• 대한기계학회논문집B
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• 제25권6호
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• pp.786-798
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• 2001

This paper describes the phenomena of wake-induced transition of the boundary layers on a NACA0012 airfoil using measured phase-averaged data. Especially, the phase-averaged wall shear stresses are reasonably evaluated using the principle of Computational Preston Tube Method. Due to the passing wake, the turbulent patch is generated in the laminar boundary layer on the airfoil and the boundary layer becomes temporarily transitional. The patches propagate downstream with less speed than free-stream velocity and merge with each other at further down stream station, and the boundary layer becomes more transitional. The generation of turbulent patch at the leading edge of the airfoil mainly depends on velocity defects and turbulent intensity profiles of passing wakes. However, the growth and merging of turbulent patches depend on local streamwise pressure gradients as well as characteristics of turbulent patches. In this transition process, the present experimental data show very similar features to the previous numerical and experimental studies. It is confirmed that the two phase-averaged mean velocity dips appear in the outer region of transitional boundary layer for each passing cycle. Relatively high values of the phase-averaged turbulent fluctuations in the outer region indicate the possibility that breakdown occurs in the outer layer not near the wall.

• 한국임상수의학회지
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• 제22권2호
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• pp.153-156
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• 2005

5살과 2살의 푸들 견이 미용 직후, 등 부위의 털의 변색과 전신적 탈모증세로 건국대학교 부속 동물 병원에 내원하였다 병변 부위에서는 육안적으로 약간의 피부 발적과 소농포가 발견되었지만 총 혈구 계산, 혈액 화학 검사에서는 특이한 소견이 발견되지 않았다. 아울러 최근 약물투여 병력도 없었다. 병변부의 trichogram에서는 모근 쪽과 모간에 멜라닌 과립이 착색되어 있었고, 병변 이외의 부위에서는 멜라닌 착색이 관찰되지 않았다. 그리고 병변부 피부 생검에서는 약한 부전 각화증이 관찰되었으며 아주 미약한 진피층의 호중구 침윤이 관찰되었다. 본 케이스에서는 melanotrichia가 미용 직후에 피부에 가해지는 각종 자극에 의해 발생할 수 있음을 보여주고 있다. 그러나, 미용 후 멜라닌 신생의 정도와 델라닌 세포의 증식 기전은 본 증례로서는 현재까지 명확하게 밝혀지지는 않았다.

• Archives of Plastic Surgery
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• 제37권5호
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• pp.687-690
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• 2010

Purpose: Hidroacanthoma simplex (HAS) is a rare benign neoplasm of the skin and known as intraepidermal poroma. Malignant transformation of HAS has been reported in the literature, but it is very rare. We experienced a case of malignant hidroacanthoma simplex (MHA) and performed the surgery of the neoplasm. Methods: A 73-year-old patient visited our department for evaluation and treatment of the skin lesion ($3.2{\times}3.0\;cm^2$) that occurred two years before on the right ankle area. The lesion was characterized by dark-brown, hyperkeratotic and protruding patch. The patient had no symptom, and any palpable lymph node was not found on physical examination. The result of laboratory was also nonspecific. The lesion was excised completely with a resection margin of 5 mm including subcutaneous tissue partially, followed by full-thickness skin graft for reconstruction. Results: The result of biopsy was reported as malignant hidroacanthoma simplex. Histologically, the epidermis showed discrete aggregates of tumor cells which had round, hyperchromatic nuclei and pale or clear abundant cytoplasm. Cystic spaces were found within the tumor and mitosis were seen, frequently. No recurrence was found one month after surgery. Conclusion: The case of malignant hidroacanthoma simplex was treated with full-thickness skin graft following wide excision of the tumor.

