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The sources and sinks of nitrous oxide, as control emissions to the atmosphere, are generally poorly constrained for most environmental systems. Initial depth-resolved analysis of nitrous oxide flux from observation wells and the proximal surface within a nitrate contaminated aquifer system revealed high subsurface production but little escape from the surface. To better understand the environmental controls of production and emission at this site, we used a combination of isotopic, geochemical, and molecular analyses to show that chemodenitrification and bacterial denitrification are major sources of nitrous oxide in this subsurface, where low DO, low pH, and high nitrate are correlated with significant nitrous oxide production. Depth-resolved metagenomes showed that consumption of nitrous oxide near the surface was correlated with an enrichment of Clade II nitrous oxide reducers, consistent with a growing appreciation of their importance in controlling release of nitrous oxide to the atmosphere. Our work also provides evidence for the reduction of nitrous oxide at a pH of 4, well below the generally accepted limit of pH 5.

Global potent greenhouse gas nitrous oxide (N2O) emissions from soil are accelerating, with increases in the proportion of reactive nitrogen emitted as N2O, i.e., N2O emission factor (EF). Yet, the primary controls and underlying mechanisms of EFs remain unresolved. Based on two independent but complementary global syntheses, and three field studies determining effects of acidity on N2O EFs and soil denitrifying microorganisms, we show that soil pH predominantly controls N2O EFs and emissions by affecting the denitrifier community composition. Analysis of 5438 paired data points of N2O emission fluxes revealed a hump-shaped relationship between soil pH and EFs, with the highest EFs occurring in moderately acidic soils that favored N2O-producing over N2O-consuming microorganisms, and induced high N2O emissions. Our results illustrate that soil pH has a unimodal relationship with soil denitrifiers and EFs, and the net N2O emission depends on both the N2O/(N2O + N2) ratio and overall denitrification rate. These findings can inform strategies to predict and mitigate soil N2O emissions under future nitrogen input scenarios.

In this study a comprehensive analysis of the influence of synthesis route of CuFe 2 O 4 spinel mixed oxides on their catalytic performance in the N 2 O decomposition was carried out. A co-precipitation technique allowed one to obtain the CuFe 2 O 4 spinel with a higher specific surface area and pore volume compared to the synthesis with the application of organic additives. This resulted in better catalytic performance of the CuFe 2 O 4 samples prepared by co-precipitation. The microwave activation step with the duration of 1 min during the co-precipitation synthesis led to the formation of the CuFe 2 O 4 spinel with a higher content of oxygen vacancies per 1 m2 in comparison with the sample obtained without the microwave activation. This fact caused a significantly higher specific activity of the CuFe 2 O 4 spinel synthesized with the application of 1 min microwave activation. The increase of the microwave treatment time led to the fast growth of the contents of the CuO and α-Fe 2 O 3 phases, which are less active in the N 2 O decomposition, resulting in the activity drop. [Display omitted] [ABSTRACT FROM AUTHOR]

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]

In their review: An examination of the ability of plantain (Plantago lanceolata L.) to mitigate nitrogen leaching from pasture systems, Eady et al. (2024) dispute both the historic estimates of typical urine patch nitrogen (N) load and leaching and the evidence for the N leaching reduction mechanisms of plantain; and question the recommended levels of plantain required to achieve N leaching reduction. We reject the suggestion that the urine patch has little influence on N leaching, and that average annual N leaching from dairy farms is 6 kg N/ha. We agree that the low dry matter content of plantain is the dominant and best documented effect of plantain on urine N dilution. We reject that there is no evidence for the effect of plantain on nitrogen partitioning to urine, and on potential nitrification rate in the urine patch. We point to empirical evidence of statistically significant reductions in nitrate leaching from plantain at paddock scale, at levels as low as 21% plantain of dry matter eaten. Current research will improve understanding of the mechanisms and magnitude of the effect of plantain on N loss, paving the way for recognition of other forage-based N loss reduction options, and ongoing development of mechanistic models that are adaptable to other forages. [ABSTRACT FROM AUTHOR]

