• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.719-728
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• 2017

This paper proposes a synthesis of new guidance law to generate an evasive maneuver against enemy's missile interception while considering its impact angle, acceleration, and field-of-view constraints. The first component of the synthesis is a new function of repulsive Artificial Potential Field to generate the evasive maneuver as a real-time dynamic obstacle avoidance. The terminal impact angle and terminal acceleration constraints compliance are based on Time-to-Go Polynomial Guidance as the second component. The last component is the Logarithmic Barrier Function to satisfy the field-of-view limitation constraint by compensating the excessive total acceleration command. These three components are synthesized into a new guidance law, which involves three design parameter gains. Parameter study and numerical simulations are delivered to demonstrate the performance of the proposed repulsive function and guidance law. Finally, the guidance law simulations effectively achieve the zero terminal miss distance, while satisfying an evasive maneuver against intercept missile, considering impact angle, acceleration, and field-of-view limitation constraints simultaneously.

• 한국임상수의학회지
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• 제25권5호
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• pp.330-339
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• 2008

세라마이드, 콜레스테롤, 자유지방산은 각질세포간 주요 지질로써 피부장벽의 생성과 유지에 있어 중요한 역할을 담당한다. 그러나, 개에서 각질세포간 지질에 대한 역할은 거의 알려져 있지 않다. 본 연구는 개에서 1.25% sodium lauryl sulphate (SLS)에 의한 피부 장벽손상 유발후 2% 세라마이드, 2%콜레스테롤, 2% 리놀레익산과 이들 세가지 지질의 혼합제 (혼합제)의 장벽손상 복구를 평가하고자 실시하였다. 피부장벽기능은 표피경유수분소실(TEWL), 피부 수화도, 피부 산도, 피부 두께 측정을 통하여 평가하였고 최종적으로 조직학적 분석과 투과 전자 현미경 (TEM)을 통하여 피부 장벽구조를 평가하였다. SLS는 개의 피부에 효과적으로 피부장벽 손상을 유발하였다. 표피경유수분소실은 세라마이드와 혼합제 적용부위에서 계면활성제 및 대조군과 비교하여 유의적인 감소를 나타내었다 (p<0.05, p<0.01). 표피경유수분소실은 12일째에 모든 지질 적용군에서 유의적으로 감소하였으나 특히 세라마이드와 혼합제에서 콜레스테롤과 리놀레익산보다 유의적으로 감소하였다 (p<0.01). 실험 기간 동안, 피부 수화도는 세라마이드와 혼합제에서 유의적 증가를 보였다 (p<0.01). 조직학적 분석에서도 각각의 지질들은 피부손상을 회복시켰다. 특히 세라마이드와 혼합제의 효과가 탁월하였고 각질층의 두께도 대조군에 비해 유의적으로 증가되었다. 피부 산도는 세라마이드, 리놀레익산, 혼합제에서 유의적으로 감소하였다 (p<0.05). 따라서 세라마이드와 혼합제의 국소적용은 계면활성제에 의한 피부 장벽 손상에 효과가 탁월함을 확인하였으며 아토피와 같은 염증성 피부염과 외부 자극에 의한 피부 장벽 손상시에도 세라마이드 또는 혼합제의 병용이 효과적일 것으로 사료된다.

• 한방안이비인후피부과학회지
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• 제21권2호
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• pp.19-27
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• 2008

Objective : The side effect of prolonged use of topical corticosteroids to skin is well-known. Moreover, resent studies have shown that prolonged use of systemic corticosteroids also negatively impacts skin barrier function. Corticosteroids have a major role in the practical management of many variable conditions. So, it is important to find the drug or the method which could protect the skin from the damage caused by corticosteroids. At former study, we investigated that Insamyangyoung-tang has some effect on skin barrier function of DNCB induced contact dermatitis hairless mice. So, this study was performed to research the effect of Insamyangyoung-tang on the TEWL with high dose steroid injected hairless mice. Method : Hairless mice were divided into 4 groups ; Control group, Group A, Group B and Group C. All groups were injected triamcinolone O.4mg for 10 times. Control group was medicated distilled water during the experimental period. Group A was medicated distilled water for 5 days before the $1^{st}$ injection day, and then medicated Insamyangyoung-tang extract during the experimental period. Group B was medicated Insamyangyoung-tang extract for 5 days before the $1^{st}$ injection day, and then medicated distilled water during the experimental period. Group C was medicated Insamyangyoung-tang extract for 5 days before the $1^{st}$ injection day, and then medicated Insamyangyoung-tang extract during the experimental period. TEWL of each group was measured for 5 times. After the $10^{th}$ injection, the tissue sample was made and the damage of epithelial cell was examined. Statistical significance was set at p<0.05 by using non parametric methods and repeated-anova.. Results : Group C showed significant effect on TEWL change of hairless mice evoked by triamcinolone injection. Group A and Group B also showed some effect, but there was no statistical significance.

