Synergistic Effect Of Irradiation Research Articles

Establishment and Application of Novel Hypoxia-driven Dual-reporter Model to Investigate Hypoxic Impact on Radiation Sensitivity in Human Nasopharyngeal Carcinoma Xenografts

Establishment and Application of Novel Hypoxia-driven Dual-reporter Model to Investigate Hypoxic Impact on Radiation Sensitivity in Human Nasopharyngeal Carcinoma Xenografts

Radiation-induced amorphization behavior of thermally-aged M23C6 in F82H-BA12 steel

ABSTRACT To improve the understanding of the microstructural stability of F82H under fusion reactor environments, the synergistic effects of irradiation and thermal aging on the instability of M23C6 particle was investigated utilizing ion accelerator irradiation. Results show that the W-rich Laves phase growing along the grain boundaries was observed in the specimen after thermal aging at 773 K up to 10,000 hr. A bilayer contrast of the M23C6 particles consisting of an amorphous-rim and inner crystalline core was observed in the specimen irradiated by 10.5 MeV-Fe3+ at 623 K, but not in the specimen irradiated at 673 K, demonstrating that the critical temperature of the radiation-induced amorphization (RIA) in thermally aged M23C6 particles falls in the range of 623–673 K. These results show that thermal aging seems to play an insignificant role in the RIA behavior of M23C6 particles. Regarding the radial distribution function analysis, a relatively poor crystallinity was observed in the unirradiated thermally aged M23C6 particles, while the crystallinity was improved in the specimen irradiated at 673 K, which is ascribed to enhanced diffusion at elevated temperatures. Results indicate that the temperature-dependent point defect generation and recovery is the key factor related to the occurrence of RIA in M23C6 particles.

Effects of 60 Coγ irradiation on storage quality and physiology of fresh hazelnut fruits

During the storage process of hazelnut fresh fruits, browning is easy to occur, which reduces the storage quality. In this study, the method of 60Coγ irradiation was used to dynamically monitor the effects of fresh hazelnuts on storage quality, physiological indicators, and sterilization effect after being irradiated and refrigerated at 4 ± 0.5°C for 3 months. The results showed that irradiation at a dose of 0.25 to 1.0 kGy could preserve the current quality of the product, delay the browning of hazelnut shells, and reduce the activity of polyphenol oxidase. In addition, 0.5 kGy irradiation inhibited the respiration intensity and the accumulation of malondialdehyde in hazelnut fruits at the later stage of storage. Further research found that the content of microorganisms in hazelnut fruits decreased with the increase in irradiation dose. In addition, 0.5 kGy was the best irradiation dose to slow down the transpiration of hazelnut water and delay the reduction of fat, but the irradiation treatment of less than 1.0 kGy was effective for hazelnuts. Fruit peroxide value had no significant effect. At the same time, through the principal component analysis of hazelnut fruits stored for 90 days, the results also show that the 60Coγ irradiation with a dose of 0.5 kGy has the best storage effect and can effectively prolong the shelf life. The results of this study provide an effective theoretical basis and technical support for the preservation of fresh hazelnut fruits and the inhibition of the browning of hazelnut shells during storage. Novelty impact statement In this study, 60Coγ irradiation inhibited the polyphenol oxidase activity of polyphenol oxidase to a certain extent, thus delaying the browning of hazelnut shells. The synergistic effect of irradiation and low temperature prolonged the shelf life of hazelnut. The results showed that treatment with 0.5 kGy had the best effect, which was validated by the results of principal component analysis.

Synergistic effect of irradiation and molten salt corrosion: Acceleration or deceleration?

The effect of helium ion irradiation with low and high ion fluences on the corrosion behaviour of nickel-based alloys in FLiNaK molten salt at 700 °C was investigated. The microstructure and element distribution were characterized to explore the corrosion behaviour of matrix and grain boundaries. The results showed that irradiation accelerates matrix corrosion in both Inconel 617 and GH3535 alloys. Moreover, the irradiation decelerated and accelerated intergranular corrosion were respectively observed under irradiation with low and high helium ion fluence, which is caused by the combined effects of the self-healing mechanism and diffusion of interstitials and helium atoms.

