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One of the great challenges in deep hydrodesulfurization (HDS) to produce ultra-low-sulfur diesel (ULSD) is the coexisting heterocyclic nitrogen-containing compounds in middle distillates, which significantly inhibit the HDS reactions. This study investigates various activated carbon (AC) samples for selectively removing nitrogen compounds from a model diesel fuel through adsorption. The physical and chemical properties of the AC samples were characterized using low-temperature N2 adsorption–desorption, SEM–EDS, and FT-IR to explore their impact on the adsorption performance. The results indicate that the adsorption performance is influenced not only by the surface area and by the number of oxygen-containing functional groups on the surface but also by the pore diameter distribution. Among all AC samples tested, AC-W exhibited the highest adsorption capacity, achieving a nitrogen removal rate of 97.8% with the addition of 10 wt.% of AC-W. The adsorption capacity was approximately 24.0 mg-N/g-A at a nitrogen equilibrium concentration of 200 ppmw. The adsorption isotherms for total nitrogen and individual nitrogen compounds in the fuel over AC can be described well by the Freundlich isotherm model. An approach for improving the ADN performance of AC is discussed based on the findings in this study. [ABSTRACT FROM AUTHOR]

Reports on the utilization of nitrogen compounds to trace oil and gas migration in oil-scarce regions are limited. This scarcity can be attributed to the lack of clarity regarding the effectiveness of nitrogen compound indices in oil-bearing sandstone extracts. To address this knowledge gap, two sets of experiments were designed, encompassing five extraction methods, to evaluate the validity of nitrogen compound indices. The results showed that as the extraction intensity increased, the ratios of 1-/4-methylcarbazole and 1, 8-/2, 7-dimethylcarbazole in the extracts gradually decreased but remained consistently elevated compared to the control oils. The benzocarbazole [a]/[c] ratio remained relatively stable and closely aligned with the control oils. Upon analysis, it was concluded that the observed variations could be attributed to the differing adsorption capacities of carbazole isomers. These differences lead to the fractionation of carbazole isomers between free and adsorbed hydrocarbons under surface conditions, as well as between the extracts and rocks during the extraction process. In comparison to 1-/4-methylcarbazole and 1, 8-/2, 7-dimethylcarbazole, the benzocarbazole [a]/[c] ratio is less susceptible to these two fractionations, with its variations primarily governed by migration fractionation. Additionally, the indicated direction of oil and gas migration aligns with geological realities. Therefore, the benzocarbazole [a]/[c] ratio can be considered an effective nitrogen compound index in oil-bearing sandstone extracts, suitable for oil migration tracing studies in oil-scarce regions.

This study evaluated the sensitivity of male and female of guppies (Poecilia reticulata) to ammonia. LC50-96h for males, females and combined sexes of P. reticulata was 37.33, 48.34, and 42.45 mg/L of total ammonia or 1.03, 1.34, and 1.17 mg/L of un-ionized ammonia. The mortality at the concentration of 40 mg/L of total ammonia differed between the sexes with higher mortality in males. These results have implications for production systems, since recommendations of ammonia toxicity reference values that do not consider the difference between the sexes, can lead to the mortality of males, and cause economic losses because males have higher commercial value in the ornamental market. [ABSTRACT FROM AUTHOR]

This study aims to investigate the adsorption capacity of ammonium NH4+, nitrite NO2- and nitrate NO3- onto rice husk biochar (RHB) obtained from 550 °C pyrolysis temperature in the context of using low-cost absorbent for recirculating aquaculture system (RAS). Raw RHB at its original size 5–8 mm has been choosen for testing its adsorption capacity as well as several key material properties (pHPZC, surface area, and elemental analysis). From surface functional group analysis, there existed the O–H group (at frequency 3443 cm-1), –CH3 (2360 cm-1), and either –C=O or C=C group (in the range of frequency 1600–1650 cm-1) as well as –COOH (1456 cm‒1) that helped enhance chemical adsorption. The experimental adsorption data has been roughly consistent with Langmuir and Freundlich models that used to calculate the maximum saturated monolayer adsorption capacity Q0max of ammonium, nitrite, and nitrate were 0.1003, 0.2477, and 0.1290 mg/g respectively. Therefore, RHB could be a potential candidate for biofilter application in both targets cost-efficient and sustainable that worth applied at scale.

