• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.509-509
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• 2011

Superhydrophobic surfaces on alloyed steels were fabricated with a non-conventional method of plasma etching and subsequent water immersion procedure. High aspect ratio nanopatterns of nanoflake or nano-needle were created on the steels with various Cr content in its composition. With CF4 plasma treatment in radio-frequence chemical vapor deposition (r.-f. CVD) method, steel surfaces were etched and fluorinated by CF4 plasma, which induced the nanopattern evolution through the water immersion process. It was found that fluorine ion played a role as a catalyst to form nanopatterns in water elucidated with XPS and TEM analysis. The hierarchical patterns in micro- and nano scale leads to superhydrophobic properties on the surfaces by deposition of a hydrophobic coating with a-C:H:Si:O film deposited with a gas precursor of hexamethlydisiloxane (HMDSO) with its lower surface energy of 24.2 mN/m, similar to that of curticular wax covering lotus surfaces. Since this method is based on plasma dry etching & coating, precise patterning of surface texturing would be potential on steel or metal surfaces. Patterned hydrophobic steel surfaces were demonstrated by mimicking the Robinia pseudoacacia or acacia leaf, on which water was collected from the humid air using a patterned hydrophobicity on the steels. It is expected that this facile, non-toxic and fast technique would accelerate the large-scale production of superhydrophobic engineering materials with industrial applications.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.24-24
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• 2018

One of the challenges in tissue engineering is the design of optimal biomedical scaffolds, which can be governed by topographical surface characteristics, such as size, shape, and direction. Of these properties, we focus on the effects of nano - to micro - sized hierarchical surface. To fabricate the hierarchical surface structure on poly(${\varepsilon}$-caprolactone) (PCL) film, we employed a nano/micro-casting technique (NCT) and modified plasma process. The micro size topography of PCL film was controlled by sizes of the micro structures on lotus leaf. Also, the nano-size topography and hydrophilicity of PCL film were controlled by modified plasma process. After the plasma treatment, the hydrophobic property of the PCL film was significantly changed into hydrophilic property, and the nano-sized structure was well developed, as increasing the plasma exposure time and applied power. The surface properties of the modified PCL film were investigated in terms of initial cell morphology, attachment, and proliferation using osteoblast-like-cells (MG63). In particular, initial cell attachment, proliferation and osteogenic differentiation in the hierarchical structure were enhanced dramatically compared to those of the smooth surface.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.799-804
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• 2012

Recently micro-nano structures has widely been reported to improve the performance of waterproof, heat isolation, sound and light absorption in various fields of electric devices such as mobiles, battery, display and solar panels. A lot of micro-sized holes on the surface of thin film provide excellent sound, or heat, or light transmission efficiency more than solid film and simultaneously nano-sized protrusions around micro hole increase the hydrophobicity of the surface of thin film because of lotus leaf effects as generally known previously. In this paper new rapid fabrication process with 355 nm UV laser ablation was proposed to get micro-nano structures on the surface of thin film, which have only been observed at higher laser fluence. Developed thin micro-nano structured film was also investigated the hydrophobic property by measuring the contact angle and demonstrated the possibility to apply to water droplet separation.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.259-261
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• 2011

생약제제 중에서 연은 수련과의 식물로서 예로부터 위염, 출혈, 설사, 치질, 두통, 해독작용 등에 사용되어 왔으며, 민들레는 국화과에 속하는 식물로 천식, 해열, 강장, 부인병 등에 사용되어왔다. 최근에는 이들 생약제제의 약리작용에 대한 연구도 활발하게 이루어져 항산화작용, 항알레르기효과. 항균작용, 항암활성 등에 관한 연구가 보고되고 있다. 이에 본 연구에서는 연잎과, 민들레의 추출물이 치아우식 원인균인 S. mutans에 미치는 항균효과를 연구하고자 하였다. 추출물의 첨가에 따른 S. mutans의 성장억제율을 측정한 결과, 추출물의 농도가 높아질수록 S. mutans의 성장억제율도 높아지는 결과를 얻었다. 이로써 연잎과 민들레 추출물은 S. mutans의 성장을 억제하는 항균효과를 가지고 있음을 본 연구에서 확인 할 수 있었다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.77-83
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• 2022

