Postoperative nausea and vomiting (PONV) are common complications, leading to prolonged hospital stays and reduced patient satisfaction. Acoustic neuroma (AN) resections are associated with a higher risk of PONV than other craniotomies. We aimed to detect if preoperative aprepitant is associated with less PONV following AN surgery. Perioperative data were collected from the electronic medical record for patients undergoing AN resection between December 19, 2017 and April 26, 2022. Variables were compared between a cohort that received aprepitant and a matched cohort. Univariable and multivariable regression analyses were performed. Our primary outcome was PONV on the day of surgery. A total of 579 patients were included, of which 49% (n=283) developed PONV. A cohort of 108 patients who received aprepitant was matched in a 1:2 manner. Aprepitant was not associated with reduced PONV (P=0.239, odds ratio=0.756 [95% CI: 0.475-1.204]). On the basis of our univariable logistic regression model, tumor size, a translabyrinthine approach, total dose of propofol, total volume of crystalloids, highest nitrous oxide concentration, and anesthetic duration were associated with decreased odds of PONV. In multivariable regression modeling, none of these characteristics were associated with decreased odds of PONV. Our results confirm that PONV is a common complication following AN resection. Preoperative aprepitant administration was not associated with reduced PONV. Intraoperative variables such as the surgical approach and duration of anesthesia might play a role in mitigating the risk of PONV. Future studies should identify other perioperative interventions to allow for the development of protocols addressing PONV.

The annual nitrogen (N) production from livestock manure is comparable to that of synthetic N fertilizers used globally in croplands. Despite its recognized value for crop nutrition, current inefficient manure application contributes ∼10% to global anthropogenic greenhouse gas (GHG) emissions. Addressing this challenge, we investigated semiliquid manure slurry, which in some regions provides up to half of the N supplied to crops. Using meta-analysis and machine learning methodology, we predicted agricultural and environmental impacts of slurry use in different climate scenarios based on 1952 paired observations in global field experiments. Current suboptimal uses of slurry generate 7% (0.1 Tg N) higher nitrous oxide emissions than synthetic fertilizers. Under future warming scenarios and without optimization, these emissions are projected to increase by an additional 3-5% (∼0.2 Tg N) and total noncarbon dioxide (CO2) GHG emissions by 30% (600 Tg CO2 equivalents year-1). Current evidence identifies the combination of subsurface slurry application and nitrification inhibitors as an effective optimization strategy. This strategy may reduce non-CO2 GHG emissions by 30%, equivalent to an 8% reduction in the total agricultural GHG emissions. We estimated that this optimization, combined with a favorable slurry N-to-total N ratio, has the technological potential to increase global cereal production by up to 20% and restore organic carbon stocks in topsoil by 5% (3400 Tg carbon). Thus, optimizing slurry use should be a priority, as it contributes to climate change mitigation, food security, and soil fertility.

ABSTRACT Accurate prediction and control of nitrogen oxide (NOx) emissions from coal combustion critically depend on understanding nitrogen release mechanisms from individual coal particles. This study establishes a model predicting the formation of nitric oxide (NO) and nitrous oxide (N2O) during the combustion of a single pulverized coal particle. The model integrates the chemical percolation devolatilization (CPD) framework with heterogeneous char surface reactions. Crucially, this model represents the first approach incorporating the significant contribution of N2O to nitrogen oxide formation pathways. This capability allows tracking concentration profiles of key species throughout the particle combustion process. The model reasonably predicts N2O formation under high-temperature, low-oxygen conditions and effectively captures dynamic interactions between NO and N2O. Under varying oxygen concentrations and initial NO levels, the model clearly reveals mechanistic influences of O2 and NO on N2O production. These results provide a robust framework for understanding nitrogen oxide formation mechanisms and informing targeted emission control strategies.

