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We present a man in his 30s with acute anterior myocardial infarction due to thrombotic occlusion of the left anterior descending artery and subsequent left ventricular thrombus formation after high-dose recreational use of nitrous oxide (N2O). Initial questioning for use of illicit substances was negative, but low vitamin B12 levels and severely elevated homocysteine levels prompted us to interrogate for the use of laughing gas. On questioning, the patient admitted to have used this substance, which he presumed to be innocent. Neither percutaneous coronary intervention with balloon dilatation nor intravenous glycoprotein IIb/IIIa receptor antagonist, nor continuous use of anticoagulation and double antiplatelet therapy resulted in thrombus resolution. Due to a severely reduced left ventricular function, despite 3 months on heart failure therapy, the patient is being counselled for intracardiac defibrillator implantation. We conclude that N2O, notably when consumed in conjunction with other proatherogenic substances, is associated with thrombosis: a relation possibly mediated by severe hyperhomocysteinaemia.

Pulmonary embolism (PE) is a common acute presentation which may be provoked by multiple factors. We present the unique case of a young man with no underlying health conditions who was diagnosed with bilateral PE which we believe was provoked by chronic use of nitrous oxide (NO), a potentially under-recognised risk factor for PE. NO is a substance that is commonly used recreationally, particularly among young adults in the UK. It has been shown to increase serum homocysteine levels which may create a prothrombotic state.Our patient had raised serum homocysteine levels on admission. He was anticoagulated and discharged with advice to stop nitrous oxide use. We recommend asking patients about recreational drug use when screening for provoking factors for PE so as to offer appropriate treatment and counselling.

We present the case of a female teenager who sustained nitrous oxide burns to the medial aspect of both thighs from contact with a nitrous oxide canister being used to fill balloons. There was a delay in presentation as the injury was not initially recognised. These burns were initially assessed as being superficial partial-thickness burns but took a prolonged time to heal despite regular wound care. This was complicated by a lack of adherence to recommended treatment for much of the patient care as well as the patient testing positive for COVID-19 during their management, which prevented surgery and significantly extended time to healing. While small numbers of similar cases have been previously described this is the first reported case outside of the Netherlands and in a child. Being aware of such cases ensures early referral to specialist burn care for appropriate management to give patients the best possible outcome.

Urban land-use change has the potential to affect local to global biogeochemical carbon (C) and nitrogen (N) cycles and associated greenhouse gas (GHG) fluxes. We conducted a meta-analysis to (1) assess the effects of urbanization-induced land-use conversion on soil nitrous oxide (N2O) and methane (CH4) fluxes, (2) quantify direct N2O emission factors (EFd) of fertilized urban soils used, for example, as lawns or forests, and (3) identify the key drivers leading to flux changes associated with urbanization. On average, urbanization increases soil N2O emissions by 153%, to 3.0 kg N ha−1 year−1, while rates of soil CH4 uptake are reduced by 50%, to 2.0 kg C ha−1 year−1. The global mean annual N2O EFd of fertilized lawns and urban forests is 1.4%, suggesting that urban soils can be regional hotspots of N2O emissions. On a global basis, conversion of land to urban greenspaces has increased soil N2O emission by 0.46 Tg N2O-N year−1 and decreased soil CH4 uptake by 0.58 Tg CH4-C year−1. Urbanization driven changes in soil N2O emission and CH4 uptake are associated with changes in soil properties (bulk density, pH, total N content, and C/N ratio), increased temperature, and management practices, especially fertilizer use. Overall, our meta-analysis shows that urbanization increases soil N2O emissions and reduces the role of soils as a sink for atmospheric CH4. These effects can be mitigated by avoiding soil compaction, reducing fertilization of lawns, and by restoring native ecosystems in urban landscapes.

Nitrous oxide (NO) is an inhalant that has become increasingly popular as a recreational drug. While it is presumed to be harmless, a number of adverse effects of NO have been described. We discuss the case of a 24-year-old man with no medical history, who initially presented to the emergency department with progressive polyneuropathy caused by vitamin B12 deficiency after NO abuse. Two days after being discharged with hydroxocobalamin supplementation, the patient returned with a severe headache, blurry vision and slurred speech. Imaging revealed cerebral venous sinus thrombosis. Hypercoagulability workup showed slightly elevated homocysteine and normalised vitamin B12 after supplementation. Genetic testing showed a heterozygous prothrombin G20210A mutation. He was treated with low-molecular-weight heparin followed by dabigatran. We hypothesise that NO use may increase the risk of developing cerebral venous thrombosis, especially in patients with multiple risk factors and elevated homocysteine levels.

A 32-year-old woman who misused multiple substances, including nitrous oxide (N

The ability to accurately assess the impact of organic soil drainage on greenhouse gas emissions (GHG) is still limited. Methane (CH4) emissions are characterized by significant variations, and GHG emissions from nutrient-rich organic soil in the region have not been extensively studied. The aim of this study was to assess CH4 and nitrous oxide (N2O) emissions from nutrient-rich organic soil in hemiboreal forests to provide insights into their role in regional GHG balance. Over the course of one year, CH4 and N2O emissions, as well as their affecting factors, were monitored in 31 forest compartments in Latvia in both drained and undrained nutrient-rich organic soils. The sites were selected to include forests of different ages, dominated by silver birch (Betula pendula Roth), Norway spruce (Picea abies (L.) Karsten), and black alder (Alnus glutinosai (L.) Gärtner), as well as clearcuts. Soil GHG emissions were estimated by collecting gas samples using the closed manual chamber method and analyzing these samples with a gas chromatograph. In addition, soil temperature and groundwater level (GW) measurements were conducted during gas sample collection. The mean annual CH4 emissions from drained and undrained soil were −4.6 ± 1.3 and 134.1 ± 134.7 kg CH4 ha−1 year−1, respectively. N2O emissions from undrained soil (4.1 ± 1.4 kg N2O ha−1 year−1) were significantly higher compared to those from drained soil (1.7 ± 0.6 kg N2O ha−1 year−1). In most of the study sites, undrained soil acted as a CH4 sink, with the soil estimated as a mean source of CH4, which was determined by one site where an emission hotspot was evident. The undrained soil acted as a CH4 sink due to the characteristics of GW level fluctuations, during which the vegetation season GW level was below 20 cm.

