• 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.

• 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.

• 한국식품과학회지
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• 제39권1호
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• pp.14-19
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• 2007

전남도내에서 자생하고 있는 무안의 백련과 나주의 홍련을 대상으로 부위별 이화학적 성분을 분석한 결과 품종별로 큰 차이는 발견할 수 없었으며 두 품종 모두 무기영양성분 중 세포 내 액의 산${\cdot}$알칼리평형에 가장 중요한 mineral인 potassium이 월등히 높은 함량을 보였고 다음으로 sodium, calcium, magnesium이 주요 무기영양성분으로 나타났다. 특이한 것은 뿌리에서의 철분 함유량이 무안의 백련에서 14.70mg%, 나주 홍련에서 9.26mg%로 다른 농산물에 비해 높게 나타나 철 결핍성 빈혈환자나 임신, 출산 등으로 철분의 균형을 잃게 될 수 있는 여성에게 연근이 좋은 영양식이 될 수 있을 것으로 사료된다. 유리당 함유량은 부위별로 큰 차이를 보여 뿌리의 경우 sucrose가 월등히 많은 반면 잎의 경우는 glucose와 fructose가 대부분을 차지하였고 종자의 경우 sucrose, raffinose 및 stachyose가 대부분을 차지하는 것으로 나타났는데 종자의 경우 oligosaccharide를 이용한 기능성 식품으로의 개발 가능성도 있다고 판단된다. 구성아미노산 함유량 또한 부위별로 큰 차이를 보여 종자와 잎에서는 glutamic acid가 가장 많이 함유되어 있는 반면 연근의 경우 간 기능 회복과 숙취제거에 효과가 있는 aspartic acid가 월등히 높은 함유량을 보여 각각 이를 이용한 기능성 식품으로의 이용 가능성도 있을 것으로 사료된다.

• 한국환경복원기술학회지
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• 제9권2호
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• pp.81-89
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• 2006

The purpose of this study was to evaluate the applicability of small RC(radio controlled) helicopter and single lens reflect camera as SFAP(Small Format Aerial Photography) aquisition system to monitor the vegetation coverage of wetland. The system used to take pictures of small artificial wetland were a common optical camera(Nikon F80 with manual lens whose focal length was 28mm) attached to the bottom of a RC helicopter with a 50 cubic inch size glow engine. Three hundreds pictures were taken at the altitude of 50m above the ground, from 23rd June to 7th September 2005. Four from the images were selected and scanned to digital images whose dimension were 2048${\times}$1357 pixels. Those images were processed and rectified with GCP(Ground Control Poins) and digital map, and then classified by the supervised- classification module of image processing program PG-steamer Version 2.2. The major findings were as follows ; 1. The final images processed had very high spatial resolution so that the objects bigger than 30mm like lotus(Nelumbo nucifera), rock and deck were easily identified. 2. The dominant plants of the monitoring site were Monochoria ragianlis, Typha latifolia, Beckmannia syzigachne etc. Because those species have narrow and long leaves and form irregular biomass, the individuals were hardly identifiable, but the distribution of population were easily identifiable depending on the color difference. 3. The area covered by vegetation was rapidly increased during the first month of monitoring. At the beginning of the monitoring 23th June 2005, The rate of area covered by vegetation were only 34%, but after 27 and 60 days it increased to 74%, and the 86% respectively.