Search

Objective Methods Results Conclusion Intranasal (IN) fentanyl and nitrous oxide (N2O) can be combined to provide procedural sedation and analgesia to children. This combination is advantageous because of rapid onset of action and non‐parenteral administration, but is associated with increased vomiting. We sought to describe the associations of demographic and procedural factors with early vomiting when using this combination in children.This was a planned secondary analysis of a randomised controlled trial comparing the effect of oral ondansetron versus placebo at a single paediatric hospital. Children aged 3 to <18 years with planned procedural sedation with IN fentanyl and N2O were randomised to receive oral ondansetron or placebo prior to N2O administration. Vomiting was defined as early if occurring during or up to 1 h after N2O delivery. We assessed the relationship between early vomiting, demographic and procedural characteristics.Participants were recruited between October 2016 and January 2019 and 62 out of 436 (14%) had early vomiting. The risk of early vomiting was 30% higher with higher total dose of fentanyl, risk ratio = 1.3 (95% confidence interval = 1.004–1.59). There was little evidence of a relationship between the occurrence of early vomiting and sex, age, weight, type of procedure, fasting duration, time between fentanyl administration and start of procedure, and procedure duration.We found that higher doses of IN fentanyl were associated with higher risk of early vomiting when administered with N2O in children. Other factors did not appear to be associated with vomiting. [ABSTRACT FROM AUTHOR]

Background: Chronic nitrous oxide (N2O) use causes inactivation of vitamin B12, resulting in neurological and psychiatric symptoms. This case series presents all N2O‐related presentations to the emergency department at Royal Perth Hospital between June 2019 and June 2021, alongside the costs of these admissions. Case Presentation: Twenty‐two patients were identified; 68% (n = 15) were male. The median age was 22.4 years (interquartile range [IQR], 20–30). Median daily number of N2O bulbs inhaled was 150 (IQR, 64–300) with a median duration of use of 9 months (IQR, 3–12). Presentations included ataxia, paraesthesia and falls (n = 18), urinary retention (n = 3) and psychotic symptoms (n = 2). Fourteen patients had severe symptoms prompting a magnetic resonance imaging of brain and spine, confirming 12 cases of subacute combined degeneration of the spinal cord. All patients had IMI vitamin B12 therapy, while 14 had oral methionine therapy. The median length of admission was 4 days (IQR 1–23 days). The median cost of admission per day for patients where costs were accessible (n = 7) was $2061 (IQR, $1903‐$2860). Discussion and Conclusions: A case series of symptomatic chronic N2O use with severe neurological sequelae and significant costs associated per admission. Triangulation of emergency department and Ecstasy and Related Drugs Reporting System data helped prompt a swift public health response, including mandatory warning labels, limits to transaction amounts and legislative changes to the Medicines and Poisons Act to make it illegal for sale if there is a suspicion that it will be abused. [ABSTRACT FROM AUTHOR]

Farmers' open‐field burning of paddy straw and the indoor burning of paddy residues as domestic fuels are significant environmental concerns since they emit dangerous pollutants. The worldwide burning of paddy residues totals 90 million tons (MT). Around 24 MT emanated from India, accounting for approximately 27% of the world's paddy straw burning. Burning residues emit smog particles, polyaromatic amines, nitrous oxides, sulfur dioxide, carbon dioxide, and carbon monoxide, methane, seriously degrading the air quality and risking human health. The combustion of dry paddy straw emits massive volumes of methane and nitrous oxide, 65 and 1.6 kilotons, respectively. This study analyzes the consequences of burning paddy residue outdoors and indoors by reviewing the relevant literature and data. Open‐field burning causes air pollution, damages soil health, and harms human health. Indoor burning of paddy residues as domestic fuels harms women's and children's health in rural areas. To mitigate the adverse effects of this practice, we magnified our research using the various literature and recent statistics to link with mushroom cultivation as an alternative to paddy residue burning. Recently, India produced almost 240,000 tons of mushrooms; Odisha, Maharashtra, and Bihar are the three leading states for mushroom production. The cultivation of mushrooms is considered advantageous for both health and the environment. This study has concentrated on mushrooms' economic potential, medicinal value, and health benefits. [ABSTRACT FROM AUTHOR]

The article discusses the consensus among healthcare institutions in the UK and Ireland to decommission piped nitrous oxide from operating theatre suites. This is due to the inefficiency of the current supply system as the use of nitrous oxide has decreased. Nitrous oxide is a potent greenhouse gas that contributes to climate change, so reducing its emissions is crucial. The article explores the challenges and implementation of decommissioning piped nitrous oxide, as well as potential mitigation strategies such as catalytic destruction. The authors emphasize the need for the medical gas industry to support waste reduction efforts and advocate for changes in the use of nitrous oxide to minimize its environmental impact. [Extracted from the article]

Background Aims Methods Results Conclusion Incorporation of cover crop (cc) shoot and root biomass can have different effects on nitrogen (N) dynamics and the transformation of soil‐derived N and cc N.The objective was to determine the effects of different ccs, cc compartments (roots and shoots), and pretreatment of cc biomass (fresh vs. dried) on mineralization processes and on the transformation of soil and cc N following incorporation into a silty loam soil.Soil columns with incorporated 15N‐labeled root and shoot biomass of two cc species (winter rye and oil radish) and different pretreatments (dried and fresh) were incubated for 70 days at a constant temperature and soil moisture (8°C, 40% water‐filled pore space). Carbon and N transformation dynamics were determined repeatedly, distinguishing between N originating from cc biomass and from soil.Net CO2 emission was related to the amount of soluble cell components added with ccs. Net N mineralization was negatively related to the C:N ratio of cc biomass. The incorporation of dried cc biomass caused higher initial soil respiration and N immobilization than fresh biomass. All treatments with cc incorporation showed increased N2O emission. Emitted N2O‐N consisted mainly of cc N (55%–57%) in treatments with fresh shoot biomass, whereas soil N was the main source of N2O (75%) in the treatment with fresh oil radish roots. Recovery of cc 15N was affected by crop compartment and pretreatment. At the end of the incubation, it was 17.5%–42.3% in soil NO3−, 0.1%–8.1% in microbial biomass N, and less than 0.23% of cc N was found in cumulative N2O emission.The incorporation of cc roots and shoots had different effects on N mobilization and immobilization processes and on the partitioning of cc N. These processes can be influenced significantly by pretreatment of the added plant biomass (dried vs. fresh). [ABSTRACT FROM AUTHOR]

Introduction: During child dental treatment, different behavior management techniques (BMTs) are applied and it is important to understand the possible discomfort in the operator. Objective: The present systematic review aimed to evaluate the acceptability of dental students and professionals concerning BMTs applied with paediatric dentistry patients. Materials and Methods: A systematic search was conducted, following the PEOS strategy: Population (P) – dental students/professionals (S); Exposure (E) – BMTs preconized by the American Academy of Paediatric Dentistry, Outcome (O) – proportion of BMT acceptance; and Study design (S) – observational studies based on data from PubMed, Scopus, Web of Science, BVS (Lilacs/BBO), Cochrane, and Open Grey databases up to September 2021. The eligible studies were submitted to data extraction and to the evaluation of methodological quality, using the Joanna Briggs Institute Critical Appraisal Tool. The certainty of evidence was evaluated by GRADE. Results: The search retrieved 710 articles; a total of 21 fulfilled the eligibility criteria and were used for qualitative analysis. Among the undergraduate students and dentists, the most accepted techniques were tell‐show‐do and positive reinforcement, while paediatric dentists preferred the tell‐show‐do technique and dental professionals with graduate degrees preferred sedation using nitrous oxide and positive reinforcement. The least accepted technique was protective stabilization. Seven students presented a low risk for bias, while 14 presented a high risk. The certainty of evidence was classified as very low. Conclusion: Although the basis of available certainty of evidence is scarce and with a considerable risk for bias, it is still possible to conclude that the more accepted techniques were based on communication. [ABSTRACT FROM AUTHOR]

This article discusses the ethical implications of removing Entonox® from labor wards as part of a strategy to mitigate the climate crisis. The authors argue that while the greenhouse gas and ozone-depleting effects of nitrous oxide are well-known, it is premature to remove it without first addressing wastage and exploring alternative strategies. They emphasize the importance of considering patient care, staff safety, and the impact on vulnerable groups when making decisions about sustainability in healthcare. The authors also call for a broader approach to sustainability that goes beyond carbon counting and includes considerations of health inequality and social justice. [Extracted from the article]