Under New Zealand grazing systems, a high proportion of the nitrogen consumed by ruminants is excreted. This experiment examined the effect of feeding morning and afternoon harvested annual ryegrass, fed shortly after harvest, on the timing of nitrogen excretion in one-year-old sheep during winter. Dry matter and water-soluble carbohydrate (WSC) content increased in the afternoon-harvested ryegrass. This resulted in increased protein and WSC intakes and a decrease in nitrogen loss in the sheep fed in the afternoon with afternoon-harvested grass. The pattern of urinary nitrogen excretion was related to feeding time with peak urinary urea excretion in the period 4–8 hours after feeding, with over 60% of the daily urinary urea excreted in the 12 hours after the feed was offered. This study suggests that shifting stock onto new pasture breaks in the afternoon could reduce nitrous oxide production by increasing the efficiency of nitrogen utilisation in animals and reducing the total amount of nitrogen excreted. It may be possible to utilise the potential diurnal differences in pasture composition to reduce nitrogen losses. This practise could also improve animal performance as well as change the timing of nitrogen excretion. [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]

In 1762, Louis-Antoine Marquis de Caraccioli (1719–1803), a prolific writer of the eighteenth century, dedicated a book to a psychological theme that medicine has forgotten: ' gaité ' in French, which we will translate as 'cheerfulness'. At the beginning of the nineteenth century, this work inspired two doctoral theses in medicine, one defended in Montpellier, the other in Paris. In their texts, Louis Monferran (1785–?) and Vincent Rémi Giganon (1794–1857) explored the therapeutic benefits of the medical prescription of cheerfulness. In addition to lifestyle recommendations, they focused on the psychotropic substances available to them: alcohol, coca, hemp and opiates. In an original and novel way, Giganon introduced and recommended ' le gaz oxydule d'azote inspiré ', or inhaled nitrous oxide gas. [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]

Feeding rate is an important factor influencing the carbon and nitrogen input and greenhouse gas emission from aquaculture systems. However, the quantitative relationship between feeding rates and GHG emissions is still poorly understood. In this study, we conducted a laboratory-scale experiment to examine the impact of feeding rate (0%, 2%, 4%, 6%, and 8%) on the CH4 and N2O emissions from a pond rice-fish co-culture system. The results showed that the total amount of CH4 emission did not significantly differ when the feeding rate was no more than 6%, but increased more than four times when the feeding rate reach to 8%. The amount of N2O emission showed a linearly increasing trend with the feeding rate. The emission factors of CH4 and N2O was significantly higher for 8% feeding rate than other feeding rates. The variation of CH4 emission was primarily attributed to the ratio of mcrA/pmoA in the sediment and the contents of biological oxygen demand (COD) and dissolved oxygen (DO) in the water; and the variation of N2O was primarily affected by the available nitrogen in the water and sediment and the content of DO in the water. The overall emission of CH4 and N2O showed an exponential relationship with feeding rate. The total yields of fish and rice did not continuously increase when the feeding rate exceeded 4%. The lowest emission intensity per unit yield was reached at the feeding rate of 2.99%. These results can provide a reference for the determination of low-carbon feeding strategy for pond rice-fish co-culture system. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) emissions are a serious global issue, with substantial evidence indicating that hydroclimate processes significantly contribute to these emissions. Forests, covering one-third of global land, are key in the water cycle and influence hydroclimate processes, which vary with climate, latitude, and forest types. The role of hydroclimate in regulating global forest N2O emission remains largely unknown. Our global analysis shows that hydroclimate factors dominate the latitudinal gradient of forest N2O fluxes, which decrease with latitude. N2O fluxes are highest in tropical forests, followed by temperate and boreal forests. Hydroclimate factors contribute 78.2% to N2O fluxes, while soil factors contribute 21.8%. Our results urgently call for future studies to investigate the relationship between N2O flux and hydroclimate factors like radiation, evapotranspiration, and vapor pressure deficits. Collectively, these findings highlight hydroclimate significant impact on N2O emissions and suggest incorporating these factors into predictive models for greater accuracy. [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]

