Search Results (257)

This research involved functionalizing polypropylene (PP) films with 2-(Diethylamino)ethyl methacrylate (DEAEM), a monomer that responds to both temperature and pH. For this, Gamma-ray irradiation was used at a dose rate of 11.75 kGy h⁻¹, doses ranging from 30 to 100 kGy, and a monomer concentration of 50% (v/v). The modified films (PP-g-DEAEM) were characterized by thermal analysis, FTIR-ATR, swelling, and contact angle. Confirming that the films were successfully grafted with DEAEM, improving the wettability of the pristine PP films, with a critical pH of 5.6 and a temperature response at 45.7 °C. Subsequently, the films were subjected to ciprofloxacin loading and release, and their in vitro efficacy against the E. coli strain was assessed using the Kirby-Bauer method. This work suggests potential applications in biomedical devices; however, further studies are needed. Full article

Aim: This ex vivo study aimed to evaluate the effect of low-energy 445 nm diode laser irradiation on permanent fluoride retention in human enamel. Materials and Methods: Eighty caries-free extracted permanent human teeth were used to prepare 480 enamel discs (2 × 2 mm). Baseline fluoride content in untreated enamel specimens (control group E) was measured using particle-induced gamma-ray emission (PIGE). All specimens then received a topical application of acidulated phosphate fluoride for 5 min, followed by rinsing with double-distilled water for 1 min. Fluoride quantification was subsequently repeated. Specimens were randomly allocated into two groups: fluoridated only (EF; n = 240) and fluoridated plus laser-treated (EFL; n = 240). Each group was further subdivided based on storage conditions: either in air or in double-distilled water at 36 °C for 7 days. Laser irradiation was performed using a 445 nm diode laser in continuous-wave mode at 350 mW for 30 s, with a beam diameter of 10 mm, an energy density of 13.375 J/cm², and a power density of 0.445 W/cm². Results: At baseline, mean fluoride content across all specimens was 702.23 ± 201 ppm. Immediately after fluoridation, fluoride levels increased to 11,059 ± 386 ppm in the EF group and 10,842 ± 234 ppm in the EFL group, with no significant difference between groups. After 7 days of storage in air, fluoride retention decreased to 5714 ± 1162 ppm in EF and 5973 ± 861 ppm in EFL, again without significant difference. However, after 7 days of immersion in double-distilled water, the EF group exhibited complete loss of acquired fluoride, with values falling below baseline (337 ± 150 ppm). In contrast, the EFL group retained a substantial portion of the fluoride acquired during fluoridation (total 1533 ± 163 ppm), indicating that laser irradiation significantly prevented fluoride loss (p < 0.001). Conclusions: Low-energy 445 nm diode laser irradiation of fluoridated enamel significantly enhances fluoride retention under aqueous conditions simulating osmotic processes. Laser treatment preserved a substantial portion of fluoride acquired during fluoridation, whereas fluoridated but unlased enamel lost nearly all fluoride, with levels dropping below baseline. This approach may offer clinical benefits for improving enamel fluoride enrichment, thereby increasing resistance to acid challenge and reducing caries risk. Full article

Background: Stereotactic radiotherapy (SRT) is a promising treatment option for patients with multiple brain metastases (BMs). Using one isocenter instead of a separate isocenter for each BM can reduce the treatment time. This work compares the calculated dose in the treatment planning system with the measured dose using film dosimetry of single-isocenter multi-target (SIMT) SRT for multiple BM. Methods: Fifty patients with 4 to 18 BMs (median = 6, in total 356 BMs) were treated with a single-isocenter non-coplanar LINAC-based treatment with six VMAT arcs. Treatment was performed using RayStation and Elekta Versa HD with Agility multileaf collimator, including a 6D robotic couch. Patient-specific QA measurements were performed with an in-house developed phantom using three layers of GafChromic EBT3 film. Film measurements were analyzed in DoseLab using global gamma with 3% and 1 mm distance-to-agreement criteria. Additionally, secondary dose calculations in Mobius3D were performed with similar gamma criteria. Results: The mean total Paddick conformity index and gradient index were 0.7 ± 0.10 and 5.2 ± 1.9, respectively. Monitor units used were 6321 ± 2510, and mean irradiation time was 600 ± 90 s. The mean global gamma passing rate for all measured films was 94.5 ± 4.6% with 3% and 1 mm criteria, while that of the dose calculations in Mobius3D was 98.2 ± 1.2% with the same criteria. A dependence of gamma passing rates of film measurements on the total PTV volume was observed, whereas such dependence was minimal for Mobius3D. Conclusions: The results demonstrate good agreement between the TPS, film measurements, and independent dose calculations, supporting the dosimetric accuracy of single-isocenter multi-target SRT for treating multiple BMs. Full article

