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Sample records for nitric oxide-sensitive p21ras-erk

  1. The nitric oxide-sensitive p21Ras-ERK pathway mediates S-nitrosoglutathione-induced apoptosis

    International Nuclear Information System (INIS)

    Tsujita, Maristela; Batista, Wagner L.; Ogata, Fernando T.; Stern, Arnold; Monteiro, Hugo P.; Arai, Roberto J.

    2008-01-01

    p21Ras protein plays a critical role in cellular signaling that induces either cell cycle progression or apoptosis. Nitric oxide (NO) has been consistently reported to activate p21Ras through the redox sensitive cysteine residue (118). In this study, we demonstrated that the p21Ras-ERK pathway regulates THP-1 monocyte/macrophage apoptosis induced by S-nitrosoglutathione (SNOG). This was apparent from studies in THP-1 cells expressing NO-insensitive p21Ras (p21Ras C118S ) where the pro-apoptotic action of SNOG was almost abrogated. Three major MAP kinase pathways (ERK, JNK, and p38) that are downstream to p21Ras were investigated. It was observed that only the activation of ERK1/2 MAP kinases by SNOG in THP-1 cells was attributable to p21Ras. The inhibition of the ERK pathway by PD98059 markedly attenuated apoptosis in SNOG-treated THP-1 cells, but had a marginal effect on SNOG-treated THP-1 cells expressing NO-insensitive p21Ras. The inhibition of the JNK and p38 pathways by selective inhibitors had no marked effects on the percentage of apoptosis. The induction of p21Waf1 expression by SNOG was observed in THP-1 cells harboring mutant and wild-type p21Ras, however in cells expressing mutant Ras, the expression of p21Waf1 was significantly attenuated. The treatment of THP-1 cells expressing wild-type p21Ras with PD98059 resulted in significant attenuation of p21Waf1 expression. These results indicate that the redox sensitive p21Ras-ERK pathway plays a critical role in sensing and delivering the pro-apoptotic signaling mediated by SNOG

  2. Nitric Oxide-Sensitive Pulmonary Hypertension in Congenital Rubella Syndrome

    Directory of Open Access Journals (Sweden)

    Francesco Raimondi

    2015-01-01

    Full Text Available Persistent pulmonary hypertension is a very rare presentation of congenital virus infection. We discuss the case of complete congenital rubella syndrome presenting at echocardiography with pulmonary hypertension that worsened after ductus ligation. Cardiac catheterization showed a normal pulmonary valve and vascular tree but a PAP=40 mmHg. The infant promptly responded to inhaled nitric oxide while on mechanical ventilation and was later shifted to oral sildenafil. It is not clear whether our observation may be due to direct viral damage to the endothelium or to the rubella virus increasing the vascular tone via a metabolic derangement.

  3. Nitric oxide-sensitive guanylyl cyclase is differentially regulated by nuclear and non-nuclear estrogen pathways in anterior pituitary gland.

    Directory of Open Access Journals (Sweden)

    Jimena P Cabilla

    Full Text Available 17β-estradiol (E2 regulates hormonal release as well as proliferation and cell death in the pituitary. The main nitric oxide receptor, nitric oxide sensitive- or soluble guanylyl cyclase (sGC, is a heterodimer composed of two subunits, α and β, that catalyses cGMP formation. α1β1 is the most abundant and widely expressed heterodimer, showing the greater activity. Previously we have shown that E2 decreased sGC activity but exerts opposite effects on sGC subunits increasing α1 and decreasing β1 mRNA and protein levels. In the present work we investigate the mechanisms by which E2 differentially regulates sGC subunits' expression on rat anterior pituitary gland. Experiments were performed on primary cultures of anterior pituitary cells from adult female Wistar rats at random stages of estrous cycle. After 6 h of E2 treatment, α1 mRNA and protein expression is increased while β1 levels are down-regulated. E2 effects on sGC expression are partially dependent on de novo transcription while de novo translation is fully required. E2 treatment decreased HuR mRNA stabilization factor and increased AUF1 p37 mRNA destabilization factor. E2-elicited β1 mRNA decrease correlates with a mRNA destabilization environment in the anterior pituitary gland. On the other hand, after 6 h of treatment, E2-BSA (1 nM and E2-dendrimer conjugate (EDC, 1 nM were unable to modify α1 or β1 mRNA levels, showing that nuclear receptor is involved in E2 actions. However, at earlier times (3 h, 1 nM EDC causes a transient decrease of α1 in a PI3k-dependent fashion. Our results show for the first time that E2 is able to exert opposite actions in the anterior pituitary gland, depending on the activation of classical or non-classical pathways. Thus, E2 can also modify sGC expression through membrane-initiated signals bringing to light a new point of regulation in NO/sGC pathway.

  4. Nitric oxide-sensitive guanylyl cyclase is differentially regulated by nuclear and non-nuclear estrogen pathways in anterior pituitary gland.

    Science.gov (United States)

    Cabilla, Jimena P; Nudler, Silvana I; Ronchetti, Sonia A; Quinteros, Fernanda A; Lasaga, Mercedes; Duvilanski, Beatriz H

    2011-01-01

    17β-estradiol (E2) regulates hormonal release as well as proliferation and cell death in the pituitary. The main nitric oxide receptor, nitric oxide sensitive- or soluble guanylyl cyclase (sGC), is a heterodimer composed of two subunits, α and β, that catalyses cGMP formation. α1β1 is the most abundant and widely expressed heterodimer, showing the greater activity. Previously we have shown that E2 decreased sGC activity but exerts opposite effects on sGC subunits increasing α1 and decreasing β1 mRNA and protein levels. In the present work we investigate the mechanisms by which E2 differentially regulates sGC subunits' expression on rat anterior pituitary gland. Experiments were performed on primary cultures of anterior pituitary cells from adult female Wistar rats at random stages of estrous cycle. After 6 h of E2 treatment, α1 mRNA and protein expression is increased while β1 levels are down-regulated. E2 effects on sGC expression are partially dependent on de novo transcription while de novo translation is fully required. E2 treatment decreased HuR mRNA stabilization factor and increased AUF1 p37 mRNA destabilization factor. E2-elicited β1 mRNA decrease correlates with a mRNA destabilization environment in the anterior pituitary gland. On the other hand, after 6 h of treatment, E2-BSA (1 nM) and E2-dendrimer conjugate (EDC, 1 nM) were unable to modify α1 or β1 mRNA levels, showing that nuclear receptor is involved in E2 actions. However, at earlier times (3 h), 1 nM EDC causes a transient decrease of α1 in a PI3k-dependent fashion. Our results show for the first time that E2 is able to exert opposite actions in the anterior pituitary gland, depending on the activation of classical or non-classical pathways. Thus, E2 can also modify sGC expression through membrane-initiated signals bringing to light a new point of regulation in NO/sGC pathway. © 2011 Cabilla et al.

  5. Heterodimerization with the β1 subunit directs the α2 subunit of nitric oxide-sensitive guanylyl cyclase to calcium-insensitive cell-cell contacts in HEK293 cells: Interaction with Lin7a.

    Science.gov (United States)

    Hochheiser, Julia; Haase, Tobias; Busker, Mareike; Sömmer, Anne; Kreienkamp, Hans-Jürgen; Behrends, Sönke

    2016-12-15

    Nitric oxide-sensitive guanylyl cyclase is a heterodimeric enzyme consisting of an α and a β subunit. Two different α subunits (α 1 and α 2 ) give rise to two heterodimeric enzymes α 1 /β 1 and α 2 /β 1 . Both coexist in a wide range of tissues including blood vessels and the lung, but expression of the α 2 /β 1 form is generally much lower and approaches levels similar to the α 1 /β 1 form in the brain only. In the present paper, we show that the α 2 /β 1 form interacts with Lin7a in mouse brain synaptosomes based on co-precipitation analysis. In HEK293 cells, we found that the overexpressed α 2 /β 1 form, but not the α 1 /β 1 form is directed to calcium-insensitive cell-cell contacts. The isolated PDZ binding motif of an amino-terminally truncated α 2 subunit was sufficient for cell-cell contact localization. For the full length α 2 subunit with the PDZ binding motif this was only the case in the heterodimer configuration with the β 1 subunit, but not as isolated α 2 subunit. We conclude that the PDZ binding motif of the α 2 subunit is only accessible in the heterodimer conformation of the mature nitric oxide-sensitive enzyme. Interaction with Lin7a, a small scaffold protein important for synaptic function and cell polarity, can direct this complex to nectin based cell-cell contacts via MPP3 in HEK293 cells. We conclude that heterodimerization is a prerequisite for further protein-protein interactions that direct the α 2 /β 1 form to strategic sites of the cell membrane with adjacent neighbouring cells. Drugs increasing the nitric oxide-sensitivity of this specific form may be particularly effective. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. 17 beta-estradiol modifies nitric oxide-sensitive guanylyl cyclase expression and down-regulates its activity in rat anterior pituitary gland.

    Science.gov (United States)

    Cabilla, Jimena P; Díaz, María del Carmen; Machiavelli, Leticia I; Poliandri, Ariel H; Quinteros, Fernanda A; Lasaga, Mercedes; Duvilanski, Beatriz H

    2006-09-01

    Previous studies showed that 17 beta-estradiol (17 beta-E2) regulates the nitric oxide (NO)/soluble guanylyl cyclase (sGC)/cGMP pathway in many tissues. Evidence from our laboratory indicates that 17 beta-E2 disrupts the inhibitory effect of NO on prolactin release, decreasing sGC activity and affecting the cGMP pathway in anterior pituitary gland of adult ovariectomized and estrogenized rats. To ascertain the mechanisms by which 17 beta-E2 affects sGC activity, we investigated the in vivo and in vitro effects of 17 beta-E2 on sGC protein and mRNA expression in anterior pituitary gland from immature female rats. In the present work, we showed that 17 beta-E2 acute treatment exerted opposite effects on the two sGC subunits, increasing alpha1 and decreasing beta1 subunit protein and mRNA expression. This action on sGC protein expression was maximal 6-9 h after 17 beta-E2 administration. 17beta-E2 also caused the same effect on mRNA expression at earlier times. Concomitantly, 17 beta-E2 dramatically decreased sGC activity 6 and 9 h after injection. These effects were specific of 17 beta-E2, because they were not observed with the administration of other steroids such as progesterone and 17 alpha-estradiol. This inhibitory action of 17beta-E2 on sGC also required the activation of estrogen receptor (ER), because treatment with the pure ER antagonist ICI 182,780 completely blocked 17 beta-E2 action. 17 beta-E2 acute treatment caused the same effects on pituitary cells in culture. These results suggest that 17 beta-E2 exerts an acute inhibitory effect on sGC in anterior pituitary gland by down-regulating sGC beta 1 subunit and sGC activity in a specific, ER-dependent manner.

  7. Dry air effects on the copper oxides sensitive layers formation for ethanol vapor detection

    International Nuclear Information System (INIS)

    Labidi, A.; Bejaoui, A.; Ouali, H.; Akkari, F. Chaffar; Hajjaji, A.; Gaidi, M.; Kanzari, M.; Bessais, B.; Maaref, M.

    2011-01-01

    The copper oxide films have been deposited by thermal evaporation and annealed under ambient air and dry air respectively, at different temperatures. The structural characteristics of the films were investigated by X-ray diffraction. They showed the presences of two hydroxy-carbonate minerals of copper for annealing temperatures below 250 deg. C. Above this temperature the conductivity measurements during the annealing process, show a transition phase from metallic copper to copper oxides. The copper oxides sensitivity toward ethanol were performed using conductivity measurements at the working temperature of 200 deg. C. A decrease of conductivity was observed under ethanol vapor, showing the p-type semi-conducting characters of obtained copper oxide films. It was found that the sensing properties of copper oxide toward ethanol depend mainly on the annealing conditions. The best responses were obtained with copper layers annealed under dry air.

  8. Dry air effects on the copper oxides sensitive layers formation for ethanol vapor detection

    Energy Technology Data Exchange (ETDEWEB)

    Labidi, A., E-mail: Ahmed_laabidi@yahoo.fr [URPSC (UR 99/13-18) Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, Universite de Carthage, BP 51, La Marsa 2070, Tunis (Tunisia); Bejaoui, A.; Ouali, H. [URPSC (UR 99/13-18) Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, Universite de Carthage, BP 51, La Marsa 2070, Tunis (Tunisia); Akkari, F. Chaffar [Laboratoire de Photovoltaique et Materiaux Semi-conducteurs, ENIT, Universite de Tunis el Manar, BP 37, Le belvedere 1002, Tunis (Tunisia); Hajjaji, A.; Gaidi, M. [Laboratoire de Photovoltaique, Centre de Recherches et de technologies de l' energie, Technopole de Borj-Cedria, BP 95, 2050 Hammam-Lif (Tunisia); Kanzari, M. [Laboratoire de Photovoltaique et Materiaux Semi-conducteurs, ENIT, Universite de Tunis el Manar, BP 37, Le belvedere 1002, Tunis (Tunisia); Bessais, B. [Laboratoire de Photovoltaique, Centre de Recherches et de technologies de l' energie, Technopole de Borj-Cedria, BP 95, 2050 Hammam-Lif (Tunisia); Maaref, M. [URPSC (UR 99/13-18) Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, Universite de Carthage, BP 51, La Marsa 2070, Tunis (Tunisia)

    2011-09-15

    The copper oxide films have been deposited by thermal evaporation and annealed under ambient air and dry air respectively, at different temperatures. The structural characteristics of the films were investigated by X-ray diffraction. They showed the presences of two hydroxy-carbonate minerals of copper for annealing temperatures below 250 deg. C. Above this temperature the conductivity measurements during the annealing process, show a transition phase from metallic copper to copper oxides. The copper oxides sensitivity toward ethanol were performed using conductivity measurements at the working temperature of 200 deg. C. A decrease of conductivity was observed under ethanol vapor, showing the p-type semi-conducting characters of obtained copper oxide films. It was found that the sensing properties of copper oxide toward ethanol depend mainly on the annealing conditions. The best responses were obtained with copper layers annealed under dry air.

  9. Nitric oxide: a physiologic messenger.

    Science.gov (United States)

    Lowenstein, C J; Dinerman, J L; Snyder, S H

    1994-02-01

    To review the physiologic role of nitric oxide, an unusual messenger molecule that mediates blood vessel relaxation, neurotransmission, and pathogen suppression. A MEDLINE search of articles published from 1987 to 1993 that addressed nitric oxide and the enzyme that synthesizes it, nitric oxide synthase. Animal and human studies were selected from 3044 articles to analyze the clinical importance of nitric oxide. Descriptions of the structure and function of nitric oxide synthase were selected to show how nitric oxide acts as a biological messenger molecule. Biochemical and physiologic studies were analyzed if the same results were found by three or more independent observers. Two major classes of nitric oxide synthase enzymes produce nitric oxide. The constitutive isoforms found in endothelial cells and neurons release small amounts of nitric oxide for brief periods to signal adjacent cells, whereas the inducible isoform found in macrophages releases large amounts of nitric oxide continuously to eliminate bacteria and parasites. By diffusing into adjacent cells and binding to enzymes that contain iron, nitric oxide plays many important physiologic roles. It regulates blood pressure, transmits signals between neurons, and suppresses pathogens. Excess amounts, however, can damage host cells, causing neurotoxicity during strokes and causing the hypotension associated with sepsis. Nitric oxide is a simple molecule with many physiologic roles in the cardiovascular, neurologic, and immune systems. Although the general principles of nitric oxide synthesis are known, further research is necessary to determine what role it plays in causing disease.

  10. Zirconium for nitric acid solutions

    International Nuclear Information System (INIS)

    Yau, T.L.

    1984-01-01

    The excellent corrosion resistance of zirconium in nitric acid has been known for over 30 years. Recently, there is an increasing interest in using zirconium for nitric acid services. Therefore, an extensive research effort has been carried out to achieve a better understanding of the corrosion properties of zirconium in nitric acid. Particular attention is paid to the effect of concentration, temperature, structure, solution impurities, and stress. Immersion, autoclave, U-bend, and constant strain-rate tests were used in this study. Results of this study indicate that the corrosion resistance of zirconium in nitric acid is little affected by changes in temperature and concentration, and the presence of common impurities such as seawater, sodium chloride, ferric chloride, iron, and stainless steel. Moreover, the presence of seawater, sodium chloride, ferric chloride, and stainless steel has little effect on the stress corrosion craking (SCC) susceptibility of zirconium in 70% nitric acid at room temperatures. However, zirconium could be attacked by fluoride-containing nitric acid and the vapors of chloride-containing nitric acid. Also, high sustained tensile stresses should be avoided when zirconium is used to handle 70% nitric acid at elevated temperatures or > 70% nitric acid

  11. Nitric oxide nanoparticles

    Science.gov (United States)

    Schairer, David O.; Martinez, Luis R.; Blecher, Karin; Chouake, Jason S.; Nacharaju, Parimala; Gialanella, Philip; Friedman, Joel M.; Nosanchuk, Joshua D.; Friedman, Adam J.

    2012-01-01

    Nitric oxide (NO) is a critical component of host defense against invading pathogens; however, its therapeutic utility is limited due to a lack of practical delivery systems. Recently, a NO-releasing nanoparticulate platform (NO-np) was shown to have in vitro broad-spectrum antimicrobial activity and in vivo pre-clinical efficacy in a dermal abscess model. To extend these findings, both topical (TP) and intralesional (IL) NO-np administration was evaluated in a MRSA intramuscular murine abscess model and compared with vancomycin. All treatment arms accelerated abscess clearance clinically, histologically, and by microbiological assays on both days 4 and 7 following infection. However, abscesses treated with NO-np via either route demonstrated a more substantial, statistically significant decrease in bacterial survival based on colony forming unit assays and histologically revealed less inflammatory cell infiltration and preserved muscular architecture. These data suggest that the NO-np may be an effective addition to our armament for deep soft tissue infections. PMID:22286699

  12. Nitrogen isotope exchange between nitric oxide and nitric acid

    International Nuclear Information System (INIS)

    Axente, D.; Abrudean, M.; Baldea, A.

    1996-01-01

    The rate of nitrogen isotope exchange between NO and HNO 3 has been measured as a function of nitric acid concentration of 1.5-4M x 1 -1 . The exchange rate law is shown to be R=k[HNO 3 ] 2 [N 2 O 3 ] and the measured activation energy is E=67.78 kJ x M -1 (16.2 kcal x M -1 ). It is concluded that N 2 O 3 participates in 15 N/ 14 N exchange between NO and HNO 3 at nitric acid concentrations higher than 1.5M x 1 -1 . (author). 7 refs., 3 figs., 4 tabs

  13. Nitric Acid Poisoning: Case Report

    International Nuclear Information System (INIS)

    Quintero Giraldo, Maria Paulina; Quiceno Calderon, William de Jesus; Melo Arango Catalina

    2011-01-01

    Nitric acid (HNO 3 ) is a corrosive fluid that, when in contact with reducing agents, generates nitrogen oxides that are responsible for inhalation poisoning. We present two cases of poisoning from nitric acid gas inhalation resulting from occupational exposure. Imaging findings were similar in both cases, consistent with adult respiratory distress syndrome (ARDS): bilaterally diffuse alveolar opacities on the chest X-ray and a cobblestone pattern on computed tomography (CT).one of the patients died while the other evolved satisfactorily after treatment with n-acetyl cysteine and mechanical ventilation. The diagnosis of nitric acid poisoning was made on the basis of the history of exposure and the way in which the radiological findings evolved.

  14. Graphene oxide-sensitized molecularly imprinted opto-polymers for charge-transfer fluorescent sensing of cyanoguanidine.

