• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.258-269
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• 2024

Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.

• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.145-156
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• 2024

Unlike resistant cells, persister cells resist antibiotics due to a decreased cellular metabolic rate and can transition back to normal susceptible cells when the antibiotic is removed. These persister cells contribute to the chronic symptoms of infectious diseases and promote the emergence of resistant strains with continuous antibiotic exposure. Therefore, eliminating persister cells represents a promising approach to significantly enhance antibiotic efficacy. Here, we found that Coicis Semen extract reduced Staphylococcus aureus persister cells at a concentration of 0.5 g/L. Linoleic acid and oleic acid, the major components of Coicis Semen extract, exhibited a comparable reduction in persister cells when combined with three antibiotics: ciprofloxacin, oxacillin, and tobramycin. Conversely, these effects were nullified in the presence of the surfactant Tween 80 (1%), suggesting that the hydrophobic characteristics of linoleic acid and oleic acids play a pivotal role in reducing the number of S. aureus persister cells. Considering the concentration-dependent effects of linoleic acid and oleic acid, the persister-reducing activity of Coicis Semen extract was primarily attributed to these fatty acids. Moreover, Coicis Semen extract, linoleic acid, and oleic acid increased the cell membrane permeability of S. aureus. Interestingly, this effect was counteracted by 1% Tween 80, indicating a close association between the reduction of persister cells and the increase in cell membrane permeability. The identified compounds could thus be used to eliminate persister cells, thereby enhancing therapeutic efficacy and shortening treatment duration. When used in conjunction with antibiotics, they may also mitigate chronic symptoms and significantly reduce the emergence of antibiotic-resistant bacteria.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.185-196
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• 1991

The rice culture, the most representative farming in humid regions of East Asia, have been playing a decisive role in supplying finance and staple food of the nations. This situation must be formed with exchange of techniques and interests in the matter betwen China, Korea and Japan. Especially Korea was obligated to playa bridge role because of geographical conditions, thereby the situations of agriculture were repeatedly reclaimed, and recovered by changes of cultures during external aggression, and internal disturbances. Thus, it is obvious that development of rice culture and its techniques was being undaunted in Korea. Nevertheless, in history of Korea, the documents of the government on chronicles of the dynasty were plentiful, while they were very poor in countryside and rural communities, so that it is very hard to search the transition process of rice culture and its techniques. Finally, the faming books that were begun editing from the early Chosun dynasty are here divided chronically and examined, and also the interrelationships are compared and discussed here. The objectives of this study were to discuss the following questions？ How were the dryfarming techniques, introduced from the ancient China by the end of Koryo dynasty, established to fit for our situations？ What were the basis for reestablishment of the techniques with originality？ How were they continued and changed through the internal and external wars in the Chosun dynasty？ What were suggested from these continuously results by the end of the Chosun dynasty?

• Molecules and Cells
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• v.43 no.10
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• pp.889-897
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• 2020

K-RAS is frequently mutated in human lung adenocarcinomas (ADCs), and the p53 pathway plays a central role in cellular defense against oncogenic K-RAS mutation. However, in mouse lung cancer models, oncogenic K-Ras mutation alone can induce ADCs without p53 mutation, and loss of p53 does not have a significant impact on early K-Ras-induced lung tumorigenesis. These results raise the question of how K-Ras-activated cells evade oncogene surveillance mechanisms and develop into lung ADCs. RUNX3 plays a key role at the restriction (R)-point, which governs multiple tumor suppressor pathways including the p14^ARF-p53 pathway. In this study, we found that K-Ras activation in a very limited number of cells, alone or in combination with p53 inactivation, failed to induce any pathologic lesions for up to 1 year. By contrast, when Runx3 was inactivated and K-Ras was activated by the same targeting method, lung ADCs and other tumors were rapidly induced. In a urethane-induced mouse lung tumor model that recapitulates the features of K-RAS-driven human lung tumors, Runx3 was inactivated in both adenomas (ADs) and ADCs, whereas K-Ras was activated only in ADCs. Together, these results demonstrate that the R-point-associated oncogene surveillance mechanism is abrogated by Runx3 inactivation in AD cells and these cells cannot defend against K-Ras activation, resulting in the transition from AD to ADC. Therefore, K-Ras-activated lung epithelial cells do not evade oncogene surveillance mechanisms; instead, they are selected if they occur in AD cells in which Runx3 has been inactivated.

