In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduce...In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduced electron transfer(PET)effect.Two perylene diimide isomers PDI-P and PDI-B were designed and synthesized,and their molecular structures were characterized by high-resolution Fourier transform mass spectrometry(HRMS),nuclear magnetic resonance hydrogen and carbon spectroscopy(~1H and~(13)C NMR).The interaction between ionizing radiation and fluorescent molecules was simulated by HCl titration.The results show that combining PDIs and HCl can improve fluorescence through the retro-PET process.Despite the similarities in chemical structures,the fluorescent enhancement multiple of PDI-B with aromatic amine as electron donor is much higher than that of PDI-P with alkyl amine.In the direct irradiation experiments of ionizing radiation,the emission enhancement multiples of PDI-P and PDI-B are 2.01 and 45.4,respectively.Furthermore,density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations indicate that the HOMO and HOMO-1 energy ranges of PDI-P and PDI-B are 0.54 e V and 1.13 e V,respectively.A wider energy range has a stronger driving force on electrons,which is conducive to fluorescence quenching.Both femtosecond transient absorption spectroscopy(fs-TAS)and transient fluorescence spectroscopy(TFS)tests show that PDI-B has shorter charge separation lifetime and higher electron transfer rate constant.Although both isomers can significantly reduce LOD during PET process,PDI-B with aromatic amine has a wider detection range of 0.118—240 Gy due to its larger emission enhancement,which is a leap of three orders of magnitude.It breaks through the detection range of gamma radiation reported in existing studies,and provides theoretical support for the further study of sensitive and effective new materials for ionizing radiation detection.展开更多
Bone marrow serves as the life-long home for hemato-poietic stem cells(HSCs)and is the most radio-sensitive organ^([1]).Acute ionizing radiation exceeding 1 Gray(Gy)causes severe damage in bone marrow while no effecti...Bone marrow serves as the life-long home for hemato-poietic stem cells(HSCs)and is the most radio-sensitive organ^([1]).Acute ionizing radiation exceeding 1 Gray(Gy)causes severe damage in bone marrow while no effective drug has been approved in clinical.In a recent work pub-lished in MedComm,Gao and her team reported,for the first time,cannabidiol(CBD)as an outstanding radioprotection agent targeting acute radiation-induced hematopoietic injury^([2]).Within two weeks post radiation,CBD can pro-mote the stemness of hematopoietic stem cells to a regular level.Using single-cell RNA sequencing(scRNA-seq)and functional assay,the authors decoded molecular changes underlying radiation-induced damage and CBD-induced recovery in HSCs.展开更多
During cellular proliferation DNA undergoes frequent rep-lication cycles in which errors inevitably accumulate.DNA simultaneously faces continuous damage from endogenous sources[e.g.,reactive oxygen species(ROS)]and e...During cellular proliferation DNA undergoes frequent rep-lication cycles in which errors inevitably accumulate.DNA simultaneously faces continuous damage from endogenous sources[e.g.,reactive oxygen species(ROS)]and environmen-tal stressors,such as ultraviolet(UV)and ionizing radiation(IR).Such lesions compromise genomic stability and may escalate into DNA double-strand breaks(DSBs).Failure to repair DSBs can ultimately trigger cell death1.展开更多
Introduction: The use of radioactive radiations in healthcare facilities must comply with radioprotection safety rules in order to avoid threatening the health of workers and patients. This study aimed to assess the w...Introduction: The use of radioactive radiations in healthcare facilities must comply with radioprotection safety rules in order to avoid threatening the health of workers and patients. This study aimed to assess the working conditions, the protective measures and the medical monitoring of workers directly involved in X-ray work at hospitals in Douala, Cameroon. Materials and Methods: A descriptive cross-sectional study was carried out during the 1st quarter of 2018, across various state and private health facilities of the city of Douala. Sampling was non-random, based on convenience and all the willing participants that fulfilled the inclusion criteria were enrolled. Quantitative analyses were conducted using EPI INFO 7.0 software and the results were presented in both univariate and bivariate forms. Results: The sample consisted of 56 men and 31 women with a mean age of 34.75 ± 8.77 years. X-ray technicians were over-represented (41.38%). Day/night shift work was the main work pattern (68.96%). The distribution of work zones A&B was known by 87.5% of the participants. Hazard warning signs were effective in work zones A and B (75.86%), and the walls of the premises were also reinforced in these work zones (88.51%), but the use of radiation dosimeters was rare (9.20%). Radiation aprons (94.30%) and hand-held dosimeters (63.20%) were the most commonly used personal protective equipment. The majority of the participants did not benefit from medical follow-up by an occupational health specialist (62.1%). Conclusion: The implementation of radiation protection measures remains a significant concern in Douala based health facilities, and requires stricter administrative controls and sanctions to prevent serious health consequences for exposed staff.展开更多
Microbial food is an important direction of sustainable food development in the future.Microorganisms such as lactic acid bacteria(LAB)are important sources of natural radioprotectors.Moderate environmental stress can...Microbial food is an important direction of sustainable food development in the future.Microorganisms such as lactic acid bacteria(LAB)are important sources of natural radioprotectors.Moderate environmental stress can induce stress response and improve biological activity of LAB.In the previous study,Lactococcus lactis subsp.lactis IL1403(L.lactis IL1403)cell-free extract induced by ionizing radiation(IR)of 500 Gy(IR-CFE)presented the stronger radioprotective effect than untreated cell-free extract in mice.To explore the radioprotective active substances of IR-CFE,the key protein was screened by proteomics and its radioprotective effect in vivo was further evaluated.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment showed that two-component systems(TCS)were enhanced to adapt the IR induction.Meanwhile,the protein LlrG belonged to TCS was screened by the protein-protein interaction.Furthermore,the recombinant protein LlrG(rLlrG)could markedly alleviate the ^(60)Coγ-induced damage to the hematopoietic system,oxidative stress and inflammation in mice,thereby exerting its radioprotective function.These results suggested LlrG protein not only played an important role in the adaptation of L.lactis IL1403 to IR environment,but also exerted a good radioprotective effect,which could be applied in the development of protein-based radioprotectors.展开更多
