• Nutrition Research and Practice
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• v.11 no.4
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• pp.275-280
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• 2017

BACKGROUND/OBJECTIVES: Re-epithelialization has an important role in skin wound healing. Astaxanthin (ASX), a carotenoid found in crustaceans including shrimp, crab, and salmon, has been widely used for skin protection. Therefore, we investigated the effects of ASX on proliferation and migration of human skin keratinocyte cells and explored the mechanism associated with that migration. MATERIAL/METHOD: HaCaT keratinocyte cells were exposed to $0.25-1{\mu}g/mL$ of ASX. Proliferation of keratinocytes was analyzed by using MTT assays and flow cytometry. Keratinocyte migration was determined by using a scratch wound-healing assay. A mechanism for regulation of migration was explored via immunocytochemistry and western blot analysis. RESULTS: Our results suggest that ASX produces no significant toxicity in human keratinocyte cells. Cell-cycle analysis on ASX-treated keratinocytes demonstrated a significant increase in keratinocyte cell proliferation at the S phase. In addition, ASX increased keratinocyte motility across the wound space in a time-dependent manner. The mechanism by which ASX increased keratinocyte migration was associated with induction of filopodia and formation of lamellipodia, as well as with increased Cdc42 and Rac1 activation and decreased RhoA activation. CONCLUSIONS: ASX stimulates the migration of keratinocytes through Cdc42, Rac1 activation and RhoA inhibition. ASX has a positive role in the re-epithelialization of wounds. Our results may encourage further in vivo and clinical study into the development of ASX as a potential agent for wound repair.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.582-586
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• 1999

The processing conditions for producing and edible alginate film from sea tangle were investigated by measuring water vapor permeability (WVP), tensile properties and colors of film. The alginates were extracted with $3\%$ sodium carbonate ($Na_2CO_3$) solution for 5 hrs, and the alginate films were prepared with extracted sodium alginates, D-gluconic acid lactone, $CaCO_3$ and various plasticizers, As the concentration of alginate in making the film was increased, the WVP and elongation of the film were decreased and the tensile strength was increased. The higher amount of plasticizer showed the higher WVP and elongation, and the order of various plasticizers in increasing the WVP and elongation of the film was glycerol, polyethylene glycol, and sorbitol. The addition of sorbitol in the film showed the highest value (89.57) in lightness of Hunter color system and the film added polyethylene glycol had the highest values (-1,12 and 11.4) in redness and yellowness.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.232-235
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• 1997

This study was investigated to determine antimutagenic effects of enzymatic browning reaction products (PEBRPs) obtained by reaction of polyphenol compouns with oxidase extracted from potato. Catechol (Ca) PEBRPs showed the strongeest inhibitor effects with 90% inhibition on benzo-($\alpha$)-pyrene(B($\alpha$)P) induced mutagenesis in Salmonella typhimurium TA98, but he least with40% inhibition on the 2-aminofluorene (2-AF) induced mutagenesis in TA98. The strong antimutagenic activities with 80% inhibition were observed in the presence of 100$\mu\textrm{g}$/plate of hydroquinone(HQ)-PEBRP on the B($\alpha$)P or 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole(Trp-P-1) induced mutagenesis in TA98, whereas HQ-PEBRP showed the least antimutagenic effect on 2-AF-induced mutagenesis. The addition of 100$\mu\textrm{g}$ hydroxyhydroquinone(HHQ)-PEBRP to the plate led to approximately 82% inhibitory effects on 2-AF or Trp-P-1 induced mutagenesis in TA98, whereas the least antimutagenicity was obsrved in the4-nitroquinoline-1-oxide(4-NQO) induced mutagenesis in the presence of 100$\mu\textrm{g}$/plate of HHQ-PEBRP. More than 80% inhibiton were observed in the presence of 200$\mu\textrm{g}$/plate of Pyrogalol(Py)-PEBRP on the B($\alpha$)P or Trp-P-1 induced mutagenesis in TA98, but the least with 38% inhibition on 4-NQO induced mutagenesis in TA98. The results indicate that enzymatic browing reaction products of potato have a strong modulatory effect on mutagen induced mutagenesis in TA98.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.31-39
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• 2012

This study aims to suggest a methodology of localizing and calibrating parameters, such as acceleration, deceleration, and lane changing which are the basis of car following model in interrupted traffic flow to overcome the limitation of origin and destination based transportation simulation and to verify the application of activity-based model for use in Korean roadway condition in a large scale area or a city. Especially, we figured out that a proper cell size reflecting Korean traffic conditions is 1.0m rather than 7.5m which is default size and a methodology of tracking vehicle behavior characteristics through tracking vehicle ID is suggested on this study. In addition, vehicle running characteristics in real interrupted traffic flow is analyzed through subdividing vehicle types and updating vehicle type ratio. For verification of suggested model, some portion of Dalgubyul-ro in the Daegu city is tested, and the possibility of realization of interrupted traffic flow in simulation is studied.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.29-45
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• 2016

