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The importance of nitrate and ammonium salts both in the environment and in biological processes cannot be questioned. In this work, using the TIP4P/2005 water model, aqueous solutions of nitrate and ammonium electrolytes are parametrized using scaled charges while keeping a rigid structure and nonpolarizable charge distributions. The models are optimized by systematically testing a set of properties for twelve electrolytes—eight nitrate and four ammonium salts—thus, enlarging the number of potential chemical species encompassed within the Madrid-2019 force field for ions. The capacity of the force field for predicting densities, ion–ion and ion–solvent structures, and transport properties of the solutions comprised by the trial batch of salts was tested and discussed. Both the dependence of the densities with the salt concentration and the solution structure were nicely reproduced by the models in the whole concentration range without any trace of precipitating events and with improved accuracy in comparison with recently reported models, while the agreement of the simulated transport properties with experimental data ranges from good to reasonable, depending on the ion/counterion pair. These scaled charge models might be considered as force fields embodying a reasonable compromise between exactness and general applicability and also as an important step in the development of accurate models for polyatomic ions. [ABSTRACT FROM AUTHOR]

The prepared NVOY electrode achieves high stability and excellent cycle performance for AZIBs by embedding polypyrrole in ammonium vanadate layers to remove excess ammonium ions, expand the interlayer spacing, and enhance electronic conductivity. [Display omitted] Ammonium vanadate with stable bi-layered structure and superior mass-specific capacity have emerged as competitive cathode materials for aqueous rechargeable zinc-ion batteries (AZIBs). Nevertheless, fragile N H...O bonds and too strong electrostatic interaction by virtue of excessive NH 4 + will lead to sluggish Zn2+ ion mobility, further largely affects the electro-chemical performance of ammonium vanadate in AZIBs. The present work incorporates polypyrrole (PPy) to partially replace NH 4 + in NH 4 V 4 O 10 (NVO), resulting in the significantly enlarged interlayers (from 10.1 to 11.9 Å), remarkable electronic conductivity, increased oxygen vacancies and reinforced layered structure. The partial removal of NH 4 + will alleviate the irreversible deammoniation to protect the laminate structures from collapse during ion insertion/extraction. The expanded interlayer spacing and the increased oxygen vacancies by the virtue of the introduction of polypyrrole improve the ionic diffusion, enabling exceptional rate performance of NH 4 V 4 O 10. As expected, the resulting polypyrrole intercalated ammonium vanadate (NVOY) presents a superior discharge capacity of 431.9 mAh g−1 at 0.5 A g−1 and remarkable cycling stability of 219.1 mAh g−1 at 20 A g−1 with 78 % capacity retention after 1500 cycles. The in-situ electrochemical impedance spectroscopy (EIS), in-situ X-ray diffraction (XRD), ex-situ X-ray photoelectron spectroscopy (XPS) and ex-situ high resolution transmission electron microscopy (HR-TEM) analysis investigate a highly reversible intercalation Zn-storage mechanism, and the enhanced the redox kinetics are related to the combined effect of interlayer regulation, high electronic conductivity and oxygen defect engineering by partial substitution NH 4 + of PPy incorporation. [ABSTRACT FROM AUTHOR]

Modern crops exhibit diverse sensitivities to ammonium as the primary nitrogen source, influenced by environmental factors such as external pH and nutrient availability. Despite its significance, there is currently no systematic classification of plant species based on their ammonium sensitivity. We conducted a meta-analysis of 50 plant species and present a new classification method based on the comparison of fresh biomass obtained under ammonium and nitrate nutrition. The classification uses the natural logarithm of the biomass ratio as the size effect indicator of ammonium sensitivity. This numerical parameter is associated with critical factors for nitrogen demand and form preference, such as Ellenberg indicators and the repertoire of nitrogen transporters for ammonium and nitrate uptake. Finally, a comparative analysis of the developmental and metabolic responses, including hormonal balance, is conducted in two species with divergent ammonium sensitivity values in the classification. Results indicate that nitrate has a key role in counteracting ammonium toxicity in species with a higher abundance of genes encoding NRT2-type proteins and fewer of those encoding the AMT2-type proteins. Additionally, the study demonstrates the reliability of the phytohormone balance and methylglyoxal content as indicators for anticipating ammonium toxicity. [ABSTRACT FROM AUTHOR]

Unlike aquaporins or potassium channels, ammonium transporters (Amts) uniquely discriminate ammonium from potassium and water. This feature has certainly contributed to their repurposing as ammonium receptors during evolution. Here, we describe the ammonium receptor Sd-Amt1, where an Amt module connects to a cytoplasmic diguanylate cyclase transducer module via an HAMP domain. Structures of the protein with and without bound ammonium were determined to 1.7-and 1.9-Ångstrom resolution, depicting the ON and OFF states of the receptor and confirming the presence of a binding site for two ammonium cations that is pivotal for signal perception and receptor activation. The transducer domain was disordered in the crystals, and an AlphaFold2 prediction suggests that the helices linking both domains are flexible. While the sensor domain retains the trimeric fold formed by all Amt family members, the HAMP domains interact as pairs and serve to dimerize the transducer domain upon activation. [ABSTRACT FROM AUTHOR]

Nitrate, the form of nitrogen often associated with kelp growth, is typically low in summer during periods of high macroalgal growth. More ephemeral, regenerated forms of nitrogen, such as ammonium and urea, are much less studied as sources of nitrogen for kelps, despite the relatively high concentrations of regenerated nitrogen found in the Southern California Bight, where kelps are common. To assess how nitrogen uptake by kelps varies by species and nitrogen form in southern California, USA, we measured uptake rates of nitrate, ammonium, and urea by Macrocystis pyrifera and Eisenia arborea individuals from four regions characterized by differences in nitrogen availability—Orange County, San Pedro, eastern Santa Catalina Island, and western Santa Catalina Island—during the summers of 2021 and 2022. Seawater samples collected at each location showed that overall nitrogen availability was low, but ammonium and urea were often more abundant than nitrate. We also quantified the internal %nitrogen of each kelp blade collected, which was positively associated with ambient environmental nitrogen concentrations at the time of collection. We observed that both kelp species readily took up nitrate, ammonium, and urea, with M. pyrifera taking up nitrate and ammonium more efficiently than E. arborea. Urea uptake efficiency for both species increased as internal percent nitrogen decreased. Our results indicate that lesser‐studied, more ephemeral forms of nitrogen can readily be taken up by these kelps, with possible upregulation of urea uptake as nitrogen availability declines. [ABSTRACT FROM AUTHOR]

Sulfide-based pathways for generating nitrite to sustain anaerobic ammonium oxidation (anammox) have garnered increasing attention. However, the presence of sulfide can also impact the anammox process, necessitating a comprehensive understanding of both its short-term and long-term effects on anammox. This study aimed to investigate the influence of sulfide on anammox, including its effects on the microbial community and process kinetics. During long-term operation, the maximum sulfide dosage tested was 30 mg S/L over 50 days of operation, exhibiting good nitrogen removal efficiency of 83.9%±4.8%. Conversely, under short-term exposure to sulfide, nitrogen removal efficiency was notably affected, decreasing to 68.98% at a considerably lower sulfide concentration of only 16 mg S/L. Within the context of long-term sulfide exposure, the maximum contribution of anammox to nitrogen removal reached 86.72% at a sulfide dosage of 25 mg S/L. However, when the influent sulfide concentration was increased to 50 mg/L , the contribution of anammox to nitrogen removal sharply declined to 41.3%. Microbial community analysis revealed as the sulfide concentration increased from 8 to 16 mg S/L , the abundance of anammox bacteria decreased from 2.46×105 to 1.67×105 copies/mL, whereas the abundance of Nitrobacter spp. increased from 2.73×102 to 8.13×102 copies/mL. However, during long-term operation, there was a more pronounced decrease in the microbial abundance of anammox, reducing from 5.3×105 to 3.77×102 copies/mL. Taking this decrease together with the improved efficiency of anammox observed during long-term operation, these findings suggest that sulfide's influence on anammox primarily impacts its metabolic activity rather than its microbial abundance. [ABSTRACT FROM AUTHOR]

