• YAKHAK HOEJI
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• v.24 no.2
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• pp.117-122
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• 1980

A new application of high pressure liquid chromatography for the determination of fenitrothion and cis- and trans-neopynamin in insecticidal preparations was investigated. Optimum conditions for a good separation and determination were determined; solvent system: dichloromethane + n-hexane = 17 + 83; Bow rate: 0.5ml/min; column: u-porasil ($4mm{\times}3Ocm$); absorbance wavelength: 254nm; 0.05 AUFS and sample size: 30 ul. Recovery of fenicrothion, cis- and trans-neopynamin from mixed artificial preparations was 99.6%, 99.7% and 99.8% respectively. Also reproducibility tests showed that the coefficient of variation was 0.89% for fenitrothion, 0.74% cis-neopynamin and 1.1% for trans-neopynamin. There was no interference with insecticidal preparation containing DDVP, allethrin, S-421 and kerosene. HPLC method was rapid, accurate and it gave better reproducibility and higher sensitivity than any other analytical method. It was considered that HPLC could be greatly applied to the analysis of fenitrothion and neopynamin in insecticidal preparations.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.153-158
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• 2021

Cordyceps militaris (CM) is one of the most important medicinal mushrooms known to possess various biological activities. Cordycepin (CP) is a bioactive compound present in the fruiting bodies of CM and is known to have anti-tumor, anti-metastatic immunomodulatory and anti-inflammatory activities. In this study, we aim to analyze CP quantitatively under various CM extraction conditions. CP was measured using high-performance liquid chromatography, quantified using a reversed phase column using a gradient elution system of water and acetonitrile, and detected with a UV absorbance wavelength of 260 nm. The CP content of CM was the highest in 100% ethanol extract of the fruiting bodies and 60% ethanol extract of the mycelium. This study provides an efficient analysis method to determine the optimal extraction conditions for CP that can be used as a basis for developing functional foods and pharmaceutical products derived from CM.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.1.2-8
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• 1995

In the present study the sesamin and sesamol contents of the sesame extracts prepared from nine provinces in Korea were determined HPLC method. A comparative test was also carried out using the Villavecchia-suarez test, the red colored reaction for the sesamol and sesamol derivatives. The contents of sesamin and sesamol of the sesame oils from each area by the HPLC method were 0.57~0.78% and 0.010-0.023%, respectively. and the paralled results were obtained by the Villavecchia-suarez test and the HPLC method. The average contents of the sesamin was $0.68{\pm}0.074%$ by the HPLC method and the average absorbance of the Villavecchia-suarez test was $0.56{\pm}0.034$. The contents of sesamol from sesame oil by the HPLC method and the Villavecchia-suarez test were so low that it was not possible to correlate with the sesamin contents. The contents of sesamol from the sesame oil produced in Kyeong-gi and Jeon-nam provinces were $0.010{\pm}0.002%$ and $0.023{\pm}0.004$, respectively.

• Analytical Science and Technology
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• v.36 no.1
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• pp.44-52
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• 2023

This protocol clarifies a simple and precise method for measuring the activity of xanthine oxidase (XO) enzyme inhibitor. XO enzyme, which accelerates oxidative stress-related disorders through its capacity to generate hydrogen peroxide and superoxide anion radicals (O₂^•-), has been found to be inhibited by several plant extracts. Enzyme samples were incubated with a suitable buffer containing adequate amounts of xanthine as a substrate to determine XO activity. The method depends on direct measurements of uric acid and hydrogen peroxide production to test XO with and without interference. The CUPRAC reagent (Cu(Nc)₂²⁺) was used to inhibit enzyme reaction after incubation was complete. The generated urate and peroxide reduced the Cu(II)-neocuproine complex (Cu(Nc)₂²⁺) to a brightly colored Cu(I)-neocuproine complex (Cu(Nc)₂⁺), which was assessed with a spectrophotometer at 450 nm. XO activity was found to be directly related to the increased absorbance of the colored Cu(I)-neocuproine complex (Cu(Nc)₂⁺). To eliminate catalase enzyme interference, the proposed method used sodium azide and was validated against XO activity using the UV method in matched samples with t-test analysis. The proposed assay can determine XO activity with high precision, as indicated by the correlation coefficient (R² = 0.9935) from comparison with the reference protocol.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.554-561
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• 2006

The objective of this study was to investigate the effects of browning inhibitors during fermentation and storage of rice-grape wine. Bentonite, polyvinylopolypyrrolidone (PVPP), and potassium metabisulfite were added to rice-grape wine during fermentation and storage in order to find an effective method of inhibiting browning. Total phenolics content, pH, amino acidity, hydroxymethylfurfural content, and absorbance at 420 nm were measured during storage to assess the effects of the different browning substrates. Potassium metabisulfite was the most effective browning inhibitior. Sensory evaluation also showed that rice-grape wine treated with potassium metabisulfite was highly Preferable in terms of color, taste, flavor, and overall quality.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.13-23
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• 2002

