• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.30 no.1
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• pp.106-117
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• 2017

Objectives : 갈근의 피부 보습 효과에 대해 알아보기 위해 본 연구를 진행하였다. Methods : HaCaT 세포주에 갈근 에탄올 추출물을 처리하였고 Retinoic Acid $1{\mu}M$을 양성 대조군으로 사용하였다. MTT assay, RT-PCR, Hyaluronidase enzyme assay, HA-ELISA kit를 통해 Hyaluronic Acid의 합성량, Hyaluronidase 저해율, 농도별 Hyaluronic Acid 생성량을 측정하였다. 더불어 실제로 피부에 도포 시 보습 능력이 있는지 등에 대하여 확인하였다. Results : 갈근 에탄올 추출물은 뚜렷한 세포독성을 나타내지는 않았고, 모든 농도에서 Hyaluronic Acid 합성과 관련된 hyaluronic acid synthase 2 유전자가 발현되었고, 실제로 Hyaluronic Acid가 생성되는 것을 확인하였다. 임상 효능 평가에서는 유의성 있는 결과를 얻을 수는 없었다. Conclusions : 갈근을 한방 외용제로 사용할 때 유의성 있는 효과를 나타낼 수 있을 것으로 기대할 수 있으며, 실험 결과를 토대로 갈근의 최적 사용 농도를 결정하기 위한 추가적 연구와 복합 처방으로 사용했을 경우에 대한 연구가 추가적으로 진행된다면 한방 외용제로서 잠재적인 가치가 있을 것으로 사료된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.397-400
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• 2008

Traditional propellants which have a hypergolic characteristic have a high performance but also have disadvantages of toxicity and complex handling requirement. In order to replace these propellants, one of the alternatives is hydrogen peroxide which generates high temperature oxygen and water vapor after catalytic reaction. In this paper, autoignition characteristics of kerosene by decomposed hydrogen peroxide were investigated to perform fundamental research for designing a thruster using hydrogen peroxide and kerosene propellants. Contraction ratio, whether flame holder exists or not, and feeding pressure of propellants were selected as variables. From the experiments for different mixture ratio, we confirmed the ignition stability is strongly affected by a feeding pressure of propellants.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.403-412
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• 2016

The tight junction, one of Intercellular junctions, performs a variety of biological functions by bonding adjacent cells, including the barrier function to control the movement of the electrolyte and water. Recent studies have revealed that unusual expression of tight junction-related genes have been shown to be related in cancer development and progression. Recently, there are many reports that control of tight junction proteins expression is closely related to the skin moisture. In this study, we are focusing on the regulating mechanism of tight junction-associated genes by the steviol and its derivatives. Steviol, used as a sweetner, is known to chemical compound isolated from stevia plant. The MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was carried out in HaCaT cells (human keratinocyte cell line) in order to determine the cytotoxicity. As a result, while steviol showing cytotoxicity from $250{\mu}M$, steviol derivatives are not cytotoxic more than $250{\mu}M$ concentration. We have observed a change in the tight junction protein via quantitative real-time PCR. Claudin 8 among tight junction proteins is only significantly reduced up to 30% in the presence of steviol. In addition, cell migration was inhibited by steviol, not by stevioside and rebaudioside. Finally, we could observe that steviol, not stevioside and rebaudioside, is able to increase the skin barrier permeability through the transepithelial electric resistance (TEER) measurements. These results suggest that the steviol and its derivatives are specifically acts on the tight junction related gene expression, but steviol derivatives are more suitable as a cosmetic material.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.257-260
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• 2012

Sundried salt was recently registered in food category in Korea in 2008, and food hygiene regulation only applied to several heavy metals and a few inorganic ions. In this report, we investigated the residual amounts of tricyclazole, a highly concerned contaminant from agricultural activity, and estimated their daily intake and hazard index. All 60 sundried salts were collected by region, and qualitatively and quantitatively were analyzed with GC-NPD. In this investigation, only three samples were confirmed the residual tricyclazole in sundried salts. Their maximum residue was $1.7{\mu}g/kg$, and their estimated average daily intake was $2.40{\times}10^{-8}{\sim}6.22{\times}10^{-8}mg/kg-day$. From these results, HI of tricyclazole for sundried salts was $7.53{\times}10^{-7}{\sim}2.07{\times}10^{-6}$ for Koreans, and the values were not considered as serious risk issues currently.

• Journal of Life Science
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• v.25 no.2
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• pp.214-222
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• 2015

Aeromonas hydrophila is the most common water fish pathogen and cause diseases such as hemorrhagic septicemia, dropsy, ulceration and asymptomatic septicemia. A. hydrophila secretes many extracellular products (ECPs) which contribute to effective infection, wide distribution and great adaptability to environmental changes. Crude ECPs of A. hydrophila CK257, a strain used in this study, exhibits a toxic activity to the animals including mouse, rabbit and fish. Toxic symptoms were indicated by tissue damage and skin injuries in animal. When ECPs were subcutaneously injected to animals, skin damages were observed, appearing like necrosis. Preliminary research demonstrated that the active factors are protein component. The crude ECPs were collected after ammonium sulfate precipitation of cell-free culture supernatant. ECPs were fractionated with the use gel filtration chromatography. Five ECP fractions were obtained, of which one fraction was found to be toxic to goldfish. MALDI-TOF analyses provided two interesting proteases called M35 and M28. Both M35 and M28 are known as metalloprotease. Accordingly, proteins in an active fraction exhibited caseinolytic activity. These proteins were difference of caseinolytic activity under different metallic ions. Also active fraction has elastolytic activity. These results suggested that peptidase M28 and M35 may be a candidate factor for tissue necrosis activity about infection with A. hydrophila.

