Highly Efficient One-pot Electrosynthesis of Oxime Ethers from NOx over Ultrafine MgO Nanoparticles Derived from Mg-based Metal-Organic Frameworks.

Oxime ethers are attractive compounds in medicinal scaffolds due to the biological and pharmaceutical properties, however, the crucial and widespread step of industrial oxime formation using explosive hydroxylamine (NH2OH) is insecure and troublesome. Herein, we present a convenient method of oxime ether synthesis in a one-pot tandem electrochemical system using magnesium based metal-organic frameworks-derived magnesium oxide anchoring in self-supporting carbon nanofiber membrane catalyst (MgO-SCM), the in situ NH2OH from nitrogen oxides electrocatalytic reduction couples with aldehyde to produce 4-cyanobenzaldoxime with a selectivity of 93% and Faraday efficiency up to 65.1%, which further reacted with benzyl bromide to directly give oxime ether precipitate with a purity of 97% by convenient filtering separation. The high efficiency was attributed to the ultrafine MgO nanoparticles in MgO-SCM, effectively inhibiting hydrogen evolution reaction and accelerating the production of NH2OH, which rapidly attacked carbonyl of aldehydes to form oximes, but hardly crossed the hydrogenation barrier of forming amines, thus leading to a high yield of oxime ether when coupling benzyl bromide nucleophilic reaction. This work highlights the importance of kinetic control in complex electrosynthetic organonitrogen system and demonstrates a green and safe alternative method for synthesis of organic nitrogen drug molecules.

Multi-index control strategy from cement calcination denitration system: a model predictive control method for combined control of nitrogen oxide and ammonia escape.

The cement industry is one of the main sources of NOx emissions, and automated denitration systems enable precise control of NOx emission concentration. With non-linearity, time delay and strong coupling data in cement production process, making it difficult to maintain stable control of the denitration system. However, excessive pursuit of denitration efficiency is often prone to large ammonia escape, causing environmental pollution. A multi-objective prediction model combining time series and a bi-directional long short-term memory network (MT-BiLSTM) is proposed to solve the data problem of the denitration system and achieve simultaneous prediction of NOx emission concentration and ammonia escape value. Based on this model, a model predictive control framework is proposed and a control strategy of denitration system with multi-index model predictive control (MI-MPC) is built based on neural networks. In addition, the differential evolution (DE) algorithm is used for rolling optimization to find the optimal solution and to obtain the best control variable parameters. The control method proposed has significant advantages over the traditional PID (proportional integral derivative) controller, with a 3.84% reduction in overshoot and a 3.04% reduction in regulation time. Experiments prove that the predictive control framework proposed in this paper has better stability and higher accuracy, with practical research significance.

Modification strategies for semiconductor metal oxide nanomaterials applied to chemiresistive NOx gas sensors: A review.

Semiconductor metal oxides (SMOs) nanomaterials are a category of sensing materials that are widely applied to chemiresistive NOx gas sensors. However, there is much space to improve the sensing performance of SMOs nanomaterials. Therefore, how to improve the sensing performance of SMOs nanomaterials for NOx gases has always attracted the interest of researchers. Up to now, there are few reviews focus on the modification strategies of SMOs which applied to NOx gas sensors. In order to compensate for the limitation, this review summarizes the existing modification strategies of SMOs, hoping to provide researchers a view of the research progress in this filed as comprehensive as possible. This review focuses on the progress of the modification of SMOs nanomaterials for chemiresistive NOx (NO, NO2) gas sensors, including the morphology modulation of SMOs, compositing SMOs, loading noble metals, doping metal ions, compositing with carbon nanomaterials, compositing with biomass template, and compositing with MXene, MOFs, conducting polymers. The mechanism of each strategy to enhance the NOx sensing performance of SMOs-based nanomaterials is also discussed and summarized. In addition, the limitations of some of the modification strategies and ways to address them are discussed. Finally, future perspectives for SMOs-based NOx gas sensors are also discussed.

Severe Xerostomia Induced by Multiple Systemic Diseases in a Patient with Psoriasis Vulgaris: A Case Report and Literature Review.

