This paper presents results of nitrites and nitrates determination in two types of baby foods： commercial products in jars and their homemade conventional counterparts. Nitrites levels in all analyzed samples were be...This paper presents results of nitrites and nitrates determination in two types of baby foods： commercial products in jars and their homemade conventional counterparts. Nitrites levels in all analyzed samples were below of the detection limit （〈 0.9 mg/kg） of applied spectrophotometric method with Griess reagent. Nitrates contents in commercial products ranged： 9.1-38.1 mg/kg while in homemade baby foods levels between 26.6 mg/kg and 118.8 mg/kg were obtained. All the contents of nitrates were lower than the EU legislation maximum limit （200 mg/kg）. Comparison of each type of commercial product with its homemade counterpart baby food evidenced significant differences （p 〈 0.05） in average nitrates levels in favor of the first type. Apart from determining and comparing the levels of nitrates in the baby food samples also risk assessment for an average 6-months old infant to nitrates exposure was conducted. The estimated nitrates intake with a typical portion of 200g of baby food ranged between 6% and 25.7% of acceptable daily intake for commercial and from 18.0% to 80.3% for homemade ones.展开更多
This study aimed to evaluate the quality of water from village boreholes by measuring physicochemical parameters such as nitrates, nitrites, and total organic carbon (TOC). Forty-five (45) village pumps from the South...This study aimed to evaluate the quality of water from village boreholes by measuring physicochemical parameters such as nitrates, nitrites, and total organic carbon (TOC). Forty-five (45) village pumps from the Southern (Basse Côte) and the Northern (Korhogo) region of Cte d’Ivoire (west Africa) were sampled. Physicochemical parameters such as temperature, pH, conductivity at 25˚C, and turbidity were determined in situ, while nitrite and nitrate were analyzed according to ISO 10304-1 (2007) standard and total organic carbon (TOC) by NF EN 1484 (1997) standard. The results showed that the borehole waters of the Basse Côte and Korhogo analyzed are acidic, with an average temperature of 27.51˚C ± 0.16˚C and 29.95˚C ± 0.51˚C respectively for the Basse Côte and Korhogo regions. The borehole waters of the Basse Côtedo not contain nitrites, while those of Korhogo have average nitrite contents of 0.32 mg/l. The average nitrate rate in the waters of the Basse Côte and Korhogo are 12.08 ± 2.11 mg/l and 11.03 ± 3.18 mg/l respectively. The average TOC concentration of the waters of the Basse Côte is 1.28 ± 0.32 mg/l and that of Korhogo is 0.56 ± 0.09 mg/L. The study showed that the borehole waters of the Basse Côte and Korhogo have average temperatures between 27.4˚C and 29.95˚C with a slightly acidic pH value and acceptable salinity. The TOC concentrations obtained at the different sampling points were all below the French standard (2 mg/L) except for certains pumps of the Basse Côte. The water samples from the Basse Côte were devoid of nitrite. On the other hand, those from Korhogo revealed the presence of nitrite. Also, the borehole waters of the regions of the Basse Côte and Korhogo contain relatively high nitrate contents, presumably due to anthropometric activity. Overall, our study on the quality of drinking water showed that the waters analyzed are in compliance with international standards and safe for consumption.展开更多
The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in...The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32x–9.51 (R2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h–LC50 value for ammonia was found to be 95.50 mg/L. A linear correla- tion between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equa- tion y=2.86x+0.89 (R2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2 862.85e-0.08x (R2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y = 127.15e-0.13x (R2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.展开更多
Temperature is an important physical factor, which strongly influences biomass and metabolic activity. In this study, the effects of temperature on the anoxic metabolism of nitrite （NO2） to nitrous oxide （N2O） by ...Temperature is an important physical factor, which strongly influences biomass and metabolic activity. In this study, the effects of temperature on the anoxic metabolism of nitrite （NO2） to nitrous oxide （N2O） by polyphosphate accumulating organisms, and the process of the accumulation of N2O （during nitrite reduction）, which acts as an electron acceptor, were investigated using 91% ：e 4% Candidatus Accumulibacterphosphatis sludge. The results showed that N2O is accumulated when Accumulibacter first utilize nitrite instead of oxygen as the sole electron acceptor during the denitrifying phosphorus removal process. Properties such as nitrite reduction rate, phosphorus uptake rate, N2O reduction rate, and polyhydroxyalkanoate degradation rate were all influenced by temperature variation （over the range from 10 to 30℃ reaching maximum values at 25℃）. The reduction rate of N2O by N2O reductase was more sensitive to temperature when N2O was utilized as the sole electron acceptor instead of NO2, and the N2O reduction rates, ranging from 0.48 to 3.53 N2O-N/（hr.g VSS）, increased to 1.45 to 8.60 mg N2O-N/（hr·g VSS）. The kinetics processes for temperature variation of 10 to 30℃ were （01 = 1.140-1.216 and θ2 = 1.139-1.167）. In the range of 10℃ to 30℃, almost all of the anoxic stoichiometry was sensitive to temperature changes. In addition, a rise in N2O reduction activity leading to a decrease in N2O accumulation in long term operations at the optimal temperature （27℃ calculated by the Arrhenius model）.展开更多
Nitrogenous compounds(i.e.,amines,amides,nitriles,oximes,amino acids and nitrogen-heterocycles derivatives)are important building blocks for synthetic chemistry,pharmaceuticals,and functional materials.Conventional sy...Nitrogenous compounds(i.e.,amines,amides,nitriles,oximes,amino acids and nitrogen-heterocycles derivatives)are important building blocks for synthetic chemistry,pharmaceuticals,and functional materials.Conventional synthetic strategies involve the use of toxic organic nitrogenous precursors or expensive heterogeneous catalysts under elevated temperatures and pressurized oxygen.Heterogeneous electrocatalysis can initiate the activation of inorganic N sources(i.e.,NH_(3)and NO^(-)_(x))under ambient reactions in liquid phase by applying a small bias,thus allowing the synthesis of value?added nitrogenous compounds from carbonyls,alkenes,keto acids,and even carbon dioxide in a sustainable manner without the use of oxidants/reductants.This review outlines recent de-velopments in electrosynthesis of nitrogenous compounds using inorganic N sources,focusing on reaction mechanisms understanding,the design and optimization of efficient electrocatalysts,and the advances in cell configurations for various C‒N coupling reactions.The limitations and challenges in applications are also discussed.展开更多
