Different Concentrations Of Ammonia Research Articles

Evolutionary compromises to metabolic toxins: Ammonia and urea tolerance in Drosophila suzukii and Drosophila melanogaster

The invasive pest Drosophila suzukii has evolved morphological and behavioural adaptations to lay eggs under the skin of fresh fruits. This results in severe damage to a wide range of small fruits. Drosophila suzukii females typically lay few eggs per fruit, preferring healthy fruits. Hence, larvae are exposed to a reduced amount of nitrogenous waste. Differently, the innocuous Drosophila melanogaster lays eggs on fermented fruits already infested by conspecifics, with larvae developing in a crowded environment with the accumulation of nitrogenous waste such as ammonia and urea. These compounds derive from nitrogen metabolism, protein degradation, and amino acids catabolism and are relatively toxic at high concentrations in an organism. The observed differences in oviposition site and larval ecological niche suggest that these species might differ in behavioural and physiological mechanisms used to cope with nitrogenous waste. We investigated how different concentrations of ammonia and urea affect oviposition and larval development in both species. Females and larvae of D. suzukii showed greater susceptibility to high concentrations of both compounds, with a dramatic decrease in the number of eggs laid and egg viability. Moreover, we tested the chemotactic response of third instar larvae to high concentrations of the compounds. Interestingly, ammonia resulted in a repulsive behaviour in respect of the control and urea groups. To better understand the pathways underlying these differences, we evaluated the effect on ornithine aminotransferase and glutathione-S-transferase, two enzymes involved in nitrogen metabolism and stress response that are expressed during larval development. Both ammonia and urea significantly reduced the expression of these enzymes in D. suzukii compared to D. melanogaster. This shows how the ecological shift of D. suzukii to fresh fruit is accompanied by less efficient detoxifying and excretory mechanisms, with important implications for evolutionary biology and applied research. Our data suggest that the ecological shift of D. suzukii to fresh fruit as oviposition substrate is accompanied by a reduced tolerance to metabolic toxins during larval development.

FFT analysis of temperature modulated semiconductor gas sensor response for the prediction of ammonia concentration under humidity interference

The increasing environmental contamination forces the need to design reliable devices for detecting of the volatile compounds present in the air. For this purpose semiconductor gas sensors, which have been widely used for years, are often utilized. Although they have many advantages such as low price and quite long life time, they still lack of long term stability and selectivity. Namely, environmental conditions have significant effect on the sensing accuracy. That is caused by the fact that sensors also respond to interfering molecules coexisting in ambient gas (e.g. humidity) and their response is highly dependent on the temperature and the gas delivery rate. Among the different strategies used to overcome those shortcomings, the modulation of the sensors' operating temperature has been reported. To perform the interpretation and extraction of useful information from dynamic nonlinear response of temperature modulated sensor, the feature extraction and data processing methods are required. In this article the method of determination the concentration of ammonia in the presence of relative humidity is presented. For this purpose the operating temperature of a single commercial SnO2 gas sensor is modulated using sinusoidal voltage applied to the heater. The measurements are performed for different concentrations of ammonia at specified levels of relative humidity. The validation data set was obtained 100 days after the set used for the calibration data. Several features from the dynamic measurements are extracted. Qualitative and quantitative analysis of the selection of the signal features containing useful and relevant information for prediction of target gas are performed. The assessment of the impact of the input vector length of the Fast Fourier Transform method on the resulting signal features is examined. The selected features are utilized as an input for Partial Least Squared regression. The calibration is performed and the prediction error of the ammonia concentration is calculated based on the validation data.

Bessel’s polynomial fitting for electrospun polyacrylonitrile/polyaniline blend nanofibers based ammonia sensor

In the present paper, we report the fabrication of electrospun polyacrylonitrile/polyaniline (PAN/PANI) blend nanofibers by electrospinning and polymerization and Bessel’s polynomial model applied for its ammonia sensing characteristics. As-fabricated PAN/PANI blend nanofibers were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy for the confirmation of fibers with nanoscale and blends of PAN and PANI. The semiconducting behavior of the PAN/PANI blend nanofibers was found to respond quickly towards ammonia gas. Sensitivity of the blend was obtained at near room temperature for different concentrations of ammonia. Bessel’s polynomial function was found to be well fitted with the experimental data for the response towards ammonia gas.

