Search Results (1,045)

Background: Ferrabis(dicarbollide) ([o-FESAN]⁻) in combination with proton–boron fusion therapy (PBFT) or boron neutron capture therapy (BNCT) are promising alternative radiation modalities for the treatment of breast cancer. The aim of this study was to explore the underlying effects of [o-FESAN]⁻ radio enhancement on breast cancer cells in vitro and in vivo, and to perform comparative dosimetry calculations. Methods: The cellular effects on SKBR-3 and MDA-MB-231 breast cancer cells and MDA-MB-231 xenograft-bearing nude mice induced by carrier-free [o-FESAN]⁻ after BNCT or PBFT were evaluated following recommended protocols. Monte Carlo (MC) dosimetry calculations were performed at the cellular scale for both radiation modalities. Results: Selective retention of [o-FESAN]⁻ within the cytoplasm and nucleus of SKBR-3 and MDA-MB-231 breast cancer cells is demonstrated. Moreover, in vivo studies with MDA-MB-231 xenograft-bearing nude mice show appreciable accumulation of [o-FESAN]⁻ in the tumor. Both radiation modalities induce loss of cellular viability and survival. Comparative dosimetry studies between proton and neutron irradiation agree with the viability data, showing a good correlation between absorbed dose vs. cellular effects. In the case of PBFT, cell structural changes are likely due to necrosis caused by the production of reactive oxygen species (ROS). To explain the radio enhancement effects in more detail, other mechanisms should be taken into consideration. Conclusions: Our results validate the effectiveness of both PBFT and BNCT therapeutic modalities, warranting further studies on carrier-free [o-FESAN]⁻ as a candidate drug for potential clinical translation of radio enhancers in binary radiation therapies. Full article

The chemical looping steam reforming of methane (CLSR) employing Fe-containing oxygen carriers can produce syngas and hydrogen simultaneously. However, Fe-based oxygen carriers exhibit low CH₄ activation ability and cyclic stability. In this work, oxygen carriers with fixed Fe content and different Fe/Ni ratios were synthesized by the sol–gel method to investigate the effects of Ni-Fe-Al interactions on CLSR performance. Ni-Fe-Al interactions promote the growth of the spinel structure and regulate both the catalytic sites and the available lattice oxygen, resulting in the CH₄ conversion and CO selectivity being maintained at 96–98% and above 98% for the most promising oxygen carrier, with an Fe₂O₃ content of 20 wt% and Fe/Ni molar ratio of 10. The surface, phase, and particle size were kept the same over 90 cycles, leading to high stability. During the CLSR cycles, conversion from Fe³⁺ to Fe²⁺/Fe⁰ occurs, along with transformation between Ni²⁺ in NiAl₂O₄ and Ni⁰. Overall, the results demonstrate the feasibility of using spinel containing earth-abundant elements in CLSR and the importance of cooperation between oxygen release and CH₄ activation. Full article

Advanced oxidation processes (AOPs) utilizing peroxymonosulfate (PMS) have recently gained attention for effectively removing organic dyes. Biochar, a carbon-based material, can act as a catalyst carrier for PMS activation. This study developed a nitrogen-doped biochar catalyst (NCMR800–2) from waste Chinese medicine residue (CMR) through one-step pyrolysis to efficiently remove Rhodamine B (RhB) from wastewater. Results indicate that NCMR800–2 rapidly achieved complete removal of 20 mg/L Rhodamine B (RhB), the primary focus of this study, within 30 min, while maintaining high degradation efficiencies for other pollutants and significantly outperforming the unmodified material. The material demonstrates strong resistance to ionic interference and operates effectively across a wide pH range. Quenching experiments and in situ testing identified singlet oxygen (¹O₂) as the primary active species in RhB degradation. Electrochemical analysis showed that nitrogen doping significantly enhanced the electrical conductivity and electron transfer efficiency of the catalyst, facilitating PMS decomposition and RhB degradation. Liquid chromatography–mass spectrometry (LC-MS) identified intermediate products in the RhB degradation process. Seed germination experiments and TEST toxicity software confirmed a significant reduction in the toxicity of degradation products. In conclusion, this study presents a cost-effective, efficient catalyst with promising applications for removing persistent organic dyes. Full article

