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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]

As a new type of green propellant, ammonium dinitramide (ADN)-based energetic propellants have wide application value and development potential in the field of space propulsion. This paper delves into the intricate impact of varying initial temperatures, pressures, and propellant component ratios on critical parameters, including temperature, combustion rate, and heat release, in the straight nozzle of an ADN-based propellant. The findings indicate that an elevation in both initial temperature and ADN ratio expedites the thermal decomposition rate of ADN, thereby elevating the average temperature in the nozzle. However, the elevation in initial temperature has a negative effect on the overall rise amplitude of average temperature. Furthermore, the initial pressure setting is crucial in determining whether the oxidation reaction of the fuel CH3OH occurs in ADN propellants. When the initial pressure is greater than 10 atm, CH3OH is completely consumed, and the final average temperature is about 2650 K, which increases by 558.89% compared with that at 1 atm. Our work aims to provide theoretical guidance and practical optimization strategies for enhancing propellant performance and optimizing thruster structure design. [ABSTRACT FROM AUTHOR]

In recent years, in the field of bioanalysis, the use of saliva as a biological fluid for the determination of biomarkers has been proposed. Saliva analysis stands out for its simplicity and non-invasive sampling. This paper proposes a method for the dual determination of ammonium and hydrogen sulfur in saliva using two colorimetric chemosensors. The ammonia reacts with 1,2-Naftoquinone 4 sulphonic acid (NQS) entrapped in polydimethylsiloxane (PDMS) and the hydrogen sulfide with AgNPs retained in a nylon membrane. The color changed from orange to brown in the case of ammonia chemosensors and from yellow to brown in the H2S. The experimental conditions to be tested have been established. Both analytes have been determined from their gaseous form; these are ammonia from ammonium and hydrogen sulfur from hydrogen sulfur. Good figures of merit have been obtained by using both measuring strategies (reflectance diffuse and digitalized images). The acquired results show that both sensors can be used and provide good selectivity and sensitivity for the determination of these biomarkers in saliva. Both measurement strategies have provided satisfactory results for the real saliva samples (n = 15). Recoveries on spiked samples were between 70% and 100%. This methodology can lead to possible in situ diagnosis and monitoring of certain diseases and pathologies related with NH4+ and/or H2S, in a fast, simple, cheap and non-invasive way. [ABSTRACT FROM AUTHOR]

A large amount of ammonium salt leaching agent will remain in the leaching site of weathered crust elution-deposited rare earth ore (WREOs). The release of residual ammonium (RA) will seriously affect the water system ecology of the mining area, and it is urgent to control it. In this paper, column eluting was used to simulate the eluting process of RA in rare earth (RE) ore tailings, and the effects of calcium chloride concentration, eluting temperature, liquid-solid ratio, eluent pH and eluent flow rate on the eluting process of RA in rare earth ore tailings were discussed. It was found that calcium chloride could effectively elute the RA from ore tailings. Eluting agent pH almost had no effect on the eluting process of RA in the pH range of 4–6, and a greater impact on it at pH 8. The flow rate could effectively enhance the elution efficiency. The optimum conditions were calcium ion concentration of 0.1 mol/L, liquid-solid ratio of 2:1, pH 4–6, flow rate of 0.6 mL/min and elution at room temperature. At this time, the elution efficiency of RA was 91.85%. The eluting process of RA in ore tailings was controlled by the inner particle diffusing according to the kinetic analysis. The reaction order was 0.368, and the activation energy of the reaction is 12.450 kJ/mol. This will provide a theoretical basis and technical support for the efficient eluting process of residual ammonium in the leaching site of WREOs. [ABSTRACT FROM AUTHOR]

