• 대한기계학회논문집B
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• 제36권1호
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• pp.37-45
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• 2012

제습로터에서 발생하는 공기누설은 로터와 브러쉬 형태의 누설방지모 틈새의 양단 사이 차압에 의해 발생하는 압력누설이 지배적이며, 실험을 통해 압력누설특성을 파악하였다. 그 결과로, 압력누설량을 로터와 누설방지모의 틈새면적과 차압의 함수로 나타내었다. 위의 상관식을 바탕으로 제습로터의 공기누설모델을 개발하였으며, 실험을 통해 측정된 값과 위 모델을 바탕으로 계산된 값을 비교함으로써 공기누설모델을 검증하였다. 그리고 풍량에 따른 제습로터의 성능실험을 수행하였으며, 공기누설모델을 적용한 성능 분석을 통하여 실질적인 제습량과 공기누설량을 확인 하였다. 또한 동일한 제습로터가 적용된 제습냉방시스템을 고려하여 차압변화에 따른 공기누설의 영향을 공기누설모델을 이용하여 고찰하였다.

• Molecules and Cells
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• 제38권2호
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• pp.163-170
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• 2015

Lipoteichoic acid (LTA) is a major component of the cell wall of Gram-positive bacteria. Its effects on living organisms are different from those of lipopolysaccharide (LPS) found in Gram-negative bacteria. LTA contributes to immune regulatory effects including anti-aging. In this study, we showed that LTA isolated from Lactobacillus plantarum (pLTA) inhibited melanogenesis in B16F10 mouse melanoma cells. pLTA reduced the cellular activity of tyrosinase and the expression of tyrosinase family members in a dose-dependent manner. The expression of microphthalmia- associated transcription factor (MITF), a key factor in the synthesis of melanin, was also decreased by pLTA. Further, we showed that pLTA activated melanogenesis signaling, such as extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinse (PI3K)/AKT. In addition, the expression of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) and HuR, which are important RNA-binding proteins (RBPs), was reduced. pLTA likely degrades MITF via regulation of melanogenic signaling and RNA stability of melanogenic proteins, resulting in the reduction of melanin. Thus, our data suggest that pLTA has therapeutic potential for treating hyperpigmentation disorders and can also be used as a cosmetic whitening agent.

• 한국정보전자통신기술학회논문지
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• 제13권5호
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• pp.344-352
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• 2020

수중음향통신의 적용을 위해 고려되어야 할 두 가지 지표인 성능과 은밀성 관점에서 다중 밴드 통신 기법 및 직접 확산 변조 방식을 적용한 효율적인 통신 모델을 설정하고 성능 분석을 하였다. 최적의 모델에 대한 성능 분석을 위해 송수신기의 채널 부호화 알고리즘을 부호화 비트 수 336 bit를 가지는 부호화율 1/3인 turbo pi 부호화기를 적용하여 등화기와 채널 복호화기를 반복하여 성능을 향상시키는 터보 등화 구조를 제시하였다. 본 논문에서는 다중 밴드 기반 대역 확산 구조의 Rake 처리 과정에서 임계값을 설정하여, 대역 확산 신호의 chip 수를 8개, 16개, 32개로, 다중 밴드 수는 1개에서 4개로 변경하면서 성능을 분석하였다. 시뮬레이션 결과 밴드 수 및 chip 수가 증가함에 따른 성능 이득을 확인할 수 있었으며, 동일한 밴드 수에서 chip 수를 증가시켰을 때 2~3dB 정도 성능이 향상되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.16-18
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• 2002

We attempted to fabricate a dendrimer Langmuir-Blodgett(LB) films containing 48 pyridinepropanol functional end group. As the pyridinepropanol functional group could form a complex structure with metal ions. In this study the samples for electrical measurement were fabricated to two types metal complexes with $Pt^{4+}$ and $Fe^{2+}$ ions by LB method. And we have investigated the surface activity at the air-water interface as well as the electrical properties for the monolayers of pure G4-48PyP dendrimer and its complex with metal ions($Pt^{4+}$ and $Fe^{2+}$ ions). In the surface pressure-area($\pi-A$) isotherms of the dendrimers, the stable condensed films formed at the air-water interface and the metal ions effect showed the difference on molecular behavior. We have studied the electrical properties of the ultra thin dendrimer LB films investigated by the current-voltage(I-V) characteristics of metal/dendrimer LB films/metal(MIM) structure. In conclusion, it is demonstrated that the metal ion around G4-48PyP dendrimer can contribute to make formation of network structure among dendrimers and it result from the change of electrical properties.

