• 대한화장품학회지
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• 제30권2호
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• pp.221-225
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• 2004

인삼(Panax ginseng C. A Meyer)의 뿌리는 전통적인 항-노화 및 항-주름제로 동양에서 사용되어 왔다. 그러나 인삼의 어떤 성분이 주름 형성을 억제하는데 효과적인지는 아직 밝혀지지 않았다. 최근 인삼의 주요 활성 성분으로 생각되는 ginsenosides가 20가지 이상 분리되었다. 이들 중 본 연구원들은 인삼에 의한 항-주름의 작용기작을 밝히기 위해 세포간질(extracellular matrix, ECM) 물질대사에 있어 ginsenoside Rg3의 진피에서의 효과를 시험하였다. 본 연구에서, ginsenoside Rg3의 항-주름 효과를 연구하기 위해 진피의 세포간질 구성 성분과 성장 인자를 ELISA (enzyme-1in14ed immunosorbent assay) 측정법으로 평가하였다. Ginsenoside Rg3은 human dermal fibroblasts 배양에서 type I procollagen과 fibronectin(FN) 생합성을 농도 증가에 비례하여 촉진시키고(p < 0.05, n=3), 농도에 비례하여 TGF-$\beta$1 수준을 증가 (p < 0.05, n=3) 시키는 것으로 밝혀졌다. RT-PCR 분석에서 AP-1 전사 인자(transcription factor)의 일부인 c-Jun의 mRNA 수준이 human dermal fibroblasts에서 ginsenoside Rg3에 의해 감소되었다. 이들 결과들은 ginsenoside Rg3이 fibroblasts에서 TGF-$\beta$1과 AP-1의 발현을 변화시킴으로써 type I collagen과 FN합성을 촉진시킴을 보여준다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.405-418
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• 2007

Mesenchymal stem cells(MSCs) have been though to be multipotent cells that can replicate that have the potential to differentiate into lineages of mesenchymal tissue including the bone, cartilage, fat, tendon, muscle, and marrow stroma. Especially, scaffolds to support cell-based tissue engineering are critical determinants of clinical efforts to regenerate and repair the body. Selection of a matrix carrier imvolves consideration of the matrix's role as a scaffold for physical support and host tissue integration as well as its ability to support of synergize the osteoinductive program of the implanted mesenchymal stem cell. The aim of this study is to evaluate the effect of autobone and Bio-$Oss^{(R)}$ to adherent mesenchymal stem cells as scaffolds on sinus augmentation with fibrin glue mixture in a rabbit model. 16 New Zealand White rabbits were divided randomly into 4 groups based on their time of sacrifice(1, 2, 4 and 8 weeks). First, mesenchymal stem cells were isolated from iliac crest marrow of rabbits and expanded in vitro. Cell culture was performed in accordance with the technique described by Tsutsumi et al. In the present study, the animals were sacrificed at 1, 2, 4 and 8 weeks after transplantation, and the bone formation ability of each sides was evaluated clinically, radiologically, histologically and histomorphologically. According to the histological observations, autobone scaffolds group showed integrated graft bone with host bone from sinus wall. At 2 and 4 weeks, it showed active newly formed bone and neovascularization. At 8 weeks, lamellae bone was observed in sinus graft material area. Radiologically, autobone with stem cell showed more radiopaque than Bio-$Oss^{(R)}$ scaffolds group. there were significant differences in bone volume between 4 and 8 weeks(p<0.05).

• 대한화장품학회지
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• 제31권4호
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• pp.311-321
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• 2005

