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Infection can hinder the process of wound healing, so it is important to begin antibacterial treatment quickly after a wound forms. Plasma activated water (PAW) can inactivate a variety of common wound infection bacteria. In this study, we compared the effects of PAW prepared with portable surface discharge plasma equipment and medical alcohol on wound healing in a mouse full-thickness skin wound model. The effectiveness of wound healing processes in mice was ranked accordingly: PAW treatment group &gt, medical alcohol treatment group &gt, control group. In order to further understand the mechanism of PAW in promoting wound healing, we tested the expression levels of the pro-inflammatory factors interleukin (IL)-1β and IL-6, the anti-inflammatory factor IL-10, and vascular endothelial growth factor (VEGF). The results showed that PAW promoted the release of pro-inflammatory factors and anti-inflammatory factors from the wounds in mice, which allowed the mice in the treatment group to transition out of the inflammatory period early and enter the next stage of wound healing. The expression level of VEGF in the wounds of mice in the PAW treatment group was higher, which indicates that the microvessels around the wound in the PAW treatment group proliferated faster, and thus the wound healed faster. PAW biosafety experiments showed that PAW did not significantly affect the appearance, morphology, or tissue structure of internal organs, or blood biochemical indicators in mice. In general, PAW prepared via portable devices is expected to become more widely used given its convenience, affordability, and lack of side effects in promoting wound healing.

Due to increasing concentrations in the atmosphere, carbon dioxide has, in recent times, been targeted for utilisation (Carbon Capture Utilisation and Storage, CCUS). In particular, the production of CO from CO2 has been an area of intense interest, particularly since the CO can be utilized in Fischer–Tropsch synthesis. Herein we report that CO2 can also be used as a source of atomic oxygen that is efficiently harvested and used as a waste-free terminal oxidant for the oxidation of alkenes to epoxides. Simultaneously, the process yields CO. Utilization of the atomic oxygen does not only generate a valuable product, but also prevents the recombination of O and CO, thus increasing the yield of CO for possible application in the synthesis of higher-order hydrocarbons., Selective formation of atomic oxygen to form epoxides in a waste free process is reported. Simultaneously generating carbon monoxide from carbon dioxide for further use.

Background: Our previous study has demonstrated an oncogenic role of PIWI-interacting RNA-54265 (piR-54265) in colorectal cancer (CRC). Here, we investigate whether it can be a blood biomarker for population screening and clinical applications. Methods: Serum piR-54265 levels were determined by a digital PCR method in 209 cancer-free healthy controls, 725 patients with CRC, 1303 patients with other types of digestive cancer and 192 patients with benign colorectal tumors. A prospective case-control analysis was conducted to assess the predictive value of serum piR-54265 for future CRC diagnosis. Receiver operating characteristic (ROC) curve was constructed to quantify the diagnostic performance of serum piR-54265 levels by assessing its sensitivity, specificity and respective areas under curve (AUC). The odds ratios (ORs) were computed using multivariate logistic regression models. Results: Serum piR-54265 levels were significantly elevated only in patients with CRC compared with controls and patients with other cancer types. The AUC for recognizing CRC was 0.896 (95% CI, 0.874-0.914), with a sensitivity and specificity being 85.7% and 65.1% at 1500 copies/µL as a cut-off value. The serum piR-54265 levels in patients declined substantially after surgery but increased significantly again when tumor relapses. The prediagnostic serum piR-54265 levels were significantly associated with future CRC diagnosis, with the ORs of 7.23, 2.80, 2.45, and 1.24 for those whose CRC was diagnosed within 1, 2, 3 and >3 years. Serum piR-54265 test is more sensitive than other blood CRC markers. Conclusion: Serum piR-54265 may serve as a valuable biomarker for CRC screening, early detection and clinical surveillance.

