• Journal of Ocean Engineering and Technology
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• v.4 no.2
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• pp.250-250
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• 1990

In this paper, fatigue tests were carried out at stress test levels of 461 MPa, 441 MPa, and 431 MPa by using smooth specimen of$2_{1/4}$ Cr-1 Mo steel with the stress ratio(R) of 0.05. The initiation, growth and coalescense process of the major cracks and sub-cracks among the fatigue cracks on the smooth specimen are investigated and measured under each stress level at a constant cycle ratio by the replica technique with optical microscope. Some of the important results are as follows: In spite of the difference of stress levels, the major crack data gather into a small band in the curve of surface crack length and crack depth against cycle ratio N/Nf. The sub-crack data, however, deviate from the band of the major crack. The growth rates, da/dN, of major and sub-crack plotted against the stress intensity factor range, ${\Delta}K$, have the tendency to be compressed on a relatively small band. But it is more effective to predict fatigue life through major cracks. The propagation behavior of surface microcracks on the smooth specimens coincides with that of the specimen having an artificial small surface defect or through crack.

• Biomolecules & Therapeutics
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• v.22 no.1
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• pp.27-34
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• 2014

Curcumin is naturally occurring polyphenolic compound found in turmeric and has many pharmacological activities. The present study was undertaken to evaluate anti-allergic inflammatory activity of curcumin, and to investigate its inhibitory mechanisms in immunoglobulin E (IgE)/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and in a mouse model of IgE/Ag-mediated passive systemic anaphylaxis (PSA). Curcumin inhibited cyclooxygenase-2 (COX-2) dependent prostaglandin $D_2$ ($PGD_2$) and 5-lipoxygenase (5-LO) dependent leukotriene $C_4$ ($LTC_4$) generation dose-dependently in BMMCs. To probe the mechanism involved, we assessed the effects of curcumin on the phosphorylation of Syk and its downstream signal molecules. Curcumin inhibited intracellular $Ca^{2+}$ influx via phospholipase $C{\gamma}1$ ($PLC{\gamma}1$) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-${\kappa}B$ (NF-${\kappa}B$) pathway. Furthermore, the oral administration of curcumin significantly attenuated IgE/Ag-induced PSA, as determined by serum $LTC_4$, $PGD_2$, and histamine levels. Taken together, this study shows that curcumin offers a basis for drug development for the treatment of allergic inflammatory diseases.

• Natural Product Sciences
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• v.22 no.3
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• pp.193-200
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• 2016

This study describes the anti-inflammatory, anti-oxidant, and melanogenesis inhibition activities of methanol extract and various organic solvent fractions of Arecae Pericarpium. We examined the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells, 1,1-diphenyl-2-picrylhydrazine (DPPH) scavenging activity, mushroom tyrosinase inhibition activity and melanin contents. The study showed that, among all tested fractions, methylene chloride fraction showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells ($IC_{50}$ value $8.89{\mu}g/mL$) and DPPH radical scavenging activity ($EC_{50}$ value $21.39{\mu}g/mL$). Methylene chloride and ethyl acetate fractions similarly inhibited mushroom tyrosinase activity. Methanol extract exhibited strongest reduction of melanin content in B16F10 melanoma cells. Based on the bioactivity assay results, methylene chloride and ethyl acetate fractions were further separated. Eight phenolic compounds were isolated, which are dimeric syringol (1), catechol (2), 4-hydroxybenzaldehyde (3), vanillin (4), 4-hydroxyacetophenone (5), apocynin (6), protocatechuic acid (7) and 4-hydroxybenzoic acid (8). Among the isolated compounds tested, catechol showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells. Catechol also showed the concentration-dependent NF-${\kappa}B$ inhibition activity. Arecae Pericarpium might have potentials to be developed as anti-inflammatory agent or dermatological product for skin-whitening agent.

• Molecules and Cells
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• v.27 no.2
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• pp.251-255
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• 2009

Sepsis is the leading cause of death in critically ill patients. Today, around 60% of all cases of sepsis are caused by Gram-negative bacteria. The cell wall component lipopolysaccharide (LPS) is the main initiator of the cascade of cellular reactions in Gram-negative infections. The core receptors for LPS are toll-like receptor 4 (TLR4), MD-2 and CD14. Attempts have been made to antagonize the toxic effect of endotoxin using monoclonal antibodies against CD14 and synthetic lipopolysaccharides but there is as yet no effective treatment for septic syndrome. Here, we describe an inhibitory effect of a phosphatidylethanolamine derivative, PE-DTPA (phosphatidylethanolamine diethylenetriaminepentaacetate) on LPS recognition. PE-DTPA bound strongly to CD14 ($K_d$, $9.52{\times}10^{-8}M$). It dose dependently inhibited LPS-mediated activation of human myeloid cells, mouse macrophage cells and human whole blood as measured by the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and nitric oxide, whereas other phospho-lipids including phosphatidylserine and phosphatidylethanolamine had little effect. PE-DTPA also inhibited transcription dependent on $NF-{\kappa}B$ activation when it was added together with LPS, and it rescued LPS-primed mice from septic death. These results suggest that PE-DTPA is a potent antagonist of LPS, and that it acts by competing for binding to CD14.