Nutrient pollution negatively affects ecology, environment and human health, due to excess contaminated nitrogen in aquatic ecosystems. Nitrogen has various forms, such as organic nitrogen, ammonia, nitrite, and nitrate. Nitrogen removal mechanisms are important for nitrogen compound pollutant control. Microbial agents provide an alternative for nitrogen removal and are implemented by natural removal mechanisms. For pollution level measurements, data collection from actual measurement processes can be only limitedly collected in some situations. The mathematical models play a role in data approximation that can describe relations of processes and reactions. Six numerical models in one-dimensional nitrogen pollutant and nitrogen remover measurement in a stream are proposed. The proposed models are combined with total nitrogen with a removal mechanism, organic nitrogen, ammonia, nitrite, nitrate, and nitrogen remover dispersion models. These models are implemented through use of an efficient numerical technique, which is the unconditionally explicit Saulyev finite difference technique, associated with the cubic spline interpolation to initial and left boundary conditions through practical simulations. All six models related to nitrogen compound measurements in a stream with removal mechanism models give accurately approximated solutions. The proposed numerical models can be applied to other realistic problems. [ABSTRACT FROM AUTHOR]

• Synthesis of novel anchored-silica vanadium-substituted Dawson-type polyoxometalate. • Selective sulfur and nitrogen compounds removal from model and real diesel oil. • The prepared catalyst show good ECODS and CODS efficiencies. • The reusability of catalyst was good in ECODS of model and real diesel. The aim of this article is to study the extractive-catalytic oxidative desulfurization (ECODS) of the model oil containing several model S-containing compounds as well as N-containing compound using a heterogeneous vanadium substituted Dawson-type polyoxometalate catalyst under atmospheric pressure and temperature lower than 100 °C. The catalyst was prepared by ion exchange with alkyl ammonium derivatives covalently anchored to silica gel. The potential of this methodology was illustrated by oxidation of 100% quinoline and 80% of total sulfur in model oil containing 500 ppmw sulfur and 70% of total sulfur in model oil 1500 ppmw in less than 30 min of reaction, in the absence of solvent. However, when acetonitrile was employed as an extractive solvent, the desulfurization was increased considerably. Under the reaction conditions, activated catalyst and acetonitrile, solvent to oil ratio 1:6, could remove approximately 100% of quinoline, 95% of sulfur from 500-ppmw model oil, 87% of sulfur from 1500-ppmw model oil in less than 30 min. The catalyst is very active in ECODS and can be reused fifth times from 500-ppmw model oil and third times from 1500-ppmw model oil without an important decrease in activity. The ECODS could remove 83% of total sulfur from 1235-ppmw-S real diesel. [ABSTRACT FROM AUTHOR]

Abstract A simultaneous observation of the water-soluble organic nitrogen (WSON) in the gaseous and particulate phases was conducted at a forested site in Japan for two years to clarify the generation mechanism and possible sources of the gaseous and particulate WSON. The concentration of the WSON in the aerosols was 0.070 μg m−3 on average, ranging from the concentration below the detection limit (DL) to 0.302 μg m−3. A large portion (about 73%) of the particulate WSON was distributed in the fine-mode range (d < 2.0 μm). The concentration of the gaseous WSON was 0.041 μg m−3 on average, ranging from the concentration below the DL to 0.195 μg m−3. About 37% of the atmospheric WSON was distributed in the gas phase, and about 59% of the gaseous WSON was basic. The coarse-mode (d = 2.0–10 μm) WSON showed an unclear seasonal trend, but increased in the summer. Its concentration showed a significant correlation only with the WSOC concentration among the measured species in the coarse aerosols. Suspended organic materials from primary sources, such as plant debris, would be a possible source for the coarse-mode WSON. The WSON in the fine-mode range showed a clear seasonality with enhanced concentrations from the spring to summer. The fine-mode WSON concentration showed a strong correlation with the acidity of the fine particles and the concentration of the gaseous basic WSON, suggesting the secondary production of the WSON in the acid fine particles from the gaseous basic WSON. The basic WSON in the gas phase showed a similar seasonal trend with the gaseous ammonia and strongly correlated with the temperature, which suggests the temperature dependent-volatilization of the gaseous basic WSON species from terrestrial vegetation and/or soil. The seasonal trend of the gaseous acid WSON was unclear, and its concentration did not show significant correlations with any parameters. The possible source and chemical forms of the gaseous acid WSON cannot be deduced at the present time. Highlights • About 73% of the WSON in the aerosols was distributed in the fine-mode range. • About 59% of the gaseous WSON was basic species. • Possible source of the coarse-mode WSON is primary emissions, such as plant debris. • Secondary production from the gaseous basic WSON is the source of the fine-mode WSON. • The gaseous basic WSON would be derived from the terrestrial vegetation and/or soil. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of short-term exposure to sublethal levels of nitrite on oxidative stress parameters and histology of juvenile Brazilian flounder Paralichthys orbignyanus. An assessment of fish recovery was also performed. Fish were exposed to 0.08 (control), 5.72, 10.43, and 15.27 NO2-N mg L−1 for 10 days followed by the same recovery time. Gill, liver, and muscle samples were collected after 1, 5, and 10 days of exposure and after recovery for the measurement of antioxidant capacity against peroxyl radicals (ACAP), glutathione-S-transferase (GST) activity, content of non-protein (NPSH) and protein thiols (PSH), and lipid peroxidation levels by thiobarbituric acid-reactive substances (TBARS) content. Nitrite exposure induced alterations which compromised the overall antioxidant system (reduced ACAP and GST activity) and enhanced oxidative damage in lipids and proteins. Increases in GST activity and NPSH and PSH contents were also demonstrated. The recovery period allowed for resumption of basal levels for all (treatment 5.72 NO2-N mg L−1) or some of the evaluated parameters (other treatments). In conclusion, exposure to nitrite concentrations from 5.72 to 15.27 NO2-N mg L−1 induced oxidative stress and antioxidant responses in juvenile Brazilian flounder. The 10-day recovery period was sufficient for a complete resumption of basal physiological condition of fish exposed to concentrations of up to 5.72 NO2-N mg L−1. [ABSTRACT FROM AUTHOR]

