• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.108-113
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• 2000

This study was carried out to propose a simple method for the extraction of seven tar dyes such as tartrazine, sunset yellow FCF, amaranth, erythrosine, allura red, brilliant blue FCF and indigo carmine using aminopropyl amine cartridge and to determine the content of the dyes in candies, soft drinks, ice bars and okchuns produced in Korea. The tar dyes were simultaneously analyzed by reverse phase high performance liquid chromatography(HPLC). The recovery rates of the dyes ranged from 65.8% to 99.6%. The contents of the dyes in candies, soft drinks, ice bars and octhuns were N.D.∼50.1 mg/kg, N.D.∼49.9 mg/kg, N.D.∼56.0 mg/kg and N.D.∼867.3 mg/kg, respectively. The types of the dyes used most frequently for candies, soft drinks and ice bars were tartrazine, brilliant blue and amaranth, respectively. Of the samples, tartrazine was used frequently, and indigo carmine was not used at all.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.3
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• pp.483-489
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• 2002

APA-01, which is an aqueous extract of five Chinese herbs, is a modified formula of Huoxiang-Zhengqi-San. The effect of new herb extract on immune response was investigated. The parameter examined to assess apparent immune response of APA-01 in mice included changes of body weight, relative weight of immune organs, cell proliferation and cytokine gene expression. The body weight and relative weight of immune organs were not significantly changed among the tested groups. In the spleen cell prolijeration assay, APA-01 increased the cell proliferation in a dose-dependent manner. Methotrexate (MTX), an agent of immune suppression, inhibited the spleen cell proliferation (IC/sub 50/: 800㎍/㎖). However, APA-01 significantly inhibited the suppression of mouse spleen cell proliferation. Therefore, it seems that APA-01 has a reducing effect of immune suppression. Immunomodulatory effect of APA-01 was further investigated using reverse transcription polymerase chain reaction (RT-PCR) in mouse spleen cells. In RT-PCR test, APA-01 enhanced the expression of cyclooxygenase-2 (COX-2) mRNA in a dose-dependent manner. In spite of immune suppression by MTX, COX-2 mRNA was induced by co-treatment with APA-01. These results suggest that APA-01 stimulates the proliferation of spleen cells, regulates the expression of COX-2 mRNA, and accelerates the recovery of inhibition of spleen cell proliferation induced by MTX, thus providing the immunological basis for clinical benefit of APA-01.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.716-722
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• 2014

Aminopeptidase-active fractions from crude extract of the hepatopancreas of a common squid (Todarodes pacificus) were obtained using acetone (AC; 30-40%) and ammonium sulfate precipitation (AS; 60-70% saturation), anion exchange (AE-II; 0.2 M NaCl) and gel filtration chromatography (GF-I; 30-50 kDa), respectively. The debittering capacity of GF-I fraction based on the aminopeptidase activity (89.2 U/mg), recovery (56.6%) and sensory evaluation (1.0) was better than that of other fractions. Release of amino acids increased as incubation time was increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides, as revealed by reverse-phase HPLC profiles. Peaks 3, 5 and 6 showed the decreased area (%), whereas peaks 1, 2 and 4 showed the increased area. The GF-I fractions were found to be suitable for reducing bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.570-577
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• 2000

A method was presented for determination of bisphenol F(BPF), bisphenol A(BPA), bisphenol F diglycidyl ether(BFDGE) and bisphenol A diglycidyl ether(BADGE) in 3 aqueous-based food simulants (water, 4% acetic acid, 20% ethanol) by reverse-phase high performance liquid chromatography(RP-HPLC)with fluorescence detection and gas chromatography with mass selective detection(GC/MSD). All the calibration lines in the range of $5{\sim}800\;{\mu}g/L$ had correlation coefficients greater than 0.9998 and detection limits of less than $1.2\;{\mu}g$ bisphenols/L. Precision at $200\;{\mu}g/L$ was under 3.1%. Recoveries of bisphenols simultaneously spiked to aqueous food simulants exceeded 95% for BPF and BPA but about 80% for BFDGE and BADGE. However, recoveris of BFDGE and BPADGE respectively spiked increased upto 95%. Detection limits in recovery test were less than $0.40\;{\mu}g$ bisphenols/L. In migration test bisphenols were determined by RP-HPLC coupled with confirmation by GC/MSD. Can coatings of epoxy phenol, modified epoxy, epoxy ester phenol and thermoset vinyl were exposed to the 3 aqueous food simulants. BPF, BFDGE and BADGE were not detected in all the can coatings but BPA was detected in 4% acetic acid and 20% ethanol in all the can coatings except modified epoxy.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.559-565
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• 2003

