• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.277-284
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• 2018

In this study, we investigated the anti-allergic effect of the ethyl acetate fraction of Ecklonia cava (EC-EtoAc) on the immunoglobulin E (IgE)/bovine serum albumin (BSA)-mediated activation of bone marrow-derived cultured mast cells (BMCMCs). We revealed that the $62.5{\mu}g/ml$ of EC-fractions ($EC-CHCl_3$, EC-Hexane and EC-EtoAc) inhibited IgE/BSA-activated ${\beta}$-hexosaminidase release from BMCMCs without cytotoxicity. Especially, EC-EtoAc showed the higher ${\beta}$-hexosaminidase release than the others. Also, EC-EtoAc reduced the expression levels of cytokines such as interleukin (IL)-$1{\beta}$, IL-4, IL-5, IL-6, IL-10, IL-13, interferon (IFN)-${\gamma}$ and tumor necrosis factor (TNF)-${\alpha}$ and a chemokine, thymus- and activation-regulated chemokine (TARC), compared to the only IgE/BSA-treated BMCMCs. Furthermore, EC-EtoAc significantly prevented the binding of IgE to Fc epsilon receptor $(Fc{\varepsilon}R)I$ and reduced the $Fc{\varepsilon}RI$ expression on the sensitized BMCMCs. Taken together, these results suggest that E. cava may be the natural agent with beneficial potentials for the treatment of type I allergic diseases induced by mast cell activation.

• Journal of Life Science
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• v.19 no.7
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• pp.983-993
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• 2009

The effects of Monascus-fermented Korean red ginseng (MFRG) on the contents of serum lipids and tissues lipid peroxidation was investigated in alcohol feeding rats (AC group). Serum contents of total lipid and free fatty acid in alcohol feeding rats were significantly increased, but these increases tended to decrease in the AMFRG group. Serum triglyceride content was also significantly decreased in the AMFRG group compared to other groups. Serum content of total-cholesterol was significantly increased in AC group compared to normal control (NC) group, whereas there was no significant difference between the AC and AMFRG groups. Content of HDL-cholesterol in serum was slightly increased in the AC group compared to the NC group, but this increase in the AC group was more significantly increased in the AMFRG group. At the same time, atherogenic index (AI) was also significantly decreased in the AMFRG group compared to the AC group. Contents of thiobarbituric acid reactive substances (TBARS) in the liver, heart, spleen and testes were significantly increased in the AC group compared to the NC group, but these increases were significantly less in the AMFRG group. Contents of liver nonheme ion was increased in the AC group and was significantly decreased in the AMFRG group, which suggested that lipid peroxidation contents are inversely correlated with liver nonheme ion content. Hepatic glutathione concentration was significantly decreased in the AC group, but this content was significantly increased in the AMFRG group and it showed the antioxidant abilities of glutathione. These results suggested that Monascus-fermented Korea red ginseng has anti-atherogenic index (AI) effects as well as antioxidative activities through reduced tissue oxidative stress in alcohol feeding rats.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1A
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• pp.1-8
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• 2004

Viterbi decoders are widely used for communication and high-density storage devices. An add-compare-select(ACS) unit has been an active research area for a long time because it is the most critical component in determining the operation speed and power-consumption of the Viterbi decoder. We propose a new comparator which is faster and consumes less power than existing ones. We also used the new comparator for a Viterbi decoder and our simulations results show the Viterbi decoder outperforms existing ones at least $20\%$ in its operating speed.

• Composites Research
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• v.15 no.3
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• pp.1-10
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• 2002

The effect of size of SiC particles and additive Mg content on the mechanical properties and wear characteristics were investigated for the SiCp/AC8A composites fabricated by pressureless infiltration process. Results showed that the hardness and the bending strength increased with decreasing the size of SiC particle. By increasing the Mg content the hardness of SiCp/AC8A composites increased due to the hard reaction products, however the bending strength decreased by formation of coarse precipitates and high porosity level. The SiCp/AC8A composites exhibited about 6 times higher wear resistance compared with AC8A alloy at high sliding velocity and as increasing the particle size, wear resistance was improved. The major wear mechanical of SiCp/AC8A composites exhibited the abrasive wear at low to high sliding velocity whereas AC8A alloy showed adhesive and melt wear at high sliding velocity.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.283-293
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• 2006

