• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.6-10
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• 2003

This study was conducted to select the ozone tolerant individuals of Cornus controversa Hemsl., and to use malondialdehyde (MDA) content as an indicator of plant damage level for several oxidative stress levels. Seeds of C. controversa were collected at 9 provinces in Korea. One-year-old seedlings were grown in greenhouses and exposed to 100 pub ozone concentration for 8h day$^{-1}$ for 10 weeks. At the termination of ozone exposure, heights of seedlings were measured and MDA contents in the leaves were analyzed. Tolerant, intermediate, and sensitive individuals were selected using the standardized indices of height and MDA content. Height and MDA content of C. controversa exposed to ozone were significantly different among individuals and provinces. MDA content showed negative correlation (r=-0.531, p$\leq$ 0.001) with height growth performance. Height and MDA content of tolerant individuals presented significant differences from those of sensitive individuals. As a result, MDA content may be suitable for the evaluation of the damage level of plants by oxidative stress.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.301-308
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• 2008

The purpose of this study was to investigate the change of physical fitness, MDA, SOD after short-term weight reduction through exercise, food restriction and exhalation of sweat among Taekwondo players. The subjects ten male collage Taekwondo players with excellent practical skills, and more than seven years of experiences. They were asked to reduce about 5% of their body weight in seven days. Physical fitness levels were analyzed through grip strength, muscle endurance, flexibility, power, agility, balance, reaction time and MDA and SOD through blood test. The results of this study were as follows; First, there was no significant change in physical fitness due to short-term weight reduction in muscle strength, muscle endurance, flexibility, power, agility, balance and reaction time. Second, The change of MDA and SOD, resulting from short-term weight reduction did not show significant difference statistically. Therefore, the results of this study indicate that the Taekwondo players' short-term weight reduction of 5% of their body weight did not influence on their athletic performance and physiological capacity. Therefore athletes and coaches should endeavor to take exercise, dietary, and dehydration into consideration when conducting 5% of their body weight reduction in a week.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.25-31
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• 1994

This study was conducted to investigate sensitivity of woody plants growing in urban and industrial regions of Seoul and Taejon, Korea. Malondialdehyde(MDA) contents were analyzed in tree foliage of Pinus densiflora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera and Platanus occidentalis. In addition, MDA contents were analyzed in the foliage of tree seedlings, i.e. Pinus densiflora. Pinus koraiensis, Ginkgo biloba and Liriodendron tulipifera, with the fumigation of $SO_2$ in gas chamber 4 hours a day for six days. MDA contents of leaves in Ginkgo biloba, Platanus occidentalis and Liriodendron tulipifera in polluted regions were higher than those in unpolluted region and among them Liriodendron tulipifera had the highest. MDA contents of Pinus densiflora and Pinus koraiensis increased with the increase of needle age. MDA contents of Liriodendron tulipifera seedlings were increased with the higher concentrations of $SO_2$ but MDA contents in other seedlings showed no changes with $SO_2$ treatment concentrations. MDA contents in all species were increased with the passage of exposure day. Especially. Liriodendron tulipifera had higher MDA content than other species. In Liriodendron tulipifera the MDA production increased with the passage of exposure day until the fourth day after that decreased.

• Nutrition Research and Practice
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• v.5 no.5
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• pp.375-380
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• 2011

This study investigated the effects of inorganic sulfur on metastasis in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were cultured in the absence or presence of various concentrations (12.5, 25, or 50 ${\mu}mol$/L) of inorganic sulfur. Cell motility, invasion, and the activity and mRNA expression of matrix metalloproteases (MMPs) were examined. Numbers of viable MDA-MB-231 cells did not differ by inorganic sulfur treatment from 0 to 50 ${\mu}mol$/L within 48 h. Inorganic sulfur significantly decreased cell motility and invasion in the MDA-MB-231 cells in a dose-dependent manner (P<0.05), as determined using a Boyden chamber assay and a Matrigel chamber. The activities of MMP-2 and MMP-9 were significantly reduced by inorganic sulfur in a dose-dependent manner (P<0.05). The inorganic sulfur also significantly inhibited MMP-2 and MMP-9 expression in the cells (P<0.05). These data suggest that inorganic sulfur can suppress cancer cell motility and invasion by inhibiting MMP-2 and MMP-9 activity and gene expression in MDA-MB-231 cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.671-676
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• 2006