When carbon dioxide in a liquid becomes supersaturated, carbon dioxide gas bubbles are generated in the liquid, and they ascend to the surface as they develop further. At this time, the inner wall of the cup with carbon gas attached is known as the entrapped gas cavity (EGS); once an EGS is established, it does not disappear and will continuously create carbon bubbles. This bubbling phenomenon can be activated or suppressed by changing the properties of the solid surface in contact with the carbonated liquid. In this study, the foaming of carbonated liquid is promoted or suppressed by modifying the wettability of the surface. A micro/nano surface structure is formed on the surface of an aluminum cup to produce a superhydrophilic surface, and a superhydrophobic surface similar to a lotus leaf is synthesized via fluorination. Experiment results show that the amount of carbon dioxide bubble generated differs significantly in the first few seconds depending on the surface, and that the amount of gas generated after it enters the stabilization period is the same regardless of the wettability of the cup surface.

• Composites Research
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• v.20 no.2
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• pp.17-20
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• 2007

Superhydrophobic polytetrafluoroethylene ($Teflon^{(R)}$, Dupont) sub-micro and nanostructures were fabricated by the dipping method, based on anodization process in oxalic acid. The polymer sticking phenomenon during the replication creates the sub-microstructures on the negative polytetrafluoroethylene nanostructure replica. This process gives a hierarchical structure with nanostructures on sub-microstructures, which looks like the same structures as lotus leaf and enables commercialization. The diameter and the height of the replicated nano pillars were 40 nm and 40 um respectively. The aspect ratio is approximately 1000. The fabricated surface has a semi-permanent superhydrophobicity, the apparent contact angle of the polytetrafluoroethylene sub-micro and nanostructures is about $160^{\circ}$, and the sliding angle is less than $1^{\circ}$.

• Journal of Life Science
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• v.29 no.4
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• pp.436-441
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• 2019

Nelumbo nucifera, also known as sacred lotus, has mainly been used as a food throughout the Asian countries. In the present study, we prepared ethanol extracts from leaf (NL), seed (NS), and seedpod (NSP) of Nelumbo nucifera and investigated their anti-inflammatory activities in mouse macrophage RAW 264.7 cells. To evaluate the anti-inflammatory activities of NL, NS, and NSP, nitric oxide (NO) production was measured in LPS-stimulated RAW 264.7 cells. NL, NS, and NSP significantly reduced NO production in a dose-dependent manner without affecting cell viabilities. NL, NS, and NSP dramatically decreased the protein expression of pro-inflammatory genes such as iNOS and COX-2. NL, NS, and NSP also suppressed phosphorylation of MAPKs and the nuclear translocation of $NF-{\kappa}B$ p65 indicating they have their anti-inflammatory activities via regulating mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B ($NF-{\kappa}B$) pathways. In addition, we analyzed the production of reactive oxygen species (ROS) by the treatment of NL, NS, and NSP. All extracts reduced ROS production in a dose-dependent manner. And also, they increased heme oxygenase-1 (HO-1) protein expression and the nuclear translocation of nuclear respiratory factor 2 (Nrf2). In conclusion, our results suggest that Nelumbo nucifera has its anti-inflammatory activity via regulating MAPKs, $NF-{\kappa}B$, and Nrf2/HO-1 pathways.

