Cold plasma turns mixed-dye-contaminated wastewater bio-safe.

The excessive and uncontrollable discharge of diverse organic pollutants into the environment has emerged as a significant concern, presenting a substantial risk to human health. Among the advanced oxidation processes used for the purification of wastewater, cold plasma technology is superior in fast and effective decontamination but often fails facing mixed pollutants. To address these issues, here we develop the new conceptual approach, plasma process, and proprietary reactor that ensure, for the first time, that the efficiency of treatment (114.7%) of two mixed organic dyes, methylene blue (MB) and methyl orange (MO), is higher than when the two dyes are treated separately. We further reveal the underlying mechanisms for the energy-efficient complete degradation of the mixed dyes. The contribution of plasma-induced ROS and the distinct degradation characteristics and mechanism of pollutants in mixed treatment are discussed. The electron transfer pathway revealed for the first time suggest that the mixed pollutants reduce the overall redox potentials and facilitate electron transfer during the plasma treatment, promoting synergistic degradation effects. The integrated frameworks including both direct and indirect mechanisms provide new insights into the high-efficiency mixed-contaminant treatment. The degradation products for mixed degradation are revealed based on the identification of intermediate species. The plasma-treated water is proven safe for living creatures in waterways and sustainable fishery applications, using in vivo zebrafish model bio-toxicity assay. Overall, these findings offer a feasible approach and new insights into the mechanisms for the development of highly-effective, energy-efficient technologies for wastewater treatment and reuse in agriculture, industry, and potentially in urban water networks.

Cold atmospheric pressure plasma: A potential physical therapy for rheumatoid arthritis hyperplastic synovium.

The most significant pathological change in rheumatoid arthritis (RA) is synovial hyperplasia within the joint. The production of a series of degrading enzymes and oxidative stress caused by synovial hyperplasia lead to severe bone and cartilage damage in rheumatoid joints. The core effector cell in hyperplastic synovium is fibroblast-like synovium cells, which can invade cartilage, cause inflammation, destroy joints, and show tumor-like anti-apoptosis characteristics. This study focused on the effect of cold atmospheric pressure plasma on proliferative synovium, and the results showed that no synovial hyperplasia, angiogenesis, or inflammatory infiltration was observed after cold atmospheric pressure plasma (CAP) treatment. The molecular and cellular mechanisms also reveal the spontaneous reactive oxygen species (ROS) cascade inducing apoptosis in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) cells. This study proposes a potential physical therapy method for treating proliferative synovium and also provides ideas for the application of CAP in other types of tumor diseases.

Plasma-microbubble treatment and sustainable agriculture application of diclofenac-contaminated wastewater.

The demand for efficient wastewater treatment is becoming increasingly urgent due to the rising threat of pharmaceutical residues in water. As a sustainable advanced oxidation process, cold plasma technology is a promising approach for water treatment. However, the adoption of the technology encounters several challenges, including the low treatment efficiency and the potentially unknown environmental impact. Here, microbubble generation was integrated with cold plasma system to enhance treatment of wastewater contaminated with diclofenac (DCF). The degradation efficiency depended on the discharge voltage, gas flow, initial concentration, and pH value. The best degradation efficiency was 90.9% after 45 min plasma-bubble treatment under the optimum process parameters. The hybrid plasma-bubble system exhibited strongly synergistic performance heralded by up to seven-times higher DCF removal rates than the two systems operated separately. The plasma-bubble treatment remains effective even after addition of SO42-, Cl-, CO32-, HCO3-, and humic acid (HA) as interfering background substances. The contributions of •O2-, O3, •OH, and H2O2 reactive species to the DCF degradation process were specified. The synergistic mechanisms for DCF degradation were deduced through the analysis of the degradation intermediates. Further, the plasma-bubble treated water was proven safe and effective to stimulate seed germination and plant growth for sustainable agriculture applications. Overall, these findings provide new insights and a feasible approach with a highly synergistic removal effect for the plasma-enhanced microbubble wastewater treatment, without generating secondary contaminants.

A Meaningful Attempt: Applying Dielectric Barrier Discharge Plasma to Induce Polarization of Macrophages.

