• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.22-29
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• 2008

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3861-3863
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• 2012

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.564-569
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• 2012

Selenium was initially considered toxic to humans, but it was then discovered that selenium is essential for normal life processes. Selenium plays important roles in antioxidants. It is expected that chitosan microcapsules containing nano-selenium will be able to be used as a key material in bio-medical and cosmetic applications. The high concentration of chitosan derivatives guarantees increased antioxidative activity. Both inorganic and organic forms of selenium can be nutritional sources. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. The objective of this experiment was to study the antioxidative activity of chitosan nano-selenium. Our experiments were divided into five groups, in the presence of various concentrations(0.1%, 0.3%, 0.5%, 0.7%, and 0.9%) of chitosan. We performed an assessment of the antioxidant properties and cytotoxicity of respective concentrations of chitosan nano-selenium. The antioxidant activity was examined by the free radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl(DPPH) assay. The cytotoxicity effect was measured by means of 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay. As a result, the electron donating abilities of 0.1%, 0.3%, 0.5%, 0.7%, and 0.9% of chitosan nano-selenium exhibited effective andioxidant scavenging activity at 12.5 ${\mu}g/m{\ell}$ against DPPH radicals. 0.3% chitosan nano-selenium did not show cytotoxicity on human keratinocytes. In general, the cytotoxicity of 0.1% and 0.9% chitosan nano-selenium showed the lowest effects. Though low cytotoxicity of 0.5% and 0.7% chitosan nano-selenium exhibited 29.67% and 38.4% against human keratinocytes on adding 100 ${\mu}g/m{\ell}$ and 50 ${\mu}g/m{\ell}$, respectively, cell vitality was recovered with 200 ${\mu}g/m{\ell}$. These findings support the notion that chitosan nano-selenium may be useful as a new active ingredient source for bioactive compounds.

• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.1-5
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• 2011

In this study, We investigated the properites of nano-emulsions containing hydrogenated lecithin prepared by high pressure homogenizer. The size of droplet of emulsions prepared by homogenizer at various rpm (rotation per minute) was not measured due to the unstability of emulsions, however, the size of droplet of nano-emulsions prepared by high pressure homogenizer was around 300 nm and the appearance of emulsions was bluish. The stability of emulsions with various lecithin concentration was tested against time. POV (Peroxide value) of emulsions were plotted against time. POVs of emulsions prepared with an egg lecithin and a soy lecithin were increased with time, however, POV of emulsion with Lecinol S-$10^{(R)}$ was kept constant within 60 hours and at $60^{\circ}C$. In consumer test, the nano-emulsion showed higher affinity regardless of skin type. Both of irritation scores of emulsions were similar.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.353-362
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• 2005

This article describes a state-of-the art review in nano-biomanipulation technologies. Nanomanipulation of biological objects enables an in-depth study of single molecules such as DNA and RNA, and of biophysical events at the molecular level like molecular motors. Controlled nanomanipulation is challenging but essential for precisely engineering biomolecules or cells and for manufacturing functional nano-biosystems. In this paper, we summarize several contact, non-contact and hybrid methods available for nanomanipulation of biological objects. Advantages currently available methods and their limitations are also compared. Finally, we discuss possible applications of nano-biomanipulation technologies to life science and molecular medicine including cell biology, genetic engineering, biophysics, and biochemistry.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.265-269
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• 2010

In this study, we varied emulsifiers and oils for obtaining nano-emulsions with low viscosity using solubilization method. We obtained the stable nano-emulsions with 100 nm droplet size composed with hexyl laurate, ceteareth-20, PEG-40 hydrogenated caster oil, glyceryl stearate, and stearic acid. This nano-emulsion was stable against time. The stability of nano-emulsions was measured through the change of particle size. The cooling process was an important factor for obtaining stable emulsions by solubilization method. Stability of nano-emulions was maximum only when cooled rapidly.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.1
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• pp.9-14
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• 2008

Formation of oil-in-water nano-emulsions has been studied in oil/hydrogenated lecithin/water systems by two shear different instrument. The influence of surfactant concentration on nano-emulsion droplet size and stability has been studied. Droplet size was determined by dynamic light scattering, and nano-emulsion stability was evaluated by measuring the variation of droplet size as a function of time. The results obtained showed that the breakdown process of nano-emulsions studied could be attributed to Ostwald ripening. An increase of nano-emulsion instability with increase in surfactant concentration was found in the droplet size in the range of 100~200nm, however, an decrease of instability was found in the droplet size in the range of 300~400nm.

• Textile Coloration and Finishing
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• v.26 no.3
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• pp.242-253
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• 2014

Morinda citrifolia, commercially known as Noni, is a tree that grows widely throughout the Pacific, and is recognized as one of the most significant sources of traditional medicines among Pacific Island societies. All parts of the plant have traditional and/or modern uses, including roots and bark(dyes, medicine), trunks(firewood, tools), and leaves and fruits(food, medicine). The bark and the roots of the tree contain red and yellow pigments respectively, which are both used in the manufacture of dyes. Dyes from Noni are being used traditionally, to color clothing and fabrics. In this study, mordanting effects on the dyeing properties of Noni root extract on silk fabrics were investigated.

• Macromolecular Research
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• v.15 no.5
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• pp.424-429
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• 2007

A procedure for the surface hydrolysis of an electrospun poly(${\epsilon}$-caprolactone) (PCL) fibrous scaffold was developed to enhance the adhesion and proliferation of osteoblasts. The surface hydrolysis of fibrous scaffolds was performed using NaOH treatment for the formation of carboxyl groups on the fiber surfaces. The hydrolysis process did not induce deformation of the fibers, and the fibers retained their diameter. The cell seeding density on the NaOH-treated PCL fibrous scaffolds was more pronounced than on the non-treated PCL fibers used as a control. The alkaline phosphatase activity, osteocalcin and a mineralization assay strongly supported that the surface-hydrolyzed PCL fibrous scaffolds provided more favorable environments for the proliferation and functions of osteoblasts compared to the non-treated PCL fibrous scaffolds use as a control.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.339-347
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• 2013

Nano-emulsions are submicron sized emulsions that are under extensive investigation as drug carriers for improving the delivery of therapeutic agents. The aim of this research is to investigate the stability of nano-emulsions containing polymers. Nano-emulsions containing high concentrations of Carbopol 941, Aristoflex AVC, Aronbis M, Permulen TR 2 and Aculyn 44 were unstable compared with macroemulsions with polymers. The size of emulsion droplet manufactured by adding polymer before emulsification were larger than that of emulsion manufactured by adding polymer after the emulsification. The stability of nano-emulsion containing a low concentration of polymer was also decreased, however the effect was lower than that in the high concentration of polymer. Under similar viscosity of polymer, the sequence of unstability was Aristoflex AVC < Carbopol 941 < Permulen TR2 < Carbopol 941 + Aculyn 44 < Aronbis M.