차(Camellia sinensis)는 세계적으로 애용되는 음료이다. 그 중, 아시아권에서 주로 소비되는 녹차는 다양한 생리활성을 가지고 있어 화장품, 기능성식품을 위한 기능성 소재로서 선호되고 있다. 녹차의 피부에 대한 활성은 세포보호에서부터 피부 기질 단백질의 합성까지 다양하게 나타난다. 녹차 폴리페놀(green tea polyphenols; GTPs)은 활성을 나타내는 주성분으로서 항산화 활성 이외에 항암, 항염증, 피부면역능 저하방지활성 등을 보이며, 세포내 신호전달 경로에도 관여한다 GTPs는 표피각질형성세포에서 자외선 조사에 의한 산화 스트레스를 감소시키고, 그에 따르는 mitogen-activated protein kinase (MAPK) 신호전달과 세포사멸을 억제한다. 또한, 같은 세포에서 tumor necrosis factor alpha $(TNF{\alpha})$나 다른 화학물질에 의해 cyclooxygenase-2(COX-2), interleukin-8 (IL-8) 및 vascular endothelial growth factor (VEGF) 같은 염증매개물질이 유발되는 것을 막아준다. 또한, GTPs는 등물실험에서 화학물질이나 자외선에 의한 피부암의 발생도 억제하는데, 경구투여 외에 경피투여로도 효과가 있었다. 피부보호작용 이외에도 GTPs는 각질형성세포의 분화촉진, 노화된 피부세포의 증식능 회복, 피부기질단백질의 분해억제 등의 기능이 있으며, 피부세포에서의 기질단백질 생합성을 직접적으로 촉진하기도 한다. 녹차성분이 보이는 이러한 피부에 대한 활성은, 제형 측면에서의 연구가 진행되어 감에 따라 보다 효과적인 피부를 위한 소재로서의 사용 가능성을 더욱 높여주고 있다.

• 한국산학기술학회논문지
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• 제20권1호
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• pp.304-312
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• 2019

4차 산업혁명 시대에 서비스기업에서도 각기 다른 다양한 차별화 정책을 내세우고 있다. 기존까지 단순하게 고객을 만족시켜 매출을 높이기위한 방법이 아닌 좀 더 원시안적 시각을 갖고 서비스를 제공하는 직원들의 마인드와 그들이 느끼는 환경에 대한 중요성이 점차 커지고 있다. 서비스기업은 궁극적으로 고객만족, 품질향상, 가치 있는 경영 등 긍정적인 경영성과를 나타내기 위하여 끊임없는 노력을 기울이고 있으며 다른 산업에 비하여 직원에 대한 높은 의존도를 가지고 있다. 따라서 고객들을 직접적으로 응대해야하는 서비스제공자인 직원의 마음가짐과 부여된 환경, 역량 등이 직 간접적으로 고객만족 및 성과에 큰 영향을 미칠 수 있다. 궁극적인 조직의 성과를 높이고 경쟁우위를 갖추기 위해서는 결국 서비스 제공자인 직원들에 대하여 개인역량 개발, 근무환경 지원 등 다양한 형태의 사회적 지지가 중요하다고 할 수 있다. 따라서 본 연구에서는 사회적 지지가 서비스종사원의 긍정심리자본, 창의성, 직무성과에 미치는 영향에 관한 연구에 대한 후속연구로 서비스프로세스 메트릭스 가운데 대량서비스영역인 도매점, 소매점, 학교, 은행 등에 종사하는 직원들을 대상으로 동료지지가 자기 효능감을 통하여 성과에 어떠한 영향을 주는지 살펴보았으며, 그 결과 총 3개의 가설 중 3개 모두 채택되었다. 동료와 전반적인 관계가 원활해지면 자기 효능감 또한 향상되고, 자기효능감이 높을수록 직무성과도 높게 나타나며, 동료와 업무적으로나 업무이외에 전반적으로 의지할 수 있다고 느끼는 경우 직무성과도 높게 나타나는 것을 알 수 있다. 본 연구는 대량서비스영역에 종사하는 직원들을 실증분석 대상으로 한 관련연구는 전무한 실정으로 지금까지 연구와는 좀 더 다른 관점으로 접근하여 서비스기업의 경쟁력을 높이기 위한 인적자원관리 측면에서의 전략을 좀 더 효율적이고 효과적으로 제시하여 관련 시사점을 제시하고자 한다.

