• Journal of IKEEE
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• v.25 no.1
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• pp.15-24
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• 2021

In this paper, 1700 V EPDT (Extended P+ shielding floating gate Double Trench) MOSFET structure, which has a smaller switching time and loss than CDT (Conventional Double Trench) MOSFET, is proposed. The proposed EPDT MOSFET structure extended the P+ shielding area of the source trench in the CDT MOSFET structure and divided the gate into N+ and floating P- polysilicon gate. By comparing the two structures through Sentaurus TCAD simulation, the on-resistance was almost unchanged, but Crss (Gate-Drain Capacitance) decreased by 32.54 % and 65.5 %, when 0 V and 7 V was applied to the gate respectively. Therefore, the switching time and loss were reduced by 45 %, 32.6 % respectively, which shows that switching performance was greatly improved.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.127-132
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• 1992

Colloidal $^{32}P$ chromic phosphate is used to prevent hepatic metastasis from colorectal cancer. It is speculated that the intravenous injection of colloidal $^{32}P$ chromic phosphate can cause genotoxicity. To evaluate the genotoxicity of intravenously injected colloidal $^{32}P$ chromic phosphate, authors performed a micronuclei test in mice bone marrow. Mice (ICR strain, $25\sim30g$) were divided to 4 groups: control, group 1 (19.166 KBq/g, usual therapeutic dose in human), group 2 (191.66 KBq/g), and group 3 (1916.6 KBq/g). Five mice of each group were sacrificed at days 1, 2, 3, 5, 7 and 14. Bone marrow were smeared and stained with Wright-Giemsa method. One thousand polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) were counted under the light microscope, and the number of micronucleated PCEs and NCEs were recorded. The frequency of micronuclei in PCE and NCE in the control group was $0.3{\pm}0.06%\;and\;0.45{\pm}0.10%$, respectively. At group 1, frequency of micronuclei is not different from the control. However, frequencies of micronuclei in PCE at groups 2 and 3 were significantly increased from day 1 and persisted to day 14. The frequency of micronuclei in NCE was increased only at group 3. In conclusion, the frequency of micronuclei increases as the dose of colloidal $^{32}P$chromic phosphate increases, while micronuclei was not induced at the usual therapeutic dose. And the frequency of micronuclei persistently elevated for 14 days in the cases of higer doses.

• Korean journal of applied entomology
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• v.20 no.4 s.49
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• pp.207-211
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• 1981

It has been documented that the resistance to planthoppers is attributed to the feeding preference of the insects. This might be related to difference in the amount of feeding plant sap between resistant and susceptible hosts. In this aspect, this study was conducted to verify it and to develop an effective screening method for resistance to planthoppers by tracer technique. An effective P-32 labelling of rice seedlings at $2\~3$ leaf stage was dipping the roots in concentration of $0.1{\mu}Ci/ml$ solution for 48 hours. Radioactivity was significantly higher in planthopers fed on susceptible variety for 48 hours as compared to those fed on resistant variety. Radioactivity of adults was higher than that of nymphs and also higher in female than male. The results were highly correlated to that indicated by the feeding preference of the insects and therefore, considered to be valid for a screening technique.

• Journal of Plant Biology
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• v.32 no.1
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• pp.23-32
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• 1989

We have developed a plasmid vector, pKCH1, for the purpose of higher plant transformation. It contains the promoter region of cauliflower mosaic virus 35S transcript (P35s) and the terminator region of nopaline synthase gene (Tnos) with unique cloning sites, Bam HI and Xba I, between them. After inserting a foreing gene at the cloning sites, P35s-foreign gene-Tnos cassette can be recovered by using a restriction enzyme Hind III.