Introduction: Psoriasis is a complex autoimmune disease associated with chronic systemic keratinization and inflammation, which can affect the skin, joints, and oral cavity. Xerostomia is a subjective feeling of oral dryness that impairs patient comfort and lowers the quality of life. The aim of this case report is to describe the clinical mechanism of xerostomia in a psoriasis patient with multiple systemic diseases. Case Report: A 51-year-old inpatient man with psoriasis vulgaris was referred to the Oral Medicine Department with complaints of difficulty swallowing due to a sore throat and dry tongue since last week. The patient had psoriasis vulgaris 15 years ago, chronic adrenal insufficiency, psoriatic arthritis, acute circulatory collapse, anemia of inflammation, acute kidney injury, dehydration, gastritis, urinary tract infections, and malnutrition. A complete anamnesis and oral examination were done. The patient was diagnosed with severe xerostomia, a fissured tongue, exfoliative cheilitis, angular cheilitis, and gingivitis by the Oral Medicine Department. Case Management: The patient was treated with petroleum jelly, chlorine dioxide mouthwash, miconazole cream, and benzydamine HCl lozenges. Conclusion: Based on case reports and reviews, multiple systemic diseases may not only increase the risk of xerostomia but also aggravate its severity.

Characteristics of NOX and NH3 emissions from in-use heavy-duty diesel vehicles with various aftertreatment technologies in China.

Some in-use China IV and China V heavy-duty diesel vehicles (HDDVs) with selective catalytic reduction (SCR) systems probably fail to mitigate nitrogen oxide (NOX) emissions as expected. Meanwhile, these SCR-equipped HDDVs might emit excessive ammonia (NH3). To better understand the NOX and NH3 emissions from typical HDDVs in China, seventeen in-use vehicles with various emission-control technologies were tested by using laboratory chassis dynamometers. The results indicated that individual NOX and NH3 emissions from HDDV fleets widely varied owing to differences in aftertreatment performance. China V and VI HDDVs with effectively functioning SCRs could substantially control their NOX emissions to be below the corresponding emission limits (i.e., 4.0 and 0.69 g/kWh for China V and China VI vehicles, respectively) but with a potential risk of high NH3 emissions caused by diesel exhaust fluid (DEF) overdosing. Furthermore, higher vehicle speed and payload resulted in lower NOX emissions and possibly higher NH3 emissions from HDDVs with effectively functioning SCRs, while higher NOX emissions from tampered- and non-SCR HDDVs. NOX emissions from China VI HDDVs were more sensitive to cold starts compared to China V and earlier vehicles, but there was no significant discrepancy in NH3 emissions between cold- and hot-start tests.

Hourly Air Pollution Exposure and Emergency Hospital Admissions for Stroke: A Multicenter Case-Crossover Study.

BACKGROUND: Daily exposure to ambient air pollution is associated with stroke morbidity and mortality; however, the association between hourly exposure to air pollutants and risk of emergency hospital admissions for stroke and its subtypes remains relatively unexplored. METHODS: We obtained hourly concentrations of fine particulate matter (PM2.5), respirable particulate matter (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) from the China National Environmental Monitoring Center. We conducted a time-stratified case-crossover study among 86 635 emergency hospital admissions for stroke across 10 hospitals in 3 cities (Jinhua, Hangzhou, and Zhoushan) in Zhejiang province, China, between January 1, 2016 and December 31, 2021. Using a conditional logistic regression combined with a distributed lag linear model, we estimated the association between hourly exposure to multiple air pollutants and risk of emergency hospital admissions for total stroke, ischemic stroke, hemorrhagic stroke, and undetermined type. RESULTS: Hourly exposure to PM2.5, PM10, NO2, and SO2 was associated with an increased risk of hospital admissions for total stroke and ischemic stroke. The associations were most pronounced during the concurrent hour of exposure and lasted for ≈2 hours. We found that the risk was more pronounced among male patients or those aged <65 years old. CONCLUSIONS: Our findings suggest that exposure to PM2.5, PM10, NO2, and SO2, but not CO and O3, is associated with emergency hospital admissions for total stroke or ischemic stroke shortly after exposure. Implementing targeted pollution emission reduction measures may have significant public health implications in controlling and reducing the burden of stroke.

