• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.230-236
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• 2000

For extension of storability, onion bulbs produced in Cheju Island were exposed to ${\gamma}$-ray irradiation at a dosage of 0, 3, or 6Krad and stored in a natural cavern, or in low (2$^{\circ}C$) or ambient temperature storage condition. Sprouting began from approximately five months in storage, regardless of storage condition, and increased as the storage period increased. From early August, sprouting as high as 50% occurred in the natural storage cavern, and 20% in ambient temperature storage when bulbs were treated with 0 krad ${\gamma}$-ray. However, bulbs treated with 3 or 6krad ${\gamma}$-ray did not any sprouting until six months in storage. No significant weight loss was observed in all treatments until sprouting occurred from 40 days after the initiation of storage. Weight loss, however, increased remarkably after 40 days in storage, indicating that it was closely related to sprouting during storage. Bulbs stored at 2$^{\circ}C$ showed 5~10% rot, but were still edible. Percent rot reached to as high as 50% in bulbs unirradiated and stored at ambient temperatures after seven months, while it in irradiated bulbs reached to 5, 33, and 30% at 2$^{\circ}C$, in a natural cavern, and ambient temperatures, respectively. Sugar contents slightly increased in irradiated bulbs in the later storage period under ambient temperatures, while sugar contents in irradiated bulbs in the later storage period under ambient temperatures, while sugar contents in Allium vegetables generally decrease in later storage if unirradiated. Sulfur content slightly increased in irradiated bulbs in the early storage period and decreased gradually in all treatments in the later storage stage.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.163-166
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• 1975

This experiment was performed to investigate the X-ray sensitivities at the various stages of life cycle and to determine the sterillizing dose of stable fly, Stomoxys calcitrans(L). A dose of 300 rad caused about $50\%$ mortality in 2-hour-old eggs as measured by egg hatch, and $100\%$ mortality was obtained with a does of 1 Krad. Sub-lethal dose $(LD_{50})$ for the pupal mortality after irradiation of 3-5days old pupae were 11.5 Krad and the mortality was decreased with increasing pupal age at irradition. A significant reduction of egg hatch by $1.5\%$ was observed when treated males with 3 Krad at pupal stage were mated to untreated virgin femleas. On the other hand, $100\%$ sterility in females was resulted by 2 Krad irradiation and oviposition was completely inhibited with 3 Krad. Thus, both sexes of stable fly could be sterilized with a dose of 4 Krad irradiated to 3-5 days old pupae.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.203-211
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• 2000

In this study to produce large-scale scopolamine we were examined in the tumor calli of Datura metel L. induced by Agrobacterium tumefaciens $Ery{101}$. The growth and scopolamine contents of tumor calli were higher under light condition than in dark. The optimum condition of growth and scopolamine production were fluence rate of 16 $\mu$mol $m^{-2}s^{-1}$, spectra of red light region and 16 hour light periods on 50 mL SH liquid medium in 4 weeks culture. To increase of the scopolamine contents in tumor calli, the optimum concentration of nitrogen source were 1.8 mM NH$_4$+ and 40 mM NO$_3$. The optimum elicitor concentration for production of scopolamine were 10 mg/L chitosan and 15 mg/L yeast extract. The effect of precursors were good at the concentration of 0.2 mM tropine and 0.3 mM tropic acid, respectively. In order to increase of growth and scopolamine contents. we induced mutant from Datura metel L. tumor callus. Mutants of tumor calli were obtained by 3 Krad, 4 Krad and 6 Krad of ${60}^Cor-ray$. Among them, 3 Krad tumor callus was excellent on the growth and teratoma induction. The 4 Krad tumor callus was negligible for both growth and teratoma induction. But the 6 Krad tumor callus was the best in growth and teratoma induction. The formation of the mutant calli can be enhanced through hormonal combination of 1 mg/L 2,4-dichlorophenoxyacetic acid and 0.5 mg/L benzyladenine. We carry out selection mutant tumor calli for high content tropane alkaloid and suspension cultures for scopolamine production.