• The Korean Journal of Food And Nutrition
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• v.21 no.4
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• pp.448-456
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• 2008

In this study, domestic wheat white breads were prepared with the substitution of 1.5, 3.0, 4.5, and 6.0% Nelumbo nucifera G. tea powder(NNTP). The samples and a control were then compared with regard to quality characteristics, including pH, total titratable acidity, fermentation power of dough expansion, specific volume, baking loss, moisture content, color, textural characteristics, external and internal surface appearances, and sensory qualities in order to determine the optimal ratio of NNTP in the formulation. As the NNTP contents increased, the pH of dough and bread, baking loss, and lightness decreased, whereas the total titratable acidity of dough and bread increased. The fermentation power of dough expansion increased with increasing incubation time. The NNTP samples evidenced significantly higher specific volume, greenness, yellowness, resilience, and crumb consistency than were observed in the control group. However, hardness and fracturability evidenced the opposite effect. The water content and uniformity of the crumb pores were highest at a substitution level of 1.5%, and were lowest at a level of 4.5%. Crumb color, flavor, and delicious taste decreased with increasing NNTP contents, whereas lotus leaf flavor, astringency, bitterness, and off-flavor increased. Density of the crumb pore and crumb springiness were not significantly different among the samples. Softness, chewiness, and overall acceptability were maximal with the 1.5% substitution, and were minimal in the 6.0% group. In conclusion, our results demonstrate that $1.5{\sim}3.0%$ NNTP may prove quite useful as a substitute for domestic wheat flour in the production of white bread, and may evidence favorable nutritional and functional properties.

• Korean Journal of Medicinal Crop Science
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• v.17 no.2
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• pp.133-138
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• 2009

Nelumbo nucifera (lotus) is known to be a useful medicinal plant and leaf extract contains several flavonoids and alkaloids. To analyze the effect of Nelumbo nucifera leaves extract (NNL) on the HBsAg production, we treated NNL on HepG2.2.15 cells which contain the hepatitis B viral genome and secrete surface antigen into media. NNL suppressed the production of hepatitis B surface antigen as a dose-dependent manner. To analyze the effect of NNL on HBV DNA replication, PCR analysis was performed. NNL was not affected the HBV DNA replication and HBsAg mRNA expression. To understand the effect of NNL on the production of HBsAg, we carried out the analysis of lipid-metabolizing gene expression using one-step RT-PCR. NNL reduced the gene expression of FASN and SREBP2 and increased the expression of LDLR. Triglyceride content of HepG2.2.15 cells was not decreased by treatment of NNL. This result suggests a possibility that NNL may have an effect for the inhibition of hepatitis B surface antigen by modulation of lipid and cholesterol metabolism.

• Journal of Korean Medical classics
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• v.30 no.1
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• pp.17-29
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• 2017

Objectives : Many curative methods are used utilized in order to rid human body of disease when people become sick. Traditional Korean medicine generally prescribe methods that involve acupunture, moxibustion, or herb formulae. However, different types of foods are sometimes used as well. While wondering the history and efficacy of Qi-elevation foods that were consumed by Koreans in the past, the author discovered that a record from the Joseon Dynasty, called The Daily Record of Royal Secretariat of Joseon Dynasty, henceforth the Records, contained information about different types of porridge. Hence, the author looked through the records of porridge as written in the historical material in an attempt to learn the examples and efficacy of medicine-porridge consumed in Joseon's royal palace. Methods : After searching for the keyword, 'porridge', in the Records as provided by the National Institute of Korean History, the author extracted the porridges recorded during the Yeongjo period that each has its own special name. Results : Different types of porridge were recorded in the Records as following: arrowroot porridge, bean-leaf porridge, mung bean porridge, bean porridge, malt-rice porridge, oriental arborvitae seed porridge, crucian porridge, lotus seed porridge, adlay porridge, red bean porridge, welsh onion porridge, milk porridge, seashell porridge, ginko nut porridge, black sesame porridge, and mandarin porridge. Each porridge was used for the purpose of alleviating any disease that afflicted the king Yeongjo or his royal family members in relation with the ingredient herb's medicinal function. Conclusions : These porridges consumed by the king Yeongjo and his royal family members were used not only with a purpose of aiding their body's recovery from disease, but with the goal to actively curing them of ailments.