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Nonthermal plasma

Jung Eun Kim, Yeong Ji Oh, Mee Yeon Won, Kwang-Sik Lee, Sea C Min
The effects of microwave-integrated cold plasma (CP) treatments against spores of Bacillus cereus and Aspergillus brasiliensis and Escherichia coli O157:H7 on onion powder were investigated. The growth of B. cereus, A. brasiliensis, and E. coli O157:H7 in the treated onion powder was assessed during storage at 4 and 25 °C, along with the physicochemical and sensory properties of the powder. Onion powder inoculated with B. cereus was treated with CP using helium as a plasma-forming gas, with simultaneous exposure to low microwave density at 170 mW m(-2) or high microwave density at 250 mW m(-2)...
April 2017: Food Microbiology
Sung-Hwan Choi, Won-Seok Jeong, Jung-Yul Cha, Jae-Hoon Lee, Hyung-Seog Yu, Eun-Ha Choi, Kwang-Mahn Kim, Chung-Ju Hwang
No abstract text is available yet for this article.
November 11, 2016: Scientific Reports
Junhyeok Bang, Y Y Sun, X-Q Liu, F Gao, S B Zhang
While being extensively studied as an important physical process to alter exciton population in nanostructures at the fs time scale, carrier multiplication has not been considered seriously as a major mechanism for phase transition. Real-time time-dependent density functional theory study of Ge_{2}Sb_{2}Te_{5} reveals that carrier multiplication can induce an ultrafast phase transition in the solid state despite that the lattice remains cold. The results also unify the experimental findings in other semiconductors for which the explanation remains to be the 30-year old phenomenological plasma annealing model...
September 16, 2016: Physical Review Letters
Sung-Hwan Choi, Won-Seok Jeong, Jung-Yul Cha, Jae-Hoon Lee, Hyung-Seog Yu, Eun-Ha Choi, Kwang-Mahn Kim, Chung-Ju Hwang
Here, we evaluated time-dependent changes in the effects of ultraviolet (UV) and nonthermal atmospheric pressure plasma (NTAPPJ) on the biological activity of titanium compared with that of untreated titanium. Grade IV machined surface titanium discs (12-mm diameter) were used immediately and stored up to 28 days after 15-min UV or 10-min NTAPPJ treatment. Changes of surface characteristics over time were evaluated using scanning electron microscopy, surface profiling, contact angle analysis, X-ray photoelectron spectroscopy, and surface zeta-potential...
2016: Scientific Reports
Zhitong Chen, Li Lin, Xiaoqian Cheng, Eda Gjika, Michael Keidar
Nonthermal atmospheric plasma (NTAP) can be applied to living tissues and cells as a novel technology for cancer therapy. The authors report on a NTAP argon solution generated in deionized (DI) water for treating human gastric cancer cells (NCI-N87). Our findings show that the plasma generated in DI water with 30-min duration has the strongest effect on apoptosis in precultured human gastric cancer cells. This result can be attributed to the presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced in water during treatment...
2016: Biointerphases
Jung-Hwan Lee, Kyoung-Nam Kim
Nonthermal atmospheric pressure plasma jets (APPJ) have been developed and applied in biomedical research as a cancer treatment or bacterial sterilization. However, the drawback of APPJ on normal oral cells during plasma treatment and underlying cell death mechanisms have not been studied and clearly explained, although there is known to be an influence from reactive oxygen species (ROS). Hence, this study investigates whether and how a nonthermal atmospheric pressure air plasma jet kills human normal gingival cells using immortalized human gingival fibroblasts (hTERT-hNOF cells)...
2016: BioMed Research International
Toshihiro Takamatsu, Hiroaki Kawano, Yota Sasaki, Kodai Uehara, Hidekazu Miyahara, Yuriko Matsumura, Atsuo Iwasawa, Takeshi Azuma, Akitoshi Okino
To identify mechanisms underlying the bacterial inactivation process by atmospheric nonthermal plasma using a unique plasma jet that can generate various gas plasmas, Staphylococcus aureus were irradiated with carbon dioxide plasma, which produces a large amount of singlet oxygens, and nitrogen plasma, which produces a large amount of OH radicals. And damaged areas of plasma-treated bacteria were observed by field emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy...
