• Journal of Magnetics
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• v.17 no.1
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• pp.42-45
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• 2012

We have developed an alternating magnetic field stimulation system consisting of a switched-mode power supply and a digital control circuit which modulates a duty ratio to maintain a magnetic field intensity of a few mT even while the frequency increases up to 4 kHz with a controllable coil temperature below $30^{\circ}C$ in air. This duty ratio modulation and water circulation are advantageous for cell culture under ac-magnetic field stimulation by preventing the incubator from exceeding a cell-viable temperature of $37^{\circ}C$. Although the temperature of the coil when subjected to a sinusoidal voltage rapidly increased, that of our system modulated by the duty factor did not change. This is a potentially valuable method to investigate the effects of intermediate frequency magnetic field stimulation on biological entities such as cells, tissues and organs.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.84-87
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• 2010

Effects of gamma irradiation on microbiological changes of Gorosoe sap were characterized during a post-irradiation storage at $4^{\circ}C$. The aseptically collected sap was irradiated and stored at $4^{\circ}C$ for 0 to 60 days and analysed for standard plate counts and 16S rDNA. There were significant differences in the total number of colony forming units(CFUs) of bacteria between irradiated and non-irradiated control sap. Bacteria of non-irradiated sap were present at levels of $1.5{\times}10^4{\sim}2.3{\times}10^8\;CFU/m{\ell}$, whereas no viable microbial cells were detected in sap after 10 kGy of irradiation during storage. According to the 16S rDNA sequence analysis, bacterial community structures decrease with time and the most abundant strain was Pseudomonas species. Our results suggested that gamma irradiation can be used to enhance the shelf-life of Gorosoe sap.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.316-322
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• 1995

A curd yogurt was prepared from milk added with skim milk powder or four kinds of cereal. Addition of cereals markedly stimulated acid production by Leuc. mesenteroides. The acidity significantly increased during fermentation by Leuc. mesenteroides for 30 hours while pH significantly decreased during fermentation. The number of viable cells markedly increased until the first 12 or 18 hours of fermentation by Leuc. mesenteroides. Acetaldehyde, acetone, ethanol, diacetyl, butanol and acetoin in curd yogurt were detected by gas chromatographic analysis. Among these compounds, acetaldehyde, ethanol, diacetyl and acetoin were produced during fermentation by Leuc. mesenteroides.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.262-265
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• 2006

The antioxidative properties of lactobacilli originating from humans (Lactobacillus acidophilus KCTC 3111, Lactobacillus jonsonii KCTC 3141, Lactobacillus acidophilus KCTC 3151, and Lactobacillus brevis KCTC 3498) were investigated using in vitro methods, including inhibition of lipid peroxidation, resistance to hydrogen peroxide and hydroxyl radical, hydroxyl radical scavenging activity, and glutathione peroxidase (GPX) activity. L. acidophilus KCTC 3111 showed the highest inhibition of lipid peroxidation in both intact cells (49.7%) and cell lysate (65.2%). This strain exhibited resistance to hydrogen peroxide and hydroxyl radical, which was viable for 7 h in the concentration of 1.0 mM hydrogen peroxide. In addition, this strain showed high hydroxyl radical scavenging activity. In the GPX activity assay, the highest activity was measured in L. brevis 3498. GPX activity of L acidophilus 3111 was lower than that of L. brevis 3498.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.249-260
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• 1994

The purpose of this study was to aid in the radiation therapy of head and neck cancer patients. For this study, radiation survival curves were generated for Bl6, MG-63 and YAC-l cell lines using semiautomated MTT assay and Dye Exclusion Assay. Irradiation of 2, 4, 6, 8, 10Gy were delivered at room temperature at a dose rate of 210.2cGy/min using / sup 60/Co γ-ray Irradiator ALOORAOO 8. The viable cells were determined for each radiation dose and compared to control values. The obtained results were as follows: 1. There was significantly different absorbance at 10Gy on B16 cell line in MTT assay(P<0.05). 2. There was significantly different absorbance at 4, 6, 8, 10Gy on MG-63 cell line in MTT assay(P<0.05). 3. YAC-l cell line was more sensitive than B16 or MG-63 cell line to all doses of radiation(P<0.05). 4. There was significantly different absorbance among all tumor cell lines except between B16 and MG-63 cell line at ZGy in MTT assay(P<0.05). 5. Good correlation was obtained between MTT assay and DEA(P<0.05). The efficient of correlation of B16, MG-63 and YAC-l cell line was 0.845, 0.824 and 0.906, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.4
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• pp.219-226
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• 2000

