• Proceedings of the PSK Conference
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• 2002.10a
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• pp.401.3-402
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• 2002

Enalapril (ENP) maleate is effective drug for the treatment of renivascular hypertension and heart failure. ENP acts as inhibitor of the enzyme angiotensin-convertase (ACE-inhibitor) and metabolized to enalaprilat (ENPT), which is the active metabolite that is really responsible for the therapeutic action. In the present study, a sensitive and rapid liquid chromatography/ electrospray ion trap tandem mass spectrometry (LC/MS/MS) method combined with high-throughput solid phase extraction (SPE) has been developed and validated for the simultaneous quantitative determination of ENP and ENPT in human plasma. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.402.3-403
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• 2002

Cilostazol. a quinolinone derivative that inhibits phosphodiesterase. is used for the treatment of intermittent claudication resulting from peripheral arterial disease. In order to perform pharmacological and pharmacokinetic studies of cilostazol, specific. sensitive and reproducible analysis methods are demanded. Therefore. in the present study. an analytical method of cilostazol in human plasma was developed using semi-microbore HPLC equipped with automated column switching system. (omitted)

• Preventive Nutrition and Food Science
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• v.22 no.2
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• pp.67-80
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• 2017

Cholesterol is a vital component of the human body. It stabilizes cell membranes and is the precursor of bile acids, vitamin D and steroid hormones. However, cholesterol accumulation in the bloodstream (hypercholesterolemia) can cause atherosclerotic plaques within artery walls, leading to heart attacks and strokes. The efficiency of cholesterol absorption in the small intestine is of great interest because human and animal studies have linked cholesterol absorption with plasma concentration of total and low density lipoprotein cholesterol. Cholesterol absorption is highly regulated and influenced by particular compounds in the food supply. Therefore, it is desirable to learn more about natural food components that inhibit cholesterol absorption so that food ingredients and dietary supplements can be developed for consumers who wish to manage their plasma cholesterol levels by non-pharmacological means. Food components thus far identified as inhibitors of cholesterol absorption include phytosterols, soluble fibers, phospholipids, and stearic acid.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1805-1808
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• 2003

The simultaneous determination of As(III), As(V), and DMA has been performed by ion chromatography (IC) coupled with inductively coupled plasma-mass spectrometry (ICP-MS). The separation of the three arsenic species was achieved by an anionic separator column (AS 7) with an isocratic elution system. The separated species were directly detected by ICP-MS as an element-selective detection method. The IC-ICP-MS technique was applied for the determination of arsenic species in a NIST SRM 1643d water sample. An As(III) only was detected in the sample. The detection limits of As(III), As(V) and DMA were 0.31, 0.45, and 2.09 ng/mL, respectively. It was also applied for the determination of arsenic species in a human urine obtained by a volunteer, and three arsenic species were identified. The determination of total As in human urines that were obtained from 25 volunteers at the different age was also carried out by ICP-MS.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.394.2-394.2
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• 2002

A sensitive and selective reversed-phase LC-ESI-MS method to quantitate pseudoephedrine in human plasma was developed and validated. Phenacetin was used as an internal standard. Samples were prepared simply by acetonitrile precipitation without an evaporation step. Chromatographic separation was achieved on a XTerra MS C18 column ($150{times}2.1$ mm I.D.. 3.5 $\mu\textrm{m}$ particles). using gradient elution with 0.5% (v/v) trifluoroacetic acid (TFA) in water and 0.5% (v/v) TFA in methanol at a flow-rate of 0.1 ml/min. (omitted)

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1571-1574
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• 2013

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.276.1-276.1
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• 2003

This study describes a simple and sensitive semi-micro HPLC method with UV detection and direct deproteinization. The plasma protein was precipitated using perchloric acid (60％) and the supernatant was directly injected onto the semi-micro HPLC system. The separation was achieved on a C18 (25 mm ${\times}$ 2.0 mm I.D) analytical column with a mobile phase of sodium acetate buffer (pH 3.5, 50 mmol) - acetonitrile (60:40, V/V). (omitted)

• Journal of Nutrition and Health
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• v.33 no.7
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• pp.745-754
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• 2000

