• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.247-248
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• 2011

• 한국식품영양과학회지
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• 제13권1호
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• pp.42-50
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• 1984

설탕이나 꿀에졸인 한국의 전통적인 한과류의 하나인 정과를 1600년대 부터 현재 까지 소개된 조리책을 중심으로 정과의 변천과정을 정리하고 아울러 연근정과를 주제로 연근의 삶는 방법과 물, 설탕, 꿀의 배합비, 졸임시간의 변화가 연근정과의 모양, 맛, 질감, 색에 어떤 영향을 주는 가를 관능검사와 기계적 방법으로 알아내어 가장 과학적이고 효과적인 제조방법을 알아낸 결과는 다음과 같다. (1) 조리책에 소개된 정과의 종류는 34종류이며 그 중 연근정과가 가장 많이 소개되었다. (2) 처음에는 정과를 졸일 때. 꿀을 사용했으나 1843년에 출판된 음식법(飮食法)에서 처음으로 설탕을 사용해서 졸인 감자정과가 소개되었다. (3) 연근을 7 mm 두께로 썰어 물 150 ml, 연근 100 g, 식초 4 ml를 넣고 12분간 삶는다. 이 때의 hardness는 5.86 mm였다. (4) 모양, 맛, 진감, 적에 가강 좋은 영향을 주는 물의 량은 200 ml 였고 이 때의 hardness는 3.3 mm 였다. (5) 모양, 맛, 질감, 색에 가장 종은 영향을 주는 설탕의 양은 30 I이었고 이때의 hardness는 3.8mm 이었다. (6) 모양, 맛, 질감, 색에 가장 좋은 영향을 주는 꿀의 앙은 40 g 이었고 이 때의 hardness는 4.9 mm 였다. (7) 가장 좋은 졸임시간은 삶은 연근 100 g에 물 200 ml, 설탕 30 g을 넣고 30분간 졸이다가 꿀 40 g을 넣어 12분간 졸인다. 이 때의 hardness는 4.9 mm 였다. (8) 연근정과를 만드는 가장 좋은 방법은 연근 100 g, 물 200 ml, 설탕 30 g꿀 40 g으로 총 42분간 졸이는 것이다.

• 한국환경과학회지
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• 제22권2호
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• pp.243-249
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• 2013

Fibers of microbial polyesters, poly(3-hydroxy butyrate) (PHB) and poly(3-hydroxy butyrate-co-3-hydroxy valerate) (HB-co-HV) were prepared by electrospinning method. The obtained fibers were evaluated by differential scanning calorimetry, scanning electron microscopy, and oil absorption. The formation of fibers was strongly dependent on a concentration of solution. At a low concentration, the fibers contained beads which is from aggregation of polymer due to short evaporation time. The fine fibers with $2-5{\mu}m$ diameter were obtained at 20 wt% concentration. The contact angle measurement showed that the fiber had higher water contact angle than the film due to the lotus-like effect. Oil absorbency showed that the fiber had higher than the film. Specially, the HB-co-HV fiber which was spinned from 20 wt% absorbed 65% oil which is much higher than that of a normal polypropylene-based oil paper.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.409-414
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• 2007

Wettability of solid surfaces with liquids is governed by the chemical properties and the microstructure of the surfaces. We report on the preparation of liquid-repellent surfaces using surface-attached monolayers of perfluorinated polymer molecules on porous silica substrates. A covalent attachment of the polymer molecules to the substrate is achieved by generation of the polymer chains through starting a surface-initiated radical-chain polymerization of a fluorinated monomer. To this, self-assembled monolayers of azo initiators are attached to silica substrates, which are used to kick off the polymerization reaction in situ. The growth of the fluorinated polymer films and the characterization of the obtained surfaces by surface plasmon spectroscopy, XPS, and contact angle measurements is described. It is shown that perfluorinated polymer films can be grown with controlled thicknesses on flat and even on porous silica surfaces, essentially without changing the surface roughness. The combination of the low surface energy coating and the surface porosity allows generation of materials which are both water and oil repellent.