Bismuth vanadate (BiVO₄) has attracted significant attention as a photoanode material for photoelectrochemical (PEC) water splitting due to its suitable bandgap (~2.4 eV), strong visible light absorption, chemical stability, and cost-effectiveness. Despite these advantages, its practical application remains constrained by intrinsic limitations, including poor charge carrier mobility, short diffusion length, and sluggish oxygen evolution reaction (OER) kinetics. This review critically summarizes recent advancements aimed at enhancing BiVO₄ PEC performance, encompassing synthesis strategies, defect engineering, heterojunction formation, cocatalyst integration, light-harvesting optimization, and stability improvements. Key fabrication methods—such as solution-based, vapor-phase, and electrochemical approaches—along with targeted modifications, including metal/nonmetal doping, surface passivation, and incorporation of electron transport layers, are discussed. Emphasis is placed on strategies to improve light absorption, charge separation efficiency (η_sep), and charge transfer efficiency (η_trans) through bandgap engineering, optical structure design, and catalytic interface optimization. Approaches to enhance stability via protective overlayers and electrolyte tuning are also reviewed, alongside emerging applications of BiVO₄ in tandem PEC systems and selective solar-driven production of value-added chemicals, such as H₂O₂. Finally, critical challenges, including the scale-up of electrode fabrication and the elucidation of fundamental reaction mechanisms, are highlighted, providing perspectives for bridging the gap between laboratory performance and practical implementation. Full article

Colorectal cancer (CRC) remains a major contributor to global cancer-related mortality, with rising incidence observed in several regions, including Saudi Arabia. This review compiles and critically analyzes recent preclinical research from Saudi-based institutions that investigates the anti-CRC potential of natural and synthetic compounds. Numerous natural products such as Nigella sativa, Moringa oleifera, Curcuma longa, and marine-derived metabolites have demonstrated cytotoxic effects through pathways involving apoptosis induction, reactive oxygen species (ROS) generation, and inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and cyclooxygenase-2 (COX-2). In parallel, synthetic and semi-synthetic agents, including C4–G4 (semi-synthetic hybrids designed from flavonoids and benzoxazole scaffolds that act as dual epidermal growth factor receptor (EGFR)/COX-2 inhibitors)), oxazole derivatives, and camptothecin-based nanocarriers, exhibit promising anti-tumor activity via molecular targeting of cyclin-dependent kinase 8 (CDK8), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), and β-catenin pathways. Selected in vivo studies primarily utilizing xenograft and chemically induced rodent models have shown reductions in tumor volume and modulation of apoptotic and inflammatory biomarkers. Additionally, green-synthesized metallic nanoparticles (NPs) and polyethylene glycol (PEG)-modified carriers have been investigated to improve bioavailability and tumor targeting of lead compounds. While these findings are encouraging, the majority remain in preclinical phases. Limitations such as poor solubility, lack of pharmacokinetic data, and absence of clinical trials impede translational progress. This review highlights the need for standardized evaluation protocols, mechanistic validation, and region-specific clinical studies to assess efficacy and safety. Given Saudi Arabia’s rich biodiversity and growing research capacity under national strategies like Vision 2030, the country is well-positioned to contribute meaningfully to CRC drug discovery. By integrating bioactive natural products, rationally designed synthetics, and advanced delivery platforms, a pipeline of innovative CRC therapeutics tailored to local and global contexts may be realized. Full article

Ultrathin oxide semiconductors are promising channel materials for next-generation thin-film transistors (TFTs), but their performance is severely limited by bulk and interface defects as the channel thickness approaches a few nanometers. In this study, we show that high-pressure hydrogen annealing (HPHA) effectively mitigates these limitations in 3.6 nm thick ZnO TFTs. HPHA-treated devices exhibit a nearly four-fold increase in on-current, a steeper subthreshold swing, and a negative shift in threshold voltage compared to reference groups. X-ray photoelectron spectroscopy reveals a marked reduction in oxygen vacancies and hydroxyl groups, while capacitance–voltage measurements confirm more than a three-fold decrease in interface trap density. Low-frequency noise analysis further demonstrates noise suppression and a transition in the dominant noise mechanism from carrier number fluctuation to mobility fluctuation. These results establish HPHA as a robust strategy for defect passivation in ultrathin oxide semiconductor channels and provide critical insights for their integration into future low-power, high-density electronic systems. Full article