Mining and tailings deposition can cause serious heavy metal(loids)pollution to the surrounding soil environment.Soil microorganisms adapt their metabolism to such conditions,driving alterations in soil function.This ...Mining and tailings deposition can cause serious heavy metal(loids)pollution to the surrounding soil environment.Soil microorganisms adapt their metabolism to such conditions,driving alterations in soil function.This study aims to elucidate the response patterns of nitrogen-cycling microorganisms under long-term heavy metal(loids)exposure.The results showed that the diversity and abundance of nitrogen-cyclingmicroorganisms showed negative feedback to heavy metal(loids)concentrations.Denitrifying microorganisms were shown to be the dominant microorganisms with over 60%of relative abundance and a complex community structure including 27 phyla.Further,the key bacterial species in the denitrification process were calculated using a random forest model,where the top three key species(Pseudomonas stutzei,Sphingobium japonicum and Leifsonia rubra)were found to play a prominent role in nitrite reduction.Functional gene analysis and qPCR revealed that nirK,which is involved in nitrite reduction,significantly accumulated in the most metal-rich soil with the increase of absolute abundance of 63.86%.The experimental results confirmed that the activity of nitrite reductase(Nir)encoded by nirK in the soil was increased at high concentrations of heavy metal(loids).Partial least squares-path model identified three potential modes of nitrite reduction processes being stimulated by heavy metal(loids),the most prominent of which contributed to enhanced nirK abundance and soil Nir activity through positive stimulation of key species.The results provide new insights and preliminary evidence on the stimulation of nitrite reduction processes by heavy metal(loids).展开更多
The authors regret<an error occurred regarding the spelling of the author’s name in the final published manuscript.The correct spelling is Jingtao Bi,but it was mistakenly published as Jingtai Bi.We hereby request...The authors regret<an error occurred regarding the spelling of the author’s name in the final published manuscript.The correct spelling is Jingtao Bi,but it was mistakenly published as Jingtai Bi.We hereby request to correct the name to Jingtao Bi as originally intended.>.The authors would like to apologize for any inconvenience caused.展开更多
Zirconia nanotube array films(ZNAF)prepared by anodic oxidation method were used as immobilization materials for acridine orange(AO),rhodamine B(RB)and AO-RB systems.A comparative study on their fluorescence emission ...Zirconia nanotube array films(ZNAF)prepared by anodic oxidation method were used as immobilization materials for acridine orange(AO),rhodamine B(RB)and AO-RB systems.A comparative study on their fluorescence emission intensity,fluorescence resonance energy transfer(FRET)and fluorescence detection of nitrite in aqueous solutions and on immobilization films with ZNAF as carriers was carried out.Results demonstrate that the solution pH values and immobilization on ZNAF have a great influence on the per-formance of these fluorescent molecules.Compared with aqueous solutions,the fluorescence emission in-tensity of AO and RB is considerably increased by immobilization,which is 8.0 and 4.2 times higher than the original,respectively.The energy transfer efficiency(E)of the AO-RB system increases from 40.9%to 84.8%by loading it on ZNAF.Moreover,after immobilization onto ZNAF,the fluorescence detection performance of nitrite is also significantly improved.The limit of detection decreases from 0.95 ng/mL to 0.22 ng/mL and the sensitivity increases from 939.18 to 15,031.68 mL/μg through loading AO onto ZNAF.展开更多
The electrochemical conversion of toxic nitrite(NO_(2)-)is a promising approach for the simultaneous removal of nitrogen contaminants and synthesis of ammonia(NH_(3)).In this study,we present the Er-doping-induced ele...The electrochemical conversion of toxic nitrite(NO_(2)-)is a promising approach for the simultaneous removal of nitrogen contaminants and synthesis of ammonia(NH_(3)).In this study,we present the Er-doping-induced electronic modulation of CoP integrated with nitrogen-doped carbon(CN)nanosheets supported on a titanium mesh(Er-CoP@NC/TM)for the electrocatalytic NO_(2)-reduction reaction(eNO_(2)-RR)for NH_(3)synthesis.The catalyst demonstrates a high Faraday efficiency of 97.08±2.22%and a high yield of 2087.60±17.10μmol h^(-1)cm^(-2)for NH_(3)production.Characterization and theoretical calculations revealed that Er-doping facilitated the electronic modulation of CoP in Er-CoP@NC/TM,which regulated the adsorption behaviors of intermediates and was the rate-limiting step for the eNO_(2)-RR,thereby enhancing the electrocatalytic performance.Quenching experiments and electron paramagnetic resonance tests suggest that both direct electrocatalytic reduction by active hydrogen and electron transfer are critical for the eNO_(2)-RR for NH_(3)synthesis.Furthermore,Er-CoP@NC/TM exhibited high performance across a wide range of NO_(2)-concentrations(0.05-0.1 mol L^(-1))and pH values(4-13).In addition,the catalyst demonstrated strong resistance to anions and a long cycle life in simulated wastewater environments.This study offers a powerful approach for the remediation of NO_(2)-wastewater and recovery of valuable inorganic compounds.展开更多
The authors regret that in 1.2.Instruments section of the article,when describing the principle of TiH300,the original content of“Briefly,ambient HONO was first absorbed by deionized water in a two-channel stripping ...The authors regret that in 1.2.Instruments section of the article,when describing the principle of TiH300,the original content of“Briefly,ambient HONO was first absorbed by deionized water in a two-channel stripping coil.The absorbed liquid nitrite was mixed with sulfanilamide,N-(1-naphthyl)-ethylenediamine dihydrochloride,and hydrogen chloride solution to form the azo dye derivative.”展开更多
Formaldehyde(FA)and excessive nitrite(NO_(2)^(-))are highly carcinogenic compounds that pose serious risks to human health.In this study,we designed a sensing platform 8-hydrazine-boron dipyrromethene(OPTY)for the det...Formaldehyde(FA)and excessive nitrite(NO_(2)^(-))are highly carcinogenic compounds that pose serious risks to human health.In this study,we designed a sensing platform 8-hydrazine-boron dipyrromethene(OPTY)for the detection of FA and nitrite in food.Upon aldimine condensation with FA,OPTY produced strong blue fluorescence.By contrast,NO_(2)^(-)underwent an intramolecular cyclization cascade reaction with OPTY to boast bright green fluorescence.OPTY has the advantages of high signal-to-noise ratio,good selectivity,and a low limit of detection(LOD=26.5 nmol/L for FA,LOD=20.8 nmol/L for NO_(2)^(-)).Furthermore,OPTY was fabricated into a portable sensing chip,which was combined with smartphone to form a portable sensing platform.This platform has been successfully applied for the determination of FA/NO_(2)^(-)in meat and seafood with high accuracy(93.49%-102.35%).Therefore,the intelligent sensing platform can realize on-site visual detection of FA/NO_(2)^(-)content in food,demonstrating great potential for ensuring food safety.展开更多
