• Toxicological Research
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• v.27 no.3
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• pp.161-166
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• 2011

Carbon black, a particulate form of pure elemental carbon, is an industrial chemical with the high potential of occupational exposure. Although the relationship between exposure to particulate matters (PM) and cardiovascular diseases is well established, the cardiovascular risk of carbon black has not been characterized clearly. In this study, the cytotoxicity of carbon black to vascular smooth muscle and endothelial cells were examined to investigate the potential vascular toxicity of carbon black. Carbon black with distinct particle size, N330 (primary size, 28~36 nm) and N990 (250~350 nm) were treated to A-10, rat aortic smooth muscle cells and human umbilical vein endothelial cell line, ECV304, and cell viability was assessed by lactate dehydrogenase (LDH) leakage assay. Treatment of carbon black N990 resulted in the significant reduction of viability in A-10 cells at 100 ${\mu}g$/ml, the highest concentration tested, while N330 failed to cause cell death. Cytotoxicity to ECV304 cells was induced only by N330 at higher concentration, 200 ${\mu}g$/ml, suggesting that ECV304 cells were relatively resistant to carbon black. Treatment of 100 ${\mu}g$/ml N990 led to the elevation of reactive oxygen species (ROS) detected by dichlorodihydrofluorescein (DCF) in A-10 cells. Pretreatment of antioxidants, N-acetylcysteine (NAC) and sulforaphane restored decreased viability of N990-treated A-10 cells, and N-acetylcysteine, but not sulforaphane, attenuated N990-induced ROS generation in A-10 cells. Taken together, present study shows that carbon black is cytotoxic to vascular cells, and the generation of reactive oxygen contributes to the development of cytotoxicity. ROS scavenging antioxidant could be a potential strategy to attenuate the toxicity induced by carbon black exposure.

• Journal of Fashion Business
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• v.21 no.1
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• pp.134-147
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• 2017

The purpose of this study is to analyze fashion brands' contents and characteristics of the participation platform of users, to assess the types and strategies of mass customization(MC). Most fashion brands sell one professional content: Shoes brands were the most common, followed by bags, unisex wear, and menswear. In consumer's design selection elements, changes in color and materials were the most common. For the personalization service elements, monogram service was the most common. The results of MC types analysis were as follows, Customized Standardization was the most common, followed by Tailored Customization, Pure Customization, and Segmented Standardization. For the types according to changes in products and expression methods, Cosmetic was the most common. And the classification according to modulation, Modularizers were the most common. For Creativity, brands in the making stage were the most common. For Flexibility, although brands different methods, high flexibility by modularizing design elements of products and accomplishing various design through participation. The Ease of use for various expression was generally high, parallel to Flexibility. For Durability, because consumers could receive end products only when they participated in the assembly stage in the on-line purchase, their continuous participation was not possible, so they participated only once. The typical types and strategy of MC were analyzed. The Customized Standardization type was the most common in shoes, bag, and womenswear brands. It was the Cosmetic type which could change colors and materials, the Modularizers, and had high Flexibility and Ease of use and low Durability.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.573-583
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• 2017

Biofilm formation on the membrane surface results in the loss of permeability in membrane bioreactors (MBRs) for wastewater treatment. Studies have revealed that cellulose is not only produced by a number of bacterial species but also plays a key role during formation of their biofilm. Hence, in this study, cellulase was introduced to a MBR as a cellulose-induced biofilm control strategy. For practical application of cellulase to MBR, a cellulolytic (i.e., cellulase-producing) bacterium, Undibacterium sp. DM-1, was isolated from a lab-scale MBR for wastewater treatment. Prior to its application to MBR, it was confirmed that the cell-free supernatant of DM-1 was capable of inhibiting biofilm formation and of detaching the mature biofilm of activated sludge and cellulose-producing bacteria. This suggested that cellulase could be an effective anti-biofouling agent for MBRs used in wastewater treatment. Undibacterium sp. DM-1-entrapping beads (i.e., cellulolytic-beads) were applied to a continuous MBR to mitigate membrane biofouling 2.2-fold, compared with an MBR with vacant-beads as a control. Subsequent analysis of the cellulose content in the biofilm formed on the membrane surface revealed that this mitigation was associated with an approximately 30% reduction in cellulose by cellulolytic-beads in MBR.

