• Korean journal of applied entomology
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• v.10 no.2
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• pp.117-120
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• 1971

This experiment was carried out to obtain basic informations on the development in sterile-male technique of rice stem borer. The species considered is Chile suppressalis Walker. Different developmental stages of the insect namely; larval, pupae and adult were irradiated with $Co^{60}$ gamma ray. The results obtained were as follows: 1) A 1:1 sex ratio in the pupal stage was observed. 2) In the pupal stage sub-lethal dosages$(LD_{50})$ were 26 KR and 26.7 KR for female and male, respectively. 3) The total number of egg masses per female increased with the increasing gamma ray dosages and average number of eggs produced per female decreased in the cross between normal female and irradiated male. 4) The sterile dosage $(SD_{90})$ of the gamma ray irradiation showed 23 KR in the male. 5) The pupal stage is most convenient developmental stage for irradiation.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.119-124
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• 2011

Silver nano-particles (AgNPs) have attracted much attention for centuries due to their unique optical properties, electrical conductivities, oxidative catalysis, and antibacterial effect. In this study, AgNPs have been prepared by using aqueous $AgNO_3$ solution in the poly(vinyl alcohol) (PVA)/poly(ethylene glycol) (PEG) hydrogels. PVA and PEG powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make hydrogels. PVA/PEG hydrogels were dipped into $1.0{\times}10^{-2}M$ $AgNO_3$ solution for 1 hour. After that, the swollen hydrogels were irradiated by gamma-ray for the formation of AgNPs. FE-SEM is used to observe the formation of AgNPs as a function of the content of PEG and the irradiation dose. Also, AgNPs in the PVA/PEG hydrogels were monitored by UV-Vis. It is observed that the content of PEG and gamma-ray irradiation in the hydrogel is crucial to the formation of AgNPs. Finally, antibacterial tests indiacted that the hydrogel containing silver nanoparticle has antibacterial activity.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.313-317
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• 2010

The struvite crystallization was applied to remove $NH_4{^+}$ in livestock wastewater. The ammonium ions can be very toxic to the aquatic creatures. In this experiments, the livestock wastewater from Gongju livestock wastewater treatment plant was used. The behaviors of various parameters such as pH, mole ratio of $Mg^{2+}$ : $NH_4{^+}$ : $PO{_4}^{3-}$ and reaction temperature for struvite crystallization of livestock wastewater and the effect of gamma ray irradiation were evaluated. As results, for the pH variation, the $NH_4{^+}$ removal efficiency showed the highest, 88%, at pH 9~9.25. The removal efficiency of $NH_4{^+}$, $Mg^{2+}$ and $PO{_4}^{3-}$ was showed highest when same molar ratio of $Mg^{2+}$ and $PO{_4}^{3-}$ were applied. The $NH_4{^+}$ removal efficiency showed 82% at $7^{\circ}C$, and 90% at $30^{\circ}C$ with temperature. When the wastewater was irradiated with 20 kGy of gamma ray, $NH_4{^+}$ was removed as much as 83%.

• Nuclear Engineering and Technology
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• v.13 no.3
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• pp.161-167
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• 1981

For determination of mutation frequency induced by chronic irradiation of low dose gamma rays, Tradescarrfia clone 4430 was exposed to Co-60 ${\gamma}$ rays with different exposure rates from 3.6mR/day to 182R/day in or out of the Gamma Field at Kumkok Experiment Farm of KAERI. Somatic mutations based on pink mutant events of the stamen hair cells were clearly observed by the treatment. The pink mutant events were increased proportionally with increasing exposure rates of gamma ray except for relatively high dose rates of 105 R/day and 182 R/day, indicating saturation effect of mutation. The somatic pink mutations could be fairly detectable even in the low dose rate of 3.6mR/day. Therefore, this stamen hair system of Tradescantia clone 4430 seemed to be an reasonable test system for detecting mutability of low level irradiation. These results imply that artificial mutation induction in the fruit and ornamental trees could be expected in the ${\gamma}$-field.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1570-1574
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• 2008

Various mechanical test were conducted on conventional and crosslinked ultra-high molecular weight polyethylene(UHMWPE) all prepared from the same lot of medical grade GUR 1050 for artificial joint. The conventional materials were not irradiated and treated by heating. The cosslinked materials were irradiated with $25kGy{\sim}200kGy$ by gamma-ray andthen annealed or remelted. Gamma-ray irradiation and heat treatment process were found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The radiation dose and heating conditions were key predictors of the uniaxial yielding, plastic flow, and failure properties of conventional and highly crosslinked UHMWPE. The correlation model from experiments would be the basic information to enhance the were resistance of artificial joint liner.

