• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.226-226
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• 2022

• Food Science and Biotechnology
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• 제18권3호
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• pp.661-666
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• 2009

The heat tolerance and the inactivation kinetics of peroxidase (POD) and polyphenol oxidase (PPO) in pineapples (Ananas comosus) were studied in the temperature range $45-95^{\circ}C$. The kinetic parameters, such as deactivation rate constant (k), activation energy ($E_a$), and decimal reduction rate (D) of the thermal inactivation process, were determined. POD in pineapples showed biphasic inactivation behavior at temperatures range $45-75^{\circ}C$ but was monophasic at $85-95^{\circ}C$. This indicate that POD has 2 isozymes, namely heat labile and heat resistant, with $E_a$ of 68.79 and 93.23 kJ/mol, respectively. On the other hand, the heat denaturation of pineapple PPO could be described as simple monophasic first-order behavior with $E_a$ of 80.15 kJ/mol. Thus, the results of this study is useful in blanching technology where it shows a shortened time with higher temperature can be applied. The determination of the heat tolerance and inactivation POD and PPO, at different temperature range as done in the present work, was very important to improve the blanching process. This also will help to optimize the pineapple canning process which is one of the most important food industries in many tropical regions.

• Biomolecules & Therapeutics
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• 제23권3호
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• pp.290-295
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• 2015

Aging is defined as a collective process that alters organism's functional capacity and appearance over the course of life. Apart from an increase in susceptibility to many diseases, aging affects the cellular system that is responsible for decoding painful stimuli. Yet, aging-associated molecular mechanisms of pain perception remains elusive. Using Drosophila, we showed a decrease in temperature tolerance and a reduction in high temperature thermal avoidance with aging. Locomotor activity assay demonstrated that the age-dependent changes in heat nociception did not stem from the general decline in muscular activity. However, we identified pain-related gene expression alteration with aging. We anticipate that our findings would help opening a new window onto developing the optimal pain treatment for the elderly.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.84-86
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• 2003

The laser welding and its analysis of thin-sheet carbon steels were carried out with high power CO$_2$1aser. Bead on plate welding of thin sheet was examined to investigate the effect of weld variables of laser welding, and to obtain optimum welding condition. Butt-welding was also carried out to show the effect of gap on the laser weldability of thin sheet. At high welding speed, the partial penetration was obtained by low heat input. Otherwise, porosity was formed in the bead at low weld speed because of too many heat input. The maximum gap tolerance on laser welding was observed to be about 0.2mm. This gap size has good relationship with beam size of laser spot(about 0.3mm). The formability of welded sheet was about 80% value of base metal and the gap size has not affected on the formability, although weld quality is dependent on the gap size.

• 열처리공학회지
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• 제13권3호
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• pp.163-169
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• 2000

Recently, uncertainty of hardeness became a major concem for the people working on the laboratory evaluation and accreditation. It is required to indicate uncertainty of hardness tester on the report after calibration. In addition to this, uncertainty of certified hardness reference block is also required to indicate on the certification sheet. Method on the evaluation of uncertainty in hardness measurement is agreed only recently for Rockwell hardness C scale. In this paper, a preliminary calculation of uncertainty based on type B evaluation has been made for hardness testers which satisfies the requirements of Korean Standards. It was found that the tolerance limit of mean value specified in KS should be increased to be compatible with the calculated uncertainty.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.111.1-111.1
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• 2007

See Full Text

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
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• pp.264-264
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• 2022

• BMB Reports
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• 제42권1호
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• pp.16-21
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• 2009

Three novel Class A genes that encode heat shock transcription factor (HSF) were cloned from Oryza Sativa L using a yeast hybrid method. The OsHSF7 gene was found to be rapidly expressed in high levels in response to temperature, which indicates that it may be involved in heat stress reception and response. Over-expression of OsHSF7 in transgenic Arabidopsis could not induced over the expression of most target heat stress-inducible genes of HSFs; however, the transcription of some HSF target genes was more abundant in transgenic plants following two hours of heat stress treatment. In addition, those transgenic plants also had a higher basal thermotolerance, but not acquired thermotolerance. Collectively, the results of this study indicate that OsHSF7 might play an important role in the response to high temperature. Specifically, these findings indicate that OsHSF7 may be useful in the production of transgenic monocots that can over-express protective genes such as HSPs in response to heat stress, which will enable such plants to tolerate high temperatures.

• Biomolecules & Therapeutics
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• 제23권1호
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• pp.77-83
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• 2015

The seed of Vigna angularis has long been cultivated as a food or a folk medicine in East Asia. Genistein (4',5,7-trihydroxyisoflavone), a dietary phytoestrogen present in this plant, has been known to possess various biological properties. In this study, we investigated the possible lifespan-extending effects of genistein using Caenorhabditis elegans model system. We found that the lifespan of nematode was significantly prolonged in the presence of genistein under normal culture condition. In addition, genistein elevated the survival rate of nematode against stressful environment including heat and oxidative conditions. Further studies demonstrated that genistein-mediated increased stress tolerance of nematode could be attributed to enhanced expressions of stress resistance proteins such as superoxide dismutase (SOD-3) and heat shock protein (HSP-16.2). Moreover, we failed to find genistein-induced significant change in aging-related factors including reproduction, food intake, and growth, indicating genistein exerts longevity activity independent of affecting these factors. Genistein treatment also led to an up-regulation of locomotory ability of aged nematode, suggesting genistein affects healthspan as well as lifespan of nematode. Our results represent that genistein has beneficial effects on the lifespan of C. elegans under both of normal and stress condition via elevating expressions of stress resistance proteins.

• Biomolecules & Therapeutics
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• 제23권6호
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• pp.582-589
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• 2015

Several theories emphasize that aging is closely related to oxidative stress and disease. The formation of excess ROS can lead to DNA damage and the acceleration of aging. Vigna angularis is one of the important medicinal plants in Korea. We isolated vitexin from V. angularis and elucidated the lifespan-extending effect of vitexin using the Caenorhabditis elegans model system. Vitexin showed potent lifespan extensive activity and it elevated the survival rates of nematodes against the stressful environments including heat and oxidative conditions. In addition, our results showed that vitexin was able to elevate antioxidant enzyme activities of worms and reduce intracellular ROS accumulation in a dose-dependent manner. These studies demonstrated that the increased stress tolerance of vitexin-mediated nematode could be attributed to increased expressions of stress resistance proteins such as superoxide dismutase (SOD-3) and heat shock protein (HSP-16.2). In this work, we also studied whether vitexin-mediated longevity activity was associated with aging-related factors such as progeny, food intake, growth and movement. The data revealed that these factors were not affected by vitexin treatment except movement. Vitexin treatment improved the body movement of aged nematode, suggesting vitexin affects healthspan as well as lifespan of nematode. These results suggest that vitexin might be a probable candidate which could extend the human lifespan.