Utilization of radiometric data for mapping primary and secondary sources of gamma radiation and radon/thoron release potentials in Ireland.

Background: This paper presents a novel approach to predict and map radon and thoron levels. We developed separate radon and thoron prediction maps for Ireland and introduced a system for producing high-resolution 3D radiation maps which may be used for planning purposes in residential areas, recycling and demolishing waste depots, and quarries of building and construction material. Additionally, we highlight the critical need to monitor thoron alongside radon in indoor surveys, as thoron's shorter half-life and higher energy levels may pose a greater health risk. Methods: We utilized Tellus radiometric survey data and indoor radon measurement records to investigate the spatial correlation between elevated indoor radon activity and anomalies in radioelement concentrations. We also estimated the degree of thoron interference in indoor radon surveys conducted in Ireland using CR-39 detectors. Field and laboratory surveys were performed to produce high-resolution radiation maps for four Irish quarries and estimate the radon and thoron potential of these quarries. Results: Our initial findings suggest that thoron may be the primary health issue in some parts of Ireland, surpassing radon. For example, our map shows that the expected thoron potential in county Donegal is significantly higher than that for radon. Our radon and thoron exhalation tests on building material samples from four random quarries confirm this. We also estimate that over 20% of the elevated indoor radon activity recorded by the EPA using CR-39 detectors may be attributed to thoron-related sources. Conclusion: This study contributes to a better understanding of the prevalence and impact of radon and thoron in Ireland, helping to determine the main radiological health issue related to indoor air quality in the country. Thoron's impact on indoor air quality and health has been understudied in Ireland, necessitating more comprehensive studies and monitoring programs to accurately assess the prevalence and impact of both radon and thoron.

Metabolomic changes in preterminal serum samples of rhesus macaques exposed to two different lethal doses of total-body gamma-radiation.

Exposure to ionizing radiation induces cellular and molecular damage leading to a cascade of events resulting in tissue and organ injury. Our study strives to characterize and validate metabolomic changes in preterminal stage (immediately prior to death) samples collected from rhesus macaques lethally irradiated with one of two different doses of radiation. Peripheral blood samples were collected pre-exposure, post-exposure, and at the preterminal stage of nonhuman primates (NHPs that did not survive exposure with 7.2 Gy or 7.6 Gy total-body radiation (LD60-80/60)). We analyzed global metabolomic alterations using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in serum samples collected at various timepoints in relation to radiation exposure. The goal of this study was to validate the metabolic shifts present in samples collected just prior to death, which were reported earlier in a preliminary study with a limited number of samples and a single dose of radiation. Here, we demonstrate that radiation exposure induced significant time-dependent metabolic alterations compared with pre-exposure samples. We observed significant metabolite dysregulation in animals exposed to 7.6 Gy compared to 7.2 Gy. Greater metabolic disruption was observed in the preterminal groups than all of the other post-irradiation timepoints in both cohorts. Metabolomic shifts in these preterminal groups also revealed consistent disturbances in sphingolipid metabolism, steroid hormone biosynthesis, and glycerophospholipid metabolism pathways. Overall, the sphingolipid metabolism pathway appears to be representative of the preterminal phenotype, confirming the results of our preliminary study. These results offer important and novel insights for identification and validation of biomarkers for lethality, and such observations would be valuable for triage during a radiological/nuclear mass casualty scenario.

X-ray Fluorescence Microscopy to Develop Elemental Classifiers and Investigate Elemental Signatures in BALB/c Mouse Intestine a Week after Exposure to 8 Gy of Gamma Rays.

