Search Results (200)

Background/Objectives: Non-enhanced computed tomography of the kidneys, ureters and bladder (NECT KUB) is the initial imaging modality for suspected nephroureterolithiasis. However, for alternative diagnoses, NECT may not be the ideal technique. Our institution changed the protocol for this cohort from NECT to intravenous contrast-enhanced CT (CECT) KUB. We aimed to retrospectively compare the rate of alternative diagnosis seen and the rates of calculus detection in CECT versus NECT KUB as a means of assessing performance. Our secondary aim was to compare the radiation dose between CECT and NECT KUB. Methods: Patients referred from the emergency department with suspected nephroureterolithiasis who underwent NECT and CECT KUB over two years were included. Key performance metrics included calculus detection rate, alternative findings, and negative studies. The metrics were compared between genders and age groups. Categorical variables were analysed using Chi-squared or Fisher’s Exact Test and continuous with T-testing. Results: A total of 423 patients had CT KUB imaging (209 NECT, 214 CECT). The incidence of alternative findings in the NECT group was 23% and 40% in CECT (p < 0.001). There were 48 findings (13 major, 11 moderate and 24 minor) in NECT studies and 85 findings (23 major, 43 moderate and 19 minor) in CECT (p < 0.001). Major diagnoses ranged from acute emergencies to more indolent findings, including suspicious nodules/masses. The calculus detection rate (NECT 56%, CECT 54%, p = 0.643) and negative studies (NECT 28%, CECT 22%, p = 0.168) did not significantly differ between protocols. CECT had a mean effective dose of 8.71 ± 2.58 mSv representing 2.4 times the exposure of NECT (p < 0.001). Conclusions: CECT is associated with a greater alternative diagnosis rate with similar calculus detection rates compared to NECT KUB, suggesting superior performance. However, CECT exposes patients to significantly greater levels of ionizing radiation. Full article

Pre-metastatic niche (PMN) formation is a critical step in metastatic progression. However, the biological effects of subtherapeutic doses of ionizing radiation (SDIRs) following radiotherapy on this process remain unclear. Using a 4T1 breast cancer mouse model, we investigated the effects of SDIRs (3 × 0.3 Gy) on lung PMN development and metastasis upon SDIR exposure on days 8–10 post-tumor injection, followed by mastectomy and analyzed on day 24. SDIRs significantly increased the total metastatic volume (TMV) in lungs, suggesting an accelerated PMN formation. Mechanistically, the SDIR acted as an early catalyst for niche priming, upregulating Bv8 expression, enhancing neutrophil recruitment, and increasing MMP9, S100A8, and Il6 production in the PMN by day 11. Moreover, SDIR drives metastasis through distinct mechanisms. Proteomic analysis revealed SDIR-driven metabolic reprogramming, with a shift away from fatty acid metabolism toward glycolysis and lipid accumulation within the PMN. This shift contributes to extracellular matrix (ECM) remodeling, immune modulation, and the upregulation of adhesion-related pathways, shaping a microenvironment that accelerates metastatic outgrowth. By reprogramming the pre-metastatic lung, the SDIR highlights the need to integrate organ-specific radiation exposure into metastasis models. Metabolic and immune-stromal pathways emerge as potential therapeutic targets, underscoring the importance of refining radiotherapy strategies to mitigate unintended pro-metastatic effects. 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