Data for the aricleA Greenhouse Gas Budget for Mexico during 2000-2019.&nbsp

Assessing the mitigation effect on greenhouse gas (GHG) reduction of the National VI Emissions Standard bears great significance in enhanced actions on climate change in China. This research established a reference scenario and National VI scenario to evaluate whether the National VI Emissions Standard could make a contribution to synergistic emission reduction. Here are the main conclusions: carbon dioxide (CO

Chemical nitrogen fixation by the Haber–Bosch method permitted industrial-scale fertilizer production that supported global population growth, but simultaneously released reactive nitrogen into the environment. This minireview highlights the potential for bacterial nitrogen fixation and mitigation of greenhouse gas (GHG) emissions from soybean and rice fields. Nitrous oxide (N2O), a GHG, is mainly emitted from agricultural use of nitrogen fertilizer and symbiotic nitrogen fixation. Some rhizobia have a denitrifying enzyme system that includes an N2O reductase and are able to mitigate N2O emission from the rhizosphere of leguminous plants. Type II methane (CH4)-oxidizing bacteria (methanotrophs) are endophytes in paddy rice roots and fix N2 using CH4 (a GHG) as an energy source, mitigating the emission of CH4 and reducing nitrogen fertilizer usage. Thus, symbiotic nitrogen fixation shows potential for GHG mitigation in soybean and rice fields while simultaneously supporting sustainable agriculture.

Substance use during adolescence might cause substantial health burden. Little is known regarding profiles of multiple illicit substance users compared to single illicit substance users in adolescent population in Taiwan.We enrolled 106 adolescent illicit drug users who received addiction treatment referred by juvenile courts in Taiwan between September, 2016 and September, 2021. We divided them into two groups: single versus multiple illicit drug users, and further compared their socio-demographic characteristics, psychiatric and substance comorbidities. The independent t test or Mann-Whitney U test was used for continuous variables and Pearson's chi-square test for nominal variables. Multivariate logistic regression was used to examine the suicide and violence risk among adolescents.71.7% of participants were multiple illicit drug users while 28.3% of them were single drug users. Multiple illicit substance users were more likely to use methamphetamine (p = 0.005), ketamine (p 0.001), new psychoactive substance (NPS) (p 0.001), MDMA (p = 0.003), and nitrous oxide (p 0.001) compared to single illicit substance users. In addition, multiple illicit drug users were more likely to have ADHD (p = 0.030), major depressive disorder (p = 0.050), and lifetime suicidal attempts (p = 0.048) compared to single illicit drug users. In further analysis (NPS vs. traditional drugs), we found NPS users tended to use larger numbers of illicit drugs (p 0.001) and were more likely to have substance-induced psychotic disorder (p = 0.008), ADHD (p = 0.011), suicidal attempts (p = 0.020).Our findings highlight the distinct profiles of multiple illicit drug users compared to single illicit drug users among adolescent population. High suicidality and high psychiatric comorbidities in multiple illicit drug users call for special need for suicide screening and a more integrated care incorporating psychiatric and substance treatment.

In the low fertility acid soils of the Orinoquian savannas of Colombia, Urochloa humidicola cv. Tully or Humidicola is one of the most widely planted tropical forage grasses for improving livestock productivity. Low nutritional quality of this grass limits sustainable livestock production in this region. In this study, we conducted a phenotypic evaluation under field and greenhouse conditions of one of the first hybrid populations of U. humidicola generated from the forage breeding program of CIAT. Our objective was to identify a set of new hybrids of U. humidicola that combine improved productivity and nutritional quality plus the biological nitrification inhibition (BNI) trait/ability to reduce nitrogen (N) losses via leaching and nitrous oxide (N2O) emissions. To this end, we tested 118 hybrids (planted in pots) in the greenhouse for over 6 months and measured potential nitrification rates (NR) using soil microcosm incubation. NR values observed ranged from 0.27 to 5.75 mg N-NO3- kg soil(-1) day(-1). Later, 12 hybrids with different levels of NR were selected and field-tested in the Orinoquia region over a 4 years period (2013-2017) for dry matter production, nutrition quality (crude protein, in vitro digestibility and fibres content) and NR in each year. In the rainy season of 2018, two hybrids with superior agronomic performance and contrasting field level NR (Uh08/1149 and 0450) were subjected to analysis of soil-borne N2O emissions after fertilization during 13 days. The NR values recorded were not directly correlated with the forage quality parameters evaluated, however, the two grasses with the lowest NR values were among those with the highest biomass production, crude protein content, and N uptake. The grass hybrid Uh08/1149 and the germplasm accession CIAT 16888 were found as materials with superior forage value, with production of 14.1 and 14.6 tons dry matter ha(-1) year(-1) (up to 8% higher than the cv. Tully), crude protein of 11.5 and 9.1% per cut (up to 20% higher than the cv. Tully), and N uptake of 31.6 and 25.7 kg N ha(-1) cut(-1) (up to 30% higher than the cv. Tully). Additionally, these two grasses are likely to exhibit high-BNI ability, with potential to improve N use efficiency in managed pastures., Grass and Forage Science, 78 (1), ISSN:0142-5242, ISSN:1365-2494

