Taming NO oxidation efficiency by γ-MnO2 morphology regulation

2020 ◽  
Vol 10 (17) ◽  
pp. 5996-6005
Author(s):  
Lei Chen ◽  
Jinping Zhang ◽  
Yuxin Li ◽  
Xiaomei Wu ◽  
Zaoxiao Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Fossil Fuels ◽  
No Oxidation ◽  
Global Concern ◽  
Oxidation Efficiency ◽  
Oxidation Of No

Nitric oxide (NO) emitted from the combustion of fossil fuels has drawn global concern, and the oxidation of NO contributes greatly to the DeNOx process.

scholarly journals Simultaneous Assessment of Endothelial Function, Nitric Oxide Synthase Activity, Nitric Oxide–Mediated Signaling, and Oxidative Stress in Individuals with and without Hypercholesterolemia

2008 ◽  
Vol 54 (2) ◽  
pp. 292-300 ◽  
Author(s):  
Renke Maas ◽  
Edzard Schwedhelm ◽  
Lydia Kahl ◽  
Huige Li ◽  
Ralf Benndorf ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Function ◽  
Urinary Excretion ◽  
Indirect Evidence ◽  
No Oxidation ◽  
Whole Body ◽  
Gas Chromatography Mass Spectrometry ◽  
Synthesis Rate ◽  
No Production

Abstract Background: Endothelial function is impaired in hypercholesterolemia and atherosclerosis. Based on mostly indirect evidence, this impairment is attributed to reduced synthesis or impaired biological activity of endothelium-derived nitric oxide (NO). It was the aim of this study to directly estimate and compare whole-body NO production in normo- and hypercholesterolemia by applying a nonradioactive stable isotope dilution technique in vivo. Methods: We enrolled 12 normocholesterolemic and 24 hypercholesterolemic volunteers who were all clinically healthy. To assess whole-body NO synthesis, we intravenously administered l-[guanidino-(15N2)]-arginine and determined the urinary excretion of 15N-labeled nitrate, the specific end product of NO oxidation in humans, by use of gas chromatography-mass spectrometry. In addition, we measured flow-mediated vasodilation (FMD) of the brachial artery, expression of endothelial NOS (eNOS) in platelets, plasma concentration of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), and urinary excretion of 8-isoprostaglandin F2α (8-iso-PGF2α). Results: After infusion of l-[guanidino-(15N2)]-arginine, cumulative excretion of 15N-labeled-nitrate during 48 h was 40% [95% CI 15%–66%] lower in hypercholesterolemic than normocholesterolemic volunteers [mean 9.2 (SE 0.8) μmol vs 15.4 (2.3) μmol/l, P = 0.003]. FMD was on average 36% [4%–67%] lower in hypercholesterolemic than normocholesterolemic volunteers [6.3 (4.0)% vs 9.4 (4.6)%, P = 0.027]. Normalized expression of NOS protein in platelets was also significantly lower in hypercholesterolemic volunteers, whereas there were no significant differences in plasma ADMA concentration or urinary excretion of 8-iso-PGF2α between the 2 groups. Conclusions: This study provides direct evidence for a decreased whole body NO synthesis rate in healthy people with hypercholesterolemia.

scholarly journals THE USE OF HYBRID VEHICLES AS A PROPOSAL FOR REDUCING CO2 EMISSIONS AND ITS CONTRIBUTION TO REDUCING GREENHOUSE GAS EMISSIONS

2009 ◽  
Vol 8 (1) ◽  
pp. 07
Author(s):  
C. A. R. De Carvalho ◽  
W. Q. Lamas
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Fossil Fuels ◽  
Climate Changes ◽  
New Technologies ◽  
New Technology ◽  
Hybrid Vehicles ◽  
Pollutant Emissions ◽  
Gas Emissions ◽  
Global Concern

The problems related to energy consumption and pollutant emissions for thetransport sector represent a major global concern regarding climate changes caused by greenhouse gases, directly related to the increased level of gas emissions from fossil fuels , the main one being carbon dioxide. One way tominimize this problem is through the introduction of new technologies. Hybrid cars are one of the new technology options that has the main advantage of reducing fuel consumption and therefore reducing the amount of CO2 in the atmosphere. This paper gives an introduction to hybrid vehicles, with the aim of presenting their main advantages and evaluate their impact on emissions of CO2 in the Brazilian fleet, compared to conventional vehicles.

From semiconductors to semimetals: bismuth as a photocatalyst for NO oxidation in air

2014 ◽  
Vol 2 (29) ◽  
pp. 11065-11072 ◽  
Author(s):  
Qian Zhang ◽  
Ying Zhou ◽  
Fang Wang ◽  
Fan Dong ◽  
Wei Li ◽  
...  
Keyword(s):  
Indoor Air ◽  
Photocatalytic Oxidation ◽  
No Oxidation ◽  
Oxidation In Air ◽  
Oxidation Of No

Black semimetallic Bi films were found to be active in the photocatalytic oxidation of NO at the indoor air level.

