Search Results (1,080)

Background/Objectives: Dental anxiety represents a major challenge in paediatric dentistry and is a frequent cause of non-cooperative behaviour during dental treatment. Nitrous oxide/oxygen inhalation conscious sedation is widely used to reduce anxiety in children, while audiovisual distraction is a non-pharmacological behavioural technique aimed at diverting attention from stressful stimuli. Evidence regarding the combined effect of these two approaches during dental treatment is still limited. Methods: This randomized crossover clinical trial included 25 paediatric patients aged 4–7 years with dental anxiety and previous failed attempts at conventional dental treatment. Each child underwent two dental treatment sessions under nitrous oxide/oxygen conscious sedation, one with and one without audiovisual distraction. Anxiety and behaviour were assessed using the Modified Venham Scale and the Facial Image Scale (FIS). Vital parameters were recorded before, during, and after sedation. Results: A significant reduction in heart rate over time was observed in both groups (p < 0.05). In children aged 4–5 years, the combined audiovisual distraction and conscious sedation approach was associated with significantly lower heart rate values compared to conscious sedation alone (p < 0.05). No significant differences were found between the two approaches for behavioural scores assessed by the Venham and FIS scales. Conclusions: Although behavioural scores did not differ significantly, audiovisual distraction contributed to greater physiological stability, particularly in terms of heart rate control. This no-pharmacological approach may complement the pharmacological effects of nitrous oxide sedation by enhancing the overall sense of relaxation and comfort during dental care. Full article

Zeolites, both natural (e.g., clinoptilolite) and synthetic (e.g., FAU, ZSM-5), provide robust, tunable platforms for the removal of air pollutants and process-stream contaminants via adsorption and catalysis. This author-led article integrates experimental and theoretical insights on the adsorption of odorous compounds and ammonia (NH₃) and the catalytic abatement of nitrogen oxides (NOx) and nitrous oxide (N₂O), highlighting how topology, acidity, and metal speciation jointly control performance. Representative theoretical results show that adsorption on Brønsted acid sites is significantly more favorable (≈−1.1 eV for NH₃ and −0.37 eV for acetaldehyde) than on Na⁺ sites (≈0.02 eV and 1.22 eV, respectively), demonstrating the critical role of acid site distribution in adsorption selectivity. We dissect structure–function relationships encompassing pore size and connectivity, Si/Al ratio, Brønsted/Lewis site distribution, hydrophilicity/hydrophobicity, and the role of water, with emphasis on hierarchical porosity to alleviate transport limitations. Metal exchange and surface functionalization are discussed as levers to tailor adsorption strength and redox activity, supported by density functional theory (DFT) analyses and reaction pathways. We propose practical design descriptors (acid strength metrics, metal nuclearity, and confinement factors) that enable faster iteration of zeolite architecture for targeted separations and reactions. Sustainability considerations include the use of abundant natural zeolites, low-energy regeneration, stability under humid, mixed-stream conditions that minimize pressure drop and waste. The article closes with a forward look at data-guided optimization to accelerate “engineering zeolites” for durable, selective, and energy-efficient clean-air and process-intensification applications. Full article

