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Plasma-activated water can efficiently inactivate pathogenic microorganisms and is considered to be a potent disinfectant in the medical, food, and agricultural industries. In this study, the air discharged by the gliding arc was mixed with different gases including O2, ambient air, synthetic air, and N2 at different flow rates to produce the activated gases, which were then activated gases were inducted into saline to prepare plasma-activated saline (PAS). The gaseous reactive species in the activated gases were composed of NO, NO2, and N2O5 and the aqueous reactive species in the PAS included H2O2, NO2−, NO3–, ⋅ OH , and 1O2 with different intensities, while the inactivation effects of the PAS also varied with the type and the flow rates of the mixed gases in the activated gases. The inactivation effects of the PAS treated by the discharged air mixed with O2, ambient air, and synthetic air started to become weak after 3 h placement. Scavenger analysis demonstrated that the 1O2 played a critical role in the inactivation process. This study indicated that air discharged by the gliding arc mixed with different gases could regulate the reactive species and the biological effects of PAS, providing insight into the preparation of PAS applied for disinfection. [ABSTRACT FROM AUTHOR]

Background: Antiviral drugs show significant efficacy in non-severe COVID-19 cases, yet there remains a subset of moderate COVID-19 patients whose pneumonia continues to progress post a complete course of treatment. Plasma-activated water (PAW) possesses anti-SARS-CoV-2 properties. To explore the potential of PAW in improving pneumonia in COVID-19 patients following antiviral treatment failure, we conducted this study. Methods: This was a randomized, controlled trial. Moderate COVID-19 patients with antiviral treatment failure were randomly assigned to the experimental group or the control group. They inhaled nebulized PAW or saline respectively. This was done twice daily for four consecutive days. We assessed improvement in chest CT on day 5, the rate of symptom resolution within 10 days, and safety. Results: A total of 23 participants were included, with 11 receiving PAW and 12 receiving saline. The baseline characteristics of both groups were comparable. The experimental group showed a higher improvement rate in chest CT on day 5 (81.8% vs. 33.3%, p = 0.036). The cumulative disappearance rate of cough within 10 days was higher in the experimental group. Within 28 days, 4 patients in each group progressed to severe illness, and no patients died. No adverse reactions were reported from inhaling nebulized PAW. Conclusion: This pilot trial preliminarily confirmed that nebulized inhalation of PAW can alleviate pneumonia in moderate COVID-19 patients with antiviral treatment failure, with no adverse reactions observed. This still needs to be verified by large-scale studies. Trial registration: Chinese Clinical Trial Registry; No.: ChiCTR2300078706 (retrospectively registered, 12/15/2023); URL: www.chictr.org.cn. [ABSTRACT FROM AUTHOR]

The application of cold atmospheric plasma (CAP) in cancer therapy has recently received extensive attention. However, researchers have mainly studied the effects of CAP on plasma-irradiated cancer cells and have not determined whether CAP affects surrounding or distant non-irradiated cancer cells. Here, the viability and intracellular reactive oxygen species levels of plasma-irradiated and non-irradiated cancer cells were monitored in vitro. Our results showed that CAP may induce plasma-irradiated cancer cells (A549 cells, A375 cells, J82 cells and HT29 cells) to secrete soluble factors into the cell culture medium, which can transmit plasma-induced anticancer effects from plasma-irradiated cancer cells to non-irradiated cancer cells. Our research confirmed that plasma-induced anticancer effects can be transmitted between cancer cells. [ABSTRACT FROM AUTHOR]

Oral diseases stemming from oral pathogenic bacteria pose a significant global health concern, and current methods for managing these pathogens have limitations. Plasma‐activated water (PAW), containing various reactive species, emerges as a promising disinfectant with impressive inactivation capabilities. In this study, PAW prepared by mixed‐mode plasma‐activated gases was applied to inactivate oral pathogenic bacteria, including Streptococcus mutans and Porphyromonas gingivalis. The PAW could reduce more than 6.1‐log10 planktonic bacteria and 4.1‐log10 bacteria within biofilm, respectively, and PAW treatment of planktonic bacteria effectively inhibited biofilm formation. Compared to chlorhexidine, PAW exhibited superior inactivation effects in both planktonic bacteria and biofilm. This study presented a potent strategy for bacteria eradication to reduce the incidence of oral diseases. [ABSTRACT FROM AUTHOR]