Nutrient removal, biomass accumulation and nitrogen-transformation functional gene response to different nitrogen forms in enhanced floating treatment wetlands

Enhanced floating treatment wetlands (EFTWs) were established to treat water with different concentrations of ammonia and nitrate, the ratios of which were set at 0:3, 1:2, 2:1 and 3:0, respectively. The results showed that the average total nitrogen (TN) removals were 80.7%, 79.2%, 47.0% and 10.1% in those four treatments, respectively. EFTWs had much better removal ability of NO3−-N (82.8–98.1%) than that of NH4+-N (25.1–59.4%). Canna indica L. in the water containing both NH4+-N and NO3−-N experienced higher relative growth rate and absorption capacity of N (7.7 g/m2) and P (1.5 g/m2) than those with the sole N source. The relative abundance of narG and nirK on the plant roots and biofilm carriers in the six nitrogen functional genes accounted for 71.1–85.6% and 58.5–90.3%, respectively, leading to high denitrification in EFTWs. Therefore, N forms in water could affect biomass accumulation and attached microorganisms, and thus affect the water purification efficiencies of EFTWs.

Nutritional and metabolic stressors on ovine oocyte development and granulosa cell functions in vitro.

The present study was undertaken to study the effect of ammonia, urea, non-esterified fatty acid (NEFA), and β-hydroxybutyric acid (β-OHB) on oocyte development and granulosa cell (GC) growth parameter of ovine (Ovis aries). Ovine oocytes were matured in vitro in the presence of different concentration of ammonia, urea, NEFA, and β-OHB for 24h, in vitro inseminated and evaluated for cleavage and blastocyst yield. Same concentrations of ammonia, urea, NEFA, and β-OHB were examined on growth parameters and hormone secretion activity of granulosa cells in vitro. Real-time reverse transcription polymerase chain reaction was used to evaluate the expression of steroidogenic genes (steroidogenic cytochrome P-450 (CYP11A1, CYP19A1)), cell proliferation-related genes (GDF9, FSHr), and apoptosis-related genes (BCL-2 and BAX). The maturation, cleavage, and blastocyst production rates were significantly lowered in media containing either 200μM ammonia or 5mM urea or high combo NEFA or 1μM β-OHB. Exposure of granulosa cell to 400μM ammonia or 1μM β-OHB or very high combo or 6mM urea significantly decreased all the parameters examined compared to lower levels of all nutritional and metabolic stressors. Elevated concentration of metabolic stressors induced GC apoptosis through the BAX/BCL-2 pathway and reduced the steroidogenic gene messenger RNA (mRNA) expression and cell proliferation gene mRNA expression. These results suggested that the decreased function of GCs may cause ovarian dysfunction and offered an improved understanding of the molecular mechanism responsible for the low fertility in metabolic stressed condition.

Application of TiO2/SnO2 nanoparticles in photoluminescence based fast ammonia gas sensing

In the present research work we reported the highly dispersible TiO2/SnO2 nanoparticles produced via a simple aqueous solution growth technique with ~50 nm average grain size. The surface morphology of the material have been studied by using scanning electron (SEM) and atomic force microscopes (AFM). Using photoluminescence, interaction between ammonia gas and TiO2/SnO2 (60:40 composition) nanoparticles were investigated. The material shows average significant increment in the PL intensity with no shifting in peak, which conform its tremendous applicability in optical gas sensor to detect ammonia gas (20 ppm) using photoluminescence technique. The gas sensing was systematically performed through photoluminescence spectrometer for different concentration of ammonia at room temperature. The response and recovery time of these samples are found to be in the range of 12 and 50 s respectively.

Distinctive NO and N2O emission patterns in ammonia oxidizing bacteria: Effect of ammonia oxidation rate, DO and pH

This study aims at investigating the relationship between the nitric oxide (NO) and nitrous oxide (N2O) production rates with the ammonia oxidation rate (AORsp) in an enriched AOB culture. Different concentrations of ammonia were applied in a sequential batch reactor (SBR) performing partial nitritation in order to determine the effect of AORsp on N2O and NO production rates. Results showed that NO linearly correlates with the AORsp whereas N2O presents an exponential relationship. The effect of changes on the dissolved oxygen (DO) concentration on the overall NO and N2O emissions was assessed by increasing and decreasing the DO maintaining a constant pH at 7. When DO decreased the AORsp was maintained at the level achieved with the starting DO and led to lower NO and N2O emissions than when DO was increased. Finally, the effect of pH on N2O and NO was also tested by maintaining the DO at 1.5–2mg O2/L while pH was gradually decreased from 8 to 6.5. Results show that NO was chemically produced due to the addition of HCl when decreasing the pH whereas N2O was only produced biologically and was not affected by the addition of HCl.