• Journal of Pharmaceutical Investigation
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• 제41권1호
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• pp.9-17
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• 2011

The objective of this work is to study transdermal delivery of calcitonin using iontophoresis and to evaluate various factors which affect the transdermal transport. We have studied the effect of polarity, current density, drug concentration, penetration enhancers (isopropyl myristate [IPM] and ethanol) and laser treatment on transdermal flux and the results were compared. We also investigated the iontophoretic flux from microemulsions containing calcitonin together with oleic acid (OA) or IPM. In vitro flux study was performed at $33^{\circ}C$, using side-by-side diffusion cell and full thickness hairless mouse skin. Anodal delivery at pH 3.0 was much larger than cathodal and passive delivery, due to the positive charge of calcitonin. Cumulative amount delivered (CUM) by cathodal or passive delivery was close to zero for 10 hours. The pretreatment of skin by neat IPM markedly increased the CUM anodically. CUM increased as the current density, drug concentration or the duration of IPM treatment increased. Microemulsion containing IPM or oleic acid was prepared and the phase diagram was constructed. CUM also increased when IPM was incorporated into a microemulsion. OA microemulsion showed similar enhancing effect to IPM microemulsion. The delivery of calcitonin from 70% (v/v) ethanol aqueous solution showed a large increase in flux. Laser treatment of skin before flux experiment exhibited about 2 fold increase in total calcitonin amount transported for 12 hours, when compared to that delivered by IPM microemulsion. Based on these results, we have evaluated the possibility of delivering enough amount of calcitonin to reach the therapeutic level. The data suggest that it is highly possible to deliver clinically effective amount of calcitonin using iontophoresis patch with small area (<10 $cm^2$).

• 대한치과보철학회지
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• 제30권2호
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• pp.155-166
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• 1992

In dentistry, precious metal alloys are, mainly due to economic factors, increasingly displaced by alternatives containing Ni-Cr-Co. There are some reports where hypersensitive reactions to Ni-Cr-Co alloys are presented and discussed. The reactions reported vary from mucosa contact stomatitis to generalized dermatitis without any oral mucosal reaction. The purpose of this study was to investigate the incidence of nickel, chrome, cobalt and copper, and to know whether subjects with positive skin reaction to nickel would also demonstrate adverse intraoral reaction to a non-precious metal nickel. The patch tests were performed in 81 subjects(male 39, female 42) and nickel sulfate 5% aq., potassium bichromate 0.5% at., cobalt chloride 2% aq., & copper sulfate 1% aq., were used for test allergens. And then the intraoral tests were performed in 16 subjects, 8 subjects with positive allergic skin reaction to nickel and 8 subjects with negative allergic skin reaction. A pure metallic nickel plate was attached to the buccal side of the upper second premolar. The results are as follows : 1. The frequency of nickel sensitivity was 9.9% (2 men, 6 women), cobalt was 4.9% (1 man, 3 women), and chrome was 2.5% (2 men) respectively and there was no positive reaction to copper 2. The positive reactions were 8 of 23 (34.8%) with a history of jewelry allergic reactions and 3 of 58 (5.1%) without a history of jewelry allergic reactions. 3. Three of 8 subjects with positive skin reaction. gave reactions to the metal plates.

• KSBB Journal
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• 제31권4호
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• pp.256-262
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• 2016

The need for natural cosmetic ingredients has been increasing over the world nowadays. Agarose, a natural polymer from red seaweeds, has high hydrophilic character and a function of scaffolder. As skin moisturizer, agarose is adequate for percutaneous absorption. While, blueberry fruits extract possesses rich procyanidins and anthocyanins which show health benefits, anti-oxidant effect, anti-aging and anti-melanogenesis. Stability, sensory preference, skin trouble of the emulsion formula are important for cosmetic product development. In this study, we manufactured an emulsion formula for skin moisturizers using the two ingredients and tested emulsion stability and skin trouble. Total phenolic contents of the blueberry fruits extract were evaluated as well as tyrosinase inhibitory and collagenase inhibitory activities. $IC_{50}$ values of blueberry fruits extract for anti-tyrosinase and anti-collagenase activities were 168 and $112{\mu}g/mL$, respectively using gallic acid as a control ($64.8{\mu}g/mL$). The stability (pH and viscosity) of the formula containing 2% blueberry fruits extracts and 0.1% agarose was measured at five different temperatures (room temp., $25^{\circ}C$, $55^{\circ}C$, $45^{\circ}C$, $55^{\circ}C$) under the sun light at 2 day intervals for 12 days. There has been little pH change at the different temperatures. According to the sensory evaluation, there was no significant flavor, discoloration and physical changes of the formula at $25-65^{\circ}C$. These results suggest that emulsion formula containing blueberry extract and agarose could be used as a candidate for lotion and essence products.

