• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.145-150
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• 2008

One of the unresolved questions in articular cartilage biomechanics is the magnitude of the dynamic modulus and tissue compressive strains under physiological loading conditions. The objective of this study was to characterize the dynamic modulus and compressive strain magnitudes of bovine articular cartilage at physiological compressive stress level and loading frequency. Four bovine calf shoulder joints (ages 2-4 months) were loaded in Instron testing system under load control, with a load amplitude up to 800 N and loading frequency of 1 Hz, resulting in peak engineering stress amplitude of ${\sim}5.8\;MPa$. The corresponding peak deformation of the articular layer reached ${\sim}27%$ of its thickness. The effective dynamic modulus determined from the slope of stress versus strain curve was ${\sim}23\;MPa$, and the phase angle difference between the applied stress and measured strain which is equivalent to the area of the hystresis loop in the stress-strain response was ${\sim}8.3^{\circ}$. These results are representative of the functional properties of articular cartilage in a physiological loading environment. This study provides novel experimental findings on the physiological strain magnitudes and dynamic modulus achieved in intact articular layers under cyclical loading conditions.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.325-330
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• 1995

The distribution of circumferential strain of arterial cross-section Is highest at intima and lowest at adventitia. However, the circumferential strain is theoretically severe at Intima because there is strain concentration. The theoretical degree of the intimal strain can not be explained in physiological condition even though artery is physiologically normal. Physiological adaptation may be undertaken to strain concentration. However, it is not clear, yet. Residual strain of artery is eagerly studied. There is experimental evidence that residual strain exists in artery. When ring of artery is longitudinally cut, it is opened. Assumption is made that intimal strain concentration is reduced with the considel'ation of residual strain. This study experimentally attempts to quantify the effect of residual strain on circumferential strain which is determined under the assumption of zero strain with zero pressure.

• Safety and Health at Work
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• v.10 no.2
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• pp.219-223
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• 2019

Background: Ice cooling vests can cause tissue damage and have no flexibility. Therefore, these two undesirable properties of ice cooling vest were optimized, and the present study was aimed to compare the impact of the optimized ice cooling vest and a commercial paraffin cooling vest on physiological and perceptual strain under controlled conditions. Methods: For optimizing, hydrogel was used to increase the flexibility and a layer of the ethylene vinyl acetate foam was placed into the inside layer of packs to prevent tissue damage. Then, 15 men with an optimized ice cooling vest, with a commercial paraffin cooling vest, and without a cooling vest performed tests including exercise on a treadmill (speed of 2.8 km/hr and slope of %0) under hot ($40^{\circ}C$) and dry (40 %) condition for 60 min. The physiological strain index and skin temperature were measured every 5 and 15 minutes, respectively. The heat strain score index and perceptual strain index were also assessed every 15 minutes. Results: The mean values of the physiological and perceptual indices differed significantly between exercise with and without cooling vests (P < 0.05). However, the difference of the mean values of the indices except the value of the skin temperature during the exercises with the commercial paraffin cooling vest and the optimized ice cooling vest was not significant (P > 0.05). Conclusions: The optimized ice cooling vest was as effective as the commercial paraffin cooling vest to control the thermal strain. However, ice has a greater latent heat and less production cost.

• Journal of Microbiology
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• v.44 no.1
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• pp.113-120
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• 2006

Candida tropicalis was treated with ultraviolet (UV) rays, and the mutants obtained were screened for xylitol production. One of the mutants, the UV1 produced 0.81g of xylitol per gram of xylose. This was further mutated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and the mutants obtained were screened for xylitol production. One of the mutants (CT-OMV5) produced 0.85g/g of xylitol from xylose. Xylitol production improved to 0.87 g/g of xylose with this strain when the production medium was supplemented with urea. The CT-OMV5 mutant strain differs by 12 tests when compared to the wild-type Candida tropicalis strain. The XR activity was higher in mutant CT-OMV5. The distinct difference between the mutant and wild-type strain is the presence of numerous chlamvdospores in the mutant. In this investigation, we have demonstrated that mutagenesis was successful in generating a superior xylitol-producing strain, CT-OMV5, and uncovered distinctive biochemical and physiological characteristics of the wild-type and mutant strain, CT-OMV5.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.87.2-87
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• 2003