Purpose: To evaluate the variability of oncogenic risk related to radiation exposure in patients frequently exposed to ionizing radiation for diagnostic purposes, specifically ICU patients, according to different risk models, including the BEIR VII, ICRP 103, and US EPA models. Methods: This was an IRB-approved observational retrospective study. A total of 71 patients (58 male, 13 female; median age, 66 years; interquartile range [IQR], 65–71 years) admitted to the ICU who underwent X-ray examinations between 1 October 2021 and 28 February 2023 were included. For each patient, the cumulative effective dose during a single hospital admission was calculated. Lifetime attributable risk (LAR) was estimated based on the BEIR VII, ICRP 103, and US EPA risk models to calculate additional oncogenic risk related to radiation exposure. The Friedman test for repeated-measures analysis of variance was used to compare risk values between different models. The intraclass correlation coefficient (ICC) was used to assess the consistency of risk values between different models. Results: Different organ, leukemia, and all-cancer risk values estimated according to different oncogenic risk models were significantly different, but the intraclass correlation coefficient revealed a good (>0.75) or even excellent (>0.9) agreement between different risk models. The ICRP 103 model estimated a lower all-cancer (median 69.05 [IQR 30.35–195.37]) and leukemia risk (8.22 [3.02–27.93]) compared to the US EPA (all-cancer: 139.68 [50.51–416.16]; leukemia: 23.34 [3.47–64.37]) and BEIR VII (all-cancer: 162.08 [70.6–371.40]; leukemia: 24.66 [12.9–58.8]) models. Conclusions: Cancer risk values were significantly different between risk models, though inter-model agreement in the consistency of risk values was found to be good, or even excellent. Full article

Hypericum perforatum L. (St John’s wort) has been widely studied and used for antidepressant treatment, as well as, rarely, featuring in studies on its chemical composition for Parkinson’s disease (PD) treatment. Five new nor-prenylated acylphloroglucinols with a cyclohexanone core, norperforatums A–E (1–5), together with four known analogs [(2R,3R,4S,6R)-3-methyl-4,6-di(3-methyl-2-butenyl)-2-(2-methyl-1-oxopropyl)-3-(4-methyl-3-pentenyl)cyclohexanone (6), hyperscabrin B (7), (2R,3R,4S,6R)-6-methoxycarbonyl-3-methyl-4,6-di(3-methyl-2-butenyl)-2-(2-methyl-1-oxopropyl)-3-(4-methyl-3-pentenyl)cyclohexanone (8), and hyperscabin K (9)], were isolated from the aerial parts of H. perforatum. The structures and absolute configurations of the new compounds were characterized by multiple spectroscopic means, including nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), ultraviolet visible absorption spectroscopy (UV), infrared spectroscopy (IR), calculated electronic circular dichroism (ECD) data, and X-ray signal crystal diffraction. In addition, the efficacy of these isolations was evaluated against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD in zebrafish larvae. Compound 9 had the best therapeutic effect, by significantly increasing the total distance traveled and the mean speed of movement in PD dyskinesia zebrafish larvae. Moreover, it enhanced superoxide dismutase (SOD) activity and inhibited reactive oxygen species (ROS) production in a dose-dependent manner. These results suggest that compound 9 may have ameliorative effects on PD symptoms by inhibiting oxidative stress. This study provides new insights into the treatment of H. perforatum for PD. Full article

With advances in space, nuclear, and defense industries, the susceptibility of semiconductor integrated circuits (ICs) to radiation has increased. Radiation-induced degradation and malfunctioning of IC performance can lead to system failure, leading to significant damage. To address this limitation, this study employed mixed-stage modeling and simulation (M&S) techniques to evaluate the reliability of complementary metal-oxide semiconductor application-specific ICs (ASICs) in radiation environments. Radiation-hardened IC chips were designed and fabricated using layout modification techniques based on M&S. The ASIC, which includes the D-latch and Operational Amplifier (Op-Amp) circuits, was validated for resistance up to a total ionizing dose of 20 kGy(Si). The proposed radiation-hardened ICs demonstrated stable performance even in radiation-exposed environments, ensuring reliable operation under such conditions. The findings provide insights into overcoming radiation-induced degradation and malfunction in semiconductor integrated circuits, which is particularly relevant for advancing space, nuclear, and defense industries. Full article

