• KSBB Journal
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• v.21 no.4
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• pp.306-311
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• 2006

Cell preservation is indispensable in animal cell culture process and should be established according to the cell characteristics. In this study, we experimented hypothermic preservation of CHO cells that is widely used in pharmaceutical industry to produce therapeutic proteins and established a stable method of preservation. The highest viability of CHO cells was obtained when the cells were preserved using rolling tube, which means the cells should be suspended to avoid the cell lumping during the preservation. Also, we obtained superior preservation result under the anaerobic condition. To evaluate the serum-free media as a preservation solution, we investigated cell growth after hypothermic preservation using serum-free media. High cell viability and normal cell growth was observed during 10 days using serum-free media. Moreover, we found that more effective preservation when ${\alpha}$-tocopherol and retinoic acid is added to media as an additive. In the case of 1 liter large scale hypothermic preservation using established protocol, cell viability and growth rate was obtained as good as small scale one. This study is considered to be helpful for hypothermic preservation of CHO cells and large scale hypothermic preservation may be available through the further studies.

• Journal of Life Science
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• v.22 no.4
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• pp.492-498
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• 2012

To investigate whether phytochemicals affect cancer cell viability, human colorectal HCT116 cells were treated with four different phytochemicals. Among these phytochemicals, curcumin is the strongest inhibitor of cell proliferation. In addition, it decreased cell viability in a dose-dependent manner. To unveil the molecular mechanisms involved in the inhibition of cell proliferation by curcumin, we carried out oligo DNA microarray analysis. We found that 137 genes were up-regulated more than 2-fold, and 141 genes were down-regulated more than 2-fold by 25 ${\mu}M$ curcumin treatment. Among the up-regulated genes, we selected 3 genes (ATF-3, GADD45A, and NR4A1) to confirm microarray data. The results of RT-PCR strongly agreed with those of the microarray data. Among the phytochemicals used in this study, curcumin is the strongest inducer of ATF3 expression, and increased ATF3 expression in a dose-dependent manner. Interestingly, FACS analysis showed that the inhibition of cell growth by curcumin was recovered by ATF3-siRNA transfection. Finally, we detected the changes of gene expression by ectopic expression of ATF3. The results indicated that many up-regulated genes were related to apoptosis. Overall, these results suggest that ATF3 may play an important role in the anti-proliferative activity of curcumin in human colorectal cancer cells.

• Journal of Digital Convergence
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• v.8 no.2
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• pp.13-28
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• 2010

Korean service industry has been rapidly growing so far and economic trends in korea is shifting to service economy. However Information Communication Technology (ICT) investment and use in service sector are still relatively low in comparison with US. Keeping the current state of the service industry in mind, this paper is to review the potential productivity growth of service industry empirically by analyzing the effect of ICT on total factor productivity after investing the ICT using outlook of Korean service industry. The results show that service sectors, with more using ICT, show high productivity growth and stable TFP change during the financial period. Sectors with lower using ICT are more sensitive to changes in the business environment when compare to sectors with highly using ICT. Concerning the period of 1997-1999, the TFP growth of most of sectors slowed down and turned to recovery immediately afterwards, 2000-2002.

• Journal of Korean Society of Forest Science
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• v.56 no.1
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• pp.51-65
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• 1982

