• YAKHAK HOEJI
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• v.50 no.5
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• pp.301-307
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• 2006

A simple and sensitive high-performance liquid chromatographic method for quantitation of hydrochlorothiazide in human plasma was developed and bioavailability parameters of hydrochlorothiazide were assessed in Korean healthy male volunteers. Caffeine was used as an internal standard. Hydrochlorothiazide and internal standard in plasma sample were extracted using tert-butylmethylether (TBME). A centrifuged upper layer was then evaporated and reconstituted with mobile phase of acetonitrile-25 mM phosphate buffer (20/80, pH 2.5). The reconstituted samples were injected into a Luna C18 column $(250{\times}4.6\;mm,\;5{\mu}m)$ at a flow-rate of 1.0 ml/min. The wavelength was set at 230 nm and no endogenous substances were found to interfere, A linear relationship for hydrochlorothiazide was found in the range of $10{\sim}300\;ng/ml$. The lower limit of quantitation (LLOQ) was 10 ng/ml with acceptable precision and accuracy. Assayed in plasma, the intra- and inter-day validation for all coefficients of variation (R.S.D.%) were found less than 15%. Main pharmacokinetic parameters of 50mg of hydrochlorothiazide were revealed as follows: $AUC_t\;1761{\pm}509.0\;ng{\cdot} hr\;ml,\;C_{max}\;296.5{\pm}95.5\;ng/ml,\;T_{max}\;1.94{\pm}0.85hr,\;K_{el}\;0.12{\pm}0.04\;hr^{-1}\;and T_{12}\;6.81{\pm}2.92\;hr.\;C_{max}\;and\;T_{max}$ were in accordance with the values $(270{\sim}350\;ng/ml\;and\;1.9{\sim}2.7\;hr)$ of Caucasian.

• Journal of Sensor Science and Technology
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• v.1 no.1
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• pp.23-34
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• 1992

In order to fabricate magnetoresistive sensor, Fe-Ni and Co-Ni alleys were evaporated on the slide glass and the silicon wafers. Saturation magnetic induction($B_{s}$), coercive field strength($H_{c}$) and magnetoresistance were measured for fabricated samples. The evaporated Fe-Ni thin films show that the saturation magnetic induction was 0.65 T, and coercive field strength was 0.379 A/cm, and this value was changed to 0.370 A/cm(//), 0.390 A/cm(${\bot}$), respectively after magnetic annealing. For the measurement of coercive field strength, magnetizing frequency of 1 kHz was used. For the fabricated sensor element, the change of magnetoresistance (${\Delta}R/R$) was excessively unstable due to oxidation in the process of fabrication. The evaporated Co-Ni alloy thin films show that saturation magnetic induction was 0.66 T, and coercive field strengthes were 5.895 A/cm(//), 5.898 A/cm(${\bot}$), respectively, after magnetic annelaing. The change of magnetoresistance(${\Delta}R/R$) was $3.6{\sim}3.7%$ of which value was excessively stable to room temperature. Fe-Ni thin film could have many problems due to large affinity in the process of fabrication of magnetoresistance sensor, but Co-Ni thin film could be a suitable material for fabrication of magnetoresistance sensor, because of its small affinity and definite magnetoresistance effects.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.1-12
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• 2001

The crystal structure of biotite-1M from Bancroft, Ontario, was determined by Rietveld refinement method using high-resolution neutron powder diffraction data at -26.3$^{\circ}C$, 2$0^{\circ}C$, 30$0^{\circ}C$, $600^{\circ}C$, 90$0^{\circ}C$. The crystal structure has been refined to a R sub(B) of 5.06%-11.9% and S (Goodness of fitness) of 2.97-3.94. The expansion rate of a, b, c unit cell dimensions with elevated temperature linearly increase to $600^{\circ}C$. The expansivity of the c dimension is $1.61{\times}10^{40}C^{-1}$, while $2.73{\times}10^{50}C^{-1}$ and $5.71{\times}10^{-50}C^{-1}$ for the a and b dimensions, respectively. Thus, the volume increase of the unit cell is dominated by expansion of the c axis as increasing temperature. In contrast to the trend, the expansivity of the dimensions is decreased at 90$0^{\circ}C$. It may be attributed to a change in cation size caused by dehydroxylation-oxidation of $Fe^{2+}$ to $Fe^{3+}$ in vacuum condition at such high temperature. The position of H-proton was determined by the refinement of diffraction pattern at low temperature (-2.63$^{\circ}C$). The position is 0.9103${\AA}$ from the O sub(4) location and located at atomic coordinates (x/a=0.138, y/b=0.5, z/c=0.305) with the OH vector almost normal to plane (001). According to the increase of the temperature, $\alpha$* (tetrahedral rotation angle), $t_{oct}$ (octahedral sheet thickness), mean distance increase except 90$0^{\circ}C$ data. But the trend is less clearly relative to unit cell dimension expansion because the expansion is dominant to the interlayer. Also, ${\Psi}$ (octahedral flattening angle) shows no trends as increasing temperature and it may be because the octahedron (M1, M2) is substituted by Mg and Fe.

