• Composites Research
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• 제20권6호
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• pp.8-14
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• 2007

스킨-보강재 시편 시험을 통해 스킨과 보강재의 분리 파손 특성을 살펴보고 접합방법, 보강재 단면 및 이차 접합 파라미터의 영향을 조사하였다. 본 시험 결과와 이전 시험[1]의 결과를 종합해 볼 때, 보강패널의 스킨-보강재 분리 파손 강도를 판단하는 기준으로 스킨-보강재 시편의 파손 변위를 이용하는 것이 타당하며 동일한 접합 방법을 사용할 경우, closed형 보다 open형 보강재를 사용하는 것이 복합재 보강 패널에서 스킨과 보강재의 분리파손을 방지하는데 유리함을 알 수 있었다. 접합방법으로는 이차접합 및 접착제를 사용한 동시성형이 좋은 파손 강도를 보였으며 접착제 없는 동시성형이 가장 나쁜 파손 강도를 나타내었다. 파손 모드는 이차접합 시편은 주로 계면 파손이 발생하였으며 동시성형 시편은 복합재료의 층간분리 파손이 발생하였다. 이차 접합 시편에서는 접착제 두께가 작을수록 높은 파손 강도를 보였다. Fillet은 시편의 강도에 영향을 미치지 않았다. 표면 조도의 영향은 open형 및 closed형 시편이 다르게 나타났다.

• BMB Reports
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• 제53권10호
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• pp.539-544
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• 2020

Skin aging appears to be the result of overlapping intrinsic (including genetic and hormonal factors) and extrinsic (external environment including chronic light exposure, chemicals, and toxins) processes. These factors cause decreases in the synthesis of collagen type I and elastin in fibroblasts and increases in the melanin in melanocytes. Collagen Type I is the most abundant type of collagen and is a major structural protein in human body tissues. In previous studies, many products containing collagen derived from land and marine animals as well as other sources have been used for a wide range of purposes in cosmetics and food. However, to our knowledge, the effects of human collagen-derived peptides on improvements in skin condition have not been investigated. Here we isolate and identify the domain of a human COL1A2-derived protein which promotes fibroblast cell proliferation and collagen type I synthesis. This human COL 1A2-derived peptide enhances wound healing and elastin production. Finally, the human collagen alpha-2 type I-derived peptide (SMM) ameliorates collagen type I synthesis, cell proliferation, cell migration, and elastin synthesis, supporting a significant anti-wrinkle effect. Collectively, these results demonstrate that human collagen alpha-2 type I-derived peptides is practically accessible in both cosmetics and food, with the goal of improving skin condition.

• 대한화장품학회지
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• 제23권3호
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• pp.134-146
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• 1997

Consumers have recently preferred to purchase extensive UV intercepting products, which are waterproof and free from side effects on skin. Testing Cytoroxicity in SR method, cell survivial ratio of UV-B interceptors decreased above 0.08W/V%, and so did that of UV-A interceptors above 0.06W/V%. Also, Patch-test of inorganic UV interceptors resulted in no skin irritation even below 10.0 and 11.25. UV interceptors in the sunlight showed yellowish discoloration in 5 to 14 days. In absorption curves, UV-B was most suitable for Octyl methoxycinnamate and UV-A for Butyl methoxy dibenzoylmethane. Fro this reason, Nylonpoly UVA/UVB the material of OMC and BMDM coated with Nylon & polyethylene, was used as the organic UV interceptor. And zinc oxide and titanium dioxide was used as inorganic UV ibterceptors. The appropriate mixture ratio of ZnO and TiO2 was 6 to 4.6% of ZnO, 4% of TiO2 and 5% of Nylonpoly UVA/UVB were all combined with our sunscreen cream. The SPF value of in-vivo applied to a guinea pig was 34.9 and that of in-vivo was 38.5. Cyclomerhicone and dimerthicone were used in water-in-Silicone system. Ceryl diverhicone and sorbitan sesquioleate were used as emulsifiers and MgSO4, 7H2O, Mg-stearate/Mg-Al-stearate copolymer as emulsification stabilizers. In practical application, each SPF duration of O/W type and W/S type containing sunscreen cream of the same content showed that W/S type of sunscreen cream was 5 times as durable as the other. This product is fit for using in swimming, climbing or skiing. This research is to minimize skin trouble used by UV interceptors and to make one with proper softness, skin safety and UV intercepting efficiency.

