• Applied Biological Chemistry
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• v.36 no.2
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• pp.134-137
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• 1993

Yongia sonchifolia Max. has been used as raw materials of traditional Kimchi and medicinal herb in Korea. This study was performed to investigate biologically active components in the plant. First, the writer carried out the experiment of antitumor screening test against Sarcoma-180A and the cytotoxic activity against Chinese hamster V-79 cells with methanol extract of the plant. And the aqueous solution of the extract from roots of Youngia sonchifolia Max. was partitioned into n-hexane. The concentrated extract of n-hexane layer was chromatographed on silica gel column and developed with n-hexane and ethylacetate. Two yellow elutes, on concentration, were recrystallized from ethylacetate, and the $R_f$ value of TLC of the crystal was 0.43. After analysis by $^{1}H-NMR$, $^{13}C-NMR$ and MS to confirm the structure, the author could identify the compound as bauerenyl acetate, a naturally occurring pentacyclic triterpene. The crystal was colorless plate and m.p. was $280{\sim}282^{\circ}C$.

• Journal of Ocean Engineering and Technology
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• v.7 no.2
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• pp.57-67
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• 1993

The fracture behavior of plain woven glass/epoxy composite plates with a crack is investigated under static tensile loading. It is shown in this paper that the characteristic length associated with the point stress criterion depends on the crack length. To predict the not ched tensile strength, the point stress criterion proposed by Whitney and Nuismer are modified. An excellent agreement is found between the experimental results and the analytical prediction of the modified point stress criterion. The condition of unstable crack growth in the presence of a per-existing flaw(machined notch) is examined by means of the maximum stress intensity factor $K_max$ using maximumload P$_max$. The values of $K_max$ evaluated from energy release rate G$_max$(the compliance me thod) indicate a wide difference. Therefore in regard to anisotropy and heterogeneity of the composite materials studied, the modified shape correction factor f(a/W) is obtained. $K_max$evaluated by the compliance method a little or insignificantly depends on the initial crack length a, the specimen thickness B, the crack angle .theta. and the specimen geometry.

• Journal of Applied Biological Chemistry
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• v.59 no.3
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• pp.261-264
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• 2016

In soybean (Glycine max (L.) Merr.) seeds, phosphorus (P) is primarily stored in the form of phytate, which is generally indigestible by monogastric animals such as human, pig, poultry, and fish. Thus, this study was conducted to isolate soybean mutants with high available P. Inorganic P content was assessed in a total of 1,266 ethyl methanesulfonate (EMS) $M_4$ lines from the Pungsannamul cultivar. Among the tested lines, four EMS lines (PE379, PE432, PE2205, and PE2503) showed higher mean inorganic P ($1.21-1.56gkg^{-1}$) than did the Pungsannamul cultivar ($0.90gkg^{-1}$). Additionally, six EMS lines (PE718, PE828, PE1466, PE1552, PE3378, and PE3386) showed lower mean inorganic P ($0.38-0.60gkg^{-1}$). The high inorganic P mutants isolated in this study will be further investigated for phytate and total P levels. Moreover, the high and low inorganic P lines will be utilized in a future study of the biochemical pathway of phytate.

• Journal of Pharmaceutical Investigation
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• v.33 no.3
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• pp.223-227
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• 2003

The purpose of this study was to investigate the effect of ketoconazole (20 mg/kg) on the pharmacokinetic parameters and the bioavailability of paclitaxel (40 mg/kg) orally coadministered in rats. The plasma concentration of paclitaxel in combination with ketoconazole was significantly (p<0.05) increased from 8 hr to 24 hr compared to that of control. Area under the plasma concentration-time curve (AUC) of paclitaxel with ketoconazole was significantly (coadministration p<0.05, pretreatment p<0.0l) higher than that of control. Peak concentration $(C_{max})$ of paclitaxel pretreated with ketoconazole were significantly (p<0.05) increased compared to that of control. Time to peak concentation $(T_{max})$ of paclitaxel pretreated with ketoconazole were significantly (p<0.05) shorter than that of control. Half-life at elimination phase $(t_{1/2{\beta}})$ of paclitaxel pretreated with ketoconazole was significantly (p<0.05) prolonged compared to that of control. Based on these results, it might be due to both inhibition of the enzyme cytochrome P450 and p-glycoprotein, which engaged in paclitaxel absorption and metabolism in liver and gastrointestinal mucosa.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.15-22
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• 2018