Effective nitrogen fertilizer management is crucial for reducing nitrous oxide (N2O) emissions while ensuring food security within planetary boundaries. However, climate change might also interact with management practices to alter N2O emission and emission factors (EFs), adding further uncertainties to estimating mitigation potentials. Here, we developed a new hybrid modeling framework that integrates a machine learning model with an ensemble of eight process‐based models to project EFs under different climate and nitrogen policy scenarios. Our findings reveal that EFs are dynamically modulated by environmental changes, including climate, soil properties, and nitrogen management practices. Under low‐ambition nitrogen regulation policies, EF would increase from 1.18%–1.22% in 2010 to 1.27%–1.34% by 2050, representing a relative increase of 4.4%–11.4% and exceeding the IPCC tier‐1 EF of 1%. This trend is particularly pronounced in tropical and subtropical regions with high nitrogen inputs, where EFs could increase by 0.14%–0.35% (relative increase of 11.9%–17%). In contrast, high‐ambition policies have the potential to mitigate the increases in EF caused by climate change, possibly leading to slight decreases in EFs. Furthermore, our results demonstrate that global EFs are expected to continue rising due to warming and regional drying–wetting cycles, even in the absence of changes in nitrogen management practices. This asymmetrical influence of nitrogen fertilizers on EFs, driven by climate change, underscores the urgent need for immediate N2O emission reductions and further assessments of mitigation potentials. This hybrid modeling framework offers a computationally efficient approach to projecting future N2O emissions across various climate, soil, and nitrogen management scenarios, facilitating socio‐economic assessments and policy‐making efforts. [ABSTRACT FROM AUTHOR]

Continental groundwaters are commonly enriched in nitrous oxide (N2O) and methane (CH4), which can discharge into the coast. The contribution of this diffuse source to coastal N2O and CH4 emissions largely depends on the biogeochemical processes of coastal aquifer exit zones, known as subterranean estuaries. Here, we study the role of subterranean estuaries in modulating N2O and CH4 exports toward the coast. The two studied subterranean estuaries are located at Panxón and Ladeira beaches (Ría de Vigo, NW Iberian Peninsula) and had opposite oxygenation at their interior. Groundwater‐borne N2O was detected in the oxygenated subterranean estuary of Panxón Beach, although denitrification attenuated N2O before porewater was discharged into the coast. An N2O hotspot was detected at about 50 cm depth in this subterranean estuary, characterized by the presence of nitrate under suboxic conditions. This N2O also seems to be consumed along the flow path before discharging into the coast. The anoxic subterranean estuary of Ladeira Beach completely removed groundwater‐borne N2O. Yet, nitrification within its suboxic upper saline plume produced and exported N2O toward the coast, hiding the role of this subterranean estuary as an N2O sink. The anoxic subterranean estuary exported CH4 toward the coast. This CH4 was not sourced by continental groundwater, hence it was produced in situ fuelled by the accumulation of organic matter within the beach. The suboxic upper saline plume in Ladeira Beach and the oxygenated subterranean estuary of Panxón Beach acted as CH4 sinks. [ABSTRACT FROM AUTHOR]

Background: Nitrous oxide use is shifting from general anesthesia to sedation and pain control. Interest in novel uses of nitrous oxide in psychiatry is also growing. Thus, understanding the consequences of using nitrous oxide remains relevant. Previous quantitative research might not have fully captured the whole spectrum of nitrous oxide, whereas qualitative analysis can provide a more comprehensive description. This qualitative study aims to describe the subjective experiences of nitrous oxide use in healthy volunteers who have no prior history of recreational substance misuse. Methods: Twenty healthy male volunteers inhaled 50% nitrous oxide for 20 min. Females were excluded due to higher incidence of nausea with nitrous oxide. Afterwards, all participants answered an open‐ended question about their experiences during sedation. The answers were then analyzed with inductive qualitative content analysis to identify emergent subcategories, categories, and overarching themes. Results: We identified two themes: nitrous oxide is mind‐altering and produces sensory overload. The mind‐altering properties were represented by dreamlike states and heightened emotions. Dreamlike states comprised changes in consciousness and scary, bizarre, or transcendental dreams. Pleasant dreams were not reported. Heightened emotions included euphoria, anxiety, and fear of losing control. Sensory overload consists of distorted perception, bodily sensations, and a heightened sense of surroundings. Conclusions: Experiences under nitrous oxide sedation are extremely variable and not always pleasant. These findings can improve our understanding of the likes/dislikes of patients undergoing nitrous oxide sedation. Further qualitative studies should focus on the experiences of other groups, such as children or women in labor. [ABSTRACT FROM AUTHOR]

In the framework of the RECCAP2 initiative, we present the greenhouse gas (GHG) and carbon (C) budget of Europe. For the decade of the 2010s, we present a bottom‐up (BU) estimate of GHG net‐emissions of 3.9 Pg CO2‐eq. yr−1 (using a global warming potential on a 100 years horizon), which are largely dominated by fossil fuel emissions. In this decade, terrestrial ecosystems acted as a net GHG sink of 0.9 Pg CO2‐eq. yr−1, dominated by a CO2 sink that was partially counterbalanced by net emissions of CH4 and N2O. For CH4 and N2O, we find good agreement between BU and top‐down (TD) estimates from atmospheric inversions. However, our BU land CO2 sink is significantly higher than the TD estimates. We further show that decadal averages of GHG net‐emissions have declined by 1.2 Pg CO2‐eq. yr−1 since the 1990s, mainly due to a reduction in fossil fuel emissions. In addition, based on both data driven BU and TD estimates, we also find that the land CO2 sink has weakened over the past two decades. A large part of the European CO2 and C sinks is located in Northern Europe. At the same time, we find a decreasing trend in sink strength in Scandinavia, which can be attributed to an increase in forest management intensity. These are partly offset by increasing CO2 sinks in parts of Eastern Europe and Northern Spain, attributed in part to land use change. Extensive regions of high CH4 and N2O emissions are mainly attributed to agricultural activities and are found in Belgium, the Netherlands and the southern UK. We further analyzed interannual variability in the GHG budgets. The drought year of 2003 shows the highest net‐emissions of CO2 and of all GHGs combined. Plain Language Summary: We have synthesized the European budgets of carbon and the greenhouse gases (GHG) carbon dioxide, methane and nitrous oxide. This synthesis includes estimates of direct emissions from fossil fuel burning, industrial production, waste management and agriculture, as well as of sources and sinks in the terrestrial biosphere. Summing up the sources and sinks of the three GHGs, we estimate for the decade of the 2010s an average annual net‐emission of 3.9 billion tons of carbon dioxide equivalents. These net‐emissions are dominated by carbon dioxide from fossil fuel emissions (4.1 billion tons of carbon dioxide). In contrast, the terrestrial biosphere acts as a net sink of carbon dioxide, the effect of which is only partly counterbalanced by net emissions of methane and nitrous oxide. The net‐effect of the terrestrial biosphere's GHG budget is a sink of 0.9 billion tons of carbon dioxide equivalents per year. Over the last three decades, European GHG emissions have declined by 1.2 billion tons carbon dioxide equivalents per year, mainly due to reductions in fossil fuel emissions. However, the sink capacity of the terrestrial biosphere has diminished since the 2000s. Key Points: We provide a bottom‐up estimate of CO2, CH4, N2O emissions of 3.9 Pg CO2‐eq. yr−1 over Europe, 2010–2019Terrestrial ecosystems acted as a greenhouse gas net sink of 0.9 Pg CO2‐eq. yr−1, dominated by CO2 sinkNet‐greenhouse gas emissions decreased by ∼1/4 since the 1990s, but land carbon sink is weakening since the 2000s [ABSTRACT FROM AUTHOR]

Atmospheric trace gas measurements can be used to independently assess national greenhouse gas inventories through inverse modeling. Atmospheric nitrous oxide (N2O) measurements made in the United Kingdom (UK) and Republic of Ireland are used to derive monthly N2O emissions for 2013–2022 using two different inverse methods. We find mean UK emissions of 90.5 ± 23.0 (1σ) and 111.7 ± 32.1 (1σ) Gg N2O yr−1 for 2013–2022, and corresponding trends of −0.68 ± 0.48 (1σ) Gg N2O yr−2 and −2.10 ± 0.72 (1σ) Gg N2O yr−2, respectively, for the two inverse methods. The UK National Atmospheric Emissions Inventory (NAEI) reported mean N2O emissions of 73.9 ± 1.7 (1σ) Gg N2O yr−1 across this period, which is 22%–51% smaller than the emissions derived from atmospheric data. We infer a pronounced seasonal cycle in N2O emissions, with a peak occurring in the spring and a second smaller peak in the late summer for certain years. The springtime peak has a long seasonal decline that contrasts with the sharp rise and fall of N2O emissions estimated from the bottom‐up UK Emissions Model (UKEM). Bayesian inference is used to minimize the seasonal cycle mismatch between the average top‐down (atmospheric data‐based) and bottom‐up (process model and inventory‐based) seasonal emissions at a sub‐sector level. Increasing agricultural manure management and decreasing synthetic fertilizer N2O emissions reduces some of the discrepancy between the average top‐down and bottom‐up seasonal cycles. Other possibilities could also explain these discrepancies, such as missing emissions from NH3 deposition, but these require further investigation. Plain Language Summary: Atmospheric nitrous oxide (N2O) is an important greenhouse gas and ozone depleting substance. Atmospheric N2O measurements made in the United Kingdom (UK) and Republic of Ireland were used to derive UK N2O emissions for 2013–2022 using two inverse methods. UK emissions derived using atmospheric N2O measurements were on average 22%–51% higher than emissions reported in the UK National Atmospheric Emissions Inventory. A pronounced seasonal cycle in N2O emissions is inferred from the atmospheric N2O observations which contrasts the seasonal N2O emissions estimated in the bottom‐up (process model and inventory‐based) UK Emissions Model (UKEM). We find increasing agricultural manure management N2O emissions and decreasing synthetic fertilizer N2O emissions reduces some of the discrepancy between the seasonal cycles. Key Points: Atmospheric N2O measurements from 2013 to 2022 are used to evaluate the UK's reported emissions using two inverse methodsEmissions derived from atmospheric data are on average 22%–51% higher than the UK's national emissions inventory values across 2013–2022Agreement between the average top‐down and bottom‐up seasonal emissions was improved by decreasing bottom‐up synthetic fertilizer emissions [ABSTRACT FROM AUTHOR]

