• Tuberculosis and Respiratory Diseases
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• v.66 no.3
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• pp.178-185
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• 2009

Background: Epigallocatechin-3-gallate (EGCG) is the major catechin in green tea, and has shown antiproliferative, antiangiogenic, antimetastatic and cell cycle pertubation activity in various tumor models. Hypoxia can be induced because angiogenesis is insufficient for highly proliferating cancer. Hypoxia-inducible factor-1$\alpha$ (HIF-1$\alpha$) and its downstream target, vascular endothelial growth factor (VEGF), are important for angiogenesis, tumor growth and metastasis. The aim of this study was to determine how hypoxia could cause changes in the cellular phenomena and microenvironment in a non-small cell culture system and to examine the effects of EGCG on a HIF-1$\alpha$ and VEGF in A549 cell line. Methods: A549 cells, a non-small cell lung cancer cell line, were cultured with DMEM and 10% fetal bovine serum. A decrease in oxygen tension was induced using a hypoxia microchamber and a $CO_2-N_2$ gas mixture. Gas analysis and a MTT assay were performed. The A549 cells were treated with EGCG (0, 12.5, 25, 50 ${\mu}mol/L$), and then examined by real-time-PCR analysis of HIF-1$\alpha$, VEGF, and $\beta$-actin mRNA. Results: Hypoxia reduced the proliferation of A549 cells from normoxic conditions. EGCG inhibited HIF-1$\alpha$ transcription in A549 cells in a dose-dependent manner. Compared to HIF-1$\alpha$, VEGF was not inhibited by EGCG. Conclusion: HIF-1$\alpha$ can be inhibited by EGCG. This suggests that targeting HIF-1$\alpha$ with a EGCG treatment may have therapeutic potential in non-small cell lung cancers.

• Journal of The Korean Association For Science Education
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• v.32 no.4
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• pp.555-569
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• 2012

Many science education research and practices are recently emphasizing the importance of collaborative learning. This study also understands learning in aspects of socio-cultural context, and regarded the creation of meaning in a same-age group as an important learning process. This is most especially true in the premise that the formation of roles in a collaborative learning is important for successful interactive learning. This study aims to find out how roles form in a group. For this purpose, university students participating in a group discussion activity about energy flow and circulation of material were selected as research participants. Discussions among the nine students in one group consisted of cognitive conversations on the topic and operational conversations for preparing a presentation. Video-clips of the discussions were made and transcribed. For the analysis, we developed a framework that includes four interaction functions (cognitive, organizational, meta-cognitive, operational), four action elements (question, simple answer, providing opinion, response to opinion), and two to four intention elements by each action elements. As a result, a total of nine roles were revealed through the interaction function and element; cognitive questioner, operational questioner, simple answerer, operational suggester, organizational commander, operational commander, cognitive explainer, terminator, reflective thinker. These roles are re-classified into seven utterance patterns by the utterance order and object, and they were categorized into three role groups (facilitating interaction, sustaining interaction, finishing interaction). The result means that role formation and function can have influence on learning and interaction. This study is meaningful to the suggestion to collaborative learning including project-based learning, investigation, club activity, and for the re-illumination of the role in an aspect of the interaction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.333-340
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• 2014

The purpose of this study was to develop functional lotus root bugak with plasma lipid reduction capacity by controlling the color of batter used for bugak preparation. Lotus root, nearly colorless, was selected to observe color effects. Gardeniae fructus (GF), Opuntia ficus-indica var. saboten (OF), and green tea (GT), which are colored yellow, red, and green, respectively, were used as coloring agents. Fermented glutinous rice was prepared naturally during winter season by placing glutinous rice and water (1:2, w/w) together in a crock pot for 7 days. Coloring materials (10%, w/w) were blended with glue made from fermented glutinous rice flour to prepare the batter. Cooked lotus root was then mixed with a 1.1-fold amount of batter (w/w) and dried at room temperature. Lotus root bugak (LRB) is pan-fried with un-roasted sesame oil, which is traditionally used as frying oil in Korea. Low-density lipoprotein receptor knockout ($LDLr^{-/-}$) mice (n=36) were fed an atherogenic diet (AD) containing various types of LRB (10 g%) for 10 weeks. Plasma triglyceride, total cholesterol, and LDL-C concentrations decreased significantly in mice fed LRB prepared with OF batter (OFB) and GT batter (GTB) (P<0.05). Protein expression levels of fatty acid synthase (FAS) and 3-hydroxyl-3-methylglutaryl coenzyme A reductase (HMGCR) in the OFB and GTB groups were suppressed compared with the LRB group (P<0.05). In accordance with the results on FAS and HMGCR expression, sterol regulatory element binding protein-I and II (SREBP-I and II), which are responsible for the regulation of FAS and HMGCR gene expression, respectively, were down-regulated compared to the LRB group (P<0.05). In conclusion, the plasma lipid reduction activities of OFB and GTB could be mediated through down-regulation of FAS and HMGCR mRNA expression via suppression of regulatory molecules, SREBP-I and II, in $LDLr^{-/-}$ mice.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.3
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• pp.214-220
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• 2001

