Different Doses Of Γ-irradiation Research Articles

Effects of Gamma Irradiation on Polyethylene Terephthalate and Detection of Microplastic Particles Down to 1 μm.

In response to increasing concern about the impact of plastic degradation on the environment, this study investigates the degradation of virgin and recycled polyethylene terephthalate (PET) under γ-irradiation in aqueous solutions, with particular focus on the resulting formation of microplastic particles (MP). By exposing both virgin and recycled PET samples to different doses of γ-irradiation (10, 50, and 100 kGy), a comprehensive analysis using UV-vis spectroscopy, dynamic light scattering (DLS) and micro-Raman spectroscopy is presented. The results, highlighted by micro-Raman spectroscopy, show that γ-irradiation produces micrometer-sized plastic particles, with the recycled PET having a significantly higher MP content than its original counterpart. Careful examination reveals the presence of a stabilizer in samples of recycled PET juice bottles. This study not only contributes to our understanding of the effects of γ-irradiation on PET but also highlights the need for further research into the environmental impact of such processes. The insights gained shed light on the behavior of PET under γ-irradiation and the resulting impact on microplastic pollution and make an important contribution to our understanding of the broader environmental context.

Enhancing the potential of rapeseed cake as protein-source food by γ-irradiation.

Rapeseed cake serves as a by-product in the oil extraction industry, characterized by its elevated protein content. However, the presence of antinutritional factors limits the utilization of rapeseed cake as a viable protein source. In this study, different doses of γ-irradiation were used to irradiate rapeseed cake and rapeseed protein isolate was extracted through a modified alkaline solution and acid precipitation method from rapeseed cake. The chemical composition and in vivo acute toxicity of rapeseed protein isolate were determined. The protein recovery rate of rapeseed protein isolate was 39.08 ± 3.01% after irradiation, while the content of antinutritional factors was significantly reduced. Moreover, γ-irradiation did not have any experimentally related effects on clinical observations or clinicopathology in mice. Overall, the reduced antinutrients and increased functional properties suggest that the irradiation of rapeseed cake (<9 kGy) could be utilized as a pre-treatment in the development of rapeseed cake-based value-added protein products.

Preparation and study of the main dosimetric properties by TL of sintered lithium silicate pellets

This work presents the structural characteristics and the dosimetric properties under ionizing radiation of the lithium silicate (LSO) (LSO) phosphor. The structure of the synthesized material was determined by X-ray diffraction (XRD) method and Rietveld refinement method. The dosimetric properties of LSOLSO in the form of pellets were studied by thermoluminescence (TL) under the effect of different doses of γ-irradiation. The phosphor exhibited a TL emission curve with four TL peaks centered at 100, 182, 250 and 290 °C, with a light emission band centered at 385 nm. The TL dose-dependent γ-radiation dose response of the TL peak at 182 °C was linear in the low-dose region, from the order of mGy to 50 Gy. In addition, the phosphor exhibits lower fading, good reproducibility, and sensitivity of the order of commercial TLD-100 dosimeters.

Enhanced Immunogenicity of a Whole-Inactivated Influenza A Virus Vaccine Using Optimised Irradiation Conditions.

Influenza A virus presents a constant pandemic threat due to the mutagenic nature of the virus and the inadequacy of current vaccines to protect against emerging strains. We have developed a whole-inactivated influenza vaccine using γ-irradiation (γ-Flu) that can protect against both vaccine-included strains as well as emerging pandemic strains. γ-irradiation is a widely used inactivation method and several γ-irradiated vaccines are currently in clinical or pre-clinical testing. To enhance vaccine efficacy, irradiation conditions should be carefully considered, particularly irradiation temperature. Specifically, while more damage to virus structure is expected when using higher irradiation temperatures, reduced radiation doses will be required to achieve sterility. In this study, we compared immunogenicity of γ-Flu irradiated at room temperature, chilled on ice or frozen on dry ice using different doses of γ-irradiation to meet internationally accepted sterility assurance levels. We found that, when irradiating at sterilising doses, the structural integrity and vaccine efficacy were well maintained in all preparations regardless of irradiation temperature. In fact, using a higher temperature and lower radiation dose appeared to induce higher neutralising antibody responses and more effective cytotoxic T cell responses. This outcome is expected to simplify irradiation protocols for manufacturing of highly effective irradiated vaccines.