Análise histológica das brí­¢nquias e do fí­­gado de Bryconops caudomaculatus em diferentes concentrações de amônia

O objetivo foi avaliar os efeitos de diferentes concentrações de amônia não ionizada (zero; 0,15; 0,30; 0,50; 1,00 mg L-1 NH3) na histologia e morfologia das brí­¢nquias e fí­­gado de juvenis de Bryconops caudomaculatus. Após 96 horas de exposição, os peixes foram anestesiados e submetidos í­Â necropsia para coleta de brí­¢nquias e fí­­gado, que foram incluí­­dos em parafina. Alterações morfológicas nas lamelas secundárias das brí­¢nquias foram observadas em concentrações a partir de 0,15 mg L-1, como hiperplasia, hipertrofia, deslocamento epitelial, fusão lamelar, edema, aneurisma lamelar com ruptura do epitélio e aumento na largura das lamelas. O fí­­gado apresentou alterações histológicas (congestão nos capilares, processos inflamatórios e pigmentação endógena) na presença de 0,30 mg L-1 de NH3, que comprometeram as funções vitais, o metabolismo, processos de respiração, desintoxicação do organismo, hematopoese e provavelmente a osmorregulação. Os resultados sugerem que as alterações nas brí­¢nquias e fí­­gado podem ser usadas para monitorar o desempenho de peixes em cultivo intensivo.

Haploid parthenotes express differential response to in vitro exposure of ammonia compared to normally fertilized embryos

In the present study, we assessed whether absence of paternal genome imparts any differential response in embryos to chemical stress such as ammonia. Parthenogenesis was induced in MII stage oocytes using 10 mM SrCl2 in M16 medium. Parthenotes and normally fertilized embryos at 2 cell stage were exposed to different concentrations of ammonia and cultured till blastocyst. Exposure of ammonia to normally fertilized embryos resulted in significant decrease in the developmental potential (p < 0.0001) and blastocyst quality (p < 0.001). Whereas, in parthenotes, even though lower concentrations of ammonia did not have any effect, at 200 μM concentration the blastocyst rate was two times higher than control. The baseline apoptotic index was higher in parthenotes compared to normally fertilized embryos, which further increased after ammonium exposure (p < 0.001). Unlike in normally fertilized embryos ammonia exposure altered the mitochondrial distribution pattern and lead to increased expression of Oct4, Nanog and Na+/K+ ion exchange channel, while the cytochrome C expression was downregulated. This indicates that haploidy and/or absence of paternal factors in the embryo results in differential tolerance to stress induced by ammonia.

Research of Ammonia Concentration Distribution Simulation in Road Transportation Leakage Based on the Gaussian Model

The leakage of liquid ammonia during road transportation is chosen as the research object in this paper, and then the model of toxic gas diffusion after leakage accident is established; MATLAB is used to achieve the accident simulation and risk analysis of continuous leakage from moving and fixed point source. On the basis of different harm to human body of different concentrations of ammonia and the spread concentration curve of the ammonia, the dangerous area is divided into five zones: mild zone, moderate zone, severe zone, dead zone and instantaneous dead zone; according to the comparison between leakage diffusion processes from moving and fixed point source, following conclusions can be reached: during the leakage, area of dangerous zones increased and after the leakage, dangerous zone areas first increased and then decreased; the peak ammonia concentration from fixed source is higher than that from moving point source, whereas influence area of the former is smaller than the latter. This method can quickly simulate the scope and severity of leakage accident in road transportation and provide references for the emergency rescue after accidents.

Ammonia-induced mitochondrial dysfunction and energy metabolism disturbances in isolated brain and liver mitochondria, and the effect of taurine administration: relevance to hepatic encephalopathy treatment

IntroductionAmmonia-induced oxidative stress, mitochondrial dysfunction, and energy crisis are known as some the major mechanisms of brain injury in hepatic encephalopathy (HE). Hyperammonemia also affects the liver and hepatocytes. Therefore, targeting mitochondria seems to be a therapeutic point of intervention in the treatment of HE. Taurine is an abundant amino acid in the human body. Several biological functions including the mitochondrial protective properties are attributed to this amino acid. The aim of this study is to evaluate the effect of taurine administration on ammonia-induced mitochondrial dysfunction.Material and methodsIsolated mice liver and brain mitochondria were exposed to different concentrations of ammonia (1, 5, 10, and 20 mM) and taurine (1, 5, and 10 mM), and several mitochondrial indices were assessed.ResultsIt was found that ammonia inhibited mitochondrial dehydrogenases activity caused collapse of mitochondrial membrane potential (MMP), induced mitochondrial swelling (MPP), and increased reactive oxygen species (ROS) in isolated liver and brain mitochondria. Furthermore, a significant amount of lipid peroxidation (LPO), along with glutathione (GSH) and ATP depletion, was detected in ammonia exposed mitochondria. Taurine administration (5 and 10 mM) mitigated ammonia-induced mitochondrial dysfunction.ConclusionsThe current investigation demonstrates that taurine is instrumental in preserving brain and liver mitochondrial function in a hyperammonemic environment. The data suggest taurine as a potential protective agent with a therapeutic capability against hepatic encephalopathy and hyperammonemia.