• Biomedical Science Letters
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• v.4 no.1
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• pp.27-33
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• 1998

This study has been designed in order to examine a physiological role of $Ca^{2+}$ which has been known as an essential factor for capacitation, to confirm whether the enzyme activity of $Ca^{2+}$-ATPase on capacitation is important or not, and to clarify relationship between various levels of the $Ca^{2+}$ concentration and $Ca^{2+}$-ATPase which has been known to be an important factor of the plasma membranes. In the present study applying quercetin, a $Ca^{2+}$-ATPase inhibitor, the enzymatic effect of $Ca^{2+}$-ATPase on capacitation was found to be remarkable: a significant increase of the transition from the original type (type A) to the type B and the type AR of the spermatozoa. This finding suggests that $Ca^{2+}$-ATPase plays an important role in the efflux and the influx of the $Ca^{2+}$ which has been known to be an essential factor the capacitation and acrosome reaction, and that the inhibitory action of the $Ca^{2+}$-ATPase might be a prerequsite step toward the acrosome reaction. The conclusion reached can be deduced as follows: increment of the intracelluar $Ca^{2+}$ concentration occurred by controlling the slope of $Ca^{2+}$ concentration through $Ca^{2+}$-ATPase activities in both the intra- and extracelluar fluid may be an important procedure for capacitation and acrosome reaction, and ultimately for fertilization of the spermatozoa and the ova.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.952-960
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• 2003

It has been reported that p53 regulates the G2-M checkpoint transition through cyclin Bl, and it has been suggested that p53 plays an important role in the development and progression of various malignancies. The aim of this study is to clarify the role of the cell cycle regulators, cyclin B1 and p53 in patients with esophageal squamous cell carcinoma (ESCC). Material and Method: Tissue samples from 46 patients with ESCC were included in this study. Expression levels of cyclin Bl and p53 in samples of normal squamous epithelium, dysplasia, and tumor cells from patients with ESCC were analyzed by immunohistochemical study Result: Several cells in the basement layer of normal epithelium expressed cyclin B1. The number of cyclin B1 positive cells tended to increase as the degree of dysplasia increased from low grade to high grade. More than 10% of tumor cells were cyclin B1 positive in 19 patients (41.3%). Several clinicopathologic parameters, including tumor stage (p<0.05), pathologic Iymph node status (p<0.05) and invasion of Iymphatic vessels (p<0.05), were correlated with the overexpression of cyclin B1. Elevated expression levels of cyclin B1 also correlated with a poor prognosis in patient with ESCC in univariate analysis (p<0.05) and multivariate analysis (p<0.05), In contrast, p53 expression exhibited significant correlation with the level of cyclin B1 expression, but was not associated with prognostic parameters in patients with ESCC. Conclusion: These findings suggest that cyclin B1 is involved in the pathogenesis of carcinoma of the esophagus and that elevated levels of cyclin B1 expression, but not p53 expression, may indicate a poor prognosis for patients with ESCC.

• Ocean and Polar Research
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• v.30 no.4
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• pp.379-399
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• 2008