The application of urea in agricultural practices leads to carbon dioxide (CO₂) emissions through hydrolysis. Urea, when applied to soil, reacts with water and undergoes hydrolysis, releasing ammonia (NH₃) and CO₂. This reaction is facilitated by soil enzymes such as urease. The released NH₃ can further undergo nitrification, producing nitrate (NO₃⁻) and nitrous oxide (N₂O). While CO₂ from urea hydrolysis is relatively small compared to other sources, cumulative emissions from agricultural activities contribute significantly to climate change and agriculture’s carbon footprint. A straightforward calculation model (CO₂ = A × 0.73) was employed to approximate CO₂ emissions in various countries based on annual urea usage. In this model, China led emissions with 40,483 Gg yr⁻¹, followed by India (26,031 Gg yr⁻¹) and the USA (12,032 Gg yr⁻¹). Out of total annual emissions (94,763 Gg), China contributed 43%, India 27%, the USA 13%, the EU 8%, Pakistan 5%, and Indonesia 4%. China’s CO₂ emissions from urea were 16% higher than India, 30% higher than the USA, 35% higher than the EU, 38% higher than Pakistan, and 39% higher than Indonesia. As expected from the deterministic IPCC formula (CO₂ = Urea × 0.73), the relationship between urea consumption and CO₂ emissions is linear with a slope of 0.73. Linear regression shows that for every 1000-ton increase in urea consumption, CO₂ emissions increase by 730 tons (0.73 Gg) (R² = 0.99, p < 0.001). Pakistan’s urea consumption grew at an average annual rate of 2.2% from 2015 to 2023, with corresponding CO₂ emissions increasing from 4015 to 4788 Gg yr⁻¹ (total increase of 20% over eight years). Optimizing fertilizer application rates, timing, and methods to enhance nutrient uptake efficiency, along with sustainable agricultural practices (organic matter management, conservation tillage, and precision agriculture), can help mitigate environmental impacts. This study emphasizes implementing sustainable agricultural practices and integrated nutrient management to minimize CO₂ emissions from urea application, enabling agricultural systems to contribute to climate change mitigation and reduced carbon footprints. Full article

Livestock production is a major source of agricultural methane (CH₄) and nitrous oxide (N₂O), making the synergistic mitigation of these two gases essential for meeting climate targets. Based on the EDGAR emission database from 2000 to 2024, this study employs international comparisons, spatial analysis, and STIRPAT-based scenario projections to characterize emissions from China’s animal husbandry and explore pathways for synergistic mitigation. The results reveal that China’s livestock CH₄ emissions exhibited a trend of early-stage fluctuation followed by a late-stage rebound, while N₂O emissions fluctuated sharply. The two gases are strongly synergistic yet driven by distinct mechanisms. China accounts for the largest share of global emissions and exhibits a distinctive emission structure—with comparable contributions from enteric fermentation and rice paddies—setting it apart from both pasture-based and intensive developed countries. High-emission areas are becoming increasingly concentrated in northern production regions. Under the baseline scenario, CH₄ and N₂O emissions are projected to peak in 2032 and 2030, respectively; under an ultra-low-carbon scenario, both gases peak around 2029, at substantially lower levels. Achieving synergistic mitigation calls for a regionally differentiated framework that combines top-down governance with bottom-up participation from farmers, integrating enteric fermentation control with optimized manure management to support a low-carbon transition. Full article

Wastewater treatment plants employ continuous aeration (CA) methods, during which nitrogen compounds including N₂O, a potent greenhouse gas, accumulate. Little research has focused on reducing N₂O emissions. Intermittent aeration (IA) suppresses NO₃⁻ accumulation, but its effectiveness in N₂O reduction remains unclear. Therefore, we investigated the relationship between N₂O emission and decreasing NO₃⁻ under different aeration conditions using swine wastewater in a 1-m³ aeration tank. Three test conditions were employed: CA, IA-1 (3 h aeration and 1 h of non-aeration), and IA-2 (ON/OFF aeration repeated every 2 h). IA suppressed N₂O emissions compared to CA, achieving decreases of 42% under IA-1 and 64% under IA-2. Microbial community analysis revealed a tendency for higher relative abundances of Nitrosomonas (ammonia-oxidizing bacteria), Nitrospira (nitrite-oxidizing bacteria), Zoogloea, Hydrogenophaga, and Dokdonella (among denitrifying bacteria) in activated sludge samples. This pilot-scale study demonstrated that changing the aeration conditions from continuous to intermittent in wastewater treatment plants may effectively reduce N₂O emissions. The mitigation of greenhouse gas emissions from wastewater treatment plants is expected to contribute to the realization of a sustainable society. Full article