Understanding of mass transfer kinetics is important for biosorption of nitrogen compounds from palm oil mill effluent (POME) to gain a mechanistic insight into future biological processes for the treatment of high organic loading wastewater. In this study, the rates of global and sequential mass transfer were determined using the modified mass transfer factor equations for the experiments to remove nitrogen by aerobic granular sludge accumulation in a sequencing batch reactor (SBR). The maximum efficiencies as high as 97% for the experiment run at [kLa]g value of 1421.8 h-1 and 96% for the experiment run at [kLa]g value of 9.6 × 1037 h-1 were verified before and after the addition of Serratia marcescens SA30, respectively. The resistance of mass transfer could be dependent on external mass transfer that controls the transport of nitrogen molecule along the experimental period of 256 days. The increase in [kLa]g value leading to increased performance of the SBR was verified to contribute to the future applications of the SBR because this phenomenon provides new insight into the dynamic response of biological processes to treat POME. [ABSTRACT FROM AUTHOR]

Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp m−2) were examined weekly during 72-day culture cycle at low-salinity water (1.9 g L−1) and zero-water exchange to examine the effects of water quality deterioration on the antennal gland (AG) of shrimp. Results showed survival rates of 87.7% and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, and chlorophyll a were not significantly different between modules but the concentrations of the nitrogen compounds were significantly different between modules with the exception of nitrite-N, showing a higher histological alteration index in M2 (32 ± 10) than M1 (22 ± 0) with a strong correlation with the nitrogen compounds. During the last weeks was evidenced in M1 inflammation and hemocytic and hemolymph infiltration, while in M2, melanization, hemocytic melanized nodules and cells with kariorrexis. [ABSTRACT FROM AUTHOR]

Background and objectives: Protein composition analysis of 81 rice samples was performed on three cultivars harvested different regions in Japan and the effects of the protein composition on the nitrogen composition in sake. Findings: Crude protein content showed a significant positive correlation with glutelin content. Yamadanishiki cultivars showed lower crude protein and glutelin contents compared with Gohyakumangoku cultivars harvested from the same field. Total nitrogen content in the enzyme digest of steamed rice grains showed a significant positive correlation with the crude protein and glutelin contents. Ten polished (70%) white rice samples were investigated in a small-scale sake brewing test. Total nitrogen compounds, bitter-tasting peptides and free amino acids in the brewed sake positively correlated with the glutelin content of the rice samples. There were no clear correlations between a-amylase and acid proteinase activities with the nitrogen compounds in the sake. Conclusions: The results indicated that the glutelin content in the cultivar rice affects sake quality through taste-active and other nitrogen-containing compounds produced from rice glutelin in the sake brewing process. Significance and novelty: We revealed that the glutelin content in the milled rice grains is important to brew high quality of sake clearly. The present results would be useful for cultivation or breeding of sake rice. [ABSTRACT FROM AUTHOR]

Background & Objectives: Excessive discharge of hazardous materials such as nitrogenous and organic compounds into the environment has negative impacts on the health of the aquatic environment. The main objective of this research was focused on evaluating the feasibility of using modified SBR reactor for the removal of nitrogenous compounds and chemical oxygen demand (COD). Materials & Methods: The experiments were performed using an up-flow continuous reactor with intermittent effluent. At first, four different cycles including aeration, settling, and decant (3, 4, 6, and 8 h) were designed for the performance of the reactor. Then, the efficiency of each cycle was determined for different concentrations of COD (250-1500 mg/L) and ammonia (40-100 mg/L). Results: Data demonstrated that all cycles had very good performances for the removal of COD. The average COD removal efficiencies of phases 1 through 4 were 91.7, 91.5, 92, and 92.7% respectively. The average NH4+ removal efficiencies of phase 3 and 4 were 92.7 and 95.8% respectively. Conclusion: The performance of phase 4 (with the cycle of 8 h) for the removal of nitrogen compound and COD was particularly high. The combination of anoxic and aerobic cycles in the reactor and providing nitrate as an electron receptor had the best performance for the removal of nitrogen from wastewater. Therefore, the continuous up-flow reactor was a good alternative to batch reactor in removing nitrogen compound and COD simultaneously.

