Synthesis of δ-MnO2 via ozonation routine for low temperature formaldehyde removal.

Nowadays, it is still a challenge to prepared high efficiency and low cost formaldehyde (HCHO) removal catalysts in order to tackle the long-living indoor air pollution. Herein, δ-MnO2 is successfully synthesized by a facile ozonation strategy, where Mn2+ is oxidized by ozone (O3) bubble in an alkaline solution. It presents one of the best catalytic properties with a low 100% conversion temperature of 85°C for 50 ppm of HCHO under a GHSV of 48,000 mL/(g·hr). As a comparison, more than 6 times far longer oxidation time is needed if O3 is replaced by O2. Characterizations show that ozonation process generates a different intermediate of tetragonal ß-HMnO2, which would favor the quick transformation into the final product δ-MnO2, as compared with the relatively more thermodynamically stable monoclinic γ-HMnO2 in the O2 process. Finally, HCHO is found to be decomposed into CO2 via formate, dioxymethylene and carbonate species as identified by room temperature in-situ diffuse reflectance infrared fourier transform spectroscopy. All these results show great potency of this facile ozonation routine for the highly active δ-MnO2 synthesis in order to remove the HCHO contamination.

Large potential of strengthening the land carbon sink in China through anthropogenic interventions.

The terrestrial ecosystem in China mitigates 21%-45% of the national contemporary fossil fuel CO2 emissions every year. Maintaining and strengthening the land carbon sink is essential for reaching China's target of carbon neutrality. However, this sink is subject to large uncertainties due to the joint impacts of climate change, air pollution, and human activities. Here, we explore the potential of strengthening land carbon sink in China through anthropogenic interventions, including forestation, ozone reduction, and litter removal, taking advantage of a well-validated dynamic vegetation model and meteorological forcings from 16 climate models. Without anthropogenic interventions, considering Shared Socioeconomic Pathways (SSP) scenarios, the land sink is projected to be 0.26-0.56 Pg C a-1 at 2060, to which climate change contributes 0.06-0.13 Pg C a-1 and CO2 fertilization contributes 0.08-0.44 Pg C a-1 with the stronger effects for higher emission scenarios. With anthropogenic interventions, under a close-to-neutral emission scenario (SSP1-2.6), the land sink becomes 0.47-0.57 Pg C a-1 at 2060, including the contributions of 0.12 Pg C a-1 by conservative forestation, 0.07 Pg C a-1 by ozone pollution control, and 0.06-0.16 Pg C a-1 by 20% litter removal over planted forest. This sink can mitigate 90%-110% of the residue anthropogenic carbon emissions in 2060, providing a solid foundation for the carbon neutrality in China.

Local ozone injection compared to local glucocorticoid injection in carpal tunnel syndrome: A randomized controlled trial.

Objectives: This study aimed to compare the effectiveness of local ozone (O3) injection versus corticosteroid injection in the treatment of mild to moderate carpal tunnel syndrome (CTS). Patients and methods: This double-blind randomized controlled trial was performed on 42 patients (9 males, 33 females; mean age: 46.7±2.1 years; range, 18 to 70 years) with mild to moderate CTS between May 2021 and June 2021. The corticosteroid group (n=21) was injected with 40 mg triamcinolone, and in the O3 group B (n=21), 4 mL of a 10 mcg/mL oxygen (O2)-O3 mixture was injected. Symptom severity and functional impairments were assessed using a Visual Analog Scale and Boston Carpal Tunnel Questionnaire. Electrodiagnostic and ultrasonographic parameters were obtained at baseline and eight weeks after the procedure. Results: The O2-O3 solution improved pain and Boston Carpal Tunnel Questionnaire score after eight weeks (p<0.001); however, the change was nonsignificant compared to the corticosteroid group (p>0.05). Sensory nerve and compound muscle action potential latencies were not significantly changed eight weeks after O2-O3 injection (p>0.05), while both were significantly decreased in the steroid injection group (p<0.001). Volar bulging and median nerve cross-section surface area were not improved after O2-O3 injection, while the improvement was significant in the corticosteroid arm (p=0.02). Conclusion: Symptoms in patients with mild to moderate CTS may be alleviated by local O2-O3 injection; however, electrodiagnostic and ultrasonographic indices may be unchanged. Corticosteroid local injection may alleviate patient symptoms along with electrodiagnostic and ultrasonographic parameters.