This review consolidates the evidence supporting endogenous HNO generation through enzymatic and non‐enzymatic pathways, emphasizing advancements in real‐time HNO sensing within living systems. Azanone (nitroxyl, HNO) is the one‐electron‐reduced congener of nitric oxide (NO•) and shares various biological actions. HNO exhibits unique properties, including positive inotropic and lusitropic effects, along with resistance to scavenging by reactive oxygen species (ROS), particularly superoxide. Research on HNO has intensified over the last two decades, focusing on its reactivity and the prospect of endogenous formation due to its potential significance. The high reactivity of HNO arises from reactions with biologically relevant species such as oxygen, NO•, and thiols, as well as self‐dimerization. Detecting and quantifying HNO has posed challenges, initially relying on nitrous oxide (N2O) detection, a byproduct of dimerization. Recent advancements, including fluorescent probes and a specific electrochemical nanomolar‐level sensor, have facilitated direct detection, enhancing understanding of HNO reactivity and formation. [ABSTRACT FROM AUTHOR]

Background Aims Materials and Methods Results Conclusions Despite clinical and economic benefits, pain during outpatient hysteroscopy (OPH) remains a barrier to use. There is a lack of evidence to support routine use of one analgesic over another versus no analgesic.To study the efficacy and safety of methoxyflurane analgesia during OPH.A single‐centre, randomised, double‐blind, placebo‐controlled experiment was performed; 90 patients were randomly assigned (1:1). Participants allocated to the treatment group (cases) received 3 mL of methoxyflurane through an inhaler. The control group received a placebo. The primary outcome was a mean difference in pain, via a change in Visual Analog Scale (VAS) score from baseline at diagnostic hysteroscopy. Secondary outcomes were a mean difference in VAS score with any subsequent operative procedures; a mean difference in VAS score at 15 min post‐procedure; participant and clinician‐reported adverse effects and events; and participant‐reported procedure acceptability, adjuvant nitrous oxide (N2O2) use and a composite of ‘distress’.During diagnostic hysteroscopy, there was a mean difference of 11.5 mm/100 (95% confidence interval (CI) 0.08–22.95), P = 0.05, with the lower score in the cases, compared with controls. During subsequent operative procedures, there was a mean difference of 15 mm/100 (95% CI 2.71–28.22), P = 0.02, with the lower pain score in the cases, compared with controls. There was no significant difference in pain 15 min post‐procedure, participant‐ and clinician‐ reported adverse effects and events, procedure acceptability and the ‘distress’ composite.Methoxyflurane significantly reduced pain during OPH compared with placebo, for diagnostic as well as operative procedures. Furthermore, methoxyflurane was well tolerated, with no adverse events. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Relay intercropping of maize and soybean can improve land productivity. However, the mechanism behind N2O emissions in this practice remains unclear. A two‐factor randomized block field trial was conducted to reveal the mechanism of N2O emissions in a full additive maize–soybean relay intercropping. Factor A was three cropping systems – that is, monoculture maize (Zea mays L.), monoculture soybean (Glycine max L. Merr.) and maize–soybean relay intercropping. Factor B was different N supply, containing no N, reduced N and conventional N. Differences in N2O emissions, soil properties, rhizosphere bacterial communities and yield advantage were evaluated.The land equivalent ratio was 1.55–2.44, and the cumulative N2O emission (CEN2O$$ \mathrm{C}{\mathrm{E}}_{{\mathrm{N}}_2\mathrm{O}} $$) was notably lower by 60.2% in intercropping than in monoculture, respectively. Reduced N declined CEN2O$$ \mathrm{C}{\mathrm{E}}_{{\mathrm{N}}_2\mathrm{O}} $$ without penalty on the yield advantages. The relay intercropping shifted soil properties – for example, soil organic matter, total N, NH4+$$ {\mathrm{NH}}_4^{+} $$ and protease activity – and improved the soil microorganism community – for example, Proteobacteria and Acidobacteria. Intercropping reduced CEN2O$$ \mathrm{C}{\mathrm{E}}_{{\mathrm{N}}_2\mathrm{O}} $$ by directly suppressing nirS‐ and amoA‐regulated N2O generation during soil N cycling, or nirS‐ and amoA‐mediated soil properties shifted to reduce CEN2O$$ \mathrm{C}{\mathrm{E}}_{{\mathrm{N}}_2\mathrm{O}} $$ indirectly. Reduced N directly reduced CEN2O$$ \mathrm{C}{\mathrm{E}}_{{\mathrm{N}}_2\mathrm{O}} $$ by decreasing soil N content and reducing soil microorganism activities to alleviate N2O produced in soil N cycling.Conducting a full additive maize–soybean relay intercropping with reduced nitrogen supply provides a way to alleviate N2O emissions without the penalty on the yield advantage by changing rhizosphere bacterial communities and soil N cycling. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nitrification inhibitors, such as nitrapyrin (NI), are increasingly co‐applied with nitrogen (N) fertilizers as part of sustainable agricultural practice. Several studies in temperate regions have documented the effectiveness of NI in retaining soil ammonium (NH4+), minimizing N loss and increasing crop yields. However, less is known about the effects of NI in Mediterranean regions, where agricultural production is challenging and requires intensive irrigation and fertilization. We investigated the short‐term impact of the nitrification inhibitor nitrapyrin (2‐chloro‐6‐(trichloromethyl)pyridine) in a two‐factor mesocosm experiment, using a typical Mediterranean soil, where NI was co‐applied with a selection of urea‐based fertilizers: urea (U), U with urease inhibitors (U + UI), methylene urea (MU) and zeolite‐coated urea (ZU). NI co‐applied with urea fertilizers resulted in higher availability of soil NH4+ and a concurrent increase in NH3 volatilization. Net cumulative soil NH4+ availability was 1.5–3.3 fold greater when NI was applied. Concurrently, net cumulative nitrate (NO3−) and nitrite (NO2−) availability was reduced by 10%–60%; this was found for all the tested fertilizer types except MU fertilizer, where the net cumulative soil NO3− and NO2− doubled. Nitrous oxide (N2O) emissions from urea fertilization were reduced by 40% with UI, 50% with NI and 66% with NI + UI. Interestingly, after 28 d, the composition of soil microbial communities was distinctly different, due to NI application. Specifically, NI application dramatically reduced the abundance of ammonia‐oxidizing and denitrifying bacterial functional groups. NI was effective in reducing N2O emissions in this calcareous soil; however, NH3 emissions were remarkably enhanced. These findings have important implications for the large‐scale adoption of inhibitor technologies in Mediterranean agroecosystems and for the reduction of greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Ammonia loss following nitrogen fertilization can degrade air quality and impact human health, whereas nitrous oxide (N2O) can contribute to global warming and climate change. Mitigation practices that target only one N‐loss pathway can lead to pollution swamping; hence, practices targeting both N‐losses are required. A 3‐year field study examined fertilizer N‐placement (broadcast urea, single‐slot injection of urea ammonium nitrate [UAN], double‐slot UAN injection) and N‐metabolization inhibitors (with/without urease and nitrification inhibitors) impacts on NH3 and N2O losses and corn yields. Ammonia volatilization was reduced (p < 0.05) by 26% with single‐slot UAN injection (10.6 kg N ha−1) and by 63% with double‐slot UAN injection (5.32 kg N ha−1) compared to broadcast urea (14.3 kg N ha−1). Dual urease and nitrification inhibitors reduced NH3 volatilization (0.84–3.86 kg N ha−1) by 57%–92% compared to no inhibitors (5.32–14.3 kg N ha−1). When no inhibitors were applied, N2O emissions from slot injection (6.43–7.62 kg N ha−1) were 2.6–3.1 times greater than from broadcast urea (2.43 kg N ha−1). Dual inhibitors reduced N2O emissions by 43% from 6.43 to 3.66 kg N ha−1 with double‐slot injection. Double‐slot UAN injection increased corn grain yields (9.73 t ha−1) by 12%–13% compared to single‐slot UAN injection (8.71 t ha−1) and broadcast urea (8.6 t ha−1). Double‐slot UAN injection effectively decreased NH3 losses and increased corn grain yields, but dual N inhibitors were required to also reduce N2O. Hence, combined productivity and environmental benefits were accrued only when fertilizer containing urease and nitrification inhibitors was combined with double‐slot injection. Core Ideas: Single‐slot and double‐slot UAN injection reduced NH3 loss by 26% and 63%, respectively, compared to broadcast urea.Dual inhibitors with broadcast urea or UAN injection reduced NH3 losses by 57%–92% compared to no inhibitors.Dual inhibitors reduced N2O emissions by 18% with single‐slot injection and by 43% with double‐slot injection.Double‐slot injection increased corn grain yields by 12%–13% compared to broadcast urea and single‐slot injection.Double‐slot injection with dual inhibitors increased yields and resulted in dramatic decreases in NH3 and N2O. [ABSTRACT FROM AUTHOR]