The effects of ammonia exposure and recovery on oxidative stress parameters and histology of juvenile Brazilian flounder Paralichthys orbignyanus were evaluated. The fish were exposed to 0.12, 0.28 and 0.57 mg NH-N L, plus a control, for 10 days followed by the same recovery time in ammonia-free water. Gill, liver and muscle samples ( n = 9) were collected after 1, 5 and 10 days of exposure and after recovery for oxidative stress analysis (antioxidant capacity against peroxyl radicals (ACAP); glutathione S-transferase (GST) activity; lipoperoxidation levels measured through thiobarbituric acid reactive substances (TBARS) content). For histological assessment, gill, liver and brain samples were collected. Exposure to all NH-N concentrations induced different time- and dose-dependent changes in oxidative stress parameters. Reduced antioxidant capacity of the liver and muscle and enhanced TBARS levels in the gills and liver were demonstrated. Differently, a high ammonia concentration elicited lower hepatic TBARS levels. Enhanced GST activity in all organs and increased antioxidant capacity of the gills were also observed. No ammonia-induced histopathological effects were demonstrated. After recovery, most parameters (liver ACAP, GST activity in the muscle and liver and TBARS in the gills) returned to baseline levels. However, liver TBARS and gill GST activity remained altered 0.57 mg NH-N L treatment. The recovery period also led to a decrease in gill antioxidant capacity and an increase in muscle antioxidant capacity. In conclusion, a concentration of 0.12 mg NH-N L induces oxidative stress and antioxidant responses in juvenile Brazilian flounder. Moreover, a 10-day recovery period is not sufficient to restore fish homeostasis. [ABSTRACT FROM AUTHOR]

Advanced drinking water treatment process using nanofiltration (NF) membranes has gained attention recently because it removes many challenging constituents in contaminated surface waters, such as dissolved organics and heavy metals. However, much literature has reported high variations and uncertainties of NF membranes for removing nitrogen compounds in the contaminated water-ammonium (NH 4 + ), nitrates (NO 3 - ), and nitrites (NO 2 - ). This study aimed to identify the ability of commercial NF membranes to remove NH 4 + , NO 2 ) could be highly rejected depending on the clearance between their hydrated radius and the membrane's pore walls. Further, the rejection of the lowest molecular-weight nitrogen compound (NH - , and NO 3 - and clarify the mechanisms underlying their transport through NF membranes. This was examined by evaluating their rejection by three commercial NF membranes using artificial and actual river waters under various conditions (variable permeate flux, temperature, pH, and ionic strength). Ammonium commonly showed the highest removal among the three nitrogen compounds, followed by nitrites and nitrates. Interestingly, ammonium removal varied considerably from 6% to 86%, depending on the membrane type and operating conditions. The results indicated that the selected nitrogen compounds (NH 4 + , NO 2 - , and NO 3 - ) could be highly rejected depending on the clearance between their hydrated radius and the membrane's pore walls. Further, the rejection of the lowest molecular-weight nitrogen compound (NH 4 + ) could be higher than NO 2 - and NO 3 - due to its highest energy barrier and larger hydrated radius. This study suggests that compliance with the drinking water regulations of NH 4 + , NO 2 - , and NO 3 - can be reliably achieved by selecting appropriate membrane types and predicting the range of their removal under various feed water quality and operating conditions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Ionic contents (Na+, K+ and Cl-) of plasma and gallbladder bile (GB) of juveniles silver catfish, Rhamdia quelen (156.1±0.2g, 28.2±0.3cm), were determined in three different times (0, 6 and 24h) after exposure to: a) control or high dissolved oxygen (DO = 6.5mg L-1) + low NH3 (0.03mg L-1); b) low DO (3.5mg L-1) + low NH3; c) high DO + high NH3 (0.1mg L-1); and d) low DO + high NH3. High waterborne NH3 or low DO levels increased plasma and GB ion levels. These parameters might have followed different mechanisms to affect osmoregulation since a synergic effect of these variables was detected.O conteúdo iônico (Na+, K+ e Cl-) do plasma e da bile vesicular (BV) de juvenis de jundiá, Rhamdia quelen (156,1±0,2g, 28,2±0,3cm), foi determinado em três diferentes tempos (0, 6 e 24h) após exposi��ão a: a) controle ou alto oxigênio dissolvido (OD = 6,5mg L-1) + baixa NH3 (0,03mg L-1); b) baixo OD (3,5mg L-1) + baixa NH3; c) alto OD + alta NH3 (0,1mg L-1); e baixo OD + alta NH3 . Alta concentração de amônia ou baixo oxigênio dissolvido na água aumentaram os níveis iônicos no plasma e na BV. Aparentemente, os efeitos osmorregulatórios desses parâmetros podem estar relacionados a mecanismos distintos, pois foi detectado efeito sinérgico sobre essa alteração osmorregulatória.