Chemical composition of fine sediments from Jeongdongjin area are analyzed with XRF method. The results are compared with previously reported results of sandstones of the nearest Simgok port. The weight percentage of $SiO_2$ of the samples are far lower than those of sandstones of Simgok. It is supposed to be happened by the selective elution of $SiO_2$ from the sediment layer of coastal terrace, as there's no evidence of selective input or precipitation of other elements from outside. As a result of chemical alteration or weathering of sediment at coastal terrace, weight percentage of $Al_2O_3$ and $Fe_2O_3$ of samples show far higher values than those of Simgok sandstone. In addition, the relative portion of $Al_2O_3$ and $Fe_2O_3$ are decreased to upward within outcrop of terrace sediment layers. It could be caused by the chemical weathering progress with time. However Chemical Index of alteration(CIA) of sediment samples are no larger than 90 and it could be interpreted that it would take over 100ka for total weathering of sediment in this area. Meanwhile the ratio of $SiO_2/Al2O_3$ of terrace sediment showed as 3.48~6.0 and it is far smaller than those of Simgok sandstones(23.9~49.0). The ratio of $SiO_2/Fe_2O_3$ of terrace sediment(19.19~55.85) showed similar pattern with $SiO_2/Al2O_3$ (Simgok sanstone: 119.6~601.8). The ratios have a weak trend of decreasing upwards within the outcrop, there also a huge difference in value among the samples. Chemical composition of reddish brown and gray layers which suspected as the result of psudogleization reveals that reddish brown parts have higher concentration of $Fe_2O_3$ than other parts, while there was no significant difference in concentration of $Al_2O_3$ and CaO.

• Polymer(Korea)
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• v.34 no.4
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• pp.326-332
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• 2010

Nanocomposite films were prepared by blending poly(amic acid)(PAA), poly(o-hydroxyamide)( PHA) and organically modified montmorillonite (OMMT) that has a layered structure. XRD, SEM and TEM were used to study the morphology of PAA/PHA nanocomposites, and DMA, TGA, UTM, LOI and PCFC techniques were used to characterize the mechanical and thermal properties, and flame retardancy of the nanocomposites. TEM images revealed that OMMT layers were well dispersed in the PAA/PHA matrix and showed exfoliation and intercalation behavior. The addition of 3 wt% OMMT to the PAA/PHA blend increased the initial modulus of PAA/ PHA blend to 3.68 GPa that was ca. 48% higher than that of the control PAA/PHA blend. Above 4 wt%, however, both the initial modulus and the tensile strength were found to decrease, which might be due to the aggregation of OMMT in PAA/PHA matrix. When the OMMT content was below 3 wt%, the thermal stability and flame retardancy of the PAA/PHA nanocomposites increased with increasing OMMT content.

• The Journal of the Petrological Society of Korea
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• v.1 no.2
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• pp.124-131
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• 1992

The Sm-Nd isotopic data on the Precambrian gneisses from Gyeonggi and Sobaegsan Massifs are presented and the crustal evolution of the Precambrian basements of the Korean Peninsula is discussed with that of the Precambrian basements of East Asia. Sm-Nd isochron plots on whole rock samples from Sobaegsan Massif give the following ages and initial Nd values. Biotite gneisses: $1.05{\pm}0.07$ Ga with ${\varepsilon}_{Nd}$ (1.05 Ga)= $-12.5{\pm}0.4$ ($2{\sigma}$); granitic gneisses: $1.70{\pm}0.59$ Ga with ${\varepsilon}_{Nd}$ (1.70 Ga)=$+9.5{\pm}6$($2{\sigma}$). Initial Nd isotopic evolution diagram for the Precambrian orthogneisses from Sobaegsan Massif with the Precambrian orthogneisses in northeastern China and Japan reveals the existence of early Archean depleted-mantle in east Asia and suggests the prevalence of nearly common or similar source accountable for these Precambrian gneisses. Such a common source is shown to have LREE-enriched feature and to have been formed from the depleted-mantle in the late Archean of ca. 2.6 Ga. On the other hand, the Sobaegsan granitic gneisses in Korea are concluded to have different evolution history. Our Sm-Nd study clearly discloses that some Precambrian orthogneisses from Korea had evolved from the protolith having the similar or same geochemical properties with the Precambrian orthogneisses in Japan and northeastern China. In addition, crustal formation age of Gyeonggi Massif in southern Korea may be different from that of Sobaegasn Massif.

