Effect Of Γ-irradiation Research Articles

Effect of γ-irradiation combined with enzymatic modification on the physicochemical properties of defatted rice bran dietary fiber

This study comprehensively examines how combining γ-irradiation and enzymatic modification influences the microstructure and physicochemical properties of dietary fiber (DF) obtained from defatted rice bran. The resulting yields of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were measured at 13.38 ± 0.40 g/100 g and 52.19 ± 0.97 g/100 g, respectively. The modifications led to a diminish in particle size, an increase in specific surface area, and an improvement in water-holding capacity, oil-holding capacity, swelling capacity, glucose adsorption capacity, and cholesterol adsorption capacity. Furthermore, the modified DF exhibited enhanced anti-digestive properties and probiotic activity. Cluster and principal component analysis results revealed that the modified SDF exhibited superior functional properties. Correlation analysis indicated a noticeable relationship between the monosaccharide composition of DF and its functional characteristics. These findings suggest that γ-irradiation combined with enzymatic modification represents a viable approach for enhancing the quality of rice bran DF.

Investigation of the Effects of Gamma Radiation and Y2O3 on the Elastic Properties of Al2024 Composites by Ultrasonic Method

In this study, the effect of Y2O3 contribution and γ-irradiation on the elastic properties of pure Al2024 and Al2024/Y2O3 composites was precisely investigated with the help of determined density and ultrasonic wave velocities. Ultrasonic longitudinal and shear wave velocity measurements of the samples were performed at room temperature using the ultrasonic pulse-echo method at 20 and 5 MHz frequencies, respectively. X-ray diffraction analysis and scanning electron microscopy examined the microstructural properties and phase characterizations of metal matrix composite (MMC) samples. A gamma cell type 60Co source was used to irradiate MMC samples in the air at room temperature. The absorbed dose rate was measured to be approximately 1.5 kGy/h, and the total delivered dose was 50 kGy. According to the findings obtained from the research, the contribution of Y2O3 to pure Al 2024 at 0.5, 1, and 5 wt.% ratios and exposure to gamma rays of 50 kGy caused a decrease in VL, L, K, and μ values and a significant increase in ρ, VS, G, HV, H, and E values. The highest Young’s modulus values compared with pure Al2024 were obtained in both unirradiated and irradiated Al2024/0.5Y2O3 composites.

Effect of γ-irradiation and antimicrobial agent on properties of poly(L-lactide) active films

Data on irradiation of poly(L-lactide) (PLLA) based active packaging is still limited. Therefore, effect of γ-irradiation on neat PLLA and active packaging with oligohexamethylene guanidine hydrochloride (OHMG·HCl) has been studied. Combined use of irradiation and active packaging technology is promising approach to maintain food safety and prolong shelf life. It has been found that regardless of the OHMG·HCl content PLLA undergoes chain scission during irradiation and this process becomes less pronounced at doses higher than 50 kGy. Slight racemization of PLLA during exposure has been observed using polarimetry and 13C NMR spectroscopy. Mechanical properties of films have been examined. Biocide addition led to a 30% decrease in films elongation at break. Irradiation either caused elongation decrease. Dose of 50 kGy and higher made PLLA active films brittle. Multiple melting behavior of irradiated PLLA has been analyzed by differential scanning calorimetry. Fraction of crystals with higher melting temperature rose with dose. Possible reason for this phenomenon is formation of α′ form with less ordered chain packaging that recrystallizes during heating. The biocide addition has not affected this process. Furthermore, in vitro antimicrobial test has shown efficacy of films with 2 wt.% of OHMG·HCl against gram-negative, gram-positive bacteria and fungi.

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.

Effect of gamma irradiation on the nutritional composition, phenolic compounds and fatty acids profiles in raw cocoa (Theobroma cacao L.) beans

AbstractThe γ-irradiation effects on nutritional composition, phenolic compounds and fatty acids profile of cocoa beans were investigated. Raw cocoa bean samples were irradiated using 60Co source at doses of 1.0, 3.0, 5.0, and 7.0 kGy. The examined nutrient contents were moisture, protein, ash and fat contents. A total of 10 phenolic compounds from the screening of 32 standards were identified and quantified by LC-MS/MS, with theobromine (2418.52–3506.95 µg/g) and epicatechin (444.24–1090.98 µg/g) being the most abundant. Overall, the irradiation treatment did not significantly influence the protein and moisture content of cocoa beans. On the other hand, 3 kGy irradiation dose led to a significant decrease in fat content of cocoa bean samples. Furthermore, fatty acid composition changed with increasing the irradiation dose. Gamma irradiation caused a significant increase in saturated fatty acids/unsaturated fatty acids ratio. On the whole, the analysis of phenolic compounds of cocoa beans showed that irradiation influence the phenolic compounds significantly, with a few exceptions. The quantities of epicatechin and luteolin 7 glucoside were higher in raw cocoa beans than in irradiated cocoa beans.