This study determined the effects of nitrite on different life stages of the Amazon river prawn Macrobrachium amazonicum. Prawns of each life stage (postlarvae, juveniles and adults) were stocked in 24 experimental units (n = 10 prawns), under a complete randomized design. Individuals were exposed to nitrite (0, 1, 2, 4, 8 and 16 mg L). The median lethal concentration after 96 h (96 h LC) was calculated through the Weibull I. The mortality results showed that M. amazonicum is slightly less tolerant to nitrite than other species of Macrobrachium. The 96 h LC for postlarvae, juveniles and adults of M. amazonicum were of 1.49, 2.36 and 2.34 mg nitrite/L, respectively. Nitrite intoxication risk quotient suggest moderated risk to low risk to the species. Usually in production systems nitrite values are lower than safe levels suggested in this study (0.1 mg L to postlarvae and 0.2 mg L nitrite to juvenile and adults), which makes our results appropriate for the production of this species. [ABSTRACT FROM AUTHOR]

In this study, bulblets samples were chosen in produced by in vitro micropropagation method, analyzed by observing the sample from 3 different time periods interferences (i.e. at the end of the first, second and third month). After extraction of these bulblets samples, alkaloid (nitrogen compounds) profile was determined by GC-MS; and was compared with the bulblets grown by in vivo method. Micropropagation analysis, allowed us to find the most suitable sampling period which was close to in vivo condition. In this research, twin scales of L. candidum were used as explant and as a result of regeneration, GC-MS was analyzed in 3 different nutrient media at 3 different sampling periods. The result of GC-MS analysis showed that the total obtained alkaloid percentage is the closed to the control (13.11%) in the third sample (7.42%) in the second nutrient media (0.2 mg/L NAA + 0.4 mg/L TDZ). The highest percentage of alkaloid (1H-Pyrrole, 2,5-dihydro-1-nitroso-) was obtained from the second nutrient medium and the third sample. [ABSTRACT FROM AUTHOR]

The buildup of nitrogenous wastes in the water reflects biological processes potentially stimulated by organic pollution. These wastes may cause physiological harm and even mortality in produced aquatic species. This study aimed at determining the effects of ammonia on different life stages of the Amazon river prawn Macrobrachium amazonicum . Experimental set-up used 240 prawns to each life stage (post-larvae, juveniles and adults), stocked in 24 experimental units, under a totally casualized arrangement, for each life stage. Individuals were exposed to 6 different concentrations of total ammonia (0, 5, 10, 20, 40 and 80 mg·L − 1 ), and the mean lethal concentration after 96 h was determined (LC 50 -96 h). Water oxygen, pH, and temperature were monitored daily; at the start and end of the experimental periods, hardness, alkalinity, ammonia, nitrite and nitrate were also measured. LC 50 -96 h was calculated through the probit method, later submitted to a linear regression (p < 0.05). LC 50 -96 h for post-larvae, juveniles, and adults of M. amazonicum was of 21.14, 21.65 and 36.59 mg·L − 1 of total ammonia, or 0.67, 0.75 and 1.08 mg·L − 1 of non-ionized ammonia. Thus, from these results, safe levels for the production of this prawn are of 0.06, 0.07 and 0.1 mg·L − 1 , from post-larvae, juveniles and adults, respectively. [ABSTRACT FROM AUTHOR]

Background: Methylene blue is the first-line therapy for methemoglobinemia, but it can be intermittently unavailable due to production issues. For this clinical scenario, alternative treatment options need to be explored. Hyperbaric oxygenation (HBO) is conventionally applied as an adjunctive therapy during the systemic administration of methylene blue. Currently, little is known regarding the effects of HBO monotherapy in methemoglobinemia. We report a case of methemoglobinemia that was successfully treated with HBO monotherapy.Case Report: A 41-year-old man presented to the Emergency Department with dyspnea and dizziness subsequent to smoking in a garage filled with motor vehicle exhaust gas. There were no abnormal heart or lung sounds. While administering oxygen flowing at 15 L/min via a mask with a reservoir bag, blood tests revealed high methemoglobin (MetHb) levels at 59.6%. He was treated with HBO monotherapy, and sequential tests showed that the MetHb level decreased significantly to 34.0%, 12.8%, 6.2%, and eventually, 3.5%. He was discharged with stable vital signs the next day. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: HBO monotherapy is an effective alternative treatment for methemoglobinemia when methylene blue is not available. [ABSTRACT FROM AUTHOR]

