Co-60 Γ-ray Research Articles

Targeting the NF-κB p65/Bcl-2 signaling pathway in hepatic cellular carcinoma using radiation assisted synthesis of zinc nanoparticles coated with naturally isolated gallic acid

PurposeOral diethylnitrosamine (DEN) is a known hepatocarcinogen that damages the liver and causes cancer. DEN damages the liver through reactive oxygen species-mediated inflammation and biological process regulation. Materials and methodsGallic acid-coated zinc oxide nanoparticles (Zn-GANPs) were made from zinc oxide (ZnO) synthesized by irradiation dose of 50 kGy utilizing a Co-60 γ-ray source chamber with a dose rate of 0.83 kGy/h and gallic acid from pomegranate peel. UV–visible (UV) spectrophotometry verified Zn-GANP synthesis. TEM, DLS, and FTIR were utilized to investigate ZnO-NPs' characteristics.Rats were orally exposed to DEN for 8 weeks at 20 mg/kg five times per week, followed by intraperitoneal injection of Zn-GANPs at 20 mg/kg for 5 weeks. Using oxidative stress, anti-inflammatory, liver function, histologic, apoptotic, and cell cycle parameters for evaluating Zn-GANPs treatment. ResultsDEN exposure elevated inflammatory markers (AFP and NF-κB p65), transaminases (AST, ALT), γ-GT, globulin, and total bilirubin, with reduced protein and albumin levels. It also increased MDA levels, oxidative liver cell damage, and Bcl-2, while decreasing caspase-3 and antioxidants like GSH, and CAT. Zn-GANPs significantly mitigated these effects and lowered lipid peroxidation, AST, ALT, and γ-GT levels, significantly increased CAT and GSH levels (p<0.05). Zn-GANPs caused S and G2/M cell cycle arrest and G0/G1 apoptosis. These results were associated with higher caspase-3 levels and lower Bcl-2 and TGF-β1 levels. Zn-GANPs enhance and restore the histology and ultrastructure of the liver in DEN-induced rats. ConclusionThe data imply that Zn-GANPs may prevent and treat DEN-induced liver damage and carcinogenesis.

Air kerma reference field with high energy photons using a 15 MeV electron beam from a clinical linear accelerator.

In the medical and nuclear fields, there are environments where exposure to photons with energies above several MeV can result in problems. The National Metrology Institute of Japan has developed a high-energy photon field using a 15 MeV electron beam of a clinical linear accelerator with a copper target and an aluminium filter unit to facilitate dosimeter calibration in terms of air kerma. To determine the air kerma rate, the energy fluence distribution at a reference point was calculated, and both calculations and experiments evaluated the effective energy and spatial dose distribution. Moreover, to validate the air kerma measurement, two commercial cavity chambers were calibrated in a developed photon field. The results obtained exhibited a 4% difference compared with those in a Co-60γ-ray reference field.

Effects of Different Irradiation Treatments on Total Saponins Content of Sapindus mukorossi.

Sapindus mukorossi Gaertn is also known as Mu Huanzi, You Huanzi, soap tree, etc. The pericarp of Sapindus mukorossi contains many saponins, which is a type of natural non-ionic surfactant. Its extract has vigorous surface activity and biological activities such as bacteriostasis, oxidation resistance, and free radical scavenging. The Sapindus mukorossi extract is an environmentally friendly washing product that microorganisms can be rapidly decompose in nature without any environmental pollution.This study aims to investigate the effects of E-beam and Co60-γ irradiation on the total saponins content in the crude extract of the S mukorossi. The S mukorossi powder is irradiated with E-beam and Co60-γ ray at doses of 0, 4, 6, 8, 10, and 12 kGy for E-beam and 0, 50, 100, 150, and 200 Gy, respectively, for Co60-γ ray. The changes in the content of total saponins in the crude extract, total detergency, and the bacteriostatic abilities before and after the irradiation were analyzed. The results showed that the content of total saponins in samples irradiated by E-beam was significantly higher than that in non-irradiated samples. The saponins yield was the highest at a radiation dose of 6 kGy, and the detergency and bacteriostatic ability were also the strongest. After low-dose Co6-γ irradiation, the total saponins in the S mukorossi crude extract, and detergency and bacteriostatic ability had no apparent change. Conclusion: E-beam irradiation at a dose of 6 kGy can effectively improve the content of total saponins in the crude extract of S mukorossi powder. In addition, its effects on detergency and bacteriostatic abilities are relatively significant. The findings provide sufficient reference data for the further development of S mukorossi commodities.