Single-atom iron catalyst with single-vacancy graphene-based substrate as a novel catalyst for NO oxidation: a theoretical study

2018 ◽  
Vol 8 (16) ◽  
pp. 4159-4168 ◽  
Author(s):  
Weijie Yang ◽  
Zhengyang Gao ◽  
Xiaoshuo Liu ◽  
Xiang Li ◽  
Xunlei Ding ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Power Plants ◽  
Theoretical Study ◽  
Iron Catalyst ◽  
No Oxidation ◽  
Single Atom ◽  
Single Vacancy ◽  
Novel Catalyst

Nitric oxide (NO) emitted from coal-fired power plants has raised global concerns.

REDUCING THE ADVERSE EFFECTS OF THE OPERATION OF GAS FIRED MELTING FURNACES ON THE ENVIRONMENT

2021 ◽  
Author(s):  
Luboslav Straka ◽  
Tibor Krenicky
Keyword(s):  
Fossil Fuels ◽  
Negative Impact ◽  
Combustion Process ◽  
Melting Furnace ◽  
Operating Mode ◽  
Global Scale ◽  
Pollutant Emissions ◽  
Experimental Measurements ◽  
Global Concern ◽  
Overall Efficiency

Due to the growing production on a global scale, the use of fossil fuels is also increasing. Therefore, the control of pollutant emissions produced in the industrial sphere has become a global concern. In general, an imperfect combustion process has a negative impact on the overall efficiency and economy of plant operation, but at the same time increases the share of total emissions in the environment. We also encounter this problem when operating gas fired melting furnaces. Therefore, the paper aimed to describe the results of experimental measurements of the number of emissions produced during the operation of a gas fired melting furnace, which in practice is mainly used for melting alloys. Experimental measurements were oriented to find the most suitable variant of the operating mode of the gas fired melting furnace with regard to minimizing the total amount of emissions produced.

Hypoxia inhibits nitric oxide synthesis in isolated rabbit lung

1997 ◽  
Vol 272 (6) ◽  
pp. L1167-L1173 ◽  
Author(s):  
S. P. Kantrow ◽  
Y. C. Huang ◽  
A. R. Whorton ◽  
E. N. Grayck ◽  
J. M. Knight ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Competitive Inhibitor ◽  
Oxidation Products ◽  
No Oxidation ◽  
Severe Hypoxia ◽  
No Production ◽  
Rabbit Lung ◽  
Vasoconstrictor Response ◽  
Hypoxic Vasoconstriction ◽  
Oxide Synthase

Nitric oxide (NO.) has been proposed to modulate hypoxic vasoconstriction in the lung. The activity of nitric oxide synthase (NOS) can be inhibited by hypoxia because molecular oxygen is a necessary substrate for the enzyme. On the basis of this mechanism, we hypothesized that NOS activity has a key role in regulation of pulmonary vascular tone during hypoxia. We measured oxidation products of NO. released into the vasculature of isolated buffer-perfused rabbit lung ventilated with normoxic (21% O2), moderately hypoxic (5% O2), or anoxic (0% O2) gas using two methods. Mean PO2 in perfusate exiting the lung was 25 Torr during anoxic ventilation and 47 Torr during moderately hypoxic ventilation. We found that the amount of the NO. oxidation product nitrite released into the perfusate was suppressed significantly during ventilation with anoxic but not moderately hypoxic gas. During normoxic ventilation, nitrite release was inhibited by pretreatment with NG-monomethyl-L-arginine, a competitive inhibitor of NOS. To confirm that changes in nitrite concentration reflected changes in NO. release into the perfusate, major oxidation products of NO. (NOx) were assayed using a method for reduction of these products to NO. by vanadium(III) Cl. Release of NOx into the perfusate was suppressed by severe hypoxia (anoxic ventilation), and this effect was reversed by normoxia. Pulmonary vasoconstriction was observed during severe but not moderate hypoxia and was related inversely to the rate of nitrite release. These observations provide evidence that decreased NO. production contributes to the pulmonary vasoconstrictor response during severe hypoxia.

scholarly journals Basal and stimulated nitric oxide in control of kidney function in the aging rat

1997 ◽  
Vol 272 (6) ◽  
pp. R1747-R1753 ◽  
Author(s):  
C. Hill ◽  
A. M. Lateef ◽  
K. Engels ◽  
L. Samsell ◽  
C. Baylis
Keyword(s):  
Nitric Oxide ◽  
Vascular Resistance ◽  
Pressor Response ◽  
Renal Vascular Resistance ◽  
Oxidation Products ◽  
No Oxidation ◽  
No Production ◽  
Sprague Dawley ◽  
Vasoconstrictor Response ◽  
Renal Vascular