Iron redistribution in the intestine after total body irradiation is an established phenomenon. However, in the literature, there are no reports about the use of X-ray fluorescence microscopy or equivalent techniques to generate semi-quantitative 2D maps of iron in sectioned intestine samples from irradiated mice. In this work, we used X-ray fluorescence microscopy (XFM) to map the elemental content of iron as well as phosphorus, sulfur, calcium, copper and zinc in tissue sections of the small intestine from eight-week-old BALB/c male mice that developed gastrointestinal acute radiation syndrome (GI-ARS) in response to exposure to 8 Gray of gamma rays. Seven days after irradiation, we found that the majority of the iron is localized as hot spots in the intercellular regions of the area surrounding crypts and stretching between the outer perimeter of the intestine and the surface cell layer of villi. In addition, this study represents our current efforts to develop elemental cell classifiers that could be used for the automated generation of regions of interest for analyses of X-ray fluorescence maps. Once developed, such a tool will be instrumental for studies of effects of radiation and other toxicants on the elemental content in cells and tissues. While XFM studies cannot be conducted on living organisms, it is possible to envision future scenarios where XFM imaging of single cells sloughed from the human (or rodent) intestine could be used to follow up on the progression of GI-ARS.

Effect of Simulated Cosmic Radiation on Cytomegalovirus Reactivation and Lytic Replication.

Human exploration of the solar system will expose crew members to galactic cosmic radiation (GCR), with a potential for adverse health effects. GCR particles (protons and ions) move at nearly the speed of light and easily penetrate space station walls, as well as the human body. Previously, we have shown reactivation of latent herpesviruses, including herpes simplex virus, Varicella zoster virus, Epstein-Barr virus, and cytomegalovirus (CMV), during stays at the International Space Station. Given the prevalence of latent CMV and the known propensity of space radiation to cause alterations in many cellular processes, we undertook this study to understand the role of GCR in reactivating latent CMV. Latently infected Kasumi cells with CMV were irradiated with 137Cs gamma rays, 150 MeV protons, 600 MeV/n carbon ions, 600 MeV/n iron ions, proton ions, and simulated GCR. The CMV copy number increased significantly in the cells exposed to radiation as compared with the non-irradiated controls. Viral genome sequencing did not reveal significant nucleotide differences among the compared groups. However, transcriptome analysis showed the upregulation of transcription of the UL49 ORF, implicating it in the switch from latent to lytic replication. These findings support our hypothesis that GCR may be a strong contributor to the reactivation of CMV infection seen in ISS crew members.

Biochemical and biological studies of irradiated and non-irradiated extracts of Solanum aculeastrum Dunal fruit.

This study explores the impact of γ-irradiation on ethanolic extracts of Solanum aculeastrum Dunal. The anti-cancer and antimicrobial properties were investigated. The obtained results revealed that total phenol (TP) and total flavonoid (TF) of total ethanol extract (100%) (FTE) were higher than 70% ethanol extract (SE), and these contents increased after gamma radiation with 5 kGy. The results of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the Solanum aculeastrum extracts suggested that FTE and 5 kGy-irradiated FTE can be used to control and prevent skin infections caused by MRSA and endocarditis, urinary tract infections, and prostatitis caused by Enterococcus faecalis. The FTE sample irradiated at 5 kGy showed cytotoxicity for A431 and Hct-116 cell lines similar to the control sample and higher than the toxicity revealed by the samples irradiated at 10 kGy. In normal cells (Bj-1), the toxicity was decreased after irradiation (IC50 = 31 µg/ml) compared to the non-irradiated extract (IC50 = 26.1 µg/ml). Molecular docking suggested Sortase A to play a role in chlorogenic acid antibacterial activity towards Staphylococcus aureus. In conclusion, γ-irradiation can be used to enhance the phytoconstituents of Solanum aculeastrum fruit extracts and, consequently, its biological properties.

X-ray/γ-ray/Ultrasound-Activated Persistent Luminescence Phosphors for Deep Tissue Bioimaging and Therapy.