Zeolite-assisted radiolysis of aromatic chlorides mitigating influence of coexisting ions in water matrix

We have studied zeolite-assisted radiolytic degradation of aromatic chlorides in the presence of radical scavengers. This study aims to determine whether the combined use of zeolite with ionizing radiation can reduce the influence of water matrix in the irradiation treatment of water-soluble organic compounds. A high-silica mordenite-type zeolite (HMOR) was used as the adsorbent for the aromatic chlorides. We investigated and compared the effects of HMOR on the radiation-induced degradation of three aromatic chlorides, 2-chlorophenol (2-ClPh), 2-chloroaniline (2-ClAn), and 2-chlorobenzoic acid (2-ClBA). The irradiation experiments were performed by using a Co-60 γ-ray source and bromide, nitrate and formate ions were used as the radical scavengers. In the presence of these radical scavengers, the degradation of 2-ClPh in water was inhibited, but the combined use of HMOR much improved the degradation yield. This improvement was attributed to high performance of HMOR in adsorption of 2-ClPh. Similarly, HMOR was effective for adsorption of 2-ClAn from water and facilitated the 2-ClAn degradation in the presence of formate ion. In contrast, HMOR was poor at adsorption of 2-ClBA and consistently the radiation-induced degradation of 2-ClBA in the water-HMOR mixture was inhibited by formate ion. These results demonstrate that HMOR can mitigate the influence of radical scavengers in water and facilitate the radiation-induced degradation of a molecule such as 2-ClPh and 2-ClAn, providing HMOR strongly adsorbs that molecule.

Dosimetric calibration of GafChromic HD-V2, MD-V3, and EBT3 films for dose ranges up to 100 kGy.

A dosimetric calibration of three types of radiochromic films (GafChromicTM HD-V2, MD-V3, and EBT3) was carried out for absorbed doses (D) ranging up to 100 kGy using a 130 TBq Co60 γ-ray source. The optical densities (ODs) of the irradiated films were acquired with the transmission-mode flatbed film scanner EPSON GT-X980. The calibration data were cross-checked using the 20-MeV proton beam from the azimuthally varying field cyclotron at the Research Center for Nuclear Physics in Osaka University. These experimental results not only present the measurable dose ranges of the films depending on the readout wavelength, but also show consistency with our hypothesis that the OD response curve [log(OD)-log(D) curve] is determined by the volumetric average of the absorption dose and does not strongly depend on the type of radiation for the excitation.

Preferential role of iron in heme degradation of hemoglobin upon gamma irradiation

It is usually believed that γ-ray interaction with biomolecules is intermediately performed by reactive oxygen species (ROS) produced from radiolysis of water. Hemoglobin (Hb) as one of the most abundant biomolecule in blood and well-studied endogenously affected by ROS, was a good candidate for study. Adult human Hb was extracted and irradiated using four distinct 20, 60, 90 and 170Gy doses from Co-60 γ-ray source. UV–vis, fluorescence and FT-IR spectroscopies were used to study the whole conformational changes and partial degradation of heme. Hb species calculated using Benesch equations indicated that the concentration of oxy-Hb was decreased from 9.97μM to 6.56μM, while the total metastable met and deoxy-Hb concentration were just increased 2.39μM and about 8.4% of total heme was diminished. Heme degradation was studied using fluorescence spectra at two 321 and 460nm excitation wavelengths as fully and partially degradation of heme respectively. Inverse behavior of these two fluorescence spectra suggested a new mechanism of heme degradation in which γ-ray preferably absorbed by heme without any intermediary effects of water. It was confirmed by FT-IR spectra at 900–1000cm−1 where the FeN and NH of porphyrin indicate their own stretching vibrational bands. Thermal stability justified that the gamma radiation induced the conformational changes of Hb which is appeared during thermal unfolding. First derivative of thermal spectra indicated that the Tm of 170Gy dose irradiated sample is 2°C lowered and total concentration of Hb was decreased 14%.