Abstract The application of digestates supports soil fertility by restoring soil organic matter (SOM) and supplying nitrogen (N). However, their application can increase greenhouse gas (GHG) emissions from agriculture. Targeted digestate application to soils where erosion has mixed subsoil into topsoil may reduce emissions, as the lower SOM saturation in this diluted topsoil could enhance stabilization of organic inputs. This study investigates whether topsoil dilution through erosion can reduce carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) emissions following digestate application. We conducted an incubation experiment simulating erosion-induced topsoil dilution. Three different soils from Uckermark region, Germany—non-eroded (LL), moderately eroded (eLL), and strongly eroded (RZ)—were incubated for 26 days in an automated gas exchange system. Topsoil was diluted with 20% subsoil, and digestate applied as organic fertilizer. CO 2 and N 2 O emissions were measured; undiluted, unfertilized soils served as controls. Digestate increased CO 2 and significantly raised N 2 O emissions in all soils. Topsoil dilution reduced CO 2 emissions in LL and showed similar trends in eLL and RZ, though the effect weakened with erosion severity, likely due to existing C-undersaturation in these soils. N 2 O responses varied: emissions decreased in eLL (high clay and reactive mineral content), possibly due to enhanced N stabilization, but increased in RZ (calcareous, high-pH soil likely promoting nitrification) and slightly in LL, possibly due to lowered carbon-to-nitrogen (C: N) ratio. Topsoil dilution can mitigate digestate-induced CO 2 but may elevate N 2 O emissions depending on soil properties. Therefore, site-specific management is key to lowering GHGs in erosion-prone soils.

Abstract. Prokaryotic and eukaryotic microscopic phototrophs (“microalgae”) can synthesize the potent greenhouse gas and ozone depleting pollutant nitrous oxide (N2O). However, we do not know how much microalgae contribute to aquatic N2O emissions because these organisms co-occur with prolific N2O producers like denitrifying and nitrifying bacteria. Here we demonstrate for the first time that microalgae produce distinct N2O isotopic signatures that will enable us to fill this knowledge gap. The eukaryotes Chlamydomonas reinhardtii and Chlorella vulgaris, and the prokaryote Microcystis aeruginosa synthesized N2O 265 – 755 nmol g-DW−1 h−1 when in darkness and supplied with 10 mM nitrite (NO2-). The N2O isotopic composition (δ15N, δ18O, and site preference, SP) of each species was determined using a modified off-axis integrated-cavity-output spectroscopy analyser with an offline sample purification and homogenisation system. The SP values differed between eukaryotic and prokaryotic algae (25.8 ± 0.3 ‰ and 24.1 ± 0.2 ‰ for C. reinhardtii and C. vulgaris, respectively vs 2.1 ± 3.0 ‰ for M. aeruginosa), as did bulk isotope values. Both values differ from SP produced by denitrifiers. This first characterization of the N2O isotopic fingerprints of microscopic phototrophs suggests that SP-N2O could be used to untangle algal, bacterial, and fungal N2O production pathways. As the presence of microalgae could influence N2O dynamics in aquatic ecosystems, field monitoring is also needed to establish the occurrence and significance of microalgal N2O synthesis under relevant conditions.

Denitrification leads to nitrogen loss from marine oxygen minimum zones. The complete metabolic pathway for denitrification reduces nitrate to dinitrogen gas in four sequential steps. Many facultatively anaerobic bacteria are capable of the initial step of nitrate reduction to nitrite. Far fewer contribute to nitrogen loss by reducing nitrite to nitric oxide, nitrous oxide or dinitrogen gas. We sequenced the genomes of 24 bacteria isolated from low-oxygen waters (23 µM) in the northern Benguela Upwelling System (nBUS) to identify species with the genetic potential for denitrification. Most isolates have the genetic potential for partial denitrification, including ten SAR11 strains with a genomic region that codes for a copper-containing nitrite reductase (NirK) and a high-affinity cbb3-type cytochrome c oxidase. Evidence that nBUS SAR11 have the potential to respire nitrite in low-dissolved-oxygen waters suggests that they could have a more direct role in marine nitrogen loss.

