Ionizing radiation can originate from naturally occurring radiation sources on the earth or it can be from man-made sources. When interacting with cells and living organisms, ionizing radiation produces free radicals, impacting biological molecules such as proteins, lipids, and DNA in the cell nucleus and membrane, leading to cell death or causing cell mutations. Epigallocathecin gallate (EGCG) and ascorbic acid (AA) are well-known natural antioxidants that have been studied and applied as potential radical scavengers. In this study, the radiation protection effects in the presence of EGCG and AA via the scavenging process of free radicals (mainly hydroxyl radicals) were examined. Saccharomyces cerevisiae yeast cells were grown in YDP liquid medium containing yeast extract, peptone, and dextrose/glucose that supplemented with EGCG and AA at different concentrations. Then, the cell cultures were irradiated with both low (gamma) and high (helium ion beam) linear energy transfer (LET) radiations to evaluate the radiation effect on the survival of the yeast cell. Both of EGCG and AA play effectively important roles as radiation-protective agent for yeast cells and the effectiveness in radiation protection of EGCG and AA at the same concentration was almost the same between these two additives

Aim. Atrial fibrillation (AF) represents one of the most critical cardiac arrhythmias, as it significantly increases the risk of stroke. Its detection is particularly challenging due to the unpredictable nature of its episodes.Methods. This study proposes a low-complexity algorithm, enabling integration into embedded devices for realtime AF episode detection. The proposed method integrates non-linear, time-domain and frequency-domain features extracted from electrocardiogram signals with The LightGBM algorithm (an extension of decision tree algorithm) is used to classify and detect AF.Results. The model was trained using the MIT-BIH AF Database (MIT-AFDB), achieving sensitivity (Se), specificity (Sp), accuracy rates (Acc), precision (PPV), F1-score and AUC of 0.9838, 0.9690, 0.9748, 0.9543, 0.9688 and 0.9957, respectively. We also performed 10‑fold cross‑validation on this dataset. The obtained values for Se, Sp, Acc, PPV, F1-score, and AUC were, respectively, 0.9837 ± 0.0020, 0.9701 ± 0.0021, 0.9755 ± 0.0007, 0.9559 ± 0.0029, 0.9696 ± 0.0008, and 0.9959 ± 0.0002. This indicates that the model achieves good performance compared to current studies in AF recognition and detection.Conclusions. The experimental results demonstrate that the model achieves high performance in the classification and detection of AF episodes. Furthermore, the model is suitable for integration into real-time arrhythmia detection systems.

Ionizing radiation induces severe oxidative stress, leading to cytotoxicity. This study investigates the radioprotective mechanism of Ascorbic Acid (AA) on Saccharomyces cerevisiae exposed to Cobalt-60 gamma irradiation. Yeast cells were treated with AA concentrations (300 µM) and subjected to radiation doses ranging from 25 to 100 Gy. Survival rates were quantified via colony formation assays and analyzed in comparison with previous studies on DNA single-strand breaks (SSB). While prior research demonstrated that AA consistently mitigates DNA damage, the current cellular results reveal a dose-dependent limitation. Specifically, 300 µM AA exhibited significant radioprotective efficacy at a low dose (25 Gy). However, at higher doses (75 - 100 Gy), AA paradoxically reduced survival rates compared to controls, diverging from its protective trend on DNA. The data may suggest a trend towards a functional transition of AA from an antioxidant to a pro-oxidant role, particularly when combined with high radiation doses. Consequently, the study implies that radioprotection observed at the molecular DNA level might not necessarily guarantee cellular survival under extreme oxidative conditions.

Introduction: This study investigated the effects of gamma irradiation on the antioxidant activity of solid-state ascorbic acid. The goal was to assess how different irradiation doses, ranging from 0 to 5 kGy, altered the molecule's ability to scavenge free radicals. Methods: The DPPH radical scavenging method was employed to determine the antioxidant capability of the irradiated samples. The researchers evaluated the reaction rate constant (K1) and the concentration required to achieve 50 % inhibition of the radicals (IC50). Furthermore, FT-IR spectroscopy was used to detect structural changes in the ascorbic acid molecule following irradiation. Results: Antioxidant activity significantly increased at low irradiation doses (1–2 kGy) compared to the control (0 kGy, IC50 of 3,39 ± 5,73 µg/mL). The lowest IC50 values, indicating maximum activity, were observed at 1 kGy (2,67 ± 1,75 µg/mL) and 2 kGy (2,55 ±1,00 µg/mL). The reaction rate constant peaked at 1 kGy (13,78 M-1.s-1), confirming the enhanced radical scavenging capacity. However, activity decreased at higher doses (≥ 3kGy). FT-IR analysis indicated structural alterations, specifically in the hydroxyl (-OH) and carbonyl (C=O) groups, following the irradiation process. Conclusions: The results demonstrated that appropriate levels of gamma irradiation can increase the antioxidant effectiveness of ascorbic acid. Conversely, excessive exposure leads to structural changes and a subsequent reduction in its effectiveness.

Introduction: The radiation absorption coefficient (µ) is a critical parameter for accurately calculating safe shielding requirements against radiation exposure. This coefficient is influenced by the type and energy of the radiation, as well as the nature and density of the shielding material. Determining this value for candidate materials is essential for safety protection applications. Method: This study focused on experimentally determining the linear absorption coefficient (µ) of three common shielding materials: copper (Cu), lead (Pb), and aluminum (Al). The measurements were conducted using gamma radiation emitted from Cesium-137 (Cs-137) and Cobalt-60 (Co-60) radioactive sources. Na-I scintillation detector counting system was employed to measure the attenuation of the gamma rays as they passed through the material samples. Results: The experimental results for the radiation absorption coefficients of copper, lead, and aluminum for the specified gamma energies were obtained. These measured values demonstrated consistency with previously published and documented results for the same materials and energy ranges. Conclusions: The findings confirm the reliability of the experimental methodology and the importance of these determined absorption coefficients for designing effective radiation shielding. The established µ values for Cu, Pb, and Al can be confidently used in safety calculations against exposure to Cs-137 and Co-60 gamma radiation.