Radiation Resistance of Fluorine-Implanted PNP Using Gated-Controlled Lateral PNP Transistor Structure

The radiation damage responses of fluorinated and non-fluorinated lateral PNP transistors are studied with specially designed gated-controlled lateral PNP transistors that allow for the extraction of the oxide trapped charge (Not) and interface trap (Nit) densities. All the samples are exposed in the Co-60γ ray with the dose rate of 0.5 Gy(Si)/s. After the irradiation, the buildup of Not and Nit of the samples with total dose is investigated by the gate sweep test technique. The results show that the radiation resistance of fluorinated lateral PNP transistors is significantly enhanced compared with the non-fluorinated ones.

Water equivalence study of some phantoms based on effective photon energy, effective atomic numbers and electron densities for clinical MV X-ray and Co-60 γ-ray beams

A previously proposed procedure has been applied to some water equivalent phantoms namely PMMA, Polystyrene, Solid Water (WT1), RW3 and ABS for the first time to compute effective photon energy (Eeff), effective atomic numbers (Zeff) and electron densities (neeff) for different MV X-ray beams and Co-60 gamma beam which are heterogeneous in energy. For the purpose of the present investigation, effective atomic cross-sections of the given materials have been determined first to obtain effective photon energies which were further used for calculation of Zeff and neeff. Similar procedure was adopted for Co-60 γ-rays to check the validity of the present method. Results were found to be quite satisfactory. When it comes to the water equivalence, the Eeff results showed that the RW3 and ABS phantoms are more effective for 6MV beam whereas RW3 and Polystyrene are more effective for 15MV and Co-60 beams, respectively. The ABS and WT1 phantoms have better water equivalences than the others according to the Zeff and neeff results, respectively.

Use of the Nonflammable Hydrofluorocarbon (HFC-43-10mee) and Tri-n-butyl Phosphate (TBP) for Nuclear Fuel Reprocessing: Phase Distribution of Uranyl Nitrate and Irradiation Effect of Co-60 γ-Ray

Use of the Nonflammable Hydrofluorocarbon (HFC-43-10mee) and Tri-n-butyl Phosphate (TBP) for Nuclear Fuel Reprocessing: Phase Distribution of Uranyl Nitrate and Irradiation Effect of Co-60 γ-Ray

Use of the Nonflammable Hydrofluorocarbon (HFC-43-10mee) and Tri-n-butyl Phosphate (TBP) for Nuclear Fuel Reprocessing: Phase Distribution of Uranyl Nitrate and Irradiation Effect of Co-60 γ-Ray

(2010). Use of the Nonflammable Hydrofluorocarbon (HFC-43-10mee) and Tri-n-butyl Phosphate (TBP) for Nuclear Fuel Reprocessing: Phase Distribution of Uranyl Nitrate and Irradiation Effect of Co-60 γ-Ray. Journal of Nuclear Science and Technology: Vol. 47, No. 6, pp. 515-520.

Experimental study on radiation effects in floating gate read-only-memories and static random access memories

Radiation effects of the floating gate read-only-memory (FG ROM) and the static random access memory (SRAM) have been evaluated using the 14 MeV neutron and 31.9MeV proton beams and Co-60 γ-rays. The neutron fluence, when the first error occurs in the FG ROMs, is at least 5 orders of magnitude higher than that in the SRAMs, and the proton fluence, 4 orders of magnitude higher. The total dose threshold for Co-60 γ-ray irradiation is about 104 rad (Si) for both memories. The difference and similarity are attributed to the structure of the memory cells and the mechanism of radiation effects. It is concluded that the FG ROMs are more reliable as semiconductor memories for storing data than the SRAMs, when they are used in the satellites or space crafts exposed to high energy particle radiation.