Sustained Release of Nitric Oxide-Mediated Angiogenesis and Nerve Repair by Mussel-Inspired Adaptable Microreservoirs for Brain Traumatic Injury Therapy.

Traumatic brain injury (TBI) triggers inflammatory response and glial scarring, thus substantially hindering brain tissue repair. This process is exacerbated by the accumulation of activated immunocytes at the injury site, which contributes to scar formation and impedes tissue repair. In this study, a mussel-inspired nitric oxide-release microreservoir (MINOR) that combines the features of reactive oxygen species (ROS) scavengers and sustained NO release to promote angiogenesis and neurogenesis is developed for TBI therapy. The injectable MINOR fabricated using a microfluidic device exhibits excellent monodispersity and gel-like self-healing properties, thus allowing the maintenance of its structural integrity and functionality upon injection. Furthermore, polydopamine in the MINOR enhances cell adhesion, significantly reduces ROS levels, and suppresses inflammation. Moreover, a nitric oxide (NO) donor embedded into the MINOR enables the sustained release of NO, thus facilitating angiogenesis and mitigating inflammatory responses. By harnessing these synergistic effects, the biocompatible MINOR demonstrates remarkable efficacy in enhancing recovery in mice. These findings benefit future therapeutic interventions for patients with TBI.

Electrocatalytic Synthesis of Pyridine Oximes using in Situ Generated NH2 OH from NO species on Nanofiber Membranes Derived from NH2 -MIL-53(Al).

Pyridine oximes produced from aldehyde or ketone with hydroxylamine (NH2 OH) have been widely applied in pharmaceutics, enzymatic and sterilization. However, the important raw material NH2 OH exhibits corrosive and unstable properties, leading to substantial energy consumption during storage and transportation. Herein, this work presents a novel method for directly synthesizing highly valuable pyridine oximes using in situ generated NH2 OH from electrocatalytic NO reduction with well-design nanofiber membranes (Al-NFM) derived from NH2 -MIL-53(Al). Particularly, 2-pyridinealdoxime, the precursor of antidote pralidoxime (2-PAM) for nerve agents suffering from scarcity and high cost, was achieved with a Faraday efficiency up to 49.8 % and a yield of 92.1 %, attributing to the high selectivity of NH2 OH production on Al-NFM, further easily reacted with iodomethane to produce 2-PAM. This study proposes a creative approach, having wide universality for synthesizing pyridine and other oximes with a range of functional groups, which not only facilitates the conversion of exhaust gas (NO) and waste water (NO2 - ) into valuable chemicals especially NH2 OH production and in situ utilization through electrochemistry, but also holds significant potential for synthesis of neuro detoxifying drugs to humanity security.

GNOME: A Gaseous Nitrogen Oxide Measuring front-End for aqueous environmental materials.

GNOME is a straightforward and easy to build sample handling apparatus, designed to prepare dissolved nitrogen oxide species in aqueous environmental samples. GNOME is designed to serve as a sample preparation device for downstream chemiluminescent analysis. It is based on the familiar chemistry ring stand; the major advantage scalability designed to accommodate the needs of the user. Additionally, since GNOME is constructed of discrete, snap-to-fit components, the modular design allows users to easily substitute or replace parts. Given that there are few to zero commercial equivalents, construction plans to fill this hardware gap are offered herein. The inlet can resolve down to a lower limit of at least 0.05 nmoles NOX, and is instrumentally linear to a ≥10 nmoles NOX. The approach increases sample throughput, data quality, and overall user experience, making it more efficient than the off-the-shelf commercial equivalent.

Involvement of the Restoration of Cerebral Blood Flow and Maintenance of eNOS Expression in the Prophylactic Protective Effect of the Novel Ferulic Acid Derivative FAD012 against Ischemia/Reperfusion Injuries in Rats.