• 대한본초학회지
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• 제37권5호
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• pp.27-35
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• 2022

Objectives : 3-Acetyl-11-keto-𝛽-boswellic acid (AKBA) is a major active compound in Boswellia serrata. We investigated the arthritic changes following AKBA administration in monosodium iodoacetate (MIA)-induced osteoarthritis rats. Methods : All rats were randomly divided into five groups: Normal, Control, INDO (indomethacin 2 mg/kg treated), AKBA30 (AKBA 30 mg/kg treated), and AKBA60 (AKBA 60 mg/kg treated); drugs were given 2 weeks before MIA injection. For all groups except the normal group, 50 µL of sterile saline with MIA (80 mg/mL) was injected into the right knee joint 2 weeks after drug administration. The drug administration was continued for 4 weeks from 1 week after osteoarthritis induction. The histomorphological changes of knee joint cartilage were observed by H&E staining. Also, the levels of glycosaminoglycan (GAG), cartilage oligomeric matrix protein (COMP), 5-lipoxygenase (5-LOX), 5-LOX-activating protein (FLAP), and leukotriene B₄ (LTB₄) in the knee joint were determined by the ELISA kits. The expressions of mitogen-activated protein kinases (MAPKs), inflammatory cytokines, and matrix metalloproteinases (MMPs) in knee joint were detected by Western blot. Results : Data show that levels of 5-LOX, FLAP, LTB4, and COMP were downregulated significantly in the AKBA treated groups when compared to those in the Control group. On the other hand, GAG levels were significantly elevated. As a result of Western blot, the AKBA-treated groups significantly inhibited phosphorylation of MAPKs. In addition, significant downregulation of the expression of inflammatory cytokines and MMPs was found in the AKBA-treated groups. Conclusion : Our findings suggest that administration of AKBA could exert better chondroprotective and anti-inflammatory effects for MIA-induced osteoarthritis rats.

• 생명과학회지
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• 제33권1호
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• pp.8-14
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• 2023

Peroxidasin (PXDN)은 촉매 도메인 외에도 세포외기질 모티프를 포함한 다양한 도메인을 가진 heme peroxidase로서, collagen IV (Col IV)에서 sulfilimine 가교를 형성하여 Col IV의 스캐폴드를 강화한다. 우리는 이전 논문에서 PXDN이 sulfilimine 가교 의존적인 기질 assembly를 통하여 내피세포 생존 및 성장 신호전달에 필요하다고 보고하였다. 이 연구에서는 내피세포에서의 PXDN 기능에 있어 peroxidase 활성의 필요성을 조사하였다. 첫번째로 peroxidase 도메인의 활성 부위에 존재하며 고도로 보존된 Q823과 D826을 각각 W823, E826으로 치환한 돌연변이체를 제작하였다. 이러한 돌연변이 단백질을 높게 발현하는 HEK293 클론을 분리하였고, 이들 세포를 무혈청 배지에서 24시간 배양하여 조건 배지를 확보하여 평가하였다. 조건 배지에 대해 비환원 조건으로 Western blot 분석을 실시하였을 때, 돌연변이 단백질은 삼량체를 형성하는 것으로 관찰되었고, proprotein convertase에 의해 야생형 PXDN처럼 절단되는 것을 확인하였다. 그러나, peroxidase 활성은 돌연변이 PXDN이 포함된 조건 배지에서 야생형 PXDN과는 대조적으로 관찰되지 않았다. 또한, sulfilimine 가교 형성 능력도 돌연변이 PXDN에서 소실되었음이 확인되었다. 이에 더하여, PXDN이 depletion된 내피세포에 돌연변이 PXDN이 포함된 조건배지를 가하였을 때, 야생형 PXDN 조건배지와 달리 증식을 촉진시키지 못함을 관찰하였다. 이러한 결과들은 PXDN의 peroxidase 활성이 sulfilimine 가교를 형성하여 내피세포 성장에 영향을 미침을 제안한다.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.80-88
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• 2002

