Ammonia Concentration Research Articles

Portable Sensing Probe for Real-Time Quantification of Ammonia in Blood Samples.

The detection of ammonia levels in blood is critical for diagnosing and monitoring various medical conditions, including liver dysfunction and metabolic disorders. However, traditional diagnostic methods are slow and cumbersome, often involving multiple contact-based steps such as ammonia separation in alkali conditions followed by distillation or microdiffusion, leading to delays in diagnosis and treatment. Herein, we developed a colorimetric assay capable of rapid detection of ammonia in whole blood or plasma samples, utilizing 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized cellulose nanocrystals (TCNC) coupled with gold nanoparticles (AuNPs). The basis of our assay relies on either (i) the interaction between the carboxylate group (-COO) of TEMPO and ammonium ions or (ii) the manipulation of AuNPs surface plasmon resonance (SPR) through the formation of Au(NH3)43+, which displaces a redox mediator, resazurin, resulting in observable multicolor displays at various concentrations of ammonia. The colorimetric assay exhibits a wide linear detection range for dissolved NH4+ (0.1-37 μM) with a low limit of detection (LOD) of 0.1 μM. Additionally, it effectively measures NH3(g) concentrations in the range of 0.5-144 μM. The fabricated electrochemical nose (E-nose) device demonstrates excellent analytical performance for plasma ammonia sensing (0.05-256 μM). Experimental results demonstrate a linear detection range suitable for clinical applications, with excellent correlation to standard laboratory methods, offering a practical solution for point-of-care (PoC) testing. We anticipate that this approach can be applied broadly to improve patient monitoring and treatment by providing immediate and accurate ammonia measurements in a clinical setting.

Machine learning optimization of a zero energy building (ZEB) by waste heat recovery in a co-generation system

Waste heat recovery is known as one of the newest methods to increase the energy and exergy efficiencies of thermal systems. The concept has been also developed in co-generation systems where productions of electricity, cooling and heating are considered, simultaneously. This study investigates tri-generation system with a co-generation ammonia-water cycle (AWC) and an organic Rankine cycle (ORC) to supply cooling, heating, and power, simultaneously. As novelty, six different working fluids of Ammonia, R124, R134a, R152a, R245fa and R290 were investigated, as six scenarios for ORC. As result, the R124 was found as the best one and the next investigations were followed just with this fluid. Minimizing total cost and maximizing exergy efficiency at the same time are the main aim of this paper. Design Expert software was used to find out about this optimum point. Four cities in Australia were selected and the effect of annual ambient temperatures of them were studied on the outputs of the system, using TRNSYS software. Also, the optimum values of the effective parameters, including the isentropic efficiencies of pumps, compressor, and turbines, heat source temperature, ammonia concentration, utmost pressures of ORC and AWC, were obtained and reported by means of TOPSIS. As results, the monthly generations in electricity, heating and cooling were estimated. It was revealed that the lower ambient temperature, the higher electricity generation, according to the thermodynamic cycle of the proposed co-generation system. Finally, the results showed that application of the suggested co-generation system can cover the electricity demand of 294 apartments, heating for 208 apartments, and cooling load for 18,999 apartments.

Self-regenerable oxygen system using microalgae-bacterial consortium for ammonium removal from wastewater

This study investigated self-regenerable oxygen system using microalagae-bacterial consortium for ammonium removal from wastewater and its kinetic modeling based on a combined mechanistic and empirical approach. By mechanistic modeling using a simple microalgal-bacterial Monod model, based on algal growth due to NH4+, NO3− and NO2−, the nitrogen and DO profiles were accurately predicted under different nitrogen conditions (low, medium, and high NH4+ concentrations). The mathematical modeling results showed that sufficient oxygen was available for nitrification at low initial NH4+ ammonium concentration levels, even when dual nitrogen substrate (NH4+–NO2−, NH4+–NO3− or NO2−–NO3−) or all three in combination (NH4+–NO2−–NO3−) were used, compared with high initial ammonium concentration levels. The DO profile was successfully used to monitor N transformation and N uptake in the PSBR based on net O2 uptake rate, O2 production rate, and O2 saturation profile. By empirical modeling of the data obtained, the actual O2 produced by microalgae with the different N species was calculated based on N mass balance and empirical equations. The empirical model further revealed that low NH4+ concentration levels (up to 82.5 mg N/L) favored successful nitrification due to the sufficient production of O2 in the system. However, NH4+ concentration in the range 82.5–132.5 mg N/L affected the nitrification efficiency due to insufficient O2 produced in the system, whereas high ammonium concentration results in nitritation/partial nitrification due to the high demand of O2 by AOB and inhibition in the growth of NOB.