December 2016: Current Microbiology
Uwe R Kortshagen, R Mohan Sankaran, Rui N Pereira, Steven L Girshick, Jeslin J Wu, Eray S Aydil
Nonthermal plasmas have emerged as a viable synthesis technique for nanocrystal materials. Inherently solvent and ligand-free, nonthermal plasmas offer the ability to synthesize high purity nanocrystals of materials that require high synthesis temperatures. The nonequilibrium environment in nonthermal plasmas has a number of attractive attributes: energetic surface reactions selectively heat the nanoparticles to temperatures that can strongly exceed the gas temperature; charging of nanoparticles through plasma electrons reduces or eliminates nanoparticle agglomeration; and the large difference between the chemical potentials of the gaseous growth species and the species bound to the nanoparticle surfaces facilitates nanocrystal doping...
September 28, 2016: Chemical Reviews
S Kahaly, F Sylla, A Lifschitz, A Flacco, M Veltcheva, V Malka
Ion acceleration from intense (Iλ(2) > 10(18) Wcm(-2) μm(2)) laser-plasma interaction is experimentally studied within a wide range of He gas densities. Focusing an ultrashort pulse (duration  ion plasma period) on a newly designed submillimetric gas jet system, enabled us to inhibit total evacuation of electrons from the central propagation channel reducing the radial ion acceleration associated with ponderomotive Coulomb explosion, a mechanism predominant in the long pulse scenario. New ion acceleration mechanism have been unveiled in this regime leading to non-Maxwellian quasi monoenergetic features in the ion energy spectra...
2016: Scientific Reports
Sara P Azerrad, Christian Lütke Eversloh, Maayan Gilboa, Manoj Schulz, Thomas Ternes, Carlos G Dosoretz
Removal of micropollutants from reverse osmosis (RO) brines of wastewater desalination by oxidation processes is influenced by the scavenging capacity of brines components, resulting in the accumulation of transformation products (TPs) rather than complete mineralization. In this work the iodinated contrast media diatrizoate (DTZ) was used as model compound due to its relative resistance to oxidation. Identification of TPs was performed in ultrapure water (UPW) and RO brines applying nonthermal plasma (NTP) and UVA-TiO2 as oxidation techniques...
October 15, 2016: Water Research
Han Hsuan Peng, Kuan Lun Pan, Sheng Jen Yu, Shaw Yi Yan, Moo Been Chang
A new NOx storage and reduction (NSR) system is developed for NOx removal by combining perovskite-like catalyst with nonthermal plasma technology. In this hybrid system, catalyst is mainly used for oxidizing NO to NO2 and storing them, while nonthermal plasma is applied as a desorption-reduction step for converting NOx into N2. An innovative catalyst with a high NOx storage capacity and good reduction performance is developed by successive impregnation. The catalysts prepared with various metal oxides were investigated for NOx storage capacity (NSC) and NOx conversion...
October 2016: Environmental Science and Pollution Research International
Patrick J Tracy, Justin C Kasper, Jim M Raines, Paul Shearer, Jason A Gilbert, Thomas H Zurbuchen
We analyze the heavy ion components (A>4  amu) in collisionally young solar wind plasma and show that there is a clear, stable dependence of temperature on mass, probably reflecting the conditions in the solar corona. We consider both linear and power law forms for the dependence and find that a simple linear fit of the form T_{i}/T_{p}=(1.35±.02)m_{i}/m_{p} describes the observations twice as well as the equivalent best fit power law of the form T_{i}/T_{p}=(m_{i}/m_{p})^{1.07±.01}. Most importantly we find that current model predictions based on turbulent transport and kinetic dissipation are in agreement with observed nonthermal heating in intermediate collisional age plasma for m/q<3...
June 24, 2016: Physical Review Letters
Ngoc Hoan Nguyen, Hyung Jun Park, Sang Sik Yang, Kyeong Sook Choi, Jong-Soo Lee
The therapeutic potential of nonthermal plasma for cancer treatment has been reported recently. The heterogeneity of cancer cells need to be addressed to design effective anticancer treatments. Here, we show that treatment with nonthermal atmospheric-pressure plasma dissolved in a liquid (liquid plasma) induces oxidative stress in heterogeneous populations of cancer cells and ultimately kills these cells via apoptosis, regardless of genetic status, e.g., mutations in p53 and other DNA-damage-response genes...
