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Atmospheric pressure cold plasma treatment on pearl millet ( Pennisetum glaucum ) with air as feed gas at an input voltage of 40 and 45 kV for 5, 10, and 15-min exposure time was studied. The influence of cold plasma on the physical, nutritional, hydration, and pasting properties of pearl millet was assessed. There was no significant difference in loose and tapped bulk density, whereas the color intensity $(\Delta E)$ and the delta chroma ( ${\Delta }C$ ) have significantly differed with the treatment. The nutritional properties, such as crude fat (3.46% ± 0.25%–4.71% ± 0.07%) were increased, whereas crude fiber (2.21% ± 0.02%–1.32% ± 0.02%), protein (10.064% ± 0.43%–8.89% ± 0.50%), and moisture (11.92% ± 0.10%–10.25% ± 0.03%) had significantly diminished. The results of hydration properties, such as swelling capacity (0.213 ± 0.003–0.320 ± 0.008 g/g), solubility (183% ± 1.00%–212% ± 2.00%), and water absorption (1.11 ± 0.02–1.51 ± 0.01 g/mL) have shown significant increment with treatment time and voltage. Besides, the pasting properties of the treated millet were significantly improved. The infrared thermal imaging was used and observed a maximum of 7 °C rise in the plasma treatment zone’s temperature throughout the treatment time. It can be concluded that the plasma treatment ameliorates hydration and pasting properties of pearl millet, paving the path for their usage in a wide range of convenient foods.

This article is intended to provide a comprehensive review of the experimental studies conducted to understand the effect of several parameters involved in the discharge plasma-based nitrogen oxides (NO $_{X}$ ) removal from real diesel engine exhausts, be it stationary or automobile, in addition to simulated ones. In the last two decades, much progress has occurred in the electric discharge-based nonthermal plasma (NTP) treatment of exhaust gas with or without cascading any additional treatment technique, such as catalysts or adsorbents. Most of these studies were conducted with the aim of enhancing the removal of NO $_{X}$ or studying the efficacy of a particular parameter on NO $_{X}$ removal or both. It is now timely to collage the findings of these studies in a way to help the present researchers to understand the effect of various parameters/measures associated with stand-alone and cascaded NTP treatments for NO $_{X}$ removal. It is also intended that the current review helps in moving closer to realizing the application of NTP in the cleansing of gaseous pollutants of diesel exhaust.

Environmental issues are to be taken into account when preparing superhydrophobic surfaces for everyday use. Fluorochemicals and organic solvents have potential risks to human health along with environment and their use should be minimized. The present work is to fabricate superhydrophobic surface through post plasma treatment of aqueous extract of rose petals coated on cotton fabric by using oxygen plasma. The contact angle measurement confirms the superhydrophobic nature of the fabric after oxygen plasma treatment. The obtained superhydrophobic fabrics have shown excellent antibacterial activity against E. coli and Staphylococcus aureus. Anti-icing, anticlinging, and other physical properties such as color fastness to light and heat, and superhydrophobicity to tea and coffee droplets have been improved by plasma surface modification.

We studied the effects of nonthermal plasma (NTP) treatment on various parameters of early germination stages of Pinus nigra seeds. In the experiment, the diffuse coplanar surface barrier discharge (DCSBD) with treatment time periods of 0, 1, 3, 5, 10, 30, and 60 s was used. Changes on the plasma-treated seed surface were studied by attenuated total reflectance-Fourier transform infrared spectroscopy. Seed germination, germination rate, germination index, length of seedling, dry seedling weight, and seedling vigor index I and II were determined in a growth test under laboratory conditions. Various statistically significant effects of seed exposure to DCSBD plasma treatment were recorded. A positive reaction was observed in the germinated seeds after exposure for 1- and 5-s. Longer exposure time periods had a rather inhibitory effect. The performance of forest nurseries of NTP modification of seeds should be evaluated in order to measure the durability of the observed growth characteristics. The potential of NTP treatment on seeds in plant ecology in future is highlighted.

This article presents five alternative plasma equipments patented by the author, designed for specific applications like activation, cleaning, decontamination, or monomer polymerization on surfaces. Two equipments perform HF cold plasma treatment of highly adherent powdery materials (pigments, plastics, drugs, and so on), that are used to modify the physical-chemical characteristics of surfaces. Another HF plasma equipment is employed for the treatment of nonwoven stratified materials used as filters for gaseous media. A specially designed afterglow plasma equipment is used for decontamination and cleaning of highly fragile flat or 3-D cultural heritage items. An equipment for producing HF torch plasma is also described.