Gamma irradiation in modulating arsenic bioremediation potential of Pseudomonas sp. AK1 and AK9

Purpose Present study deals with the role of gamma irradiation in modulating arsenic bioremediation of Pseudomonas sp. AK1 and AK9 strains Materials and methods The bacterial strains AK1 and AK9 of Pseudomonas sp. were irradiated at different doses (5 Gy, 10 Gy, 15 Gy and 20 Gy) of gamma irradiation. The effect of γ-irradiation on the growth and arsenic modulating ability of AK1 and AK9 strains was determined in the presence and absence of arsenic along with non-irradiated strains. Further, a comparative study of non-irradiated and irradiated strains by protein profiling in absence and presence of arsenic was carried out to confirm of the increased expression ofarsenite oxidase. Results Both strains were able to transform AsIII to AsV. Both strains AK1 and AK9 decrease the arsenic concentration by 626.68 ppb (13.36%) and 686.40 ppb (14.71%) after an incubation period of 96 h in presence of arsenic. Gamma irradiated AK9 strains showed doubled growth in presence of arsenic as compared to non-irradiated strains at 10 Gy treatment whereas no changes in growth was observed in irradiated AK1 strains. Gamma irradiated AK9 strain decrease 378.65 ppb (7.27%) more arsenic concentration from natural water sample supplemented with AsIII than non-irradiated AK9 strain. Further, in the protein profile, increased expression of arsenite oxidase (∼85 kDa) was observed in irradiated AK9 strains in presence of arsenic. Conclusions Overall, the results suggested that the gamma irradiated AK9 strain having potential for arsenic accumulation and increased arsenite tolerance may play a great role in the bioremediation of the arsenite at arsenic contaminated sites.

Effects of γ-Irradiation and Sample Aging on the AC-Electrical Properties of Epoxy/ZnO/CB Hybrid Nanocomposites

The goal of this paper is to study the effects of gamma irradiation and samples’ aging on the AC-electrical properties of hybrid epoxy resin as a function of frequency, temperature, and (zinc oxide) ZnO content (0, 0.049, 0.099, 0.149, and 0.199 wt) at 0.001 wt of conductive (carbon black) CB nanoparticles. The irradiation processes were administered at room temperature in a gamma chamber utilizing a Cobalt 60 source of average energy = 1.25 MeV with doses = 100, 750, and 1000 Gy. The AC-electrical properties, including the impedance, dielectric constant, dielectric loss, conductivity, and activation energy of the nanocomposites, were initially studied after years of sample preparations. The collected empirical data were later analyzed before and after the gamma irradiation. The results showed that exposing samples to different doses of gamma radiation affects these AC-electrical properties significantly. It was found that the energy gap decreased as the dosage of gamma radiation increased. This could be explained as the gamma-irradiation processes induce changes in the structure of the epoxy hybrid nanocomposites by reinforcing the metal–polymer bonding and hence, causing the release of more free electrons inside the hybrid nanocomposites. Moreover, the sample aging results showed that the AC-electrical conductivity decreased with time for all samples. Hence, this study demonstrated why the γ-irradiation technique can be considered a powerful way to treat, recover, and/or enhance the electrical features of the tested epoxy hybrid nanocomposites.

Effect Of Thermal Treatments And γ-Irradiation On The Volatile, Phenolic acids, , and Antioxidant Activity of Egyptian Fennel Essential Oil.

Effect Of Thermal Treatments And γ-Irradiation On The Volatile, Phenolic acids, , and Antioxidant Activity of Egyptian Fennel Essential Oil.

