• Geomechanics and Engineering
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• 제16권6호
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• pp.589-597
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• 2018

Centrifuge model tests were used to simulate pile-raft composite foundation and pile-geogrid composite foundation with different pile spacing for researching the time effect of negative skin friction of rigid piles in high-speed railways. The research results show that the negative skin friction has a significant impact on the bearing capacity of composite foundation. Pile-raft composite foundation has higher bearing capacity compared to pile-geogrid composite foundation to reduce the effect of negative skin friction on piles. Both the foundation settlement and negative skin friction have significant time effect. The distribution of skin friction can be simplified as a triangle along the pile. The neutral point position moves deeper in the postconstruction stage at larger pile spacing. For pile-geogrid composite foundation, the setting of pile-cap affects the position of neutral point in the post-construction stage. Reinforced cushion with geotextile may promote the better performance of cushion for transmitting the loads to piles and surrounding soils. Arching effect in the cushion of the composite foundation is a progressive process. The compression of the rigid piles contributes less than 20% to 25% of the total settlement while the penetration of the piles and the compression of the bearing stratum below the pile tips contribute more than 70% of the total settlement. Some effective measures to reduce the settlement of soils need to be taken into consideration to improve the bearing capacity of pile foundation.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.464-478
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• 2003

Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental facts play critical roles in cellular damage and aging. The extract of tinged autumnal leaves of maple tree(Acer palmatum) has proven to be a powerful antioxidant. The Acer palmatum extract is very effective on the stabilization of biological membranes( containing unsaturated fatty acid). We studied photoprotective effect of the extract against UVB-induced cytotoxicity in human keratinocytes. The extract improved cell viability comparing to control after UVB irradiation. In the determination test of pro inflammatory cytokines the extract decreased expression of interleukin 1 a and 6, which play an important role in inflammation and skin erythema caused by UV. We also studied property of varying cosmetic formulations on the percutaneous absorption of the extract. After 24 hour in vitro penetration study, the content of the extract was more highly detected in skin residue part. This result showed the extract had relatively high compatibility of skin in our emulsion system. On human skin, after appling the product containing the extract we obtained a good result of antiwrinkle effect by skin visiometer. In conclusion, the Acer palmatum extract is a photoprotective and very effective in stressed and aged skin care. And we can predict the extract mainly affects on the skin cell and tissue in our emulsion system.

• 대한한의학회지
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• 제31권2호
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• pp.36-47
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• 2010

Objective: The purpose of this study was to investigate the effects of skin application with Gelidium amansii extract on skin with deep second degree burns in mice. Methods: BALB/c mice were divided into four groups: normal (NOR) group; burn-elicited mice (CON) group, Silmazine-treated mice after burn elicitation (ST) group, and Gelidium amansii-extract treated mice after burn elicitation (GT) group. To examine the skin recovery effect after burn, changes of burn area, angiogenesis and histologic structure were analyzed. To measure effect of edema regulation, matrix metalloproteinase-9 (MMP-9) was analyzed. To estimate the skin regenerative & stable effect, 5-bromo-2'-deoxyuridine (BrdU) and substance P were analyzed. Results: 2 weeks later, 1. The size of burn area decreased in the GT and ST groups more than the CON group. 2. Alleviation of angiogenesis appeared in the GT and ST groups more than in the CON group. 3. Blood clot, epithelial cell hyperplasia, and inflammatory cell infiltration declined in the GT and ST groups more than in the CON group. 4. MMP-9, BrdU, and substance P positive reaction decreased in the GT and ST groups more than in the CON group 5. In the comparative study, the GT group was superior to the ST group. Conclusion: The skin application of Gelidium amansii extract could lessen skin damage by the medium of regulation MMP-9 activation. This skin stabilization was induced in mice with deep second degree burns.

• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.149-158
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• 2007

To investigate the permeability of lidocaine, percutaneous absorption studies were performed using excised hairless mouse skin and the penetration of lidocaine via the skin was determined. To increase the skin permeation of lidocine, the effects of $Labrasol^{(R)}$, $Labrafil^{(R)}$, $Labrafac^{(R)}$ and $Transcutol^{(R)}$ were investigated. The skin permeation of lidocaine was increased when $Labrasol^{(R)}$ and $Transcutol^{(R)}$ were used as permeation enhancer. To evaluate the influence of ultrasound, various factors such as application modes (continuous mode and pulsed mode), frequency (1.0 and 3.0 MHz) and intensity (1.0, 1.5 and 2.0 w/$cm^2$) were investigated with lidocaine hydrogel. The pronounced effect of ultrasound on the skin permeation of lidocaine was observed at all ultrasound energy levels. The influence of frequency having an effect on skin permeation rate was higher in the case of using 1 MHz, 2.0 w/$cm^2$ and continuous treatment. As the intensity of ultrasound increased, the permeation of lidocaine was accelerated. The in vivo anesthetic effects were evaluated by two aspects as mechanical threshold and electrical threshold. Six healthy volunteers consented to the randomized, double-blind, and cross-over designed study in each group. In each subject, 3 groups were adapted such as K group (ultrasound with gel base only), L group (lidocaine gel) and B group (ultrasound with lidocaine gel). In conclusion, lidocaine was potent anesthetic which could be block pain threshold effectively. And ultrasound could accelerate the skin penetration of lidocaine. The phonophoretic delivery system could be a good candidate for lidocaine as a local anaesthetic to improve the skin permeation and in vivo anaesthetic effect.

• 대한화장품학회지
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• 제24권3호
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• pp.24-30
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• 1998

Inhibitory effects of the new material obtained from Areca catechu seed (CC-516) according to a special process, and its applicability to the skin as a cosmetic raw material in terms of its efficacy were presented. Areca catechu extract out of 150 medicinal plants, exhibited high inhibitory effect on the porcine pancreatic elastase ($IC_{50}$ : $40.8{\mu}$g/ml). It also had an inhibitory effect on the human leukocyte elastase ($IC_{50}$ : 48.1$\mu$g/ml), hyaluronidase ($IC_{50}$ : $416{\mu}$g/ml), antioxidative activity ($IC_{50}$ : $45.4\mu$g/ml) and free radical scavenging activity ($SC_{50}$ : $10.2{\mu}$g/ml). The cream contained 3％ of CC-516 improved skin hydration above 16.5％. Especially, the skin elasticity increases more than 35% and skin wrinkles decreased more than 23％. The CC-516 was designed to be utilized in cosmetology. The cream containing 3％ of this product has not only protecting effect on the skin mechanical properties provided by the collagen and the elastin in the derm but also restructuring effect of scarring or aging tissue.

• 한국임상수의학회지
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• 제36권2호
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• pp.98-101
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• 2019

Lactobacillus spp. are the bacteria most commonly used as probiotics and it has been proven that they inhibit pathogenic bacterial growth and improve skin repair in humans. This study was conducted to investigate the growth inhibitory effect of Lactobacillus on Staphylococcus pseudintermedius, the most commonly isolated pathogen in canine pyoderma, and whether Lactobacillus could inhibit the adhesion capability of S. pseudintermedius to canine corneocytes. For this study, L. salivarius and S. pseudintermedius were isolated from healthy beagle fecal samples and the skin surface of dogs with skin infection, respectively. S. pseudintermedius was co-cultured with L. salivarius to assess the inhibitory effect. For the adhesion assay, corneocytes were collected from healthy beagle ventral abdominal skin. Both bacterial species attached to corneocytes and were assessed in number. As a result, L. salivarius significantly inhibited the growth of S. pseudintermedius in the culture medium. Moreover, L. salivarius reduced attachment of S. pseudintermedius in the adhesion assay. These results suggest that L. salivarius has an inhibitory effect on S. pseudintermedius and may be effectively used in the topical therapy of canine skin infections.

