Nitrite Concentrations Research Articles

Metal ferrite nanocomposite treatment reduced oxidative stress to improve the growth dynamics of Cucumis sativus in hydroponics

Abstract Green synthesized nanoparticles have various applications but their use for improving plant productivity and agricultural sustainability recommends their usage as nano-fertilisers. In this context, the present study reports the positive influence of hydroponically exposed green synthesized Tri-metal ferrite TiO2-Al2O3-ZnFe2O4 nanocomposites (TMFN) on Cucumis sativus (cucumber). Cucumber is rich in polyphenols and an important part of the human diet because of its water-rich and low-calorie nature. A considerable increase in the length of shoot-roots, relative water content, and chlorophyll level of cucumber was observed on TMFN exposure. An increase of 25–82 and 94–220% in carbohydrate and protein levels on TMFN treatment was observed. Likewise, the phenols, flavonoids, and free radical scavenging potential of the plants were increased by 22-88, 64-211, and 4-18%, respectively, on TMFN exposure. As a result, there was an observable decrease of 62-86 and 14-68% in the oxidative stress indicators, MDA and H2O2, respectively. A simultaneous and significant increase in the inorganic nitrate, nitrite content, nitrate reductase, and glutamate synthetase activity was evident. However, ammonia content and glutamate dehydrogenase activity decreased significantly by 27-82 and 31-85%, respectively. Overall, the TMFN induced significant morphological and biochemical changes in cucumber indicated their probable role as potential plant growth promoters. However further research is required for understanding the molecular and genetic aspects of the effects of green synthesised TMFN on other plants as well as crops grown hydroponically.

Nitrites in Meat Products in Serbia: Harmful or Safe?

Nitrate and nitrite, commonly added to meat products as sodium or potassium salts, serve multiple functions such as developing characteristic flavor, inhibiting microbial growth, and controlling rancidity by preventing lipid oxidation. Nitrites are recognized for their potential health risks to humans. The present research aimed to determine the amount of nitrite in four meat product categories in Serbia over a period from 2015 to 2021. A total of 923 samples were analyzed, including 293 finely chopped sausages, 203 coarsely chopped sausages, 160 canned meats, and 267 smoked meats. The smoked meat category consisted of eight distinct products, such as smoked pork ribs, sirloin, and chicken drumsticks. An ISO 2918 method was used to measure the nitrite content. The average nitrite content, expressed as sodium nitrite (NaNO2), was found to be 61.5 mg/kg in finely chopped sausages, 57.6 mg/kg in coarsely chopped sausages, 48.4 mg/kg in canned meat, and 41.8 mg/kg in smoked meat. The results collectively demonstrate nitrite concentrations within regulatory limits. In conclusion, the nitrite concentrations in all tested products were below the maximum allowable limits as per national and European regulations, ensuring compliance with safety standards while highlighting the importance of continuous monitoring to mitigate public health risks.

Is Industrial-Scale Wastewater Treatment Possible with a Commercially Available Atmospheric Pressure Plasma System? A Practical Study Using the Example of a Car Wash

The topic of water reuse is becoming increasingly important. It might be possible to use the well-known antibacterial effect of atmospheric pressure plasma due to its special mixture of reactive species, UV, and electromagnetic fields in a scaled-up, industrially interesting area to remove bacteria from wastewater, and thus, make it usable again. To review this question, water volumes of 5L and of different qualities (turbidity and different degrees of hardness) were treated with a commercially available plasma system. The change in water-specific values such as pH, EC, ORP, nitrate, and nitrite content was determined. To test the antibacterial effect, both direct and indirect treatment of the test germ Pseudomonas aeruginosa was conducted. In the first case, the inoculated water samples were plasma-treated, while in the second case, the water samples were treated before inoculation with the germ. The viable bacteria were counted via the spread plate method. The best reduction rate of at least 6 log levels was achieved when inoculated deionized water samples were treated directly with plasma. A significant reduction in viability was also observed in directly treated clear tap water samples, whereby the different degrees of hardness did not influence the effectiveness of the plasma. The bacterial load remained almost unchanged when reused water samples from a car wash were treated. Based on the results, a possible application in a car wash was discussed including a cost estimation and possible limitations.

Simultaneous removal of methane and high nitrite from the wastewater by Methylomonas sp. with soluble methane monooxygenase.