• Advances in pediatric surgery
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• v.3 no.2
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• pp.133-142
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• 1997

Hepatoblastoma is a rare pediatric malignancy which frequently presents at an advanced un resectable stage. With the neoadjuvant chemotherapy, improved resectability and survival have been reported. Twenty children with biopsy proven hepatoblastoma were treated during the period between January 1987 and June 1995. Median age at diagnosis was 13 months(2 months to 7 year and 10 months), and 13 were male. Histologic profile was 13 epithelial(5 fetal, 4 mixed, 1 embryonal, 3 undetermined), and 5 mixed mesenchymal and epithelial and 2 of undetermined type. Chemotherapy effectively reduced the tumor volume($p$=0.008), and was able to convert 7 out of 9 initially unresectable cases(78%) to resectable ones. Twelve radical and 2 palliative operations were done with or without adjuvant chemotherapy. The Median follow up period was 33 months and the median survival was 26 months. The group with curative resection had a 61.1% 5 year survival rate, but none of palliative resection group survived more than 13 months($p$=0.0001). In univariate analysis for prognostic factors revealed, large tumor size at diagnosis and abscence of thrombocytopenia were associated with poor survival, but these differences were not statistically significant. Histological pure fetal type did not mean a better prognosis. Even with a recent neoadjuvant chemotherapy, the strategy should be focused on the radical resection as early as possible.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.87-92
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• 1996

This study describes a stable and simple method for the measurement of cholesteryl ester transfer protein(CETP) activities using reconstituted HDL and LDL as substrates. Apolipoproteins (apo) A-I and -B were purified from hog plasma by a new strategy without ultracentrifugation and delipidation. a simple two-step column chromatography was administered. In the first step of phenyl-sepharose CL-4B column chro-matography, hydrophobic plasma proteins were isolated. The most hydrophobic proteins bound to the column appeared to be A-I and apo-B. Contaminat proteins were efficiently eliminated from the sample by washing the column with 0.3M NaCI containing buffer after loading the plasma on the column. Two pure proteins showing each single band on SDS-PSGE of apo A-I and apo-B were individually obtained by a subsequent gel filtration column chromatography(Sephadex G-200). This two-step purification was simple and inexpensive compared to the ultracentrifugation and/or delipidation method that are most commonly used. Reconstituted hight-density lipoproteins(HDL) and low-density lipoproteins(LDL) were prepared using the purified apo A-I and-B, respectively. When these artificially prepared HDL and LDL were used in the assays for CETP as the cholesteryl ester(CE) donor and acceptor respectively, the specific transfer of CE increased up to two fold compared to that used the native HSL and LDL.

• Journal of Korea Port Economic Association
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• v.31 no.2
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• pp.85-101
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• 2015

This study formulates a development strategy for Gwangyang port through the analysis of its competition with other major Northeast Asian ports. A revised BCG matrix is applied to estimate the change in competition between the major ports in Northeast Asia and the Lotka-Volterra model is used for the competitor analysis. The growing competitive power and influence of Chinese ports, continued competitive advantage of Busan port, diminishing competitiveness of Gwangyang and Incheon ports, and disappearing competitive position of Japanese ports in Northeast Asia are all confirmed. In addition, according to the relationship between Gwangyang port and other major Northeast Asian ports from 2007 to 2014, Gwangyang port has changed to a predatory from a win/win relation with Busan port and has maintained its predatory relationship with Hong Kong port in terms of transshipment cargoes. Moreover, Gwangyang port has formed predatory relationships with Shanghai and Ningbo ports, a pure competitive relation with Tianjin port, and a win/win relation with Qingdao and Dalian ports. Overall, predatory relationships between Gwangyang port and other Northeast Asia ports increased from 2007 to 2014. The counterstrategies for Gwangyang port to address this situation include establishing cooperative relations and continuing the win/win relationships with cooperative ports.

• Journal of English Language & Literature
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• v.55 no.2
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• pp.215-240
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• 2009

