• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.56.2-56.2
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• 2015

Nonthermal Atmospheric Pressure Plasmas and their Applications to Plasma Bioscience and Medicines have been introduced for next generation human healthcare's quantum developments. Various kinds of nonthermal atmospheric pressure plasmas have been introduced and their electron temperature and plasma densities along with reactive oxygen and nitrogen species have been diagnosed and analyzed for biological cell interactions, especially, used in Plasma Bioscience Research Center (PBRC), Korea. Herein, we have also introduced the plasma-initiated ultraviolet photolysis, which might be a generation mechanism for the reactive oxygen and nitrogen species (RONS) intracellular and extracellular regions inside the liquid when the plasma has been bombarded onto the water. Finally we have investigated the interactions of these RONS with the various cancer cells resulting in apoptotic cell death.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1835-1837
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• 1996

Characteristics of Discharge and nonthermal plasma generation in a micro-air gap spacing between a micro-dielectric barrier and a electrode have been investigated experimentally to chert the potential to be used as a micro-scale nonthermal plasma generator. It is found that the output ozone concentration, as a nonthermal plasma intensity parameter, of the micro-air gnp nonthermal plasma generator depended greatly upon the air gap spacing and thickness of the dielectric barrier. As a result, there is a optimal air gap sparing in the same micro dielectric barrier to generate ozone effectively. And the higher ozone concentration was generated from the thinner micro-barrier.

• Journal of Life Science
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• v.23 no.6
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• pp.838-846
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• 2013

As a forth state of material, plasma is ionized gas, which generates characteristically various reactive species. After late of $20^{th}$ century, plasma has been widely used in industry. After nonthermal atmospheric plasma was developed, it has been applied to biomedical fields. Nonthermal atmospheric plasma does not give thermal damages to human tissues, and it shows the high efficiency in cancer treatment, sterilization, tooth bleaching, coagulation, and wound healing. Because the application of plasma to biomedicine has been expanded through interdisciplinary studies, its value of high medical technology is increasing now. Since nonthermal atmospheric plasma was first applied to the mammalian cells and microorganisms, many valuable studies has been performed for about last 10 years, so that now the new research area called 'plasma medicine' has been formed. This article introduces the recent data resulted from plasma medicine and helps to understand the plasma medicine.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.2
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• pp.31-36
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• 2016

For the purpose of indoor air purification, air conditioner or purifier is generally used, but the long operating time induced the contamination by cumulation of bacteria in the air filter. The ozone sterilization method can be one of the effective sterilization method for this case. Ozone has not leave a secondary residual contaminants, as well as a strong sterilization power. In this study, nonthermal plasma technology is investigated as an ozone generator for the air filter sterilization. Additionally, nonthermal plasma technology is possible to obtain the generation of negative ions and electrostatic force by simply adjusting the applied voltage.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.245-249
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• 1999

A new type of nonthermal plasma reactor utilizing ferroelectric pellets is proposed to generate nonthermal plasma efficiently, which is used for simultaneous control of various pollutant gases. Electric charges stored on ferroelctric pellets by corona discharge between a corona tip and a mesh electrode provide partial electrical discharges among ferroelectric pellets. These partial electrical discharges can enhance partial discharges around the surface of ferroelectric pellets. This method utilizes wide reacting area of ferroelectric pellets and partial discharge. Positive and negative dc voltage are applied to the corona tip to generate partial discharges, and corona currents are estimated to investigate charge storage on ferroelectric pellets as function of time and charge relaxation time constants of ferroelectric pellects. As a result, charge relaxationtime, dielectric constants of ferroelectric pellets, polarity of applied voltage and applied time influence partial discharges among ferroelectric pellect.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.174-174
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• 2012

The nature of feed gas is essential for the active species formed in the nonthermal plasma jets, which would induce various biological phenomena. We investigated the different physiological effects of atmospheric pressure soft-plasma jets on Esherichia coli and blood cells according to the feed gas. Cell death rate, growth curve, membrane molecular changes and induced genes were examined. The relationship between cellular reactions and active species generated by discharge will be discussed.

