Abstract Low‐temperature atmospheric pressure plasmas applied to the surface of an aqueous solution have been shown be efficient bactericides for bacteria suspended in solution, if is sufficiently acidic. Especially interest finding that there a critical pH value about 4.7 bactericidal effects, below which are efficiently inactivated and above hardly affected by plasma application. It has also found presence superoxide anion radicals O • essential bacterial inactivation Therefore, may arise...

Plasma medicine is an attractive new research area, but the principles of plasma modification biomolecules in aqueous solution remain elusive. In this study, we investigated chemical effects atmospheric-pressure cold on 20 naturally occurring amino acids solution. High-resolution mass spectrometry revealed that modifications 14 were observed after treatment: (i) hydroxylation and nitration aromatic rings tyrosine, phenylalanine tryptophan; (ii) sulfonation disulfide linkage formation thiol...

Plasma-treated water (PTW), i.e. distilled (DW) exposed to low-temperature atmospheric pressure helium plasma, exhibited strong bactericidal activity against Escherichia coli in suspension even within a few minutes of preparation. This effect was enhanced under acidic conditions. The PTW attenuated according first-order kinetics and the half-life highly temperature dependent. electron spin resonance (ESR) signal an adduct superoxide anion radical () detected aqueous solution using...

Abstract Plasma medicine is an attractive new research area, but fundamental information related to plasma modification of biomacromolecules in aqueous solution remains elusive. As described herein, we investigated the chemical effects low‐temperature atmospheric pressure on protein using lysozyme as a model. treatment decreased enzymatic activity and changed secondary structure that results from increased molecular weight with modification. These arise neither UV light nor heat, suggesting...

Water-dispersible gold nanoparticles with narrow size distributions were prepared by irradiation of nonequilibrium atmospheric-pressure dielectric-barrier-discharge (DBD) helium plasma jets to tetrachloroauric acid solutions containing poly(ethylene glycol) (PEG) that had a pentaethylenehexamine at one end each polymer chain (N6-PEG). N6-PEG is known interact aurate cations facilitate nucleation and growth as surface-modification agent. The helium-based DBD contain energetic electrons free...

To understand plasma-induced chemical processing in liquids, we investigated the formation of free radicals aqueous solution exposed to different types non-contact atmospheric-pressure helium plasma using spin-trapping technique. Both hydroxyl radical (OH·) and superoxide anion (O2−·) adducts were observed when neutral oxygen gas was additionally supplied plasma. In particular, O2−· can be dominantly induced via flow into afterglow This type treatment potentially used medical applications...

Sterilization of certain infected areas the human body surface is necessary for dental and surgical therapies. Because blood filled with fluid, sterilization in solution essential. In vitro has been successively carried out using a combination low-temperature atmospheric-pressure plasma reduced pH method, where sufficiently acidic. Here, we show molecular mechanism such based on microbiology. Three kinds bacteria were inactivated by treatment under various conditions. The theoretical...

Radio-frequency glow-like plasmas have been produced in Ar bubbles water that flows a quartz tube equipped with electrodes. Plasmas bubbles, (or 'bubble plasmas' short) may be used to induce some specific chemical reactions liquids. It has demonstrated bubble can decompose methylene blue (MB) dissolved and hydroxyl (OH) radicals are present the gas-phase plasmas. Therefore it presumed decomposition of MB is caused either directly by OH generated diffuse into aqueous solution or indirectly...

Atmospheric-pressure plasmas were produced on the surface of liquid water by radio-frequency (RF) power supply. A quartz chamber with an off-center inner electrode was used to generate discharges a wide range filling gas pressures. When filled fuel and sufficient RF supplied system, observed be around as well surface. Optical emission spectroscopy (OES) identified generation oxidative hydroxyl (OH) radicals decoloration methylene blue in solution demonstrated capacity generated this system.

Non-mechanical procedures for removing caries-infected dentin are warranted in dentistry. We previously demonstrated the marked sterilization effect direct irradiation of low-temperature plasma using model infected with Streptococcus mutans. However it requires 180 s intraoral to eliminate bacteria. alternatively investigated whether plasma-treated water (PTW), i.e., pure exposed an atmosphere, has a same bactericidal activity irradiation. In model, viable S. mutans counts recovered by bur...