Radiological or nuclear accidents can lead to serious outcomes for individuals exposed to ionizing radiation,with health effects that are either acute or delayed,deterministic or stochastic,depending on the effective ...Radiological or nuclear accidents can lead to serious outcomes for individuals exposed to ionizing radiation,with health effects that are either acute or delayed,deterministic or stochastic,depending on the effective dose of exposure.Mechanistically,ionizing radiation can inflict damage either directly on DNA or through oxidative stress,which may trigger a cascade of damages to tissues and organs.The development of effective radiation medical countermeasures is an unmet need and should be a top priority in preparing for radiation emergencies.This paper aims to address the critical questions of whether current countermeasures are available,what additional measures are needed,and what actions can be taken to enhance the development of radiation medical countermeasures from a systematic perspective.展开更多
Circadian rhythm is a self-sustaining endogenous oscillation that serves as an internal timekeeping mechanism adapted to the Earth’s 24-h rotational schedule.It exists ubiquitously in nearly all organisms,from prokar...Circadian rhythm is a self-sustaining endogenous oscillation that serves as an internal timekeeping mechanism adapted to the Earth’s 24-h rotational schedule.It exists ubiquitously in nearly all organisms,from prokaryotes to mammals,and regulates diverse physiological and behavioral processes by synchronizing them with environmental fluctuations[1].Previous reports indicated that circadian rhythms exist in biological individuals and cells cultured in vitro[2].The mammalian circadian rhythm system consists of a central pacemaker located in the suprachiasmatic nucleus(SCN)of the hypothalamus,which coordinates peripheral rhythms through the sympathetic and parasympathetic nervous systems[3].This hierarchical mechanism uses neural populations as optimal models for circadian rhythm research.展开更多
Accidental exposure to overdose ionizing radiation will inevitably lead to severe biological damage,thus detecting and localizing radiation is essential.Traditional measurement techniques are generally restricted to t...Accidental exposure to overdose ionizing radiation will inevitably lead to severe biological damage,thus detecting and localizing radiation is essential.Traditional measurement techniques are generally restricted to the detection range of few centimeters,posing a great risk to operators.The prospect in remote sensing makes femtosecond laser filament technology a great candidate for constructively addressing this challenge.Here we propose a novel filament-based ionizing radiation sensing method,and clarify the interaction mechanism between filaments and ionizing radiation from systematic experiment to microscopic theory.Specifically,it is demonstrated that the energetic electrons produced byαradiation in air can be effectively accelerated within the filament,serving as seed electrons,which will enhance nitrogen fluorescence.The extended nitrogen fluorescence lifetime of~1 ns is also observed.Lastly,the combined microscopic model was elaborately established to quantitatively explain the modulation of nitrogen fluorescence emission from filament by ionizing radiation.These findings provide insights into the intricate interaction among ultra-strong light field,plasma and energetic particle beam,potentially suggesting a promising novel avenue for remote sensing of ionizing radiation.展开更多
Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages.To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in anim...Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages.To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation.Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation.We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor.Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression.Sodium butyrate pretreatment reversed these changes.These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression.The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No.KIRAMS16-0002)on December 30,2016.展开更多
This paper presents the effects of the low-dose irradiation on Tilapia Nilotica. In laboratory experiments the Tilapia Nilotica irradiated by integrated flux of fast neutrons 1×10 9 neutrons/m2 and 1 ×10 10...This paper presents the effects of the low-dose irradiation on Tilapia Nilotica. In laboratory experiments the Tilapia Nilotica irradiated by integrated flux of fast neutrons 1×10 9 neutrons/m2 and 1 ×10 10 neutrons/m2 gave a growth rate more than 40% and 32 % compared with those of controls respectively. The yield of the irradiated Tilapia Nilotica growing with non-irradiated carps and silver carps in a mixed feed condition increased by 8. 6%, 157% and 11. 0% more than those of the controls in the pilot test. The survival rate increases by 21. 8%, 149% and 16. 2% for the aboye-mentioned three species. An increased yield of 52 098 kg fish under irradiation with low dose was obtained in 18. 7 hectare water surface. The results of biological experiments show that the main organic coefficients of the Tilapia Nilotica are greater than those of the controls, and this may be related to the increase of the capabilities of metabolism and resistance to diseases.展开更多