Streams and rivers are important sources of nitrous oxide (N

In shallow, open-water engineered wetlands, design parameters select for a photosynthetic microbial biomat capable of robust pharmaceutical biotransformation, yet the contributions of specific microbial processes remain unclear. Here, we combined genome-resolved metatranscriptomics and oxygen profiling of a field-scale biomat to inform laboratory inhibition microcosms amended with a suite of pharmaceuticals. Our analyses revealed a dynamic surficial layer harboring oxic-anoxic cycling and simultaneous photosynthetic, nitrifying, and denitrifying microbial transcription spanning nine bacterial phyla, with unbinned eukaryotic scaffolds suggesting a dominance of diatoms. In the laboratory, photosynthesis, nitrification, and denitrification were broadly decoupled by incubating oxic and anoxic microcosms in the presence and absence of light and nitrogen cycling enzyme inhibitors. Through combining microcosm inhibition data with field-scale metagenomics, we inferred microbial clades responsible for biotransformation associated with membrane-bound nitrate reductase activity (emtricitabine, trimethoprim, and atenolol), nitrous oxide reduction (trimethoprim), ammonium oxidation (trimethoprim and emtricitabine), and photosynthesis (metoprolol). Monitoring of transformation products of atenolol and emtricitabine confirmed that inhibition was specific to biotransformation and highlighted the value of oscillating redox environments for the further transformation of atenolol acid. Our findings shed light on microbial processes contributing to pharmaceutical biotransformation in open-water wetlands with implications for similar nature-based treatment systems.

Biodiesel usage is increasing steadily worldwide as the push for renewable fuel sources increases. The increased oxygen content in biodiesel fuel is believed to cause decreased particulate matter (PM) and increased nitrous oxides within its exhaust. The addition of fuel additives to further increase the oxygen content may contribute to even further benefits in exhaust composition. The aim of this study was to assess the toxicity of 10% (v/v) diethylene glycol dimethyl ether (DGDME) added as a biodiesel fuel additive. Primary human airway epithelial cells were grown at the air-liquid interface and exposed to diluted exhaust from an engine running on either grapeseed, bran, or coconut biodiesel or the same three biodiesels with 10% (v/v) DGDME added to them; mineral diesel and air were used as controls. Exhaust properties, culture permeability, epithelial cell damage, and IL-6 and IL-8 release were measured postexposure. The fuel additive DGDME caused a decrease in PM and nitrous oxide concentrations. However, exhaust exposure with DGDME also caused decreased permeability, increased epithelial cell damage, and increased release of IL-6 and IL-8 (

Nitrous oxide (N

Manure is a key source of N for crops, especially in organic farming systems, but also a driver of N2O emissions from soil. Treatment technologies removing manure organic matter affect soil N2O emissions, but the direction and magnitude of these effects remain uncertain. We explored the effects of four fertilizer materials derived from cattle manure on soil N2O emissions. Treatments included: untreated cattle manure (CA), cattle manure co-digested with grass-clover silage (DD); a liquid fraction (LF) produced by mechanical separation of digestate; and a concentrated fertilizer with NH4+-N and sulfate (NS) produced from stripped H2S and NH3. These fertilizers were surface-applied to a sandy loam (Foulum) and a clay loam soil (Askov) at 55% water-filled pore space (WFPS) in 28-day laboratory experiments with monitoring of CO2 and N2O. Samples were sectioned during or after incubation to describe mineral N and microbial dynamics. Although the WFPS in both soils was 58–61%, N2O emissions varied greatly, and this was explained by differences in water potential, and in the relative gas diffusivity which was approx. 0.011 and 0.030 in Foulum and Askov soil, respectively. Unexpectedly, treatment LF with the lowest manure organic matter input had the highest N2O emissions. Denitrification was the main pathway producing N2O as determined by 15N enrichment of soil NO3−. The vertical distribution of mineral N and microbial activities, and PLFA, indicated that N2O emissions from the organic fertilizers depended on their interaction with the soil, as modified by soil water potential and gas diffusivity at the time of application.

Flavodiiron nitric oxide reductases (FNORs), found in pathogenic bacteria, are capable of reducing nitric oxide (NO) to nitrous oxide (N(2)O) to detoxify NO released by the human immune system. Previously, we reported the first FNOR model system that mediates direct NO reduction (Dong et al., J. Am. Chem. Soc. 2018, 140, 13429–13440), but no intermediate of the reaction could be observed. Here we present a new set of model complexes that, depending on the ligand substitution, can either mediate direct NO reduction or stabilize a highly activated high-spin (hs) {FeNO}(7) complex, the first intermediate of the reaction. The precursors, [{Fe(II)(MPA-(RPhO)(2))}(2)] (1, R = H and 2, R = (t)Bu, Me), were prepared first and fully characterized. Complex 1 (without steric protection) directly reduces NO to N(2)O almost quantitatively, which constitutes only the second example for this reaction in model systems. Contrarily, reaction of sterically protected 2 with NO forms the stable mononitrosyl complex 3, which shows one of the lowest N-O stretching frequencies (1689 cm(−1)) observed so far for a mononuclear hs-{FeNO}(7) complex. This study confirms that an N-O stretch ≤1700 cm(−1) represents the appropriate level of activation of the FeNO unit to enable direct NO reduction. The higher activation level of these hs-{FeNO}(7) complexes compared to those formed in FNORs emphasizes the importance of hydrogen bonding residues in the active sites of FNORs to activate the bound NO ligands for direct N–N coupling and N(2)O formation. The implications of these results for FNORs are further discussed.

Nitrous oxide (N

Exploring the responses of greenhouse gas (GHG) emissions to land use conversion or reversion is significant for taking effective land use measures to alleviate global warming. A global meta-analysis was conducted to analyze the responses of carbon dioxide (CO

Inhalational inductions with sevoflurane (up to 8% inspired concentration) have been the standard for inducing anesthesia in children for over three decades. However, when sevoflurane was first introduced, clinicians reported isolated cases of unexpected myoclonic jerking movements during the induction in children without epilepsy. These cases raised concerns regarding the widespread use of sevoflurane particularly after reports of seizures and epileptiform electroencephalographic (EEG) discharges surfaced. The latter reports prompted recommendations to reduce the concentration of sevoflurane during induction of anesthesia. More recently, a shift away from the use of nitrous oxide has prompted some to question whether sevoflurane has a role as an induction agent in children. The preponderance of evidence supports the practice of safely inducing anesthesia with 8% sevoflurane with or without nitrous oxide in children but recommended strategies to mitigate against epileptiform discharges may be more harmful than beneficial.