The plasma healing of acute wound on 56 hairless mice is examined and initiated by several externally controlled physical parameters such as driving frequency and power, duration and interval of plasma treatment, a fraction of air mixture, the gap distance between plasma and wound, and others. The variation of these physical parameters results in a different amount of reactive oxygen and nitrogen species (RONS), which stimulate the regulation of RONS in mouse tissue before revealing several important bioindicators in the process of wound healing. While focusing on an important physical indicator such as the wound size, the limited examination with 56 mice showed promising results [much improved over the previous mice experiments by single-frequency plasma (SP)] by Dual-frequency plasma (DP) with 2% air mixture to argon, which effectively correlates with the observation of optical emission spectra. Circular acute wounds treated by DP (2%) were reduced to 24% in just 8 h after the treatment and further reduced to 5% within a few days.

This paper reports on the behavior of red and black ink from a historical printed book, subjected to a plasma discharge treatment, applied for the decontamination and cleaning of naturally aged paper. As some preliminary experiments using high-frequency (HF) plasma showed a slight fading of red ink, the study was focused on the comparison of HF cold plasma and afterglow plasma treatments in order to get conclusive information on the effect of plasma active species on the red ink. Energy Dispersive X-ray Scanning Electron Microscopy SEM-EDX and Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy FTIR-ATR analyses were used for the identification of inks and binder, while the impact of plasma on inks was assessed by SEM analysis and color determinations. The experiments have been performed on an especially designed modular equipment, allowing the samples to be subjected alternately to HF cold plasma or afterglow plasma treatment. The study proved that direct HF plasma could result in a more important deterioration at treatment duration exceeding 5 min, while in afterglow plasma, this discoloration is not observable. The color fading is imputable to the corrosion of pigment crystallites produced by direct plasma discharge.

This paper describes an investigation of plasma influence on the germination rate of brown mustard seeds (Brassica juncea L.). It was found that five pulses of a nanosecond microspark have a suppressing action increasing the time of the seeds germination by 5 h; the plasma influence and UV-radiation of the nanosecond surface discharge with the frequency of 1 Hz for the course of 15 min being at a distance of 25 mm from the surface of the seed have a stimulating action on it reducing the germination time by 3 h; a combined treatment using the discharges of both types showed that germination rate may look as two-pulse mode. Repeated experiments confirmed this conclusion. Visual observation of the seeds after the UV-radiation and plasma treatment revealed cracks on the seed coats. The cracks significantly increase moisture penetration into the coat.

The aim of this paper is to show and discuss the influence of cold plasma treatment on a germination enhancement of wheat and oat caryopses in wider context. Wheat and oat corns have been stimulated by cold plasma discharge under power of 500 W, air gas flow of 200 ml/min for different time durations (from 0 to 2400 s). Wheat seed coat showed an eroded surface after plasma treatment. Plasma treatment inhibited the germinating acceleration of wheat in first days but enhancement of footstalk was observed on plants grown from seeds treated for medium time. On the other hand, plasma treatment did not affect germination of oat seeds, but accelerated the rootlet generation at plants grown from treated seeds. The different content of phenolic compounds between control sprouts and sprouts from treated seedlings was discovered. The different contents illustrated changes in metabolism processes in both tested species. These phenomena indicate penetration of active species from plasma through the porous seed coat inside the seed where they react with seed cells.

A nonthermal plasma torch has been developed to study the targeted killing of melanoma cells. In this paper, 1205Lu melanoma cells and keratinocytes were exposed to the plasma. These cells were transfected with green fluorescent protein in order to establish a system for coculture with primary keratinocytes. Results show that a 10 s treatment with plasma causes a morphological change in the melanoma cells, as observed after 18 h. However, after only 15 min following plasma treatment, a significant killing of melanoma cells was observed, with a much reduced killing of keratinocytes. Nonthermal plasma may serve as an effective tool for future therapeutic cancer treatment.

To date, research on the inactivation of microorganisms by nonequilibrium atmospheric pressure plasmas has mainly been concerned by the killing efficiency and/or with the study of the roles played by various plasma agents (ultraviolet, radicals, ions, etc.) in the inactivation process. In this paper, the authors look at the problem from the cells' side. More specifically, the following questions are asked: What part of the spore structure plays a crucial role in its defense against the unfavorable plasma environment, and if the cells do survive plasma treatment, do they emerge the same or do they undergo some kind of noticeable changes? Although complete and comprehensive answers to these questions are not at the authors' grasp at this time, this paper presents convincing preliminary data that show that the integrity of the proteins of a spore's coat plays a major role in its survivability and that cells that survive air plasma exposure emerge with a changed metabolism

For the first time, quantitative data was obtained on plasma treatment of living mammalian cells. The nonthermal atmospheric discharge produced by the plasma needle was used for treatment of mammalian endothelial and smooth muscle cells. The influence of several experimental parameters on cell detachment and necrosis was tested using cell viability assays. Interruption of cell adhesion (detachment) was the most important cell reaction to plasma treatment. Treatment times of 10 s were enough to detach cells in the cultured cell sheet. Under extreme conditions, cell necrosis occurred. Cell detachment without necrosis could be achieved at low voltages. It was shown that the thickness of the liquid layer covering the cells was the most important factor, which had more influence than treatment time or applied voltage. The results show no remarkable differences between the responses of the two cell types.