Ionizing radiation caused by medical treatments,nuclear events or even space flights can irreversibly damage structure and function of brain cells.That can result in serious brain damage,with memory and behavior disor...Ionizing radiation caused by medical treatments,nuclear events or even space flights can irreversibly damage structure and function of brain cells.That can result in serious brain damage,with memory and behavior disorders,or even fatal oncologic or neurodegenerative illnesses.Currently used treatments and drugs are mostly targeting biochemical processes of cell apoptosis,radiation toxicity,neuroinflammation,and conditions such as cognitive-behavioral disturbances or others that result from the radiation insult.With most drugs,the side effects and potential toxicity are also to be considered.Therefore,many agents have not been approved for clinical use yet.In this review,we focus on the latest and most effective agents that have been used in animal and also in the human research,and clinical treatments.They could have the potential therapeutical use in cases of radiation damage of central nervous system,and also in prevention considering their radioprotecting effect of nervous tissue.展开更多
Objective To investigate the effect of ionizing radiation on the expression of p16, CyclinDl, and CDK4 in mouse thymocytes and splenocytes. Methods Fluorescent staining and flow cytometry analysis were employed for th...Objective To investigate the effect of ionizing radiation on the expression of p16, CyclinDl, and CDK4 in mouse thymocytes and splenocytes. Methods Fluorescent staining and flow cytometry analysis were employed for the measurement of protein expression. Results In time course experiments, it was found that the expression of p16 protein was significantly increased at 8, 24, and 48 h for thymocytes (P<0.05, P<0.01, and P<0.05, respectively) and at 24 h for splenocytes (P<0.05) after whole body irradiation (WBI) with 2.0 Gy X-rays. However, the expression of CDK4 protein was significantly decreased from 8 h to 24 h for thymocytes (P<0.05,P<0.01) and from 8 h to 72 h for splenocytes (P<0.05-P<0.01). In dose effect experiments, it was found that the expression of p16 protein in thymocytes and splenocytes was significantly increased at 24 h after WBI with 1.0, 2.0, and 4.0 Gy (P<0.05-P<0.01), whereas the expression of CDK4 protein was significantly decreased with 2.0Gy for thymocytes (P<0.05) and 0.5-6.0 Gy for splenocytes (P<0.05-P<0.01). Results also showed that the expression of CyclinDl protein decreased markedly in both thymocytes and splenocytes after exposure. Conclusion The results indicate that the expression of p 16 protein in thymocytes and splenocytes can be induced by ionizing radiation, and the p16-CyclinD1/CDK4 pathway may play an important role for G1 arrest of thymocytes induced by X-rays.展开更多
DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pa...DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pathways is subject to regulation by multiple other factors that are not well understood. We have proposed two conceptual models to explain the delayed and variable cell death response to DNA damage： integrative surveillance versus autonomous pathways. In this review, we discuss how these two models may explain the in vivo regulation of cell death induced by ionizing radiation （IR） in the developing central nervous system, where the death response is regulated by radiation dose, cell cycle status and neuronal development.展开更多
Aim: To study the effect of the combined use of genistein and ionizing radiation (IR) on prostate DU145 cancer cells. Methods: DU145, an androgen-independent human prostate cancer cell line, was used in the experiment...Aim: To study the effect of the combined use of genistein and ionizing radiation (IR) on prostate DU145 cancer cells. Methods: DU145, an androgen-independent human prostate cancer cell line, was used in the experiment. Clonogenic assay was used to compare the survival of DU145 cells after treatments with genistein alone and in combination with graded IR. Apoptosis was assayed by DNA ladder and TUNEL stain. Cell cycle alterations were observed by flow cytometry and related protein expressions by immunoblotting. Results: Clonogenic assay demonstrated that genistein, even at low to medium concentrations, enhanced the radiosensitivity of DU145 cells. Twenty-four hours after treatment with IR and/or genistein, apoptosis was mainly seen with genistein at high concentrations and was minimally related to IR. At 72 h, apoptosis also occurred in treatment with lower concentration of genistein, especially when combined with IR. While both IR and genistein led to G2/M cell cycle arrest, combination of them further increased the DU145 cells at G2/M phase. This Gz/M arrest was largely maintained at 72 h, accompanied by increasing apoptosis and hyperdiploid cell population. Cell-cycle related protein analysis disclosed biphasic changes in cyclin B1 and less dramatically cdc-2, but stably elevated p21cipl levels with increasing genistein concentrations. Conclusion: Genistein enhanced the radiosensitivity of DU145 prostate cancer cells. The mechanisms might be involved in the increased apoptosis, prolonged cell cycle arrest and impaired damage repair.展开更多
Diisopropylthiourea（DPT）, an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater.This compound cannot be completely removed b...Diisopropylthiourea（DPT）, an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater.This compound cannot be completely removed by conventional biological processes due to its antimicrobial property. Ionizing radiation has been applied in the decomposition of refractory pollutants in recent years and has proved effective. Therefore, the decomposition of DPT by γ-irradiation was studied. The compound was irradiated at the dose of 150–2000 Gy before a change of concentration and UV absorption of the solutions was detected.Furthermore, the decomposition kinetics and radiation yield（G-value） of DPT was investigated. The results of radiation experiments on DPT-containing aqueous showed that the DPT can be effectively degraded by γ-radiation. DPT concentration decreased with increasing absorbed doses. G-values of radiolytic decomposition for DPT（20 mg/L） were 1.04 and 0.47 for absorbed doses of 150 and 2000 Gy, respectively. The initial concentration and p H of the solutions affected the degradation. As the concentration of substrate increased,the decomposition was reduced. The decrease of removal rate and radiation efficacy under alkaline condition suggested that lower p H values benefit the γ-induced degradation. UV absorption from 190 to 250 nm decreased after radiation while that from 250 to 300 nm increased, indicating the formation of by-products.展开更多
AIM To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism.METHODS Human hepatocel...AIM To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism.METHODS Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species(ROS) were quantified using the fluorescent probe DCFH-DA.RESULTS Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3 II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation.CONCLUSION Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.展开更多