    Science.gov (United States)

    Liu, Huilin; Zhou, Kaiwen; Chen, Xiaomo; Wang, Jing; Wang, Shuo; Sun, Baoguo

    2017-11-15

    The hierarchical structuring of materials offers exciting opportunities to construct functional sensors. Multiple processes were combined to create complex materials for the selective detection of cyanoguanidine (CYA) using graphene oxide-sensitized molecularly imprinted opto-polymers (MIOP). Molecular imprinting was used to construct molecular-scale analyte-selective cavities, graphene oxide was introduced to provide a platform for the polymerization, and increase the stability and binding kinetic properties, and 3-methacryloxy propyl trimethoxy silane-modified quantum dots were combined with a functional monomer to increase the fluorescence quantum yield. Polymer cross-linking and fluorescence intensity were optimized for molecular recognition and opto-sensing detection. Selective and sensitive, fluorescence sensing of CYA was possible at concentrations as low as to 1.6μM. It could be applied to the rapid and cost-effective monitoring of CYA in infant formula. The approach is generic and applicable to many molecules and conventional opto-sensors, based on molecularly imprinted polymer formulations, individually or in multiplexed arrays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Corrosion resistance of zirconium in nitric acid

    International Nuclear Information System (INIS)

    Kajimura, H.; Morikawa, H.; Nagano, H.

    1987-01-01

    Slow strain rate tests are effected on zirconium in boiling nitric acid to study the influence of nitric acid concentration, of oxidizing ions (Cr and Ce) and of electric potential. Corrosion resistance is excellent and stress corrosion cracking occurs only for severe conditions: 350 mV over electric potential for corrosion with nitric acid concentration of 40 % [fr

  16. Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Kessel, Kurt R.

    2016-01-01

    Corrosion is an extensive problem that affects the National Aeronautics and Space Administration (NASA) and European Space Agency (ESA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. It is vital to reduce corrosion costs and risks in a sustainable manner. The primary objective of this effort is to qualify citric acid as an environmentally-preferable alternative to nitric acid for passivation of stainless steel alloys.

  17. Resveratrol and Endothelial Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Ning Xia

    2014-10-01

    Full Text Available Nitric oxide (NO derived from the endothelial NO synthase (eNOS has antihypertensive, antithrombotic, anti-atherosclerotic and antiobesogenic properties. Resveratrol is a polyphenol phytoalexin with multiple cardiovascular and metabolic effects. Part of the beneficial effects of resveratrol are mediated by eNOS. Resveratrol stimulates NO production from eNOS by a number of mechanisms, including upregulation of eNOS expression, stimulation of eNOS enzymatic activity and reversal of eNOS uncoupling. In addition, by reducing oxidative stress, resveratrol prevents oxidative NO inactivation by superoxide thereby enhancing NO bioavailability. Molecular pathways underlying these effects of resveratrol involve SIRT1, AMPK, Nrf2 and estrogen receptors.

  18. Nanocarriers for Nitric Oxide Delivery

    Directory of Open Access Journals (Sweden)

    Juliana Saraiva

    2011-01-01

    Full Text Available Nitric oxide (NO is a promising pharmaceutical agent that has vasodilative, antibacterial, and tumoricidal effects. To study the complex and wide-ranging roles of NO and to facilitate its therapeutic use, a great number of synthetic compounds (e.g., nitrosothiols, nitrosohydroxyamines, N-diazeniumdiolates, and nitrosyl metal complexes have been developed to chemically stabilize and release NO in a controlled manner. Although NO is currently being exploited in many biomedical applications, its use is limited by several factors, including a short half-life, instability during storage, and potential toxicity. Additionally, efficient methods of both localized and systemic in vivo delivery and dose control are needed. One strategy for addressing these limitations and thus increasing the utility of NO donors is based on nanotechnology.

  19. Nitric oxide and chronic colitis

    Directory of Open Access Journals (Sweden)

    Matthew B Grisham

    1996-01-01

    Full Text Available Nitric oxide (NO is thought to play an important role in modulating the inflammatory response by virtue of its ability to affect bloodflow, leukocyte function and cell viability. The objective of this study was to assess the role that NO may play in mediating the mucosal injury and inflammation in a model of chronic granulomatous colitis using two pharmacologically different inhibitors of nitric oxide synthase (NOS. Chronic granulomatous colitis with liver and spleen inflammation was induced in female Lewis rats via the subserosal (intramural injection of peptidoglycan/polysaccharide (PG/PS derived from group A streptococci. Chronic NOS inhibition by oral administration of NG-nitro-L-arginine methyl ester (L-NAME (15 µmol/kg/day or amino-guanidine (AG (15 µmol/ kg/day was found to attenuate the PG/PS-induced increases in macroscopic colonic inflammation scores and colonic myeloperoxidase activity. Only AG -- not L-NAME – attenuated the PG/PS-induced increases in colon dry weight. Both L-NAME and AG significantly attenuated the PG/PS-induced increases in spleen weight whereas neither was effective at significantly attenuating the PG/PS-induced increases in liver weight. Although both L-NAME and AG inhibited NO production in vivo, as measured by decreases in plasma nitrite and nitrate levels, only AG produced significantly lower values (38±3 versus 83±8 µM, respectively, P<0.05. Finally, L-NAME, but not AG, administration significantly increased mean arterial pressure from 83 mmHg in colitic animals to 105 mmHg in the PG/PS+ L-NAME-treated animals (P<0.05. It is concluded that NO may play an important role in mediating some of the pathophysiology associated with this model of chronic granulomatous colitis.

  20. 21 CFR 862.3080 - Breath nitric oxide test system.

    Science.gov (United States)

    2010-04-01

    ... Systems § 862.3080 Breath nitric oxide test system. (a) Identification. A breath nitric oxide test system... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath nitric oxide test system. 862.3080 Section... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to...

  1. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-05-24

    May 24, 2010 ... chronic periodontitis (CP), 31 with gingivitis (G) and 50 healthy controls. Probing depth ..... Periodontal disease in pregnancy I. Prevalence and severity. ... endothelial nitric oxide synthase gene in premenopausal women with.

  2. Flavonoids as scavengers of nitric oxide radical.

    NARCIS (Netherlands)

    van Acker, S.A.B.E.; Tromp, M.N.J.L.; Haenen, G.R.M.M.; van der Vijgh, W.J.F.; Bast, A.

    1995-01-01

    Flavonoids are a group of naturally occurring compounds used, e.g., in the treatment of vascular endothelial damage. They are known to be excellent scavengers of oxygen free radicals. Since the nitric oxide radical (

  3. Nitric oxide in the stress axis

    OpenAIRE

    Lopez-Figueroa, M.O.; Day, H.E.W.; Akil, H.; Watson, S.J.

    1998-01-01

    In recent years nitric oxide (NO) has emerged as a unique biological messenger. NO is a highly diffusible gas, synthesized from L-arginine by the enzyme nitric oxide synthase (NOS). Three unique subtypes of NOS have been described, each with a specific distribution profile in the brain and periphery. NOS subtype I is present, among other areas, in the hippocampus, hypothalamus, pituitary and adrenal gland. Together these structures form the limbichypothalamic- ...

  4. 21 CFR 868.5165 - Nitric oxide administration apparatus.

    Science.gov (United States)

    2010-04-01

    ... apparatus. (a) Identification. The nitric oxide administration apparatus is a device used to add nitric oxide to gases that are to be breathed by a patient. The nitric oxide administration apparatus is to be used in conjunction with a ventilator or other breathing gas administration system. (b) Classification...

  5. Containment of Nitric Acid Solutions of Plutonium-238

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Silver, G.L.; Pansoy-Hjelvik, L.; Ramsey, K.

    1999-01-01

    The corrosion of various metals that could be used to contain nitric acid solutions of Pu-238 has been studied. Tantalum and tantalum/2.5% tungsten resisted the test solvent better than 304L stainless steel and several INCONEL alloys. The solvent used to imitate nitric acid solutions of Pu-238 contained 70% nitric acid, hydrofluoric acid, and ammonium hexanitratocerate

  6. Electroreduction of nitric acid to hydroxylamine

    International Nuclear Information System (INIS)

    Haque, I.U.; Saima, W.

    2008-01-01

    This article reviews recent studies concerned with the synthesis of hydroxylamine Hydroxylamine plays a significant role in agriculture, photographic developing, as a component in liquid propellants and as a reducing agent etc. In this regard modification of carbon electrode surface greatly increases hydrogen overpotential in nitric acid solutions and allows electrochemical generation of hydroxylamine with good current efficiency. (author)

  7. ORIGINAL ARTICLE Relationship between endothelial nitric oxide ...

    African Journals Online (AJOL)

    salah

    The haplotype analysis confirmed ... hand, no consistent association was shown between the two SNPs and SBP or. DBP. ... Endothelial nitric oxide synthase gene polymorphisms and risk of MI .... type (-786T*+894G), the haplotypes ... Tests adjusted for age, BMI, diabetes, current smoking and alcohol consumption.

  8. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)

    Endothelial nitric oxide synthase (NOS3) is involved in key steps of immune response. Genetic factors predispose individuals to periodontal disease. This study's aim was to explore the association between NOS3 gene polymorphisms and clinical parameters in patients with periodontal disease. Genomic DNA was obtained ...

  9. Nitric oxide enhances osmoregulation of tobacco ( Nicotiana ...

    African Journals Online (AJOL)

    This study was carried out to investigate the effect of the intracellular signaling molecule nitric oxide (NO) on osmoregulation of tobacco cells under osmotic stress caused by phenylethanoid glycosides 6000 (PEG 6000). The results show that the PEG stress induced a specific pattern of endogenous NO production with two ...

  10. Ropivacaine-Induced Contraction Is Attenuated by Both Endothelial Nitric Oxide and Voltage-Dependent Potassium Channels in Isolated Rat Aortae

    Directory of Open Access Journals (Sweden)

    Seong-Ho Ok

    2013-01-01

    Full Text Available This study investigated endothelium-derived vasodilators and potassium channels involved in the modulation of ropivacaine-induced contraction. In endothelium-intact rat aortae, ropivacaine concentration-response curves were generated in the presence or absence of the following inhibitors: the nonspecific nitric oxide synthase (NOS inhibitor Nω-nitro-L-arginine methyl ester (L-NAME, the neuronal NOS inhibitor Nω-propyl-L-arginine hydrochloride, the inducible NOS inhibitor 1400W dihydrochloride, the nitric oxide-sensitive guanylyl cyclase (GC inhibitor ODQ, the NOS and GC inhibitor methylene blue, the phosphoinositide-3 kinase inhibitor wortmannin, the cytochrome p450 epoxygenase inhibitor fluconazole, the voltage-dependent potassium channel inhibitor 4-aminopyridine (4-AP, the calcium-activated potassium channel inhibitor tetraethylammonium (TEA, the inward-rectifying potassium channel inhibitor barium chloride, and the ATP-sensitive potassium channel inhibitor glibenclamide. The effect of ropivacaine on endothelial nitric oxide synthase (eNOS phosphorylation in human umbilical vein endothelial cells was examined by western blotting. Ropivacaine-induced contraction was weaker in endothelium-intact aortae than in endothelium-denuded aortae. L-NAME, ODQ, and methylene blue enhanced ropivacaine-induced contraction, whereas wortmannin, Nω-propyl-L-arginine hydrochloride, 1400W dihydrochloride, and fluconazole had no effect. 4-AP and TEA enhanced ropivacaine-induced contraction; however, barium chloride and glibenclamide had no effect. eNOS phosphorylation was induced by ropivacaine. These results suggest that ropivacaine-induced contraction is attenuated primarily by both endothelial nitric oxide and voltage-dependent potassium channels.

  11. Nitric oxide in the rat cerebellum after hypoxia/ischemia.

    Science.gov (United States)

    Rodrigo, José; Fernández, Ana Patricia; Alonso, David; Serrano, Julia; Fernández-Vizarra, Paula; Martínez-Murillo, Ricardo; Bentura, María Luisa; Martinez, Alfredo

    2004-01-01

    Nitric oxide is a regulatory biological substance and an important intracellular messenger that acts as a specific mediator of various neuropathological disorders. In mammals and invertebrates, nitric oxide is synthesized from L-arginine in the central and peripheral neural structures by the endothelial, neuronal and inducible enzymatic isoforms of nitric oxide synthase. Nitric oxide may affect the function of various neurotransmitter-specific systems, and is involved in neuromodulation, reproductive function, immune response, and regulation of the cerebral blood circulation. This makes nitric oxide the main candidate in brain responses to brain ischemia/hypoxia. The cerebellum has been reported to be the area of the brain that has the highest nitric oxide synthase activity and the highest concentration of glutamate and aspartate. By glutamate receptors and physiological action of nitric oxide, cyclic guanisine-5'-monophosphate may be rapidly increased. The cerebellum significantly differs with respect to ischemia and hypoxia, this response being directly related to the duration and intensity of the injury. The cerebellum could cover the eventual need for nitric oxide during the hypoxia, boosting the nitric oxide synthase activity, but overall ischemia would require de novo protein synthesis, activating the inducible nitric oxide synthase to cope with the new situation. The specific inhibitors of nitric oxide synthesis show neuroprotective effects.

  12. Therapeutic strategies to address neuronal nitric oxide synthase deficiency and the loss of nitric oxide bioavailability in Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Timpani, Cara A; Hayes, Alan; Rybalka, Emma

    2017-05-25

    Duchenne Muscular Dystrophy is a rare and fatal neuromuscular disease in which the absence of dystrophin from the muscle membrane induces a secondary loss of neuronal nitric oxide synthase and the muscles capacity for endogenous nitric oxide synthesis. Since nitric oxide is a potent regulator of skeletal muscle metabolism, mass, function and regeneration, the loss of nitric oxide bioavailability is likely a key contributor to the chronic pathological wasting evident in Duchenne Muscular Dystrophy. As such, various therapeutic interventions to re-establish either the neuronal nitric oxide synthase protein deficit or the consequential loss of nitric oxide synthesis and bioavailability have been investigated in both animal models of Duchenne Muscular Dystrophy and in human clinical trials. Notably, the efficacy of these interventions are varied and not always translatable from animal model to human patients, highlighting a complex interplay of factors which determine the downstream modulatory effects of nitric oxide. We review these studies herein.

  13. A plasma needle generates nitric oxide

    International Nuclear Information System (INIS)

    Stoffels, E; Gonzalvo, Y Aranda; Whitmore, T D; Seymour, D L; Rees, J A

    2006-01-01

    Generation of nitric oxide (NO) by a plasma needle is studied by means of mass spectrometry. The plasma needle is an atmospheric glow generated by a radio-frequency excitation in a mixture of helium and air. This source is used for the treatment of living tissues, and nitric oxide may be one of the most important active agents in plasma therapy. Efficient NO generation is of particular importance in the treatment of cardiovascular diseases. Mass spectrometric measurements have been performed under various plasma conditions; gas composition in the plasma and conversion of feed gases (nitrogen and oxygen) into other species has been studied. Up to 30% of the N 2 and O 2 input is consumed in the discharge, and NO has been identified as the main conversion product

  14. Interactions between cytokines and nitric oxide.

    Science.gov (United States)

    Liew, F Y

    1995-01-01

    There is now an impressive range of evidence supporting the important role of cytokines in sleep regulation (see Krueger et al., 1995; De Simoni et al., 1995). It has also been reported that inhibition of nitric oxide (NO) synthesis suppresses sleep in rabbits (Kapás et al., 1994). This is not surprising, since NO is closely involved in neurotransmission (Garthwaite, 1991; Schuman and Madison, 1994) and cytokines are the major inducers of NO synthesis (Hibbs et al., 1990). Further, it is now clear that NO plays an important role in modulating immune responses, possibly through the differential regulation of cytokine synthesis (Taylor-Robinson et al., 1994). In this article, I will provide evidence for the interactions between cytokines and nitric oxide, and discuss their implications in the regulation of immune responses. I shall illustrate these mainly with results from my coworkers and I, from our laboratory rather than attempting an exhaustive review of the subject.

  15. Alternative to Nitric Acid Passivation Project Overview

    Science.gov (United States)

    Lewis, Pattie L.

    2013-01-01

    The standard practice for protection of stainless steel is a process called passivation. This procedure results in the formation of a metal oxide layer to prevent corrosion. Typical passivation procedures call for the use of nitric acid which exhibits excellent corrosion performance; however, there are a number of environmental, worker safety, and operational issues associated with its use. The longtime military specification for the passivation of stainless steel was cancelled in favor of newer specifications which allow for the use of citric acid in place of nitric acid. Citric acid offers a variety of benefits that include increased safety for personnel, reduced environmental impact, and reduced operational costs. There have been few studies, however, to determine whether citric acid is an acceptable alternative for NASA and DoD. This paper details activities to date including development of the joint test plan, on-going and planned testing, and preliminary results.

  16. On hydrazine oxidation in nitric acid media

    International Nuclear Information System (INIS)

    Zil'berman, B.Ya.; Lelyuk, G.A.; Mashkin, A.N.; Yasnovitskaya, A.L.

    1988-01-01

    Yield of products of radiolytic ( 60 Co gamma radiation) and chemical hydrazine (HZ) oxidation in nitric acid media is studied. Under radiolyte HZ oxidation by nitric acid hydrazoic acid, ammonia and nitrogen appear to be the reaction products. HN 3 yield maximum under HZN oxidation makes up ∼ 0.35 mol per a mol of oxiduzed HZN. Under chemical oxidation HZN is oxidized by HNO 3 according to reaction catalysed by technetium HN 3 yield makes up ∼ 0.35 mol per a mol of oxidized HZN. Radiation-chemical oxidation of HN 3 proceeds up to its complete decomposition, decomposition rate is comparable with HZ oxidation rate. Under the chemical oxidation HN 3 is more stable, it is slowly decomposed after complete HZ decomposition

  17. Removal of fluoride from aqueous nitric acid

    International Nuclear Information System (INIS)

    Pruett, D.J.; Howerton, W.B.; Mailen, J.C.

    1981-06-01

    Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca 2+ -Al 3+ ) chemical trap-distillation system. Zirconium oxynitrate solutions were found to be superior in preventing volatilization of fluoride during distillation of the nitric acid, producing decontamination factors (DFs) on the order of 2 x 10 3 (vs approx. 500 for the Ca 2+ -Al 3+ system). Several other metal nitrate systems were tested, but they were less effective. Alumina and zirconia columns proved highly effective in removing HF from HF-HNO 3 vapors distilled through the columns; fluoride DFs on the order of 10 6 and 10 4 , respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO 3 solutions, producing a fluoride DF of approx. 10 4

  18. Radiation, nitric oxide and cellular death

    International Nuclear Information System (INIS)

    Dubner, D.; Perez, M.R. Del; Michelin, S.C.; Gisone, P.A.

    1997-01-01

    The mechanisms of radiation induced cellular death constitute an objective of research ever since the first biological effects of radiation were first observed. The explosion of information produced in the last 20 years calls for a careful analysis due to the apparent contradictory data related to the cellular system studied and the range of doses used. This review focuses on the role of the active oxygen species, in particular the nitric oxides, in its relevance as potential mediator of radiation induced cellular death

  19. Oxygen, nitric oxide and articular cartilage

    Directory of Open Access Journals (Sweden)

    B Fermor

    2007-04-01

    Full Text Available Molecular oxygen is required for the production of nitric oxide (NO, a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O2, while the deep zone exists at less than 1% O2. Furthermore, oxygen tension can alter matrix synthesis, and the material properties of articular cartilage in vitro.The increase in nitric oxide associated with arthritis can be caused by pro-inflammatory cytokines and mechanical stress. Oxygen tension significantly alters endogenous NO production in articular cartilage, as well as the stimulation of NO in response to both mechanical loading and pro-inflammatory cytokines. Mechanical loading and pro-inflammatory cytokines also increase the production of prostaglandin E2 (PGE2. There is a complex interaction between NO and PGE2, and oxygen tension can alter this interaction. These findings suggest that the relatively low levels of oxygen within the joint may have significant influences on the metabolic activity, and inflammatory response of cartilage as compared to ambient levels. A better understanding of the role of oxygen in the production of inflammatory mediators in response to mechanical loading, or pro-inflammatory cytokines, may aid in the development of strategies for therapeutic intervention in arthritis.