Microemulsion‐based biopreservatives and γ‐irradiation as combined treatments to provide healthy and safe orange juice

Radiosensitization of Aspergillus niger, Penicillium chrysogenum, and Saccharomyces cerevisiae was investigated in orange juice containing plant oil (lemongrass and oregano)/citrus extracts-loaded microemulsion or coarse emulsion treated with different doses of γ-irradiation. D10 value (kGy) (γ-irradiation dose required to eliminate 90% of fungal population) of targeted fungi in presence of microemulsion in compared to control and coarse emulsion was evaluated in orange juice as food model. Microemulsion resulted in 1.55, 2.33 and 2.10 times increment in relative fungal radio-sensitivity (RS) for A. niger, P. chrysogenum and S. cerevisiae, respectively, in compared to control sample without antifungal formulation. Furthermore, in situ challenge tests against pathogenic fungi were performed during 35 days of storage at 4°C. Results demonstrated synergistic antifungal activity between the plant oil/citrus extracts-loaded microemulsion and γ-irradiation (1 kGy) by enhancing the RS of fungi and completely eradicating the molds growth and yeasts in orange juice. Practical applications This study strongly evidenced that combined treatment of γ-irradiation with natural plant extracts-loaded microemulsion can be a remarkable alternative to synthetic preservatives while providing healthy, safe, and tasty foods with high added-values and consumer acceptability.

Possible ameliorative effect of aqueous extract of date (Phoenix dactylifera) pits in rats exposed to gamma radiation

Purpose: To evaluate the radioprotective efficacy of date (Phoenix dactylifera) pits extract (DPE) against γ-irradiation-induced liver damage in the male albino rats. For this study, 30-day survival, dose reduction factor (DRF), antioxidant status and some biochemical changes in the serum and hepatic tissue were evaluated.Materials and methods: To calculate 30-day survival, median lethal dose of 30 days (LD50/30) and DRF, DPE was orally administered to rats for 21 days before irradiation with different doses (5, 6, 8, 10 and 12 Gy) of γ-rays and the rats were observed for 30 days post-irradiation. To evaluate the radioprotective efficacy of DPE against γ-irradiation induced-liver tissue damage, animals were divided into four groups (eight animals in each group). (i) Control: rats not subjected to any treatment; (ii) DPE: DPE was orally administrated (1000 mg/kg body weight) for 21 days; (iii) RAD: rats’ whole body exposed to 5 Gy of γ-rays; (iv) DPE + RAD: rats received DPE treatment for 21 days before γ-irradiation. Animals were sacrificed on the seventh day postexposure to radiation.Results: The results showed that pretreatment prior to irradiation with DPE resulted in a significantly higher 30-day survival rate of rats after exposure to different doses of γ-irradiation. Furthermore, DPE treatment resulted in a significant improvement in the hepatic redox state, manifested by a marked increase of superoxide dismutase (SOD) and catalase (CAT) activities and glutathione content associated with a significant decrease of malondialdehyde (MDA) level. In addition, DPE exhibited hepatoprotective effect evidenced by a marked increase in serum levels of insulin, testosterone, high-density lipoprotein-cholesterol (HDL-c) and hepatic glucose 6 phosphate dehydrogenase (G6PHD) activity associated with a significant decrease in serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-glutamyl transferase (γ-GT), glucose, total cholesterol (TC), triglycerides (TG), low density-lipoprotein cholesterol (LDL-c) and hepatic glucose 6 phosphatase (G6Pase) activity, compared with irradiated group. Moreover, DPE showed positive modulation in the levels of hepatic metals [(iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn)].Conclusions: DPE treatment prior to gamma irradiation produced biochemical changes that could lead to a reduction in radiation-induced oxidative stress. Hence, we suggest that DPE may be useful as a new natural radioprotective agent.

Study on the Effect of γ-Irradiation on Gadolinium Oxysulfide Nanophosphors (Gd2O2S-NPs)

Gadolinium oxysulfide nanophosphors (Gd2O2S-NPs) have been successfully synthesized using γ-irradiation and hydrogenation treatment. The primary stage of Gd2O2S-NPs synthesis was carried out using various doses of γ-irradiation to form diverse sizes of Gd2(SO4)3 precursor, followed by hydrogenation treatment at 900°C for 2 hours to form Gd2O2S-NPs. Then, the nanophosphors were characterized for the structure, morphology, and luminescence properties through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and photoluminescence spectrometer (PL). Pure hexagonal phase of Gd2O2S-NPs was obtained with high crystallinity and without any impurities. The morphologies were observed from grain-like nanostructures transformed to spherical shape as the irradiation dose reached 40 kGy. Besides, Gd2O2S-NPs which were prepared at highest irradiation dose of 40 kGy show highest intensity of emission peak at 548 nm and corresponded to Stark level transition from the GJ6 state of Gd3+ ion. It can be emphasized that the different doses of γ-irradiation influenced the nucleation event of Gd2(SO4)3 precursor thus affecting the morphology and size particles of Gd2O2S-NPs. Hence, from the results, it can be suggested that Gd2O2S-NPs can be a promising host for optical applications.