Preparation of polystyrene particles with narrow particle size distribution by γ-ray initiated miniemulsion polymerization stabilized by polymeric surfactant

Co-60 γ-ray initiated miniemulsion polymerization of styrene stabilized by an alkali soluble polymeric surfactant (ASPS) was studied in this work. The affecting factors, including absorbed dose, dose rate, surfactant concentration, and hexadecane (HD) concentration, were systematically studied. The particle size and particle size distribution (PSD) of final latexes was determined by transmission electron microscope (TEM). The results indicated that polystyrene (PS) particles with narrow PSD could be easily prepared by this method, and the particle size could be controlled from 50 nm to 250 nm by adjusting the concentration of HD and ASPS. HD concentration, surfactant concentration, dose rate and total absorbed dose strongly affected the particle size and PSD of PS latexes.

A study of radiation dosimeters based on synthetic HPHT diamond

We investigated the applicability of synthetic diamond crystals routinely produced by the HPHT (High Pressure High Temperature) technique for the detection of ionising radiation. Split-sphere-type multi-anvil equipment was used to produce these HPHT diamonds. Both as-grown type Ib and HPHT treated type IaA diamonds were examined at the Centre of Oncology in Kraków using a therapeutic Co-60 γ-ray beam. Detectors fabricated from type IaA diamonds showed, on average, better performance than those based on type Ib diamonds. IaA- type synthetic diamonds containing up to 150-200 ppm nitrogen showed sensitivity up to 160 nC/(Gy mm 3), charge collection distance up to 180 μm and close to linear dose-rate response. Considerable variations in the detecting characteristics were observed for the devices containing similar concentrations of nitrogen. From our preliminary qualitative analysis we conclude that the observed response variations may be associated with varying concentration of the nickel impurity present in these diamond crystals.

Synthesis and properties of poly (N-isopropylacrylamide) and poly (N-isopropylacrylamide-co-acrylamide) hydrogels

The thermosensitive poly (N-isopropylacrylamide) (PNIPAAm) and poly (N-isopropylacrylamide-co-acrylamide) [poly (NIPAAm-co-AAm)] hydrogels with different acrylamide molar percentage are prepared by radiation polymerization using Co60 γ-ray. Their swelling equilibrium data in the media of deionized water, NaCl aqueous solutions and different pH buffer solutions are determined. It appears that lower critical solution temperature (LCST) of the hydrogels will drop with the increase of ionic strength and increase with the rising of acrylamide content. A semi-empirical formula is set up with the experimental results. Moreover, it also indicates that this copolymer is pH-sensitive, which is similar to the homopolymer of PNIPAAm.

Optimization of Cucumber Doubled Haploid Line Production Using In Vitro Rescue of In Vivo Induced Parthenogenic Embryos

Homozygous doubled haploid lines (DHLs) from new cucumber (Cucumis sativus L.) accessions could be useful to accelerate breeding for resistant varieties. DHLs have been generated by in vitro rescue of in vivo induced parthenogenic embryos. The protocol developed involves the following: 1) induction of parthenogenic embryos by pollinating with pollen irradiated with a Co60 γ-ray source at 500 Gy; 2) in vitro rescue of putative parthenogenic embryos identified by their morphology and localized using a dissecting scope or X-ray radiography; 3) discrimination of undesirable zygotic individuals from the homozygous plants using cucumber and melon SSR markers; 4) determination of ploidy level from homozygous plants by flow cytometry; 5) in vitro chromosome doubling of haploids; and 6) acclimation and selfing of selected lines. Codominant markers and flow cytometry confirmed the gametophytic origin of plants regenerated by parthenogenesis, since all homozygous lines were haploids. No spontaneous doubled haploid plants were rescued. Chromosome doubling of haploid plants was accomplished by an in vitro treatment with 500 μm colchicine. Rescue of diploid or chimeric plants was shown by flow cytometry, prior to their acclimation and planting in the greenhouse. Selfing of colchicine-treated haploid plants allowed for the perpetuation by seed of homozygous lines. The high rate of seed set, 90% of the lines produced seed, facilitated the recovery of inbred lines. Despite some limiting factors, parthenogenesis is routinely used in a cucumber-breeding program to achieve complete homozygosity in one generation. Breeding for new commercial hybrid cultivars will be accelerated. DHLs are ideal resources for genomic analyses.