Radiosensitization of rice weevil Sitophilus oryzae using combined treatments of essential oils and ionizing radiation with gamma-ray and X-Ray at different dose rates

Insect pests of stored products such as the rice weevil, Sitophilus oryzae can be controlled in bulk and packaged grains by ionizing radiation (γ-radiation or X-ray radiation) and plant essential oils, used in combination or alone, as an alternative to standard chemical fumigantion. Irradiation source and dose rate may be factors influencing the efficacy of plant essential oils. We evaluated the effects of γ-radiation at three dose rates (10.445, 4.558, and 0.085 kGy/h) and X-ray irradiation at two dose rates (0.76 and 0.19 kGy/h) in combination with Eucalyptus (Eucalyptus globules) or Tea tree (Melaleuca alternifolia) essential oil (EO) on the short-term mortality of S. oryzae. Adult weevils on rice in sealed Petri dishes were fumigated with 10 μL EO applied to a sponge then irradiated with a dose of 100, 250, 500, or 750 Gy. The combined treatment of Eucalyptus or Tea tree EOs with γ-irradiation or X-ray irradiation increased the mortality by 3–6 times as compared to irradiation treatment alone. The LD90 (predicted dose killing 90% of individuals) values for Eucalyptus EO plus γ-irradiation treated samples were 250.6, 252.8, and 522.4 Gy at dose rates of 10.445, 4.558, and 0.085 kGy/h, respectively, whereas the LD90 values for Tea tree EO plus γ-irradiation were similar (250.1, 255.07, and 574.3 Gy) when treated at dose rate of 10.445, 4.558, and 0.085 kGy/h dose rates, respectively. The lowest dose rate of γ-irradiation had the lowest efficacy in the combined treatment for both EOs. For the combined treatment of Eucalyptus or Tea tree EO with X-ray irradiation, LD90 values were 746.02 and 737.1 Gy with Eucalyptus EO and 632.03 and 615.5 Gy with Tea tree EO, at dose rates of 0.76 and 0.19 kGy/h, respectively. Overall, combined treatment LD90 values were significantly higher (less effective treatment) for X-ray than for γ-irradiation. Unlike γ-irradiation, the dose rate of X-ray irradiation did not affect efficacy in the combined treatments. Gamma or X-ray irradiation and plant EOs such as Eucalyptus or Tea tree EOs applied alone or in combination, are effective insecticidal treatments. The synergistic effects of irradiation and EOs may be source and dose rate dependent. Our results showed that synergistic effects with EOs against S. oryzae in rice was more effective (lower LD90 values) using higher dose rates of high energy γ-irradiation than at lower dose rates with either high energy γ-irradiation or low energy X-ray irradiation.

HLMIF, a facility for investigating the synergistic effect of ion-irradiation and LBE corrosion

The synergistic effect of irradiation and Lead Bismuth Eutectic (LBE) corrosion on structural materials is of vital importance for the research and development of future lead cooled nuclear energy systems. A Heavy Liquid Metal and Irradiation Facility (HLMIF) was therefore designed and constructed at National Laboratory of Heavy ion Accelerator in Lanzhou. The facility provides a capability to use heavy ions in situ to irradiate a specimen in simultaneous contact with flowing LBE. In this experiment, a thin disc of material serves as both a beam window isolating high temperature LBE loop from the accelerator, and as a specimen irradiated by ions, allowing studying the synergistic effect. The facility has been successfully tested by using 247 MeV Ar ion beam to irradiate a sample of SIMP steel simultaneously exposed to flowing LBE at 350 °C. The initial experiment was continuously conducted for 92h without any accident or unexpected failures. The preliminary results showed that the LBE corrosion of SIMP steel was obviously accelerated by ion irradiation even at low damage.

Changes in masa and tortillas obtained from maize irradiated and nixtamalized with nejayote

Abstract Maize grains were treated with electromagnetic fields and nixtamalized with nejayote, in order to analyze the effect of such treatments on the microbiological and viscoelastic properties of masa, and on sensory tests of tortilla. A sample of maize grains was irradiated by electromagnetic fields for 7 and 12 min.Then, following the nixtamalization with nejayote, masa and tortillas were obtained. The application of electromagnetic fields did not decrease the growth of moulds in maize grains. However, a synergistic effect of irradiation (12 min) and nixtamalization with diluted nejayote (50 water/50 whole nejayote) improved the sanitary quality of masa. Elastic and viscous moduli showed significant differences in all treatments. The masa from maize grains irradiated for 12 min showed the highest values of elastic and viscous moduli, while the masa from grains irradiated for 7 min and nixtamalized with diluted nejayote (70 water/30 whole nejayote) presented the lowest values. These results seem to indicate that the application of electromagnetic fields modifies the viscoelastic modulus of masa. Sensory tests showed that tortillas obtained from irradiated (12 min) maize grains, nixtamalized with nejayote (70 water/30 whole nejayote), had the highest score of all the attributes, i.e. texture, chewiness and taste.