Background: Space management after the premature extraction of second primary molars remains a challenge. Distal Shoe space maintainers (DSSMs) have been recommended after such extraction before the eruption of first permanent molars (FPMs) to prevent space loss and subsequent complications. There is lack of evidence for their clinical use and possible complications after their insertion. Therefore, this study aims to investigate survival rates and complications of DSSMs. Methods: Digital patients’ records were retrospectively screened for inserted DSSMs between 2014 and 2022, identifying 190 appliances in 141 children, of whom 113 appliances in 82 children had sufficient data to be included in the main outcome and survival analysis. Mean follow-up of the appliances and any reported complications were recorded. Results: Mean age of the included study sample (n = 82) at the time of insertion was 5.1 ± 0.93 years and almost identical to the whole sample (n = 141; 4.99 ± 0.90 years). Most children were uncooperative with high levels of caries (mean dmft: 6.6 ± 3.48). Appliances were mainly inserted under advanced behaviour management techniques such as general anaesthesia (n = 141, 74.2%) and nitrous-oxide sedation (n = 42, 22.1%). The main recorded complication was complete loss due to decementation (10.6%). Mean follow-up time was 17 months with a success rate of 83.2%. Kaplan–Meier survival analysis showed an estimated mean survival time of 42.7 months (SE 2.4, 95% CI 37.9–47.5). Conclusions: DSSMs were mainly placed under general anaesthesia in young children with high caries levels. The DSSM demonstrated acceptable clinical longevity till the eruption of the FPM, thus suggesting its use as a reliable option. Minor complications such as decementation could occur but are generally manageable. Full article

This study examines the impact of climate change on the performance of Egypt’s fish foreign trade during the period from 1995 to 2022. The analysis incorporates a set of climate indicators, including average surface air temperature, relative humidity, rainfall, carbon dioxide emissions, methane emissions, and nitrous oxide emissions, in addition to fish trade indicators represented by exports, imports, total trade volume, trade balance, and export-to-import coverage ratio. The study employs the Autoregressive Distributed Lag (ARDL) model to investigate both the short-run and long-run relationships between climate change variables and fish foreign trade performance in Egypt. Unit root tests confirmed that the variables were integrated at mixed orders I(0) and I(1), supporting the suitability of the ARDL methodology. The findings reveal the existence of a statistically significant long-run equilibrium relationship between climate change indicators and Egyptian fish exports. In particular, nitrous oxide emissions exerted a significant negative effect on fish exports in the long run, while rainfall showed a positive short-run effect. The results also indicate that approximately 57% of short-run disequilibria are corrected annually toward the long-run equilibrium. In contrast, no long-run cointegration relationship was found between climate variables and fish imports, total fish trade volume, or the fish trade balance, indicating that climate impacts on these indicators are mainly short-term in nature. The study concludes that climate change represents an important determinant of Egypt’s fish trade performance through its effects on productivity, environmental quality, and trade competitiveness. The findings highlight the need for integrated adaptation and mitigation policies to strengthen the sustainability and resilience of Egypt’s fisheries sector under changing climatic conditions. Full article

Understanding nitrogen dynamics in arid agricultural systems is essential for mitigating greenhouse gas (GHG) emissions in climate-constrained environments. This study evaluated the effects of planting density, organic fertilization, and saline water irrigation on soil chemical properties, carbon and nitrogen stocks, and emissions of CO₂, CH₄, and nitrous oxide (N₂O) in cactus pear cultivation systems. A 2 × 2 × 2 factorial arrangement was used to test two planting densities (30,000 and 75,000 plants ha⁻¹), two organic fertilizer rates (0 and 30 Mg ha⁻¹), and two saline irrigation depths (0 and 25% of ET₀). Higher planting density increased soil moisture and carbon content while reducing CO₂ and CH₄ emissions. Organic fertilization increased the soil C ratio and phosphorus availability and significantly enhanced N₂O emissions, whereas unfertilized systems showed negative N₂O fluxes. Saline water irrigation reduced N₂O emissions, resulting in negative fluxes (−12.50 µg N m⁻² h⁻¹), indicating potential suppression of nitrification and denitrification pathways. None of the evaluated factors significantly affected soil nitrogen stocks. Total GHG emissions (CO₂-eq) were lower in denser cultivation systems. These results demonstrate that the interaction among high planting density, organic fertilization, and supplementary saline irrigation modulates nitrogen transformations and N₂O emissions in semi-arid soils, highlighting management strategies to mitigate nitrogen-derived GHG emissions in cactus-based agroecosystems. Full article