2016: Scientific Reports
C M Edelblute, M A Malik, L C Heller
The use of nonthermal plasma in the clinic has gained recent interest, as the need for alternative or supplementary strategies are necessary for preventing multi-drug resistant infections. The purpose of this study was to evaluate the antibacterial efficacy of a novel plasma reactor based on a high current version of sliding discharge and operated by nanosecond voltage pulses without an applied gas flow. This modification is advantageous for both portability and convenience. Bacterial inactivation was determined within a chamber by direct quantification of colony Jing units...
December 2016: Bioelectrochemistry
Yi-Wen Hung, Li-Tzu Lee, Yen-Chun Peng, Chiou-Tuz Chang, Yong-Kie Wong, Kwong-Chung Tung
BACKGROUND: The use of a nonthermal plasma (NTP) jet in the treatment of living tissue has been the subject of considerable interest in the field of medical technology, and has the potential to reduce the recovery time of open wounds. We aimed to investigate the wound-healing process by clinical observation, blood tests, and expression of cell adhesion markers and reactive oxygen species in NTP jet-treated rats. METHODS: This study utilized Sprague-Dawley (SD) rats as experimental subjects, and wounds measuring 2 cm × 2 cm were produced on the animals' backs...
June 2016: Journal of the Chinese Medical Association: JCMA
Yi Cai, Ya-Jie Zhang, De-Fu Wu, Yong-Liang Yu, Jian-Hua Wang
The low atomization and excitation capability of nonthermal microplasma, e.g., dielectric barrier discharge (DBD), has greatly hampered its potential applications for the determination of metals in solution. In the present work, an inspiring development is reported for direct atomization and excitation of cadmium in aqueous solution by DBD and facilitates highly sensitive determination. A DBD microplasma is generated on the nozzle of a pneumatic micronebulizer to focus the DBD energy on a confined space and atomize/excite metals in the spray...
April 19, 2016: Analytical Chemistry
Samuel R Totorica, Tom Abel, Frederico Fiuza
The possibility of studying nonthermal electron energization in laser-driven plasma experiments of magnetic reconnection is studied using two- and three-dimensional particle-in-cell simulations. It is demonstrated that nonthermal electrons with energies more than an order of magnitude larger than the initial thermal energy can be produced in plasma conditions currently accessible in the laboratory. Electrons are accelerated by the reconnection electric field, being injected at varied distances from the X points, and in some cases trapped in plasmoids, before escaping the finite-sized system...
March 4, 2016: Physical Review Letters
Soee Choi, Pradeep Puligundla, Chulkyoon Mok
Nonthermal techniques for microbial decontamination are becoming more common for ensuring food safety. In this study, a corona discharge plasma jet (CDPJ) was used for inactivation of microbial contaminants of dried Alaska pollock shreds. Corona plasma jet was generated at a current strength of 1.5 A, and a span length of 25 mm was maintained between the electrode tip and the sample. Upon the CDPJ treatment (0 to 3 min) of dried shreds, microbial contaminants namely aerobic and marine bacteria, and Staphylococcus aureus were inactivated by 2...
April 2016: Journal of Food Science
Qian Zhang, Ruonan Ma, Ying Tian, Bo Su, Kaile Wang, Shuang Yu, Jue Zhang, Jing Fang
Disinfection of hazardous microorganisms that may challenge environmental safety is a crucial issue for economic and public health. Here, we explore the potential of a novel electrochemical disinfectant named plasma activated water (PAW), which was generated by nonthermal plasma, for inactivating Staphylococcus aureus (S. aureus). Meanwhile, the influence of bovine serum albumin (BSA) on the PAW disinfection efficacy was investigated. In the presence of BSA, PAW treatments achieved a reduction of S. aureus ranging from 2...
March 15, 2016: Environmental Science & Technology
Y Liu, Q Liu, Q S Yu, Y Wang
It is well known that the service life of contemporary composite restoration is unsatisfactory, and longevity of dentin bonding is one of the major culprits. Bonding is essentially a hybridization process in which dental substrate and adhesive resin interact with each other through an exchange process. Thus, the longevity of dentin bonding can only be improved with enhanced qualities in substrate, adhesive resin, and their interaction within the hybridization zone. This review aims to collect and summarize recent advances in utilizing nonthermal atmospheric plasmas (NTAPs)-a novel technology that delivers highly reactive species in a gaseous medium at or below physiologic temperature-to improve the durability of dentin bonding by addressing these 3 issues simultaneously...
May 2016: Journal of Dental Research
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