• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.149-152
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• 2009

Recent trends show an increased usage of 'colored concrete', a inorganic pigmented concrete mix, especially in smalll to large scale buildings. However, due to lack of varieties, current usage of colored concrete is limited to the one or two simple color of the time in construction work. so, this study is to investigate the properties of concrete adding temperature reactive pigment. The results of the experiment, the basic material characteristics of concrete such as of compressive strength and slump is affected by the amount rate of adding the temperature reactive pigment. And, it showed the excellent color expression and changing with temperature reactive pigment.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.437-438
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• 2009

This study is to investigae the properties of mortar with temperature reactive pigment. The results of the experiment, the compression strength of mortar increases by the rate of chemical admixture and temperature reactive pigment. And it is also excellent color expression with the use of chemical admixture.

• BMB Reports
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• v.56 no.2
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• pp.84-89
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• 2023

The implications of nutrient starvation due to aging on the degeneration of the retinal pigment epithelium (RPE) is yet to be fully explored. We examined the involvement of AMPK activation in mitochondrial homeostasis and its relationship with the maintenance of a healthy mitochondrial population and epithelial characteristics of RPE cells under nutrient starvation. Nutrient starvation induced mitochondrial senescence, which led to the accumulation of reactive oxygen species (ROS) in RPE cells. As nutrient starvation persisted, RPE cells underwent pathological epithelial-mesenchymal transition (EMT) via the upregulation of TWIST1, a transcription regulator which is activated by ROS-induced NF-κB signaling. Enhanced activation of AMPK with metformin decelerated mitochondrial senescence and EMT progression through mitochondrial biogenesis, primed by activation of PGC1-α. Thus, by facilitating mitochondrial biogenesis, AMPK protects RPE cells from the loss of epithelial integrity due to the accumulation of ROS in senescent mitochondria under nutrient starvation.

• ALGAE
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• v.29 no.4
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• pp.311-319
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• 2014

The biocide sodium hypochlorite (NaOCl) is widely used for controlling algal growth, and this application can be extended to marine environments as well. This study evaluates the biocidal efficiency and cellular toxicity of NaOCl on the harmful dinoflagellate Cochlodinium polykrikoides, with emphasis on pigment production and antioxidant enzyme activity. The test organism showed dose-dependent decrease in growth rate on exposure to NaOCl, and the 72 h $EC_{50}$ was measured to be $0.584mg\;L^{-1}$. NaOCl significantly decreased pigment levels and chlorophyll autofluorescence intensity, indicating possible detrimental effects on the photosystem of C. polykrikoides. Moreover, it significantly increased the activities of antioxidant enzymes, suggesting the production of reactive oxygen species in the cells. These data indicate that NaOCl exerted deleterious effects on the photosynthetic machinery and induced oxidative damage in the dinoflagellate and this biocide could be effectively used for the control of algal blooms.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.210-219
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• 2021

It was intended to conduct basic research to reduce development lead time and cost consumed in DTP process technology development. For the simulation of HTPE fabric, virtual engineering software was used to generate fiber model, yarn model, fabric model, and finite element model of HTPE fiber. The purpose of this study is to analyze the correlation and error rate between the stiffness numerical analysis results according to the direct DTP process parameters using reactive dyes in the generated finite element model and the stiffness measurements of the actual sample ac- cording to ASTM D1388. And, after dyeing the HTPE plain fabric according to the direct DTP process parameters, we want to analyze the dyeability of the HTPE fabric fabrics according to the direct DTP process parameters through the color fastness analysis. When looking at the results of the analysis of the finite element model, a higher value was shown when the distance between the nozzle and the fabric was 3mm than when the distance was 10mm. When the distance between the nozzle and the fabric was 10mm and 7mm, the reactive dye did not penetrate sufficiently, resulting in poor clarity when viewed with the naked eye.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2018.10a
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• pp.231-231
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• 2018

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.6
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• pp.322-330
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• 2003