Aerobic methanotrophs play a crucial role in controlling methane emission in wastewater treatment. However, the high nitrite produced during ammonium oxidation, nitrate assimilation, and denitrification hinders methane oxidation and nitrogen removal. In this study, Methylomonas sp. HYX-M1, possessing two methane monooxygenase and multiple nitrite reductase genes, demonstrated efficient methane oxidation, coupled with nitrite removal abilities up to 6mM. Strain HYX-M1 presented methane oxidation rate of 0.05mmol/d and nitrite removal rate of 0.53mM/d under low-oxygen conditions. Assimilation and denitrification mainly accounted for 94.6-96.06% and 3.10-5.03% of nitrite removal. Methane monooxygenase genes, pmoA and mmoX expressed in different nitrite concentrations. Meanwhile, the nirB and nirD of strain HYX-M1 upregulated by 2.7- and 8.5-fold in 6mM, respectively. The sod and ahpC genes upregulated, contributing to the survival of strain HYX-M1 in high nitrite. These findings provide a new strategy for the application of aerobic methanotrophs in regulating methane emission of wastewater with high nitrite.

Water quality within the greater Suva urban marine environment through spatial analysis of nutrients and water properties.

Coastal ecosystems in Pacific Island Countries and Territories are vital to local livelihoods, yet increasingly face pressures from urbanization. In Fiji, the Greater Suva Urban Area, where one-third of the nation's population live, exemplifies these challenges. This study examines spatial and temporal water quality variations in the coastal zone, focusing on physicochemical, nutrients, and clarity parameters. Using a Seabird Scientific SBE19 CTD and Thermo Scientific Orion™ AQUAfast™ colorimeter, coupled with hierarchical clustering and principal component analysis, six water quality clusters were identified, influenced by oceanic processes, river inputs, and anthropogenic activities. Key findings highlight nutrient enrichment near urban centers particularly at the Kinoya Sewage Treatment Plant outfall, where ammonia exceeded 17.8mg/L, and significant variation observed in nitrate (up to 0.24±0.06mg/L) and nitrite (up to 0.24±0.06mg/L) concentrations near river mouths. Seasonal runoff contributed to elevated turbidity (up to 3.5 NTU) and total suspended solids (up to 14.7mg/L) levels during wet months. Salinity, and temperature exhibited strong spatial and seasonal variability, reflecting land-ocean interactions and restricted water exchange. These findings emphasize the need for targeted action to mitigate nutrient pollution, urban runoff, and wastewater impacts. This study provides a cost-effective monitoring framework for water quality management, offering insights for sustainable coastal resource management in Fiji and other Pacific regions amidst urbanization and climate change.

Effect of Remote Ischemic Conditioning on the Form and Function of Red Blood Cells in Patients With Acute Ischemic Stroke.

Remote ischemic conditioning (RIC) is a simple and low-cost intervention that is thought to increase collateral blood flow through the vasodilatory effects of nitric oxide (NO) produced by the endothelium and red blood cells (RBCs). This study aims to investigate whether RIC affects RBC deformability and levels of NO and nitrite in patients with ischemic stroke. This is a predefined substudy to the RESIST (Remote Ischemic Conditioning in Patients With Acute Stroke Trial) randomized clinical trial conducted in Denmark. RIC was started in the ambulance and continued at the hospital for seven days. Blood samples were collected at different time points: prehospital in the ambulance, in-hospital upon arrival, 2 hours postadmission, and 24 hours postadmission. RBC deformability and erythrocyte aggregation rate were assessed using ektacytometry, NO using flowcytometry, and nitrite content using ozone chemiluminescence. Of 1500 prehospital randomized patients, 486 patients were included in this study between July 28, 2020, and November 11, 2023, and had blood samples taken. Of these, 249 (51%) had AIS, and here RIC treatment was not associated with increased RBC maximal deformability (RIC, 0.549; sham, 0.548; P=0.31), RBC NO (RIC, 35 301 median fluorescence intensity; sham, 34979 median fluorescence intensity; P=0.89), or nitrite (RIC, 0.036 µmol/L; sham, 0.034 µmol/L; P=0.38), but RIC treatment was associated with a significantly reduced aggregation pressure and a slower erythrocyte aggregation rate (RIC, 323.76 millipascal; sham, 352.74 millipascal; P=0.0113). Prehospital and in-hospital RIC significantly reduced erythrocyte aggregation rate in patients with acute ischemic stroke, while there was no change in RBC deformability, NO content, or whole blood nitrite levels. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03481777.

