• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.674-680
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• 2020

Quantitative real-time polymerase chain reaction (qPCR) was applied for the early detection of red tides in the coastal areas of South Gyeongsang in 2019. Cochlodinium polykrikoides (Dinophyceae) was detected at very low cell densities (0.0015~0.0058 cells mL^-1) in early June, but its cell density increased by up to 0.163 cells mL^-1 in mid-August. Higher cell densities were detected mainly in Namhaedo using both qPCR and microscopy (maximum 24 cells mL^-1) in late-August. Accordingly, a red tide alert was issued on September 2 (maximum 200 cells mL^-1) on this island. C. polykrikoides cell density in Namhaedo peaked on September 11 (12,000 cells mL^-1). Our results indicate that C. polykrikoides was detected at very low cell density in Namhaedo prior to bloom, which occurred in the same area. Therefore, qPCR is a useful tool to detect even at very low cell densities of C. polykrikoides for early warning of blooms.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.99-105
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• 2010

The purpose of this study was to evaluate relative bioavailability of the coenzyme Q10 (CoQ10) in emulsion and three liposome formulations after a single oral administration (60 mg/kg) into rats. Emulsion formulation of CoQ10 was prepared by conventional method using Phospholipon 85G as an emulsifier, and three liposome formulations (neutral, anionic, and cationic) of CoQ10 were prepared by traditional lipid film hydration technique using Phospholipon 85G, cholesterol, and charge carrier lipids (1,2-dioleoyl-3-trimethylammonium-propane chloride salt for cationic liposome and 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt for anionic liposome). Mean particle size of all CoQ10-loaded liposome was less than a micron, and size distribution of the liposome population was homogeneous. Bioavailability of CoQ10 in emulsion was 1.5 to 2.6-fold greater than liposome formulations in terms of $AUC_{0-24\;h}$. $T_{max}$ was 3 h when administered as emulsion while it was greater than 6 h in liposome formulations. Notably, it was approximately 8 h in cationic liposome. $C_{max}$ was highest in emulsion and was significantly decreased when administered as liposome. Charged liposome showed even lower $C_{max}$ than neutral liposome, especially in cationic liposome. In conclusion, therefore, it is suggested that clinicians and patients consider bioavailability issue a primary concern when choosing a CoQ10 product, especially when very high plasma level is required such as in the treatment of heart failure and Parkinson's disease.

• Korean Journal of Materials Research
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• v.19 no.6
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• pp.305-312
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• 2009

The effects of Quenching and Partitioning (Q&P) and Annealed Martensite (AM) heat treatment on the microstructure and tensile properties were investigated for 0.24C-0.5Si-1.5Mn-1Al steels. The Q&P steels were annealed at a single phase ($\gamma$) or a dual phase (${\gamma}+{\alpha}$), followed by quenching to a temperature between $M_s$ and $M_f$. Then, enriching carbon was conducted to stabilize the austenite through the partitioning, followed by water quenching. The AM steels were intercritically annealed at a dual phase (${\gamma}+{\alpha}$) temperature and austempered at $M_s$ and $M_s{\pm}50^{\circ}C$, followed by cooling in oil quenching. The dual phase Q&P steels showed lower tensile strength and yieldyield strength than those of the single phase Q&P steels, and tThe elongation for the dual phase Q&P steel was partitioning 100s higher than that of that for the single phase Q&P steels as the partitioning time was less than 100s up to partitioning 100s. For AM steels, the tensile/yield strength decreased and the total elongation increased as the austempering temperature increased. The stability of the retained austenite controlled the elongation for Q&P steels and the volume fraction of the retained austenite controlled the elongation for AM steels.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.475-485
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• 2006

The physical properties of the central and southwestern crust of South Korea were estimated by comparing values of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ in the Kimcheon and Mokpo areas. In order to get ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ values, seismic data were collected from two stations of the KIGAM network (KMC and MUN) and four stations of the KMA network (CPN, KUC, MOP, and WAN). An extended coda-normalization method was applied to these data. Estimates of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ show variations depending on frequency. As frequencies vary from 3 Hz to 24 Hz, the estimates decrease from $(1.4{\pm}3.9){\times}10^{-3}\;to\;(2.3{\pm}3.5){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(1.8{\pm}1.3){\times}10^{-3}\;to\;(1.9{\pm}1.5){\times}10^{-4}\;for\;{Q_S}^{-1}$ in central South Korea, and $(5.9{\pm}4.8){\times}10^{-3}\;to\;(2.2{\pm}3.8){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(0.5{\pm}2.8){\times}10^{-3}\;to\;(1.8{\pm}1.6){\times}10^{-4}\;for\;{Q_S}^{-1}$ in southwestern South Korea. According that a frequency-dependent power law is applied to the data, the best fits of ${Q_P}^{-1}\;and\;{Q_S}^{-1}\;are\;0.003f^{-0.49}\;and\;0.005f^{-1.03}$ in central South Korea, and $0.026f^{-1.47}$ and $0.001f^{-0.49}$ in southwestern South Korea, respectively. These values almost correspond to those of seismically stable regions although ${Q_P}^{-1}$ values of southwestern South Korea are a little high due to lack of data used.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.151-159
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• 1989