Urinary Response to Consuming Plant-Based Meat Alternatives in Persons with Normal Kidney Function: The SWAP-MEAT Pilot Trial.

Consuming excess animal meat may exacerbate kidney disorders such as urinary stone disease and chronic kidney disease. Plant-based meat alternatives imitate animal meat, and replace animal with vegetable protein, but it is unclear whether eating plant-meat confers similar health benefits as eating whole vegetables. We hypothesized that eating plant-meat when compared with animal meat decreases dietary acid load but increases dietary phosphorus and nitrogen. SWAP-MEAT was a randomized eight-week, crossover trial (NCT03718988) of participants consuming >2 servings/day of either plant-meat or animal meat for each eight-week phase. We measured urine sulfate, ammonium, pH, phosphorus, urea nitrogen, citrate, and creatinine concentrations, and serum creatinine and bicarbonate concentrations from stored participant samples from each phase. At a single site, we enrolled 36 generally healthy participants (mean±SD age 50.2 ± 13.8 years, 67% women, and 69% White). Eating the plant-meat diet vs. eating the animal meat diet was associated with lower mean concentration of urine sulfate (-6.7 mEq/L; 95% CI -11.0, -2.4), urine ammonium (-4.2 mmol/L; 95% CI -8.2, -0.1), urine phosphorus (-9.0 mg/dL; 95% CI -17.5, -0.5), and urine urea nitrogen (-124.8 mg/dL; 95% CI -226.9, -22.6). Eating plant-meat compared with eating animal meat was associated with higher mean urine pH (+0.3 units; 95% CI 0.2, 0.5) and mean urine citrate/creatinine ratio (+111.65; 95% CI 52.69-170.60). After participants consumed a plant-meat diet compared with when they consumed an animal meat diet, mean serum creatinine concentration was lower (-0.07 mg/dL, 95% CI -0.10, -0.04), whereas mean serum bicarbonate concentration was not different. Eating plant-based meat products, compared with eating animal meat, was associated with lower urinary excretion of sulfate, ammonium, phosphorus, and urea nitrogen and higher urinary excretion of citrate. Our findings provide rationale for examining whether plant-based meat will benefit patients with kidney disease.

Tank formation transforms nitrogen metabolism of an epiphytic bromeliad and its phyllosphere bacteria.

Up to half of tropical forest plant species grow on other plants. Lacking access to soils, vascular epiphytes have unique adaptations for mineral nutrition. Among the most distinctive is the tank growth form of certain large bromeliads, which absorb nutrients that are cycled by complex microbial communities in water trapped among their overlapping leaf bases. However, tanks form only after years of growth by juvenile plants, which must acquire nutrients differently. Understanding how nutrient dynamics change during tank bromeliad development can provide key insights into the role of microorganisms in the maintenance of tropical forest biodiversity. We evaluated variations in plant morphology, growth, foliar nitrogen physiology, and phyllosphere bacterial communities along a size gradient spanning the transition to tank formation in the threatened species Tillandsia utriculata. Sequential morphological and growth phases coincided with the transition to tank formation when the longest leaf on plants was between 14 and 19 cm. Before this point, foliar ammonium concentrations were very high, but after, leaf segments absorbed significantly more nitrate. Leaf-surface bacterial communities tracked ontogenetic changes in plant morphology and nitrogen metabolism, with less-diverse communities in tankless plants distinguished by a high proportion of taxa implicated in ureolysis, nitrogen fixation, and methanotrophy, whereas nitrate reduction characterized communities on individuals that could form a tank. Coupled changes in plant morphology, physiology, and microbiome function facilitate the transition between alternative nutritional modes in tank bromeliads. Comparing bromeliads across life stages and habitats may illuminate how nitrogen-use varies across scales.