  20. Cannula sensor for nitric oxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Glazier, S.A. [National Institute of Standard and Technology, Gaithersburg, MD (United States)

    1995-12-31

    Nitric oxide (NO) has received much attention because of its numerous roles in mammalian systems. It has been found in the brain and nervous system to act as a neurotransmitter, in blood vessels as a blood pressure regulator, in the immune system to act as a bactericide and tumorcide, and in other postulated roles as well. Nitric oxide is produced in mammalian cells by the enzyme nitric oxide synthetase. Once produced, NO is oxidized or reacts rapidly with components in living systems and hence has a short half-life. Only a few sensors have been constructed which can detect NO at nanomolar to micromolar levels found in these systems. We are currently examining the use of a cannula sensor employing oxyhemoglobin for NO detection. This sensor continuously draws in liquid sample at a low rate and immediately reacts it with oxyhemoglobin. The absorbance changes which accompany the reaction are monitored. The sensor has a linear response range from approximately 50 to 1000 nM of NO in aqueous solution. Its utility in monitoring NO produced by stimulated murine macrophage cells (RAW 264.7) in culture is currently being examined. The sensor design is generic in that it can also employ fluorescence and chemiluminescence detection chemistries which may allow lower detection limits to be achieved. Details of the sensor`s performance will be given.

  1. Neuroprotective properties of nitric oxide and S-nitrosoglutathione

    International Nuclear Information System (INIS)

    Rauhala, Pekka; Andoh, Tsugunobu; Chiueh, C.C.

    2005-01-01

    Oxidative stress and apoptosis may play an important role in the neurodegeneration. The present paper outlines antioxidative and antiapototic mechanisms of nitric oxide and S-nitrosothiols, which could mediate neuroprotection. Nitric oxide generated by nitric oxide synthase or released from an endogenous S-nitrosothiol, S-nitrosoglutathione may up-regulate antioxidative thioredoxin system and antiapototic Bcl-2 protein through a cGMP-dependent mechanism. Moreover, nitric oxide radicals have been shown to have direct antioxidant effect through their reaction with free radicals and iron-oxygen complexes. In addition to serving as a stabilizer and carrier of nitric oxide, S-nitrosoglutathione may have protective effect through transnitrosylation reactions. Based on these new findings, a hypothesis arises that the homeostasis of nitric oxide, S-nitrosothiols, glutathione, and thioredoxin systems is important for protection against oxidative stress, apoptosis, and related neurodegenerative disorders

  2. Involvement of inositol biosynthesis and nitric oxide in the mediation of UV-B induced oxidative stress

    Directory of Open Access Journals (Sweden)

    Dmytro I Lytvyn

    2016-04-01

    Full Text Available The involvement of NO-signaling in ultraviolet B (UV-B induced oxidative stress in plants is an open question. Inositol biosynthesis contributes to numerous cellular functions, including the regulation of plants tolerance to stress. This work reveals the involvement of inositol-3-phosphate synthase 1 (IPS1, a key enzyme for biosynthesis of myo-inositol and its derivatives, in the response to NO-dependent oxidative stress in Arabidopsis. Homozygous mutants deficient for IPS1 (atips1 and wild-type plants were transformed with a reduction-oxidation-sensitive green fluorescent protein 2 (grx1-rogfp2 and used for the dynamic measurement of UV-B-induced and SNP (sodium nitroprusside-mediated oxidative stresses by confocal microscopy. atips1 mutants displayed greater tissue-specific resistance to the action of UV-B than the wild type. SNP can act both as an oxidant or repairer depending on the applied concentration, but mutant plants were more tolerant than the wild type to nitrosative effects of high concentration of SNP. Additionally, pretreatment with low concentrations of SNP (10, 100 μM before UV-B irradiation resulted in a tissue-specific protective effect that was enhanced in atips1. We conclude that the interplay between nitric oxide and inositol signaling can be involved in the mediation of UV-B-initiated oxidative stress in the plant cell.

  3. Nitric oxide synthase gene G298 allele

    International Nuclear Information System (INIS)

    Nagib El-Kilany, Galal E.; Nayel, Ehab; Hazzaa, Sahar

    2004-01-01

    Background: Nitric oxide (NO) has an important effect on blood pressure, arterial wall, and the basal release of endothelial NO in hypertension (HPN) may be reduced. Until now, there is no solid data revealing the potential role of the polymorphism of the nitric oxide synthase gene (NOS) in patients with HPN and microvascular angina. Aim: The aim of the present study is to investigate the gene of endothelial nitric oxide synthase (eNOS), as the polymorphism of this gene may be a putative candidate for HPN and initiate the process of atherosclerosis. Methods: Sixty participants were recruited for this study; 50 were hypertensive patients complaining of chest pain [30 of them have electrocardiogram (EKG) changes of ischemia], 20 had isolated HPN, and 10 healthy volunteers served as control. All patients underwent stress myocardial perfusion imaging (MPI) and coronary angiography. Genotyping of eNOS for all patients and controls was performed. The linkages between HPN, microvascular angina and eNOS gene polymorphism were investigated. Results: MPI and coronary angiography revealed that 15 patients had chest pain with true ischemia and reversible myocardial perfusion defects (multiple and mild) but normal epicardial coronary arteries (microvascular angina), while 15 patients had significant coronary artery disease (CAD), and 20 hypertensive patients showed normal perfusion scan and coronary angiography. The prevalence of the NOS G 298 allele was higher in the hypertensive group with microvascular angina (documented by MPI) than it was among the control participants (P<.005). The eNOS allele was significantly higher in the hypertensive group than in the control participants, but there was no significant difference in homozygote mutants among hypertensive participants, x-syndrome and patients with CAD. Conclusion: eNOS gene polymorphism is proved to be an important etiology in microvascular angina (x-syndrome) among hypertensive patients. In addition, the eNOS mutant

  4. Circulating nitric oxide products do not solely reflect nitric oxide release in cirrhosis and portal hypertension

    DEFF Research Database (Denmark)

    Afzelius, Pia; Bazeghi, Nassim; Bie, Peter

    2011-01-01

    Patients with cirrhosis often develop a systemic vasodilatation and a hyperdynamic circulation with activation of vasoconstrictor systems such as the renin-angiotensin-aldosterone system (RAAS), and vasopressin. Increased nitric oxide (NO) synthesis has been implicated in the development of this ...

  5. Nitric oxide synthase inhibition and cerebrovascular regulation

    DEFF Research Database (Denmark)

    Iadecola, C; Pelligrino, D A; Moskowitz, M A

    1994-01-01

    tone and may play an important role in selected vasodilator responses of the cerebral circulation. Furthermore, evidence has been presented suggesting that NO participates in the mechanisms of cerebral ischemic damage. Despite the widespread attention that NO has captured in recent years and the large......There is increasing evidence that nitric oxide (NO) is an important molecular messenger involved in a wide variety of biological processes. Recent data suggest that NO is also involved in the regulation of the cerebral circulation. Thus, NO participants in the maintenance of resting cerebrovascular...

  6. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M

    2014-01-01

    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed......-nitroso-N-acetylpenicillamine (SNAP) (1) confirmed denitrification as the main NO consumption pathway, with N2O as its major product, (2) showed that denitrification combines one free NO molecule with one NO molecule formed from nitrite to produce N2O, and (3) suggested that NO inhibits N2O reduction....

  7. Processes regulating nitric oxide emissions from soils

    DEFF Research Database (Denmark)

    Pilegaard, Kim

    2013-01-01

    , the net result is complex and dependent on several factors such as nitrogen availability, organic matter content, oxygen status, soil moisture, pH and temperature. This paper reviews recent knowledge on processes forming NO in soils and the factors controlling its emission to the atmosphere. Schemes......Nitric oxide (NO) is a reactive gas that plays an important role in atmospheric chemistry by influencing the production and destruction of ozone and thereby the oxidizing capacity of the atmosphere. NO also contributes by its oxidation products to the formation of acid rain. The major sources...

  8. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    Directory of Open Access Journals (Sweden)

    Nevzat Selim Gokay

    2016-01-01

    Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  9. EFFECTS OF NITRIC ACID ON CRITICALITY SAFETY ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, B.

    2011-08-18

    As nitric acid molarity is increased, there are two competing phenomena affecting the reactivity of the system. First, there is interaction between each of the 10 wells in the basket-like insert. As the molarity of the nitric acid solution is increased (it moves from 100% water to 100% HNO{sub 3}), the hydrogen atom density decreases by about 80%. However, it remains a relatively efficient moderator. The moderating ratio of nitric acid is about 90% that of water. As the media between the wells is changed from 100% water to 100% nitric acid, the density of the media increases by 50%. A higher density typically leads to a better reflector. However, when the macroscopic scattering cross sections are considered, nitric acid is a much worse reflector than water. The effectiveness of nitric acid as a reflector is about 40% that of water. Since the media between the wells become a worse reflector and still remains an effective moderator, interaction between the wells increases. This phenomenon will cause reactivity to increase as nitric acid molarity increases. The seond phenomenon is due to the moderating ratio changing in the high concentration fissile-nitric acid solution in the 10 wells. Since the wells contain relatively small volumes of high concentration solutions, a small decrease in moderating power has a large effect on reactivity. This is due to the fact that neutrons are more likely to escape the high concentration fissile solution before causing another fission event. The result of this phenomenon is that as nitric acid molarity increases, reactivity decreases. Recent studies have shown that the second phenomenon is indeed the dominating force in determining reactivity changes in relation to nitric acid molarity changes. When considering the system as a whole, as nitric acid molarity increases, reactivity decreases.

  10. Nitric oxide in the stress axis.

    Science.gov (United States)

    López-Figueroa, M O; Day, H E; Akil, H; Watson, S J

    1998-10-01

    In recent years nitric oxide (NO) has emerged as a unique biological messenger. NO is a highly diffusible gas, synthesized from L-arginine by the enzyme nitric oxide synthase (NOS). Three unique subtypes of NOS have been described, each with a specific distribution profile in the brain and periphery. NOS subtype I is present, among other areas, in the hippocampus, hypothalamus, pituitary and adrenal gland. Together these structures form the limbic-hypothalamic-pituitary-adrenal (LHPA) or stress axis, activation of which is one of the defining features of a stress response. Evidence suggests that NO may modulate the release of the stress hormones ACTH and corticosterone, and NOS activity and transcription is increased in the LHPA axis following various stressful stimuli. Furthermore, following activation of the stress axis, glucocorticoids are thought to down-regulate the transcription and activity of NOS via a feedback mechanism. Taken together, current data indicate a role for NO in the regulation of the LHPA axis, although at present this role is not well defined. It has been suggested that NO may act as a cellular communicator in plasticity and development, to facilitate the activation or the release of other neurotransmitters, to mediate immune responses, and/or as a vasodilator in the regulation of blood flow. In the following review we summarize some of the latest insights into the function of NO, with special attention to its relationship with the LHPA axis.

  11. Vascular nitric oxide: Beyond eNOS

    Directory of Open Access Journals (Sweden)

    Yingzi Zhao

    2015-10-01

    Full Text Available As the first discovered gaseous signaling molecule, nitric oxide (NO affects a number of cellular processes, including those involving vascular cells. This brief review summarizes the contribution of NO to the regulation of vascular tone and its sources in the blood vessel wall. NO regulates the degree of contraction of vascular smooth muscle cells mainly by stimulating soluble guanylyl cyclase (sGC to produce cyclic guanosine monophosphate (cGMP, although cGMP-independent signaling [S-nitrosylation of target proteins, activation of sarco/endoplasmic reticulum calcium ATPase (SERCA or production of cyclic inosine monophosphate (cIMP] also can be involved. In the blood vessel wall, NO is produced mainly from l-arginine by the enzyme endothelial nitric oxide synthase (eNOS but it can also be released non-enzymatically from S-nitrosothiols or from nitrate/nitrite. Dysfunction in the production and/or the bioavailability of NO characterizes endothelial dysfunction, which is associated with cardiovascular diseases such as hypertension and atherosclerosis.

  12. Catalytic abatement of nitrous oxide from nitric and production

    NARCIS (Netherlands)

    Oonk, J.

    1998-01-01

    Nitric acid production is identified as a main source of nitrous oxide. Options for emission reduction however are not available. TNO and Hydro Agri studied the technological and economic feasibility of catalytic decomposition of nitrous oxide in nitric acid tail-gases. Although in literature

  13. Influence of nitric oxide on histamine and carbachol – induced ...

    African Journals Online (AJOL)

    The study aimed to determine the influence of nitric oxide (NO) on the action of histamine and carbachol on acid secretion in the common African toad – Bufo regularis. Gastric acidity was determined by titration method. The acid secretion was determined when nitric oxide was absent following administration of NO synthase ...

  14. The correlation between total antioxidant capacity and nitric oxide ...

    African Journals Online (AJOL)

    DNA damage was measured by comet assay and nitric oxide concentration was evaluated by Griess assay. TAC was measured in seminal plasma based on the generation of peroxyl radicals from 2,2-azinobis (2-amidino propane) dihydrochlorid (AAPH). Our results show that the means of DNA damage and nitric oxide ...

  15. Nitric Oxide Metabolites and Asymmetric Dimethylarginine Concentrations in Breast Milk

    Directory of Open Access Journals (Sweden)

    Hakan Öztürk

    2017-04-01

    Full Text Available Objective: Nitric oxide plays a preventive role in the development of necrotizing enterocolitis. Oral nitrite and nitrate intake has gained importance with the discovery of the conversion of nitrite to nitric oxide in acidic medium out of the synthesis of nitric oxide from L-arginine. Objective of this study was to examine the breast milk concentrations of nitric oxide and asymmetric dimethylarginine which is a competitive inhibitor of nitric oxide and to compare these concentrations in terms of gestational age and maturity of breast milk. Study Design: Forty-one women were included in the study. Milk samples were collected from 3 groups of mothers as term, late preterm and preterm on the postpartum days 3, 7 and 28. Results: When breast milk concentrations of nitric oxide were compared according to the postnatal day of the milk independently from gestational age; nitric oxide concentration was higher in the colostrum than in the transition milk and mature milk (p=0,035; p=0,001; respectively. For the comparison of asymmetric dimethylarginine concentrations among these groups and days; no statistically significant difference was observed in terms of gestational age and maturity of the milk (p=0.865, p=0.115; respectively. Conclusion: The highest nitric oxide concentration was found in the colostrum, suggesting that colostrum is a valuable food for newborns. Plasma concentrations of asymmetric dimethylarginine were negatively correlated with nitric oxide and did not show a correlation with breast milk, suggesting that asymmetric dimethylargininedoesn’t make nitric oxide inhibition in breast milk.

  16. Nitric oxide, human diseases and the herbal products that affect the nitric oxide signalling pathway.

    Science.gov (United States)

    Achike, Francis I; Kwan, Chiu-Yin

    2003-09-01

    1. Nitric oxide (NO) is formed enzymatically from l-arginine in the presence of nitric oxide synthase (NOS). Nitric oxide is generated constitutively in endothelial cells via sheer stress and blood-borne substances. Nitric oxide is also generated constitutively in neuronal cells and serves as a neurotransmitter and neuromodulator in non-adrenergic, non-cholinergic nerve endings. Furthermore, NO can also be formed via enzyme induction in many tissues in the presence of cytokines. 2. The ubiquitous presence of NO in the living body suggests that NO plays an important role in the maintenance of health. Being a free radical with vasodilatory properties, NO exerts dual effects on tissues and cells in various biological systems. At low concentrations, NO can dilate the blood vessels and improve the circulation, but at high concentrations it can cause circulatory shock and induce cell death. Thus, diseases can arise in the presence of the extreme ends of the physiological concentrations of NO. 3. The NO signalling pathway has, in recent years, become a target for new drug development. The high level of flavonoids, catechins, tannins and other polyphenolic compounds present in vegetables, fruits, soy, tea and even red wine (from grapes) is believed to contribute to their beneficial health effects. Some of these compounds induce NO formation from the endothelial cells to improve circulation and some suppress the induction of inducible NOS in inflammation and infection. 4. Many botanical medicinal herbs and drugs derived from these herbs have been shown to have effects on the NO signalling pathway. For example, the saponins from ginseng, ginsenosides, have been shown to relax blood vessels (probably contributing to the antifatigue and blood pressure-lowering effects of ginseng) and corpus cavernosum (thus, for the treatment of men suffering from erectile dysfunction; however, the legendary aphrodisiac effect of ginseng may be an overstatement). Many plant extracts or

  17. Inhaled nitric oxide augments nitric oxide transport on sickle cell hemoglobin without affecting oxygen affinity

    OpenAIRE

    Gladwin, Mark T.; Schechter, Alan N.; Shelhamer, James H.; Pannell, Lewis K.; Conway, Deirdre A.; Hrinczenko, Borys W.; Nichols, James S.; Pease-Fye, Margaret E.; Noguchi, Constance T.; Rodgers, Griffin P.; Ognibene, Frederick P.

    1999-01-01

    Nitric oxide (NO) inhalation has been reported to increase the oxygen affinity of sickle cell erythrocytes. Also, proposed allosteric mechanisms for hemoglobin, based on S-nitrosation of β-chain cysteine 93, raise the possibilty of altering the pathophysiology of sickle cell disease by inhibiting polymerization or by increasing NO delivery to the tissue. We studied the effects of a 2-hour treatment, using varying concentrations of inhaled NO. Oxygen affinity, as measured by P50, did not respo...

  18. Oxygen binding to nitric oxide marked hemoglobin

    International Nuclear Information System (INIS)

    Louro, S.R.W.; Ribeiro, P.C.; Bemski, G.

    1979-04-01

    Electron spin resonance spectra of organic phosphate free human hemoglobin marked with nitric oxide at the sixth coordination position of one of the four hemes allow to observe the transition from the tense (T) to the relaxed (R) conformation, as a function of parcial oxygen pressure. The spectra are composites of contributions from α sub(T), α sub(R) and β chains spectra, showing the presence of only two conformations: T and R. In the absence of organic phosphates NO binds to α and β chains with the same probability, but in the presence of phosphates NO combines preferentially with α chains. The dissociation of NO proceeds at least an order of magnitude faster in T than in R configuration. (author) [pt

  19. Nitric oxide: cancer target or anticancer agent?

    Science.gov (United States)

    Mocellin, Simone

    2009-03-01

    Despite the improved understanding of nitric oxide (NO) biology and the large amount of preclinical experiments testing its role in cancer development and progression, it is still debated whether NO should be considered a potential anticancer agent or instead a carcinogen. The complexity of NO effects within a cell and the variability of the final biological outcome depending upon NO levels makes it highly challenging to determine the therapeutic value of interfering with the activity of this intriguing gaseous messenger. This uncertainty has so far halted the clinical implementation of NO-based therapeutics in the field of oncology. Accordingly, only an in depth knowledge of the mechanisms leading to experimental tumor regression or progression in response to NO will allow us to exploit this molecule to fight cancer.

  20. Citric Acid Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  1. Nitric oxide and mitochondria in metabolic syndrome

    Science.gov (United States)

    Litvinova, Larisa; Atochin, Dmitriy N.; Fattakhov, Nikolai; Vasilenko, Mariia; Zatolokin, Pavel; Kirienkova, Elena

    2015-01-01

    Metabolic syndrome (MS) is a cluster of metabolic disorders that collectively increase the risk of cardiovascular disease. Nitric oxide (NO) plays a crucial role in the pathogeneses of MS components and is involved in different mitochondrial signaling pathways that control respiration and apoptosis. The present review summarizes the recent information regarding the interrelations of mitochondria and NO in MS. Changes in the activities of different NO synthase isoforms lead to the formation of metabolic disorders and therefore are highlighted here. Reduced endothelial NOS activity and NO bioavailability, as the main factors underlying the endothelial dysfunction that occurs in MS, are discussed in this review in relation to mitochondrial dysfunction. We also focus on potential therapeutic strategies involving NO signaling pathways that can be used to treat patients with metabolic disorders associated with mitochondrial dysfunction. The article may help researchers develop new approaches for the diagnosis, prevention and treatment of MS. PMID:25741283

  2. Radiolysis of concentrated nitric acid solutions

    International Nuclear Information System (INIS)

    Nagaishi, R.; Jiang, P.Y.; Katsumura, Y.; Domae, M.; Ishigure, K.