Moisture-mediated effects of γ-irradiation on antioxidant properties of mung bean ( Vigna radiate L.) cultivars

Abstract The present investigation is the very first report about the effect of γ-irradiation along with moisture on antioxidant properties of mung bean. Mung bean cultivars were conditioned to moisture level of 10 (control), 12, and 14% and treated with different doses of γ-irradiation (1.0, 2.5, and 5.0 kGy). The total phenolic content (TPC) decreased upon very low (1 kGy) and low dose (2.5 kGy) of γ-irradiation while significantly increased upon further increase in dose (5 kGy) at 10% moisture. However, γ-irradiation (1 and 2.5 kGy) at 12% moisture increased the TPC by 8 and 9%, respectively, and at 5 kGy dose lowered by 15% as compared to control. Antioxidant activity (AOA) was decreased by 10% (1 kGy and 10% moisture) and increased by 13% (5 kGy and 10%) while significantly increased at all doses (at 12%) by 106%. Total flavonoids content and reducing power also affected significantly upon γ-irradiation at various moisture. Industrial relevance The present investigation is the first report revealing the impacts of moisture-mediated γ-irradiation of mung bean. Since γ-irradiation is a popular method for safe storage of food including legumes and cereals, the moisture content between 10 and 14% was considered safe for grain storage. But γ-irradiation of mung bean at these levels of moisture significantly changed the antioxidant potential. By selecting suitable moisture content and dose of γ-irradiation, the antioxidant potential of mung bean may be improved to get the maximum health benefit. Therefore, the legume processing industry can utilize these combinations (moisture and dose of irradiation) to improve the antioxidant properties of mung bean.

Cellular response of blood and hepatic tissue to gamma irradiation

BackgroundGamma radiation produces numerous biological perturbations in cells by direct ionization of DNA and cellular targets and by indirect effect through damage by free radical production. AimTo study the cellular response of blood and hepatic tissue to different doses of γ-irradiation. ResultsAlthough relative viscosity and conductivity of hemoglobin were significantly elevated in rats exposed to a single dose of 2 Gy, these elevations were statistically non significant in irradiated rats exposed to 4 and 6 Gy as compared to control animals. Serum levels of pro-inflammatory cytokines were significantly elevated in addition to up-regulation of hepatic NF-кB and down-regulation of p53 and p21 in irradiated groups. ConclusionElevated levels of hepatic NF-κB mRNA and low levels of p53 mRNA prove lack of apoptosis and induction of the inflammatory pathway in hepatic cells to face the harmful effects of the present γ-irradiated model.

Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy

Herein, the ability of gamma irradiation to enhance the photoluminescence properties of graphene quantum dots (GQDs) was investigated. Different doses of γ-irradiation were used on GQDs to examine the way in which their structure and optical properties can be affected. The photoluminescence quantum yield was increased six times for the GQDs irradiated with high doses compared to the nonirradiated material. Both photoluminescence lifetime and values of optical band gap were increased with the dose of applied gamma irradiation. In addition, the exploitation of the gamma-irradiated GQDs as photosensitizers was examined by monitoring the production of singlet oxygen under UV illumination. The main outcome was that the GQDs irradiated at lower doses act as better photoproducers than the ones irradiated at higher doses. These results corroborate that the structural changes caused by gamma irradiation have a direct impact on GQD ability to produce singlet oxygen and their photostability under prolonged UV illumination. This makes low-dose irradiated GQDs promising candidates for photodynamic therapy.

Gamma-ray irradiation effects on the optical properties of KHSeO4 single crystals

Potassium hydrogenselenate KHSeO4 single crystals were successfully grown by the solution growth technique. The structure of the grown crystals was confirmed by XRD diffraction spectrum to be the structure of the desired KHSeO4 single crystal. The crystals were irradiated by different doses of γ-irradiation in the range 0.4–2.4 kGy and the optical absorption spectra were recorded along the a-, b- and c-axes. The optical inter-band transitions were of the indirect allowed ones and the optical energy gap Eg was determined along the three crystallographic directions. The effect of the irradiation on the optical energy gap is reported along the principle crystallographic directions. Urbach rule suggested the formation of Urbach tail and the effect of irradiation on this band tail is reported. These observations are attributed to the radiation-induced defects on the bulk crystal.