This work aimed to synthesize a graft copolymer with temperature- and pH-responsive properties. The synthesis of SR-cat-g-(NVCL/NVIM) was carried out using the direct irradiation method with a ⁶⁰Co gamma-ray source (Gammabeam 651 PT). The temperature- and pH-responsive monomers, N-vinylcaprolactam (NVCL) and N-vinylimidazole (NVIM), respectively, were grafted onto silicone catheters. The effects of irradiation dose and monomer concentration on grafting efficiency were studied. A direct relationship was found between grafting efficiency and both irradiation dose and monomer concentration. As these parameters increased, the grafting percentage also increased. The biomaterial was characterized by using Fourier-Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), swelling, and a water contact angle measurement. The swelling behavior was also investigated by varying temperature and pH. The Lower Critical Solution Temperature (LCST) was observed around 34 °C, and pH sensitivity was detected between pH 8 and 8.5. Mechanical tests were performed to conduct a systematic analysis relating to the grafting percentage and the ratio between grafted polymers and Young’s modulus. Finally, the loading and release capacity of norfloxacin in the modified catheters was evaluated. Full article

Zinc ions, as essential trace elements in the human body, play a crucial role in promoting wound healing. They have significant applications in the medical field. In this paper, chitosan (CS)/polyvinyl alcohol (PVA)/zinc gluconate hydrogel was synthesized via gamma ray irradiation cross-linking. The hydrogel exhibited excellent antibacterial properties, and could continuously release zinc ions. Antibacterial assays demonstrated that the combination of CS and zinc ions improved the antibacterial properties of hydrogel. The inhibition zones against both Staphylococcus aureus and Escherichia coli exceed 12 mm. The cell viability can reach 108.25%. The prepared hydrogel could continuously release zinc ions over a period of 70 h. The pore and chemical structure were, respectively, performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). And its comprehensive properties, such as gel content, water evaporation ratio and swelling behavior were investigated. The hydrogels showed potential application value in the hydrogel dressing for zinc ion delivery. Full article

Background/Objectives: Kaempferol (KAE) is used to treat gamma radiation-induced damage. However, poor water solubility of KAE restricts its application. Therefore, we developed a KAE-loaded zeolitic imidazolate framework-8 (KAE@ZIF-8) to improve the solubility and bioavailability of KAE, thereby enhancing the radioprotective effect against gamma radiation. Methods: The composite was characterized using scanning electron microscopy (SEM), nitrogen adsorption/desorption analysis, X-ray diffraction (XRD), differential scanning calorimetry (DSC), equilibrium solubility assessments, in vitro release studies, stability evaluations, and drug-loading capacity measurements. The cytotoxic effects of KAE@ZIF-8 on Caco-2 cells were assessed in vitro. Meanwhile, the bioavailability of the preparation was also investigated. Finally, the protective efficacy of KAE@ZIF-8 against total body irradiation was evaluated in C57BL/6 mice. Results: The results indicated that KAE@ZIF-8 was successfully constructed, exhibiting a uniform hexagonal crystal morphology, with KAE transitioning from a crystalline to an amorphous state. As a carrier, ZIF-8 significantly enhanced the solubility of KAE by 9.2-fold, and the cumulative release within 12 h reached approximately 89%. Meanwhile, ZIF-8 could significantly enhance the bioavailability of KAE and reduce its toxicity. We found that pretreatment with KAE@ZIF-8 prolonged mouse survival time after 9 Gy total body irradiation (TBI). Mice were scarified on the 7th day after 7 Gy TBI. Results showed that KAE@ZIF-8 exhibited an improvement of the radioprotective effects, including weight loss mitigation, spleen index increase, radiation-induced intestinal injury attenuation, and modulation expression of IL-1β, IL-6, TNF-α and TGF-β1 following radiation. Conclusions: These results suggest the potential effect of ZIF-8 as an oral drug delivery carrier for radioprotective drugs. Full article