Ammonia (NH 3) and biomass are recognised as renewable energy carriers with substantial promise for reducing carbon emissions. However, the issue of nitrogen oxides (NO X , including NO and NO 2) and nitrous oxide (N 2 O) emissions from ammonia combustion and soot from biomass combustion, remains a pressing concern due to their detrimental impacts on the environment and human health. This study investigated the mechanism of pollutant formation during ammonia-lignin co-firing through reactive molecular dynamics (RMD) simulations. The results indicate that co-firing a certain amount of ammonia with lignin can reduce the formation of soot. This is mainly due to NH 2 radicals converting a portion of polycyclic aromatic hydrocarbon (PAH) precursors into C–N compounds. However, it is necessary to maintain higher ammonia concentrations. Adding a small quantity of ammonia would decrease the extent of oxidative reactions within the system and fail to generate enough NH 2 radicals to consume the carbon atoms forming PAH precursors, ultimately resulting in increased soot production. The impact of lignin on the formation of NO X and N 2 O during ammonia combustion has two main aspects: Firstly, the oxidising radicals formed during the initial decomposition of lignin promote the generation of N–O bonds, leading to an increase in the quantities of NO X and N 2 O during the initial reaction stage. Secondly, the carbon-containing products produced from lignin decomposition consume nitrogen atoms by forming N–C bonds, thereby diminishing available nitrogen atoms for nitrogen oxides formation. This study provides new insights into the formation of primary pollutants of ammonia and biomass co-firing on an atomic scale, which can help develop pollutant mitigation measures. • The chemical mechanism of pollutant formation during the co-firing of ammonia and biomass lignin is revealed. • A small quantity of ammonia promotes soot formation but increased quantities have the opposite effect. • NO production is enhanced by lignin in the initial stage of the co-firing, but the trend is reversed subsequently. • NO 2 formation is linked to oxidative reactions, while N 2 O formation depends on NH 2 concentration. [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]