Nitrate in raw and cooked vegetables: content, variation and influence of cooking methods

Nitrate concentrations in vegetables are pivotal in dietary nitrate benefit-risk assessments. This study examined nitrate and nitrite levels in vegetables commonly consumed in Jordan, highlighting the impact of different cooking methods (boiling, steaming, baking, stir-frying, and deep frying) on nitrate content. The study examined the nitrate and nitrite levels in 270 raw vegetables and vegetable-based dishes purchased from retail markets and restaurants in Amman, Jordan, during the winter months of 2022 and 2023. Furthermore, 91 experimentally -cooked vegetables were tested for their nitrate and nitrite contents before and after cooking to determine the effect of cooking methods on nitrate levels. The nitrate and nitrite concentrations were measured using an in-house validated molecular absorption spectrometric method. Nitrate levels varied considerably within and between vegetable groups and species. Celery had the highest mean nitrate content (1700 mg/kg), and radish (1300 mg/kg) and beetroot (900 mg/kg) were next. Approximately 32% of vegetables contained moderate amounts of nitrate (200–1000 mg/kg). Leafy greens such as spinach, tossa jute, and lettuce contain nitrates in averages exceeding 500 mg/kg. Among fruit vegetables, zucchini and eggplant have the highest mean nitrate levels (311.6 and 221.6 mg/kg, respectively). Flower, root (excluding radishes and beetroot), and legume (excluding green beans) vegetables have nitrate levels below 200 mg/kg. On average, the mean nitrite level in raw and cooked vegetables was less than 1 mg/kg. Different cooking methods influence vegetable nitrate content differently. Boiling reduced nitrate by 22-40%. Steaming had no significant impact. Although deep-frying, stir-frying, and baking increased nitrate by 130%, 66.7%, and 57.6%, respectively, the overall effect was not statistically significant for deep-frying and baking. These findings are essential for public health and food safety authorities in evaluating nitrate exposure and assessing the risk and benefit of dietary nitrate intake. The data may support the development of evidence-based guidelines for safe nitrate intake. Key words: Nitrate, nitrite, raw vegetables, cooked vegetables, cooking methods

Residual nitrite and nitrate in processed meats and meat analogues in the United States

Residual nitrite (NO2−) and nitrate (NO3−) have been widely studied in the past few decades for their function to improve processed meat quality and their impact on human health1, 2, 3–4. In this study we examined how the residual nitrite and nitrate (NOx−) content of major classes of processed meats products (n = 1132) produced locally from three regions (East Coast, Midwest and West Coast) and plant protein-based meat analogues (n = 53) available at retail in the United States was influenced by their composition, processing, and geographical attributes. We also conducted time-dependent depletion studies and observed different patterns of NOx− depletion and conversion during processing and storage and correlated them with product quality. Together, our results reveal a comprehensive prospective of NOx− content in processed meats and meat analogues. The NO2− in processed meats and meat analogues averaged (± standard error; minimum and maximum value in parentheses) 13.7 ± 0.62 (0.0-214.5) and 1.7 ± 0.34 (0.0–11.0), respectively, and the NO3− in processed meats and meat analogues averaged 32.6 ± 0.90 (2.0–205.9) and 7.2 ± 0.56 (4.0-25.3) ppm, respectively.

Bioassays to Assess the Safety of Potassium and Sodium Nitrates and Nitrites

(1) Background: Advances in food processing practices and health care are some of the most significant advances in modern daily life. The goal of this study is to evaluate the safety of potassium and sodium nitrates and nitrites when they are used as fertilizers in agriculture and food additives, as well as the known conversion of nitrate to nitrite in humans. (2) Methods: Various bioassays were conducted to investigate the effects of nitrates and nitrites in the Drosophila melanogaster genetic tester system. These assays focused on the modulation of degenerative processes at the molecular, cellular, individual, and population levels. Additionally, we assessed the chemopreventive potential and the ability to induce DNA strand breaks in HL-60 tumour cells. (3) Results: All nitrate and nitrite concentrations tested were shown to not be toxic or genotoxic in Drosophila since none of the compounds reached the LD50 and significant genetic mutation. A positive or null protective capacity against a toxic agent was found for nitrates, not for nitrites, showing that sodium nitrite has a synergistic effect when combined with the oxidant toxin hydrogen peroxide; and a nutraceutical potential in the lifespan only for sodium nitrate to improve the quality of life in 5 days at ADI concentration. The in vitro results in human leukemia cells showed a chemopreventive potential only for potassium nitrate and sodium nitrite due to reducing the viability of HL-60 cells growth to 18% and 29%, respectively, compared to the controls at ADI (acceptable daily intake) concentrations. However, neither of these showed DNA damage or methylation modifications. (4) Conclusions: The tested compounds were shown to be safe to use during in vivo and in vitro tests when used at the extrapolated ADI concentrations.