Novel physics-informed optimization framework for complex multi-physics problems: Implementation for a sweeping gas membrane distillation module

The application of advanced machine learning algorithms such as deep learning is limited for the surrogate-based process optimization of complex multi-physics problems because high-quality experimental and numerical training samples required for deep-learning model training are expensive and scarce. To address this issue, in this study, a novel physics-informed process optimization (PIPO) framework was introduced. In the first step, surrogate models based on conventional neural networks (NN) were trained using a few available high-quality training samples. In the second step, the trained NN models were coupled to the process optimization solver in which the loss of physical laws was added to the optimizer’s objective function to find optimal design points that satisfy the laws of physics. As a result, the generalization performance of the framework was greatly improved for design targets outside the training range of NN models. PIPO is substantially different from the physics-informed neural networks where the loss of physics is added to the loss function used during NN model training. The PIPO framework was used to optimize a sweeping gas membrane distillation (SGMD) module. Eight input design variables, including process and geometrical parameters, were optimized for different challenging targets to achieve the best SGMD performance in terms of ammonia recovery ratio and concentration. It was shown that for noticeably few training samples of 68 experiments, the proposed framework was able to achieve the optimization targets within a reasonable computational cost. The optimum designs were verified and analyzed in detail by high-resolution computational fluid dynamics models.

Mechanisms of ammonium detoxification in submerged macrophytes under shade conditions

Excessive ammonium disrupts the biological and physical characteristics of aquatic freshwater ecosystems, causing nutrient imbalances and toxicity. Different macrophytes exhibit varying tolerance levels to ammonium stress, influenced by species-specific adaptations. However, eutrophic water bodies not only have high nutrient loads but also exhibit low light transparency, necessitating an understanding of how submerged macrophytes cope with both high ammonium concentrations and low light conditions. In this study, we explored the tolerance of submerged macrophytes under these challenging conditions by testing various ammonium concentrations and light intensities. Our findings reveal that Myriophyllum spicatum demonstrates high ammonium tolerance under both optimal and low light intensities. Specifically, under optimal light, the primary ammonium assimilation pathway is catalyzed by NADH-GDH (Nicotinamide Adenine Dinucleotide-dependent Glutamate Dehydrogenase), with its activity increasing 4-fold at 50 mg L−1 [NH4+-N] compared to the control. Conversely, under low light intensity, the GS (Glutamine Synthetase)-catalyzed pathway becomes predominant, with GS activity rising 3-fold at 50 mg L−1 [NH4+-N] compared to the control. These results provide new insights into the adaptive mechanisms of M. spicatum, highlighting its flexible strategies for ammonium assimilation and its potential application in water restoration efforts. This study offers valuable information on the enzymatic pathways involved in ammonium detoxification, which is essential for developing effective strategies to manage and restore eutrophic aquatic systems.

Core-Shell PEDOT-PVDF Nanofiber-Based Ammonia Gas Sensor with Robust Humidity Resistance.

Current ammonia sensors exhibit cross-sensitivity to water vapor, leading to false alarms. We developed a core-shell nanofiber (CSNF) structure to address these issues, using conductive poly(3,4-ethylenedioxythiophene) (PEDOT) as the core and hydrophobic polyvinylidene fluoride-tetrafluoroethylene (PVDF-TrFE) as the shell. The PEDOT-PVDF CSNF, with a diameter of ~500 nm and a 300 nm thick PVDF layer, showed a superior sensitivity and humidity resistance compared to conventional PEDOT membranes for ammonia concentrations of 10-100 ppm. In humid environments, CSNF sensors outperformed membrane sensors, exhibiting a tenfold increase in performance at 51% relative humidity (RH). This study highlights the potential of CSNF sensors for practical ammonia detection, maintaining a high performance under varying humidity levels.

Efficient electrochemical removal of ammoniacal nitrogen from livestock wastewater: The role of the electrode material