Ammonium dinitramide (ADN), which has the advantages of high energy density, no halogen and low characteristic signal, is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidizer ammonium perchlorate (AP) in solid propellants, but also a good performance explosive in itself. However, due to the strong hygroscopicity of ADN, its application in solid propellants and explosives is greatly limited. Solving the hygroscopicity of ADN is the key to realize the wide application of ADN. In this paper, we systematically review the research progress of anti-hygroscopic strategies of ADN coating. The surface coating methods are focusing on solvent volatilization, solventnon- solvent, melt crystallization and atomic layer deposition technology. The characteristics of the different methods are compared and analyzed, and the basis for the classification and selection of the coating materials are introduced in detail. In addition, the feasibility of material for surface coating of ADN is evaluated by several compatibility analysis methods. It is highly expected that the liquid phase method (solvent volatilization method, solvent-non-solvent method) would be the promising method for future ADN coating because of its effective, safety and facile operation. Furthermore, polymer materials, are the preferred coating materials due to their high viscosity, easy adhesion, good antihygroscopic effect, and heat resistance, which make ADN weak hygroscopicity, less sensitive, easier to preserve and good compatibility. [ABSTRACT FROM AUTHOR]

On the basis of previous work, this paper systematically investigates the influence parameters and leaching kinetics of the ammonia leaching process of molybdenum calcine obtained by microwave roasting. The conditions of the ammonia leaching process of calcined molybdenum were optimized by changing the parameters of ammonia concentration, solid–liquid ratio, and leaching temperature. The results show that, when the concentration of ammonia was 25%, the mass of calcined molybdenum and the volume of ammonia were 1/2 g/ml, the leaching temperature was 75°C, and the leaching time was 60 min, the leaching efficiency of molybdenum can reach 91.74%, and the content of ammonium molybdate in the leaching product was 97.23 wt.%. In the leaching process, MoO3 in the solid phase is dissolved by ammonia to form ammonium molybdate, which conforms to the shrinking core model. The activation energy of the reaction is 57.8 kJ/mol and the rate control step is determined by the mixed model of chemical reaction and product layer diffusion. The apparent rate equation is expressed as: 1 3 ln 1 - x + 1 - x - 1 3 - 1 = 14.97 ω ammonia 2.004 (L / S) - 2.44 e - 57800 RT t . [ABSTRACT FROM AUTHOR]

The production of hydrogen via photocatalytic water splitting is one of the most promising technologies for obtaining chemical energy from direct solar energy while maintaining the least possible waste and pollutants. In this paper, we obtain the kinetic parameters necessary for the design of a photoreactor for photolysis and photocatalysis of ammonium sulfite solution. For the case of photolysis, we obtain the kinetics for the effect of changing the pH on the produced amount of hydrogen. For the case of photocatalysis, the intrinsic kinetic parameters of photocatalysis of water splitting reaction of ammonium sulfite and water in the presence of cadmium sulfide as a catalyst under solar radiation was inspected by developing MATLAB codes that can predict the kinetics based on the results of experimental work done. The resulted kinetics are compared to experimental work already done. These obtained kinetic parameters provide guidance for the design or scale-up of a solar photoreactor. [ABSTRACT FROM AUTHOR]

Anaerobic ammonium oxidation has been considered as an environmental-friendly and energy-efficient biological nitrogen removal (BNR) technology. Recently, new reaction pathway for ammonium oxidation under anaerobic condition had been discovered. In addition to nitrite, iron trivalent, sulfate, manganese and electrons from electrode might be potential electron acceptors for ammonium oxidation, which can be coupled to traditional BNR process for wastewater treatment. In this paper, the pathway and mechanism for ammonium oxidation with various electron acceptors under anaerobic condition is studied comprehensively, and the research progress of potentially functional microbes is summarized. The potential application of various electron acceptors for ammonium oxidation in wastewater is addressed, and the N 2 O emission during nitrogen removal is also discussed, which was important greenhouse gas for global climate change. The problems remained unclear for ammonium oxidation by multi-electron acceptors and potential interactions are also discussed in this review. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, a new type of highly efficient intumescent flame-retardant low-density polyethylene composite was prepared using two key technologies, namely, microencapsulation encapsulation technology and novel carbon formation technology. Precisely, β-cyclodextrin encapsulated modified ammonium polyphosphate@melamine formaldehyde resin (β-CDMCAPP@MF) was prepared by using Si-IFR synergistic flame retardant effect combined with the gel-solution method, and then flame retardant low-density polyethylene (LDPE) was prepared by compounding with tris-(2-hydroxyethyl) isocyanate (THEIC). The results showed that β-CDMCAPP@MF was modified with MF, β-CD, and silica coating. This modification resulted in excellent hydrophobicity and good compatibility with LDPE. The addition of IFR containing β-CDMCAPP@MF significantly improved the flame retardancy of the LDPE composites. Specifically, when 30 wt% of β-CDMCAPP@MF was added, the ultimate oxygen index of the composites reached 24.7 %, and V-0 grade and the tensile strength went 11.41 MPa. Compared with IFR/LDPE with the same proportion of MF@MCAPP and β-CD@MCAPP, the ultimate oxygen indices were increased by 9.72 % and 12.15 %, respectively. The introduction of THEIC into the flame retardant system resulted in a LOI value of 36.5 % and an FRI value of 2.523, which is 32.33 % higher than that of the composites containing 30 wt% of the flame retardant system (without THEIC). Cone calorimetry test results showed that introducing β-CDMCAPP@MF and THEIC significantly improved the smoke emission. [Display omitted] [ABSTRACT FROM AUTHOR]