Effects of plasma surface treatment on the bond strength of zirconia with an adhesive resin luting agent.

The purpose of this study was to evaluate the effect of the atmospheric pressure plasma treatment as a surface treatment method on the contact angle and shear bond strength (SBS) of zirconia ceramics and the failure mode between the self-adhesive resin luting agent and zirconia. The zirconia specimens were divided into eight groups based on the surface treatment method: alumina blasting, air plasma, argon plasma (AP), Katana cleaner, ozonated water, ozonated water+AP, Katana cleaner+AP, and tap water+AP. The contact angles, SBS, and fracture modes were tested. AP treatment significantly reduced the contact angle (p<0.0001). The combination of AP and other cleaning methods showed a higher bond strength and more mixed fractures. Our findings indicate that using atmospheric pressure plasma with argon gas, combined with other cleaning methods, results in a stronger bond than when using alumina blasting alone.

Multi-source observations on the effect of atmospheric blocking on air quality in Istanbul: a study case.

Air pollution is affected by the atmospheric dynamics. This study aims to determine that air pollution concentration values in Istanbul increased significantly and reached peak values due to atmospheric blocking between the 30th of December 2022 and the 5th of January 2023. In this study, hourly pollutant data was obtained from 16 air quality monitoring stations (AQMS), the exact reanalysis data was extracted from ERA5 database, and inversion levels and meteorological and synoptic analyses were used to determine the effects of atmospheric blocking on air pollution. Also, cloud base heights and vertical visibility measurements were taken with a ceilometer. Statistical calculations and data visualizations were performed using the R and Grads program. Omega-type blocking, which started in Istanbul on December 30, 2022, had a significant impact on the 1st and 2nd of January 2023, and PM10 and PM2.5 concentration values reached their peak values at 572.8 and 254.20 µg/m3, respectively. In addition, it was found that the average concentration values in the examined period in almost all stations were higher than the averages for January and February. As a result, air quality in Istanbul was determined as "poor" between these calendar dates. It was found that the blocking did not affect the ozone (µg/m3) concentration. It was also found that the concentrations of particulate matter (PM) 10 µm or less in diameter (PM10) and PM 2.5 µm or less in diameter (PM2.5) were increased by the blocking effect in the Istanbul area. Finally, according to the data obtained using the ceilometer, cloud base heights decreased to 30 m and vertical visibility to 10 m.

Exploring behavioural and physiological adaptations in mountain pine beetle in response to elevated ozone concentrations.

Elevated ozone (eO3) concentrations pose a threat to insect populations by potentially altering their behaviour and physiology. This study investigates the effects of eO3 concentrations on the mountain pine beetle which is a major tree-killing species of conifers in northwestern North America. We are particularly interested in understanding the effects of eO3 concentrations on beetle behaviour and physiology and possible transgenerational impacts on bark beetle broods. We conducted O3-enrichment experiments in a controlled laboratory setting using different O3 concentrations (100-200 ppb; projected for 2050-2100) and assessed various beetle responses, including CO2 respiration, mating behaviour, survival probability, locomotion, and attraction behaviour. Transgenerational impacts on the first and second generations were also analyzed by studying brood morphology, mating behaviour, survival, and pheromone production. We found that beetles exposed to eO3 concentrations had shorter oviposition galleries and reduced brood production. Beetle pheromones were also degraded by eO3 exposure. However, exposure to eO3 also prompted various adaptive responses in beetles. Despite reduced respiration, eO3 improved locomotor activity and the olfactory response of beetles. Surprisingly, beetle survival probability was also improved both in the parents and their broods. We also observed transgenerational plasticity in the broods of eO3-exposed parents, suggesting potential stress resistance mechanisms. This was evident by similar mating success, oviposition gallery length, and brood numbers produced in both control and eO3 concentration treatments. This study demonstrates the sensitivity of mountain pine beetles to increased O3 concentrations, contributing crucial insights into the ecological implications of eO3 concentrations on their populations. Overall, the outcome of this study contributes to informed climate change mitigation strategies and adaptive management practices for the development of resilient forests in response to emerging forest insect pests worldwide.