Background: Remimazolam is an ultrashort-acting benzodiazepine. Few studies have evaluated the effects of remimazolam-based total intravenous anesthesia (TIVA) on emergence agitation (EA). This study aimed to compare the incidence and severity of EA between TIVA using remimazolam and desflurane. Methods: This prospective randomized controlled study enrolled 76 patients who underwent nasal surgery under general anesthesia. Patients were randomized into two groups of 38 each: desflurane-nitrous oxide (N2O) (DN) and remimazolam-remifentanil (RR) groups. The same protocol was used for each group from induction to emergence, except for the use of different anesthetics during maintenance of anesthesia according to the assigned group: desflurane and nitrous oxide for the DN group and remimazolam and remifentanil for the RR group. The incidence of EA as the primary outcome was evaluated using three scales: Ricker Sedation-Agitation Scale, Richmond Agitation-Sedation Scale, and Aono's four-point agitation scale. Additionally, hemodynamic changes during emergence and postoperative sense of suffocation were compared. Results: The incidence of EA was significantly lower in the RR group than in the DN group in all three types of EA assessment scales (all P < 0.001). During emergence, the change in heart rate differed between the two groups (P = 0.002). The sense of suffocation was lower in the RR group than in the DN group (P = 0.027). Conclusions: RR reduced the incidence and severity of EA in patients undergoing nasal surgery under general anesthesia. In addition, RR was favorable for managing hemodynamics and postoperative sense of suffocation. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Controlled studies have extensively documented that concentrate supplements typically increase enteric CH 4 emissions and milk yield and reduce emissions per unit of milk produced and dry matter intake. However, no studies have been conducted to determine the effect of concentrate on predicted greenhouse gas emissions from dairy farms representing the Australian pasture-based farming system. Thus, this study sought to determine how dietary concentrate supplementation affects enteric and manure CH 4 , and N 2 O of Australian pasture-based dairy farms. The Australian Dairy Carbon Calculator was used, which incorporates emission factors and methodologies used in the National Greenhouse Gas Inventory as reported to the Intergovernmental Panel on Climate Change. Primary data were collected and analyzed from 120 commercial farms in Australia's major dairy regions. Then the farms were divided into 4 groups based on their dietary concentrate supplementation: ≤1 (low; 15 farms), 1 to 2 (moderate; 35 farms), 2 to 3 (high; 35 farms), and ≥3 (very high; 35 farms) t of concentrate dry matter (tDM) per cow per year. Sources of greenhouse gas emissions were CO 2 from concentrate production, enteric CH 4 , and manure CH 4 and N 2 O. Total dry matter intake, milk yield, and daily enteric CH 4 production (g/d) quadratically increased with concentrate level, whereas greenhouse gas emission intensity of milk production (kg of CO 2 equivalent per kg of fat- and protein-corrected milk) decreased by 14% for farms supplementing with ≥3 tDM/cow per year compared with those supplementing with ≤1 tDM/cow per year of dietary concentrate. The N 2 O and CH 4 emissions from manure increased quadratically and linearly, respectively, with the increasing supplementation of concentrate. Farms supplementing 2 to 3 tDM/cow per year showed substantial increases in gross income, gross margin, earnings before interest and tax, and net income ($/cow per year) compared with those supplementing of ≤1, 1 to 2, and ≥3 tDM/cow per year. Overall, increasing dietary concentrate supplementation for dairy cows resulted in increased milk production per cow, reduced greenhouse gas emissions per unit of milk produced, and increased income and profit. However, a comprehensive life cycle assessment study is needed to account for carbon sequestration by other farm components, such as pastures and trees, which were not considered in the present study. In addition, the present study was based on modeling and did not gather ground truth information for DMI, digestibility, crude protein, and urinary and fecal N excretion. Therefore, data should be interpreted with caution, and studies gathering such information are encouraged. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the effect of biochar on N2O emissions in soils with different pH levels. Soils with five pH levels (4.0, 5.1, 5.8, 6.6, and 7.2) were incubated in two conditions, with 0% biochar (CK) and 1% biochar (BC), for 23 days. N2O emissions were measured at nine time points, and soil chemical properties, AOA-amoA, AOB-amoA, nirK, nirS, and nosZ, were analyzed. Partial least squares path modelling (PLS-PM) was used to assess the effect of nitrification and denitrification pathways on potential N2O emissions. The results showed that biochar reduced N2O emissions in highly acidic soil (pH 4.0) but increased emissions in soils with pH values ranging from 5.1 to 7.2. In highly acidic soils, decreased N2O emission was associated with increased soil pH (p < 0.05) and decreased dissolved organic carbon content (p < 0.05), leading to higher nosZ gene abundance (p < 0.05). Meanwhile, in acidic to neutral soils, biochar application increased soil pH (6.6–11.7%), dissolved organic nitrogen (5.9–29.5%), dissolved organic carbon (8.6–41.0%), stimulated AOB-amoA, nirK, nirS gene abundance (p < 0.05), and thus increased N2O emissions. The results verified the influence of nitrification and denitrification genes on N2O production in soils with different pH values. In conclusion, biochar had different effects on N2O emissions based on soil pH, highlighting the need to consider pH when using biochar to mitigate N2O emissions in subtropical citrus orchards. [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]

Aims: Nitrous oxide (N2O) plays an important role in global climate change. Plant expansion can alter soil nutrient cycling and greenhouse gas (GHG) fluxes but the effects of fine root litter mixing from plant expansion on litter decomposition, nutrient cycling, and GHG fluxes are poorly understood. Methods: To evaluate the impacts of fine root litter mixing from plant expansion on GHG budgets, we conducted an in situ study over sixteen months in Japanese cedar (Cryptomeria japonica) plantations experiencing moso bamboo (Phyllostachys edulis) expansions. Litter decomposition and N2O production were quantified in a full-factorial complete-randomized design by comparing fine root litter of Japanese cedar, moso bamboo or their mixtures, with or without nitrogen (N) addition. Results: We found that litter mixing accelerated decomposition, demonstrating a synergistic non-additive effect (19% increase in mass loss). This might have accelerated release of chemicals that inhibit microbial activities because litter mixtures had lower microbial biomass. Soil N2O emissions in the mixed litter treatment were 16.8% and 24.4% lower than those with only cedar or bamboo litter, respectively. N deposition promoted mass loss of mixed litter (28% increase in mass loss) and increased N2O emissions by 36.7%, 60.6% and 33.6% from cedar, mixed and bamboo litter treatments, respectively. Conclusion: The expansion of moso bamboo promotes the return of soil nutrients, reduces N2O emissions, and potentially mitigates GHG emissions. However, with increasing N deposition in the future, moso bamboo expansion will likely contribute to global warming. [ABSTRACT FROM AUTHOR]