Electrocatalytic reduction of nitrate pollutants to produce ammonia offers an effective approach to realizing the artificial nitrogen cycle and replacing the energyintensive Haber-Bosch process.Nitrite is an important...Electrocatalytic reduction of nitrate pollutants to produce ammonia offers an effective approach to realizing the artificial nitrogen cycle and replacing the energyintensive Haber-Bosch process.Nitrite is an important intermediate product in the reduction of nitrate to ammonia.Therefore,the mechanism of converting nitrite into ammonia warrants further investigation.Molecular cobalt catalysts are regarded as promising for nitrite reduction reactions(NO_(2)^(−)RR).However,designing and controlling the coordination environment of molecular catalysts is crucial for studying the mechanism of NO_(2)^(−)RR and catalyst design.Herein,we develop a molecular platform of cobalt porphyrin with three coordination microenvironments(Co-N_(3)X_(1),X=N,O,S).Electrochemical experiments demonstrate that cobalt porphyrin with O coordination(CoOTPP)exhibits the lowest onset potential and the highest activity for NO_(2)^(−)RR in ammonia production.Under neutral,nonbuffered conditions over a wide potential range(−1.0 to−1.5 V versus AgCl/Ag),the Faradaic efficiency of nearly 90%for ammonia was achieved and reached 94.5%at−1.4 V versus AgCl/Ag,with an ammonia yield of 6,498μgh^(−1)and a turnover number of 22,869 at−1.5V versus AgCl/Ag.In situ characterization and density functional theory calculations reveal that modulating the coordination environment alters the electron transfer mode of the cobalt active center and the charge redistribution caused by the break of the ligand field.Therefore,this results in enhanced electrochemical activity for NO_(2)^(−)RR in ammonia production.This study provides valuable guidance for designing adjustments to the coordination environment of molecular catalysts to enhance catalytic activity.展开更多
Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen carrier.Consequently,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are ...Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen carrier.Consequently,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are desired eminently.The nitrite(NO_(2)^(-))reduction reaction(NO_(2-)RR)to NH_(3)offers a feasibly low-energy consumption and continuable approach to replace industrial NH_(3)synthesis.Herein,polyethyleneimine(PEI)modified Au core Rh shell nanodendrites(Au@Rh-NDs)nanohybrid(Au@Rh-NDs/PEI)with branched structure is synthesized,which achieves the high NH_(3)yield(1.68 mg h^(-1)mg_(cat)^(-1))and Faradaic efficiency(FE)of 95.86%for NO_(2)^(-)-RR at-0.39 V potential in neutral electrolyte.Particularly,the introduction of PEI significantly enhances the electroactivity of Au@Rh-NDs at low concentration of 1 mM NaNO_(2),which originates from the enrichment function of PEI for NO_(2)^(-)-ion.In addition,the Au basement permits the sustainable solar power to expedite the NO_(2)^(-)-RR at Au@Rh-NDs/PEI owing to the localized surface plasmon resonance(LSPR)of the Au core substrate.This work may provide an admissible tactic to build excellent catalysts on account of organic molecule-mediated interfacial engineering in a variety of fields of catalysis and electrocatalysis.展开更多
To prevent bacterial growth and ensure food safety,common practice involves the use of nitrite and phosphate salts.Neverthe-less,elevated nitrite levels in the body can contribute to the development of stomach and eso...To prevent bacterial growth and ensure food safety,common practice involves the use of nitrite and phosphate salts.Neverthe-less,elevated nitrite levels in the body can contribute to the development of stomach and esophageal cancers,while excessive phosphate levels may increase the risk of kidney dysfunction and the onset of osteoporosis.Electrochemical sensing has emerged as a reliable tech-nique for detecting nitrites and phosphates.This study specifically focuses on the use of TiO_(2)-based sensing materials for such detection.The synthesis of nanoparticulate TiO_(2) and Ag-doped TiO_(2) was successfully achieved through a solution combustion technique.The com-position of the materials was examined using X-ray diffraction(XRD)and X-ray absorption near-edge structure(XANES)methods,re-vealing a predominant anatase composition.Doping resulted in particle refinement,contributing to an increased specific surface area and enhanced electron transfer efficiency,as indicated in the examination by electrochemical impedance spectroscopy(EIS).Cyclic voltam-metry(CV)assessed the electrochemical behavior,demonstrating that in nitrite detection,a significant oxidation reaction occurred at an applied voltage of approximately 1.372 V,while in phosphate detection,the main reduction peak occurred at a voltage close to-0.48 V.High sensitivity(2μA·μM^(-1)·mm^(-2) for sodium nitrite and 2.1μA·μM^(-1)·mm^(-2) for potassium phosphate)and low limits of detection(0.0052 mM for sodium nitrite and 0.0045 mM for potassium phosphate)were observed.Experimental results support the potential use of Ag-doped TiO_(2) as a sensing device for nitrites and phosphates.展开更多
The electrochemical biomass valorization of industrial by-products or pollutants using renewable electricity offers significant promise for carbon neutrality.However,the huge challenges still exist in the development ...The electrochemical biomass valorization of industrial by-products or pollutants using renewable electricity offers significant promise for carbon neutrality.However,the huge challenges still exist in the development of efficient bifunctional electrocatalysts.Herein,we put forward a high-efficiency coelectrolysis system by coupling the nitrite reduction reaction(NO_(2)RR)and the glycerol oxidation reaction(GOR)over a novel heterogeneous β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl catalyst.Theβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl shows excellent bifunctional performance with high Faradaic efficiencies of formate(90.1%)and NH_(3)(91.9%)at cell voltage of 1.5 V,high yield rate of formate(89.6 mg h^(-1)cm^(-2))and NH_(3)(36.07 mg h^(-1)cm^(-2))at cell voltage of 1.9 V,and superior stability in an anion exchange membrane co-electrolyzer.The in-situ Raman result confirms the unique Co/Cu-based bimetallic synergistic sites of β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl towards superior GOR performance,while the operando Fourier transform infrared spectroscopy demonstrates the improved protonation kinetics of key intermediates and optimized water dissociation ability ofβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl for high NO_(2)RR activity.Our work illuminates alternative avenues to exploit the innovative and energy-saving technology for the co-production of high-added chemicals.展开更多
AIM： To study the association between nitrite and nitrosamine intake and gastric cancer （GC）, between meat and processed meat intake, GC and oesophageal cancer （OC）, and between preserved fish, vegetable and smok...AIM： To study the association between nitrite and nitrosamine intake and gastric cancer （GC）, between meat and processed meat intake, GC and oesophageal cancer （OC）, and between preserved fish, vegetable and smoked food intake and GC. METHODS： In this article we reviewed all the published cohort and case-control studies from 1985-2005, and analyzed the relationship between nitrosamine and nitrite intake and the most important related food intake （meat and processed meat, preserved vegetables and fish, smoked foods and beer drinking） and GC or OC risk. Sixty-one studies, 11 cohorts and 50 case-control studies were included. RESULTS： Evidence from case-control studies supported an association between nitrite and nitrosamine intake with GC but evidence was insufficient in relation to OC. A high proportion of case-control studies found a positive association with meat intake for both tumours （11 of 16 studies on GC and 11 of 18 studies on OC）. A relatively large number of case-control studies showed quite consistent results supporting a positive association between processed meat intake and GC and OC risk （10 of 14 studies on GC and 8 of 9 studies on OC）. Almost all the case-control studies found a positive and significant association between preserved fish, vegetable and smoked food intake and GC. The evidence regarding OC was more limited. Overall the evidence from cohort studies was insufficient or more inconsistent than that from case-control studies.CONCLUSION： The available evidence supports a positive association between nitrite and nitrosamine intake and GC, between meat and processed meat intake and GC and OC, and between preserved fish, vegetable and smoked food intake and GC, but is not conclusive.展开更多