• Archives of Reconstructive Microsurgery
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• 제8권2호
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• pp.139-148
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• 1999

Since Nakayama's first report about venous flap, many experimental and clinical studies were done about this new type of flap. And due to its various benefits, its applications as arterialized venous free flap type have increased recently. In this study we have attempted to reconstruct composite of defects of the hand with new modification of arterialized venous free flap and simultaneous reconstruction of skin, nerve, tendon were performed successfully. From 1994 to 1999, the defects of the hands in 35 patients were reconstructed with various modifications of arterialized venous free flaps. The range of age was from 19 to 55 years and size of flap ranged from $1{\times}2cm\;to\;14{\times}9cm$. Among them, 12 cases of flap over 20cm in size were included. Indications of flaps were as follows: resurfacing of the defects of the skin (9 cases), simultaneous reconstruction of extensor, skin and digital nerve(2 cases), reconstruction of the skin with extensor(5 cases), as a flap-through type vascular reconstruction(6 cases), for digital nerve reconstruction(2 cases), contracture release(3 cases), and finger tip reconstruction(9 cases). All of the cases except one survived with marginal skin necrosis less than 10%. And relatively large flaps over 20cm in size successfully survived without any delay procedures. Composite reconstructions including tendon and nerve were successful with new modifications of this flap. Arterialized venous free flap is one of the useful procedure in reconstruction of the hand because it has many advantages such as non-bulky and good quality of flap, variable length of pedicle, preservation of major vascular pedicle, less operation time, single operative field and in addition possibility of various modifications.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권1호
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• pp.33-42
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• 2000

The purpose of this study was to compare the wound healing process after skin incision using scalpel, $CO_2$ laser and pulsed Nd:YAG laser in rats. After skin on the back was incised 3 cm long, rats were sacrificed at 1, 3, 7, 14, 21 and 28 days. Macroscopic, histologic and immunohistochemical examinations using the collagen type IV and the CD34 antibodies which are necessary to the forming process of new capillary were performed. Results obtained were as follows ; Macroscopically the initial wound healing of the laser group was about $1{\sim}2$ weeks slower than that of the scalpel group. There weren't however any remarkable differences in all groups in 4 weeks after incision. By histologic finding, acute inflammatory cells were more prominent during the initial wound healing in the scalpel group than in the other groups. Epithelialization started in the order of scalpel, $CO_2$ and Nd:YAG laser group after skin incision. By the Masson's trichrome stain, collagen synthesis in the Nd:YAG laser group was more slowly initiated than in the other groups. But it was completed at the $3{\sim}4$ weeks in all groups. Immunohistochemically, collagen type IV and CD34 expression were markedly increased at 2 weeks in the scalpel and $CO_2$ laser group. Meanwhile, in the Nd:YAG laser group, these reactions were observed later tan the other groups. Collagen type IV and CD34 expression were decreased in all groups after 4 weeks. These results suggest that $CO_2$ and Nd:YAG laser showed similar healing process compared with scalpel and a potential substitute for scalpel in skin incision.

• 한방안이비인후피부과학회지
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• 제34권2호
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• pp.1-20
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• 2021

Objective : The object of this study was to assess the efficacy of hydrolysate from Phellinus igniarius(HPI) on anti-aging activities in vitro measurement and mini clinical study performed on 5 subjects. Methods : To evaluate skin anti-aging efficacy of HPI, 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity, type I collagen synthesis, inhibition of nitric oxide(NO) production, inhibiton of tyrosinase, hyaluronan synthase(HAS)2, 3 mRNA expression were measured in vitro. Also, mini clinical study of skin hydration was performed on 5 subjects using HPI in distilled water(DW) and 1,3-butylene glycol diluted solution(30% in DW). Results : 1. DPPH radical scavenging activity of HPI was increased in a dose-dependant. 2. Type I collagen synthesis was increased in 50, 100 and 500㎍/㎖ of HPI. 3. NO production was not inhibited in all concentrations of HPI. 4. Tyrosinase was inhibited in 500, 1000, 2500 and 5000㎍/㎖ of HPI. 5. HAS2 mRNA expression was increased in 50, 100, 150 and 200㎍/㎖ of HPI, HAS3 mRNA expression was increased in 100, 150, and 200㎍/㎖ of HPI. 6. In the mini clinical study of 5 subjects, there was a difference in skin hydration over time for each solutions, but it was not statistically siginificant. Conclusions : HPI increased DPPH radical scavenging activity, type I collagen synthesis, and HAS2, HAS3 mRNA expression. HPI also suppressed tyrosinase. The findings of this study suggest that HPI can be used as an skin anti-aging material.