MoS 2 and WS 2 are two promising candidates for photocatalytic hydrogen production, and pyrolysis is one of the conventional and useful methods for their preparations. However, systematic investigations about the influences of pyrolysis conditions on their photocatalytic hydrogen production performances are still unreported. Then in this paper, a series of pyrolysis products of ammonium tetrathiomolybdate (ATM) and ammonium tetrathiotungstate (ATT) were prepared by changing the pyrolysis temperature and time. Besides, detailed characterizations were conducted to find out the changes in composition, crystallinity, and morphology. Especially, to get optimal pyrolysis conditions for the preparation of high-performance MoS 2 and WS 2 , their photocatalytic hydrogen production activities were investigated. The results showed that although along with the changes in pyrolysis conditions, the overall changes in composition, crystallinity and morphology are similar for ATM and ATT products, there are significant differences in their performances. For the pyrolysis of ATM, the products obtained under lower temperatures exhibit relatively higher activity than those obtained under higher temperatures. The performance of sample ATM-400-1 (the pyrolysis product obtained under 400 °C 1 h) is the highest and those of two ATM-600 samples (obtained under 600 °C 1 h and 600 °C 2 h) are the lowest. On the contrary, for the pyrolysis of ATT, the higher-temperature products possess much higher performance than the lower-temperature ones. The activity of ATT-400-2 is the highest and those of two ATT-250 samples are the lowest. On the other hand, unconventional crystallized WS 3 was unexpectedly obtained through the pyrolysis of ATT at 300 °C for the first time. This work can offer useful information for the preparation of WS 2 and MoS 2 -based photocatalysts. The optimal conditions for preparation of MoS 2 and WS 2 by pyrolysis of ammonium tetrathiomolybdate (ATM) and ammonium tetrathiotungstate (ATT) were achieved and the reasons for performance difference of different products were elucidated. [Display omitted] • Pyrolysis products of ATM and ATT were systematically characterized. • Hydrogen production performances of pyrolysis products were detailed investigated. • Reasons for performance differences between ATM and ATT products were elucidated. • Crystalline WS 3 was achieved for the first time by the pyrolysis of ATT. [ABSTRACT FROM AUTHOR]

Synthetic polymer surfaces provide an excellent opportunity for developing materials with inherent antimicrobial and/or biocidal activity, therefore representing an answer to the increasing demand for antimicrobial active medical devices. So far, biologists and material scientists have identified a few features of bacterial cells that can be strategically exploited to make polymers inherently antimicrobial. One of these is represented by the introduction of cationic charges that act by killing or deactivating bacteria by interaction with the negatively charged parts of their cell envelope (lipopolysaccharides, peptidoglycan, and membrane lipids). Among the possible cationic functionalities, the antimicrobial activity of polymers with quaternary ammonium centers (QACs) has been widely used for both soluble macromolecules and non-soluble materials. Unfortunately, most information is still unknown on the biological mechanism of action of QACs, a fundamental requirement for designing polymers with higher antimicrobial efficiency and possibly very low toxicity. This mini-review focuses on surfaces based on synthetic polymers with inherently antimicrobial activity due to QACs. It will discuss their synthesis, their antimicrobial activity, and studies carried out so far on their mechanism of action. [ABSTRACT FROM AUTHOR]