Wastewater from livestock farms contains high concentrations of suspended solids, organic contaminants, and nitrogen compounds, such as ammoniacal nitrogen. Discharging livestock effluents into water bodies without appropriate treatment leads to severe environmental pollution. Compared to conventional treatment methods, electrochemical oxidation exhibits higher nitrogen removal efficiencies. In the present work, the electrochemical removal of ammoniacal nitrogen from real livestock wastewater was investigated through a lab-scale reactor. Preliminary experiments were carried out to investigate the effects of different anode materials, including boron-doped diamond and iridium/ruthenium-coated titanium, on the total nitrogen removal efficiency using synthetic wastewater. Boron-doped diamond, a well-known non-active electrode, allowed to obtain 63.7 ± 1.21 % of total nitrogen degradation efficiency. However, the iridium/ruthenium-coated titanium electrode, belonging to the class of active anodes, showed a higher performance, achieving 78.8 ± 0.76 % contaminant degradation. Coupling iridium/ruthenium-coated titanium anode with a stainless-steel cathode improved the performance of the system, achieving even 96.2 ± 2.73 % of total nitrogen removal. The optimized cell configuration was used to treat livestock wastewater, resulting in the degradation of 67.0 ± 2.25 % of total nitrogen and 37.3 ± 0.68 % of total organic carbon when sodium chloride was added. At the end of the process, the ammonium content was completely removed, and only 17.7 ± 0.51 % of the initial nitrogen turned into nitrate. The results show that the proposed system is a promising approach to treating livestock wastewater by coupling high contaminant removal efficiencies with low operational costs. Anyway, further studies on process optimization with an emphasis on power requirements and electrode costs need to be carried out.

The optimization of a low-temperature geothermal-driven combined cooling and power system: Thermoeconomic and advanced exergy assessments

Switching from fossil fuels to geothermal energy can provide a solution to environmental issues and the energy crisis caused by power and cooling generation systems. In this regard, this study examines an innovative cogeneration system that utilizes low-temperature geothermal energy to generate power and cool the built environment simultaneously. The proposed system incorporates a Kalina-34 cycle, complemented by an integrated absorption refrigeration cycle. System analysis encompasses thermodynamic and exergoeconomic assessments, as well as parametric investigations to gauge the effects of critical parameters on system performance. Following a parametric study, the TOPSIS multicriteria decision-making technique is applied to optimize turbine inlet pressure, vapor generator temperature difference, and ammonia concentration. Finally, the main source of irreversibility is compared by conventional and advanced exergy analyses under optimal conditions. Results show that under optimal conditions, the energy utilization factor (EUF), exergy efficiency, and unit co-generation cost (UCGC) are 11.15 % (30.5 % improvement), 45.54 % (20.1 % improvement), and 6.04 $/GJ (1.63 % reduction), respectively. Furthermore, while conventional exergy analysis prioritizes the improvement of the condenser-1, vapor generator, and turbine in that order, advanced exergy analysis suggests a different priority order, with condenser-1, turbine, and vapor generator being the main objects of improvement, respectively. Implementing this study will significantly improve and optimize the proposed system.

Achieving nitrite shunt using in-situ free ammonia enriched by natural zeolite: Pilot-scale mainstream anammox with flexible nitritation strategy

The mainstream partial nitritation/anammox (PN/A) process represents a significant innovation in decarbonizing municipal wastewater treatment. However, its implementation is considerably hampered by the challenge of stable nitrite supply. In this study, a pilot-scale PN/A system receiving real sewage (20 m3) was operated at room temperature for nearly one year. Remarkable PN performance with relatively high nitrite accumulation ratio of 75.04 ± 10.05 % was obtained via in-situ free ammonia (FA) strategy. The ammonium concentration enriched in the zeolite increased significantly by 548.8 times compared to that in the aqueous phase by ion exchange. This substantial increase robustly inhibited nitrite-oxidizing bacteria (NOB), resulting in high relative abundance ratio of ammonia-oxidizing bacteria (AOB) to NOB of 37.93 ± 12.61 in the zeolite biofilm, compared to 10.22 ± 1.67 in suspended floc sludge. The significant differences in FA concentrations between zeolite biofilm and suspended floc sludge resulted in distinct spatial distribution disparities of AOB and NOB, which were central to achieving stable nitrite accumulation without complex multiple selective pressures. Consequently, compliant effluent with total nitrogen of 10.91 ± 4.23 mg N/L was achieved at 10.4-31.1 °C without external carbon source addition. The biocarriers in the anammox process played a key role in enhancing functional genes and electron flow, supporting anammox-dominated nitrogen removal. This study presents a flexible and adaptable strategy for mainstream nitrite shunting, highlighting its potential for large-scale implementation of mainstream anammox treatment.

