• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1697-1699
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• 1996

EPDM compound can be cured with either the sulfur and peroxide based systems. In this study, heat resistance and weatherability of EPDM compounds depending on curing systems were investigated. The test results showed that the peroxide-cured EPDM was more resistant to heat ageing and UV photo-degradation than the sulfur-cured EPDM and it is due to C-C bond is more stable than C-S, S-S bond.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.409.2-409.2
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• 2002

Retinol is widely used for skin care. the improvement of the appearance of aging. photo-damaged or oxidatively stressed skin. and especially for the improvement of the appearance of wrinkled skin. Retinol. however. is extremely sensitive to atmospheric oxygen. and easily decomposed by exposure to air. Retinol is commonly formulated as the ointments or creams for cosmetic preparations. (omitted)

• Journal of Ginseng Research
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• 제48권4호
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• pp.435-436
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• 2024

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.235-237
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• 2007

In this paper, fabrication of Sn-3.0Ag-0.5Cu solder bumping having accurate composition and behavior of intermetallic compounds(IMCs) growth at interface between Sn-Ag-Cu bumps and Cu substrate were studied. The ternary alloy of the Sn-3.0Ag-0.5Cu solder was made by two binary(Sn-Cu, Sn-Ag) electroplating on Cu pad. For the manufacturing of the micro-bumps, photo-lithography and reflow process were carried out. After reflow process, the micro-bumps were aged at $150^{\circ}C$ during 1 hr to 500 hrs to observe behavior of IMCs growth at interface. As a different of Cu contents(0.5 or 2wt%) at Sn-Cu layer, behavior of IMCs was estimated. The interface were observed by FE-SEM and TEM for estimating of their each IMCs volume ratio and crystallographic-structure, respectively. From the results, it was found that the thickness of $Cu_3Sn$ layer formed at Sn-2.0Cu was thinner than the thickness of that layer be formed Sn-0.5Cu. After aging treatment $Cu_3Sn$ was formed at Sn-0.5Cu layer far thinner.

• Toxicological Research
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• 제35권4호
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• pp.353-359
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• 2019

The purpose of this study was to investigate the effect of $7-MEGA^{TM}$ 500 on the improvement of skin aging in an UVB-induced photo-aging model of hairless mice. The dorsal skin of hairless mice was exposed to UVB three times a week for 12 weeks to induce skin wrinkle. After inducing the wrinkle, $7-MEGA^{TM}$ 500 was orally administered once a day for 4 weeks. Skin thickness, skin barrier function, and wrinkle indicators were improved by treatment with $7-MEGA^{TM}$ 500. Both gene and protein expression levels of MMP-3 and c-Jun in skin were significantly decreased by $7-MEGA^{TM}$ 500. Therefore, the intake of $7-MEGA^{TM}$ 500 is thought to have a positive effect on the improvement of skin aging, although further studies are needed.

• 한국대기환경학회지
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• 제27권5호
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• pp.534-544
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• 2011

The secondary aerosol forming potential of ambient air was first measured with the Potential Aerosol Mass(PAM) chamber at Gosan supersite on Jeju island from October 22 to November 5, 2010. PAM chamber is a small flowthrough photo-oxidation chamber with extremely high OH and $O_3$ levels. The OH exposure in the PAM chamber was $(2{\pm}0.4){\times}10^{11}{\sim}(6{\pm}1.2){\times}10^{11}$ molecules $cm^{-3}$ s and was similar to 2 to 5 days of aging in the atmosphere. By periodically turning on and off UV lamps in the PAM chamber, ambient aerosol and newly formed aerosol (e.g. called as PAM aerosol) was alternately measured. Aerosol number and mass concentration in the range of 10~487 nm in diameter was measured by SMPS 3034. With UV lamps on, the nucleation mode particles smaller than 50 nm in diameters were formed. Their number concentration was greater than 105 $cm^{-3}$, leading to increase in aerosol mass by 0~8 ${\mu}gm^{-3}$. The variations of PAM and ambient aerosols were greatly dependent on characteristics of air masses such as precursor concentrations and degree of aging. This preliminary results suggests that PAM chamber is useful to assess the aerosol formation potential of air mass and its impact on the air quality. The further analysis of data with gaseous and particulate measurements will be done.

• 융합정보논문지
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• 제11권3호
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• pp.205-211
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• 2021

본 연구는 연령별 은퇴자들의 삶의 경험을 심층적으로 탐구하여 이를 바탕으로 은퇴자들의 성공적 노화에 요구되는 사회 복지적 함의를 도출하고자 질적 연구방법인 포토보이스를 활용하였다. 연구 참여자는 70대, 60대, 50대 각 2명씩 선정하였고, 집단 활동과 개인면담으로 수집한 사진 24장, 설명 24건, 이야기 44건, 총 92건의 자료를 분석한 결과, 성공적 노화의 인식으로 70대는 <사회적 책임감과 품위 있는 높은 경지의 삶을 준비함>, 60대는 <비움과 보은의 자세로 사회적 책임과 봉사의 삶>, 50대는 <경제적 안정과 배려로 자립하는 삶>이었다. 노년기가 길어진 은퇴자들의 사회적 문제를 예방하는 차원에서 이들의 사회적 일자리와 봉사자리 마련에 대한 연구와 사회복지정책지원이 시급하며, 또한 충분한 준비를 할 수 있도록 준비교육의 시행기간이 빠를수록 좋을 것으로 사료된다. 본 연구는 은퇴자를 위한 노년기 사회 복지적 대안 마련의 기초자료 제시에 중요한 역할을 한 점에서 연구의 의의를 가진다.