To investigate the activity of nitric oxide (NO) in control of renal hemodynamics during aging, studies were conducted on conscious Sprague-Dawley rats aged 3-5 mo (young, Y) and 18-22 mo (old, O). Blood pressure (BP) and renal vascular resistance (RVR) were higher in O vs. Y in control, and acute systemic NO synthesis inhibition (NOSI) increased BP and RVR, with an enhanced renal vasoconstrictor response in O. Infusion of the NO substrate L-arginine produced similar, selective renal vasodilation in both groups. The endothelium-dependent vasodilator acetylcholine caused similar falls in BP and RVR, whereas sodium nitroprusside produced an exaggerated depressor response in O vs. Y without falls in RVR in either age group. Urinary excretion of the stable NO oxidation products (NOx) decreased with age, suggesting a decline in the overall somatic NO production. In conclusion, basal tonically produced NO has a more pronounced role in maintenance of renal perfusion in aging, whereas L-arginine- and agonist-stimulated renal vasodilation is not impaired with age. NO production from some source may be reduced with aging, as indicated by falls in 24-h NOX excretion, although the similarity in pressor response and enhanced renal vasoconstrictor response to NOSI suggests that the role of NO in control of total peripheral and renal vascular resistance is maintained.

The inhibition effect and deactivation mechanism of H2O and SO2 on selective catalytic oxidation of NO over the Mn–Ca–Ox–(CO3)y catalyst

2019 ◽  
Vol 43 (48) ◽  
pp. 19279-19285 ◽  
Author(s):  
Chi Wang ◽  
Ruiyuan Zhang ◽  
Yishan Zhang ◽  
Ping Ning ◽  
Xin Song ◽  
...  
Keyword(s):  
Particle Size ◽  
Catalytic Oxidation ◽  
No Oxidation ◽  
Inhibition Effect ◽  
Selective Catalytic Oxidation ◽  
Oxidation Of No ◽  
Deactivation Mechanism

H2O and SO2 had an inhibition effect on NO oxidation. SO2 increased the particle size of the catalyst. H2O decreased the particle size of the catalyst.

scholarly journals Catalytic oxidation of NO over MnOx–CoOx/TiO2 in the presence of a low ratio of O3/NO: activity and mechanism

RSC Advances ◽  
2020 ◽  
Vol 10 (41) ◽  
pp. 24493-24506
Author(s):  
Meng Si ◽  
Boxiong Shen ◽  
Lijun Liu ◽  
Haohao Zhang ◽  
Wenjun Zhou ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalytic Oxidation ◽  
No Oxidation ◽  
Oxidation Of No

O3 promotes the formation of monodentate nitrates at low temperature, thus improving the efficiency of NO oxidation.

Acute effect of insulin on nitric oxide synthesis in humans: a precursor-product isotopic study

2007 ◽  
Vol 293 (3) ◽  
pp. E776-E782 ◽  
Author(s):  
Paolo Tessari ◽  
Anna Coracina ◽  
Lucia Puricelli ◽  
Monica Vettore ◽  
Alessandra Cosma ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Acute Effect ◽  
Oxidation Products ◽  
No Oxidation ◽  
Metabolic Effects ◽  
Whole Body ◽  
Fasting State ◽  
Isotopic Study ◽  
Euglycemic Hyperinsulinemic Clamp

Nitric oxide (NO) is a key regulatory molecule with wide vascular, cellular, and metabolic effects. Insulin affects NO synthesis in vitro. No data exist on the acute effect of insulin on NO kinetics in vivo. By employing a precursor-product tracer method in humans, we have directly estimated the acute effect of insulin on intravascular NOx (i.e., the NO oxidation products) fractional (FSR) and absolute (ASR) synthesis rates in vivo. Nine healthy male volunteers were infused iv with l-[15N2-guanidino]arginine ([15N2]arginine) for 6 h. Timed measurements of 15NOx and [15N2]arginine enrichments in whole blood were performed in the first 3 h in the fasting state and then following a 3-h euglycemic-hyperinsulinemic clamp (with plasma insulin raised to ≈1,000 pmol/l). In the last 60 min of each experimental period, at ≈steady-state arginine enrichment, a linear increase of 15NOx enrichment (mean r = 0.9) was detected in both experimental periods. In the fasting state, NOx FSR was 27.4 ± 4.3%/day, whereas ASR was 0.97 ± 0.36 mmol/day, accounting for 0.69 ± 0.27% of arginine flux. Following hyperinsulinemia, both FSR and ASR of NOx increased (FSR by ≈50%, to 42.4 ± 6.7%/day, P < 0.005; ASR by ≈25%, to 1.22 ± 0.41 mmol/day, P = 0.002), despite a ≈20–30% decrease of arginine flux and concentration. The fraction of arginine flux used for NOx synthesis was doubled, to 1.13 ± 0.35% ( P < 0.003). In conclusion, whole body NOx synthesis can be directly measured over a short observation time with stable isotope methods in humans. Insulin acutely stimulates NOx synthesis from arginine.

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