Background: Cancer occurs in 83% of liver diseases. Other risk factors for liver cancer include viral hepatitis, alcohol consumption, industrial chemicals, and a number of toxins. Another major disease that occurs following liver damage is hepatic encephalopathy. This condition arises primarily due to increased blood ammonia levels. Carvacrol, with antioxidant properties, reduces oxidative stress on the liver. The aim of this study was to investigate the effect of carvacrol on the improvement of hepatic encephalopathy in rats. Methods: In this experimental study, 60 male Wistar rats were randomly divided into six groups of 10 each. Liver damage and induction of oxidative stress were caused in the rats by administering thioacetamide (100 mg/kg/day) intraperitoneally for three consecutive days. Carvacrol was administered by gavage at 25, 50, or 100 mg/kg/day after thioacetamide treatment. We investigated the biomarkers of liver damage in the blood, such as alanine transaminase, lactate dehydrogenase, total protein, and bilirubin. We also assessed the effect of oxidative stress, as the key inducer of hepatic encephalopathy, on the liver by measuring the lipid peroxidation, antioxidants, reactive oxygen species, glutathione reserves, and ammonium levels in the serum and brain. Results: Thioacetamide significantly increased the biochemical markers in the rat sera, reflecting ammonium release and the development of oxidative stress (P<0.05). Conversely, the various doses of carvacrol significantly reduced the levels of biomarkers that are indicative of liver damage (P<0.05). Conclusion: The study findings provided experimental evidence in favor of the therapeutic effects of carvacrol and against liver injury induced by thioacetamide, leading to encephalopathy. [ABSTRACT FROM AUTHOR]

The ammonia/ammonium (NH3/NH4+, AM) concentration in human erythrocytes (RBCs) is significantly higher than in plasma. Two main possible mechanisms for AM transport, including simple and facilitated diffusion, are described; however, the driving force for AM transport is not yet fully characterized. Since the erythroid ammonium channel RhAG forms a structural unit with anion exchanger 1 (eAE1) within the ankyrin core complex, we hypothesized the involvement of eAE1 in AM transport. To evaluate the functional interaction between eAE1 and RhAG, we used a unique feature of RBCs to swell and lyse in isotonic NH4+ buffer. The kinetics of cell swelling and lysis were analyzed by flow cytometry and an original laser diffraction method, adapted for accurate volume sensing. The eAE1 role was revealed according to (i) the changes in cell swelling and lysis kinetics, and (ii) changes in intracellular pH, triggered by eAE1 inhibition or the modulation of eAE1 main ligand concentrations (Cl− and HCO3−). Additionally, the AM import kinetics was analyzed enzymatically and colorimetrically. In NH4+ buffer, RBCs concentration-dependently swelled and lysed when [NH4+] exceeded 100 mM. Cell swelling and hemolysis were tightly regulated by chloride concentration. The complete substitution of chloride with glutamate prevented NH4+-induced cell swelling and hemolysis, and the restoration of [Cl−] dose-dependently amplified the rates of RBC swelling and lysis and the percentage of hemolyzed cells. Similarly, eAE1 inhibition impeded cell swelling and completely prevented hemolysis. Accordingly, eAE1 inhibition, or a lack of chloride anions in the buffer, significantly decreased NH4+ import. Our data indicate that the eAE1-mediated chloride gradient is required for AM transport. Taken together, our data reveal a new player in AM transport in RBCs. [ABSTRACT FROM AUTHOR]

Metallocene catalysts have attracted much attention from academia and industry for their excellent catalytic activity in the field of olefin polymerization. Cocatalysts play a key role in metallocene catalytic systems, which can not only affect the overall catalytic activity, but also have an obvious influence on the structure and properties of the polymer. Although methylaluminoxane (MAO) is currently the most widely used cocatalyst, its price increases the production cost of polyolefin materials. Ammonium tetrakis(pentafluorophenyl)borate has shown excellent performance in polymerization, being one of the best substitutes for the traditional cocatalyst MAO. Compared with the main catalyst, whose composition and structure are relatively complex, the research on cocatalyst is very limited. This review mainly introduces the research history, preparation methods, and application progress in polymerization of ammonium tetrakis(pentafluorophenyl)borate, deepening our understanding of the role of cocatalyst in polymerization, with the hope of inspiring brand-new thinking on improving and enhancing the overall performance of catalyst systems. [ABSTRACT FROM AUTHOR]