The clinical application of the three-dimensional radiographic technique had been limited to standard Broadbent-Bolton cephalometer with biplanar stereoradiography. We developed a new method for compensating the error of head position in ordinary non-biplanar cephalostat. It became to possible to use the three dimensional cephalogram commonly in clinical bases. 1. The method of methemetical compensation of head positioning error in non-biplanar condition was evaluated with dry skull. The error of the method of first and the second trial was $0.46{\pm}1.21$, $0.33{\pm}0.90mm$, which means the error of the head positioning correction in conventional cephalogram was within clinical acceptance. 2. The reproducibility of this system for clinical application was 0.54 mm ($-2.99{\sim}2.26mm$) which defines the absolute mean difference of the first and second trial. Compare to the The landmark identification error $1.2{\pm}1.6mm$, the error of the measurement was within the range of landmark identification error. The result indicates the adequate clinical accuracy of the computation of three-dimensional coordinates by compensation of the error of the head position in ordinary non-biplanar cephalostat.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.347-358
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• 2016

Brassinosteroid (BR), a plant steroid hormone, plays key roles in numerous growth and developmental processes as well as tolerance to both abiotic and biotic stress. To understand the biological networks involved in BR-mediated signaling pathways and stress tolerance, we performed comparative genome-wide transcriptome analysis of a constitutively activated BR bes1-D mutant with an Agilent Arabidopsis $4{\times}44K$ oligo chip. As a result, we newly identified 1,091 (562 up-regulated and 529 down-regulated) significant differentially expressed genes (DEGs). The combination of GO enrichment and protein network analysis revealed that stress-related processes, such as metabolism, development, abiotic/biotic stress, immunity, and defense, were critically linked to BR signaling pathways. Among the identified gene sets, we confirmed more than a 6-fold up-regulation of NB-ARC and FLS2 in bes1-D plants. However, some genes, including TIR1, TSA1 and OCP3, were down-regulated. Consistently, BR-activated plants showed higher tolerance to drought stress and pathogen infection compared to wild-type controls. In this study, we newly developed a useful, comprehensive method for large-scale identification of critical network and gene sets with global transcriptome analysis using a microarray. This study also showed that gain of function in the bes1-D gene can regulate the adaptive response of plants to various stressful conditions.

• Journal of Life Science
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• v.19 no.1
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• pp.101-110
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• 2009

The regulation of gene expression plays an important role in cell cycle controls. In this study, a novel $mas2^+$ (mitosis associated protein) gene, a homolog of human SMARCAD1 was isolated and characterized from a fission yeast Schizosaccharomyces pombe (S. pombe) using gene-specific polymerase chain reaction. The isolated gene contained a complete open reading frame capable of encoding 922 amino acid residues with a typical promoter, as judged by nucleotide sequence analysis. It was also found that an SNF2 domain is located, which is involved in the chromosome remodeling. The quantitative analysis of the $mas2^+$ transcript against $adh1^+$ showed that the expression level of $mas2^+$ is high before septum formation in S. pombe. When $mas2^+$ null mutant cells were grown at 27 and $35^{\circ}C$, the cytokinesis of $mas2^+$ null mutant was greatly delayed and a large number of multi-septate and mis-segregated cells were produced. In addition, the number of multi-septate cells significantly increased. When cells were cultured in YES rich medium to increase proliferation, the abnormal phenotypes $mas2^+$ null mutant dramatically increased. These phenotypes could be rescued by an over-expression of the mast gene. The Mas2 protein localized in the nuclei of S. pombe, as evidenced by Mas2-EGFP signals. These results suggest that the $mas2^+$ is homologous to human SMARCAD1 gene and involved in septum formation and chromosome remodeling control.