Macrophage polarization plays an important role in many macrophage-related diseases. This study was designed to preliminarily explore the effects of dielectric barrier discharge (DBD) plasma on the polarization direction and cell activity of macrophages with different phenotypes (ie, M0, M1, and M2). The M1 macrophage marker inducible nitric oxide synthase (iNOS) and M2 macrophage marker cluster of differentiation 206 (CD206) were detected by western blot (WB). The effects of DBD plasma on macrophage viability were analyzed by using a cell counting kit-8 detection kit. M0, M1, and M2 macrophages exhibited a decrease in iNOS expression and an increase in CD206 expression after the DBD plasma intervention. Additionally, the decrease in macrophage viability remained non-significant after initiating the intervention. DBD plasma can promote the transformation of M0 and M1 macrophages to M2 macrophages, and can further enhance the expression of the M2 macrophage phenotype marker CD206. Our study not only demonstrates the potential therapeutic value of DBD plasma for macrophage-related diseases, but it also provides a new direction for research to improve the treatment of macrophage-related diseases. © 2023 Bioelectromagnetics Society.

Fabrication of Antimicrobial Multilayered Nanofibrous Scaffolds-Loaded Drug via Electrospinning for Biomedical Application.

Nanofibers prepared by biobased materials are widely used in the field of biomedicine, owing to outstanding biocompatibility, biodegradable characters, and excellent mechanical behavior. Herein, we fabricated multilayered nanofibrous scaffolds in order to improve the performance of drug delivery. The composite layer-by-layer scaffolds were incorporated by hydrophobic poly(l-lactic acid) (PLA): polycaprolactone (PCL) and hydrophilic poly(vinyl alcohol) (PVA) nanofibers via multilayer electrospinning. Morphological and structural characteristics of the developed scaffolds measured by scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed smooth and uniform fibers ranging in nanometer scale. The differences in contact angles and Fourier transform infrared spectrum (FTIR) between single-layered PVA nanofibers and multilayered scaffolds verified the existence of PLA: PCL surface. In vitro biodegradable and drug release analysis depicted multilayered scaffolds had good biodegradability and potential for medical application. Due to the model drug incorporation, scaffolds exhibited good antibacterial activity against Escherichia coli and Staphylococcus aureus by the zone of inhibition test. These results revealed that the multilayered scaffolds were proved to be desirable antibacterial materials for biomedical application.

The Potential Effects of Dielectric Barrier Discharge Plasma on the Extraction Efficiency of Bioactive Compounds in Radix Paeoniae Alba.

Radix paeoniae alba (RPA) is a kind of herbal medicine of traditional Chinese medicine (TCM) that is widely used for the treatment of liver diseases and rheumatoid arthritis in clinical practice. As a result of the low extraction efficiency of RPA by the conventional method, many patients are given high dosages. In this study, four exposure doses of dielectric barrier discharge (DBD) plasma (0, 60, 120, and 180 s) were applied to modify the extraction efficiency of paeoniflorin, benzoylpaeoniflorin, tannic acid, gallic acid, 2'-hydroxy-4'-methoxyacetophenone, and polysaccharide in RPA. Finally, the application of plasma for 180 s exhibited a 24.6% and 12.0% (p < 0.001) increase of tannic acid and polysaccharide contents, however, a 2.1% (p < 0.05) and 5.4% (p < 0.001) reduction of paeoniflorin and gallic acid composition, respectively, and no significant difference (p > 0.05) in results obtained from benzoylpaeoniflorin and 2'-hydroxy-4'-methoxyacetophenone contents. Our results of scanning electron microscopy (SEM), automatic specific surface area and pore analyzer, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric analysis (TGA) indicated that DBD plasma can etch the surface and undergo graft polymerization by reactive species thereby changing the water/oil holding capacity and eventually changing the extraction efficiency of bioactive compounds in RPA. Overall, our observations provide a scientific foundation for modifying the extraction efficiency of bioactive ingredients related to the pharmacological activities of RPA.

Effect of non-ionizing reaction rate (assumed to be controllable) on the plasma generation mechanism and communication around RAMC vehicle during atmospheric reentry.

Radio frequency (RF) blackout occurs during radio attenuation measurement C (RAMC) vehicle reentry due to the attenuation effect of the plasma sheath on the communication signal. In recent years, the mitigation mechanism of chemical reaction for RF blackout problem has gradually been studied numerically and experimentally. However, the effect of non-ionization reaction rate has been ignored because it does not directly involve the generation of electrons. In the present study, the influence of non-ionizing reaction rate on the plasma generation mechanism and EM wave attenuation was numerically solved by the plasma flow and multilayer transmission model. According to the simulation results, only the reaction rate of [Formula: see text] has a significant effect on the electron number density in all non-ionizing reactions, and the degree of influence is less than the ionization reaction rate. The EM wave attenuation decreases with the decrease of the reaction rate of [Formula: see text]. When the reaction rate is reduced by 25 times, the maximum attenuation of electromagnetic wave can be reduced by 12 dB. Finally, a potential scheme by reducing the reaction rate of [Formula: see text] was proposed to mitigate the RF blackout problem.