The therapeutic effect of sufficient oxygen-rich PRP injection in facial rejuvenation by multiple objective evaluations in 26 cases.

Background: Ozone can enhance the expression of some growth factors (GFs) in platelet rich plasma (PRP), recent study showed oxygen-rich PRP (ozonized PRP) have better therapeutic effects on bone and joint diseases. PRP injection has been widely used in the treatment of facial rejuvenation, but the efficacy of sufficient oxygen-rich PRP in facial rejuvenation has not been studied. Objective: Firstly, we examined whether ozone treatment can increase the concentration of GFs of PRP in vitro. And then a variety of subjective and objective detection methods were used to evaluate the effect of sufficient(10-12 mL each time for the injection of face and neck) oxygen-rich (ozonized PRP) PRP injection in facial rejuvenation by follow-up for 6 months. At last, we investigated the satisfaction, side effects and pain score of the treatment through a questionnaire survey. Methods: The concentration of main GFs in PRP treated with different dose of ozone in vitro was measured by ELISA. Clinical picture, the collagen thickness of dermis by reflectance confocal microscope(RCM), skin conditions (including spots, ultraviolet (UV) spots, brown spots, red area, pores, wrinkles, texture and porphyrin) by VISIA were collected before treatment and each month follow-up visit after treatment until 6-month follow-up period was finished. Patients' satisfaction, side effects and pain score were collected at the end of follow-up period. Results: PRP treated by high-dose ozone (57 µg/mL, ozone/PRP volume ratio:1/1) in vitro showed a significant increase in endothelial growth factor (EGF) and transforming growth factor-ß (TGF-ß) compared to baseline(P < 0.05). Collagen thickness of forehead, cheek and neck improved significantly compare to the baseline until to the 6 months after treatment. Spots, UV spots, brown spots, red area and texture improved significantly compare to the baseline(P < 0.05). All of participants reported improvement and have a median pain score of 4.19. No serious adverse events were observed. Conclusions: Ozone treatment can increase the concentration of GFs such as EGF and TGF-ß in PRP in vitro. Sufficient oxygen-rich PRP injection may be an effective and promising method to treat facial rejuvenation.

Association between short-term ozone exposure and allergic conjunctivitis in China: A multi-city case-crossover study.

Short-term exposure to ozone has been linked to multiple allergic diseases, but the relationship between ozone exposure and allergic conjunctivitis (AC) remains unclear. This study aimed to investigate the association between short-term exposure to ozone and the risk of AC. We conducted a time-stratified case-crossover study across five Chinese cities from 2014 to 2022. Daily outpatient visit records for AC were identified in five hospitals using either the diagnosis name or ICD-10 code H10.1. Data on air pollution and meteorological conditions were also collected. We first examined the city-specific association between short-term ozone exposure and AC using conditional logistic regression. A random-effects meta-analysis was then conducted to obtain overall estimates. During the study period, 130,093 outpatient visits for AC occurred, with 58.8% (76,482) being male and 41.2% (53,611) female. A one-standard-deviation (SD) increase in ozone was associated with an 8.3% increase (95% CI: 3.8%, 13.0%) in AC outpatient visits. Similar positive associations were observed when adjusting for other pollutants (PM2.5, CO, SO2 and NO2) in two-pollutant and multi-pollutant models. Furthermore, the positive association remained consistent when using mixed-effects regression models or further adjusting for meteorological conditions. In addition, no effect modification of the AC-ozone association by sex, age and season was apparent. This study provides evidence supporting a positive association between short-term ozone exposure and AC risk in China. This highlights the potential value of mitigating ozone pollution to reduce the risk of ocular surface disorders.

