• 한국재료학회지
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• 제16권12호
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• pp.719-724
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• 2006

Ultrafine mullite powder was prepared from aluminium-secbutoxide and tetraethyl orthosilicate(TEOS) in the molar $Al_2O_3/SiO_2$=3/2. Sol-gel method by partial hydrolysis technique, as it were, first, TEOS was partially hydrolysized and then mixed with Al-secbutoxide for complete hydrolysis was used. X-ray diffraction, infrared spectroscopy and transmission electron microscopy, etc. confirmed that the mullite powder prepared by this method is in the stoichiometric $Al_2O_3/SiO_2$ ratio. Al-Si spinel was formed at $980^{\circ}C$ and ultrafine mullite powder with about 20 nm particle size was obtained above $1,200^{\circ}C$. Also mullite powders calcined at $1,600^{\circ}C$ had a stoichiometric composition, $3Al_2O_3{\cdot}2SiO_2$ and the lattice constants of the mullite powders calcined above $1,200^{\circ}C$ were almost coincided with theoretical values.

• Journal of Ship and Ocean Technology
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• 제3권1호
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• pp.12-26
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• 1999

A new concept of collision energy absorbing system for ;he New Oil-tankers with Advanced Double Hull Structure(NOAHS and NOAHS II) are presented through the joint-research pro-gran between Inha and Hamburg-Harburg University. A comparative study on col vision resistance of these proposed side structures with standard double hull structure of 310K DWT class VLCC, is carried out. The fatigue investigation of structural detail parts is also included. It contains a comparative fatigue study based on pertinent regulations of Classification Societies.

• 한국가금학회지
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• 제42권4호
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• pp.315-325
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• 2015

최근 소비자의 소득 수준이 향상되고, 육제품의 다원화 성향이 증가하면서 가축개량은 과거 성장 및 육량 중심의 개량에서 품질 중심의 개량으로 중심이 이동하고 있다. 특히, 식육의 품질 중에서 육색은 소비자가 식육을 선택 및 질을 판단하는 기준으로 작용하기 때문에 매우 중요한 형질이라고 볼 수 있다. 경제적으로 유용한 형질은 대부분 측정가능한 연속변이에 해당하고, 이러한 형질은 대부분 여러 유전자가 형질에 영향을 미치는 양적형질 좌위(Quantitative Trait Loci;QTL)에 속한다. Chicken QTL db에 보고된 닭의 육색형질과 관련된 형질들은 육색(Bco, Mco), 가열감량(DL), pH가 보고되어 있으며, 이는 닭의 13개 염색체에서 33개 QTL 및 association 영역이 보고되고 있다. 이 중에서 육색관련 후보 유전자는 APP, BCMO1, COL1A2, FTO, KPNA2, PSMD12, G0S2, FTSJ3가 있으며, 가열감량관련 후보유전자는 AGRP, FTO, pH와 관련된 후보유전자는 GALNT1, PCDH19, DIAPH1, SPP2 유전자로 총 14개 유전자가 확인되었다. 이렇게 확인된 후보유전자 및 QTL 연구결과는 한국재래닭에 적용 및 활용 가능성을 확인해 볼 필요가 있으며, 이러한 적용은 낮은 성장속도의 단점을 가진 한국재래닭의 개발에 있어 품질의 개량속도를 높여 산업적 가치를 빠르게 끌어올릴 수 있는 중요한 표지인자가 될 수 있을 것으로 사료된다.

• 자연과학논문집
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• 제5권2호
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• pp.63-73
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• 1992

There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

• Molecules and Cells
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• 제42권11호
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• pp.763-772
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• 2019