We investigated the effect of gingerol (Zingiber officinale Roscoe, Zingiberaceae) on Bcl-2 and Bax expression in MDA-MB-231 human breast cell lines. The oleoresin from rhizomes of ginger contains [6]-gingerol (1-[4'-hydroxy-3'-methoxyphenyl]-5-hydroxy-3-decanone). We previously reported that [6]-gingerol inhibits cell proliferation in MDA-MB-231 human breast cancer cell lines. In this study, we examined protein and mRNA expression associated with cell apoptosis in MDA-MB-231 human breast cancer cell lines. We cultured MDA-MB-231 cells in presence of various concentrations 0, 2.5, 5 and $10\;{\mu}M$ of [6]-gingerol. Bcl-2 protein and its mRNA levels were decreased dose-dependently in cells treated with [6]-gingerol, but Bax protein and its mRNA levels were unchanged by [6]-gingerol treatment. Bcl-2/Bax ratio was decreased in a dose dependent manner treated with [6]-gingerol. Caspase-3 activity was significantly increased dose-dependently in cell treated with [6]-gingerol (p<0.05). In conclusion, we have shown that [6]-gingerol induces apoptosis in MDA-MB-231 human breast cancer cell lines.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.356-361
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• 1996

Cure kinetics of diglycidyl ether of bisphenol A(DGEBA)/4,4'-methylene dianiline(MDA) with hydroquinone-phenyl glycidyl ether(HQ-PGE) as a reactive additive, which was preliminarily synthesized, was investigated by DSC and FT-IR analyses. Kissinger equation and Arrhenius' equation were used to calculate activation energy and pre-exponential factor. When HQ-PGE was added to DGEBA/MDA system, it reduced activation energy of system. When the 5 phr of HQ-PGE was added to DGEBA/MDA system, activation energy was 7.8 kcal/mol by FT-IR analysis and 11.3 kcal/mol by DSC, in comparison with the system without HQ-PGE, activation energy decreased about 30% and 9%, respectively. According to these results, HQ-PGE, introducing agent of this system, acted as a catalyst.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.195-199
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• 2003

An analysis method for the determination of methylendedioxymethamphetamine (MDMA) and its metabolite methylendedioxymethamphetamine (MDA) in hair by gas chromatography/mass spectrometry was proposed. For MDMA and MDA analysis, hair samples were incubated in MeOH (1％ HCl), derivatized with trifluoroacetic anhydride and assayed by GC/MS. Hair of 18 subjects for drug abuse was analyzed for MDMA and MDA. Calibration curves for the determination of MDMA and MDA in hair showed a good linearity at a concentration range from 0.5 ng to 250 ng ($r^2$=0.999) The extraction recovery was determined from hair blanks at 50, 100 ng. The percentage of recovery were found to be 96.08∼103.48 with CV value of 1.62∼3.89. The concentrations of MDMA and MDA ranged 1.14∼38.06 ng/mg and 0.07∼3.91 ng/mg, respectively in 18 hair samples from MDMA abusers. The ratio of MDMA to MDA ranged from 9.65∼28.46 in all specimen. Hair analysis for MDMA is a useful method for identification of long-term drug abuser.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.883-889
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• 2008