Purpose Respiratory motion during PET/MRI acquisition may result in image blurring and error in measurement for volume and quantification of lesion. The aim of this study was to evaluate changes of quantitative accuracy, tumor size and image quality by applying MR based respiratory motion correction technique (MBRMCT) using integrated PET/MR scanner. Materials and Methods Data of 30 patients (aged $62.5{\pm}10.2y$) underwent $^{18}F-FDG$ liver PET/MR (Biograph mMR 3.0T, Siemens) study were collected. PET listmode data for 7 minutes was simultaneously acquired with maximum average gate (MAG), minimum time gate (MTG) and non gate (NG) T1 weighted MR images. Gated PET reconstruction was performed using mu-maps generated from MAG and MTG by setting 35% of efficiency window. Maximum SUV ($SUV_{max}$), peak SUV ($SUV_{peak}$), tumor size and full width at half maximum (FWHM) in the z-axis direction of MAG, MTG and NG PET images were evaluated. Results Compared to NG, mean $SUV_{max}$ and $SUV_{peak}$ were increased in MAG 13.15%(p<0.0001), 8.66%(p<0.0001), MTG 13.27%(p<0.0001), 8.80%(p<0.0001) and mean tumor size and FWHM were decreased in MAG 14.47%(p<0.0001), 15.49%(p=0.0004), MTG 14.89%(p<0.0001), 15.79%(p=0.0003) respectively. Mean $SUV_{max}$ and $SUV_{peak}$ of MTG were increased by 0.07%(p=0.8802), 0.13%(p=0.7766). Mean tumor size and FWHM of MTG were decreased by 0.49%(p=0.2786), 0.36%(p=0.2488) compared to MAG. There was no statistically significant difference between MAG and MTG which increase total scan time for about 7 and 2 minutes. Conclusion SUV, accuracy of tumor size and spatial resolution were improved in both of MAG and MTG by applying MBRMCT without installing additional hardware in liver PET/MR study. More accurate information can be provided with the increase of 2 minutes scan time if applying MTG of MBRMCT to various abdominal PET/MR studies affected by respiratory motion.

• Journal of Nutrition and Health
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• v.36 no.7
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• pp.711-719
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• 2003

The effects of taurine, carnitine or glutamine supplementation on endurance exercise performance along with related fatigue factors were evaluated in male college students in the Department of Physical Education, who's maximal oxygen consumption rates (VO$_2$max) were equivalent to those of endurance athletes. Twenty four subjects were randomly divided into 4 groups (n=6), and given placebo, taurine (4 g/day), carnitine (4 g/day), or glutamine (4 g/day) tablets for 2 weeks. Subjects could run 6.9 min or 9.0 min longer until exhausted on a treadmill at the intensity of 75% VO$_2$max following taurine or camitine supplementation for 2 weeks, respectively, compared to the value measured prior to each supplementation. Glutamine or placebo supplementation did not improve the endurance exercise performance based on the running time until exhausted on a treadmill. Serum lactate concentrations measured 1 hr after the initiation of the endurance exercise, as well as at all-out state tended to be decreased by taurine, carnitine, or glutamine supplementation, and were significantly lowered (43% decrease) by carnitine supplementation (p < 0.05). Taurine supplementation significantly reduced the serum inorganic phosphorus concentration measured at all-out state (14% decrease, p < 0.05), while carnitine supplementation significantly lowered the resting state serum inorganic phosphorus level (20% decrease, p < 0.05). Taurine (32% reduction) or carnitine (23% reduction) supplementation significantly decreased serum ammonia concentration measured at all-out state (p < 0.05). From these results, 4 g/day of taurine or carnitine supplementation appears to improve the endurance exercise performance and related human fatigue factors.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.187-193
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• 2003