• 인간식물환경학회지
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• 제22권1호
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• pp.39-52
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• 2019

To evaluate the protective effect of collagen peptide-coated coffee extract on skin aging, cell viability was measured with a MTT assay using cultured CCD-986sk fibroblasts, and its effect on wrinkles in the skin of hairless mice induced by UVB-irradiation was examined. In addition, its effect on procollagen synthesis and anti-oxidative, and its inhibitory activity against collagenase, elastase, tyrosinase and MMP-1 were analysed. After the 30-minute topical treatment, the animals were exposed to UVB irradiation (60-100 mJ/cm²) for 4 weeks and its intensity increased during the period. Under the experimental conditions set in this study, the skin thickness of hairless mice significantly decreased (11.8-21.3%) compared to the control group. Based on these results, the prolonged oral intake of a collagen peptide mixture with coffee is expected to significantly increase the synthesis of procollagen in dermal fibroblasts, thereby contributing to the alleviation of wrinkling and lowered elasticity due to structural damage to the dermal layer caused by UV. The oral intake of collagen-coated coffee contributes to increasing collagen biosynthesis in a dose-dependent manner and alleviates the symptoms of thickened keratin caused by UV irradiation. However, it did not inhibit the enzymes involved in skin aging, whitening, wrinkle improvement, and antioxidation. Based on the these results, it can be concluded that the intake of collagen peptide-coated coffee extract can be utilized as an alternative material for the prevention or treatment of diseases associated with photoaging.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.135-141
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• 2023

Protection of skin cells from chronic infrared-A (IRA) irradiation is crucial for anti-photoaging of the skin. In this study, we investigated the protective activity of Rg3(S) and Rg3(S)-incorporated anionic soybean lecithin liposomes (Rg3/Lipo) with a size of approximately 150 nm against IRA-induced photodamage in human fibroblasts. The formulated Rg3/Lipo showed increased solubility in aqueous solution up to a concentration of 200 ㎍/ml, compared to free Rg3(S). In addition, Rg3/Lipo exhibited superior colloidal stability in aqueous solutions and biocompatibility for normal human dermal fibroblasts (NHDFs). After repeated IRA irradiation on NHDFs, elevated levels of cellular and mitochondrial reactive oxygen species (ROS) were greatly reduced by Rg3(S) and Rg3/Lipo. In addition, cells treated with Rg3/Lipo exhibited noticeably reduced apoptotic signals following IRA irradiation compared to untreated cells. Thus, considering aqueous solubility and cellular responses, Rg3/Lipo could serve as a promising infrared protector for healthy aging of skin cells.

• 대한화장품학회지
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• 제38권1호
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• pp.91-101
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• 2012

본 연구는 중앙아메리카의 폴리페놀 화합물로 이루어진 선바위고사리과에 속하는 양치식물 칼라구알라(Polipodium leucotomos)가 자외선 유해성으로부터 피부를 보호할 수 있는 항산화력과 활성 산소 유리기 농도를 알아보는데 그 목적을 두었다. 본 연구를 위하여 30대 이상 남녀 14명을 대상으로 4주 간 2개의 그룹으로 나누어 각각 칼라구알라와 위약을 섭취, 30 min 후 자외선에 노출되도록 하였다. 노출 후 3 h이 경과된 후에 각각 전완정맥에서 채혈하여 활성 산소 유리기(free oxygen radical) 농도와 총항산화능(total antioxidant capacity, TAC)을 비교 분석하여 다음과 같은 결과를 요약할 수 있었다. 첫째, 칼라구알라는 4주 후 활성 산소 유리기 농도를 유의하게 감소시켰고, 자외선 노출 30 min 후와 3 h 후의 활성 산소 유리기 농도는 위약군에 비해 유의하게 감소시키는 것으로 나타났다. 둘째, 칼라구알라는 4주 후 안정 시 총항산화능력을 유의하게 증가시키지 못하였지만, 자외선 노출 30 min 후와 3 h 후의 총항산화능력은 위약군에 비해 유의하게 감소시키는 것으로 나타났다. 사회가 급속도로 성장함에 따라 발생하는 대기오염, 각종 공해로 인하여 성층권에서 지속적으로 오존을 감소시켜 지상에 도달하는 유해 자외선량이 증가한다. 이는 활성화산소를 증가시켜 질병과 노화를 촉진시키는 요인이 된다. 기존의 반사와 산란작용으로 1차 피부를 차단하는 보호제외에도 칼라구알라와 같이 신체 내부에서 2차 차단을 할 수 있는 경구용 광항산화제의 연구가 계속적으로 이루어져야 할 것으로 사료된다.