Plasma is highly efficient in the inactivation of microorganisms and is tried to be applied to the treatment of wounds. The gas activated by plasma, named plasma-activated gas, can also effectively inactivate microorganisms and get rid of the limitations of direct plasma treatment. However, the details of the interaction of plasma-activated gas on the tissue are still unclear. In this study, the agarose gel models in the presence of microorganisms to simulate the infected tissues were used to study the inactivation effects and mechanisms of plasma-activated gas. The inactivation depths in the gel models in the presence of microorganisms were related to the types of plasma-activated gas and the species of microorganisms. The Mixed-gas exhibited the strongest inactivation effects, and the inactivation depths in the gel models in the presence of bacteria were deeper than those in the presence of fungi. The long-lived species in the plasma-activated gas penetrated to more than 5.2 mm while the short-lived species only penetrated less than 2.3 mm, demonstrating the distinct roles of reactive species in the inactivation process. Moreover, the pig muscle was covered on the gel models to assess the penetration depths of the plasma-activated gas in muscle tissue and the focused plasma-activated gas could penetrate 1–1.5 mm of pig muscle. This study explored the inactivation effects and mechanisms on the gel models and the penetration depths in the real tissues of plasma-activated gas, which supplied the theoretical basis for the further application of plasma-activated gas in biomedical fields. [ABSTRACT FROM AUTHOR]

As an indirect application of cold atmospheric plasma, the use of plasma-activated solutions has recently attracted significant attention for intracavity tumor perfusion therapy. Here, an underwater plasma-bubble reactor with three discharge modes was applied to activate a cell culture medium, with the aim of inhibiting the growth of bladder cancer T24 cells in vitro. The results showed that although the reactive species in cell culture medium generated by the underwater bubble plasma varied between the dielectric barrier discharge (DBD) mode, spark mode, and hybrid mode, the plasma-activated cell culture medium (PAM) corresponding to all three discharge modes effectively decreased the viability of T24 cells. However, after co-culturing the PAM-pretreated T24 cells with normal T24 cells, it was observed that normal T24 cells were not affected by either the DBD or spark mode; however, the hybrid mode PAM-pretreated T24 cells further induced inactivation and apoptosis of normal T24 cells. Further studies suggested that the aqueous reactive species generated by the underwater bubble plasma in hybrid mode not only induced the apoptosis of T24 cells directly but also triggered PAM-pretreated T24 cell-derived exosome-mediated anticancer activity toward cancer cells. These results may provide a strategy for enhancing the anticancer extent and effect of PAM as well as advancing its clinical application. [ABSTRACT FROM AUTHOR]

The interaction between an atmospheric pressure plasma jet (APPJ) and an aqueous solution has great application prospects in biomedicine and many other fields. Reactive species adjacent to a water surface is critical to the activation of APPJ-treated water, which is affected by both the water evaporation and the admixture of ambient air. In this paper, taking He APPJ as an example, a two-dimensional (2D) cylindrically symmetric fluid model is developed to obtain the spatial distributions of gas components before discharging, and a series of global models are developed for the discharge in the boundary gas layer adjacent to the water surface. The interfacial distributions of reactive species and their fluxes onto the water surface are quantified. It is found that the electron density is 1016–1017 m−3 and it shows an annular distribution in the boundary gas layer. The density distributions of most reactive species there reveal ring-like shapes as well. The dominant cation and anion in such a boundary layer are H3O+ and OH−, respectively. The most abundant metastable is O2(a1Δ), the most abundant reactive oxygen species are H2O2 and OH, and the most abundant reactive nitrogen species are NO and HNO2. The species of H2O2, OH, HO2, and HNO2 are reportedly to have significant biological effects, and in our simulation, their fluxes onto the water surface are remarkable, higher than 1017 m−2 s−1. In addition, the effects of radial gas velocity and water evaporation on the particle flux distributions are also revealed. [ABSTRACT FROM AUTHOR]