Spatial-temporal variations in physiochemical water qualities (temperature, salinity, DO, SPM, POC and nutrients) of surface and bottom waters were investigated along the mid-western coastal area (Taean Peninsula to Gomso Bay) of Korea. Spatial distribution patterns of temperature and salinity were mostly controlled by the physical mixing process of freshwater from Geum River and/or Gyunggi Bay with nearby coastal water. A strong tidal front is formed off Taean Peninsula during spring and summer. Seasonal variations in nutrient concentrations, lower in spring and summer and higher in fall and winter, are primarily regulated by magnitude of phytoplankton occurrence rather than freshwater loadings into the bay. Based on seasonal and spatial variability of physicochemical parameters, water quality of the study area can be divided into four water masses; Gyunggi Bay-influenced Water Mass (GBWM), Geum River-influenced Water Mass (GRWM), Yellow Sea Bottom Cold Water Mass (YSBCWM) and Cheonsu Bay Water Mass (CBWM). Water quality of the GBWM (Taean Peninsula coastal area), which has relatively low salinity and high concentrations of nutrients, is strongly controlled by the Gyunggi Bay coastal water, which is under influence of the Han River freshwater. In this water mass, the mixed layer is always developed by strong tidal mixing. As a result, a tidal front is formed along the offshore boundary of the mixed layer. Such tidal fronts probably play an important role in the distribution of phytoplankton communities, SPM and nutrients. The GRWM, with low salinity and high nutrients, especially during the flood summer season, is closely related to physiochemical properties of the Geum River. During the flood season, nutrient-enriched Geum River water mass extends up to 60 km away from the river mouth, potentially causing serious environmental problems such as eutrophication and unusual and/or noxious algal blooms. Offshore (<$30{\sim}40m$ in water depth) of the study area, YSBCWM coupled with a strong thermocline can be identified in spring-summer periods, exhibiting abundant nutrients in association with low temperature and limited biological activity. During spring and summer, a tidal front is formed in a transition zone between the coastal water mass and bottom cold water mass in the Yellow Sea, resulting in intensified upwelling and thereby supplying abundant nutrients to the GBWM and GRWM. Such cold bottom water mass and tidal front formation seems to play an important role in controlling water quality and further regulating physical ecosystem processes along mid-western Korean coastal area.

• The Journal of Art Theory & Practice
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• no.2
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• pp.191-213
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• 2004

The trend of "Blockbuster Exhibitions" over the past decade has led to the unfortunate reality that museums, losing sight of their role as an Academic organization, are becoming increasingly influenced by the corporate world. In my dissertation entitled "The Commercialization of Blockbuster Exhibitions in Museums," I explore the modern tendency toward Blockbuster exhibitions in art museums and the negative impact of those exhibitions on the art world. Museums of the modern day have expanded their territory from the traditional venue of public education to the hybrid cultural space. This mission, evident in the museum's attempt to satisfy audiences with the offering of diverse activities, has changed the concept of the museum, giving priority to the desire for financial gain. From the viewpoint of this new museology, the museum considers Blockbuster exhibitions as the safest method to increase ticket sales. As a program that openly reveals the commercialism of the museum, I explore the Blockbuster show and its strategies as a means of exposing the influence of the corporate world on art. A key component to the Blockbuster exhibition is the "hype" that is created to attract an audience. This devotion to increased publicity distracts from what should be the goal of public education, as the primary focus leans towards the desire for a large number of visitors. Consequently, this unavoidably standardized exhibition is presented to the public in a manner that deprives the audience of a unique experience. With large crowds and increased ticket prices, it is difficult to form a genuine appreciation of the artwork. In addition to the profit gained by increased ticket prices and the commercial sales of "souvenirs" from the museum gift shop, Blockbuster shows are used as a means to attract the attention of corporate sponsors. As explained in my dissertation, the importance that the museum places on corporate sponsorship as a capital resource is evident, however the degree to which the museum allows itself to he influenced by the desire for capital gain poses a threat to its function as an academic organization. Circumstances in American museum history, in particular, have influenced the transition from academic resource to corporation within museology. In keeping with the nation's tendency towards capitalism, art museums in the United States were initially established and developed by individual capitalists who applied principals of corporate operation to museum management. As a result, in modern days, We witness the influence of enterprise on museum programs, while corporate management may be able to guarantee immediate fiscal benefits, however, it is unable insure the future of the museum. In Slim, my dissertation discusses the mechanism of the commercialized "Blockbuster Exhibition" and the impact that it has on the future of the museum as an industry. This research provides an opportunity to reconsider the role of the museum as an academic institution, particularly in regard to the need to decrease the capitalization of exhibitions and refocus their influence on the art world as an educational resource.

