• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.181-182
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• 1998

In previous study for correlation between P-wave Signal Averaged Electrocardiography (SAECG) and Paroxysmal Atrial Fibrillation (PAF) subjects, we showed that the duration of P-wave in subjects is longer than in controls. In this respect, the P-wave SAECG is a new method proving to be an accurate and independent noninvasive marker for the risk of PAF. To prove this suggestion, accurate detection and alignment of P-wave are indispensible. In previous study, we measured P-wave duration by manual. So it was not accurate and consistent. To measure the P-wave duration accurately and automatically, we have developed an automatic algorithm for P-wave duration measurement. We showed that the duration of P- wave in the subjects is longer than in controls with this algorithm.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.191-192
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• 1998

We report on the design of a low-noise 40 channel SQUID system for biomagnetism. We used low-noise SQUID sensor with the pickup coil integrated on the same wafer as the SQUID. The SQUID electronics were simplified by increasing the voltage output of the SQUID. The SQUID insert was designed to have low thermal load, minimizing the liquid helium loss. The digital signal processing provides versatile analysis tools and the software is based on the object-oriented programming. For the effective localization of the source location, solutions of the inverse problems based on the lead-field and the simulated anneal ins were studied.

• Journal of Biomedical Engineering Research
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• v.36 no.4
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• pp.103-108
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• 2015

Discrimination of Parkinson's disease (PD) from Essential tremor (ET) is often misdiagnosed in clinical practice. Since tremor is time-varying signal, and dominant and harmonic frequencies are shown in tremor only with moderate or severe symptom, there are some limitations to use frequency related features. Moreover, patients with PD or ET can suffer from both resting tremor and postural tremor. In this study, 28 patients with PD and 17 patients with ET were enrolled. Tremor was measured with accelerations on the more affected hand during resting and postural conditions. The ratio of root mean square (RMS) of resting tremor to RMS of postural tremor, the mean coefficients of autocorrelation function (ACF), and the mean of differences of two adjacent coefficients of ACF at resting and postural were calculated and compared between PD and ET. The performance showed 98% accuracy with support vector machine and leave-one-out cross validation. In addition, the method accurately differentiated the patients with tremor-dominant PD from patients with ET, with 100% accuracy. Therefore, the developed algorithm can assist clinicians in diagnosing and categorizing patients with tremor, especially, patients with mild symptom or the early stage of a disease, for proper treatment.

• Journal of Biomedical Engineering Research
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• v.34 no.2
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• pp.63-68
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• 2013

Activeness of exercise is critical for stroke rehabilitation so that application of stimulation in response to patient's intention would be effective in FES cycling. The purpose of this study was to investigate the relationship between muscle reaction force (MRF) and electromyogram (EMG) during cycling exercise, for the future usage of MRF as patients' intention signal. Seven young men ($24{\pm}1.63$ yrs) participated in this study. Cycling speed was set to 20 RPM and 60 RPM. MRF and EMG were measured in the vastus lateralis muscle of right leg. Active cycling was performed at the maximal load (16 Nm) of an ergometer. Angle dependent artifact in MRF was measured from passive cycling and was subtracted from the MRF of active cycling. The delay of MRF with respect to EMG envelope and their correlation coefficients were derived from the best of cross correlation. MRF was significantly correlated with EMG amplitude in all subjects (p<0.01). Their mean correlations were 0.84 and 0.91 for 20 RPM and 60 RPM, respectively. Mean delay in MRF was 59.14 ms and 53.14 ms for 20 RPM and 60 RPM, respectively. The result suggests that MRF can be used to assess patient's intention for exercise as a substitute to EMG. The method may be applied to FES cycling to encourage patient's effort which is critical for stroke rehabilitation.

• Molecules and Cells
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• v.28 no.1
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• pp.13-17
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• 2009

Basic fibroblast growth factor (bFGF) plays an important role in angiogenesis. However, the underlying mechanisms are not clear. $Mg^{2+}$ is the most abundant intracellular divalent cation in the body and plays critical roles in many cell functions. We investigated the effect of bFGF on the intracellular $Mg^{2+}$ concentration ($[Mg^{2+}]_i$) in human umbilical vein endothelial cells (HUVECs). bFGF increased ($[Mg^{2+}]_i$) in a dose-dependent manner, independent of extracellular $Mg^{2+}$. This bFGF-induced $[Mg^{2+}]_i$ increase was blocked by tyrosine kinase inhibitors (tyrphostin A-23 and genistein), phosphatidylinositol 3-kinase (PI3K) inhibitors (wortmannin and LY294002) and a phospholipase $C{\gamma}$ ($PLC{\gamma}$) inhibitor (U73122). In contrast, mitogen-activated protein kinase inhibitors (SB202190 and PD98059) did not affect the bFGF-induced $[Mg^{2+}]_i$ increase. These results suggest that bFGF increases the $[Mg^{2+}]_i$ from the intracellular $Mg^{2+}$ stores through the tyrosine kinase/PI3K/$PLC{\gamma}$-dependent signaling pathways.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1154-1161
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• 2005

Yin Yang theory is the first and the last one to interpret diseases apply to treatment in oriental medicine. So it is regarded as the way of heaven and earth, the discipline of all things, the origin of change, the beginning of giving birth and death, the source of spirit. These regulatory passages are needed to compare with western medical physiology and analyzed whether it has scientific bases or not. The Yin Yang theory of traditional oriental medicine are summerized from the descriptions of Scripture of Documents, Ying Wei theory of Huangdi Neijing. Meanwhile up-to-date neurobiological and molecular genetic theories on circadian physiology are reviewed in western medicine. Sunshine is transferred through RGC to SCN, herein the central circadian rhythm is made by zeitgeber and interaction of melatonin secreted from pineal body and orexin from mp pan of hypothalamus. So HPA axis is activated and controlled under the circadian rhythm and affects peripheral tissues and cells of whole body through glucocorticoid hormones. First of all, the circadian rhythm makes the basic patterns of human life in biological and sociological meaning. It is almost same context with the record of the Scripture of Documents. Also the Ying Qi and Wei Qi is basically same with the sleep-awake mechanism, that is melatonin/orexin signal or per/clk/bmal/cry genes with circadian activation and activity of each organ's physiological function. Conclusively it can be said that Yin Yang is a priori principle of living things and the beginning of giving birth and death for activation of them biologically, as is described in Huangdi Neijing.