• Animal cells and systems
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• v.9 no.4
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• pp.191-198
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• 2005

The effects of 6-aminonicotinamide (6-AN) on viability of IMR32 neuroblastoma cells in the presence of ATP or $NAD^+$ have been investigated. 6-AN caused marked reduction in cell viability and similar observations were also made with cells treated with 6-AN+ATP. However, cells treated with $6-AN+NAD^+$ showed cell viability similar to untreated cells. Morphologically, 6-AN and 6-AN+ATP treated cells showed loss of neurites, polyhedric shapes, shrinkage of cell bodies and formation of lysed cells, while $6-AN+NAD^+$ cells did not show any such changes. The flow cytometry analysis demonstrated that 6-AN increased cell population in $G_0/G_1$ phase and decreased cell population in Sand $G_2/M$ phase following a 72 h exposure. Western blot analysis showed that 6-AN stimulated a substantial increase in the level of the cdk inhibitor $p27^{kip1}$, but lowered the levels of cdk2, cyclin E and p-Rb. However, cdc25A and p53R2 were not significantly affected. Immunofluorscence staining of $p27^{kip1}$, cdk2, cyclin E and p-Rb revealed close correlation between the signal observed in the Western blot analysis. 6AN+ATP treated cells showed similar results obtained with 6-AN treated cells in expression of cdk2, cyclin E, p-Rb proteins and $p27^{kip1}$, $6-AN+NAD^+$ cells showed greater expression of cdk2, cyclin E and p-Rb than those in 6-AN and 6-AN+ATP treated cells. The results suggest that 6-AN induced the $G_0/G_1$ phase arrest in IMR32 neuroblastoma cell lines through the increase of $p27^{kip1}$ and the decrease of cdk2, cyclin E and p-Rb.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.63-67
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• 2010

Proteases catalyze hydrolytic cleavage of a peptide bond between amino acids and occupy pivotal positions in application in physiological and commercial fields. During the screening for novel bacteria producing extracellular protease, two bacterial strains, WD12 and WD32, were isolated from rotten trees and they made clear zone on LB plates supplemented with 1% skim milk. The similarities of 16S rRNA gene sequence of either WD12 or WD32 to GenBank database showed the highest to Pseuoxanthomonas mexicana as 97.8 and 99.8%, respectively. Phylogenetic analysis showed that both isolated was located within the cluster comprising P. mexicana and P. japonesis. WD12 and WD32 were catalase- and oxidase-positive, Gram-negative rod strains. In case of WD12, it could assimilate malate, but could not assimilate D-mannose, which were different characteristics from P. mexicana. Both Pseuoxanthomonas sp. WD12 and WD32 optimally produced extracellular protease at $35-37^{\circ}C$, and maximal activity showed as 656 unit/ml and 267 unit/ml, respectively.

• Journal of Life Science
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• v.29 no.3
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• pp.362-368
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• 2019

For the practical application and development of biopolymer flocculant Biopol32 produced by Pseudomonas sp. GP32, its flocculation effect on wastewater from food processing, slaughter houses, and the dyeing industry was investigated. In the food processing wastewater, Biopol32 led to a chemical oxygen demand (COD) reduction rate of 70% and a suspended solid (SS) removal rate of 49% at pH 6.0. In the slaughter house wastewater at pH 4.0, a COD reduction rate of 61% and SS removal rate of 91% were observed, and in the dyeing wastewater, the rates were 72% and 92%, respectively, at pH 5.0. The size of floc formed during the flocculation process was 10 mm at a final concentration of 20 ppm, and the dehydration efficiency was 62%. In both the bioflocculant Biopol32 group and a PAA synthetic flocculant group, optimal flocculant concentration that yielded the best overall dehydration efficiency was 20 ppm, and, at this concentration, the shortest filtration time to reach the natural critical moisture content of 78.1% was attained.

