• Proceedings of the Korean Information Science Society Conference
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• 2007.06a
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• pp.125-126
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• 2007

• Journal of Power System Engineering
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• v.9 no.4
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• pp.110-117
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• 2005

Underwater wet arc welds were experimentally performed on 11mm thick KR-RA steel plate using six different types of flux coated electrodes of 4.0mm diameter, KSKR, KSKT, USBL, JPUW, UWEA and UWEB. From analysis of bead appearance, detachability of weld slag, spatter occurrence and arc stability, JPUW gives the best result, and UWEB is superior to KSKR and KSKT. By experimental result of hardness distribution on the weld bonds, UWEB weld has the narrowest bond structure which is probable condition to get the best mechanical properties of weld. UWEB and JPUW welds have more even hardness distribution across weld deposit and base metal. Upon polarization test to measure the respondency of corrosion, the electrode of UWEB shows the most excellent degree due to the low open circuit potential difference.

• Journal of Power System Engineering
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• v.10 no.4
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• pp.111-118
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• 2006

Underwater wet arc welds were experimentally performed on 11mm thick KR-RA steel plate using six different types of flux coated electrodes of 4.0mm diameter, KSKR, KSKT, USBL, JPUW, UWEA and UWEB. From analysis of bead appearance, detachability of weld slag, spatter occurrence and arc stability, JPUW gives the best result, and UWEB is superior to KSKR and KSKT. By experimental result of hardness distribution on the weld bonds, UWEB weld has the narrowest bond structure which is probable condition to get the best mechanical properties of weld. UWEB and JPUW welds have more even hardness distribution across weld deposit and base metal. Upon polarization test to measure the respondency of corrosion, the electrode of UWEB shows the most excellent degree due to the low open circuit potential difference.

• Tuberculosis and Respiratory Diseases
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• v.53 no.1
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• pp.5-16
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• 2002

Background : Though mononuclear phagocytes serve as the final effectors in killing intracellular Mycobacterium tuberculosis, the bacilli readily survive in the intracellular environment of resting cells. The mechanisms through which cellular activation results in the intracellular killing is unclear. In this study, we sought to explore an in vitro model of a low-level infection of human mononuclear phagocytes with MAC and $H_{37}Ra$ and determine the extent of the lymphocyte dependent cytotoxicity of human monocytes and alveolar macrophages. Materials and Methods : The peripheral monocytes were prepared using the Ficoll gradient method from PPD positive healthy people and tuberculosis patients. The alveolar macrophages were prepared from PPD positive healthy people via a bronchoalveolar lavage. The human mononuclear phagocytes were infected at a low infection rate (bacilli:phagocyte 1:10) with MAC(Mycobacterium avium) and Mycobacterium tuberculosis $H_{37}Ra$. Non-adherent cells(lymphocyte) were added at a 10:1 ratio. After 1,4, and 7 days culture in $37^{\circ}C$, 5% CO2 incubator, the cells were harvested and inoculated in a 7H10/OADC agar plate for the CFU assay. The bacilli were calculated with the CFU/$1{\times}10^6$ of the cells and the cytotoxicity was expressed as the log killing ratio. Results : The intracellular killing of MAC and $H_{37}Ra$ within the monocyte was greater in patients with tuberculosis compared to the PPD positive controls (p<0.05). Intracellular killing of MAC and $H_{37}Ra$ within the alveolar macrophage appeared to be greater than that within the monocytes of the PPD positive controls. There was significant lymphocyte dependent inhibition of intracellular growth of the mycobacteria within the monocytes in both the controls and tuberculosis patients and within the macrophages in the controls(p<0.05). There was no specific difference in the virulence between the MAC and the $H_{37}Ra$. Conclusion : This study is an in vitro model of a low-level infection with MAC and $H_{37}Ra$ of human mononuclear phagocytes. The intracellular cytotoxicity of the mycobacteria within the phagocytic cells was significantly lymphocyte dependent. During the 7 days culture after the intracellular phagocytosis, the actual confinement of the mycobacteria was observed within the monocytes of tuberculosis patients and the alveolar macrophages of the controls as in the case of adding lymphocytes.

• BMB Reports
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• v.40 no.6
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• pp.952-958
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• 2007

We isolated many genes induced from pepper cDNA microarray data following their infection with the soybean pustule pathogen Xanthomonas axonopodis pv. glycines 8ra. A full-length cDNA clone of the Capsicum annuum ankyrin-repeat domain $C_3H_1$ zinc finger protein (CaKR1) was identified in a chili pepper using the expressed sequence tag (EST) database. The deduced amino acid sequence of CaKR1 showed a significant sequence similarity (46%) to the ankyrin-repeat protein in very diverse family of proteins of Arabidopsis. The gene was induced in response to various biotic and abiotic stresses in the pepper leaves, as well as by an incompatible pathogen, such as salicylic acid (SA) and ethephon. CaKR1 expression was highest in the root and flower, and its expression was induced by treatment with agents such as NaCl and methyl viologen, as well as by cold stresses. These results showed that CaKR1 fusion with soluble, modified green fluorescent protein (smGFP) was localized to the cytosol in Arabidopsis protoplasts, suggesting that CaKR1 might be involved in responses to both biotic and abiotic stresses in pepper plants.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.5
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• pp.1122-1129
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• 2001