Background & Objectives: Excessive discharge of hazardous materials such as nitrogenous and organic compounds into the environment has negative impacts on the health of the aquatic environment. The main objective of this research was focused on evaluating the feasibility of using modified SBR reactor for the removal of nitrogenous compounds and chemical oxygen demand (COD). Materials & Methods: The experiments were performed using an up-flow continuous reactor with intermittent effluent. At first, four different cycles including aeration, settling, and decant (3, 4, 6, and 8 h) were designed for the performance of the reactor. Then, the efficiency of each cycle was determined for different concentrations of COD (250-1500 mg/L) and ammonia (40-100 mg/L). Results: Data demonstrated that all cycles had very good performances for the removal of COD. The average COD removal efficiencies of phases 1 through 4 were 91.7, 91.5, 92, and 92.7% respectively. The average NH4+ removal efficiencies of phase 3 and 4 were 92.7 and 95.8% respectively. Conclusion: The performance of phase 4 (with the cycle of 8 h) for the removal of nitrogen compound and COD was particularly high. The combination of anoxic and aerobic cycles in the reactor and providing nitrate as an electron receptor had the best performance for the removal of nitrogen from wastewater. Therefore, the continuous up-flow reactor was a good alternative to batch reactor in removing nitrogen compound and COD simultaneously. [ABSTRACT FROM AUTHOR]

Cancer of the esophagus is an underestimated, poorly understood, and changing disease. Its overall 5-year survival is less than 20%, even in the United States, which is largely a function of a delay in diagnosis until its more advanced stages. Additionally, the epidemiologic complexities of esophageal cancer are vast, rendering screening and prevention limited at best. First, the prevalence of esophageal cancer is unevenly distributed throughout the world. Second, the two histological forms (squamous cell and adenocarcinoma) vary in terms of their geographic prevalence and associated risk factors. Third, some populations appear at particular risk for esophageal cancer. And fourth, the incidence of esophageal cancer is in continuous flux among groups. Despite the varied prevalence and risks among populations, some factors have emerged as consistent associations while others are only now becoming more fully recognized. The most prominent, scientifically supported, and long-regarded risk factors for esophageal cancer are tobacco, alcohol, and reflux esophagitis. Inasmuch as the above are regarded as important risk factors for esophageal cancer, they are not the sole contributors. Dietary habits, nutrition, local customs, and the environment may be contributory. Along these lines, vitamins, minerals, fruits, vegetables, meats, fats, salted foods, nitrogen compounds, carcinogens, mycotoxins, and even the temperature of what we consume are increasingly regarded as potential etiologies for this deadly although potentially preventable disease. The goal of this review is to shed light on the less known role of nutrition and dietary habits in esophageal cancer. [ABSTRACT FROM AUTHOR]

The Ordos Basin is an important intracontinental sedimentary basin in western China for its abundant Mesozoic crude oil resources. The southern part of the Tianhuan Depression is located in the southwestern marginal area of this Basin, in which the Jurassic and Triassic Chang-3 are the main oil-bearing strata. Currently, no consensus has been reached regarding oil source and oil migration in the area, and an assessment of oil accumulation patterns is thus challenging. In this paper, the oil source, migration direction, charging site and migration pathways are investigated through analysis of pyrrolic nitrogen compounds and hydrocarbon biomarkers. Oil source correlations show that the oils trapped in the Jurassic and Chang-3 reservoirs were derived from the Triassic Chang-7 source rocks. The Jurassic and Chang-3 crude oils both underwent distinct vertical migration from deep to shallow strata, indicating that the oils generated by Chang-7 source rocks may have migrated upward to the shallower Chang-3 and Jurassic strata under abnormally high pressures, to accumulate along the sand bodies of the ancient rivers and the unconformity surface. The charging direction of the Jurassic and Chang-3 crude oils is primarily derived from Mubo, Chenhao, and Shangliyuan, which are located northeast of the southern Tianhuan Depression, with oils moving toward the west, southwest, and south. The results show that an integration of biomarker and nitrogen-bearing compound analyses can provide useful information about oil source, migration, and accumulation. [ABSTRACT FROM AUTHOR]

Ionic contents (Na+, K+ and Cl-) of plasma and gallbladder bile (GB) of juveniles silver catfish, Rhamdia quelen (156.1±0.2g, 28.2±0.3cm), were determined in three different times (0, 6 and 24h) after exposure to: a) control or high dissolved oxygen (DO = 6.5mg L-1) + low NH3 (0.03mg L-1); b) low DO (3.5mg L-1) + low NH3; c) high DO + high NH3 (0.1mg L-1); and d) low DO + high NH3. High waterborne NH3 or low DO levels increased plasma and GB ion levels. These parameters might have followed different mechanisms to affect osmoregulation since a synergic effect of these variables was detected. [ABSTRACT FROM AUTHOR]