An analytical method the determination of benzo(a)pyrene (BaP) and its hydroxylated metabolites, 1-hydroxybenzo(a)pyrene (1-OHBaP), 3-hydroxybenzo(a)pyrene (3-OHBaP), benzo(a)pyrene-4,5-dihydrodiol (4,5-diolBaP) and benzo(a)pyrene-7,8-dihydrodiol (7,8-diolBaP), in rat urine and plasma has been developed by HPLC/FLD and GC/MS. The derivatization with alkyl iodide was employed to improve the resolution and the detection of two mono hydroxylated metabolites, 1-OHBaP and 3-OHBaP, in LC and GC. BaP and its four metabolites in spiked urine were successfully separated by gradient elution on reverse phase ODS $C_{18}$ column (4.6 mm I.D., 100 mm length, particle size 5 ㎛) using a binary mixture of MeOH/H₂O (85/15, v/v) as mobile phase after ethylation at 90 ℃ for 10 min. The extraction recoveries of BaP and its metabolites in spiked samples with liquid-liquid extraction, which was better than solid phase extraction, were in the range of 90.3- 101.6% in n-hexane for urine and 95.7-106.3% in acetone for plasma, respectively. The calibration curves has shown good linearity with the correlation coefficients (R²) varying from 0.992 to 1.000 for urine and from 0.996 to 1.000 for plasma, respectively. The detection limits of all analytes were obtained in the range of 0.01-0.1 ng/mL for urine and 0.1-0.4 ng/mL for plasma, respectively. The metabolites of BaP were excreted as mono hydroxy and dihydrodiol forms after intraperitoneal injection of 20 mg/kg of BaP to rats. The total amounts of BaP and four metabolites excreted in dosed rat urine were 3.79 ng over the 0-96 hr period from adminstration and the excretional recovery was less than 0.065% of the injection amounts of BaP. The proposed method was successfully applied to the determination of BaP and its hydroxylated metabolites in rat urine and plasma for the pharmacokinetic studies.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.3
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• pp.193-198
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• 2013

In general, boron recovery of 40-90% could be achieved by Reverse Osmosis (RO) membranes in neutral pH condition. As an emerging technology, Forward Osmosis (FO) membrane has attracted growing interest in wastewater treatment and desalination. The objective of this study is to evaluate the possibility of the boron removal in radioactive liquid waste by FO. In this study, the performance of FO was investigated to remove boron in the simulated liquid waste as the factors such as pH, osmotic pressure, ionic strength of solution, etc. The pH of feed solution is a major operating parameter which strongly influences to the permeation of boron and more than 80% of boron content can be separated when conducted at pH values less than 7. The water flux is not influenced but the boron flux and permeation rate tends to decrease in the low salt concentration of 1,000 mg/L. The boron flux increases linearly, but the permeation ratio of reducing boron is nearly constant even with changes in the draw solution concentration.

• Journal of Ginseng Research
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• v.37 no.4
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• pp.401-412
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• 2013