In this work, we investigated the feasibility of ammonium removal by electrodialysis (ED), a well‐known electro‐membrane process, based on the selective migration of anions and cations through anion exchange membranes (AEMs) and cation exchange membranes (CEMs). ED experiments are performed using a laboratory pilot. The ion exchange membranes (IEMs) pair used is AXE/CMX, AXE as an AEMs and CMX as a CEMs. The first tests are performed with real groundwater solutions from Kenitra city (Morocco), spiked with an initial concentration of 3 mg/L NH4Cl. The results gave a specific demineralization (SD) to NH4+ ions of 84.60 %; for a demineralization rate (DR) of 80 % and a time of 60 min. The multivariate principal component analysis (PCA) presents a total inertia of 99.23 %, the majority of the variables of which are positively correlated on the C1 axis with a variance of 95.5 % than that of C2 of 3.78 %. The quality of the diluted water determined by the Legrand‐Poirier method showed that the water was aggressive and that the addition of 4.54 mg/L Ca2+ was necessary to balance the water and make it fit for human consumption. [ABSTRACT FROM AUTHOR]

Background: The presence of oxygen in the growth medium is absolutely essential for root development and the overall metabolic processes of plants. When plants do not have an adequate oxygen supply for respiration, they can experience a condition known as hypoxia. In order to investigate the impact of different nitrogen forms and varying oxygen levels in nutrient solutions on the growth, photosynthesis, and chlorophyll fluorescence parameters of bell pepper plants, a comprehensive study was conducted. The experiment was designed as a factorial experiment, considering two main factors: nitrogen forms (calcium nitrate and ammonium sulfate) with a fixed nitrogen concentration of 5 mM, and the oxygen levels of the nutrient solutions (ranging from 1.8 ± 0.2 to 5.3 ± 0.2 mg. L-1). Results: The study examined the effects of nitrogen (NH4+ and NO3−) application on various parameters of vegetative growth. The results demonstrated that the use of ammonium (NH4+) led to a reduction in the most measured parameters, including the fresh and dry mass of both the root and shoot, at low O2 concentrations of 1.8 ± 0.2; 2.6 ± 0.2 and 3.8 ± 0.2 mg. L-1. However, an interesting observation was made regarding the impact of oxygen levels on root growth in plants grown with nitrate (NO3−). Specifically, the highest levels of oxygen significantly increased root growth in NO3−-fed plants. Additionally, the application of NH4+ resulted in an increase in chlorophyll concentration in the leaves, particularly when combined with high oxygen levels in the nutrient solution. On the other hand, leaves of plants fed with NO3− exhibited higher photosynthetic rate (A), intrinsic water use efficiency (iWUE), and instantaneous carboxylation efficiency (A/Ci) compared to those fed with NH4+. Furthermore, it was found that NO3−-fed plants displayed the highest instantaneous carboxylation efficiency at oxygen levels of 3.8 and 5.3 mg. L-1, while the lowest efficiency was observed at oxygen levels of 1.8 and 2.6 mg. L-1. In contrast, NH4+-grown plants exhibited a higher maximal quantum yield of PSII photochemistry (Fv/Fm), as well as increased variable fluorescence (Fv) and maximum fluorescence (Fm), compared to NO3−-grown plants. Interestingly, the NO3−-fed plants showed an increase in Fv/Fm, Fv, and Fm with the elevation of oxygen concentration in the nutrient solution up to 5.3 mg. L-1. Conclusion: This study showed that, the growth and photosynthesis parameters in bell pepper plants are sensitive to oxygen stress in floating hydroponic culture. Therefore, the oxygen level in the nutrient solution must not be lower than 3.8 and 5.3 mg. L-1 in NH4+ and NO3− –supplied culture media or nutrient solutions, respectively. [ABSTRACT FROM AUTHOR]

The integrated fixed‐film activated sludge (IFAS) process is considered one of the cutting‐edge solutions to the traditional wastewater treatment challenges, allowing suspended sludge and attached biofilm to grow in the same system. In addition, the coupling of IFAS with anaerobic ammonium oxidation (Anammox) can further improve the efficiency of biological denitrification. This paper summarises the research progress of IFAS coupled with the anammox process, including partial nitrification anammox, simultaneous partial nitrification anammox and denitrification, and partial denitrification anammox technologies, and describes the factors that limit the development of related processes. The effects of dissolved oxygen, influent carbon source, sludge retention time, temperature, microbial community, and nitrite‐oxidising bacteria inhibition methods on the anammox of IFAS are presented. At the same time, this paper gives an outlook on future research focus and engineering practice direction of the process. [ABSTRACT FROM AUTHOR]

Extensive industrial activities and anthropogenic agricultural practices have led to substantial ammonia release to the environment. Although croplands can act as ammonia sinks, reduced crop production under high concentrations of ammonium has been documented. Alpha-ketoglutarate (AKG) is a critical carbon source, displaying pleiotropic physiological functions. The objective of the present study is to disclose the potential of AKG to enhance ammonium assimilation in poplars. It showed that AKG application substantially boosted the height, biomass, and photosynthesis activity of poplars exposed to excessive ammonium. AKG also enhanced the activities of key enzymes involved in nitrogen assimilation: glutamine synthetase (GS) and glutamate synthase (GOGAT), elevating the content of amino acids, sucrose, and the tricarboxylic acid cycle (TCA) metabolites. Furthermore, AKG positively modulated key genes tied to glucose metabolism and ATP synthesis, while suppressing ATP-depleting genes. Correspondingly, both H+-ATPase activity and ATP content increased. These findings demonstrate that exogenously applying AKG improves poplar growth under a high level of ammonium treatment. AKG might function through sufficient carbon investment, which enhances the carbon–nitrogen balance and energy stability in poplars, promoting ammonium assimilation at high doses of ammonium. Our study provides novel insight into AKG's role in improving poplar growth in response to excess ammonia exposure. [ABSTRACT FROM AUTHOR]

A protocol for the synthesis of 3,4-dihydropyrano[c]chromenes (DHPCs) using tris(2-hydroxyethyl)ammonium lactate (THAL) as an ionic liquid (IL) and biodegradable catalyst has been developed. This method involves the reaction of aldehydes, malononitrile, and 4-hydroxycoumarin under solvent-free conditions at 80 °C. The efficiency of THAL as catalyst was evaluated by conducting a series of control experiments using dimedone, 2-hydroxynaphthalene-1,4-dione, and 1,3-dimethylbarbituric acid as substrates under optimized conditions. [ABSTRACT FROM AUTHOR]

Algal blooms are increasing worldwide, driven by elevated nutrient inputs. However, it is still unknown how tropical benthic algae will respond to heatwaves, which are expected to be more frequent under global warming. In the present study, a multifactorial experiment was carried out to investigate the potential synergistic effects of increased ammonium inputs (25 μM, control at 2.5 μM) and a heatwave (31°C, control at 25°C) on the growth and physiology (e.g., ammonium uptake, nutrient assimilation, photosynthetic performance, and pigment concentrations) of two bloom‐forming algal species, Cladophoropsis sp. and Laurencia sp. Both algae positively responded to elevated ammonium concentrations with higher growth and chlorophyll a and lutein concentrations. Increased temperature was generally a less important driver, interacting with elevated ammonium by decreasing the algaes' %N content and N:P ratios. Interestingly, this stress response was not captured by the photosynthetic yield (Fv/Fm) nor by the carbon assimilation (%C), which increased for both algae at higher temperatures. The negative effects of higher temperature were, however, buffered by nutrient inputs, showing an antagonistic response in the combined treatment for the concentration of VAZ (violaxanthin, antheraxanthin, zeaxanthin) and thalli growth. Ammonium uptake was initially higher for Cladophoropsis sp. and increased for Laurencia sp. over experimental time, showing an acclimation capacity even in a short time interval. This experiment shows that both algae benefited from increased ammonium pulses and were able to overcome the otherwise detrimental stress of increasingly emerging temperature anomalies, which provide them a strong competitive advantage and might support their further expansions in tropical marine systems. [ABSTRACT FROM AUTHOR]

