• Journal of the Korean Electrochemical Society
• /
• v.6 no.4
• /
• pp.250-254
• /
• 2003

In this study, the IR drop theory was adopted to explain the initiation of crevice corrosion in the framework of IR drop in crevice electrolyte. Furthermore, the electrochemical polarization was measured to study the mechanism of crevice corrosion for type STS430 stainless steel. lest method adopts under condition that the size of specimen is $10\times20\times5mm,\;in\;1N\;H_2SO_4+0.1N\;NaCl$ solution, and the artificial crevice gap sizes are three kinds, the Micro capillary tube size is inner diameter 0.04 mm, outer diameter 0.08 mm. Crevice corrosion is measured under the applied voltage of passivation potential -200mV/SCE, resulted from anodic potentio-dynamic polarization to the external surface along the crevice. The potential difference was measured by depth profile by Micro capillary tube which inserted in the crevice. The obtained results of this study showed that 1) As artificial crevice gap size became narrow, the current density was increased, whereas no crevice corrosion was found in the crevice gap size $3\times0.5\times16mm\;in\;1N\;H_2SO_4+0.1N\;NaCl\;solution\;at\;20^{\circ}C$ 2) potential of the crevice was about from -220 to -358mV which is lower than that of external surface potential of -200mV The results so far confirmes that the potential drop(so-called IR drop) in the crevice is one of the major mechanisms the process of crevice corrosion for 430 stainless steel.

• The Korean Journal of Pesticide Science
• /
• v.16 no.4
• /
• pp.267-272
• /
• 2012

Vitex trifolia L. is a full grown fruit of Vitex rotundifolia L. (Verbenaceae). It has been used for treating headache, dizziness, toothache and removal of fever as a traditional medicine in Korea. V. trifolia (500 g) were extracted three times with 80% aqueous MeOH at room temperature. The MeOH extract (38 g) was successively partitioned with n-hexane, EtOAc, n-BuOH and $H_2O$. Both n-hexane and EtOAc fractions showed more than 80% antifungal activity in vivo against several plant pathogens at 2000 ppm. Successive repeated silica gel, Sephadex LH-20, preparative TLC, and preparative HPLC of these fractions led to isolation of three compounds. Using mainly mass spectroscopy and nuclear magnatic resonance (NMR) spectroscopy, their chemical structures were determined as agnuside(1), chrysosplenol B(2), and artemetin(3). Compound 2 was isolated for the first time from V. trifolia. Study on in vitro and in vivo antifungal activities of the isolated compounds is in progress.

• Journal of Life Science
• /
• v.23 no.8
• /
• pp.1019-1024
• /
• 2013

The aims of this study were to determine antioxidation effect and neuroblastoma cell protection effect of donkey's bone and skin extracts (DBSE). DBSE was extracted by a pressure-cooker for 48 h and lyophilized. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was significantly increased with increased doses of DBSE and 40 mg/ml of DBSE showed 95.43% of the DPPH scavenging effect, which was equivalent to 1 mg/ml of vitamin C. The 2,2'-azino-bis (3-ethylbenzothiazoline-6- sulphonic acid) (ABTS) radical scavenging activity was also increased in a dose-dependent manner, and 20 mg/ml of DBSE showed 88.73% of the ABTS scavenging effect. The oxygen radical absorbance capacity (${\mu}M$ Trolox equivalent) of DBSE was significantly increased at a concentration of 10 mg/ml, which showed $132.53{\mu}M$ TE. The viability of oxidatively stressed brain cells induced by $500{\mu}M\;H_2O_2$ was protected by DBSE at concentrations greater than $50{\mu}M$. Cell viability after DBSE treatment at 50 and $100{\mu}g/ml$ was 53.78 and $54.34{\mu}M$ TE, respectively. There was no significant difference between both doses; however, 200 and $500{\mu}g/ml$ of DBSE showed 59.74 and 66.08% of cell viability, respectively indicating that DBSE protected SK-N-SH from oxidation stress. These results suggest that DBSE may have potential to be used as natural antioxidants in food industry, while in vivo evidence is necessary to support DBSE's in vitro-based antioxidative efficiency.