Exposure to ionizing radiation (IR) poses a significant risk for all organisms. Although plants are generally more resistant than animals, radiation still impacts their structure and function. Plant resistance to ionizing radiation is a pivotal property to guarantee their survival. This study evaluates bean leaves’ early and long-term responses to oxidative stress induced by ionizing radiation. To assess the early response, we measured a battery of photosynthetic efficiency and oxidative stress markers after exposure of dwarf bean plants to X-ray doses of 0.3, 10, 50, and 100 Gy. We observed that doses started to impact photosynthetic activity at 50 Gy and that markers aggregate in two kinds of behaviors. To test the capacity to recover from radiation-induced damages, 50 Gy-irradiated plants were evaluated with the same markers 3-, 10-, 12-, and 20-days post-irradiation. Dwarf beans displayed remarkable resilience, recovering photosynthetic activity to pre-stress level after three days and pigment content after ten days. The remodulation of oxidative stress markers is slower and more complex, with catalase and total polyphenols failing to recover completely and residual antioxidant activity after twenty days. Despite that, PARP activity recovers to pre-irradiation after three days. The restoration of photosynthesis to pre-irradiated conditions highlights the DNA-repairing efficiency of poly(ADP-ribose) polymerase and antioxidant machinery in providing resilience to radiation-induced oxidative stress. Understanding resilience mechanisms sheds light on the ability of plants to survive and thrive in radiation-intense environments, such as space or radioactively contaminated areas. Full article

A comparative study on the synergistic effect of the total ionizing dose and neutron single event effect on a SiC MOSFET and Si MOSFET was performed based on the ⁶⁰Co γ source and the high-pressure multiplier 14 MeV neutron source at the China Institute of Atomic Energy. First, a γ-ray total ionizing dose experiment was performed on these two devices, and the differences in the total ionizing dose damage of the SiC and Si MOSFETs were analyzed. Then, neutron single event effect experiments were performed to investigate the effects of different doses on the single event effect for the devices. The results indicate that the unhardened SiC MOSFET has stronger resistance to the total ionizing dose compared with hardened Si MOSFET. During the 14 MeV neutron irradiation experiment, no single event burnout was observed in either device, but single event transients were observed. Even though the hardened Si MOSFETs are capable of suppressing single event transient currents at a higher drain bias, the trapped charge concentration of SiC MOSFETs due to irradiation is smaller than that of Si MOSFETs, which improves their resistance to the total ionizing dose and makes them less affected by the synergistic effect of the total ionizing dose and neutron single event effects. The research results can provide some guidelines for the radiation hardening technology of power devices used in aerospace and nuclear industries. Full article

Hybrid ceramics exhibit low wear on antagonist tooth enamel, which may positively impact the oral rehabilitation of head-and-neck irradiated patients who experience alterations in tooth microstructure and wear resistance. This study aimed to evaluate the wear resistance of hybrid ceramics after gamma radiation exposure in contact with irradiated tooth enamel, as well as their mechanical and chemical properties. Notably, no previous studies focusing on the effects of radiation on hybrid ceramics were found in the literature. Vita Enamic discs and tooth fragments were subjected to daily doses of 2 Gy, totaling 0, 20, 40, 50, 60, and 70 Gy. The wear resistance of hybrid ceramics and a ceramic enamel analog (steatite) was tested against tooth enamel using a chewing simulation machine. Hybrid ceramic specimens underwent hardness, biaxial flexural strength, roughness, and FT-IR analyses. The data were analyzed using an ANOVA and Tukey’s test (α = 0.05). Enamic exposed to 60 and 70 Gy exhibited higher wear and caused less tooth enamel loss compared to steatite. The mechanical and chemical properties remained unchanged after irradiation. The roughness decreased across all groups after a chewing simulation but was not affected by irradiation. In conclusion, ionizing radiation did not alter the material’s properties but increased its wear. Full article

The impacts of total ionizing dose (TID) were investigated in 28 nm 3D charge trapping (CT) NAND Flash memories. This study focused on the variations in the raw bit error rate (RBER) of irradiated flash across different operational modes and bias states. It was observed that the data pattern stored in Flash influences the bit error count after irradiation. The experimental findings demonstrated a dose-dependent relationship with standby current, read operation current, and threshold voltage shifts. Additionally, TID was found to affect the time required for erasure and programming operations. These results were then bench-marked against similar NAND Flash devices, revealing superior resistance to TID effects. Full article