Background/Objectives: Ulcerative colitis (UC) involves chronic colon inflammation and oxidative stress. Treating UC is challenging due to systemic drug side effects and poor targeted delivery. Nanocarriers responsive to the UC microenvironment, particularly elevated reactive oxygen species (ROS), could overcome these limitations. This study developed an oral delivery system for ROS-triggered drug release and active targeting. Using ferulic acid (FER), a system was designed to enhance site-specific accumulation and therapeutic efficacy against colitis. Methods: A ROS-sensitive covalent organic framework (COF) was synthesized from γ-cyclodextrin and functionalized with folic acid (FA) to create a carrier (COF-FA) designed for potential active targeting. This carrier was loaded with FER to form FER@COF-FA. The system was characterized (SEM, FTIR, TGA), and its ROS scavenging and sustained drug release profiles were confirmed in vitro. Biocompatibility was evaluated in cell lines, and therapeutic efficacy was tested in a DSS-induced murine colitis model. Results: The synthesized FER@COF-FA demonstrated high drug loading, potent ROS-scavenging capability, and a sustained drug release profile. It showed excellent biocompatibility and, in the murine model, significantly outperformed free FER. Treatment alleviated disease severity, prevented colon shortening, restored healthy tissue histology, and rebalanced pro- and anti-inflammatory cytokines. Conclusions: The FER@COF-FA system represents a highly promising therapeutic strategy for UC. Its superior efficacy is attributed to a synergistic multi-mechanism approach, combining sustained release, ROS-responsive drug delivery, intrinsic antioxidant activity, and potential folate receptor-mediated targeting, which collectively enhance site-specific accumulation and therapeutic outcomes in the inflammatory colon microenvironment. Full article

Background/Objectives: Triple-negative breast cancer (TNBC) exhibits pronounced biological heterogeneity, aggressive behavior, and a high risk of recurrence and metastasis. The conventional treatments for TNBC have notable limitations: surgical resection may leave residual tumor cells; chemotherapy (CT) frequently induces systemic toxicity and drug resistance; and radiotherapy damages surrounding organs and compromises the patients’ immune function. Methods: Herein, we designed a carrier-free nanodrug delivery system composed of self-assembled Curcumin nanoparticles (NPs) coated with a tannic acid (TA)/Fe(III) network (denoted as CUR@TA-Fe(III) NPs). We systematically evaluated the in vitro cytotoxicity and photothermal–ferroptosis synergistic therapeutic efficacy of CUR@TA-Fe(III) NPs in 4T1 breast cancer cells, as well as the in vivo antitumor activity using 4T1 tumor-bearing mouse models. Results: CUR@TA-Fe(III) NPs had high drug loading efficiency (LE) of 27.99%, good dispersion stability, and photothermal properties. Curcumin could inhibit the growth of 4T1 cancer cells, while TA-Fe(III) efficiently converted light energy into heat upon exposure to near-infrared (NIR) light, leading to direct thermal ablation of 4T1 cells. Additionally, TA-Fe(III) could supply Fe(II) via TA, increase intracellular Fe(II) content, and generate reactive oxygen species (ROS) through the Fenton reaction, in turn inducing lipid peroxidation (LPO), a decrease in mitochondrial membrane potential (MMP), and glutathione depletion, eventually triggering ferroptosis. Conclusions: This treatment strategy, which integrates CT, PTT, and ferroptosis, is expected to overcome the limitations of traditional single-treatment methods and provide a more effective method for the treatment of TNBC. Full article

Perovskites (ABX₃) exhibit remarkable potential in optoelectronic conversion, catalysis, and diverse energy-related fields. However, the tunability of A, B, and X-site compositions renders conventional screening methods labor-intensive and inefficient. This review systematically synthesizes the roles of physical simulations and machine learning (ML) in accelerating perovskite discovery. By harnessing existing experimental datasets and high-throughput computational results, ML models elucidate structure-property relationships and predict performance metrics for solar cells, (photo)electrocatalysts, oxygen carriers, and energy-storage materials, with experimental validation confirming their predictive reliability. While data scarcity and heterogeneity inherently limit ML-based prediction of material property, integrating high-throughput computational methods as external mechanistic constraints—supplementing standardized, large-scale training data and imposing loss penalties—can improve accuracy and efficiency in bandgap prediction and defect engineering. Moreover, although embedding high-throughput simulations into ML architectures remains nascent, physics-embedded approaches (e.g., symmetry-aware networks) show increasing promise for enhancing physical consistency. This dual-driven paradigm, integrating data and physics, provides a versatile framework for perovskite design, achieving both high predictive accuracy and interpretability—key milestones toward a rational design strategy for functional materials discovery. Full article