    1995-01-01

    A study on electron pulse- and 60 Co γ-radiolysis of concentrated nitric acid and nitrate solutions has been carried out to elucidate the radiation induced reactions taking place in the solutions. Dissociation into NO 2 - and O( 3 P) was proposed as a direct action of the radiation on nitrate and gave the G-values were dependent on the chemical forms of nitrate: g s2 (-NO 3 - )=1.6 and g s2 (-HNO 3 )=2.2 (molecules/100eV). Based on the experimental yields of HNO 2 and reduced Ce IV , the primary yields of radiolysis products of water, g w , were evaluated to clarify the effects of nitrate on spur reactions of water in various nitrate solutions. (author)

  3. The role of nitric oxide in reproduction

    Directory of Open Access Journals (Sweden)

    McCann S.M.

    1999-01-01

    Full Text Available Nitric oxide (NO plays a crucial role in reproduction at every level in the organism. In the brain, it activates the release of luteinizing hormone-releasing hormone (LHRH. The axons of the LHRH neurons project to the mating centers in the brain stem and by afferent pathways evoke the lordosis reflex in female rats. In males, there is activation of NOergic terminals that release NO in the corpora cavernosa penis to induce erection by generation of cyclic guanosine monophosphate (cGMP. NO also activates the release of LHRH which reaches the pituitary and activates the release of gonadotropins by activating neural NO synthase (nNOS in the pituitary gland. In the gonad, NO plays an important role in inducing ovulation and in causing luteolysis, whereas in the reproductive tract, it relaxes uterine muscle via cGMP and constricts it via prostaglandins (PG.

  4. Auroral nitric oxide concentration and infrared emission

    Science.gov (United States)

    Reidy, W. P.; Degges, T. C.; Hurd, A. G.; Stair, A. T., Jr.; Ulwick, J. C.

    1982-05-01

    Rocket-borne measurements of infrared auroral emission by nitric oxide are analyzed. Four rocket flights provided opportunities to measure 5.3- and 2.7-micron NO emission by means of infrared fixed band radiometers and CVF spectrometers, narrow band photometers, and incident energy spectra on various occasions. Analysis of infrared emission profiles and electron flux data indicates the NO density to be significantly enhanced with respect to midlatitude values. NO emission in the fundamental 5.3-micron band is attributed to resonance excitation by warm earth radiation, collisional excitation primarily by O atoms and chemiluminescence from the reaction of N with O2; with an energy efficiency of 0.015. The overtone band emission at 2.7 microns is accounted for by chemiluminescence produced with an energy efficiency of 0.0054. Total photon yield for the chemiluminescence reaction is estimated to range from 1.2 to 2.4 vibrational quanta per NO molecule.

  5. Studies of molybdenite interaction with nitric acid

    International Nuclear Information System (INIS)

    Potashnikov, Yu.M.; Lutsik, V.I.; Chursanov, Yu.V.

    1984-01-01

    Product composition and their effect on the reaction rate of molybdenite with nitric acid are specified. It is shown that alongside with NO NO 2 is included in the composition of the products of MoS 2 and HNO 3 interaction and it produces catalytic effect on the process considered. Under the conditions studied MoS 2 dissolution proceeds in the mixed regime, conditioned by similar values of molybdenite oxidation rate and reaction product diffusion into solution volume (Esub(act.=28.9 kJ/mol, K 298 =6.3x10 -7 , cmxs -1 ), at that due to catalytic effect of NO 2 the dependence V approximately αsup(-g.37) is observed

  6. Nitric oxide and plant iron homeostasis.

    Science.gov (United States)

    Buet, Agustina; Simontacchi, Marcela

    2015-03-01

    Like all living organisms, plants demand iron (Fe) for important biochemical and metabolic processes. Internal imbalances, as a consequence of insufficient or excess Fe in the environment, lead to growth restriction and affect crop yield. Knowledge of signals and factors affecting each step in Fe uptake from the soil and distribution (long-distance transport, remobilization from old to young leaves, and storage in seeds) is necessary to improve our understanding of plant mineral nutrition. In this context, the role of nitric oxide (NO) is discussed as a key player in maintaining Fe homeostasis through its cross talk with hormones, ferritin, and frataxin and the ability to form nitrosyl-iron complexes. © 2015 New York Academy of Sciences.

  7. Nitric oxide-induced calcium release: activation of type 1 ryanodine receptor by endogenous nitric oxide.

    Science.gov (United States)

    Kakizawa, Sho; Yamazawa, Toshiko; Iino, Masamitsu

    2013-01-01

    Ryanodine receptors (RyRs), located in the sarcoplasmic/endoplasmic reticulum (SR/ER) membrane, are required for intracellular Ca2+ release that is involved in a wide range of cellular functions. In addition to Ca2+-induced Ca2+ release in cardiac cells and voltage-induced Ca2+ release in skeletal muscle cells, we recently identified another mode of intracellular Ca2+ mobilization mediated by RyR, i.e., nitric oxide-induced Ca2+ release (NICR), in cerebellar Purkinje cells. NICR is evoked by neuronal activity, is dependent on S-nitrosylation of type 1 RyR (RyR1) and is involved in the induction of long-term potentiation (LTP) of cerebellar synapses. In this addendum, we examined whether peroxynitrite, which is produced by the reaction of nitric oxide with superoxide, may also have an effect on the Ca2+ release via RyR1 and the cerebellar LTP. We found that scavengers of peroxynitrite have no significant effect either on the Ca2+ release via RyR1 or on the cerebellar LTP. We also found that an application of a high concentration of peroxynitrite does not reproduce neuronal activity-dependent Ca2+ release in Purkinje cells. These results support that NICR is induced by endogenous nitric oxide produced by neuronal activity through S-nitrosylation of RyR1.

  8. Nitric oxide in the psychobiology of mental disorders

    Directory of Open Access Journals (Sweden)

    Altan Eşsizoğlu

    2009-03-01

    Full Text Available Nitric oxide is in a gaseous form and is widespread in the human body. It functions by acting as a secondary messenger in the modulatory activities of neuronal functions of the central nervous system. Nitric oxide is the first identified neurotransmitter of the nontraditional neurotransmitter family.Studies conducted on experimental animals demonstrate that nitric oxide has a neuromodulatory efficacy on the secretions of other neurotransmitters and that it has an effect on learning and memory functions, and on various neuronal mechanisms. Many studies have been conducted to investigate the location of nitric oxide in the central nervous system, its effect on anxiety and depression, its relationship with other neurotransmitters, and also about its role on neurotoxicity. There are clinical studies concerning the level of nitrate, a product of nitric oxide metabolism, and also experimental studies concerning its rewarding effect of alcohol and substance use, in patients with depression and schizophrenia. However, limited studies have been conducted to investigate its relationship with stress, which is an important factor in the etiology of psychiatric disorders. These studies demonstrate that nitric oxide is closely related with stress physiology.Nitric oxide is a neuromodulator, which is frequently being mentioned about nowadays in psychiatry. Clinical and experimental studies play an important role in the psychobiology of psychiatric disorders.

  9. Dissolution behavior of PFBR MOX fuel in nitric acid

    International Nuclear Information System (INIS)

    Kelkar, Anoop; Kapoor, Y.S.; Singh, Mamta; Meena, D.L.; Pandey, Ashish; Bhatt, R.B.; Behere, P.G.

    2017-01-01

    Present paper describes the dissolution characteristics of PFBR MOX fuel (U,Pu)O 2 in nitric acid. An overview of batch dissolution experiments, studying the percentage dissolution of uranium and plutonium in (U, Pu)O 2 MOX sintered pellets with different percentage of PuO 2 with reference to time and nitric acid concentration are described. 90% of uranium and plutonium of PFBR MOX gets dissolves in 2 hrs and amount of residue increases with the decrease in nitric acid concentration. Overall variation in percentage residue in PFBR MOX fuel after dissolution test also described. (author)

  10. Thermal decomposition studies of aqueous and nitric solutions of hydroxyurea

    International Nuclear Information System (INIS)

    Shekhar Kumar; Pranay Kumar Sinha; Kamachi Mudali, U.; Natarajan, R.

    2012-01-01

    Hydroxyurea and its derivatives are important nonsalt forming reductants in partitioning of uranium and plutonium in the nuclear fuel reprocessing operations. There is no experimental data available in open literature describing pressurization due to the thermal decomposition of aqueous and nitric solutions of hydroxyurea at elevated temperatures. Authors studied thermal decomposition of hydroxyurea-nitric acid system and resultant pressurization at various concentrations of nitric acid in an adiabatic calorimeter in closed-vent conditions. During these experiments, pressurization was observed. In this paper, results of these experiments have been discussed. (author)

  11. Leaching of sodium carbonate cakes by nitric acid

    International Nuclear Information System (INIS)

    Troyanker, L.S.; Nikonov, V.N.

    1977-01-01

    The interaction has been studied of soda cakes of fluorite-rare-earth concentrate with nitric acid. The effect of a number of factors on extraction of REE into a nitric solution has been considered: the final acidity of the pulp, the duration of leaching, and the ratio between solid and liquid phases. The effect of adding aluminium nitrate into the pulp has also been studied. It has been shown that three-stage counterflow leaching of soda cakes with nitric acid increases REE extraction approximately by 10%

  12. Zeolites as catalyzer to environmental control. Nitric oxide removal

    International Nuclear Information System (INIS)

    Montes, C.; Zapata N, M; Villa H, A.L.

    1995-01-01

    Zeolites and the microporous materials related to them are a class of environmental catalysts, it which are used to remove the produced gases in combustion process (as mobile sources). In this work the importance that has catalysis for environment improvement is emphasized. A review of recent progress in the use of certain zeolitic material as catalysts for nitric oxide elimination of combustion systems is presented. More used nitric oxide removal methods are presented, as well as its advantages and disadvantages. Furthermore, it is emphasized on the need of accomplishing more investigation projects on the development of an active catalyst for the decomposition of the nitric oxide in its elements (N and O)

  13. 76 FR 63878 - New Source Performance Standards Review for Nitric Acid Plants

    Science.gov (United States)

    2011-10-14

    ... technologies. Nitric acid production is also one of the industrial sectors for which ``white papers'' were... standards (NSPS) for nitric acid plants. Nitric acid plants include one or more nitric acid production units. These proposed revisions include a change to the nitrogen oxides (NO X ) emission limit, which applies...

  14. The nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Kurbonov, A.S.; Mamatov, E.D.; Suleymani, M.; Borudzherdi, A.; Mirsaidov, U.M.

    2011-01-01

    Present article is devoted to nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit of Tajikistan. The obtaining of boric acid from pre backed danburite concentrate by decomposition of nitric acid was studied. The chemical composition of danburite concentrate was determined. The laboratory study of danburite leaching by nitric acid was conducted. The influence of temperature, process duration, nitric acid concentration on nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit was studied as well. The optimal conditions of nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit, including temperature, process duration, nitric acid concentration and particle size were proposed.

  15. Acute Respiratory Distress Syndrome (ARDS After Nitric Acid Inhalation

    Directory of Open Access Journals (Sweden)

    Gülay Kır

    2014-12-01

    Full Text Available Lung injury resulting from inhalation of chemical products continues to be associated with high morbidity and mortality. Concentrated nitric acids are also extremely corrosive fuming chemical liquids. Fumes of nitric acid (HNO3 and various oxides of nitrogen such as nitric oxide (NO and nitrogen dioxide (NO2 may cause fatal illnesses such as severe pulmonary edema and acute respiratory distress syndrome (ARDS when inhaled. Intensive respiratory management including mechanical ventilation with positive end expiratory pressure (PEEP, inverse ratio ventilation, replacement of surfactant and extracorporeal membrane oxygenation (ECMO, steroids and n-acetylcysteine (NAC may improve survival. In this case report we present the diagnosis and successful treatment of a 57 years old male patient who developed ARDS following pulmonary edema due to nitric acid fumes inhalation.

  16. Studies on the reaction of nitric acid and sugar

    International Nuclear Information System (INIS)

    MacDougall, C.S.; Bayne, C.K.; Roberson, R.B.

    1982-01-01

    The design of vessels and off-gas systems for denitrating acidic radioactive process solutions by reacting nitric acid with sugar requires a fairly accurate determination of the rate of the controlling step. Therefore, the reaction of sugar with concentrated nitric acid was closely examined at temperatures of 100 and 110 0 C and in the presence of low levels of iron )0 to 0.2 M Fe(III)). Efficiencies of the sugar destruction by nitric acid ranged from 2.56 to 2.93 mol of acid consumed per mole of carbon added. Product off-gases were examined throughout the reaction. Release of CO was fairly constant throughout the reaction, but amounts of CO 2 increased as the nitric acid began to attack the terminal carboxylic acids produced from the consumption of sucrose. Voluminous quantities of NO 2 were released at the beginning of the reaction, but larger relative concentrations of NO were observed toward the end

  17. Modulation of glucose uptake in adipose tissue by nitric oxide ...

    Indian Academy of Sciences (India)

    Madhu

    ion-dependent breakdown and trans-nitrosation reactions are ... [McGrowder D, Ragoobirsingh D and Brown P 2006 Modulation of glucose uptake in adipose tissue by nitric oxide-generating ... Briefly, nicotinamide (Sigma Chemical Co.,.

  18. Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by ...

    African Journals Online (AJOL)

    Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by Methanol Extract of Polyopes affinis in Lipopolysaccharide-stimulated BV2 Microglial Cells through Suppression of Akt-dependent NF-kB Activity and MAPK Pathway.

  19. Inducible nitric oxide synthase mediates bone loss in ovariectomized mice.

    NARCIS (Netherlands)

    Cuzzocrea, S.; Mazzon, E.; Dugo, L.; Genovese, T.; Paola, R. Di; Ruggeri, Z.; Vegeto, E.; Caputi, A.P.; Loo, F.A.J. van de; Puzzolo, D.; Maggi, A.

    2003-01-01

    Several clinical studies have shown that bone loss may be attributed to osteoclast recruitment induced by mediators of inflammation. In different experimental paradigms we have recently demonstrated that estrogen exhibits antiinflammatory activity by preventing the induction of inducible nitric

  20. Nitric oxide inhibits glycogen synthesis in isolated rat hepatocytes

    NARCIS (Netherlands)

    Sprangers, F.; Sauerwein, H. P.; Romijn, J. A.; van Woerkom, G. M.; Meijer, A. J.

    1998-01-01

    There is increasing evidence for the existence of intrahepatic regulation of glucose metabolism by Kupffer cell products. Nitric oxide (NO) is known to inhibit gluconeogenic flux through pyruvate carboxylase and phosphoenolpyruvate carboxykinase. However, NO may also influence glucose metabolism at

  1. Control of instability in nitric acid evaporators for plutonium processing

    International Nuclear Information System (INIS)

    1998-03-01

    Improved control of the nitric acid process evaporators requires the detection of spontaneously unstable operating conditions. This process reduces the volume of contaminated liquid by evaporating nitric acid and concentrating salt residues. If a instability is identified quickly, prompt response can avert distillate contamination. An algorithm applied to the runtime data was evaluated to detect this situation. A snapshot of data from a histogram in the old process control software was captured during the unstable conditions and modeled

  2. Acute chemical pneumonitis caused by nitric acid inhalation: case report

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Hyung Shim; Lee, In Jae; Ko, Eun Young; Lee, Jae Young; Kim, Hyun Beom; Hwang, Dae Hyun; Lee, Kwan Seop; Lee, Yul; Bae, Sang Hoon [Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of)

    2003-06-01

    Chemical pneumonitis induced by nitric acid inhalation is a rare clinical condition. The previously reported radiologic findings of this disease include acute permeability pulmonary edema, delayed bronchiolitis obliterans, and bronchiectasis. In very few published rare radiologic reports has this disease manifested as acute alveolar injury; we report a case of acute chemical pneumonitis induced by nitric acid inhalation which at radiography manifested as bilateral perihilar consolidation and ground-glass attenuation, suggesting acute alveolar injury.

  3. Formation of nitric acid hydrates - A chemical equilibrium approach

    Science.gov (United States)

    Smith, Roland H.

    1990-01-01

    Published data are used to calculate equilibrium constants for reactions of the formation of nitric acid hydrates over the temperature range 190 to 205 K. Standard enthalpies of formation and standard entropies are calculated for the tri- and mono-hydrates. These are shown to be in reasonable agreement with earlier calorimetric measurements. The formation of nitric acid trihydrate in the polar stratosphere is discussed in terms of these equilibrium constants.

  4. Nitric acid recycling and copper nitrate recovery from effluent.

    Science.gov (United States)

    Jô, L F; Marcus, R; Marcelin, O

    2014-01-01

    The recycling of nitric acid and copper nitrate contained in an industrial effluent was studied. The experiments conducted on such a medium showed that the presence of copper nitrate significantly improves nitric acid-water separation during distillation in an azeotropic medium. At the temperature of the azeotrope, however, this metal salt starts to precipitate, making the medium pasty, thus inhibiting the nitric acid extraction process. The optimisation of parameters such as column efficiency and adding water to the boiler at the azeotrope temperature are recommended in this protocol in order to collect the various components while avoiding the formation of by-products: NOx compounds. Thus, the absence of column, along with the addition of a small volume of water at a temperature of 118 °C, significantly increases the yield, allowing 94 % nitric acid to be recovered at the end of the process, along with the residual copper nitrate. The resulting distillate, however, is sufficiently dilute to not be used as is. Rectification is required to obtain concentrated nitric acid at 15 mol·l(-1), along with a weakly acidic distillate from the distillation front. This latter is quenched using potassium hydroxide and is used as a fertiliser solution for horticulture or sheltered market gardening. This process thus allows complete recycling of all the medium's components, including that of the distillate resulting from the nitric acid rectification operation.

  5. Cellular signaling with nitric oxide and cyclic GMP

    Directory of Open Access Journals (Sweden)

    F. Murad

    1999-11-01

    Full Text Available During the past two decades, nitric oxide signaling has been one of the most rapidly growing areas in biology. This simple free radical gas can regulate an ever growing list of biological processes. In most instances nitric oxide mediates its biological effects by activating guanylyl cyclase and increasing cyclic GMP synthesis. However, the identification of effects of nitric oxide that are independent of cyclic GMP is also growing at a rapid rate. The effects of nitric oxide can mediate important physiological regulatory events in cell regulation, cell-cell communication and signaling. Nitric oxide can function as an intracellular messenger, neurotransmitter and hormone. However, as with any messenger molecule, there can be too much or too little of the substance and pathological events ensue. Methods to regulate either nitric oxide formation, metabolism or function have been used therapeutically for more than a century as with nitroglycerin therapy. Current and future research should permit the development of an expanded therapeutic armamentarium for the physician to manage effectively a number of important disorders. These expectations have undoubtedly fueled the vast research interests in this simple molecule.

  6. Americium removal from nitric acid waste streams

    International Nuclear Information System (INIS)

    Muscatello, A.C.; Navratil, J.D.

