• Mycobiology
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• 제33권2호
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• pp.121-123
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• 2005

Extracellular keratinase isolated from Aspergillus flavus K-03 was immobilized on calcium alginate. The properties and reaction activities of free and immobilized keratinase with calcium alginate were characterized. The immobilized keratinase showed proteolytic activity against soluble azo-casein and azo-keratin, and insoluble feather keratin. Heat stability and pH tolerance of keratinase were greatly enhanced by immobilization. It also displayed a higher level of heat stability and an increased tolerance toward alkaline pHs compared with free keratinase. During the durability test at $40^{\circ}C$, 48% of the original enzyme activity of the immobilized keratinase was remained after 7 days of incubation. The immobilized keratinase exhibited better stability, thus increasing its potential for use in industrial application.

• Journal of Ginseng Research
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• 제13권1호
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• pp.8-13
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• 1989

The effects of orally administered ginseng leaf saponins(GLS) on the analgesic action of morphine, the development of morphine induced tolerance and physical dependence, and the hepatic flutathione contents in mice were investigated. GLS antagonized the analgesic action of morphine and inhibited the development of morphine induced tolerance and physical dependence. It also inhibited the decrease in hepatic glutathione level induced by multiple injections of morphine.

• 미생물학회지
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• 제25권3호
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• pp.229-237
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• 1987

To determine the characteristics of heterotrophic bacterial community in estuarine ecosystem, water and sediment samples were taden from Naktong estuary. All isolates were compared with 73 characters and described by cluster analysis. With same characters, 30 reference strains were able to divide into approximate species level at 80% similarity (S value). Diversity indices ($H^{1}$) of sediment column isolates were higher than water column isolates. The bacterial community commonly appeared in water and sediment column was reduced with going to downstream. Tolerance indices for temperature (Pt) and salinity (Ps) were also higher in sediment isolates than in water isolates. The bacterial community in sediment column is believed to be composed with diverse populations compared to water column and maintains its stability against various environmental changes with high physiological tolerances.

• Journal of Plant Biotechnology
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• 제38권3호
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• pp.203-208
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• 2011

We transferred Dhn5 (dehydrin5) gene from barley to poplar to determine the effect of its expression on the transgenic poplars. The results from northern blot analysis showed that the expression level of gene varied among the transgenic lines. During their culture on tissue culture media, the transgenic poplars formed vigorous growing callus in the presence of 5% PEG. When the transgenic poplars were growing in pots and witheld watering, they stayed much healthier than nontransgenic poplars. The transgenic poplars showed higher rates of photosynthetic rates, stomatal conductance and evaporation rates under the drought stress, although there was no significant difference in soil water content within the treatments. The relative electrical conductivity of the transgenic poplars after 20% PEG treatment was lower than that of nontransgenic poplars. The results provide evidence that the expression of hvDhn5 gene conferred drought tolerance in the transgenic poplars.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 추계학술대회
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• pp.41-47
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, $50-80\%$ of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, Improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 춘계학술대회
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• pp.41-47
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.

• Journal of the Optical Society of Korea
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• 제10권3호
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• pp.118-123
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• 2006

We present an optical security method for binary data information by using 4-step phase-shifting digital holography and we analyze tolerance error for the decrypted data. 4-step phase-shifting digital holograms are acquired by moving the PZT mirror with equidistant phase steps of ${\pi}/2$ in the Mach-Zender type interferometer. The digital hologram in this method is a Fourier transform hologram and is quantized with 256 gray level. The decryption performance of the binary data information is analyzed. One of the most important errors is the quantization error in detecting the hologram intensity on CCD. The greater the number of quantization error pixels and the variation of gray level increase, the more the number of error bits increases for decryption. Computer experiments show the results for encryption and decryption with the proposed method and show the graph to analyze the tolerance of the quantization error in the system.

• 대한의생명과학회지
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• 제11권4호
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• pp.539-543
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• 2005

Elevated level of serum cholesterol in humans is a risk factor correlated with the development of coronary heart disease. We have screened lactic acid bacteria from pig and human feces for the development of probiotics which have an anti-cholesterol effect. We have used special media to isolate only lactic acid bacteria and they were subjected to the experiments such as oxgal test, carbohydrate fermentation test. Results from the acid tolerance test and growth test in the presence of oxgal demonstrated that some strains would likely survive in thuman stomach, where acidity is high, and in small intestine, where bile fluid is present. In conclusion, we were able to screen lactic acid bacteria which were tolerant against bile acid and supposed to be prominent to lower the cholesterol level in human serum.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.244-251
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• 2011

We propose a new 2-step phase-shifting digital holographic optical encryption technique and analyze tolerance error for this cipher system. 2-step phase-shifting digital holograms are acquired by moving the PZT mirror with phase step of 0 or ${\pi}$/2 in the reference beam path of the Mach-Zehnder type interferometer. Digital hologram with the encrypted information is Fourier transform hologram and is recorded on CCD camera with 256 gray-level quantized intensities. The decryption performance of binary bit data and image data is analyzed by considering error factors. One of the most important errors is quantization error in detecting the digital hologram intensity on CCD. The more the number of quantization error pixels and the variation of gray-level increase, the more the number of error bits increases for decryption. Computer experiments show the results to be carried out encryption and decryption with the proposed method and the graph to analyze the tolerance of the quantization error in the system.

• Reproductive and Developmental Biology
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• 제34권4호
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• pp.305-308
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• 2010

In this study, we conducted an oral glucose tolerance test (OGTT) so as to compare antidiabetic activities of general potatoes, purple-flesh potatoes, and potato pigments in rats at various concentration levels. After allowing the rats to abstain from food for 12 hours, 10%/20% general potato, purple-flesh potato, and potato extract was orally administered to rats at 100 and 500 mg/kg concentrations. The blood glucose level was measured after an hour. Then, immediately, 1.5 g/kg of sucrose was administered through the abdominal cavity and the blood glucose measured after 30, 60, 120, and 180 minutes. 20% purple-flesh potato group and 10% general potato group, both 100 and 500 mg/kg, showed a significant concentration-dependent decrease in blood glucose levels after 30 minutes. The 100 mg/kg potato pigment group also showed a statistically significant decrease after 30 minutes. In conclusion, administration of 10% general potato, 20% purple-flesh potato, and potato pigment can reduce blood glucose level in an OGTT using rats.