• Journal of Animal Science and Technology
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• 제60권6호
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• pp.10.1-10.6
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• 2018

Background: Stress causes inflammation that impairs intestinal barrier function. Dietary spray-dried plasma (SDP) has recognized anti-inflammatory effects and improvement of gut barrier function. Therefore, the purpose of this study was to investigate the effects of dietary SDP on intestinal morphology of mated female mice under stress condition. Results: Villus height, width, and area of small intestines were low on gestation day (GD) 3 or 4 under stress conditions, and higher later (Time, P < 0.05). Crypt depth of colon was low on GD 4 and higher later (Time, P < 0.05). Meanwhile, the SDP treatments improved (P < 0.05) intestinal morphology, indicated by increased villus height, villus width, villus area, and ratio between villus height and crypt depth of small intestines and crypt depth of colon, and by decreased crypt depth of small intestines, compared with the control diet. The SDP treatments also increased (P < 0.05) the number of goblet cells in intestines compared with the control diet. There were no differences between different levels of SDP. Conclusion: Dietary SDP improves intestinal morphology of mated female mice under stress condition.

• Asian-Australasian Journal of Animal Sciences
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• 제22권12호
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• pp.1667-1675
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• 2009

This study was conducted to determine whether L-arginine (Arg) supplementation could improve intestinal function in weaned pigs after an Escherichia coli lipopolysaccharide (LPS) challenge. Treatments included: i) non-challenged control (CONTR, pigs fed a control diet and injected with sterile saline); ii) LPS-challenged control (LPS, pigs fed the same control diet and challenged by injection with Escherichia coli LPS); iii) LPS+0.5% Arg (pigs fed a 0.5% Arg diet and challenged with LPS); and iv) LPS+1.0% Arg (pigs fed a 1.0% Arg diet and challenged with LPS). On d 16, pigs were administrated with LPS or sterile saline. D-xylose was orally administrated at 2 h following LPS challenge, and blood samples were collected at 3 h following LPS challenge. At 6 h post-challenge, pigs were sacrificed and intestinal mucosa samples were collected. Supplementation of Arg attenuated LPS-induced damage in gut digestive and barrier functions, as indicated by an increase in ileal lactase activity, and duodenal and ileal diamine oxidase activities (p<0.05). Arg administration also prevented the increase of jejunal malondialdehyde content and the decrease of ileal superoxide dismutase activity by LPS challenge (p<0.05). Furthermore, the jejunal nitric oxide level and inducible nitric oxide synthase activity were also improved after Arg supplementation (p<0.05). These results indicate that Arg supplementation has beneficial effects in alleviating the impairment of gut function induced by LPS challenge.

• 한국식품저장유통학회지
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• 제24권2호
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• pp.320-324
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• 2017

본 연구에서 루꼴라(Eruca sativa)에 대한 다양한 생리활성을 조사하여 기능성소재 응용가능성을 검토하였다. 루꼴라 추출물은 B. subtilis, E. coli, C. albicans에 대한 항균활성이 매우 우수하게 나타났으며 특히 그람양성세균 B. subtilis에 대한 항균활성이 높았다. 또한, 인볼루크린 발현에 대한 면역조직화학 분석을 인공피부를 이용하여 분석한 결과 루꼴라 추출물을 처리(50 mg/L)한 경우에 0.1% DMSO로 처리한 대조군에 비하여 인볼루크린 발현이 뚜렷하게 증가하였으며 동일농도로 처리된 합성물질 WY14643과 비교하였을 때에도 비슷한 발현양상을 보여 주었다. 이와 같은 결과로 미루어 볼 때 루꼴라 추출물은 피부염 개선 및 피부장벽 기능을 향상할 수 있는 천연물 기반의 소재로 활용하기 위한 매우 효과적인 재료가 될 수 있다고 사료된다.

• 한국전기전자재료학회논문지
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• 제22권5호
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• pp.425-430
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• 2009

$ZrO_2$ film was deposited by facing target sputtering (FTS) system on polyethylene naphthalate (PEN) substrate as a gas barrier layer for flexible organic light emitting devices (FOLEDs), In order to control the heat of the FTS system caused by the ion bombardment in the cathode compared with the conventional sputtering system, the process characteristics of the FTS apparatus are investigated under various sputtering conditions such as the distance between two targets ($d_{TT}$), the distance between the target and the substrate ($d_{TS}$), and the deposition time. The $ZrO_2$ film by the FTS system can reduce the damage on the films because the ion bombardment with high-energy particles like gamma-electrons, Moreover, the $ZrO_2$ film with optimized condition ($d_{TT}$=140 mm) as a function of the distance from center to edge showed a very uniform thickness below 5 % for a deposition time of 3 hours, which can improve the interface property between the anode and the plastics substrate for flexible displays, It is concluded that the $ZrO_2$ film prepared by the FTS system can be applied as a gas barrier layer or an interlayer between the anode and the plastic substrate with good properties of an uniform thickness and a low deposition-temperature.