To understand the correlations between the abundance of Trichodina spp. and the water quality parameters, the abundance of Trichodina spp. on the gill of yellow catfish in aquaculture water was investigated. Meanwhile...To understand the correlations between the abundance of Trichodina spp. and the water quality parameters, the abundance of Trichodina spp. on the gill of yellow catfish in aquaculture water was investigated. Meanwhile, the temperature and total phosphorus, available phosphorus, total nitrogen, nitrite and ammonia nitro- gen contents of the aquaculture water were measured and determined. The results showed that the abundance of Trichodina spp. on the gill of yellow catfish was negatively correlated with the total phosphorus, available phosphorus and total nitro- gen contents in the aquaculture water, and was positively correlated with the nitrite content in the aquaculture water （P〈0.05）; there were no significant correlations between the abundance of Trichodina spp. and the temperature and ammonia nitrogen content of the aquaculture water （P〉0.05）.展开更多
AIM:Adrenomedullin (ADM) is a potent vasodilator peptide. ADM and nitric oxide (NO) are produced in vascular endothelial cells.Increased ADM level has been linked to hyperdynamic circulation and arterial vasodilatatio...AIM:Adrenomedullin (ADM) is a potent vasodilator peptide. ADM and nitric oxide (NO) are produced in vascular endothelial cells.Increased ADM level has been linked to hyperdynamic circulation and arterial vasodilatation in cirrhotic portal hypertension (CPH).The role of ADM in non-cirrhotic portal hypertension (NCPH) is unknown,plasma ADM levels were studied in patients with NCPH,compensated and decompensated cirrhosis in order to determine its contribution to portal hypertension (PH) in these groups. METHODS:There were 4 groups of subjects.Group 1 consisted of 27 patients (F/M:12/15) with NCPH due to portal and/or splenic vein thrombosis (mean age:41±12 years),group 2 consisted of 14 patients (F/M:6/8) with compensated (Child-Pugh A) cirrhosis (mean age:46±4), group 3 consisted of 16 patients (F/M:6/10) with decompensated (Child-Pugh C) cirrhosis (mean age:47±12). Fourteen healthy subjects (F/M:6/8) (mean age:44±8) were used as controls in Group 4.ADM level was measured by ELISA.NO was determined as nitrite/nitrate level by chemoluminescence. RESULTS:ADM level in Group 1 (236±61.4 pg/mL) was significantly higher than that in group 2 (108.4±28.3 pg/mL) and group 4 (84.1±31.5 pg/mL) (both P<0.0001) but was lower than that in Group3 (324±93.7 pg/mL) (P=0.002).NO level in group 1 (27±1.4 μmol/L) was significantly higher than that in group 2 (19.8±2.8 μmol/L) and group 4 (16.9±1.6 μmol/L) but was lower than that in Group 3 (39±3.6 μmol/L) (for all three P<0.0001).A strong correlation was observed between ADM and NO levels (r=0.827,P<0.0001). CONCLUSION:Adrenomedullin and NO levels were high in both non-cirrhotic and cirrhotic portal hypertension and were closely correlated,Adrenomedullin and NO levels increased proportionally with the severity of cirrhosis,and were significantly higher than those in patients with NCPH. Portal hypertension plays an important role in the increase of ADM and NO.Parenchymal damage in cirrhosis may contribute to the increase in these parameters.展开更多
It was demonstrated that xanthine oxidoreductase (XOR), during ischemia, catalyzes the formation of nitric oxide (NO) from nitrite (NO_2^-) and this NO_2^--derived NO protects the isolated perfused rat heart against t...It was demonstrated that xanthine oxidoreductase (XOR), during ischemia, catalyzes the formation of nitric oxide (NO) from nitrite (NO_2^-) and this NO_2^--derived NO protects the isolated perfused rat heart against the damaging effects of ischemia-reperfusion (I/R) when conventional nitric oxide synthase (NOS) -dependent NO production is impaired. Liver is one of the organs with the highest XOR concentration. This study was designed to determine whether NO_2^--derived NO by XOR protects liver against I/R injury in vivo. For its minute amounts and active reactivity, NO can not be detected directly in real time in vivo by this time. We have to prove the above hypothesis indirectly. METHODS:Wistar rats were pretreated with saline, NOS inhibitor L-NAME (10 mg/kg intravenously), XOR inhibitor allopurinol (1.5 mg/kg orally), L-NAME +allopurinol and NO scavenger carboxy-PTIO (0.6 mg/kg intravenously) respectively (12 animals per group). And then, they were subjected to total liver ischemia for 40 minutes followed by reperfusion. Blood samples and liver tissues were obtained for analysis after 3 hours of reperfusion. Survival was also investigated. RESULTS:Allopurinol-treated animals exhibited further increased serum alanine aminotransferase (ALT) levels and liver myeloperoxidase (MPO) activities, but further decreased liver adenosine triphosphate (ATP) stores after I/R compared to saline-treated counterparts (830.5±108.3 U/L, 56.5±11.0 U/mg protein and 1.93±0.47 μmol/g vs. 505.8± 184.2 U/L, 41.5±10.2 U/mg protein and 3.05±0.55 μmol/g respectively, P<0.01, P<0.05 and P<0.01 respectively). The hepatocyte injury was further exacerbated and the overall survival rate was significantly decreased after I/R in animals given by allopurinol compared to those pretreated by saline (P<0.05). L-NAME and allopurinol co-treated animals exhibited more severe liver injury (P<0.05 and P<0.01) and a further decreased overall survival rate (P<0.05) compared to L-NAME or allopurinol alone-treated counterparts, but they were not different from carboxy-PTIO treated animals (P>0.05). CONCLUSION:NO_2^--derived NO by XOR in the hypoxic and acidic environment induced by hepatic I/R protects the liver against I/R injury in vivo.展开更多
文摘This paper presents results of nitrites and nitrates determination in two types of baby foods： commercial products in jars and their homemade conventional counterparts. Nitrites levels in all analyzed samples were below of the detection limit （〈 0.9 mg/kg） of applied spectrophotometric method with Griess reagent. Nitrates contents in commercial products ranged： 9.1-38.1 mg/kg while in homemade baby foods levels between 26.6 mg/kg and 118.8 mg/kg were obtained. All the contents of nitrates were lower than the EU legislation maximum limit （200 mg/kg）. Comparison of each type of commercial product with its homemade counterpart baby food evidenced significant differences （p 〈 0.05） in average nitrates levels in favor of the first type. Apart from determining and comparing the levels of nitrates in the baby food samples also risk assessment for an average 6-months old infant to nitrates exposure was conducted. The estimated nitrates intake with a typical portion of 200g of baby food ranged between 6% and 25.7% of acceptable daily intake for commercial and from 18.0% to 80.3% for homemade ones.