• Journal of Food Hygiene and Safety
• /
• v.31 no.1
• /
• pp.21-27
• /
• 2016

The objectives of this study are to produce monoclonal antibodies (MAbs) against Vibrio parahaemolyticus and to develop an immuno-selective filtration (ISF) method for the rapid and sensitive detection of V. parahaemolyticus. The characterization of the MAb produced from HKVP 4H9-9 hybridoma cell was validated by enzyme-linked immunosorbent assay (ELISA) and western blot. The produced MAb was specific to V. parahaemolyticus and showed weak cross-reaction to V. alginolyticus, V. vulnificus and Staphylococcus aureus. After optimization of the method, $5{\times}10^1cell/mL$ of V. parahaemolyticus in a pure culture could be detectable. Although weak cross-reactivity to V. vulnificus, V. alginolyticus and Staphylococcus aureus was observed, the ISF was confirmed to be highly specific to V. parahaemolyticus. Especially, the ISF showed the most sensitivity compared to the immunoassays currently reported is easier to perform and quicker than ID-ELISA.

• Korean journal of food and cookery science
• /
• v.25 no.1
• /
• pp.8-15
• /
• 2009

This study was carried out to examine changes in the quality characteristics of Aralia continentalis Kitagawa (AcK) Jangachi made with different $CaCl_2$ and seasoning treatments during storage at $4^{\circ}C$ for 6 months. The results exhibited there were no significant changes in pH, acidity, and salinity in the various samples. The numbers of total bacterial counts and lactic acid bacteria increased slowly during the early storage period and then increased rapidly in the third month. In the fifth month they reached their highest level near $6.6{\times}10^{6}cfu/ml$ and then decreased thereafter. The sample treated with $CaCl_2$ exhibited a higher degree of hardness than the untreated sample. Finally, the sensory characteristics of the AcK Jangachi were highly acceptable during the entire storage period in terms of color, smell, bitterness, texture, and general preference regardless of the $CaCl_2$ treatments.

• Journal of Embryo Transfer
• /
• v.20 no.3
• /
• pp.297-302
• /
• 2005

Artificial insemination (AI) technology has widely applied in domestic animals including cattle for production and preservation of valuable animals. However, AI in goat was poorly studied. We here compared two different estrus synchronization methods, CIDR (controlled intravaginal drug release)+$PGF_2a$ and CIDR+PMSG, in Korean native goats. After treatment of CIDR+$PGF_2a$ or CIDR+PMSG for estrus synchronization, AI was applied to 38 recipients. Of 18 recipients treated with CIDR+$PGF_2a$, 4 recipients produced offsprings. However, no pregnancy was obtained in 20 recipients treated with CIDR+PMSG. Especially, after treatment of CIDR+$PGF_2a$, AI with fresh or frozen sperm showed markedly higher parturition rates than that of CIDR+PMSG. From these results, we suggest that combination of CIDR and $PGF_2a$ could be used as good method for estrus synchronization in Korean native goats.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.1
• /
• pp.41-48
• /
• 1982

A comparison was made for growth and yield of two rowed and six rowed barley varieties to differentiate their fundamental characteris in relation with brewing quality. Heading and maturing time of two rowed barley varieties were similar to those of six rowed covered but were earlier than those of six rowed naked ones. Most of two rowed varieties were spring barley and low temperature susceptible, but they were relatively photoinsensitive compared to six rowed varieties. Eventhough malting barley has heavier stands and grains, they were quite similar in yielding ability with six rowed cultivars with decreased number of grains per spike. In quality characters, malting barley has better germination energy and rate, lower protein content than the common six rowed barley and decisively better for brewing that six rowed barley with higher malt yield, extract yield and quality and enzyme activity. In comparison of malting barley varieties produced in Korea and Japan indicated that those varieties produced in Japan were better in germination characters, extract yield and quality, Kolback index and enzyme activity than those produced in Korea.

