• Korean Journal of Agricultural Science
• /
• v.45 no.1
• /
• pp.94-104
• /
• 2018

Nitrite is an essential additive for cured meat product. Plasma is ionized gas and reactive nitrogen species in plasma can be infused into meat batter and subsequently generate nitrites by reaction with water molecules after plasma treatment. However, the increase of nitrite in meat batter is limited with direct treatment of atmospheric pressure cold plasma because of the increase of meat batter temperature. Therefore, this study investigated the influence of indirect treatment of atmospheric pressure cold plasma on the physicochemical properties of meat batter. Meat batter was indirectly treated with plasma at 1.5 kW for 60 min. The pH of meat batter decreased while the temperature increased with plasma treatment time. The total aerobic bacterial count of meat batter was not affected by plasma treatment. The nitrite content of meat batter was increased to 377.68 mg/kg after 60 min of plasma treatment. The residual nitrite content of cooked meat batter also increased with plasma treatment time. The CIE $a^*$-value of cooked meat batter increased. As plasma treatment time increased, lipid oxidation tended to increase and protein oxidation significantly increased. According to these results, the indirect treatment of atmospheric pressure cold plasma can be used as a new curing method for replacing synthetic nitrite salts.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.32 no.4
• /
• pp.354-361
• /
• 2008

Cold rolled steel sheet for automotive was treated by Ar/$O_2$ atmospheric pressure plasma to improve the adhesive bonding strength. Through the contact angle test and calculation of surface free energy for cold rolled steel sheet, the changes of surface properties were investigated before and after plasma treatment. The contact angle was decreased and surface free energy was increased after plasma treatment. And the change of surface roughness and morphology were observed by AFM(Atomic Force Microscope). The surface roughness of steel sheet was slightly changed. Based on Taguchi method, single lap shear test was performed to investigate the effect of experimental parameter such as plasma power, treatment time and flow rate of $O_2$ gas. Results shows that the bonding strength of steel sheet treated in Ar/$O_2$ atmospheric pressure plasma was improved about 20% compared with untreated sheet.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.6
• /
• pp.768-775
• /
• 2022

In this study we aimed to derive the response surface models for Escherichia coli reduction in wheat flour using atmospheric cold plasma (ACP) with three types of gas. The jet-type atmospheric cold plasma wand system was used with a 30 W power supply, and three gases (argon, air, and nitrogen) were applied as the treatment gas. The operating parameters for process optimization considered were wheat flour mass (g), treatment time (min), and gas flow rate (L/min). The wheat flour samples were artificially contaminated with E. coli at a concentration of 9.25 ± 0.74 log CFU/g. ACP treatments with argon, air, and nitrogen resulted in 2.66, 4.21, and 5.55 log CFU/g reduction of E. coli, respectively, in wheat flour under optimized conditions. The optimized conditions to reduce E. coli were 0.5 g of the flour mass, 15 min of treatment time, and 0.20 L/min of nitrogen gas flow rate, and the predicted highest reduction level from modeling was 5.63 log CFU/g.

• Biomolecules & Therapeutics
• /
• v.31 no.5
• /
• pp.496-514
• /
• 2023

Cold atmospheric plasma (CAP), a redox modulation tool, is capable of inhibiting a wide spectrum of cancers and has thus been proposed as an emerging onco-therapy. However, with incremental successes consecutively reported on the anticancer efficacy of CAP, no consensus has been made on the types of tumours sensitive to CAP due to the different intrinsic characteristics of the cells and the heterogeneous design of CAP devices and their parameter configurations. These factors have substantially hindered the clinical use of CAP as an oncotherapy. It is thus imperative to clarify the tumour types responsive to CAP, the experimental models available for CAP-associated investigations, CAP administration strategies and the mechanisms by which CAP exerts its anticancer effects with the aim of identifying important yet less studied areas to accelerate the process of translating CAP into clinical use and fostering the field of plasma oncology.

• Medical Lasers
• /
• v.9 no.2
• /
• pp.187-189
• /
• 2020

Cold atmospheric plasma (CAP) is a material that generates free radicals through the ionization of air. Despite the application in various medical fields, the efficacy and safety of CAP on post-inflammatory hyperpigmentation due to atopic dermatitis have not been reported. Herein, we report the improvement in post-inflammatory hyperpigmentation of atopic dermatitis, after CAP treatment of three sessions weekly, 10 minutes per session. We examined the clinical severity indexes before and after treatment, including the Investigator's Global Assessment, modified Atopic Dermatitis Antecubital Severity, Eczema Area and Severity Index, and pruritus visual analogue scores. Our results indicate that CAP alleviates the post-inflammatory hyperpigmentation and clinical severity of atopic dermatitis, and effectively improves the atopic skin lesion without severe safety issues. We believe that the previously reported anti-bacterial effects and production of interleukin-6 after CAP treatment are probably responsible for the underlying mechanisms leading to clinical improvement.