文摘This study aimed to evaluate the quality of water from village boreholes by measuring physicochemical parameters such as nitrates, nitrites, and total organic carbon (TOC). Forty-five (45) village pumps from the Southern (Basse Côte) and the Northern (Korhogo) region of Cte d’Ivoire (west Africa) were sampled. Physicochemical parameters such as temperature, pH, conductivity at 25˚C, and turbidity were determined in situ, while nitrite and nitrate were analyzed according to ISO 10304-1 (2007) standard and total organic carbon (TOC) by NF EN 1484 (1997) standard. The results showed that the borehole waters of the Basse Côte and Korhogo analyzed are acidic, with an average temperature of 27.51˚C ± 0.16˚C and 29.95˚C ± 0.51˚C respectively for the Basse Côte and Korhogo regions. The borehole waters of the Basse Côtedo not contain nitrites, while those of Korhogo have average nitrite contents of 0.32 mg/l. The average nitrate rate in the waters of the Basse Côte and Korhogo are 12.08 ± 2.11 mg/l and 11.03 ± 3.18 mg/l respectively. The average TOC concentration of the waters of the Basse Côte is 1.28 ± 0.32 mg/l and that of Korhogo is 0.56 ± 0.09 mg/L. The study showed that the borehole waters of the Basse Côte and Korhogo have average temperatures between 27.4˚C and 29.95˚C with a slightly acidic pH value and acceptable salinity. The TOC concentrations obtained at the different sampling points were all below the French standard (2 mg/L) except for certains pumps of the Basse Côte. The water samples from the Basse Côte were devoid of nitrite. On the other hand, those from Korhogo revealed the presence of nitrite. Also, the borehole waters of the regions of the Basse Côte and Korhogo contain relatively high nitrate contents, presumably due to anthropometric activity. Overall, our study on the quality of drinking water showed that the waters analyzed are in compliance with international standards and safe for consumption.
文摘The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32x–9.51 (R2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h–LC50 value for ammonia was found to be 95.50 mg/L. A linear correla- tion between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equa- tion y=2.86x+0.89 (R2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2 862.85e-0.08x (R2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y = 127.15e-0.13x (R2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.
基金supported by the National High Technology Research and Development Program (863) of China (No. 2012AA063406)the National Natural Science Foundation of China (No. 51008005)
文摘Temperature is an important physical factor, which strongly influences biomass and metabolic activity. In this study, the effects of temperature on the anoxic metabolism of nitrite （NO2） to nitrous oxide （N2O） by polyphosphate accumulating organisms, and the process of the accumulation of N2O （during nitrite reduction）, which acts as an electron acceptor, were investigated using 91% ：e 4% Candidatus Accumulibacterphosphatis sludge. The results showed that N2O is accumulated when Accumulibacter first utilize nitrite instead of oxygen as the sole electron acceptor during the denitrifying phosphorus removal process. Properties such as nitrite reduction rate, phosphorus uptake rate, N2O reduction rate, and polyhydroxyalkanoate degradation rate were all influenced by temperature variation （over the range from 10 to 30℃ reaching maximum values at 25℃）. The reduction rate of N2O by N2O reductase was more sensitive to temperature when N2O was utilized as the sole electron acceptor instead of NO2, and the N2O reduction rates, ranging from 0.48 to 3.53 N2O-N/（hr.g VSS）, increased to 1.45 to 8.60 mg N2O-N/（hr·g VSS）. The kinetics processes for temperature variation of 10 to 30℃ were （01 = 1.140-1.216 and θ2 = 1.139-1.167）. In the range of 10℃ to 30℃, almost all of the anoxic stoichiometry was sensitive to temperature changes. In addition, a rise in N2O reduction activity leading to a decrease in N2O accumulation in long term operations at the optimal temperature （27℃ calculated by the Arrhenius model）.
基金Ren Su thanks the NSFC(No.22472112)the Suzhou Foreign Academician Workstation(No.SWY2022001)for financial supports。
文摘Nitrogenous compounds(i.e.,amines,amides,nitriles,oximes,amino acids and nitrogen-heterocycles derivatives)are important building blocks for synthetic chemistry,pharmaceuticals,and functional materials.Conventional synthetic strategies involve the use of toxic organic nitrogenous precursors or expensive heterogeneous catalysts under elevated temperatures and pressurized oxygen.Heterogeneous electrocatalysis can initiate the activation of inorganic N sources(i.e.,NH_(3)and NO^(-)_(x))under ambient reactions in liquid phase by applying a small bias,thus allowing the synthesis of value?added nitrogenous compounds from carbonyls,alkenes,keto acids,and even carbon dioxide in a sustainable manner without the use of oxidants/reductants.This review outlines recent de-velopments in electrosynthesis of nitrogenous compounds using inorganic N sources,focusing on reaction mechanisms understanding,the design and optimization of efficient electrocatalysts,and the advances in cell configurations for various C‒N coupling reactions.The limitations and challenges in applications are also discussed.
基金supported by the National Natural Science Foundation of China(No.41977029).