• Archives of Pharmacal Research
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• 제27권7호
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• pp.683-692
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• 2004

Curcumin (diferuloylmethane) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. Curcumin has shown anti-carcinogenic activity in animal models. Curcumin possesses anti-inflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes such as lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible nitric oxide synthase; and an effective inducer of heme oxygenase-1. Curcumin is also a potent inhibitor of protein kinase C(PKC), EGF(Epidermal growth factor)-receptor tyrosine kinase and LĸB kinase. Subsequently, curcumin inhibits the activation of NF(nucleor factor)KB and the expressions of oncogenes including c-jun, c-fos, c-myc, NIK, MAPKs, ERK, ELK, PI3K, Akt, CDKs and iNOS. It is proposed that curcumin may suppress tumor promotion through blocking signal transduction path-ways in the target cells. The oxidant tumor promoter TPA activates PKC by reacting with zinc thiolates present within the regulatory domain, while the oxidized form of cancer chemopreventive agent such as curcumin can inactivate PKC by oxidizing the vicinal thiols present within the catalytic domain. Recent studies indicated that proteasome-mediated degradation of cell proteins playa pivotal role in the regulation of several basic cellular processes including differentiation, proliferation, cell cycling, and apoptosis. It has been demonstrated that curcumin-induced apoptosis is mediated through the impairment of ubiquitin-proteasome pathway. Curcumin was first biotransformed to dihydrocurcumin and tetrahydrocurcumin and that these compounds subsequently were converted to monoglucuronide conjugates. These results suggest that curcumin-glucuronide, dihydrocurcumin-glucuronide, tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are the major metabolites of curcumin in mice, rats and humans.

• 대한본초학회지
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• 제30권2호
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• pp.25-30
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• 2015

Objectives : Laver (Porphyra tenera), a red algae species, is one of the most widely consumed edible seaweed in Korea. Laver contains various substances such as essential amino acid, fiber, minerals and polyphenols that benefit human health. In the present study, we prepared ethanol extracts from commercially processed product of Porphyra tenera, and evaluated the growth inhibitory effect against human oral squamous carcinoma YD-10B cells. Methods : Cell viability was measured by MTT assay. Apoptosis was confirmed by TUNEL assay and flow cytometry with the green fluorescent dye FITC annexin V entering apoptotic cells and the red fluorescent dye PI not entering. The expression of the relevant proteins was detected using Western blot. Results : Ethanol extracts of Porphyra tenera (PTE, $50-200{\mu}g/m{\ell}$) caused a significant decrease of cell viability in a dose dependant manner. The cell death occurred as a result of apoptotic process as determined by TUNEL assay and flow cytometric analysis. In line with this observation, decrease in procaspase proteins and increase in cytosolic cytochrome c were observed in cells treated with PTE. In addition, exposure to PTE decreased the expression levels of Bcl-2, and induced PARP cleavage and AIF translocation from mitochondria to nucleus. Conclusions : In conclusion, PTE exerts anti-cancer effects by inducing apoptosis via caspase activation and AIF nuclear translocation in YD-10B cells. These results provide evidence for the possible therapeutic effect of Porphyra tenera in oral cancer cells.

• Journal of Ginseng Research
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• 제46권1호
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• pp.39-53
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• 2022

Ginsenoside Rb₁ (Rb₁), one of the most important ingredients in Panax ginseng Meyer, has been confirmed to have favorable activities, including reducing antioxidative stress, inhibiting inflammation, regulating cell autophagy and apoptosis, affecting sugar and lipid metabolism, and regulating various cytokines. This study reviewed the recent progress on the pharmacological effects and mechanisms of Rb₁ against cardiovascular and nervous system diseases, diabetes, and their complications, especially those related to neurodegenerative diseases, myocardial ischemia, hypoxia injury, and traumatic brain injury. This review retrieved articles from PubMed and Web of Science that were published from 2015 to 2020. The molecular targets or pathways of the effects of Rb₁ on these diseases are referring to HMGB1, GLUT4, 11β-HSD1, ERK, Akt, Notch, NF-κB, MAPK, PPAR-γ, TGF-β1/Smad pathway, PI3K/mTOR pathway, Nrf2/HO-1 pathway, Nrf2/ARE pathway, and MAPK/NF-κB pathway. The potential effects of Rb₁ and its possible mechanisms against diseases were further predicted via Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and disease ontology semantic and enrichment (DOSE) analyses with the reported targets. This study provides insights into the therapeutic effects of Rb₁ and its mechanisms against diseases, which is expected to help in promoting the drug development of Rb₁ and its clinical applications.

