• The Korea Journal of Herbology
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• v.23 no.3
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• pp.127-134
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• 2008

Objectives : The present study was designed to investigate whether Ostericum koreanum (OK) could regulate lipopolysaccharide (LPS)-induced inflammatory response in vitro and in vivo. Methods : To evaluate of anti-inflammatory effect of OK, we examined Nitric oxide (NO), proinflammatory cytokines production in LPS-stimulated RAW264.7 cells. Furthermore, we checked molecular mechanism especially in the phosphorylation of mitogen-activated protein kinases (MAPKs) and the degradation of inhibitory kappa B a ($Ik-B{\alpha}$) using western blot and also investigated survival of mice in LPS-mediated endotoxin shock. Results : 1. Extract from OK itself have weak cytotoxic effect on RAW264.7 cells. Extract from OK inhibited LPS-induced NO, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), interleukin $(IL)-1{\beta}$, IL-6 and IL-10 production in RAW264.7 cells. 2. OK inhibited the phosphorylation of MAPKs, such as p38, extracelluar signal-regulated kinase (ERK1/2) and c-Jun NH2-terminal kinase (JNK) and also the degradation of $I{\kappa}-B{\alpha}$ in the LPS-stimulated RAW264.7 cells 3. OK did not inhibit LPS-induced endotoxin shock. Conclusions : OK down-regulated LPS-induced NO and cytokines production through suppressing activation of MAPKs and degradation of $I{\kappa}-B{\alpha}$. Our results suggested that OK may be a beneficial drug against inflammatory diseases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1888-1894
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• 2011

In this study, large-current (75 - 400 A), high-voltage (500 - 1000 $V_{rms}$), reliable capacitors with capacitances (C) of 100 - 1000 nF were developed for energy storage facility applications. Mica was used as the dielectric of the capacitors. In order to form a parallel stack of a capacitor element, 50 ${\mu}m$ thick mica sheets with a size of $30mm{\times}35mm$ were used with lead foils for the plate lead type of mica capacitors (HCM-L), while the same sizes of mica sheets coated by Ag paste were employed with lead foils for the parallel plate terminal type (HCM-C). The developed capacitors exhibited well behaviored device characteristics which meet the requirements of the capacitors. The developed capacitors also showed excellent characteristics for thermal shock test. The stability characteristics of developed capacitors for large current stress was superior to those measured for the capacitors prepared recently by CDETm.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.299-302
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• 2008

A unified numerical analysis including combustion was conducted in order to study on performance of ramjet propulsion. The geometry of concern includes the entire flow path of a ramjet extending from intake to exhaust nozzle. Acceleration mode and cruise mode were considered in several equivalence ratios. Pressure distributions, terminal shock train range at the intake, temperature distributions in the combustors, and fuel mass fraction at the nozzle exit were investigated for each flight mode.

• Journal of Aquaculture
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• v.12 no.2
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• pp.91-100
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• 1999

The complete nucleotide sequence of olive flounder (Paralichthys olivaceus) hsp70-related rDNA was determined by RT- and RACE-PCR methods. A full-length of hsp70-related cDNA has an open reading frame of 1.95 kb encoding 650 amino acids with a calculated molecular weight of 71.1 kD. A corresponding hsp70-related protein contains a number of conserved elements including an ATP-binding domain, a nuclear localization signal and the carboxyl terminal motif, EEVD, which may have a role in chaperone function. Comparison of nucleotide and predicted amino acid sequence between olive flounder hsp70-related gene and hsp/hsc70 genes of other species revealed a high similarity with the cognate form of these genes. These results indicated that we recovered likely to be a olive flounder cognate hsc70 gene.