Periodontitis is characterized by the loss of periodontal tissues, especially alveolar bone. Common therapies cannot satisfactorily recover lost alveolar bone. Periodontal ligament stem cells (PDLSCs) possess the capacity of self-renewal and multilineage differentiation and are likely to recover lost alveolar bone. In addition, periodontitis is accompanied by hypoxia, and hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) is a master transcription factor in the response to hypoxia. Thus, we aimed to ascertain how hypoxia affects runt-related transcription factor 2 (RUNX2), a key osteogenic marker, in the osteogenesis of PDLSCs. In this study, we found that hypoxia enhanced the protein expression of $HIF-1{\alpha}$, vascular endothelial growth factor (VEGF), and RUNX2 ex vivo and in situ. VEGF is a target gene of $HIF-1{\alpha}$, and the increased expression of VEGF and RUNX2 proteins was enhanced by cobalt chloride ($CoCl_2$, $100{\mu}mol/L$), an agonist of $HIF-1{\alpha}$, and suppressed by 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1, $10{\mu}mol/L$), an antagonist of $HIF-1{\alpha}$. In addition, VEGF could regulate the expression of RUNX2, as RUNX2 expression was enhanced by human VEGF ($hVEGF_{165}$) and suppressed by VEGF siRNA. In addition, knocking down VEGF could decrease the expression of osteogenesis-related genes, i.e., RUNX2, alkaline phosphatase (ALP), and type I collagen (COL1), and hypoxia could enhance the expression of ALP, COL1, and osteocalcin (OCN) in the early stage of osteogenesis of PDLSCs. Taken together, our results showed that hypoxia could mediate the expression of RUNX2 in PDLSCs via $HIF-1{\alpha}$-induced VEGF and play a positive role in the early stage of osteogenesis of PDLSCs.

• 대한화장품학회지
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• 제47권3호
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• pp.265-271
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• 2021

나노입자(nanoparticles)는 그 크기가 피부를 구성하는 세포보다 작다. 따라서 세포막을 통과하고 약물 또는 유전자를 전달하는 매개체로서의 역할에 매우 적합하며 특정 성분을 피부 속에 전달할 수도 있다. 본 연구에서는 쑥으로부터 나노입자를 추출하여 dynamic light scattering (DLS)를 통해 100 nm 전후 크기의 입자를 얻었음을 확인하였고, MTT assay를 통하여 섬유아세포에서 cell viability를 농도 의존적으로 증진시키는 결과를 얻었다. 또한, quantitative real time PCR 분석법을 통해서 COL1A1 mRNA 발현량을 증가시키고 IL-6 mRNA 발현량은 감소시킴을 확인하였다. 세포실험뿐 아니라 화장품 제형에서도 적용 가능하며, 안정함을 확인하였다. 최근 화장품 산업 동향에서 화학 성분을 배제하고 식물 유래 성분 수요가 지속적으로 높아지고 있는 반면, 식물에서 유래된 나노입자의 응용분야를 제시하는 연구 결과가 거의 없다는 한계가 있다. 따라서 현시점에서의 화장품 산업의 한계점을 극복하고자 본 연구를 통해 얻은 결과를 견주어 쑥으로부터 유래된 나노입자를 고기능성 화장품 소재로서 제시하고자 한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1211-1213
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• 2004

In this paper, in other the study shift a degradation and electrical properties on ZnO based grain beurdry layer, we mearured thermally stmulated current. Also the TSC was investigated for understanding of GBL's interfacial carrier shift on bias voltage, bias time, bias temperature. as a result, the two peahs of $p_1$, $p_2$ was observed by conduction of the trapped carrier of border between the oxidation layer and the grains $P_3$ and $P_4$ Peaks observed to the ionization excition excitation in the grain.

• Journal of Plant Biotechnology
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• 제45권2호
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• pp.83-89
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• 2018

The interplay of plant hormones is one of the essential mechanisms for plant growth and development. A recent study reported that Brassinosteroids (BR) and ABSCISIC ACID (ABA) interact antagonistically in early seedling developments through the BR-mediated epigenetic repression of ABSCISIC ACID-INSENSITIVE 3 (ABI3). However, the other physiological roles of the BR-mediated regulation of ABI3 and ABA responses beyond early seedling developments remain largely unknown. Here, we showed that the activation of BR signaling by high temperatures promotes flowering time through the suppression of ABI3 expressions. Elevated ambient temperature induced early flowering in wild type Col-0 plants, but not in BR-defective bri1-116 mutant plants. Conversely, a hyper BR biosynthetic dwf4-D mutant displayed more sensitive thermomorphic long shoot elongation and early flowering. Both expression patterns and physiological responses supported the biological roles of ABI3 in the regulation of floral transition and reproduction under high temperature conditions. Finally, we confirmed that the lowered expressions of the transcript and protein levels of ABI3 brought on by elevated temperature were correlated with warmth-induced early flowering phenotypes. In conclusion, our data suggest that the BR- and warmth-mediated regulation of ABI3 are important in thermomorphic reproductive phase transitions in plants.