This paper focuses on how Younghill Kang internalizes whiteness ideology through interracial romance to build himself as an oriental Yankee and recover his masculinity in his autobiographical novel East Goes West. This paper also focuses on Kang's strategy of racial and cultural hybridity presented in this novel. The theoretical basis of my argument is a mixture of Fanon's psychoanalysis in his Black Skin, White Masks, Bhabha's notion of mimicry in The Location of Culture, and notions related to race and gender of some Asian critics such as Patricia Chu, Jinqi Ling, and Lisa Lowe. In East Goes West, white women appear as "ladder of success" of successful assimilation and serve as cultural mediators and instructors and sometimes adversaries who Korean male immigrants have to win to establish identities in which Americanness, ethnicity, and masculinity are integrated. However, three Korean men, Chungpa Han, To Wan Kim, George Jum, who fall in love with white women fail to win their beloveds in marriage. George Jum fails to sustain a white dancer, Jun' interest. Kim wins the affection of Helen Hancock, a New England lady, but Kim commits suicide when he knows Helen killed herself because her family doesn't approve their relationship. Han's love for Trip remains vague, but Kang implies Han will continue his quest for "the spiritual home" as the name of "Trip." In East Goes West, Kang also attempts to challenge the imagining of a pure, monolithic, and naturalized white dominant U.S. Culture by exploring the cultural and racial hybridity shown by June and the various scenes of Halem in the 1920s. June who works for a Harlem cabaret is a white woman but she wears dark makeup. Kang questions the white face of America's self-understanding and racial constitution of a unified white American culture through June's racial masquerade. Kang shows that like Asian and black Americans, the white American also has an ambivalent racial identity through June's black mimicry and there is no natural and unchanging essence behind one's gender and race identity constitution.

• Journal of Preventive Medicine and Public Health
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• v.55 no.1
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• pp.10-18
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• 2022

Disability-adjusted life-year (DALY) estimates may vary according to factors such as the standard life expectancy, age weighting, time preference and discount rate, calculation of disability weights, and selection of the estimation method. DALY estimation methods are divided into the following 3 approaches: the incidence-based approach, the pure prevalence-based approach, and the hybrid approach. These 3 DALY estimation approaches each reflect different perspectives on the burden of disease using unique characteristics, based on which the selection of a suitable approach may vary by the purpose of the study. The Global Burden of Disease studies, which previously estimated DALYs using the incidence-based approach, switched to using the hybrid approach in 2010, while the National Burden of Disease studies in Korea still mainly apply the incidence-based approach. In order to increase comparability with other international burden of disease studies, more DALY studies using the prevalence-based approach need to be conducted in Korea. However, with the limitations of the hybrid approach in mind, it is necessary to conduct more research using a disease classification system suitable for Korea. Furthermore, more detailed and valid data sources should be established before conducting studies using a broader variety of DALY estimation approaches. This review study will help researchers on burden of disease use an appropriate DALY estimation approach and will contribute to enhancing researchers' ability to critically interpret burden of disease studies.

• Korean Journal of Materials Research
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• v.33 no.11
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• pp.447-457
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• 2023

Single-atom Pd clusters anchored on t-BaTiO₃ material was synthesized using hydrothermal and ultrasonic methods for the effective piezoelectric catalytic degradation of pollutants using vibration energy. XRD patterns of BaTiO₃ loaded with monoatomic Pd were obtained before and after calcining, and showed typical cubic-phase BTO. TEM and HAADF-STEM images indicated single-atom Pd clusters were successfully introduced into the BaTiO₃. The piezoelectric current density of the prepared Pd-BaTiO₃ binary composite was significantly higher than that of the pristine BaTiO₃. Under mechanical vibration, the nanomaterial exhibited a tetracycline decomposition rate of ~95 % within 7 h, which is much higher than the degradation rate of 56.7 % observed with pure BaTiO₃. Many of the piezo-induced electrons escaped to the Pd-doped BaTiO₃ interface because of Pd's excellent conductivity. Single-atom Pd clusters help promote the separation of the piezo-induced electrons, thereby achieving synergistic catalysis. This work demonstrates the feasibility of combining ultrasonic technology with the piezoelectric effect and provides a promising strategy for the development of ultrasonic and piezoelectric materials.

• Journal of the Korean Geotechnical Society
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• v.39 no.11
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• pp.63-70
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• 2023

Underground carbon dioxide (CO₂) storage emerges as a pivotal strategy for mitigating atmospheric CO₂ emissions and addressing global warming concerns. This study investigates techniques to optimize storage efficiency in aquifers, which stand out for their superior capacity compared to other geological layers. The focus is on the application of nonionic and anionic surfactants to enhance CO₂ storage efficiency within confined spaces. A specialized micromodel facilitating fluid flow observation was employed for the evaluation. Experimental results revealed a noteworthy minimum 40% increase in storage efficiency at the lowest injection rate when utilizing nonionic and anionic surfactants, in comparison to pure water injection. Interestingly, no significant variations in storage efficiency were observed based on the ionicity and concentration of the surfactants under investigation. These findings have implications for guiding the selection and concentration determination of surfactants in future underground CO₂ storage endeavors.