Persistent luminescence phosphors (PLPs) can remain luminescent after excitation ceases and have been widely explored in bioimaging and therapy since 2007. In bioimaging, PLPs can efficiently avoid tissue autofluorescence and light scattering interference by collecting persistent luminescence signals after the end of excitation. Outstanding signal-to-background ratios, high sensitivity, and resolution have been achieved in bioimaging with PLPs. In therapy, PLPs can continuously produce therapeutic molecules such as reactive oxygen species after removing excitation sources, which realizes sustained therapeutic activity after a single dose of light stimulation. However, most PLPs are activated by ultraviolet or visible light, which makes it difficult to reactivate the PLPs in vivo, particularly in deep tissues. In recent years, excitation sources with deep tissue penetration have been explored to activate PLPs, including X-ray, γ-ray, and ultrasound. Researchers found that various inorganic and organic PLPs can be activated by X-ray, γ-ray, and ultrasound, making these PLPs valuable in the imaging and therapy of deep-seated tumors. These X-ray/γ-ray/ultrasound-activated PLPs have not been systematically introduced in previous reviews. In this review, we summarize the recently developed inorganic and organic PLPs that can be activated by X-ray, γ-ray, and ultrasound to produce persistent luminescence. The biomedical applications of these PLPs in deep-tissue bioimaging and therapy are also discussed. This review can provide instructions for the design of PLPs with deep-tissue-renewable persistent luminescence and further promote the applications of PLPs in phototheranostics, noninvasive biosensing devices, and energy harvesting.

Effects of 60Coγ-irradiation combined with sodium dehydrogenate on post-harvest preservation and physiological indices of Volvariella volvacea.

Volvariella volvacea is a mushroom known for its high palatability and nutritional value. However, it is susceptible to spoilage thus making it challenging to preserve and keep fresh after harvest, resulting in constraints in long-distance transportation and long-term storage. This study aimed to investigate the feasibility of using irradiation and sodium dehydrogenate (SD) as a preservative in the preservation process of V. volvacea. The effects of three treatments of 0.8 kGy 60Coγ irradiation (B), 0.04% SD (C), combined with 0.04% SD and 0.8 kGy 60Coγ irradiation (A) on the postharvest freshness of V. volvacea were investigated. The assessment indices for V. volvacea, including appearance, browning rate, weight loss, respiration rate, MDA content, antioxidant enzyme activities, vitamin C (Vc), and soluble protein content, were measured and compared. The three treatments were compared to determine the changes in storage time over 7 days post-harvest. The results demonstrated that the hardness of the fruiting body exhibited a significant increase of 81.19%, 97.96% and 168.81% in comparison to the control, B and C, respectively, following the application of the treatment A. Compared to the control group, the soluble protein content was significantly increased by 20.28%. Respiration intensity and browning rate were significantly lower in the control treatment, decreasing by 35.07% and 45.49% respectively. On the 6th day of storage, the activities of SOD and POD increased by 81.06% and 73.71%, respectively, compared to the control, which significantly delayed the senescence of the fruiting bodies. The Vc content was significantly increased by 50.27%, 133.90%, and 101.39% in treatment B, which received 0.8 kGy 60Coγ irradiation alone, compared to the control, treatment A, and treatment C, respectively. The treatment C alone significantly reduced respiratory intensity and MDA variables by 39.55% and 31.01%, respectively, compared to the control. The findings can provide theoretical references and technical support for extending the preservation period of V. volvacea after harvesting by using irradiation and sodium dehydrogenate as a preservative.

Mitigation of radiation-induced jejunum injuries in rats through modulation of the p53-miR34a axis using etoricoxib-loaded nanostructured lipid carriers.

The most widely used cancer therapy is radiation therapy, but radiation damage to healthy tissues, particularly the gastrointestinal (GI) system, frequently reduces its effectiveness. This study investigates whether etoricoxib-loaded nanostructured lipid carriers (Et-NLC) could help shield the rat jejunum from radiation damage. Gamma irradiation (6 Gy) was used to damage the jejunum of Wistar albino rats, and then Et or Et-NLC (10 mg/kg b.w.) was administered orally for 14 days. It was found that the amounts of glutathione S-transferase (GST), superoxide dismutase (SOD), and nitric oxide (NO) decreased after irradiation but increased after Et-NLC therapy. Molecular analysis showed radiation-induced expression of microRNA-34a (miR34a), which may be involved in cellular stress response. Et-NLC treatments modulated the expression of miR34a, suggesting possible regulatory roles. Western blot analysis revealed changes in P53, interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and cyclooxygenase-2 (COX-2) levels. Et-NLC treatments decreased TNF-α, IL-6, IL-10, and COX-2 levels, indicating anti-inflammatory actions. DNA fragmentation analysis revealed a decrease in apoptotic activity after Et-NLC treatments. A histopathological examination confirmed that Et-NLC treatments had attenuated radiation damage, which had improved vascularization and reduced inflammation. The findings show that Et-NLC is more effective than Et-alone at reducing damage to the jejunum caused by radiation by controlling inflammation, oxidative stress, and apoptotic activity.