• 한국응용과학기술학회지
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• 제31권1호
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• pp.14-22
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• 2014

본 연구에서는 거동이 불편한 환자와 바쁜 현대인들을 위하여 헹굼이 필요없는 에탄올베이스 드라이샴푸를 제조했다. 물로 헹구지 않는 드라이샴푸에는 저자극 세정원료의 적용이 필요하다. 이 실험에서 세정원료는 저자극 세정원료를 첨가하고 세정원료의 세포독성실험과 드라이샴푸의 피부자극, 항균효과를 확인하였다. 본 연구에서 펜틸렌글리콜을 적용하여 제조한 에탄올베이스 드라이샴푸가 항균력을 갖고 피부에 가장 안전함을 확인 하였다. 또한 미용목적뿐만 아니라 위생적인 모발관리를 가능하게 하여 젖은 샴푸를 할 수 없는 상황에서도 청결과 위생, 안전성을 동시에 만족할 수 있을 것으로 기대된다.

• Applied Biological Chemistry
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• 제48권4호
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• pp.404-410
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• 2005

Sopoongsan is an oriental medicinal composition including 12 medicinal herbs. Sopoongsan is known to have anti-inflammatory, antimicrobial, anti-allergic, and anticancer effects on human skin. The results of stability test showed that the creams containing Sopoongsan extracts were very stable at both accelerated temperature conditions and sun-light. And pH and viscosity of each cream did not change greatly for 56 days. From the particle size and rheological measurements, it can be known that when the amount of the Sopoongsan extracts increases, the mean value of particle size decreases, and the value of the complex modulus and loss angle increases, which means the Sopoongsan extracts help stabilize the emulsion. From the result of human patch test to assess the safety of cream containing Sopoongsan extracts, there was no stimulus of negative reaction on skin. In result of the user tests, it can be known that the higher concentration of the Sopoongsan was preferred by customers.

• Smart Structures and Systems
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• 제8권1호
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• pp.93-105
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• 2011

This paper presents a flexible low-profile antenna sensor for fatigue crack detection and monitoring. The sensor was inspired by the sense of pain in bio-systems as a protection mechanism. Because the antenna sensor does not need wiring for power supply or data transmission, it is an ideal candidate as sensing elements for the implementation of engineering sensor skins with a dense sensor distribution. Based on the principle of microstrip patch antenna, the antenna sensor is essentially an electromagnetic cavity that radiates at certain resonant frequencies. By implementing a metallic structure as the ground plane of the antenna sensor, crack development in the metallic structure due to fatigue loading can be detected from the resonant frequency shift of the antenna sensor. A monostatic microwave radar system was developed to interrogate the antenna sensor remotely. Fabrication and characterization of the antenna sensor for crack monitoring as well as the implementation of the remote interrogation system are presented.

• 대한본초학회지
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• 제21권2호
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• pp.47-53
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• 2006

Objectives : This study was conducted to determine if Scutellaria baicalensis can be used in cosmetic emulsion cream for patients with atopic dermatitis. Methods : Scutellaria baicalensis extract was obtained with the use of butylene glycol through the pressurized solvent extraction(PSE). The antioxidative activity was assessed through SOD-like activity measurement and skin irritating potential was tested using human patch test. Antimicrobial activity was measured by the clear zone formed against Staphylococcus aureus and Escherichia coli and the rheological effects on the emulsion creams were examined using oscillation test. Results : The SOD-like activity increased dose-dependently and was about 90% at 1,000ppm of Scutellaria baicalesis extract. And Scutellaria baicalensis extract did not show any potential to be irritating to the human skin, but it could not be used as an antimicrobial agent for its poor antimicrobial activity against Staphylococcus aureus. The complex modulus decreased by 1,000 pascals and the loss angle also decreased by 20% with the addition of Scutellaria baicalensis extract into the cosmetic emulsion creams, that is, the extract can confer more elastic property on the vehicle. Conclusion : From those results, Scutellaria baicalensis extract can be effectively used as an antioxidant and reinforces the elastic skincare film formed by the application of cream for patients with atopic dermatitis.