Two experiments were conducted to investigate the effects of dietary activated charcoal mixed with wood vinegar (AC) on broiler performance and antibiotics residue in eggs. In experiment 1, a total of low hundred fifty, 1-day-old male broile. chicks (Ross) were divided into 6 groups, consisting 3 replicates of 25 birds each, and 134 one of the six experimental diets: devoid of AC and antibiotics (negative control), devoid of AC with 0.1% antibiotics (positive control), devoid of antibiotics with 1% AC, with 0.1% antibiotics and 1% AC, devoid of antibiotics with 2% AC, with 0.1% antibiotics and 2% AC, for 5 wks. Feed consumption and body weights were measured weekly. At the end of the experiment, eight birds from each group were selected and sacrificed. The relative weight of organs and characteristics of breast muscle were investigated. There were no significant differences in feed intake, body weight gain and feed conversion rate among the treatments. There were also no significant differences in the relative weight of breast meat, leg and liver. The abdominal fat tended to be decreased by the dietary AC. Significant differences were shown (P<0.05) in meat redness (a) and yellowness (b) among the treatments. However, the sensual characteristics of breast muscle was not affected by the dietary treatments. There were significant differences in total microbes, Coli forms and lactic acid bacteria (P<0.05) among the treatments. In experiment 2, a total of ninety, 40-wk-old Hy-line Brown laying hens were divided into 3 groups, consisting 3 replicates of 10 birds each and fed medicated control diet devoid of AC or diets containing 1% AC and 2% AC for 2 wks. The residue of antibiotics in Plasma and egg Yolk were significantly decreased (P<0.05) in 2% AC group compared to that of control. This study suggest that dietary AC may improve the external quality of edible meat and reduced antibiotics residue in chicken eggs without affecting laying performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.3
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• pp.244-252
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• 2002

In this paper, do link ripple currents for three-phase ac/dc/ac PWM converters feeding adjustable speed ac machine drives are analysed in a frequency domain. The expression of the harmonic currents is developed by using switching functions of the converter and exponential courier series expansion. The effect of the displacement angle between the switching Periods of line-side converters and motor-side inverters on the dc link ripple currents is Investigated. Also, the influence of asynchronization of PWM is observed. The result of analysis is compared with frequency spectrum which results from PSIM simulation. The proposed analysis technique is useful to understand the principles of P% and to derive an equivalent model of the dc link capacitors in a high frequency range.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.21-30
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• 2003

Background : Mucin synthesis in airways has been reported to be regulated by the epidermal growth factor receptor (EGFR) system. Epidermal growth factor receptor transactivation was identified as a critical element in G-protein-coupled receptors (GPCRs)-induced mitogenic signaling. EGF receptor transactivation by G-protein-coupled receptors requires metalloproteinase cleavage of proHB-EGF. This study was hypothesized that lipopolysaccharide (LPS)-induced mucin production associates with epidermal growth factor receptor transactivation, and MUC5AC production associates with epidermal growth factor receptor transactivation by G-protein-coupled receptors that regulates by metalloproteinase. Method : MUC5AC mucin production was examined in NCI-H292 cells and MUC5AC protein synthesis was assessed using ELISA. For the evaluation of mechanism of LPS-induced MUC5AC production, $TNF{\alpha}$ was measured using ELISA with or without pretreatment of heterotrimeric G-protein inhibitor, mastoparan. MUC5AC protein was measure with pretreatment of polyclonal $TNF{\alpha}$ antibody or mastoparan on LPS-induced MUC5AC production. For the evaluation of relation of G-protein and MUC5AC production, G-protein stimulant, mastopara-7, or matrix metalloproteinase, ADAM10, was added to NCI-H292 cells. MUC5AC protein was measure with pretreatment of polyclonal EGF antibody on mastoparan-7-induced MUC5AC production. Results : LPS alone did not increase significantly MUC5AC production. LPS with $TNF{\alpha}$ induced dose-dependently MUC5AC production in NCI-H292 cells. LPS increased dose-dependently $TNF{\alpha}$ secretion, which was inhibited by mastoparan. LPS with $TNF{\alpha}$-induced MUC5AC production was inhibited by neutralizing polyclonal $TNF{\alpha}$ antibody, mastoparan or AG 1472. Mastoparan-7 or ADAM10 increased dose-dependently MUC5AC production, which was inhibited by polyclonal neutralizing EGF antibody. Conclusion : In LPS-induced MUC5AC synthesis, LPS causes $TNF{\alpha}$ secretion, which induces EGFR expression. EGFR tyrosine kinase phosphorylation result in MUC5AC production. EGF-R transactivation by G-protein-coupled receptors requires matrix metalloproteinase cleavage of proHB-EGF.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.49-61
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• 2014