Much effort is invested in the development of tissue-saving methods in dentistry. Cleaning and sterilization of infected tissue in a dental cavity or in a root channel can be accomplished using mechanical or laser techniques. However, with both approaches, heating and destruction of healthy tissue can occur. Recently, a nonthermal atmospheric plasma (plasma needle) has been developed. In this work, the interactions of this plasma with dental tissue is studied, and its capability of bacterial inactivation is tested. A plasma needle is an efficient source of various radicals, which are capable of bacterial decontamination; however, it operates at room temperature and thus, does not cause bulk destruction of the tissue. Plasma treatment is potentially a novel tissue-saving technique, allowing irregular structures and narrow channels within the diseased tooth to be cleaned.

We report the results of experiments aimed at the investigation of the destruction of spore-forming bacteria, which are believed to be among the most resistant micro-organisms, using a novel atmospheric-pressure capillary plasma electrode discharge plasma. Various well-characterized cultures of Bacillus Subtilis were prepared, subjected to atmospheric-pressure plasma jets emanating from a plasma-shower reactor operated either in He or in air (N/sub 2//O/sub 2/ mixture) at various power levels and exposure times, and analyzed after plasma treatment. Reductions in colony-forming units ranged from 10/sup 4/ (He plasma) to 10/sup 8/ (air plasma) for plasma exposure times of less than 10 min.

Squamous cell carcinoma of the bladder is a rare type of bladder cancer that forms as a result of chronic irritation of the epithelial lining of the bladder. The cell line used in this paper is SCaBER (ATCC HTB3) derived from squamous cell carcinoma of the human urinary bladder. Current treatments of bladder cancer include surgery, radiation, and chemotherapy. However, the cost of these treatments, potential toxicity of the chemotherapeutic agents, and systemic side-effects warrant an alternative to current cancer treatment. In this paper, we present images of SCaBER cells treated by the plasma pencil, a device that generates a low temperature plasma plume at atmospheric pressure. The images show that after plasma treatment of only a few minutes substantial killing of SCaBER cells occur and that the cells die in a delayed manner, postplasma treatment.

Cold plasma treatment of wounds is gaining much interest, because it will offer a noncontact, painless, and harmless therapy to manage large-area lesions (burn wounds and chronic ulcerations). One of the important issues in plasma wound healing is the safety of the method. In this paper, we study in vitro the effects of plasma treatment on cell death, proliferation, and wound healing. We performed a parametric study of plasma-treated 3T3 fibroblast cells. For the treatment, a cold atmospheric plasma needle (13.56-MHz microjet in helium) was used. Cells were cultured in six well plates and subsequently deposited on the bottom of the well. As a wound model, a scratch was made in the cell culture. Then, the proliferation of the cells from the sidewalls into the scratch was observed by microscopy. It appeared that plasma treatment stimulates the proliferation of cells into the scratch. This suggests that plasma treatment could result in accelerated wound healing.

Bacterial biofilms are microbial communities that are less susceptible to standard killing methods than free-living bacteria. Gas-discharge plasmas were used to treat biofilms for various exposure times. After 5-min plasma exposure, 90% of culturable cells were removed. Atomic-force-microscope images that reveal the sequential changes in cell morphology occurring during plasma treatment are presented.

Plasma treatment changes the outermost layer of a material without interfering with the bulk properties. However, textiles are several millimeters thick and need to be treated homogeneously throughout the entire thickness. In this paper, the dielectric-barrier-discharge treatment in He of three different textile layers is studied for several medium pressure values, and images of the discharge footprints are presented to demonstrate the pressure effect on plasma penetration.

A newly developed middle-frequency (2 MHz) inductively coupled plasma (ICP) source with internal oscillating current is used to treat biodegradable food packaging surfaces. Initially hydrophilic packaging turns to hydrophobic after being processed by ICP. The investigation of optical emission from hydrocarbon radicals in the Ar/CH4 plasma helps us to understand the property of the hydrophobicity of the surfaces.