共查询到20条相似文献,搜索用时 15 毫秒
1.
Effects of a cold atmospheric pressure plasma (CAPP) treatment on the germination, production of biomass, vigor of seedlings, uptake of water of wheat seeds ( Triticum aestivum L. cv. Eva) were investigated. The CAPP treatment influence on the inactivation of microorganisms occurring on the surface of wheat seeds was investigated also. The so-called Diffuse Coplanar Surface Barrier Discharge generating a cold plasma in ambient air with high power volume density of some 100 W/cm 3 was used for the treatment of seeds at exposure times in the range of 10–600 s. The optical emission spectroscopy and the electrical measurements were used for estimation of CAPP parameters. The obtained results indicate that the germination rate, dry weight and vigor of seedlings significantly increased for plasma treatment from 20 to 50 s. The plasma treatment of seeds led to an extensive increase in wettability and faster germination comparing with the untreated seeds. The growth inhibition effect of CAPP on the surface microflora of wheat seeds increased with the increase of the treatment time. The efficiency of the treatment of wheat seeds artificially contaminated with pure cultures of filamentous fungi decreased in the following order: Fusarium nivale > F. culmorum > Trichothecium roseum > Aspergillus flavus > A. clavatus. 相似文献
2.
Plasma Chemistry and Plasma Processing - The possibility to improve the germination characterization of the wheat seeds by cold atmospheric nitrogen plasma jet treatment was report. Spectroscopic... 相似文献
3.
Plasma Chemistry and Plasma Processing - Cold atmospheric pressure plasma treatment is currently being explored as an alternative way to improve the germination and growing parameters of plant... 相似文献
4.
Plasma Chemistry and Plasma Processing - This study investigated the effect of cold atmospheric pressure air plasma pre-treatment on pea (Pisum sativum L.) seeds. The aim of our study was to verify... 相似文献
5.
The objective of this study is to investigate the bactericidal efficiency of atmospheric pressure non-thermal (cold) dielectric barrier discharge plasma on biofilms of Staphylococcus aureus and Escherichia coli. In general, cold plasma is a mixture of electrons, ions, neutral atoms and molecules. The different particles in cold plasmas exhibit different energies, i.e. electrons are much more energetic than other particles. This feature of cold plasmas allows to produce chemically reactive species at near room temperature that can be used in biological applications. Bacteria inactivation was performed using the air direct plasma (with reactive species, UV light, excited species and electric fields). Discharge power density during the experiment was equal to 70 mW/cm 2 and plasma dose was regulated by the treatment time. Bacterial biofilms were treated with the non-thermal plasma for 10–300 s. The most effective reduction in the number of S. aureus cells was found after 300 s of treatment and was 2.77 log 10 that is 99.83%. When the biofilm of E. coli was used in the experiment, killing of bacteria was independent of the exposure time and the mortality of cells did not exceed 0.48 that is 66.7% kill. The lethal effect on E. coli and S. aureus cells were observed after 300 and 120 s of plasma treatment, respectively but it was necessary to remove the layers of dead cells. The proposed process of removing dead cell layers was carried out due to the probable shielding effect, i.e. dead cells prevent further penetration of active plasma species into the deeper layers of the biofilm. It was shown that the effectiveness of cell destruction by the non-thermal plasma depends on the thickness of biofilm. 相似文献
6.
Plasma Chemistry and Plasma Processing - Cold atmospheric plasma discharges in air above air–water surface interface and discharges inside water with injection of air bubbles, show... 相似文献
7.
Plasma Chemistry and Plasma Processing - Cold atmospheric pressure plasmas (CAPPs) increasingly attracted scientific attention in the field of medicine, especially oncology. Because of the surface... 相似文献
8.
Atmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties and biocompatibility are enhanced. Polymers are used in many biomedical applications; such as implants, because of their variable bulk properties. On the other hand, their surface properties are inadequate which demands certain surface treatments including atmospheric pressure plasma treatment. In biomedical applications, surface treatment is important to promote good cell adhesion, proliferation, and growth. This article aim is to give an overview of different atmospheric pressure plasma treatments of polymer surface, and their influence on cell-material interaction with different cell lines. 相似文献
9.
Plasma Chemistry and Plasma Processing - Cold atmospheric plasma (CAP) is a novel technology which is widely used in the biomedical field and has developed quickly over the past few years,... 相似文献
10.
Novel types of non-thermal plasma sources at atmospheric pressure based on multi-pin DC (direct current) diffusive glow discharge and AC (alternative current) streamer barrier corona have been elaborated and tested successfully for cold surface treatment of polymer films [polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET),] and polyester fabric. Results on physical properties ofdischarges mentioned and output energy characteristics of new plasma sources as well as data on after-treatment changes in wettability of films and fabrics are presented. The main goal of this study was to find out the experimental conditions for gas discharge and surface processing to achieve a remarkable wettability change for a short treatment time. 相似文献
11.