The ultimate goal of periodontal therapy is directed to arresting the progression of the disease, and regenerating the fibrous attachment. In order to achieve such treatment aim, the plaque and calculus must be eliminated and the physiological conditions of the root surface must be changed to facilitate the attachment and migration of the new fibroblasts, The method of changing the proper root surface conditions to promote the healing of periodontal tissue involves mechanical procedures, such as scaling and root planing, and chemical procedures such as tetracycline-HCl. However, the formation of a long junctional epithelium was most frequently observed type of healing. Thus, the aim of this study was to examine in vitro the influence of surface conditioning of dentin by TC-HCl on human gingival epithelial cell attachment. Human gingival epithelial cells were obtained from healthy retromolar pad area(under the age 23 years). Seventy two teeth extracted from severe periodontitis were used as study material. To evaluate the epithelial cell attachment to dentin, the prepared specimen was divided to four groups. For the control group, only scaling and root planing were carried out, and for the test group, 1 to 3, the concentration of the TC-HCl was 50, 125 and 250mg/ml respectively. After cell cultivation time of 1-, 3-. 24 hour, for the indirect quantitative assessment of gingival epithelial cell attached to dentin sample, the absorbance of epithelial cell unattached to dentin was measured. The results were as follows; 1. There was no statistically significant difference between scaling and root planing group and TC-HCl 50mg/ml 125mg/ml and 250mg/ml group about absorbance of unattached epithelial cell to dentin sample(p>0.5). 2. As time passes, the absorbance of unattached gingival epithelial cell to dentin sample was decreased statistically significant(p<0.05). 3. There was no statistically significant difference among the TC-HCl group(p>0.05) We concluded that there was similar effect on gingival epithelial cell attachment between TC-HCl conditioning on root surface and only scaling and root planing treatment

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.204-212
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• 2021

Resazurin, an oxidized blue dye, is reduced to resorufin, showing a peak absorbance change and emitting fluorescence due to the metabolic activity of living cells. In this study, the growth of Lactobacillus rhamnosus GG (LGG) and the redox potential of living probiotic bacteria were evaluated based on changes in the absorbance or fluorescence of resazurin. Fluorescence analysis is a more accurate and sensitive method for quantifying viable LGG than the colorimetric absorbance measurement of resazurin change. Fluorescence measurement could detect LGG of 6.5-9.5 log CFU/mL within 30 min with R2=0.99. No significant effect of further reduction of resorufin to dihydroresorufin by LGG was observed. Various probiotics showed different resazurin-reducing activities, and L. kimchicus had the highest reducing activity among the six probiotics tested. These findings suggests that fluorescence measurement in a resazurin-based assay is useful for analyzing bacterial growth and the redox potential of living probiotics.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.700-707
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• 2021

This study aimed to understand the effects of apricot kernel oil on the improvement of hair texture by producing a hair texture improvement agent added with apricot kernel oil and then applying it to damaged hair. In the test method and measurement, the agent was produced by putting different contents of apricot kernel oil like 0 g, 1 g 2 g, and 3 g. After applying the produced agent to bleached sample hair, it was heat treated and then left as it was. The comparative analysis was conducted by measuring each sample before and after application. To understand its effects on the improvement of hair texture, the tensile strength, absorbance with the use of methylene blue, and gloss were measured. In the results of this study, the tensile strength was increased in every sample except for healthy hair after application. In the results of analyzing the absorbance with the use of methylene blue, it was decreased in samples like 7L(1), 7L(2), 7L(3), and 9L(3) after application. In the results of measuring the gloss, it was increased in the samples like 7L(1), 7L(2), 7L(3), and 9L(3). Such changes in the tensile strength, absorbance, and gloss showed the effects of apricot kernel oil on the texture improvement of damaged hair. In the future, it would be necessary to have researches on various methods of measurement and treatment.

• Journal of the Korean Applied Science and Technology
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• v.39 no.3
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• pp.471-478
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• 2022

This study attempted to find out the improvement effect the improvement effect of Babassu oil on damaged hair by damaged hair by applying a hair-improving formulation with Babassu oil to damaged hair after manufacturing. As the experimental raw material, the contents of babassu oil were changed to 0 g, 3 g 6 g, and 9 g and added to the perm base agent. The prepared formulation was applied to 8 levels of bleached sample hair. Each sample and damaged hair were measured and compared and analyzed. As for the measurement method, tensile strength, absorbance using methylene blue, and gloss were measured to know the effect of improving damage hair Statistical analysis was conducted for the reliability of the research results. As a result of the research, it was found that the tensile strength was higher than that of the damaged hair in all samples applied by adding babassu oil. As a result of absorbance analysis using methylene blue, it was found that absorbance was decreased in all samples compared to damaged hair. As a result of the gloss measurement, it was found that the gloss was increased in all samples compared to the damaged hair. In conclusion, it was found that babassu oil had an improvement effect on damaged hair.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.267-272
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• 2005

We deposited thin films of organic light-emitting-material $Alq_3$(alumina quinoline) on silicon and slide-glass substrates using thermal evaporation method, and measured spectra of ellipsometry angles ${\Delta}$ and ${\Psi}$ in the photon-energy range of 1.5~5.0 eV using a variable angle spectroscopic ellipsometer. The optical constants, refractive index and extinction coefficient, of $Alq_3$ were determined via the dispersion parameters extracted from the curve-fitting process based on Jellison-Modine dispersion function. The reliability of determined optical constants were verified through the comparison of measured and simulated transmittance curves and the good agreement between simulated absorption-coefficient curves and absorbance spectra measured using a spectrophotometer.