trace and rare earth elements were determined by inductively coupled plasma–mass spectrometry. The trace element composition and metaluminous nature of the parent granite confirm its I-type classification. Kaolinization and bauxitization were observed in the weathered layers, with Al₂O₃ and Fe₂O₃T contents ranging from 25.21–46.50% and 6.99–8.76%, respectively. Total REE content in the weathered horizons (up to 76 ppm) is lower than in the parent rock (214 ppm). Nevertheless, the soft, near-surface materials offer potential for future REE utilization. Clay minerals are the main REE hosts, while the enrichment from the C-horizon upward is influenced by higher organic matter near the surface. Similar Eu and Ce anomaly patterns indicate minimal feldspar in the original granite or limited feldspar breakdown during weathering.