Background/Objectives: Preoperative anxiety is common in adult patients undergoing oral and dentoalveolar surgical procedures under local anesthesia and may impair cooperation, physiological stability, and overall treatment experience. While intravenous sedation and general anesthesia provide effective anxiolysis, they increase anesthetic exposure and recovery demands. Targeted preoperative anxiolysis offers a less invasive strategy to reduce anxiety while preserving responsiveness. However, approaches vary and standardized protocols are lacking. This systematic review evaluated the efficacy and safety of preoperative anxiolytic interventions—including both pharmacological and non-pharmacological strategies—in adult patients undergoing oral surgical procedures under local anesthesia without general anesthesia or deep sedation. Methods: The review adhered to the PRISMA 2020 guidelines and was prospectively registered in PROSPERO (CRD420261281592). Randomized and quasi-randomized controlled trials published between 2016 and 2026 were identified through structured searches of PubMed/MEDLINE, ScienceDirect, and Springer Nature Link. Eligible studies included adult patients undergoing oral surgery under local anesthesia and evaluated preoperative anxiolysis using validated instruments such as the Dental Anxiety Scale (DAS), State–Trait Anxiety Inventory (STAI), and Visual Analog Scale for Anxiety (VAS-A). Risk of bias was assessed using the Cochrane RoB 2 tool. Owing to methodological heterogeneity, results were synthesized narratively. Results: Eight trials (n = 617) met the inclusion criteria. Interventions included oral benzodiazepines, melatonin, pregabalin, herbal agents, nitrous oxide, and auriculotherapy. Benzodiazepines consistently reduced anxiety scores (p < 0.05) without significant interagent differences. Pregabalin at a dose of 150 mg significantly lowered STAI-S and VAS-A scores (p < 0.001). Passiflora incarnata was comparable to midazolam and superior to placebo, whereas Erythrina mulungu showed no effect. Melatonin results were inconsistent. Hemodynamics remained stable, and adverse events were mild. Conclusions: Preoperative anxiolysis under local anesthesia effectively reduces anticipatory anxiety in oral surgery, with benzodiazepines demonstrating the most consistent efficacy. Further standardized trials are warranted. Full article

Background: This study aims to measure Greenhouse Gas (GHG) emission fluxes at the soil–air and water–air interfaces in urban wetlands on the Qinghai–Tibet Plateau and identify the primary controlling factors. The objective is to elucidate the key drivers of carbon and nitrogen processes at different interface levels in wetlands within high-altitude urban settings, thereby providing a scientific basis for accurately estimating their contribution to greenhouse gas emissions. Results: In the wetlands of Xining City, with the exception of soil pH, bulk density, and moisture content (which showed no significant change over time), all other soil physicochemical properties differed significantly among the three wetlands and among the sampling periods (p < 0.05). Soil moisture content was less affected by variations across different wetlands and over time, and differences in soil physicochemical properties among different wetlands were small (p > 0.05). Significant differences were observed in the spatiotemporal variations in the physicochemical properties of water bodies in Xining’s wetlands (p < 0.05), although water pH and total organic carbon (TOC) were less affected by the interaction between different wetlands and time periods. There were no significant differences in the bulk density and moisture content of wetland sediments in Xining over time (p > 0.05), while all other physicochemical indicators of sediments showed significant differences (p < 0.05). The physicochemical properties of sediments were influenced by both different wetland types and different time periods. GHG fluxes at the water–air interface in Xining wetlands were greater than those at the soil–air interface; overall, GHG emissions from both interfaces acted as “sources.” Seasonal variations in wetland GHG emissions were pronounced, with emission peaks occurring from June to August. The study found that the primary soil factor influencing GHG emissions at the soil–air interface was total phosphorus (TP), while the primary sediment factors affecting emissions at the water–air interface were TP and nitrate nitrogen (NO₃⁻-N), and the primary water factor was TOC. The interannual cumulative emissions from both interfaces in the wetland totaled 705.88 g·m⁻². GHG emissions from the soil–air and water–air interfaces contributed 47.88% and 52.12%, respectively, to the global warming potential (GWP) of the wetland, while methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) contributed 32.55%, 62.33%, and 5.12%, respectively, to the GWP. Conclusions: Investigating the GHG emission patterns in Xining’s wetlands and identifying the primary factors influencing these emissions provides a scientific basis for the protection and restoration of these wetlands. This is of great significance for safeguarding the ecological security of Xining’s wetlands as well as the overall ecological security of high-altitude wetlands. Full article