• 대한본초학회지
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• 제38권3호
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• pp.19-26
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• 2023

Objectives : Agrimoniae Herba is a herbal medicine widely distributed in Asia and contains flavonoids including catechin, quercitrin, rutin, hyperoside, and quercetin. This study aimed to investigate the anti-oxidant activity and skin barrier function of different solvent fractions (Hexane; methylene chloride, MC; ethyl acetate, EA; n-butanol, Bu; Water) obtained from Agrimoniae Herba. Methods : Anti-oxidant activity of different solvent fractions obtained from Agrimoniae Herba was investigated through total polyphenol contents, total flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity measurements. Then, filament aggregating protein (Filaggrin), Type I collagen, ceramide synthase (CERS) 3, and CERS4 were analyzed to evaluate the skin barrier strengthening effect of different solvent fractions obtained from Agrimoniae Herba on UVB-stimulated HaCaT cells. Results : As a result of measuring total polyphenol contents, total flavonoid contents, DPPH free radical scavenging activity, and ABTS radical scavenging activity, antioxidant activity was found to be excellent in the order of EA > Bu > MC > Hexane > Water. As a result of measuring mRNA gene expression of Type I collagen, Filaggrin, CERS3, and CERS4 after UVB-stimulated was applied to HaCaT cells treated with different solvent fractions obtained from Agrimoniae Herba, it was found to increase significantly in the Bu-treated group. Conclusion : Our findings show that the Bu sample obtained from Agrimoniae Herba has excellent anti-oxidant ability, which increases Type I collagen, Filaggrin, and ceramide synthetase in UVB-stimulated HaCaT cells to control the skin barrier improvement effect.

• 대한두개안면성형외과학회지
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• 제21권2호
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• pp.87-91
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• 2020

Background: The incidence of skin cancer, which is primarily caused by exposure to ultraviolet radiation, has steadily increased in recent years. The authors of the present study sought to investigate changes in the epidemiology of skin cancer by conducting a retrospective review of patients diagnosed with skin cancer who received related care at a single medical institution. Methods: The present study included patients who were diagnosed with skin cancer and received treatment at Gyeongsang National University Hospital from 2008 to 2018. The site and type of skin cancer, the number of patients with skin cancer each year, the sex and sex ratio of the patients, and changes in patients' age at first diagnosis were examined through retrospective chart reviews. Results: The number of patients with skin cancer significantly increased, but statistically significant changes were not found in patients' sex, skin cancer sites, or the types of skin cancer. However, patients' age at the first diagnosis of skin cancer showed a statistically significant decrease starting in 2015. Conclusion: In this study, the number of patients with skin cancer increased over time. However, patients' age at first diagnosis has decreased since 2015. Therefore, younger patients should take care to prevent skin cancer, and further research on the causes of skin cancer in younger patients is needed.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.203-224
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• 2003

In recent years, a miniature spectrometer has been extensively developed due to the combination of fiber optics and semiconductor detector arrays. This type of miniature spectrometer has advantages of low price and robustness because of the capability of mass production and no moving parts are required such as lenses, mirrors and scanning monochromator. In this study, for skin diagnostics, a portable near infrared (NIR) system has been developed using a LlGA microspectrometer, which is photo-diode arrays-type.(omitted)

• Journal of Oral Medicine and Pain
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• 제20권1호
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• pp.117-126
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• 1995

In order to evaluate objectively the level of tension and relaxation in dental practices, the author used Biotrainer(BF-102R), one of the GSR biofeedback apparatus, to examine 119 dental outpatients on their changes of GSR due to infection, preparation, extraction and readjustment. The obtained results were as follows : 1. There were no differences in the baseline GSR between the control group and the patient groups. 2. Changes in GSR by practices were significantly larger than the baseline GSR. 3. GSR in female was larger than that in male 4. While the GSR after injection, preparation and extraction revealed lower level, the GSR after readjustment revealed higher level. 5. Most of subjects just after injection, preparation and extraction were more frequent in decrease of GSR and those just after readjustment more were frequent n increase of GSR. 6. Type 1,2(increase in skin resistance) showed greater in injection, preparation and extraction group, while type 3(decrease in skin resistance) did in readjustment group.