• Journal of The Korean Astronomical Society
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• v.51 no.2
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• pp.37-48
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• 2018

Massive stars blow powerful stellar winds throughout their evolutionary stages from the main sequence to Wolf-Rayet phases. The amount of mechanical energy deposited in the interstellar medium by the wind from a massive star can be comparable to the explosion energy of a core-collapse supernova that detonates at the end of its life. In this study, we estimate the kinetic energy deposition by massive stars in our Galaxy by considering the integrated Galactic initial mass function and modeling the stellar wind luminosity. The mass loss rate and terminal velocity of stellar winds during the main sequence, red supergiant, and Wolf-Rayet stages are estimated by adopting theoretical calculations and observational data published in the literature. We find that the total stellar wind luminosity due to all massive stars in the Galaxy is about ${\mathcal{L}}_w{\approx}1.1{\times}10^{41}erg\;s^{-1}$, which is about 1/4 of the power of supernova explosions, ${\mathcal{L}}_{SN}{\approx}4.8{\times}10^{41}erg\;s^{-1}$. If we assume that ~ 1 - 10 % of the wind luminosity could be converted to Galactic cosmic rays (GCRs) through collisonless shocks such as termination shocks in stellar bubbles and superbubbles, colliding-wind shocks in binaries, and bow-shocks of massive runaway stars, stellar winds might be expected to make a significant contribution to GCR production, though lower than that of supernova remnants.

• Herbal Formula Science
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• v.16 no.2
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• pp.101-114
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• 2008

Objective : The purpose of this study was to investigate the anti-inflammatory effects of Hwagae-san extract(HGSE) on the peritoneal macrophage. Methods : To evaluate anti-inflammatory effects of HGSE, We measured cytokines(interleukin-6; IL-6, interleukin-12; IL-12, tumor necrosis factor-${\alpha}$; TNF-${\alpha}$) and nitric oxide(NO) production in lipopolysaccharide(LPS)-induced macrophages. Furthermore, We examined molecular mechanism using western blot and also LPS-induced endotoxin shock. Results : 1. HGSE did not have any cytotoxic effect in the peritoneal macrophages. 2. HGSE reduced LPS-induced IL-6, TNF-${\alpha}$, IL-12 and NO production in peritoneal macrophages. 3. HGSE inhibited the activation of extracelluar signal-regulated kinase(ERK), C-Jun NH2-terminal kinase(JNK) but not of p38, degradation of IkB-${\alpha}$ in the LPS-stimulated peritoneal macrophages. 4. HGSE inhibited the production of TNF-$\alpha$, IL-6 and IL-12 in serum after LPS injection. Conclusion : These results suggest that HGSE may inhibit the production of TNF-${\alpha}$, IL-6, and IL-12 through inhibition of ERK and JNK activation, and that HGSE may be beneficial for inflammatory diseases.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.411-414
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• 2010

In supersonic propulsion system, the inlet buzz phenomenon in the subcritical operation arises large pressure oscillation, combustion instability, and thrust loss, etc. Inlet Buzz phenomenon and the spray injection/combustion are figured out by the unified unsteady numerical analysis. TAB(Taylor Analogy Breakup) model was applied. Acoustic mode of the entire engine was investigated by detail analysis of pressure fluctuation at each location of the engine.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1207-1215
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• 2008

To investigate the occurrence and species diversity of mycobacteria in waters, surface water samples were collected monthly from the Han River and tap water samples at the terminal sites of the distribution system. Mycobacteria in each water sample were isolated by decontamination using cetylpyridinium chloride (CPC) and cultivation on Middlebrook 7H10 agar, and then identified by polymerase chain reaction-restriction fragment length polymorphism analysis (PRA) and sequencing of the 65-kDa heat-shock protein gene (hsp65 gene). Mycobacteria were detected in 59% of the surface water samples and 26% of the tap water samples. Over half of the 158 isolates could not be identified by hsp65 PRA and gene sequencing, and several identification discrepancies were observed between the two methods. The most frequently isolated species was Mycobacterium gordonae in surface water and M. lentiflavum in tap water. M. avium complex (MAC), the most important pathogen among environmental mycobacteria, was detected in the surface water samples but not found in the tap water samples. The result demonstrated that water is an important environmental source of mycobacteria and the combined application of hsp65 PRA and sequencing was more reliable than hsp65 PRA alone to accurately identify mycobacteria present in water.