Tissue plasminogen activator, aiming to restore cerebral blood flow (CBF), has been used for acute ischemic strokes in clinics; however, its narrow therapeutic time window remains a serious concern. To develop novel prophylactic drugs to alleviate cerebral ischemia/reperfusion injuries, ferulic acid derivative 012 (FAD012) was synthesized and showed comparable antioxidant properties to ferulic acid (FA) and probably possesses the potent ability to cross the blood-brain barrier. A more potent cytoprotective effect of FAD012 against H2O2-induced cytotoxicity in PC12 cells was also observed. In vivo toxicity was not observed in rats given a long-term oral administration of FAD012, indicating its good tolerability. A one-week-course oral administration of FAD012 significantly alleviated middle cerebral artery occlusion (MCAO)-induced cerebral ischemia/reperfusion injuries in rats, accompanied by the restoration of CBF and endothelial nitrogen oxide synthetase (eNOS) expression. Treatment with FAD012 significantly restored the cell viability and eNOS expression damaged by H2O2, used to mimic MCAO-triggered oxidative stress, in rat brain microvascular endothelial cells. Our findings suggested that FAD012 protected the viability of vascular endothelium and maintained eNOS expression, ultimately contributing to the restoration of CBF, and may provide a rationale for the development of FAD012 into an effective prophylactic drug for patients at high risk of stroke.

Electrosynthesis of α-Amino Acids from NO and other NOx species over CoFe alloy-decorated Self-standing Carbon Fiber Membranes.

The conversion of industrial exhaust gases of nitrogen oxides into high-value products is significantly meaningful for global environment and human health. And green synthesis of amino acids is vital for biomedical research and sustainable development of mankind. Herein, we demonstrate an innovative approach for converting nitric oxide (NO) to a series of α-amino acids (over 13 kinds) through electrosynthesis with α-keto acids over self-standing carbon fiber membrane with CoFe alloy. The essential leucine exhibits a high yield of 115.4 µmol h-1 corresponding a Faradaic efficiency of 32.4 %, and gram yield of products can be obtained within 24 hours in lab as well as an ultra-long stability (>240 h) of the membrane catalyst, which could convert NO into NH2 OH rapidly attacking α-keto acid and subsequent hydrogenation to form amino acid. In addition, this method is also suitable for other nitrogen sources including gaseous NO2 or liquidus NO3 - and NO2 - . Therefore, this work not only presents promising prospects for converting nitrogen oxides from exhaust gas and nitrate-laden waste water into high-value products, but also has significant implications for synthetizing amino acids in biomedical and catalytic science.

Effect of Manganese Distribution on Sensor Properties of SnO2/MnOx Nanocomposites.

Nanocomposites SnO2/MnOx with various manganese content (up to [Mn]/[Sn] = 10 mol. %) and different manganese distribution were prepared by wet chemical technique and characterized by X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and mapping, IR and Raman spectroscopy, total reflection X-ray fluorescence, mass-spectrometry with inductive-coupled plasma (ICP-MS), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy. A different distribution of manganese between the volume and the surface of the SnO2 crystallites was revealed depending on the total Mn concentration. Furthermore, the identification of surface MnO2 segregation was performed via Raman spectroscopy. There is a strong dependence of the sensor signal toward CO and, especially, NO) on the presence of MnO2 surface segregation. However, manganese ions intruding the SnO2 crystal structure were shown to not almost effect on sensor properties of the material.

Electrocatalytic Synthesis of Essential Amino Acids from Nitric Oxide Using Atomically Dispersed Fe on N-doped Carbon.

How to transfer industrial exhaust gases of nitrogen oxides into high-values product is significantly important and challenging. Herein, we demonstrate an innovative method for artificial synthesis of essential α-amino acids from nitric oxide (NO) by reacting with α-keto acids through electrocatalytic process with atomically dispersed Fe supported on N-doped carbon matrix (AD-Fe/NC) as the catalyst. A yield of valine with 32.1 µmol mgcat -1 is delivered at -0.6 V vs. reversible hydrogen electrode, corresponding a selectivity of 11.3 %. In situ X-ray absorption fine structure and synchrotron radiation infrared spectroscopy analyses show that NO as nitrogen source converted to hydroxylamine that promptly nucleophilic attacked on the electrophilic carbon center of α-keto acid to form oxime and subsequent reductive hydrogenation occurred on the way to amino acid. Over 6 kinds of α-amino acids have been successfully synthesized and gaseous nitrogen source can be also replaced by liquid nitrogen source (NO3 - ). Our findings not only provide a creative method for converting nitrogen oxides into high-valued products, which is of epoch-making significance towards artificial synthesis of amino acids, but also benefit in deploying near-zero-emission technologies for global environmental and economic development.