The correlation of the modulation complexity score (MCS) with the number of segments and local gamma passing rate for the Intensity Modulated Radiation Therapy (IMRT) treatment planning delivery.

OBJECTIVE: To compare the modulation complexity scores across treatment sites, and to examine their connection with monitor unit, segment number and global and local gamma passing percentage. METHODS: The cross-sectional study was conducted at the Baghdad Centre for Radiation Therapy and Nuclear Medicine, Baghdad Medical City, Baghdad, Iraq, from May 2021 to February 2022. Included were 34 patients, with the age range between 20 - 50 years, subjected to intensity-modulated radiation therapy for head and neck tumours in group A or pelvic tumours in group B. Treatment planning was done using Monaco 5.1, and radiotherapy was done using Synergy linear accelerator. Modulation complexity scores were calculated using MATLAB 2019a. Data was analysed using SPSS 24. RESULTS: Of the 34 patients, 22(64.7%) were in group A; 12(54.5%) males and 10(45.5%) females. There were 12(35.3%) patients in group B; 8(66.7%) females and 4(33.3%) males. The number of segments was greater in group B than group A. A modest positive linear association was seen in group A, demonstrating that an increase in segment numbers resulted in a rise in modulation complexity score (R2=0.0244). Group B tumours had inverse negative linear correlation (R2=0.0189). As the complexity of plans increased in group A, local gamma passing percentage decreased (R2=0.0452). Group B showed a slight negative connection with modulation complexity score (R2=0.0622). CONCLUSIONS: The modulation complexity score may be used to provide a simple prediction for pre-treatment verification, and it may also serve as a simple quality assurance tool for intensity-modulated radiation therapy plans.

The evaluation of the two-dimensional gamma passing rate efficiency for the unilateral breast cancer dosimetry using the Intensity-Modulated Radiation Therapy.

OBJECTIVE: To evaluate the efficacy of the commonly used two-dimensional gamma passing rate of 3%/3mm for females with unilateral breast cancer. METHODS: The cross-sectional study was conducted at Al-Andalus Private Hospital, Baghdad, Iraq, from November 2021 to April 2022 after approval from the Medical Physics and Physiology Department of Mustansiriyah University, Baghdad, and comprised female patients with unilateral breast carcinomas. All the patients were subjected to a computed tomography simulation, and data was transferred to treatment planning system Monaco 5.1 for contouring and planning. An intensity-modulated radiation therapy method was selected. The planning comprised phantom detector and linear agility accelerator for pre-treatment verification. All patients were evaluated using two alternative dosimetry methods: 3%/3mm and 3%/2mm at the threshold of 10% and 5%. The Two-dimensional gamma analysis took each transversal slice in the simulation image for comparison. Data was analysed using SPSS 24. RESULTS: There were 15 female patients aged 26-65 years. There was a better impact of 3%/3mm compared to 3%/2mm criterion for 5% and 10% thresholds. The proportion was 10% higher than the cutoff point of 5%. CONCLUSIONS: The 3%/2mm criterion should be used for plans that give a high dosage to organs at risk, while the 3 %/3 mm criterion should be used for uncomplicated situations with moderate dosages to at-risk organs.

Measurement of radioactivity and hazard index of Gonadal dose in selected Cement samples in Iraq.