• Journal of Chest Surgery
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• v.16 no.3
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• pp.301-309
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• 1983

Twenty-three patients with aneurysm were operated between Jan. 1956 to July 1983 at the Department of Thoracic surgery, Seoul National University Hospital. There were 18 males and 5 females in this series. The age ranged from 14 to 68 years with the mean age of 41 years. The etiology of aortic aneurysms was atherosclerosis in 10, trauma in 2, annuloaortic ectasia in 4, syphilis in 1, and unknown etiology in six cases. Among the 4 patients with ascending aortic aneurysm, aortic valve replacement with aneurysmorrhaphy in three patients and Bentall operation in one patient were performed successfully. One patient with entire aortic arch aneurysm was received Dacron graft replacement with anastomosis of brachiocephalic arteries separately under cardiopulmonary bypass. There was no complication. Among 6 patients involving the descending thoracic aorta, three patients were managed by prosthetic bypass graft and aneurysm resection, and another three patients were also managed by prosthetic graft replacement. There were three hospital deaths. There were two thoracoabdominal aortic aneurysm. One patient in shock state due to preoperative rupture died from cardiac arrest during operative procedure. In another patient who had extensive involvement from the midportion of descending thoracic aorta to the terminal abdominal aorta, the aneurysm was successfully repaired with Dacron graft. In this instance celiac axis, superior and inferior mesenteric arteries and right renal artery were anastomosed separately. Eight of the 10 abdominal aortic aneurysms was replaced with prosthetic graft. One saccular aneurysm was treated by resection and primary closure. In another patient, cardiac arrest occurred during operation before definitive procedure. There was one another hospital death in the patient with preoperative rupture.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.1-9
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• 2006

Peroxiredoxins (Prxs) are ubiquitously distributed and play important functions in diverse cellular signaling systems. The proteins are largely classified into three groups, such as typical 2-Cys Prx, atypical 2-Cys Prx, and 1-Cys Prx, that are distinguished by their catalytic mechanisms and number of Cys residues. From the three classes of Prxs, the typical 2-Cys Prx containing the two-conserved Cys residues at its N-terminus and C-terminus catalyzes $H_2O_2$ with the use of thioredoxin (Trx) as an electron donor. During the catalytic cycle, the N-terminal Cys residue undergoes a peroxide-dependent oxidation to sulfenic acid, which can be further oxidized to sulfinic acid at the presence of high concentrations of $H_2O_2$ and a Trx system containing Trx, Trx reductase, and NADPH. The sulfinic acid form of 2-Cys Prx is reduced by the action of sulfiredoxin which requires ATP as an energy source. Under the strong oxidative or heat shock stress conditions, 2-Cys Prx in eukaryotes rapidly switches its protein structure from low-molecular-weight species to high-molecular-weight protein structures. In accordance with its structural changes, the protein concomitantly triggers functional switching from a peroxidase to a molecular chaperone, which can protect its substrate denaturation from external stress. In addition to its N-terminal active site, the C-terminal domain including 'YF-motif' of 2-Cys Prx plays a critical role in the structural changes. Therefore, the C-terminal truncated 2-Cys Prxs are not able to regulate their protein structures and highly resistant to $H_2O_2$-dependent hyperoxidation, suggesting that the reaction is guided by the peroxidatic Cys residue. Based on the results, it may be concluded that the peroxidatic Cys of 2-Cys Prx acts as an '$H_2O_2$-sensor' in the cells. The oxidative stress-dependent regulation of 2-Cys Prx provides a means of defense systems in cells to adapt stress conditions by activating intracellular defense signaling pathways. Particularly, 2-Cys Prxs in plants are localized in chloroplasts with a dynamic protein structure. The protein undergoes conformational changes again oxidative stress. Depending on a redox-potential of the chloroplasts, the plant 2-Cys Prx forms super-molecular weight protein structures, which attach to the thylakoid membranes in a reversible manner.