Purpose: With the aging of the population, the attack rate of osteoporotic vertebral compression fracture is in the increasing trend, and percutaneous vertebroplasty (PVP) is the most commonly performed standardized treatment. Although there is a research report of the excellence of usefulness of the SPECT/CT examination in terns of the exact diagnosis before and after the procedure, the bone cement material used in the procedure influences the image quality by forming an artifact in the CT image. Therefore, the objective of the research lies on evaluating the effect the bone cement gives to a SPECT/CT image. Materials and Methods: The images were acquired by inserting a model cement to each cylinder, after setting the background (3.6 kBq/mL), hot cylinder (29.6 kBq/mL) and cold cylinder (water) to the NEMA-1994 phantom. It was reconstructed with Astonish (Iterative: 4 Subset: 16), and non attenuation correction (NAC), attenuation correction (AC+SC-) and attenuation and scatter correction (AC+SC+) were used for the CT correction method. The mean count by each correction method and the count change ratio by the existence of the cement material were compared and the contrast recovery coefficient (CRC) was obtained. Additionally, the bone/soft tissue ratio (B/S ratio) was obtained after measuring the mean count of the 4 places including the soft tissue(spine erector muscle) after dividing the vertebral body into fracture region, normal region and cement by selecting the 20 patients those have performed PVP from the 107 patients diagnosed of compression fracture. Results: The mean count by the existence of a cement material showed the rate of increase of 12.4%, 6.5%, 1.5% at the hot cylinder of the phantom by NAC, AC+SC- and AC+SC+ when cement existed, 75.2%, 85.4%, 102.9% at the cold cylinder, 13.6%, 18.2%, 9.1% at the background, 33.1%, 41.4%, 63.5% at the fracture region of the clinical image, 53.1%, 61.6%, 67.7% at the normal region and 10.0%, 4.7%, 3.6% at the soft tissue. Meanwhile, a relative count reduction could be verified at the cement adjacent part at the inside of the cylinder, and the phantom image on the lesion and the count increase ratio of the clinical image showed a contrary phase. CRC implying the contrast ratio and B/S ratio was improved in the order of NAC, AC+SC-, AC+SC+, and was constant without a big change in the cold cylinder of the phantom. AC+SC- for the quantitative count, and AC+SC+ for the contrast ratio was analyzed to be the highest. Conclusion: It is considered to be useful in a clinical diagnosis if the application of AC+SC+ that improves the contrast ratio is combined, as it increases the noise count of the soft tissue and the scatter region as well along with the effect of the bone cement in contrast to the fact that the use of AC+SC- in the spine SPECT/CT examination of a PVP performed patient drastically increases the image count and enables a high density of image of the lesion(fracture).

• Journal of the Korean institute of surface engineering
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• v.41 no.1
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• pp.28-32
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• 2008

In this paper CdS thin films, which were widely used window layer of the CdS/CdTe and the CdS/$CuInSe_2$ heterojunction solar cell, were grown by chemical bath deposition, which is a very attractive method for low-cost and large-area solar cells, and the structural, optical and electrical properties of the films was studied. As the thiourea/$CdAc_2$ mole ratio was increased, the deposition rate of CdS films prepared by CBD was increased due to increasing reaction velocity in solution and the optical bandgap was increased at higher thiourea/$CdAc_2$ mole ratio due to larger grain size and continuous microstructure. The minimum resistivity of the films was at thiourea/$CdAc_2$ mole ratio of 3.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.127-135
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• 2009

In this paper, the Interleaved AC/DC boost converter using two inductor with voltage-doubler characteristic when it operates with a duty cycle greater than 0.5 is proposed. Generally, the low-line(Input AC 110[V]) operation of the AC/DC boost converter is much less efficient than high-line (Input AC 220[V]) operation. The proposed Interleaved AC/DC boost converter operates as a voltage doubler at low-line. Its low-line range have higher power factor and improved efficiency compared with that of conventional converter. This research proposed the Interleaved AC/DC boost converter for voltage-doubler characteristic. The principle of operation, feature and design considerations is illustrated and the validity of verified through the experiment with a 300[W] based experimental circuit.