This study presents the synthesis, structural architecture, density functional theory (DFT) investigations, third-order nonlinear optical (NLO) properties, and biological evaluations of two organic–inorganic hybrid compounds based on the dicationic 1-(4-pyridyl)piperazine ligand: (C9H15N3)2+.HgCl42- (Compound I) and (C9H15N3)2+.CuCl42- (Compound II) Single-crystal X-ray diffraction reveals that both hybrid compounds assemble into robust 3D supramolecular networks governed by extensive ionic charge-assisted (N–H···Cl, C–H···Cl) hydrogen bonds. Hirshfeld surface analysis demonstrates that H···Cl (up to 37.1) and H···H contacts dominate the crystal packing. Quantum theory of atoms in molecules (QTAIM), non-covalent interaction (NCI) calculations and Time-dependent DFT (TD-DFT) validate the purely non-covalent character of these lattice-stabilizing interactions. Single-beam Z-scan measurements under continuous-wave excitation show that both complexes exhibit strong reverse saturable absorption (RSA) and thermal self-defocusing behavior. Compound II demonstrates a significantly enhanced third-order susceptibility χ3 = 1.899 × 10–5 compared to Compound I χ3= 1.25 × 10–5 driven by efficient dication-to-halometalate electronic coupling and LMCT interactions. Furthermore, Compound I exhibited pronounced antibacterial efficacy against Escherichia coli 19 mm and S. aureus 21 mm while Compound II demonstrated superior cytotoxic potency against MDA-MB-231 triple-negative breast cancer cells with an IC50 of 10.96 μg/mL (compared to 25.25 μg/mL for Compound I). These results highlight the dual potential of compound I and II in photonic devices and as next-generation anti-cancer therapeutics.
The present study aimed to synthesize suggested Cu-Ag Bimetallic (NPs) as antimicrobial agents for biomedical applications, using two-stages Nd: YAG laser ablation (maximum energy 800 mJ, 900 pulses, 1064 nm, 9 ns, 1 Hz) in dimethylformamide (DMF )solvent. The synthesized nanoparticles were further evaluated by molecular docking to investigate their potential inhibitory effects against bacterial targets. The prepared nanoparticles were characterized using (UV-Vis spectroscopy), Xray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), Atomic force microscopy (AFM) and Zeta Potential (ZP). TEM analysis demonstrated semi-spherical nanostructures with average particle sizes of 25.5 nm for (AgNPs), 10.8 nm for (CuNPs), and 15 nm for suggested Cu-Ag Bimetallic NPs. The antimicrobial effect of different concentrations of the prepared NPs was tested on two types of bacteria; a gram-negative (Pseudomonas aeruginosa) and a gram-positive (Streptococcus mutans). At (100 ) μ g/mL concentration for AgNPs, CuNPs and Cu@AgNPs exhibited inhibition zones of (21.04 ± 0.10 mm, 20.07 ± 0.10 mm and 23.00 ± 0.10 mm) for (P. aeruginosa) bacteria and (31.04 ± 0.12 mm, 24.07 ± 0.12 mm and 32.21 ± 0.11 mm) for (S. mutans) bacteria respectively. The results indicate that suggested Cu-Ag BimetallicNPs exhibit enhanced antibacterial activity compared with monometallic Ag and Cu nanoparticles. Furthermore, biofilm inhibition assays demonstrated a higher capacity of Cu@Ag nanoparticles to suppress bacterial growth relative to the individual nanoparticle. Molecular docking was employed to evaluate the antibacterial potential of Cu, Ag, and core–shell Cu@Ag nanoparticles against Pseudomonas aeruginosa (PDB ID: 1IX1) and Streptococcus mutans (PDB ID: 3BJV). The copper-silver (Cu and Ag) monometallic nanoparticles exhibited moderate binding energies to their target proteins in bacteria. The binding energies to Pseudomonas aeruginosa ranged from − 5.44 to − 6.5 kcal/mol. Cu-Ag Bimetallic NPs exhibited higher binding energy (− 8.50 kcal/mol) with the same bacteria, indicating a stronger and more specific interaction within the binding site. Coordination interactions between silver and amino acid residues (ASN101, ASP103, and TYR147), along with π-donor interactions between copper and TYR147, demonstrate a genuine and stable chemical bond. For Streptococcus mutans, copper and silver particles exhibited relatively similar binding behavior with low binding energies.
GaN nanostructures have been formed by utilizing both pulsed laser ablation in liquid (PLAL) and the hydrothermal method to create nanostructures. The use of three different energy levels of pulsed laser (100, 200, and 300 mJ) allowed researchers to measure the impact of the changing energy on the structural, morphological, optical, chemical, and electrical properties of the final product. This was done through a variety of different means of measuring these connections. Comparing both colloidal GaN and those films grown on hydrothermally treated substrates, it was found that crystallinity and overall quality of the final material had been improved considerably with the use of the laser. This revealed that the use of the laser for the growth of crystals is critical. Optical measurements showed an increase in the energy band gap 3.05–3.18 eV for colloidal and 3.22–3.55 eV for hydrothermally deposited thin film. FESEM analysis demonstrated improved morphology and uniformity due to the high-temperature and high-pressure conditions of the hydrothermal process. XRD patterns revealed distinct peaks at 2θ = 34.85°, 38.35°, and 59.15°, corresponding to the (002), (100), and (200) planes, respectively, confirming the hexagonal wurtzite structure of GaN. Electrical characterization showed decreased resistivity with increased reaction temperature. Based on optimal performance from the figure of merit, a photodetector was fabricated by depositing GaN films onto n-type and p-type Si substrates. The GaN/n-Si device exhibited superior electrical performance compared to GaN/p-Si, with an ideality factor of 1.6. The photodetector demonstrated high stability. The (GaN /n-Si) detector showed the highest response at short wavelengths (UV region), with a response of 0.025 AW at 320 nm. The GaN /p-Si detector also showed good responsivity at 320 nm. However, it was lower, reaching 0.020 AW, and had high detectivity, confirming its potential for optoelectronic applications.
Information security incidents continue to grow exponentially amidst the developing technological solutions. Malicious developers unabatedly introduce sophisticated strategies, while security experts and developers lag in response. Micro and Small Enterprises (MSE) in developing countries struggle to address information security issues effectively as they do not have the required resources, hence the cyber criminals capitalize on their weaknesses. MSE’s account for 90
The study explores the recognition of obstetric danger signs, barriers to their recognition, and the facilitators that support recognition among postnatal mothers in Oyo State, Nigeria. A phenomenological qualitative research design was used to explore the lived experiences of postnatal mothers regarding obstetric danger sign recognition. Twelve postnatal mothers from two primary health facilities in Oyo State were purposively selected. Data were collected via in-depth interviews, recorded, transcribed verbatim, and thematically analyzed using NVivo 12. Sampling continued until data saturation was reached. Findings were organized based on the three key research questions of the study. The recognition of obstetric danger signs generated four major themes: physical and sensory changes, antenatal education, past experiences and traumatic outcomes, and digital media and visual aids. Four major themes emerged for barriers to recognition: cultural and spiritual misinterpretation, family and community influence, illiteracy and low health literacy, and minimization or mislabeling of symptoms. Emerged themes for facilitators of recognition included supportive antenatal education, peer experiences, media and community campaigns, and family encouragement. The recognition of obstetric danger signs is influenced by a complex interplay of knowledge, culture, experience, and support systems. Interventions to improve maternal outcomes should focus on enhancing antenatal education, addressing cultural misconceptions, increasing health literacy, and leveraging both digital platforms and community networks to support early identification and timely response to obstetric danger signs.