Agroforestry systems (AFS) contribute to carbon (C) sequestration and reduction in greenhouse gas emissions from agricultural lands. However, previously understudied differences among AFS may underestimate their climate change mitigation potential. In this 3-year field study, we assessed various C stocks and greenhouse gas emissions across two common AFS (hedgerows and shelterbelts) and their component land uses: perennial vegetated areas with and without trees (woodland and grassland, respectively), newly planted saplings in grassland, and adjacent annual cropland in central Alberta, Canada. Between 2018 and 2020 (~April-October), nitrous oxide emissions were 89% lower under perennial vegetation relative to the cropland (0.02 and 0.18 g N m

Condensed tannins are a potentially important treatment option to mitigate N

Nitrous oxide (N2O) is not only recognized as a potent greenhouse gas, but it is also used in industry as a clean energy source. In this study, different electrode materials of carbon felt and graphite were equipped in the ΔnosZP. aeruginosa/microbial electrolysis cell (MEC) systems to explore the optimization mechanism for long-term N2O recovery during incineration leachate treatment. The carbon felt group showed a better performance in N2O recovery across 45 days of operation. The N2O conversion efficiency was above 80% and the proportion of N2O in biogas accounted for 80.6% in the carbon felt group. qRT-PCR analysis was conducted to evaluate the expression of genes involved in denitrification (norB) and electroactivity (phzG, phzM, and phzH) of ΔnosZ P. aeruginosa. The results showed a significant upregulation in the suspended biomass (day 21) and the electron-attached biomass (day 45) from the carbon felt-equipped reactor, which was highly related to the opportunity of biomass exposed to the phenazine derivatives. By the carbon felt optimization in the system, 82.6% of the Pseudomonas genus survived after 45 days of operation. These results indicate that the carbon felt electrode has a more sustainable performance for N2O recovery in the ΔnosZ P. aeruginosa/MEC system.

Trace elements can have a wide variety of effects on microbial populations and their function in the aquatic environment. However, specific impacts on chemical and biological processes are often difficult to unravel, due to the wide variety of chemical species involved and interactions between different elemental cycles. A replicated mesocosm experiment was used to test the effect of increasing copper concentrations, i.e., from 6 mg kg−1 to 30 and 120 mg kg−1, on nitrogen cycling in a freshwater sediment under laboratory conditions. Nitrous oxide emissions from the treated sediments were measured over three consecutive 24 h periods. This was followed by measurements of iron, manganese, copper and mineral nitrogen species (nitrate and ammonium) mobilisation in the sediments using the diffusive gradients in thin films (DGT) and diffusive equilibria in thin films (DET) techniques and sequential extractions. Increasing copper concentrations are shown to have resulted in significantly reduced nitrate formation near the sediment–water interface and increased nitrous oxide emissions from the sediment overall. The concomitant mobilisation and sequestration of iron with ammonium in the sediment with the highest Cu treatment strongly imply links between the biogeochemical cycles of the two elements. Modest Cu contamination was shown to affect the nitrogen cycle in the tested freshwater sediment, which suggests that even relatively small loads of the metal in fresh watercourses can exert an influence on nutrient loads and greenhouse gas emissions from these environments.

Chinese milk vetch (CMV) is a leguminous green manure that is commonly cultivated in paddy fields and can partially substitute synthetic nitrogen fertilizer. However, the impacts of incorporating CMV on CH4 and N2O emissions are still a subject of controversy. Therefore, we conducted a field experiment over three years to investigate emissions under different substitution ratios: urea only (CF); incorporating a traditional amount of CMV (MV); and with incorporation ratios of 1/3 (MV1/3), 2/3 (MV2/3), and 4/3 (MV4/3) of MV for partial urea substitution. Compared with CF, MV2/3, MV, and MV 4/3 resulted in increased yields. MV and MV4/3 reduced N2O emissions but increased CH4 emissions by 28.61% and 85.60% (2019), 32.38% and 103.19% (2020), and 28.86% and 102.98% (2021), respectively, resulting in an overall increase in total global warming potential (except for MV in 2021). MV2/3 exhibited a low greenhouse gas intensity value ranging from 0.46 to 0.47. Partial least-squares-path model results showed that CH4 and N2O emissions were influenced by substitution ratios, which indirectly regulated the gene abundances of mcrA and nosZ. Overall, the impact of CMV on CH4 and N2O emissions was determined by substitution ratios. MV2/3, which involved partial substitution of synthetic N fertilizer with 15.0 t ha−1 of CMV, resulted in improved rice productivity without increasing CH4 and N2O emissions, making it a recommended approach in the study area.

Management of agricultural production systems interferes with greenhouse gases (GHG) emissions, thereby altering physical, chemical, and biological attributes of soil; therefore, it is important to understand the relationship between soil attributes and GHG emissions. This study evaluated GHG emissions and their relationship with soil attributes in off-season soybean, maize, brachiaria and eucalyptus production systems. The experiment was carried out in Brejo, Maranhão, Brazil, with soybean ( Glycine max ), maize ( Zea mays ), brachiaria ( Urochloa ruzizienses ), and eucalyptus ( Eucalyptus grandis ). Fluxes of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were evaluated using air samples analyzed by gas chromatography. Soil attributes were ammonium and nitrate contents, total organic carbon, moisture, pH, density, total porosity, and water-filled pore space. N2O flux was 287.1 µg m-2 h -1 for eucalyptus cultivation, while areas cultivated with soybeans, maize and brachiaria had influxes of 46.7, 7.2, and 13.17 µg m-2 h-1, respectively. In the off-season, the highest emissions of N2O and CO2 were measured in eucalyptus areas due to soil moisture and porosity conditions provided by accumulation of litter on the soil surface.