The unicellular green alga Haematococcus pluvialis has recently attracted great inter-est due to its large amounts of ketocarotenoid astaxanthin, 3,3'-dihydroxy-${\beta}$,${\beta}$-carotene-4,4'-dione, widely used commercially as a source of pigment for aquaculture. In the life cycle of H. pluvialis, astaxanthin biosynthesis is associated with a remarkable morphological change from green motile vegetative cells into red immotile cyst cells as the resting stage. In recent years we have studied this morphological process from two aspects: defining conditions governing astaxanthin biosynthesis and questioning the possible function of astaxanthin in protecting algal cells against environmental stress. Astaxanthin accumulation in cysts was induced by a variety of environmental conditions of oxidative stress caused by reactive oxygen species, intense light, drought, high salinity, and high temperature. In the adaptation to stress, abscisic acid induced by reactive oxygen species, would function as a hormone in algal morphogenesis from veget ative to cyst cells. Furthermore, measurements of both in vitro and in vivo antioxidative activities of astaxanthin clearly demonstrated that tolerance to excessive reactive oxygen species is greater in astaxanthin-rich cysts than in astaxanthin-poor cysts or astaxanthin-less vegetative cells. Therefore, reactive oxygen species are involved in the regulation of both algal morph O-genesis and carotenogenesis, and the accumulated astaxanthin in cysts can function as a protective agent against oxidative stress damage. In this study, the physiological roles of astaxanthin in stress response and cell protection are reviewed.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.161.2-161.2
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• 2015

Melanin is a black pigment, responsible for hair and skin color. In order to find the melanin stimulatory technique which prove useful for a gray and a white hair-preventive agent or tanning agent, we developed atmospheric pressure plasma jet (APPJ) and tested for tyrosinase activity and melanin production in melanoma (B16F10) cells in vitro. We found plasma dose dependent increase in melanin production. To explore the contributing mechanism in melanin synthesis, intracellular reactive oxygen species (ROS) and MAP kinase signaling pathways were studied. Furthermore, the development of plasma technology for melanin synthesis and planning for in-vivo future studies will be discussed.

• Korean Journal of Pharmacognosy
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• v.51 no.2
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• pp.131-138
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• 2020

Ultraviolet (UV)-induced damage plays a major role in ocular diseases, such as cataracts and retinal degeneration. UV irradiation can generate free radicals including reactive oxygen species (ROS), which are known to cause lipid peroxidation of cellular membranes. It has also been shown that UV can damage DNA directly and induce apoptosis. Rhynchosia volubilis Loureiro (the small black bean or yak-kong, RV) and Beta bulgaris (beet, BB) are used as health supplements. In this study, we explored the protective effects of RV and BB against UVA-induced damage in human pigment epithelial (ARPE-19) cells and in mice. RV and BB mixture and their effective constituents (cyanidin, delphidin, petunidin glycosides) improved cell viability and suppressed intracelluar ROS generation. Phosphorylation of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), Erk1/2 was analyzed by immunoblotting. RV and BB mixture inhibited UVA-induced phosphorylation of p38 MAPK, JNK, Erk1/2 in APRE-19 cells. RV and BB treatment also showed protective effects on ocular damage in UVA-irradiated mice by increasing the levels of endogenous antioxidants such as superoxide dismutase and glutathione. RV and BB have the potential to be used in a range of ocular diseases and conditions, based on in vitro and in vivo study.

• BMB Reports
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• v.53 no.5
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• pp.284-289
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• 2020

Tamoxifen, a nonsteroidal estrogen receptor (ER) antagonist, is used routinely as a chemotherapeutic agent for ER-positive breast cancer. However, it is also causes side effects, including retinotoxicity. The retinal pigment epithelium (RPE) has been recognized as the primary target of tamoxifen-induced retinotoxicity. The RPE plays an essential physiological role in the normal functioning of the retina. Nonetheless, potential therapeutic agents to prevent tamoxifen-induced retinotoxicity in breast cancer patients have not been investigated. Here, we evaluated the action mechanisms of sulfasalazine against tamoxifen-induced RPE cell death. Tamoxifen induced reactive oxygen species (ROS)-mediated autophagic cell death and caspase-1-mediated pyroptosis in RPE cells. However, sulfasalazine reduced tamoxifen-induced total ROS and ROS-mediated autophagic RPE cell death. Also, mRNA levels of tamoxifen-induced pyroptosis-related genes, IL-1β, NLRP3, and procaspase-1, also decreased in the presence of sulfasalazine in RPE cells. Additionally, the mRNA levels of tamoxifen-induced AMD-related genes, such as complement factor I (CFI), complement factor H (CFH), apolipoprotein E (APOE), apolipoprotein J (APOJ), toll-like receptor 2 (TLR2) and toll-like receptor 4 (TLR4), were downregulated in RPE cells. Together, these data provide novel insight into the therapeutic effects of sulfasalazine against tamoxifen-induced RPE cell death.