King Faisal University

Cancer is a complex disease characterized by uncontrolled cell proliferation and metastasis, with breast cancer remaining a leading cause of mortality among women worldwide. Hypoxia-inducible factor (HIF) and vascular endothelial growth factor (VEGF) are key mediators of angiogenesis, sustaining tumor growth and progression. RNA interference (RNAi) has emerged as a promising gene-silencing strategy for targeted cancer therapy. In this study, we designed small interfering RNAs (siRNAs) against VEGF mRNA using computational approaches. VEGF gene sequences were retrieved from NCBI, and siRNAs were designed using siDirect v2.0 and i-Score Designer. Candidate siRNAs were screened based on GC content (30-52 %), secondary structure, and thermodynamic stability. Hybridization energy analysis revealed favourable binding to VEGF mRNA, ranging from -31.1 to -37.3 kcal/mol. Molecular docking with h-Argonaute-2 (h-Ago2) yielded docking scores between -330 and -351 kcal/mol, indicating efficient RISC loading. Molecular dynamics (MD) simulations further demonstrated stable siRNA-Ago2 complexes, with RMSD values stabilizing around 2.1-2.6 Å and RMSF fluctuations primarily localized to the PAZ and MID domains. These findings confirm strong binding affinity, structural stability, and specificity of the designed siRNAs. Overall, our results suggest that RNAi-based silencing of VEGF holds significant potential as a therapeutic strategy for inhibiting angiogenesis in breast cancer.

Exploring of the behavior of hydrogen bonds and their dynamics in systems with varying strengths through the analysis of their respective polarized infrared spectral density (SD) continues to be a subject of significant interest. This paper introduces a quantum model aimed at elucidating how the synergistic effects of vibrational modes and their interactions with the surrounding environment of the hydrogen bond can elucidate and theoretically replicate the SD of theυ_SN-H⃗ band in the crystals of the 3-phenylpyrazole (3PhPz) polymorphs, referred to as 'alpha' (α-3PhPz) and'beta' (β-3PhPz). In doing so, this study incorporates a quantum framework that encompasses various mechanisms commonly found in hydrogen-bonded systems: (i) a Morse potential is used to mimic the anharmonic behavior of the low-frequency mode, (ii) the fast mode is treated as exhibiting harmonic oscillation, (iii) an illustration depicting the effect of phase coherence delocalization on the absorption band,υ_SN-H⃗, resulting from the interplay between the two primary vibrational modes, the fast and slow modes, along with the way the bending and rapid modes interact, which gives rise to Fermi resonances, and (iv) the integration of the direct damping mechanism on the absorption band using the quantum method suggested by Rösch and Ranter, where the autocorrelation function (ACF) shows exponential decay over time. The SD is derived from Kubo's theory, which asserts that the SD is the transition dipole moment's Fourier transform of the ACF, defining the band contours of the mid-infrared absorption band. By employing a combination of parameters that accurately represent the various mechanisms considered in our model, numerical experiments validate the efficiency of this simple approach in describing the primary spectral characteristics of the υ_SN-H⃗ band in both 3PhPz polymorphs by anharmonically coupling the three main vibrational modes. Theoretical and/or experimentally significant results were utilized to substantiate the discussion regarding the validity of the used parameters. A strong correlation between the theoretical band contours and the experimental band shapes is demonstrated, along with an inherent analysis of the contribution of each mechanism to the overall spectral behavior.

Aging demographics heighten the need for undergraduate nurses who are prepared to deliver competent, compassionate geriatric care. Simulation and performance-based learning are increasingly used to bridge theory-practice gaps.

To explore undergraduate nursing students' experiences of simulation and performance-based learning and how these strategies shape perceived competence in geriatric care.

Qualitative exploratory study.

Sixteen students who completed geriatric-focused simulation and performance assessments participated in semi-structured interviews. Data were analyzed using Colaizzi's seven-step approach. Trustworthiness was supported through member checking, audit trail, and peer debriefing.

Four themes emerged: (1) bridging theory and practice; (2) developing empathy and emotional insight; (3) building professional confidence and identity; and (4) recognizing systemic barriers. Students reported enhanced clinical reasoning, greater familiarity with geriatric assessment tools, stronger empathic engagement, and increased readiness for practice, while noting constraints related to preceptor engagement and time in clinical settings.

Simulation and performance-based learning foster geriatric care competence across cognitive, affective, and professional domains. Aligning academic and clinical environments is crucial to sustain transfer of skills to practice.

Early, longitudinal integration of geriatrics-focused simulation, structured debriefing, and preceptor-aligned clinical opportunities may strengthen readiness for an aging population.