• Toxicological Research
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• v.22 no.4
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• pp.397-402
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• 2006

Lipid mediator such as lysophosphatidic acid (LPA) plays an important role in inflammation and wound heating, has been recently reported to induce influx of extracellular calcium into erythrocytes. This elevation in intracellular calcium level may cause destruction of membrane asymmetry and procoagulant microvesicle formation. Thus, we investigated if the lipid mediator could induce microvesicle formation as a result of extracellular calcium influx in human erythrocytes. Treatment with lipid mediator to erythrocytes resulted in microvesicle generation In a concentration-, time-dependent manner. Microvesicles formed expressed procoagulant phosphatidylserine (PS) on their surface membrane significantly as well. LPA did not affect the band 3 phosphorylation which is involved in morphological change in erythrocytes. Pretreatment with suramin did not inhibit LPA-induced microvesicle generation, suggesting microvesicle generation was not receptor-dependent pathway. Depletion of intracellular ATP levels in erythrocytes was suggested to be one of the mechanism for these events.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.1 no.1
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• pp.52-57
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• 2020

Bacterial symbionts are common across insects, including ants (Hymenoptera: Formicidae). Reproduction-manipulating endosymbionts, such as Wolbachia, Spiroplasma, Rickettsia, and Cardinium, are closely associated with many aspects of host-insect life. In addition, phage WO plays an essential role in the phenotypic effects of Wolbachia. Although endosymbionts are possible biological control agents, there is a lack of knowledge of their rate of infection of ants in Korea. We tested a range of Korean ant species for the presence of Wolbachia, Spiroplasma, Rickettsia, Cardinium, and phage WO by extracting DNA from the ants and using specific primer sets to test the status of infections. In addition, the mitochondrial cytochrome c oxidase I (COI) gene of the host ants was amplified to confirm the molecular identification and phylogenetic relationship between the hosts. We found that infection with Wolbachia (29.6% of species) is relatively common when compared with that of other endosymbionts. Only one species was infected with Spiroplasma. Infection with Rickettsia and Cardinium was not detected in the examined ants. Most Wolbachia in ants were infected with phage WO. Although the phenotypic effects of endosymbionts in ants are still unknown, this first survey of endosymbionts in Korea is the first step toward the use of reproduction-manipulating endosymbionts.

• The Journal of Information Systems
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• v.24 no.1
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• pp.67-94
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• 2015

Recently, the popularity of Social Network Service (SNS) along with the spread of smart phone, personal computer and tablet PC helps personal network to construct new forms of services in cyberspace. As such, SNS plays a significant role in constructing diverse online networks and there is a growing interest on SNS at societal level. In this vein, the purpose of the research was to find the factors affecting the continuance intention to use social network services. The major findings are summarized as follows. First, "System Quality", "Contents Quality", "Personal Innovativeness", "Self-Efficiency", "Honor Benefit" has significant effects on "Relationship Quality". Yet, "Economic Benefit" is not statistically significant on "Relationship Quality". Second, "Relationship Quality" has a significant effect on "Continuous Usage Intention". Last, our research discovered the relationship between exogenous variables which would serve as valuable inputs in the development of strategic guideline and plan for SNS companies and related services.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.699-717
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• 2020

Propagation time on permissionless blockchain plays a significant role in terms of stability and performance in the decentralized systems. A large number of activities are disseminated to the whole nodes in the decentralized peer-to-peer network, thus causing propagation delay. The stability of the system is our concern in the first place. The propagation delay opens up opportunities for attackers to apply their protocol. Either by accelerating or decelerating the propagation time directly without proper calculation, it brings numerous negative impacts to the entire blockchain system. In this paper, we thoroughly review and elaborate on several parameters related to the propagation time in such a system. We describe our findings in terms of data communication, transaction propagation, and the possibility of an interference attack that caused an extra propagation time. Furthermore, we present the influence of block size, consensus, and blockchain scalability, including the relation of parameters. In the last session, we remark several points associated with the propagation time and use cases to avoid dilemmas in the light of the experiments and literary works.

• YAKHAK HOEJI
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• v.56 no.6
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• pp.347-351
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• 2012

5-Lipoxygenase (5-LO) catalyzes the formation of two major groups of leukotrienes, LTB4 and cysteinyl leukotrienes (CysLT), and it has been implicated as a promising drug target to treat various inflammatory diseases. Since its role in mature osteoclasts (mOCs) had not been reported, we investigated the effect of 5-LO inhibitors on mOCs. We showed that 5-LO inhibitors dose-dependently decreases the number of mOCs. The effects of 5-LO inhibitors were reversible, suggesting that they did not cause any cellular damages in mOCs. We further demonstrated that the suppression of mOCs by 5-LO inhibitors was caused mainly by disruption of the actin ring formation. Similar effects were shown with CysLT receptor (CysLTR)1 antagonist in mOCs. The mRNA expression of CysLTR1 and the production of CysLT were increased in mOCs. These results indicate that CysLTR1 mediates the suppression of mOCs by 5-LO inhibitors. Taken together, this study demonstrated that 5-LO plays important role in mOCs and possibly a novel therapeutic target for bone resorption diseases.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.3
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• pp.281-292
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• 2019

This paper proposed a new technology to control a path forging parts in limited narrow space of manufacturing process automation for smart factory. In the motion control, we adapted the obstacle avoidance technology based on ultrasonic sensors. The new motion control performance test for a mobile robot is experimented in narrow space environments. The travelling path control is performed by a fuzzy control logic. which plays a role for selecting an appropriate behavior in accordance with the situation in the vicinity of the mobile robot. Ultrasonic sensors installed at the front face of the mobile robot are used. In order to update the current position and heading angle of the mobile robot, a new approch is adapted. The reliability is illustrated by simulation and experiments.

