• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.11-16
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• 1976

This experiment was carried out to determine the most adequate type and period of nursery for the late seasonal cultivation of the new varieties of rice, Yusin and Josaengtongil. The results obtained are summarized as follows: 1. Semi-hot up-land nursery was much effective for the increase of the number of tillerings and the roots of rise seedlings compared with the semi-hot low-land nursery. The number of tillerings and roots was increased in 60 days seedlings compared with 50 or 60 days seedlings. 2. The abnormal heading has not appeared at the variety Yusin at all. The seedlings of Josaengtongil grown over 50 days at the semi-hot low-and nursery showed the abnormal heading, but the abnormal heading was not checked out at the seedlings of same variety grown for 60 days on the semi-hot upland nursery. 3. On the nursery not to cause the abnormal heading, earlier seeding was much effective for the hastening of the heading time and the hastening effect of heading time by earlier seeding was significantly greater at the variety Josaengtongil than Yusin 4. The number of ears per hill was significantly increased in the seedlings from the semi-hot up-land nursery compared with the semi-hot low-land nursery. 5. When the growing period of rice seedlings was not considered, the semi-hot up-land nursery resulted in higher yield of rice than the semi-hot low-land nursery. Considering the growing periods of rice seedlings, 40 days seedlings showed high yield at the semi-hot low-land nursery, however, at the semi-hot up-land nursery, 60 days seedlings showed higher yield of rice.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.118-127
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• 1985

The grain temperature is a crucial factor determining the deterioration rate of stored grain. Therefore, it is used to be predicted in order to evaluate the various stored methods rapidly and inexpensively. In this study, a mathematical model was developed to simulate the temperatures of grain stored in a cylinderical bin. It was formulated for the two dimensional heat transfer by the finite difference method. Then, it was verified statistically using the actual test deta and the predicted. The changes of grain temperature were analyed using the simulated data of one year for a safe stoarge and the following results were obtained: 1. Simulation model developed by the finite difference method was validated with the actual and the predicted grain temperatures and it's result showed that it could predict the grain temperature of storage bin reasonably well. 2. Grain temperature near the wall of storage bin were changed with $6-7^{\circ}C$ higher then average atmospheric temperature from June to September. Therefore, the parts of stored grain near the wall is supposed to be deteriorated fast. 3. When the dimension of bin diameter is about the same as the bed height, the changes of grain temperature of radial direction was higher than the verticals. 4. The predicted temperature showed that the grain temperature of which were from the end of April to mid October were higher than the safe storage limit at Yusung, Korea.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.219-223
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• 2010

Purpose: To test the radiosensitizing effect of the newly synthesized novel histone deacetylase inhibitor, SK-7041 in vivo. Materials and Method: The RIF-l cell line was implanted into the back of a 6-week-old female C3H mouse, intradermally, The mice were grouped into control, drug, radiation (RT), and RT+drug group. SK-7041, 4 mg/kg was administered intraperitoneally for six cycles every 12 hours for mice in the drug and RT+drug group, An identical volume of phosphate buffered saline (PBS) was administered at the same frequency to mice in the control and RT groups. A single 5 Gy fraction was delivered to mice in RT and RT+drug group 6 hours after the fourth delivery. The volume of the implanted tumor was measured every 2~3 days to formulate the growth delay curve. Results: For the control, drug, RT, and RT +drug groups, the average duration for implanted tumor to reach a volume of $1,500mm^3$ was 10 days, 10 days, 9 days, and 12 days, respectively. Moreover, the tumor volume on D14 was $276.7mm^3$, $279.9mm^3$, $292.5mm^3$, and $185.5mm^3$, respectively (p=0.0004). The difference for the change in slope for the control and drug versus the RT and RT+drug groups were borderline significant (p=0.0650). Conclusion: The results of this study indicate that SK-7041 has a radiosensitizing effect for the RIF-1 cell line in vivo at a low concentration and this effect may be synergistic. Implementing this result to clinical trial is warranted.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.267-274
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• 2014

High pressure processing (HPP) is a non-thermal method used to prevent bacterial growth in the food industry. Currently, pasteurization is the most common method in use for most milk processing, but this has the disadvantage that it leads to changes in the milk's nutritional and chemical properties. Therefore, the effects of HPP treatment on the microbiological and chemical properties of milk were investigated in this study. With the treatment of HPP at 600 MPa and $15^{\circ}C$ for 3 min, the quantity of microorganisms and lactic acid bacteria were reduced to the level of 2-3 log CFU/ml, and coliforms were not detected during a storage period of 15 d at $4^{\circ}C$. An analysis of milk proteins, such as ${\alpha}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin by on-chip electorophoresis revealed that the electrophoretic pattern of the proteins from HPP-treated milk was different from that of conventionally treated commercial milk. While the quantities of vitamins and minerals in HPP-treated milk were seen to be comparable to amounts found in raw milk, the enzyme activity of lipase, protease and alkaline phosphatase after HPP treatment was reduced. These results suggest that HPP treatment is a viable method for the control of undesirable microorganisms in milk, allowing for minimal nutritional and chemical changes in the milk during the process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.975-982
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• 2015