Radiotherapy employs high-energy X-rays to precisely target tumor tissues while minimizing damage to the surrounding healthy structures. Although its clinical efficacy is well established, the immunomodulatory effects of ionizing radiation remain complex and context-dependent. This study investigated the biological effects of radiotherapeutic doses on immune cells by evaluating lymphocyte viability, phenotypic profiles, and cytokine expression levels. Peripheral blood mononuclear cells (PBMCs) were isolated from six healthy donors and irradiated with 0, 2, or 6 Gy using a 6 MV linear accelerator (LINAC). Dose validation with an ionization chamber demonstrated strong agreement between estimated and measured values (intraclass correlation coefficient = 1, 95% CI). Immune subsets, including T cells (CD3+), helper T cells (CD3+CD4+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+CD4+Foxp3+), and natural killer (CD3-CD56+) cells, along with intracellular cytokines interleukin-12 (IL-12) and interferon-gamma (IFN-γ), were analyzed via flow cytometry at multiple time points. The results showed a significant, dose-dependent decline in overall lymphocyte viability (p < 0.01) compared to control. Cytotoxic T cells were the most radiosensitive, followed by helper and regulatory T cells, while NK cells were the most radioresistant. IL-12 expression initially increased post-irradiation, while IFN-γ levels remained variable. These findings demonstrate that radiation induces distinct alterations in immune phenotypes and cytokine profiles, which may shape the immune response. Immune profiling following irradiation may therefore provide valuable insights for optimizing combination strategies that integrate radiotherapy and immunotherapy in cancer treatment. Full article

The accumulation of high levels of manganese ions complexed with small molecules has been proposed as a pivotal factor contributing to the extraordinary radiation resistance of Deinococcus radiodurans. However, the molecular mechanisms governing the manganese ion homeostasis remain elusive. In this study, we characterize the role of the MntABC transporter system for Mn ion accumulation in D. radiodurans. Its cellular membrane localization is unequivocally demonstrated through fluorescence labeling techniques. Mutation of the protein components of the MntABC led to a significant decrease in intracellular Mn ion accumulation, concomitant with impaired cellular growth, decreased resistance against hydrogen peroxide, and gamma-ray irradiation-induced oxidative stresses, indicating that the MntABC system plays an indispensable role in resistance of D. radiodurans to oxidative stresses. Protein structure modeling and molecular docking are employed to analyze the key active sites of the MntABC proteins and their intermolecular interactions. The results demonstrate that the MntABC system is essential for maintaining Mn ion homeostasis and the oxidative stress resistance of D. radiodurans. Full article

In this research, silicone films (SR) were modified by grafting ethylene glycol dicyclopentenyl ether acrylate (EGDEA) through gamma-ray irradiation using both direct and pre-irradiation methods at a dose rate of 10.8 kGy/h, with doses ranging from 10 to 50 kGy. Several techniques, including TGA, DSC, contact angle measurement, mechanical testing, swelling, and FTIR, confirmed the grafting of EGDEA onto SR films. The highest grafting efficiency was achieved at 50 kGy using the direct method. Subsequently, SR-g-EGDEA films were loaded with silver for microbial testing, showing promising results for potential biomedical applications. Full article

We developed a novel dosimetric method using DNA molecules as a radiation sensor. The amount of neutron or gamma rays irradiated DNA damage was determined by evaluating the amount of DNA serving as a template for qPCR. The absorbed doses in the samples were estimated using the tally of the “t-product” in the data from the PHITS Monte Carlo particle transport simulation code. The neutron fluence for each sample was measured using the niobium activation reaction ⁹³Nb (n, 2n) ^92mNb, and the absorbed dose per neutron fluence was estimated to be 7.1 × 10⁻¹¹ Gy/(n/cm²). Based on the PHITS modeling, the effects of neutron beams are attributed to the combination of proton and alpha particle beams. The results from qPCR showed that neutrons caused more DNA damage than gamma rays. The qPCR method demonstrated that neutron irradiation caused 1.13-fold more DNA damage compared to gamma ray irradiation; however, this result did not show a statistically significant difference. This method we developed, using DNA molecules as a radiation sensor, may be useful for biodosimetry. Full article

This study systematically investigates the mechanism by which total ionizing dose (TID) affects the lifetime degradation of NMOS devices induced by hot-carrier injection (HCI). Experiments involved Cobalt-60 (Co-60) gamma-ray irradiation to a cumulative dose of 500 krad (Si), followed by 168 h annealing at 100 °C to simulate long-term stability. However, under HCI stress conditions (V_D = 2.7 V, V_G = 1.8 V), irradiated devices show a 6.93% increase in threshold voltage shift (ΔV_th) compared to non-irradiated counterparts. According to the IEC 62416 standard, the lifetime degradation of irradiated devices induced by HCI stress is only 65% of that of non-irradiated devices. Conversely, when the saturation drain current (I_Dsat) degrades by 10%, the lifetime doubles compared to non-irradiated counterparts. Mechanistic analysis demonstrates that partial neutralization of E’ center positive charges at the gate oxide interface by hot electrons weakens the electric field shielding effect, accelerating ΔV_th drift, while interface trap charges contribute minimally to degradation due to annealing-induced self-healing. The saturation drain current shift degradation primarily correlates with electron mobility variations. This work elucidates the multi-physics mechanisms through which TID impacts device reliability and provides critical insights for radiation-hardened design optimization. Full article