• 농업생명과학연구
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• 제46권2호
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• pp.115-127
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• 2012

Antioxidant and neuronal cell protective effects of aqueous extract from lotus (Nelumbo nucifera) leaf tea (LLTE) were investigated. The 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging effect, ferric reducing antioxidant power, and malondialdehyde inhibition of LLTE were increased in a dose dependent manner. Intracellular reactive oxygen species accumulation resulting from hydrogen peroxide ($H_2O_2$) treatment was significantly reduced when LLTE were present in the media compared to PC12 cells treated with $H_2O_2$ only. In neuronal cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT), LLTE showed protective effect against $H_2O_2$-induced neurotoxicity. In addition, lactate dehydrogenase release into medium was also inhibited by LLTE (7.13-43.89%). Total phenolics of LLTE were 33.16 mg/g and a quercetin was identified as major phenolics (105.93 mg/100g). Therefore, above these data suggest that LLTE including quercetin may be useful in the natural antioxidant substance, and may reduce the risk of neurodegenerative disease.

• 한국자원식물학회지
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• 제20권2호
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• pp.177-184
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• 2007

새로운 기능성 소재를 탐색하기 위하여, 13종의 식용 및 약용식물의 종자추출물을 조제하여 생리활성물질 함량, 항산화활성 그리고 tyrosinase 억제활성을 분석하였다. 총 폴리페놀 및 플라보노이드 함량은 주목에서 각각 $57.51mg{\cdot}g^{-1}$과 $7.98mg{\cdot}g^{-1}$으로 가장 높게 나타났다. 종자추출물의 DPPH 라디칼 소거 활성은 머루$\times$'캠벨얼리' 교배종에서 $RC_{50}$이 $0.03mg{\cdot}ml^{-1}$로 가장 높았고, ABTS 라디칼 소거활성은 고음나무 종자에서 $RC_{50}$이 $0.109mg{\cdot}ml^{-1}$로 가장 높게 나타났다. Ferric thiocyanate(FTC) 방법으로 linoleic acid에 대한 과산화 억제효과를 조사한 결과, 감나무, 고욤나무, 당후박나무, 쪽동백나무, 머루, 머루$\times$'캠벨얼리' 교배종, 묏대추나무, 대추나무의 종자추출물에서 BHT와 유사한 수준의 억제활성을 보였다. 종자추출물의 tyrosinase 억제활성은 감나무, 고욤나무, 탱자나무, 벚나무, 묏대추나무, 대추나무에서만 나타났으며, 특히 고음나무에서 가장 높았다.

• 동의신경정신과학회지
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• 제24권3호
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• pp.309-320
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• 2013

Objectives : There is a possibility LRE as remedy in Alzheimer disease (AD), but it's nerve protection effect and mechanism have to be elucidate. In this research, we applied LRE on $A{\beta}_{25-35}$ pre-treated SH-SY5Y cells, to find out the nerve protection effect and mechanism in AD cell model. Methods : We tried to confirm that effect by experimenting with 20, 50, and $100{\mu}g/ml$ concentration of LRE as a medicine. Next experiment, we assessed damage effect which induced $A{\beta}_{25-35}$, known to cause AD, on SH-SY5Y cell. In addition, cellular viability test is executed under $H_2O_2$ treatment condition in a SH-SY5Y cell. Results : 1. In $A{\beta}_{25-35}$ treated SH-SY5Y cell, LRE exhibited an anti-phosphorylation effect about tau protein, JNK, and IKB. 2. LRE prevent nerve cell apoptosis, which indued $A{\beta}_{25-35}$ and oxidative stress, modify JNK engaged synaptic structure and $NF{\kappa}B$ induced p75-neurotrophin receptor polymorphism. Conclusions : We found that LRE prevented oxidative stress-induced cellular destruction, for example, increased SOD activity of $A{\beta}_{25-35}$ treated SH-SY5Y cell and reduced toxicity of oxygen free radical. Consequently, the ingredients of LRE have a role as a catalyzer for $A{\beta}_{25-35}$ clearance and as scavenger for active oxygen free radical.