• Korean Journal of Food Science and Technology
• /
• v.27 no.1
• /
• pp.124-128
• /
• 1995

The present study was conducted to elucidate nitrite scavenger derived from seeds of Cassia tora L. Methanolic extract of Cassia tora L was refractionated into ethyl ether, chloroform, ethyl acetate and water farction, and nitrite scavenging abilities of these fractions were investigated. Among these fractions, ethyl acetate fraction had the strongest nitrite scavenging ability(97%/2 mg). Therefore, to further investigate nitrite scavenger, ethyl acetate fraction was fractionated by silica gel column chromatography with a chloroform-methanol($10:0{\sim}0:10$) and then compound A and B were isolated. Compound A had a stronger nitrite-scavenging effect than compound B. Therefore the further separation of compound A was carried out by HPLC(32% acetonitrile. 1 ml/min) using ${\mu}Bondapak$C18 column$(3.9{\times}300 mm)$ and finally compound A-1 was obtained from compound A. Compound A-1 had by far nitrite-scavenging ability as compared with that of ascorbic acid. Compound A-1 was identified as $nor-rubrofusarin-6-{\beta}-mono-D-glucoside$ from the profiles of UV, IR and $^1H-NMR$.

• Herbal Formula Science
• /
• v.5 no.1
• /
• pp.169-178
• /
• 1997

To investigate effect of water extract of Asparagi Tuber(天門冬) on human cancer cell-lines and immunocytes, this research estimated proliferation of A431 cell line, KHOS-NP cell line, mouse thymocytes and mouse splenocytes, Nitric Oxide(NO) from macrophage, apoptosis and subpopulation of the mouse thymocytes. The result were obtained as follows ; 1. Asparagi Tuber inhibited the proliferation of A431 cell line. 2. Asparagi Tuber inhibited the proliferation of KHOS-NP cell line. 3. Asparagi Tuber accelerated the proliferation of mouse thymocytes. 4. Asparagi Tuber inhibited the proliferation of mouse splenocytes. 5. Asparagi Tuber $100{\mu}g/m{\ell}$ inhibited the production of NO from macrophages in vitro, being compared NPS+IFN treated group. 6. Asparagi Tuber inhibited the production of NO from macrophages in vivo, being compared LPS+IFN treated group. 7. Asparagi Tuber accelerated the induction of apoptosis of the mouse thymocytes. 8. In subpopulation Asparagi Tuber increased $T_H$ of the mouse thymocytes, but decreased $T_C/T_S$ of the mouse thymocytes.

• Korean Chemical Engineering Research
• /
• v.43 no.1
• /
• pp.110-117
• /
• 2005

In this work, solid-state inclusion complex powders of itraconazole and $2-hydroxypropyl-{\beta}-cyclodextrin(HP-{\beta}-CD)$ were produced by a supercritical anti-solvent (SAS) process. In order to evaluate the degree of complexation, the thermal behavior of the microparticulate complexes was investigated using differential scanning calorimetry. The experimental results obtained for the solubility and dissolution rate of the microparticulate inclusion complexes in a buffer solution of pH 1.2 showed that the complexation of itraconazole with $HP-{\beta}-CD$ results in a significant increase in the solubility and dissolution rate of itraconazole. The particle size of the SAS-produced inclusion complexes was dramatically reduced ($<0.1-0.5{\mu}m$) compared with untreated itraconazole ($30-50{\mu}m$) and $HP-{\beta}-CD$ ($50-100{\mu}m$). The solubility of itraconazole was increased with the increase of pressure at a constant temperature to ca. $758.6{\mu}g/mL$ in an aqueous medium of pH 1.2. The dissolution rate of itraconazole was observed to be significantly improved and about 90% of itraconazole was found to be dissolved within 5-10 min.