• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.329-332
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• 2004

Changes in activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in vitro were examined by measuring maximum absorbances of ADH and ALDH at 340 nm to determine influence of Maesil (Prunus mume) on alcohol metabolism. Facilitating rates of ADH activity were 137.92, 131.58, 152,96, 218.70, 111.76, and 144.27% in Maesil juice, 5, 10, and 15% GMT, and 0.5 and 1.0% aspartic acid, respectively, ALDH activity increased in the order of Maesil juice > ALDH > GMT > aspartic acid, and facilitating rate of ALDH activity in Maesil juice was the highest at 976.44%. These results indicate alcohol metabolizing activity can be enhanced by Maesil juice.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.97-102
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• 2022

In this study, the antibacterial effect of silkworm extract and Momordica charantia extract on S. mutans and F. nucleatum was investigated. S. mutans or F. nucleatum and 0%, 2%, 4%, 8% concentration of silkworm powder or Momordica charantia powder extract were added to the BHI liquid medium and cultured, and the sample was measured at an optical density of 600nm. As a result, S. mutans, the absorbance value was significantly decreased only in 8% of the silkworm extract, and the absorbance value was significantly decreased in all concentrations in the Momordica charantia extract. The absorbance of F. nucleatum was significantly decreased in a concentration-dependent manner in both the silkworm extract and the Momordica charantia extract. This suggests the possibility that silkworm extract and Momordica charantia extract can be used as materials for the prevention and treatment of oral diseases.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.185-191
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• 2000

The water-soluble glucan produced by Lactococcus lactis 1370 affects the formation of dental plaque by Streptococcus mutans. In this study the factors affecting the formation of water-soluble glucan were assessed as the optical density of culture supernatant of Lactococcus lactis 1370 in the spectrophotometer. 1. The optical density of culture supernatant was high when Lactococcus lactis 1370 was cultured in M17 broth with 5% sucrose, while being low in culture supernatant of Streptococcus mutans. 2. The optical density of culture supernatant was higher when Lactococcus lactis 1370 was cultured in M17 broth with 10% sucrose than when being cultured without sucrose (p<0.05), and was higher at pH 7 than pH 5 (p<0.05). 3. The optical density of culture supernatant was the highest at $37^{\circ}C$ among $32^{\circ}C,\;37^{\circ}C\;and\;42^{\circ}C$, and was higher in the anaerobic incubator than in the aerobic incubator (p<0.05). 4. The optical density of culture supernatant was the highest in the media containing 1.0mM $CaCl_2$ (p<0.05), 2.5mM KCl (p<0.05), and 1.6mM $MgCl_2$. 5. When Streptococcus mutans was cultured in the media containing a quarter culture supernatant of Lactococcus lactis 1370 grown in M17 broth, the mean weight of produced artificial plaque was 103.0mg on the wire, whereas being significantly reduced to 5.6mg in the media containing a quarter culture supernatant of Lactococcus lactis 1370 grown in M17 broth containing 5% sucrose (p<0.05). These results indicate that the water-soluble glucan is more formed by Lactococcus lactis 1370 in the media containing sucrose or under the adequate conditions for the growth of bacteria, and inhibits the formation of artificial plaque by Streptococcus mutans.

• Analytical Science and Technology
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• v.6 no.4
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• pp.359-362
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• 1993

To find compromise experimental conditions that will allow a group of elements to be run on flame atomic absorption spectrometer without changing the burner height or gas flow rates, measurements were carried out. The optimum absorbance for simultaneous analysis of ten elements was observed at high flow rate of air-$C_2H_2$ as fuel and at 2mm of burner height. At the condition, 73% of mean relative absorbance were achieved.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.199-199
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• 2012