Objective The purpose of the present study was to observe the changes in CD4＋CD25＋Nrpl＋Treg cells after irradiation with different doses and explore the possible molecular mechanisms involved. Methods ICR mice and ...Objective The purpose of the present study was to observe the changes in CD4＋CD25＋Nrpl＋Treg cells after irradiation with different doses and explore the possible molecular mechanisms involved. Methods ICR mice and mouse lymphoma cell line （EL-4 cells） was used. The expressions of CD4, CD25, Nrpl, calcineurin and PKC-α were detected by flow cytometry. The expressions of TGF-131, IL-10, PKA and cAMP were estimated with ELISA. Results At 12 h after irradiation, the expression of Nrpl increased significantly in 4.0 Gy group, compared with sham-irradiation group （P〈0.05） in the spleen and thymus, respectively, when ICR mice received whole-body irradiation （WBI）. Meanwhile the synthesis of Interleukin 10 （IL-20） and transforming growth factor-β1 （TGF-β1） increased significantly after high dose irradiation （HDR） （〉 or = 1.0 Gy）. In addition, the expression of cAMP and PKA protein increased, while PKC-α, calcineurin decreased at 12h in thymus cells after 4.0 Gy X-irradiation. While TGF-β1 was clearly inhibited when the PLC-PIP2 signal pathway was stimulated or the cAMP-PKA signal pathway was blocked after 4.0 Gy X-irradiation, this did not limit the up-regulation of CD4＋CD25＋Nrpl＋Treg cells after ionizing radiation. Conclusion These results indicated that HDR might induce CD4＋CD25＋Nrpl＋Treg cells production and stimulate TGF-β1 secretion by regulating signal molecules in mice.展开更多
BACKGROUND The thyroid-gut axis has a great influence on the maintenance of human health;however,we know very little about the effects of low-dose ionizing radiation(LDR) on thyroid hormone levels and gut microbiota c...BACKGROUND The thyroid-gut axis has a great influence on the maintenance of human health;however,we know very little about the effects of low-dose ionizing radiation(LDR) on thyroid hormone levels and gut microbiota composition.AIM To investigate the potential effects of low-dose X-ray radiation to male C57BL/6J mice.METHODS Peripheral blood was collected for enzyme-linked immunosorbent assay(ELISA),and stool samples were taken for 16S ribosomal RNA(rRNA) gene sequencing after irradiation.RESULTS We found that LDR caused changes in thyroid stimulating hormone(TSH) levels in the irradiated mice,suggesting a dose-dependent response in thyroid function to ionizing radiation.No changes in the diversity and richness of the gut microbiota were observed in the LDR-exposed group in comparison to the controls.The abundance of Moraxellaceae and Enterobacteriaceae decreased in the LDR-exposed groups compared with the controls,and the Lachnospiraceae abundance increased in a dose-dependent manner in the radiated groups.And the abundances of uncultured_bacterium_g_Acinetobacter,uncultured_bacterium_o_Mollicutes_RF39,uncultured_bacterium_g_Citrobacter,and uncultured_bacterium_g_Lactococcus decreased in the radiated groups at the genus level,which showed a correlation with radiation exposure and diagnostic efficacy.Analysis of functional metabolic pathways revealed that biological metabolism was predicted to have an effect on functional activities,such as nucleotide metabolism,carbohydrate metabolism,and glycan biosynthesis and metabolism.Furthermore,Kyoto Encyclopedia of Genes and Genomes pathway annotation also suggested that changes in the gut microbiota were related to processing functions,including translation,replication and repair.CONCLUSION LDR can change thyroid function and the gut microbiota,and changes in the abundances of bacteria are correlated with the radiation dose.展开更多
Objective miR-663 a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1.The goal of this study was to explore the role of mi R-663 a during rad...Objective miR-663 a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1.The goal of this study was to explore the role of mi R-663 a during radiation-induced Epithelium-to-mesenchymal transition(EMT).Methods TGF-β1 or IR was used to induce EMT.After mi R-663 a transfection,cell migration and cell morphological changes were detected and the expression levels of mi R-663 a,TGF-β1,and EMT-related factors were quantified.Results Enhancement of cell migration and promotion of mesenchymal changes induced by either TGF-β1 or radiation were suppressed by mi R-663 a.Furthermore,both X-ray and carbon ion irradiation resulted in the upregulation of TGF-β1 and downregulation of mi R-663 a,while the silencing of TGF-β1 by mi R-663 a reversed the EMT process after radiation.Conclusion Our findings demonstrate an EMT-suppressing effect by mi R-663 a via TGF-β1 in radiationinduced EMT.展开更多
The perovskite-like NaMgF3 polycrystalline powder samples, pure and rare earth doped, were synthesized by conventional solid state reaction method. The perovskite material was doped with 0.2 mol.% of EuF3 and CeF3 imp...The perovskite-like NaMgF3 polycrystalline powder samples, pure and rare earth doped, were synthesized by conventional solid state reaction method. The perovskite material was doped with 0.2 mol.% of EuF3 and CeF3 impurity. Phase purity of synthe-sized compounds was analyzed by powder X-ray diffraction technique. The thermoluminescence response of polycrystalline samples showed a linear response up to 12 Gy and then became sub linear at higher doses. The order of kinetics （b）, activation energy （E） and other trapping parameters were calculated using peak shape method and variable heating rate method. From glow curve analysis the symmetric factor was calculated. The glow curve showed two peaks at 404 and 488 K, and both of them confirmed the thermolumi-nescence in the phosphor, which obeyed second-order kinetics. The experimental resulted showed that this phosphor could have po-tential applications in radiation dosimetry.展开更多
基金financial support from the National Natural Science Foundation of China(Grant No.21801016)the Science and Technology on Applied Physical Chemistry Laboratory(Grant No.6142602220304)。