The general trend in biomining (i.e., bioleaching and biooxidation) is the use of media with high concentrations of the nutrients (nitrogen as ammonium, phosphorous as phosphate, and K), which are considered to be essential for microbial growth. The depletion of any of the nutrients would affect negatively the bioleaching (and biooxidation) capacity of the microorganisms, so the formulation of the different media ensures that there is a surplus of nutrients. However, some of these nutrients (e.g., phosphate, K) may be already present in the ore and are made available to the microorganisms when the ore is exposed to the low-pH media used during bioleaching. The effect of phosphate addition (109 mg/L) and depletion on the bioleaching of low-grade sulfidic ore alongside the determination of ammonium (i.e., 25 mg/L, 50 mg/L, 109 mg/L, 409 mg/L, and 874 g/L) requirements were studied. The results of the experiments presented showed that the addition of phosphate did not have any effect on the bioleaching of the low-grade sulfidic ore while the addition of ammonium was necessary to obtain higher redox potentials (>650 mV vs. Ag/AgCl) and higher metal (Co, Cu, Ni, and Zn) dissolutions. Temperature was the factor that shaped the microbial communities, at 30°C, the microbial community at the end of all the experiments was dominated by Acidithiobacillus sp. as well as at 42°C, except when nutrients were not added and Sulfobacillus sp. was the dominant microorganism. At 55°C, DNA recovery was unsuccessful, and at 60°C, the microbial communities were dominated by Sulfolobus sp. In conclusion, the amount of nutrients in bioleaching could be reduced significantly to achieve the redox potentials and metal dissolution desired in bioleaching without affecting the microbial communities and bioleaching efficiencies. [ABSTRACT FROM AUTHOR]

In this study, the response surface method is used to develop a model for analyzing and optimizing zinc leaching experiments. An investigation into the leaching kinetics of smithsonite in ammonium citrate solution is also conducted. A model of kinetics is studied in order to represent these effects. The experimental data show that an increase in the solution temperature, concentration, and stirring speed has a positive impact on the leaching rate, while an increase in the particle size has a negative impact on it. The optimal experimental conditions consist of a leaching temperature of 70 °C, ammonium citrate concentration of 5 mol/L, particle size of 38 µm, and rotational speed of 1000 rpm. Under these optimal conditions, the leaching rate of zinc from smithsonite is 83.51%. It is speculated that the kinetic model will change when the temperature is higher than 60 °C. When the temperature is lower than 60 °C, the leaching process is under the control of the shrinking core model of the surface chemical reactions. The calculated activation energy of the leaching reaction is equal to 42 kJ/mol. The model of the leaching process can be described by the following equation: 1 − 1 − x 1 / 3 = k 0 ⋅ (C) 0.6181 ⋅ r 0 − 0.5868 ⋅ S S 0.6901 exp ⁡ − 42 / R T ] t . This demonstrates that an ammonium citrate solution can be used in the leaching process of zinc in smithsonite as an effective and clean leaching agent. [ABSTRACT FROM AUTHOR]

[Display omitted] • We used AG, a bioactive compound extracted from Licorice root, as surfactant. • We have shown the AG ability to self-assemble in homogeneous and stable vesicular structures. • AG niosomes obtained, showed an important antinflammatory activity. • AG niosomes were investigate as carrier of other compounds such as curcumin. In this paper, the surfactant properties of Ammonium Glycyrrhizate, a bioactive compound present in Licorice root were studied. Considering the ability of this bioactive molecule to form micelles, we investigated for the first time the self-assemble of Ammonium Glycyrrhizate in vesicle structures. The organization of Ammonium Glycyrrhizate in vesicles allows to increase its bioavailability and, so, efficacy but also to use them as carrier of other drugs for potential combination therapy. Niosomes made up of Ammonium Glycyrrhizate were prepared using thin layer evaporation technique without the use of additional excipients and characterized in term of size, polydispersion index, Zeta potential and colloidal stability. Moreover, the performance of these innovative vesicles as carriers of hydrophilic drug (Fluorescein sodium) or a lipophilic molecule (Curcumin), was evaluated. Nanocarriers showed nanometric sizes, hexagonal shape, high colloidal stability and ability to encapsulate both hydrophilic and hydrophobic molecules. These vesicles did not showed cytotoxicity nor antimicrobial activityMoreover, it was found that these niosomes enhanced skin permeation and diffusion in several media and an important ability to interact with mucin. Considering its antinflammatory nature, in vitro inhibition of albumin denaturation assay was also carried out to test if the drug maintains these properties also when organized in colloidal structures. The obtained results highlighted an important antinflammatory activity suggesting the potential role of these nanodevices alone or loaded with other therapeutic molecules for the treatment of inflammatory-based diseases. [ABSTRACT FROM AUTHOR]