Effects of oral taurine supplementation (6g/day)for 2-4 weeks on activities of red blood cell(RBC)total superoxide dismutase (SOD) and plasma glutathione peroxidase(GSH-Px) and the level of malondialdehyde(MDA) were evaluated in healthy female adults (23.6$\pm$0.3 years old). Compared to the value for 0 week plasma GSH-Px activity of the subjects was significantly lower after 2 weeks of taurine supplementation(p<0.05) and recovered to the value similar to 0 week after 4 weeks of taurine supplementation. RBC total SOD activity tended to be decreased after 2 weeks of taurine supplmentation compared to the values for 0 week although the difference between the means of the two group was not statistically significant. Plasma MDA level was not significantly decreased by taurine supplementation most probably due to the fact that the subjects participated in the present study were healthy and their antioxidant defense system had been in the 'normal' range. Plasma MDA concentration was negatively correlated with plasma taurine concentration(r=-0.2003m p<0.05) but tended to be positively correlated with plasma cholesterol concentration(r=0.2465, p=0.0645) as expected Plasma GSH-Px activity was positively associated with the percentage of 22:0 (r=0.2892, p<0.05) or 20:4w6(r=0.2939, p<0.05). On the other hand plasma MDA concentration was positively correlated with the percentage of 20:5w3 in plasma total lipids(r=0.2635 p<0.05) and negatively correlated with $\Delta$5 desaturation index of w6 fatty acids(20:3w6⇒20:4w6) in plamsa total lipids(r=-0.2714, p<0.05) as well as in phospholipids(r=-0.2864, p<0.05). From these results protective effect of taurine supplementation against lipid peroxidation and antioxidant defense system in humans appears to be minimal when the subjects are in a relatively healthy state. Further studies concerning the antioxidant efficacy of taurine should be conducted in human subjects under various disease states related to oxidative stress such as diabetes and artheroxclerosis.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.526-535
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• 2016

Recently, fine dust in atmosphere have been considerably issued as a harmful element for human. Nitrogen oxide ($NO_x$) exhausted from diesel engines and power plants has been disclosed as a main source of secondary production of fine dust. In order to prevent exhausting these nitrogenous compounds into atmosphere, a treatment system with selective catalytic reduction (SCR) catalyst with ammonia as a reductant has been used in various industries. Urea solution has been widely studied to supply ammonia into a SCR catalytic reactor, safely. However, the conversion of urea solution to ammonia has several challenges, especially on a slow conversion velocity. In the present study, a fast urea conversion system including a plasma burner was suggested and designed to evaluate the performances of urea conversion and initial operation time. A designed lab-scale facility has a plasma burner, urea nozzle, mixer, and SCR catalyst which is for hydrolysis of isocyane. Flow rate of methane that is a fuel of the plasma burner was varied to control temperatures in the urea conversion facility. From experimental results, it is found that urea can be converted into ammonia using high temperature condition of above $400^{\circ}C$. In the designed test facility, it is found that ammonia can be produced within 1 min from urea injection and the result shows prospect commercialization of proposed technology in the SCR facilities.

• International Journal of Oral Biology
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• v.41 no.4
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• pp.243-251
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• 2016

This study was undertaken to achieve a high bleaching efficacy with plasma, through longer application and reparative bleaching processes, by different shade evaluation methods. Extracted human teeth were divided into 6 groups (n=10). All teeth were treated in pairs. Low concentration of 15% carbamide peroxide (CP) was applied, with and without plasma, for 10, 20, and 30-min tooth bleaching, respectively. The bleaching procedure was repeated once daily for four days. The teeth were maintained in a moist environment provided by artificial saliva. The Vitapan Classical shade guide and Commission Internationale de L'Eclairage (CIELAB) color system were collectively used to measure the bleaching efficacy. Color evaluation was statistically analyzed using Student t-test and one-way analysis of variance (ANOVA) complemented by Tukey's test. Combining the plasma with 15% CP showed significantly greater color changes compared to bleaching without plasma (p<0.05). A high bleaching efficacy with plasma is proportional to the repetitive application and the treatment time. A 30-min application with plasma provided the best bleaching. Repetitive bleaching showed lower probability of color relapse of the bleached tooth. The color change by shade guide correlated with the changes in CIELAB color system. A value of 1 color change units (CCU) conversion factor for overall color change (${\Delta}E$) values comparisons was 3.724 values. The two measuring methods provide a more accurate correspondence of color change. The repetitive and longer application for tooth bleaching, combined with plasma, has a strong bleaching effect and produces whiter teeth.