Background: A large number of studies have been conducted to investigate associations between genetic variants and esophageal cancer risk in the past several decades. However, findings from these studies have been generally inconsistent. We aimed to provide a summary of the current understanding of the genetic architecture of esophageal cancer susceptibility. Methods: We performed a comprehensive field synopsis and meta-analysis to evaluate associations between 95 variants in 70 genes or loci and esophageal cancer risk using data from 304 eligible publications, including 104,904 cases and 159,797 controls, through screening a total of 21,328 citations. We graded levels of cumulative epidemiologic evidence of a significant association with esophageal cancer using the Venice criteria and false-positive report probability tests. We constructed functional annotations for these variants using data from the Encyclopedia of DNA Elements Project and other databases. Results: Thirty variants were nominally significantly associated with esophageal cancer risk. Cumulative epidemiologic evidence of a significant association with overall esophageal cancer, esophageal squamous cell carcinoma, or esophageal adenocarcinoma was strong for 13 variants in or near 13 genes (ADH1B, BARX1, CDKN1A, CHEK2, CLPTM1L, CRTC1, CYP1A1, EGF, LTA, MIR34BC, PLCE1, PTEN, and PTGS2). Bioinformatics analysis suggested that these variants and others correlated with them might fall in putative functional regions. Conclusions: Our study summarizes the current literature on the genetic architecture of esophageal cancer susceptibility and identifies several potential polymorphisms that could be involved in esophageal cancer susceptibility. Impact: These findings provide direction for future studies to identify new genetic factors for esophageal cancer.

Background: Drug resistance is one of the major problems encountered in clinical therapy of multiple myeloma treatment. Combination treatment with several drugs may increase the sensitivity and overcome drug resistance. Methods: Here, we combined chemotherapy with a newly developed technology, cold atmospheric plasma, to enhance drug sensitivity. Results: We found that plasma treatment had a synergistic anti-cancer effect with a first line drug (bortezomib). Based on our previous study, we further found that plasma treatment could inhibit Notch pathway and down-regulate cyp1a1 expression and enzyme activity, which contributing to the enhanced drug sensitivity to bortezomib after combination of bortezomib with gas plasma. Conclusions: Our results showed a new strategy to overcome drug resistance by combination of traditional chemotherapy with cold atmospheric plasma.

Background It was reported that tumor-expressed dickkopf-related (DKK) proteins affect micro-environment. However, the influence of DKK1 on colorectal cancer (CRC) liver oligometastases (CRCLOM) remains unclear. Methods CRC cases after resection of liver oligometastases were enrolled in Sun Yat-Sen University Cancer Center with intact clinical data. Serum DKK1 was detected by ELISA assay. Immunofluorescent staining examination for CD3 and CD8 in slices were also conducted. Results Among 65 patients included, the recurrence-free survival (RFS) and overall survival (OS) were significantly better in the low serum DKK1 group (RFS: P = 0.021; OS: P = 0.043). DKK1 was overexpressed in stage IV CRC patients in TCGA data. The number of CD8+ tumor-infiltrating lymphocytes (TILs) in invasive margin of CRC liver oligometastases was significantly higher in low serum DKK1 group (P = 0.042). Conclusion Elevated serum DKK1 level was associated with poorer RFS and OS, and less CD8+ TILs in invasive margin in CRC liver oligometastases. DKK1 might serve as a supplementalprognostic factor for clinical risk score and a potential target for immunotherapy.

Systemic infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are life-threatening due to their strong multidrug resistance, especially since the biofilms formed by MRSA are more difficult to inactivate by antibiotics, causing long term recurrence of infection. Plasma-activated saline (PAS), a derived form of cold atmospheric-pressure plasma, can effectively inactivate bacteria and cancer cells and has been applied to sterilization and cancer treatment. Previous studies have demonstrated that the pretreatment of MRSA with PAS could promote the action of antibiotics. Here, the PAS was used as an antibiotic adjuvant to promote the inactivation of MRSA biofilms by rifampicin and vancomycin, and the combined treatment reduced approximately 6.0-log10 MRSA cells in biofilms. The plasma-activated saline and rifampicin synergistically and effectively reduced the systemic infection in the murine model. The histochemical analysis and the blood hematological and biochemical test demonstrated that the combined treatment with plasma-activated saline and rifampicin improved the blood hematological and biochemical parameters of infected mice by reducing the infection. Therefore, PAS based on plasma technology represents a new strategy for the treatment of infectious disease caused by multidrug-resistant bacteria and alleviating antibiotic resistance.