    1986-01-01

    Separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve americium removal from nitric acid (7M) waste streams generated by plutonium purification operations. Partial neutralization of the acid waste followed by solid supported liquid membranes (SLM) are useful in transferring and concentrating americium from nitrate solutions. Specifically, DHDECMP (dihexyl-N,N-diethylcarbamoylmethylphosphonate) supported on Accurel polypropylene hollow fibers assembled in modular form transfers >95% of the americium from high nitrate (6.9M), low acid (0.1M) feeds into 0.25M oxalic acid stripping solution. Maximum permeabilities were observed to be 0.001 cm/sec, consistent with typical values for other systems. The feed:strip volume ratio shows an inverse relationship to the fraction of metal ion transferred. Cation exchangers may be used to concentrate americium from the strip solution. Furthermore, O0D (iB)CMPO (or CMPO) (octylphenyl-N-N-diisobutylcarbamoylmethylphosphine oxide) has been tested in an extraction chromatography mode. Preliminary results show CMPO to be effective in removing americium if the feed is neutralized to 1.0M acidity and iron(III) is complexed with 0.20M oxalic acid. 3 figs

  7. Nitric oxide bioavailability dysfunction involves in atherosclerosis.

    Science.gov (United States)

    Chen, Jing-Yi; Ye, Zi-Xin; Wang, Xiu-Fen; Chang, Jian; Yang, Mei-Wen; Zhong, Hua-Hua; Hong, Fen-Fang; Yang, Shu-Long

    2018-01-01

    The pathological characteristics of atherosclerosis (AS) include lipid accumulation, fibrosis formation and atherosclerotic plaque produced in artery intima, which leads to vascular sclerosis, lumen stenosis and irritates the ischemic changes of corresponding organs. Endothelial dysfunction was closely associated with AS. Nitric oxide (NO) is a multifunctional signaling molecule involved in the maintenance of metabolic and cardiovascular homeostasis. NO is also a potent endogenous vasodilator and enters for the key processes that suppresses the formation vascular lesion even AS. NO bioavailability indicates the production and utilization of endothelial NO in organisms, its decrease is related to oxidative stress, lipid infiltration, the expressions of some inflammatory factors and the alteration of vascular tone, which plays an important role in endothelial dysfunction. The enhancement of arginase activity and the increase in asymmetric dimethylarginine and hyperhomocysteinemia levels all contribute to AS by intervening NO bioavailability in human beings. Diabetes mellitus, obesity, chronic kidney disease and smoking, etc., also participate in AS by influencing NO bioavailability and NO level. Here, we reviewed the relationship between NO bioavailability and AS according the newest literatures. Copyright © 2017. Published by Elsevier Masson SAS.

  8. Nasal nitric oxide in unilateral sinus disease.

    Directory of Open Access Journals (Sweden)

    Chia-Hsiang Fu

    Full Text Available Unilateral sinus disease (USD can sometimes be difficult to accurately diagnose before surgery. The application of nasal nitric oxide (nNO for USD diagnosis and its surgical outcome in USD has not been reported in the literature. We prospectively enrolled sixty-six USD patients who underwent endoscopic sinus surgery for fungal rhinosinusitis (n = 19, chronic rhinosinusitis (CRS without nasal polyps (n = 13, CRS with nasal polyps (n = 12 and sinonasal mass lesions (n = 22. nNO levels were measured preoperatively and at three and six months postoperatively. Correlations between nNO levels and potential clinical parameters, type of disease, disease severity, and disease-related quality of life (QOL were assessed. Unlike bilateral CRS, in USD, nNO levels did not correlate with disease severity or postoperative QOL improvements. Except for fungus group, there were no differences in nNO levels between lesion and non-lesion sides in all the other groups. nNO levels on both sides were significantly elevated six months postoperatively in all groups. Fungal rhinosinusitis patients had the lowest preoperative nNO levels, and a cutoff of 239.3 ppb had the best sensitivity (79.0% and specificity (87.2% for preoperative diagnosis. While preoperative nNO levels cannot serve as an alternative marker for disease severity of USD, they were lower in fungal rhinosinusitis patients than in other USD patients and may be useful for more accurate diagnosis prior to surgery.

  9. Nitric oxide and cardiovascular risk factors

    Directory of Open Access Journals (Sweden)

    Livio Dai Cas

    2007-06-01

    Full Text Available The endothelium is a dynamic organ with many properties that takes part in the regulation of the principal mechanisms of vascular physiology. Its principal functions include the control of blood-tissue exchange and permeability, the vascular tonus, and the modulation of inflammatory or coagulatory mechanisms. Many vasoactive molecules, produced by the endothelium, are involved in the control of these functions. The most important is nitric oxide (NO, a gaseous molecule electrically neutral with an odd number of electrons that gives the molecule chemically reactive radical properties. Already known in the twentieth century, NO, sometimes considered as a dangerous molecule, recently valued as an important endogenous vasodilator factor. Recently, it was discovered that it is involved in several physiological mechanisms of endothelial protection (Tab. I. In 1992, Science elected it as “molecule of the year”; 6 yrs later three American researchers (Louis Ignarro, Robert Furchgott and Fried Murad obtained a Nobel Prize for Medicine and Physiology “for their discoveries about NO as signal in the cardiovascular system”.

  10. Nitric acid adduct formation during crystallization of barium and strontium nitrates and their co-precipitation from nitric acid media

    International Nuclear Information System (INIS)

    Mishina, N.E.; Zilberman, B.Ya.; Lumpov, A.A.; Koltsova, T.I.; Puzikov, E.A.; Ryabkov, D.V.

    2015-01-01

    The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate concentration is presented and described by the mass action law, indicating on formation of the adducts with nitric acid. Precipitates of Ba(NO 3 ) 2 and Sr(NO 3 ) 2 crystallized from nitric acid were studied by ISP OES and IR spectroscopy. The data obtained confirmed formation of metastable adducts with nitric acid. IR and X-ray diffraction studies of the mixed salt systems indicated conversion of the mixed salts into (Ba,Sr)(NO 3 ) 2 solid solution of discrete structure in range of total nitrate ion concentration ∼6 mol/L. (author)

  11. Extraction of nitric acid, uranyl nitrate, and bismuth nitrate from aqueous nitric acid solutions with CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B.B.

    1995-08-01

    DOE sponsored development of the transuranium extraction (TRUEX) process for removing actinides from radioactive wastes. The solvent is a mixture of CMPO and TBP. Since the extraction characteristics of CMPO are not as well understood as those of TBP, the extraction of nitric acid, uranyl nitrate, and bismuth nitrate with CMPO (dissolved in n-dodecane) were studied. Results indicate that CMPO extracts nitric acid with a 1:1 stoichiometry; equilibrium constant is 2. 660{plus_minus}0.092 at 25 C, and extraction enthalpy is -5. 46{plus_minus}0.46 kcal/mol. Slope analysis indicates that uranyl nitrate extracts with a mixed equilibria of 1:1 and 2:1 stoichiometries in nearly equal proportion. Equil. constant of the 2: 1 extraction was 1.213 {times} 10{sup 6}{plus_minus}3.56 {times} 10{sup 4} at 25 C; reaction enthalpy was -9.610{plus_minus}0.594 kcal/mol. Nitration complexation constant is 8.412{plus_minus}0.579, with an enthalpy of -10.72{plus_minus}1.87 kcal/mol. Bismuth nitrate also extracts with a mixed equilibria of (perhaps) 1:1 and 2:1 stoichiometries. A 2:1 extraction equilibrium and a nitrate complexation adequately model the data. Kinetics and enthalpies were also measured.

  12. Extraction of nitric acid, uranyl nitrate, and bismuth nitrate from aqueous nitric acid solutions with CMPO

    International Nuclear Information System (INIS)

    Spencer, B.B.

    1995-08-01

    DOE sponsored development of the transuranium extraction (TRUEX) process for removing actinides from radioactive wastes. The solvent is a mixture of CMPO and TBP. Since the extraction characteristics of CMPO are not as well understood as those of TBP, the extraction of nitric acid, uranyl nitrate, and bismuth nitrate with CMPO (dissolved in n-dodecane) were studied. Results indicate that CMPO extracts nitric acid with a 1:1 stoichiometry; equilibrium constant is 2. 660±0.092 at 25 C, and extraction enthalpy is -5. 46±0.46 kcal/mol. Slope analysis indicates that uranyl nitrate extracts with a mixed equilibria of 1:1 and 2:1 stoichiometries in nearly equal proportion. Equil. constant of the 2: 1 extraction was 1.213 x 10 6 ±3.56 x 10 4 at 25 C; reaction enthalpy was -9.610±0.594 kcal/mol. Nitration complexation constant is 8.412±0.579, with an enthalpy of -10.72±1.87 kcal/mol. Bismuth nitrate also extracts with a mixed equilibria of (perhaps) 1:1 and 2:1 stoichiometries. A 2:1 extraction equilibrium and a nitrate complexation adequately model the data. Kinetics and enthalpies were also measured

  13. Nitric oxide amplifies the rat electroretinogram.

    Science.gov (United States)

    Vielma, Alex; Delgado, Luz; Elgueta, Claudio; Osorio, Rodrigo; Palacios, Adrián G; Schmachtenberg, Oliver

    2010-11-01

    It is well established that nitric oxide (NO) participates in retinal signal processing through stimulation of its receptor enzyme, soluble guanylyl cyclase (sGC). However, under pathological conditions such as uveoretinitis, diabetic or ischemic retinopathy, elevated NO concentrations may cause protein S-nitrosation and peroxynitrite formation in the retina, promoting cellular injury and apoptosis. Previous electroretinogram (ERG) studies demonstrated deleterious effects of NO on the retinal light response, but showed no evidence for a role in normal signal processing. To better understand the function of NO in ocular physiology, we investigated the effects of exogenous NO, produced by NO donors with different release kinetics, on the flash ERG of the rat. Within a limited concentration range, NO strongly amplified ERG a- and b-waves, oscillatory potentials, and the scotopic threshold response. Amplification exceeded 100% under dark adaptation, whereas the photopic ERG and the isolated cone response were increased by less than 50%. Blocking photoreceptor-bipolar cell synapses by AP-4 demonstrated a significant increase of the isolated a-wave by NO, and modeling the ERG generator PIII supported photoreceptors as primary NO targets. The sGC inhibitors ODQ and NS2028 did not reduce NO-dependent ERG amplification, ruling out an involvement of the classical NO effector cyclic GMP. Using immunohistochemistry, we show that illumination and exogenous NO altered the S-nitrosation level of the photoreceptor layer, suggesting that direct protein modifications caused by elevated levels of NO may be responsible for the observed phenomenon. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Genetic responses against nitric oxide toxicity

    Directory of Open Access Journals (Sweden)

    B. Demple

    1999-11-01

    Full Text Available The threat of free radical damage is opposed by coordinated responses that modulate expression of sets of gene products. In mammalian cells, 12 proteins are induced by exposure to nitric oxide (NO levels that are sub-toxic but exceed the level needed to activate guanylate cyclase. Heme oxygenase 1 (HO-1 synthesis increases substantially, due to a 30- to 70-fold increase in the level of HO-1 mRNA. HO-1 induction is cGMP-independent and occurs mainly through increased mRNA stability, which therefore indicates a new NO-signaling pathway. HO-1 induction contributes to dramatically increased NO resistance and, together with the other inducible functions, constitutes an adaptive resistance pathway that also defends against oxidants such as H2O2. In E. coli, an oxidative stress response, the soxRS regulon, is activated by direct exposure of E. coli to NO, or by NO generated in murine macrophages after phagocytosis of the bacteria. This response is governed by the SoxR protein, a homodimeric transcription factor (17-kDa subunits containing [2Fe-2S] clusters essential for its activity. SoxR responds to superoxide stress through one-electron oxidation of the iron-sulfur centers, but such oxidation is not observed in reactions of NO with SoxR. Instead, NO nitrosylates the iron-sulfur centers of SoxR both in vitro and in intact cells, which yields a form of the protein with maximal transcriptional activity. Although nitrosylated SoxR is very stable in purified form, the spectroscopic signals for the nitrosylated iron-sulfur centers disappear rapidly in vivo, indicating an active process to reverse or eliminate them.

  15. Myeloperoxidase potentiates nitric oxide-mediated nitrosation.

    Science.gov (United States)

    Lakshmi, Vijaya M; Nauseef, William M; Zenser, Terry V

    2005-01-21

    Nitrosation is an important reaction elicited by nitric oxide (NO). To better understand how nitrosation occurs in biological systems, we assessed the effect of myeloperoxidase (MPO), a mediator of inflammation, on nitrosation observed during NO autoxidation. Nitrosation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ; 10 mum) to 2-nitrosoamino-3-methylimidazo[4,5-f]quinoline (N-NO-IQ) was monitored by HPLC. Using the NO donor spermine NONOate at pH 7.4, MPO potentiated N-NO-IQ formation. The minimum effective quantity of necessary components was 8.5 nm MPO, 0.25 mum H(2)O(2)/min, and 0.024 mum NO/min. Autoxidation was only detected at >/=1.2 mum NO/min. MPO potentiation was not affected by a 40-fold excess flux of H(2)O(2) over NO or less than a 2.4-fold excess flux of NO over H(2)O(2). Potentiation was due to an 8.8-fold increased affinity of MPO-derived nitrosating species for IQ. Autoxidation was inhibited by azide, suggesting involvement of the nitrosonium ion, NO(+). MPO potentiation was inhibited by NADH, but not azide, suggesting oxidative nitrosylation with NO(2)(.) or an NO(2)(.)-like species. MPO nonnitrosative oxidation of IQ with 0.3 mm NO(2)(-) at pH 5.5 was inhibited by azide, but not NADH, demonstrating differences between MPO oxidation of IQ with NO compared with NO(2)(-). Using phorbol ester-stimulated human neutrophils, N-NO-IQ formation was increased with superoxide dismutase and inhibited by catalase and NADH, but not NaN(3). This is consistent with nitrosation potentiation by MPO, not peroxynitrite. Increased N-NO-IQ formation was not detected with polymorphonuclear neutrophils from two unrelated MPO-deficient patients. Results suggest that the highly diffusible stable gas NO could initiate nitrosation at sites of neutrophil infiltration.

  16. Mechanism of nitric acid generation on Ag-X Zeolite

    International Nuclear Information System (INIS)

    Kanazawa, T.; Kishimoto, T.; Haseba, S.; Mitoh, Y.; Itoh, S.; Nakai, I.

    1983-01-01

    When Ag-X Zeolite is used for the removal of iodine from the off gas streams of nuclear facilities, it is possible that nitric acid is formed on Ag-X Zeolite from co-existing nitrogen dioxide and water vapor. If nitric acid is formed on the surface of Ag-X zeolite, Ag-X zeolite is damaged and is not able to operate for a long time. When Ag-X zeolite is used in NO 2 -O 2 -H 2 O mixture, the nitric acid generation reaction is varied, depending upon the reaction temperature, and concentration of NO 2 and H 2 O. At a temperature of more than 40 deg. C, however, only the surface reaction will be progressed on the zeolite surface. The generation of nitric acid solution on the zeolite can be forecasted through the relationship between the concentration of nitric acid solution, equilibrium vapor pressure of H 2 O, and equilibrium vapor pressure of HNO 3 . Concerning the surface reaction caused on the zeolite, the adsorption water reacts on NO 2 , and the resulting HNO 3 is adsorbed firmly by the zeolite, which is thought to interfere with the surface reaction for generation of the HNO 3 . When the adsorption bed is long, the time required for adsorbed HNO 3 to saturate is increased in proportion to the bed length

  17. Mitochondrial dysfunction associated with nitric oxide pathways in glutamate neurotoxicity.

    Science.gov (United States)

    Manucha, Walter

    Multiple mechanisms underlying glutamate-induced neurotoxicity have recently been discussed. Likewise, a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with neurodegeneration, oxidative stress, and inflammation. This article highlights nitric oxide, an atypical neurotransmitter synthesized and released on demand by the post-synaptic neurons, and has many important implications for nerve cell survival and differentiation. Consequently, synaptogenesis, synapse elimination, and neurotransmitter release, are nitric oxide-modulated. Interesting, an emergent role of nitric oxide pathways has been discussed as regards neurotoxicity from glutamate-induced apoptosis. These findings suggest that nitric oxide pathways modulation could prevent oxidative damage to neurons through apoptosis inhibition. This review aims to highlight the emergent aspects of nitric oxide-mediated signaling in the brain, and how they can be related to neurotoxicity, as well as the development of neurodegenerative diseases development. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Nitric Oxide in Astrocyte-Neuron Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nianzhen [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca2+ elevations in response to neurotransmitters. A Ca2+ elevation can propagate to adjacent astrocytes as a Ca2+ wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca2+-dependent mechanism, thus modulating neuronal activity and synaptic transmission. In this dissertation, the author investigated the roles of another endogenous signal, nitric oxide (NO), in astrocyte-neuron signaling. First the author tested if NO is generated during astrocytic Ca2+ signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a natural messenger, ATP, caused a Ca2+-dependent NO production. To test the roles of NO in astrocytic Ca2+ signaling, the author applied NO to astrocyte cultures via addition of a NO donor, S-nitrosol-N-acetylpenicillamine (SNAP). NO induced an influx of external Ca2+, possibly through store-operated Ca2+ channels. The NO-induced Ca2+ signaling is cGMP-independent since 8-Br-cGMP, an agonistic analog of cGMP, did not induce a detectable Ca2+ change. The consequence of this NO-induced Ca2+ influx was assessed by simultaneously monitoring of cytosolic and internal store Ca2+ using fluorescent Ca2+ indicators x-rhod-1 and mag-fluo-4. Blockage of NO signaling with the NO scavenger PTIO significantly reduced the refilling percentage of internal stores following ATP-induced Ca2+ release, suggesting that NO modulates internal store refilling. Furthermore, locally photo-release of NO to a single astrocyte led to a Ca2+ elevation in the stimulated astrocyte and a subsequent Ca2+ wave to neighbors. Finally, the author tested the role of NO inglutamate-mediated astrocyte-neuron signaling by

  19. Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

    Science.gov (United States)

    Benzing, A; Loop, T; Mols, G; Geiger, K

    1999-10-01

    Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the

  20. Photochemical reactions of neptunium in nitric acid solution containing photocatalyst

    International Nuclear Information System (INIS)

    Fukasawa, Tetsuo; Kawamura, Fumio

    1991-01-01

    Photochemical oxidation and reduction behaviors of neptunium were preliminarily investigated in 3 mol/l nitric acid solution. Nitric acid of 3 mol/l simulated the high level waste solution from a spent fuel reprocessing process. Concentrations of Np(V), Np(VI) and nitrous acid were determined with a photospectrometer, and solution potential with an electrode. Without additives, Np(VI) was reduced to Np(V) by nitrous acid which was photolytically generated from nitric acid. With a scavenger for nitrous acid, Np(V) was oxidized to extractable Np(VI) by a photolytically generated oxidizing reagent which were predicted by the solution potential measurement. The reduction rate was higher than the oxidation rate because of the larger quantity and higher reactivity of nitrous acid than an oxidizing reagent. Photocatalyst was proved to be effective for the oxidation of Np(V) to Np(VI). (author)

  1. Pain modulation by nitric oxide in the spinal cord.

    Directory of Open Access Journals (Sweden)

    Marco Aurelio M Freire

    2009-09-01

    Full Text Available Nitric oxide (NO is a versatile messenger molecule first associated with endothelial relaxing effects. In the central nervous system (CNS, NO synthesis is primarily triggered by activation of N-methyl-D-aspartate (NMDA receptors and has a Janus face, with both beneficial and harmful properties, depending on concentration and the identity of its synthetic enzyme isoform. There are three isoforms of the NO synthesizing enzyme nitric oxide synthase (NOS: neuronal (nNOS, endothelial (eNOS, and inducible nitric oxide synthase (iNOS, each one involved with specific events in the brain. In CNS, nNOS is involved with modulation of synaptic transmission through long-term potentiation in several regions, including nociceptive circuits in the spinal cord. Here, we review the role played by NO on central pain sensitization.

  2. Vapor-liquid equilibria for nitric acid-water and plutonium nitrate-nitric acid-water solutions

    International Nuclear Information System (INIS)

    Maimoni, A.