Hovenia dulcis T. extract and Glycyrrhiza glabra as natural antioxidants in Bologna mortadella

Pseudo-fruits of Hovenia dulcis T. are sweet-tasting, edible, and contain numerous nutrients and a significant amount of phenolic compounds, which could serve as a source of natural antioxidants. In this context, this study aimed to evaluate the addition of H. dulcis T. extract and licorice root extract (licrezzTM) in the formulation of Bologna-type mortadella and to investigate the inhibition of lipid oxidation during cold storage, to assess their antioxidant properties. Mortadella samples were prepared in duplicate with sodium erythorbate (control), licrezzTM (commercial extract from Glycyrrhiza glabra), and H. dulcis extract, at a concentration of 0,1%. The samples were evaluated for proximate composition, microbiological characteristics, texture profile, lipid oxidation, nitrite content, instrumental color, pH, and water activity. Mortadella with H. dulcis extract did not show significant differences from the control in terms of proximate composition, microbiological characteristics, or texture profile. However, they exhibited slightly lower, but comparable results in the Thiobarbituric Acid Reactive Substances (TBARS) assay during the 28 days of refrigerated storage. The control and H. dulcis extract samples showed approximately a ninefold increase in TBARS values by the end of storage, while licrezzTM showed a twenty-sixfold increase. On the other hand, H. dulcis extract exhibited similar behavior to licrezzTM regarding residual nitrite content. Thus, H. dulcis pseudo-fruits extract shows potential for use as a natural antioxidant in emulsified meat products, alone or in combination with Glycyrrhiza glabra.

Rapid detection of hydrogen peroxide and nitrite in adulterated cow milk using enzymatic and nonenzymatic methods on a reusable platform.

Cow milk is readily adulterated due to its complex properties that can emulsify many adulterants. Among the commonly used adulterants in cow milk are hydrogen peroxide (HP) and nitrite. Commercially available HP is added to extend cow milk's shelf life, while nitrite enters through the tap or pond water added to increase cow milk's volume. HP disrupts human free radical balance, while nitrite can cause methemoglobinemia. This study aims to rapidly detect these adulterants on-site by developing a point-of-care kit. A modified streptavidin-horseradish peroxidase (Strep-HRP)-tetramethylbenzidine (TMB) assay was used for designing the biosensor for HP detection. The Strep-HRP complex was immobilized on 8-well polystyrene strips with glutaraldehyde crosslinking. TMB was used as the substrate to detect HP at concentrations of 0.04% (v/v) and higher. Nitrite was detected using a modified Griess assay, wherein for the biosensor, the Griess reagent was coated on polystyrene strips with polyethylene glycol (PEG) used as the stabilizer to identify nitrite concentrations of 32 μg mL-1 and above. The Strep-HRP and Griess assay strips prepared in this investigation were stable for 25 and 10 days, with three times reusability for HP and twice for nitrite detection. Both strips were accurate, up to 95%, for detecting HP and nitrite in cow milk samples.

Methyl Derivatives of Flavone as Potential Anti-Inflammatory Compounds.

Flavones are natural compounds that are broadly distributed in our diet. Their unique properties provide the possibility to control the immune system and the process of inflammation. A high intake of flavonoids, including flavones, may offer protection against reactive oxygen species, inflammation, and chronic diseases. In this research, we evaluated the anti-inflammatory effect of five methylflavones, 2'-methylflavone (5C), 3'-methylflavone (6C), 4'-methylflavone (7C), 6-methylflavone (8C), and 6-methyl-8-nitroflavone (12C), in lipopolysaccharide (LPS) stimulated RAW 264.7 cells (murine macrophage cell line). We estimated the nitrite concentration and detected reactive oxygen species using the chemiluminescence method. Moreover, we measured the production of pro-inflammatory cytokines using the Bio-Plex Magnetic Luminex Assay. As a result of our findings, we have established that some of the methyl derivatives of flavone inhibit nitric oxide (NO) production and chemiluminescence generated by LPS-stimulated macrophages, but they also have an influence on pro-inflammatory cytokines production. This study showed that 2'-methylflavone (5C) and 3'-methylflavone (6C) possess the strongest anti-inflammatory activity among all tested derivatives of flavone. In conclusion, our study demonstrated that methylflavones may be potentially valuable compounds for the alleviation of inflammatory reactions.