Plasma-activated liquid (PAL) can effectively and selectively kill various types of cancer cells both in superficial and deeper tumors. As a promising novel approach to oncotherapy, the safety of PAL is essential in the clinic but has not been thoroughly assessed. In myeloma and blood tumors, the pathogenesis is in the bone marrow cavity. We have therefore evaluated the safety of PAL in New Zealand rabbits by intra-bone marrow injection, and provide a basis of further clinical research and application of PALs. In this study, both a plasma jet and plasma surface were used to treat saline solution, phosphate-buffered solution, and cell culture medium, to produce PAL. Then, oscillograms and optical emission spectra were evaluated to characterize the plasma discharge. Acute toxicity tests and safety evaluation studies were conducted by intra-bone marrow injection of PAL into New Zealand rabbits, while control rabbits received saline only. Body weight, vital organ coefficient, organ appearance, organ histopathology, blood cell and hemoglobin parameters, and blood biochemical indicators were tested on the 30th day after injection. We found that there was no mortality or loss of mobility throughout the experimental period. Acute toxicity tests showed that there were no PAL-related side effects in rabbits receiving the maximum dose of 700 μL PAL. PAL treatments did not affect body weight, organ coefficient, organ appearance, organ histopathology, or blood biochemical indicators. However, the percentage of lymphocytes decreased while the percentage of neutrophil granulocytes increased compared with the control group. In summary, our results indicate that PAL can be safely injected into bone marrow of New Zealand rabbits without significant toxicity.

Biofilm infections in wounds seriously delay the healing process, and methicillin-resistant Staphylococcus aureus is a major cause of wound infections. In addition to inactivating micro-organisms, low-temperature gas plasma can restore the sensitivity of pathogenic microbes to antibiotics. However, the combined treatment has not been applied to infectious diseases. In this study, low-temperature gas plasma treatment promoted the effects of different antibiotics on the reduction of S. aureus biofilms in vitro. Low-temperature gas plasma combined with rifampicin also effectively reduced the S. aureus cells in biofilms in the murine wound infection model. The blood and histochemical analysis demonstrated the biosafety of the combined treatment. Our findings demonstrated that low-temperature gas plasma combined with antibiotics is a promising therapeutic strategy for wound infections.

Sebaceous gland tumour (SGT) is a rare tumour with a low incidence rate, which mainly occurs in the eyelid and periocular sebaceous gland. In 2019, our laboratory received a case involving a sebaceous gland tumour of the external auditory meatus for pathological diagnosis. It is a rare malignant tumour in the whole body. Data regarding a sebaceous gland tumour in the dogís external auditory meatus are few. This case is instructive for veterinary diagnosis and treatment. The dog recovered well after surgery at the outpatient department, and no recurrence was observed in the follow-up visit one year later. This study will help the identification of SGT in Spaniel dogs.

Biofilms formed by multidrug-resistant bacteria are a major cause of hospital-acquired infections. Cold atmospheric-pressure plasma (CAP) is attractive for sterilization, especially to disrupt biofilms formed by multidrug-resistant bacteria. However, the underlying molecular mechanism is not clear. In this study, CAP effectively reduced the living cells in the biofilms formed by methicillin-resistant Staphylococcus aureus, and 6 min treatment with CAP reduced the S. aureus cells in biofilms by 3.5 log10. The treatment with CAP caused the polymerization of SaFtsZ and SaClpP proteins in the S. aureus cells of the biofilms. In vitro analysis demonstrated that recombinant SaFtsZ lost its self-assembly capability, and recombinant SaClpP lost its peptidase activity after 2 min of treatment with CAP. Mass spectrometry showed oxidative modifications of a cluster of peaks differing by 16 Da, 31 Da, 32 Da, 47 Da, 48 Da, 62 Da, and 78 Da, induced by reactive species of CAP. It is speculated that the oxidative damage to proteins in S. aureus cells was induced by CAP, which contributed to the reduction of biofilms. This study elucidates the biological effect of CAP on the proteins in bacterial cells of biofilms and provides a basis for the application of CAP in the disinfection of biofilms.

Post-surgical residual tumor cells are the primary cause of relapse and progression of cancer but unfortunately, there are limited therapeutic options. In this work, a fillable plasma-activated biogel is produced on a thermosensitive biogel [(Poly-DL-lactide)-(poly-ethylene glycol)-(poly-DL-lactide), PLEL] with the aid of a discharge plasma for local post-operative treatment of cancer. In vivo data show that the plasma-activated PLEL biogel (PAPB) eliminates residual tumor tissues after removal surgery and also inhibits in situ recurrence while showing no evident systemic toxicity. Moreover, the PAPB possesses excellent storage capability, allows for slow release of plasma-generated reactive oxygen species (ROS), and exhibits good ROS-mediated anticancer effects in vitro. Our results reveal that the novel plasma-activated biogel is an effective therapeutic agent for local post-operative treatment of cancer.

