• Nutrition Research and Practice
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• v.9 no.2
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• pp.123-128
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• 2015

BACKGROUND/OBJECTIVES: Natural products or active components with a protective effect against oxidative stress have attracted significant attention for prevention and treatment of degenerative disease. Oligonol is a low molecular weight polyphenol containing catechin-type monomers and oligomers derived from Litchi chinensis Sonn. We investigated the protective effect and its related mechanism of oligonol against oxidative stress. MATERIALS/METHODS: Oxidative stress in C6 glial cells was induced by hydrogen peroxide ($H_2O_2$) and the protective effects of oligonol on cell viability, nitric oxide (NO) and reactive oxygen species (ROS) synthesis, and mRNA expression related to oxidative stress were determined. RESULTS: Treatment with oligonol inhibited NO and ROS formation under cellular oxidative stress in C6 glial cells. In addition, it recovered cell viability in a dose dependent-manner. Treatment with oligonol also resulted in down-regulated mRNA expression related to oxidative stress, nuclear factor kappa-B (NF-${\kappa}B$) p65, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS), compared with the control group treated with $H_2O_2$. In particular, expression of NF-${\kappa}B$ p65, COX-2, and iNOS was effectively reduced to the normal level by treatment with $10{\mu}g/mL$ and $25{\mu}g/mL$ of oligonol. CONCLUSIONS: These results indicate that oligonol has protective activity against oxidative stress-induced inflammation. Oligonol might be a promising agent for treatment of degenerative diseases through inhibition of ROS formation and NF-${\kappa}B$ pathway gene expression.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.169-175
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• 2014

PAHs (Polycyclic Aromatic Hydrocarbons: PAHs) is the hydrophobic inorganic material composed of carbon and hydrogen that is easily adsorbed biological organisms in the ocean. Bivalves is the indicator of environment monitoring because of reflect growth, physiological response of bivalve followed their habitat environment. The aim of research is understand the change of oysters (Crassostrea gigas) physiological response under exposed PAHs concentration for control, 1, 10 and $100{\mu}g/L$. We investigated induced immune change response for oyster hemocyte and effect of tissue RNA/DNA ratio for mantle, gill and adductor muscle individually. As a result of experiment change of immune response the oyster hemocyte when exposed PAHs showed that viability and adhesion is no significant difference (ANOVA test, p < 0.05). However phagocytosis decreased under the over $10{\mu}g/L$ of PAHs concentration and ROS increased with the increase of PAHs concentration. The change of RNA/DNA ratio is R/D ratio decreased with the increase of PAH concentration in adductor muscle. However gill and mantle showed no change of R/D ratio with PAHs concentration. The oysters when exposed inorganic pollutant that decreased of physiological condition and damaged protein synthesis of adductor muscle.

• Journal of Powder Materials
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• v.23 no.3
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• pp.235-239
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• 2016

This study is performed to fabricate a Ti porous body by freeze drying process using titanium hydride ($TiH_2$) powder and camphene. Then, the Ti porous body is employed to synthesize carbon nanotubes (CNTs) using thermal catalytic chemical vapor deposition (CCVD) with Fe catalyst and methane ($CH_4$) gas to increase the specific surface area. The synthesized Ti porous body has $100{\mu}M$-sized macropores and $10-30{\mu}m$-sized micropores. The synthesized CNTs have random directions and are entangled with adjacent CNTs. The CNTs have a bamboo-like structure, and their average diameter is about 50 nm. The Fe nano-particles observed at the tip of the CNTs indicate that the tip growth model is applicable. The specific surface area of the CNT-coated Ti porous body is about 20 times larger than that of the raw Ti porous body. These CNT-coated Ti porous bodies are expected to be used as filters or catalyst supports.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.638-644
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• 2018

In this study, the immobilization of xylanase using a protein-inorganic hybrid nanoflower system was assessed to improve the enzyme properties. The synthesis of hybrid xylanase nanoflowers was very effective at $4^{\circ}C$ for 72 h, using 0.25 mg/ml protein, and efficient immobilization of xylanase was observed, with a maximum encapsulation yield and relative activity of 78.5% and 148%, respectively. Immobilized xylanase showed high residual activity at broad pH and temperature ranges. Using birchwood xylan as a substrate, the $V_{max}$ and $K_m$ values of xylanase nanoflowers were 1.60 mg/ml and $455{\mu}mol/min/mg$ protein, compared with 1.42 mg/ml and $300{\mu}mol/min/mg$ protein, respectively, for the free enzyme. After 5 and 10 cycles of reuse, the xylanase nanoflowers retained 87.5% and 75.8% residual activity, respectively. These results demonstrate that xylanase immobilization using a proteininorganic hybrid nanoflower system is an effective approach for its potential biotechnological applications.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.63-68
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• 2000