The present study has been designed to define the effects of photosynthetically active radiation, leaf temperature, and water stress on photosynthesis and respiration of leaves of four oak species (Quercus mongolica, Quercus aliens, Quercus variabilis, and Quercus serrate). The results obtained are as follows : 1. The estimated light compensation points at which Pn approached zero were 38, 24, 20, and $18{\mu}Em^{-2}s^{-1}$ for Q. aliens, Q. variabilis, Q, mongolica, and Q. serrate, respectively. The light saturation points occurred at $500{\mu}Em^{-2}s^{-1}$ in three oak species except Q, aliens. 2. The maximum rates of Pn were 19.7, 15.2, 11.2, and 11.0 mg $CO_2$ $dm^{-2}h^{-1}$ for Q. variabilis, Q. serrate, Q. monglica, and Q. aliens leaves, respectively. 3. The transpiration rates of Q. variabilis and Q. serrate leaves were slightly higher than those of Q. mongolica and Q. aliens leaves at various photosynthetically active radiations(PAR), but cuticular transpiration rates at dark were similar in four oak species. 4. The optimum photosynthesis occurred at $25^{\circ}C$ in Q. aliens, Q. variabilis, and Q. serrate leaves, but $20^{\circ}C$ in Q. mongolica leaves. In four oak species, the net photosynthesis approached zero at about $40^{\circ}C$. 5. The dark respiration rates of leaves exhibited the following ranking of species : Q, variabilis > Q. mongolica > Q. aliens > Q. serrate. 6. The maximum productive efficiency (Pg/Rd) of leaves occurred highest in Q, serrate at $20^{\circ}C$, then in Q. mongolica at $20^{\circ}C$, then in Q, aliens at $25^{\circ}C$, and finally in Q. variabilis at $15^{\circ}C$. 7. The decrease of net photosynthesis in Q. serrate began at about -1.2 MPa, and then approached zero at -2.9 MPa of leaf water potential. The decrease of net photosynthesis began at 3% of water loss, and then approached zero at 17.5% of water loss. 8. As indicated by tissue-water relations parameters, it may be suggested that Q. aliens and Q. variabilis are more tolerant and favored on xeric forest soils than Q. mongolica and Q. serrate.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.115-125
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• 2022

Flavonoids are bioactive plant metabolites that have a range of beneficial effects on human health. Quercetin 4'-glycoside (Q4'G), quercetin 3,4'-diglycoside (Q3,4'G), and quercetin aglycone (QA) are the main flavonoids found in onions. QA, in particular, is likely to have a greater biological effect than glycosides. To develop an onion extract with high quercetin content, the optimal extraction conditions for red onion powder containing the outer layer of the onion were determined. The effects of acid treatment on the concentration of quercetin glycosides and QA were evaluated. The flavonoids of red onion powder were optimally extracted under 60-70% ethanol at 70℃ for 2 h. The deglycosylation of Q3,4'G and an increase in Q4'G content occurred within 6 h of 0.2% acetic acid treatment. The QA content and deglycosylation of Q4'G eventually peaked at 24 h. In addition, QA content and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were highly correlated, with a correlation coefficient of 0.90.

• Analytical Science and Technology
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• v.22 no.6
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• pp.514-518
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• 2009

Coenzyme $Q_{10}$($CoQ_{10}$), a vitamin E-like substance, represents a components of the complex antioxidant system of the human organism. $CoQ_{10}$ levels in human plasma were determined by high performance liquid chromatography (HPLC) with UV detection. It was dissociated from lipoproteins by methanol and extracted into n-hexane with liquid-liquid extraction procedure, after centrifugation, the supernatant was dried under nitrogen gas stream. The residue was dissolved in the absolute ethanol. Determination of $CoQ_{10}$ was performed on a $C_{18}$ reversed-phase analytical column with ultraviolet detection at 275 nm and the mobile phase containing 15% (v/v) ethanol in methanol at a flow rate of 1.7 mL/min. The low limit of quantitation was 0.02 mg/L (S/N=10), the linearity between the concentration and peak height is from 0.1 to 2.0 mg/L. Twenty-four randomly selected plasma samples from apparently healthy, 27 to 44 year old individuals (males and females) were analyzed for total $CoQ_{10}$. The average level in these subjects was $0.62{\pm}0.13mg/L$ with the range of 0.41-0.98 mg/L. This method has a specific and a sufficient limit of quantitation (LOQ) for analysis of $CoQ_{10}$ in human plasma in both a clinical study and research at laboratories.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10585-10589
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• 2015