Abstract: Gas Hure Oilfield is an area rich in oil and gas in the Qaidam Basin and contains E3 1 and N1-N2 1 oil reservoirs. Through conventional column chromatographic extraction of 48 oil samples, this paper investigates the oil migration and charge direction using nitrogen compounds, sandbody distribution in E3 1 and N1-N2 1, and the E3 1 reservoir dissection. Oil in the I+II and III+IV oil layers of the E3 1 reservoir migrates from the middle-north of the anticline to its south and north, and its oil source areas are the Mangya hollow and the Gas rift-subsidence. The injection spots of the III+IV oil layer are the two sides of well 9-7 in the middle of the anticline, and the injection spots of the ?+? oil layer are wells 8-34 and 9-38. The N1-N2 1 reservoir oil is mainly from the Mangya hollow and migrates upwards along faults to reservoirs. Faults and sandbodies are the main transport channels in the field and most reservoirs are anticlinal. [Copyright &y& Elsevier]

Several researchers have hypothesized that organic nitrogen extracted using neutral phosphate buffer, termed phosphate buffer extractable organic nitrogen (PEON), is absorbed and utilized by some plant species as a nitrogen source without prior mineralization. Earlier reports have suggested that leaf lettuce ( Lactuca sativa L.) depends mainly on inorganic nitrogen, whereas qing-geng-cai ( Brassica chinensis L.) can absorb PEON. We tested leaf lettuce and qing-geng-cai growth under aseptic conditions using three nitrogen sources under different light conditions to investigate this hypothesis. Nitrate, amino acids or purified PEON were supplied as the sole nitrogen source. Five different levels of light intensity were used to detect the contribution of carbon to plant growth supplied from PEON. Leaf lettuce growth was promoted only by nitrate, whereas growth of qing-geng-cai was promoted by nitrate and amino acids. The positive effect of amino acids on qing-geng-cai was pronounced at higher light intensity. However, PEON imparted no significant effect on either of the plants under any of the light conditions. Our results do not support the hypothesis that PEON is used as a nitrogen source by plants. [ABSTRACT FROM AUTHOR]

Based on the migration track of the Silurian oil pools along the faults in central Tarim by the nitrogen compounds and the maturity parameters of saturated hydrocarbon and aromatic hydrocarbon, the formation of the Silurian oil pools was totally concerned with vertical migration that faults were the dominant migration channels. The comprehensive analysis shows that the dominant geological element, which contributed to the migration and accumulation of the Silurian oil pools in central Tarim, was the strike-slip fault, which developed from Ordovician to Permian. The future work will focus on conducting a more intensive study of the formation, evolution and distribution of the strike-slip faults for making sure of favorable hydrocarbon accumulation and favorable exploration targets. [ABSTRACT FROM AUTHOR]

C2-carbazole isomers have been investigated in crude oils from the Hui-Liu Structure Ridge (HLSR) in the Pearl River Mouth Basin (PRMB), South China Sea. The NH shielded isomer, as well as the NH partially shielded isomers, was detected in high abundance and the NH exposed isomers in lower abundance. A small-enrichment trend of 1,8-dimethylcarbazole (DMC) was observed in crude oils along the western part of HLSR (WPHLSR), which may indicate little effect of migration on the C2-carbazole distributions. Two strikingly different distribution patterns of NH partially shielded isomers were observed in the reservoirs along the WPHLSR: one with a preference of 1,3-and 1,6-DMCs and the other with a preference of 1,4-and 1,5-DMCs. All of the oils occurring in the Upper reservoirs have a preference of 1,3-and 1,6-DMCs, whereas those trapped in the Lower reservoirs show a preference of 1,4-and 1,5-DMCs, which may indicate there are two petroleum migration systems in the WPHLSR. [ABSTRACT FROM AUTHOR]

The chemical constituents of the African medicinal plant Croton lobatus were elucidated and characterised using 1D and 2D-NMR analysis and the application of the technique of High Resolution Electron Ionization Mass Spectrometry (HREIMS) and High Resolution Mass Spectrometry (HRMS). The novel triglyceride lobaceride or 3-((6Z,9Z)dodeca-6,9-dienoyloxy)-2-octanoyloxypropyl (6Z,9Z)dodeca-6,9-dienoate, along with ten compounds were isolated from the stems and leaves of Croton lobatus. [ABSTRACT FROM AUTHOR]