• Journal of Chest Surgery
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• v.40 no.8
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• pp.529-535
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• 2007

Background: An imbalance between oxidants and antioxidants leads to oxidative stress, and this has been proposed to play an important role in the pathogenesis of lung neoplasm. Apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE/ref-1) is a multifunctional protein involved in DNA base excision repair and the redox regulation of many transcription factors. However, the alteration of the expressed levels of APE/ref-1 in non-small cell lung cancer is unknown. Material and Method: Forty-nine patients with surgically resected non-small cell lung cancer (NSCLC) were included in this study. Immunohistochemical staining with APE/ref-1 antibodies was performed, and their expressions were analyzed via Western blotting for specific antibodies. Result: APE/ref-1 was localized at the nucleus and mainly in the non-tumor region of the NSCLC tissue specimens; it was expressed in the cytoplasm and nucleus of the NSCLC. The nuclear and cytoplasmic expressions of APE/ref-1 in lung cancers were markedly up-regulated in the NSCLC, and this was correlated with the clinical stage. Catalase, as first-line antioxidant defense, was dramatically decreased in the NSCLC. Conclusion: Taken together, our results suggest that APE/ref-1, and especially cytoplasmic APE/ref-1, was upregulated in the lung cancer regions, and this may contribute to the compensatory defense system against oxidative stress. A low expression of catalase might have fundamental effects on the extracellular redox state of lung tumors, along with the potential consequences for the tumors.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.1-6
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• 2001

This experiment was conducted to evaluated the effect of maturity at harvest on the changes in quality of round baled rye silage at forage experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon in 1998. The experimental design was a split-plot design with three replications. The main plots were three different harvest stages : boot, heading and flowering stages, and the subplots were days after ensiling : 1, 2, 3, 5, 10, 30, 45, and 60 days. The wilting period of boot, heading and flowering stages were 1, 0.5 and 0.5 days, respectively. The final pH of rye silage was higher in the order of flowering, boot and heading stages. And pH of flowering stage began to change at early fermentation period, but that of boot and heading stages was delayed 1~2 days. Ammonia-N content of boot stage was highest. and that was increased as fermentation progressed. But Ammonia-N of heading stage was decreased to 30 days. then that was increased after 45 days fermentation. Among fermentation periods, inside temperature of deep place was not affected by external temperature. And that of deep place was increased to 3$0^{\circ}C$ at early fermentation. then decreased as fermentation progressed. However surface temperature was affected by external temperature after 10 days. Acetic acid content was not changed with 5 days by harvest stages, but that of boot stage was increased after 10 days. Butyric acid of boot stage was increased after 5 days. but that of heading stage was increased after 10 days. However lactic acid was increased from 1~2% to 6~8%. Lactic acid bacteria (LAB) of heading and flowering stages were highest at 5 days fermentation, and that of boot stage was highest at 10 days fermentation. The results of this study indicate that fermentation of round baled rye silage occur within 5 days. Therefore, any modification should be applied with an 5 days for high quality of round baled rye silage.

• Journal of Life Science
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• v.21 no.11
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• pp.1625-1630
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• 2011

Heme oxygenase-1 (HO-1) is a stress-responsive protein that is known to regulate cellular functions such as cell proliferation, inflammation, and apoptosis. In this study, we investigated the role of NADPH oxidase on the expression of HO-1 in human liver hepatoma cell line HepG2. Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, markedly inhibited HO-1 expression and the nuclear translocation of transcription factor Nrf2 in cobalt protoporphyrin (CoPP) or hemin-treated HepG2 cells. Similarly, the knockdown of $p47^{phox}$, a cytosolic factor for NADPH oxidase activity, by siRNA inhibited the CoPP-induced expression of HO-1. In addition, GSHmee, an intracellular antioxidant, blocked the expression of HO-1 in CoPP-treated cells. Based on these results, we conclude that the blockage of NADPH oxidase with DPI or $p47^{phox}$ siRNA inhibits CoPP-induced HO-1 expression in HepG2 cells, and also suggest that the expression of HO-1 in CoPP-induced HepG2 cells is associated with increase of intracellular ROS by NADPH oxidase activity.

• Journal of The Korean Association For Science Education
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• v.35 no.2
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• pp.217-229
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• 2015

In this study, we explored the development of scientific model through the social-construction process on "combustion." Students were 8th graders from one middle school class. Each student engaged in small group discussions three times and made a group model on combustion. Discourses between peers and teacher were videotaped, audiotaped, and transcribed. The results show that the small groups constructed an initial concept: 'Conditions of combustion', which they then evaluated and revised the initial concept through combustion experiment. Following the discussions, some small groups evaluated their model and made a revised model. Then, the small groups compared various models and constructed a scientific model through consensus within the small group and as a whole class. Finally, students kept revising their model to 'Burning needs oxygen.' This tells us that the social construction process of scientific model made a meaningful role to build scientific model through diverse discussion between the students and their teacher, although they have had some difficult process to reach the final consensus. The data also showed some group features: the members were open to other's ideas. They analyzed the differences between their own ideas from others and revised their model after the whole class discussion. Lastly, they showed the tendency to make a good use of teacher's guidance. This study implies the importance of having social interaction process for students to understand the scientific model and learn the nature of scientific inquiry in class.