Given the importance of cement as a basic material in construction, this study was undertaken to evaluate the level of radioactivity in a selected group of cement samples most used in construction to determine whether they are safe for human health. In this investigative study, nine samples of cement, both domestic and imported, that are often used in construction projects in Iraq were gathered. A NaI (Tl) gamma-ray spectrometer (3"x3") was used to measure the radioactivity in the samples. The average specific activity levels in the tested cement samples were 11.373±0.522, 5.795 ± 0.230, and 179.123±2.207 Bq/Kg, respectively. Also calculated was the average of the radium, which was equivalent to 33.449±1.022 Bq/kg. As for the risk indicators, the internal risk coefficient was 0.121±0.004 and external risk coefficient was 0.090 ±0.002. While studying the radiation doses, the values of effective annual internal dose was 0.080 mSv/y, external dose rates were 0.020 mSv/y, absorbed dose ratio was 16.321±0.476 nGy/h, and gamma index was 0.253±0.007. In the end, and depending on what was studied from various variables, with an average of 115.59 Sv/y, the annual gonadal equivalent dose risk (AGED) was calculated. The world average values were used to compare all the results. Finally, it was discovered that the radiation parameter levels of none of the samples had a detrimental effect on human health.

The radiological hazard and potential for generating acid mine drainage from a coal tailings dam.

The aim of this study was to analyze the radiological hazards and the potential for generating acid mine drainage from the fine coal waste commonly stored in tailings dams. The magnetic susceptibility, natural gamma radioactivity, and net neutralization potential of the tailings are characterized. The results show that the fine coal waste has a uranium equivalent concentration (eU) of 46-48 Bq kg-1, which is 37.14% higher than the world average, and 39-47 Bq kg-1 equivalent concentration of thorium (eTh), which is 56.66% higher than the world average. Also, the absorbed gamma radiation dose rate is higher than the world average. Acid-base balance tests indicate that the net neutralization potential ranged from 0.38 to 2.44. The physical properties indicate a possible radiological risk, while the chemical properties show that generating and non-generating acid drainage can coexist in the fine dam tailings.

Modeling the oxygen effect in DNA strand break induced by gamma-rays with TOPAS-nBio.

Objective.To present and validate a method to simulate from first principles the effect of oxygen on radiation-induced double-strand breaks (DSBs) using the Monte Carlo Track-structure code TOPAS-nBio.Approach.Two chemical models based on the oxygen fixation hypothesis (OFH) were developed in TOPAS-nBio by considering an oxygen adduct state of DNA and creating a competition kinetic mechanism between oxygen and the radioprotective molecule WR-1065. We named these models 'simple' and 'detailed' due to the way they handle the hydrogen abstraction pathways. We used the simple model to obtain additional information for the •OH-DNA hydrogen abstraction pathway probability for the detailed model. These models were calibrated and compared with published experimental data of linear and supercoiling fractions obtained with R6K plasmids, suspended in dioxane as a hydroxyl scavenger, and irradiated with137Cs gamma-rays. The reaction rates for WR-1065 and O2with DNA were taken from experimental works. Single-Strand Breaks (SSBs) and DSBs as a function of the dose for a range of oxygen concentrations [O2] (0.021%-21%) were obtained. Finally, the hypoxia reduction factor (HRF) was obtained from DSBs.Main Results.Validation results followed the trend of the experimental within 12% for the supercoiled and linear plasmid fractions for both models. The HRF agreed with measurements obtained with137Cs and 200-280 kVp x-ray within experimental uncertainties. However, the HRF at an oxygen concentration of 2.1% overestimated experimental results by a factor of 1.7 ± 0.1. Increasing the concentration of WR-1065 from 1 mM to 10-100 mM resulted in a HRF difference of 0.01, within the 8% statistical uncertainty between TOPAS-nBio and experimental data. This highlights the possibility of using these chemical models to recreate experimental HRF results.Significance.Results support the OFH as a leading cause of oxygen radio-sensitization effects given a competition between oxygen and chemical DNA repair molecules like WR-1065.