Underwater wet arc welding process was experimentally investigated by using the six types of flux coated electrodes of 3.2 mm diameter and the KR-RA steel plate of 11 mm thickness as base metal. Two types of electrodes were domestic covered arc welding electrode(CR13, CR14) and another two types of wet welding electrodes(UWCS, TN20)were imported goods, and the other two type (UWX1, UWX2) were individually designed flux coated electrodes for experimental welding purpose. Main experimental results are summerized as follows: 1. It is ascertained that individually designed flux coated electrode(UWX1) could be used in practice with KR-RA steel plate for underwater wet arc bead welds. 2. Welding arc can be generated easily and considerably kept in stable using TN20 and UWX1 electrodes. 3. The micro Vickers hardness value and the portion of martensite in the HAZ were increased in all the electrodes by rapid cooling rate, but it is relatively maintain stable for UWCS, TN20 and UWX1 electrodes.

• Archives of Pharmacal Research
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• v.29 no.5
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• pp.375-383
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• 2006

The anti platelet effects of a novel guanidine derivative, KR-32570 ([5-(2-methoxy-5-chlorophenyl) furan-2-ylcarbonyl]guanidine), were investigated with an emphasis on the mechanisms underlying its inhibition of collagen-induced platelet aggregation. KR-32570 significantly inhibited the aggregation of washed rabbit platelets induced by collagen $(10{\mu}g/mL)$, thrombin (0.05 U/mL), arachidonic acid $(100{\mu}M)$, a thromboxane (TX) $A_2$ mimetic agent U46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin $F_2,\;1{\mu}M$) and a $Ca^{2+}$ ATPase inhibitor thapsigargin $(0.5{\mu}M)$ ($IC_{50}$ values: $13.8{\pm}1.8,\;26.3{\pm}1.2,\;8.5{\pm}0.9,\;4.3{\pm}1.7\;and\;49.8{\pm}1.4{\mu}M$, respectively). KR-32570 inhibited the collagen-induced liberation of $[^3H]$arachidonic acid from the platelets in a concentration dependent manner with complete inhibition being observed at $50{\mu}M$. The $TXA_2$ synthase assay showed that KR-32570 also inhibited the conversion of the substrate $PGH_2$ to $TXB_2$ at all concentrations. Furthermore, KR-32570 significantly inhibited the $[Ca^{2+}]_i$ mobilization induced by collagen at $50{\mu}M$, which is the concentration that completely inhibits platelet aggregation. KR-32570 also decreased the level of collagen $(10{\mu}g/mL)$induced secretion of serotonin from the dense-granule contents of platelets, and inhibited the NHE-1-mediated rabbit platelet swelling induced by intracellular acidification. These results suggest that the antiplatelet activity of KR-32570 against collagen-induced platelet aggregation is mediated mainly by inhibiting the release of arachidonic acid, $TXA_2$ synthase, the mobilization of cytosolic $Ca^{2+}$ and NHE-1.

• Journal of Magnetics
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• v.7 no.3
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• pp.63-71
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• 2002

Three fabrication techniques for forming thin barrier layer with uniform thickness and large barrier height in magnetic tunnel junction (MTJ) are discussed. First, the effect of immiscible element addition to Cu layer, a high conducting layer generally placed under the MTJ, is investigated in order to reduce the surface roughness of the bottom ferromagnetic layer, on which the barrier is formed. The Ag addition to the Cu layer successfully realizes the smooth surface of the ferromagnetic layer because of the suppression of the grain growth of Cu. Second, a new plasma source, characterized as low electron energy of 1 eV and high density of $10^{12}$ $cm^{-3}$, is introduced to the Al oxidation process in MTJ fabrication in order to reduce damages to the barrier layer by the ion-bombardment. The magnetotransport properties of the MTJs are investigated as a function of the annealing temperature. As a peculiar feature, the monotonous decrease of resistance area product (RA) is observed with increasing the annealing temperature. The decrease of the RA is due to the decrease of the effective barrier width. Third, the influence of the mixed inert gas species for plasma oxidization process of metallic Al layer on the tunnel magnetoresistance (TMR) was investigated. By the use of Kr-O$_2$ plasma for Al oxidation process, a 58.8 % of MR ratio was obtained at room temperature after annealing the junction at $300{^{\circ}C}$, while the achieved TMR ratio of the MTJ fabricated with usual Ar-$0_2$ plasma remained 48.4%. A faster oxidization rate of the Al layer by using Kr-O$_2$ plasma is a possible cause to prevent the over oxidization of Al layer and to realize a large magnetoresistance.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.497-509
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• 2002

Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.

• Journal of Ocean Engineering and Technology
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• v.17 no.4
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• pp.52-58
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• 2003

Underwater wet arc welds were experimentally performed on the KR-RA steel plate as base metal by using four different types of flux coated electrodes: KT33, UWEE, UWCS, and TN20, UWEE, the individually designed flux coated underwater electrode, had good operability when compared with other domestic terrestrial electrodes, and imported goods. The hardness value and the portion of martensite of HAZ were increased, by using a rapid cooling rate, Mechanical properties were also examined experimentally with a multi-pass butt-welding specimen test. The individually designed flux coated electrode UWEE could be used in practice for underwater wet welds.