High Energy Chemistry - It has been shown that as a result of surface treatment of seeds in nonthermal atmospheric-pressure glow-discharge plasma, the surface becomes hydrophilic and is... 相似文献
12.
Low pressure plasma technologies have been widely and successfully utilized for the production of a large variety of organic–inorganic nanocomposite (NC) thin films consisting of metal or metal oxide nanoparticles embedded in a polymer matrix. Recently, the deposition of this class of coatings has been also accomplished by atmospheric pressure cold plasmas using aerosol-assisted processes in which a dispersion containing preformed inorganic nanoparticles and the liquid precursor of the polymeric component is atomized and injected in aerosol form in the atmospheric plasma. This short review is aimed at presenting this approach which is expected to enlarge the range of structures and properties of organic–inorganic NC coatings deposited by cold plasma technologies. 相似文献
13.
Plasma Chemistry and Plasma Processing - Propagation of orchid (Cymbidium tracyanum L. Castle) treated by using an air cold atmospheric pressure plasma jet at room temperature was investigated. The... 相似文献
14.
Air atmospheric dielectric barrier discharge plasma (DBD) was attempted to pretreat wheat seed to improve its germination and growth in this study. The effects of the DBD plasma treatment on the wheat seed germination, seedling growth, osmotic-adjustment products, lipid peroxidation level, and antioxidant enzymes activity were investigated. The experimental results showed that the DBD plasma treatment with an appropriate time scale could promote the wheat seed germination and seedling growth. The germination potential, germination rate, germination index, and vigor index increased by 26.7, 9.1, 16.9, and 46.9% after 7 min’s DBD plasma treatment, respectively; the root length, shoot length, fresh weight, and dry weight of the seedlings also increased after the DBD plasma treatment. The osmotic-adjustment products, proline and soluble sugar contents, in the wheat seedlings were significantly enhanced after the DBD plasma treatment with an appropriate time scale, while the malondialdehyde content decreased. Moreover, the activities of superoxide dismutase and peroxidase also increased after the DBD plasma treatment. The DBD plasma treatment led to etching effect on the wheat seed coat, resulting in the improvement of its water absorption capacity. 相似文献
15.
We have finally succeeded in producing the plasma jet by use of the surface discharge plasma torch that can be expected to
make larger the diameter of torch in the comparatively easy way. It can be checked that the active species in the jet obtained
are different depending on the direction of connection, and also it was clearly found that much O and N 2 is included in them. Consequently, etching was confirmed at the position of 10 mm from the torch end in the surface treatment
of polypropylene film, but etching was not confirmed at the position of 20 mm. 相似文献
16.
We review studies of surface-interaction mechanisms for a surface microdischarge (SMD) and an atmospheric pressure plasma jet (APPJ) with model polymers and biomolecules in our laboratory. We discuss the influence of plasma source type, operating parameters, and gaseous environments on surface modifications and biological deactivation. We focus on mild, remote conditions where the visible plasma plume does not contact the surface. For an APPJ fed with Ar, the interaction of the plasma plume with O 2 and/or N 2 gaseous environments leads to oxidation and surface-bound NO x even on materials containing neither oxygen nor nitrogen. The APPJ also modifies photo-sensitive polymers. Using optical filters, these modifications were shown to result in part from irradiation with vacuum ultraviolet (VUV) photons in a spectral range corresponding to Ar excimer emission. No VUV-induced effects were seen for the SMD source operated with O 2/N 2. SMD treatments using O 2/N 2 mixtures result in surface oxidation and nitridation. A new surface-bound species, NO 3, has been measured on the polymers and biomolecules. Depending on the gas chemistry and film molecular structure, the NO 3 surface concentration can reach 10 %. Both surface NO 3 on plasma-treated films of lipopolysaccharide (LPS), an immune stimulating biomolecule found in bacteria such as E. c oli, and overall surface oxidation correlate with LPS biological deactivation as evaluated using an enzyme-linked immunosorbent assay. Ambient humidity was studied using the SMD and was found to decrease overall surface modifications including NO 3 and biodeactivation for O 2-rich conditions. Lastly, we discuss possible mechanisms and compare our results with published simulation studies. 相似文献
17.