Development of simple and sensitive hydrogel based colorimetric sensor array for the real-time quantification of gaseous ammonia

A real-time colorimetric sensor array (CSA) offers the advantages of diversity and accuracy for the quantification of multiple analytes; however, traditional sensors require a complex fabrication process. Therefore, to take full advantage of this sensing platform, we have developed a simple CSA system composed of a polymer, a reducing agent, and different pH indicators. Distinctive color response patterns were classified by extracting the hidden information, (i.e., red, green, and blue (RGB) values) from the indicators. This triple-channel sensing platform is further applied for statistical analysis, to quantify different concentrations of ammonia and other analytes. The sensor array showed a limit of detection of 0.3ppm, which is well below the diagnostic criteria for ammonia concentration in the breath of healthy individuals and of patients with end-stage renal disease. As this sensor would be able to quantify gaseous ammonia in the breath, it is relevant to the point-of-care diagnosis of patients with renal diseases.

Reduced graphene oxide (rGO) decorated TiO2 microspheres for selective room-temperature gas sensors

Reduced graphene oxide (rGO) decorated TiO2 microspheres are prepared by using the hydrothermal method. The as-synthesized sample shows that TiO2 particles are connected by the rGO nanosheets while some TiO2 particles are found to be partly covered by rGO sheets. The rGO-decorated TiO2 based chemoresistive-type sensor shows good sensitivity and excellent selectivity to different concentrations of ammonia from 5ppm to 50ppm at room temperature. However, the response and recovery speeds of the sensor to ammonia are sluggish and need further optimization.

Reduced graphene oxide (rGO) encapsulated Co3O4 composite nanofibers for highly selective ammonia sensors

The reduced graphene oxide (rGO) encapsulated Co3O4 nanocrystals were fabricated by using the electrospinning technology. The sample shows nanofiber morphology and the Co3O4 nanocrystals were wrapped by rGO thin layers. The as-electrospun rGO–Co3O4 nanofibers based chemoresistive sensor exhibited a p-type semiconductor behavior in ambient conditions and showed an excellent sensitivity with a fast response and recovery to different concentrations of ammonia from 5 to 100ppm at room temperature. The sensor displays selectivity to several potential interferrents such as methanol, ethanol, formaldehyde, acetone, benzene, and methylbenzene. It may be attributed to the unique hierarchical wrapping microstructure and the selective NH3 adsorption at both the wrapping layer of rGO and the polarized CCo3+ covalent centers within the nanofibers.

Acute toxicity of ammonia in Meagre (Argyrosomus regiusAsso, 1801) at different temperatures

Argyrosomus regius (3.0 ± 0.9 g) were exposed to different concentrations of ammonia in a series of acute toxicity tests by the static renewal method at three temperature levels (18, 22 and 26°C) at a pH of 8.2. Low temperature clearly increased the tolerance of the fish to total ammonia nitrogen (TAN) and unionized ammonia (NH3) (P < 0.05). While the 96-h LC50 values of TAN were 19.79, 10.39 and 5.06 mg L−1, the 96-h LC50 of NH3 were 1.00, 0.70 and 0.44 mg L−1 at 18, 22 and 26°C respectively. The safe levels of NH3 for A. regius was estimated to be 0.10, 0.07 and 0.04 mg L−1 at 18, 22 and 26°C respectively (P < 0.05). This study clearly indicates that A. regius is more sensitive to ammonia than other marine fish species cultured on the Mediterranean and Eastern Atlantic coasts.

Microbial communities in liquid and fiber fractions of food waste digestates are differentially resistant to inhibition by ammonia.

The effect of different concentrations of ammonia (1.0-7.0 g/L) during mesophilic anaerobic digestion with fiber or liquid digestate as inoculum was examined. Evolution of microbial community within fiber and liquid digestates was quantitatively assessed by the intact lipid analysis methods and qualitatively by DNA fingerprint methods in order to determine their resistance to ammonia inhibition. The results showed that an increased level of total ammonia nitrogen prolonged the lag phase of fiber digestates while reduced the metabolic rate of liquid digestates. Fiber digestates had 19.6-50.9-fold higher concentrations of phospholipid fatty acids (PLFA) compared to liquid digestates, whereas concentrations of phospholipid ether lipids (PLEL) in the fiber digestates were only 2.91-17.6-fold higher compared to liquid digestates. Although the cell concentration in liquid fraction was far lower than that in the fiber one, the ammonia-resistant ability and the methanization efficiency of the liquid digestate was superior to the fiber digestate. The bacterial profiles were affected more by the type of digestate inoculum compared to the concentration of ammonia. Principal component analysis indicated that the lipids technique was superior to the DNA technique for bacterial quantification but detected less archaeal diversity.

