• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.291-303
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• 2003

This work is proposed an alternative identification method of outlying cell which is one of important issues in categorical data analysis. One finds that there is a strong relationship between the location of an outlying cell and the corresponding parameter estimates of the well-fitted log-linear model. Among parameters of log-linear model, an outlying cell is affected by interaction terms rather than main effect terms. Hence one could identify an outlying cell by investigating of parameter estimates in an appropriate log-linear model.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.483-483
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• 2012

Recently, nonthermal bioplasma has been attracted by researchers due to their potentials to modulate cellular functions resulting in changes of biomolecular electron band structures as well as cell morphologies. We have investigated the secondary electron emission characteristics from the surface of the erythrocyte, i.e., red blood cell (RBC) with and without the nonthermal bioplasma treatment in morphological and biomolecular aspects. The morphologies have been controlled by osmotic pressure and biomolecular structures were changed by well known reactive oxygen species. Ion-induced secondary electron emission coefficient have been measured by using gamma-focused ion beam (${\gamma}$-FIB) system, based on the quantum mechanical Auger neutralization theory. Our result suggests that the nonthermal bioplasma treatment on biological cells could result in change of the secondary electron emission coefficient characterizing the biomolecular valence band electron energy structures caused by the cell morphologies as well as its surface charge distributions.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.182.1-182.1
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• 2003

Occupational exposure to cadmium (Cd) can result in brain disorders and olfactory dysfunction is the most well-known symptom. Recently Cd has been shown to induce apoptosis by activating MAPKs in various cell types. However, intracellular signaling pathways of Cd-induced cytotoxicity in neuronal cells is not known well. Thus, in the present study, we studied role of JNK and its well-known downstream transcription factor, c-JUN, in Cd-induced neuronal cell death. (omitted)

• Journal of Biomedical Engineering Research
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• v.31 no.2
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• pp.87-93
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• 2010

Researches for stem cells have been focused on scientists in biomedical sciences as well as clinical application for its great therapeutic potentials. Stem cells have two distinct characteristics: self-renewal and differentiation. In this short review, the links between stem cell research and biomedical engineering is discussed based on the basic characteristics of stem cells. This concept can be extended to the fundamental questions of biological sciences for cells such as proliferation, apoptosis, differentiation, and migration. For understanding proliferation and apoptosis of stem cells, techniques from biomedical engineering such as surface patterning, MEMS, nanotechnologies have been used. The advanced technologies such as microfluidic technologies, three dimensional scaffold fabrication, and mechanical/electrical stimulation have also been used in cell differentiation and migration. Basic and unsolved questions in the stem cell research field have limitations by studying conventional technologies. Therefore, the strategic fusion between stem cell biology and novel biomedical engineering field will break the barriers for understanding fundamental questions of stem cells, which can open the window for the clinical applications of stem cell based therapeutics as well as regeneration of damaged tissues.

• Journal of KIISE:Information Networking
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• v.29 no.2
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• pp.181-187
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• 2002

Connection admission control(CAC), which decides whether or not to accept a new call request, is one of the most Important preventive congestion control techniques in asynchronous transfer mode(ATM) networks. To develop a practical CAC scheme, first we propose a "Modified Cell Loss Probability MP${\nu}"$, which is based on "Virtual Cell Loss Probability P${\nu}"$, taking into account mean burst duration of input traffic source and buffer size in ATM networks. MP${\nu}"$ computes more accurate cell loss probability than P${\nu}"$ without increasing computational complexity, since P${\nu}"$ is formulated simply form the maximum and the average cell rate of input traffic. P${\nu}"$ is overestimated as compared to the real cell loss probability when the mean burst duration is relatively small to the buffer capacity. Then, we Propose a CAC scheme, based on "Modified Virtual Bandwidth(MVB)" method, which may individualize the cell loss probabilities in heterogeneous traffic environments. For the proposed approach, we define the interference intensity to identify interferences between heterogeneous traffic sources and use it as well as MP${\nu}"$ to compute MVB. Our approach is well suitable for ATM networks since it provides high bandwidth utilization and guarantees simple and real time CAC computation for heterogeneous traffic environments.heterogeneous traffic environments.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2655-2661
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• 2014

Background: Talin-1 is a cytoskeleton protein that participates in cell migration and plays a role in tumor formation, migration, and metastasis in different types of cancer. Chinese investigators have observed that the levels of Talin-1 protein and mRNA expression in HCC tissues are significantly lower than in the adjacent non-cancerous tissue. However, Japanese investigators have reported that Talin-1 is upregulated in HCC. Tln2 as homologous gene of Tln-1, which encodes a very similar protein, but the role of Talin-2 is very little known in primary liver cancer (PLC). We investigated whether the expression of Talin-1 in PLC may be associated with the histological subtype as well as the role of Talin-1 in tumor cell invasion and migration using human hepatocellular carcinoma cell lines. Materials and Methods: We measured the mRNA expression levels of Talin-1 and Talin-2 in five human liver cancer cell lines and normal human liver cell ($LO_2$ cell line) by real-time PCR and the protein expression levels of Talin-1 by Western blot. Migration and invasion of the cells were assessed using transwell assays and cell scratch experiments, respectively, and proliferation was assessed by soft AGAR colony formation. Results: Talin-1 and Talin-2 expression differed significantly between the five human liver cancer cell lines and $LO_2$ cell line (p<0.05). Compared with the $LO_2$ cell line, the invasion and migration capabilities of the five cancer cell lines differed significantly (p<0.05). Similarly, the colony-forming ability differed (p<0.05). Conclusions: High levels of Talin-1 expression are correlated with reduced invasion and migration as well as decreased malignancy in human liver cancer cell lines; the suppression of Talin-1 promotes invasion and migration. In addition, Talin-2 may be correlated with invasion and migration in human hepatocellular carcinoma.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.210-221
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• 1995