Nitrous acid (HONO) plays a vital role in atmospheric oxidation capacity (AOC) and ozone (O₃) formation. Based on 2017–2021 observations at urban Pudong (PD) and suburban Qingpu (QP) in Shanghai, HONO concentrations ranged from 0.74 ± 0.45 to 1.38 ± 0.52 ppb in PD and 0.82 ± 0.50 to 1.19 ± 0.62 ppb in QP, with higher levels in summer and a typical morning peak at 8–9 a.m. HONO photolysis produced an average of 1.9 ppb h⁻¹ of OH in summer, significantly elevating AOC. Under HONO constraints, summer O₃ production rates via HO₂ + NO and RO₂ + NO increased by 16% and 20%, respectively. These results highlight the key contribution of HONO chemistry to photochemical pollution and provide implications for air quality control in the Yangtze River Delta. Full article

Conservation tillage (CT) practices, including no-tillage and stover mulching, are increasingly recognized for their capacity to enhance soil health, sequester carbon, and mitigate greenhouse gas emissions in conventional agricultural systems. However, their application and mechanistic implications in medicinal crop cultivation—where soil quality directly influences not only yield but also the accumulation of pharmaceutically active secondary metabolites—remain underexplored. This review synthesizes recent advances in understanding how CT modulates soil microbial communities, with particular emphasis on nosZ II-type denitrifiers, to reduce nitrous oxide (N₂O) emissions and improve nitrogen use efficiency. The mechanistic pathways through which CT-induced changes in soil structure, moisture regimes, and organic matter dynamics influence the abundance, community composition, and activity of nitrogen-cycling microorganisms were examined. Based on evidence from black soil ecosystems and other agricultural systems, it is demonstrated that no-tillage with full stover mulching (NT100) selectively enriches specific nosZ II subclades (IIB, IIE, IIG) through deterministic community assembly processes, effectively decoupling N₂O emissions from nitrification activity. The implications of these soil improvements for medicinal plant growth, root development, nutrient acquisition, and stress tolerance were further explored, and case studies linking organic amendments, mycorrhizal associations, and microbial inoculants to enhanced accumulation of alkaloids, flavonoids, terpenoids, and saponins were synthesized. Importantly, findings from spatial phylogenetics and biocultural diversity research were integrated to examine how CT can support in situ conservation of medicinal flora and associated microbial communities in ethnomedicinally significant hotspots such as the Hengduan Mountains, southeastern Tibet, and subtropical refugia. Policy and community-based approaches for integrating CT into biocultural conservation strategies are discussed. By bridging agronomy, microbial ecology, phytochemistry, and ethnobotany, a framework for “eco-pharmacological” management is proposed, aligning sustainable soil practices with medicinal crop quality, climate mitigation, and the preservation of both biological and cultural heritage. Full article

An in-depth analysis of the drivers of agricultural emissions at the farm-gate level is crucial for achieving net-zero emissions by 2050. This study examines the short- and long-run effects of crop production on farm-gate emissions in the regional trading bloc (RTB) member states in Africa. Crop production was proxied by cereals, roots and tubers, vegetables, and fruits production, and emissions were split into methane (CH₄) and nitrous oxide (N₂O) emissions. Data on these variables were collected from 30 RTB member states from 1990 to 2022 and were analyzed using the cross-sectionally augmented autoregressive distributive lag approach. The pooled mean group was used as a robustness check, and a sensitivity analysis was conducted to ensure the reliability of the study findings. The results revealed that cereal production increases farm-gate CH₄ and N₂O emissions in the short and long run. The average increase ranges from 1.0021 to 1.0033 kilotons CO₂–eq yr⁻¹ for CH₄, and from 1.0024 to 1.0035 kilotons CO₂–eq yr⁻¹ for N₂O. In addition, fruit production increases farm-gate CH₄ emissions by an average of 1.0023 kiloton CO₂–eq yr⁻¹ in the long run. Thus, cereal production has a more adverse effect on N₂O than CH₄ emissions, while the opposite is true for fruit production in the RTB member states’ Nationally Determined Contributions. With respect to mediation, cropland expansion (proxied by area harvested) plays a partial intermediary role in the impact of crop production on farm-gate CH₄ and N₂O emissions in the short run and CH₄ emissions in the long run. However, it assumes a full mediation role in the long run and has an effect on crop production in farm-gate N₂O emissions. Therefore, targeted use of nitrogen fertilizer and crop rotations to reduce cereal-related N₂O and CH₄ emissions, respectively, would be viable strategies. The use of a drip irrigation system in fruit production to reduce CH₄ emissions and the scaling up of secured subsidies should also be explored. Finally, these recommendations should be incorporated into the Africa’s RTB member states’ Nationally Determined Contributions and the African Union’s Agenda 2063. Full article