Synthesis, characterization, DC-electrical conductivity and γ-ray effect on Ag1+, Y3+ double doped nano lithium manganates (LiMn2−2x AgxYxO4) for rechargeable batteries

Abstract Pristine lithium manganate (LiMn2O4) and Ag1+, Y3+ double doped nano lithium manganate [LiMn2−2x AgxYxO4, (x = 0.025, 0.05)] spinels were synthesized via a coprecipitation method for rechargeable batteries applications. The synthesized LiMn1.9Ag0.05Y0.05O4 was exposed to different doses of γ-irradiation (10 and 30 kGy). The resulting spinel products were characterized by using thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), electronic (UV-Vis) and electron spin resonance (ESR) spectra. LiMn2O4 exhibited a discharge capacity of 124 mAhg−1 while LiMn1.9Ag0.05Y0.05O4 had discharge capacities of 129 and 137 mAhg−1 for non irradiated and γ-irradiated (30 kGy) samples, respectively. The effects of the dopant cations and γ-irradiation on the discharge capacity and DC-electrical conductivity of some synthesized spinels were studied.

Inhibition of Polo-Like Kinase 1 Induces Cell Cycle Arrest and Sensitizes Glioblastoma Cells to Ionizing Radiation

Despite efforts to improve surgical, radiologic, and chemotherapeutic strategies, the outcome of patients with glioblastoma (GBM) is still poor. Polo-like kinase 1 (PLK1) is a serine/threonine kinase that plays key roles in cell cycle control and has been associated with tumor growth and prognosis. Here, we aimed at testing the radiosensitizing effects of the PLK1 inhibitor BI 2536 on eight GBM cell lines. For cell cycle analysis, T98G, U251, U343 MG-a, LN319, SF188, U138 MG, and U87 MG cell lines were treated with 10, 50, or 100 nM of BI 2536 for 24 hours. In addition, cell cultures exposed to BI 2536 50 nM for 24 hours were irradiated with γ-rays from (60)Cobalt source at final doses of 2, 4, and 6 Gy. Combinatorial effects were evaluated through proliferation and clonogenic capacity assays. Treatment with BI 2536 caused mitotic arrest after 24 hours, and increased apoptosis in GBM cells. Moreover, our results demonstrate that pretreatment with this drug sensitized six out of seven GBM cell lines to different doses of γ-irradiation as shown by decreased growth and abrogation of colony-formation capacity. Our data suggest that PLK1 blockage has a radiosensitizing effect on GBM, which could improve treatment strategies for this devastating tumor.

The extent of paternal sperm DNA damage influences early post-natal survival of first generation mouse offspring

To study the post-natal characteristics and the survival of offspring derived from DNA damaged sperm. This experimental prospective study was conducted on Swiss Albino mice (Mus musculus). Sperm DNA damage was induced by different doses of γ-irradiation in male mice who were then mated with healthy female mice. The post-natal characteristics including the survival of first generation offspring were studied and then correlated with the amount of paternal sperm DNA damage. A significant reduction of survival in the early post-natal period was observed in the first generation offspring derived from the DNA damaged sperm, and a strong association was observed between the extent of sperm DNA damage and the survival of the offspring. The DNA damage load in sperm at the time of fertilization influences early post-natal survival of the mouse offspring.

EFFECT OF γ-IRRADIATION ON THE PHYSICOCHEMICAL PROPERTIES, AND MICROBIAL AND SENSORY QUALITIES OF COLD-STORED ONION PUREE

The present study was conducted to evaluate the effect of different doses (0, 1, 2, 3, 5 and 7 kGy) of γ-irradiation on the physicochemical properties (pH, titratable acidity, total soluble solid, color, organic acid content), and also the microbial and sensory qualities of onion puree during cold storage at 4C for 28 days. The different doses of γ-irradiation were found to not have any negative effect on titratable acidity, pH, total soluble solid and organic acid contents of onion puree immediately after irradiation and also during cold storage. Irradiation at 3 kGy and above was able to control the development of yeasts and molds in the onion puree, but had negative effects on the color and sensory quality of the onion puree. This study indicates that irradiation at 2 kGy reduced microbial counts with minimum adverse effects on color and sensory qualities.

Gamma-stimulated change of the photoluminescence properties of Cd1−xZnxTe thin films

The low-temperature photoluminescence properties of Cd0.9Zn0.1Te thin film grown on CdTe substrate were investigated in the connection with the dependencies on different doses of γ-irradiation. It was obtained that γ-irradiation leads to the substantial changes in the photoluminescence properties of the Cd0.9Zn0.1Te/CdTe system. At first, it induces the rise of the intensities of the near-band-edge photoluminescence emission lines at the doses lower than 50kGy due to the improving of the crystalline quality of the films. At high doses it leads to the decrease of the intensities of observed photoluminescence lines because of disordering of the crystalline structure. Secondly, γ-irradiation induces the redshift in the energy peak positions of all observed emission lines, which is caused by relaxation of the strain in the layers of Cd0.9Zn0.1Te film near CdTe substrate.