文摘In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduced electron transfer(PET)effect.Two perylene diimide isomers PDI-P and PDI-B were designed and synthesized,and their molecular structures were characterized by high-resolution Fourier transform mass spectrometry(HRMS),nuclear magnetic resonance hydrogen and carbon spectroscopy(~1H and~(13)C NMR).The interaction between ionizing radiation and fluorescent molecules was simulated by HCl titration.The results show that combining PDIs and HCl can improve fluorescence through the retro-PET process.Despite the similarities in chemical structures,the fluorescent enhancement multiple of PDI-B with aromatic amine as electron donor is much higher than that of PDI-P with alkyl amine.In the direct irradiation experiments of ionizing radiation,the emission enhancement multiples of PDI-P and PDI-B are 2.01 and 45.4,respectively.Furthermore,density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations indicate that the HOMO and HOMO-1 energy ranges of PDI-P and PDI-B are 0.54 e V and 1.13 e V,respectively.A wider energy range has a stronger driving force on electrons,which is conducive to fluorescence quenching.Both femtosecond transient absorption spectroscopy(fs-TAS)and transient fluorescence spectroscopy(TFS)tests show that PDI-B has shorter charge separation lifetime and higher electron transfer rate constant.Although both isomers can significantly reduce LOD during PET process,PDI-B with aromatic amine has a wider detection range of 0.118—240 Gy due to its larger emission enhancement,which is a leap of three orders of magnitude.It breaks through the detection range of gamma radiation reported in existing studies,and provides theoretical support for the further study of sensitive and effective new materials for ionizing radiation detection.
文摘Bone marrow serves as the life-long home for hemato-poietic stem cells(HSCs)and is the most radio-sensitive organ^([1]).Acute ionizing radiation exceeding 1 Gray(Gy)causes severe damage in bone marrow while no effective drug has been approved in clinical.In a recent work pub-lished in MedComm,Gao and her team reported,for the first time,cannabidiol(CBD)as an outstanding radioprotection agent targeting acute radiation-induced hematopoietic injury^([2]).Within two weeks post radiation,CBD can pro-mote the stemness of hematopoietic stem cells to a regular level.Using single-cell RNA sequencing(scRNA-seq)and functional assay,the authors decoded molecular changes underlying radiation-induced damage and CBD-induced recovery in HSCs.
基金supported by grants fromthe Shenzhen Medical Research Fund(Grant No.A2302040).
文摘During cellular proliferation DNA undergoes frequent rep-lication cycles in which errors inevitably accumulate.DNA simultaneously faces continuous damage from endogenous sources[e.g.,reactive oxygen species(ROS)]and environmen-tal stressors,such as ultraviolet(UV)and ionizing radiation(IR).Such lesions compromise genomic stability and may escalate into DNA double-strand breaks(DSBs).Failure to repair DSBs can ultimately trigger cell death1.
文摘Introduction: The use of radioactive radiations in healthcare facilities must comply with radioprotection safety rules in order to avoid threatening the health of workers and patients. This study aimed to assess the working conditions, the protective measures and the medical monitoring of workers directly involved in X-ray work at hospitals in Douala, Cameroon. Materials and Methods: A descriptive cross-sectional study was carried out during the 1st quarter of 2018, across various state and private health facilities of the city of Douala. Sampling was non-random, based on convenience and all the willing participants that fulfilled the inclusion criteria were enrolled. Quantitative analyses were conducted using EPI INFO 7.0 software and the results were presented in both univariate and bivariate forms. Results: The sample consisted of 56 men and 31 women with a mean age of 34.75 ± 8.77 years. X-ray technicians were over-represented (41.38%). Day/night shift work was the main work pattern (68.96%). The distribution of work zones A&B was known by 87.5% of the participants. Hazard warning signs were effective in work zones A and B (75.86%), and the walls of the premises were also reinforced in these work zones (88.51%), but the use of radiation dosimeters was rare (9.20%). Radiation aprons (94.30%) and hand-held dosimeters (63.20%) were the most commonly used personal protective equipment. The majority of the participants did not benefit from medical follow-up by an occupational health specialist (62.1%). Conclusion: The implementation of radiation protection measures remains a significant concern in Douala based health facilities, and requires stricter administrative controls and sanctions to prevent serious health consequences for exposed staff.
基金supported by the National Natural Science Foundation of China(32172211,32572557)the Key Science Research Projects of Higher Education Institutions in Henan Province(21A530006)+3 种基金the Key Research and Development and Promotion Projects of Henan Province(232102310293)the Henan Provincial Natural Science Foundation General Program(252300421403)the Zhongyuan Sci-Tech Innovation Leading Talents(254200510040)the Innovative Research Team(in Science and Technology)in University of Henan Province(26IRTSTHN030).
文摘Microbial food is an important direction of sustainable food development in the future.Microorganisms such as lactic acid bacteria(LAB)are important sources of natural radioprotectors.Moderate environmental stress can induce stress response and improve biological activity of LAB.In the previous study,Lactococcus lactis subsp.lactis IL1403(L.lactis IL1403)cell-free extract induced by ionizing radiation(IR)of 500 Gy(IR-CFE)presented the stronger radioprotective effect than untreated cell-free extract in mice.To explore the radioprotective active substances of IR-CFE,the key protein was screened by proteomics and its radioprotective effect in vivo was further evaluated.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment showed that two-component systems(TCS)were enhanced to adapt the IR induction.Meanwhile,the protein LlrG belonged to TCS was screened by the protein-protein interaction.Furthermore,the recombinant protein LlrG(rLlrG)could markedly alleviate the ^(60)Coγ-induced damage to the hematopoietic system,oxidative stress and inflammation in mice,thereby exerting its radioprotective function.These results suggested LlrG protein not only played an important role in the adaptation of L.lactis IL1403 to IR environment,but also exerted a good radioprotective effect,which could be applied in the development of protein-based radioprotectors.