    1980-01-01

    The liquid-vapor equilibrium data for nitric acid and nitric acid-plutnonium nitrate-water solutions were examined to develop correlations covering the range of conditions encountered in nuclear fuel reprocessing. The scanty available data for plutonium nitrate solutions are of poor quality but allow an order of magnitude estimate to be made. A formal thermodynamic analysis was attempted initially but was not successful due to the poor quality of the data as well as the complex chemical equilibria involved in the nitric acid and in the plutonium nitrate solutions. Thus, while there was no difficulty in correlating activity coefficients for nitric acid solutions over relatively narrow temperature ranges, attempts to extend the correlations over the range 25 0 C to the boiling point were not successful. The available data were then analyzed using empirical correlations from which normal boiling points and relative volatilities can be obtained over the concentration ranges 0 to 700 g/l Pu, 0 to 13 M nitric acid. Activity coefficients are required, however, if estimates of individual component vapor pressures are needed. The required ternary activity coefficients can be approximated from the correlations

  3. Unsymmetrical phosphate as extractant for the extraction of nitric acid

    International Nuclear Information System (INIS)

    Gaikwad, R.H.; Jayaram, R.V.

    2016-01-01

    Tri-n-butyl phosphate (TBP) was first used as an extractant in 1944, during Manhattan project for the separation of actinides and further explored by Warf in 1949 for the extraction of Ce(IV) from aqueous nitric acid. TBP was further used as an extractant in the Plutonium Uranium Recovery by Extraction (PUREX) process. To meet the stringent requirements of the nuclear industry TBP has been extensively investigated. In spite of its wide applicability, TBP suffers from various disadvantages such as high aqueous solubility, third phase formation, chemical and radiation degradation leading to the formation of undesired products. It also suffers from incomplete decontamination of the actinides from fission products. Various attempts have been made to overcome the problems associated with TBP by way of using higher homologues of TBP such as Tri-iso amyl phosphate (TiAP), Tri-secondary butyl phosphate (TsBP), Tri amyl phosphate (TAP). It was found that in some cases the results were considerably better than those obtained with TBP for uranium/thorium extraction. The extraction of nitric acid by TBP and its higher homologues which are symmetrical are well documented. However, no solvent has emerged clearly superior than TBP. Here in we report the extraction of nitric acid with neutral unsymmetrical phosphates and study them as extractants for the extraction of nitric acid. Dibutyl secbutyl phosphate, dibutyl pentyl phosphate and dibutyl heptyl phosphate were synthesised for this purpose and the extraction of nitric acid was studied in n-dodecane. The results indicate that the substitution of one of the alkyl groups of the symmetrical phosphate adjacent to the phosphoryl (P=O) group of the phosphate does not have any pronounced effect on the extraction capacity of nitric acid. (author)

  4. Study of niobium V compounds in nitric medium

    International Nuclear Information System (INIS)

    Gue, J.-P.; Kikindai, Tivadar; CEA Centre d'Etudes Nucleaires de Fontenay-aux-Roses, 92

    1976-01-01

    Nitric solutions of niobium V were studied in the range of concentrations of 5.10 -6 M to 0,5.10 -3 M in niobium and 0,4 to 10N in nitric acid. Methods used were light scattering, electron microscopy, electrophoresis and ultracentrifugation. It is shown that niobium was in a colloidal hydroxide form. Solvent extraction studies were performed with dibutyl phosphoric acid diluted in dodecane. It appears that floculation of the sol occurs for weak organic acid concentrations. But if the concentration increases, the precipitated niobium compound is redissolved in the organic phase [fr

  5. Corrosion resistance of zirconium: general mechanisms, behaviour in nitric acid

    International Nuclear Information System (INIS)

    Pinard Legry, G.

    1990-01-01

    Corrosion resistance of zirconium results from the strong affinity of this metal for oxygen; as a result a thin protective oxide film is spontaneously formed in air or aqueous media, its thickness and properties depending on the physicochemical conditions at the interface. This film passivates the underlying metal but obviously if the passive film is partially or completely removed, localised or generalised corrosion phenomena will occur. In nitric acid, this depassivation may be chemical (fluorides) or mechanical (straining, creep, fretting). In these cases it is useful to determine the physicochemical conditions (concentration, temperature, potential, stress) which will have to be observed to use safely zirconium and its alloys in nitric acid solutions [fr

  6. Adrenoceptor-activated nitric oxide synthesis in salivary acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia; Dissing, Steen; Tritsaris, Katerina

    2000-01-01

    We investigated the cellular regulation of nitric oxide synthase (NOS) activity in isolated acinar cells from rat parotid and human labial salivary glands, using the newly developed fluorescent nitric oxide (NO) indicator, DAF-2. We found that sympathetic stimulation with norepinephrine (NE) caused...... a strong increase in NO synthesis that was not seen after parasympathetic stimulation with acetylcholine. In rat parotid acinar cells, we furthermore investigated to which extent the NOS activity was dependent on the intracellular free Ca2+ concentration ([Ca2+]i) by simultaneously measuring NO synthesis...

  7. A nitric oxide donor (nitroglycerin) triggers genuine migraine attacks

    DEFF Research Database (Denmark)

    Thomsen, L L; Kruuse, C; Iversen, Helle Klingenberg

    1994-01-01

    Supersensitivity to induction of headache and arterial dilatation by a donor of nitric oxide (nitroglycerin) has recently been demonstrated in migraine sufferers. The aims of the present study were to examine whether the nitric oxide donor nitroglycerin may induce a typical migraine attack......, to exclude placebo-related effects and to describe the relation between middle cerebral artery dilatation and provoked migraine. Nitroglycerin (0.5 μg/kg/min for 20 min) or placebo was infused into 12 migraine patients in a double-blind cross-over trial. Blood velocity in the middle cerebral artery...

  8. Detection of nitric acid and nitric oxides in the terrestrial atmosphere in the middle-infrared spectral region

    Directory of Open Access Journals (Sweden)

    M. I. Blecka

    1996-11-01

    Full Text Available A proposal for combined space and ground-based observations of the vertical distributions and the column densities of nitric acid and nitric oxide concentrations in the earth's atmosphere is discussed. We focus on the aspects that are particular to the idea of correlative measurements: geometrical considerations, simulations of the solar absorption spectra in the middle-infrared region corresponding to the different observational geometries, and the associated retrieval methods. These studies are done specifically for the Belgian-French experiment MIRAS (MIR Infrared Atmospheric Spectrometer onboard the Russian Space Station MIR and correlative ground-based FTIR measurements in the Tatra mountains.

  9. Production of nitric oxide using a microwave plasma torch and its application to fungal cell differentiation

    International Nuclear Information System (INIS)

    Na, Young Ho; Kang, Min-Ho; Cho, Guang Sup; Choi, Eun Ha; Park, Gyungsoon; Uhm, Han Sup; Kumar, Naresh

    2015-01-01

    The generation of nitric oxide by a microwave plasma torch is proposed for its application to cell differentiation. A microwave plasma torch was developed based on basic kinetic theory. The analytical theory indicates that nitric oxide density is nearly proportional to oxygen molecular density and that the high-temperature flame is an effective means of generating nitric oxide. Experimental data pertaining to nitric oxide production are presented in terms of the oxygen input in units of cubic centimeters per minute. The apparent length of the torch flame increases as the oxygen input increases. The various levels of nitric oxide are observed depending on the flow rate of nitrogen gas, the mole fraction of oxygen gas, and the microwave power. In order to evaluate the potential of nitric oxide as an activator of cell differentiation, we applied nitric oxide generated from the microwave plasma torch to a model microbial cell (Neurospora crassa: non-pathogenic fungus). Germination and hyphal differentiation of fungal cells were not dramatically changed but there was a significant increase in spore formation after treatment with nitric oxide. In addition, the expression level of a sporulation related gene acon-3 was significantly elevated after 24 h upon nitric oxide treatment. Increase in the level of nitric oxide, nitrite and nitrate in water after nitric oxide treatment seems to be responsible for activation of fungal sporulation. Our results suggest that nitric oxide generated by plasma can be used as a possible activator of cell differentiation and development. (paper)

  10. Reproducibility of exhaled nitric oxide measurements in overweight and obese adults

    NARCIS (Netherlands)

    Thijs, Willemien; de Mutsert, Renée; le Cessie, Saskia; Hiemstra, Pieter S.; Rosendaal, Frits R.; Middeldorp, Saskia; Rabe, Klaus F.

    2014-01-01

    Exhaled nitric oxide is a noninvasive measure of airway inflammation that can be detected by a handheld device. Obesity may influence the reproducibility of exhaled nitric oxide measurements, by - for instance - decreased expiratory reserve volume. We analyzed triple exhaled nitric oxide

  11. Variation of nitric oxide levels in imported Plasmodium falciparum ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... ISSN 1684–5315 © 2008 Academic Journals. Full Length Research Paper. Variation of nitric oxide levels in imported Plasmodium falciparum malaria episodes. De Sousa, Karina*, Silva, Marcelo S. and Tavira, Luís T. Instituto de Higiene e Medicina Tropical, Centro de Malária e outras Doenças Tropicais, ...

  12. Methanol Extract of Codonopsis pilosula Inhibits Inducible Nitric ...

    African Journals Online (AJOL)

    Purpose: To evaluate the mechanism of antioxidant activity of the methanol extract of Codonopsis pilosula. Methods: Anti-oxidative properties were assessed by measuring free radical scavenging activity, nitric oxide (NO) levels, protein oxidation and reducing power, while the mechanism of antioxidative effect of ...

  13. Nitric oxide radical scavenging potential of some Elburz medicinal ...

    African Journals Online (AJOL)

    Some plants scavenge nitric oxide (NO) with high affinity. For this purpose, forty extracts from 26 medicinal plants, growing extensively in Elburz mountains, were evaluated for their NO scavenging activity. Total phenolic and flavonoid contents of these extracts were also measured by Folin Ciocalteu and AlCl3 colorimetric ...

  14. On EPR detection of nitric oxide in vivo

    NARCIS (Netherlands)

    van Faassen, E.E.H.

    2008-01-01

    Nitric oxide (NO ) is a peculiar radical: Ground state is not paramagnetic (g = 0 since orbital and spin magnetic moments cancel); low reactivity with other molecules except superoxide (O2 ); thermodynamically unstable; dimerizes to N2O2; difficult to detect in-vivo.

  15. Estimation of the nitric oxide formed from hydroxylamine by Nitrosomonas

    Science.gov (United States)

    Anderson, J. H.

    1965-01-01

    1. Nitric oxide that was produced by reducing nitrite with an excess of acidified potassium iodide under nitrogen in Warburg respirometer flasks was rapidly absorbed by a solution of permanganate in sodium hydroxide held in the side arm. A small amount of nitrous oxide (or nitrogen) that was also produced was not absorbed. 2. By using a quantitative method for the recovery of nitrite from samples of the alkaline permanganate, it was found that the sum of the nitrite N formed and the residual nitrous oxide N was equivalent to the nitrite N used to generate the gases. These results showed that alkaline permanganate completely oxidized nitric oxide to nitrite. The method was suitable for determining 0·4–20 μmoles of nitric oxide. 3. The technique was used to determine the nitric oxide content of the nitrogenous gas that was produced anaerobically from hydroxylamine by an extract of the autotrophic nitrifying micro-organism Nitrosomonas in the presence of methylene blue as electron acceptor. PMID:14342235

  16. Variation of nitric oxide levels in imported Plasmodium falciparum ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... Nitric oxide (NO) has been recognized during the past two decades as one of the most versatile players in the immune system. Even though the molecular mechanisms responsible by the naturally acquired immunity against malaria are still to be clarified, the production of NO seems to play an important role.

  17. Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 ...

    African Journals Online (AJOL)

    HP

    Won Chung, Jin Uk Oh, Sehyung Lee and Sung-Jin Kim* ... was determined by Western blot analysis for iNOS and COX-2 expression in LPS-stimulated RAW ..... Nitric oxide-scavenging and antioxidant effects ofUraria crinite root. Food.

  18. Nitric oxide and neopterin in bipolar affective disorder

    NARCIS (Netherlands)

    Hoekstra, R.; Fekkes, D.; Pepplinkhuizen, L.; Loonen, A.J.M.; Tuinier, S.; Verhoeven, W.M.A.

    2006-01-01

    Background: There is an increasing interest in the role of nitric oxide (NO) and pterines in the pathophysiology of neuropsychiatric disorders. The results so far show an inconsistent pattern. Methods: In the present study, neopterin and a measure of NO synthesis in plasma of symptomatic and

  19. Total Glucosides of Paeonia lactiflora Pall Suppress Nitric Oxide ...

    African Journals Online (AJOL)

    iNOS) expression and ... Keywords: Total glucosides, Paeonia lactiflora, Nitric oxide, iNOs, Nuclear factor-κB. Tropical Journal of Pharmaceutical Research ... Nuclear factor (NF)-κB is the key transcriptional factor regulating iNOS gene transcription.

  20. Localization of nitric oxide synthase in human skeletal muscle

    DEFF Research Database (Denmark)

    Frandsen, Ulrik; Lopez-Figueroa, M.; Hellsten, Ylva

    1996-01-01

    The present study investigated the cellular localization of the neuronal type I and endothelial type III nitric oxide synthase in human skeletal muscle. Type I NO synthase immunoreactivity was found in the sarcolemma and the cytoplasm of all muscle fibres. Stronger immunoreactivity was expressed...

  1. Nitric oxide in health and disease of the respiratory system

    NARCIS (Netherlands)

    Ricciardolo, Fabio L. M.; Sterk, Peter J.; Gaston, Benjamin; Folkerts, Gert

    2004-01-01

    During the past decade a plethora of studies have unravelled the multiple roles of nitric oxide (NO) in airway physiology and pathophysiology. In the respiratory tract, NO is produced by a wide variety of cell types and is generated via oxidation of l-arginine that is catalyzed by the enzyme NO

  2. Serum Iron and Nitric Oxide Production in Trypanosoma brucei ...

    African Journals Online (AJOL)

    JTEkanem

    reduction in the serum iron status and a modulation of nitric oxide synthase activity of T. brucei infected rats. ... inflammation and tissue damage15. ... The serum iron level was determined ... concentration or of total nitrate and nitrite ... 15. 16. 17. 18. Days. S e ru m iro n lev e l mg. /ml. Infected treated. Infected untreated. 0.

  3. Cellular inactivation of nitric oxide induces p53-dependent ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research August 2016; 15 (8): 1595-1603 ... Cellular inactivation of nitric oxide induces p53-dependent apoptosis in ... apoptosis induced by a selective iNOS inhibitor, N-[(3-aminomethyl) benzyl] acetamidine (1400W), .... and nitrate. ... Nitrite production was measured in culture media.

  4. Endothelial nitric oxide synthase polymorphism G298T in ...

    Indian Academy of Sciences (India)

    Supplementary data: Endothelial nitric oxide synthase polymorphism G298T in association with oxidative DNA damage in coronary atherosclerosis. Rajesh G. Kumar, Mrudula K. Spurthi, Kishore G. Kumar, Sanjib K. Sahu and Surekha H. Rani. J. Genet. 91, 349–352. Table 1. The demographic and clinical data of the CHD ...

  5. Aluminium dissolution for spray pulverization with nitric acid

    International Nuclear Information System (INIS)

    Rodrigo Otero, A.; Rodrigo Vilaseca, F.; Morales Calvo, G.

    1977-01-01

    A comparative study of the nitric acid dissolution of aluminium, by immersion and spray pulverization has been carried out in laboratory scale. As a result, the optimum operation conditions to control reaction in the plant are fixed. Operation costs are also evaluated. (author) [es

  6. Mechanisms of electrochemical reduction and oxidation of nitric oxide

    NARCIS (Netherlands)

    Vooys, de A.C.A.; Beltramo, G.L.; Riet, van B.; Veen, van J.A.R.; Koper, M.T.M.

    2004-01-01

    A summary is given of recent work on the reactivity of nitric oxide on various metal electrodes. The significant differences between the reactivity of adsorbed NO and NO in solution are pointed out, both for the reduction and the oxidation reaction(s). Whereas adsorbed NO can be reduced only to

  7. Nitric acid flowsheet with late wash PHA testing

    International Nuclear Information System (INIS)

    Zamecnik, J.R.

    1993-01-01

    This Task Technical Plan outlines the activities to be conducted in the Integrated DWPF Melter System (IDMS) in ongoing support of the Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) utilizing the Nitric Acid Flowsheet in the Sludge Receipt and Adjustment Tank (SRAT) and Precipitate Hydrolysis Aqueous (PHA) produced by the Late Wash Flowsheet. The IDMS facility is to be operated over a series of runs (2 to 4) using the Nitric Acid Flowsheet. The PHA will be produced with the Late Wash Flowsheet in the Precipitate Hydrolysis Experimental Facility (PHEF). All operating conditions shall simulate the expected DWPF operating conditions as closely as possible. The task objectives are to perform at least two IDMS runs with as many operating conditions as possible at nominal DWPF conditions. The major purposes of these runs are twofold: verify that the combined Late Wash and Nitric Acid flowsheets produce glass of acceptable quality without additional changes to process equipment, and determine the reproducibility of data from run to run. These runs at nominal conditions will be compared to previous runs made with PHA produced from the Late Wash flowsheet and with the Nitric Acid flowsheet in the SRAT (Purex 4 and Purex 5)

  8. Simulated dry deposition of nitric acid near forest edges

    NARCIS (Netherlands)

    DeJong, JJM; Klaassen, W; Jong, J.J.M. de

    1997-01-01

    Dry deposition is simulated to understand and generalize observations of enhanced deposition of air pollution near forest edges. Nitric acid is taken as an example as its deposition velocity is often assumed to be determined by turbulent transport only. The simulations are based on the

  9. Extraction of fission product rhodium from nitric acid solutions. 1

    International Nuclear Information System (INIS)

    Gorski, B.; Beer, M.; Russ, L.

    1988-01-01

    The extraction of noble metals from nitric acid solutions represents one problem of separating valueable substances from nuclear wastes in nuclear fuel reprocessing. Results of distribution experiments demonstrate the possibility of solvent extraction of rhodium using tertiary amines in presence of nitrite. Even short mixing times realize high distribution coefficients allowing quantitative separation from aqueous solutions. (author)

  10. Water vapour and carbon dioxide decrease nitric oxide readings

    NARCIS (Netherlands)

    vanderMark, TW; Kort, E; Meijer, RJ; Postma, DS; Koeter, GH

    Measurement of nitric oxide levels in exhaled ah-is commonly performed using a chemiluminescence detector. However, water vapour and carbon dioxide affect the chemiluminescence process, The influence of these gases at the concentrations present in exhaled air has not vet been studied. For this in

  11. Melatonin inhibits endothelin-1 and induces endothelial nitric oxide ...

    African Journals Online (AJOL)

    Although, I/R augmented the endothelin-1 (ET-1) gene expression and the level of big endothelin-1 (big ET-1) in liver tissue, melatonin attenuated these increases. Conversely, non-significant decrease in endothelial nitric oxide synthase (eNOS) mRNA expression in I/R group was significantly elevated by melatonin in ...

  12. Analysis of genetic variation of inducible nitric oxide synthase and ...

    African Journals Online (AJOL)

    The genetic diversity of 100 Malaysian native chickens was investigated using polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) for two candidate genes: inducible nitric oxide synthase (INOS) and natural resistance-associated macrophage protein 1 (NRAMP1). The two genes were selected ...

  13. Arginine, citrulline and nitric oxide metabolism in sepsis

    Science.gov (United States)

    Arginine has vasodilatory effects, via its conversion by nitric oxide (NO) synthase into NO, and immunomodulatory actions that play important roles in sepsis. Protein breakdown affects arginine availability, and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore a...