Refining regional estimates of N2O emissions from agricultural soils: A modelling study from Austria.

Abstract Peppermint ( Mentha piperita ) is a perennial herb valued for its menthol‐rich oil and requires high nitrogen (N) inputs for its irrigated production. Optimizing N management can reduce nitrous oxide (N 2 O) emissions, a potent greenhouse gas associated with fertilizer N input. A 2‐year experiment (2022–2023) was conducted in western Nebraska to evaluate the effects of N fertilizer sources (urea and polymer‐coated urea; PCU) applied at different rates on peppermint yield and N 2 O emissions. Application rates were lower in 2022 than in 2023 due to transplanting and herbicide injury issues. Therefore, dry matter yield was lower in 2022 (3.38–3.84 Mg ha −1 ) than in 2023 (7.56–14.11 Mg ha −1 ). In 2023, PCU at the highest rate (332 kg N ha −1 ) had a greater peppermint dry matter yield than all other treatment combinations except for urea at the same rate. In 2023, yield did not vary with N source, except at the low rate, where PCU had a greater yield (12.14 Mg ha −1 ) than urea (9.31 Mg ha −1 ). In both years, urea had greater N 2 O emissions than PCU, except for the lowest N rate (34 kg N ha −1 ) in 2022. Nitrous oxide emissions varied by N rates for urea but not for PCU. Fertilizer‐induced emission factors (FIEF) were within the range of the Intergovernmental Panel on Climate Change (IPCC) disaggregated emission factor of 0.5% (0.0%–1.1%) for dry climates. Nitrogen source‐specific FIEF disaggregation might narrow the current IPCC uncertainty range.

Streaming potential generation through water flow in porous media represents an ancient and ubiquitous geophysical phenomenon. For centuries, this process has been regarded as merely a process of charge redistribution without involving any redox reactions. By using NO3- reduction as a model reaction, this study demonstrated for the first time that water flow drives abiotic denitrification associated with streaming potential generation. The nitrate (NO3-) reduction rate reached 10.6 μmol·L-1·d-1, which is comparable to that of FeS-driven chemical NO3- reduction (75.0-380 μmol·L-1·d-1) and significantly higher than that of photochemistry-driven NO3- reduction (0.1-1 μmol·L-1·d-1). Through monitoring of nitrogenous products and 15NO3- isotopic experiments, we showed that NO3- was selectively reduced to nitrogen (99%) via nitrite and nitrous oxide, confirming a denitrification process. Electron paramagnetic resonance (ESR) spectroscopy using DMPO as the probe detected the generation of hydrogen radicals (H•), which served as the reducing force for NO3- reduction. Using TEMPO as the electron probe, linear electron production was observed with an electron efficiency of 6.3% for NO3- denitrification. Moreover, H218O isotope experiments demonstrated that water oxidation is the ultimate electron source for NO3- reduction, indicating a chemical-free NO3- reduction process. An electric field strength of approximately 106 V/cm was detected using surface-enhanced Raman scattering, providing evidence of a strong interfacial electric field (IEF)-induced electron transfer process during water flow. This work reveals ubiquitous but long-overlooked redox reactions associated with streaming potentials. Water-flow-driven denitrification also highlights a newly identified abiotic NO3- elimination pathway, suggesting potent chemical-free NO3- remediation strategies.