Cu doped ceria nanoparticles-rhodamine B as a novel chemiluminescence system and its application for nitrite detection in water and food samples.

Fe, Ni, and Cu doped ceria nanoparticles (CeNPs) were prepared with a simple and one-pot hydrothermal synthesis method. We investigated the chemiluminescence (CL) interaction between these NPs and rhodamine B (Rh B) and found that the highest CL intensity was related to the Rh B- Cu doped CeNPs. We assigned that to the higher catalytic property of Cu doped NPs compared to the others. Cu doped CeNPs have been applied for the first time as a catalyst in chemiluminescence reactions. Rh B- Cu doped CeNPs reaction was introduced as a novel CL system, and its mechanism was studied. Considering the sensitivity, simplicity, portability, and rapidness of the CL methods, we applied the introduced reaction to the development of a CL sensor for nitrite monitoring. In the presence of nitrite, the CL intensity of the system decreased, and there was a linear relationship between the CL intensity and nitrite concentration in the range 0.5-100 µM. Based on this fact, a sensitive and selective CL sensor with the detection limit of 0.2µM was established for nitrite detection in various food and water samples.

Chronic enrichment affects nitrogen removal in tidal freshwater river and estuarine creek sediments.

Population growth in coastal areas increases nitrogen inputs to receiving waterways and degrades water quality. Wetland habitats, including floodplain forests and marshes, can be effective nitrogen sinks; however, little is known about the effects of chronic point source nutrient enrichment on sediment nitrogen removal in tidally influenced coastal systems. This study characterizes enrichment patterns in two tidal systems affected by wastewater treatment facility (WWTF) effluent and assesses the impact on habitat nitrogen removal via denitrification. We collected intact sediment cores from prevalent habitats in a tidal freshwater river (TFZ; swamp forest) and a tidal estuarine creek system (EST; salt marsh) upstream and downstream of a WWTF outfall, and quantified dissolved gas fluxes across the sediment-water interface during wet conditions in early summer and dry conditions in late summer. Data collected during two synoptic water quality monitoring campaigns complimented laboratory experiments to provide environmental context for biogeochemical processing. The two systems exhibited different enrichment patterns such that the river-dominated TFZ system was characterized by consistently elevated nitrate + nitrite concentrations downstream of the WWTF, whereas precipitation and tidal influence affected nutrient distributions in the EST creek. Downstream sediments in TFZ exhibit an apparent saturation response, while upstream rates may be limited by other factors, such as labile organic matter availability. In contrast, downstream sediments in EST denitrify at higher rates than upstream during wet conditions that may enhance transport of effluent. This work provides information on ecosystem functioning in human-influenced environments and can be of use in developing nature-based solutions, such as water treatment wetlands, for nitrogen removal.

Optimal nitrite degradation by isolated Bacillus subtilis sp. N4 and applied for intensive aquaculture water quality management with immobilized strains.

The toxicity of nitrite is an issue that cannot be overlooked in nitrogen pollution within aquaculture. A highly efficient bacterium capable of simultaneous nitrification and denitrification was screened from natto, and its 16S rRNA gene sequence was compared to existing records, confirming its identification as Bacillus subtilis sp. N4. The optimal conditions for nitrite degradation by B. subtilis sp. N4 were identified using response surface methodology as 167rpm, pH 6.4, 1g/8mL feed, 0.6 OD600, and 30°C, with a predicted 99 % nitrite removal efficiency. The B. subtilis sp. N4 demonstrated a maximum nitrite concentration tolerance of 60mg/L, with μmax and Ks values calculated using a Monod model analysis of 1.67mg/L/h and 0.29mg/L, respectively. Immobilized B. subtilis sp. N4 could be reused for ten cycles while maintaining a nitrite degradation efficiency of >99 %, and retained a high nitrite-degrading ability after being refrigerated at 4°C for three months. Immobilized B. subtilis sp. N4 effectively reduced ammonia nitrogen, nitrite, and nitrate concentrations in Nile tilapia aquaculture, maintaining them at consistently low levels. Therefore, free or immobilized B. subtilis sp. N4, with both nitrification and denitrification capabilities, has considerable potential for application in the aquaculture industry in the future.