Proposal of an in vivo comet assay using haemocytes of Drosophila melanogaster

This study presents the first application of an in vivo alkaline comet assay using haemocytes of Drosophila melanogaster larvae. These cells, which play a role similar to that of mammalian blood, can be easily obtained and represent an overall exposure of the treated larvae. To validate the assay, we evaluated the response of these cells to three well-known mutagenic agents: ethyl methanesulfonate (EMS), potassium dichromate (PD), and gamma radiation (γ-irradiation). Third-instar Drosophila larvae were exposed to different concentrations of EMS (1, 2, and 4 mM) and PD (0.5, 1, and 2.5 mM) and to different doses of γ-irradiation (2, 4, and 8 Gγ). Subsequently, haemolymph was extracted from the larvae, and haemocytes were isolated by centrifugation and used in the comet assay. Haemocytes exhibited a significant dose-related increase in DNA damage, indicating that these cells are clearly sensitive to the treatments. These results suggest that the proposed in vivo comet test, using larvae haemocytes of D. melanogaster, may be a useful in vivo assay for genotoxicity assessment.

Transgenerational changes in somatic and germ line genetic integrity of first-generation offspring derived from the DNA damaged sperm

To report a more quantitative approach to study the influence of varying levels of sperm DNA damage on transgenerational changes in genomic instability in a mouse model. Experimental prospective study. Embryology research laboratory. Swiss albino mice. The sperm DNA damage was induced by different doses of gamma-irradiation to male mice followed by mating with healthy female mice. Genomic integrity in embryos, fetus, and spermatozoa of F1 mice derived from the DNA-damaged sperm. The transgenerational changes in genetic integrity were attributed by a dose-dependent increase in the frequency of micronuclei in preimplantation embryos and a concomitant increase in genomic instability in fetal liver cells and sperm chromatin modifications in F1 males. A strong positive correlation was observed between the extent of sperm DNA damage and somatic and germ-line genomic instability. Sperm-mediated transgenerational genomic instability is dependent on the amount of DNA damage present in the sire's sperm at the time of fertilization.

Influence of γ-irradiation on optical properties of manganese phthalocyanine thin films

The optical absorption of thermally evaporated MnPc thin film has been studied in the UV–vis region. The absorption spectra for the as-deposited and irradiated films showed two well-defined absorption bands of phthalocyanine molecule, namely the Q-band and Soret band (B). The optical properties of thermally evaporated manganese phthalocyanine thin films were characterized using spectrophotometric measurements of transmittance and reflectance at normal incidence of light in the wavelengths range 200–2500 nm. The refractive index ( n) and the absorption index ( k) were calculated. The effects of γ-irradiation on the optical properties were investigated for dosimetry applications. The values of the optical band gap E opt, the transport gap and the dispersion parameters for as-deposited and irradiated films with different doses of γ-irradiation were also estimated and discussed.

How does γ-irradiation influence the phase transition of α-NiMoO 4?

An attempt has been made to stabilize the high temperature β-NiMoO 4 phase which is catalytically more selective in oxidative dehydrogenation of alkanes at room temperature through irradiation by γ-rays. Different samples of stoichiomertic α-NiMoO 4 were subjected to different doses of γ-irradiation in the range of 50–500 kGy. The effect of γ-irradiation on the α- to β-NiMoO 4 transition temperature was studied using differential thermal analysis (DTA) technique with controlled rate of heating and cooling. The formation of β-NiMoO 4 phase was investigated by means of XRD and FT-IR techniques. The catalytic performance of the resulting catalyst samples in the oxidative dehydrogenation of cyclohexane at 500 °C was investigated. The DTA investigation revealed that γ-irradiation effectively lowers the temperature of the α → β transition in NiMoO 4 but did not affect the temperature of β-to-α return transition. A new peak characteristic of β-phase was detected at 2 θ = 26.3° in the XRD patterns of γ-irradiated samples. FT-IR analysis also confirmed the formation of β-NiMoO 4 where a new band characteristic of β-phase was observed at 879 cm −1 in the spectra of these samples. In view of the XRD results, the observed change in the α- to β-NiMoO 4 transition temperature was attributed to the fact that radiation induced a strain in the α-NiMoO 4 crystals. On the other hand, catalytic activity results indicated that γ-irradiated nickel molybdate catalysts showed a high selectivity towards cyclohexene at isoconversion (5%) in comparison with that of unirradiated parent α-NiMoO 4.