• Journal of Korea Multimedia Society
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• v.6 no.2
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• pp.352-359
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• 2003

In this paper, we designed the bluetooth receiver using the microstrip bandpass filter and the high gain low noise amplifier with the 0.2$\mu\textrm{m}$ CMOS technology. A cascode inverter is adopted to implement the low noise amplifier and is one stage amplifier with a voltage reference and without the choke inductor. The designed 2.4GHz LNA was achieved a power gain of 18dB, a noise figure of 2.8dB, and the power consumption of 255mW at 2.5V power supply. Also, the microstrip receiver bandpass filter was designed that the center frequency was 2.45GHz, the bandwidth was 4% and the insert attenuation was -1.9dB. When the microstrip bandpass filter and LNA was simulated together the power gain was 16.3dB.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.27-39
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• 2023

Extensive research supported the therapeutic potential of curcumin, a naturally occurring compound, as a promising cytokine-suppressive anti-inflammatory drug. This study aimed to investigate the synergistic anti-inflammatory and anti-cytokine activities by combining 6-shogaol and 10-shogaol to curcumin, and associated mechanisms in modulating lipopolysaccharides and interferon-γ-induced proinflammatory signaling pathways. Our results showed that the combination of 6-shogaol-10-shogaolcurcumin synergistically reduced the production of nitric oxide, inducible nitric oxide synthase, tumor necrosis factor and interlukin-6 in lipopolysaccharides and interferon-γ-induced RAW 264.7 and THP-1 cells assessed by the combination index model. 6-shogaol-10-shogaol-curcumin also showed greater inhibition of cytokine profiling compared to that of 6-shogaol-10-shogaol or curcumin alone. The synergistic anti-inflammatory activity was associated with supressed NFκB translocation and downregulated TLR4-TRAF6-MAPK signaling pathway. In addition, SC also inhibited microRNA-155 expression which may be relevant to the inhibited NFκB translocation. Although 6-shogaol-10-shogaol-curcumin synergistically increased Nrf2 activity, the anti-inflammatory mechanism appeared to be independent from the induction of Nrf2. 6-shogaol-10-shogaol-curcumin provides a more potent therapeutic agent than curcumin alone in synergistically inhibiting lipopolysaccharides and interferon-γ induced proinflammatory mediators and cytokine array in macrophages. The action was mediated by the downregulation of TLR4/TRAF6/MAPK pathway and NFκB translocation.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.448-452
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• 2005

Neurofibromatosis(NF) is an autosomal dominant disorder, probably of neural crest origin that affects all three germinal layers. It is a group of heterogeneous multisystemic neurocutaneous disorders involving both neuroectodermal and mesenchymal derivatives. Type 1(von Recklinghausen disease) is the most common neurocutaneous disorder among the eight subtypes. Previous reports showed various involvements in the renal organ. Renovascular hypertension is the most common major manifestation of renal involvement in this disease. However, we experienced a case of ectopic kidney concurrent with neurofibromatosis type 1. The diagnosis of neurofibromatosis had been made by typical skin manifestation on physical examination, and ectopic kidney was discovered accidentally during routine abdominal sonography. The etiological basis of this association is not clear. We report a rare case of coexisting neurofibromatosis and ectopic kidney in a 7-year-old girl with a brief review.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.188-199
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• 2004

Transglutaminase 2 (TGase 2) is an enzyme that is widely used in many biological systems for generic tissue stabilization purposes or immediate defenses for wounds. Many reports have showed that TGase 2 is aberrantly activated in tissues and cells and contributes to a variety of diseases, including neurodegenerative diseases and autoimmune diseases. In most cases, the TGase 2 appears to be a factor in the formation of inappropriate proteinaceous aggregates that may be cytotoxic. However, in other cases such as celiac disease, arthritis, lupus, amyotrophic lateral sclerosis, TGase 2 is involved in the generation of autoantibodies. This suggests the possibility that the inappropriate expression and/or presentation of TGase 2 to T cells might contribute to these diseases in genetically predisposed individuals. Others and we have found that TGase 2 expression is also increased in the inflammation process. We also demonstrated reverse of inflammation by TGase inhibition. Furthermore we discovered the genuine role of TGase 2 in immune cell activation. Increase of TGase activity induces or exacerbates inflammation via NF-κB activation without I-κBα kinase signalings. This review will examine a possibility of TGase inhibitors as therapeutic agents in a variety of inflammatory diseases.

• Journal of Acupuncture Research
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• v.31 no.2
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• pp.75-85
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• 2014

Objectives : We investigated whether bee venom(BV) inhibit cell growth through enhancement of death receptor expressions in the human cervix cancer C33A cells. Methods : BV($1{\sim}5{\mu}g/ml$) inhibited the growth of cervix cancer C33A cells by the induction of apoptotic cell death in a dose dependent manner. Results : Consistent with apoptotic cell death, expression of Fas, death receptor(DR) 3, 4, 5 and 6 was increased concentration dependently in the cells. Moreover, Fas, DR3 and DR6 revealed more sensitivity to BV. Thus, We reconfirmed whether they actually play a critical role in anti-proliferation of cervix cancer C33A cells. Consecutively, expression of DR downstream pro-apoptotic proteins including caspase-8, -3, -9 was upregulated and Bax was concomitantly overwhelmed the expression of Bcl-2. NF-${\kappa}B$ were also inhibited by treatment with BV in C33A cells. Conclusions : These results suggest that BV could exert anti-tumor effect through induction of apoptotic cell death in human cervix cancer C33A cells via enhancement of death receptor expression, and that BV could be a promising agent for preventing and treating cervix cancer.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.189-192
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• 2004

A LNA module, integrated microwave assemblies (IMAs) were developed for use in Ka-band Satellite Communication Satellite Payload that operates in the frequency range of 29,6 ${\~}$ 30.0GHz. The module will be placed directly behind their respective antenna feed horns to minimize the required waveguide and system noise figure impact. Two MMIC LNA Chips were used in the module design. The measured result shows that the module has 32dB gain and 2.4dB NF performance. The module size is 51m ${\times}$ 36m ${\times}$ 22 and the mass is 92g. The Noise Figure performance is the best result of currently available modules for satellite payload operating in the same frequency range. The module will be assembled using space-qualified process and tested for space qualification.