Olive oil and castor oil-based self-nanoemulsifying drug delivery system of flurbiprofen can relieve peripheral pain and inflammation through reduction of oxidative stress and inflammatory biomarkers: a comprehensive formulation and pharmacological insights.

Flurbiprofen (FBP) is poorly water-soluble BCS class II drug with anti-inflammatory and analgesic effects, used to treat arthritis and degenerative joint diseases. This study was aimed to develop SNEDDS loaded with FBP. Six SNEDDS using two oils olive oil (F1OLV, F2OLV, F3OLV) and castor oil (F4CAS, F5CAS, F6CAS) with three different Smix ratios consisting of Tween 20 and PEG 400 (1:1, 1:2, 2:1) were prepared and characterized. Compatibility between FBP and polymers was investigated using FTIR. SNEDDS were characterized for physicochemical attributes. Two optimized formulations were investigated at 10mg/kg dose given orally in Wistar rats for analgesic activity by hot plate and tail flick methods, and anti-inflammatory activity by carrageenan induced paw edema method. Anti-inflammatory activity was further explored by motor coordination and motility by Rota rod and cage activity tests. Following anesthesia blood samples were collected before dissection to measure inflammatory mediators and oxidative stress markers. Sciatica nerves and hind paws of rats were also removed for histopathological evaluation.FTIR studies revealed compatibility of FBP with other components. Droplet size of F1OLV, F2OLV, F3OLV was 128.5 ± 0.7 nm, 202.5 ± 1.3 nm, and 541.5 ± 1.7 nm, whereas it was 142.5 ± 1.1 nm, 215.4 ± 1.2 nm and 349.9 ± 1.8 nm for F4CAS, F5CAS, F6CAS. %EE of F1OLV, F2OLV, F3OLV was found 85 ± 4.89%-91 ± 4.67%, whereas the %EE F4CAS, F5CAS, F6CAS was 84 ± 4.15%-90 ± 4.21%. DSC curves of F1OLVand F4CASrevealed amorphous nature of the FBP. SEM showed spherical shape of globules. % of drug released in the pH medium 1.2 for plain FBP, F1OLVand F4CASwas 25%, 59% and 57%. % drug released in the pH 6.8 for plain FBP, F1OLVand F4CASwas 59%, 85% and 83%. Oral administration of FBP-loaded SNEDDS (F1OLV and F4CAS) significantly decreased paw diameter and enhanced motor coordination in rats when compared to the disease control group. This was linked to the ability of FBP to reduce inflammation and oxidative stress, with histological studies indicating decreased tissue damage in SNEDDS treated groups, implying the possibility of tissue recovery. Administration of both formulations started to demonstrate analgesic and anti-inflammatory effects after one hour of administration. In addition to anti-inflammatory effect, both formulations improved motor coordination, motility, and reduced infiltration of inflammatory cells in the inflamed paws. The anti-inflammatory and analgesic activities were attributed to decreased serum levels of IL-6 and TNF-α, increased activity of SOD and reduced nitrite content in sciatic nerves. Histopathological evaluation revealed reduced vascularity, inflammation and synovial hyperplasia. The overall findings suggest that the FBP loaded SNEDDS can be used as carriers for improved delivery of FBP which can effectively be used to cure pain and inflammation.

Oral microbiome and nitric oxide biomarkers in older people with mild cognitive impairment and APOE4 genotype.