Recent studies demonstrate that collagen IV selectively pro-motes the repair of physiological processes in sublethally injured renal proximal tubular ceils (RPTC). We sought to further define the mechanisms of cell repair by measuring the effects of toxicant injury and stimulation of repair by L-ascorbic acid-2-phosphate (AscP), exogenous collagen IV, or function-stimulating integrin antibodies on the expression and subcellular localization of collagen-binding integrins (CBI) in RPTC. Expression of CBI subunits ${\alpha}_1$, ${\alpha}_2$, and ${\beta}_1$ in RPTC was not altered on day 1 after sublethal injury by S-(1,2-dichlorovinyl)-L-cysteine (DCVC). On day 6, expression of ${\alpha}_1$ and ${\beta}_1$ subunits remained unchanged, whereas a 2.2-fold increase in ${\alpha}_2$ expression was evident in injured RPTC. CBI localization in control RPTC was limited exclusively to the basal membrane. On day 1 after injury, RPTC exhibited a marked inhibition of active $Na^+$ transport and a loss of cell polarity characterized by a decrease in basal CBI localization and the appearance of CBI on the apical membrane. On day 6 after injury, RPTC still exhibited marked inhibition of active $Na^+$ transport and localization of CBI to the apical membrane. However, DCVC-injured RPTC cultured in pharmacological concentrations of AscP (500 ${\mu}$M)or exogenous collagen IV (50 ${\mu}$g/ml) exhibited an increase inactive $Na^+$ transport, relocalization of CBI to the basal membrane, and the disappearance of CBI from the apical membrane on day 6. Function-stimulating antibodies to CBI ${\beta}_1$ did not promote basal relocalization of CBI despite stimulating the repair of $Na^+$/$K^+$-ATPase activity on day 6 after injury. These data demonstrate that DCVC disrupts integrin localization and that physiological repair stimulated by AscP or collagen IV is associated with the basal relocalization of CBI in DCVC-injured RPTC. These data also suggest that CBI-mediated repair of physiological functions may occur independently of integrin relocalization.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.993-994
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• 2008

Electrochromic (EC) devices are capable of reversibly changing their optical properties upon charge injection and extraction induced by the external voltage. The characteristics of the EC device, such as low power consumption, high coloration efficiency, and memory effects under open circuit status, make them suitable for use in a variety of applications including smart windows and electronic papers. Coloration due to reduction or oxidation of redox chromophores can be used for EC devices (e-paper), but the switching time is slow (second level). Recently, with increasing demand for the low cost, lightweight flat panel display with paper-like readability (electronic paper), an EC display technology based on dye-modified $TiO_2$ nanoparticle electrode was developed. A well known organic dye molecule, viologen, was adsorbed on the surface of a mesoporous $TiO_2$ nanoparticle film to form the EC electrode. On the other hand, ZnO is a wide bandgap II-VI semiconductor which has been applied in many fields such as UV lasers, field effect transistors and transparent conductors. The bandgap of the bulk ZnO is about 3.37 eV, which is close to that of the $TiO_2$ (3.4 eV). As a traditional transparent conductor, ZnO has excellent electron transport properties, even in ZnO nanoparticle films. In the past few years, one-dimension (1D) nanostructures of ZnO have attracted extensive research interest. In particular, 1D ZnO nanowires renders much better electron transportation capability by providing a direct conduction path for electron transport and greatly reducing the number of grain boundaries. These unique advantages make ZnO nanowires a promising matrix electrode for EC dye molecule loading. ZnO nanowires grow vertically from the substrate and form a dense array (Fig. 1). The ZnO nanowires show regular hexagonal cross section and the average diameter of the ZnO nanowires is about 100 nm. The cross-section image of the ZnO nanowires array (Fig. 1) indicates that the length of the ZnO nanowires is about $6\;{\mu}m$. From one on/off cycle of the ZnO EC cell (Fig. 2). We can see that, the switching time of a ZnO nanowire electrode EC cell with an active area of $1\;{\times}\;1\;cm^2$ is 170 ms and 142 ms for coloration and bleaching, respectively. The coloration and bleaching time is faster compared to the $TiO_2$ mesoporous EC devices with both coloration and bleaching time of about 250 ms for a device with an active area of $2.5\;cm^2$. With further optimization, it is possible that the response time can reach ten(s) of millisecond, i.e. capable of displaying video. Fig. 3 shows a prototype with two different transmittance states. It can be seen that good contrast was obtained. The retention was at least a few hours for these prototypes. Being an oxide, ZnO is oxidation resistant, i.e. it is more durable for field emission cathode. ZnO nanotetropods were also applied to realize the first prototype triode field emission device, making use of scattered surface-conduction electrons for field emission (Fig. 4). The device has a high efficiency (field emitted electron to total electron ratio) of about 60%. With this high efficiency, we were able to fabricate some prototype displays (Fig. 5 showing some alphanumerical symbols). ZnO tetrapods have four legs, which guarantees that there is one leg always pointing upward, even using screen printing method to fabricate the cathode.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.537-539
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• 2006