The decline in global plant diversity has raised concerns about its implications for carbon fixation and global greenhouse gas emissions (GGE), including carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4). Therefore, we conducted a comprehensive meta‐analysis of 2103 paired observations, examining GGE, soil organic carbon (SOC) and plant carbon in plant mixtures and monocultures. Our findings indicate that plant mixtures decrease soil N2O emissions by 21.4% compared to monocultures. No significant differences occurred between mixtures and monocultures for soil CO2 emissions, CH4 emissions or CH4 uptake. Plant mixtures exhibit higher SOC and plant carbon storage than monocultures. After 10 years of vegetation development, a 40% reduction in species richness decreases SOC content and plant carbon storage by 12.3% and 58.7% respectively. These findings offer insights into the intricate connections between plant diversity, soil and plant carbon storage and GGE—a critical but previously unexamined aspect of biodiversity–ecosystem functioning. [ABSTRACT FROM AUTHOR]

Background: The factors underlying the topography of nitrous oxide (N2O)‐induced neurological complications are unknown. Methods: We included all consecutive patients admitted to the university hospital of Marseille for N2O‐induced neurological complications in a prospective observational study. Patients underwent neurological examination, spinal cord magnetic resonance imaging, and nerve conduction studies within the first 4 weeks after admission. Results: In total, 61 patients were included: 45% with myeloneuropathy, 34% with isolated myelopathy, and 21% with isolated neuropathy. On multivariable analysis, the odds of myelopathy were associated with the amount of weekly N2O consumption (~600 g cylinder per week, odds ratio [OR] = 1.11, 95% confidence interval [CI] = 1.001–1.24). The extent of the myelopathy (number of vertebral segments) was correlated with the number of ~600‐g cylinders consumed weekly (ρ = 0.40, p < 0.005). The odds of neuropathy were associated with the duration of consumption (per month; OR = 1.29, 95% CI = 1.05–1.58). Mean lower‐limb motor nerve amplitude was correlated with the duration of consumption (in months; ρ = −0.34, p < 0.05). Conclusions: The odds of myelopathy increased with the amount of N2O consumption, and the odds of neuropathy increased with the duration of N2O exposure, which suggests distinct pathophysiological mechanisms underlying these two neurological complications. [ABSTRACT FROM AUTHOR]

Permeable sediments, which make up almost half of the continental shelf worldwide, are potential sources of the important greenhouse gas N2O from coastal regions. Yet, the extent to which interactions between these sediments and anthropogenic pollution produce N2O is still unknown. Here we use laboratory experiments and modeling to explore the factors controlling N2O production at a eutrophic site in a temperate shallow marine embayment (Port Phillip Bay, Australia). Our results show that denitrification is the main source of N2O production within permeable sediments, but the extent to which N2O is actually released is determined by the rate of seawater exchange with the sediment bed (which governs solute residence time within the bed). In wave‐dominated coastal areas, shallower water with more intense waves (wave height > 1 m) release the most N2O, with up to 0.5% of dissolved inorganic nitrogen pumped into biologically active eutrophic sediment being released as N2O. Our results suggest rates of N2O production in coastal permeable sediments are generally low compared to other environments. Plain Language Summary: Permeable sands cover almost half of the coastal continental shelf around the world. The permeability of sand sediments, means water can flow through these sediments in complex patterns driven by waves and currents. This flow through the sediment can control nitrous oxide and methane production which are poorly understood. This is particularly important in regions impacted by nitrogen pollution where production of these greenhouse gases can be high. Here we combine experiments and modeling to explore the factors controlling N2O production at a sandy site impacted by nitrogen pollution (Port Phillip Bay, Australia). Our results show the rate of nitrous oxide release to the water column is governed by the rate of seawater exchange with the bed. Shallower water with more intense waves (wave height exceeding 1 m) releases the most N2O, with up to 0.5% of dissolved nitrogen pumped into the sediment being released as N2O. Overall, these results suggest permeable sediments have relatively low rates of nitrous oxide release most of the time. Key Points: Coastal hydrodynamics impose an important boundary condition on the production of N2O in permeable sedimentsLess than 0.5% of seawater dissolved inorganic nitrogen is converted to N2O due to forcing imposed by passing surface gravity wavesPermeable sediments are a relatively minor source of N2O emission in coastal waters of Port Phillip Bay [ABSTRACT FROM AUTHOR]

A low‐valent GaI complex with the superbulky β‐diketiminate ligand DIPePBDI (HC[C(Me)N−DIPeP]2, DIPeP=2,6‐C(H)Et2‐phenyl)) was obtained by reduction of (DIPePBDI)GaI2 (1) with KC8 in toluene. Considering that (BDI)GaI and analogue (BDI)AlI complexes are prone to decomposition and can generally only be obtained in low yields (20–40 %), the quantitative formation of (DIPePBDI)GaI (2) is remarkable and no doubt related to its excellent thermal stability even in refluxing toluene. Although the low‐valent metal center in 2 is sterically protected by the superbulky DIPePBDI ligand, it is readily oxidized by N2O to give intermediate (DIPePBDI)Ga=O which readily decomposed by abstracting a proton from the backbone Me‐substituent. Reaction with trimethylsilyl azide gave an intermediate imido complex (DIPePBDI)Ga=N(SiMe3)2 which reacted with a second equivalent of Me3SiN3 to a mixture of an azide/amido complex (DIPePBDI)GaN3[N(SiMe3)2] (4) and a tetrazagallole complex (DIPePBDI)Ga[N4(SiMe3)2] (5) in a 1 : 2 ratio. Whereas the azide/amido complex 4 could be structurally characterised, the tetraazagallole complex 5 was identified by NMR spectroscopy. DFT calculations on (DIPePBDI)GaI (2) and its reaction products complement this study. [ABSTRACT FROM AUTHOR]

Background and Aim: Recreational use of nitrous oxide (N2O) has been associated with the development of severe nitrous oxide‐induced neuropathy (N2On). Follow‐up of these patients poses challenges, and their clinical progression remains largely unknown. The identification of prognostic factors is made difficult by the lack of standardized longitudinal assessments in most studies. The objective was to document the course of neuropathy through systematic follow‐up assessments in N2On patients to identify prognostic factors for persistent disability after 6 months. Methods: We gathered demographic, clinical, biological, and electrophysiological data from N2On patients hospitalized in the Referral center in Marseille, both at baseline and during a standardized follow‐up assessment at 6 months. Results: We retrospectively included 26 N2On patients (mean age 22.6 ± 4.4). Significant improvements were observed in all main clinical scores including Rankin, ONLS, and MRC testing (p <.01). Electrophysiological studies (EDX) revealed a predominantly motor neuropathy with marked reduction in CMAP in the lower limbs at baseline, and no significant improvement in motor parameters (p =.543). Rankin score at 6 months correlated with the initial weekly N2O consumption (r =.43, p =.03) and the CMAP sum score in the lower limbs at the first EDX (r = −.47, p =.02). Patients with and without myelitis showed similar Rankin and ONLS score after 6 months. Interpretation: The clinical course generally improved favorably at 6 months with notable amelioration in the primary disability scores, sensory deficits, and ataxia. However, distal motor impairment associated with peripheral neuropathy persisted, with distal axonal loss emerging as the main prognostic factor for long‐term disability in these young patients. [ABSTRACT FROM AUTHOR]

We describe the genome of an Eremiobacterota population from tundra soil that contains the minimal set of nif genes needed to fix atmospheric N2. This putative diazotroph population, which we name Candidatus Lamibacter sapmiensis, links for the first time Eremiobacterota and N2 fixation. The integrity of the genome and its nif genes are well supported by both environmental and taxonomic signals. Ca. Lamibacter sapmiensis contains three nifH homologues and the complementary set of nifDKENB genes that are needed to assemble a functional nitrogenase. The putative diazotrophic role of Ca. Lamibacter sapmiensis is supported by the presence of genes that regulate N2 fixation and other genes involved in downstream processes such as ammonia assimilation. Similar to other Eremiobacterota, Ca. Lamibacter sapmiensis encodes the potential for atmospheric chemosynthesis via CO2 fixation coupled with H2 and CO oxidation. Interestingly, the presence of a N2O reductase indicates that this population could play a role as a N2O sink in tundra soils. Due to the lack of activity data, it remains uncertain if Ca. Lamibacter sapmiensis is able to assemble a functional nitrogenase and participate in N2 fixation. Confirmation of this ability would be a testament to the great metabolic versatility of Eremiobacterota, which appears to underlie their ecological success in cold and oligotrophic environments. [ABSTRACT FROM AUTHOR]