Long-term repeated culturing of biocontrol agents on a certain medium often results in reduced biocontrol efficacy and altered physiology. Effect of culturing media on biocontrol ability and physiological state of Burkholderia gladioli strain B543 was investigated. Over 20 times repeated cultivation of B. giadioli strain B543 on Kings B medium or nutrient agar medium showed improved biological control of cucumber damping-off caused by Pythium ultimum, while one time cultivation on KB or NA did not. The repeated cultivation also induced the physiological changes of the biocontrol agent such as antifungal activity and the production of protease and siderophore. Our result indicates that adaptation to proper culturing medium can alter biocontrol ability and must consider in optimizing the use of biocontrol agents.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.777-780
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• 1995

A strain US50-3 producing water-soluble red pigment was isolated from the pond separating oil from water near the oil storage tanks. The strain US50-3 was identified as a strain of Serratia marcescens considering its morphological and physiological characteristics, and DNA G+C contents. It showed a little difference comparing to the Type strain and was considered to be another biotype strain.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.161-165
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• 2007

Cultivation of a biocontrol agent on a certain medium often results in reduced biocontrol efficacy and alters physiological state. In our previous study, Burkholderia gladioli strain B543 with long-term subculture on tryptic soy agar resulted in significantly reduced biocontrol ability against cucumber damping-off caused by P. ultimum. Therefore, we investigated the influence of laboratory culturing media on biocontrol activity and physiological state of Burkholderia gladioli strain B543 by using long-term repeated culture on a certain medium. When isolate B543 were successionally cultured on King's B agar (KBA), tryptic soy agar, nutrient agar (NA), or soil extract agar more than 20 times, the isolate cultured on KBA or NA showed a significantly enhanced biocontrol efficacy and higher population density in the rhizosphere of cucumber compared to that of the others. However, the isolates cultured on KBA more than 20 times showed the lowest production of protease, siderophore, or antifungal substance(s), measured by skim milk agar, Chrome-Azurol-S agar, and potato dextrose agar amended with 10% of the culture filtrate, respectively. Our results suggest that adaptation to proper culturing medium can alter biocontrol ability and physiological state, and we must consider laboratory media in optimizing the use of biocontrol agents.

• Food Science of Animal Resources
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• v.42 no.6
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• pp.996-1008
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• 2022

Lactic acid bacteria are representative probiotics that have beneficial effects on humans. Nineteen strains among the 167 single strains from kimchi was selected and their physiological features were investigated. The selection of a strain was based on strong enzyme (lipase, α-amylase, and α-glucosidase) inhibitory activities and anti-obesity effects in the adipocytes. For the final selection, the strain Lactiplantibacillus plantarum KC3 was tested for its potential as a starter. To assess its functionality, a freeze-dried culture of L. plantarum KC3 was administered to a diet-induced obese mouse model receiving a high-fat diet. The animal group administered with L. plantarum KC3 showed significant body weight loss during the 12-week feeding period compared to the high-fat control group. This study investigated the physiological characteristics of selected strain and evaluated its potential as an anti-obesity probiotic in mice.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.164-168
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• 1994

Identification of the Actinomycetes isolate strain No. 1372, a producer of Actinomycin X$_{2}$ was performed by using ISP method.l The strain, designated as No. 1372, was identified as Streptomyces floridae based on its morphological, physiological and biochemical characteristics. The highest production of the antibiotics by the strain was achieved in a fermentation medium containing soluble starch, yeast extract, (NH$_{4}$)SO$_{4}$, K$_{2}$HPO$_{4}$, NaCl$_{2}$, CaCO$_{3}$, and trace element.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.155-159
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• 1996

The strain which produces 2-phenylethanol (PEA) from styrene oxide was isolated from soil samples near Ulsan PO/SM plant. The isolated strain was identified as Pseudomonas putida through its morphological, physiological characteristics, and DNA G+C contents. Its metabolic pathway from styrene oxide to 2-phenylethanol was studied and it was found that styrene oxide was transformed to phenylacetaldehyde, to 2phenylethanol (PEA), and then to phenylacetic acid by this strain.