Dr Mohammed Mahmoud Youssif

Background: A comprehensive review of the literature published between 2021 and 2024 in analytical and pharmaceutical chemistry journals has been conducted, focusing on the instrumental methods employed for the determination of Remdesivir (REM). Given its widespread use as an antiviral agent during the COVID-19 pandemic, Remdesivir has been the subject of numerous analytical studies aimed at understanding its pharmacokinetics and ensuring the accuracy of its dosing in various formulations. Aim of Review: The methods reviewed span spectrophotometric, spectrofluorimetric, chromatographic, and electroanalytical techniques, with a particular emphasis on liquid chromatography coupled with UV or mass spectrometric detection, which has become a prominent choice due to its sensitivity and reliability. Concepts of review: These techniques have been applied for the quantification of Remdesivir in bulk drug substances, pharmaceutical formulations, and biological matrices, supporting quality control and therapeutic monitoring. Conclusion: The review critically evaluates the reported methodologies, highlighting advancements in analytical precision and the growing importance of robust, validated techniques for clinical and regulatory purposes. This analysis reflects the evolving role of instrumental techniques in ensuring the safe and effective use of Remdesivir in clinical settings and underscores their relevance beyond the pandemic era.

Background: Oils from medicinal plants, including thyme (Thymus vulgaris), cinnamon (Cinnamomum verum), and black seed (Nigella sativa), are recognized for their antibacterial and antioxidant properties. While several studies have investigated individual oils and binary combinations, fewer reports have examined ternary mixtures using systematic optimization approaches. Accordingly, the present study aimed to optimize the antibacterial and antioxidant performance of combinations of these three plant-derived oils using a statistical mixture design strategy supported by in silico exploration. Methods: An Augmented Simplex Centroid Mixture Design was applied to evaluate the individual and combined effects of thyme, cinnamon, and black seed oils. Antibacterial activity was assessed by determining the minimum inhibitory concentrations (MICs) against Escherichia coli and Staphylococcus aureus, while antioxidant activity was measured using the DPPH radical scavenging assay (IC50). The experimental data were fitted to a special cubic model, and model validity was verified through ANOVA parameters, including F-values, R2, and adjusted R2. Multi-response optimization was performed using a desirability function. Potential interactions among oils were further examined using checkerboard assays. Molecular docking and ADMET predictions were conducted as supportive, hypothesis-generating tools. Results: The special cubic model was statistically significant for all responses (p < 0.0001), with R2 values of 0.9763, 0.9944, and 0.9841 for MICE. coli, MICS. aureus, and DPPH IC50, respectively. Response surface analysis and multi-response optimization identified the optimal oil mixture as thyme (41.7%), cinnamon (41.7%), and black seed (16.7%), achieving MIC values of 0.5 µL/mL for E. coli and 0.517 µL/mL for S. aureus, and a DPPH IC50 of 5.32 ± 0.52 mg/mL. Checkerboard assays confirmed synergistic interactions for the optimized formulation, with ΣFIC values of 0.15 and 0.29 against E. coli and S. aureus, respectively. Cytotoxicity testing of the optimized formulation on WI-38 normal fibroblasts indicated high cell viability (>92%) at all tested concentrations. In silico docking showed favorable binding affinities of major oil constituents with bacterial targets, and ADMET analysis suggested acceptable pharmacokinetic and safety profiles. Conclusions: The study demonstrated that specific combinations of thyme, cinnamon, and black seed oils can synergistically enhance antibacterial and antioxidant activities. The optimized formulation exhibited enhanced antibacterial and antioxidant activities with minimal cytotoxicity, while in silico analyses provided supportive mechanistic insights.