Headwater streams play a large role in aquatic greenhouse gas emissions. Carbon dioxide (CO2) and dissolved oxygen in streams often undergo changes through diel cycles. However, methane (CH4) and nitrous oxide (N2O) have unknown diel dynamics. Here, we reveal consistent patterns in CO2, CH4, and N2O over diel cycles and during flood events using high‐frequency continuous observations in a subtropical headwater stream. Diel cycles were most pronounced during baseflow. Increased nighttime discharge due to higher groundwater inputs enhanced gas transfer velocities and concentrations. Overall nocturnal emissions were 31%, 68%, and 32% greater than daytime for CO2, CH4, and N2O, respectively. Floods dampened diel signals. If both flood events and diel patterns are neglected, estimates of greenhouse gas emissions from headwaters may be greatly underestimated. Overall, CH4 and N2O emissions from headwater streams may be underestimated by ~ 20–40% due to a lack of observations during nighttime, floods, and in warmer climates. [ABSTRACT FROM AUTHOR]

Widespread adoption of regenerative agriculture practices is an integral part of the US plan to achieve net‐zero greenhouse gas emissions by 2050. National incentives have particularly increased for the adoption of cover crops (CCs), which have presumably large carbon (C) sequestration potential. However, assessments of national CC climate benefits have not fully considered regional variability, changing C sequestration rates over time, and potential N2O trade‐offs. Using the DayCent soil biogeochemical model and current national survey data, we estimate CC climate change mitigation potential to be 39.0 ± 24.1 Mt CO2e year−1, which is 45%–65% lower than previous estimates, with large uncertainty attributed to N2O impacts. Three‐fourths of this climate change mitigation potential is concentrated in the North Central, Southern Great Plains and Lower Mississippi regions. Public investment should be focused in these regions to maximize CC climate benefits, but the national contribution of CC to emissions targets may be lower than previously anticipated. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a potent greenhouse gas and a strong ozone‐depleting substance. Ocean is an important natural source of atmospheric N2O, which has attracted increasing attention recently as to understand the biogeochemical cycles of nitrogen in marine systems. Nitrification is one of the major N2O production pathways during which N2O is produced as a side product and hydroxylamine (NH2OH) is produced as an obligate intermediate. However, few studies have reported the NH2OH variability in natural seawater and its relationship between N2O remains ambiguous. In summer 2022, spatial distribution and influencing factors of N2O and NH2OH in the northern South China Sea (SCS) were investigated. Dissolved N2O varied from 5.79 to 34.80 nmol L−1 in water column and generally increased with water depth above 800 m. N2O was correlated with dissolved oxygen and nitrate, inferring that N2O was mainly produced via nitrification. NH2OH varied from below detection limit to 3.91 nmol L−1. The adoption of multiple standard additions can largely reduce the bias in NH2OH measurement. Structural equation modeling showed that NH2OH has a potential effect favoring excessive N2O. Surface N2O saturation ranged between 102% and 278%, indicating that the northern SCS was a net source of atmospheric N2O in summer. Plain Language Summary: Hydroxylamine (NH2OH) is an important intermediate product and a precursor of N2O in nitrification, but debates persist regarding NH2OH variability and N2O production. We investigated the distribution, variation and regulatory mechanism of dissolved N2O and NH2OH in the northern SCS, analyzed their potential relationship during nitrification, and provided a new perspective for the greenhouse gas research in the future. We have also proved that a shift in recovery factor can cause large error and thus necessitate the introduction of multiple calibration curves in NH2OH measurement. We have found a weak but positive correlation between NH2OH and ∆N2O, indicating the potential contribution of NH2OH to N2O production during ammonia oxidation. Key Points: A shift in recovery factor from different depths necessitates the introduction of multiple calibration curves in NH2OH measurementA weak correlation between NH2OH and excessive N2O indicated the potential NH2OH oxidation to N2O production via nitrificationThe northern South China Sea (SCS) is a net source of atmospheric N2O [ABSTRACT FROM AUTHOR]

Knowledge of the ecological mechanisms governing N2O cycling in marine sediments lags that of water columns and terrestrial soils, leaving much to be learned about how microbial community dynamics relate to variability in sediment N2O fluxes. The present study assesses these relationships across two distinct environments by focusing on the community structure and activity of N2O reducing microorganisms. The N2O sink capacity of minimally impacted Bermudian mangrove sediments was first estimated using trace‐level microsensors and profile interpretation modeling. Molecular data obtained from these sediments were then compared with those from the Northeast Subarctic Pacific (NESAP) outer continental margin, where previous measurements suggest considerable N2O effluxes. Net N2O uptake was observed for mangrove sediments under ambient and elevated dissolved inorganic nitrogen concentrations (−0.22 ± 0.15 to −0.30 ± 0.26 μmol N2O m−2 d−1), suggesting the microbial potential for N2O consumption exceeded the potential for production via combined nitrification and denitrification. Targeting of bacterial nosZI and nosII gene clusters for quantification using qPCR indicated higher abundance and expression of non‐denitrifier nosZII genes in mangrove sediments demonstrating net N2O uptake. Net N2O production in NESAP sediments was associated with higher abundance and expression of nosZI genes associated with canonical denitrifiers. These results suggest that organisms possessing atypical nosZII genes may act as important N2O scavengers in low‐nitrogen coastal sediments. Plain Language Summary: Nitrous oxide (N2O) is potent greenhouse gas that contributes to ozone depletion in the stratosphere, and atmospheric concentrations a rising as a result of human activities. The production and consumption of N2O in the environment is mediated by microorganisms, and the balance between the two processes is governed by environmental factors such as concentrations of dissolved oxygen and fixed nitrogen. However, little is known about the relationships between microbial community dynamics and rates of N2O production and consumption, especially in sediment environments. We found that minimally impacted mangrove sediments of Bermuda are net consumers of N2O, and continue to consume N2O following short term nitrogen enrichments. This N2O sink capacity was linked to higher abundances and activity levels of atypical N2O reductase genes when compared to sediments that produce N2O. These genes facilitate the consumption of N2O, and frequently occur in microbes that do not have the capacity to produce N2O via denitrification. This study provides further insight into the role of microbial community structure in regulating sediment N2O cycling, and argues for targeted conservation and restoration of coastal systems where sediment environments are in close proximity to the atmosphere. Key Points: The N2O sink capacity of minimally impacted Bermudian mangrove sediments is resilient against modest, short‐term nutrient enrichmentHigh prevalence of non‐denitrifier nosZII genes in mangrove sediments implies a crucial role as N2O scavengers in low‐nitrogen systemsNet N2O production in NESAP sediments is associated with higher expression of nosZI genes associated with canonical denitrifiers [ABSTRACT FROM AUTHOR]

This study investigates the abnormal reliability degradations observed under positive bias temperature stress (PBTS) in a‐IGZO TFTs treated by N2O plasma treatment and proposes a solution according to the presence of N2O plasma in the subsequent postprocess. In mass manufacture of a‐IGZO TFTs, N2O plasma is usually completely removed during the subsequent post‐plasma treatment processes. However, we maintained the presence of N2O plasma and analyzed its effect on device performance and reliability. While a‐IGZO TFTs fabricated with N2O plasmaremoved during the post‐process exhibited non‐ideal negative Vth shifts under PBTS, the devices fabricated with N2O plasma present during post‐processing showed superior electrical performance and reliability, avoiding the non‐ideal Vth shift phenomenon. This study shows that maintaining N2O plasma during the post‐process is an effective method for ensuring device reliability as well as improved performance of a‐IGZO TFTs in mass production. [ABSTRACT FROM AUTHOR]

To examine nurses' and physicians' assessments of pain in children with cancer, and to identify the methods in use to diagnose, evaluate, and treat pain. In addition, to examine whether/how the healthcare professionals' assessment and management of pain has changed compared to 1995 and identify the needs for training. The study has a descriptive and comparative design. 363 nurses and physicians working with children with cancer in Sweden were invited to participate in April 2017. Participants answered an updated version of a questionnaire used in 1995 by Ljungman et al. focusing on the healthcare professionals' experience of pain among their patients, their pain treatment strategies, and need for training. 120 nurses and 65 physicians participated. Fifty percent of nurses and 55% of physicians answered that moderate‐to‐severe pain was experienced often or very often by children with cancer. Methods recommended in international guidelines to diagnose, evaluate, and treat pain were generally followed. Compared with findings from 1995 by Ljungman et al., nurses, and physicians assessed that moderate‐to‐severe pain was seen more often. The greatest need for training was reported for pharmacology, different routes for administration of opioids, treatment with nitrous oxide, and nonpharmacological interventions. Nurses and physicians assessed that moderate‐to‐severe pain is often present in children with cancer. More time to treat pain in the department and training in certain areas seem to be needed to improve pain management. [ABSTRACT FROM AUTHOR]