The study of solid flame model of diffusion jet flame for the ammonia and propane mixed gas under the inclined ceiling

In order to solve the environmental pollution and energy dilemma, the ammonia has been considered as a new fuel and a carbon-free hydrogen carrier, which can be blended into the traditional hydrocarbon fuels. In this study, the evolution of flame emissivity, view factor and radiative heat flux have been investigated under different mass flow rates of ammonia and propane, and inclined angle of ceiling. A radiation prediction model of ammonia-propane mixed gas jet flame under inclined ceiling with different inclined angles has been developed. This prediction model can accurately describe the flame morphology and simplify the calculations, and consider the influence of mixing ratio on combustion reaction. The experimental results indicated that the flame emissivity, view factor, and radiative heat flux decrease with the increase of ammonia concentration. The prediction error of the traditional model will be enlarged with the increase in the inclined angle of ceiling. The modified model added the undersurface of ceiling jet flame, which reduces the prediction error from 25 % to 14 %. These prediction models are helpful in predicting the thermal radiation of jet flame under inclined ceiling.

Hydrogel‐Based Capacitive Sensor Model for Ammonium Monitoring in Aquaculture

Monitoring aquaculture water quality, especially ammonium levels affecting fish health, is challenging due to limitations in traditional methods. This study presents an innovative capacitive sensor with an ionic hydrogel transducer for real‐time ammonium concentration monitoring. The sensor operates through ammonium‐induced dissociation in the hydrogel, causing osmotic pressure changes and altering electrode capacitance. Analytical formulations verified by finite element simulations demonstrate the sensor's ability to detect varying ammonium levels. Detailed analysis covers diffusion kinetics, swelling behavior, stress distributions, voltage variations, and ion equilibrium concentrations. The findings show a 20% increase in capacitance change within 200 s, even with a 3 μM ammonium concentration exposure. Additionally, the capacitance change plateau at ammonium levels exceeding 1 mM. The presented concept offers a promising and cost‐effective approach to addressing the limitations of traditional methods, paving the way for future research and development in real‐time water quality monitoring in aquaculture systems.

The Effective Separation of Gallium, Vanadium, and Aluminum from a Simulated Bayer Solution by Resin Exchange.

The effective recovery of gallium from wastewater discharge in the Bayer process is promising for the long-term development of gallium resources. The adsorption and desorption behavior of gallium (Ga), vanadium (V), and aluminum (Al) ions on a strong acidic styrene cation exchange resin (JK resin) from a simulated Bayer solution was systematically investigated by static experiments. The results showed that the optimum conditions for separating Ga from V and Al were at low temperatures and short contact times, with 78.30%, 15.16%, and 6.63% of the adsorption efficiency at 25 °C and 60 min, respectively, for Ga, V, and Al. The adsorption kinetics of Ga3+ conformed to the pseudo-second order model, and the static saturation adsorption capacity was 18.25 mg/g. The Langmuir model fitted the adsorption isotherm of gallium well, and the maximum adsorption capacity was 1.11 mg/g at 25 °C. FT-IR spectroscopy and XPS showed that the mechanism of the Ga3+ adsorption was only related to the interaction of the oxygen atoms of the amide oxime group (C=NOH). The separation of Ga, V, and Al can be achieved by desorbing 98% of Al with low concentrations of ammonia and 90% of Ga with low concentrations of hydrochloric acid. The results indicate that JK resin is an efficient adsorbent for separating gallium and vanadium in alkaline solutions.

Performance evaluation and microbial community analysis of a continuous stirred tank reactor–anaerobic ceramic membrane bioreactor system for practical swine wastewater treatment

To treat swine wastewater from a practical piggery, a continuous stirred tank reactor (CSTR)–anaerobic ceramic membrane bioreactor (AnCMBR) was operated for 201 days. A high chemical oxygen demand (COD) removal efficiency of 95 % and biogas production rate of 0.31 L/L·d were achieved at an organic loading rate (OLR) of 1.19 g-COD/L·d. Although the free ammonia concentration reached a maximum of 200 mg/L during the last operational phase, no evident inhibitory effect on AnCMBR performance was observed. Microbial community analyses indicated that six bacterial phyla were responsible for the hydrolysis, acidification, and fermentation of organics and environmental stabilization. Hydrotrophic methanogenic archaea were dominant, indicating that the main methane production pathway involved the use of H2 and CO2 as substrates. The results demonstrated that CSTR–AnCMBR systems exhibit excellent organics removal performance and energy recovery at high organic concentrations and possess strong anti-shock ability. Thus, they represent alternative green and sustainable anaerobic technologies for practical swine wastewater treatment.