Fertilizer-induced N2O and NO emissions in tea gardens and the main controlling factors: A recent three-decade data synthesis.

Tea gardens have been widely documented to be hotspots for nitrogen (N) oxide emissions (i.e., nitrous oxide (N2O) and nitric oxide (NO)). However, a quantitative understanding of N oxide emissions related to different fertilizer regimes and the main controlling factors is lacking. Here, we performed a meta-analysis of 56 peer-reviewed publications on N oxide emissions from global tea gardens over the past three decades. Overall, fertilization increased N2O and NO emissions (p < 0.001) by 584 % and 790 %, respectively. The stimulating effect of fertilizer on N2O and NO emissions was mainly related to high N application rates. Furthermore, organic fertilizer treatment, combined fertilizer treatment, biochar amendment, and inhibitor amendment reduced N2O emissions (p < 0.05) by 63 %, 64 %, 69 %, and 94 %, respectively, relative to chemical fertilizer treatment. For NO emissions, only biochar amendment decreased fertilizer-driven stimulation (by 80 %, p < 0.05). Notably, the dominant factors that influenced fertilizer-induced N2O and NO emissions in tea gardens were fertilization regimes, climatic conditions, and soil properties. On a global scale, fertilization increased mean N2O and NO emissions (p < 0.05) from global tea gardens by 44.5 Gg N yr-1 and 34.3 Gg N yr-1, respectively, whereas compared with no amendment application, inhibitors reduced N2O emissions (p < 0.05) by 32.2 Gg N yr-1 and biochar reduced NO emissions (p < 0.05) by 23.6 Gg N yr-1. Our results suggest that to obtain maximum ecological and economic benefits, appropriate N fertilizer and biochar and inhibitor amendments should be applied for site-specific mitigation purposes, and long-term, multiarea, in situ experiments and microbial mechanism studies should be conducted.

Differences between VOCs and NOx transport contributions, their impacts on O3, and implications for O3 pollution mitigation based on CMAQ simulation over the Yangtze River Delta, China.

The relationship between O3 and its precursors during urban polluted episodes remains unclear. In this study, the simultaneous source apportionment of VOCs, NOx, and O3 over the Yangtze River Delta (YRD) region during the O3 polluted episode on July 24-30, 2018, was performed based on the Integrated Source Apportionment Method (ISAM) embedded in the Community Multiscale Air Quality Modeling System (CMAQ). The results of the ISAM were compared with those of the Brute Force Method (BFM) and Positive Matrix Factorization (PMF). Furthermore, the differences between the transport contributions of VOCs and NOx, and their impacts on O3 were analyzed. The results indicate that observations of VOCs species can be well captured by simulated VOCs, and the ISAM has a significant advantage in the source apportionment of VOCs, especially for sources emitting highly reactive species. In the clean and polluted periods, the local contribution percentages of VOCs in urban sites ranged from 60 % to 77 %, much higher than those of NOx (31 %-43 %) and O3 (16 %-33 %). NOx and O3 have strong transport abilities with high and close contribution percentages, which are highly correlated, mainly because oxygen atoms produced by the photolysis of NO2 in the aged air mass combined rapidly with O2 to form O3 during transport. The VOCs chemical loss caused by the oxidation of OH radicals during transport makes the ability of VOCs for long-distance transport much weaker than that of NOx. Furthermore, owing to the sufficient aging of VOCs, those contributed by long-distance transport have little effect on O3. To a certain extent, controlling one's NOx emissions can help other cities more, while controlling one's VOCs emissions can help itself more. Therefore, it is recommended to attach enough importance to joint prevention and control of NOx among cities and even long-distance areas to alleviate regional O3 pollution.

Biochar amendments and climate warming affected nitrification associated N2O and NO production in a vegetable field.