The growth characteristics and appropriate fertilizer-managements in the rejuvenating bamboo grove were studied with Phyllostachys reticulata. The bamboo soil was the sandy loam with rich humus. In the fertilized plots, the N-fertilizer was significantly absorbed, and it was necessary to fertilize the K-fertilizer continuously. According to the development of rejuvenating after flowering, the temperature and relative illumination became lower. while the moisture became higher. The relationship between the diameter at eye height (D) and the culm length (H) of each bamboo can be expressed as follow; $H=2.5538D^{0.5031}$ The leaf area is the major factor for the production of the bamboo grove. Therefore in the rejuvenating grove, we should refrain form pruning or felling of not -flowering bamboo. The theoretical distribution of the internodal length was obtained by the distribution curve line of the internodal length derived from the regular distribution curve line. Relatively long and even internodal length was found in the fertilized plots 2 and 4. The relation between $D^2H$ and dry weight of culm or dry weight of the above ground part were given by linear regression in both relations respectively on the logarithmic coordinates, but the propertional relation was not established in these relations. The biomass of the above ground part obtained by the allometry method showed high values in the fertilized plots 2.5 and 6. The appropriate amounts of the three elements, N, P and K for the maximum dry matter were 24.19, 15.51, 8.63 kg/10a, respectively.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.109-116
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• 1999

Purpose: Insulin-like growth factor(IGF)-I and -II are peptide growth factor whose activity is modulated by interaction with the family of six IGF-binding proteins(IGFBPs). IGF-I is detected in rat kidney and has metabolic and growth effects. This study was designed to examine temporal expression of IGFBPs in kidney during renal development and postischemic regeneration in rat. Method: The expression of IGFBPs in kidney during renal development from 15th day of gestation to adult life by using Northern blot analysis. We also examined the renal IGF-IGFBP axis in uremic rat by using Northern blot and immunohistochemistry. Results: The mRNA of IGFBP-1 and -3 were not or barely detected in fetal stages. However, the mRNA level of IGFBP-1 and -3 were increased gradually from day 7 after birth to adult. In contrast, the mRNA of IGFBP-2 and -5 were highly expressed in fetal stages and maintained almost same levels until day 7 (IGFBP-2) or day 30 (IGFBP-5) after birth, then their levels decreased markedly. The mRNA of IGFBP-4 were expressed moderately in fetal kidney and increased gradually after birth. Interestingly, the mRNA of IGFBP-1 and-4 were induced up to 3-5 fold during maximum regeneration period and were recovered to normal levels after acute ischemic injury. In contrast, the mRNA level of IGFBP-3 and-IGFBPrP-1 were decreased slightly at 1 day after ischemic injury, then recovered to normal level during maximum regeneration period. Conclusion: There were differential expressions of IGFBPs in kidney that can modulate IGF action on developing, differentiating, maintaining, and regenerating renal structure and function.

• Korean Journal of Materials Research
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• v.10 no.6
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• pp.422-429
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• 2000

To investigate the effect of annealing temperature and time on the recrystallization behavior and microstructure of Zr-based alloys, the specimens of Zr-0.8Sn-0.4Nb-0.4Fe-0.2Cu, Zr-1Nb, Zircaloy-4, and unalloyed Zr were cold-worked and annealed at 400, 500, 600, 700, 800, $900^{\circ}C$ for 30 to 5000 minutes. The hardness, microstructure and precipitate of the specimens were investigated by using micro-hardness tester, optical microscope and transmission electron microscope, respectively. The recrystallization of Zr-based alloys occurred between $400^{\circ}C$ and $600^{\circ}C$. As the content of alloying elements increased, the hardness and recrystallization temperature of the alloys increased though the grain sizes after recrystallization decreased. It was supposed that the hardness of Zr-based alloy with Fe or Cu increased during recovery by the formation of Fe or Cu precipitates.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.3
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• pp.103-111
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• 2016

Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.1-7
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• 2002

