• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.227-227
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• 2017

This study was conducted to analyze the reduction of quality and ripening rate of rice due to submergence during ripening stage and identify the physiological cause. Korean japonica type rice cultivars, Nampyeong was used in the experiment. The following 7, 14 day after heading, they were then moved into submergence treatment facility and we conducted the tests under three different submergence conditions - T1(clear water and overhead submergence), T2(Muddy water and exposure of Flag leaf end ), T3(Muddy water and overhead submergence), and the treatment lasted for 4days. The decrease of ripening rate was most severe in T3 treatment at 7days after heading, and the decrease of head rice ratio was most severe in T3 treatment at 14days after heading. Meanwhile the starch synthesis was inhibited, as the supply of assimilation products was inhibited in grain during the submergence treatment. And in stem, sucrose content was increased because the soluble carbohydrates accumulated before heading were decomposed. These changes may be due to the consumption of respiratory substrate in anaerobic conditions and the inhibition of the production of photosynthetic products by light interception. In order to see what kind of reaction occurs at the molecular level, we examined the degree of RNA expression in grain, stem and leaf. First, the expression of rna associated with starch synthesis in grain was decreased in all submergence treatment. and especially Ospul(DBE) was more decreased in 14days after heading treatment than 7days after heading treatment. This difference can explain the result that the decrease of head rice ratio was more severe at 14days after heading. And in stem, the expression of rna associated with the supply of assimilation products was decreased in submergence treatment. Finally in leaf, the expression of rna(ADH, ALDH) associated with anaerobic respiration was increased, while the expression of rna associated with photosynthesis was decreased. These results of physiological analysis can used to develop the cultivation technique and to offer the information for breeding the cultivars with tolerant characteristics to submergence stress during ripening stage in rice.

• Journal of Life Science
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• v.27 no.7
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• pp.826-833
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• 2017

The rising concentration of atmospheric carbon dioxide is causing ocean acidification and global warming. The seahorse is an important species in marine ecosystems and fishery markets, however, their populations have recently decreased due to ocean acidification. As a result, we examined changes in the physiological responses of the spotted seahorse Hippocampus kuda when it was exposed to acidic sea water (pH 6.0, 6.5, and 7.0) and normal seawater (pH 8.0 as the control) over a period of 15 days. As the pH decreased, the seahorses' body weight and length also decreased. Components in body of ash, the crude lipids and crude proteins also differed significantly with changes in pH, due to stress caused by the seahorses' exposure to the acidic water conditions. The superoxide dismutase levels were significantly lower in the pH 6.0 and 6.5 groups than they were in the pH 7.0 and pH 8.0 groups. However, the catalase and glutathione levels were significantly higher in the acidic sea water groups. We suggest that decreasing the pH level of rearing water induces a stress response in H. kuda, damaging their ability to maintain their homeostasis and energy metabolism. Antioxidant enzymes are generally sensitive to acidic stress; in this study, the antioxidant activity was significantly affected by the pH level of the rearing water. These results indicate that physiological stress, induced by exposure to acidification, induces an antioxidant reaction, which can reduce general components in the body and the growth of H. kuda.

• Journal of Photoscience
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• v.9 no.2
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• pp.424-426
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• 2002

Recently, much attention has been paid to the physiological functions of flavonoids associated with their antioxidant properties. However, there was a lack of information on the molecular mechanism at which flavonoids play the antioxidative role. We have already studied on the oxidation of quercetin with hydrogen peroxide and sodium hypochlorite in alcoholic aqueous solution and determined the oxidation products. Through the structural analysis of the oxidation products, it was clarified that the hydroxyl group at C-3 in the C ring plays the important role in the antioxidative action of quercetin. Successively, rutin and (+)-catechin were oxidized with sodium hypochlorite and their mono- and di-chlorinated derivatives were obtained. These facts indicate that these flavonoids can directly scavenge hypochlorous acid and the active site in this scavenging reaction is not the hydroxyl group at C-3.

• YAKHAK HOEJI
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• v.46 no.6
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• pp.441-447
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• 2002

It has been well known that vanadium shows various physiological and pharmacological properties such as an insulin-mimetic effect. In view of the reported toxic effects there is the problems that the safety margin is narrow because of its strong toxicity, Vanadate was tested for its ability to cause blood aggregation. Although vanadate or $H_2O$$_2$ alone had little effect on platelet aggregation, treatment of vanadate and $H_2O$$_2$ together induced platelet aggregation indicated that it was occurred by pervandate or hydroxyl radical produced from the reaction of vanadate and $H_2O$$_2$. It was dependent on extracellular $Ca^{2+}$ion. Platelet aggregation caused by vanadate and $H_2O$$_2$ was inhibited by ascorbic acid, tocopherol, catalase, mannitol, and Tiron. In contrast to vanadate, vanadium yeast prepared by uptaking vanadate in yeast cells did not induce platelet aggregation in the presence of $H_2O$$_2$.>.