Fusarium verticillioides pigment: production, response surface optimization, gamma irradiation and encapsulation studies.

BACKGROUND: Natural pigments are becoming more significant because of the rising cost of raw materials, pollution, and the complexity of synthetic pigments. Compared to synthetic pigments, natural pigments exhibit antimicrobial properties and is less allergic. Pigments from microbial sources could easily be obtained in an inexpensive culture media, produced in high yields, and microbes are capable of producing different colored pigments. Searching for new sources for natural pigments to replace synthetic ones in food applications has become an urgent necessity, but the instability of these compounds is sometimes considered one of the obstacles that reduce their application. Encapsulation provides an ideal solution for natural dye protection through a controlled release strategy. Thus, this study aims at isolation of several soil fungi and subsequent screening their pigment production ability. The chosen pigment-producing fungal strain underwent full identification. The produced pigment was extracted with ethyl acetate and estimated spectrophotometrically. As there is a necessity to obtain a high pigment yield for efficient industrial application, the best production medium was tested, optimum conditions for maximum dye production were also investigated through the response surface methodology, and gamma irradiation was also employed to enhance the fungal productivity. Encapsulation of the produced pigment into chitosan microsphere was tested. The pigment release under different pH conditions was also investigated. RESULTS: A new strain, Fusarium verticillioides AUMC 15934 was chosen and identified for a violet pigment production process. Out of four different media studied, the tested strain grew well on potato dextrose broth medium. Optimum conditions are initial medium pH 8, 25 °C-incubation temperature, and for 15-day incubation period under shaking state. Moreover, a 400 Gy irradiation dose enhanced the pigment production. Chitosan microsphere loaded by the pigment was successfully prepared and characterized by infrared spectroscopy and scanning electron microscopy. CONCLUSION: This irradiated Fusarium strain provides a more economically favorable source for production of a natural violet dye with an optimum productivity, enhanced yield, and improved properties (such as, enhanced stability, controlled release, and bioaccessibility) by encapsulation with chitosan for efficient application in food industry.

Enhancing biomass, hydrocarbon and biodiesel properties of green microalga Botryococcus braunii KMITL through gamma and UV radiation exposure.

This study investigated the effects of gamma (137Cs, 0-250 Gy) and UV (UV-C, 0-12 h) radiation on growth and biodiesel properties of Botryococcus braunii KMITL. For gamma radiation, maximum biomass (1.37 ± 0.02 g L-1) was achieved with 50 Gy, while a dose of 200 Gy resulted in the highest hydrocarbon content (51.84 ± 0.20%) and yield (0.66 ± 0.01 g L-1). For UV radiation, a 9 h exposure produced the highest biomass (2.45 ± 0.05 g L-1), hydrocarbon content (55.01 ± 1.22%), and yield (1.35 ± 0.04 g L-1). Algae exposed to gamma radiation within the range of 0-150 Gy exhibited C16:0 as the dominant fatty acid methyl ester (FAME), similar to those exposed to UV radiation, while algae exposed to 200-250 Gy displayed C18:1n9t as the dominant FAME. High levels of gamma and UV radiation were observed to lengthen fatty acid chains and increase unsaturated fatty acids. The cetane values of biodiesel from algae exposed to gamma and UV radiation ranged from 64.55 ± 0.14-66.47 ± 0.20 and 59.43 ± 0.04-65.27 ± 0.22, respectively, all meeting standard criteria. Both gamma and UV radiation also improved the saponification value and cold flow properties of the biodiesel. These findings suggest that controlled levels of gamma and UV radiation effectively enhance hydrocarbon yields with significant implications for biofuel production.

Gamma irradiation green synthesis of (polyacrylamide/chitosan/silver nanoparticles) hydrogel nanocomposites and their using as antifungal against Candida albicans and anti-cancer modulator.

