• The korean journal of orthodontics
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• v.40 no.4
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• pp.239-249
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• 2010

Objective: The aim of this study was to identify the expression of nitric oxide synthases (NOS) in the mandibular condyle during mandible advancement by functional appliance and to correlate it with the histologic changes and bone remodeling. Methods: Twenty-four female, 35-day-old Sprague-Dawley rats were randomly divided into 3 experimental groups. In all experimental groups, the mandibles of the rats were kept in a continuous forward position with a fixed bite jumping appliance. The rats were sacrificed on the 3rd, 14th, and 30th days of experiment. More than 2 rats in each group were used for staining. Results: There were no remarkable histologic changes and NOS expression differences in the control group. The most prominent histologic changes occurred in the 14th day experimental group. NOS decreased in the 30th day experimental group. There was increased expression of $NOS_2$ and $NOS_3$ in all experimental groups, comparative to the control group. In all the experimental groups and control group, the expression of $NOS_2$ was greater than that of $NOS_3$. Conclusions: It is postulated that $NOS_2$ and $NOS_3$ in the mandibular condyle might play an important role in bone remodelling of the mandibular condyle.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1112-1117
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• 2008

Purpose : We intended to observe cell death and apoptotic changes in neurons in organotypic hippocampal slice cultures following oxygen-glucose deprivation (OGD), using propidium iodide (PI) uptake, Fluoro-Jade (FJ) staining, TUNEL staining and immunofluorescent staining for caspase-3. Methods : The hippocampus of 7-day-old rats was cut into $350{\mu}m$ slices. The slices were cultured for 10 d (date in vitro, DIV 10) and and exposed to OGD for 60 min at DIV 10. They were then incubated for reperfusion under normoxic conditions for an additional 48 h. Fluorescence of PI uptake was observed at predetermined intervals, and the cell death percentage was recorded. At 24 h following OGD, the slices were Cryo-cut into $15{\mu}m$ thicknesses, and Fluoro-Jade staining, TUNEL staining, and immunofluorescence staining for caspase-3 were performed. Results : 1) PI uptake was restricted to the pyramidal cell layer and DG in the slices after OGD. The fluorescent intensities of PI increased from 6 to 48 h during the reperfusion stage. The cell death percentage significantly increased time-dependently in CA1 and DG following OGD (P<0.05). 2) At 24 h after OGD, many FJ positive cells were detected in CA1 and DG. Some neurons had distinct nuclei and processes while others had fragmented nuclei and disrupted processes in CA1. TUNEL and immunofluorescent staining for caspase-3 showed increased expression of TUNEL labeling and caspase-3 in CA1 and DG at 24 h after OGD. Conclusion : The numerous dead cells in the slice cultures after OGD tended to display apoptotic changes mediated by the activation of caspase-3.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.141-146
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• 2004

Fungal products indirectly mediate anti-tumor effects in vitro and in vivo. To investigate whether Lentinus edodes might possess direct anti-tumor substance, L. edodes was extracted and tested on human papillomavirus (HPV) 16 oncogenes-associated animal tumor cells (TC-1) and in an animal tumor model. Only water extract displayed direct anti-proliferative effects in TC-1 tumor cells in vitro. This inhibition was dose-dependent, and inhibitory concentration ($IC_{50}$) was $800\;{\mu}g/mL$. Fungal extracts also showed growth inhibition to human cervical cancer cells (CaSki and HeLa) similarly to TC-1 tumor cells. When fungal extracts were added at a high dose (1.5 mg/mL), cell growth was inhibited within 6 hr following extract treatment. Cell growth inhibition was blocked by heat treatment, but not by low pH, which is indicative of heat sensitivity of this anti-proliferative substance. Cell growth suppression was mediated by apoptosis, as determined by Annexin V and propidium iodide staining. When challenged with TC-1 cells, direct intratumoral injection of fungal extracts resulted in some positive effect on tumor growth inhibition, as compared to oral delivery. Results suggest that heat labile substance of L. edodes suppresses growth of HPV oncogenes-associated tumor cells through apoptosis.