Enhancing the thermal safety of hydrophobic SiO 2 aerogels (SAs) is crucial for its practical thermal insulation applications. Here, we explore a facile method to enhance the thermal safety of hydrophobic SAs with the introduction of ammonium polyphosphate intercalated layered double hydroxide (APP-LDH). The obtained results show that as-produced APP-LDH/SA composites maintain excellent fundamental properties, including low density (0.14–0.16 g/cm3), high porosity (92.8–93.5 %), high specific surface area (680.0–762.6 m2/g), and low thermal conductivity (25.3–26.9 mW/m/K). Notably, APP-LDH effectively inhibits the thermal oxidation decomposition of SAs. In comparison to pristine SAs and those modified solely with LDH, the APP-LDH/SA composites exhibit significantly improved thermal stability. The gross calorific value of the APP-LDH/SA-20 % (i.e., containing 20 wt% APP-LDH) decreases by 13.9 % and 5.2 % compared with that of neat SAs and SAs modified solely with 20 wt% LDH, respectively. The improved thermal stability and reduced gross calorific value completely confirm the enhancement of the thermal safety of the APP-LDH/SA composites. This work provides a simple method to improve the thermal safety of hydrophobic SAs, which expands the thermal insulation application scenarios of SAs. [ABSTRACT FROM AUTHOR]

Two-dimensional/three-dimensional hierarchical self-supporting potassium ammonium vanadate@MXene hybrid films exhibit excellent electrochemical performance. [Display omitted] Currently, aqueous zinc ion batteries (AZIBs) have grown to be a good choice for large-scale energy storage systems due to their high theoretical specific capacity, low redox potential, low cost, and non-toxicity of the aqueous electrolyte. However, it is still challenging to obtain high specific capacity and stability suitable cathodes. Herein, hierarchical self-supporting potassium ammonium vanadate@MXene (KNVO@MXene) hybrid films were prepared by vacuum filtration method. Due to the three-dimensional nanoflower structure of KNVO with dual ions intercalation, high conductivity of two-dimensional Ti 3 C 2 T x MXene, and the hierarchical self-supporting structure, the AZIB based on the KNVO@MXene hybrid film cathode possessed superior specific capacity (481 mAh/g at 0.3 A/g) and cycling stability (retaining 125 mAh/g after 1000 cycles at a high current density of 10 A/g). In addition, the storage mechanism was revealed by various ex-situ characterizations. Hence, a new viewpoint for the preparation of AZIB self-supporting cathode materials is presented. [ABSTRACT FROM AUTHOR]

Microbes contribute biologically available nitrogen to the ocean by fixing nitrogen gas from the atmosphere and by mineralizing organic nitrogen into bioavailable dissolved inorganic nitrogen (DIN). Although the large concentration of plants and algae in marine coastal environments provides ample habitat and reliable resources for microbial communities, the role of the microbiome in host-microbe nitrogen cycling remains poorly understood. We tested whether ammonification by epiphytic microbes increased water column ammonium and improved host access to nitrogen resources by converting organic nitrogen into inorganic nitrogen that is available for assimilation by hosts. When bull kelp (Nereocystis luetkeana) in the northeast Pacific was incubated with 15N labelled amino acid tracers, there was accumulation of 15N in kelp tissue, as well as accumulation of 15NH4 in seawater, all consistent with the conversion of dissolved organic nitrogen to ammonium. Metagenomic analysis of surface microbes from two populations of Nereocystis indicated relative similarity in the percentage of genes related to ammonification between the two locations, though the stressed kelp population that had lower tissue nitrogen and a sparser microbiome had greater ammonification rates. Microbial communities on coastal macrophytes may contribute to the nitrogen requirements of their hosts through metabolisms that make ammonium available. [ABSTRACT FROM AUTHOR]

Background: In viticulture, iron (Fe) chlorosis is a common abiotic stress that impairs plant development and leads to yield and quality losses. Under low availability of the metal, the applied N form (nitrate and ammonium) can play a role in promoting or mitigating Fe deficiency stresses. However, the processes involved are not clear in grapevine. Therefore, the aim of this study was to investigate the response of two grapevine rootstocks to the interaction between N forms and Fe uptake. This process was evaluated in a hydroponic experiment using two ungrafted grapevine rootstocks Fercal (Vitis berlandieri x V. vinifera) tolerant to deficiency induced Fe chlorosis and Couderc 3309 (V. riparia x V. rupestris) susceptible to deficiency induced Fe chlorosis. Results: The results could differentiate Fe deficiency effects, N-forms effects, and rootstock effects. Interveinal chlorosis of young leaves appeared earlier on 3309 C from the second week of treatment with NO3−/NH4+ (1:0)/-Fe, while Fercal leaves showed less severe symptoms after four weeks of treatment, corresponding to decreased chlorophyll concentrations lowered by 75% in 3309 C and 57% in Fercal. Ferric chelate reductase (FCR) activity was by trend enhanced under Fe deficiency in Fercal with both N combinations, whereas 3309 C showed an increase in FCR activity under Fe deficiency only with NO3−/NH4+ (1:1) treatment. With the transcriptome analysis, Gene Ontology (GO) revealed multiple biological processes and molecular functions that were significantly regulated in grapevine rootstocks under Fe-deficient conditions, with more genes regulated in Fercal responses, especially when both forms of N were supplied. Furthermore, the expression of genes involved in the auxin and abscisic acid metabolic pathways was markedly increased by the equal supply of both forms of N under Fe deficiency conditions. In addition, changes in the expression of genes related to Fe uptake, regulation, and transport reflected the different responses of the two grapevine rootstocks to different N forms. Conclusions: Results show a clear contribution of N forms to the response of the two grapevine rootstocks under Fe deficiency, highlighting the importance of providing both N forms (nitrate and ammonium) in an appropriate ratio in order to ease the rootstock responses to Fe deficiency. [ABSTRACT FROM AUTHOR]

Catalpa bungei is a precious timber species distributed in North China where drought often occurs. To clarify adaptive responses of C. bungei to partial- and full- root-zone drought under the influence of nitrogen forms, a two-factor experiment was conducted in which well-watered (WW), partial root-zone drought in horizontal direction (H-PRD) and in vertical direction (V-PRD), and full root-zone drought (FRD) were combined with nitrate-nitrogen (NN) and ammonium-nitrogen (AN) treatments. C. bungei responded to FRD by sharply closing stomata, decreasing gas exchange rate and increasing leaf instantaneous water use efficiency (WUEi). Under FRD condition, the growth of seedlings was severely inhibited and the effect of N forms was covered up by the drastic drought effect. In comparison, stomata conductance and gas exchanges were moderately inhibited by PRDs. WUEi in V-PRD treatment was superior to H-PRD due to the active stomata regulation resulting from a higher ABA level and active transcription of genes in abscisic acid (ABA) signaling pathway under V-PRD. Under both PRDs and FRD, nitrate benefited antioxidant defense, stomata regulation and leaf WUEi. Under V-PRD, WUEi in nitrate treatment was superior to that in ammonium treatment due to active stomata regulation by signaling network of nitric oxide (NO), Ca2+ and ABA. Under FRD, WUEi was higher in nitrate treatment due to the favoring photosynthetic efficiency resulting from active NO signal and antioxidant defense. The interactive effect of water and N forms was significant on wood xylem development. Superoxide dismutase (SOD) and catalase (CAT) largely contributes to stress tolerance and xylem development. [ABSTRACT FROM AUTHOR]