• Journal of Radiation Industry
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• v.4 no.3
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• pp.247-252
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• 2010

The present study has been performed to select the osmotic tolerant lines using polyethylene glycol (PEG 6000) through an in vitro and in vivo mutagensis with a gamma-ray. During the screening, we selected three mutant lines that seemed to confer elevated osmotic tolerance in high concentrations of PEG 6000. Fruits of these mutants (Os-HK101, Os-HK102 and Os-HK103) were increased to sugar concentration, L-glutamine acid, vitamin C content and lycopine content than those of the wild type. Also the chlorophyll contents were few decreased more in the three mutant lines than the WT plants. Our results suggest that the Os-HK101 is characterized as osmotic stress tolerance considering the sugar concentration and lycopine content. It is expected that the result of this study can be used for breeding more competitive species with respect to contents in sugar or functional chemicals from the selected osmotic resistant lines.

• Food Science and Preservation
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• v.18 no.1
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• pp.1-6
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• 2011

Kochujang-gulbi, a Korean traditional food, was prepared with kochujang and freeze-dried gulbi slices. Kochujang-gulbi was treated with high hydrostatic pressure (200, 400 and 600 MPa) and gamma-irradiation (7, 10, 20 and 30 KGy) to improve its quality and shelf-life. The pH of high hydrostatic pressure and gamma-irradiation treated kochujang-gulbi samples did not significantly different compared to that of control. However, Hunter L value slightly increased, and Hunter a and b values decreased by high hydrostatic pressure and gamma-irradiation treatment. During storage, the pH and color of high hydrostatic pressure and gamma-irradiation treated kochujang-gulbi samples did not significantly changed. The VBN and TBA level decreased by the increase treatment of high hydrostatic pressure and then slowely increased during storage. The VBN and TBA level of kochujang-gulbi samples treated by the strong gamma ray emission slowely increased during storage. In particular, gamma-irradiation treatment was very effective to sterilize microorganisms when compared to that of high hydrostatic pressure in kochujang-gulbi products. In addition, the high hydrostatic pressure and gamma-irradiation treated kochujang-gulbi samples shown significantly lower total viable cell number than control for the 20 days of storage at room temperature with retort pouch packaging.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.45-49
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• 2013

In tissue engineering application, a fibrous structure of scaffolds has been issued as an alternative system to regulate cell survival and tissue regeneration, and electrospinning technique has been popularly used to generate fibrous meshes or sheets mimicking the structure of native extracellular matrix (ECM). However, recent strategy in the scaffold development is expanded to provide the structural property as well as a biological property of native ECM, a variety of surface modification techniques have been used to introduce biological property. In this study, we developed biomimetic poly(L-lactide-co-${\varepsilon}$-caprolactone) (PLCL) nano- and micro-fibrous scaffolds as a unique platform with structural and biological properties with native ECM using electrospinning method and gamma-ray irradiation. Surface morphology of the scaffolds was observed by scanning electron microscopy, and alteration of surface property was evaluated with toluidine blue O staining, water contact angle measurement and ATR-FTIR analysis.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.139-145
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• 2012

Gold nanoparticles (GNPs) have led to the development of a new field in the diagnosis and treatment of diseases such as cancer. An efficient synthesis of gold nanoparticles within the range of 8~57 nm was established by ${\gamma}-ray$ irradiation. The good point of a radiation-based method is the production of gold nanoparticles with a higher concentration and narrower size distribution compared with conventional methods. The size of gold nanoparticles was controlled using two methods. : (i) varying the ${\gamma}-ray$ irradiation dose of 10 to 25 kGy and (ii) varying the concentration of $HAuCl_4$ solution from 4 to 40 mM. In addition, the GNPs were radiolabeled using $[^{125}I]NaI$ in a simple and fast manner with high yields. The produced gold nanoparticles were characterized using a transmission electron microscopy (TEM), a UV-visible spectrophotometer, and a radio-TLC imaging scanner. From these results, these radiolabeled GNPs can be applicable for a radioisotope tag of biomolecules.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.365-373
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• 2010

TILLING (Targeting Induced Local Lesions IN Genomes) is broadly regarded as an excellent methodology for reverse genetics applications. Approximately 15,000 $M_3$ TILLING lines have been developed via the application of gamma-ray irradiation to rice seeds (cv. Donganbyeo), followed by subsequent selections. In an effort to evaluate the genetic diversity of the TILLING population, we have employed the AFLP multiple dominant marker technique. A total of 96 (0.64%) TILLING lines as well as Donganbyeo were selected randomly and their genetic diversity was assessed based on AFLP marker polymorphisms using 5 primer combinations. An average of 100.4 loci in a range of 97 to 106 was detected using these primer combinations, yielding a total of 158 (31.4%) polymorphic loci between Donganbyeo and each of the 96 lines. A broad range of similarity from 80% to 96% with an average of 89.4% between Donganbyeo and each of the 96 lines was also observed, reflecting the genetic diversity of the TILLING population. Approximately 28 polymorphic loci have been cloned and their sequences were BLAST-searched against rice whole genome sequences, resulting in 20 matches to each of the gene bodies including exon, intron, 1 kb upstream and 1 kb downstream regions. Six polymorphic loci evidenced changes in the coding regions of genes as compared to the rice pseudomolecules, 4 loci of which exhibited missense mutations and 2 loci of which exhibited silent mutations. Therefore, the results of our study show that the TILLING rice population should prove to be a useful genetic material pool for functional genomics as well as mutation breeding applications.