Nitrous oxide is used as an anaesthetic and analgesic agent in the medical setting and is known to cause raised intracranial pressure. The use of nitrous oxide recreationally for the drug's euphoric and relaxant properties has been linked to multiple neurological and psychiatric sequelae including neuropathy, myelopathy, and psychosis. We describe a case of a young person who declared heavy nitrous oxide use resulting in vision-threatening papilloedema secondary to raised intracranial pressure. He underwent emergency lumbar drainage alongside high-dose acetazolamide and parenteral vitamin B12 injections. To our knowledge, there have yet to be other reports of cases where heavy nitrous oxide use has caused secondary pseudotumor cerebri syndrome. [ABSTRACT FROM AUTHOR]

Nitrous oxide, an inhalational anaesthetic, is popular with adolescents worldwide as an accessible recreational drug which induces a euphoric effect. However, chronic abuse leads to serious complications such as myeloneuropathy and bone marrow suppression by inactivation of vitamin B12. A 17-year-old girl presented with nitrous oxide-induced myeloneuropathy. She reported chronic nitrous oxide inhalation for 10 months and was admitted to the emergency department on account of repeated falls for 2 weeks. She also had ascending paraesthesia in both legs and urinary incontinence. Neurological examination demonstrated bilateral lower extremity weakness [motor power: proximal muscles 4/5, plantar flexion and extensor hallucis longus (EHL) 3/5], decreased sensation, proprioception and vibration of the lower extremities. Deep tendon reflexes were absent in the ankles and knees. Laboratory results demonstrated mild anaemia [Hb 11.2 g/dL (12.0–16.0), haematocrit 35.4% (36–50), MCV 89.4 fl (78–102)] with significant hypersegmented neutrophils in a peripheral blood smear. Serum vitamin B12 was 340 pg/mL (197–771), but serum homocysteine was increased at 65.8 µmol/L (5–15). A nerve conduction study was prolonged, and F-waves were absent from the bilateral perineal and tibial nerves, indicating diffuse demyelinating motor polyneuropathy. Magnetic resonance imaging of the whole spine demonstrated faint T2 hypersignal intensity and an inverted V-shape appearance at the posterior column of the upper thoracic cord (around T2–T6), a pathognomonic sign of vitamin B12 deficiency or subacute combined degeneration of the nitrous oxide-induced myeloneuropathy. A 7-day course of 1000 µg cyanocobalamin was given intramuscularly, followed by weekly doses for 4 weeks. Supplements of daily oral vitamin B1, B6 and B12 (65 µg vitamin B12) were administered, along with rehabilitation. At the 6-months outpatient follow-up, there were a few residual neurological abnormalities: weakness of the left EHL (grade 4/5) and an absent deep tendon reflex in the left ankle. This case emphasises the significant health consequences of chronic abuse of nitrous oxide, myeloneuropathy and megaloblastic anaemia, by inactivation of vitamin B12. The myelopathy is noticeably improved by cyanocobalamin. Abbreviations: EHL: extensor hallucis longus; MRI: magnetic resonance imaging; NCS: nerve conduction study [ABSTRACT FROM AUTHOR]