• Journal of Life Science
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• v.10 no.5
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• pp.533-541
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• 2000

Compared to mammal including human, many bioreactive genes that regulate various biological events has not been cloned and characterized yet in fishes, especially shark, Scyliorhinus torazame. In orther to isolate genes that regulate physiological processes in cartilaginors fishes, we performed reverse transcription-polymerase chain reaction (RT-PCR) using the RNA of cartilage tissues of Scyliofhinus torazame. The cloned partial genes were 86%, 80%, 73%, 84%, 75%, 79% identical to $\alpha$- actin, 90-kDa heat-shock protein, methyle-neterahydrofolate dehydrogenase-methenyltertrahydrofolate cyclohudrolase-formyltetrahydrofolate synthetase, ubiquitin, glutamine synthetase and connective tissue growth factor genes of human, respectively. They also have similar nucleotide sequence homologues with those of another species. These partial bioreactive genes elucidated in this study may support to studies of phylogenetic analysis based on evolutionary relationships between shark and other species.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.819-829
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• 2010

By referring thirty-seven previous studies on manual material handling (MMH), this paper analyzed guidelines and main factors of one-handed tasks. The previous studies concerned main factors of distance, weight, frequency, posture, gender, age, training, direction of force, height of the force exerted, and object shape and size. Based on these factors, the criteria used to understand one-handed tasks were objective measures of maximum strength, reaction force, etc., psychophysical measures of maximum acceptable frequency and weight, etc., and physiological measures of oxygen uptake, heart rate, electromyography, etc. An allowance threshold model regarding quantitative and objective fatigue and workload would be suggested for future research. This study would be expected that it serve to establish and Korean recommendations of one-handed tasks.

• BMB Reports
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• v.34 no.2
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• pp.95-101
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• 2001

Tissue transglutaminase (TGII, $G{\alpha}h$) belongs to a family of enzymes which catalyze post-translational modification of proteins by forming isopeptides via $Ca^{2+}$-dependent reaction. Although TGII-mediated formation of isopeptides has been implicated to play a role in a variety of cellular processes, the physiological function of TGII remains unclear. In addition to this Tease activity, TGII is a guanosine triphosphatase (GTPase) which binds and hydrolyzes GTP It is now well recognized that the GTPase action of TGII regulates a receptor-mediated transmembrane signaling, functioning as a signal transducer of the receptor. This TGII function signifies that TGII is a new class of GTP-binding regulatory protein (G-protein) that differs from "Classical" heterotrimeric G-proteins. Regulation of enzyme is an important biological process for maintaining cell integrity. This review summarizes the recent development in regulation of TGII that may help for the better understanding of this unique enzyme. Since activation and inactivation of GTPase of TGII are similar to the heterotrimeric G-proteins, the regulation of heterotrimeric G-protein in the transmembrane signaling is also discussed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.554-559
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• 2005

It seems to be dangerous to use a cellular phone while driving since it increases driver's mental stress and makes driver's reaction time slow. This study is to investigate driver's psycho-physiological responses on mobile telephoning while driving. Among the three experimental factors (mobile-phone types, message IODs over mobile-phone, road types), only the message IODs over mobile-phone changed R-R intervals of electrocardiograph significantly. This result suggests that the regulations on the mobile telephoning while driving be changed.

• Korean Journal of Microbiology
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• v.12 no.1
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• pp.37-51
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• 1974

Three strains which accumulated large quantities of L-hlutamic acid as the chief product of metabolism in the presence of glucose and inorhanic ammonium salt under the aerobic condition sere newly isolated. These strains have the general characters as follows: Gram-positive, short fod-shaped, non-sporulating, non-motile, and facultative anaerobe. A change of cell shates was not almost observed in their life cycles and neither a phenomenon of cell-elongation nor a pleomorphism was recognized in any cases. Together with rigid stability in Gram-stain, these characters as above indicated evidences that newly isolates would belong to genus Brevibacterium clearly differentiated from genus Corynebacterium. At the same time the newly isolates, in addition to nutritional requirement of biotin and thiamine, showed the distinctive character of requirement of special amino acid such as histidine or cysteine for their considerable growth. These physiological characters including nitrates reduction, reaction on milk, and slow formation of acid from sugar also were useful in confirming that these bacteria would be Brevibacterium ammoniagenes.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1505-1512
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• 2005

Bile salt deconjugation is the most biologically significant reaction among the bacterial alterations of bile acids in the gastrointestinal tract of human and animal. The responsible enzyme, bile salt hydrolase (BSH), catalyzes the hydrolysis of glycineand/or taurine-conjugated bile salts into amino acid residues and deconjugated bile acids. Herein we review current knowledge on the distribution of BSH activity among various microorganisms with respect to their biochemical and molecular characteristics. The proposed physiological impact of BSH activity on the host animal as well as on the BSH-producing bacterial cells is discussed. BSH activity of the probiotic strains is examined on the basis of BSH hypothesis, which was proposed to explain cholesterol-lowering effects of probiotics. Finally, the potential applications of BSH research are briefly discussed.