Piceatannol (trans-3,4,3',5'-trihydroxystilbene), a natural stilbene, is an analogue of resveratrol. In the present study, possible mechanisms by which piceatannol exerts its pro-apoptotic action in cultured human oral cancer YD-15 cells were investigated. To investigate whether or not piceatannol has effects on cancer cell viability, human oral YD-15 cells were treated with piceatannol (0, 50, and $100{\mu}M$). Piceatannol treatment ($100{\mu}M$) showed the strongest inhibition of cell proliferation and reduced cell viability in a dose-dependent manner. Chromatin condensation detected by DAPI staining significantly increased in a concentration-dependent manner, indicating apoptosis. Piceatannol treatment activated initiator Bax (pro-apoptotic) and cPARP in a concentration-dependent manner. Further, piceatannol induced down-regulation of Bcl-2 (anti-apoptotic). We also evaluated the activity of piceatannol against oral cavity cancer tumors in mice. Piceatannol-treated nude mice bearing YD-15 xenograft tumors exhibited significantly reduced tumor volume and weight due to the potent effect of piceatannol on tumor cell apoptosis, as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Immunohistochemistry staining showed elevated expression of cleaved-caspase-3 as well as reduced expression of Ki-67 in the piceatannol-treated group. Therefore, piceatannol can be developed as a cancer preventive medicine due to its growth inhibitory effects and induction of apoptosis in human oral cancer cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.989-994
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• 2007

This study was designed to investigate whether Sasa borealis leaves extracts (SLE) may inhibit yeast ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities and postprandial hyperglycemia in STZ-induced diabetic mice. Freeze-dried SLE was extracted with 70% methanol and followed by a sequential fractionation with dicholoromethan, ethylacetate, butanol, and water. Both ethylacetate and butanol fractions showed high inhibitory activities against the ${\alpha}-glucosidase$ and ${\alpha}-amylase$ enzymes. The $IC_{50}$ of ethylacetate and butanol fractions against ${\alpha}-glucosidase$ were 0.54 and 0.63 mg/mL, respectively, indicating a greater inhibition effect than acarbose (0.68 mg/mL) (p<0.05). Likewise, the two fractions exhibited a smaller $IC_{50}$ against ${\alpha}-amylase$, compared with acarbose (p<0.05). However, the yield of ethylacetate fraction of SLE was relatively small. Postprandial blood glucose testing of normal mice and STZ-induced diabetic mice by starch soln. loading (2 g/kg B.W.) showed that postprandial blood glucose level at 30, 60, and 120 min were markedly decreased by single oral administration of SLE butanol fraction (200 mg/kg B.W.) in both normal (p<0.0l) and diabetic mice (p<0.0l). Furthermore, the incremental area under the curve (AUC) was significantly lowered via SLE administration (5,745 versus 12,435 $mg{\cdot}mim/dL$) in the diabetic mice (p<0.0l). The incremental AUC in normal mice corroborated the hypoglycemic effect of SLE (p<0.0l) found in the diabetic mice. These results suggest that SLE may delay carbohydrate digestion and thus glucose absorption. In addition, SLE may have the potential to prevent and treat diabetes via its ability on lowering postprandial hyperglycemia.

• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.163-170
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• 1977

Potato diseases, especially mosaics and leaf roll, appear to reduce potato yield in Korea more than any other factor. A seed potato certification program was established at the Alpine Experiment Station (AES) in 1961 to produce high quality seed potatoes for distribution to Korean farmers. The present program for production of certified seed of Namjak (Irish Cobbler), the only variety recommended for spring plantings, is outlined. In 1976, approximately 10,000 MT of certified grade Namjak seed was produced by members of two Seed Producers Cooperatives in the Daekwanryeong area for distribution by the Office of Seed Production and Distribution (OSPD). The seed was inspected and certified by officers of the National Agricultural Products Inspection Office (NAPIO). Although the quality of the certified seed is far superior to that used by many farmers, the supply planted less than 1/5 of the 1977 potato crop. Certified seed of Shimabara, the variety recommended for autumn plantings, is not produced in Korea. The yield response of virus infected seed to improved cultural practices is poor. Therefore, an increase in potato acreage and yields appears to be possible only if more good quality seed is used by Korean farmers. A two or three fold increase in seed supply would be desirable. The volume of seed could be increased by expanding the production area and by improving yield in seed fields. More land is available in the alpine area and good seed potatoes could be grown in other parts of Korea. Planting better quality seeds and using better cultural pracitces would improve seed yields. Several techniques could be used to improve the quality of elite seed produced at AES. Changes in seed potato certification program should be made so that healthy seed stocks of new varieties can be released rapidly.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.453-457
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• 2016