Four new tirucallane-type triterpenoids, polystanins H–K (1–4), were obtained from the stems and leaves of Aphanamixis polystachya. Their structures were elucidated by analysis of the spectroscopic data and comparison with literature data. Compounds 1 and 2 showed week inhibitory effects against NO production in LPS-stimulated RAW264.7 cells. All the isolates were investigated for their antifungal activities against drug-resistant Candida albicans. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N 2 O) emissions sourced from agricultural and industrial activities have gained much attention because of their contribution to the global greenhouse effect and ozone layer depletion. Significant efforts have been devoted to developing the cost-effective and highly efficient technologies for N 2 O removal. The direct N 2 O decomposition is limited by the thermodynamic equilibrium at high temperatures. Recently, catalytic reduction of N 2 O with carbon-free hydrogen derived from in situ ammonia decomposition is considered as an ideal approach. Herein, thermal decomposition of N 2 O is investigated by employing a BaCe 0.85 Fe 0.15 O 3-δ -BaCe 0.15 Fe 0.85 O 3-δ (BCF8515-BCF1585) hydrogen-transporting membrane or a Ce 0.85 Sm 0.15 O 1.925 -Sm 0.6 Sr 0.4 FeO 3-δ (SDC-SSF) oxygen-transporting membrane respectively. It is noted that the membrane catalysis of N 2 O decomposition by reacting with permeated hydrogen or via in-situ oxygen removal displayed significant advantages over the direct thermal decomposition of N 2 O under a fixed bed condition. Moreover, the N 2 O conversion as well as hydrogen/oxygen permeability of such membranes were greatly improved by the introduction of porous Ni–CeO 2 or SDC-NCO layers due to the increased catalytic activities and hydrogen/oxygen surface exchange kinetics. [ABSTRACT FROM AUTHOR]

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]

A three-year field experiment was carried out to investigate the methane (CH4) and nitrous oxide (N2O) emissions and calculate the global warming potential (GWP) according to all energy input in response to the nitrogen (N) rate in the typical rice-wheat rotation system in Jiangsu, China. Four N treatments, including R220W180 (local practice), R220W140 (cutting 10% total N in wheat season), R180W180 (cutting 10% total N in rice season) and R180W140 (cutting 20% total N in rice and wheat seasons separately), were designed in the study. Results showed that annual CH4 emission was decreased by 25.7% in response to cutting 20% N, which was ascribed to the 24.6% reduction of CH4 emission in rice season (P < 0.05) compared to local practice. The mitigation of N2O emissions in R220W140 and R180R180 treatments contributed to the 8.5% and 15.7% decrease in annual N2O emission, which was the 23.5% decrease in cutting 20% N treatment compared to local practice, respectively. Specifically, under the same amount of N rate condition (10% N cutting), the transfer N from rice season (R220W140) to wheat season (R180W180) led to the 8.5% increase in N2O emission (P < 0.05). In the end, the cutting of 20% N decreased GWP and yield-scale GWP by 19% and 17%, which mainly originated from CH4 and N2O emissions. However, cutting N did not significantly decrease grain yield (P > 0.05). These results suggested that the 180 kg N/ha for rice and 140 kg N/ha for wheat in one rotation season were the beneficial N rate to achieve the co-benefit of yield and GWP in the typical rice-wheat rotation system in Jiangsu, China. [ABSTRACT FROM AUTHOR]

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The demand for biomass energy production in the Philippines has led to substantial rice husk ash (RHA) generation. We combined alternate wetting and drying (AWD) and varying RHA rates (10, 20, and 30 t ha–1) to evaluate the yield, water productivity (WP), and greenhouse gas (GHG) emissions in paddy rice for four cropping seasons (CS). We compared these treatments with continuous flooding (CF) and no RHA as controls. The RHA decreased N2O emissions by 8–22%, in the order of RHA30 > RHA20 > RHA10 relative to the control. The AWD had a marginal effect (P < 0.10) on CH4 emissions, with a 10% reduction relative to CF. While yields did not differ among treatments, AWD saved 39% water, and WP increased by 0.56 kg m–3 relative to CF. A significant interaction (P < 0.05) among water, RHA, and CS on N2O emissions was associated with rice stubble management in the first CS just after the harvest of the previous crop (dry incorporation), while the other seasons incorporated stubbles during wetland preparation. Although the highest RHA rate was likely to increase N2O emissions under AWD conditions, the global warming potential (GWP) was still significantly lower (P < 0.05) in the first CS in either water management by up to 15 times lower compared to other CS at all RHA rates. Our results indicated that the primary RHA effects mitigated N2O emissions, while AWD had only marginal effects on CH4 emissions but maintained grain yield under our experimental conditions. The low total GWP in the first CS suggests that the additional mitigation measures of RHA application and water management need to be associated with the proper management of rice stubbles first. [ABSTRACT FROM AUTHOR]