文摘Mining and tailings deposition can cause serious heavy metal(loids)pollution to the surrounding soil environment.Soil microorganisms adapt their metabolism to such conditions,driving alterations in soil function.This study aims to elucidate the response patterns of nitrogen-cycling microorganisms under long-term heavy metal(loids)exposure.The results showed that the diversity and abundance of nitrogen-cyclingmicroorganisms showed negative feedback to heavy metal(loids)concentrations.Denitrifying microorganisms were shown to be the dominant microorganisms with over 60%of relative abundance and a complex community structure including 27 phyla.Further,the key bacterial species in the denitrification process were calculated using a random forest model,where the top three key species(Pseudomonas stutzei,Sphingobium japonicum and Leifsonia rubra)were found to play a prominent role in nitrite reduction.Functional gene analysis and qPCR revealed that nirK,which is involved in nitrite reduction,significantly accumulated in the most metal-rich soil with the increase of absolute abundance of 63.86%.The experimental results confirmed that the activity of nitrite reductase(Nir)encoded by nirK in the soil was increased at high concentrations of heavy metal(loids).Partial least squares-path model identified three potential modes of nitrite reduction processes being stimulated by heavy metal(loids),the most prominent of which contributed to enhanced nirK abundance and soil Nir activity through positive stimulation of key species.The results provide new insights and preliminary evidence on the stimulation of nitrite reduction processes by heavy metal(loids).
文摘The authors regret<an error occurred regarding the spelling of the author’s name in the final published manuscript.The correct spelling is Jingtao Bi,but it was mistakenly published as Jingtai Bi.We hereby request to correct the name to Jingtao Bi as originally intended.>.The authors would like to apologize for any inconvenience caused.
基金supported by the National Natural Science Foundation of China(No.51972095).
文摘Zirconia nanotube array films(ZNAF)prepared by anodic oxidation method were used as immobilization materials for acridine orange(AO),rhodamine B(RB)and AO-RB systems.A comparative study on their fluorescence emission intensity,fluorescence resonance energy transfer(FRET)and fluorescence detection of nitrite in aqueous solutions and on immobilization films with ZNAF as carriers was carried out.Results demonstrate that the solution pH values and immobilization on ZNAF have a great influence on the per-formance of these fluorescent molecules.Compared with aqueous solutions,the fluorescence emission in-tensity of AO and RB is considerably increased by immobilization,which is 8.0 and 4.2 times higher than the original,respectively.The energy transfer efficiency(E)of the AO-RB system increases from 40.9%to 84.8%by loading it on ZNAF.Moreover,after immobilization onto ZNAF,the fluorescence detection performance of nitrite is also significantly improved.The limit of detection decreases from 0.95 ng/mL to 0.22 ng/mL and the sensitivity increases from 939.18 to 15,031.68 mL/μg through loading AO onto ZNAF.
文摘The electrochemical conversion of toxic nitrite(NO_(2)-)is a promising approach for the simultaneous removal of nitrogen contaminants and synthesis of ammonia(NH_(3)).In this study,we present the Er-doping-induced electronic modulation of CoP integrated with nitrogen-doped carbon(CN)nanosheets supported on a titanium mesh(Er-CoP@NC/TM)for the electrocatalytic NO_(2)-reduction reaction(eNO_(2)-RR)for NH_(3)synthesis.The catalyst demonstrates a high Faraday efficiency of 97.08±2.22%and a high yield of 2087.60±17.10μmol h^(-1)cm^(-2)for NH_(3)production.Characterization and theoretical calculations revealed that Er-doping facilitated the electronic modulation of CoP in Er-CoP@NC/TM,which regulated the adsorption behaviors of intermediates and was the rate-limiting step for the eNO_(2)-RR,thereby enhancing the electrocatalytic performance.Quenching experiments and electron paramagnetic resonance tests suggest that both direct electrocatalytic reduction by active hydrogen and electron transfer are critical for the eNO_(2)-RR for NH_(3)synthesis.Furthermore,Er-CoP@NC/TM exhibited high performance across a wide range of NO_(2)-concentrations(0.05-0.1 mol L^(-1))and pH values(4-13).In addition,the catalyst demonstrated strong resistance to anions and a long cycle life in simulated wastewater environments.This study offers a powerful approach for the remediation of NO_(2)-wastewater and recovery of valuable inorganic compounds.
文摘The authors regret that in 1.2.Instruments section of the article,when describing the principle of TiH300,the original content of“Briefly,ambient HONO was first absorbed by deionized water in a two-channel stripping coil.The absorbed liquid nitrite was mixed with sulfanilamide,N-(1-naphthyl)-ethylenediamine dihydrochloride,and hydrogen chloride solution to form the azo dye derivative.”
基金the Natural Science Foundation of Guangxi(No.2020GXNSFDA297030)the National Natural Science Foundation of China(Nos.22464002,22468014,21978222)the China Postdoctoral Science Foundation(No.2023M741129)。
文摘Formaldehyde(FA)and excessive nitrite(NO_(2)^(-))are highly carcinogenic compounds that pose serious risks to human health.In this study,we designed a sensing platform 8-hydrazine-boron dipyrromethene(OPTY)for the detection of FA and nitrite in food.Upon aldimine condensation with FA,OPTY produced strong blue fluorescence.By contrast,NO_(2)^(-)underwent an intramolecular cyclization cascade reaction with OPTY to boast bright green fluorescence.OPTY has the advantages of high signal-to-noise ratio,good selectivity,and a low limit of detection(LOD=26.5 nmol/L for FA,LOD=20.8 nmol/L for NO_(2)^(-)).Furthermore,OPTY was fabricated into a portable sensing chip,which was combined with smartphone to form a portable sensing platform.This platform has been successfully applied for the determination of FA/NO_(2)^(-)in meat and seafood with high accuracy(93.49%-102.35%).Therefore,the intelligent sensing platform can realize on-site visual detection of FA/NO_(2)^(-)content in food,demonstrating great potential for ensuring food safety.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC2105800National Natural Science Foundation of China,Grant/Award Numbers:21901084,21905106,22279041+2 种基金Higher Education Discipline Innovation Project,Grant/Award Number:B17020Specific Research Fund of the Innovation Platform for Academicians of Hainan Province,China,Grant/Award Number:YSPTZX202321Natural Science Foundation of Jilin Province,Grant/Award Number:SKL202302017.