• Progress in Medical Physics
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• v.10 no.1
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• pp.1-7
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• 1999

In this study, the dose distributions of a $^{32}$ p uniform cylindrical volume source and a surface source, a pure $\beta$emitter, were calculated in order to obtain information relevant to the utilization of a balloon catheter and a radioactive stent. The dose distributions of $^{32}$ p were calculated by means of the EGS4 code system. The sources are considered to be distributed uniformly in the volume and on the surface in the form of a cylinder with a radius of 1.5 mm and length of 20 mm. The energy of $\beta$particles emitted is chosen at random in the $\beta$ energy spectrum evaluated by the solution of the Dirac equation for the Coulomb potential. Liquid water is used to simulate the particle transport in the human body. The dose rates in a target at a 0.5mm radial distance from the surface of cylindrical volume and surface source are 12.133 cGy/s per GBq (0.449 cGy/s per mCi, uncertainty: 1.51%) and 24.732 cGy/s per GBq (0.915 cGy/s per mCi, uncertainty: 1.01%), respectively. The dose rates in the two sources decrease with distance in both radial and axial direction. On the basis of the above results, the determined initial activities were 29.69 mCi and 1.2278 $\mu$Ci for the balloon catheter and the radioactive stent using $^{32}$ P isotope, respectively. The total absorbed dose for optimal therapeutic regimen is considered to be 20 Gy and the treatment time in the case of the balloon catheter is less than 3 min. Absorbed doses in targets placed in a radial direction for the two sources were also calculated when it expressed initial activity in a 1 mCi/ml volume activity density for the cylindrical volume source and a 0.1 mCi/cm$^2$ area activity density for the surface source. The absorbed dose distribution around the $^{32}$ P cylindrical source with different size can be easily calculated using our results when the volume activity density and area activity density for the source are known.

• Korean Journal of Poultry Science
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• v.18 no.1
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• pp.9-31
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• 1991

The purpose of this study was to investigate the effects of dietary methionine and lysine levels on laying hen performance. The level of protein was fixed 15% during whole experiment period, but the levels of methionine and lysine were 0.30% and 0.58% (Low), 0.32% and 0.64% (Medium), 0.35% and 0 70% (High), respectively. Total 288 laying pullets of 22 weeks age were reared from January 28, 1989 to March 23, 1990 for 60weeks. The results obtained were summarized as follows : 1. The e99 Productions were highest in medium treatment in phase I (22~42weeks of age), phase II (42~62 weeks of age) and phase III (62~82weeks of age) and especially, there was significant difference among treatments during phase II (P＜0.05). 2. Egg weight was significantly increased as the levels of methionine and lysine were increased up to methionine and lysine were 0.32% and 0.64%, respectively(P＜0.01). 3. Daily egg mass was highest when the levels of methionine and lysine were 0.32% and 0.64%, respectively and there were significant differences among treatments during phase I and phase II (P＜0.01) 4. Daily feed intake was increased as the levels of methionine and lysine were increased, and there was significant difference among treatments during phase III (P＜0.05). 5. Feed efficiency was best in medium treatment in phase I and phase II (P＜0.01) 6, Viability was highest in medium treatment, but there was no significant difference among treatments. 7. Nutrient utilizability of experimental diets was not significantly different among treatments. 8. Eviscerated yield was highest and abdominal fat accumulation was lowest in medium treatment, but there was no significant difference among treatments. 9. Egg shell quality and chemical composition of egg content were not different among treatments. 10. The feed cost per kg egg mass was lowest in medium treatment and there were significant differences among treatments in phase I, phase II and whole egg laying period(P＜0.05)

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.198-201
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• 1989

Steptomyces sp. GI 32 with high production of glucose isomerase was isolated from soil. The maximum enzyme production was observed in the culture medium containing 1% sorbitol, 0.6% tryptone, 0.4% yeast extract, 1mM Fe$_2$(SO$_4$)$_3$ with initial pH 7.0 when the cell was cultured at 35$^{\circ}C$ about 18 hours with shaking. The enzyme was partially purified by ammonium sulfate fractionation and DEAE cellulose chromatography. The enzyme was also appeared to be relatively thermostable, and no apopreciable inactivation was observed after incubation at 7$0^{\circ}C$ for 1 hour. The optimal pH and temperature of the enzyme were pH 8.0 and 7$0^{\circ}C$, respectively.