基金Beijing Nova Program,Grant/Award Number:20220484086。
文摘Radiological or nuclear accidents can lead to serious outcomes for individuals exposed to ionizing radiation,with health effects that are either acute or delayed,deterministic or stochastic,depending on the effective dose of exposure.Mechanistically,ionizing radiation can inflict damage either directly on DNA or through oxidative stress,which may trigger a cascade of damages to tissues and organs.The development of effective radiation medical countermeasures is an unmet need and should be a top priority in preparing for radiation emergencies.This paper aims to address the critical questions of whether current countermeasures are available,what additional measures are needed,and what actions can be taken to enhance the development of radiation medical countermeasures from a systematic perspective.
基金funded by the National Natural Science Foundation of China(no.12275329,Nan Ding,and no.12175289,Jufang Wang)the West Light Foundation of The Chinese Academy of Sciences(xbzglzb2022003,Nan Ding)+2 种基金the Science and Technology Research Project of Gansu Province(no.145RTSA012,Jufang Wang,and no.21JR7RA108,Nan Ding)the Gansu Provincial Science Fund for Distinguished Young Scholars(no.22JR5RA942,Wei Wang)the CuiYing Science and Technology Innovation Program of the Second Hospital of Lanzhou University(CY2023-MS-A03,Wei Wang).
文摘Circadian rhythm is a self-sustaining endogenous oscillation that serves as an internal timekeeping mechanism adapted to the Earth’s 24-h rotational schedule.It exists ubiquitously in nearly all organisms,from prokaryotes to mammals,and regulates diverse physiological and behavioral processes by synchronizing them with environmental fluctuations[1].Previous reports indicated that circadian rhythms exist in biological individuals and cells cultured in vitro[2].The mammalian circadian rhythm system consists of a central pacemaker located in the suprachiasmatic nucleus(SCN)of the hypothalamus,which coordinates peripheral rhythms through the sympathetic and parasympathetic nervous systems[3].This hierarchical mechanism uses neural populations as optimal models for circadian rhythm research.
基金financial supports from National Key Research and Development Program of China(2024YFB3613900)National Natural Science Foundation of China(W2412044)+1 种基金Russian Science Foundation(25-4900154)Fundamental Research Funds for the Central Universities(63253214)。
文摘Accidental exposure to overdose ionizing radiation will inevitably lead to severe biological damage,thus detecting and localizing radiation is essential.Traditional measurement techniques are generally restricted to the detection range of few centimeters,posing a great risk to operators.The prospect in remote sensing makes femtosecond laser filament technology a great candidate for constructively addressing this challenge.Here we propose a novel filament-based ionizing radiation sensing method,and clarify the interaction mechanism between filaments and ionizing radiation from systematic experiment to microscopic theory.Specifically,it is demonstrated that the energetic electrons produced byαradiation in air can be effectively accelerated within the filament,serving as seed electrons,which will enhance nitrogen fluorescence.The extended nitrogen fluorescence lifetime of~1 ns is also observed.Lastly,the combined microscopic model was elaborately established to quantitatively explain the modulation of nitrogen fluorescence emission from filament by ionizing radiation.These findings provide insights into the intricate interaction among ultra-strong light field,plasma and energetic particle beam,potentially suggesting a promising novel avenue for remote sensing of ionizing radiation.
基金supported by the Nuclear Research and Development Program(NRF-2012M2A2A7012377,NRF-2015M2B2B1068627 and NRF-2015R1C1A2A01053041)of the National Research Foundation of Korea(NRF)funded by the Korean Government Ministry of Science,ICT&Future Planning
文摘Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages.To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation.Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation.We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor.Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression.Sodium butyrate pretreatment reversed these changes.These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression.The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No.KIRAMS16-0002)on December 30,2016.
文摘This paper presents the effects of the low-dose irradiation on Tilapia Nilotica. In laboratory experiments the Tilapia Nilotica irradiated by integrated flux of fast neutrons 1×10 9 neutrons/m2 and 1 ×10 10 neutrons/m2 gave a growth rate more than 40% and 32 % compared with those of controls respectively. The yield of the irradiated Tilapia Nilotica growing with non-irradiated carps and silver carps in a mixed feed condition increased by 8. 6%, 157% and 11. 0% more than those of the controls in the pilot test. The survival rate increases by 21. 8%, 149% and 16. 2% for the aboye-mentioned three species. An increased yield of 52 098 kg fish under irradiation with low dose was obtained in 18. 7 hectare water surface. The results of biological experiments show that the main organic coefficients of the Tilapia Nilotica are greater than those of the controls, and this may be related to the increase of the capabilities of metabolism and resistance to diseases.
文摘Ionizing radiation caused by medical treatments,nuclear events or even space flights can irreversibly damage structure and function of brain cells.That can result in serious brain damage,with memory and behavior disorders,or even fatal oncologic or neurodegenerative illnesses.Currently used treatments and drugs are mostly targeting biochemical processes of cell apoptosis,radiation toxicity,neuroinflammation,and conditions such as cognitive-behavioral disturbances or others that result from the radiation insult.With most drugs,the side effects and potential toxicity are also to be considered.Therefore,many agents have not been approved for clinical use yet.In this review,we focus on the latest and most effective agents that have been used in animal and also in the human research,and clinical treatments.They could have the potential therapeutical use in cases of radiation damage of central nervous system,and also in prevention considering their radioprotecting effect of nervous tissue.