Ascorbate and endocytosed Motexafin gadolinium induce lysosomal rupture

Motexafin gadolinium (MGd) sensitizes malignant cells to ionizing radiation, although the underlying mechanisms for uptake and sensitization are both unclear. Here we show that MGd is endocytosed by the clathrin-dependent pathway with ensuing lysosomal membrane permeabilization, most likely via formation of reactive oxygen species involving redox-active metabolites, such as ascorbate. We propose that subsequent apoptosis is a synergistic effect of irradiation and high MGd concentrations in malignant cells due to their pronounced endocytic activity. The results provide novel insights into the mode of action of this promising anti-cancer drug, which is currently under clinical trials.

Impact of Irradiation on Fish and Seafood Shelf Life: A Comprehensive Review of Applications and Irradiation Detection

Irradiation is one of the most important and effective methods towards food preservation despite the consumer lack of trust and aversion towards this method. Irradiation effectiveness greatly depends on the dose provided to food. This review aims at summarizing all available information regarding the impact of irradiation dose on the shelf life and microflora and sensory and physical properties of fish, shellfish, molluscs, and crustaceans. The synergistic effect of irradiation in conjunction with other techniques such as salting, smoking, freezing, and vacuum packaging was also reported. Another issue covered within the frame of this review is the detection (comparison of methods in terms of their effectiveness and validity) of irradiated fish and seafood. The information related to fish and seafood irradiation and its detection is presented by means of 11 comprehensive tables and 9 figures.

Stressed capsules of austenitic and martensitic steels irradiated in SINQ Target-4 in contact with liquid lead–bismuth eutectic

In the MEGAPIE target, the steels used for the proton beam entrance window and other components in the spallation reaction zone suffer not only from the irradiation damage produced by protons and neutrons but also from the corrosion and embrittlement induced by liquid lead–bismuth eutectic (LBE). Although these effects have been separately studied by a number of authors, the synergistic effects of irradiation, LBE corrosion and embrittlement are little understood. This work presents detailed analyses of two stressed capsules made of the austenitic steel EC316LN and the martensitic steel 9Cr2WVTa, which were irradiated in SINQ Target-4 in contact with LBE at calculated temperatures of 315 and 225 °C, respectively. The Electron Probe Microanalysis (EPMA) on the cross-sections of the capsules showed that the stagnant LBE induced only slight corrosion on both capsules and no cracks existed in the wall of the EC316LN capsule. Some cracks were observed in the electron beam weld (EBW) and its vicinity of the 9Cr2WVTa capsule, which can be attributed to the high stress inside the wall, the hardening of the material induced by either welding (without re-tempering) or irradiation, and the effects of LBE embrittlement.

Synergistic Effect of Irradiation and Hyperthermia on Established Cell Lines Derived from Maxillary CarcinomaReport I

Cultured tumor cells of an established cell line derived from cancer of the head and neck (maxillary and lingual cancer) were irradiated with X-rays (5 or 10 Gy). This treatment inhibited cell proliferation in a dose-dependent way. Cell cycle analysis showed that the ratio of cells in the S phase to the population of viable cells was higher than that in a non-irradiated control group. Thus, the S phase was prolonged by exposure to X-rays. Cell proliferation was also inhibited by 1 h of heat treatment at 43 degrees C. However, movement through the cell cycle was slowed down overall and no cell aggregation in any phase of the cell cycle was found. Proliferation of not only radioresistant but also radiosensitive cells was inhibited by this treatment. Hyperthermia at 43 degrees C for 1 h did not affect cell proliferation, nor did it influence the pattern of cell cycle distribution. However, it caused a decrease in intracellular polyamine amount. The combination of irradiation and hyperthermia caused a stronger inhibition than either treatment alone. The synergistic effect of the two treatments probably arose from the S-phase cells being heat-labile although radioresistant.

Synergistic Effects of Irradiation and Hyperthermia on Established Cell Lines Derived from Maxillary CarcinomaReport II

We studied in vitro the capability of radiation, hyperthermia, and their combination to inhibit growth of cell strains isolated from maxillary carcinoma and their radiation tolerant strains. Synergic effects of the combination were studied by investigating effects of hyperthermia and radiation on cell cycles with BrdU pulse labelling to establish optimal conditions for the combination. Growth of cell strains from maxillary carcinoma was remarkably inhibited by thermal treatment because of retarded cellular cycles. Cells at the S-phase were so sensitive to heat that their intake of BrdU was debilitated. Radiation increased the proportion of cells at the S-phase that poorly synthesized DNA. When combining radiation with hyperthermia, the heat killed cells at the S-phase, which was prolonged by radiation, and survivors showed retarded cellular cycles; that is, synergism was found.