The pulse-modulated radio frequency (RF) and kHz sinusoidal voltages are used for the excitation of two plasma jets, for which the reactive species in the plasma plumes and in the treated water are comparatively studied. With the same discharge power, it is found that concentrations of aqueous reactive species generated by the kHz sinusoidal plasma jet are higher than that of the pulse-modulated RF plasma jet, especially for the short-lived species OH. In addition, the comparison between the bacterial inactivation results is in accordance with that for the concentrations of aqueous reactive species for the two types of plasma jets. On the contrary, the emission spectra indicate that the gaseous reactive species such as OH(A) and O(3p5P) have much higher densities for the pulse-modulated RF plasma jet, which should ascribe to its higher electron density and electron temperature. Moreover, the concentrations of the aqueous reactive species and the emission intensities of the gaseous reactive species have similar variation trends for each of the plasma jets, as a function of the discharge power and the gap width. These results imply that the emission intensity could not reflect the relative concentration of an aqueous reactive species between these two plasma jets, but it could be used as an indicator of the concentration variation of an aqueous reactive species for each of the plasma jets. In addition, the phenomenon of electron trapping effect also indicates that the aqueous reactive species can be effectively generated only when more electrons act on the water sample.

The effect of framework (pore) disorder on gas sorption of azole-based isoreticular Cu(II) MOFs with rtl (rutile) topology and characteristic 1D tubular pore channels is investigated for the first time., Metal–organic frameworks with highly ordered porosity have been studied extensively. In this paper, the effect of framework (pore) disorder on the gas sorption of azole-based isoreticular Cu(II) MOFs with rtl topology and characteristic 1D tubular pore channels is investigated for the first time. In contrast to other isoreticular rtl metal–organic frameworks, the Cu(II) metal–organic framework based on 5-(1H-imidazol-1-yl)isophthalate acid has a crystallographically identifiable disordered framework without open N-donor sites. The framework provides a unique example for investigating the effect of pore disorder on gas sorption that can be systematically evaluated. It exhibits remarkable temperature-dependent hysteretic CO2 sorption up to room temperature, and shows selectivity of CO2 over H2, CH4 and N2 at ambient temperature. The unique property of the framework is its disordered structure featuring distorted 1D tubular channels and DMF-guest-remediated defects. The results imply that structural disorder (defects) may play an important role in the modification of the performance of the material.

In this paper, in order to obtain an atmospheric-pressure plasma jet with high activity and safe performance, the plasma jets generated with three distinct needle–ring electrodes, i.e., completely covered needle with insulating dielectric, partially covered needle (PCN) with insulating dielectric, and noncovered needle with any insulating dielectric, are studied and compared. Corresponding characteristics of three types of plasma jets are diagnosed and compared under the same excitation conditions. The results show that the PCN electrode is the best optimized one of three electrodes and presents the best cost performance among them in terms of discharge morphology, safety performance, propagation speed, and concentration of reactive species. It is mainly attributed to the addition of the partial insulating dielectric between the needle electrode and the ring electrode, which would not only effectively limit current rapid growth and prevent the rapid transformation of discharge mode, but also promote the charge overflow and strengthen the chemical activity of the plasma jet.

BRAF and MLH1 promoter methylation testings have been proven effective prescreens for Lynch Syndrome. We aimed to compare different screening strategies for Lynch Syndrome in patients with MLH1(-) CRC. Patients with MLH1(-) CRC who had been tested for BRAF mutation and germline variants of DNA mismatch repair genes were included. We compared the sensitivities and specificities for identifying Lynch Syndrome and the cost-effectiveness of four screening approaches that used the following tests as prescreens: BRAF testing, MLH1 methylation testing, MLH1 methylation & BRAF testing, and MLH1 methylation testing & Revised Bethesda Criteria. Of 109 patients included, 23 (21.1%) were Lynch Syndrome patients. BRAF mutation and MLH1 methylation occurred in 6 (5.5%) and 40 (36.7%) patients, respectively. The sensitivity for identifying Lynch syndrome of BRAF testing was 100%, but the specificity was only 7%. MLH1 methylation testing had a lower sensitivity than BRAF testing (97.5% vs 100%), but had a markedly higher specificity (45.3% vs 7%). The combination of the two testings had a slightly higher specificity than MLH1 methylation testing alone (47.7% vs 45.3%). The MLH1 methylation testing approach had a 10% lower cost of identifying MLH1(-) Lynch syndrome carriers per case than universal genetic testing, but it missed 4.5% of patients. BRAF and MLH1 promoter methylation testings as prescreens for Lynch syndrome are less effective in Chinese patients with MLH1(-) CRC than in their Western counterparts. Universal genetic testing could be considered an up-front option for this population.