Effect of Ozone Therapy on Diabetes-related Foot Ulcer Outcomes: A Systematic Review and Meta-analysis.

PURPOSE: This study aimed to assess the effectiveness of ozone therapy in treating Diabetes-related Foot Ulcer (DFU) and its outcomes. METHODS: A systematic search was conducted in PubMed/MEDLINE, Scopus, Web of Science, and ProQuest databases for published studies evaluating the use of ozone as an adjunct treatment for DFU, from inception to December 21, 2022. The primary outcome measure was the change in wound size after the intervention compared to pretreatment. Secondary outcomes included time to complete ulcer healing, number of healed patients, adverse events, amputation rates, and hospital length of stay. Quantitative data synthesis for the meta-analysis was performed using a random-effects model and generic inverse variance method, while overall heterogeneity analysis was conducted using a fixed-effects model. Interstudy heterogeneity was assessed using the I2 index (<50%) and the Cochrane Q statistic test. Sensitivity analysis was performed using the leave-one-out method. RESULTS: The meta-analysis included 11 studies comprising 960 patients with DFU. The results demonstrated a significant positive effect of ozone therapy on reducing foot ulcer size (Standardized Mean Difference (SMD): -25.84, 95% CI: -51.65 to -0.04, p = 0.05), shortening mean healing time (SMD: -38.59, 95% CI: -51.81 to -25.37, p < 0.001), decreasing hospital length of stay (SMD: -8.75, 95% CI: -14.81 to -2.69, p < 0.001), and reducing amputation rates (Relative Risk (RR): 0.46, 95% CI: 0.30-0.71, p < 0.001), compared to standard treatment. CONCLUSION: This meta-analysis indicates that ozone therapy has additional benefits in expediting complete DFU healing, reducing the amputation rates, and decreasing hospital length of stay, though its effects do not differ from standard treatments for complete ulcer resolution. Further research is needed to address the heterogeneity among studies and to better understand the potential beneficial effects of ozone therapy.

Short-term ozone exposure and cancer mortality in Brazil: A nationwide case-crossover study.

Exposure to ambient ozone (O3) is linked to increased mortality risks from various diseases, but epidemiological investigations delving into its potential implications for cancer mortality are limited. We aimed to examine the association between short-term O3 exposure and site-specific cancer mortality and investigate vulnerable subgroups in Brazil. In total 3,459,826 cancer death records from 5570 Brazilian municipalities between 2000 and 2019, were included. Municipal average daily O3 concentration was calculated from a global estimation at 0.25°×0.25° spatial resolution. The time-stratified case-crossover design was applied to assess the O3-cancer mortality association. Subgroup analyses by age, sex, season, time-period, region, urban hierarchy, climate classification, quantiles of GDP per capita and illiteracy rates were performed. A linear and non-threshold exposure-response relationship was observed for short-term exposure to O3 with cancer mortality, with a 1.00% (95% CI: 0.79%-1.20%) increase in all-cancer mortality risks for each 10-µg/m3 increment of three-day average O3. Kidney cancer was most strongly with O3 exposure, followed by cancers of the prostate, stomach, breast, lymphoma, brain and lung. The associated cancer risks were relatively higher in the warm season and in southern Brazil, with a decreasing trend over time. When restricting O3 concentration to the national minimum value during 2000-2019, a total of 147,074 (116,690-177,451) cancer deaths could be avoided in Brazil, which included 17,836 (7014-28,653) lung cancer deaths. Notably, these associations persisted despite observed adaptation within the Brazilian population, highlighting the need for a focus on incorporating specific measures to mitigate O3 exposure into cancer care recommendations.