A facile hydrothermal-calcination process was employed to fabricate Fe3O4/α-Fe2O3 heterogeneous nanosheets utilizing NH4H2PO4 as the restricted growth agent and FeCl3 as the iron source. The morphologies and properties of the obtained nanomaterials were investigated by SEM, XRD, VSM, and TEM techniques. In the hydrothermal process, an H2PO4− concentration of 1.44 mM, Fe3+ concentration of 20 mM, a hydrothermal temperature of 220 °C, and a hydrothermal time of 24 h were selected as the optimal conditions for α-Fe2O3 nanosheets, their average diameter and thickness of the resulting nanosheets were approximately 150 and 53 nm. Subsequently, glucose was utilized as a reducing agent to partially reduce the precursor of α-Fe2O3 to Fe3O4, thereby forming Fe3O4/α-Fe2O3 heterogeneous nanosheets. During the calcination process, the effects of calcination time, calcination temperature, and glucose content on the morphology and properties of the nanosheets were investigated. The morphology and size of the prepared nanosheets did not change significantly during the calcination process, while the magnetic properties of the products underwent significant changes. When the product was calcined at 600 °C for 4 h with a mass ratio of precursor to glucose was 1:12, the saturation magnetization of as-prepared Fe3O4/α-Fe2O3 heterogeneous nanosheets reached the largest of 80 emu/g. The results indicated that the Fe3O4/α-Fe2O3 heterogeneous nanosheets with satisfactory saturation magnetization were successfully fabricated with glucose as the reductant. [ABSTRACT FROM AUTHOR]

Nitrogen and brassinosteroids (BRs) play a vital role in modulating the growth, development, and yield of rice. However, the influences of BRs on nitrogen assimilation and metabolism in rice are not fully understood. In this study, we analyzed the impact of BRs on nitrogen utilization in rice using the indica variety 'Zhongjiazao 17' and the japonica variety 'Nipponbare' in hydroponic conditions. The results showed that BR treatment could efficiently elevate nitrate and ammonium nitrogen accumulation in both shoots and roots. Furthermore, some genes involved in the uptake of nitrate and ammonium in roots were stimulated by BRs, though we noted subtle variances between the two rice cultivars. Moreover, BRs augmented the activity of nitrate reductase (NR) and glutamine synthetase (GS) in roots, along with NR in shoots. Interestingly, BRs also spiked the total free amino acid content in both the shoots and roots. Gene expression analysis uncovered a robust induction by BRs of NR genes and GS-related genes in the roots of both 'Nipponbare' and 'Zhongjiazao 17'. Collectively, our data suggest that BRs significantly enhance the accumulation of both nitrate and ammonium in rice and trigger a series of reactions related to nitrogen utilization. [ABSTRACT FROM AUTHOR]

This study aimed to use colloidal silver nanoparticles (AgNPs) for ammonium adsorption. Several factors were considered, including pH value, contact time, amount of adsorbent, and beginning ammonium content. The ideal parameters for ammonium adsorption onto the AgNPs were an a pH of 9, a contact period of 60 minutes, a concentration of 1.824 mg AgNPs/25 mL of ammonium solution, and a starting concentration of 80 mL, as determined. The optimum ammonium adsorption capacity onto the AgNPs was 276.84 mg/g, and the Langmuir model described the isotherm adsorption with R2, KL, and calculated qmax values of 0.9339, 0.518 L/mg, and 263.37 mg/g, respectively. The experimental data were most closely matched by the Elovich model, as seen by its R2, α, and β values of 0.885, 0.055, and 0.180, respectively. Temperature release values for the exothermic adsorption were 23,084 kJ/mol at 20°C, −23872 kJ/mol at 30°C, and 24,660 kJ/mol at 40°C. [ABSTRACT FROM AUTHOR]

New ammonium hydrazones have been synthesized by the reaction of Girard's reagents T and P with isatin derivatives that contain various alkyl or geranyl substituents in position 1. A pronounced anti-anthropo- and antiphyto-pathogenic effect of resulting compounds has been revealed. The n-octyl and octadiene derivatives have the highest selectivity for resistant strains of Staphylococcus aureus when there is no negative effect on the hemostasis system. The aggregation and adsorption properties of the compounds have been studied using tensiometry, conductometry, and UV spectroscopy. The found values of the critical micelle concentration of amphiphilic ammonium hydrazones are an order of magnitude lower than those of quaternary ammonium salts. [ABSTRACT FROM AUTHOR]

The reaction of 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde with analogs of Girard's reagents was used to synthesize new water-soluble ammonium acylhydrazones as individual EC=N,synN-C(O) isomers. The introduction of an additional sterically hindered phenolic moiety into ammonium N-acylhydrazone leads to the emergence of antimicrobial activity against gram-negative pathogens of bacterial (Pseudomonas aeruginosa, Escherichia coli) and fungal origin (Candida albicans). [ABSTRACT FROM AUTHOR]

The presence of ammonium (NH4+) in natural waters has increased in the last years due to the rising use of agricultural fertilizers, industrial activity and sewage discharges without any decontamination treatment. The great amounts of this inorganic cation in water bodies have been considered an environmental problem, due to its influence on the eutrophication process which leads to the deterioration of water quality. The application of ZnO nanoparticles to assess nutrient elimination, including ammonium, from water bodies has not been exhaustively studied. In this work, the capability of ZnO nanoparticles to remove ammonium cation from aqueous samples induced by adsorption is investigated. In this regards, experiments tending to determine the efficiency of nanomaterials have been performed employing two different NH4+ concentrations aiming to replicate two feasible real water-impacted environments. The interactions between adsorbent and adsorbate have been explored by employing experimental characterization techniques as well as theoretical DFT simulations. The achieved data demonstrated that the efficiency of ZnONPs shows a dependency on the ammonium concentration, ranging between 0.79 and 11.6 mg of ammonium adsorbed per gram of ZnONPs. According to the data on characterization prior and post adsorption of the ZnO nanomaterials the electrostatic interaction would not be favored, being the coordination ones the most feasible as suggested experimental and DFT results. [ABSTRACT FROM AUTHOR]

A novel method has been developed to use ammonium tetrafluoroborate (NH4BF4) directly as catalyst in Biginelli reaction. A new paradigm of the Biginelli reaction for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones derivatives found the use of ammonium tetrafluoroborate as a novel, inexpensive, readily available, non‐toxic and mild catalyst in good to excellent yields. Notably, this is the first time that ammonium tetrafluoroborate is directly used as a catalyst in organic synthesis. So far, no organic reaction is available in literature where NH4BF4 is directly used as catalyst. However, some reactions are found where NH4BF4 is used with other catalysts as promoters or additives. The protocol developed has several advantages, such as highly efficient, simple, atom‐economical, environmentally friendly, easy synthetic and purification methods. [ABSTRACT FROM AUTHOR]

The access of vinasse leachates to water bodies and groundwater exacerbates environmental problems, especially eutrophication. Therefore, a column experiment was performed to examine the effect of adding zeolite (ZL), bone char (BC), and wood chips biochar (WCB) in the presence of vinasse on carbon dioxide (CO2) emission, leaching dissolved organic carbon (DOC) and ammonium (NH4+) in calcareous sandy soil, as well as studying the kinetics of leaching dissolved organic carbon and ammonium. This column experiment contains four treatments: soil alone (CK), soil + zeolite (SZL), soil + bone char (SBC), and soil + wood chips biochar (SWCB). These amendments were applied to the soil at a level of 4%. Vinasse was added to all treatments at a level of 13 mL per column. The leached total cumulative DOC and total cumulative soluble ammonium amounts decreased significantly with applying ZL, BC, and WCB compared with the soil alone. The effectiveness of these amendments in lowering the total cumulative DOC leaching is in the order of SBC > SWCB > SZL > CK. However, the effectiveness of these amendments in decreasing the total cumulative NH4+ leaching is in the order of SZL > SWCB > SBC > CK. The rate constant (k) of DOC leaching decreased significantly with the application of bone char compared to soil alone treatment. In the presence of vinasse, the apparent half-life of leached DOC from the soil was 8.1, 12.9, 36.7, and 15.5 days for soil CK, SZL, SBC, and SWCB treatments, respectively. Half-life values of leached soluble ammonium from the soil in the presence of vinasse addition were 10.1, 39.5, 28.5, and 37.9 days for CK, SZL, SBC, and SWCB treatments, respectively. Amending soil with BC increased significantly the phosphorus availability, however, applying ZL and BC caused a significant increase in the available potassium in calcareous sandy soil compared to the control treatment. According to these results, it is recommended not to add vinasse alone to sandy soils, but it is preferred to be co-applied with BC amendment at the level of 4% better than ZL and WCB. This would decrease leaching DOC and ammonium to the water table and groundwater as well as enhance nutrient retention in the soil, which in turn, plays a vital role in reducing the harmful effect of vinasse and improving soil fertility. [ABSTRACT FROM AUTHOR]