Nitrous oxide, N2O, exhibits unique reactivity in oxidation catalysis, but the high manufacturing costs limit its prospective uses. Direct oxidation of ammonia, NH3, to N2O can ameliorate this issue but its implementation is thwarted by suboptimal catalyst selectivity and stability, and the lack of established structure-performance relationships. Systematic and controlled material nanostructuring offers an innovative approach for advancement in catalyst design. Herein low-valent manganese atoms stabilized on ceria, CeO2, are discovered as the first stable catalyst for NH3 oxidation to N2O, exhibiting two-fold higher productivity than the state-of-the-art. Detailed mechanistic, computational and kinetic studies reveal CeO2 as the mediator of oxygen supply, while undercoordinated manganese species activate O-2 and facilitate N2O evolution via N-N bond formation between nitroxyl, HNO, intermediates. Synthesis via simple impregnation of a small metal quantity (1 wt%) predominantly generates isolated manganese sites, while full atomic dispersion is achieved upon redispersion of sporadic oxide nanoparticles during reaction, as confirmed by advanced microscopic analysis and electron paramagnetic resonance spectroscopy. Subsequently, manganese speciation is maintained, and no deactivation is observed over 70 h on stream. CeO2-supported isolated transition metals emerge as a novel class of materials for N2O production, encouraging future studies to evaluate their potential in selective catalytic oxidations at large., Advanced Materials, 35 (24), ISSN:0935-9648, ISSN:1521-4095

As a greenhouse gas, nitrous oxide (N2O) is increasingly damaging the atmosphere and environment, and the capture of N2O using ionic liquids (ILs) has recently attracted wide attention. Machine learning can be utilized to rapidly screen ILs suitable for N2O removal. In this study, intelligent predictions of nitrous oxide capture in designable ionic liquids are proposed based on a series of machine learning methods, including linear regression, voting, and a two-layer feed-forward neural network (TLFFNN). The voting model can utilize various algorithms and is highly generalizable to various systems. The TLFFNN model produced the most accurate prediction, with an MSE of 0.00002 and R2 of 0.9981 on test sets. The acceptable performance of the TLFFNN model demonstrates its utility as an accurate and promising candidate model for the prediction of N2O solubility in ILs over other intelligent models. Based on the analysis of the thermodynamic and molecular properties of ionic liquids, in the low-pressure zone, components of [(OH)2IM] and [AC] perform best in capturing N2O, while in the high-pressure zone, components of [(ETO)2IM] and [SCN] are best. This finding will provide new chemical insights for the industrial synthesis of ionic liquids in capturing N2O.

measurements. To address this, we conducted a two-year study using large lysimeters in an ecotron facility, continuously measuring ecosystem-level CO 2 , N 2 O, and H 2 O fluxes. We investigated the impact of endogeic and anecic earthworms on GHG emissions and ecosystem water use efficiency (WUE) in an agricultural setting. Although we observed transient stimulations of carbon fluxes in the presence of earthworms, cumulative fluxes over the study indicated no significant increase in CO 2 emissions. Endogeic earthworms marginally reduced N 2 O emissions during the wheat culture (-44.6%), but this effect was not sustained throughout the experiment. No consistent effects on ecosystem evapotranspiration or WUE were found. Our study suggests that earthworms do not significantly contribute to GHG emissions over a two-year period in experimental conditions that mimic an agricultural setting. These findings highlight the need for realistic experiments enabling continuous GHG measurements.

Food waste is a dominant organic constituent of landfills, and a large global source of greenhouse gases. Composting food waste presents a potential opportunity for emissions reduction, but data on whole pile, commercial-scale emissions and the associated biogeochemical drivers are lacking. We used a non-invasive micrometeorological mass balance approach optimized for three-dimensional commercial-scale windrow compost piles to measure methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions continuously during food waste composting. Greenhouse gas flux measurements were complemented with continuous oxygen (O2) and temperature sensors and intensive sampling for biogeochemical processes. Emission factors (EF) ranged from 6.6 to 8.8 kg CH4–C/Mg wet food waste and were driven primarily by low redox and watering events. Composting resulted in low N2O emissions (0.01 kg N2O–N/Mg wet food waste). The overall EF value (CH4 + N2O) for food waste composting was 926 kgCO2e/Mg of dry food waste. Composting emissions were 38–84% lower than equivalent landfilling fluxes with a potential net minimum savings of 1.4 MMT CO2e for California by year 2025. Our results suggest that food waste composting can help mitigate emissions. Increased turning during the thermophilic phase and less watering overall could potentially further lower emissions.

Paddy rice production based on traditional soil management emits large amounts of methane (CH4) into the atmosphere. This study assessed the potential of no-tillage (NT) and winter cover crops (WCC) to mitigate net greenhouse gas (GHG) emissions in a subtropical paddy rice ecosystem. A long-term (20-yrs) experiment was evaluated regarding the effect of NT combined with winter fallow or three WCC (ryegrass, white oat, and birdsfoot trefoil) on seasonal CH4 -C and nitrous oxide (N2O-N) emissions and on soil organic carbon (SOC) stocks in comparison to conventional tillage (CT) under winter fallow in a Gleysol of Southern Brazil. The changes in SOC were used as a proxy for annual net carbon dioxide (CO2) exchanges in the soil-atmosphere, taking the CT treatment as a reference. The GHG balance (summation of CH4 , N2O and CO2 emissions multiplied by their global warming potential of 34, 298, and 1, respectively) and emissions intensity of GHG emissions were calculated. Across winter managements, NT decreased 25 % of GHG emissions in comparison to CT system. This effect was mainly related to the decrease of seasonal CH4 -C emissions (31-113 kg ha-1) and by promoting SOC accumulation (0.45-0.65 Mg ha-1yr-1) in comparison to CT system, since soil N2 O-N emission was not affected by management practices. Increased soil CH4 -C emissions offset the positive effect of WCC on SOC accumulation compared with winter fallow. Based on our findings, NT mitigates net GHG emissions in subtropical paddy rice ecosystems, but no additional effect is observed combining NT with WCC.