• Journal of the Korean Society of Food Culture
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• v.36 no.1
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• pp.130-142
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• 2021

This study examined the antioxidative and lipid accumulation inhibitory effects of 14 plants from Mongolia and Myanmar on 3T3-L1 and HepG2 cells. The total phenolic and flavonoid contents (TPC and TFC) of 14 plant extracts were measured, and the antioxidative activities were analyzed using DPPH, ABTS, FRAP, and ORAC. After measuring the pancreatic lipase levels and performing the thiobarbituric acid assay, the degree of lipid accumulation was determined by lipid (Oil Red O) staining and triglyceride assay in 3T3-L1 and HepG2 cells. M. paniculate (259.43 mgGAE/g) and C. benghalensis (130.78 mgNAE/g) had the highest TPC and TFC, respectively, among the 14 plants. R. acicularis Lindl. had the highest antioxidant activity in DPPH. The ABTS, FRAP, and ORAC results showed that the antioxidant activity of 11 species was higher than that of the positive control. The pancreatic lipase inhibitory effect of C. angustifolium Scop. was reduced to 23.65% at 0.1 mg/mL, and the level of lipid peroxidation of C. abrorescens Lam. was 0.63 nmol/mg. Five selected plants inhibited the lipid accumulation and triglyceride content, respectively, in 3T3-L1 and HepG2 cells. These results provide scientific evidence for developing functional foods using 14 plants from Mongolia and Myanmar, which have antioxidant activities and lipid accumulation reduction effects.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.334-337
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• 2001

This study was conducted to investigate the effect of highland (Daekwallyung, altitude of 800m above sea level) production of cucumber (Cucumis sativus L.) seedlings for retarding culture in lowland (Kangnung, altitude of 20m above sea level). Cucumbers (cv. Jangilbanbaek, Jeongsunyeoreum and Ginseollok) were raised during 25 days from 31st July to 25th August, and then planted under the rain-shelter at Kangnung 25th August. Mean and minimum temperature during raising seedlings at Daekwallyung, $20.9^{\circ}C$ and $16.1^{\circ}C$ were $3.7^{\circ}C$ and $5.3^{\circ}C$ lower than those of Kangnung, respectively. T/R ratio of the seedlings produced at Daekwallyung was lower than that of Kangnung, but chlorophyll contents were higher. Daekwallyung seedlings were higher female/male ratio compared with seedlings from Kangnung. Marketable yield from cucumber seedlings (cv. Jeongsunyeoreum) produced at Daekwallyung was 32% higher than that of Kangnung. These results showed that cucumber seedling raising place was Daekwallyung for the retarding culture during summer season, particularly, and the best cultivars was Baekchim (cv. Jeongsunyeoreum).

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.177-178
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• 2008

오늘날 DC 케이블은 도서간의 장거리 전력전송 및 서로 다른 주파수간의 계통연계를 위해서 널리 확대되어 사용되고 있다. 일반적으로 AC케이블의 전계는 절연체의 유전율에 의해서 결정되는 용량성 전계분포를 가지며, DC케이블은 과전 초기에는 절연체의 유전율 뿐만 아니라 저항율에 의해서 결정이 되며 충분한 시간이 흐른 후에는 저항율에 의해서 결정되는 저항성 전계분포를 가진다. 본 논문에서는 해저 HVDC 케이블용 함침 절연지 절연저항의 온도 및 전계 의존성을 평가하기 위해서 저항율을 측정 하였으며 통계처리를 통해서 온도 및 전계의존성을 구하였다.

• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1244-1253
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• 1998

This study investigated the effects of vitamin C supplementation on immune status in smoking and nonsmoking male college students. Blood samples were obtained from 15 healthy smoking and from 15 healthy nonsmoking volunteers before and 4 weeks after vitamin C supplementation (1000mg/day). Daily nutrient intakes was also calculated. Plasma vitamin C, E, and A concentrations, white blood cells and subpopulations, lymphocytes and subpopulations, NK cell percentage,plasma immunoglobulin A, G, M and complement C3, plasma interleukin-2 , and prostagladin E2 were measured . Daily vitamin C consumption was lower in smokers than in nonsmokers. Vitamin C supplementation significantly increased plasma vitamin C in smokers, and increased NK cell percentage in smokers and nonsmokers. Plasma IL-2 concentrations were significantly increased by vitamin C supplementation in nonsmokers, and decreased helpe $r^pressor T cell ratio were decreased by vitamin C supplementatiion , but the differences were not significant. White blood cells and subpopulation percentage and plasma prostaglandin E2 concentration were not affected by smoking and vitamin C supplementation. These findings as nonsmokers.rs.

• Korean Journal of Clinical Pharmacy
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• v.22 no.3
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• pp.228-233
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• 2012

Purpose: The purpose of this study was to elucidate the effect of dissolved oxygen in alcohol to blood pressure of healthy persons. Methods: Subjects (n=30) were randomized in a double blind crossover study to receive 120 mL, 240 mL, 360 mL of alcohol (Korean spirit, 19.59 v/v%, dissolved oxygen is 8 ppm and 20 ppm). Blood alcohol concentration (BAC) and blood pressure were measured applying Lion SD-400 Alcolmeter$^{(R)}$ Breathalyser and Tensoval duo control. Pharmacokinetic parameters ($C_{max}$, $T_{max}$, $AUC_{last}$, $K_{el}$, $V_d$, Clearance) were calculated using Winnonlin$^{(R)}$ program. The difference of parameters and values were analysed by student t-test using Microsoft$^{(R)}$ Excel program. Results: The $AUC_{last}$ values of 8 ppm group and 20 ppm group in 240 ml administration were $6.15{\pm}2.60cg{\cdot}min/ml$, $5.33{\pm}1.84cg{\cdot}min/ml$ (p<0.05) and those in 360 mL were $11.93{\pm}5.70cg{\cdot}min/ml$, $10.33{\pm}4.60cg{\cdot}min/ml$ (p < 0.01), respectively. Thus, the $AUC_{last}$ was significantly decreased. On the other hands, there was a significant change in systolic blood pressure (SBP) after alcohol administration. All measured value after 360 mL of alcohol administration was significantly decreased (p < 0.01). Conclusions: The dissolved oxygen in alcoholic beverage has no effect on blood pressures but the alcohol administration has an effect on blood pressure. Thus, SBP can be used as a biomarker of alcohol administration and utilized in PK/PD modeling of alcohol.

• Elastomers and Composites
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• v.44 no.4
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• pp.436-441
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• 2009

Semi flexible polyesters containing aromatic rings and pentamethylene groups in the main chain were synthesized by direct polycondensation reaction. The structures of these polymers were investigated by $^1H$-NMR and FT-IR and the phase transition behavior was characterized with DSC, TGA and crossed polarizing microscope. Inherent viscosities ($\eta_{inh}$) of polymers measured in phenol/p-chlorophenol/1,1,2,2-tetrachloroethane were between 0.46 and 1.30 dL/g. As increasing the linearlity of rigid moieties in polyster, melting transition temperatures ($T_m$) increased and solubilities in organic solvents decreased. P-H, P-mH and P-4H of the polymers formed turbid melts that showed stir-opalescence and nematic phase at the broad anisotropic region, However, P-R, P-C and P-2B did not exhibit any textures related to the liquid crystallinity.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.318-324
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• 2015

Purpose: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. Materials and methods: One hundred zirconia samples were air-abraded ($50{\mu}mAl_2O_3$). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), $Clearfil^{TM}$ SA Luting (C), $Multilink^{(R)}$ Speed (M), $RelyX^{TM}$ U200 Automix (R), G-Cem $LinkAce^{TM}$ (G). All bonded specimens were stored in distilled water ($37^{\circ}C$) for 24 h and half of them were additionally aged by thermocycling ($5^{\circ}C$, $55^{\circ}C$, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test ($\alpha$=.05). Results: Before and after thermocycling, $Multilink^{(R)}$ Speed (M) revealed higher shear-bond strength than the other cements. G-Cem $LinkAce^{TM}$ (G) showed significantly lower bond strengths after thermocycling than before treatment (P<.05), but the other groups were not significantly different (P>.05). Conclusion: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.