Soil nitrification driven by ammonia-oxidizing microorganisms is the most important source of nitrous oxide (N2O) and nitric oxide (NO). Biochar amendment has been proposed as the most promising measure for combating climate warming; both have the potential to regulate the soil nitrification process. However, the comprehensive impacts of different aged biochars and warming combinations on soil nitrification-related N2O and NO production are not well understood. Here, 1-octyne and acetylene were used to investigate the relative contributions of ammonia-oxidizing bacteria (AOB) and archaea (AOA) to potential nitrification-mediated N2O and NO production from the fertilized vegetable soil with different aged biochar amendments and soil temperatures in microcosm incubations. Results demonstrated that AOB dominated nitrification-related N2O and NO production across biochar additions and climate warming. Biochar amendment did not significantly influence the relative contribution of AOB and AOA to N2O and NO production. Field-aged biochar markedly reduced N2O and NO production via inhibiting AOB-amoA gene abundance and AOB-dependent N2O yield while fresh- and lab-aged biochar produced negligible effects on AOB-dependent N2O yield. Climate warming significantly increased N2O production and AOB-dependent N2O yield but less so on NO production. Notably, the relative contribution of AOB to N2O production was enhanced by climate warming, whereas AOB-derived NO showed the opposite tendency. Overall, the results revealed that field-aged biochar contributed to mitigating warming-induced increases in N2O and NO production via inhibiting AOB-amoA gene abundance and AOB-dependent N2O yield. Our findings provided guidance for mitigating nitrogen oxide emissions in intensively managed vegetable production under the context of biochar amendments and climate warming.

Rational Regulation of Reducibility and Acid Site on Mn-Fe-BTC to Achieve High Low-Temperature Catalytic Denitration Performance.

Selective catalytic reduction with ammonia is the mainstream technology of flue gas denitration (de-NOx). The reducibility and acid site are two important factors affecting the de-NOx performance, and effective regulation between them is the key to obtain a highly efficient de-NOx catalyst. Herein, a series of Mn-Fe-BTC with different ratios of Mn and Fe are synthesized, among which 2Mn-1Fe-BTC with 2:1 molar ratio of Mn and Fe has excellent low-temperature (LT) de-NOx performance (above 90% NO conversion between 60 and 270 °C) and good tolerance to H2O and SO2 poisoning (88% NO conversion at 150 °C with 100 ppm of SO2 and/or 6% H2O). It is revealed that the reducibility properties and acid sites of Mn-Fe-BTC can be flexibly tuned by the ratio of Mn and Fe. The difference in electronegativity between Fe and Mn leads to the redistribution of valence electrons, which enables the controllable reducibility of Mn-Fe-BTC. Furthermore, different amounts of Mn and Fe lead to different electron transport, which determines the type and number of acid sites. The synergistic effect of Mn and Fe endows Mn-Fe-BTC with enhanced surface molecular adsorption capacity and enables the catalyst to selectively chemisorb NH3 and NO at different active sites. This research provides guidance for the flexible regulation of reducibility and acid site of LT de-NOx catalyst.

Association of air pollution with dementia: a systematic review with meta-analysis including new cohort data from China.

It remains unclear whether a total exposure to air pollution (AP) is associated with an increased risk of dementia. Little is known on the association in low- and middle-income countries. Two cohort studies in China (in Anhui cohort 1402 older adults aged ≥ 60 followed up for 10 years; in Zhejiang cohort 6115 older adults followed up for 5 years) were conducted to examine particulate matter - PM2.5 associated with all dementia and air quality index (AQI) with Alzheimer's disease, respectively. A systematic literature review and meta-analysis was performed following worldwide literature searched until May 20, 2020 to identify 15 population-based cohort studies examining the association of AP with dementia (or any specific type of dementia) through PubMed, MEDLINE, PsycINFO, SocINDEX, CINHAL, and CNKI. The cohort studies in China showed a significantly increased relative risk (RR) of dementia in relation to AP exposure; in Anhui cohort the adjusted RR was 2.14 (95% CI 1.00-4.56) in people with PM2.5 exposure at ≥ 64.5 µg/m3 versus <63.5 µg/m3 and in Zhejiang cohort the adjusted RR was 2.28 (1.07-4.87) in AQI>90 versus ≤ 80. The systematic review revealed that all 15 studies were undertaken in high income countries/regions, with inconsistent findings. While they had reasonably good overall quality of studies, seven studies did not adjust smoking in analysis and 13 did not account for depression. Pooling all eligible data demonstrated that dementia risk increased with the total AP exposure (1.13, 1.08-1.19). Data analysis of air pollutants showed that the RR significantly increased with PM2.5 (1.06, 1.03-1.10 in 2nd tertile exposure; 1.13, 1.07-1.19 in 3rd tertile versus 1st tertile), PM10 (1.05, 0.86-1.29; 1.62, 0.60-4.36), carbon monoxide (1.69, 0.72-3.93; 1.52, 1.35-1.71), nitrogen dioxide (1.06, 1.03-1.09; 1.18, 1.10-1.28) and nitrogen oxides (1.09, 1.04-1.15; 1.26, 1.13-1.41), but not ozone. Controlling air pollution and targeting on specific pollutants would reduce dementia globally.

