High Doses Of Gamma Radiation Research Articles

Modifying the Resistant Starch Content and the Retrogradation Characteristics of Potato Starch Through High-Dose Gamma Irradiation

Potato starch is widely utilized in the food industry. Gamma irradiation is a cost-effective and environmentally friendly method for starch modification. Nevertheless, there is a scarcity of comprehensive and consistent knowledge regarding the physicochemical characteristics of high-dose gamma-irradiated potato starch, retrogradation properties in particular. In this study, potato starch was exposed to gamma rays at doses of 0, 30, 60, 90, and 120 kGy. Various physicochemical properties, including retrogradation characteristics, were investigated. Generally, the apparent amylose content (AAC), water absorption, gel viscosity, gel hardness, and gumminess decreased as the doses of gamma irradiation increased. Conversely, the resistant starch (RS), amylose content evaluated by the concanavalin A precipitation method, water solubility, and enthalpy of gelatinization were increased. Additionally, swelling power, crystalline structure, and amylopectin branch chain length distribution either remained stable or exhibited only minor changes. Notably, the degree of retrogradation of potato starches on day 7 was positively correlated with the doses of gamma irradiation.

Integration methods: H3PO4 immersion and gamma irradiation exposure in modified activated carbon from banana (Musa paradisiaca L. sp.) stems biomass

Abstract Indonesia has abundant natural resources or tropical fruit like bananas (Musa paradisiaca L.sp.). Waste from natural resources can be identified as biomass. In Musa paradisiaca L.sp., biomass is derived from banana peels, stems, and leaves. This biomass can be used as activated carbon. Banana stems can be processed into activated carbon because they contain galacturonic acid. This a combine method of chemical activation via phosphate acid (H3PO4) immersion and gamma irradiation exposure to synthesize activated carbon from banana stems. These combined methods can make the surface area increase and make its function improve. Gamma irradiation exposure used variant doses 10 kGy, 30 kGy, and 50 kGy. Synthesized activated carbon was characterized using Teller Brunauer Emmett (BET) to analyze surface area of Activated Carbon and to identify the functional groups using Fourier Transform Infrared Spectroscopy (FTIR). The result shows the hidroxyl functional group decreases, and the transmission between irradiated carbons decreases with the increasing irradiation dose used. Effect of integration methods of acid immersion and gamma irradiation exposure on increasing surface area is enlarger of activated carbon banana stem. However, high-dose gamma irradiation exposure did not significantly impact surface area formation.

Gamma-induced stress, strain and p-type doping in MBE-grown thin film MoTe2.

A thorough examination of the stability of a 2D MoTe2 thin film exposed to high-dose gamma radiation (γ) is addressed in this study. This study compares the film before and after irradiation (10-600 kGy dosage) to report the impact of γ radiation on the surface morphology, work function, tensile strain and charge redistribution in the MoTe2 thin film. The radiation damage to the film is monitored by optical micrographs (OM) and with atomic force microscopy (AFM) and conceptualized by thermal strain in the film. Raman spectroscopy has been used to analyze the shifting and to address the strain that arises due to irradiation in its vibrational mode. Kelvin probe force microscopy (KPFM) has been performed to evaluate the work function of the film, which increases by 0.14 eV for the 600 kGy γ-irradiated sample, implying shifting of the Fermi-level to the valence band of the spectrum and thus it results in p-type doping in the film. Owing to the reduced atomic mass and high energy of tellurium atoms, γ-irradiation causes tellurium vacancies, which lead to the formation of dangling bonds at unoccupied sites. When oxygen is adsorbed at these reactive spots, a charge-transfer mechanism takes place. This mechanism involves the transfer of electrons from the thin MoTe2 film to the adsorbed oxygen, forming oxides and causing p-type doping. Furthermore, p-doping is verified by the valence band shifting by 1.27 eV in 600 kGy in γ-irradiated samples in X-ray photoelectron spectroscopy. This comprehensive study shows how γ irradiation affects the chemical and physical characteristics of the MoTe2 thin film. Consequently, it shows that if devices integrating MoTe2 thin films are meant to be used in high-dose radiation conditions, the adsorbate concentrations, radiation shielding and required lifetimes must be carefully evaluated.