ABSTRACT Sewage-sludge compost contains nutrients and organic matter as well as heavy metals which can affect soil microbial activities. The objective of this study was to investigate the initial and long-term effects of two kinds of sewage-sludge compost applications, either with saw dust (SD) or rice husk (RH), on soil heavy metal and microbial biomass (SMB) contents in mesocosms compared to chemical fertilizer (CF) alone, during the first 3 years application period, and 21 years post application period. Zinc (Zn) contents tended to increase in the first 3 years and kept higher (+5–10%) in RH and SD than CF plots, also in upper (1–16 cm) soil layer than lower (16–31 cm) soil layer in RH, while copper (Cu) contents tended to be higher (+15–27%) in RH than SD and CF. Nitrous oxide (N2O) emission showed sharp increases soon after compost and fertilizer application in the initial third year, being higher in RH and SD than CF plots. SMB C and N also showed increase after compost and fertilizer application in the initial period, tending to be higher in SD and RH than CF plots. Twenty-one years after application period, Zn contents in upper soils of SD and RH plots were 5–10% higher than that of CF plot, while Cu contents were 15–27% higher in SD and RH than CF not only in upper layers but also in lower layers. ATP (adenosine 5’ triphosphate) contents in the upper soil were 45–52% lower in SD and RH than CF plot, while no significant change was observed in the lower soil. Soil surface in Petri dishes had visible algal colony formation in the upper soil only of CF, while lower soil of all plots after growth-chamber incubation. Contents of chlorophyll-type compounds in the upper soil amended with RH were 71% lower than in CF and tended to be so in SD (23% lower) after incubation. These results suggest that initial effects of compost on SMB and N2O emission increases attribute organic matter in the sewage sludge composts even with heavy metal increases in soil, while residual suppressive effects on SMB and its activities remained with residual heavy metals in the soil 21 years after sewage sludge compost application stopped, which can be monitored by soil microbial properties as useful sensitive indicators for soil health. Heavy metals in sewage sludge and its residual effects in soil should be monitored carefully in the long term.

BACKGROUND Snare polypectomy and endoscopic mucosal resection (EMR) are effective and widely utilized for treating duodenal adenomas. However, circumferential, recurrent and fibrotic adenomas can be challenging to treat with these techniques. AIM To develop a safe and effective treatment for these challenging lesions. METHODS Between 2022 and 2024, a retrospective review was performed for all patients treated with cryoballoon for duodenal adenomas at two institutions. Cryoballoon focal ablation was performed using nitrous oxide, in which a 1-second “pre-puff” of nitrous oxide was performed, followed by delivery for 10 seconds to 14 seconds. Repetition was performed as needed. Surveillance endoscopy was performed at 3 months to 12 months post-ablation to assess efficacy. RESULTS A total of ten individuals were treated, including six patients with recurrent adenomas following previous incomplete endoscopic resections, one patient with an extensive flat adenoma surrounding an ampullary polyp that could not be resected with a snare, and two patients with circumferential sessile duodenal adenomas longer than 5 cm that were considered unresectable by EMR. Follow-up endoscopy demonstrated no efficacy (< 20% improvement) in the two patients with circumferential sessile adenomas. Of the eight patients with non-circumferential adenomas, three had no residual adenoma. Five had significant improvement with < 40% of the adenoma remaining and were treated again with cryoballoon (3) or cold snare (2). Three of the five patients had no recurrence following the second treatment. The remainder are awaiting repeat endoscopy. Seven patients were treated as outpatients and had no adverse events. Two patients undergoing concomitant snare ampullectomy were hospitalized for observation; one developed mild pancreatitis and was discharged following a 48-hour admission, and the second patient was asymptomatic. CONCLUSION Cryoballoon treatment may be effective for non-circumferential flat duodenal adenomas that are not amenable to snare polypectomy or EMR, such as those with severe fibrosis from prior treatment. More than one treatment may be required. However, the treatments are safe and well-tolerated. Limited experience in two patients suggests that cryotherapy is not an effective treatment for bulky circumferential adenomas.