Influence of γ–radiation input dose and post-radiation high temperature shear grinding on polypropylene functional group composition

The effect of γ-irradiation in vacuum and air followed by HTSG of polypropylene (PP) is studied using both infrared (IR) spectroscopy and computational chemistry at the correlated G3(MP2)B3 molecular orbital theory level. γ-irradiation of PP in vacuum was found to primarily induce unsaturation and hydroxyl formation from residual system water whereas γ-irradiation of PP in air oxidizes the polymer and degrades the backbone in a thin layer due to oxygen permeability limitations as supported by the computational thermodynamics results. HTSG of the irradiated PP produced smaller particles than un-irradiated PP. HTSG of the irradiated PP led to a decrease in the IR band intensity from degradation due to a nominal homogenization of the pellet. HTSG of air irradiated PP led to a reduction in IR vibrational band intensity from oxidation due to thermal degradation. High-temperature shear grinding of γ-irradiated PP produces variable chemical and physical composition depending on irradiation input dose and environmental conditions. The combination of γ-irradiation and HTSG may be of benefit in recycling polypropylene.

Effect of γ-Irradiation of Seeds on Intravariety Variability of the Quantitative Characters of Yellow Lupin

Effect of γ-Irradiation of Seeds on Intravariety Variability of the Quantitative Characters of Yellow Lupin

Combined effect of γ-irradiation and antibacterial formulations based on natural compounds for preservation of mother's milk

The antibacterial potential of citrus extract, EOs (mediterranean formulation, oregano, lemongrass, cinnamon and clove), organic acids and salts (citric acid, lactic acid and sodium carbonate) was evaluated against E. sakazakii, E. coli O157:H7, S. aureus, L. monocytogenes, S. Typhimurium, B. cereus by determining the minimal inhibitory concentration (MIC). Based on the results, MIC value ranges from 312.5 to 5000 ppm against tested bacterial strains, with citrus extract showing the highest antibacterial activity (312.5 ppm). Four antimicrobial formulations based on quaternary combination of compounds were developed based on the fractional inhibitory concentration (FIC) index. Formulation 1 (Oregano/Mediterranean formulation/Citrus extract/Lactic acid), Formulation 2 (Cinnamon/Lemongrass/Citrus extract/Citric acid), Formulation 3 (Oregano/Mediterranean formulation/Citrus extract/Citric acid), Formulation 4 (Cinnamon/Lemongrass/Citrus extract/Lactic acid) showed a synergistic effect against all tested pathogens. Results demonstrated that bacterial radiosensitivity (1.34–3.99) was increased by the combined treatment of γ-irradiation with developed formulations in frozen mother's milk. Formulation 3 and 4 induced greater radiosensitivity in bacterial strains including sporulated B. cereus (1.90 and 1.89 respectively) compared to formulation 1 and 2. Therefore, the combined treatment can be an effective method to reduce the γ-irradiation dose (kGy) required to eliminate the pathogens and assures the safety of frozen mother's milk.

Rheological Properties of Gel Systems Based on Gamma-Irradiated Lightly Crosslinked Polyacrylic Acid

The effect of γ-irradiation of the gelling agent Carbomer 141 G, which is lightly crosslinked polyacrylic acid, on the rheological properties of gels based on the carbomer has been studied. It has been found that an increase in the dose of γ-irradiation in air has a destructive effect on the polymer, leading to a decrease in rheological parameters, such as viscosity, yield strength, and hysteresis area. Irradiation of the carbomer in air with doses greater than 300 kGy leads to a significant decrease or the complete loss of its gel-forming properties. At the same time, irradiation of the carbomer with the same dose in vacuum causes as small a decline in viscosity as 2% compared to the initial systems. It has been established that the optimal gelling agent for obtaining stable antibacterial gels is the carbomer irradiated with a dose of 30 kGy.

The effect of γ-irradiation at a dose of 1 Gy on the adenylate- and guanylate cyclase systems of rat platelets at different times of the post-radiation period

Objective. To study the effect of total γ-irradiation of the organism of rats at a dose of 1 Gy on the adenylate- and guanylate cyclase systems and their relationship with Ca2+ levels in the platelet cytoplasm.Materials and methods. The studies were carried out on outbred white male rats of mature age (6-7 months) weighing 250±30 g. Animals were irradiated (once and evenly) on the IGUR unit with 137Сs γ-quanta at a dose of 1 Gy (dose rate 0.62 Gy/min, for 1.61 min). Animals of the corresponding age served as controls. To determine the content of cyclic nucleotides, RIO cAMP/cGMP-iodine125-M-IBOX reagent kits were used. The amount of calcium in platelets was determined using a Fura-2/AM fluorescent probe using spectrofluorimeter SM 2203 “SOLAR” (Minsk, Belarus).Results. In the short period after irradiation, an increase in the activity of the adenylate cyclase system is observed. The cAMP level rises 1.8-1.5 times during 3-30 days of the post-radiation period. However, the increase in [Ca2+]cyt on the 3rd day after irradiation leads to its predominance by 1.8 times in relation to cAMP, which explains the appearance of an increased aggregation activity of the blood platelets in the immediate post-radiation period. An increase in the activity of the guanylate cyclase system and an increase in the intracellular content of cGMP are observed on the 90th day, which leads to a decrease in the Ca2+/cGMP ratio by 1.83 times and corresponds to a reduced platelet aggregation activity and the probability of bleeding in the long term of the rehabilitation period.Conclusion. The effects of radiation on the platelets of rats irradiated at a dose of 1 Gy are due to systemic disorders of the main intracellular regulatory mechanisms: Ca2+, cAMP, cGMP. Based on the data obtained, it can be concluded that pharmacological correction in the short-term after irradiation should be aimed at inhibiting the effects of [Ca2+]cyt and adenylate cyclase system activity, and in the long-term, at inhibition of guanylate cyclase system activity.