• Journal of Life Science
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• v.34 no.4
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• pp.236-244
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• 2024

Melanin is a natural pigment found in most plants and animals, and it is involved in determining the color of the skin and hair. Melanogenesis is a reactive occurrence in melanocytes aiming to protect the skin from external stimuli, such as ultraviolet rays. Tyrosine is involved in the biosynthesis of the substrate tyrosine into melanin. However, melanin overproduction can lead to skin diseases, such as melasma, blotching, hyperpigmentation, and skin cancer. Although many studies have been conducted on whitening substances, such as kojic acid and arbutin, some countries have banned or refrained from using them due to their side effects. Therefore, this study assessed the potential of horseradish (HR) as a new whitening agent in cosmetic products. For efficient extraction, subcritical water extraction was conducted. The results showed that the horseradish subcritical water 200℃ (SW 200) extract showed high DPPH radical scavenging ability, total phenolic contents (TPC), inhibiting tyrosinase activity and inhibiting melanin production of B16-F10 melanoma cell lines. To investigate its cytotoxicity to the B16-F10 melanoma cell lines, MTT reduction assay and morphological changes were observed. No cytotoxicity was found in horseradish methanol extract and SW 200. In conclusion, this research suggests the possibility of horseradish subcritical water may be useful as a natural whitening ingredient to be used in cosmetic products.

• Journal of Environmental Science International
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• v.6 no.6
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• pp.659-670
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• 1997

Vehicle occupant exposure to volatile organic compounds (VOCs) has been a subject of concern In recent years because of higher levels of VOCs Inside vehicles as compared to the surrounding ambient atmosphere and because of the toxicity of VOCs. The effectiveness of two commercial ACDs for the removal of selected VOCs in the interior of automobiles was evaluated on 115 commutes throegh urban (Taegu) commutes by two cars and 9 idles. The idling and commuting studios conducted under four different driving conditions showed that the ho commercial ACDs were not effective for the removal of VOCs in the interior of vehicles. The concentrations of all target VOCs except benzene were significantly higher (p<0.05) in the interior of older car than of newer cu. The mean levels of benzene and toluene measured in thins study were well excess of earlier other studios In the United States, besides Los Angeles with which was comparable. It was reported that the in-vehicle exposure to benzene and corresponding upper-bound cancel risk were about 8 times higher than those for outdoor environment, while they were about half of those from Indoor environment.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.239-254
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• 2004

It has been debating about conducting and interpretating of 2-year rodent carcinogenicity bioassay. Although some criticisms arising in usefulness, it has been still known that long-term carcinogenicity studies using rodents would be the only assay system to predict any possible human risks, which would not be replaced. Both regulatory agencies and academies have developed some assay models, however, there have been controversy whether those study designs and interpretations are based on sound scientific rationale and validated data. Such kinds of issues including choice of species/strain, dose level selection, duration of study, number of animals per group, historical control data, monitoring parameters, terminal investigations, peer review, statistics, alternative assay models, interpretation of neoplastic lesions, and risk assessments, were reviewed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.47-54
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• 2018

Concrete undergoes various deterioration on surface. Impregnant with silicate is usually applied to concrete surface and forms insoluble hydrates, which can provide many engineering advantages. In the work, concrete impregnated with colloidal silicate is used for durability enhancement in surface and self-clearing performance is evaluated with photocatalyst-$TiO_2$ spraying. For the work, various tests are performed both for strength evaluation and durability evaluation such as absorption ratio, drying shrinkage, chloride penetration, sulfate resistance, and freezing/ thawing action. Furthermore, removal and self-clearing performance are evaluated with Acetaldehyde decomposition and Methylene blue decolorization. Through silicate impregnation and photocatalyst spraying, the impregnated concrete can have not only durability enhance but also self-clearing performance.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.116-122
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• 2017

Basic dyes such as malachite green and methylene blue have been used as disinfectants to control water fungal infections since the 1930s. However, after succeeding reports of carcinogenicity and bioaccumulation of the dye, their use was forbidden in lieu of public health. This study undertook to evaluate the therapeutic effect of sulfur solution processed by effective microorganisms (EM-PSS) against Saprolegnia parasitica infection, and its safety in fish. In vitro antifungal evaluation of EM-PSS inhibited the growth of S. parasitica mycelia at concentrations of 50 ppm or higher. The acute toxicity test of EM-PSS to the mud fish (Misgurnus mizolepis) measured a no effect concentration (NOEC) at 100 ppm, the lowest effect concentration (LOEC) at 125 ppm, and the half-lethal concentration ($LC_{50}$) at 125 ppm in juvenile and 250 ppm in the immature stage. In addition, the ecotoxicity test of EM-PSS using Daphnia magna inhibited swimming of D. magna at concentrations of 100 ppm or less. Lastly, the EM-PSS prevented infection of S. parasitica to mud fish, at concentrations of 50 ppm. Furthermore, at 100 ppm concentration, the EM-PSS showed no acute toxicity on mud fish, nor any eco-toxic effects on D. magnano. Therefore, we conclude that carcinogenic disinfectants such as malachite green and methylene blue could be replaced by EM-PSS to remove S. parasitica in mud fish farming, and might be a potential eco-friendly disinfectant in aquaculture.