The increasing deterioration of freshwater bodies has prompted the development of legislation for priority substances (PSs) and contaminants of emerging concern (CECs). In parallel, advanced treatment processes have been investigated to remove these contaminants from wastewaters and the assessment of the potential impacts of some of these processes has been performed throughout their life cycle. In this paper, a comparative life cycle assessment of the solar heterogeneous photocatalysis treatment of secondary urban wastewater using a carbon-based composite (consisting of graphene oxide and titanium dioxide, GO-TiO 2) or commercially available titanium dioxide material (TiO 2 –P25) as photocatalysts is conducted. It was found that the solar/GO-TiO 2 treatment, which implements GO-TiO 2 synthesized by the liquid phase deposition method, has higher potential impacts than the solar/TiO 2 option in all categories assessed under the present conditions due to the high potential impacts of the GO-TiO 2 synthesis method (i.e. , using ammonium hexafluorotitanate and boric acid as precursors to obtain TiO 2 in the composite). A composite prepared with TiO 2 –P25 and GO via a mechanical process seems to be a better solution to reduce all potential environmental impacts, but the resulting photocatalytic activity should also be considered before reaching a decision. [Display omitted] • Using GO-TiO 2 instead of TiO 2 –P25 increases all potential environmental impacts. • (NH 4) 2 TiF 6 and H 3 BO 3 use in GO-TiO 2 synthesis is highly impactful. • Alternatives for the source of TiO 2 in the GO-TiO 2 composite are needed. • Synthesizing GO-TiO 2 by other methods may be a more interesting option. • The impact of GO synthesis is not relevant in comparison to TiO 2 addition to the composite. [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]

The California Current system (CCS) hosts one of the largest oxygen minimum zones (OMZs) in the world: the eastern North Pacific (ENP) OMZ, which is dissociated into subtropical and tropical regions (i.e. the ESTNP and ETNP). In the modern ENP OMZ, bioavailable nitrogen (N) is lost via denitrification and anaerobic ammonium oxidation (anammox). Even so, paleo-reconstructions of N loss have focused solely on denitrification. Fluctuations in bulk sedimentary δ15 N over glacial–interglacial cycles have been interpreted to reflect variations in denitrification rates in response to ETNP OMZ intensity changes. This δ15 N signal is thought to be transported northwards to the ESTNP OMZ. Here, we present the first CCS sedimentary record of ladderane lipids, biomarkers for anammox, located within the ESTNP OMZ (32° N, 118° W). Over the last two glacial terminations (∼ 160 kyr cal BP), ladderane concentrations were analysed in combination with the index of ladderanes with five cyclobutane moieties (NL 5), short-chain (SC) ladderane degradation products, and productivity proxies. This shows that (1) ladderanes were derived from anammox bacteria living within the ESTNP OMZ water column; (2) ladderanes were continuously present, with relatively high concentrations during both glacial and interglacial periods, showcasing that the ESTNP OMZ must have retained an anoxic core in which N loss occurred; and (3) anammox abundance appears to have been driven by both organic matter (OM) remineralization and advection changes, which regulated nutrient and oxygen levels. Our study shows that anammox was an important feature in the CCS, and it provides a more holistic picture of N-loss dynamics and the development of the ESTNP OMZ over glacial–interglacial cycles. Lastly, ladderanes and their SC products were also detected in 160–500 kyr cal BP sediments (15.7–37.5 m b.s.f., metres below sea floor; analysed at a low temporal resolution), highlighting their potential as anammox biomarkers in relatively deeper buried sediments for future studies. [ABSTRACT FROM AUTHOR]