Korean Red Ginseng (KRG) is an oriental herbal preparation obtained from Panax ginseng Meyer (Araliaceae). To expand our understanding of the action of KRG on central nervous system (CNS) function, we examined the effects of KRG on tissue plasminogen activator (tPA)/plasminogen activator inhibitor-1 (PAI-1) expression in rat primary astrocytes. KRG extract was treated in cultured rat primary astrocytes and neuron in a concentration range of 0.1 to 1.0 mg/mL and the expression of functional tPA/PAI-1 was examined by casein zymography, Western blot and reverse transcription-polymerase chain reaction. KRG extracts increased PAI-1 expression in rat primary astrocytes in a concentration dependent manner (0.1 to 1.0 mg/mL) without affecting the expression of tPA itself. Treatment of 1.0 mg/mL KRG increased PAI-1 protein expression in rat primary astrocytes to $319.3{\pm}65.9%$ as compared with control. The increased PAI-1 expression mediated the overall decrease in tPA activity in rat primary astrocytes. Due to the lack of PAI-1 expression in neuron, KRG did not affect tPA activity in neuron. KRG treatment induced a concentration dependent activation of PI3K, p38, ERK1/2, and JNK in rat primary astrocytes and treatment of PI3K or MAPK inhibitors such as LY294002, U0126, SB203580, and SP600125 (10 ${\mu}M$ each), significantly inhibited 1.0 mg/mL KRG-induced expression of PAI-1 and down-regulation of tPA activity in rat primary astrocytes. Furthermore, compound K but not other ginsenosides such as Rb1 and Rg1 induced PAI-1 expression. KRG-induced up-regulation of PAI-1 in astrocytes may play important role in the regulation of overall tPA activity in brain, which might underlie some of the beneficial effects of KRG on CNS such as neuroprotection in ischemia and brain damaging condition as well as prevention or recovery from addiction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.378-385
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• 2021

The production of plum jangachi requires the cleaning of plums, immersion in saltwater, separation of seed and pulp, removal of impurities, and addition of sugar. In most farms, the separation of plum seed and pulp is carried out manually, requiring considerable labor, which is why plum jangachi is expensive. To solve this problem, this study designed and manufactured automatic, semi-automatic plum seed and pulp separators. During the design process, the characteristics were compared, and the machine power was determined through on-site test after manufacture. As a result, automatic machines used plums 180° arrayed and six reverse-edged blades, semi-automated plums 180° arrayed, and six blades, each with a 68% and 57% pulp recovery rate and a machine power of 80 kg/h and 62 kg/h respectively. Overall, the mechanization of plum processed food will reduce labor and increase the market value of plums compared to the previous method.

• Journal of Korea Trade
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• v.26 no.5
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• pp.23-38
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• 2022

Purpose - This research intends to find out whether R&D cost stickiness shows differentiated aspects depending on exports in Korea. A cost behavior that indicates a lower rate of costs decrease when sales decrease than the rate of costs increase when sales increase is called cost stickiness. This sticky cost behavior is caused by considering the adjusting costs. This study aims to empirically verify that R&D cost stickiness is greater in export firms than in non-export firms. We also investigate the effect of exports on R&D cost stickiness is nonlinear. Design/methodology - We obtain data for the analysis from Kis-Value and TS2000 from 2012 to 2020. This study tests for R&D cost stickiness of exports using the cost stickiness model developed by Anderson et al. (2003) that is used in a lot of prior literature. To explore the nonlinear behavior of R&D cost stickiness we include a quadratic term of exports in our model. Findings - The results of our analysis are as follows. First, we observed that R&D costs of export firms are more sticky than that of non-export firms. Our result indicated that export firms are less likely to reduce R&D costs in decreasing sales periods in preparation for future sales recovery. Second, our empirical evidence shows that export firms view R&D costs much favorably. However, we hypothesize that the effect of export intensity on R&D costs may not necessarily be linear. Our result shows the effect of exports intensity on R&D stickiness is thus nonlinear, forming a reverse U-shaped curve. When export intensity exceeds a certain threshold, the growth rate of R&D costs appears to be viewed negatively. Firms with relatively high export intensity do not support R&D costs, viewing them as taking away firms' resources from other more productive costs. On the contrary, those with export intensity under the threshold view R&D costs as beneficial and therefore promote further R&D costs when revenue decreases. Originality/value - The results of this research can contribute academically to the expansion of empirical research on R&D cost stickiness. R&D cost stickiness varies by industry. As a result of our research, the managers of export firms recognize the importance of R&D to lead innovation. We expected that this research contributes to further studies on R&D costs and cost stickiness. Second, this research has implications from a business perspectives. Our findings of export firms' R&D stickiness suggest that export firms' managers should consider keeping the stickiness of R&D when revenue decreases because it is essential for exporting firms to maintain their R&D stickiness to secure long-term competitiveness. R&D stickiness can be used on a practical basis to emphasize the need for continuous investment in exporting firms' R&D activities.