The purpose of this study was performed to investigate the mineralization and differentiation of osteobalsts for bone regeneration in vitro and the effect of rate of the composition in periodontal cells on mineralization. For this study, healthy gingival tissues were surgically obtained from the patients during 1st premolar extraction for the purposes of orthodontic treament. Gingival tissue was washed several time with Phosphate buffered saline contained high concentration of antibiotics and antifungal agent, and cultured in Dulbecco's Modified Eagle's Medium(DMEM, Gibco, U.S.A.). Every cell were cultured in state at $37^{\circ}C$, 100% of humidity, 5% of $CO_2$ incubator. Bone marrow stromal cells were isolated from 5-clay-old rat femur with using medium irrigation mathod by syringe. Cell suspension medium were centrifuged at 1500 rpm for 5 min and then cultured in the petri dish. Two kinds of cell were freezed and stocked in the liquid nitrogen tank until experiment. Cell were incubated into the 24 multi-well plate with $5{\times}10^4$cell/well of medium at $37^{\circ}C$, 100% of humidity 5% $CO_2$ incubator for 24 hours. After discarded of the supernatent of medium, O.5ml of medium were reapplied and incubated. And counted the number of cell using the hemocytometer and inverted light microscope. We have measured the number of mineralized nodule with using Alizarin red S. staining in microscope. Furthermore every cell were observed the morphological change between every rate of co-culture of the two kinds of cell. The results were as follows; The rate of proliferation of co-culture cell revealed high rate tendency compared the bone marrow stromal cell only and low growth rate to compared with gingival fibroblast only. The tendency of formation of the mineralized nodule were observed dose-depend pattern of bone marrow stromal cell. It is concluded that the gingival fibroblast may inhibit the formation of mineralized nodule in the culture of the bone marrow stromal cell.

• Biomedical Science Letters
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• v.20 no.1
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• pp.14-24
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• 2014

Hypoxia is one of the main reasons for islet apoptosis after transplantation as well as during isolation. In this study, we attempted to determine the potential usefulness of NF-${\kappa}B$ inhibitor for suppression of hypoxia-induced ${\beta}$-cell apoptosis as well as the relationship between IP-10 induction and ${\beta}$-cell apoptosis in hypoxia. To accomplish this, we cultured the mouse pancreatic ${\beta}$-cell line MIN6 in hypoxia (1% $O_2$). Among several examined chemokines, only IP-10 mRNA expression was induced under hypoxia, and this induced IP-10 expression was due to NF-${\kappa}B$ activity. Since a previous study suggested that IP-10 mediates ${\beta}$-cell apoptosis, we measured hypoxia-induced IP-10 protein and examined the effect of anti-IP-10 neutralizing Ab on hypoxia-induced ${\beta}$-cell apoptosis. However, IP-10 protein was not detected, and anti-IP-10 neutralizing Ab did not rescue hypoxia-induced MIN6 apoptosis, indicating that there is no relationship between hypoxia-induced IP-10 mRNA expression and hypoxia-induced ${\beta}$-cell apoptosis. Since it was still not clear if NF-${\kappa}B$ functions as an apoptotic or anti-apoptotic mediator in hypoxia-induced ${\beta}$-cell apoptosis, we examined possible involvement of NF-${\kappa}B$ in hypoxia-induced ${\beta}$-cell apoptosis. Treatment with 1 ${\mu}M$ NF-${\kappa}B$ inhibitor suppressed hypoxiainduced apoptosis by more than 50%, while 10 ${\mu}M$ AP-1 or 4 ${\mu}M$ NF-AT inhibitor did not, indicating involvement of NF-${\kappa}B$ in hypoxia-induced ${\beta}$-cell apoptosis. Overall, these results suggest that IP-10 is not involved in hypoxia-induced ${\beta}$-cell apoptosis, and that NF-${\kappa}B$ inhibitor can be useful for ameliorating hypoxia-induced ${\beta}$-cell apoptosis.

• Genomics & Informatics
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• v.18 no.3
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• pp.26.1-26.6
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• 2020

Single-cell RNA sequencing (scRNA-seq) has been widely applied to provide insights into the cell-by-cell expression difference in a given bulk sample. Accordingly, numerous analysis methods have been developed. As it involves simultaneous analyses of many cell and genes, efficiency of the methods is crucial. The conventional cell type annotation method is laborious and subjective. Here we propose a semi-automatic method that calculates a normalized score for each cell type based on user-supplied cell type-specific marker gene list. The method was applied to a publicly available scRNA-seq data of mouse cardiac non-myocyte cell pool. Annotating the 35 t-stochastic neighbor embedding clusters into 12 cell types was straightforward, and its accuracy was evaluated by constructing co-expression network for each cell type. Gene Ontology analysis was congruent with the annotated cell type and the corollary regulatory network analysis showed upstream transcription factors that have well supported literature evidences. The source code is available as an R script upon request.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1812-1820
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• 2017

This paper analyzes a symmetric active cell balancer for a battery management system. The considered cell balancer uses a forward converter in which the circuit structure is symmetric. This cell-balancing method uses fewer switches and is simpler than the previously proposed active cell-balancing circuits. Active power switches of this cell-balancing circuit operate simultaneously with the same pulse width modulation signals. Therefore, this cell-balancing circuit requires less time to be balanced than a previous bidirectional-forward-converter-based cell balancer. This paper analyzes the operational principles and modes of this cell balancer with computer-based circuit simulation results as well as experimental results in which each unbalanced cell is equalized with this cell balancer. The maximum power transfer efficiency of the investigated cell balancer was 87.5% from the experimental results. In addition to the experimental and analytical results, this paper presents the performance of this symmetric active cell-balancing method.