Layered two‐dimensional (2D) perovskites are emerging as promising optoelectronic materials owing to their excellent environmental stability. Regulating the dipole moment of organic spacers has the potential to reduce the exciton binding energy (Eb) of 2D perovskites and improve their photovoltaic performance. Here, we developed two azetidine‐based secondary ammonium spacers with different electron‐withdrawing groups, namely 3‐hydroxyazatidine (3‐OHAz) and 3,3‐difluoroazetidine (3,3‐DFAz) spacers, for 2D Ruddlesden‐Popper (RP) perovskites. It was found that the large dipole moment of the fluorinated dipole spacer could effectively enhance the interaction between organic spacers and inorganic layers, leading to improved charge dissociation in 2D RP perovskite. In contrast to 3‐OHAz spacer, the 2D perovskite using 3,3‐DFAz as spacer also shows improved film quality, optimized energy level alignment, and reduced exciton binding energy. As a result, the 2D perovskite (n=4) device based on 3,3‐DFAz yields an outstanding efficiency of 19.28 %, surpassing that of the 3‐OHAz‐Pb device (PCE=11.35 %). The efficiency was further improved to 19.85 % when using mixed A‐site cation of MA0.95FA0.05. This work provides an effective strategy for modulating the energy level alignment and reducing the Eb by regulating the dipole moment of organic spacers, ultimately enabling the development of high‐performance 2D perovskite solar cells. [ABSTRACT FROM AUTHOR]

Layered two‐dimensional (2D) perovskites are emerging as promising optoelectronic materials owing to their excellent environmental stability. Regulating the dipole moment of organic spacers has the potential to reduce the exciton binding energy (Eb) of 2D perovskites and improve their photovoltaic performance. Here, we developed two azetidine‐based secondary ammonium spacers with different electron‐withdrawing groups, namely 3‐hydroxyazatidine (3‐OHAz) and 3,3‐difluoroazetidine (3,3‐DFAz) spacers, for 2D Ruddlesden‐Popper (RP) perovskites. It was found that the large dipole moment of the fluorinated dipole spacer could effectively enhance the interaction between organic spacers and inorganic layers, leading to improved charge dissociation in 2D RP perovskite. In contrast to 3‐OHAz spacer, the 2D perovskite using 3,3‐DFAz as spacer also shows improved film quality, optimized energy level alignment, and reduced exciton binding energy. As a result, the 2D perovskite (n=4) device based on 3,3‐DFAz yields an outstanding efficiency of 19.28 %, surpassing that of the 3‐OHAz‐Pb device (PCE=11.35 %). The efficiency was further improved to 19.85 % when using mixed A‐site cation of MA0.95FA0.05. This work provides an effective strategy for modulating the energy level alignment and reducing the Eb by regulating the dipole moment of organic spacers, ultimately enabling the development of high‐performance 2D perovskite solar cells. [ABSTRACT FROM AUTHOR]

Protecting the population from aerosol pollution relies on forecasts using models with aerosol composition, yet the respective contributions of aerosol components are poorly known. In particular, the contribution of inorganic condensable particulate matter (PM) to aerosols is likely to be underestimated in most models because condensable particulate matter exceeds the amount of filterable particulate matter in emissions from stationary combustion sources. Moreover, condensable particulate matter is rarely included in current emission inventories. Here, we estimated the emissions of inorganic condensable particulate matter from stationary combustion sources based on monitoring information in China. Then we modeled the contributions of condensable particulate matter to simulated inorganic aerosols, e.g., sulfate, ammonium, and nitrate by designing a series of sensitivity simulation scenarios. The results show that the estimated emissions of inorganic components over mainland China are increased about five times after including inorganic condensable particulate matter, for both 2014 and 2017. Specifically, taking into account the inorganic condensable particulate matter, increased the average concentrations of sulfate by 104%, ammonium by 10%, nitrate by 11%, and PM2.5 by 21% for the Hangzhou site in December 2017. Similarly, the simulated average daily concentrations of sulfate from December 3 to 31, 2017, more than doubled, increasing from 3.17 to 8.41 μg m−3 for Gucheng, 7.70 to 16.75 μg m−3 for Chengdu, 4.08 to 9.43 μg m−3 for Lin'an, and 3.19 to 7.22 μg m−3 for Dalian. [ABSTRACT FROM AUTHOR]

Coastal and estuarine waters of the northern California Current system and southern Salish Sea host an observational network capable of characterizing biogeochemical dynamics related to ocean acidification, hypoxia, and marine heatwaves. Here, we compiled data sets from a set of cruises conducted in estuarine waters of Puget Sound (southern Salish Sea) and its boundary waters (Strait of Juan de Fuca and Washington coast). This data product provides data from a decade of cruises with consistent formatting, extended data quality control, and multiple units for parameters such as oxygen with different end use needs and conventions. All cruises obtained high-quality temperature, salinity, inorganic carbon, nutrient, and oxygen observations to provide insight into the dynamic distribution of physical and biogeochemical conditions in this large urban estuary complex on the west coast of North America. At all sampling stations, conductivity–temperature–depth (CTD) casts included sensors for measuring temperature, conductivity, pressure, and oxygen concentrations. Laboratory analyses of discrete water samples collected at all stations throughout the water column in Niskin bottles provided measurements of dissolved inorganic carbon (DIC), dissolved oxygen, nutrient (nitrate, nitrite, ammonium, phosphate, and silicate), and total alkalinity (TA) content. This data product includes observations from 35 research cruises, including 715 oceanographic profiles, with >7490 sensor measurements of temperature, salinity, and oxygen; ≥6070 measurements of discrete oxygen and nutrient samples; and ≥4462 measurements of inorganic carbon variables (i.e., DIC and TA). The observations comprising this cruise compilation collectively characterize the spatial and temporal variability in a region with large dynamic ranges of the physical (temperature = 6.0–21.8 ∘ C, salinity = 15.6–34.0) and biogeochemical (oxygen = 12–481 µmolkg-1 , dissolved inorganic carbon = 1074–2362 µmolkg-1 , total alkalinity = 1274–2296 µmolkg-1) parameters central to understanding ocean acidification and hypoxia in this productive estuary system with numerous interacting human impacts on its ecosystems. All observations conform to the climate-quality observing guidelines of the Global Ocean Acidification Observing Network, the US National Oceanic and Atmospheric Administration's Ocean Acidification Program, and ocean carbon community best practices. This ongoing cruise time series supports the estuarine and coastal monitoring and research objectives of the Washington Ocean Acidification Center and US National Oceanic and Atmospheric Administration (NOAA) Ocean and Atmospheric Research programs, and it provides diverse end users with the information needed to frame biological impacts research, validate numerical models, inform state and tribal water quality and fisheries management, and support decision-makers. All 2008–2018 cruise time-series measurements used in this publication are available at 10.25921/zgk5-ep63 (Alin et al., 2022). [ABSTRACT FROM AUTHOR]