Thin amorphous oxide films (a-SiO₂, a-Al₂O₃, a-MgO) were prepared by magnetron sputtering deposition. Their response to high-energy heavy ion beams (23 MeV I, 18 MeV Cu, 2.5 MeV Cu) and gamma-ray (1.25 MeV) irradiation was studied by elastic recoil detection analysis and infrared spectroscopy. It was established that their high radiation hardness is due to a high level of disorder, already present in as-prepared samples, so the high-energy heavy ion irradiation cannot change their structure much. In the case of a-SiO₂, this resulted in a completely different response to high-energy heavy ion irradiation found previously in thermally grown a-SiO₂. In the case of a-MgO, only gamma-ray irradiation was found to induce significant changes. Full article

Infrared image sensors are crucial across various industries. However, with technological advancements, the growing scale of infrared image sensors has made the impact of transient dose rate effects increasingly significant. It is necessary to conduct relevant radiation effect studies to provide the theoretical and data basis for future radiation-hardened design. This study explores the response of large-area N-wells in the readout circuit of infrared detectors to transient dose rate effects. The TCAD simulation results indicate that the expansive N-well area in the merged-design pixel units generates significant current pulses when exposed to gamma-ray irradiation. Specifically, at dose rates of 3 × 10¹¹ rad/s, 5 × 10¹¹ rad/s, 7 × 10¹¹ rad/s, and 9 × 10¹¹ rad/s, the pulse currents measured are 39 nA, 64 nA, 89 nA, and 119 nA, respectively. Due to the spatial constraints of the 55 nm merged design, the close proximity of the GND to the N-well creates a high potential barrier near the N-well, obstructing the path between the GND and the substrate, which results in the pulse current exhibiting a stepped-like characteristic. Full article

The widespread presence of antibiotics in aquatic environments poses significant ecological and public health risks due to their persistence, antimicrobial activity, and contribution to resistance gene proliferation. This review systematically evaluated the advancements in antibiotic degradation using ionizing radiation (γ-rays and electron beam) from laboratory studies to practical applications. By using keywords such as “antibiotic degradation” and “ionizing irradiation OR gamma radiation OR electron beam,” 328 publications were retrieved from Web of Science, with China contributing 33% of the literature, and a number of global representative studies were selected for in-depth discussion. The analysis encompassed mechanistic insights into oxidative (•OH) and reductive (e_aq⁻) pathways, degradation kinetics influenced by absorbed dose (1–10 kGy), initial antibiotic concentration, pH, and matrix complexity. The results demonstrated ≥90% degradation efficiency for major antibiotic classes (macrolides, β-lactams, quinolones, tetracyclines, and sulfonamides), though mineralization remains suboptimal (<50% TOC removal). Synergistic integration with peroxymonosulfate (PMS), H₂O₂, or O₃ enhances mineralization rates. This review revealed that ionizing radiation is a chemical-free, compatible, and highly efficient technology with effective antibiotic degradation potential. However, it still faces several challenges in practical applications, including incomplete mineralization, matrix complexity in real wastewater, and operating costs. Further improvements and optimization, such as hybrid system development (e.g., coupling electron beam with other conventional technologies, such as flocculation, membrane separation, anaerobic digestion, etc.), catalytic enhancement, and life-cycle assessments of this emerging technology would be helpful for promoting its practical environmental application. Full article

Ionizing radiation at early stages leads to radiation-induced death of Langerhans islet cells and acinar cells, resulting in the development of acute/subacute pancreatitis. Conducting studies on radiation-induced changes in the pancreas following electron beam irradiation appears to be of great interest, and the evaluation of radioprotective agents for safeguarding normal tissues from radiation is equally important. The aim of this study was to preclinically investigate the antioxidant properties of N-Acetylcysteine in an animal model of radiation-induced pancreatitis over a three-month period. In this study, it was proven for the first time that even electrons can lead to characteristic signs of radiation-induced pancreatitis, the degree of which was assessed based on the levels of insulin, glucose, and amylase. Thus, conducting electron therapy also increases the risks of insulin resistance, as well as X-ray and gamma radiation. For the first time, a comprehensive analysis of biochemical, morphological, and immunohistochemical markers in the pancreas of a large cohort of electron-irradiated animals was conducted, including both acute and delayed effects of electron exposure. The crucial role of interleukins in shaping both the cellular and vascular components of the inflammatory response was identified. Additionally, the radioprotective properties of N-Acetylcysteine during electron irradiation of the pancreas were evaluated for the first time, and its effectiveness in reducing both acute and late complications of electron therapy was demonstrated. Thus, it can be concluded that N-Acetylcysteine is capable of effectively suppressing the inflammatory response in the pancreas. Full article