• 한국응용과학기술학회지
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• 제38권6호
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• pp.1383-1392
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• 2021

호장근, 적하수오, 대황, 알로에 등과 같은 생약재의 주요 약리 활성 성분인 emodin은 항산화, 항균, 항염, 항암, 간보호 등에 효능이 있는 것으로 보고되었다. 본 연구에서는 emodin의 피부 질환 및 기능성 소재로서의 활용 가능성을 알아보기 위해 염증 개선과 피부장벽기능 개선 관련 활성을 확인하였다. human keratinocyte인 HaCaT 세포에 대하여 항염효과를 관찰하기 위해 cytokine억제능은 ELISA kit로, 단백질 발현은 western blot으로 확인하였다. TNF-α (10 ng/mL)/IFN-γ (10 ng/mL)로 활성화된 HaCaT 세포에서 emodin을 농도별(5, 10, 20, 40) µM로 처리한 결과 TNF-α, IL-1β 및 IL-6의 생성량은 emodin의 농도가 증가함에 따라 감소됨을 확인하였다. 염증관련 단백질인 iNOS, COX-2 발현량에 대한 실험결과에서도 emodin 20 µM 농도에서 control 대비 iNOS는 48%, COX-2는 29%가 저해됨을 확인하였다. 피부장벽기능 개선의 지표로써 filaggrin, involucrin, loricirn의 mRNA 발현 정도와 filaggrin, involucrin, loricirn의 생성량을 확인한 결과 에모딘 농도에 의존적으로 증가하는 우수한 결과가 얻어졌다. 특히 20 µM 농도에서 대조군 대비 2배의 생성량 증가를 보인 filaggrin은 천연보습인자인 NMF의 형성에 관계되는 단백질로 각질층의 보습에 중요한 역할을 하는 것으로 알려져 있다. 결론적으로 emodin의 피부 질환 및 기능성 소재로서의 활용 가능성 중 염증 개선 및 피부장벽기능 개선 소재로 활용될 수 있음을 확인하였으며 향후 추가적인 연구가 수행되면 그 활용 범위가 더 넓어질 수 있을 것으로 사료된다.

• Journal of Korean Dental Science
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• 제14권1호
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• pp.12-25
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• 2021

Purpose: (i) To evaluate the biologic properties of a bi-layered 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride-cross-linked collagen membrane (CCM) in vitro. (ii) To assess the efficacy of CCM for localized bone regeneration in vivo. Materials and Methods: Biodegradation of CCM compared to a native collagen membrane (NCM) was assessed in vitro. In vivo, twelve male New Zealand White rabbits were used. Four calvarial, circular defects (diameter 8 mm) were created in each animal. The sites were randomly allocated to i) CCM+biphasic calcium phosphate (BCP) (CCM-BCP group), ii) CCM alone (CCM), iii) BCP alone (BCP) and, iv) negative control (control). Animals were sacrificed at 2 (n=6) and 8 weeks (n=6). Outcome measures included: micro-computed tomography (μCT) analysis (total augmented volume [TAV], new bone volume) and histomorphometry (total augmented area [TAA], newly formed bone, remaining membrane thickness [RMT]). Result: CCM was more resistant to degradation than NCM. μCT analysis showed CCM-BCP (196.43±25.30 mm³) and BCP (206.23±39.13 mm³) groups had significantly (P<0.01) larger TAV than the control (149.72±12.28 mm³) after 8 weeks. Histomorphometrically, CCM-BCP group (17.75±5.97 mm²) had significantly (P<0.01) greater TAA compared to the CCM group (7.74±2.25 mm²) and the control (8.13±1.81 mm²) after 8 weeks. After 8 weeks, RMT was reduced by 67%. Conclusion: CCM can be a favorable choice of barrier membrane when performing guided bone regeneration (GBR) in localized bone defects. CCM has better resistance to degradation than the natural collagen membrane, in vitro. In vivo, CCM provides an advantageous integration of prolonged barrier function and biocompatibility for GBR.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.44-44
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• 2010

In this presentation, noise control materials will be discussed from several points-of-view. First, materials will be categorized in terms of their intended function: i.e., as dissipative materials, as barriers, and as media intended to modify some aspect of the sound field. Within each category, example implementations will be described as will modeling procedures. In the context of barrier materials, recent developments in the area of metamaterials will be described briefly, and problems with some recently suggested approaches will be highlighted. Acoustical cloaking will be described as a method of modifying a sound field in such a way that a sensitive area is shielded from noise exposure; the practical difficulties of this approach will also be described. Finally, within each category of material and approach, a series of suggested research challenges will be described.