• Journal of Applied Biological Chemistry
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• v.42 no.4
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• pp.191-196
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• 1999

A multiresidue analytical method was developed for eight acaricides including benzoximate, clofentezine, fenazaquin, fenothiocarb, fenpyroximate, hexythiazox, pyridaben, and tebufenpyrad in four major fruits using high-performance liquid chromatography (HPLC). All the confounds were extracted with acetone from apple, pear, grape, and citrus samples. The extract was diluted with saline water, and n-heaxane partition was followed to recover the acaricides. Florisil column chromatography was employed to further purify the sample extract. HPLC with ultraviolet absorption detection, using an octadecylsilyl column under the isocratic mobile phase of acetonitrile/water mixture, was successfully applied to separate and quantitate all the compounds in the purified extract. Recoveries of the eight acaricides from for fortified samples ranged 86.4~97.0%. Relative standard deviations of the analytical method were all less than 10%. Detection limits of the method were in the range of 0.02~0.05 mg/kg. The proposed method was reproducible and sensitive enough to evaluate the terminal residue of the eight acaricides in the fruit harvest.

• The Journal of Fisheries Business Administration
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• v.45 no.2
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• pp.85-95
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• 2014

Fish stocking is important element of land-based aquaculture management. To maintain constant stocking rate considering biological and economic condition is a convenient strategy in intensive aquaculture. This study is aimed to analyze the effect of over-stocking(more than aquaculture capacity) for certain periods of time. This study make the mathematical decision making model that finds the value of decision variable to minimize cost that sums up the water pool usage cost and sorting cost under critical standing corp constraint. The proposed mathematical decision making model was applied to 12 sample combination of sorting cost and the number of fish on the Oliver flounder culture farms. If a immature fish can be sold for high price than farming cost, restricted over-stocking resulted in a improvement of economic performance. When extensive comparable biological and market data become available, analysis model can be widely applied to yield more accurate results.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2359-2364
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• 2012

Two new chemosensors, rhodamine 6G derivative bearing hydroxyethyl group (1) and rhodamine base derivative bearing 15-crown-5 group (2) were synthesized and their sensing behaviors toward various metal ions were investigated by UV/Vis and fluorescence spectroscopies. Addition of $Hg^{2+}$ ion to a $CH_3CN$ solution of 1 and 2 gave visual color changes as well as fluorescent OFF-ON observations. Selectivity and sensitivity of 1 towards $Hg^{2+}$ are excellent enough to detect micromolar level of $Hg^{2+}$ ion, even in equeous media and biological sample (HeLa cell).

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.26-28
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• 1961

Microgram quantities of thallirum in meteorites, rocks, minerals, alloys and biological samples have been analyzed by rapid neutron activation analysis. A l0-minute radiochemical separation procedure coupled with a gas-flow proportional detector for 4.2-minute half life measurement and a gamma or beta scintillation detector placed in close proximity to the sample permitted detection of the 4.2-min Tl206. Samples were irradiated for 10-minutes at a thermal neutron flux of approximately $0.95{\times}10^{11}$ neutron-$cm^{-2}-sec^{-1}.$ The low limits of detection was about $10^{-7}$ gm of thallium.

• Analytical Science and Technology
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• v.18 no.6
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• pp.520-528
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• 2005

Two biological Certified Reference Materials (CRMs), KRISS 108-04-001 (oyster tissue) and 108-05-001 (water dropwort stem), were prepared by Korea Research Institute of Standards and Science (KRISS)during FY '01. The certified values of these materials had been determined by Isotope Dilution Mass Spectrometry (IDMS) for six elements (Cd, Cr, Cu, Fe, Pb and Zn). Additional analytical works are now progressing to certify the concentrations of a number of the environmental and nutrimental elements in these CRMs. The certified values in a CRM are usually determined by using a single primary method with confirmation by other method(s) or using two independent critically-evaluated methods. Instrumental Neutron Activation Analysis (INAA) plays an important role in the determination of certified values as it can eliminate the possibility of common error sources resulting from sample dissolution. In this study INAA procedure was used in determination of 23 elements in these two biological CRMs to acquire the concentration information and the results were compared with KRISS certified values.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.455-458
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• 1997