Highlights An overview on photophysical properties of conductive metal–organic frameworks (MOFs) including photoconductivity and photoluminescence is provided.Miscellaneous applications of MOFs with photophysical properties are discussed.Recent advances in integration of photoactive MOFs with practical devices are summarized., Metal–organic frameworks (MOFs) are a class of hybrid materials with many promising applications. In recent years, lots of investigations have been oriented toward applications of MOFs in electronic and photoelectronic devices. While many high-quality reviews have focused on synthesis and mechanisms of electrically conductive MOFs, few of them focus on their photophysical properties. Herein, we provide an in-depth review on photoconductive and photoluminescent properties of conductive MOFs together with their corresponding applications in solar cells, luminescent sensing, light emitting, and so forth. For integration of MOFs with practical devices, recent advances in fabrication of photoactive MOF thin films are also summarized.

// Dehui Xu 1, 2, * , Yujing Xu 1, * , Qingjie Cui 2 , Dingxin Liu 1 , Zhijie Liu 1 , Xiaohua Wang 1 , Yanjie Yang 3 , Miaojuan Feng 4 , Rong Liang 4 , Hailan Chen 5 , Kai Ye 6, 7 and Michael G. Kong 1, 5, 8 1 State Key Laboratory of Electrical Insulation and Power Equipment, Center for Plasma Biomedicine, Xi’an Jiaotong University, Xi’an, Shaanxi, 710049, P.R. China 2 The School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi, 710049, P.R. China 3 Department of Cardiovascular Medicine, First Affiliated Hospital of the Medical School, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, P.R. China 4 Department of Hematology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, 710032, P.R. China 5 Frank Reidy Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA 6 School of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi, 710049, P.R. China 7 First Affiliated Hospital of the Medical School, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, P.R. China 8 Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, 23529, USA * These authors have contributed equally to this work Correspondence to: Michael G. Kong, email: mkong@odu.edu Kai Ye, email: ed_kaiye@mail.xjtu.edu.cn Keywords: multiple myeloma; cold atmospheric plasma; reactive oxygen species; CD95; selective inactivation Received: November 09, 2017 Accepted: January 30, 2018 Published: April 06, 2018 ABSTRACT Multiple myeloma (MM) is a fatal and incurable hematological malignancy thus new therapy need to be developed. Cold atmospheric plasma, a new technology that could generate various active species, could efficiently induce various tumor cells apoptosis. More details about the interaction of plasma and tumor cells need to be addressed before the application of gas plasma in clinical cancer treatment. In this study, we demonstrate that He+O 2 plasma could efficiently induce myeloma cell apoptosis through the activation of CD95 and downstream caspase cascades. Extracellular and intracellular reactive oxygen species (ROS) accumulation is essential for CD95-mediated cell apoptosis in response to plasma treatment. Furthermore, p53 is shown to be a key transcription factor in activating CD95 and caspase cascades. More importantly, we demonstrate that CD95 expression is higher in tumor cells than in normal cells in both MM cell lines and MM clinical samples, which suggests that CD95 could be a favorable target for plasma treatment as it could selectively inactivate myeloma tumor cells. Our results illustrate the molecular details of plasma induced myeloma cell apoptosis and it shows that gas plasma could be a potential tool for myeloma therapy in the future.

Graphical abstract, Highlights • Plasma-activated water inactivates the pseudoviruses with the SARS-CoV-2 S protein. • Plasma-activated water inactivates the RBD domain and prevents it from binding to hACE2. • Plasma-activated water can be developed as a potential disinfectant to combat the epidemic., SARS-CoV-2 is a highly contagious virus and is causing a global pandemic. SARS-CoV-2 infection depends on the recognition of and binding to the cellular receptor human angiotensin-converting enzyme 2 (hACE2) through the receptor-binding domain (RBD) of the spike protein, and disruption of this process can effectively inhibit SARS-CoV-2 invasion. Plasma-activated water efficiently inactivates bacteria and bacteriophages by causing damage to biological macromolecules, but its effect on coronavirus has not been reported. In this study, pseudoviruses with the SARS-CoV-2 S protein were used as a model, and plasma-activated water (PAW) effectively inhibited pseudovirus infection through S protein inactivation. The RBD was used to study the molecular details, and the RBD binding activity was inactivated by plasma-activated water through the RBD modification. The short-lived reactive species in the PAW, such as ONOO−, played crucial roles in this inactivation. Plasma-activated water after room-temperature storage of 30 days remained capable of significantly reducing the RBD binding with hACE2. Together, our findings provide evidence of a potent disinfection strategy to combat the epidemic caused by SARS-CoV-2.