Silver nanoparticles-loaded hydrogel nanocomposites are exploited for medicinal and pharmaceutical applications. Hydrogel nanocomposites were prepared from acrylamide (Am), chitosan (CS) and AgNO3 utilizing gamma rays. Diverse variables were applied in preparation of silver nanoparticles-laoded hydrogel nanocomposites of (PAm/CS)-AgNPs such as influence of radiation dose and influnece of CS concentration. Diverse techniques were utilized to characterize hydrogel nanocomposites; Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and scanning electron microscopy (SEM). Results confirmed formation of silver nanoparticles-loaded hydrogel nanocomposites of (PAm/CS)-AgNPs. Antifungal activity of (PAm/CS)-AgNPs hydrogel nanocomposites on viability of C. albicans was esitmated. Results displayed the efficient microbial inhibition activity of treatment against C. albicans compared to control. Furthermore, (PAm/CS)-AgNPs hydrogel nanocomposite against cervical cancer HeLa cell line was investigated. Cytotoxicity of (PAm/CS)-AgNPs hydrogel nanocomposites on prior cancer cell line empolyed to prohibition of cell growth assesssed by MTT test. HeLa cancer cell is treated by (PAm/CS)-AgNPs for 48 h exposed a potential apoptotic activity by noticeable up-regulation of p53 gene expression. Moreover, anticancer activity was investigated by down-regulation of platelet-based growth variable receptor beta (PDGFR-ß), Bcl2, Cathepsine, and MMP-2 gene expression. antioxidant activity was investigated and results showed antioxidant activity of (PAm/CS) hydrogel and (PAm/CS)-AgNPs hydrogel nanocomposite are 87.8% and 62.9%, respectively.

The senomorphic impact of astaxanthin on irradiated rat spleen: STING, TLR4 and mTOR contributed pathway.

OBJECTIVES: Exposure of spleen tissues to ionizing radiation during radiotherapy can induce cellular stress and immune-dysfunction leading to cellular senescence. INTRODUCTION: The process of a cancerous development is facilitated by the accumulation of senescent cells. This justifies the incorporation of anti-senescent medications during splenic irradiation (SI). METHODS: In this study senescence was induced in the spleen of male albino rats by radiation exposure (5Gy-single whole body gamma-irradiation) then after 2 weeks, oral astaxanthin regimen was started once daily in a dose of 25 mg/kg for 7 consecutive days. Concurrent control groups were carried out. RESULTS: the present data reflected that irradiation provoked an increase in the oxidative stress biomarkers (nitric oxide, lipid peroxidation and total reactive oxygen species levels)and the inflammatory biomarkers (Myeloperoxidase and interleukin-6). In addition irradiation led to the over expression of stimulator of interferon genes (cGAS-STING), mammalian target of rapamycin (mTOR) and Toll-like receptor 4 (TLR4) along with the lactate dehydrogenase (LDH), cyclin-dependent kinase inhibitor 1 (p21) cyclin-dependent kinase inhibitor 2A (p16) increment with elevation of tumor suppressor protein (p53) level. However, reduced glutathione contents and catalase activity were reduced post irradiation in spleen tissues, all these changes reflecting induction of cellular senescence. Astaxanthin treatment showed an improvement in the antioxidant/oxidative stress balance, inflammatory biomarkers, histopathological examination and immunohistochemical expressions of the tested proteins in the irradiated rats. CONCLUSION: the current findings offer a new insight into the senomorphic effect of astaxanthin following radiation-induced spleen senescence via STING, mTOR, and TLR4 signalling pathways.

Accelerated Aging Effects Observed In Vitro after an Exposure to Gamma-Rays Delivered at Very Low and Continuous Dose-Rate Equivalent to 1-5 Weeks in International Space Station.