• Biomolecules & Therapeutics
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• v.24 no.1
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• pp.25-32
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• 2016

Lichens have been known to possess multiple biological activities, including anti-proliferative and anti-inflammatory activities. Vascular cell adhesion molecule-1 (VCAM-1) may play a role in the development of atherosclerosis. Hence, VCAM-1 is a possible therapeutic target in the treatment of the inflammatory disease. However, the effect of lobaric acid on VCAM-1 has not yet been investigated and characterized. For this study, we examined the effect of lobaric acid on the inhibition of VCAM-1 in tumor necrosis factor-alpha (TNF-${\alpha}$)-stimulated mouse vascular smooth muscle cells. Western blot and ELISA showed that the increased expression of VCAM-1 by TNF-${\alpha}$ was significantly suppressed by the pre-treatment of lobaric acid ($0.1-10{\mu}g/ml$) for 2 h. Lobaric acid abrogated TNF-${\alpha}$-induced NF-${\kappa}B$ activity through preventing the degradation of $I{\kappa}B$ and phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 mitogen activated protein (MAP) kinase. Lobaric acid also inhibited the expression of TNF-${\alpha}$ receptor 1 (TNF-R1). Overall, our results suggest that lobaric acid inhibited VCAM-1 expression through the inhibition of p38, ERK, JNK and NF-${\kappa}B$ signaling pathways, and downregulation of TNF-R1 expression. Therefore, it is implicated that lobaric acid may suppress inflammation by altering the physiology of the atherosclerotic lesion.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.464-473
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• 2018

Cripto is a small glycosylphosphatidylinositol-anchored signaling protein that can detach from the anchored membrane and stimulate proliferation, migration, differentiation, vascularization, and angiogenesis. In the present study, we demonstrated that Cripto positively affected proliferation and survival of mesenchymal stem cells (MSCs) without affecting multipotency. Cripto also increased expression of phosphorylated janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), 78 kDa glucose-regulated protein (GRP78), c-Myc, and cyclin D1. Notably, treatment with an anti-GRP78 antibody blocked these effects. In addition, pretreatment with STAT3 short interfering RNA (siRNA) inhibited the increase in p-JAK2, c-Myc, cyclin D1, and BCL3 levels caused by Cripto and attenuated the pro-survival action of Cripto on MSCs. We also found that incubation with Cripto protected MSCs from apoptosis caused by hypoxia or $H_2O_2$ exposure, and the level of caspase-3 decreased by the Cripto-induced expression of B-cell lymphoma 3-encoded protein (BCL3). These effects were sensitive to down-regulation of BCL3 expression by BCL3 siRNA. Finally, we showed that Cripto enhanced expression levels of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF). In summary, our results demonstrated that Cripto activated a novel biochemical cascade that potentiated MSC proliferation and survival. This cascade relied on phosphorylation of JAK2 and STAT3 and was regulated by GRP78. Our findings may facilitate clinical applications of MSCs, as these cells may benefit from positive effects of Cripto on their survival and biological properties.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.202-211
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• 2006

Our objective is to identify molecular factors which contribute to the increased risk of smoke in human. About 677 workers who had control and experimental groups according to their urinary Naphthol levels were enrolled in our study. In the present study, we investigated the effects of smoking on gene expression profiles in human. We determined differential gene expression patterns in smoker versus non-smoker using cDNA microarray. Specific genes were up-or down-regulated according to smoking and age. Inflammatory related genes such as cytokine, interleukin, and tumor necrosis factor were up-regulated, DNA repair related genes such as high-mobility group (nonhistone chromosomal) protein 1, and protein 2 were down-regulated, apoptosis related genes such as myeloperoxidase and Bcl-2-associated athanogene were down-regulated, and cell cycle related genes were down-regulated. In our epidemiological study, notably, inflammatory, DNA repair, apoptosis, signal transduction, metabolism, cell cycle, cell proliferation, transcription related genes were regulated.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.162-173
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• 2013

The purpose of this paper is to classify VOC gases by emulating the characteristics found in biological olfaction. For this purpose, we propose new signal processing method based a polymeric chemical sensor array consisting of 4096 sensors which is created by NEUROCHEM project. To remove unstable sensors generated in the manufacturing process of very large scaled chemical sensor array, we used discrete wavelet transformation and cosine similarity. And, to remove the supernumerary redundancy, we proposed the method of selecting candidates of representative sensor representing sensors with similar features by Fuzzy c-means algorithm. In addition, we proposed an improved algorithm for selecting representative sensors among candidates of representative sensors to better enhance classification ability. However, Classification for very large scaled sensor array has a great deal of time in process of learning because many sensors are used for learning though a redundancy is removed. Throughout experimental trials for classification, we confirmed the proposed method have an outstanding classification ability, at transient state as well as steady state.