• Korean Journal of Food Science and Technology
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• v.2 no.1
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• pp.104-112
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• 1970

Korean Paldal variety rice, harvested November and hulled into polished and unpolished forms in April, 1969, packed in the straw bags and the kraft paper bags. Being irradiated with 10, 30 and 50 krad ${\gamma}-ray$, the samples were stored at room temperature for testing infestation, uric acid content, fat acidity, riboflavin content and panel test. The results are as follows. 1. The kraft bag lot with polished rice or unpolished rice manifested the apparent disinfestation with $30{\sim}50$ krad irradiation. On the other hand, in the straw bag lot the irradiation effects on disinfestation were weakened through summer on account of the second contamination. 2. The changes of uric acid content in rice were proportional to the state of infestation. 3. Fat acidity, which has a close relation with the rancidity of fat in rice, increased during storage and showed some increasing tendency in the irradiated lot with $30{\sim}50$ krad. 4. In comparison with the control lot, riboflavin content was not affected by 50 krad irradiation. 5. With 10, 30 and 50 krad dose, the irradiated lot should have no significant difference in taste, odour, color and viscosity for the panel test.

• Korean journal of applied entomology
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• v.11 no.1
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• pp.25-30
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• 1972

Five to seven day old pupae were irradiated with gamma rays, the mating ability, and competability of the irradiated males were examined. The results obtained are summarized as follows: 1. There is no difference in percentage of males that mated, nor in the maximum number of matings of the males, when individual matings were made, and fresh females were provided every day for his life time. 2. The average days for the first mating of the emerged were 1.5 days for the control, and 2.4 days for the males irradiated with 25 and 30 Krad. The average days between first and second mating were 3.0 days for the irradiated males, and 1.3 days for the control. 3. The average matings of a male were 1.2 and 2.5 times when 5 and 10 females were provided to a normal male respectively. No significant different in average numbers of mated female per male were observed between the normal and irradiated males. 4. To test the mating competitiveness of the irradiated and normal males (1:0, 1:1, 2:1, 1:2, 5:1, 1:5, 0:1) were confined together with five virgin females. The greatest reduction in hatching percentage was found with 5 : 1 : 1 (30 Krad) where $26.6\%$ was hatched.5, The results showed that the irradiated males were not fully competitive with normal males, but if the reduced number of eggs produced by the female mated with irradiated male is considered, it might be used sterile male techniques in rice stem borer control.

• Journal of Ginseng Research
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• v.26 no.4
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• pp.219-225
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• 2002

Study was performed to know the effects of Panax ginseng C.A. Meyer hairy root due to $^{60}$ Co ${\gamma}$-ray irradiation. We irradiated the hairy roots under the various $^{60}$ Co ${\gamma}$-ray; 0.5~4 Krad. The growth of hairy roots is inhibited over 3 Krad treatment. The lateral roots are used as a cell line after removing the apical meristem of hairy roots irradiated below 2 Krad. We selected 206 hairy root cell lines having various different growth rates and forms, and incubated in the 1/2 Murashige & Skoog(MS) medium in the absence of hormone. We selected 10 out of 206 showing superior growth. Among those, ${\gamma}$-GHR 70 and ${\gamma}$-GHR 94 showed higher growth; 34.5, 44.7%, respectively. We observed shapable, sizable characteristics according to the width of the primary roots, the process formation of the lateral roots, and the growth of lateral roots. The discriminable cell line showed that primary root is thinner, and has a vigorous growth. 8 out of 10 had much more contents than control in the aspect of the ginsenoside. ${\gamma}$-GHR 59 and ${\gamma}$-GHR 94 showed higher contents; 19, 16.9%, respectively. Therefore, we selected ${\gamma}$-GHR 70, ${\gamma}$-GHR 94 as a superior cell line in the aspect of ginsenoside contents, and growth among those irradiated by ${\gamma}$-ray. According to content of ginsenoside, Rb$_2$ effective in anticancer has 7.5% of ${\gamma}$-GHR 59. Rc, also effective in anticancer showed 16.2% content increasement of ${\gamma}$-GHR 69. It is thought that those lines will be effective in manufacturing ginsenoside. Gene analysis (VNTRP) related to the mutation is in progress.