Radiation impacts on space-based systems operating on various orbits are evaluated in this paper. Specifically, satellite operations in Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and Geosynchronous Orbit (GEO) are analyzed. Special focus is given on quantifying the effect of high-energy particle space radiation on materials used for critical power components, where component fault can lead to total mission failure. Methods, using multiple computational platforms for the quantification of non-ionizing energy loss (NIEL) and displacement damage dose (DDD), are used to assess semiconductor damage at specific orbital altitudes. Detailed simulations were conducted for Gallium Arsenide Indium Phosphide (GaInP/GaAs/Ge) solar cells with various cover glass thicknesses, and the survivability of GaInP/GaAs/Ge cells was compared with that of Si cells. It was assessed that radiation exposure due to high-energy protons at 10,000 km is more prevalent than 20,000 km orbits and that electron bombardment is a major electronic damage culprit. For MEO at 10,000 km, MEO at 20,000 km, and GEO at 36,000 km, we determined the 1-year maximum power (Pmax) losses due to protons to be 23%, 8%, and 1% and losses due to electrons to be 11%, 14%, and 10%. Total integrated spectra Pmax losses for those altitudes are 25%, 16%, and 10%, respectively. Full article

Background/Objectives: With technological development, ionizing radiation has found applications in numerous occupations. However, the determination and quantification of the damage resulting from exposure to it remains rather unclear, along with the damage to particular organs. The aim of this systematic review was to investigate the relationship between low-dose ionizing radiation (LDIR) in exposed workers and possible functional changes and cancer development in the thyroid gland. Methods: We included observational studies evidencing the correlation under study. Data extraction and analysis was conducted on all included studies. The research strategy included three electronic databases (PubMed, Scopus, and Web of Science). The systematic review followed PRISMA guidelines, and the research protocol was submitted to PROSPERO (CRD:42023425839). Results: The search initially yielded 166 articles and, once duplicates and irrelevant articles were removed, a total of 15 useful articles were reviewed. Qualitative analysis of the studies showed that the TSH value does not change following exposure, while a reduction in fT3 and an increase or reduction in fT4 can be observed. Furthermore, the correlation between thyroid cancer and occupational exposure to radiation was not shown with certainty, but there was some evidence of increased gland volume and nodule formation. Conclusions: Even at low doses, ionizing radiation adversely affects thyroid activity. In this regard, new studies should be carried out in order to further investigate and define this issue and, consequently, outline useful measures to ensure the protection of workers in contact with this particular physical agent. Full article

Naturally occurring radionuclides are ubiquitous at various levels of concentration, while exposure to ionizing radiation by humans is of global concern. Radiological health risk assessment due to the consumption of natural spring mineral water is critical for ensuring public health and safety. This study aims at investigating the radioactivity concentration levels of natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K and the associated radiological health risk in commercial natural spring bottled water in South Africa. A total of 21 of the most-consumed bottled drinking water brands from grocery stores, were analysed using the HPGe gamma detector. The results indicate that the range of radioactivity concentrations is from 1.060 ± 0.067 to 2.571 ± 0.143 BqL⁻¹, with a mean of 1.766 ± 0.399 BqL⁻¹ for ²²⁶Ra; 1.736 ± 0.112 to 7.807 ± 0.099 BqL⁻¹, with a mean of 3.688 ± 1.371 BqL⁻¹ for ²³²Th and 149.000 ± 38.480 to 242.900 ± 59.700 BqL⁻¹ with a mean of 220.229 ± 22.297 BqL⁻¹ for ⁴⁰K. The potential radiological health risks evaluated show mean values for Ra_eq, D_Ab, AEID and AGED as 23.976 ± 0.446 BqL⁻¹, 12.232 ± 1.445 nGyh⁻¹, 0.060 ± 0.007 mSvy⁻¹ and 0.090 ± 0.027 mSvy⁻¹, respectively. The radiation dose based on age group is in the order of infants (≤1 year) > teenagers (12–17 years) > children (1–12 years) > adults (>17 years). The activity concentrations of radionuclides in bottled water are ranked in the order of ⁴⁰K > ²³²Th > ²²⁶Ra, with ²³²Th contributing the highest radiation dose, consistent with findings reported in previous studies. The findings reveal that the activity concentration levels and estimated radiological health risks are within the permissible limits set by UNSCEAR guidelines. Therefore, the consumption of bottled water is radiologically safe. However, the findings also suggest that 12 out of 1000 individuals may suffer cancer fatality, while 6 out of 1 million individuals may experience hereditary effects over their lifetime from the consumption of bottled water. Regular monitoring and stringent regulatory controls are recommended to ensure the radiological safety of bottled drinking water in South Africa. Full article