The carbon-rich substance known as biochar, which is made by pyrolysing organic wastes like wood chips, manure and agricultural waste, has attracted more attention lately because of its potential to improve soil fertility and mitigate climate change. The physicochemical characteristics, surface morphology and soil stability of biochar made from different agricultural feedstocks are all thoroughly examined in this paper. The study assesses how the pore structure, nutrient content and functional groups of biochar are influenced by varying pyrolysis temperatures, heating rates and feedstock compositions. These factors thereby impact the qualities of soil. Key findings reveal that biochar application improves soil structure, promotes water-holding ability and increases cation exchange capacity, consequently enhancing nutrient retention and plant growth. It also increases microbial activity and variety, which strengthens the resilience of soil ecosystems. In addition to its agronomic advantages, biochar stabilises organic carbon in the soil and lowers methane and nitrous oxide emissions, which is essential for long-term carbon sequestration. Biochar is an essential component of climate-smart agriculture since it combines these benefits to provide a sustainable means of boosting agricultural output, recovering degraded soils and reducing global warming.

Beyond climate: the emerging physiological roles of methane and nitrous oxide.

Uncoupled nitrification-denitrification reduces nitrous oxide emissions in canals affected by ship disturbance.

Regulation mechanism of N2O metabolic footprint during the black soldier fly manure composting system amended with biochar, humic acid, and tea residue.

Intensive greenhouse cultivation, characterized by high agrochemical inputs and minimal organic amendments, maximizes crop productivity but often leads to soil degradation and environmental harm, notably through nitrate leaching and increased nitrous oxide (N 2 O) emissions. To reduce agricultural inputs that may lead to soil degradation, this study evaluates an alternative fertilization strategy based in ecological intensification (EI). Specifically, a management system incorporating horticultural crop residues and organic amendments—with limited use of inorganic fertilizers—was compared to a conventional fertilization system (C) over a six-year period. Soil quality was assessed using physical and chemical indicators alongside microbial gene abundance (16s, ITS) and genes related to denitrification processes ( nirK , nirS , nosZ 1, and nosZ 2) measured by Real-Time PCR. The EI system enhanced soil organic matter and soil structure by enhancing macroporosity and aggregate stability. However, it also increased the risk of salinization. Fungal abundance and the key denitrification genes ( nosZ1 and nosZ2 ) were significantly higher under EI management. The fungal-to-bacterial ratio approached, but did not reach, statistical significance, and the nos/nir gene ratio—an indirect indicator of N 2 O emission potential—remained similar between treatments. These findings suggest a complex interaction between soil quality and denitrifier community dynamics that warrants further investigation, particularly to assess potential N 2 O emissions.

Nitrogen enrichment and sea-level rise are two critical drivers affecting estuarine and coastal wetland ecosystems globally. However, the effects of these drivers on soil nitrous oxide (N 2 O) production, consumption, and resulting ultimate emissions remain poorly understood. In this study, nitrogen input (+N treatment), increased inundation (+I treatment), and their combination (+N+I treatment) were simulated in situ using a weir device to explore the individual and interactive effects of enhanced nitrogen loading and sea-level rise on soil N 2 O dynamics. Our results showed that nitrogen input (+N treatment) significantly increased soil N 2 O emission (82.9%), primarily by stimulating gross N 2 O production. In contrast, the inundation increases alone (+I treatment) did not alter soil N 2 O production and consumption process dynamics. The Combined treatment of increased nitrogen input and inundation (+N+I treatment) dramatically promoted soil gross N 2 O production (85.3%). However, an elevated proportion of N 2 O consumption mitigates its effect on N 2 O emissions. This implies that increased inundation resulting from the sea level rise may counteract nitrogen-stimulated soil N 2 O emissions. The contents of soil carbon and nitrogen substrate (e.g., DOC and NH 4 + ), along with the gene abundances (e.g., nosZ) involved in N 2 O production and consumption, were the pivotal factors in mediating the changes in N 2 O dynamics under various treatments. Overall, our findings highlighted the importance of increased inundation caused by sea-level rise in alleviating N 2 O emissions under high nitrogen conditions, yet widely overlooked.