This study was conducted to investigate insecticidal mechanisms of the new insecticides DBI-1015 and DBI-3204 with label compounds of chitin precursors, [$^{14}C$] N-acetylglucosamine and [$^{14}C$] UDP-N-acetylglucosamine in Spodoptera litura. The concentrations of the insecticides for incorporation of chitin precursors into chitin were founded to be functional relationship. The result of in vivo test, $I_{50}$ (ppm) of the DBI-1015, DBI-3024 and diflubenzuron to [$^{14}C$] N-acetylglucosamine were 0.57, 0.89 and 0.26 ppm respectively, and to [$^{14}C$] UDP-N-acetylglucosaminen were 0.99, 0.53 and 0.45 ppm respectively. in vitro test of DBI-1015, DBI-3024 and diflubenzuron by integument fragments, the incorporation rate in the cuticle were low, however, $40{\sim}60%$ inhibitions were observed at $2{\mu}M$ when compared to the untreated control.

• Journal of Nutrition and Health
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• v.34 no.2
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• pp.150-157
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• 2001

Intestinal absorption of dietary taurine is one of the regulatory component maintaining taurine homeostasis along with renal reabsorption, bile acid conjugation and secretion, and de nobo synthesis of taurine in mammals. Recent observations of decreased enterocytic levels of taurine in response to trauma, infection and surgical insults, postulate the possibility that intestinal taurine absorption might be impaired in such stressed conditions. The aim of the present study was to evaluate changes in enterocytic taurine transporter activity using the human intestinal colon carcinoma cell line, HT-29, in various stress-induced conditions. Pretreatment of the HT-29 cells with dexamethasone, a stress hormone(0.1,1,10 or 100$\mu$M) for 3 hrs, or with E coli heat-stable enterotoxin(10, 100, or 200nM) for 30 minutes in order to induce the condition of enterotoxigenic infection did not influence taurine uptake as compared to the value found in control cells. In contrast, pretreatment of the cells with cholera toxin(10, 100, 500, or 1000ng/ml)for 3hr or 24hr significantly decreased taurine uptake by HT-29 cells to 40~50% of the value found in untreated control cells. Kinetic studies of the taurine transporter activity were conducted in control and cholera toxin treated HT-29 cells with varying taurine concentrations(2~60$\mu$M) in the uptake medium. Pretreatment of the cells with cholera toxin(100ng/ml) for 3hr did not influence the Vmax, but resulted in a 55% increase in the Michaelis-Menten constant(Km) of the taurine transporter compared to those in control cells. These results suggest that cholera toxin-induced reduction in taurine transporter activity in HT-29 cells is associated with decreased affinity of the taurine transporter without altering the amount of transporter protein. Intestinal taurine absorption appears to be reduced in the condition of water-borne diseases caused by bacteria such as V. cholerae. This might influence the taurine status of infants and young children more readily, an age group in which the prevalence of intestinal infection is high and the role of intestinal absorption is crucial for maintaining the body taurine pool. (Korean J Nutrition 34(2) : 150-157, 2001)

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.251-257
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• 2000

Chitin synthases are identified as key enzymes of chitin biosynthesis in most of the fungi. Among them, chitin synthase II has been reported to be and essential enzyme in chitin biosynthesis, and exists as a membrane-bound form. To search and screen new antifungal agents from natural resources to inhibit chitin synthase II, the assay conditions were established using the enzyme isolated from Saccharomyces cerevisiae ECY38-38A(pAS6) that overproduces only chitin synthase II. This enzyme was activated only by partial proteolysis with trypsin. Its actibity reached the maximum at $80{\;}\mu\textrm{g}/ml$ of trypsin and was strongly stimulated by 2.0 mM $Co^{2+}$, 1.0 nM UDP-[$^{14}C$]-GicNAc, and 32 mM free-GlcNAc. Under these assay conditions, the highest chitin synthase II activity was observed by incubation at $30^{\circ}C$ for 90 min. However, and extremely narrow range of organic solvents up to as much as 25% of DMSO and 25% of MeOH was useful for determining optimal assay conditions. After a search or potent inhibitors of chitin synthase II from natural resources, prodigiosin was isolated from Serratia marcescens and purified by solvent extration and silica gel column chromatographies. The structure of prodigiosin was determined by UV, IR, Mass spectral, and NMR spectral analyses. Its molecular weight and formula were found to be 323 and $C_{20}H_{25}N_{3}O$, respectively. Prodigiosin ingibited chitin synthase II by 50% at the concentration of $115{\;}\mu\textrm{g}/ml$.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.306-310
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• 2006