• 대한의생명과학회지
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• 제7권1호
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• pp.47-51
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• 2001

To investigate an effect of the topical toluene application to .at skin on the liver injury, toluene (35 mg/$cm^2$) was sequentially applied for 3 or 5 days to rat skin and then the animals were sacrificed. 5 day toluene-treated rats showed the slight increase of live. weight per body weight(%) compared with control. Serum levels of xanthine oxidase and alanine aminotransferase activity were significantly increased both in 3 days and 5 days toluene-treated animals compared with control. In the histopathological findings, cytoplasmic degeneration of hepatocytes around the central vein was noted in the liver of rats applied with toluene to the skin. These results indicate toluene application to rat skin feds to somewhat slight liver injury. On the other hand, the hepatic benzylalcohol or aldehyde dehydrogenase activities were significantly decreased by toluene application to rat skin. In conclusion, the liver min was induced by toluene application to rat skin, and it can be hypothesized that accumulation of benzaldehyde in liver cell may be responsible for liver injury.

• 대한의생명과학회지
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• 제14권3호
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• pp.193-198
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• 2008

In order to evaluate on the effect of kaempferol on the cytotoxicity of oxygen tree radicals, XTT assay was performed to determine the cell viability after skin fibroblasts derived from human (Detroit 51) that were treated with various concentrations of hydrogen peroxide $(H_2O_2)$. And also, the effect of kaempferol on the cytotoxicity induced by H202 that was examined by cell viability, lactate dehydrogenase (LDH) activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in these cultures. $H_2O_2$ decreased cell viability in dose-dependent manner in these cultures and the $XTT_{90}\;and\;XTT_{50}$ values were determined at concentration of $35{\mu}M\;and\;90{\mu}M$ of $H_2O_2$ after skin fibroblasts derived from human were treated with $15{\sim}90{\mu}M$ of $H_2O_2$ for 6 hours, respectively. $H_2O_2$ was highly toxic on cultured skin fibroblasts derived from human by toxic criteria of Brenfreund and Puerner (1984). In the protective effect of kaempferol on $H_2O_2$-induced cytotoxicity, kaempferol increased DPPH radical scavenging activity and significantly decreased LDH activity. From these results, it is suggested that oxygen tree radical, $H_2O_2$, was highly toxic on cultured skin fibroblasts derived from human, and also kaempferol of flavonoid showed the protection on $H_2O_2$-induced cytotoxicity.

• 약학회지
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• 제49권2호
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• pp.174-179
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• 2005

The human skin is constantly exposed to environmental irritants such as ultraviolet, smoke, chemicals. Free radicals and reactive oxygen species (ROS) caused by these environmen tal facts play critical roles in cellular damage. These irritants are in themselves damaging to the skin structure but they also participate the immensely complex inflammatory reaction. The purpose of this study was to investigate the skin cell protective effect of Campsis grandiflora extract on the UVB-irradiated human dermal fibroblasts (HDFs). We tested free radical and superoxide scavenging effect in vitro. C. grandiflora extracts had potent radical scavenging effect by 82% at $100{\mu}g/ml$, respectively. For testing intracellular ROS scavenging activity the cultured HDFs were analyzed by increase in DCF fluorescence upon exposure to UVB 20 $MJ/cm^2$ after treatment of C.grandiflora extracts. The results showed that oxidation of CM-DCFDA was inhibited by C.grandiflora extracts effectively and C.grandiflora extracts has a potent free radical scavenging activity in UVB- irradiated HDFs. In ROS imaging using confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our results suggest that C.grandiflora can be effectively used for the prevention of UV-induced adverse skin reactions such as radical production, and skin cell damage.

• Journal of Pharmaceutical Investigation
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• 제25권3호spc1호
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• pp.53-59
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• 1995

Ethinylestradiol (EE)-containing matrix was fabricated with ethylene-vinyl acetate(EVA) copolymer to control the release of the drug, Effect of addition of PEG 400 as receptor solution, the stripping of skin and Azone pretreatment on skin on the permeation of EE through the excised mouse skin was also studied. The permeation rate of EE through the excised mouse skin was affected by the PEG 400 volume fraction. The Azone pretreatment on skin didn't affect on the steady state flux, however, the lag time was shortened. The permeation rate of EE through the stripped skin was much larger than that through the whole skin. It showed that the stratum corneum acts as a barrier of skin permeation. The fact that there is little difference in EE permeation between the intact skin and the stripped skin with EVA membrane shows the permeation of EE through the mouse skin is mainly controlled by the membrane.