Fe–porphyrin/g-C₃N₄ composites have emerged as promising visible-light photocatalysts, but their performance remains limited by inefficient charge separation and low reactive oxygen species (ROS) yield. Here, iron–tetra(4-carboxyphenyl) porphyrin (Fe–TCPP) was coupled with g-C₃N₄ nanotubes (CNNTs) via a facile self-assembly strategy, creating a morphology-coordinated system. Comprehensive characterization (XRD, FTIR, SEM/TEM, BET, UV–Vis diffuse reflectance, PL, XPS, and EPR) confirmed the structural integrity, electronic coupling, and ROS generation capability of the composites. Fe–TCPP incorporation narrowed the bandgap from 2.78 to 2.56 eV, prolonged the average carrier lifetime from 6.3 to 7.5 ns, and significantly enhanced the generation of •OH and ¹O₂. The optimized 1 wt% Fe–TCPP@CNNTs achieved complete Rhodamine B degradation within 30 min under visible light, with the highest two-stage apparent rate constants (k₁ = 0.0964 min⁻¹, k₂ = 0.328 min⁻¹). In addition, the hybrids retained over 90% activity after six consecutive runs, confirming their stability and recyclability. The synergistic effect of Fe–N coordination and nanotubular architecture thus promotes light harvesting, charge separation, and ROS utilization, offering a promising design principle for high-performance photocatalysts in environmental remediation. Full article

Organ transplantation has significantly progressed since the 1950s, with notable advancements in surgical procedures and immunosuppression. However, current organ preservation techniques, mainly static cold storage, have not evolved at the same pace and remain insufficient to prevent ischemic and oxidative damage. This damage, primarily caused by the cessation of aerobic metabolism, limits organ viability and transplant outcomes. In this study, we investigated whether supplementing a storage solution with a hemoglobin-based oxygen carrier (HBOC) could improve the condition of ex vivo rabbit kidneys by maintaining oxygenation and supporting aerobic metabolism. In a paired, randomized design, contralateral rabbit kidneys were preserved either in a Krebs-Ringer-based solution enriched with the polymerized hemoglobin OxyVita^®C (15 g/L, p50 4–6 mmHg, MW ≈ 17 MDa, pH adjusted to 7.4) or in an HBOC-free control solution. Physicochemical characterization of OxyVita^®C included oxygen equilibrium curves, zeta potential, polydispersity index, and dynamic light scattering. Biochemical markers (AST, ALT, LDH, K⁺, pH) and histopathological assessments were used to evaluate tissue integrity over 24 h. Histology was additionally stratified according to rinsing protocols (unwashed, NaCl single flush, triple flush), and tubular necrosis was scored by blinded pathologists. Group comparisons were analyzed using ANOVA with Tukey’s HSD test. The HBOC-enriched solution showed improved tissue preservation, higher cell survivability, and better histomorphological profiles, with significantly reduced tubular necrosis scores compared to controls. These findings suggest that active oxygen delivery via HBOCs offers a promising strategy to mitigate ischemic damage during ex vivo kidney storage. Limitations include the lack of transplantation outcomes and direct ROS quantification, which will be addressed in future work integrating hypothermic and normothermic machine perfusion. Full article

Current Pt-based methane combustion catalysts require high noble metal loadings (≥1 wt%) and exhibit insufficient low-temperature activity. To address this, we developed a 0.5 wt% Pt catalyst supported by sulfate-modified Fe-Ce-TiO₂ (denoted 0.5Pt/CFT-TS) via sol–gel synthesis using titanium oxysulfate (TiOSO₄) precursor. Control catalysts prepared with TiCl₄, titanium butoxide, or commercial TiO₂ showed inferior performance. Structural characterization revealed that the TiOSO₄ derived carrier possesses a mesoporous framework (156.2 m²/g surface area, 8.1 nm pore size) with residual SO₄²⁻ inducing strong Brønsted acidity (1.23 mmol/g NH₃ adsorption) and elevated Ce³⁺ concentration (49.45%). These properties synergistically enhanced oxygen vacancy density (51.16% O_α fraction) and stabilized sub-nm Pt nanoparticles. The resulting Pt⁰-Fe³⁺/Ce⁴⁺-Oᵥ interface facilitated dynamic redox cycling (Fe³⁺ + Ce⁴⁺ + 0.5O²⁻ ⇌ Fe²⁺ + Ce³⁺ + 0.5Oᵥ + 0.25O₂), lowering oxygen vacancy regeneration barriers (H₂-TPR peak reduced by 45 °C) and decreasing methane activation energy to 46.77 kJ/mol. This catalyst achieved T₉₀ = 163 °C and complete conversion at 450 °C under industrial conditions (1% CH₄/4% O₂, GHSV = 30,000 h⁻¹), establishing a novel design strategy for low-Pt combustion catalysts. Full article