To confirm the formation of superoxide anion radical (O2−) in liquids by atmospheric-pressure plasma, we investigated plasma-induced species water using electron spin resonance (ESR) spin-trapping technique combined with two proteins: dismutase (SOD), which has enzymatic activity to quench radical, and bovine serum albumin (BSA), does not have this activity. Different setups contact non-contact helium plasma were tested an additional supply oxygen gas. For each setup no adduct ESR signal was...

The electron densities of argon inductively coupled plasmas were measured by terahertz time-domain spectroscopy (THz-TDS). At a low pressure, the also with Langmuir-type double probe and validity THz-TDS electron-density measurement in plasma has been corroborated. As input radio-frequency (RF) power increases, density gas temperature increase, which makes less reliable or even impossible, due to large heat load surface. On contrary, is unaffected becomes more higher at for generation.

Low-temperature atmospheric-pressure plasma was applied to degenerate amyloid-ß (Aß) fibrils, which are a major component of neuritic plaque associated with Alzheimer's disease (AD). We showed that an Aß fibril exposed low-frequency (LF) jet in aqueous solution retained its morphology, molecular weight, and cytotoxicity, but, intriguingly, decreased protease resistance ß-sheet content. These results suggested LF could be utilized for the treatment AD eliminate by accelerating proteolysis fibrils.

Low-temperature atmospheric-pressure plasma has been studied for disinfection purposes. When is exposed to water, reactive oxygen and nitrogen species are generated preserved in the water fraction (plasma-treated [PTW]), which consequently exhibits bactericidal activity. At low temperatures, one of components PTW peroxynitric acid (PNA). Importantly, PNA can also be synthesized by chemical reaction, without exposure plasma. In this study, we evaluated properties based on reaction kinetics...

Experiments on additional heating by neutral beam injection and application of a low frequency wave to plasma with an extremely high averaged beta value about 90% - field reversed configuration (FRC) are carried out using the FRC Injection Experiment (FIX) apparatus. These experiments made possible translating produced in formation region theta pinch confinement order secure better accessibility facilities control density. By determining appropriate geometry mirror ratio region, it became...

Field-reversed configurations (FRCs) driven by rotating magnetic fields (RMFs) with spatial high harmonics have been studied in the metal flux conserver of FRC injection experiment. The experimental results show that fundamental RMF component is observed to penetrate plasma column, while are screened at edge due their slower or reversed rotation. This selective penetration provides good compatibility radial and azimuthal force balances; significant inward <j[over](z)B[over](theta)> mostly...

The carboxyl (HOCO) radical, which is an important species in atmospheric chemistry and combustion, intermediate the reaction: CO + OH → CO2 H serves as a hydrogen donor to reaction partners. cis-HOCO one of ground-state HOCO radicals, supposed be decomposed into atom by tunneling effect. In order prove hypothesis, we performed electron spin resonance (ESR) measurements investigate decay mechanisms DOCO radicals gamma-ray-irradiated hydrates, may hold stably. decayed according second-order...

Plasma disinfection using low-temperature atmospheric pressure plasma is widely studied in many applications, and the use of plasma-treated water (PTW) for being developed by researchers. Exposing to supplies preserves reactive oxygen nitrogen species (RONS) water, this PTW exhibits bactericidal activity. In our previous study, it was revealed that peroxynitric acid (O2NOOH, PNA) dominant component PTW. PNA can be easily synthesized without treatment, physicochemical properties have been...

An effective heating method and experimental verification for a field-reversed configuration (FRC) plasma by applying the low-frequency magnetic pulse is presented. The field applied an antenna that consists of two single-turn coils, frequency lower than ion cyclotron at separatrix. increase energy fluctuation internal are simultaneously observed. comparison total temperature shows mostly due to heating. directly observed probe arrays. analysis phase velocity along equilibrium implies Alfvén...

Purpose: In recent years, attention has been drawn to disinfection techniques by plasma irradiation on human bodies, however, the efficacy is not sufficient in root canal. Therefore, authors generated plasma-treated water (PTW) concentrate active species, and investigated of PTW as a canal irrigant.