The accurate determination of uranium content in geological samples is extremely important for the exploration and development of uranium resources. In this study, based on titration method for the determination of uranium content of the nuclear industry standard test, the pretreatment process such as sample dissolution, sample dissolution reagent and test method has been improved according to the characteristics of geological samples. The results showed that the sample was moistened with water before acid treatment, and the dissolving vessel was adjusted from 100 mL beaker to 150 mL triangle flask, which basically avoided the problem of sputtering during the boiling process. The amount of phosphoric acid added in the sample dissolution reagent was increased to ensure that the ferrous could completely reduce the hexavalent uranium in the sample at the appropriate phosphoric acid concentration, and the low measurement result caused by the low phosphoric acid concentration is avoided. In the test, the amount of reducing agent ferrous sulfate is changed to 1 mL, and the amount of sodium nitrite was changed to 3–4 drops, which improved the sensitivity of titration endpoint and realized clear determination of titration end point. The RSD of the improved test method is better than 2.5%, and the standard recovery is between 99 and 102%. The results are accurate and reliable, can meet the needs of scientific research and production. It can provide technical support for uranium exploration and natural uranium production. [ABSTRACT FROM AUTHOR]

SUMMARY: In natural and agricultural situations, ammonium (NH4+) is a preferred nitrogen (N) source for plants, but excessive amounts can be hazardous to them, known as NH4+ toxicity. Nitrate (NO3−) has long been recognized to reduce NH4+ toxicity. However, little is known about Brassica napus, a major oil crop that is sensitive to high NH4+. Here, we found that NO3− can mitigate NH4+ toxicity by balancing rhizosphere and intracellular pH and accelerating ammonium assimilation in B. napus. NO3− increased the uptake of NO3− and NH4+ under high NH4+ circumstances by triggering the expression of NO3− and NH4+ transporters, while NO3− and H+ efflux from the cytoplasm to the apoplast was enhanced by promoting the expression of NO3− efflux transporters and genes encoding plasma membrane H+‐ATPase. In addition, NO3− increased pH in the cytosol, vacuole, and rhizosphere, and down‐regulated genes induced by acid stress. Root glutamine synthetase (GS) activity was elevated by NO3− under high NH4+ conditions to enhance the assimilation of NH4+ into amino acids, thereby reducing NH4+ accumulation and translocation to shoot in rapeseed. In addition, root GS activity was highly dependent on the environmental pH. NO3− might induce metabolites involved in amino acid biosynthesis and malate metabolism in the tricarboxylic acid cycle, and inhibit phenylpropanoid metabolism to mitigate NH4+ toxicity. Collectively, our results indicate that NO3− balances both rhizosphere and intracellular pH via effective NO3− transmembrane cycling, accelerates NH4+ assimilation, and up‐regulates malate metabolism to mitigate NH4+ toxicity in oilseed rape. [ABSTRACT FROM AUTHOR]

Big Soda Lake, Nevada, is a multi‐extreme meromictic lake, whose hypersaline hyperalkaline bottom waters feature permanent anoxia and high concentrations of arsenic, sulphide and ammonia. These properties make Big Soda Lake—and the adjacent Little Soda Lake—a fascinating system for exploring life's boundaries, discovering novel microbial taxa and identifying biotechnologically useful strains. To date, the taxonomic diversity and metabolic capabilities of microorganisms in this system remain largely unknown. Here, we fill this gap using microbiome surveys across the Big and Little Soda Lake water columns, including 16S rRNA sequencing, fungal ITS2 sequencing and gene‐ and genome‐resolved metagenomics. We accompany these surveys with measurements of salinity, pH, temperature, oxygen, ammonium and ammonia concentrations. Our analyses reveal rich bacterial communities, taxonomically and functionally differentiated along Big Soda Lake's oxycline and, to lesser extent, between lakes. Fungal communities were dominated by a small number of families, while nearly no archaea were detected. Pathways related to perchlorate reduction, anoxygenic phototrophy, fermentation, dissimilatory metabolism of arsenite/arsenate, sulphur compounds, nitrogen compounds and hydrogen, were particularly prevalent. A total of 129 high‐quality bacterial and archaeal metagenome‐assembled genomes (completeness ≥ 80%, contamination ≤ 5%) were recovered, yielding insight into the taxonomic distribution of microbial metabolic pathways. [ABSTRACT FROM AUTHOR]

Biostimulation through the enrichment of indigenous ureolytic bacteria has been proven to be a feasible approach for implementing microbially induced carbonate precipitation (MICP). To apply this method to real-world engineering situations, researchers are focusing on (1) increasing the cementation content to improve the mechanical performance of biocemented sand, and (2) minimizing the negative impact of ammonium, a harmful byproduct. In this study, biochars of different shapes (powdered or flaked) were used as additives in calcareous sand. The effects of biochar on shear strength improvement and ammonium removal were investigated through isotropically consolidated drained (CD) triaxial shear tests, as well as ammonium adsorption and leaching tests, respectively. Experimental results indicated that biochar positively impacted cementation content, particularly for powdered biochar with smaller particle sizes, which enhanced shear strength in CD tests. Microscopic analysis of biochar-amended biocemented sand revealed that biochar can serve as additional nucleation sites for precipitation. Moreover, the contributions of friction, dilatancy, and mobilized cohesion of biocemented sand at peak strength and in the maximum dilatancy state were elucidated. Furthermore, biochar demonstrated significant ammonium removal under both aqueous and sand column conditions. These findings hold practical significance for the stabilization of local calcareous sand, as well as for other coastal cities worldwide. [ABSTRACT FROM AUTHOR]

Dearomatization of quinoline/isoquinoline quaternary ammonium salts to synthesize valuable tetrahydroquinolines was firstly reported. Under this method, we used phenylsilane as a reducing agent to prepare a series of tetrahydroquinoline and tetrahydroisoquinoline derivatives conveniently and quickly in moderate to good yields. This method showed good functional group tolerance, wide substrate range, mild reaction conditions and simple operation. [ABSTRACT FROM AUTHOR]

Resin-based dental materials have been one of the ideal choices among various materials in the treatment of dental caries. However, resin-based dental materials still have some drawbacks, such as the lack of inherent antibacterial activity. Extensive research has been conducted on the use of novel quaternary ammonium monomers (QAMs) to impart antibacterial activity to dental materials. This review provides a comprehensive overview of the recent advances in quaternary ammonium monomers (QAMs) for dental applications. The current progress and limitations of QAMs are discussed based on the evolution of their structures. The functional diversification and enhancement of QAMs are presented. QAMs have the potential to provide long-term antibacterial activity in dental resin composites, thereby prolonging their service life. However, there is a need to balance antibacterial performance with other material properties and the potential impact on the oral microbiome and general health. Finally, the necessity for further scientific progress in the development of novel quaternary ammonium monomers and the optimization of dental resin formulations is emphasized. [ABSTRACT FROM AUTHOR]

Ammonium and polyamines are essential nitrogen metabolites in all living organisms. Crosstalk between ammonium and polyamines through their metabolic pathways has been demonstrated in plants and animals, while no research has been directed to explore this relationship in algae or to investigate the underlying molecular mechanisms. Previous research demonstrated that high concentrations of ammonium and putrescine were among the active substances in bacteria-derived algicide targeting dinoflagellates, suggesting that the biochemical inter-connection and/or interaction of these nitrogen compounds play an essential role in controlling these ecologically important algal species. In this research, putrescine, ammonium, or a combination of putrescine and ammonium was added to cultures of three dinoflagellate species to explore their effects. The results demonstrated the dose-dependent and species-specific synergistic effects of putrescine and ammonium on these species. To further explore the molecular mechanisms behind the synergistic effects, transcriptome analysis was conducted on dinoflagellate Karlodinium veneficum treated with putrescine or ammonium vs. a combination of putrescine and ammonium. The results suggested that the synergistic effects of putrescine and ammonium disrupted polyamine homeostasis and reduced ammonium tolerance, which may have contributed to the cell death of K. veneficum. There was also transcriptomic evidence of damage to chloroplasts and impaired photosynthesis of K. veneficum. This research illustrates the molecular mechanisms underlying the synergistic effects of the major nitrogen metabolites, ammonium and putrescine, in dinoflagellates and provides direction for future studies on polyamine biology in algal species. [ABSTRACT FROM AUTHOR]