Crude oils in the rhizoma of fresh and dried Gastrodia elata were obtained by a simultaneous steam distillation and extraction(SDE) method using n-pentane/diethyl ether (1 : 1) as solvent, and their volatile constituents were analyzed by gas chromatography-mass spectrometry(GC/MS) A total of 39 volatile flavor constituents (11 acids, 13 alcohols,6 hydrocarbons,7 carbonyls,2 esters) and 25 constituents (6 alcohols, 13 acids, 4 hydrocarbons, 1 carbonyl, ester) were identified in the fresh and dried Gastrodia elate respectively. The major volatile components of the fresh and dried sample were hexadecanoic acid(66.78%, 50.72%), 9-hexadecenoic acid(8.07%, 9.58%), heptadecanoic acid(2.01%, 0.13%), pentadecanoic acid(6.41%, 4.94%), p-cresol(1.43%,0.52%) and cyclododecene(1.83%, 6.00%).

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.299-306
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• 1999

For the synthesis of new antifungal agents, We have synthesized four new ketoconazole derivatives were synthesized by the reaction of cis-[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)-1,3-dioxolan-4-yl]methane sulfonate with isolated fig compounds. These compounds were showed strong antifungal activity against C, albicans ATCC 10231. C, utilis. S, cerevisiae ATCC 9763. A and niger ATCC 9029. Among them, sample No.(13) showed potent inhibition activity. Generally, other samples showed biological activity in vitro test. The above results showed the possibility of the development of new antifungal agents.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.87-91
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• 2019

The contents of major ginsenosides (ginsenosides Rb1, ginsenoside Rc, ginsenoside Rd, ginsenoside Re, ginsenoside Rf, and ginsenoside Rg1) in ginseng cultivated in different areas in Korea, ginseng that underwent different cultivation processes and ages, and ginseng cultivated in different countries were determined using high-performance liquid chromatography equipped with UV/VIS detector. Ginsenoside Rc was the most abundant ginsenoside in all different ginseng samples. The highest total concentration of major ginsenosides was found in the ginseng cultivated in Jinan (0.931 mg/g) and 4-year grown red ginseng (1.785 mg/g). Major ginsenosides were the most abundant in Korean ginseng (1.264 mg/g), compared to those in Chinese and American ginseng. The results of this study showed the different contents of major ginsenosides in the ginseng samples tested and emphasized which sample could contain high yield of ginsenosides.

• Journal of Korean Biological Nursing Science
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• v.25 no.2
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• pp.123-130
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• 2023

Purpose: Sitting time, smoking, and perceived stress strongly influence physical health independent of physical activity. However, the associations among perceived stress, sedentary behavior, and smoking are poorly understood. Therefore, we examined the relationships between sitting time, smoking, and perceived stress in Korean adults aged < 65 years. Methods: We analyzed data from the seventh National Health and Nutrition Survey. In this cross-sectional study, data from 6,890 Korean adults aged < 65 years were analyzed. Complex-sample logistic regression was used to examine the relationships between sitting time, smoking, and perceived stress. Results: The group with a high sitting time (≥ 8 h/day) and those who smoked had significantly higher odds of experiencing stress than the low sitting time (< 8 h/ day) and non-smoking groups (odds ratio: 1.88, 95% confidence interval: 1.42-2.50). Conclusion: Perceived stress was positively correlated with current smoking status and increased sitting time. High sitting time (≥ 8 h/day) and current smoking were associated with a higher risk of perceived stress in Korean adults aged < 65 years.

• Current Optics and Photonics
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• v.7 no.1
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• pp.65-72
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• 2023

The motion of organelles inside a cell is an important intrinsic indicator for assessing cell physiology and tissue viability. Dynamic contrast full-field optical coherence tomography (D-FFOCT) is a promising imaging technology that can visualize intracellular movements using the variance of temporal interference signals caused by biological motions. However, double-path interferometry in D-FFOCT can be highly vulnerable to surrounding noise, which may cause turbulence in the interference signals, contaminating the sample dynamics. Therefore, we propose a method for stabilized D-FFOCT imaging in noisy environments by using common-path interferometry in D-FFOCT. A comparative study shows that D-FFOCT with the proposed method achieves stable dynamic contrast imaging of a scattering phantom in motion that is over tenfold more noise-insensitive compared to the conventional one, and thus this imaging capability can provide cleaner motion contrast images. With the proposed approach, the intracellular dynamics of biological samples are imaged and monitored.