Proper organic substitution attenuated both N2O and NO emissions derived from AOB in vegetable soils by enhancing the proportion of Nitrosomonas.

The ammonia oxidation process driven by microorganisms is an essential source of nitrous oxide (N2O) and nitric oxide (NO) emissions. However, few evaluations have been performed on the changes in the community structure and abundance of soil ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) under substituting portion of chemical fertilizers with organic manure (organic substitution) and their relative contribution to the ammonia oxidation process. Here, five long-term fertilization strategies were applied in field (SN: synthetic fertilizer application; OM: organic manure; M1N1: substituting 50 % of chemical N fertilizer with organic manure; M1N4: substituting 20 % of chemical N fertilizer with organic manure; and CK: no fertilizer). We investigated the response characteristics of AOB and AOA community structures by selective inhibitor shaking assays and high-throughput sequencing and further explained their relative contribution to the ammonia oxidation process during three consecutive years of vegetable production. Compared to SN and M1N4, the potential of ammonia oxidation (PAO) was significantly reduced by 26.4 % and 22.3 % in OM and 9.5 % and 4.4 % in M1N1, resulting in N2O reductions of 38.9 % and 30.8 % (OM) and 31.2 % and 21.1 % (M1N1), respectively, and NO reductions of 45.0 % and 34.1 % (OM) and 40.1 % and 28.3 % (M1N1). RDA and correlation analyses showed that the soil organic carbon and ammonium nitrogen content increased while AOB gene abundance and diversity significantly decreased with increasing organic replacement ratio; however, the relative abundance of Nitrosomonas in AOB increased in OM and M1N1, which further demonstrates that AOB are the main driver in vegetable soils. Therefore, the appropriate proportion of organic substitution (OM and M1N1) could decrease the N2O and NO emissions contributed by AOB by affecting the soil physicochemical properties and AOB community structure.

An assessment of NO2 atmospheric air pollution over three cities in South Africa during 2020 COVID-19 pandemic.

To contain the spread of COVID-19 in 2020, several governments around the world imposed national lockdowns including that of South Africa. The purpose of this study was to investigate and give an overview of nitrogen dioxide column levels during the year 2020 over three South African cities (Johannesburg, Durban and Cape Town) using AURA OMI derived measurements, the HYSPLIT model, complemented with NCEP/NCAR reanalysis data. Our findings were that in 2020, all the cities recorded their daily maximum mean NO2 column levels during the winter season at 14.1 × 1015 molecules per cm2, 3.1 × 1015 molecules per cm2 and 1.7 × 1015 molecules per cm2 for Johannesburg, Durban, and Cape Town respectively. Across all seasons, Cape Town recorded the lowest seasonal mean at 0.6 × 1015 molecules per cm2 (summer 2020) while the highest seasonal mean was recorded over Johannesburg at 9 × 1015 molecules cm2 (winter 2020). Furthermore, an interannual comparison analysis indicated that during summer, there were increases of 6%, 1% and 30% for Johannesburg, Durban and Cape Town respectively. During winter, Johannesburg saw an increase of 19% while a 2% increase was recorded in Durban with Cape town recording a 16% decrease in NO2 column levels. The study also recorded that Cape Town and Durban were mainly influenced by long-range transport air masses originating from the South Atlantic Ocean, South America, Antarctica and the Indian Ocean particularly during the summer and autumn seasons possibly leading to the formation of marine nitrate aerosols.