University of Zululand

Study of metal enrichment in water and sediment was carried out in the tropical estuarine environment of Sibuti river in northern Borneo, Malaysia. In this study, a novel approach of PMF-Monte Carlo Integration was used to assess the source-oriented health risk that effectively allows source-based mitigation of metal pollution with higher accuracy. Targeted metals (Fe, Cu, Zn, Co, Mn, Cd, Cr, Se, Al, Ba) were modelled using the PMF receptor model and FreeViz projection via Orange ML for source apportionment, where Monte Carlo Simulation (MCS) assessed probabilistic health risks in adults and children. Results showed that erosion and leaching of geogenic formations (peat soil and marine shale, pyrite concretions) significantly contributes to metal enrichment denoted by decade long agricultural deforestation. Higher release and deposition of Se, Cu, and Zn was noted in estuary and were facilitated by Mn and clay minerals. The dominance of sources towards health risk contribution was observed as agricultural effluents (>90 %) > Leaching from Pyrite concretion > Peat soil leaching for adults and children in both mediums. Metal concentrations in Sibuti estuary water were within safe limits for non-carcinogenic risk, with mean THI values of 7.392E-05 (children) and 6.471E-05 (adults). However, TCR values for Cr and Cd exceeded guidelines in 100 % of water and sediment scenarios. Co and Cr in sediments posed non-carcinogenic risks in over 97 % of scenarios for children and 57 % for adults. These findings highlight the need for preventive measures against metal contamination. The results underscore the importance of monitoring and managing metal sources such as agricultural activities along with rapid land use changes.

Orexinergic system dysfunction is the fundamental basis for several neurological illnesses like narcolepsy, insomnia, and drug dependency, yet none of the existing medications are subtype receptor specific. This study examines 124 chemicals from neem to determine if they can be utilised as specific orexinergic receptor modulators using advanced computational methods. The methodology includes detailed clustering, pharmacophoric interaction, pharmacokinetic, statistical, and clustering analyses. Molecular property profiling indicated the majority of the compounds exhibit excellent drug-like qualities (MW 350-450 Da, LogP 0-2), while principal component analysis captured 100 % structural variability between two components (92.5 % and 7.5 %, respectively). Molecular docking simulations indicated selective binding to the 6V9S receptor (-11.3 to -4 kcal/mol) over 4S0V (-9.7 to -4 kcal/mol). Lead compounds Neem_PDB_10257 (Tirucallol) (-11.3 kcal/mol) and Neem_PDB_12072821 ([(5 R,7 R,8 R,9 R,10 R,13S,17 R) -17-(2-methoxy-5-oxo-4,4,8,10,13-pentamethyl-3-oxo-5,6,7,9,11,12,16,17-octahydrocyclopenta[a]phenanthren-7-yl] acetate) were particularly 6V9S selective (>2 kcal/mol difference), whereas Neem_PDB_10160319 ((4S,4aS,5S,10S,13S,14S,17-4,4,10,13,14-pentam -1, 2, 3, 5, 6, 7, 11, 12, 15, 17-decahydrocyclopenta[a]phenanthren-16-one) was most sensitive towards 4S0V. Two top-ranked compound families were discovered by hierarchical cluster analysis with a distance requirement of 35 units, and receptor-specific dendrograms revealed distinctive subcluster branching patterns (4S0V: 5.5 and 6.7 unit subclusters; 6V9S: 7.1 and 7.2 unit subclusters). Interaction pattern (heatmap analysis) identified major interaction hotspots, including TYR348, TRP120, PHE227, and HIS350. Neem_PDB_163184214 (Meliatetraolenone) specifically targeted ASN318 in 6V9S, while Neem_PDB_54580354 (7-Benzoylnimbocinol) favored interaction with GLN134 in 4S0V (>90 interactions). These findings dispute the "one-pharmacophore" theory for orexinergic modulators, showing that intentional functionalization of NEM templates can deliver subtype-selective treatments with maximal sleep-wake modulation and low off-target effects.

ZnSe thin films were deposited on nonconducting glass substrates using different Zn[Formula: see text] ion concentrations. The films were deposited at 80°C for 2.0[Formula: see text]h via photo-assisted chemical bath technique and annealed for 2.0[Formula: see text]h at 250°C. X-ray diffraction revealed a hexagonal structure with preferred orientation along the (002) plane and the average crystallite size decreased from 10.5[Formula: see text]nm to 6.8[Formula: see text]nm with increased Zn[Formula: see text] ions. Raman spectra were used to confirm ZnSe phonon modes whose intensity increased with Zn[Formula: see text] ion concentrations although with fluctuation. Optical analysis showed higher absorbance and low transmittance in the visible region than near infrared making the thin films good materials for selective absorber surfaces. The band gap increased from 2.52[Formula: see text]eV to 2.78[Formula: see text]eV as the Zn[Formula: see text] ion concentration varied from 0.05% to 0.25%. The presence of the desired elements was confirmed by the EDS. Photoluminescence studies revealed three emission peaks which were all ascribed to defect state levels in ZnSe and all the samples emitted in reddish color according to CIE color chromaticity analysis. The selective absorption, wide band gap and broad emission properties suggest that the material is promising for optoelectronic applications.