• 동의생리병리학회지
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• 제27권5호
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• pp.631-636
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• 2013

This study was to evaluate the antioxidant properties of the leaf extracts of Diospyros lotus (DLE) on the chemical-induced free radical and rat red blood cell (RBC) oxidative damage in vitro. DLE were prepared by extracting with water. DLE showed the high antioxidant activities on the scavenging of 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)-induced radicals. An antioxidant activities of DLE was similar to the reference antioxidant butylated hydroxytoluene (BHT) and (${\pm}$)6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox). Reducing power of $1,000{\mu}g/mL$ DLE also was similar to the vitamin C. In RBC, oxidative hemolysis induced by the aqueous peroxyl radical generator (2,2'-Azobis (2-methylpropionamidine) dihydrochloride (AAPH)) were significantly suppressed by DLE in a dose-dependent manner. Furthermore, DLE prevented the depletion of cytosolic antioxidant glutathione in RBC damaged with AAPH. These results suggest that DLE may has value as natural product with its high quality antioxidant properties against oxidative stress.

• Tribology and Lubricants
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• 제22권5호
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• pp.237-242
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• 2006

Surfaces found in nature, including biological surfaces have been providing inspiration to modify/fabricate artificial surfaces as solutions for tribological applications. As an example, the concept of 'lotus-effect' has motivated tribologists world wide to modify/fabricate surfaces for enhanced tribological performance. These was done by creating nano/micro-scale asperities on various surfaces using ion beam milling and ion-beam assisted roughening. In order to understand the attributes of natural surfaces, which are inspirational to tribologists, we characterized the surface of two natural surfaces-Nelumbo nucifera (lotus) and Colocasia esculenta leaves. Further, we evaluated their micro-scale friction property, both in their fresh and dried conditions. The characterization of surfaces was conducted using a confocal microscope and SEM, which involved the evaluation of size and distribution of protuberances. The micro-scale friction property was evaluated using a ball-on-flat type micro-tribo tester, under reciprocating motion. A soda lime glass ball (2 mm diameter) was used in these tests. Tests were conducted at the applied normal load of $3000{\mu}N$, at a sliding speed of 1 mm/sec for a scan length of 3 mm. All experiments were conducted at ambient temperature ($24{\pm}1^{\circ}C}$) and relative humidity ($45{\pm}5%$). It was observed that the friction behaviour of the natural surfaces was influenced by their surface characteristics (morphology and distribution of protuberances) and also by the condition (fresh or dried) in which they were tested.

• Preventive Nutrition and Food Science
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• 제20권1호
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• pp.22-28
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• 2015

Phenolic rich ethyl acetate fraction (EAF) from lotus leaves was prepared and its bioactive components, antioxidant and cytoprotective effects were investigated. EAF showed high total phenolic content and flavonoid content and contained rutin ($11,331.3{\pm}4.5mg/100g\;EAF$), catechin ($10,853.8{\pm}5.8mg/100g\;EAF$), sinapic acid ($1,961.3{\pm}5.6mg/100g\;EAF$), chlorogenic acid ($631.9{\pm}2.3mg/100g\;EAF$), syringic acid ($512.3{\pm}2.5mg/100g\;EAF$), and quercetin ($415.0{\pm}2.1mg/100g\;EAF$). EAF exerted the $IC_{50}$ of $4.46{\mu}g/mL$ and $5.35{\mu}g/mL$ toward DPPH and ABTS cation radicals, respectively, and showed strong reducing power, which was better than that of ascorbic acid, a positive control. Additionally, EAF protected hydroxyl radical-induced DNA damage indicated by the conversion of supercoiled pBR322 plasmid DNA to the open circular form and inhibited lipid peroxidation of polyunsaturated fatty acid in a linoleic acid emulsion. In cultured hepatocytes, EAF exerted a cytoprotective effect against oxidative stress by inhibiting intracellular reactive oxygen species formation and membrane lipid peroxidation. In addition, depletion of glutathione under oxidative stress was remarkably restored by treatment with EAF. The results suggest that EAF have great potential to be used against oxidative stress-induced health conditions.