Lipid peroxidation (LPO) has been identified as an important component of atherosclerosis. In this study, the effects of supplementation with cholesterol (0.5%), olive oil (5%) and vitamin E (0.05%) on erythrocyte glutathione (GSH), plasma malondialdehyde (MDA), total cholesterol, HDL-LDL cholesterol and triacylglycerol, brain and liver MDA and GSH concentrations of rats were investigated. A total of 50 Sprague-Dawley male rats aged 6 months, and of equal body weight were used and fed a standard ration ad libitum. Animals were housed in the University of Selcuk, Veterinary Faculty Experimental Animals Unit. The experiment lasted 60 days and there were five experimental groups as follows: 1. Control, 2. Cholesterol (0.5%), 3. Olive oil (5%), 4. Cholesterol plus vitamin E (0.05%), 5. Olive oil plus vitamin E (0.05%). At the end of the experiment, blood samples were taken by cardiac puncture and erythrocyte GSH, plasma MDA, cholesterol, HDL-LDL cholesterol, triacylglycerol and also GSH and MDA concentrations in brain and liver tissue of rats were spectrophotometrically determined. Supplementation of olive oil and cholesterol into rat diets (groups 2 and 3) caused significant differences in lipid parameters; HDL cholesterol concentrations were increased in the olive oil group and LDL cholesterol was lower than in the cholesterol fed group. Moreover, these decreases in LDL and triacylglycerol concentrations were more significant with vitamin E supplementation. The high plasma MDA concentrations showed that lipid peroxidation occurred in the olive oil group and the highest brain MDA concentrations were determined also in the olive oil group. These findings suggest that vitamin E addition may decrease the sensitivities of several oils to oxidation and that monounsaturated fatty acids in olive oil may decrease the incidence of atherosclerosis by regulating blood lipid profiles.

• Molecules and Cells
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• v.40 no.1
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• pp.54-65
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• 2017

Although cancer/testis antigen DDX53 confers anti-cancer drug-resistance, the effect of DDX53 on cancer stem cell-like properties and autophagy remains unknown. MDA-MB-231 ($CD133^+$) cells showed higher expression of DDX53, SOX-2, NANOG and MDR1 than MDA-MB-231 ($CD133^-$). DDX53 increased in vitro self-renewal activity of MCF-7 while decreasing expression of DDX53 by siRNA lowered in vitro self-renewal activity of MDA-MB-231. DDX53 showed an interaction with EGFR and binding to the promoter sequences of EGFR. DDX53 induced resistance to anti-cancer drugs in MCF-7 cells while decreased expression of DDX53 by siRNA increased the sensitivity of MDA-MB-231 to anti-cancer drugs. Negative regulators of DDX53, such as miR-200b and miR-217, increased the sensitivity of MDA-MB-231 to anti-cancer drugs. MDA-MB-231 showed higher expression of autophagy marker proteins such as ATG-5, $pBeclin1^{Ser15}$ and LC-3I/II compared with MCF-7. DDX53 regulated the expression of marker proteins of autophagy in MCF-7 and MDA-MB-231 cells. miR-200b and miR-217 negatively regulated the expression of autophagy marker proteins. Chromatin immunoprecipitation assays showed the direct regulation of ATG-5. The decreased expression of ATG-5 by siRNA increased the sensitivity to anti-cancer drugs in MDA-MB-231 cells. In conclusion, DDX53 promotes stem cell-like properties, autophagy, and confers resistance to anti-cancer drugs in breast cancer cells.

• Korean Journal of Materials Research
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• v.9 no.5
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• pp.467-472
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• 1999

The isothermal cure behavior of diglycidyl ether of bisphenol A(DGEBA) 4,4'-methylene dianiline(MDA) system with various contents of neopentyl glycol(NPG) has been analyzed by differential scanning calorimetry(DSC). TO increase the cure rate of DGEBA/MDA system, NPG was introduced as an accelerator. Regardless of the NPG content, the shape of the conversion curves showed sigmoid indication that DGEBA/MDA/NPG system followed autocatalytic cure reaction. The cure reaction of DGEBA/MDA system increased with the increment of NPG content and it was due to the catalytic role of hydroxyl groups of NPG.