BackgroundDickkopf 1 (DKK1) is associated with tumor progression. However, whether DKK1 influences the tumor response to programmed cell death protein 1 (PD-1) blockade in colorectal cancers (CRCs) with deficient mismatch repair (dMMR) or microsatellite instability (MSI) has never been clarified.MethodsTumor tissues from 80 patients with dMMR CRC were evaluated for DKK1 expression and immune status via immunohistochemistry. Serum DKK1 was measured in another set of 43 patients who received PD-1 blockade therapy. CT26 cells and dMMR CRC organoids were cocultured with T cells, and CT26-grafted BALB/c mice were also constructed. T-cell cytotoxicity was assessed by apoptosis assays and flow cytometry. The pathway through which DKK1 regulates CD8+ T cells was investigated using RNA sequencing, and chromatin immunoprecipitation and luciferase reporter assays were conducted to determine the downstream transcription factors of DKK1.ResultsElevated DKK1 expression was associated with recurrence and decreased CD8+ T-cell infiltration in dMMR CRCs, and patients with high-serum DKK1 had a poor response to PD-1 blockade. RNA interference or neutralization of DKK1 in CRC cells enhanced CD8+ T-cell cytotoxicity, while DKK1 decreased T-bet expression and activated GSK3β in CD8+ T cells. In addition, E2F1, a downstream transcription factor of GSK3β, directly upregulated T-bet expression. In organoid models, the proportion of apoptotic cells was elevated after individual neutralization of PD-1 or DKK1 and was further increased on combined neutralization of PD-1 and DKK1.ConclusionsDKK1 suppressed the antitumor immune reaction through the GSK3β/E2F1/T-bet axis in CD8+ T cells. Elevated serum DKK1 predicted poor tumor response to PD-1 blockade in dMMR/MSI CRCs, and DKK1 neutralization may restore sensitivity to PD-1 blockade.

A new surface dielectric barrier discharge source containing a matrix of holes in the dielectric slice is put forward in this paper, for which the plasma characteristics and the delivery of reactive species to the downstream sample are studied for three experimental conditions, i.e., EC1 with a helium gas flow of 1 SLM through the holes, EC2 with an artificial air flow of 1 SLM, and EC3 without any gas flow. All the other conditions are kept the same. For the same discharge power of 2 W, it is found that the surface plasma in EC1 is comparatively more homogeneous, the discharge voltage is lower by ~12%, and the densities of reactive species are much higher, since the emission spectral lines of N2(C), N2+(B), He(3s3S), and O(3p5P) are stronger by at least sixfold. A petri dish of deionized water is put 5-mm downstream the surface discharge, in which the concentrations of nitrite, nitrate, H2O2, and NO are measured after the plasma treatment of 3 min. Compared with EC1, EC2, and EC3, it is found that the gas flow can increase the concentration of H2O2 by ~1.4-fold, but when helium is participated, a further increase of sixfold is achieved. Similarly, further increase is also found for the other three reactive species, which may be ascribed to the higher densities of gaseous reactive oxygen and nitrogen species in the helium-participated plasma and their larger diffusion coefficients in helium compared with that in air.

A new plasma jet array source is reported, which has two plasma regions: a cylindrical bottle in which plasmas are generated to deposit charged species on the inner wall, and the outside atmosphere in which plasma jets are generated between the small holes in the underside of the bottle and the grounded sample underneath the bottle. Four temporal regions of discharge are found to exist during a voltage cycle, in which the first one has maximal amount of charge transfer but minimal discharge energy. The surface charges supply the seed charge to initiate and sustain the plasma jets, while restricting the intensity of each plasma jet because their amount is limited. Only the surface charges near the underside hole of the cylindrical bottle are possible to participate in the discharge. Therefore, the plasma jets have a good jet-to-jet homogeneity relatively independent of the number of jets and their relative positions, indicating that the plasma jets can be arbitrarily arranged to a large extent. This is an application advantage but with a limitation, i.e., two plasma jets cannot be closer than 2.5 mm, because the surface charge between them will be shunted, and therefore, the plasma jets will be weakened.