文摘Electrocatalytic reduction of nitrate pollutants to produce ammonia offers an effective approach to realizing the artificial nitrogen cycle and replacing the energyintensive Haber-Bosch process.Nitrite is an important intermediate product in the reduction of nitrate to ammonia.Therefore,the mechanism of converting nitrite into ammonia warrants further investigation.Molecular cobalt catalysts are regarded as promising for nitrite reduction reactions(NO_(2)^(−)RR).However,designing and controlling the coordination environment of molecular catalysts is crucial for studying the mechanism of NO_(2)^(−)RR and catalyst design.Herein,we develop a molecular platform of cobalt porphyrin with three coordination microenvironments(Co-N_(3)X_(1),X=N,O,S).Electrochemical experiments demonstrate that cobalt porphyrin with O coordination(CoOTPP)exhibits the lowest onset potential and the highest activity for NO_(2)^(−)RR in ammonia production.Under neutral,nonbuffered conditions over a wide potential range(−1.0 to−1.5 V versus AgCl/Ag),the Faradaic efficiency of nearly 90%for ammonia was achieved and reached 94.5%at−1.4 V versus AgCl/Ag,with an ammonia yield of 6,498μgh^(−1)and a turnover number of 22,869 at−1.5V versus AgCl/Ag.In situ characterization and density functional theory calculations reveal that modulating the coordination environment alters the electron transfer mode of the cobalt active center and the charge redistribution caused by the break of the ligand field.Therefore,this results in enhanced electrochemical activity for NO_(2)^(−)RR in ammonia production.This study provides valuable guidance for designing adjustments to the coordination environment of molecular catalysts to enhance catalytic activity.
基金supported by the National Natural Science Foundation of China(22273056)the National Training Program of Innovation and Entrepreneurship for Undergraduates(202410718010)+2 种基金the Natural Science Basic Research Project of Shaanxi Province(2024JC-YBQN-0092)the Scientific research project of Shaanxi Institute of Basic Sciences(23JHQ003)the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(23JK0694)。
文摘Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen carrier.Consequently,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are desired eminently.The nitrite(NO_(2)^(-))reduction reaction(NO_(2-)RR)to NH_(3)offers a feasibly low-energy consumption and continuable approach to replace industrial NH_(3)synthesis.Herein,polyethyleneimine(PEI)modified Au core Rh shell nanodendrites(Au@Rh-NDs)nanohybrid(Au@Rh-NDs/PEI)with branched structure is synthesized,which achieves the high NH_(3)yield(1.68 mg h^(-1)mg_(cat)^(-1))and Faradaic efficiency(FE)of 95.86%for NO_(2)^(-)-RR at-0.39 V potential in neutral electrolyte.Particularly,the introduction of PEI significantly enhances the electroactivity of Au@Rh-NDs at low concentration of 1 mM NaNO_(2),which originates from the enrichment function of PEI for NO_(2)^(-)-ion.In addition,the Au basement permits the sustainable solar power to expedite the NO_(2)^(-)-RR at Au@Rh-NDs/PEI owing to the localized surface plasmon resonance(LSPR)of the Au core substrate.This work may provide an admissible tactic to build excellent catalysts on account of organic molecule-mediated interfacial engineering in a variety of fields of catalysis and electrocatalysis.
基金Kasetsart University Research and Development Institute(KURDI,Grant No.FF(KU)51.67)ASEAN University Network/Southeast Asia Engineering Education Development Network(AUN/SEED-Net)for financial support+2 种基金financially supported by the Office of the Ministry of Higher Education,Science,Research and Innovationthe Thailand Science Research and Innovation through the Kasetsart University Reinventing University Program 2021support from the Department of Material Engineering,Faculty of Engineering,Kasetsart University is also acknowledged.
文摘To prevent bacterial growth and ensure food safety,common practice involves the use of nitrite and phosphate salts.Neverthe-less,elevated nitrite levels in the body can contribute to the development of stomach and esophageal cancers,while excessive phosphate levels may increase the risk of kidney dysfunction and the onset of osteoporosis.Electrochemical sensing has emerged as a reliable tech-nique for detecting nitrites and phosphates.This study specifically focuses on the use of TiO_(2)-based sensing materials for such detection.The synthesis of nanoparticulate TiO_(2) and Ag-doped TiO_(2) was successfully achieved through a solution combustion technique.The com-position of the materials was examined using X-ray diffraction(XRD)and X-ray absorption near-edge structure(XANES)methods,re-vealing a predominant anatase composition.Doping resulted in particle refinement,contributing to an increased specific surface area and enhanced electron transfer efficiency,as indicated in the examination by electrochemical impedance spectroscopy(EIS).Cyclic voltam-metry(CV)assessed the electrochemical behavior,demonstrating that in nitrite detection,a significant oxidation reaction occurred at an applied voltage of approximately 1.372 V,while in phosphate detection,the main reduction peak occurred at a voltage close to-0.48 V.High sensitivity(2μA·μM^(-1)·mm^(-2) for sodium nitrite and 2.1μA·μM^(-1)·mm^(-2) for potassium phosphate)and low limits of detection(0.0052 mM for sodium nitrite and 0.0045 mM for potassium phosphate)were observed.Experimental results support the potential use of Ag-doped TiO_(2) as a sensing device for nitrites and phosphates.
基金financially supported by the National Natural Science Foundation of China(22205205)the Science Foundation of Zhejiang Sci-Tech University(ZSTU)under Grant No.21062337-Y。
文摘The electrochemical biomass valorization of industrial by-products or pollutants using renewable electricity offers significant promise for carbon neutrality.However,the huge challenges still exist in the development of efficient bifunctional electrocatalysts.Herein,we put forward a high-efficiency coelectrolysis system by coupling the nitrite reduction reaction(NO_(2)RR)and the glycerol oxidation reaction(GOR)over a novel heterogeneous β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl catalyst.Theβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl shows excellent bifunctional performance with high Faradaic efficiencies of formate(90.1%)and NH_(3)(91.9%)at cell voltage of 1.5 V,high yield rate of formate(89.6 mg h^(-1)cm^(-2))and NH_(3)(36.07 mg h^(-1)cm^(-2))at cell voltage of 1.9 V,and superior stability in an anion exchange membrane co-electrolyzer.The in-situ Raman result confirms the unique Co/Cu-based bimetallic synergistic sites of β-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl towards superior GOR performance,while the operando Fourier transform infrared spectroscopy demonstrates the improved protonation kinetics of key intermediates and optimized water dissociation ability ofβ-Co(OH)_(2)/Cu_(2)(OH)_(3)Cl for high NO_(2)RR activity.Our work illuminates alternative avenues to exploit the innovative and energy-saving technology for the co-production of high-added chemicals.