CO2 reduction is appealing for the long‐term production of high‐value fuels and chemicals. Herein, using density functional theory (DFT) based calculations, we study the CO2 reduction pathway to formic acid using aluminum hydride and phosphine derivatives. Our primary focus is on aluminum hydride derivatives, aimed at improving the efficiency of the CO2 reduction process. Substituents with σ‐donating properties at the aluminum center are discovered to lower the activation barriers. We demonstrate how di‐tert‐butylphosphine oxide (LB‐O)/di‐tert‐butylphosphine sulfide (LB‐S)/di‐tert‐butylphosphanimine (LB‐N) work together with aluminum hydride to facilitate CO2 reduction process and generate in‐situ frustrated Lewis pairs (FLPs), such as FLP‐O, FLP‐S, and FLP‐N. The activation strain model (ASM) analysis reveals the significance of strain energy in determining activation barriers. EDA‐NOCV and PIO analyses elucidate the orbital interactions at the corresponding transition states. Furthermore, the study delves into the activation of various small molecules, such as dihydrogen, acetylene, ethylene, carbon dioxide, nitrous oxide, and acetonitrile, using those in‐situ generated FLPs. The study highlights the low activation barriers and emphasizes the potential for small molecule activation in this context. [ABSTRACT FROM AUTHOR]

Tunnel oxide passivated contact (TOPCon) silicon solar cells have been developed and transferred into industrial mass production, which is beneficial to the future production of perovskite/silicon tandem solar cells (TSCs) in a large scale. However, the doped polycrystalline silicon (poly‐Si) layer in the poly‐Si‐based passivating contact structure yields a profound optical loss from reflection and parasitic absorption, which obstacles the efficiency promotion of TSCs. In this work, the optical property of poly‐Si is improved by in‐situ oxygen incorporation using plasma enhanced chemical vapor deposition (PECVD) with nitrous oxide (N2O) as the oxygen source. The p‐type oxygen‐incorporated poly‐Si (poly‐SiOx) shows a reduced refractive index and extinction coefficient over 700–1200 nm wavelength, leading to a reduced reflection, a lower parasitic absorption and a higher transmission. After applying an optimized p‐type oxygen‐incorporated poly‐Si in the front‐side poly‐Si passivating contact structure of c‐Si bottom cell, the short‐circuit current density and efficiency of a perovskite/c‐Si tandem cell increases by ≈0.32 mA cm−2 and ≈0.8%, respectively, leading to 25.12% tandem cell efficiency. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a greenhouse gas produced in the manufacture of 6,6‐nylon and nitric acid. While an attractive oxidant that releases only N2 as a by‐product, the kinetic stability of N2O typically requires high temperatures and pressures for activation. This work describes initial kinetics of oxygen transfer in the epoxidation of cholesteryl acetate with N2O catalysed by D4‐Ru(VI)(por)(O)2 complexes in efforts to provide a better mechanistic understanding of this chemistry. Insights include a need for low concentrations of the alkene to avoid competitive binding to the metal, possible saturation behavior at high N2O pressures, transfer of only one oxygen of RuVI(O)2 to substrate and a possible catalyst turnover involving disproportionation of RuIV(O) and RuIV(O)(N2O) to active RuVI(O)2, RuIV(O) and N2. These insights will be used in future designs of improved catalysts and reaction protocols that may operate efficiently at low pressures of N2O and ambident temperature. [ABSTRACT FROM AUTHOR]

Due largely to the high stability and the potential ozone‐depleting, the transformation of greenhouse gas nitrous oxide has gained much attentions. In present paper, a new insight into the deoxygenation of nitrous oxide with silane was reported by using oriented external electric field (OEEF) as a catalytic strategy. When the OEEF was employed, the reaction barrier of deoxygenation was marvelously decreased as it was oriented along the positive NO/OSi bond‐axis. Especially the field strength is 300 × 10−4 a.u., the differences are up to 22.4/18.3 kcal mol−1 as compared with that of nonfield. In addition, once the H atom in SiH4 was replaced by methyl, two reaction modes were obtained, in which the deoxygenation process was easier when the N2O captured the H atom attached to the Si atom, not attached to the C atom. Further, the solvent effects of deoxygenation reaction were also considered, but with a weak influence were obtained. [ABSTRACT FROM AUTHOR]

Microbial communities that reduce nitrous oxide (N2O) are divided into two clades, nosZI and nosZII. These clades significantly differ in their ecological niches and their implications for N2O emissions in terrestrial environments. However, our understanding of N2O reducers in aquatic systems is currently limited. This study investigated the relative abundance and diversity of nosZI‐ and nosZII‐type N2O reducers in rivers and their impact on N2O emissions. Our findings revealed that stream sediments possess a high capacity for N2O reduction, surpassing N2O production under high N2O/NO3‐ ratio conditions. This study, along with others in freshwater systems, demonstrated that nosZI marginally dominates more often in rivers. While microbes containing either nosZI and nosZII were crucial in reducing N2O emissions, the net contribution of nosZII‐containing microbes was more significant. This can be attributed to the nir gene co‐occurring more frequently with the nosZI gene than with the nosZII gene. The diversity within each clade also played a role, with nosZII species being more likely to function as N2O sinks in streams with higher N2O concentrations. Overall, our findings provide a foundation for a better understanding of the biogeography of stream N2O reducers and their effects on N2O emissions. [ABSTRACT FROM AUTHOR]

Straw‐decomposing microbial inoculants (MIs) have been increasingly applied to straw‐amended soils. However, the interactive effects and underlying microbial mechanisms of straw and decomposing MIs on nitrous oxide (N2O) emissions remain unclear. Here, a pot experiment with an Aquic Inceptisol was conducted to determine soil N2O emissions and the abundance and composition of microbial functional genes under six amendments: wheat straw (W), Bacillus subtilis MI (B), Streptomyces rochei MI (S), a combination of straw and B. subtilis MI (WB), a combination of straw and S. rochei MI (WS), and a control without wheat straw or MI (C). Compared with the control, the amendments of straw, decomposing MIs, and their combinations decreased soil N2O emissions by 43%, 22–30%, and 46–60%, respectively. Mechanistically, the positive relationship between ammonia‐oxidizing bacteria (AOB) and soil potential nitrification rate (PNR), along with decreased AOB abundance (−36%) following straw and decomposing MI amendments, further suggested that AOB predominated soil nitrification and was responsible for the suppressed nitrification. In addition, straw amendment increased nirK gene abundance (by 48%) and potential denitrification rate (by 11%), while the increase in nosZI gene abundance (+25%) involved in N2O consumption contributed to the decrease in N2O emissions. Overall, the additive effect of straw and decomposing MIs on soil N2O emissions was associated with two amendment‐induced changes in the abundance and composition of AOB and straw‐stimulated the abundance of the nosZI gene. Our results revealed the potential for mitigating N2O emissions following the amendments of straw and MI by influencing soil N2O‐related microbial groups. [ABSTRACT FROM AUTHOR]

Soil management strategies involving the application of organic matter (OM) inputs (crop residues, green and livestock manure, slurry, digestate, compost and biochar) can increase soil carbon storage but simultaneously lead to an increase in non‐CO2 greenhouse gas (GHG) emissions such as N2O. Although multiple meta‐analyses have been conducted on the topic of OM input impacts on GHG, none has focused specifically on European arable soils. This study plugs this gap and can assist policymakers in steering European agriculture in a more sustainable direction. The objective of this meta‐analysis was to quantify how OM inputs of different nature and quality, but also the application strategy, can mitigate soil N2O emissions in different pedoclimatic conditions in Europe. We quantitatively synthesised the results of over 50 field experiments conducted in 15 European countries. Diverse arable crops, mainly cereals, were cultivated in monoculture or in crop rotations on mineral soils. Cumulative N2O emissions were monitored during periods of 30–1070 days in treatments, which received OM inputs, alone or in combination with mineral N fertiliser; and in controls fertilised with mineral N. The overall effect of OM inputs had a slight tendency to reduce N2O emissions by 10% (n = 53). With the increasing carbon‐to‐nitrogen ratio of the OM inputs, this mitigation effect became more pronounced. In particular, compost and biochar significantly reduced N2O emissions by 25% (n = 6) and 33% (n = 8) respectively. However, their effect strongly depended on pedoclimatic characteristics. Regarding the other types of OM inputs studied, a slight N2O emission reduction can be achieved by their application alone, without mineral N fertiliser (by 16%, n = 17). In contrast, their co‐application with mineral N fertiliser elevated emissions to some extent compared to the control (by 14%, n = 22). We conclude that amongst the seven OM inputs studied, the application of compost and biochar are the most promising soil management practices, clearly demonstrating N2O emission reduction compared to mineral N fertiliser. In contrast, other OM inputs had a small tendency to mitigate N2O emissions only when applied without mineral N fertiliser. [ABSTRACT FROM AUTHOR]