• BMB Reports
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• v.56 no.8
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• pp.417-425
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• 2023

In various organisms, the Hippo signaling pathway has been identified as a master regulator of organ size determination and tissue homeostasis. The Hippo signaling coordinates embryonic development, tissue regeneration and differentiation, through regulating cell proliferation and survival. The YAP and TAZ (YAP/TAZ) act as core transducers of the Hippo pathway, and they are tightly and exquisitely regulated in response to various intrinsic and extrinsic stimuli. Abnormal regulation or genetic variation of the Hippo pathway causes a wide range of human diseases, including cancer. Recent studies have revealed that Hippo signaling plays a pivotal role in the immune system and cancer immunity. Due to pathophysiological importance, the emerging role of Hippo signaling in blood cell differentiation, known as hematopoiesis, is receiving much attention. A number of elegant studies using a genetically engineered mouse (GEM) model have shed light on the mechanistic and physiological insights into the Hippo pathway in the regulation of hematopoiesis. Here, we briefly review the function of Hippo signaling in the regulation of hematopoiesis and immune cell differentiation.

• Journal of Korean Society for Quality Management
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• v.51 no.2
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• pp.247-261
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• 2023

Purpose: This study investigates the relationship between service compensation, consumer sentiment and revisit intention for service recovery in the Chinese foodservice industry, and the moderating effect of employee authenticity. Methods: Data were collected from people who experienced eating out in a city located in central China, and the hypothesis was verified through multiple regression analysis and hierarchical regression analysis. Results: The results indicate that the specificity of compensation affects both positive and negative emotions of customers, and the activeness of compensation also influences positive emotions of customers. Also, employee autheticity moderates the effect of specificity of compensation on customers' positive emotions. Both positive and negative emotions of customers influences revisit intention. Conclusion: These results show that the role of service compensation is important in service recovery in the rapidly expanding Chinese foodservice industry. In addition, since the sincerity of employees plays an important role in maximizing the recovery effect in the process of service recovery, it suggests that it is important not only to improve services in the quantitative aspect but also in the qualitative aspect through employee training.

• Molecules and Cells
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• v.27 no.5
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• pp.609-613
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• 2009

It has been reported that selenoprotein W (SelW) mRNA is highly expressed in the developing central nerve system of rats, and its expression is maintained until the early postnatal stage. We here found that SelW protein significantly increased in mouse brains of postnatal day 8 and 20 relative to embryonic day 15. This was accompanied by increased expression of SOD1 and SOD2. When the expression of SelW in primary cultured cells derived from embryonic cerebral cortex was knocked down with small interfering RNAs (siRNAs), SelW siRNA-transfected neuronal cells were more sensitive to the oxidative stress induced by treatment of $H_2O_2$ than control cells. TUNEL assays revealed that $H_2O_2$-induced apoptotic cell death occurred at a higher frequency in the siRNA-transfected cells than in the control cells. Taken together, our findings suggest that SelW plays an important role in protection of neurons from oxidative stress during neuronal development.

• Development and Reproduction
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• v.18 no.2
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• pp.107-115
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• 2014

Cardiovascular system is the primary organ to develop and reach a functional state, which underscores the essential role of the vasculature in the developing embryo. The vasculature is a highly specialized organ that functions in a number of key physiological works including the carrying of oxygen and nutrients to tissues. It is closely involved in the formation of heart, and hence it is essential for survival during the hatching period. The expression of genes involved during vascular development in the olive flounder (Paralichthys olivaceus) in the days after hatching is not fully understood. Therefore, we examined the expression patterns of genes activated during the development of flounder. Microscopic observations showed that formation of blood vessels is related to the expression of the vimentin gene. Also, the temporal expression patterns of this vimentin-like gene in the developmental stages and in the normal tissues of olive flounder. The purpose of this study was to examine the expression patterns of vimentin in normal tissues of the olive flounder and during the development of the vascular system in newly hatched olive flounders and HIF-1 plays a vital role in the formation of blood vessels during development. Vimentin expression was strong at the beginning of the development of blood vessels, and was present throughout all developmental stages. Our findings have important implications with respect to the roles of vimentin and HIF-1 in the development and evolution of the first blood vessels in olive flounder. Further studies are required to elucidate the vimentin-mediated hypoxic response signal transduction and to decipher the functional role of vimentin in developmental stages.