Chemical looping combustion (CLC) provides an inherently cost-effective method for carbon capture by employing a solid oxygen carrier (OC) to transfer lattice oxygen from air to fuel. The search for low-cost, high-performance natural OCs is crucial for the large-scale deployment of this technology. A natural iron ore containing 41.34% Fe₂O₃ was systematically evaluated as OC for the CLC of CO. Its redox performance was quantified in a fixed-bed reactor between 750 °C and 900 °C with CO concentrations of 10–20%. Multi-cycle tests were conducted to assess stability. Kinetic analysis of the initial cycles was performed using an integral model fitting method. Multi-cycle tests revealed that the fresh ore achieved peak conversions of 48.9% at 750 °C and 77.2% at 900 °C. However, severe sintering occurred beyond 850 °C after the first cycle, causing approximately a 50% drop in OC conversion. Interestingly, once sintered, a self-activation phenomenon was observed during subsequent cycles; the OC conversion slowly recovered from 32% to 37% from the second to the fifteenth cycle under the aggressive conditions (900 °C, 20% CO). Kinetic analysis of the initial cycles (before sintering) revealed low apparent activation energies, ranging from 15.93 to 19.13 kJ mol⁻¹, which are significantly lower than the typical literature values for iron-based ores. This work underscores the potential of natural iron ores as economical and sustainable OCs for CO-rich fuels. The observed self-activation ability of the sintered OC is a promising finding for long-term operation. The results also highlight the critical importance of operating conditions to avoid deep reduction and sintering, necessitating a high solids inventory and a moderate oxygen-to-fuel ratio in practical CLC systems. Full article

With the aim of reducing catalysts’ cost while maintaining high performance in water splitting, ZnO and RuO₂ were combined into composites with ZnO to RuO₂ mass ratios of 1:1, 2:1, and 10:1. The ZnO/RuO₂ composites were prepared by microwave processing of a suspension containing Zn(OH)₂ in situ precipitated onto RuO₂ powder, and subsequently thermally modified at 600 °C to promote heterojunction formation and alter the defect chemistry. Phase composition, crystal structure, morphology, and optical properties were analyzed in detail employing XRD, TEM/HRTEM, HAADF-STEM with EDS, PL and XPS spectroscopy. The photoelectrocatalytic (PEC) activity of the composites toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) was evaluated by linear sweep voltammetry in alkaline electrolyte (0.1 M NaOH, pH 13), before and after one hour of electrochemical system illumination. The analysis focused on surface and bulk oxygen vacancies, which may have a crucial impact in PEC activity, by (1) promoting charge separation and increasing the number of active sites thus enhancing PEC activity, or (2) acting as electron–hole traps and recombination centers, reducing the lifetime of photo-induced charge carriers and thus deteriorating PEC activity. The presented results demonstrate that the combination of ZnO with RuO₂ in a specific mass ratio, along with controlled defect structure, offers a worthwhile route for developing bifunctional, noble-metal-reduced catalysts for green hydrogen and oxygen production. Full article

This study explores the dual functionality of cadmium-based pigments (CdS, CdSe, and CdS_1−xSe_x solid solutions) as historical colorants and visible-light photocatalysts. Synthesized pigments here replicated hues of traditional cadmium reds. At the same time, their photocatalytic efficiency was evaluated using model dyes, such as indigo carmine (anionic) and fuchsine (cationic), as a representative of heritage materials. Structural and optical characterization confirmed tunable bandgaps (1.63–2.28 eV) and phase-dependent microstructures, with CdS_1−xSe_x composites exhibiting compositional heterogeneity. Photocatalytic tests revealed specific degradation mechanisms. Indigo carmine degradation was dominated by superoxide radicals (O₂^•−), while fuchsine degradation relied on photogenerated electrons (e′). Scavenger experiments highlighted the synergistic role of reactive oxygen species (ROS) and charge carriers, with CdS and CdSe showing the highest activity. Intermediate composites displayed selective reactivity, suggesting trade-offs between phase homogeneity and surface interactions. Reduced photocatalytic efficiency in composites aligns with cultural heritage needs, where pigment stability under light exposure is critical. This work bridges material science and conservation, demonstrating how the compositional tuning of CdS_1−xSe_x can balance color fidelity, photocatalytic activity, and longevity in art preservation. Full article