Sandy loamy soils are widely distributed in fluvial floodplains and experience flooding events frequently, resulting in a large amount of nitrous oxide (N2O) emissions. This case is more serious when the soil use is changed to paddies. It is of great significance to figure out the N2O consumption and its influencing factors in sandy loamy paddy soils to mitigate N2O emissions. In this study, three sandy loamy paddy soils (0–5 cm) originated from lake deposits were selected (S1, S2, and S3) as objectives. A certain concentration of exogenous N2O was added at the bottom of the flooded soil column to monitor the dynamics of N2O and nitrogen (N2) on the soil surface. Total N2O consumption, N2O uptake, and N2 production were quantified, and the abundance of nitrous oxide reductase genes (nosZI, and nosZII) and other soil properties (ammonium‐nitrogen, nitrate‐nitrogen, and dissolved organic carbon [DOC] content) were analyzed. The results showed that the sandy loamy paddy soil column with a depth of 0–5 cm could intercept more than 95% of the exogenous N2O under the flooded anaerobic condition, indicating that the three sandy loamy paddy soils all had extremely strong N2O consumption capacities. And the increment of N2 accounted for 68.73%–76.09% of the total N2O consumption, which had a stronger relationship with the increase of nosZI gene abundance than nosZII gene. In addition, the total N2O consumption and N2 increment of S1 and S3 soils were significantly higher than those of S2 soil. This difference was mainly related to soil organic matter content, total nitrogen content, DOC consumption, and the increase of nosZI gene abundance (p < 0.05). The strong N2O consumption potential of sandy loamy soils can provide feasible solutions for regulating N2O emissions in a wide range of similar environments in fluvial floodplains. Core Ideas: Over 95% of N2O in 5‐cm‐soil depth was consumed by flooded sandy loamy paddy soils.The microbial reduction of N2O to N2 is the main pathway of N2O consumption.N2O consumption and N2 increment dominated by nosZI‐containing microorganisms. [ABSTRACT FROM AUTHOR]

Incorporating large amounts of woody biomass into soil, such as in whole orchard recycling (WOR), can promote carbon sequestration, nutrient recycling, and ecosystem health in agricultural fields. Yet uncertainty regarding the effects of WOR on soil carbon (C) and nitrogen (N) dynamics influences management decisions. The objective of this research was to evaluate the effects of woodchip (WC) size and interaction with N fertilization on carbon dioxide (CO2) and nitrous oxide (N2O) emissions. An 8‐month incubation experiment incorporating WC (4% w/w, equivalent to ∼40 tons per acre) in four sieved sizes (0.2–1.6, 1.6–3.2, 3.2–6.4, and 6.4–12.7 mm) with and without N applications was conducted. All treatments with WC showed that CO2 emission peaked within the first week, then decreased drastically afterward. The CO2 peak delayed as the peak value decreased (WC size increased). The finest WC (<1.6 mm) yielded the lowest total CO2 emissions and resulted in the greatest increase in soil C at the end of incubation. Nitrogen application reduced total CO2 emissions by 1% in the smallest WC size and by 8%–9% for those larger than 1.6 mm. The N2O emissions spiked following each fertilizer application with lowest total emissions from the smallest WC size, suggesting substantial N immobilization. The results imply that larger WC sizes can delay C mineralization and reduce initial N immobilization risks, but the smallest WC size may have stabilized and increased soil organic carbon. This research increased our understanding on WC mineralization that can be used in WOR management. Core Ideas: There is a significant interaction between woodchip size and N application on both CO2 and N2O emissions.Smallest woodchip size gave highest initial CO2 emissions, but lowest total loss while increasing soil organic carbon.N application with woodchips resulted in significantly lower CO2 emissions.Woodchip size showed different impact on peak N2O emissions with time but no impact on total loss and soil N.Larger woodchip sizes showed delay in C mineralization, minimizing the initial N immobilization risk. [ABSTRACT FROM AUTHOR]

A stable dialkylgermanone was generated by mixing a solid of the corresponding dialkylgermylene and gaseous N2O. While the dialkylgermanone is marginally persistent in solution and gradually converts to its head‐to‐tail dimer at room temperature, the addition of THF to the dialkylgermanone provided an isolable THF‐coordinated dialkylgermanone. The THF‐coordinated dialkylgermanone reacts with H2O, THF, and B(C6F5)3 similar to the corresponding base‐free two‐coordinate dialkylsilanone. The dialkylgermanone undergoes deoxygenation in the presence of triphenylphosphine to provide the corresponding germylene and olefination upon treatment with phosphaylide Ph3PCHPh to afford the corresponding Ge=C bond compound (germa‐Wittig reaction). [ABSTRACT FROM AUTHOR]

Plant metabolites significantly affect soil nitrogen (N) cycling, but their influence on nitrous oxide (N2O) emissions has not been quantitatively analyzed on a global scale. We conduct a comprehensive meta‐analysis of 173 observations from 42 articles to evaluate global patterns of and principal factors controlling N2O emissions in the presence of root exudates and extracts. Overall, plant metabolites promoted soil N2O emissions by about 10%. However, the effects of plant metabolites on N2O emissions from soils varied with experimental conditions and properties of both metabolites and soils. Primary metabolites, such as sugars, amino acids, and organic acids, strongly stimulated soil N2O emissions, by an average of 79%, while secondary metabolites, such as phenolics, terpenoids, and flavonoids, often characterized as both biological nitrification inhibitors (BNIs) and biological denitrification inhibitors (BDIs), reduced soil N2O emissions by an average of 41%. The emission mitigation effects of BNIs/BDIs were closely associated with soil texture and pH, increasing with increasing soil clay content and soil pH on acidic and neutral soils, and with decreasing soil pH on alkaline soils. We furthermore present soil incubation experiments that show that three secondary metabolite types act as BNIs to reduce N2O emissions by 32%–45%, while three primary metabolite classes possess a stimulatory effect of 56%–63%, confirming the results of the meta‐analysis. Our results highlight the potential role and application range of specific secondary metabolites in biomitigation of global N2O emissions and provide new biological parameters for N2O emission models that should help improve the accuracy of model predictions. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) emissions from livestock manure contribute significantly to the growth of atmospheric N2O, a powerful greenhouse gas and dominant ozone‐depleting substance. Here, we estimate global N2O emissions from livestock manure during 1890–2020 using the tier 2 approach of the 2019 Refinement to the 2006 IPCC Guidelines. Global N2O emissions from livestock manure increased by ~350% from 451 [368–556] Gg N year−1 in 1890 to 2042 [1677–2514] Gg N year−1 in 2020. These emissions contributed ~30% to the global anthropogenic N2O emissions in the decade 2010–2019. Cattle contributed the most (60%) to the increase, followed by poultry (19%), pigs (15%), and sheep and goats (6%). Regionally, South Asia, Africa, and Latin America dominated the growth in global emissions since the 1990s. Nationally, the largest emissions were found in India (329 Gg N year−1), followed by China (267 Gg N year−1), the United States (163 Gg N year−1), Brazil (129 Gg N year−1) and Pakistan (102 Gg N year−1) in the 2010s. We found a substantial impact of livestock productivity, specifically animal body weight and milk yield, on the emission trends. Furthermore, a large spread existed among different methodologies in estimates of global N2O emission from livestock manure, with our results 20%–25% lower than those based on the 2006 IPCC Guidelines. This study highlights the need for robust time‐variant model parameterization and continuous improvement of emissions factors to enhance the precision of emission inventories. Additionally, urgent mitigation is required, as all available inventories indicate a rapid increase in global N2O emissions from livestock manure in recent decades. [ABSTRACT FROM AUTHOR]

The slowly establishing salt‐tolerant perennial grasses reduced nitrous oxide (N2O‐N) emissions from saline/sodic soil compared to barren areas. Other salt‐tolerant species may accelerate vegetative establishment and reduce N2O‐N emissions. In a greenhouse study, barley (Hordeum vulgare L.), Florida broadleaf mustard (Brassica juncea L.), and Kernza intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] were grown for 63 days to compare shoot biomass and chemical composition, N2O‐N emissions, and the soil microbiome between saline/sodic and productive (non‐salt impacted) soils. Emissions were measured six times daily from 1 to 22 and 42 to 63 days after planting (DAP). Shoot and soil microbial biomass and communities were quantified 63 DAP. N2O‐N emissions were 87% greater from no‐plant saline/sodic than no‐plant productive soil (p < 0.05). N2O‐N emissions were reduced from planted treatments soon after plant emergence. N2O‐N emissions reductions from saline/sodic soil during the first 22 DAP were 84%, 76%, and 61% for barley, mustard, and Kernza, respectively. Barley had the greatest shoot biomass and impact on the soil microbial community, increasing the fungi to bacteria ratio from 0.063 to 0.094 in the productive soil and from 0.056 to 0.076 in the saline/sodic soil. Plant‐induced changes to the soil microbiome, and decreased soil inorganic N and water, contributed to N2O‐N emission reductions. Archived field samples from grass‐established saline/sodic soil areas had a fourfold increase in nos‐Z gene copy number compared to no‐plant controls, which may, in part, explain decreased N2O‐N emissions. Establishing these vigorous species may aid in restoring multiple ecosystem services to saline/sodic areas. Core Ideas: Barren Northern Great Plains saline/sodic soils provide few ecosystem services.Barley, Florida broadleaf mustard, and Kernza wheatgrass reduced N2O‐N emissions from saline/sodic soil soon after emergence.N2O‐N emission reductions were attributed to plants decreasing soil water and N and changing the soil microbiome. [ABSTRACT FROM AUTHOR]