基金This work was supported by a grant from the National Natural Science Foundation of China(No.39770193).
文摘Objective To investigate the effect of ionizing radiation on the expression of p16, CyclinDl, and CDK4 in mouse thymocytes and splenocytes. Methods Fluorescent staining and flow cytometry analysis were employed for the measurement of protein expression. Results In time course experiments, it was found that the expression of p16 protein was significantly increased at 8, 24, and 48 h for thymocytes (P<0.05, P<0.01, and P<0.05, respectively) and at 24 h for splenocytes (P<0.05) after whole body irradiation (WBI) with 2.0 Gy X-rays. However, the expression of CDK4 protein was significantly decreased from 8 h to 24 h for thymocytes (P<0.05,P<0.01) and from 8 h to 72 h for splenocytes (P<0.05-P<0.01). In dose effect experiments, it was found that the expression of p16 protein in thymocytes and splenocytes was significantly increased at 24 h after WBI with 1.0, 2.0, and 4.0 Gy (P<0.05-P<0.01), whereas the expression of CDK4 protein was significantly decreased with 2.0Gy for thymocytes (P<0.05) and 0.5-6.0 Gy for splenocytes (P<0.05-P<0.01). Results also showed that the expression of CyclinDl protein decreased markedly in both thymocytes and splenocytes after exposure. Conclusion The results indicate that the expression of p 16 protein in thymocytes and splenocytes can be induced by ionizing radiation, and the p16-CyclinD1/CDK4 pathway may play an important role for G1 arrest of thymocytes induced by X-rays.
文摘DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pathways is subject to regulation by multiple other factors that are not well understood. We have proposed two conceptual models to explain the delayed and variable cell death response to DNA damage： integrative surveillance versus autonomous pathways. In this review, we discuss how these two models may explain the in vivo regulation of cell death induced by ionizing radiation （IR） in the developing central nervous system, where the death response is regulated by radiation dose, cell cycle status and neuronal development.
文摘Aim: To study the effect of the combined use of genistein and ionizing radiation (IR) on prostate DU145 cancer cells. Methods: DU145, an androgen-independent human prostate cancer cell line, was used in the experiment. Clonogenic assay was used to compare the survival of DU145 cells after treatments with genistein alone and in combination with graded IR. Apoptosis was assayed by DNA ladder and TUNEL stain. Cell cycle alterations were observed by flow cytometry and related protein expressions by immunoblotting. Results: Clonogenic assay demonstrated that genistein, even at low to medium concentrations, enhanced the radiosensitivity of DU145 cells. Twenty-four hours after treatment with IR and/or genistein, apoptosis was mainly seen with genistein at high concentrations and was minimally related to IR. At 72 h, apoptosis also occurred in treatment with lower concentration of genistein, especially when combined with IR. While both IR and genistein led to G2/M cell cycle arrest, combination of them further increased the DU145 cells at G2/M phase. This Gz/M arrest was largely maintained at 72 h, accompanied by increasing apoptosis and hyperdiploid cell population. Cell-cycle related protein analysis disclosed biphasic changes in cyclin B1 and less dramatically cdc-2, but stably elevated p21cipl levels with increasing genistein concentrations. Conclusion: Genistein enhanced the radiosensitivity of DU145 prostate cancer cells. The mechanisms might be involved in the increased apoptosis, prolonged cell cycle arrest and impaired damage repair.
基金supported by the financial support by the National High Technology ResearchDevelopment Program of the Chinese Ministry of Science and Technology(No.2009AA063905)the Independent Research Project of Tsinghua University(No.20101081929)
文摘Diisopropylthiourea（DPT）, an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater.This compound cannot be completely removed by conventional biological processes due to its antimicrobial property. Ionizing radiation has been applied in the decomposition of refractory pollutants in recent years and has proved effective. Therefore, the decomposition of DPT by γ-irradiation was studied. The compound was irradiated at the dose of 150–2000 Gy before a change of concentration and UV absorption of the solutions was detected.Furthermore, the decomposition kinetics and radiation yield（G-value） of DPT was investigated. The results of radiation experiments on DPT-containing aqueous showed that the DPT can be effectively degraded by γ-radiation. DPT concentration decreased with increasing absorbed doses. G-values of radiolytic decomposition for DPT（20 mg/L） were 1.04 and 0.47 for absorbed doses of 150 and 2000 Gy, respectively. The initial concentration and p H of the solutions affected the degradation. As the concentration of substrate increased,the decomposition was reduced. The decrease of removal rate and radiation efficacy under alkaline condition suggested that lower p H values benefit the γ-induced degradation. UV absorption from 190 to 250 nm decreased after radiation while that from 250 to 300 nm increased, indicating the formation of by-products.
基金Supported by Science and Technology Program of Chongqing,No.2013-2-179
文摘AIM To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism.METHODS Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species(ROS) were quantified using the fluorescent probe DCFH-DA.RESULTS Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3 II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation.CONCLUSION Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.