• International Journal of Oral Biology
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• v.43 no.2
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• pp.83-91
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• 2018

Nonthermal atmospheric plasma has been studied for its many biomedical effects, such as tooth bleaching, wound healing, and coagulation. In this study, the effects of dentinal tubules occlusion were investigated using fluoride-carboxymethyl cellulose (F-CMC) gel, nano-sized hydroxyapatite (n-HA), and nonthermal atmospheric plasma. Human dentin specimens were divided to 5 groups (group C, HA, HAF, HAP, and HAFP). Group HA was treated with n-HA, group HAF was treated with n-HA after a F-CMC gel application, group HAP was treated with n-HA after a plasma treatment and group HAFP was treated with n-HA after a plasma and F-CMC gel treatment. The occlusion of dentinal tubules was investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), which shows Ca/P ratio. In the EDS results, a higher Ca/P ratio was shown in the groups including n-HA than in the control group. The specimens of group HAP and HAFP had a higher Ca/P ratio in retentivity. In the SEM results, there was not a significant difference in the amount of times applied. Therefore, this study suggests F-CMC gel and n-HA treatment using nonthermal atmospheric plasma will be a new treatment method for decreasing hypersensitivity.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.3
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• pp.199-205
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• 2018

Purpose: This study evaluated the effect of nonthermal plasma treatment on the bond strength of autopolymerizing relining resin to the injection molded thermoplastic denture base resins (TDBRs) with different surface treatments. Materials and methods: Acrylic Resin (Acrytone), Polyester (Estheshot-Bright), Polyamide (Valplast) and Polypropylene (Weldenz) were subjected to various surface treatments: No treatment, Nonthermal plasma, Sandblasting, Sandblasting and nonthermal plasma. Specimens were bonded using an autopolymerizing relining resin. Shear bond strength was tested using universal testing machine with crosshead speed of 1 mm/min. Statistical analysis by two-way analysis of variance with Tukey's test post hoc was used. Results: Acrytone showed significantly higher shear bond strength value among other TDBR group while Weldenz had the lowest. The sandblasting and nonthermal plasma condition had significantly higher shear bond strength value in all of the resin groups (P < .05). Conclusion: The use of nonthermal plasma treatment showed limited effect on the shear bond strength between TDBRs and relining resin, and combination of nonthermal plasma and sandblasting improved the shear bond strength between TDBR and reline material.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.211.1-211.1
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• 2016

Several reports have demonstrated the wide range of nonthermal plasma applications in biomedical field including cancers, diabetics, wound healing and cosmetics. Recently, it has been shown that plasma is able to modulate the p38 MAPK and JUN level in cells which has a crucial role in melanin synthesis and skin pigmentation. Therefore we investigated the effect of plasma on melanogenesis in-vitro using melanoma (B16F10) cells and in-vivo using mouse and zebra fish. To investigate the mechanism of plasma action, plasma device characteristics were measured, reactive species inside and outside the cells were detected, and western blot was performed to find the signaling pathway involved in melanin activation in-vitro and in-vivo. This is the first report presenting the role of nonthermal plasma for melanogenesis which provides a new perspective of plasma in the field of dermatology.

• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.308-314
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• 2018

PURPOSE. Plasma activation of hydrophobic zirconia surfaces might be suitable to improve the bond strength of luting materials. The aim of this study was to analyze the influence of nonthermal argon-plasma on the shear bond strength (SBS) between zirconia and different combinations of 10-MDP adhesive systems and luting composites after artificial aging. MATERIALS AND METHODS. Two hundred forty Y-TZP specimens were ground automatically with $165{\mu}m$ grit and water cooling. Half of the specimens received surface activation with nonthermal argon-plasma. The specimens were evenly distributed into three groups according to the adhesive systems ([Futurabond U, Futurabond M, Futurabond M + DCA], VOCO GmbH, Germany, Cuxhaven) and into further two subgroups according to the luting materials ([Bifix SE, Bifix QM], VOCO GmbH). Each specimen underwent artificial aging by thermocycling and water storage. SBS was measured in a universal testing machine. Statistical analysis was performed using ANOVA and $Scheff{\grave{e}}$ procedure with the level of significance set to 0.05. RESULTS. Surface activation with nonthermal plasma did not improve the bond strength between zirconia and the tested combinations of adhesive systems and luting materials. The plasma-activation trended to reveal higher bond strength if the self-etch luting material (Bifix SE) was used, irrespective of the adhesive system. CONCLUSION. Plasma-activation seems to be suitable to improve bond strength between zirconia and self-etch resin materials. However, further research is necessary to identify the influence of varying plasma-parameters.