• Nutrition Research and Practice
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• 제11권3호
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• pp.190-197
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• 2017

BACKGROUND/OBJECTIVES: Gallus gallus domesticus (GD) is a natural mutant breed of chicken in Korea with an atypical characterization of melanin in its tissue. This study investigated the effects of melanin extracts of GD on osteoblast differentiation and inhibition of osteoclast formation. MATERIALS/METHODS: The effects of the melanin extract of GD on human osteoblast MG-63 cell differentiation were examined by evaluating cell viability, osteoblast differentiation, and expression of osteoblast-specific transcription factors such as bone morphogenetic protein 2 (BMP-2), small mothers against decapentaplegic homologs 5 (SMAD5), runt-related transcription factor 2 (RUNX2), osteocalcin and type 1 collagen (COL-1) by reverse transcription-polymerase chain reaction and western blotting analysis. We investigated the inhibitory effect of melanin on the osteoclasts formation through tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains in Raw 264.7 cell. RESULTS: The melanin extract of GD was not cytotoxic to MG-63 cells at concentrations of $50-250{\mu}g/mL$. Alkaline phosphatase (ALP) activity and bone mineralization of melanin extract-treated cells increased in a dose-dependent manner from 50 to $250{\mu}g/mL$ and were 149% and 129% at $250{\mu}g/mL$ concentration, respectively (P < 0.05). The levels of BMP-2, osteocalcin, and COL-1 gene expression were significantly upregulated by 1.72-, 4.44-, and 2.12-fold in melanin-treated cells than in the control cells (P < 0.05). The levels of RUNX2 and SMAD5 proteins were higher in melanin-treated cells than in control vehicle-treated cells. The melanin extract attenuated the formation of receptor activator of nuclear factor kappa-B ligand-induced TRAP-positive multinucleated RAW 264.7 cells by 22%, and was 77% cytotoxic to RAW 264.7 macrophages at a concentration of $500{\mu}g/mL$. CONCLUSIONS: This study provides evidence that the melanin extract promoted osteoblast differentiation by activating BMP/SMADs/RUNX2 signaling and regulating transcription of osteogenic genes such as ALP, type I collagen, and osteocalcin. These results suggest that the effective osteoblastic differentiation induced by melanin extract from GD makes it potentially useful in maintaining bone health.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.424-435
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• 2023

본 연구 결과 DPPH 라디칼 소거 활성은 갈랑가 뿌리 70% 에탄올 추출물(AG.E) 100 ㎍/mL 농도에서 81.8%이었으며 ABTS⁺ 라디칼 소거 활성은 AG.E 50 ㎍/mL의 낮은 농도에서 L-Ascorbic acid (AA)와 유사한 99.8%로 확인되었다. 항노화 활성을 측정하기 위하여 collagenase와 elastase 저해 활성을 측정한 결과 둘 모두에서 AG.E는 50 ㎍/mL의 낮은 농도부터 epigallocatechin (EGCG)보다 더 높은 저해 효과를 나타내었다. 특히 500 ㎍/mL 농도에서 EGCG 대비 3배 이상의 저해 효과를 보였다. CCD-986sk 세포내에서 AG.E의 항노화 효과를 검증하기 위해 UVB로 자극한 다양한 실험에서도 우수한 항노화 효과가 얻어졌다. RT-PCR을 통한 유전자 발현 분석 실험에서 COL1A mRNA 발현량은 AG.E 20 ㎍/mL 저농도에서 무첨가 대비 2.90배 증가시키는 결과가 얻어져 항노화관련 우수한 기능성 소재로 개발 가능성이 확인되었다. 제형에 소재의 적용 시 생리활성의 경시적 보전성에 대한 기초 연구로서 AG.E 및 AA등을 안정한 W/O type emulsion에 첨가하여 25 ℃ 항온조에 보관하면서 1일차, 30일차, 60일차에 DPPH와 ABTS+ 라디칼소거 활성을 측정한 결과 모두 경시적으로 항산화 효과가 높은수준 유지됨을 확인하였다.