The application of recombinant DNA technology to restructure metabolic net-work can change metabolite and protein products by altering the biosynthetic pathways in an organism. Although some success has been achieved, a more detailed and thorough investigation of this approach is certainly warranted since it is clear that such methods hold great potential based on the encouraging results obtained so far. In last decade, there have been tremendous advances in the field of glycobiology and the stage has been set for the biotechnological production of glycoproteins for therapeutic use. Today glycoproteins are one of the most important groups of pharmaceutical products. In this study the attempt was made to focus on identifying technologies that may have general application for modifying glycosylation pathway of the yeast cells in order to produce glycoproteins of therapeutic use. The carbohydrates of therapeutic recombinant glycoproteins play very important roles in determining their pharmacokinetic properties. A number of biological interactions and biological functions mediated by glycans are also being targeted for therapeutic manipulation in vivo. For a commercially viable production of therapeutic glycoproteins a metabolic engineering of a host cell is yet to be established.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.299-306
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• 2001

As a part of basic investigation for utilization of canned food processing by-products, a food components of the canned oyster processing waste water such as boiled and released water(BRW), wash water(WW) were investigated and compared with hot-water extracts from oyster. From the results of measuring heavy metal conte수, viable cells and coliform group, the canned oyster processing waste waters might not invoke health risk in using food resource. The contents of taste compounds (free amino acids, ATP related compounds, TMA (O) and total creatinine) of BRW and WW accounted for about 254% and 95%, respectively, in comparison with those of control (hot-water extract from oyster). The BRW showed a very high content of salt in comparing to the WW and control. In descending order, the values of whiteness index was WW, control and BRW. Sensory scores for color, oyster flavor intensity and saline taste were not significantly different between WW and control. But, BRW had the highest score in oyster flavor intensity, while had the lowest score in color and saline taste. But, the color and saline taste of BRW might be able to control by some pretreatment (concentration and drying in mild condition, desalination and recipe control etc). These results indicated that BRW and WW generated from various step during canned oyster processing could be a potential food resource by controlling of saline taste and color intensity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.600-605
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• 2012

In this study, we investigated the mechanism of inhibition of pathogenic bacteria by Pediococcus pentosaceus strain SH-10 isolated from hard Clam Meretrix meretrix sikhae. When P. pentosaceus SH-10 was co-cultured in MRS broth with pathogenic bacteria, including Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis and Staphyloccus aureus, no viable pathogenic cells were detected after 18 h of incubation. However, pediocin or a pediocin-like bacteriocin was not detected in cultures of P. pentosaceus SH-10 by the agar diffusion method. Organic acids were produced in MRS broth in proportion to the incubation time of P. pentosaceus SH-10. These results indicate that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria by lowering the pH of the growth medium through the production of organic acids, including sodium lactate, sodium acetate, and sodium citrate.

• Toxicological Research
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• v.13 no.4
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• pp.393-400
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• 1997

The effects of superoxide dismutase(SOD) and catalase on the toxicity of paraquat(PQ) were studied using diethyldithiocarbamate(DDC), 3-amino-1,2,4-triazole(AT) which are inhibitors of Cu, Zn-SOD and catalase in rats. Sprague Dawley rats were divide into 6 groups: control, DDC, PQ, AT, DDC+PQ, and AT+PQ group. The PQ (50 mg/kg body weight(BW); about half dose of $LD_{50}$) was administered with orally, otherwise AT(1.0g/kg BW) and DDC(1.0g/kg BW) were administered by intrperitoneal(iP) injection. The survival rate of rats in PQ+AT group was significantly decreased compared with PQ group while the difference of survival rate between DDC group and DDC+PQ group was not significant. The SOD activity after administration of DDC was decreased in liver, lung and kidney, but catalase activity was not changed. The catalase activity in liver, lung and kidney of AT treated rats was decreased, while SOD activity was not changed in this group. The effects of DDC and AT to the PQ toxicity was also observed in primary cultured rat Skin fibroblasts. The viable cells that was measured with MTT method, was decreased in AT+PQ treated group compared to PQ treated group, but the difference of cell viability between DDC treat group and DDC+PQ treated group was not observed. This result, AT potentlate PQ toxicity while DDC were not affect, suggested that the decreased catalase activity lead to elevation of hydrogen peroxide levels and PQ toxicity may be correlate with the hydrogen peroxide rather than the superoxides.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.55-62
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• 1997

This study was carried out to investigate the microbiological and chemical properties of natural water during storage. The water samples were taken at the time of purchase and the opened bottles and unopened bottles stored at the temperature of 4$^{\circ}C$, 18$^{\circ}C$, and 3$0^{\circ}C$. The bacterial content normally rose to 2.06$\times$102 CFU/$m\ell$ for the unopened bottles and 2.91$\times$102 CFU/$m\ell$ for the opened bottles after 2 weeks of storage, and 1.21$\times$102 CFU/$m\ell$ and 2.64$\times$102, respectively, after 24 weeks of storage. The number of viable cells of bacteria peaked more rapidly at the storage temperature of 3$0^{\circ}C$ than 18$^{\circ}C$. But the total samples were found to be negative for coliforms test during the study period. The average range of pH value was from 7.39 to 7.76. The results showed that the nitrates and chlorides satisfied the Korea Drinking Water Quality Standards during the storage period of 24 weeks. However, the undesirable changes of the taste and odor were detected within 2 weeks and 3 weeks, respectively.