• Animal Bioscience
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• v.34 no.12
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• pp.1912-1920
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• 2021

Objective: This study investigated the effects of 5-aminolevulinic acid (5-ALA) on the motility parameters, mitochondrial membrane depolarization, and ATP levels in chicken sperm. Methods: The pooled semen from Barred Plymouth Rock males was used. In the first experiment, the semen was diluted 4-times with phosphate-buffered saline (PBS (-)) containing various concentrations (0, 0.01, 0.05, and 0.1 mM) of 5-ALA, and then the sperm motility parameters after incubation were evaluated by computer-assisted sperm analysis (CASA). In the second experiment, the semen was diluted 4-times with PBS (-) containing 0.05 mM 5-ALA, and then sperm mitochondrial membrane depolarization and ATP levels after 1.5 h of incubation were analyzed with the MitoPT^® JC-1 Assay and ATP Assay kits, respectively. In the third experiment, the semen was removed from the seminal plasma and resuspended with the mediums of PBS (-), PBS (-) supplemented with CaCl₂ and MgCl₂ (PBS (+)) + 5-ALA, PBS (+) + caffeine, and PBS (+) + caffeine + 5-ALA. Then, the sperm motility parameters after incubation were evaluated by CASA. In the last experiment, the semen was treated with the mediums of PBS (-), PBS (-) + 5-ALA, 5.7% glucose, 5.7% glucose + 5-ALA after removing the seminal plasma, and then the sperm motility parameters were evaluated by CASA. Results: The addition of 0.05 mM 5-ALA significantly increased the chicken sperm motility, progressive motility, linearity, average path velocity, curvilinear velocity, straight-line velocity, and the wobble. The sperm mitochondrial membrane depolarization was also increased by the 5-ALA treatment. The 5-ALA treatment decreased the sperm ATP levels. Both the caffeine treatment and glucose treatment decreased the sperm motility during incubation period. Conclusion: 5-ALA might increase sperm mitochondrial membrane depolarization to utilize the ATP for enhancing sperm movement.

• Atmosphere
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• v.29 no.2
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• pp.131-147
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• 2019

On the urban scale, Micro-climate analysis models for urban scale have been developed to investigate the atmospheric characteristics in urban surface in detail and to predict the micro-climate change due to the changes in urban structure. BioCAS (Biometeorological Climate Impact Assessment System) is a system that combines such analysis models and has been implemented internally in the Korea Meteorological Administration. One of role in this system is the analysis of the health impact by heat waves in urban area. In this study, the vegetation cooling models A and B were developed and linked with BioCAS and evaluated by the temperature drop at the vegetation areas during ten selected heat-wave days. Smaller prediction errors were found as a result of applying the vegetation cooling models to the heat-wave days. In addition, it was found that the effects of the vegetation cooling models produced different results according to the distribution of vegetation area in land cover near each observation site - the improvement of the model performance on temperature analysis was different according to land use at each location. The model A was better fitted where the surrounding vegetation ratio was 50% or more, whereas the model B was better where the vegetation ratio was less than 50% (higher building and impervious areas). Through this study, it should be possible to select an appropriate vegetation cooling model according to its fraction coverage so that the temperature analysis around built-up areas would be improved.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.2
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• pp.121-130
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• 2019

Glutamate toxicity-mediated mitochondrial dysfunction and neuronal cell death are involved in the pathogenesis of several neurodegenerative diseases as well as acute brain ischemia/stroke. In this study, we investigated the neuroprotective mechanism of dieckol (DEK), one of the phlorotannins isolated from the marine brown alga Ecklonia cava, against glutamate toxicity. Primary cortical neurons ($100{\mu}M$, 24 h) and HT22 neurons (5 mM, 12 h) were stimulated with glutamate to induce glutamate toxic condition. The results demonstrated that DEK treatment significantly increased cell viability in a dose-dependent manner ($1-50{\mu}M$) and recovered morphological deterioration in glutamate-stimulated neurons. In addition, DEK strongly attenuated intracellular reactive oxygen species (ROS) levels, mitochondrial overload of $Ca^{2+}$ and ROS, mitochondrial membrane potential (${\Delta}{\Psi}_m$) disruption, adenine triphosphate depletion. DEK showed free radical scavenging activity in the cell-free system. Furthermore, DEK enhanced protein expression of heme oxygenase-1 (HO-1), an important anti-oxidant enzyme, via the nuclear translocation of nuclear factor-like 2 (Nrf2). Taken together, we conclude that DEK exerts neuroprotective activities against glutamate toxicity through its direct free radical scavenging property and the Nrf-2/HO-1 pathway activation.