Corrosion evaluation and wall thickness measurement on large-diameter pipes by tangential radiography using a Co-60 gamma-ray source

This paper contains some useful parameters which can be applied to the tangential radiography technique to detect and measure the internal and external corrosion attack on large-diameter insulated and non-insulated carbonsteel and stainless steel pipes using a Co-60 γ-ray source. The tangential radiography technique has been successfully applied to specially designed 8 diam (219 mm) and 12 diam (324 mm) steel pipes, having internal and external machined steps of different thicknesses. The application of this technique has given 96% accuracy in the determination of the real thicknesses, for both reference pipes when they were covered with insulation, and 98% accuracy in the determination of the real thicknesses for both reference pipes when they were not insulated.

Effect of megestrol acetate and prepulsid on nutritional improvement in patients with head and neck cancers undergoing radiotherapy

Background and purpose: Anorexia is a common problem in cancer patients who receive radiotherapy. In this current study, we attempt to determine the effect of megestrol acetate and prepulsid on appetite and nutritional improvement in patients with head and neck cancers undergoing radiotherapy. Materials and Methods: One hundred twenty-nine consecutive patients with head and neck cancers treated between July 1993 and June 1994 were prospectively randomized to receive either megestrol acetate, 40 mg qid (megace group), prepulsid, 5 mg tid (cisapride group), or a placebo treatment (control group) during radiotherapy. Before radiotherapy, body weight (kg), appetite score, performance status, biochemical parameters and hematological parameters were evaluated, and the above-noted clinical and biochemical parameters were assessed and recorded every other week. All patients received 6–10 MV X-rays or Co-60 γ-ray to head and neck region for a full course of radiotherapy, 61.2–75.6 Gy/7–9 weeks. Results: Forty-eight patients were enrolled in the megace group, 41 patients in the cisapride group, and 40 patients in the control group. At the 2nd, 4th, 6th and 8th week, as the radiation dose escalated, the megace group had significantly less body weight loss than did the cisapride and control groups ( P = 0.045, 0.024, 0.006, 0.003, respectively). The appetite scores of the megace group were significantly higher than those of the cisapride and control groups ( P = 0.0001). However, there were no statistically significant differences in the change of albumin level among these three groups at the 2nd, 4th, 6th and 8th week ( P > 0.05, respectively). Conclusions: Megestrol acetate can significantly decrease the degree of body weight loss, and can prevent the deterioration of appetite in patients with head and neck cancers receiving radiotherapy. However, prepulsid lacks the above-mentioned clinical benefits.

Anneal technique to recover the electrical characteristics of the packaged bipolar junction transistors damaged by Co-60 radiation

Radiation-induced degradation in packaged bipolar junction transistors (BJT) can be efficiently removed by an anneal treatment carried out at 400 °C for 12 min in N2. The electrical characteristics of BJTs including current gain β, base current IB, and collector current IC were examined in the recovery of device performance. The radiation was performed by a Co-60 (γ-ray) source with the total doses ranging from 10 K rad to 10 M rad. The determinations of anneal temperature and anneal time were also discussed. It was shown that this anneal treatment did not degrade the radiation and hot-carrier hardnesses of devices.

Effect of γ-radiation on ointment cold cream

In this paper, Co-60γ ray was used to irradiate the ointment cold cream at room temperature (25°C). We also used FTIR, GC and thin film chromatogram to analyse various irradiated samples. It was found that the ointment cold cream can be irradiated at dose of 5–35 kGy and at dose rate from 0.2 to 0.6 kGy/h at room temperature (25°C) without evident decomposition. At dose of 5–15 kGy, the number of bacteria can be reduced to hygienic standard value. The radiation sterilization is a safe method for killing the bacteria in the ointment cold cream.

Positron irradiation effects on polypropylene

Positron irradiation effects on polypropylene (PP) and polyethylene during the positron lifetime measurements have been studied in detail. The effect, which was to decrease I 3 , has been found to be larger in air than in vacuum. For PP, when the lifetime measurements were performed at temperatures above 348K, the radiation effect was scarcely observable. However at low temperature the radiation effect was accumulated and I 3 was decreased during the measurements. Irradiation of Co-60 γ-ray up to the dose of 300 MRad also lead to similar decrease in I 3 , but the decrease due to γ-irradiation was not as large as that due to the positron irradiation. Irradiation effect of positrons appears to be different from that of γ-rays