巴哈原子能研究中心

Multifunctional nanoplatforms capable of integrating therapy and imaging functions are of significant interest for cancer research. In this work, we report the synthesis of bovine serum albumin (BSA)-functionalized manganese ferrite nanoassemblies (MnFe2O4@BSA NAs) as a multifunctional platform for chemo-photodynamic therapy and magnetic functionality. Ethylenediamine-modified MnFe2O4 nanoassemblies were first prepared via a thermal decomposition route and subsequently conjugated with BSA to improve aqueous stability, biocompatibility, and drug-loading capability. The resulting nanoassemblies exhibited well-defined morphology (50–60 nm), good colloidal stability, and superparamagnetic behavior that was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, zeta-potential, DLS and magnetic measurements. The anticancer drug doxorubicin hydrochloride (DOX) and the photosensitizer Rose Bengal (RB) were successfully loaded into MnFe2O4@BSA NAs, showing high loading efficiency and pH-responsive DOX release. Under visible-light irradiation, RB-loaded MnFe2O4@BSA NAs generated reactive oxygen species (ROS) through combined photodynamic and photo-Fenton-like processes. In vitro studies using MCF-7 breast cancer cells demonstrated that the combined RB-DOX-loaded MnFe2O4@BSA NAs exhibited enhanced cytotoxicity under light irradiation compared to individual chemotherapy or photodynamic therapy, indicating a synergistic chemo-photodynamic effect. Moreover, MnFe2O4@BSA NAs showed good heating efficacy under an AC magnetic field and significant signal reduction on the T2-weighted phantom image with transverse relaxivity (r2) of 123.7 mM−1 s−1. Overall, this study presents MnFe2O4@BSA NAs as a multifunctional in-vitro platform integrating drug delivery, photodynamic activity, magnetic heating, and MRI contrast properties, providing a foundation for future image-guided and in vivo therapeutic investigations.

Postharvest spoilage of plum (Prunus domestica L.) is primarily associated with rapid senescence, microbial proliferation, tissue softening, and moisture loss, resulting in significant quality deterioration and economic losses during storage and distribution. The present study investigated the effectiveness of combined salicylic acid (SA) and gamma irradiation treatment as an integrated hurdle technology for improving microbial safety and extending the postharvest shelf life of plum cv. Stanley. Fruits were treated with SA (1.0–2.5 mmol L−1) individually or in combination with gamma irradiation (1.5 kGy) and stored under refrigerated conditions (3 ± 1°C, 80% RH) for 28 days followed by ambient shelf-life evaluation. To provide a comprehensive evaluation of postharvest performance, physicochemical (fruit firmness and physiological weight loss), biochemical (ascorbic acid and total phenolics), microbiological (yeast and mold counts), and commercial shelf-life parameters (decay incidence and post-refrigerated ambient storage performance) were systematically monitored throughout storage. The combined treatments significantly (p ≤ 0.05) reduced physiological weight loss, delayed firmness degradation, suppressed decay development, and preserved ascorbic acid and total phenolic compounds compared to untreated and individually treated fruits. The optimized treatment (2.5 mmol L−1 SA + 1.5 kGy) exhibited the highest preservation efficacy, maintaining fruits virtually decay-free during refrigerated storage and extending marketable shelf life by an additional 7 days under ambient conditions. Yeast and mold counts remained below detectable limits up to 21 days of storage in the optimized treatment, demonstrating enhanced microbiological safety and spoilage control. The preservation effect was attributed to the combined action of irradiation-mediated microbial decontamination and SA-induced enhancement of host defense responses and antioxidant stability. The findings demonstrate that the integration of salicylic acid with low-dose gamma irradiation represents a sustainable and residue-free preservation strategy for improving food safety, reducing postharvest losses, and enhancing storage stability of fresh plum fruit in commercial supply chains.

Abstract Borosilicate glass is used for the immobilization of high-level liquid waste (HLW). HLW originates in a reprocessing plant during the extraction of U and Pu from spent nuclear fuel. This waste contains high levels of α , β , and γ radioactivity, a wide range of elements, and salts. Its immobilization in a glass matrix helps in the containment of radioactivity. However, the stability of the glass network plays a vital role in determining how effectively the radioactivity can be contained without any release into the environment. The thermal, chemical, and mechanical stability of the product glass primarily depends on the additives present in the base glass. In this study, four sodium borosilicate base glass matrices were systematically investigated to evaluate the influence of CaO, K 2 O, Al 2 O 3 , and P 2 O 5 on their structural, thermal, and chemical properties. Raman spectroscopy, along with the Dell–Bray model, revealed significant changes in the distribution of silicon- and boron-based structural units with compositional variations. Glasses containing mixed modifiers (Na 2 O–CaO–K 2 O) exhibited superior performance and were found to be more suitable for the immobilization of high-sodium HLW compared with glasses containing only one modifier. The incorporation of mixed modifiers and Al 2 O 3 enhanced the chemical durability by approximately tenfold compared with the base composition. In contrast, the addition of 5 mol percent P 2 O 5 adversely affected the glass network, reducing the glass transition temperature ( Tg ) by approximately 45°C and decreasing the chemical durability by factors of 2–5. These findings provide valuable guidance for selecting and optimizing base glass matrices for the vitrification of diverse HLW streams.

Abstract Topoisomerase 1 (TOP1) is essential for relieving DNA supercoils during replication and transcription. However, its transient reaction intermediates (TOP1 cleavage complexes or TOP1-DNA covalent complexes, i.e., TOP1ccs) become highly genotoxic when stabilized. While mechanisms that resolve chemotherapy-induced TOP1ccs are well-characterized, how cells prevent their accumulation under physiological conditions for securing genomic stability has remained elusive. Here, we elucidate a novel regulatory pathway in which CHK1-mediated phosphorylation of TOP1 at Serine-320 regulates its religation activity and hence limits steady-state TOP1cc levels during unperturbed cellular metabolism. We further demonstrate a distinct mechanism of TOP1cc stabilization, which escapes recognition by proteasomal and autophagic machineries, while being susceptible to CtIP, SPRTN, and p97-mediated removal. Defective phosphorylation of TOP1 at S320 impairs replication-fork progression, leading to replication- and transcription-associated DSBs, R-loop stabilization, genomic instability, and hypersensitivity to TOP1 poisons. Overall, our study assigns a new function to CHK1 in direct regulation of human TOP1cc dynamics, with critical implications for genomic integrity and combinatorial chemotherapy.

Loofah sponges, traditionally grown in Asia for centuries, could be a sustainable and abundant source of carbon material for energy storage applications owing to their lignocellulosic fibrous structure. Herein, waste loofah sponges were transformed into activated carbon (LAC) for use as high-performance supercapacitor electrodes. The capacitive performance of the LAC was further enhanced by hybridizing it with nanostructured copper oxide (Cu2O). A two-step process, involving the pyrolysis of copper-salt-soaked loofah sponge biomass and CO2-activation process, was carried out to prepare a Cu2O nanoparticle-anchored activated-LAC composite (Cu2O@LAC). The as-prepared activated Cu2O@LAC composite possesses a high specific surface area of 1757.63 m2 g−1 with a large fraction of mesopores, which allows large molecules or ions to easily diffuse through the material to reach active Cu2O sites, enhancing its capacitance with improved rate performance. The Cu2O@LAC electrode achieved a high gravimetric specific capacitance of up to 520 F g− 1 at 0.2 A g−1, along with excellent capacitance retention of 91.7