Rhizochalinin Exhibits Anticancer Activity and Synergizes with EGFR Inhibitors in Glioblastoma In Vitro Models.

Rhizochalinin (Rhiz) is a recently discovered cytotoxic sphingolipid synthesized from the marine natural compound rhizochalin. Previously, Rhiz demonstrated high in vitro and in vivo efficacy in various cancer models. Here, we report Rhiz to be highly active in human glioblastoma cell lines as well as in patient-derived glioma-stem like neurosphere models. Rhiz counteracted glioblastoma cell proliferation by inducing apoptosis, G2/M-phase cell cycle arrest, and inhibition of autophagy. Proteomic profiling followed by bioinformatic analysis suggested suppression of the Akt pathway as one of the major biological effects of Rhiz. Suppression of Akt as well as IGF-1R and MEK1/2 kinase was confirmed in Rhiz-treated GBM cells. In addition, Rhiz pretreatment resulted in a more pronounced inhibitory effect of γ-irradiation on the growth of patient-derived glioma-spheres, an effect to which the Akt inhibition may also contribute decisively. In contrast, EGFR upregulation, observed in all GBM neurospheres under Rhiz treatment, was postulated to be a possible sign of incipient resistance. In line with this, combinational therapy with EGFR-targeted tyrosine kinase inhibitors synergistically increased the efficacy of Rhiz resulting in dramatic inhibition of GBM cell viability as well as a significant reduction of neurosphere size in the case of combination with lapatinib. Preliminary in vitro data generated using a parallel artificial membrane permeability (PAMPA) assay suggested that Rhiz cannot cross the blood brain barrier and therefore alternative drug delivery methods should be used in the further in vivo studies. In conclusion, Rhiz is a promising new candidate for the treatment of human glioblastoma, which should be further developed in combination with EGFR inhibitors.

Effect of gamma irradiation on total phenolic contents and antioxidant activities of methanolic extract of java plum seeds

<p>The synthetic antioxidant butylated hydroxyanisole (BHA) has been widely added to lipids and food products as a preservative due to inhibiting lipid oxidation. However, concerns have arisen about the potential health impacts of this synthetic antioxidant on consumers. Therefore, there is a need for an alternative substitute for BHA that is safe for human health. The methanolic extract of Java Plum seeds (MEJS) contains a diverse group of phenolic compounds and has the potential to serve as a natural antioxidant. The antioxidant must remain stable during food processing, such as irradiation. This research aimed to determine the effect of γ-irradiation on the total phenolic content and antioxidant activity of MEJS. When γ-irradiation was applied to MEJS at doses up to 12.5 kGy, there was a slight decrease in total phenolic and tannin content but a significant increase in total flavonoid content. This increase in total flavonoids led to a rise in both free radical scavenging and reducing power activities</p>

Optical properties of γ-sensing β-GaLaS3:Er crystal

An erbium-doped β-GaLaS3 crystal has been grown by the solution-melt method, and the effect of γ-irradiation on their vibrational and radiative properties has been investigated. Experiments have demonstrated that the crystal is transparent in the near and mid-infrared (IR) regions (transparency ∼62% in the range of 350–7100 cm−1), which allows it to be used as an effective matrix for creating lasers in this spectral range. For the first time, the vibrational spectrum of the crystal and the density of phonon states have been calculated using the density-functional theory (DFT) method. Both the original and γ-irradiated β-GaLaS3:Er crystals were investigated by Raman and IR spectroscopy. It has been established that irradiation with a dose of up to 5000 Gray does not lead to structural changes in the crystals. The effect of the formed defects is more clearly manifested in the IR reflection spectra, compared to the Raman spectra. The mechanism of the occurrence of excited states and the emission of Er ions embedded in the lattice has been established, and the effect of γ-irradiation on the radiative properties of β-GaLaS3:Er due to the occurrence of radiation-induced defects has been analyzed. A model has been constructed that explains the Stokes and anti-Stokes radiation of the erbium ions in the crystal. It has been demonstrated that the grown crystal has good prospects for sensor and laser technology of the near and mid-IR ranges due to relatively high values of optical transparency and the intense radiative capacity of the erbium ions.