• The Journal of Art Theory & Practice
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• no.2
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• pp.75-120
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• 2004

Studies on western art in Korea has been caught in a dilemma that they could deal with only those things which had been arranged according to their 'historical generalization' in their contexts because of the bounds of time and space. It is not trivial that such conditions affect art studies in Korea. Access to the original texts and to their contexts of production is so restricted that the studies on them are prone to he superficial. And it is not independent on the politics of Korean art scene. Such factors are on the background of Korean art's excessive 'assimilation or accordance' with western art. The domestic studies on western art history and art theory have failed to notice the differences in context and Korean art has simply mediated or reproduced the restricted information by those studies. Also the studies on western art in Korea have been made use of as a justifying method of one's own academic domains. In such situations we should lead the studies on western art history and western art theory to a more reflective direction and confirm that the studies should not have any privileges of the realities. And we should try to reform a scholarship which participates in our life and existence. The field of domestic studies on western art history and western art theory should free itself from the invention of objectivity or the neutrality of mechanical reading and turn its eyes to the realities of life where events happens. Constantly suggesting which way Korean art and world art should go has to be the field's new coordinates.

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.324-339
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• 2013

This study aims to investigate the characteristics of cyber communities composed of migrant workers from communities without propinquity in Korea. Its methods are both qualitative and quantitative. It further seeks to discover the relationship between the social capital formed and reproduced within these cyber communities and participants' cultural adaptation to Korean society. The study revealed that ethnic and non-ethnic communities differed in terms of strength of cohesion, space constraints, and links with the outside world. The former showed characteristics of a localized community type. The main motivations for migrant workers' participation in the ethnic cyber community were communication and friendship rather than cooperation and sharing among members. They usually used cyber communication media to communicate with one another. Conversely, the latter showed characteristics of an integrative type. Despite the difficulties in applying for membership and information provided in Korean, a high percentage of migrant workers participated in the community to obtain crucial information. The results did not show a significant correlation between social capital and migrant workers' traits within the cyber community, while a strong correlation emerged among four factors of social capital: faith, norms, networking, and political participation. The study showed that social capital in the cyber community was in direct proportion to an integrative type of cultural adaptation to Korean society. In particular, there was a strong connection between the cultural adaptation exhibited by members of the migrant subculture and their participation in discussions on political issues and human rights, with some migrants even functioning as agents of social change as participants in citizens' movements. The findings suggest that the cyber community facilitates the migrant subculture's communication with and integration into the indigenous Korean culture. Migrant workers' participation in the cyber community is therefore validated as an instrumental practice for members of this subculture to adapt to Korean society.

• Applied Biological Chemistry
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• v.51 no.2
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• pp.142-147
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• 2008

Nuruk is the Korean traditional Koji that contains various microorganisms and has been used to make the traditional fermented foods including alcoholic beverages. Rhizopus oryzae KSD-815 was isolated from the alcohol-fermenting Nuruk used for manufacturing traditional alcohol. In this study, the authors reported the isolation and identification of four lipids from the Nuruk (Rhizopus oryzae KSD-815) that inoculated wheat with Rhizopus oryzae KSD-815. The dried and powdered Nuruk (Rhizopus oryzae KSD-815) were extracted three times at room temperature with 80% aqueous MeOH. The extracts were partitioned with EtOAc, n-BuOH, and water, successively. The EtOAc extract was suspended in 80% MeOH and partitioned repeatedly with n-hexane. From the n-hexane fraction, four lipids were isolated through the repeated silica gel and ODS column chromatographies. According to the results of physico-chemical data including NMR, GC and MS, the chemical structures of the compounds were determined as linolenic acid methyl ester (1), palmitic acid methyl ester (2), linoleic acid (3), palmitic acid (4). Cytotoxicity was evaluated in huamn breast cancer cells, MDA-MB-231 and human hepatocarcinoma, SK-HEP-1 cells using MTT assay. Exposure of compounds 1 and 3 led to a dose-dependent inhibition of cell viability in both cancer cell lines. In addition, treatment of RAW264.7 cells with compound 3 caused inhibition of lipopolysaccharide/interferon-${\gamma}$-induced nitric oxide production.

• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.101-109
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• 2017

This study investigated the effect of the dichloromethane fraction form Katsuwonus pelamis heart on anti-inflammatory responses in lipopolysaccharide-stimulated RAW 264.7 cells and mouse models. Ethanol extract was partitioned with dichloromethane, ethyl acetate, butanol, and water. Among the fractions, the dichloromethane fraction showed a significant decrease in nitric oxide (NO) and pro-inflammatory cytokines [interleukin (IL)-6, $IL-1{\beta}$, and tumor necrosis $factor-{\alpha}$] production compared to ethanol extract. The dichloromethane fraction attenuated the expression of inducible nitric oxide synthase and nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) p65 proteins in a dose-dependent manner. In addition, the expression of phosphorylation of mitogen-activated protein kinases (MAPKs) was also inhibited by the dichloromethane fraction. Moreover, the administration of 10, 50, and 250 mg/kg body weight-dose dependently inhibited the formation of edema by croton-oil and the application of dichloromethane (2 mg/ear) significantly reduced epidermal and dermal thickness and the infiltrated mast cell numbers. Therefore, the dichloromethane fraction exhibited an anti-inflammation effect by inhibiting $NF-{\kappa}B$ and MAPK signaling activation in macrophages.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.213-219
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• 2009