Modification of WS2 thin film properties using high dose gamma irradiation

The tunability of the transition metal dichalcogenide properties has gained attention from numerous researchers due to their wide application in various fields including quantum technology. In the present work, WS2 has been deposited on fluorine doped tin oxide substrate and its properties have been studied systematically. These samples were irradiated using gamma radiation for various doses, and the effect on structural, morphological, optical and electrical properties has been reported. The crystallinity of the material is observed to be decreased, and the results are well supported by x-ray diffraction, Raman spectroscopy techniques. The increase in grain boundaries has been supported by the agglomeration observed in the scanning electron microscopy micrographs. The XPS results of WS2 after gamma irradiation show evolution of oxygen, carbon, C=O, W–O and SO4 −2 peaks, confirming the addition of impurities and formation of point defect. The gamma irradiation creates point defects, and their density increases considerably with increasing gamma dosage. These defects crucially altered the structural, optical and electrical properties of the material. The reduction in the optical band gap with increased gamma irradiation is evident from the absorption spectra and respective Tauc plots. The I–V graphs show a 1000-fold increase in the saturation current after 100 kGy gamma irradiation dose. This work has explored the gamma irradiation effect on the WS2 and suggests substantial modification in the material and enhancement in electrical properties.

Optical properties of thin films monitored in real-time at high gamma radiation doses using long period fiber gratings

In this work, we report an all-optical-fiber-based method to monitor in real-time the changes in thin film optical properties when exposed to harsh environments such as high doses of gamma radiation. The method is based on a long period grating (LPG) inscribed in a radiation resistant optical fiber, which is coated with a thin film to be analyzed. Due to impact of the environment on the film properties, the transmission spectrum of the LPG changes. To validate this methodology, we deposited oxides of various metals, i.e. aluminum (Al2O3), titanium (TiO2), and tantalum (Ta2O5), as well as a polymeric film, namely polystyrene (PS), on the LPG surface and measured the resonant wavelength shift induced by high doses of gamma exposure (dose rate of 2.3 kGy/h, up to a total dose of 46 kGy). The changes could be observed in real-time up to maximum reached dose and during the recovery period. The results are significantly dependent on thin film material. Among the oxides, TiO2 thin film demonstrated the highest susceptibility to irradiation, whereas Al2O3 exhibited the least impact. Additionally, a good recovery potential for Ta2O5 thin film was observed, hinting at its promising application in dosimetry. Conversely, the PS film exhibited a permanent effect induced by irradiation. This is the first real-time experimental study of the impact of high dose gamma radiation on thin film optical properties using a universal optical-fiber-based device. The findings pave the way for assessing radiation hardness of thin film materials or utilizing such a method to optimize material treatment involving ionizing radiation.

Study of bulk damage of high dose gamma irradiated p-type silicon diodes with various resistivities

The bulk damage of p-type silicon detectors caused by high doses of gamma irradiation has been studied. The study was carried out on three types of n+-in-p silicon diodes with comparable geometries but different initial resistivities. This allowed to determine how different initial parameters of studied samples influence radiation-induced changes in the measured characteristics. The diodes were irradiated by a Cobalt-60 gamma source to total ionizing doses ranging from 0.50 up to 8.28 MGy, and annealed for 80 minutes at 60 °C. The Geant4 toolkit for simulation of the passage of particles through matter was used to simulate the deposited energy homogeneity, to verify the equal distribution of total deposited energies through all the layers of irradiated samples, and to calculate the secondary electron spectra in the irradiation box. The main goal of the study was to characterize the gamma-radiation induced displacement damage by measuring current-voltage characteristics (IV), and the evolution of the full depletion voltage (V FD) with the total ionizing dose, by measuring capacitance-voltage characteristics (CV). It has been observed that the bulk leakage current increases linearly with total ionizing dose, and the damage coefficient depends on the initial resistivity of the silicon diode. The effective doping concentration and therefore V FD significantly decreases with increasing total ionizing dose, before starting to increase again at a specific dose. We assume that this decrease is caused by the effect of acceptor removal. Another noteworthy observation of this study is that the IV and CV measurements of the gamma irradiated diodes do not reveal any annealing effect.