Hydrogen active pre-chamber (H2-APC) jets igniting ammonia (NH3) provides a promising pathway for efficient NH3 combustion. However, the effect of gas flow exchange between main chamber (MC) and APC, as well as the synergistic optimization strategies for NH3-H2 mixture preparation and H2 jet flame evolution on enhancing NH3 engine efficiency remains unclear. This study conducts a numerical investigation to analyze the effect of intake vortex, in-cylinder NH3-H2 mixture reactivity, H2 injection and spark timing strategies within APC on engine performance, and further summarizes the efficiency improvement pathways of large-bore NH3-H2 engine. NH3-H2 mixture and air are separately supplied through split-channel supercharge and fuel-air mixing technology with different intake swirl ratios. Results indicate that under 5 % H2 blend with NH3 and an excess air ratio (λ) of 1.6, increasing in-cylinder swirl intensity, H2-APC jet flames penetrate axially with higher speed while vortex-induced mixing promotes radial flame expansion. This synergistic flame propagation accelerates combustion and reduces unburned NH3 emissions. When H2 is injected at −150°CA aTDC with an injection energy of 1.5 %, a near-stoichiometric mixture forms around spark plug inside APC, resulting in a peak indicated thermal efficiency (ITE) of 46.06 %. Furthermore, increasing H2 blending ratio to 20 % yields further enhancement in combustion characteristics but along with increased NOX emissions. Then extend lean combustion of λ to 2.0 through optimized spark timing, a maximum ITE of 46.2 % is achieved along with suitable emissions.

ABSTRACT Blocking the p53-MDM2 and/or p53-MDMX protein−protein interaction (PPI) by small-molecule inhibitors has been tracked as a potentially effective cancer treatment approach. Herein, we present the discovery of a new series of spirooxindole-tethered pyrazolopyridine derivatives. The development of the new congeners was based on the analysis of the co-crystal structures of the inhibitors bound to both MDM2 and MDMX and studying the binding interactions between the substituents of small molecules and the three subpockets of the p53-MDM2/MDMX. The spirooxindoles 6b, 6k, and 6n attained the most pronounced activity in the MULTI-ARRAY MDM2-p53 complex assay with IC50 values of 1.26, 1.30, and 1.25 µM, respectively, in comparison with nutlin-3 (IC50 = 2.03 µM). The counterparts 6b, 6k, and 6n also revealed notable inhibitory potential against p53-MDMX. The antiproliferative efficacy of the most active target compounds was assessed in HCT-116 colon cancer cell line that overexpressed MDM2 and harbored wild-type p53. The derivative 6k accomplished the highest antiproliferative activity against HCT-116 compared to nutlin-3. Moreover, 6k displayed minimal toxicity compared to the reference nutlin-3 when examined on a normal cell line. Flow cytometric analysis revealed that 6k controlled cell growth via cell cycle arrest at the G1 phase and induced cell death via apoptosis. Additionally, compound 6k revealed a prominent effect in raising p53 levels with a 6.464-fold increase compared to the control. Molecular docking and molecular dynamics simulations justified the observed efficacy. Collectively, this study showcased a new class of potent p53-MDM2/MDMX dual inhibitors possessing a spirooxindole scaffold which can be subjected to future development.

During the COVID-19 pandemic, urban parks emerged as vital public spaces, experiencing surges in visitation as people sought safe environments for physical and mental relief. While many other social infrastructures faced sharp declines due to gathering restrictions, parks played a crucial role in supporting public health. This study adopts a multiscale approach, analyzing state- and city-level data to assess how urban park dynamics influenced public health outcomes. By integrating visitation patterns, park design characteristics, policy interventions, and demographic variables, the research captures a comprehensive picture of parks’ role on public health from 2020 to 2022, with park visitation accounting for 41%, 24%, and 19% of the variation in physical, mental, and chronic health outcomes across U.S. states. Park accessibility emerged as the strongest predictor, showing robust associations with lower rates of obesity, diabetes, and coronary heart disease, particularly after accessibility surpassed thresholds of 95%, 60%, and 71%, respectively. These findings underscore the importance of urban parks for public health and as a critical asset during crises, highlighting the need for equitable, resilient urban planning.

Urban flooding represents one of the most pressing challenges for cities worldwide, exacerbated by climate change and rapid urbanization. Conventional grey infrastructure often proves inadequate in addressing these complex hydrological threats, prompting increased attention to Nature-based Solutions (NbS) as sustainable alternatives. This review examines the role of NbS in advancing climate-resilient urban development through effective flood management. Analyzing 42 peer-reviewed studies, key implementation trends across geographic regions and climatic contexts were identified. NbS strategies—including sponge city concepts, green infrastructure, and blue-green corridors—can reduce stormwater runoff by 30–75% while providing co-benefits such as enhanced biodiversity, urban heat island mitigation, and improved public well-being. Barriers include institutional fragmentation, limited funding, and regulatory constraints. Successful implementation requires integrated governance, updated planning frameworks, dedicated financial instruments, and community engagement. NbS are essential components of climate adaptation strategies, offering multifunctional pathways toward resilient, sustainable, and livable urban environments.