• Journal of Distribution Science
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• v.13 no.3
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• pp.93-100
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• 2015

Purpose - Since the early 1990s, it has been observed that the number and substance of studies on female leadership have been increasing. One of the reasons for this development may be concerned with the increasing number of female labor market participants as well as the greater opportunities for them to take higher positions in various organizations. In addition to this, the transition from mechanistic organizational structures that emphasize authority, control, and efficiency toward organic ones that focus on environmental adaptability, equality, and trust has also encouraged research on female leadership. The research tendency is based on the assumption that male and female leaders tend to exhibit different leadership styles according to their gender differences. Recent research has cast doubt on this assumption, by showing that the sociological gender roles of men and women are independent such that some female leaders show authoritative and control-oriented leadership, which were once considered to be male leadership styles. Research design, data, and methodology - This research attempts to carry out an empirical study on the gender-related leadership styles of female leaders and to examine their effect on group performance in the K business organization. This study also focuses on leader attributes such as trust, and it aims to discover whether these attributes should be regarded as independent or as moderating variables between leadership styles and performance. For these purposes, this study generated four hypotheses based on a review of the literature and it tested them using a survey. Female workers in the sales departments of the K Company, all of whom are women, were asked to provide answers to the presented questionnaires. This study hypothesizes that the type of gender roles played by women leaders will affect the job satisfaction and organizational commitment among the members of the sales group, and that the level of trust that is garnered by women leaders will also affect the types of gender roles that they play as well as employee job satisfaction and organizational commitment. Results - The results of this study show that both androgynous and masculine leadership styles are superior to the feminine leadership style in terms of employee job satisfaction and organizational commitment. However, contrary to our expectations, this study fails to show the superiority of the androgynous leadership style over the masculine leadership style. Moreover, there are no significant differences between these two leadership styles with regard to group performance. Conclusions - This study shows that it is important that different attributes of leaders, such as how trusted they are, be treated as moderating variables between leadership and performance rather than as independent variables. Finally, as this is the first attempt to view the role of the gender in a new perspective, the managerial implications of this study for leadership research, as well as its limitations, are presented. Suggestions for future related research are also proposed.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.487-493
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• 2018

Cluster of differentiation 44 (CD44), a cell surface receptor for hyaluronic acid (HA), is involved in aggressive cancer phenotypes. Herein, we investigated the role of the CD44 standard isoform (CD44s) in hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) regulation using MCF7 overexpressing CD44s (pCD44s-MCF7). When pCD44s-MCF7 was incubated under hypoxia, levels of $HIF-1{\alpha}$, vascular endothelial growth factor, and the $HIF-1{\alpha}$ response element-derived luciferase activity were significantly increased compared to those in the control MCF7. Incubation of pCD44s-MCF7 cells with HA further increased $HIF-1{\alpha}$ accumulation, and the silencing of CD44s attenuated $HIF-1{\alpha}$ elevation, which verifies the role of CD44s in $HIF-1{\alpha}$ regulation. In addition, the levels of phosphorylated extracellular signal-regulated kinase (ERK) was higher in hypoxic pCD44s-MCF7 cells, and $HIF-1{\alpha}$ accumulation was diminished by the pharmacological inhibitors of ERK. CD44s-mediated $HIF-1{\alpha}$ augmentation resulted in two functional outcomes. First, pCD44s-MCF7 cells showed facilitated cell motility under hypoxia via the upregulation of proteins associated with epithelial-mesenchymal transition, such as SNAIL1 and ZEB1. Second, pCD44s-MCF7 cells exhibited higher levels of glycolytic proteins, such as glucose transporter-1, and produced higher levels of lactate under hypoxa. As a consequence of the enhanced glycolytic adaptation to hypoxia, pCD44s-MCF7 cells exhibited a higher rate of cell survival under hypoxia than that of the control MCF7, and glucose deprivation abolished these differential responses of the two cell lines. Taken together, these results suggest that CD44s activates hypoxia-inducible $HIF-1{\alpha}$ signaling via ERK pathway, and the $CD44s-ERK-HIF-1{\alpha}$ pathway is involved in facilitated cancer cell viability and motility under hypoxic conditions.