Studies of chemical bonds loss and optical modifications of CR-39 caused by gamma rays

The induced impacts of high doses of gamma irradiation on the structural variations of poly-allyl-diglycol carbonate (PADC) polymers (CR-39) were studied in terms of X-ray diffraction (XRD) patterns. CR-39 samples were irradiated separately at different ranging from 200 to 800 kGy; (step 200). A deconvolution process of the XRD spectra of CR-39 samples for all gamma irradiation doses was performed. The results of this deconvolution process for the pristine specimen show three diffraction peaks at about 20.30°, 28.16° and 41.70° of 2θ. The broad peaks at 28.16o and 41.70°, and the highest peak at 20.30° of XRD confirm the amorphous nature and low degrees of crystallinity, respectively. The position, area, intensity and full width at half maximum of these peaks are changed with further doses of gamma irradiation. With additional gamma irradiations, the intensities of all peaks decrease significantly. The highest and sharpest peak properties are employed to determine the crystallinity, crystallite size, and radiation chemical yield (G-value) for the loss of carbonate ester bonds using a proposed method. Higher doses of gamma irradiation result in a decrease in crystallinity while increasing crystallite size. Furthermore, the optical band gaps reduced from 4.81 to 3.49 eV when the irradiated dose increased from 0 to 800 kGy. Furthermore, the third order nonlinear susceptibility increased from 0.84x10−12 esu to 2.25x10−12 esu with increasing the radiation doses from 0 to 800 kGy. Moreover, the nonlinear refractive increased from 1.52x10−11 to 3.69x10−11 with increasing the radiation doses from 0 to 800 kGy. On the other hand, the number of carbon atoms in each cluster increased from 51 to 97 when the irradiated dose increased from 0 kGy to 800 kGy.

Gamma Irradiation Doses reduce Cooking time and Improve Nutritional Profile of selected Pigeon pea [Cajanus cajan (L.) Millsp] Genotypes in Nigeria

Pigeon Pea (Cajanus cajan L.) is a self-pollinating perennial legume shrub with over 30,000 accessions deposited world-wide. Despite the nutritional importance of pigeon peas, its detrimental traits such as its long cooking time, has led to low cultivation of the crop and inhibit its consumers’ request. Concerted efforts to improve both the quality and quantity of this crop through mutation breeding informed this research. It was based on this premise that the study was aimed to evaluate gamma irradiation influences on the nutrient quality and cooking duration of selected pigeon pea varieties in Nigeria. Four accessions of pigeon peas (‘NG/SA/11/08/108’, ‘NG/AO/MAY/00/021/01’, ‘TCC-2’ and ‘NG/SA/07/191’) were obtained from National Centre for Genetic Resources and Biotechnology (NACGRAB), Ibadan. They were irradiated at the Oncological Department ABU Teaching Hospital, Shika, Zaria, using Cobalt-60 (60CO) irradiation source. Standard procedures were followed to determine the effects of the irradiation on cookability and nutritional profile of the M1 plants and their respective controls. It was established that all the parameters tested were irradiation dose dependent. In NG/AO/MAY/00/021/01, 100 Gy produced the highest protein (20.40 %) and highest carbohydrate (68.93 %) contents. Anti-nutritional factors such as cyanide were lower (48.83, 46.22, 43.65 and 44.75 mg/kg in NG/AO/MAY/00/021/01, NG/SA/11/08/108, NG/SA/07/191 and TCC-2) at 400 Gy than those of their respective controls (54.83, 56.83, 53. and 53.55 mg/kg). The amount of Magnesium increased with higher doses of gamma irradiation (1.37 g/100 g for 200 Gy NG/AO/MAY/00/021/01; 1.03 g/100g for 400 Gy NG/SA/11/08/108 and 1.13 g/100 g for TCC-2). There were significant reductions in cooking time in 400 Gy treatments for all the genotypes. The differences between the control and the least cooking time in 400 Gy were 11, 16, 22 and 15 minutes for NG/AO/MAY/00/021/01, NG/SA/11/08/108, NG/SA/07/191 and TCC-2, respectively. It was therefore concluded that these variations could be exploited for further improvement of the crop for food security. Keywords: Cooking time, Mutation breeding, Gamma irradiation, Cookability, Dose dependent