• 대한한방내과학회지
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• 제43권6호
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• pp.1089-1104
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• 2022

Objective: The aim of this study was to identify the efficacy and underlying mechanism of cloves as an osteoarthritis (OA) treatment in a monosodium iodoacetate (MIA)-induced rat OA model. Osteoarthritis (OA) is nowadays one of the most prevalent degenerative joint diseases. Methods: Sprague-Dawley rats treated with MIA (50 μL; 80 mg/mL) were used as in vivo OA models. Cloves (100 and 200 mg/kg b.w.) were administered orally once daily for 2 weeks from 7 days after MIA injection. Changes in hindpaw weight distribution (HWD) were measured as a joint discomfort index. Activation markers related to inflammatory responses and cartilage degeneration in the right knee joints were evaluated by serum analysis and western blotting. Results: HWD decreased in the MIA control group but showed a dose-dependent elevation after clove treatment. Clove treatment inhibited inflammatory factors by PI3K/Akt/NF-κB signaling pathways, while also activating antioxidant factors through Sirt1/AMPK signaling pathways. Clove treatment also suppressed matrix metalloproteinase (MMP) overexpression and significantly increased the levels of tissue inhibitors of metalloproteinases (TIMPs). Conclusions: Treatment with cloves effectively reversed MIA-induced effects. Therefore, clove treatment could have the potential to protect against or treat OA.

• 융합보안논문지
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• 제22권1호
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• pp.29-38
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• 2022

감염 질병의 심각한 확산으로 인해 방역의 중요성이 점점 커지고 있다. 또한 방역 이슈가 없는 언택트 산업에 대한 관심도 늘어나고 있다. 본 논문에서는 등록된 사용자의 얼굴을 인식함으로써 비접촉 방식으로 출입을 통제하는 비용 효율적인 라즈베리파이 기반 도어락 시스템을 설계하고 개발한다. 우선, OpenCV의 Haar-based cascade를 사용하여 매우 단순한 특징들을 조합하여 객체를 찾고, 얼굴 인식을 진행한다. 그리고 LBPH (Local Binary Pattern Histogram)을 사용하여 이미지의 질감을 이진화하여 특징을 찾아낸다. 라즈베리파이 3B+ 보드, 초음파 센서, 카메라 모듈, 모터 등으로 언택트 도어락 하드웨어를 구현하고, 얼굴 인식 및 매칭 알고리즘을 포함한 소프트웨어를 기반으로 약 500장의 이미지 데이터를 학습시켜 실험한 결과, 최대 85.7%의 인식률을 보이며 사용자를 구분하는 성능을 검증할 수 있었다. 또한, Haar-cascade 알고리즘 성능의 광원에 대한 영향성을 파악하여 그 개선 가능성을 살펴보았다.

• 한국육종학회지
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• 제41권3호
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• pp.292-298
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• 2009

"금오3호"는 소득작물 전 후작에 적응하는 벼를 육성하고자, 1997년 국립식량과학원 기능성작물부에서 내도복성인 농안벼에 내만식성인 신금오벼가 여교배된 $F_1$ 개체에 도열병에 저항성이고 단기성인 YR15727-B-B-B-102 계통을 교배하여 YR19124 조합을 작성 하였다. 이후 집단 및 계통육종법으로 YR19124-B-B-B-69-3 계통을 선발하고 밀양201호라는 계통명으로 지역적응성검정 시험에 공시한 결과, 그 주요특성과 수량성은 다음과 같다 1. 출수기는 평야지의 소득작물 후작 만기재배에서 8월 26일로 금오벼 보다 4일 빠른 조생종 품종이다. 2. 직립 초형이고 탈립은 약간되는 편이고, 이삭추출은 양호 하고 까락이 거의 없는 편이다. 3. 주당수수는 금오벼 보다 약간 많으며, 수당립수는 적은편이고 현미천립중은 금오벼와 비슷하였다. 4. 도정특성은 금오벼와 비슷하지만 고품질 상품에서 중요한 완전미율과 외관특성은 금오벼 보다 좋은 편이고 밥맛은 금오벼 보다 떨어 젓다. 5. 못자리 육묘기간이 50일 이상이면 본답에서 불시출수가 발생하며, 성숙기 엽노화는 금오벼 보다 빠른 편이다. 내냉성 검정에서 냉수구의 임실율이 금오벼 보다 낮았다. 6. 잎도열병 밭못자리 검정 결과 12개 시험지에서 강한 반응을 보였고, 내구저항성도 높았다. 흰잎마름병 레이스 $K_1$, $K_2$, $K_3$에는 저항성이며, $K_{3a}$에는 이병성이다. 줄무늬잎마름 병에는 저항성이며, 오갈병에는 중도 저항성이고, 검은줄오갈병에는 이병성이다. 내충성에서는 끝동매미충에 저항성이고, 벼멸구와 애멸구에는 감수성이다. 7. 지역적응시험에서 "금오3호"의 쌀 수량성은 4.48 MT/ha로 표준품종 금오벼 대비 6% 증수하였다.