This study was performed to investigate the possibility of water purification by a wild train of Oenanthe javanica DC. Three commercially available dishwashing detergents and a standard surfactant, linear alkylbenzene sulfonate (LAS), were used for this study. The experiment was done in 1.5 ι transluscent aquariums. The plants were distributed into various concentrations of detergents and various kinds of detergent in the separate aquariums. The wet weight of the plants was significantly decreased (p<0.05), and the visual vitality of the plants also decreased in 2 days. The higher the concentration of detergent was, and the more time the plants were exposed to the detergents, the more decrease of growth was observed. The pH value of the culture media decreased in 2 days and in 4 days, then slightly increased in 6 days. However, the pH value of the media did not return to the initial neutral level of pH in 6 days. The pH value of the culture media containing the LAS remarkably increased in 6 days and increased to a neutral pH value in 18 days (p<0.01) as the pH of the other culture media. The chemical oxygen demand (COD) of the culture media gradually increased over the 4 days. A decrease of COD was observed in 6 days, but no tendency was observed between 12 and 18 days. The detergent in the culture media was highly significantly decreased in 2 days (p<0.01) and gradually decreased after this. After 6 days the remaining detergent was 12.4∼23.7% from the various levels of initially added concentration, and 22.4 ∼34.2% from the flour kinds of detergents. These results show that the reduction of detergent was caused by Oenanthe javanica and the effect was significant during the first 6 days when the plants were still growing well. These results indicate that the plant purifies contaminated water for several days and the effect could be variable according to the level of contamination and the environment in which the plant grows.

• Journal of Veterinary Clinics
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• v.29 no.6
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• pp.474-482
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• 2012

Elongation of cheek teeth roots in pet rabbits is very common, and is associated with malocclusion followed by reduced appetite, salivation, periapical abscess, and epiphora. Conservative methods including medication, drainage, irrigation, tooth trimming, intraoral and extraoral extraction, surgical treatment of periapical abscessation, and diet control have been adapted as the only treatments to resolve elongation of teeth roots. However, remaining challenges include the long-term period of cure and recurrence. This study was performed to investigate the possibility of nonvital pulp therapy on elongation of the mandibular cheek teeth roots in pet rabbits. Thirty-one pet rabbits with dental problems due to root elongation were submitted. Ten pet rabbits among them were treated by nonvital pulp therapy procedures (group A), while the others were treated by conservative methods (group B). Appetite improved within 1-5 days after nonvital pulp therapy and the treatment was discontinued 1 month postoperatively in group A. Abscess occurred in another site not treated with nonvital pulp therapy in only two rabbits. Growth of the mandibular cheek teeth treated with nonvital pulp therapy stopped, resulting in malocclusion, intraoral inflammation from the enamel spur, and abscess of the teeth roots. In the group B rabbits treated with conservative therapy, partial drainage, long term medication, recurrent oral trimming and control of repeated oral inflammation occurred. Consequently, buccotomy or tooth extraction was performed in group B. Owners were satisfied with nonvital pulp therapy preventing dental root abscess and repeated troubles including inflammation and malocclusion and reduction of the treatment period. These results suggest that nonvital pulp therapy can be performed on pet rabbits with elongation of mandibular cheek teeth roots.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.120-123
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• 2001

Objectives : The present study was performed to analyze results of hydroxyurea treatment for unresectable and recurrent meningiomas as adjuvant chemotherapeutic agent. Material and Methods : Among 87 cases of meningioma patients who treated surgically between Jauary 1988 and December 1997 in our department, unresectable and recurrent cases were 4 cases. Histologically, 3 cases were meningothelial type, 1 case was angiomatous type. Tumor orgin was cerebellopontine angle(CPA) in 3 cases, cavernous sinus in 1 case. Three of 4 cases received radiation treatment. All patients received a daily dosage of 20mg/kg/day of hydroxyurea. Hematological monitorning was performed monthly and tumor measurement was assessed by MR imaging before treatment and every 6 months. Mean follow-up period was 34 months. Rerults : All cases showed no enlargement of tumor mass without any shrinkage. Trigeminal neuralgia in 1 case was improved and external herniation of brain on craniectomy site in 1 case was shrunken. None of the patients had any serious side effects. White blood cell count fell below $3000/{\mu}l$ in 1 case, but recovered 2 weeks later with cessation of medication. Conclusion : Hydroxyurea stopped cell growth by triggering the apoptotic cascade. Our preliminary data indicate that hydroxyurea provides adjuvant medical treatment in patients of unresectable and recurrent meningiomas