Impact of the gamma and electron beam irradiations on yeast-spot disease fungal agent and physicochemical attributes of hazelnut (Corylus avellana L.)

In this study, the effects of gamma irradiation (GMI) and electron beam irradiation (EBI) on the yeast spot fungus Eremothecium coryli isolated from hazelnuts and the physicochemical features of irradiated hazelnut samples were evaluated. Results demonstrated that GMI doses ≥2 and EBI doses ≥4 effectively removed E. coryli from artificially contaminated hazelnuts and reduced the contamination by 5 log CFU/g. GMI and EBI at higher doses resulted in an increment in malondialdehyde content (MDA) and a change in the profile of fatty acids. Both treatments caused an enhancement in total phenolic content (TPC) and antioxidant activity in the DPPH assay but declined antioxidant activity in the ABTS assay at a dose of 6 kGy. L*, a*, and b* color indices were changed, and the surface color of the hazelnuts became darker. Total protein solubility (TSP) and protein profile of the samples were affected by GMI and EBI. Higher doses of GMI and EBI reduced the hardness of the hazelnuts and led to a more fragile texture. The overall acceptability of the samples was adversely affected by GMI, but it was not affected by EBI treatment. Hence, GMI (≥2 kGy) and EBI (≥4 kGy) have the potential to be applied as a fungal disinfection method; lower doses (≥2 kGy) of both treatments can sustain desirable physicochemical attributes and sensory characteristics of hazelnuts.

Changes in physicochemical characteristics of cation exchange resins by high dose gamma irradiation

Chemical and thermal characteristics of cation exchange resins were examined after irradiation of gamma rays. The degradation of cation exchange resins was mainly observed at doses of up to 500 kGy, whereas the balance between degradation and cross-linking reactions was sustained at 700 kGy. While the carbon content decreased significantly up to a maximum dose of 500 kGy, it showed an increase at higher doses. Conversely, the oxygen content exhibited a decrease in contrast to the carbon content. The continuous reduction in sulfur content was attributed to the decomposition of sulfonic groups. Gamma-ray irradiation caused a decrease in the initiation temperature of sulfonic groups and PS-DVB, but unlike the chemical properties of cation exchange resins due to gamma-ray irradiation, the thermal properties of resins remained unaffected.

Low-Dose Ionizing Radiation-Crosslinking Immunoprecipitation (LDIR-CLIP) Identified Irradiation-Sensitive RNAs for RNA-Binding Protein HuR-Mediated Decay.

Although ionizing radiation (IR) is widely used for therapeutic and research purposes, studies on low-dose ionizing radiation (LDIR) are limited compared with those on other IR approaches, such as high-dose gamma irradiation and ultraviolet irradiation. High-dose IR affects DNA damage response and nucleotide-protein crosslinking, among other processes; however, the molecular consequences of LDIR have been poorly investigated. Here, we developed a method to profile RNA species crosslinked to an RNA-binding protein, namely, human antigen R (HuR), using LDIR and high-throughput RNA sequencing. The RNA fragments isolated via LDIR-crosslinking and immunoprecipitation sequencing were crosslinked to HuR and protected from RNase-mediated digestion. Upon crosslinking HuR to target mRNAs such as PAX6, ZFP91, NR2F6, and CAND2, the transcripts degraded rapidly in human cell lines. Additionally, PAX6 and NR2F6 downregulation mediated the beneficial effects of LDIR on cell viability. Thus, our approach provides a method for investigating post-transcriptional gene regulation using LDIR.