A hydrophobic cationic-ionomer layer of quaternary ammonium poly(N-methyl-piperidine-co-p-terphenyl) and PTFE is presented to enhance the CO2 electroreduction in a zero-gap membrane electrode assembly (MEA) electrolyzer under acidic and low alkali ion concentration conditions. The modified MEA achieved a maximum CO faradaic efficiency of 95.6% at 100 mA cm−2. [ABSTRACT FROM AUTHOR]

It is generally accepted that hydrogen is generated by ferrous iron oxidation and/or water radiolysis but no attempt has been done so far to explain the origin of the nitrogen that is associated to 'hydrogen systems' such as those located in Brazil and Oman and New Caledonian ophiolites. We carried out 25–300 °C geochemical equilibrium calculations on model water and water-mineral systems including ammonium (NH 4 +) to see if this ion could be a 'precursor' in the generation of hydrogen and/or nitrogen. The considered minerals of the water-mineral systems were the magnetite-hematite or fayalite-magnetite-quartz redox-buffering assemblages. The water systems including NH 4 + only or NH 4 + and ferrous iron co-generate hydrogen and nitrogen through the ammonium decomposition reaction: NH 4 + = 1.5 H 2 + 0.5 N 2 + H+ In the water-mineral systems, hydrogen is generated by the magnetite and fayalite ferrous iron oxidation while nitrogen is generated independently by the hematite and magnetite ferric iron reduction by NH 4 +: 3 Fe3+ + NH 4 + = 0.5 N 2 + 3 Fe2+ + 4 H+ With magnetite-hematite, the produced gas is mainly composed of nitrogen. At low temperature with fayalite-magnetite-quartz, the produced gas is mainly composed of hydrogen; approaching 300 °C, and with a sufficient initial ammonium stock, a significant amount of nitrogen is produced to form a mixed gas. If we consider low (magnetite-hematite) or high (fayalite-magnetite-quartz) reducing conditions occurring respectively within the central or peripheral zones of the hydrogen systems, NH 4 + passing through and reacting with these two kinds of redox environments could explain why the central zones release mainly hydrogen (with some amounts of nitrogen) and why mainly nitrogen is emitted at the peripheries. • Modeling of ammonium oxidation in redox-unbuffered and -buffered aqueous systems. • Hydrogen and nitrogen co-generation through ammonium decomposition. • Nitrogen generation through ferric iron reduction by ammonium. • Hydrogen to nitrogen gas ratios as function of redox conditions. • Explanation of hydrogen and nitrogen association within natural hydrogen seepages. [ABSTRACT FROM AUTHOR]

The nitrite efficient utilization microorganism Wickerhamomyces anomalus RZWP01 was identified. Using nitrite and ammonium as the sole nitrogen source, the nitrogen removal rate of W. anomalus RZWP01 was 97.4% and 87.1%, respectively. W. anomalus RZWP01 grew well in the nitrite medium with glucose or xylose as the only carbon source. However, the W. anomalus RZWP01 cannot live on the nitrite medium with lactose, citric acid, and methanol as the only carbon source. The maximal cell concentration occurred in the nitrite medium with glucose as the only carbon source at a C/N ratio of 20 for 48 h, reaching 8.92 × 108 cell mL−1. W. anomalus RZWP01 was the first reported yeast that can efficiently utilize nitrite. The isolation and identification of W. anomalus RZWP01 enriched the microbial resources of nitrite-degrading microorganisms and provided functional microorganisms for the water treatment of sustainable aquaculture. [ABSTRACT FROM AUTHOR]

Mechanically robust anion-exchange membranes (AEMs) with high conductivity and long-term alkali resistance are needed for water electrolysis application. In this work, aryl-ether free polyaromatics containing isatin moieties were prepared via super acid-catalyzed copolymerization, followed by functionalization with alkaline stable cyclic quaternary ammonium (QA) cationic groups, to afford high performance AEMs for application in water electrolysis. The incorporation of side functional cationic groups (pyrrolidinium and piperidinium) onto a polymer backbone via a flexible alkyl spacer aimed at conductivity and alkaline stability improvement. The effect of cation structure on the properties of prepared AEMs was thoroughly studied. Pyrrolidinium- and piperidinium-based AEMs showed similar electrolyte uptakes and no obvious phase separation, as revealed by SAXS and further supported by AFM and TEM data. In addition, these AEMs displayed high conductivity values (81. 5 and 120 mS cm−1 for pyrrolidinium- and piperidinium-based AEM, respectively, at 80 °C) and excellent alkaline stability after 1 month aging in 2M KOH at 80 °C. Especially, a pyrrolidinium-based AEM membrane preserved 87% of its initial conductivity value, while at the same time retaining its flexibility and mechanical robustness after storage in alkaline media (2M KOH) for 1 month at 80 °C. Based on 1H NMR data, the conductivity loss observed after the aging test is mainly related to the piperidinium degradation that took place, probably via ring-opening Hofmann elimination, alkyl spacer scission and nucleophilic substitution reactions as well. The synthesized AEMs were also tested in an alkaline water electrolysis cell. Piperidinium-based AEM showed superior performance compared to its pyrrolidinium analogue, owing to its higher conductivity as revealed by EIS data, further confirming the ex situ conductivity measurements. [ABSTRACT FROM AUTHOR]

Refractive indices and optical birefringence of improper ferroelectric ammonium fluoroberyllate (AFB) crystals with the incommensurate phase are studied in a wide temperature range. Temperature characteristics of the optical indicatrix of AFB are examined and two quasi-isotropic points are found, the temperature positions T0 of which are almost independent of the light wavelength. Unlike the dielectric permittivity affected by the incommensurate-ferroelectric phase transition (PT) at TC, the optical characteristics of AFB are influenced only by the normal-incommensurate PT located at Ti ≈ 183.1 K. Using a Ginzburg criterion and the experimental Ginzburg number G ≈ 2.5×10-3, we have determined the temperature region around Ti where the critical fluctuations are small and a canonical mean-field theory can be applied. Outside the critical region, the spontaneous birefringence arising due to the incommensurate PT is described perfectly by the Landau theory, with the critical index of the order parameter β ≈ 0.50. [ABSTRACT FROM AUTHOR]

The exchange of ammonium across cellular membranes is a fundamental process in all domains of life and is facilitated by the ubiquitous Amt/Mep/Rh transporter superfamily. Remarkably, despite a high structural conservation in all domains of life, these proteins have gained various biological functions during evolution. It is tempting to hypothesise that the physiological functions gained by these proteins may be explained at least in part by differences in the energetics of their translocation mechanisms. Therefore, in this review, we will explore our current knowledge of energetics of the Amt/Mep/Rh family, discuss variations in observations between different organisms, and highlight some technical drawbacks which have hampered effects at mechanistic characterisation. Through the review, we aim to provide a comprehensive overview of current understanding of the mechanism of transport of this unique and extraordinary Amt/Mep/Rh superfamily of ammonium transporters. [ABSTRACT FROM AUTHOR]