Shortening the duration of the viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is critical to controlling viral transmission, alleviating the burden on the healthcare system, and ultimately mitigating the impact of the pandemic. This randomized, single‐blind, placebo‐controlled clinical trial aimed to investigate the safety and efficacy of gargling with plasma‐activated water (PAW) on prolonged viral shedding in patients infected with SARS‐CoV‐2 Delta and Omicron variants. Sixty‐two subjects, aged 18–80 years and infected with SARS‐CoV‐2, were recruited at two coronavirus disease 2019 (COVID‐19)‐designated hospitals in Shaanxi from January to March 2022. Primary outcomes included cumulative conversion rates, incidence of adverse reactions, and biosafety parameters. Results suggested that PAW gargling treatment might contribute to reducing the duration of SARS‐CoV‐2 Delta and Omicron variant infections and alleviating symptoms. [ABSTRACT FROM AUTHOR]

In photocatalysis, catalysts are crucial for effective charge transfer and separation. Using Mo-MOF and CdCo-MOF as precursors, we have designed an effective Cd0.76Cd0.17Mo0.07S (Ethy-CCMS) photocatalyst. We compared the performance of samples prepared in different environments and found that the rod-shaped Ethy-CCMS prepared in an alkaline environment provided by ethylenediamine exhibited the highest photocatalytic hydrogen production activity with an efficiency of 30.14 mmol g−1 h−1, which was 32.2 times higher than that of the CdS prepared under aqueous solution conditions. The solid solution formed can accelerate the separation of photogenerated electrons and avoid the formation of high oxidation power h+ compared to CdS alone. In addition, adding Mo and Co enables these three metals to form bonds with S. The shared S-bond improves the stability of the material and significantly mitigates the photocorrosion phenomenon. This study investigates the role of sulfides derived from Mo-MOF and CdCo-MOF as sustainable and promising co-catalyst candidates to enhance the photocatalytic performance of CdS-based composites. [ABSTRACT FROM AUTHOR]

Ammonia plays a crucial role in industry and agriculture worldwide, but traditional industrial ammonia production methods are energy‐intensive and negatively impact the environment. Ammonia synthesis using low‐temperature plasma technology has gained traction in the pursuit of environment‐benign and cost‐effective methods for producing green ammonia. This Review discusses the recent advances in low‐temperature plasma‐assisted ammonia synthesis, focusing on three main routes: N2+H2 plasma‐only, N2+H2O plasma‐only, and plasma coupled with other technologies. The reaction pathways involved in the plasma‐assisted ammonia synthesis, as well as the process parameters, including the optimum catalyst types and discharge schemes, are examined. Building upon the current research status, the challenges and research opportunities in the plasma‐assisted ammonia synthesis processes are outlined. The article concludes with the outlook for the future development of the plasma‐assisted ammonia synthesis technology in real‐life industrial applications. [ABSTRACT FROM AUTHOR]

The present study introduces a novel method for online vacuum monitoring of vacuum circuit breakers, which overcomes the limitations of conventional offline monitoring methods in engineering applications. Specifically, the proposed method uses laser-induced breakdown spectroscopy (LIBS) in combination with the random forest (RF) algorithm to monitor the vacuum level of the breaker. The experimental setup included the selection spectral lines from four elements (one in the target material and three in the ambient gas). Spectral data were collected using the LIBS platform under various pressure conditions ranging from 10−3 Pa to 105 Pa. An RF model was established to classify the pressure level using spectral data. The classification performance is tested with a confusion matrix. We employed various spectral preprocessing techniques to enhance the distinctiveness of spectral features. The choice of the optimal preprocessing method was determined by assessing the correlation coefficient (R2) and root mean square error (RMSE), resulting in improved accuracy in vacuum level classification. The variable importance random forest (VIRF) algorithm was also employed for feature selection on the raw spectra to eliminate redundant information, thus enhancing the model's efficiency and accuracy. Utilizing out-of-bag (OOB) error as the evaluation metric, we systematically explored the impact of decision tree quantity (ntree) and the number of selected features (mtry) on the model's performance, optimizing it to its highest performance. The results indicate that the proposed method can achieve an accuracy of over 99% of vacuum classification, comparable to traditional offline vacuum monitoring technology. This demonstrates that LIBS technology combined with the RF algorithm represents a promising new approach for online vacuum monitoring of vacuum circuit breakers. [ABSTRACT FROM AUTHOR]