High-Dose Ionizing Radiation Impairs Healthy Dendrite Growth in C. elegans

PurposeThe nervous system is vulnerable to radiation damage, and further optimization is required to increase the efficacy of radiotherapy while reducing harm to neurons. Given recent developments in heavy ion therapy, experimental models would be valuable to improve these therapies. Here, we utilized the nematode Caenorhabditis elegans (C. elegans) to evaluate the effects of high-dose radiation on neuron development. Methods and MaterialsIn this study, we used confocal microscopy to assess dendritic growth of the PVD nociceptor following high-dose gamma-irradiation from a Cs-137 source. ResultsIrradiation during an early larval stage (L2) delayed overall development but also independently impaired dendrite outgrowth in the PVD nociceptive neuron. Irradiation at L4 larval stage did not result in significant alterations in dendrite morphology. ConclusionsThe nematode C. elegans can serve as a high-throughput model to study the effects of high-dose radiation on dendrite growth. We propose that C. elegans can be useful for studies of experimental radiation therapy modalities and dose rates for translational research.

A human lung alveolus-on-a-chip model of acute radiation-induced lung injury

Acute exposure to high-dose gamma radiation due to radiological disasters or cancer radiotherapy can result in radiation-induced lung injury (RILI), characterized by acute pneumonitis and subsequent lung fibrosis. A microfluidic organ-on-a-chip lined by human lung alveolar epithelium interfaced with pulmonary endothelium (Lung Alveolus Chip) is used to model acute RILI in vitro. Both lung epithelium and endothelium exhibit DNA damage, cellular hypertrophy, upregulation of inflammatory cytokines, and loss of barrier function within 6 h of radiation exposure, although greater damage is observed in the endothelium. The radiation dose sensitivity observed on-chip is more like the human lung than animal preclinical models. The Alveolus Chip is also used to evaluate the potential ability of two drugs - lovastatin and prednisolone - to suppress the effects of acute RILI. These data demonstrate that the Lung Alveolus Chip provides a human relevant alternative for studying the molecular basis of acute RILI and may be useful for evaluation of new radiation countermeasure therapeutics.

Synergistic effect of Gamma-Irradiation on morphological, structural, and optical properties of Carbon-coated Nickel Cobalt Oxide/rGO nanocomposites

Radiation exposure induces defects in the crystal structure, leading to alterations in the structural, optical, and morphological properties of metal oxides. These irradiated metal oxides have found extensive use in various household applications. In this particular investigation, carbon-coated nickel cobalt oxide/rGO nanocomposites were synthesized through ultrasonication. Subsequently, these nanocomposites were subjected to three different doses of gamma radiation using a 60Co source. Both un-irradiated and irradiated samples were subjected to characterization using FTIR, SEM, XRD, and UV-Vis spectroscopy. The FTIR analysis confirmed the presence of a spinel-type structure in NiCo2O4. SEM analysis revealed the presence of crumbled sheets of rGO, and the irradiation process caused a transformation of these stacked sheets into thinner sheets. XRD analysis indicated a decrease in crystalline size and an increase in dislocation density with higher doses of gamma irradiation. UV-Vis spectroscopy demonstrated a reduction in both direct and indirect optical band gaps as a result of gamma irradiation. Furthermore, it was observed that Urbach energy and refractive index increased with gamma irradiation. Based on these findings, it can be concluded that gamma irradiation has a significant impact on the morphological, structural, and optical properties of NiCo2O4/rGO@C nanocomposites.

Transcriptomic and genomic effects of gamma-radiation exposure on strains of the black yeast Exophiala dermatitidis evolved to display increased ionizing radiation resistance.