基金supported by grants from the National Natural Science Foundation of China(No.30870584,No.81201737)the Doctoral Program Foundation of Institutions of Higher Education of China(No.20120061110063)
文摘Objective The purpose of the present study was to observe the changes in CD4＋CD25＋Nrpl＋Treg cells after irradiation with different doses and explore the possible molecular mechanisms involved. Methods ICR mice and mouse lymphoma cell line （EL-4 cells） was used. The expressions of CD4, CD25, Nrpl, calcineurin and PKC-α were detected by flow cytometry. The expressions of TGF-131, IL-10, PKA and cAMP were estimated with ELISA. Results At 12 h after irradiation, the expression of Nrpl increased significantly in 4.0 Gy group, compared with sham-irradiation group （P〈0.05） in the spleen and thymus, respectively, when ICR mice received whole-body irradiation （WBI）. Meanwhile the synthesis of Interleukin 10 （IL-20） and transforming growth factor-β1 （TGF-β1） increased significantly after high dose irradiation （HDR） （〉 or = 1.0 Gy）. In addition, the expression of cAMP and PKA protein increased, while PKC-α, calcineurin decreased at 12h in thymus cells after 4.0 Gy X-irradiation. While TGF-β1 was clearly inhibited when the PLC-PIP2 signal pathway was stimulated or the cAMP-PKA signal pathway was blocked after 4.0 Gy X-irradiation, this did not limit the up-regulation of CD4＋CD25＋Nrpl＋Treg cells after ionizing radiation. Conclusion These results indicated that HDR might induce CD4＋CD25＋Nrpl＋Treg cells production and stimulate TGF-β1 secretion by regulating signal molecules in mice.
基金the Natural Science Foundation of Shanghai,No.21ZR1449600Shanghai Tenth People’s Hospital,Tongji University School of Medicine,No.2021SYPDRC064the Natural Science Foundation of China,No.82071964
文摘BACKGROUND The thyroid-gut axis has a great influence on the maintenance of human health;however,we know very little about the effects of low-dose ionizing radiation(LDR) on thyroid hormone levels and gut microbiota composition.AIM To investigate the potential effects of low-dose X-ray radiation to male C57BL/6J mice.METHODS Peripheral blood was collected for enzyme-linked immunosorbent assay(ELISA),and stool samples were taken for 16S ribosomal RNA(rRNA) gene sequencing after irradiation.RESULTS We found that LDR caused changes in thyroid stimulating hormone(TSH) levels in the irradiated mice,suggesting a dose-dependent response in thyroid function to ionizing radiation.No changes in the diversity and richness of the gut microbiota were observed in the LDR-exposed group in comparison to the controls.The abundance of Moraxellaceae and Enterobacteriaceae decreased in the LDR-exposed groups compared with the controls,and the Lachnospiraceae abundance increased in a dose-dependent manner in the radiated groups.And the abundances of uncultured_bacterium_g_Acinetobacter,uncultured_bacterium_o_Mollicutes_RF39,uncultured_bacterium_g_Citrobacter,and uncultured_bacterium_g_Lactococcus decreased in the radiated groups at the genus level,which showed a correlation with radiation exposure and diagnostic efficacy.Analysis of functional metabolic pathways revealed that biological metabolism was predicted to have an effect on functional activities,such as nucleotide metabolism,carbohydrate metabolism,and glycan biosynthesis and metabolism.Furthermore,Kyoto Encyclopedia of Genes and Genomes pathway annotation also suggested that changes in the gut microbiota were related to processing functions,including translation,replication and repair.CONCLUSION LDR can change thyroid function and the gut microbiota,and changes in the abundances of bacteria are correlated with the radiation dose.
基金funded by the National Natural Science Foundation of China[no.U1932208,YANG Kai]the Science and Technology Research Project of Gansu Province[no.17JR5RA307 and 145RTSA012,WANG Ju Fang]the Science and Technology Research Project of Gansu Province[no.21JR7RA108,DING Nan]
文摘Objective miR-663 a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1.The goal of this study was to explore the role of mi R-663 a during radiation-induced Epithelium-to-mesenchymal transition(EMT).Methods TGF-β1 or IR was used to induce EMT.After mi R-663 a transfection,cell migration and cell morphological changes were detected and the expression levels of mi R-663 a,TGF-β1,and EMT-related factors were quantified.Results Enhancement of cell migration and promotion of mesenchymal changes induced by either TGF-β1 or radiation were suppressed by mi R-663 a.Furthermore,both X-ray and carbon ion irradiation resulted in the upregulation of TGF-β1 and downregulation of mi R-663 a,while the silencing of TGF-β1 by mi R-663 a reversed the EMT process after radiation.Conclusion Our findings demonstrate an EMT-suppressing effect by mi R-663 a via TGF-β1 in radiationinduced EMT.
基金Project supported by Indira Gandhi Centre for Atomic Research(IGCAR),Department of Atomic Energy,Government of India(W.O.N.O.IGC/SG/RSD/WO/2009)
文摘The perovskite-like NaMgF3 polycrystalline powder samples, pure and rare earth doped, were synthesized by conventional solid state reaction method. The perovskite material was doped with 0.2 mol.% of EuF3 and CeF3 impurity. Phase purity of synthe-sized compounds was analyzed by powder X-ray diffraction technique. The thermoluminescence response of polycrystalline samples showed a linear response up to 12 Gy and then became sub linear at higher doses. The order of kinetics （b）, activation energy （E） and other trapping parameters were calculated using peak shape method and variable heating rate method. From glow curve analysis the symmetric factor was calculated. The glow curve showed two peaks at 404 and 488 K, and both of them confirmed the thermolumi-nescence in the phosphor, which obeyed second-order kinetics. The experimental resulted showed that this phosphor could have po-tential applications in radiation dosimetry.