Effect of γ-irradiation on the physicochemical and sensory properties of fresh walnut kernels (Juglans regia) during storage

The current study examined the total phenol content, antioxidant activity, sensory quality and fatty acid composition of fresh walnut kernels as a function of irradiation dose to determine dose levels that resulted in the least amount of undesirable changes to fresh walnut kernels at regular intervals of time. Fresh walnut kernels were exposed to 60Co radiation at doses of 0.5, 1.5, 3, 6, 8, and 10 kGy and stored at ± 4 °C for 28 days. Irradiation doses of 0.5 and 0.1 KGry have no significant effect on total phenol content (1.56±0.04–1.30±0.02mgGAE/g), antioxidant activity (95±0.02–85±0.01%), peroxide value (0.49±0.04–0.72±0.03%) and free fatty acid values (0.14±0.01–0.29±0.03%) respectively. However, irradiation doses of 1.0, 2.0, 3.0 and 4.0 resulted in increased peroxide values (0.89±0.02%, 0.98±0.01%, 1.05±0.01%, 1.17±0.03%), increased free fatty acid values(0.05±0.01%, 0.58±0.03%, 0.63±0.02±0.01%, 0.67±0.04%) and also the organoleptic quality were decreased (2.0 ± 0.01, 1.7 ± 0.03, 1.4 ± 0.02%, 1.2 ± 0.03%) during 28 days of storage. The use of gamma irradiation appears to be a promising technology for improving the chemical quality of fresh walnut kernels, but food safety concerns must be addressed before it can be recommended as a useful conservation alternative.

Effect of γ-Irradiation on the Semitransparent Gray Color Obsidian in the 5 to 500 kGy Range

Effect of γ-Irradiation on the Semitransparent Gray Color Obsidian in the 5 to 500 kGy Range

Physico-chemical properties of γ-irradiated International Simple Glass (ISG) nuclear waste simulants with low levels of iron impurities

The effect of γ-irradiation on physico-chemical properties of International Simple Glass (ISG) nuclear waste glass simulants with low iron impurities was investigated. The study was performed on glasses produced by Corning Inc. (named ISG-1, ISG-2) following a 0.95 MGy dose. Fourier-transform infrared and Raman spectroscopy, chemical durability tests, dilatometry, differential scanning calorimetry, electron paramagnetic resonance (EPR), optical absorption, and photoluminescence (PL) spectroscopy appraisals were done in comparison with pristine glasses. The data indicated that structural, chemical, and thermal properties were not significantly altered following γ-ray exposure. EPR spectroscopy showed radiogenic signatures from spin defects for the γ-irradiated glasses which were absent in the pristine. Optical absorption also changed significantly for the γ-irradiated glasses which exhibited defects-related features around 3.45 and 2.25 eV. The optical band gap and Urbach energies were then determined and compared with those obtained for the γ-irradiated original ISG produced by Mo-SCI Corporation. PL spectroscopy revealed distinct changes after irradiation showing enhanced high-energy emission, contrasting with the γ-irradiated original ISG. The effects of thermal treatment on optical properties of γ-irradiated glasses were finally evaluated. Potential causes at the origin of the contrasting results are discussed based on the effects of different impurities.

Investigation of the Effect of γ-Irradiation on the Optical Properties of Lithium Niobate by Optical Absorption and Raman Scattering Methods

The paper presents the results of studies of the effect of γ-irradiation on the photorefractive properties of lithium niobate (LiNbO3), using optical absorption and Raman spectroscopy of Raman scattering. It is shown that with γ-irradiation, the optical density of the lithium niobate crystal increases, i.e. the shift of the optical absorption edge towards long waves, with an increase in the irradiation dose, the refractive index increases, in the interval 1300 ÷ 1600 cm–1 with γ-irradiation at a frequency of 1375 cm–1, peaks appear due to centers of significant changes in Raman scattering frequencies.