Breast cancer susceptibility gene 1 (BRCA1), mapped on chromosome 17q21, is implicated in the mechanisms of cellular DNA repair. Inactivation of this gene is involved in the development of many human cancers, including breast cancer. This study aimed to investigate the prognostic value of BRCA1 promoter hypermethylation and expression in breast cancer cases. Sixty-one breast cancers were examined for BRCA1 hypermethylation by methylation-specific polymerase chain reaction (PCR), and 45 paired normal breast tissues were analyzed for altered BRCA1 mRNA levels by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Aberrant methylation status in BRCA1 was detected in 15 of 61 cases (24.6%), while reduced expression was found in 7 of 45 (15.6%). BRCA1 hypermethylation was statistically associated with tumor grade III (p=0.04), a high frequency of stage IIB (p=0.02), and triple-negative phenotype (OR= 3.64, 95%CI =1.1-12.3, p=0.03). Our findings indicated that BRCA1 promoter hypermethylation is a useful prognostic marker for breast cancer.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.87-92
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• 2004

Soil respiration rate was measured from March to November 2003 using the KOH absorption method in Pinus densiflora, Quercus variabilis, Platycarya strobilacea stands in Jinju, Gyeongnam Province. Throughout the study period, average soil temperature and moisture content were 16.2$^{\circ}C$, 25.1% for P. densiflora stand, 17.1$^{\circ}C$, 24.3% for Q. variabilis stand, and 17.6$^{\circ}C$, 25.1% for P. strobilacea stand, respectively. The seasonal fluctuations of soil respiration rate increasing in summer and decreasing in winter, which there were strong positive correlations of soil respiration and soil temperature in all study stands. However, there were no significant correlations between soil moisture and soil respiration. Soil respiration rates throughout the study period ranged from 0.12 to 0.77 for P. densiflora stand, 0.23 to 1.37 for Q. valiabilis stand, and 0.30 to 1.47 g $CO_2\cdotm^{-2}\cdothr^{ -1}$ for P. strobilacea stand, respectively. Mean soil respiration rates in P. densiflora, Q. variabilis, P. strobilacea stands were 0.43, 0.80, and 0.90 g $CO_2\cdotm^{-2}\cdothr^{ -1}$, respectively. The Q$_{10}$ values were 2.38 for P. densiflora stand, 2.11 for Q. variabilis stand, and 2.07 for P. strobilacea stand. Annual total soil respiration was 24 for P. densiflora stand, 49.3 for Q. variabilis stand, and 55.3 t $CO_2\cdotha^{-1}\cdotyr^{ -1}$ for P. strobilacea stand, respectively.y.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.286-292
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• 2010

Native oak tree species dominate the deciduous forests of South Korea. Although the acorns of these oak trees represent the main food source for many wildlife species, information pertaining to their nutrient composition and associated seasonal changes is limited. Thus, the objective of this study was to describe the seasonal changes in the acorn nutrient composition of six oak species in terms of nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), and sodium (Na) concentrations, Quercus acutissima, Q. aliena, Q. mongolica, Q. variabilis, Q. dentata, and Q. serrata. The results indicated that N concentrations of Q. aliena acorns were constant, whereas those of Q. dentata changed over the seasons. Those of Q. acutissima acorns were higher in summer and autumn but Q. mongolica acorns were higher in spring and summer. Q. serrata acorns were highest in autumn but Q. variabilis acorns were found to be the lowest in N concentration. P concentrations of acorns of six species tended to decline in the summer but increased in the spring and autumn. Ca and Mg concentrations showed an obvious trend of decline over the seasons for all species except Q. mongolica. Na concentrations of Q. aliena, Q. dentata, and Q. serrata acorns were constant over the seasons whereas those of Q. dentata tended to increase. Q. variabilis acorns were highest in autumn but Q. acutissima acorns were lowest in Na concentration. Overall, these results showed that acorn nutrient composition varies by season, and that the nature of the variability is largely species dependent.