• Journal of Microbiology
• /
• v.44 no.3
• /
• pp.269-275
• /
• 2006

Atmospheric-pressure cold plasma (APCP) using helium/oxygen was developed and tested as a suitable sterilization method in a clinical environment. The sterilizing effect of this method is not due to UV light, which is known to be the major sterilization factor of APCP, but instead results from the action of reactive oxygen radicals. Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae deposited on a nitrocellulose filter membrane or Bacillus subtilis spores deposited on polypropylene plates were exposed to helium/oxygen plasma generated with AC input power at 10 kHz, 6 kV. After Plasma treatment, nitrocellulose filter membranes were overlaid on fresh solid media and CFUs were counted after incubation overnight. D-values were 18 sec for E. coli, 19 sec for S. aureus, 1 min 55 sec for S. cerevisiae, and 14 min for B. subtilis spores. D-values of bacteria and yeast were dependent on the initial inoculation concentration, while the D-value of B. subtilis spores showed no correlation. When treated cells were observed with a scanning electron microscope, E. coli was more heavily damaged than S. aureus, S. cevevisiae exhibited peeling, and B. subtilis spores exhibited shrunken morphology. Results showed that APCP using helium/oxygen has many advantages as a sterilization method, especially in a clinical environment with conditions such as stable temperature, unlimited sample size, and no harmful gas production.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1539-1542
• /
• 2008

Plasma is 4th state of matters, which consists of electrons, neutral, and ionized particles. In biomedical research, cold plasma, which is generated in atmospheric condition, has been applied to disinfect microorganisms such as bacteria and yeast cells. Because of its low temperature condition, the heat-sensitive medical device can be easily sterilized by the cold plasma treatment. In recent years, the effects of plasma on mammalian cells have arisen as a new issue. Generally, plasma induces intensity dependent necrotic cell death. In this research, we investigate the feasibility of cold plasma treatment for cancer therapy by conducting comparative study of plasma effects on normal and cancer cells. We use THLE-2 (human liver normal cell) and SK-Hep1 (human liver metathetic cancer cell) as our target cells. The needle type of cold plasma is generated by the Helium plasma device. Two types of cells have different onset plasma conditions for the necrosis, which may be explained by difference in electrical properties of these two cell types.

• Biomolecules & Therapeutics
• /
• v.22 no.6
• /
• pp.477-490
• /
• 2014

Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

• Food Science of Animal Resources
• /
• v.37 no.4
• /
• pp.477-485
• /
• 2017

Novel, effective methods to control and prevent spoilage and contamination by pathogenic microorganisms in meat and meat products are in constant demand. Non-thermal pasteurization is an ideal method for the preservation of meat and meat products because it does not use heat during the pasteurization process. Atmospheric pressure cold plasma (APCP) is a new technology for the non-thermal pasteurization of meat and meat products. Several recent studies have shown that APCP treatment reduces the number of pathogenic microorganisms in meat and meat products. Furthermore, APCP treatment can be used to generate nitrite, which is an essential component of the curing process. Here, we introduce the effectiveness of APCP treatment as a pasteurization method and/or curing process for use in the meat and meat product processing industry.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.29 no.3
• /
• pp.351-357
• /
• 2019

Objectives: The objectives of this study were to investigate fungal contamination in a 31-year old university building in Seoul, Korea, and to study the inactivation of fungi using cold atmospheric pressure plasma(CAP). Methods: To investigate the fungal contamination in a university building, air samples were collected from five locations in the building, including two study rooms, a storage room, a laboratory, and a basement. The sampling was performed in a dry season(February to April) and in a wet season(July). To study the inactivation efficacy of fungi by CAP, airborne fungal concentrations were measured before and after the operation of the CAP generator. Results: Humidity was an important factor affecting fungal growth. The airborne fungal concentrations determined in the wet season(July) were significantly higher than those determined in the dry season(February to April). In the basement, the values determined in the dry and wet season were 319 and $3,403CFU/m^3$, respectively. The inactivation efficiency of fungi by CAP was 83-90% over five to nine days of operation. Conclusions: The university building was highly contaminated by airborne fungi, especially in summer. It is concluded that humidity is an important factor affecting fungal growth and CAP is a highly useful technique for inactivation of indoor airborne fungi.