Effects of Salinity on Acute Toxicity of Ammonia and Oxygen Consumption Rates in Common Prawn, Palaemon serratus (Pennat, 1777)

AbstractPalaemon serratus juveniles (0.18 ± 0.06 g) were exposed to different concentrations of ammonia in a series of acute toxicity tests by the static renewal method at four salinity levels (10, 20, 30, and 40 ppt) at 29 C and at a pH of 8.0. Oxygen consumption rate (OCR) was also measured. The mortality rate increased with increasing concentrations of ammonia and longer exposure times. High salinity levels clearly increased the tolerance of shrimp to total ammonia nitrogen (TAN) and unionized ammonia (NH3) (P &lt; 0.05). The safe level for P. serratus was estimated to be 2.1, 3.5, 3.8, and 8.5 mg/L for TAN and 0.13, 0.21, 0.24, and 0.53 mg/L for NH3 at 10, 20, 30, and 40 ppt salinity levels, respectively. OCR of P. serratus increased with increasing salinity and TAN concentrations. This study clearly indicated that there is a relationship between an increment in salinity or TAN and the OCR of P. serratus juveniles (P &lt; 0.05).

Propagation of acoustic waves in metal oxide nanoparticle layers with catalytic metals for selective gas detection

A novel array comprised of six Love-wave sensors based on metal oxide nanoparticles layers (ZnO and TiO2) mixed with different metals (Co and Pt) was developed to detect, discriminate and classify toxic gases. The metal oxide nanoparticles worked as guiding and sensitive layers at the same time for every sensor. The properties of the different layers of nanoparticles change due to that interaction with the gases, and consequently each sensor suffers a different frequency shift. The array has been tested with different concentrations of ammonia, toluene and xylene. Very low concentrations of these samples have been detected and discriminated by principal component analysis, such as 10ppm of ammonia, 5ppm of toluene and 10ppm of xylene. A correct classification of the measurements has been carried out by means of probabilistic neural network.

&lt;sub&gt;&lt;/sub&gt;Mg&lt;sub&gt;2&lt;/sub&gt;Cu&lt;sub&gt;x&lt;/sub&gt;Fe&lt;sub&gt;1&lt;/sub&gt;O&lt;sub&gt;3.5+x &lt;/sub&gt;Mixed Metal Oxides as Ammonia Sensitive Material of Ammonia Sensors

Mg2CuxFe1O3.5+xmixed metal oxides were found to be active catalysts for the selective oxidation of ammonia. In this paper, Mg2CuxFe1O3.5+xmixed metal oxides were prepared by co-precipitation method and calcined at 600°C for 12 h in an air atmosphere, then ammonia sensors have been made by screen-printed Mg2CuxFe1O3.5+xelectrode on the electrolyte (8moleYSZ) surface and sintered at 1126°C for 1h in an air atmosphere. The samples were characterized by XRD and ESEM. The performance of ammonia sensors were tested in different concentration of ammonia. It can be found that Mg2Cu0.25Fe1O3.75electrode showed a higher response value and good sensitivity to ammonia at 350°C, the value of sensitivity is 226.6mV/decsde. The influences of Cu content on the ammonia response performance of Mg2CuxFe1O3.5+xmixed metal oxides electrodes are discussed.

${\rm NH}_{3}$ Sensing by $p$-ZnO Thin Films

AlN and AlAs codoped <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -ZnO thin films are fabricated by RF magnetron sputtering for gas sensing applications. For comparison, Al monodoped <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -ZnO film is also grown. The conductivity of the films is confirmed by the Van der Pauw Hall effect measurement system. The structural and elemental properties of the films are studied by X-ray diffraction and time-of-flight secondary ion mass spectroscopy. Sensitivity measurements are performed with the fabricated <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -ZnO films for different concentrations of ammonia (200-1200 ppm) at different operating temperatures (room temperature: 100 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C and 150 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C). It is found that both <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -ZnO films have higher sensitivity than that of the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -ZnO film. Furthermore, both <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -ZnO films exhibit lower response and recovery times than <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -ZnO film.