  14. Mechanism of nitric acid reduction and kinetic modelling

    International Nuclear Information System (INIS)

    Sicsic, David; Balbaud-Celerier, Fanny; Tribollet, Bernard

    2014-01-01

    In France, the recycling of nuclear waste fuels involves the use of hot concentrated nitric acid. The understanding and prediction of the behaviour of the structural materials (mainly austenitic stainless steels) requires the determination and modelling of the nitric acid reduction process. Nitric acid is indirectly reduced by an autocatalytic mechanism depending on the cathodic overpotential and acid concentration. This mechanism has been widely studied. All the authors agree on its autocatalytic nature, characterized by the predominant role of the reduction products. It is also generally admitted that neither nitric acid nor the nitrate ion is the electro-active species. However, the nature of the electro-active species, the place where the catalytic species regenerates and the thermodynamic and kinetic behaviour of the reaction intermediates remain uncertain. The aim of this study was to clarify some of these uncertainties by performing an electrochemical investigation of the reduction of 4 M nitric acid at 40 C at an inert electrode (platinum or gold). An inert electrode was chosen as the working electrode in a first step to avoid its oxidation and focus the research on the reduction mechanism. This experimental work enabled us to suggest a coherent sequence of electrochemical and chemical reactions. Kinetic modelling of this sequence was then carried out for a gold rotating disk electrode. A thermodynamic study at 25 C allowed the composition of the liquid and gaseous phases of nitric acid solutions in the concentration range 0.5-22 M to be evaluated. The kinetics of the reduction of 4 M nitric acid was investigated by cyclic voltammetry and chrono-amperometry at an inert electrode at 40 C. The coupling of chrono-amperometry and FTIR spectroscopy in the gaseous phase led to the identification of the gaseous reduction products as a function of the cathodic overpotential. The results showed that the reduction process is autocatalytic for potentials between 0

  15. Non-asthmatic patients show increased exhaled nitric oxide concentrations

    Directory of Open Access Journals (Sweden)

    Beatriz M. Saraiva-Romanholo

    2009-01-01

    Full Text Available OBJECTIVE: Evaluate whether exhaled nitric oxide may serve as a marker of intraoperative bronchospasm. INTRODUCTION: Intraoperative bronchospasm remains a challenging event during anesthesia. Previous studies in asthmatic patients suggest that exhaled nitric oxide may represent a noninvasive measure of airway inflammation. METHODS: A total of 146,358 anesthesia information forms, which were received during the period from 1999 to 2004, were reviewed. Bronchospasm was registered on 863 forms. From those, three groups were identified: 9 non-asthmatic patients (Bronchospasm group, 12 asthmatics (Asthma group and 10 subjects with no previous airway disease or symptoms (Control group. All subjects were submitted to exhaled nitric oxide measurements (parts/billion, spirometry and the induced sputum test. The data was compared by ANOVA followed by the Tukey test and Kruskal-Wallis followed by Dunn's test. RESULTS: The normal lung function test results for the Bronchospasm group were different from those of the asthma group (p <0.05. The median percentage of eosinophils in induced sputum was higher for the Asthma [2.46 (0.45-6.83] compared with either the Bronchospasm [0.55 (0-1.26] or the Control group [0.0 (0] (p <0.05; exhaled nitric oxide followed a similar pattern for the Asthma [81.55 (57.6-86.85], Bronchospasm [46.2 (42.0 -62.6] and Control group [18.7 (16.0-24.7] (p< 0.05. CONCLUSIONS: Non-asthmatic patients with intraoperative bronchospasm detected during anesthesia and endotracheal intubation showed increased expired nitric oxide.

  16. Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds

    Directory of Open Access Journals (Sweden)

    A.C. Pereira

    2011-09-01

    Full Text Available During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP production, which in turn leads to protein kinase G (PKG activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described.

  17. Interleukin 1 beta induces diabetes and fever in normal rats by nitric oxide via induction of different nitric oxide synthases

    DEFF Research Database (Denmark)

    Reimers, J I; Bjerre, U; Mandrup-Poulsen, T

    1994-01-01

    Substantial in vitro evidence suggests that nitric oxide may be a major mediator of interleukin 1 (IL-1) induced pancreatic beta-cell inhibition and destruction in the initial events leading to insulin-dependent diabetes mellitus. Using NG-nitro-L-arginine methyl ester, an inhibitor of both...

  18. Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

    Energy Technology Data Exchange (ETDEWEB)

    Reger, Nina A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Meng, Wilson S. [Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282 (United States); Gawalt, Ellen S., E-mail: gawalte@duq.edu [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219 (United States)

    2017-04-15

    Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

  19. Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

    International Nuclear Information System (INIS)

    Reger, Nina A.; Meng, Wilson S.; Gawalt, Ellen S.

    2017-01-01

    Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

  20. Nitric oxide-induced interstrand cross-links in DNA.

    Science.gov (United States)

    Caulfield, Jennifer L; Wishnok, John S; Tannenbaum, Steven R

    2003-05-01

    The DNA damaging effects of nitrous acid have been extensively studied, and the formation of interstrand cross-links have been observed. The potential for this cross-linking to occur through a common nitrosating intermediate derived from nitric oxide is investigated here. Using a HPLC laser-induced fluorescence (LIF) system, the amount of interstrand cross-link formed on nitric oxide treatment of the 5'-fluorescein-labeled oligomer ATATCGATCGATAT was determined. This self-complimentary sequence contains two 5'-CG sequences, which is the preferred site for nitrous acid-induced cross-linking. Nitric oxide was delivered to an 0.5 mM oligomer solution at 15 nmol/mL/min to give a final nitrite concentration of 652 microM. The resulting concentration of the deamination product, xanthine, in this sample was found to be 211 +/- 39 nM, using GC/MS, and the amount of interstrand cross-link was determined to be 13 +/- 2.5 nM. Therefore, upon nitric oxide treatment, the cross-link is found at approximately 6% of the amount of the deamination product. Using this system, detection of the cross-link is also possible for significantly lower doses of nitric oxide, as demonstrated by treatment of the same oligomer with NO at a rate of 18 nmol/mL/min resulting in a final nitrite concentration of 126 microM. The concentration of interstrand cross-link was determined to be 3.6 +/- 0.1 nM in this sample. Therefore, using the same dose rate, when the total nitric oxide concentration delivered drops by a factor of approximately 5, the concentration of cross-link drops by a factor of about 4-indicating a qausi-linear response. It may now be possible to predict the number of cross-links in a small genome based on the number of CpG sequences and the yield of xanthine derived from nitrosative deamination.

  1. Nitric oxide signalling and neuronal nitric oxide synthase in the heart under stress.

    Science.gov (United States)

    Zhang, Yin Hua

    2017-01-01

    Nitric oxide (NO) is an imperative regulator of the cardiovascular system and is a critical mechanism in preventing the pathogenesis and progression of the diseased heart. The scenario of bioavailable NO in the myocardium is complex: 1) NO is derived from both endogenous NO synthases (endothelial, neuronal, and/or inducible NOSs [eNOS, nNOS, and/or iNOS]) and exogenous sources (entero-salivary NO pathway) and the amount of NO from exogenous sources varies significantly; 2) NOSs are located at discrete compartments of cardiac myocytes and are regulated by distinctive mechanisms under stress; 3) NO regulates diverse target proteins through different modes of post-transcriptional modification (soluble guanylate cyclase [sGC]/cyclic guanosine monophosphate [cGMP]/protein kinase G [PKG]-dependent phosphorylation, S -nitrosylation, and transnitrosylation); 4) the downstream effectors of NO are multidimensional and vary from ion channels in the plasma membrane to signalling proteins and enzymes in the mitochondria, cytosol, nucleus, and myofilament; 5) NOS produces several radicals in addition to NO (e.g. superoxide, hydrogen peroxide, peroxynitrite, and different NO-related derivatives) and triggers redox-dependent responses. However, nNOS inhibits cardiac oxidases to reduce the sources of oxidative stress in diseased hearts. Recent consensus indicates the importance of nNOS protein in cardiac protection under pathological stress. In addition, a dietary regime with high nitrate intake from fruit and vegetables together with unsaturated fatty acids is strongly associated with reduced cardiovascular events. Collectively, NO-dependent mechanisms in healthy and diseased hearts are better understood and shed light on the therapeutic prospects for NO and NOSs in clinical applications for fatal human heart diseases.

  2. Smoking and gingivitis: focus on inducible nitric oxide synthase, nitric oxide and basic fibroblast growth factor.

    Science.gov (United States)

    Özdemir, B; Özmeric, N; Elgün, S; Barış, E

    2016-10-01

    Periodontal disease pathogenesis has been associated with smoking. Gingivitis is a mild and reversible form of periodontal disease and it tends to progress to periodontitis only in susceptible individuals. In the present study, we aimed to examine the impact of smoking on host responses in gingivitis and to evaluate and compare the inducible nitric oxide synthase (iNOS) activity in gingival tissue and NO and basic fibroblast growth factor (bFGF) levels in the gingival crevicular fluid of patients with gingivitis and healthy individuals. Forty-one participants were assigned to the gingivitis-smoker (n = 13), gingivitis (n = 13), healthy-smoker (n = 7) and healthy groups (n = 8). Clinical indices were recorded; gingival biopsy and gingival crevicular fluid samples were obtained from papillary regions. iNOS expression was evaluated by immunohistochemical staining. The immunoreactive cells were semiquantitatively assessed. For the quantitative determination of nitrite and nitrate in gingival crevicular fluid, the NO assay kit was used. The amount of bFGF in gingival crevicular fluid was determined by enzyme-linked immunosorbent assay. The gingivitis-smoker group demonstrated a stronger iNOS expression than the non-smoker gingivitis group. iNOS expression intensity was lower in the non-smoker healthy group compared to that in healthy-smokers. No significant gingival crevicular fluid NO and bFGF level changes were observed between groups. Among patients with gingivitis, a positive correlation was detected between gingival crevicular fluid NO and bFGF levels (r = 0.806, p = 0.001). Our data suggest that smoking has significant effects on iNOS expression but not on gingival crevicular fluid NO or bFGF levels in healthy and patients with gingivitis. However, our results suggest that bFGF might be involved in the regulation of NO production via iNOS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Regulation and control of nitric oxide (NO) in macrophages

    DEFF Research Database (Denmark)

    Kovacevic, Zaklina; Sahni, Sumit; Lok, K.H.

    2017-01-01

    We recently demonstrated that a novel storage and transport mechanism for nitric oxide (NO) mediated by glutathione-S-transferase P1 (GSTP1) and multidrug resistance protein 1 (MRP1/ABCC1), protects M1-macrophage (M1-MØ) models from large quantities of endogenous NO. This system stores and transp......We recently demonstrated that a novel storage and transport mechanism for nitric oxide (NO) mediated by glutathione-S-transferase P1 (GSTP1) and multidrug resistance protein 1 (MRP1/ABCC1), protects M1-macrophage (M1-MØ) models from large quantities of endogenous NO. This system stores...... be responsible for delivering cytotoxic NO as DNICs via MRP1 from M1-MØs, to tumor cell targets....

  4. Arginine affects appetite via nitric oxide in ducks.

    Science.gov (United States)

    Wang, C; Hou, S S; Huang, W; Xu, T S; Rong, G H; Xie, M

    2014-08-01

    The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P ducks were allotted to 1 of 2 treatments. After 2 h fasting, birds in the 2 groups were intraperitoneally administrated saline and l-NG-nitro-arginine methyl ester HCl (L-NAME) for 3 d, respectively. Feed intake (P study implied that arginine modifies feeding behavior possibly through controlling endogenous synthesis of nitric oxide in Pekin ducks. © Poultry Science Association Inc.

  5. Reactivity of Resorcinol Formaldehyde Resin with Nitric Acid

    International Nuclear Information System (INIS)

    King, William D.; Fondeur, Fernando F.; Wilmarth, William R.; Pettis, Myra E.

    2005-01-01

    Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. The threshold conditions promoting reaction have been identified. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 C applied temperature and 0.625 M at 66 C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material

  6. NITRIC OXIDE AND ENDOTHELIN-1 IN CHILDREN WITH DIGESTIVE DISORDERS

    Directory of Open Access Journals (Sweden)

    I. V. Panova

    2012-01-01

    Full Text Available The important part in the group of biological compounds, participating in the regulation of the functions of the gastro-intestinal tract, is assigned to endothelial factors because of their impact on the majority of physiological and pathophysiological processes of the digestive system. The article provides information about physiological role of nitric oxide and endothelin-1 and presents a review of scientific data on the participation of nitric oxide and endothelin-1 in the pathogenesis of many digestive system diseases, emphasizing chronic inflammatory disorders of the upper gastrointestinal tract. The authors accentuate the importance of endothelium endocrine function research in children with esophagogastroduodenal disorders at the beginning of puberty, which is the critical period of ontogenesis.

  7. Fate of aliphatic compounds in nitric acid processing solutions

    International Nuclear Information System (INIS)

    Clark, W.E.; Howerton, W.B.

    1975-01-01

    The reaction of hyperazeotropic iodic acid-saturated nitric acid with short chain aliphatic iodides, nitrates, and acids was studied in order to determine the conditions for complete removal of organic materials from nitric acid systems. The aliphatic iodides are converted to the nitrates and the nitrates in strong HNO 3 are extensively converted into CO 2 and acids. The aliphatic acids are rather stable; acetic acid was unattacked by boiling in 20M HNO 3 and n-butyric acid was 80 percent unattacked. The dibasic acids oxalic and malonic are extensively attacked, but succinic acid is relatively stable. A wet oxidation method is successful in destroying acetic acid in 5 to 8M HNO 3 . (U.S.)

  8. Buffering effects on electrograining of aluminium in nitric acid

    International Nuclear Information System (INIS)

    Koroleva, E.V.; Thompson, G.E.; Skeldon, P.; Hollrigl, G.; Lockwood, S.; Smith, G.

    2005-01-01

    Electrograining of a binary Al-Si alloy has been undertaken in nitric acid based electrolytes, with the resultant surfaces examined by scanning and transmission electron microscopies. Depending on electrograining conditions, the pit appearance varies from hemispherical to large lateral pits, with the latter favoured in relatively acidic electrolytes. The conditions prevailing in the pit have been explored through use of aluminium ion additions to the nitric acid electrolyte as well as additions of species which influence the precipitation and dissolution of aluminium hydroxide. These confirm that control of the pit solution pH, through hydroxide generation, as a result of the selected electrograining conditions and consequent anodic and cathodic polarisation, enables tailoring of the resultant electrograined surface appearance

  9. Nitric-glycolic flowsheet testing for maximum hydrogen generation rate

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site is developing for implementation a flowsheet with a new reductant to replace formic acid. Glycolic acid has been tested over the past several years and found to effectively replace the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the chemical generation of hydrogen and ammonia, allows purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective adjustment of the SRAT/SME rheology, and is favorable with respect to melter flammability. The objective of this work was to perform DWPF Chemical Process Cell (CPC) testing at conditions that would bound the catalytic hydrogen production for the nitric-glycolic flowsheet.

  10. Nitric oxide synthase isoforms in spontaneous and salt hypertension

    Czech Academy of Sciences Publication Activity Database

    Hojná, Silvie; Kuneš, Jaroslav; Zicha, Josef

    2007-01-01

    Roč. 25, Suppl. 2 (2007), S 338-S 338 ISSN 0263-6352. [European Meeting on Hypertension /17./. 15.06.2007-19.06.2007, Milan] R&D Projects: GA MŠk(CZ) 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : nitric oxide synthase isoforms * spontaneous and salt hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  11. Isoxazole derivatives as new nitric oxide elicitors in plants

    Directory of Open Access Journals (Sweden)

    Anca Oancea

    2017-04-01

    Full Text Available Several 3,5-disubstituted isoxazoles were obtained in good yields by regiospecific 1,3-dipolar cycloaddition reactions between aromatic nitrile oxides, generated in situ from the corresponding hydroxyimidoyl chlorides, with non-symmetrical activated alkynes in the presence of catalytic amounts of copper(I iodide. Effects of 3,5-disubstituted isoxazoles on nitric oxide and reactive oxygen species generation in Arabidopsis tissues was studied using specific diaminofluoresceine dyes as fluorescence indicators.

  12. Features of molybdenum disulfide interaction with nitric acid

    International Nuclear Information System (INIS)

    Chursanov, Yu.V.; Potashnikov, Yu.M.; Rumyantsev, V.K.

    1987-01-01

    Experiments on studying composition of products of molybdenite concentrate (MoS 2 ) oxidation by HNO 3 solutions were conducted. Molybdenite oxidation was conducted in a glass temperature controlled vessel in absence of oxygen. It was shown that nitrogen (2) oxide represented the final product of molybdenite interaction with nitric acid. The process was accompanied as well by separation of NO 2 and HNO 2 under dynamic conditions, and nitrogen (4) oxide acted as catalyst of oxidation at that

  13. Enhancement of vascular targeting by inhibitors of nitric oxide synthase

    International Nuclear Information System (INIS)

    Davis, Peter D.; Tozer, Gillian M.; Naylor, Matthew A.; Thomson, Peter; Lewis, Gemma; Hill, Sally A.

    2002-01-01

    Purpose: This study investigates the enhancement of the vascular targeting activity of the tubulin-binding agent combretastatin A4 phosphate (CA4P) by various inhibitors of nitric oxide synthases. Methods and Materials: The syngeneic tumors CaNT and SaS growing in CBA mice were used for this study. Reduction in perfused vascular volume was measured by injection of Hoechst 33342 24 h after drug administration. Necrosis (hematoxylin and eosin stain) was assessed also at 24 h after treatment. Combretastatin A4 phosphate was synthesized by a modification of the published procedure and the nitric oxide synthase inhibitors L-NNA, L-NMMA, L-NIO, L-NIL, S-MTC, S-EIT, AMP, AMT, and L-TC, obtained from commercial sources. Results: A statistically significant augmentation of the reduction in perfused vascular volume by CA4P in the CaNT tumor was observed with L-NNA, AMP, and AMT. An increase in CA4P-induced necrosis in the same tumor achieved significance with L-NNA, L-NMMA, L-NIL, and AMT. CA4P induced little necrosis in the SaS tumor, but combination with the inhibitors L-NNA, L-NMMA, L-NIO, S-EIT, and L-TC was effective. Conclusions: Augmentation of CA4P activity by nitric oxide synthase inhibitors of different structural classes supports a nitric oxide-related mechanism for this effect. L-NNA was the most effective inhibitor studied

  14. Nitric oxide and non-quantal acetylcholine release

    Czech Academy of Sciences Publication Activity Database

    Vyskočil, František

    2003-01-01

    Roč. 7, č. 3 (2003), s. 241-243 ISSN 1211-7579. [Celostátní konference biologické psychiatrie /11./. Luhačovice, 11.06.2003-14.06.2003] R&D Projects: GA ČR GA305/02/1333 Institutional research plan: CEZ:AV0Z5011922; CEZ:MSM 113100003 Keywords : nitric oxide Subject RIV: ED - Physiology

  15. Exercise promotes collateral artery growth mediated by monocytic nitric oxide.

    Science.gov (United States)

    Schirmer, Stephan H; Millenaar, Dominic N; Werner, Christian; Schuh, Lisa; Degen, Achim; Bettink, Stephanie I; Lipp, Peter; van Rooijen, Nico; Meyer, Tim; Böhm, Michael; Laufs, Ulrich

    2015-08-01

    Collateral artery growth (arteriogenesis) is an important adaptive response to hampered arterial perfusion. It is unknown whether preventive physical exercise before limb ischemia can improve arteriogenesis and modulate mononuclear cell function. This study aimed at investigating the effects of endurance exercise before arterial occlusion on MNC function and collateral artery growth. After 3 weeks of voluntary treadmill exercise, ligation of the right femoral artery was performed in mice. Hindlimb perfusion immediately after surgery did not differ from sedentary mice. However, previous exercise improved perfusion restoration ≤7 days after femoral artery ligation, also when exercise was stopped at ligation. This was accompanied by an accumulation of peri-collateral macrophages and increased expression of endothelial nitric oxide synthase and inducible nitric oxide synthase (iNOS) in hindlimb collateral and in MNC of blood and spleen. Systemic monocyte and macrophage depletion by liposomal clodronate but not splenectomy attenuated exercise-induced perfusion restoration, collateral artery growth, peri-collateral macrophage accumulation, and upregulation of iNOS. iNOS-deficient mice did not show exercise-induced perfusion restoration. Transplantation of bone marrow-derived MNC from iNOS-deficient mice into wild-type animals inhibited exercise-induced collateral artery growth. In contrast to sedentary controls, thrice weekly aerobic exercise training for 6 months in humans increased peripheral blood MNC iNOS expression. Circulating mononuclear cell-derived inducible nitric oxide is an important mediator of exercise-induced collateral artery growth. © 2015 American Heart Association, Inc.