Biochar (BC) and hydrochar (HC) have attracted considerable attention owing to their versatile characteristics and proven effectiveness in diverse technical fields. Solid BC is generated as a result of the dry carbonisation process of pyrolysis, in contrast to the slurry HC, which is produced during the hydrothermal carbonisation process. In this study, we evaluated the adsorption potential of two hydrochar samples (HCs) and three biochar samples (BCs) produced from sugar cane bagasse. The adsorption capacity of these samples was tested for ammonium, nitrate, and phosphate ions under various conditions. The BCs and HCs were subjected to characterisation using a CHNS/O analyser, the zeta potential, and Fourier transform infrared (FTIR). Elevating the pyrolysis temperature of the biochar resulted in changes in the fixed carbon and ash contents, while the volatile matter and H/C and O/C atomic ratios decreased. As the residence time increased, the H/C ratio and volatile matter content of the hydrochars (HCs) decreased. However, the fixed carbon content, ash content, and O/C and C/N ratios exhibited an increase. Thermodynamics, adsorption isotherms, and pH were also taken into consideration. The FTIR spectra analysis indicated that the carboxyl and ester functional groups present in both the BCs and HCs displayed reduced peak intensities subsequent to the adsorption of the three ions. While the adsorption was exothermic, we noticed that the adsorption capacity increased with temperature. The results indicate that sorption was homogenous across all binding sites, as evidenced by the optimal fit to the Langmuir isotherm. The research findings indicate that the adsorption capacity of various BC and HC adsorbents is significantly influenced by the surface area of the adsorbents in the case of nitrate and phosphate, but in the case of ammonia, adsorption is dictated by the functional polar groups present on the adsorbent surface. [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]

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]

Anaerobic digestion of sewage sludge is limited at the hydrolysis stage of the process. The goal of this study was to assess the effects of sludge retention times and ultrasound pretreatment on the ammonium concentration and organic matter transformation in anaerobic digesters treating sewage sludge. To achieve this, two laboratory-scale semicontinuous anaerobic digesters were operated for a period of over 70 d, including a control reactor and another fed by pretreated sludge. Both anaerobic systems were fed with mixed sludge (50%/50% primary/secondary treatment) in mesophilic conditions (37 °C), with solid retention times (SRT) of 7.5 d (Phase I) and 3 d (Phase II). The performance of the anaerobic digestion process was assessed in terms of the methane yield and the total and soluble chemical organic demand, total solids, and volatile solids removal. The results showed that the ultrasound pretreatment caused an increase of around 22.2% in CODt removal for an SRT of 7.5 d. Meanwhile, an SRT of 3 d resulted in a decrease of up to 92.4% in CODt removal. The performance in terms of biogas production and organic matter removal was significantly affected by the SRT reduction to 3 d, showing that the process is not viable in these conditions. [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]

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]

In recent years, in the field of bioanalysis, the use of saliva as a biological fluid for the determination of biomarkers has been proposed. Saliva analysis stands out for its simplicity and non-invasive sampling. This paper proposes a method for the dual determination of ammonium and hydrogen sulfur in saliva using two colorimetric chemosensors. The ammonia reacts with 1,2-Naftoquinone 4 sulphonic acid (NQS) entrapped in polydimethylsiloxane (PDMS) and the hydrogen sulfide with AgNPs retained in a nylon membrane. The color changed from orange to brown in the case of ammonia chemosensors and from yellow to brown in the H2S. The experimental conditions to be tested have been established. Both analytes have been determined from their gaseous form; these are ammonia from ammonium and hydrogen sulfur from hydrogen sulfur. Good figures of merit have been obtained by using both measuring strategies (reflectance diffuse and digitalized images). The acquired results show that both sensors can be used and provide good selectivity and sensitivity for the determination of these biomarkers in saliva. Both measurement strategies have provided satisfactory results for the real saliva samples (n = 15). Recoveries on spiked samples were between 70% and 100%. This methodology can lead to possible in situ diagnosis and monitoring of certain diseases and pathologies related with NH4+ and/or H2S, in a fast, simple, cheap and non-invasive way.