Evaluation of postoperative pain in endodontic retreatment with apical periodontitis using ozonated 2% chlorhexidine and 0.1% octenidine application: A randomized clinical trial.

Introduction: This study aimed to evaluate and compare postoperative pain (PP) in single-visit nonsurgical endodontic retreatment (SV NSER) with 2% chlorhexidine (CHX), 0.1% octenidine (OCT) with or without ozone, and 5.25% sodium hypochlorite (NaOCl). Materials and Methods: In this randomized, parallel, prospective, double-blind, clinical trial, 132 single-rooted, root-filled teeth with symptomatic apical periodontitis (AP) requiring NSER were allocated into six groups randomly (n = 22/group): 2% CHX with NaOCl (CHXH), 2% Ozonated CHX without NaOCl (OCHX), 2% Ozonated CHX with NaOCl (OCHXH), 0.1% OCT with NaOCl (OCTH), 0.1% Ozonated OCT without NaOCl (OOCT), and 0.1% Ozonated OCT with NaOCl (OOCTH). Standard NSER protocol was followed groups were irrigated with 15 ml of ozonated or nonozonated irrigant (CHX/OCT) for 3-5 min with ultrasonic agitation. PP at baseline, after 6, 12, 24, 48 h, and 7 days was recorded using the Visual Analog Scale (VAS). Logistic regression of predictor variables was compared using the Chi-square test. For group-wise and time-wise comparisons, a two-way analysis of variance followed by the post hoc Bonferroni test was carried out. Results: None of the patient-related variables in logistic regression obtained a statistically significant (P > 0.05) role in PP. The VAS score after 6 h was OCHX (4.72) > OOCT (4.42) > CHXH (4.23) > OCTH (3.95) > OCHXH (3.42) > OOCTH (3.21). OOCTH and OCHXH groups demonstrated statistically significant reductions in VAS scores at various time intervals (P < 0.05). Conclusion: SV NSER with ozonated OCT, CHX irrigation, and NaOCl resulted in lesser PP at all time intervals, i.e., 6, 12, 24, 48 h, and 7 days in patients with symptomatic AP.

The adjunctive use of antimicrobial photodynamic therapy, light-emitting-diode photobiomodulation and ozone therapy in regenerative treatment of stage III/IV grade C periodontitis: a randomized controlled clinical trial.

OBJECTIVES: To assess the short-term efficacy of multiple sessions of antimicrobial photodynamic therapy (aPDT), light-emitting-diode (LED) photobiomodulation, and topical ozone therapy applications following surgical regenerative treatments on clinical parameters, patient-centered outcomes, and mRNA expression levels of VEGF, IL-6, RunX2, Nell-1, and osterix in gingival crevicular fluid samples in patients with stage III/IV, grade C periodontitis. MATERIALS AND METHODS: Forty-eight systemically healthy patients were assigned into four groups to receive adjunctive modalities with regenerative periodontal surgical treatment. A 970 ± 15 nm diode laser plus indocyanine-green for aPDT group, a 626 nm LED for photobiomodulation group, and topical gaseous ozone were applied at 0, 1, 3, and 7 postoperative days and compared to control group. The clinical periodontal parameters, early wound healing index (EHI), and postoperative patients' morbidity were evaluated. The mRNA levels of biomarkers were assessed by real-time polymerase chain reaction. RESULTS: No significant difference in the clinical parameters except gingival recession (GR) was identified among the groups. For group-by-time interactions, plaque index (PI) and probing pocket depths (PD) showed significant differences (p = 0.034; p = 0.022). In sites with initial PD > 7 mm, significant differences were observed between control and photobiomodulation groups in PD (p = 0.011), between control and aPDT, and control and photobiomodulation groups in CAL at 6-month follow-up (p = 0.007; p = 0.022). The relative osterix mRNA levels showed a statistically significant difference among the treatment groups (p = 0.014). CONCLUSIONS: The additional applications of aPDT and LED after regenerative treatment of stage III/IV grade C periodontitis exhibited a more pronounced beneficial effect on clinical outcomes in deep periodontal pockets.