The paper presents the results of an experiment on the effect of cold plasma (He?+?O2 and He?+?Air) generated in a radio frequency cold atmospheric plasma jet on the process of germination of onion cv. Wolska (Allium cepa L.) seeds. In order to determine the impact of the gas flow on the seed surface, CFD simulations and Schlieren imaging were performed and surface characteristics were studied using a digital microscope. Plasma treatment of the seeds was carried out four times (2, 5, 10 and 15 s) with one control group. Pre-sowing plasma stimulation of seeds improved the germination capacity and germination energy for all tested groups in comparison to the control. The best germination capacity and energy were obtained for seeds stimulated with 10 s of plasma treatment. Analysis of the data showed a statistically significant impact of plasma treatment on the onion seed’s germination parameters. Plasma treatment did not induce significant changes on the seed surface, as microscope images showed but length of all plasma-treated seedlings increased in comparison to control. 相似文献
18.
Cold atmospheric pressure plasma (CAPP) is widely used in medicine for the treatment of diseases and disinfection of bio-tissues due to its antibacterial, antiviral, and antifungal properties. In agriculture, CAPP accelerates the imbibition and germination of seeds and significantly increases plant productivity. Plasma is also used to fix molecular nitrogen. CAPP can produce reactive oxygen and nitrogen species (RONS). Plasma treatment of bio-tissue can lead to numerous side effects such as lipid peroxidation, genotoxic problems, and DNA damage. The mechanisms of occurring side effects when treating various organisms with cold plasma are unknown since RONS, UV-Vis light, and multicomponent biological tissues are simultaneously involved in a heterogeneous environment. Here, we found that CAPP can induce in vitro oxidation of the most common water-soluble redox compounds in living cells such as NADH, NADPH, and vitamin C at interfaces between air, CAPP, and water. CAPP is not capable of reducing NAD + and 1,4-benzoquinone, despite the presence of free electrons in CAPP. Prolonged plasma treatment of aqueous solutions of vitamin C, 1,4-hydroquinone, and 1,4-benzoquinone respectively, leads to their decomposition. Studies of the mechanisms in plasma-induced processes can help to prevent side effects in medicine, agriculture, and food disinfection. 相似文献
19.
We report on an atmospheric pressure plasma (APP) treatment of fused silica and its related surface and near-surface effects. Such treatment was performed in order to improve laser micro-structuring of fused silica by a plasma-induced modification of the glass boundary layer. In this context, an APP jet applying a hydrogenous process gas was used. By the plasma treatment, the transmission of the investigated glass samples was significantly decreased. Further, a decrease in the superficial index of refraction of approx. 3.66 % at a wavelength of 636.7 nm was detected ellipsometrically. By surface energy measurements, a decrease of the surface polarity of 30.23 % was identified. These determined modifications confirm a reduction of silicon dioxide to UV-absorbing silicon suboxide as already reported in previous work. Further, a change in reflexion by maximum 0.26 % was detected which is explained by the superposition of constructive and destructive interferences due to a surface wrinkling. With the aid of atomic force microscopy, an increase of the surface root mean squared roughness by a factor of approx. 19 was determined. It was found that both the surface energy and the strength of the fused silica surface were reduced by the plasma treatment. Even though such treatment led to a clustering of carbonaceous contaminants, a surface-cleaning effect was confirmed by secondary ion mass spectroscopy and energy-dispersive X-ray spectroscopy. The increase in UV-absorption allows enhanced laser ablation results as shown in previous work. 相似文献
20.
The increasing incidence of antifungal resistance represents a great challenge in the medical area and, for this reason, new therapeutic alternatives for the treatment of fungal infections are urgently required. Cold atmospheric plasma (CAP) has been proposed as a promising alternative technique for the treatment of superficial candidiasis, with inhibitory effect both in vitro and in vivo. However, little is known on the association of CAP with conventional antifungals. The aim of this study was to evaluate the effects of the association between CAP and conventional polyene antifungals on Candida albicans biofilms. C. albicans SC 5314 and a clinical isolate were used to grow 24 or 48 h biofilms, under standardized conditions. After that, the biofilms were exposed to nystatin, amphotericin B and CAP, separately or in combination. Different concentrations of the antifungals and sequences of treatment were evaluated to establish the most effective protocol. Biofilms viability after the treatments was compared to negative control. Data were compared by One-way ANOVA and post hoc Tukey (5%). The results demonstrate that 5 min exposure to CAP showed more effective antifungal effect on biofilms when compared to nystatin and amphotericin B. Additionally, it was detected that CAP showed similar (but smaller in magnitude) effects when applied in association with nystatin and amphotericin B at 40 µg/mL and 60 µg/mL. Therefore, it can be concluded that the application of CAP alone was more effective against C. albicans biofilms than in combination with conventional polyene antifungal agents. 相似文献
|