Within oxygen minimum zones, anaerobic processes transform bioavailable nitrogen (N) into the gases dinitrogen (N2) and nitrous oxide (N2O), a potent greenhouse gas. Mesoscale eddies in these regions create heterogeneity in dissolved N tracers and O2 concentrations, influencing nonlinear N cycle reactions that depend on them. Here, we use an eddy‐resolving model of the Eastern Tropical South Pacific to show that eddies enhance N2 production by between 43% and 64% at the expense of reducing N2O production by between 94% and 104% due to both the steep increase of progressive denitrification steps at vanishing oxygen, and the more effective inhibition of N2O consumption relative to production. Our findings reveal the critical role of eddies in shaping the N cycle of oxygen minimum zones, which is not currently represented by coarse models used for climate studies. Plain Language Summary: Nitrogen limits photosynthesis over large swaths of the ocean. Oxygen minimum zones are important oceanic environments where the presence of low O2 concentrations allow anaerobic microbial communities to transform bioavailable forms of nitrogen into the gases dinitrogen (N2) and nitrous oxide (N2O, a powerful greenhouse gas), which together lead to nitrogen loss from the oceans. The large scale ocean circulation acts to maintain these oxygen minimum zones, and the gradients in nitrogen and oxygen concentrations surrounding them. Turbulence also generates eddies and filaments which stir these gradients, promoting chemical heterogeneity. However, it is uncertain how eddies impact the nitrogen transformation rates dependent on nitrogen and oxygen tracer concentrations. Using a high resolution ocean model of the Eastern Tropical South Pacific oxygen minimum zone, we explore the contributions from eddies to total N2 and N2O production. We highlight that roughly half of total N2 production is caused by the presence of eddies, while N2O production is drastically reduced or even consumed. These findings expand our understanding of the ways in which eddies alter nitrogen loss from the oceans, and challenge the ability of non‐eddy resolving models to accurately represent N2 and N2O production in a changing ocean. Key Points: A high resolution model is used to estimate the effect of mesoscale eddies on the N cycle in a major oxygen minimum zoneEddies simultaneously enhance fixed N loss and suppress nitrous oxide productionThese eddy effects result from the progressive inhibition of the denitrification steps by oxygen concentrations [ABSTRACT FROM AUTHOR]

Improving the selectivity in the oxidative coupling of methane to ethane/ethylene poses a significant challenge for commercialization. The required improvements are hampered by the uncertainties associated with the reaction mechanism due to its complexity. Herein, we report about 90 % selectivity to the target products at 11 % methane conversion over Gd2O3‐based catalysts at 700 °C using N2O as the oxidant. Sophisticated kinetic studies have suggested the nature of adsorbed oxygen species and their binding strength as key parameters for undesired methane oxidation to carbon oxides. These descriptors can be controlled by a metal oxide promoter for Gd2O3. [ABSTRACT FROM AUTHOR]

Background: Prevalence of nitrous oxide (N2O) use appears to be increasing in numerous countries worldwide, and excessive use has been associated with physical and mental problems. Because there currently is no consensus whether N2O has addictive potential, we aimed to evaluate the evidence for the presence and prevalence of DSM‐5 substance use disorder (SUD) symptoms in N2O users. Analysis: A literature search was conducted to assess the evidence for the presence of any of the 11 DSM‐5 SUD symptoms in N2O users and the prevalence experiencing those symptoms. A substantial part of the studied N2O users use more than intended (i.e. 46% to 98%) and spend a substantial amount of time using N2O. At least some of the studied N2O users experience interpersonal problems (i.e. 13% to 80%) and use N2O in risky situations, such as driving under the influence. Evidence for the other criteria is either insufficient or inconclusive. Conclusions: The literature base for the presence and prevalence of DSM‐5 substance use disorder (SUD) symptoms in nitrous oxide (N2O) users is limited and largely consists of qualitative studies and case studies, but it provides consistent evidence for the presence of at least four SUD criteria in heavy N2O users. N2O could well be addictive and should be treated as a potentially addictive substance until systematic assessments can provide evidence‐based guidance to users, healthcare professionals and legislators. [ABSTRACT FROM AUTHOR]

Objective: To compare the carbon footprint of caesarean and vaginal birth. Design: Life cycle assessment (LCA). Setting: Tertiary maternity units and home births in the UK and the Netherlands. Population: Birthing women. Methods: A cradle‐to‐grave LCA using openLCA software to model the carbon footprint of different modes of delivery in the UK and the Netherlands. Main Outcome Measures: 'Carbon footprint' (in kgCO2 equivalents [kgCO2e]). Results: Excluding analgesia, the carbon footprint of a caesarean birth in the UK was 31.21 kgCO2e, compared with 12.47 kgCO2e for vaginal birth in hospital and 7.63 kgCO2e at home. In the Netherlands the carbon footprint of a caesarean was higher (32.96 kgCO2e), but lower for vaginal birth in hospital and home (10.74 and 6.27 kgCO2e, respectively). Emissions associated with analgesia for vaginal birth ranged from 0.08 kgCO2e (with opioid analgesia) to 237.33 kgCO2e (nitrous oxide with oxygen). Differences in analgesia use resulted in a lower average carbon footprint for vaginal birth in the Netherlands than the UK (11.64 versus 193.26 kgCO2e). Conclusion: The carbon footprint of a caesarean is higher than for a vaginal birth if analgesia is excluded, but this is very sensitive to the analgesia used; use of nitrous oxide with oxygen multiplies the carbon footprint of vaginal birth 25‐fold. Alternative methods of pain relief or nitrous oxide destruction systems would lead to a substantial improvement in carbon footprint. Although clinical need and maternal choice are paramount, protocols should consider the environmental impact of different choices. [ABSTRACT FROM AUTHOR]

Rivers significantly contribute to global biogeochemical cycles; however, we have a limited understanding of how drying may influence these cycles. Drying fragments river networks, thereby influencing important ecosystem functions such as the processing of carbon and nitrogen, and associated fluxes of greenhouse gases (GHGs) both locally, and at the river network scale. Our objective was to assess, using a network‐scale approach, the lateral, longitudinal, and temporal dynamics of GHG fluxes in a river network naturally fragmented by drying. We used a closed‐loop chamber with automated analyzers to measure carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes from dry sediments, flowing waters, isolated pools, and riparian soils, along with a suite of environmental variables, over 9 months at 20 sites across a non‐perennial river network in France. Network‐scale drying had a spatial and temporal legacy effect on GHG fluxes. On average, CO2 fluxes were up to 29 times higher from perennial than non‐perennial sites under flowing conditions. At non‐perennial sites, CO2 and N2O fluxes positively covaried with time since rewetting. In addition, CO2 and N2O fluxes at perennial sites positively covaried with the percent of non‐perennial reaches upstream, indicating a spatial effect of drying. GHG fluxes from riparian soil and dry riverbed sediments had markedly different magnitudes and covariates. This research demonstrates that drying not only has a local‐scale impact but also influences GHG fluxes at the network scale, contributing valuable insights for upscaling global riverine GHG estimates. [ABSTRACT FROM AUTHOR]

Croplands that experience seasonal soil freezing and thawing have been shown to be significant sources of N2O emissions. Yet, there is a paucity of year-round N2O emission data for one of the most significant crop production regions that seasonally freeze, the Prairies. Here, we present micrometeorological N2O fluxes measured over 4 years in Saskatchewan, Canada, to evaluate the magnitude of freeze-thaw N2O emissions and investigate its driving factors. Significant thaw related emissions occurred in 2 of the 4 years and were associated with relatively higher fall nitrate levels and a more gradual soil thawing period. Overall, fall soil nitrate levels were a strong explanatory variable for the differences in non-growing season (NGS) N2O emission (r² = 0.485). Measured cumulative N2O emissions for the NGS were 123-938 g N ha-1 and were much smaller than those obtained at other cold climate sites but amounted to 52% of annual totals on average. The November to April period contributed 30% of the annual total emissions in years without major thaw events, but 70% in years with significant thaws. NGS N2O emissions were not explained by cumulative freezing degree days unlike most other cold climate sites. We propose that NGS N2O emissions are more strongly influenced by thaw dynamics during freezing-thawing conditions in dry regions, whereas freezing intensity is the dominant factor for wetter regions. Our results indicate that even for a semi-arid region freezethaw is an important source of N2O emissions and must be considered for more accurate reporting and development of mitigation strategies. [ABSTRACT FROM AUTHOR]

Shang et al. (2024) recently suggested to include nitrous oxide (N2O) emissions during the fallow period to better estimate N2O emission factors (EFs). We however highlighted several pitfalls of the proposed adjusted EFs for croplands in the specific case of dry subhumid, semiarid, and arid regions with dry fallow periods, these regions covering about 47% of the Earth's terrestrial area. [ABSTRACT FROM AUTHOR]

The article discusses the estimation of nitrous oxide (N2O) emissions during the fallow period in cropland and the adjustment of the global-scale N2O emission factor (EF) based on the Intergovernmental Panel on Climate Change (IPCC) Tier 1 method. The authors address concerns raised by Cardinael et al. regarding the extrapolation of EF defaults, the adjusted EF for countries with dry fallow periods, and the representativeness of observations. They argue that their approach is robust and that including fallow-period precipitation (FP) does not significantly improve model performance. The authors agree on the need for more observations in under-represented regions to further improve global estimates. [Extracted from the article]