Ambipolar Heterojunction Sensors: Another Way to Detect Polluting Gases.

Gas sensors based on ambipolar materials offer significant advantages in reducing the size of the analytical system and enhancing its efficiency. Here, bilayer heterojunction devices are constructed using different octafluorinated phthalocyanine complexes, with Zn and Co as metal centers, combined with a lutetium bisphthalocyanine complex (LuPc2). Stable p-type behavior is observed for the ZnF8Pc/LuPc2 device under both electron-donating (NH3) and -oxidizing (NO2 and O3) gaseous species, while the CoF8Pc/LuPc2 device exhibits n-type behavior under reducing gases and p-type behavior under oxidizing gases. The nature of majority of the charge carriers of Co-based devices varies depending on the nature of target gases, displaying an ambipolar behavior. Both heterojunction devices demonstrate stable and observable response toward all three toxic gases in the sub-ppm range. Remarkably, the Co-based device is highly sensitive toward ammonia with a limit of detection (LOD) of 200 ppb, whereas the Zn-based device demonstrates exceptional sensitivity toward oxidizing gases, with excellent LOD values of 4.9 and 0.75 ppb toward NO2 and O3, respectively, which makes it one of the most effective organic heterojunction sensors reported so far for oxidizing gases.

Effect of Medical Ozone Therapy in Preventing Compromised Nasal Skin in Revision Rhinoplasty.

BACKGROUND: Ozone is often used as an additive therapy for skin conditions like infectious diseases, wound healing, diabetic foot, and pressure ulcers. The viability of the nasal skin has crucial importance in revision rhinoplasty cases. The study investigates the potential benefits of medical ozone therapy in healing the nasal skin in multiple-operated cases. METHODS: The study retrospectively examined 523 revision rhinoplasty patients operated by the first author from January 2017 to January 2024. Patients consenting to ozone therapy received 3 major autohemotherapy sessions post-surgery. Patients were divided into 2 groups: those with compromised nasal skin (infection, poor vascular supply) and those with normal healing. Age, gender, smoking, diabetes, previous surgeries, grafting materials, and techniques were considered. RESULTS: Of the 523 patients, 12 (2.3%) experienced major skin complications like infection and necrosis, while 511 (97.7%) had no or minor issues, such as discoloration. In total, 301 patients accepted and received ozone therapy. Of the patients without major complications, 299 (58.3%) received ozone therapy, while 212 (41.7%) did not. Among the 12 with major complications, two (16.7%) received ozone therapy, and the remaining 10 (83.3%) did not. Ozone therapy recipients showed statistically fewer skin problems (p<0.05). Costal cartilage as tip and septal extension graft was linked to skin issues (p<0.05). No major adverse effects from ozone therapy were noted. CONCLUSIONS: Our findings indicate that ozone therapy may be a safe and potentially effective option for patients undergoing revision rhinoplasty, especially those with compromised nasal skin. It appears to aid in skin healing and regeneration, possibly through enhancing oxygen delivery and modulation of the immune response. Ozone therapy is a promising adjunct treatment for managing skin complications in revision rhinoplasty patients. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Unraveling the difference of sensitivity to ozone between non-hybrid native poplar and hybrid poplar clones: A flux-based dose-response analysis.