Microbial communities regulate the transformation and stabilization of nutrients during composting; however, current knowledge on their specific functional roles across composting stages remains poorly integrated. This review examines the pivotal role of microbial mediation in nitrogen (N) and phosphorus (P) dynamics during composting and their subsequent impact on soil health. We analyze how biotechnological interventions—specifically the inoculation of functional microbial consortia (phosphate-solubilizing bacteria, phosphate-accumulating bacteria, and nitrifiers) and the application of physicochemical additives such as biochar—reconfigure microbial succession patterns to mitigate gaseous losses and enhance nutrient bioavailability. Several studies have reported substantial reductions in ammonia (NH₃) and nitrous oxide (N₂O) emissions under specific composting conditions, while simultaneously promoting the stabilization of labile P into more recalcitrant forms, including polyphosphates. Furthermore, the application of mature compost to agricultural systems induces a profound ecological reassembly of the soil microbiome, shifting community composition toward copiotrophic dominance (Pseudomonadota and Bacteroidota) and increasing functional redundancy. These microbial and functional shifts enhance soil resilience to environmental stressors—such as drought and temperature fluctuations—by stabilizing extracellular enzyme activity and reinforcing microbial co-occurrence networks. We conclude that managing microbial interactions along the compost–soil continuum is essential for developing organic amendments optimized for specific soil and crop requirements. This integrated approach represents a cornerstone of precision sustainable agriculture and contributes to climate change mitigation through soil health restoration. Full article

This study provides an empirical assessment of greenhouse gas emissions and the environmental performance of hybrid vehicles in the European Union. The analysis integrates a macro-level examination of nitrous oxide (N₂O) emission trends in EU Member States for road and pipeline transport with a micro-level econometric investigation of emissions generated by the internal combustion engines of hybrid vehicles. The empirical analysis is based on a large sample of hybrid vehicles of different brands and variants, including 1350 observations used to examine the relationship between CO₂ emissions and fuel consumption per 100 km, and 123 observations to analyze nitrogen oxides (NO_x) emissions. CO₂ is assessed as the principal greenhouse gas emitted during vehicle operation, while NO_x (NO and NO₂) is examined as a major regulated atmospheric pollutant relevant to environmental performance. A bibliometric analysis of NO_x-related publications further highlights increasing scientific attention to this pollutant, supporting the relevance of the current study. Results reveal significant heterogeneity across hybrid vehicle models in terms of fuel consumption and NO_x emissions, indicating that environmental performance is strongly influenced by technological design and operational characteristics. Robust multiple regression models (R² = 0.84 for vehicle with low CO₂ emissions, 0.82 for high CO₂ emissions and R² = 0.72 for NO_x emissions) revealed significant correlations between pollutant emissions and fuel consumption, providing valuable tools for predicting emissions and informing environmental policies and hybrid vehicle design. Overall, the findings indicate that hybrid vehicles can contribute to improved environmental performance and lower greenhouse gas emissions relative to conventional vehicles, while their effectiveness depends on model specific characteristics and broader sectoral emission dynamics in the EU. These insights provide evidence for policymakers and industry stakeholders to support the transition toward cleaner vehicle technologies and align climate neutrality targets in the European Union. Full article