Apolipoprotein E4 (APOE4) genotype and nitric oxide (NO) deficiency are risk factors for age-associated cognitive decline. The oral microbiome plays a critical role in maintaining NO bioavailability during aging. The aim of this study was to assess interactions between the oral microbiome, NO biomarkers, and cognitive function in 60 participants with mild cognitive impairment (MCI) and 60 healthy controls using weighted gene co-occurrence network analysis and to compare the oral microbiomes between APOE4 carriers and noncarriers in a subgroup of 35 MCI participants. Within the MCI group, a high relative abundance of Neisseria was associated with better indices of cognition relating to executive function (Switching Stroop, rs = 0.33, P = 0.03) and visual attention (Trail Making, rs = -0.30, P = 0.05), and in the healthy group, Neisseria correlated with working memory (Digit Span, rs = 0.26, P = 0.04). High abundances of Haemophilus (rs = 0.38, P = 0.01) and Haemophilus parainfluenzae (rs = 0.32, P = 0.03), that co-occurred with Neisseria correlated with better scores on executive function (Switching Stroop) in the MCI group. There were no differences in oral nitrate (P = 0.48) or nitrite concentrations (P = 0.84) between the MCI and healthy groups. Linear discriminant analysis Effect Size identified Porphyromonas as a predictor for MCI and Prevotella intermedia as a predictor of APOE4-carrier status. The principal findings of this study were that a greater prevalence of oral P. intermedia is linked to elevated genetic risk for dementia (APOE4 genotype) in individuals with MCI prior to dementia diagnosis and that interventions that promote the oral Neisseria-Haemophilus and suppress Prevotella-dominated modules have potential for delaying cognitive decline.

Influence of high-load shocks on achieving mainstream partial nitrification: Microbial community succession.

Driving microbial community succession through the regulation of operational strategies is crucial for achieving partial nitrification (PN) in municipal wastewater. However, at present, there is a decoupling between the strategic regulation of PN systems and the succession characteristics of the microbial community. This study examined the correlation between microbial community succession and PN performance under two high-load shocks (HLS1 and HLS2) treating actual sewage. During HLS1, the influent organic loading rate (OLR) and nitrogen loading rate (NLR) increased from 116.7 ± 37.7 to 219.7 ± 24.7 mg COD/(g VSS·d) and 0.21±0.02 to 0.33±0.02 kg N/m3/d respectively, with the nitrite concentration and nitrite accumulation ratio only reaching 11.7 ± 2.7 mg/L and 49.3 ± 13.9 %, respectively. During HLS2, the influent OLR and NLR increased from 123.5 ± 17.2 to 300.3 ± 49.2 mg COD/(g VSS·d) and 0.19±0.03 to 0.32±0.03 kg N/m3/d respectively, resulting in a nitrite accumulation ratio of 89.4 ± 10.7 %. The system achieved efficient PN performance and sustained for 124 days. High-throughput sequencing results showed that community diversity remained consistently high, and the community composition returned to its initial state following a minor succession during HLS1. During HLS2, the high-load shock reduced the richness and evenness of the microbial community. The community underwent succession in a new direction, leading to community composition and function changes. The results indicate that the realization, stabilization, and disruption of PN are influenced not only by operational parameters but also by microbial community structure.

Effects of ultrasound-assisted plasma-activated water pretreatment combined with electrohydrodynamics on drying characteristics, active ingredients and volatile components of yam (Dioscorea opposita).

This paper explores the effect of ultrasound (US) assisted plasma-activated water (PAW) or deionized water (DW) pretreatment combined with electrohydrodynamics (EHD) on the drying of yam. The activity characteristics of four pretreatments (plasma activated water combined with ultrasound (PAW+US), plasma activated water (PAW), deionized water combined with ultrasound (DW+US), and deionized water (DW) (control)) and their effects on drying characteristics, rehydration rate, color, reducing sugars, total phenols, infrared spectra, and volatile compositions of yam under EHD drying process were investigated. The results showed that the media pretreaded by ultrasound (US) combined with plasma-activated water (PAW) has lower media of pH (53.84% lower than that of US+DW), higher nitrite ion concentration (311 times over US+DW), higher oxidation reduction potential (50.58% higher than that of US+DW), and higher electrical conductivity (99.29 times over US+DW). And ultrasonic pretreatment (US) combined with plasma-activated water (PAW) drying resulted in faster drying, better rehydration rate, higher brightness L * (18.35% higher than that of US+DW) and whiteness (1.1% higher than that of US+DW), and retention of more reducing sugars (10.96% higher than that of US+DW) and total phenols (14.04% higher than that of US+DW), and a higher variety and content of volatile components. This provides an experimental and theoretical basis for the application of ultrasonic (US) combined with plasma-activated water (PAW) pretreatment to electrohydrodynamic drying.

An Optical Sensor for In Situ Real-Time Detection of Intermediate Products in Nitrate Reduction Reactions

The nitrate reduction reaction (NO3RR) is a promising method for ammonia production, but detecting intermediate NO2- in situ during the reaction is challenging. We propose a nitrite concentration sensor based...