Radiation impacting astronauts in their spacecraft come from a "bath" of high-energy rays (0.1-0.5 mGy per mission day) that reaches deep tissues like the heart and bones and a "stochastic rain" of low-energy particles from the shielding and impacting surface tissues like skin and lenses. However, these two components cannot be reproduced on Earth together. The MarsSimulator facility (Toulouse University, France) emits, thanks to a bag containing thorium salts, a continuous exposure of 120 mSv/y, corresponding to that prevailing in the International Space Station (ISS). By using immunofluorescence, we assessed DNA double-strand breaks (DSB) induced by 1-5 weeks exposure in ISS of human tissues evoked above, identified at risk for space exploration. All the tissues tested elicited DSBs that accumulated proportionally to the dose at a tissue-dependent rate (about 40 DSB/Gy for skin, 3 times more for lens). For the lens, bones, and radiosensitive skin cells tested, perinuclear localization of phosphorylated forms of ataxia telangiectasia mutated protein (pATM) was observed during the 1st to 3rd week of exposure. Since pATM crowns were shown to reflect accelerated aging, these findings suggest that a low dose rate of 120 mSv/y may accelerate the senescence process of the tested tissues. A mathematical model of pATM crown formation and disappearance has been proposed. Further investigations are needed to document these results in order to better evaluate the risks related to space exploration.

Chronic Low-Dose-Rate Radiation-Induced Persistent DNA Damage and miRNA/mRNA Expression Changes in Mouse Hippocampus and Blood.

Our previous study demonstrated that the acute high-dose-rate (3.3 Gy/min) γ-ray irradiation (γ-irradiation) of postnatal day-3 (P3) mice with 5 Gy induced depression and drastic neuropathological changes in the dentate gyrus of the hippocampus of adult mice. The present study investigated the effects of chronic low-dose-rate (1.2 mGy/h) γ-irradiation from P3 to P180 with a cumulative dose of 5 Gy on animal behaviour, hippocampal cellular change, and miRNA and mRNA expression in the hippocampus and blood in female mice. The radiation exposure did not significantly affect the animal's body weight, and neuropsychiatric changes such as anxiety and depression were examined by neurobehavioural tests, including open field, light-dark box, elevated plus maze, tail suspension, and forced swim tests. Immunohistochemical staining did not detect any obvious loss of mature and immature neurons (NeuN and DCX) or any inflammatory glial response (IBA1, GFAP, and PDGFRα). Nevertheless, γH2AX foci in the stratum granulosum of the dentate gyrus were significantly increased, suggesting the chronic low-dose-rate irradiation induced persistent DNA damage foci in mice. miRNA sequencing and qRT-PCR indicated an increased expression of miR-448-3p and miR-361-5p but decreased expression of miR-193a-3p in the mouse hippocampus. Meanwhile, mRNA sequencing and qRT-PCR showed the changed expression of some genes, including Fli1, Hs3st5, and Eif4ebp2. Database searching by miRDB and TargetScan predicted that Fli1 and Hs3st5 are the targets of miR-448-3p, and Eif4ebp2 is the target of miR-361-5p. miRNA/mRNA sequencing and qRT-PCR results in blood showed the increased expression of miR-6967-3p and the decreased expression of its target S1pr5. The interactions of these miRNAs and mRNAs may be related to the chronic low-dose-rate radiation-induced persistent DNA damage.

Molecular modification of chlorogenic acid via radiolysis with inhibitory effects on NO production.

The molecular modification of chlorogenic acid (1) through γ-irradiation resulted in the formation of five new products: chlorogenosins A (2), B (3), C (4), D (5), and E (6) along with known compounds rosmarinosin B (7), protocatechuic acid (8), and protocatechuic aldehyde (9). The structures of the new compounds were elucidated using spectroscopic methods, including one-dimensional and two-dimensional nuclear magnetic resonance, high-resolution electrospray ionization mass spectroscopy, and circular dichroism spectroscopy. The potential anti-inflammatory activities of all the isolated compounds were determined by evaluating their inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide-induced RAW 264.7 macrophages. Notably, compounds 2 and 3, which contained two hydroxymethyl functionalities instead of the trans-olefinic moiety present in the original chlorogenic acid, exhibited stronger inhibitory effects on NO production than that of the original compound. These findings suggest that the predominant chemical changes induced in chlorogenic acid by γ-irradiation may enhance its anti-inflammatory properties.