For screening of the compounds exhibiting antimicrobial activities against the D-alanyl-D-alanine of Gram positive bacteria, approximately 2,500 actinomycetes isolated from soil were examined far antimicrobial activity. In consequence, we recently isolated the Streptomyces sp. G91353 strain produced an active compound, A91353, that inhibits the growth of Gram positive bacteria. A91353 was identified as N-acetyl-phenylalanine by various spectroscopic methods. The minimum inhibitory concentration (MIC) values of N-acetyl-phenylalanine on Gram positive bacteria such as Streptococcus pyogenes 308A, Streptococcus pyogenes 77A were determined as $50{\mu}g/ml$, respectively, but did not effect on Gram negative strains. These results indicate that N-acetyl-phenylalanine have an antimicrobial activity, which may be caused by the disturbance of D-alanyl-D-alanine synthesis.

• YAKHAK HOEJI
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• v.14 no.1_2
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• pp.1-14
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• 1970

Seventeen N,N/sup I/-disubstituted thiourea derivatives were synthesized by the Hugershof reaction and reported. Antitumor activities of the synthesized compounds against ascitic Ehrlich Carcinoma and ascitic sarcoma 180 were reported. It was found that 1,1/sup I/-(p-Phenylene)-3,3/sup I/-bis (2-carboxyphenyl)-2,2/sup I/-dithiourea was considerably active against ascitic Ehrlich Carcinoma and Sarcoma 180 respectively. 1-(2-Carboxyphenyl)-3-(p-ethoxyphenyl)-2 thiourea was active against ascitic Sarcoma 180. 1-Salicyloyl-3-(p-ethoxyphenyl)-2-thiourea and 1,1/sup I/-(p-Phenylene)-3,3/sup I/-bis(2-hydroxyethyl)-2,2/sup I/-dithiourea were active against ascitic Ehrlich Carcinoma. Antitubercular activities of the synthesized compounds against Mycobacterium tuberculosis H/sub 37/ R/sub v/ were also reported. It was found that 1-Isonicotinyl-4-cyclohexyl-3-thiosemicarbazide was considerably active at 100 .mu.g/ml. 1,1/sup I/-(p-Phenylene)-3,3/sup I/-bis(2-hydroxyethyl)-2,2/sup I/-dithiourea and 1-Salicyloyl-3-(p-ethoxyphenyl)-2-thiourea were active at 1000 .mu.g/ml respectively. Antibacterial activities of nine compounds of the synthesized compounds against S. aureus and E. Coli were reported. It was found that 1,1-(p-Phenylene)-4,4/sup I/-bis(isonicotinyl)-2,2/sup I/-dithiosemicarbazide and 1-Isonicotinyl-4-cyclohexyl-3-thiosemicarbazide were considerably active against S. aureus and E. Coli respectively. 1-(6-Methyl-2-benzothiazolyl)-3-(1-naphthyl)-2-thiourea was active against S. aureus. 1,1/sup I/-(p-Phenylene)-3,3/sup I/-bis (2-hydroxyethyl)-2,2/sup I/-dithiourea was active against E. Coli.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.3 s.345
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• pp.40-47
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• 2006

The finite-field multiplication can be applied to the elliptic curve cryptosystems. However, an efficient algorithm and the hardware design are required since the finite-field multiplication takes much time to compute. In this paper, we propose a radix-4 systolic multiplier on $GF(2^m)$ with comparative area and performance. The algorithm of the proposed standard-basis multiplier is mathematically developed to map on low-cost systolic cells, so that the proposed systolic architecture is suitable for VLSI design. Compared to the bit-parallel, bit-serial and systolic multipliers, the proposed multiplier has relatively effective high performance and low cost. We design and synthesis $GF(2^{193})$ finite-field multiplier using Hynix $0.35{\mu}m$ standard cell library and the maximum clock frequency is 400MHz.