Purpose:Iron is a critical nutritional element that is essential for a variety of important biological processes, including cell growth and differentiation, electron transfer reactions, and oxygen transport, activation, and detoxification. Iron is also required for neoplastic cell growth due to its catalytic effects on the formation of hydroxyl radicals, suppression of host defense cell activities, and promotion of cancer cell multiplication. Chronic transfusion-dependent patients receiving chemotherapy may have iron overload, which requires iron-chelating therapy. We performed this study to demonstrate whether the iron chelating agent deferoxamine induces apoptosis in Saos-2 osteosarcoma cells, and to investigate the underlying apoptotic mechanism. Methods:To analyze the apoptotic effects of an iron chelator, cultured Saos-2 cells were treated with deferoxamine. We analyzed cell survival by trypan blue and crystal violet analysis, apoptosis by nuclear condensation, DNA fragmentation, and cell cycle analysis, and the expression of apoptotic related proteins by Western immunoblot analysis. Results:Deferoxamine inhibited the growth of Saos-2 cell in a time- and dose-dependent manner. The major mechanism for growth inhibition with the deferoxamine treatment was by the induction of apoptosis, which was supported by nuclear staining, DNA fragmentation analysis, and flow cytometric analysis. Furthermore, bcl-2 expression decreased, while bax, caspase-3, caspase-9, and PARP expression increased in Saos-2 cells treated with deferoxamine. Conclusion:These results demonstrated that the iron chelating agent deferoxamine induced growth inhibition and mitochondrial-dependent apoptosis in osteosarcoma Saos-2 cells, suggesting that iron chelating agents used in controlling neoplastic cell fate can be potentially developed as an adjuvant agent enhancing the anti-tumor effect for the treatment of osteosarcoma.

• Korean Journal of Cognitive Science
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• v.12 no.3
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• pp.29-46
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• 2001

This study attempted to demonstrate that the integration of the two premises in linear syllogism is mediated by the middle term the term that is repeated in the two premises. In Experiment 1. we examined whether representing the middle term is more important than representing the end terms. We asked a question to each premise. Depending on the order of the questions either the two end terms or the middle term became the answer in both premises. Participants solved the problems better when the middle term became the answer suggesting that it is more important to represent the middle term than the end terms. In Experiment 2 we examined whether additional processing is needed for the integration beyond establishing co-referential link through the middle term. We pronominalized the middle term in the second premise and provided two kinds of information to disambiguate the pronoun. In the direct information condition we provided information about who the pronoun is whereas in the indirect information condition we provided information about the relative location of the pronoun. Participants solved the problems more quickly in the indirect information condition than in the direct information condition indicating that mere co-referential link was not enough and that the relative location of the middle term needs to be computed for the integration of the two premises.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.659-672
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• 2001

Generally, design flood for a hydraulic structure is estimated using statistical analysis of runoff data. However, due to the lack of runoff data, it is difficult that the statistical method is applied for estimation of design flood. In this case, the synthetic unit hydrograph method is used generally and the models such as NYMO method, Snyder method, SCS method, and HYMO method have been widely used in Korea. In this study, these methods and KICT method, which is developed in year 2000, are compared and analyzed in 10 study areas. Firstly, peak flow and peak time of representative unit hydrograph and synthetic unit hydrograph in study area are compared, and secondly, the shape of unit hydrograph is compared using a root mean square error(RMSE). In Nakayasu method developed in Japan, synthetic unit hydrograph is very different from peak flow, peak time, and the shape of representative unit hydrograph, and KICT method(2000) is superior to others. Also, KICT method(2000) is superior to others in the aspects of using hydrologic and topographical data. Therefore, Nakayasu method is not a proper in hydrological practice. Moreover, it is considered that KICT model is a better method for the estimation of design flood. However, if other model, i.e. SCS method, Nakayasu method, and HYMO method, is used, parameters or regression equations must be adjusted by analysis of real data in Korea.