Translocation of probiotics via gut–lung axis enhanced pulmonary immunity of weaned piglets exposed to low concentrations of ammonia

ObjectiveLactobacillus salivarius is a probiotic bacteria strain in human and animal diets. The administration of probiotics to weaned piglets may improve their growth by optimizing the gastrointestinal bacterial composition. To further investigate the effect of bacterial communication between the gastrointestinal tract and lungs on bodily immunity, we reared weaned piglets in a low-ammonia gas environment. L. salivarius was supplemented to explore its effects on pulmonary immunity and its potential for bacterial translocation. ResultsOne hundred sixty weaned piglets were allocated to four groups: L. salivarius-supplemented, L. reuteri-supplemented, control, and antibiotic drug (aureomycin)-supplemented. The feeding duration was 28 d. The body weights of piglets administered a strain of Lactobacillus were better than those of the control (P < 0.01). The transcription level of immune factors interleukin 2 (IL-2), IL-4, interferon α (IFN-α), and tumor necrosis factor α (TNF-α) in cells of the ileum and lung was significantly higher (P < 0.01). Lung and ileal mucus tissues were isolated to sequence the bacterial composition, which suggested a higher richness in the lungs at the phylum level, which was not significant in the ileum. Functional bacteria were more abundant in the ileum and lungs. The proportion of the genera of Lactobacillus, Prevotella, Actinobacillus, and Prevotellaceae_ NK3B31_group increased in two tissues, and a lower ratio of Streptococcus, Escherichia-Shigella, and mycoplasma was detected. The correlation between the microbial genus composition and the levels of immune factors suggests that the abundance of Lactobacillus plays the same positive role in the lungs and ileum. Mycoplasmas play a negative role in ileal and pulmonary immunity. More Lactobacillus reuteri and anaerobic probiotic bacteria were detected in the lungs. ConclusionThe colonization of Lactobacillus salivarius and Lactobacillus reuteri in the membrane of the ileum optimized the ileal microbial composition, enrolled other probiotic bacteria translating to the lung, improved the abundance of pulmonary microbiota, and enhanced immunity after exposure to low concentrations of ammonia.

Balance of Nitrate and Ammonium in Tropical Soil Conditions: Soil Factors Analyzed by Machine Learning

The nitrogen/N dynamic is complex and affected by soil management (i.e., residue accumulation and correction/fertilization). In soil, most of the N is combined with organic matter (organic forms), but the N forms absorbed by plants are ammonium/NH4+ and nitrate/NO3− (inorganic forms). The N recommendation for agriculture crops does not observe the N available in the soil (organic or inorganic), indicating a low efficiency in nitrogen management in soil. Based on the hypothesis that the stocks of NO3− and NH4 can be used as indicative of N status in soil but with high variation according to soil factors (soil uses and management), the objective of the study was to (i) analyze the balance of nitrate and ammonium in tropical soil with different uses and management and (ii) use machine learning to explain the nitrogen dynamic in soil and the balance of nitrate and ammonium. The results showed that soil N stocks and pH promoted the formation of three clusters with the similarity between Cluster 1 (clay texture) and Cluster 2 (loam texture), represented by higher contents of nitrate as a result of high nitrification rate and lower contents of ammonium in soil. Cluster 3 (sand texture) was isolated with different N dynamics in the soil. In agricultural soils, the content of NO3− tends to be higher than the content of NH4+. There is a high nitrification rate in clay soil explained by higher organic matter and clay content that promotes soil biology. Based on the results of machine learning, for clay and loam soil, the contents of NO3 can be used as indicative of N status as a final result of nitrification rate and higher variation in soil. However, in sandy soil, NO3 can not be used as indicative of N status due to N losses by leaching.

Severity-adjusted evaluation of initial dialysis on short-term health outcomes in urea cycle disorders