Ionizing radiation poses a significant threat to living organisms and human health, given its destructive nature and widespread use in fields such as medicine and the potential for nuclear disasters. Melanized fungi exhibit remarkable survival capabilities, enduring doses up to 1,000-fold higher than mammals. Through adaptive laboratory evolution, we validated the protective role of constitutive upregulation of DNA repair genes in the black yeast Exophiala dermatitidis, enhancing survival after radiation exposure. Surprisingly, we found that evolved strains lacking melanin still achieved high levels of radioresistance. Our study unveiled the significance of robust activation and enhancement of redox homeostasis, as evidenced by the profound transcriptional changes and increased accumulation of mutations, in substantially improving ionizing radiation resistance in the absence of melanin. These findings underscore the delicate balance between DNA repair and redox homeostasis for an organism's ability to endure and recover from radiation exposure.

Gamma irradiation synthesis and modification of palladium supported on graphene oxide as oxygen reduction reaction electrocatalyst

This work aims to investigate the preparation of palladium (Pd) particles on graphene oxide (GO) support via gamma radiolysis and to study their electrochemical activity towards the oxygen reduction reaction (ORR). The results show that the Pd precursor concentration used in the preparation process influences the loading, size, and distribution of the Pd particles. The electrochemical analysis shows that the Pd/GO samples synthesized through gamma radiolysis exhibit excellent activity toward ORR. Additionally, the gamma irradiation used in the synthesis process shows beneficial effects on the Pd/GO. High gamma irradiation doses increase the electron transfer number and reduce the peroxide yield of the Pd/GO.

High Dose Gamma Radiation Induced Modifications in Chemical, Electrical and Morphological Properties of PES Polymer

High Dose Gamma Radiation Induced Modifications in Chemical, Electrical and Morphological Properties of PES Polymer

Fourier Transform IR Spectroscopic Study of the Influence of a High Dose of Gamma Radiation on the Composition of Functional Groups in Potato Tubers

Fourier Transform IR Spectroscopic Study of the Influence of a High Dose of Gamma Radiation on the Composition of Functional Groups in Potato Tubers

Novel polyvinyl alcohol film dosimeter containing 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye for high dose application

A new dyed polyvinyl alcohol (PVA) film dosimeter based on 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MMT) tetrazolium dye is proposed in this study for measuring high gamma radiation dose. Gamma cell irradiator that contains Co-60 gamma-ray source was used to expose the novel MMT-PVA films to different doses up to 25 kGy. The changed in optical property of irradiated and unirradiated films were characterized by UV–Vis spectrophotometer. The results show that the dose sensitive and the linear range of irradiated films were increased considerably with increase of MMT concentration from 1 to 5 mM. The dose response of dyed PVA film changed substantially with changing relative humidity (12–74%) as well as irradiation temperature (10–40 °C). The absorbance of the un-irradiated films does not change up to 10 days in dark while a significant increase in their absorbance was reported for similar films under fluorescent light. The irradiated dosimeters that kept in dark showed a perfect stability for 54 days. It was found that no obvious impact of dose rate on the irradiated MMT-PVA film dosimeters.

Fourier Transform IR Spectroscopic Study of the Influence of a High Dose of Gamma Radiation on the Composition of Functional Groups in Potato Tubers

This article considers physicochemical changes in the composition of potato tubers gamma-irradiated to doses of 5000 kGy, as studied by Fourier transform IR spectroscopy. Functional groups in the powders of skin, pulp, and juice of irradiated tubers have been examined. The carbonization and radiationinduced oxidation of the molecules of tuber constituents have been established. At doses above 1000 kGy, the hardness of tubers was completely lost, the integrity of the skin surface was violated, and an intense release ofjuice began. It has been found that γ-radiolysis at a dose to 5000 kGy does not lead to the complete destruction of chemical bonds in the structure of the main compounds contained in potato tubers.