Poplars are economically important tree crops and biologically important model plants, which are known to be sensitive to ozone (O3). Although surface O3 is considered as a significant global environmental issue because of its phytotoxicity and greenhouse effect, the knowledge of the dose-response (DR) relationships in poplars for the assessment of O3 risk is still limited. Hence, this study aimed at collecting data of studies with manipulative O3 exposures of poplars within FACE (Free Air Concentration Enhancement) and OTC (Open-Top Chamber) facilities. The datasets contain studies on hybrid poplar clones and a non-hybrid native poplar (Populus nigra L.) reporting both AOT40 (Accumulated exposure Over a Threshold of 40 ppb) and POD1 (Phytotoxic Ozone Dose above a threshold of 1 nmol m-2 Projected Leaf Area [PLA] s-1) to compare exposure- and flux-based indices. As a result, linear regression analysis showed that the flux-based POD1 was better than the exposure-based AOT40 to explain the biomass response of poplars to O3. From the DR relationships, a critical level (CL) of 5.7 mmol m-2 POD1 has been derived corresponding to 4% biomass growth reduction for hybrid poplar clones, which can be considered very sensitive to O3, while the non-hybrid native poplar was less sensitive to O3 (CL: 10.3 mmol m-2 POD1), although the potential risk of O3 for this taxon is still high due to very high stomatal conductance. Moreover, the different experimental settings (OTC vs. FACE) have affected the AOT40-based DR relationships but not the POD1-based DR relationships, suggesting that poplar responses to O3 were principally explained by stomatal O3 uptake regardless of the different experimental settings and exposure patterns. These results highlight the importance of the flux-based approach, especially when scaling up from experimental datasets to the O3 risk assessment for poplars at the regional or global scale.

Unique impacts of strong and westward-extended Western Pacific subtropical high on ozone pollution over eastern China.

As a subtropical anticyclonic high-pressure system that typically forms over the northwestern Pacific Ocean in summer, the Western Pacific subtropical high (WPSH) affects meteorological conditions and ozone pollution in China. The relationship between maximum daily 8-h average ozone (MDA8 O3) concentrations and the extremely strong and westward-extended WPSH occurred in 2022 is investigated using observations, reanalysis data and atmospheric chemistry model simulations. During July-August 2022, a significant positive relationship existed between the intensity of the WPSH and MDA8 O3 over southern China, with a correlation coefficient of +0.44, but the correlation is negative (-0.40) in northern China. During the strong WPSH days, MDA8 O3 increased by 16.5 µg·m-3 (16.4% relative to July-August average) over southern China and decreased by 19.0 µg·m-3 (14.5%) in northern China compared to the weak WPSH days. The unique dipole pattern in the relationship between ozone levels and the WPSH in 2022 exhibited a contrast to that during 2015-2021. The difference is primarily due to the extremely strong WPSH intensity and its unusual westward expansion in 2022. In this case, an anomalous anticyclone at 500 hPa dominates over southern China, which creates conditions conducive for ozone formation and accumulation. The anticyclone weakened horizontal winds and reduced the dispersion of ozone, alongside a high temperature and low relative humidity, which favored the chemical production of ozone. In contrast, abnormal northerly winds enhanced ozone diffusion in northern China and the low temperature reduced ozone chemical production. This study reveals the mechanism for the significant impact of strong and westward-extended WPSH on ozone concentrations over China, emphasizing the role of the WPSH location in modulating meteorology and ozone levels.

Performance Evaluation of Sinusoidal Power Supplies for Ozone Generation in Water Purification Applications.

Ozone generation is a water disinfection method, superior to chlorine in terms of fewer byproducts and no residual taste. However, its high production cost limits its widespread adoption. This paper designs an ozone generation sinusoidal power supply for water treatment. Ozone generation requires a high-frequency and high-voltage power supply to produce ozone from oxygen molecules. The study evaluates two power supply topologies, one with a parallel LC filter and the other with an LCL filter, assessing their feasibility, effectiveness, and reliability. Theoretically, the LCL filter achieves higher gains than the parallel LC filter. The larger inductance in the parallel LC filter reduces gain, while the larger inductance in the LCL filter increases gain. Simulation and practical results validate these findings, achieving gains of 40 for the parallel LC filter and 150 for the LCL filter.