• Journal of Environmental Health Sciences
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• v.8 no.1
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• pp.45-53
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• 1982

To determine the effect of r-irradiation on the microorganisms destruction and the changes of general constituents of Ginseng Powder, three samples were analyzed at 1st and 3rd month after r-irradiation. The results were as follows: 1. Total bacterial counts were decreased during storage as the irradiation dose increased. It seems that about 300 Krad was satisfactory to the regulation of ginseng powder. ($5.0 \times 10^4 /g$) 2. Coliform group was also decreased during storage as the irradiation dose increased. Coliform group was not detected at the irradiation dose higher than 500 Krad. 3. Total bacterial counts and coilform group were in proportion to the content of moisture in ginseng powder. 4. The contents of moisture, ash, crude protein, crude lipid and total sugar in ginseng powder during storage had nearly no changes. 5. The content of reducing sugar in ginseng powder during storage had the increasing tendencies as the irradiation dose increased. 6. The content of amino-nitrogen in ginseng powder during storage had the decreasing tendencies as the irradiation does increased.

• Korean Journal of Food Science and Technology
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• v.5 no.1
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• pp.65-69
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• 1973

Effect of various dosages of gamma ray ranging from 0 to 16 krad on wound periderm formation was investigated with aging potato tuber slices $(1cm{\times}2mm)$ under aseptic condition. Cell division was gradually inhibited with increasing dosage, and completely prevented with 16 krad treatment. Solanine content was not significantly different due to dosages. Gas chromatographic separation of 2,4-dinitrophenylhydrazone precipitate from radiation-induced carbonyl compounds in potato tubers showed that formaldehyde and acetone tended to be increased only with high dosages.

• Transactions on Electrical and Electronic Materials
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• v.5 no.2
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• pp.71-75
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• 2004

This paper proposes a new bandgap reference (BGR) circuit which takes advantage of a cascode current mirror biasing to reduce the V$\_$ref/ variation, and sizing technique, which utilizes two related ratio numbers k and N, to reduce the PNP BJT area. The proposed BGR is designed and fabricated on a test chip with a goal to provide a reference voltage to the 10 bit A/D(4-4-4 pipeline architecture) converter of the CMOS Active Pixel Sensor (APS) imager to be used in X-ray imaging. The basic temperature variation effect on V$\_$ref/ of the BGR has a maximum delta of 6 mV over the temperature range of 25$^{\circ}C$ to 70$^{\circ}C$. To verify that the proposed BGR has radiation hardness for the X-ray imaging application, total ionization dose (TID) effect under Co-60 exposure conditions has been evaluated. The measured V$\_$ref/ variation under the radiation condition has a maximum delta of 33 mV over the range of 0 krad to 100 krad. For the given voltage, temperature, and radiation, the BGR has been satisfied well within the requirement of the target 10 bit A/D converter.

• Microbiology and Biotechnology Letters
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• v.7 no.1
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• pp.1-8
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• 1979

A new method for immobilization of glucose oxidate by the aerobic gamma radiation of synthetic monomers was developed. The radiocopolymerization was conducted aerobically at -70 to -8$0^{\circ}C$ with the mixture of several polyfunctional esters, acrylates and native enzyme. The retained activity of immobilized glucose oxidase was about 50 to 55％ when a NK 23G ester, acrylamide-bis and water mixture (1:1:2) in cold toluene treated with 450 krad of gam-ma radiation. The radiation dose did not influence significantly to the enzyme activity. The solvents used to prepare the beads of glucose oxidase and monomers were toluene, n-hexane, petoleum ether and chloroform. 0.05M tris-gycerol (pH 7.0) was a more suitable bugger solution for immobilizing the enzyme than was 0.02M phosphate. Immobilization of glucose oxidase shifted the optimum pH for its reaction from 6.0 to 6.5. The pH profile for the immobilized enzyme showed a broad range of optimum activity while the native enzyme gave a sharp pick for its optimum pH value. The immobilized enzyme reaction temperature was at the range of 30~4$0^{\circ}C$.