Abstract: A new method to remove the nitrogen compounds from lubricating base stocks was revealed by using the complexing and crystallization of oxalic acid and nitrogen compounds in this paper. The data indicated that the reaction and filtration temperatures obviously influence the nitrogen removal efficiency. The suitable reaction temperature was 100–130 °C and the reaction time is more than 20 min. The crystal water in oxalic acid can lower the removal efficiency, which can be improved when inert gas is introduced to take out the crystal water in oxalic acid. When clay was used in the reaction system, the nitrogen removal efficiency was improved and the filtration temperature was also elevated. Oxalic acid can remove more than 98% of basic nitrogen compounds and more than 70% of nonbasic nitrogen compounds from the lubricating base stocks. The removal of basic nitrogen showed a linear relationship with the removal of nonbasic nitrogen. [Copyright &y& Elsevier]

A chemometric resolution method is described for the identification of nitrogen compounds in crude oil. Prefractionation of crude oil into discrete chemical classes was performed by adsorption column chromatography using small quantities of neutral aluminum oxide and silicic acid. Subsequent high-resolution separation of individual components was achieved by using capillary column gas chromatography, and compound types were detected by mass spectrometer. In conjunction with a combined chemometric method, each principal chemical class was further resolved and separated, which made it possible to identify some nitrogen compounds in the investigated oils. To a certain extent, this method could relieve classical analysis of difficulty in identifying those species with poorly low contents or partially chromatographic overlaps, particularly in the cases where authentic standards were not available for addition into the unknown analytical systems to reveal what indeed existed in them. [Copyright &y& Elsevier]

This study aimed to assess whether the addition of calcium carbonate (CaCO 3) to increase Calcium levels reduces the long-term nitrite (NO 2 −) toxicity in pacu Piaractus mesopotamicus juveniles. The fish were exposed for 60 days to six treatments comprised by the interaction of three NO 2 − concentrations (0, 15 and 30 NO 2 −-N mg L−1) and two Calcium levels (60 and 150 CaCO 3 mg L−1), all in triplicate. The zootechnical indices, as well as blood and oxidative stress parameters were evaluated at the end of experimental period. The results showed that at lower hardness, NO 2 − exposure led to enhanced lipid peroxidation (LPO) levels of muscle and gills and compromised the food conversion rate. Otherwise, the LPO levels were kept at basal condition and no changes were found in zootechnical parameters at higher hardness treatments. Thus, the increase in Calcium levels up to 150 CaCO 3 mg L−1 using CaCO 3 may reduce the NO 2 − toxic levels in pacu juveniles, and may be an interesting strategy of water quality management, especially in intensive production systems. • The prolonged exposure to nitrite (NO2-) levels result in tertiary stress responses in pacu Piaractus mesopotamicus. • The addition of calcium carbonate (CaCO3) to increase water hardness reduces the long- term NO2- toxicity in juvenile pacu. • At lower hardness, NO2- exposure led to enhanced levels of lipid peroxidation (LPO) of muscle and gills in juvenile pacu. • The increase in hardness is an interesting strategy of water quality management, especially in intensive production systems. [ABSTRACT FROM AUTHOR]

Nitrogen (N) addition and mowing can significantly influence micronutrient cycling in grassland ecosystems. It remains largely unknown about how different forms of added N affect micronutrient status in plant-soil systems. We examined the effects of different N compounds of (NH 4) 2 SO 4 , NH 4 NO 3 , and urea with and without mowing on micronutrient Fe, Mn, Cu, and Zn in soil-plant systems in a meadow steppe. The results showed that (NH 4) 2 SO 4 addition had a stronger negative effect on soil pH compared with NH 4 NO 3 and urea, resulting in higher increases in soil available Fe and Mn herein. Nitrogen addition decreased plant community-level biomass weighted (hereafter referred to as community-level) Fe concentration but increased Mn concentration, with a greater effect under (NH 4) 2 SO 4 addition. Community-level Cu concentration increased with (NH 4) 2 SO 4 and NH 4 NO 3 addition only under mowing treatment. Mowing synergistically interacted with urea addition to increase community-level Mn and Zn concentrations even with decreased soil organic matter, possibly because of compensatory plant growth and thus higher plant nutrient uptake intensity under mowing treatment. Overall, responses of plant-soil micronutrients to N addition varied with mowing and different N compounds, which were mainly regulated by soil physicochemical properties and plant growth. Different magnitude of micronutrient responses in plants and soils shed light on the necessity to consider the role of various N compounds in biogeochemical models when projecting the effects of N enrichment on grassland ecosystems. [Display omitted] • The impacts of N addition on micronutrient availability vary with N form and mowing. • (NH 4) 2 SO 4 addition increased soil available Fe and Mn more than NH 4 NO 3 and urea did. • Antagonism led to lower plant community-level biomass weighted Fe but higher Mn. • Mowing synergistically interacted with urea addition to increase plant Mn and Zn. • Shift in plant species dominance influenced plant community micronutrient uptake. [ABSTRACT FROM AUTHOR]