Adaptation to anoxia by synthesizing a denitrification proteome costs metabolic energy, and the anaerobic respiration conserves less energy per electron than aerobic respiration. This implies a selective advantage of the stringent O(2) repression of denitrification gene transcription, which is found in most denitrifying bacteria. In some bacteria, the metabolic burden of adaptation can be minimized further by phenotypic diversification, colloquially termed “bet-hedging,” where all cells synthesize the N(2)O reductase (NosZ) but only a minority synthesize nitrite reductase (NirS), as demonstrated for the model strain Paracoccus denitrificans. We hypothesized that the cells lacking NirS would be entrapped in anoxia but with the possibility of escape if supplied with O(2) or N(2)O. To test this, cells were exposed to gradual O(2) depletion or sudden anoxia and subsequent spikes of O(2) and N(2)O. The synthesis of NirS in single cells was monitored by using an mCherry-nirS fusion replacing the native nirS, and their growth was detected as dilution of green, fluorescent fluorescein isothiocyanate (FITC) stain. We demonstrate anoxic entrapment due to e(−)-acceptor deprivation and show that O(2) spiking leads to bet-hedging, while N(2)O spiking promotes NirS synthesis and growth in all cells carrying NosZ. The cells rescued by the N(2)O spike had much lower respiration rates than those rescued by the O(2) spike, however, which could indicate that the well-known autocatalytic synthesis of NirS via NO production requires O(2). Our results bring into relief a fitness advantage of pairing restrictive nirS expression with universal NosZ synthesis in energy-limited systems. IMPORTANCE Denitrifying bacteria have evolved elaborate regulatory networks securing their respiratory metabolism in environments with fluctuating oxygen concentrations. Here, we provide new insight regarding their bet-hedging in response to hypoxia, which minimizes their N(2)O emissions because all cells express NosZ, reducing N(2)O to N(2), while a minority express NirS + Nor, reducing NO(2)(−) to N(2)O. We hypothesized that the cells without Nir were entrapped in anoxia, without energy to synthesize Nir, and that they could be rescued by short spikes of O(2) or N(2)O. We confirm such entrapment and the rescue of all cells by an N(2)O spike but only a fraction by an O(2) spike. The results shed light on the role of O(2) repression in bet-hedging and generated a novel hypothesis regarding the autocatalytic nirS expression via NO production. Insight into the regulation of denitrification, including bet-hedging, holds a clue to understanding, and ultimately curbing, the escalating emissions of N(2)O, which contribute to anthropogenic climate forcing.

In New Zealand, nitrous oxide emissions from grazed hill pastures are estimated using different emission factors for urine and dung deposited on different slope classes. Allocation of urine and dung to each slope class needs to consider the distribution of slope classes within a landscape and animal behavior. The Nutrient Transfer (NT) model has recently been incorporated into the New Zealand Agricultural GHG Inventory Model to account for the allocation of excretal nitrogen (N) to each slope class. In this study, the predictive ability of the transfer function within the NT model was explored using urine deposition datasets collected with urine sensor and GPS tracker technology. Data were collected from three paddocks that had areas in low (12°), medium (12-24°), and high slopes (24°). The NT model showed a good overall predictive ability for two of the three datasets. However, if the urine emission factors (% of urine N emitted as NThe Nutrient Transfer model allocates urine from grazing livestock to different slope classes. The predictive ability of the model was explored using urine sensor and tracker data of grazing livestock. The model showed a good overall predictive ability for two of the three datasets explored. There is a need for more geospatial urine deposition and animal location data on complex land.

Rapid technological advances in the natural gas industry raised access to natural gas reserves, related to increased greenhouse gas emissions, including CO

Dairy effluent is a potential source of gaseous pollutants associated with global warming and soil acidification. Mitigating such emissions during handling and storage requires substantial financial and labor input. This study evaluated a low-cost technology for mitigating gaseous emissions from dairy wastewater. For 9 mo, a pilot-scale vermifilter system installed on a commercial dairy farm was studied. Bimonthly samples of the dairy wastewater influent and effluent from the vermifilter system were collected. These samples' potential gas emissions (ammonia [NH

Approximately 17% of the land worldwide is considered highly vulnerable to non-native plant invasion, which can dramatically alter nutrient cycles and influence greenhouse gas (GHG) emissions in terrestrial and wetland ecosystems. However, a systematic investigation of the impact of non-native plant invasion on GHG dynamics at a global scale has not yet been conducted, making it impossible to predict the exact biological feedback of non-native plant invasion to global climate change. Here, we compiled 273 paired observational cases from 94 peer-reviewed articles to evaluate the effects of plant invasion on GHG emissions and to identify the associated key drivers. Non-native plant invasion significantly increased methane (CH

Agricultural soils are leading sources of reactive nitrogen (Nr) species including nitrogen oxides (NO

Recreational nitrous oxide (N

Agricultural practices have created tens of millions of small artificial water bodies ("farm dams" or "agricultural ponds") to provide water for domestic livestock worldwide. Among freshwater ecosystems, farm dams have some of the highest greenhouse gas (GHG) emissions per m

Two new trends in adolescent substance use have emerged: e-cigarette use and nitrous oxide (N20) use. E-cigarettes are often tried out before traditional cigarettes, are easily available and regarded as harmless by adolescents. Studies increasingly show negative health effects of regular e-cigarette use, including the risk of becoming a smoker of traditional cigarettes and nicotine addiction. N20 use has also become increasingly popular, and follows after cannabis and ecstasy use in prevalence rates. As with e-cigarette use, most users are not aware of potential health risks of N20 use, while particularly longer-term and heavy use may yield negative neurological and psychiatric effects. The misconception of risks, and high availability of both inhalants warrant better education to prevent poor outcomes.