Antibiotic resistance genes (ARGs) pose a serious threat to the environment worldwide. The guts of soil animals are a hotspot for ARGs and denitrification in soils. However, it is unclear how denitrification affects the spread of ARG in the earthworm’s gut. In this study, the typical soil earthworm Pheretima guillelmi was employed, and was used for performing anoxic incubation with gut content amended with nitrate and nitrite. To analyze the data, a combination of chemical analysis, 16S rRNA-based Illumina sequencing, and high-throughput qPCR were employed. Nitrate treatments, particularly at 5 mM, caused substantial reductions in nitrate concentrations, with a corresponding increase in nitrite, nitrous oxide (N2O), and nitric oxide (NO) emissions compared to the treatments with the addition of 1 and 2 mM nitrate. Nitrite (0.2, 0.5 and 1 mM) amendments also enhanced the accumulation of nitrogen intermediates. Organic acid production, including acetate and pyruvate, was the highest under the 5 mM nitrate treatment. This treatment also promoted the highest level of glucose utilization, suggesting that glucose metabolism supports enhanced organic acid production. Both nitrate and nitrite treatments exhibited the pronounced enrichment in ARGs, particularly for beta-lactam and multidrug resistance genes. Denitrifying bacteria such as Aeromonas, Bacillus, Raoultella, and Enterobacter were identified as key hosts for these ARGs. These results emphasized that denitrifying bacteria play a pivotal role in the horizontal transfer of ARGs, underscoring the need for careful nitrogen management in agricultural practices to control the spread of antibiotic resistance in natural environments.

This study estimates and projects livestock-related greenhouse gas (GHG) emissions in Nepal between 2002 and 2022, providing crucial insights for climate change mitigation strategies. The latest secondary data on livestock population was collected from the Ministry of Agriculture and Livestock Development (MoALD) Nepal. The IPCC tier 1 methods were used to estimate emissions and forecast future trends. Studies reveal that Nepal livestock-related GHG emissions reached 28,603Gg CO2 e /year in 2022,with buffalo accounting for 39 % of the total emissions followed by cattle and goats. In 2022, the primary sources of emissions were direct nitrous oxide (48.2%), enteric methane (44.7%), manure methane (4.5%), and indirect nitrous oxide (0.6%). Future projections indicate a potential increase in total GHG emissions by 3.06 % and 3.56% up to 2050, suggesting a growing environmental impact if current practices continue. The provincial (regional) analysis identified Koshi province as the highest emitter in 2022. This research underscores the need for effective management strategies to mitigate emissions from the livestock sector in Nepal. Further, it recommends transitioning to the IPCC Tier 2 approach when sufficient national-level data becomes available to enhance the accuracy of future inventories

Agricultural soils are the largest anthropogenic source of nitrous oxide (N2O), primarily due to excessive nitrogen (N) fertilization and inefficient N management. Mitigating N2O emissions from croplands without compromising productivity is therefore a major global challenge for climate and environmental sustainability. A three-year split-plot field experiment was conducted in an arid maize production region of northwestern China to examine how green manure intercropping combined with reduced chemical N input regulates N2O emissions and soil N residues. The main plots comprised maize monoculture (M), maize intercropped with common vetch (M/V), and maize intercropped with rape (M/R), while subplots consisted of local conventional N application (N1: 360 kg N ha−1) and a 25% reduced rate (N2: 270 kg N ha−1). Results indicated that intercropping with green manure can offset the reduction in maize grain yield caused by a 25% decrease in N supply. Green manure intercropping significantly decreased cumulative N2O emissions compared with monoculture maize, and the mitigation effect was further strengthened under reduced N input. The M/V system under reduced N input exhibited the strongest mitigation effect, reducing N2O emissions per unit of grain yield by 9.2–11.5% compared with the M/R system. This reduction was driven by the ability of M/V to stabilize soil mineral N availability. Notably, the independent maize growth stage contributed 52.6–66.9% of total seasonal N2O emissions, emphasizing it as a critical period for emission mitigation. Overall, integrating green manure intercropping with reduced chemical N input effectively mitigates N2O emissions while maintaining maize productivity in arid regions, providing a practical strategy for sustainable and environmentally responsible agricultural intensification.