Prediction of hydroxyl radical exposure during ozonation using different machine learning methods with ozone decay kinetic parameters.

The abatement of micropollutants by ozonation can be accurately calculated by measuring the exposures of molecular ozone (O3) and hydroxyl radical (•OH) (i.e., ∫[O3]dt and ∫[•OH]dt). In the actual ozonation process, ∫[O3]dt values can be calculated by monitoring the O3 decay during the process. However, calculating ∫[•OH]dt is challenging in the field, which necessitates developing models to predict ∫[•OH]dt from measurable parameters. This study demonstrates the development of machine learning models to predict ∫[•OH]dt (the output variable) from five basic input variables (pH, dissolved organic carbon concentration, alkalinity, temperature, and O3 dose) and two optional ones (∫[O3]dt and instantaneous ozone demand, IOD). To develop the models, four different machine learning methods (random forest, support vector regression, artificial neural network, and Gaussian process regression) were employed using the input and output variables measured (or determined) in 130 different natural water samples. The results indicated that incorporating ∫[O3]dt as an input variable significantly improved the accuracy of prediction models, increasing overall R2 by 0.01-0.09, depending on the machine learning method. This suggests that ∫[O3]dt plays a crucial role as a key variable reflecting the •OH-yielding characteristics of dissolved organic matter. Conversely, IOD had a minimal impact on the accuracy of the prediction models. Generally, machine-learning-based prediction models outperformed those based on the response surface methodology developed as a control. Notably, models utilizing the Gaussian process regression algorithm demonstrated the highest coefficients of determination (overall R2 = 0.91-0.95) among the prediction models.

Tropospheric ozone effect on olfactory perception and olfactory bulb dopaminergic interneuron excitability.

Ozone (O3) forms in the Earth's atmosphere, both naturally and by reactions of man-made air pollutants. Deleterious effects of O3 have been found in the respiratory system. Here, we examine whether O3 alters olfactory behavior and cellular properties in the olfactory system. For this purpose, mice were exposed to O3 at a concentration found in highly polluted city air [0.8 ppm], and the behavior elicited by social and non-social odors in habituation/dishabituation tests was assessed. In addition, the electrical responses of dopaminergic olfactory bulb (OB) neurons were also evaluated. O3 differentially compromises olfactory perception to odors: it reduces responses to social and non-social odors in Swiss Webster mice, while this effect was observed in C57BL/6J mice only for some non-social odors. Additionally, O3 reduced the rate of spontaneous spike firing in periglomerular dopaminergic cells (PG-DA) of the OB. Because this effect could reflect changes in excitability and/or synaptic inputs, the ability of O3 to alter PG-DA spontaneous activity was also tested together with cell membrane resistance, membrane potential, rheobase and chronaxia. Taken together, our data suggest the ability of O3 to affect olfactory perception.

Characterization of Mild Delayed Gestational Hypertension in Rats Following Ozone Exposure.

The contribution of air pollution-induced cardiopulmonary damage on the development of hypertensive disorders of pregnancy and other adverse outcomes of pregnancy has gained increased attention as epidemiological data continue to highlight spatiotemporal pregnancy trends related to air pollution exposure. However clinical mechanistic data surrounding gestational complications remain sparse, necessitating the need for the use of animal models to study these types of complications of pregnancy. The current study seeks to examine the real-time effects of mid-gestational ozone exposure on maternal blood pressure and body temperature through the use of radiotelemetry in a rat model. The exposure resulted in acute depression of heart rate and core body temperature as compared to control animals. Ozone-exposed animals also presented with a slight but significant increase in arterial blood pressure which was perpetuated until term. The data presented here illustrates the feasibility of murine models to assess cardiovascular complications caused by inhaled toxicants during the window of pregnancy.