This study investigates the hatching periods and hatchability of the eggs of Pochazia shantungensis at different collection times from 2011 to 2014, and the effect of temperature on the growth of P. shantungensis nymphs in an area of its outbreak. The hatchability of P. shantungensis eggs varies with their collection time; their hatchability in late November was higher than that in March of the next year, but no difference was observed in their hatching periods. The hatching periods of the eggs were 51.2, 31.3, 24.8, 19.4, 17.1, and 19.4 days at 15, 18, 21, 24, 27, and $30^{\circ}C$, respectively. The hatchability was above 70% at temperatures ranging from 18 to $27^{\circ}C$. The hatching time of the overwintered eggs in the Gurye region in Korea was reduced by 9 days from 2011 to 2014. The hatching rate was relatively higher when the average temperature in the winter season was relatively warmer. The dvelopmental periods of the first to fifth nymphs were 82.8, 58.0, 45.8, and 39.6 days at 18, 21, 24, and $27^{\circ}C$, respectively, at the relative humidity of 40~70%, and a photoperiod off 14 h light:10 h dark. The higher the temperature, the shorter the developmental period. At $30^{\circ}C$, all life stages after the fourth nymph died. Thus, the optimum growth temperature was estimated to be $27^{\circ}C$. For all life stages from the egg to the fourth nymph, the relationship between the temperature and developmental rate was expressed by the linear equation Y = 0.0015 X - 0.014. The lower developmental threshold was $9.3^{\circ}C$ and the effective cumulative temperature was 693.3 degree-days. The lower developmental threshold of approximately $3.8^{\circ}C$ was the lowest at the fourth nymph stage.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.338-349
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• 1999

Polymorphonuclear leukocytes(PMN) are the predominant inflammatory cells recruited in acute lung injury such as adult respiratory distress syndrome, pneumonia and also chronic lung disease such as idiopathic pulmonary fibrosis and pulmonary emphysema. Interleukin-8(IL-8) is an 8,000 D protein produced by many cells and has potent neutrophil chemoattractant and activating properties. The GRO, also called melanoma growth-stimulatory activity(MGSA), referring to a peptide of 73 amino acids, was reported to be mitogenic for cultured human melanoma cells. Mature GRO/MGSA has marked sequence similarity to IL-8. In view of the structural similarities to IL-8, it was of particular interest to test GRO for neutrophil activating and chemotactic properties. We found a significant release of IL-8 and GRO/MGSA from the cultured human umbilical vein endothelial cell(HUVEC) which was stimulated either with TNF$\alpha$ or IL-1$\beta$ and also found the expression of IL-8 and GRO/MGSA mRNA. Neutrophil chemotactic activity was enhanced in accordance with the increased IL-8 and GRO/MGSA. Our study also suggest that the IL-8 is more important in the increased neutrophil chemotactic activity than GRO/MGSA when endothelial cell is stimulated with TNF$\alpha$ or IL-1$\beta$ in vitro.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.842-851
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• 1996

Background : Rifampicin(RFP) is a key component of the antituberculous shon-course chemotherapy and the RFP-resistance is a marker of multi-drug resistant(MDR) M. tuberculosis. rpoB gene encodes the ${\beta}$-subunit of RNA polymerase of M. tuberculosis which is the target of RFP. Recent reports show that rpoB gene mutations are the cause of RFP resistance of M. tuberculosis and the main mechanism of rpoB gene mutation is point mutation. And PCR-SSCP is a rapid and easy method for detecting point mutations. So we performed PCR-SSCP of rpoB gene of M. tuberculosis and compared the result with traditional RFP sensitivity test. Method : The 27 RFP sensitive M. tuberculosis culture isolates and 25 RFP resistant isolates were evaluated. The RFP sensitivity test was done at the Korean Tuberculosis istitute. The DNA was extracted by bead beater method and was amplified with primers TR-8 and TR-9 in a 20ul PCR reaction containing 0.1ul(luCi) [${\alpha}-^{32}P$] - dCTP. After amplification, SSCP was done using non-denaturaring polyacrylamide gel electrophoresis. Then direct sequencing was done in cases of different eletrophoretic mobility compared with that of H37Rv. In 19 cases, we compared PCR-SSCP results with patient's clinical course and the results of traditional RFP sensitivity test. Results : 1) All 27 RFP sensitive M. tuberculosis isolates showed the same electrophoretic mobility compared with that of H37Rv. And all 25 RFP resistant M. tuberculosis isolates showed different electrophoretic mobility. 2) The mechanism of rpoB gene mutation of M. tuberculosis is mainly point mutation. 3) The PCR-SSCP results correlate well with traditional RFP sensitivity and patient's clinical response to antituberculous treatment. Conclusion: The PCR-SSCP of rpoB gene is a very sensitive and rapid mehod in detecting RFP- resistant M. tuberculosis.