Nitrous oxide (NWe systematically searched PubMed, the Cochrane Library, Embase, Web of science, China National Knowledge Infrastrusture (CNKI) and Wanfang Database up to August 10th, 2021. Randomized controlled trials (RCTs) were included if they compared N14 RCTs with 1751 patients were included. Pooled analysis suggested that NThe present meta-analysis suggested that N

The application of organic amendments to agricultural soils enables the recycling of nutrients, further reducing the inputs of synthetic fertilizers for crop production. However, the production of N2O emissions is a concern that arises from such a practice. A 35 d incubation experiment was conducted with soils receiving three contrasting types of biosolids — mesophilic anaerobic digested (BM), composted (BC), and alkaline-stabilized (BA) — at four water-filled pore spaces (WFPS): 28%, 40%, 52%, and 64%. A zero-N-addition control was also evaluated. Across all the three types of biosolids, N2O production increased with soil moisture content, with BM and BC producing the overall highest N2O fluxes. The most intense pulses of N2O production were exhibited by BC at the beginning of the incubation. The highest cumulative N2O production was found with 64% WFPS and from BC- (409 μg N2O–N·kg−1 soil) or BM-amended soils (390 μgN2O–N·kg−1 soil), which produced more than four and two times the emissions from the control and BA-amended soils at 64% WFPS, respectively. We also found the highest nitrification rates in the BM- and BC-amended soils. The total N2O production was exponentially associated with the NO3−–N concentration present at the end of the experiment (R2 = 0.83). Changes in the concentration of the soil available N indicated the occurrence of mineralization, nitrification, and denitrification over the incubation. These results provided insight into the interacting responses of N2O production to soil moisture contents, biosolids treatment stabilization and properties, and soil N availability.

Although several case series have described nitrous-oxide-associated neurological disorders, a comprehensive assessment of exposure characteristics (e.g., time to onset, level of exposure) in substance abusers has not been performed. The aim of this study was to describe the onset patterns of recreational use of nitrous-oxide-induced neurological disorders.All cases of neurological disorders related to nitrous oxide recreational use reported to the Hauts-de-France addictovigilance center between January 2019 and August 2020 were selected. Only cases requiring hospitalization with informative data to perform the nitrous oxide causality assessment were included.A total of 20 cases from five hospitals were included. The male-to-female ratio was 6:1 and the median age was 19 years (range 16-34). The neurological presentation (myeloneuropathy 64%, 7/11; sensorimotor neuropathy 36%, 4/11) included for all patients gait disorders due to proprioceptive ataxia and limb hypoesthesia. The median dose used per occasion was 100 cartridges (range 5-960; n = 19). The median time from the start of nitrous oxide use to the onset of neurological symptoms was 6 months (range 0.7-54; n = 16). The cumulative dose was significantly higher in patients with damage to all four limbs than in patients with lower limb symptoms only (p = 0.042).A low intermittent exposure may be sufficient to cause neurological damage in some subjects, suggesting that, at the population level, there is no safe exposure to nitrous oxide in recreational settings. The severity of neurological impairment could increase once used at high doses and for prolonged durations of nitrous oxide.

Inland waters (rivers, reservoirs, lakes, ponds, streams) and estuaries are significant emitters of methane (CH

Background Inefficiency of lung gas exchange during general anesthesia is reflected in alveolar (end-tidal) to arterial (end-tidal–arterial) partial pressure gradients for inhaled gases, resulting in an increase in alveolar deadspace. Ventilation–perfusion mismatch is the main contributor to this, but it is unclear what contribution arises from diffusion limitation in the gas phase down the respiratory tree (longitudinal stratification) or at the alveolar–capillary barrier, especially for gases of high molecular weight such as volatile anesthetics. Methods The contribution of longitudinal stratification was examined by comparison of end-tidal–arterial partial pressure gradients for two inhaled gases with similar blood solubility but different molecular weights: desflurane and nitrous oxide, administered together at 2 to 3% and 10 to 15% inspired concentration (FiG), respectively, in 17 anesthetized ventilated patients undergoing cardiac surgery before cardiopulmonary bypass. Simultaneous measurements were done of tidal gas concentrations, of arterial and mixed venous blood partial pressures by headspace equilibration, and of gas uptake rate calculated using the direct Fick method using thermodilution cardiac output measurement. Adjustment for differences between the two gases in FiG and in lung uptake rate (VG) was made on mass balance principles. A 20% larger end-tidal–arterial partial pressure gradient relative to inspired concentration (PetG – PaG)/FiG for desflurane than for N2O was hypothesized as physiologically significant. Results Mean (SD) measured (PetG – PaG)/FiG for desflurane was significantly smaller than that for N2O (0.86 [0.37] vs. 1.65 [0.58] mmHg; P < 0.0001), as was alveolar deadspace for desflurane. After adjustment for the different VG of the two gases, the adjusted (PetG – PaG)/FiG for desflurane remained less than the 20% threshold above that for N2O (1.62 [0.61] vs. 1.98 [0.69] mmHg; P = 0.028). Conclusions No evidence was found in measured end-tidal to arterial partial pressure gradients and alveolar deadspace to support a clinically significant additional diffusion limitation to lung uptake of desflurane relative to nitrous oxide. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Multiply substituted isotopic species of nitrous oxide (N2O), referred to as clumped isotopes, represent a promising new tool for distinguishing production pathways of this potent greenhouse gas. This work presents the first determination of enrichment factors of N2O clumped isotopes during bacterial denitrification. Samples of N2O obtained after 1-, 3-, and 7-day incubations of a pure culture of the denitrifier Pseudomonas aureofaciens at 20 °C and 30 °C were analysed by the recently developed quantum cascade laser absorption spectroscopy (QCLAS) method. Enrichment factors εp/s of the cumulative product (p) relative to the substrate (s) were determined using a Rayleigh model for the seven most abundant isotopically substituted molecules (isotopocules) of N2O. Values of the enrichment factors εp/s (with uncertainty expressed as expanded standard uncertainty at the 95% confidence interval) at the two incubation temperatures (20 °C/30 °C) are:14N15N16O (456): ε456 = (−40.3 ± 2.6)‰/(−35.1 ± 0.7)‰15N14N16O (546): ε546 = (−38.1 ± 3.4)‰/(−31.2 ± 0.6)‰14N14N17O (447): ε447 = (21.3 ± 1.2)‰/(24.5 ± 0.5)‰14N14N18O (448): ε448 = (38.8 ± 1.5)‰/(46.4 ± 1.2)‰14N15N18O (458): ε458 = (−8.9 ± 2.0)‰/(−11.7 ± 0.6)‰15N14N18O (548): ε548 = (−3.4 ± 1.1)‰/(−1.8 ± 0.5)‰15N15N16O (556): ε556 = (−85.9 ± 1.5)‰/(−63.9 ± 1.4)‰Temporal evolutions of the abundances of singly substituted N2O isotopocules during nitrate reduction agree with previously published experiments: there is normal isotope effect associated with the production of 14N15N16O and 15N14N16O; i.e., intermediates leading to 14N14N16O react faster than intermediates leading to 14N15N16O and 15N14N16O. However, the production of 14N14N17O and 14N14N18O is associated with inverse isotope effect; i.e., intermediates leading to 14N14N16O react slower than intermediates leading to 14N14N17O and 14N14N18O due to preferential cleavage of 16O during nitrate reduction to N2O. Isotopic fractionation at the incubation temperature of 30 °C was significantly lower compared to 20 °C. We observed a large kinetic isotope effect of the 15N site preference (SP) and the 15N–18O site preference (SP18) at the onset of the reaction. SP18 was found to be closer to 0‰ than SP, which is thought to arise from similar rates of breakage of the 15N–O and 14N–O bonds in the reaction intermediates. The 15N–18O clumped isotope anomalies in two isotopic isomers (isotopomers) 14N15N18O and 15N14N18O (Δ458+548avg) follow a temporal trend similar to those of SP and SP18. The 15N–15N clumped isotope anomalies in 15N15N16O are greater than 0‰ and show no clear temporal trend or influence of incubation temperature, suggesting no strong combinatorial effects involved during the N–N bond formation. Overall, our data illustrate that clumped N2O isotopes may be used as independent tracers for reaction mechanisms of N2O conversion and may establish themselves as a worthwhile tool to study the biogeochemical cycle of N2O., Geochimica et Cosmochimica Acta, 328, ISSN:0016-7037, ISSN:1872-9533