基金Supported by a fellowship of the 'FundacióPrivada Institut D' investigacio Biomédica de Bellvitge (IDIBELL) partially funded by the ISCⅢnetwork (RCESP C03/09) Spain and ECNIS Network from the 6FP of the EC
文摘AIM： To study the association between nitrite and nitrosamine intake and gastric cancer （GC）, between meat and processed meat intake, GC and oesophageal cancer （OC）, and between preserved fish, vegetable and smoked food intake and GC. METHODS： In this article we reviewed all the published cohort and case-control studies from 1985-2005, and analyzed the relationship between nitrosamine and nitrite intake and the most important related food intake （meat and processed meat, preserved vegetables and fish, smoked foods and beer drinking） and GC or OC risk. Sixty-one studies, 11 cohorts and 50 case-control studies were included. RESULTS： Evidence from case-control studies supported an association between nitrite and nitrosamine intake with GC but evidence was insufficient in relation to OC. A high proportion of case-control studies found a positive association with meat intake for both tumours （11 of 16 studies on GC and 11 of 18 studies on OC）. A relatively large number of case-control studies showed quite consistent results supporting a positive association between processed meat intake and GC and OC risk （10 of 14 studies on GC and 8 of 9 studies on OC）. Almost all the case-control studies found a positive and significant association between preserved fish, vegetable and smoked food intake and GC. The evidence regarding OC was more limited. Overall the evidence from cohort studies was insufficient or more inconsistent than that from case-control studies.CONCLUSION： The available evidence supports a positive association between nitrite and nitrosamine intake and GC, between meat and processed meat intake and GC and OC, and between preserved fish, vegetable and smoked food intake and GC, but is not conclusive.
基金Supported by National Natural Science Foundation of China(31402343)Project of Wuhan Academy of Agricultural Science(Cxfzx201503)~~
文摘To understand the correlations between the abundance of Trichodina spp. and the water quality parameters, the abundance of Trichodina spp. on the gill of yellow catfish in aquaculture water was investigated. Meanwhile, the temperature and total phosphorus, available phosphorus, total nitrogen, nitrite and ammonia nitro- gen contents of the aquaculture water were measured and determined. The results showed that the abundance of Trichodina spp. on the gill of yellow catfish was negatively correlated with the total phosphorus, available phosphorus and total nitro- gen contents in the aquaculture water, and was positively correlated with the nitrite content in the aquaculture water （P〈0.05）; there were no significant correlations between the abundance of Trichodina spp. and the temperature and ammonia nitrogen content of the aquaculture water （P〉0.05）.
文摘AIM:Adrenomedullin (ADM) is a potent vasodilator peptide. ADM and nitric oxide (NO) are produced in vascular endothelial cells.Increased ADM level has been linked to hyperdynamic circulation and arterial vasodilatation in cirrhotic portal hypertension (CPH).The role of ADM in non-cirrhotic portal hypertension (NCPH) is unknown,plasma ADM levels were studied in patients with NCPH,compensated and decompensated cirrhosis in order to determine its contribution to portal hypertension (PH) in these groups. METHODS:There were 4 groups of subjects.Group 1 consisted of 27 patients (F/M:12/15) with NCPH due to portal and/or splenic vein thrombosis (mean age:41±12 years),group 2 consisted of 14 patients (F/M:6/8) with compensated (Child-Pugh A) cirrhosis (mean age:46±4), group 3 consisted of 16 patients (F/M:6/10) with decompensated (Child-Pugh C) cirrhosis (mean age:47±12). Fourteen healthy subjects (F/M:6/8) (mean age:44±8) were used as controls in Group 4.ADM level was measured by ELISA.NO was determined as nitrite/nitrate level by chemoluminescence. RESULTS:ADM level in Group 1 (236±61.4 pg/mL) was significantly higher than that in group 2 (108.4±28.3 pg/mL) and group 4 (84.1±31.5 pg/mL) (both P<0.0001) but was lower than that in Group3 (324±93.7 pg/mL) (P=0.002).NO level in group 1 (27±1.4 μmol/L) was significantly higher than that in group 2 (19.8±2.8 μmol/L) and group 4 (16.9±1.6 μmol/L) but was lower than that in Group 3 (39±3.6 μmol/L) (for all three P<0.0001).A strong correlation was observed between ADM and NO levels (r=0.827,P<0.0001). CONCLUSION:Adrenomedullin and NO levels were high in both non-cirrhotic and cirrhotic portal hypertension and were closely correlated,Adrenomedullin and NO levels increased proportionally with the severity of cirrhosis,and were significantly higher than those in patients with NCPH. Portal hypertension plays an important role in the increase of ADM and NO.Parenchymal damage in cirrhosis may contribute to the increase in these parameters.
文摘It was demonstrated that xanthine oxidoreductase (XOR), during ischemia, catalyzes the formation of nitric oxide (NO) from nitrite (NO_2^-) and this NO_2^--derived NO protects the isolated perfused rat heart against the damaging effects of ischemia-reperfusion (I/R) when conventional nitric oxide synthase (NOS) -dependent NO production is impaired. Liver is one of the organs with the highest XOR concentration. This study was designed to determine whether NO_2^--derived NO by XOR protects liver against I/R injury in vivo. For its minute amounts and active reactivity, NO can not be detected directly in real time in vivo by this time. We have to prove the above hypothesis indirectly. METHODS:Wistar rats were pretreated with saline, NOS inhibitor L-NAME (10 mg/kg intravenously), XOR inhibitor allopurinol (1.5 mg/kg orally), L-NAME +allopurinol and NO scavenger carboxy-PTIO (0.6 mg/kg intravenously) respectively (12 animals per group). And then, they were subjected to total liver ischemia for 40 minutes followed by reperfusion. Blood samples and liver tissues were obtained for analysis after 3 hours of reperfusion. Survival was also investigated. RESULTS:Allopurinol-treated animals exhibited further increased serum alanine aminotransferase (ALT) levels and liver myeloperoxidase (MPO) activities, but further decreased liver adenosine triphosphate (ATP) stores after I/R compared to saline-treated counterparts (830.5±108.3 U/L, 56.5±11.0 U/mg protein and 1.93±0.47 μmol/g vs. 505.8± 184.2 U/L, 41.5±10.2 U/mg protein and 3.05±0.55 μmol/g respectively, P<0.01, P<0.05 and P<0.01 respectively). The hepatocyte injury was further exacerbated and the overall survival rate was significantly decreased after I/R in animals given by allopurinol compared to those pretreated by saline (P<0.05). L-NAME and allopurinol co-treated animals exhibited more severe liver injury (P<0.05 and P<0.01) and a further decreased overall survival rate (P<0.05) compared to L-NAME or allopurinol alone-treated counterparts, but they were not different from carboxy-PTIO treated animals (P>0.05). CONCLUSION:NO_2^--derived NO by XOR in the hypoxic and acidic environment induced by hepatic I/R protects the liver against I/R injury in vivo.