To determine the properties for juice preperation of Black Omija (Schizandra nigra Max.) and Omija (Schizandra chinensis), yield of extraction, chromaticity and lightness, pH and soluble solid of the extract were investigated. The rate of extract yield from Schizandra nigra was highest when extracted for 3 hours at 80$^{\circ}C$ in 20％ ethanol solution. For the desirable chromaticity coordinates, the optimum extraction time and temperature of Schizandra nigra extract were 3 hours at 80$^{\circ}C$. The lightness of the extract was low of the value when extraction time and temperature was long and high. The sugar content of the extract of S. nigra was 2.0­2.6％ Brix, lower than that of S. chinensis, but the difference was insignificant. The pH of the extract from S. nigra was 0.1­0.2 higher than that of S. chinensis. Although the pH of the extract from S. nigra was a little low when extracted by water, the pH range was enough to maintain the stability of color of extract from the S. chinensis.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.355-361
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• 2019

The red pigment extracted from Serratia marcescens 2354 (ATCC 25419) was prodigiosin (PG), which was dissolved in methanol and measured for ultraviolet and visible light absorption spectra. It was the typical absorption spectrum of PG in an acid solution with ${\lambda}_{max}=537nm$. When the concentration of PG was increased from $1.0{\times}10-5M$ to $9.0{\times}10-5M$ in the methanol solution, the absorption intensity at 537 nm was increased, the absorption intensity at 467 nm was decreased, and the isosbestic point at 500 nm was observed. This phenomenon can be regarded as a result of reversible acid-base equilibrium reaction considering 537 nm and 467 nm of PG absorption band in acid and base solution respectively and isosbestic point of 500 nm. On the other hand, when the concentration of PG was reduced from $6.0{\times}10-4$ to $1.0{\times}10-4M$ in acetic acid buffer solution at pH 4.75, a new absorption band with ${\lambda}$ max at 500 nm appeared. This absorption band appears only in the aqueous solution of pH 4.75 and does not appear in the pure methanol solution of the same pH. This is due to the conversion of the PG molecule from the ${\alpha}$-isomer to the ${\beta}$-isomer by $H_2O$. In other words, it was confirmed that the color change of the PG can be caused by the concentration of the solution and the characteristics of the solvent.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.387-388
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• 2008

In this paper, we have designed and fabricated hyperabrupt varactor diodes. Capacitance variations of hyperabrupt-doped varactor diodes are larger than those of uniform-doped varactor diodes. The measured reverse breakdown voltage of the fabricated varactor diodes was about 20 V. For the anode contact diameter of $50\;{\mu}m$, the maximum capacitance of the fabricated varactor diode was 2.1 pF and the minimum capacitance 0.44 pF. Therefore, the $C_{max}/C_{min}$ ratio was 4.77. Also, for the anode contact diameter of $60\;{\mu}m$, the maximum and minimum capacitances were 2.9 and 0.62 pF, respectively. And, thus, the $C_{max}/C_{min}$ ratio was 4.64.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.297-300
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• 2005

Effects of allyl sulfides on kinetic behavior of cytochrome P450 1 (CYP1)-catalyzed ethoxyresorufin O-deethylase (EROD) activity were studied using microsomes from benzo[a]pyrene-treated human hepatoma cells. Apparent $K_m$ and $V_{max}$ values were calculated as $2.8\;{\mu}M$ and $3.0\;{\mu}mol$ resorufin/min/mg protein based on Lineweaver-Burk plot of microsomal EROD activity, respectively. Diallyl disulfide (DADS) and diallyl trisulfide (DATS) affected $K_m$ and $V_{max}$ values of EROD activity and acted as mixed-type inhibitors for CYP1 isozymes. Apparent Ki values of DADS and DATS were calculated as 1.07 and 0.88 mM, respectively, by re-plotting slopes of Lineweaver-Burk plot and inhibitor concentrations.