Advanced oxidation processes (AOPs), including ionizing radiation treatment, are increasingly recognized as an effective method for the degradation of pharmaceutical pollutants, including non-steroidal anti-inflammatory drugs (NSAIDs). Nabumetone (NAB), a widely used NSAID prodrug, poses an environmental risk due to its persistence in aquatic ecosystems and its potential toxicity to non-target organisms. In this study, the radiolytic degradation of NAB was investigated under different experimental conditions (dose rate, radical scavenging, pH, matrix effect), and the toxicity of its degradation products was evaluated. NAB was rapidly degraded at 300 Gy with prolonged irradiation. Mineralization of about 88% of NAB solutions was observed based on the evaluation of total organic carbon (TOC). The most efficient degradation of NAB occurred under N₂O conditions, while it was retarded in the presence of thiourea. The water matrix components had a significant influence on the efficiency of degradation. In addition, the main degradation products were identified by LC-HRMS. Toxicity studies on different bacteria showed no significant impact of the NAB degradation products, while in silico predictive methods revealed their slightly increased toxicity compared to the parent compound, but considerably lower toxicity in comparison to its main active form 6-methoxy-2-naphthylacetic acid (MNA). Additionally, significantly lower toxicities are predicted for degradation products in N₂O saturated solution. These results underline the importance of optimizing irradiation parameters for effective degradation and minimizing the formation of harmful by-products. Understanding all aspects of the AOP processes and the toxicological effects of the degradation products ensures effective mitigation of potential environmental and health risks of water treatment processes. Full article

The application of energy-saving policies in buildings could lead to a decrease in the air exchange rate in dwellings, which could consequently lead to an increase in indoor radon concentration and, therefore, to an increase in resident exposure to ionizing radiation. The aim of the research presented in this paper is to investigate radiological exposure to residents due to the usage of different granites commonly used in Serbia as a building material. From the total of 10 analysed granite samples, a wide range of radon and thoron exhalation rates were found: from <161 μBq m⁻² s⁻¹ to 5220 ± 200 μBq m⁻² s⁻¹ and from <7 mBq m⁻² s⁻¹ to 5140 ± 320 mBq m⁻² s⁻¹, respectively. Assuming a low air exchange rate of 0.2 h⁻¹, the contribution of the measured granite material to the indoor radon concentration could go up to 150 Bq m⁻³. The estimated annual effective doses due to exposure to radon and thoron exhalation from the granite samples were (0.05–3.79) mSv and (<0.01–1.74) mSv, respectively. The specific activity of radionuclides ranged from 6.6 ± 0.5 Bq kg⁻¹ to 131.8 ± 9.4 Bq kg⁻¹ for ²²⁶Ra, from 0.5 ± 0.1 Bq kg⁻¹ to 120.8 ± 6.5 Bq kg⁻¹ for ²³²Th, and from 0.22 ± 0.01 Bq kg⁻¹ to 1321 ± 86 Bq kg⁻¹ for ⁴⁰K. The obtained external hazard index ranged from 0.03 to 1.48, with three samples above or very close to the accepted safety limit of 1. In particular, dwellings with a low air exchange rate (causing elevated radon) could lead to an elevated risk of radiation exposure. Full article