Antibiotics usage is a double-edged sword among the production promotion and environmental aggravation of aquaculture system. In this study, the effects of sulfadiazine addition on algal-bacterial-based aquaponic (AA) system were thoroughly investigated. Results showed that sulfadiazine addition increased the nitrogen (N) and carbon (C) recovery of AA system by 1.3 times and 2.9 times, respectively. Meanwhile, the global warming potential was increased by 63% due to aggravated nitrous oxide (N

External cephalic version (ECV) is a technique used to reduce the incidence of cesarean deliveries due to malpresentation. Nitrous oxide is an inhaled analgesic that may be used for pain relief for women undergoing external cephalic version.To compare the conversion rate of non-cephalic to cephalic presentation in ECV with and without nitrous oxide.A retrospective cohort analysis was performed including all singleton, term gestation ECVs between January 2016 and June 2017 at a single institution. Multivariable logistic regression was used to compare women who had ECV with nitrous oxide versus ECV without nitrous oxide. The primary outcome was successful rate of conversion to cephalic presentation and the secondary outcome was the rate of vaginal delivery.During the study period, 167 women underwent ECV: 77 with nitrous oxide and 90 without nitrous oxide. Of the 77 women who used nitrous oxide, 25 (32.5%) were successful and 17 of these women delivered vaginally (68%). Of the women who underwent ECV without nitrous oxide, 29 (32.2%) successfully converted and 21 of these delivered vaginally (72%). After controlling for confounders, the use of nitrous oxide had no clinically or statistically significant difference on ECV success rates (OR 1.08, 95% CI 0.52-2.23).Nitrous oxide does not seem to affect conversion rate to cephalic presentation in ECV. Further studies are needed to determine the impact of nitrous oxide on women's decision to undergo ECV and on patient satisfaction and tolerability.

BACKGROUND Neurologic presentations resulting from nitrous oxide (N2 O) abuse are increasing in Australia and worldwide. Despite known neuropsychiatric sequelae nitrous oxide canisters remain readily available and its use unregulated. AIMS To examine the demographics, clinical and electrophysiological findings of patients presenting with neurological complications of N2 O abuse, and thus inform clinicians and public health decision makers of the significant public health concerns of this increasing practice. METHODS Consecutive patients presenting to a tertiary referral, metropolitan hospital were included in this series. Patients were identified by a search of discharge summaries of patients admitted with acute or subacute neuropathy or myelopathy and a history of N2 O abuse, and from the electrophysiology database. RESULTS Thirteen patients were identified, most presenting with subacute paraesthesia, sensory ataxia and lower limb weakness. Eleven had low serum vitamin B12 . Spinal magnetic resonance imaging was consistent with subacute combined degeneration (SACD) in 8. Nerve conduction studies revealed a motor or sensorimotor axonal neuropathy (3 with motor predominance). There was a bimodal demographic distribution consisting of socially isolated, international university students and local residents with a history of mental illness and polydrug abuse. CONCLUSIONS Recreational N2 O use is an emerging health problem in Australia. International university students and patients with pre-existing mental illness or polydrug use appear to be at increased risk. A severe motor neuropathy may emerge following Vitamin B12 replacement. Public health measures are required to limit the availability of N2 O and to educate adolescents and young adults about the potential for significant harm. This article is protected by copyright. All rights reserved.