• Drying of solid digestate was investigated in thin-layer at a laboratory-scale. • The kinetics of ammonium degradation and drying exhibited a similar characteristic. • Both processes occured in three similar distinguishable periods. • In the first reaction period, NH 4 -N degradation is a first-order chemical reaction. • The development of the pH value clearly followed the reaction course. Fundamental knowledge of the drying behavior and ammonia emission from digestate is required in order to properly design efficient drying processes. In this study, laboratory-scale drying experiments with two different digestates (D1 and D2) were conducted at four different drying temperatures (50, 60, 70, and 80 °C). The solid digestate D1 mainly consisted of plant silage (88.7%), while D2 comprised primarily of manure (55.9%). The drying experiments were performed in a controlled drying chamber using relatively small-sized samples of digestate (30 g for D1, 37 g for D2). These samples were characterized by an initial moisture content of about 74% wb (D1) and 78% wb (D2). This sample size mass was deliberately chosen to ensure homogeneous drying conditions within a thin layer and to facilitate precise laboratory quality measurements of parameters including water content, nitrogen contents (N-total, NH 4 -N), and pH values before and after the drying process. Both types of digestate exhibited a similar kinetics of drying and ammonium degradation. The first period of constant drying rate was followed by two periods with decreasing rates. Similarly, the ammonium degradation was characterized by three periods with decreasing reaction rates. Considering only the first reaction period herein, ammonium degradation was determined as a first-order reaction. The activation energy for this reaction period was obtained to be 20.00 kJ mol−1 for digestate D1 and 18.44 kJ mol−1 for digestate D2. The results of this study may serve as a basis for the conceptualization and design of optimized, continuous drying processes tailored to digestate materials. [ABSTRACT FROM AUTHOR]

Carveol is a rare fine chemical with specific biological activities and functions in nature. The artificial synthesis of carveol from plentiful and cheap turpentine is expected to further improve development of pharmaceutical and industrial applications. A new green catalytic system for the preparation of high-value carveol from α-epoxypinane is presented. A novel ammonium salt solid acid (AC-COIMI-NH4PW) was obtained from phosphotungstic acid bonded with imidazole basic site on nitrogen-doped activated carbon which, after ammonia fumigation, presented an excellent catalytic performance for the selective rearrangement of α-epoxypinane to carveol in DMF as solvent under mild reaction conditions. At 90 °C for 2 h, the conversion of α-epoxypinane could reach 98.9% and the selectivity of carveol was 50.6%. The acidic catalytic sites exhibited superior durability and the catalytic performance can be restored by supplementing the lost catalyst. Based on the investigation of catalytic processes, a parallel catalytic mechanism for the main product was proposed from the rearrangement of α-epoxypinane on AC-COIMI-NH4PW. [ABSTRACT FROM AUTHOR]

Amino acid L-arginine (Arg), usually presented in food products and biological liquids, can serve both as a useful indicator of food quality and an important biomarker in medicine. The biosensors based on Arg-selective enzymes are the most promising devices for Arg assay. In this research, three types of amperometric biosensors have been fabricated. They exploit arginine oxidase (ArgO), recombinant arginase I (ARG)/urease, and arginine deiminase (ADI) coupled with the ammonium-chelating redox-active nanoparticles. Cadmium-copper nanoparticles (nCdCu) as the most effective nanochelators were used for the development of ammonium chemosensors and enzyme-coupled Arg biosensors. The fabricated enzyme/nCdCu-containing bioelectrodes show wide linear ranges (up to 200 µM), satisfactory storage stabilities (14 days), and high sensitivities (A⋅M−1⋅m−2) to Arg: 1650, 1700, and 4500 for ADI-, ArgO- and ARG/urease-based sensors, respectively. All biosensors have been exploited to estimate Arg content in commercial juices. The obtained data correlate well with the values obtained by the reference method. A hypothetic scheme for mechanism of action of ammonium nanochelators in electron transfer reaction on the arginine-sensing electrodes has been proposed. [ABSTRACT FROM AUTHOR]

This article explores the applications of ammonium ylide based rearrangements in transforming amines into natural products. Specifically, it discusses the [2,3]-sigmatropic and [1,2]-Stevens rearrangements, which involve the exchange of carbon-nitrogen and carbon-carbon bonds. The article showcases the use of these rearrangements in the synthesis of natural products such as cephalotaxine and amathaspiramide F. It also discusses the synthesis of other complex molecules, including strictamine, 6-deoxytetracycline antibiotics, tylophorine, iboga alkaloids, vinblastine, and chiral indolizidines. The article emphasizes the efficiency and selectivity of these rearrangements in accessing bioactive polycyclic frameworks. Additionally, it explores the use of magnesium iodide and trimethyl phosphate in the synthesis of organic compounds. Overall, the article demonstrates the utility of ammonium ylide based rearrangements in the synthesis of diverse natural products. [Extracted from the article]

Heterogeneous nucleation of ice from supercooled water is the process responsible for triggering nearly all ice formation in the natural environment. Understanding of heterogeneous ice nucleation is particularly key for understanding the formation of ice in clouds, which impacts weather and climate. While many effective ice nucleators are known, the mechanisms of their actions remain poorly understood. Some inorganic nucleators have been found to nucleate ice at warmer temperatures in dilute ammonium solution than in pure water. This is surprising, analogous to salty water melting at a warmer temperature than pure water. Here, the magnitude of this effect is rationalized as being due to thermodynamically favorable ammonium-induced disordering of the hydrogen bond network of ice critical clusters formed on inorganic ice nucleators. Theoretical calculations are shown to be consistent with new experimental measurements aimed at finding the maximum magnitude of the effect. The implication of this study is that the ice-nucleating sites and surfaces of many inorganic ice nucleators are either polar or charged and, therefore, tend to induce formation of hydrogen-ordered ice clusters. This work corroborates various literature reports, indicating that some inorganic ice nucleators are most effective when nominally neutral, and implies a commonality in mechanism between a wide range of inorganic ice nucleators. [ABSTRACT FROM AUTHOR]

Antibody drug conjugates (ADCs) have emerged as a highly promising class of cancer therapeutics, comprising antibodies, effector molecules, and linkers. Among them, DS-8201a with DXd as the effector molecule, has shown remarkable anti-tumor efficacy against solid tumors, sparking a surge of interest in ADCs with camptothecin derivatives as ADC effector molecules. In this study, we introduced and successfully constructed quaternary ammonium ADCs utilizing camptothecin derivatives WL-14 and CPTS-1 for the first time. All four ADCs displayed excellent stability under physiological conditions and in plasma, facilitating their prolonged circulation in vivo. Moreover, the four ADCs, employing Val-Cit or Val-Ala dipeptide linkers effectively achieved complete release of the effector molecules via cathepsin B. Although, the in vitro antitumor activity of these ADCs was comparatively limited, the development of quaternary ammonium ADCs based on novel camptothecin derivatives as effector molecules is still a viable and promising strategy. Significantly, our study provides valuable insights into the crucial role of linker optimization in ADCs design. [ABSTRACT FROM AUTHOR]

Due to the presence of the hierarchical freestanding structure, outstanding MXene conductive networks and abundant oxygen vacancy, the d-NVO@MXene hybrid film exhibits excellent electrochemical properties. [Display omitted] Aqueous zinc ion batteries (AZIBs) have gained extensive attention due to the numerous advantages of zinc, such as low redox potential, high abundance, low cost as well as high theoretical specific capacity. However, the development of AZIBs is still hampered due to the lack of suitable cathodes. In this work, the freestanding defective ammonium vanadate@MXene (d-NVO@MXene) hybrid film was synthesized by simple vacuum filtration strategy. Due to the presence of the hierarchical freestanding structure, outstanding MXene conductive networks and abundant oxygen vacancy (in the d-NVO nanoribbons), the d-NVO@MXene hybrid film can not only expose more active sites but also possess outstanding conductivity and kinetics of charge transfer/ion diffusion. When the d-NVO@MXene hybrid film was directly used as the cathode, it displayed a high specific capacity of 498 mAh/g at 0.5 A/g and superior cycling stability performance with near 100 % coulomb efficiency. Furthermore, the corresponding storage mechanism was elucidated by ex situ various characterizations. This work provides new ideas for the development of freestanding vanadium-based cathode materials for AZIBs. [ABSTRACT FROM AUTHOR]