Display에 사용되는 투명전극의 경우, 가시광 영역에서의 투과도는 중요한 요소 중의 하나이다. 투명 전도막의 광흡수, 반사 및 투과즉성은 박막 내에 존재하는 전공밴드의 전자, 자유전자, polar optical phonon 등의 빛과의 반응에 의해 결정된다고 알려져 있다. 많은 연구결과를 통해 투과 및 반사특성은 알려져 있으나, 가시광 영역내의 흡광특성에 관해서는 밝혀진 연구결과가 많지 않다. 본 연구에서는 ITO 박막의 투과도와 흡광도의 상호관계를 규명하였다.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.291-293
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• 2010

알카리성 과황산칼륨을 이용한 자외선 흡광광도법은 수중의 총질소를 간편하면서도 신속하고 정확하게 분석할 수 있는 방법으로 각각의 질소성분을 standard method에 의해 분석한 후 이들을 합산하는 방법보다 회수율이 좋게 나타났다. 자외선 흡광광도법을 이용할 경우 Cr(VI)이온과 Br이온에 의해 방해를 받으므로, Br이온을 다량 함유하는 해수의 총질소 분석방법으로는 적합하지 않은 것으로 관찰되었다. 전처리를 한 후 220 nm에서 흡광도를 측정하기 위해서는 탄산염의 방해를 방지하기 위해 pH를 2~3으로 조절한 후 분석해야만 하고, 알카리성 과황산칼륨을 이용한 자외선 흡광광도법은 총질소를 분석하는 방법으로 우수성이 입증되었으나 각 형태별 질소의 농도를 측정할 수 없는 단점이 있으므로 각 형태별 질소의 농도를 측정하기 위해서는 standard method를 이용해야 된다. 본 연구에서 알카리성 과황산칼륨을 이용한 자외선 흡광광도법은 총질소를 분석하는데 있어서 standard method에 의한 합산법보다 시간과 노력을 절약할 수 있는 것으로 검토되었다.

• Applied Biological Chemistry
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• v.31 no.1
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• pp.52-57
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• 1988

The difference of absorbance before and after oxidation of L-ascorbic acid(AsA) from cucumber was directly proportional to the concentration of AsA. The effect of pH, enzyme concentration and reaction time on the AsA assay were examined. The values of AsA obtained by the present method and HPLC method agreed well in all cases.

• Journal of the Korean Chemical Society
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• v.26 no.4
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• pp.218-223
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• 1982

The absorbance and fluorescence yields of chl-a vs. concentration of n-prOH in diethyl ether, benzene and iso-octane were shown the characteristic point which chl-a structures are changed to monomer by the solvation of oligomer, and the spectral differences of fluorescence excitation between oligomer and monomer were identified by fluorimetry. All the maximum wavelength of absorbance, fluorescence excitation and fluorescence emission were shifted to longer wavelength. The ratios of soret/red band were depended on the band intensions and the polarities of solution in organic solvents mixed with n-prOH.

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.477-477
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• 1989

The rates of the reaction of $[MoO_2(S_2CNEt_2)_2]$ with triphenylphosphine in 1,2-dichloroethane have been determined by the spectrophotometric method. The increase in the initial absorbance has been interpreted as a result of the production of $[Mo_2O_3(S_2CNEt_2)_4]$ and the decrease in absorbance then corresponds to the reduction of $[M_2O_3(S_2CNEt_2)_4]$. The data suggest mechanisms involving the enzymatic reaction in the first stage and the decay of intermediate, ${\mu}$-oxo molybdenum (V) dimer in the second stage.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.75-80
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• 1992

The electrochemical spectral sensitization of a $SnO_2$ electrode with eosin B, a Xanthene dye, has been studied in acetonitrile. Measurements of the photocurrent have been carried out in the presence of supersensitizers such as thiourea, 1-allyl-2-thiourea, NaSCN, and NaI. The magnitude of the supersensitized photocurrent was greater than that of the sensitized photocurrent for all of the supersensitizers studied. However, the long time span of irradiation causes a significant decrease of the supersensitized photocurrent as well as the absorbance. These results, together with infrared spectra and fluorescence spectra, are taken into account to elucidate the mechanism of photoreaction between eosin B and supersensitizers in acetonitrile.