ObjectiveIn individuals with urea cycle disorders (UCDs) and neonatal disease onset, extracorporeal detoxification by continuous kidney replacement therapy is considered the therapeutic method of choice in addition to metabolic emergency treatment to resolve hyperammonemic decompensation. However, the indications for the initiation of dialysis are heterogeneously implemented transnationally, thereby hampering our understanding of (optimal) short-term health outcomes. MethodsWe performed a retrospective comparative analysis evaluating the therapeutic effects of initial dialysis on survival as well as neurocognitive outcome parameters in individuals with UCDs in comparison to a severity-adjusted non-dialyzed control cohort. Overall, 108 individuals with a severe phenotype of male ornithine transcarbamylase deficiency (mOTC-D), citrullinemia type 1 (CTLN1) and argininosuccinic aciduria (ASA) were investigated by stratification based on a recently established and validated genotype-specific disease prediction model. ResultsMortality is associated with the height of initial peak plasma ammonium concentration, but appears to be independent from treatment with initial dialysis in mOTC-D. However, improved survival after initial dialysis was observed in CTLN1, while there was a trend towards improved survival in ASA. In survivors, annual frequency of (subsequent) metabolic decompensations did not differ between the dialyzed and non-dialyzed cohorts. Moreover, treatment with initial dialysis was not associated with improved neurocognitive outcomes. InterpretationThe present severity-adjusted comparative analysis reveals that general practice of initial dialysis is neither associated with improved survival in individuals with mOTC-D nor does it differ with regard to the neurocognitive outcome for the investigated UCD subtypes. However, initial dialysis might potentially prove beneficial for survival in CTLN1 and ASA.Clinical trial registration: The UCDC database is recorded at the US National Library of Medicine (https://clinicaltrials.gov).

Optical investigation on lubricant combustion characteristics under the ammonia-methane premixed environment

The combustion process is an indispensable energy conversion step in modern industry and energy production. Especially in high-performance engines and energy conversion systems, understanding and controlling the combustion process is critical to improving efficiency and reducing environmental pollution. As a key component of mechanical systems, the combustion characteristics of lubricants at high temperatures and pressures have a direct impact on system performance and emissions. This study investigated the combustion characteristics of lubricant films in an ammonia-methane premixed environment using Planar Laser-Induced Fluorescence (PLIF) and Planar Laser-Induced Incandescence (PLII). It focused on the effects of varying ammonia concentrations on the emission of soot and polycyclic aromatic hydrocarbons (PAHs) in the constant volume combustion vessel. Experiments varied the ammonia-to-methane molar ratios, initial oil film thickness, and base oil type to study their influence on the lubricant combustion characteristics. Results indicated that ammonia significantly reduced soot formation by altering the dynamics of NH* and OH* and impacting PAH distribution. For the lubricating oil soot formation factors, the increase of the initial mean oil film thickness was more obvious for the promotion of soot formation, the increase of the unsaturated hydrocarbon content in the oil film also promoted the generation of carbon soot to a certain extent, and the initial flame energy ratio had the least influence on the promotion of soot formation. Overall, the study contributed to the understanding of the formation mechanism of soot caused by lubricating oil in zero-carbon and low-carbon blended atmospheres and provided a new insight into the interaction between nitrogen-containing zero-carbon fuels and large-carbon-number hydrocarbons, which is of great significance for controlling soot emissions from engines under zero-carbon fuel blending.

Self-Assembled Plasmonic Structural Color Colorimetric Sensor for Smartphone-Based Point-Of-Care Ammonia Detection in Water.

Monitoring chemical levels is crucial for safeguarding both the environment and public health. Elevated levels of ammonia, for instance, can harm both humans and aquatic ecosystems, often indicating contamination from agriculture, industry, or sewage. Developing portable, high-resolution, and affordable methods for in situ monitoring of ammonia is thus imperative. Plasmonic sensors offer a promising solution, detecting ammonia by correlating changes in their optical response to the target analyte's concentration. While they are highly sensitive and can be fabricated in a variety of portable and user-friendly formats, some still require reagents or expensive optical equipment, which hinder their widespread adoption. Here, we present a self-assembled nanoplasmonic colorimetric sensor capable of directly detecting ammonia concentrations in aqueous matrices. The proposed sensor exploits the plasmonic resonance of the nanostructures to transduce changes in the chemical environment into alterations in color, offering a label-free method for real-time analysis. The sensor is fabricated using a self-assembling technique compatible with low-cost mass production based on aluminum and aluminum oxide, ensuring affordability and avoiding the use of other toxic chemicals. We developed a model to predict ammonia concentrations based on visible color change of the sensor, achieving a detection limit of 8.5 ppm. Furthermore, to address the need for on-site detection, we integrated smartphone technology for real-time color change analysis, eliminating the need for expensive, bulky optical instruments. Indeed, our approach offers a cost-effective, portable, and user-friendly solution for ammonia detection in water without the need for chemical reagents or spectrometers, making it ideal for field applications. Interestingly, this platform extends its applicability beyond ammonia detection, enabling the monitoring of various chemicals using a smartphone, without the need for any additional costly equipment.