We developed an 4.5" $192{\times}64$ active matrix organic light-emitting diode display on a glass using organic thin-film transistor (OTFT) switching-arrays with two transistors and a capacitor in each sub-pixel. The OTFTs has bottom contact structure with a unique gate insulator and pentacene for the active layer. The width and length of the switching OTFT is $800{\mu}m$ and $10{\mu}m$ respectively and the driving OTFT has $1200{\mu}m$ channel width with the same channel length. On/off ratio, mobility, on-current of switching OTFT and on-current of driving OTFT were $10^6,0.3{\sim}0.5\;cm^2/V{\cdot}sec$, order of 10 ${\mu}A$ and over 100 ${\mu}A$, respectively. AMOLEDs composed of the OTFT switching arrays and OLEDs made using vacuum deposition method were fabricated and driven to make moving images, successfully.

• 대한치과보철학회지
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• 제28권2호
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• pp.1-28
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• 1990

The severe atrophic edentulism with poor neuromuscular control militates against successful conventional denture therapy. To such situation, a prescribing of dental implant treatment has been considered with some probability. Implant materials used as a trial for dental implants includes metals, plastic polymers and ceramics. The purpose of this study was to observe histologic response in osseointegration process at titanium implant-tissue interface based on biocompatibility at specific period of sequential natures which were divided into a half month, one, month, two months, three months and immediate as a base line. In this study, unilateral lower left premolar and molar teeth were extraced in three dogs. After allowing to heal for 6 months, three kinds of osseointegrated implant, $Br{\aa}nemark$, Corevent and kimplant(a prototype of SNU implant study)were inserted in each dog respectively according to the above sequence from front to back. The specimens were taken from those dogs at the same time since implant were inserted quite reverse order of the specified periods, and decalcified and processed for histologic examination for the light microscopy and the electron microscopy. The microscopic histologic findings at the interface between titanium implants and tissue were interpretated as follows : A. Light microscopic findings : a. Immediate : Implant were surrounded by compact bone and spongy bone. Microcrak was observed in the superficial bone tissue. Osteocytes were disappeared and bone lacunae were observed as a vacant space in some parts. In the contacting with the spongy bone, bone trabeculae and bone marrow were in contact with the implant. b. A half Month : Osteoblasts exist as a monolayer in th inner bone trabeculae and do bone additiocn. Osteoblasts&inflammatory cells were observed in some parts. c. One Month : The presence of osteoclasts decreased. Osteoblasts did active bone fromation, and bone marrow was in contact with the implant in the many places. d. Two Months : Bone formation was advanced in comparison with the b and c. The presence of osteoclsts was not observed. e. Three Months : The superficial bone tissue contacted with the implants was entirely composed by the compact bone. B. Electron microscopic findings : a. A half month and one month group : In the parts of the active bone formation, osteoblasts with the well developed endoplasmic reticulum and Golgi apparatus were arranged in the monolayer. In the parts of the bone resorption, ruffled border was well developed and many osteoclasts with the well-developed golgi apparatus, mitochondria, vacuole, vesicle and lysosome were existed. b. Three months group : No osteoblasts were observed in the superficial bone tissue. Bone matrix with collaen fiber was observed. c. No significant dirrerence in the histologic findings was observed in $Br{\aa}nemark$, Core-vent and kimplant.