  16. Stainless steel welding method with excellent nitric acid corrosion resistance

    International Nuclear Information System (INIS)

    Matsushita, Yukinobu; Inazumi, Toru; Hyakubo, Tamako; Masamura, Katsumi.

    1996-01-01

    The present invention concerns a welding method for a stainless steel used in a circumstance being in contact with a highly oxidizing nitric acid solution such as nuclear fuel reprocessing facilities, upon welding 316 type austenite steel containing Mo while giving excellent nitric acid resistance. A method of TIG welding using a filler metal having a composition of C, Si, Mn, P, S, Ni, Cr, Mo and Cu somewhat different from a stainless steel mother material in which C, Si, Mn, P, S, Ni, Cr and Mo are specified comprises a step of TIG-welding the surface of the mother material and a step of TIG-welding the rear face of the mother material, in which the welding conditions for the rear face of the mother material are such that the distance between the surface of the outermost welding metal layer on the side of the surface of the mother material and the bottom of the groove is not less than 5mm, and an amount of welding heat is made constant. As a result, even if the method is used in a circumstance being in contact with a highly corrosive solution such as nitric acid, corrosion resistance is not degraded. (N.H.)

  17. Uranium carbide dissolution in nitric solution: Sonication vs. silent conditions

    International Nuclear Information System (INIS)

    Virot, Matthieu; Szenknect, Stéphanie; Chave, Tony; Dacheux, Nicolas; Moisy, Philippe; Nikitenko, Sergey I.

    2013-01-01

    The dissolution of uranium carbide (UC) in nitric acid media is considered by means of power ultrasound (sonication) or magnetic stirring. The induction period required to initiate UC dissolution was found to be dramatically shortened when sonicating a 3 M nitric solution (Ar, 20 kHz, 18 W cm −2 , 20 °C). At higher acidity, magnetic stirring offers faster dissolution kinetics compared to sonication. Ultrasound-assisted UC dissolution is found to be passivated after ∼60% dissolution and remains incomplete whatever the acidity which is confirmed by ICP–AES, LECO and SEM–EDX analyses. In general, the kinetics of UC dissolution is linked to the in situ generation of nitrous acid in agreement with the general mechanism of UC dissolution; the nitrous acid formation is reported to be faster under ultrasound at low acidity due to the nitric acid sonolysis. The carbon balance shared between the gaseous, liquid, and solid phases is strongly influenced by the applied dissolution procedure and HNO 3 concentration

  18. Uranium carbide dissolution in nitric solution: Sonication vs. silent conditions

    Science.gov (United States)

    Virot, Matthieu; Szenknect, Stéphanie; Chave, Tony; Dacheux, Nicolas; Moisy, Philippe; Nikitenko, Sergey I.

    2013-10-01

    The dissolution of uranium carbide (UC) in nitric acid media is considered by means of power ultrasound (sonication) or magnetic stirring. The induction period required to initiate UC dissolution was found to be dramatically shortened when sonicating a 3 M nitric solution (Ar, 20 kHz, 18 W cm-2, 20 °C). At higher acidity, magnetic stirring offers faster dissolution kinetics compared to sonication. Ultrasound-assisted UC dissolution is found to be passivated after ∼60% dissolution and remains incomplete whatever the acidity which is confirmed by ICP-AES, LECO and SEM-EDX analyses. In general, the kinetics of UC dissolution is linked to the in situ generation of nitrous acid in agreement with the general mechanism of UC dissolution; the nitrous acid formation is reported to be faster under ultrasound at low acidity due to the nitric acid sonolysis. The carbon balance shared between the gaseous, liquid, and solid phases is strongly influenced by the applied dissolution procedure and HNO3 concentration.

  19. Nitric oxide-related drug targets in headache

    DEFF Research Database (Denmark)

    Olesen, Jes

    2010-01-01

    SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so-called del......SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so......-called delayed headache that fulfils criteria for migraine without aura in migraine sufferers. Blockade of nitric oxide synthases (NOS) by L-nitromonomethylarginine effectively treats attacks of migraine without aura. Similar results have been obtained for chronic the tension-type headache and cluster headache....... Inhibition of the breakdown of cyclic guanylate phosphate (cGMP) also provokes migraine in sufferers, indicating that cGMP is the effector of NO-induced migraine. Similar evidence suggests an important role of NO in the tension-type headache and cluster headache. These very strong data from human...

  20. Experimental study on thermal hazard of tributyl phosphate-nitric acid mixtures using micro calorimeter technique

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qi; Jiang, Lin; Gong, Liang; Sun, Jin-Hua, E-mail: sunjh@ustc.edu.cn

    2016-08-15

    Highlights: • Heat flows after mixing TBP with nitric acid are of different orders of magnitude. • Thermodynamics and kinetics of tributyl phosphate-nitric acid mixtures are derived. • Tributyl phosphate directly reacts with nitric acid and form organic red oil. • Thermal runaway could occur at 79 °C with a high nitric acid concentration. - Abstract: During PUREX spent nuclear fuel reprocessing, mixture of tributyl phosphate (TBP) and hydrocarbon solvent are employed as organic solvent to extract uranium in consideration of radiation contaminated safety and resource recycling, meanwhile nitric acid is utilized to dissolve the spent fuel into small pieces. However, once TBP contacts with nitric acid or nitrates above 130 °C, a heavy “red oil” layer would occur accompanied by thermal runaway reactions, even caused several nuclear safety accident. Considering nitric acid volatility and weak exothermic detection, C80 micro calorimeter technique was used in this study to investigate thermal decomposition of TBP mixed with nitric acid. Results show that the concentration of nitric acid greatly influences thermal hazard of the system by direct reactions. Even with a low heating rate, if the concentration of nitric acid increases due to evaporation of water or improper operations, thermal runaway in the closed system could start at a low temperature.

  1. Extraction of antimony from nitric acid solutions using tributyl phosphate. II. Tributyl phosphate-antimony(V)-nitric acid system

    International Nuclear Information System (INIS)

    Lakaev, V.S.; Smelov, V.S.

    1989-01-01

    The extraction of pentavalent antimony from nitric acid solutions using tributyl phosphate has been investigated. A possible mechanism for the extraction of antimony(V) has been determined and the (pre)concentration constant for the process has been calculated. The composition of the extracted antimony(V) complex has been deduced. A negative effect of temperature on the distribution coefficient for antimony(V) has also been demonstrated

  2. Flavone inhibits nitric oxide synthase (NOS) activity, nitric oxide production and protein S-nitrosylation in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenzhen; Yang, Bingwu; Fu, Huiling; Ma, Long; Liu, Tingting; Chai, Rongfei; Zheng, Zhaodi [Shandong Provincial Key Laboratory of Animal Resistant Biology, School of Life Sciences, Shandong Normal University, Jinan 250014 (China); Zhang, Qunye, E-mail: wz.zhangqy@sdu.edu.cn [Key Laboratory of Cardiovascular Remodeling and Function Research Chinese Ministry of Education and Ministry of Public Health, Qilu Hospital, Shandong University, Jinan, Shandong (China); Li, Guorong, E-mail: grli@sdnu.edu.cn [Shandong Provincial Key Laboratory of Animal Resistant Biology, School of Life Sciences, Shandong Normal University, Jinan 250014 (China)

    2015-03-13

    As the core structure of flavonoids, flavone has been proved to possess anticancer effects. Flavone's growth inhibitory functions are related to NO. NO is synthesized by nitric oxide synthase (NOS), and generally increased in a variety of cancer cells. NO regulates multiple cellular responses by S-nitrosylation. In this study, we explored flavone-induced regulations on nitric oxide (NO)-related cellular processes in breast cancer cells. Our results showed that, flavone suppresses breast cancer cell proliferation and induces apoptosis. Flavone restrains NO synthesis by does-dependent inhibiting NOS enzymatic activity. The decrease of NO generation was detected by fluorescence microscopy and flow cytometry. Flavone-induced inhibitory effect on NOS activity is dependent on intact cell structure. For the NO-induced protein modification, flavone treatment significantly down-regulated protein S-nitrosylation, which was detected by “Biotin-switch” method. The present study provides a novel, NO-related mechanism for the anticancer function of flavone. - Highlights: • Flavone inhibits proliferation and induces apoptosis in MCF-7 cells. • Flavone decreases nitric oxide production by inhibiting NOS enzymatic activity in breast cancer cells. • Flavone down-regulates protein S-nitrosylation.

  3. Flavone inhibits nitric oxide synthase (NOS) activity, nitric oxide production and protein S-nitrosylation in breast cancer cells

    International Nuclear Information System (INIS)

    Zhu, Wenzhen; Yang, Bingwu; Fu, Huiling; Ma, Long; Liu, Tingting; Chai, Rongfei; Zheng, Zhaodi; Zhang, Qunye; Li, Guorong

    2015-01-01

    As the core structure of flavonoids, flavone has been proved to possess anticancer effects. Flavone's growth inhibitory functions are related to NO. NO is synthesized by nitric oxide synthase (NOS), and generally increased in a variety of cancer cells. NO regulates multiple cellular responses by S-nitrosylation. In this study, we explored flavone-induced regulations on nitric oxide (NO)-related cellular processes in breast cancer cells. Our results showed that, flavone suppresses breast cancer cell proliferation and induces apoptosis. Flavone restrains NO synthesis by does-dependent inhibiting NOS enzymatic activity. The decrease of NO generation was detected by fluorescence microscopy and flow cytometry. Flavone-induced inhibitory effect on NOS activity is dependent on intact cell structure. For the NO-induced protein modification, flavone treatment significantly down-regulated protein S-nitrosylation, which was detected by “Biotin-switch” method. The present study provides a novel, NO-related mechanism for the anticancer function of flavone. - Highlights: • Flavone inhibits proliferation and induces apoptosis in MCF-7 cells. • Flavone decreases nitric oxide production by inhibiting NOS enzymatic activity in breast cancer cells. • Flavone down-regulates protein S-nitrosylation

  4. Behaviour of Pu-IV with various ion exchangers in solutions containing nitric acid and oxalates

    International Nuclear Information System (INIS)

    Walter, E.; Ali, S.A.

    1982-02-01

    The distribution of Pu-IV on the ion exchangers Dowex 50W-X8, Dowex 1-X8 und Dowex Chelating Resin Al-X8 in the presence of various concentrations of nitric acid and oxalate were investigated. The results indicate that nitric acid and oxalic acid influence each other during complexation of Pu-IV with oxalate ions solutions containing nitric acid it is not possible to neglect the formation of Pu-IV nitrate complexes. The complex Pu(IV) (C 2 O 4 ) 3 2 - only is formed in solutions containing low nitric acid and high oxalic acid concentrations. The separation of Pu-IV in Dowex Chelating Resin from nitric acid solution in the presence of higher oxalate concentrations is possible, provided that the nitric acid concentration is lower than 0.25 molar [fr

  5. Method of improving the decontaminating efficiency of ruthenium in evaporating treatment of nitric acid

    International Nuclear Information System (INIS)

    Kubota, Kanya; Yamana, Hajime; Takeda, Seiichiro.

    1984-01-01

    Purpose: To significantly improve the ruthenium removing efficiency in a nitric acid solution in an acid recovery system for the recovery of nitric acid from nitric acid liquid wastes through evaporating condensation. Method: Upon evaporating treatment of nitric acid solution containing ruthenium by supplying and heating the solution to a nitric acid evaporating device, hydrazine is previously added to the nitric acid solution. Hydrazine and intermediate reaction product of hydrazine such as azide causes a reduction reaction with intermediate reaction product of ruthenium tetraoxide to suppress the oxidation of ruthenium and thereby improve the decontaminating efficiency of ruthenium. The amount of hydrazine to be added is preferably between 20 - 500 mg/l and most suitably between 200 - 2000 mg/l per one liter of the liquid in the evaporating device. (Seki, T.)

  6. Influence of nitric acid on the kinetic of complexation of uranyl nitrate extracted by TBP

    International Nuclear Information System (INIS)

    Pushlenkov, M.F.; Zimenkov, V.V.

    1982-02-01

    The effect of nitric acid on the solvatation rate of uranyl nitrate with tributyl phosphate is studied. In the process of mass transfer, it is shown that nitric acid enables the extraction of uranyl nitrate, therefore its concentration in the organic phase exceeds that in equilibrium solution. Subsequently uranyl nitrate ''displaces'' nitric acid. The presence of the acid in aqueous and organic phases affects in a complicated manner the rate of solvatation of uranyl nitrate with tributyl phosphate [fr

  7. 4.3. Decomposition of danburite concentrate of Ak-Arkar Deposit by nitric acid

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to decomposition of danburite concentrate of Ak-Arkar Deposit by nitric acid. The influence of temperature on reaction process was studied. The dependence of extraction rate of oxides (B 2 O 3 , Al 2 O 3 , Fe 2 O 3 and Ca O) at nitric acid processing on temperature ranges from 25 to 95 deg C was defined. The dependence of extraction rate of oxides (B 2 O 3 , Al 2 O 3 , Fe 2 O 3 and Ca O) at nitric acid processing on process duration (5-60 minutes) was defined as well. The optimal conditions of decomposition of danburite concentrate by nitric acid were proposed.

  8. Optimization of conditions to produce nitrous gases by electrochemical reduction of nitric acid

    International Nuclear Information System (INIS)

    Lemaire, M.; CEA Centre d'Etudes de la Vallee du Rhone, 30 -Marcoule

    1996-01-01

    Gaseous nitrogen oxides (NO and NO 2 ) involved as oxidizing agents in nuclear fuel reprocessing can be an produced by electrochemical reduction of nitric acid. This could be an interesting alternative to the usual process because no wastes are generated. Voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0.05 V S HE and 0.3 V S HE and O.5 V S HE and 1 V S HE. The highest potential region reduction mechanism was studies by: classical micro-electrolysis methods; macro-electrolysis methods; infra-red spectroscopy couplet to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric acid reduction can also be explained by an other chemical reaction. In the potential value of platinum electrode is above 0.8 V S HE, products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author)

  9. Optimization of the nitrous vapors experimental conditions production by nitric acid electrochemical reduction

    International Nuclear Information System (INIS)

    Lemaire, M.

    1996-01-01

    Gaseous nitrogen oxides (NO and NO 2 ) involved as oxidizing agents in nuclear fuel reprocessing can be produced by electrochemical reduction of nitric acid. This is an interesting alternative to the existing process because no wastes are generated. voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0,05 V SHE and between 0,5 V SHE and 1 V SHE . The highest potential region reduction mechanism was studied by: classical micro-electrolysis methods, macro-electrolysis methods, infrared spectroscopy coupled to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric reduction can also explained by an other chemical reaction. If the potential value of platinum electrode is above 0,8 V SHE , products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author)

  10. Dysfunctional nitric oxide signalling increases risk of myocardial infarction.

    Science.gov (United States)

    Erdmann, Jeanette; Stark, Klaus; Esslinger, Ulrike B; Rumpf, Philipp Moritz; Koesling, Doris; de Wit, Cor; Kaiser, Frank J; Braunholz, Diana; Medack, Anja; Fischer, Marcus; Zimmermann, Martina E; Tennstedt, Stephanie; Graf, Elisabeth; Eck, Sebastian; Aherrahrou, Zouhair; Nahrstaedt, Janja; Willenborg, Christina; Bruse, Petra; Brænne, Ingrid; Nöthen, Markus M; Hofmann, Per; Braund, Peter S; Mergia, Evanthia; Reinhard, Wibke; Burgdorf, Christof; Schreiber, Stefan; Balmforth, Anthony J; Hall, Alistair S; Bertram, Lars; Steinhagen-Thiessen, Elisabeth; Li, Shu-Chen; März, Winfried; Reilly, Muredach; Kathiresan, Sekar; McPherson, Ruth; Walter, Ulrich; Ott, Jurg; Samani, Nilesh J; Strom, Tim M; Meitinger, Thomas; Hengstenberg, Christian; Schunkert, Heribert

    2013-12-19

    Myocardial infarction, a leading cause of death in the Western world, usually occurs when the fibrous cap overlying an atherosclerotic plaque in a coronary artery ruptures. The resulting exposure of blood to the atherosclerotic material then triggers thrombus formation, which occludes the artery. The importance of genetic predisposition to coronary artery disease and myocardial infarction is best documented by the predictive value of a positive family history. Next-generation sequencing in families with several affected individuals has revolutionized mutation identification. Here we report the segregation of two private, heterozygous mutations in two functionally related genes, GUCY1A3 (p.Leu163Phefs*24) and CCT7 (p.Ser525Leu), in an extended myocardial infarction family. GUCY1A3 encodes the α1 subunit of soluble guanylyl cyclase (α1-sGC), and CCT7 encodes CCTη, a member of the tailless complex polypeptide 1 ring complex, which, among other functions, stabilizes soluble guanylyl cyclase. After stimulation with nitric oxide, soluble guanylyl cyclase generates cGMP, which induces vasodilation and inhibits platelet activation. We demonstrate in vitro that mutations in both GUCY1A3 and CCT7 severely reduce α1-sGC as well as β1-sGC protein content, and impair soluble guanylyl cyclase activity. Moreover, platelets from digenic mutation carriers contained less soluble guanylyl cyclase protein and consequently displayed reduced nitric-oxide-induced cGMP formation. Mice deficient in α1-sGC protein displayed accelerated thrombus formation in the microcirculation after local trauma. Starting with a severely affected family, we have identified a link between impaired soluble-guanylyl-cyclase-dependent nitric oxide signalling and myocardial infarction risk, possibly through accelerated thrombus formation. Reversing this defect may provide a new therapeutic target for reducing the risk of myocardial infarction.

  11. THE ESTROGENS / CHROMIUM INTERACTION IN THE NITRIC OXIDE GENERATION.

    Science.gov (United States)

    Sawicka, Ewa; Piwowar, Agnieszka; Musiala, Tomasz; Dlugosz, Anna

    2017-05-01

    The interaction of estrogens with environmental toxins in free radicals generation: reactive oxygen species (ROS) or reactive nitrogen species (RNS) which participates in cancerogenesis is not yet recognized. Chromium(VI) is widely present in environment. One of its toxicity pathway is free radicals generation. Estrogens have the ability to scavenge free radicals, but may also act as prooxidants. Both chromium(VI) and estrogens are classified by International Agency for Research on Cancer (IARC) as carcinogens, so synergistic effect seems very dangerous. The interaction of chromium and estrogens in ROS generation are partly described but there are no reports on estrogen/chromium interaction on nitric oxide (NO) generation. The aim of the study was to examine the interaction of chromium(VI) and 17-p-estradiol (E2) on NO level in human blood as well as the role of E2 metabolites: 4-hydroxyestradiol (4-OHE2) and 16a-hydroxyestrone (16α-OHE1) in these processes. The NO level was estimated with the diagnostic kit (Nitric Oxide Colorimetric Detection Kit from Arbor Assays) in human blood in vitm. The results showed that Cr(VI) in used concentration (0.5; 1.0 and 5.0 gg/mL) decreases significantly NO level in blood, acting antagonistically to E2 and 4-OHE2. Estrogens (E2, 4-OHE2 and 16α-OHEI) do not protect against inhibiting effect of Cr(VI) on nitric oxide generation in blood because after combined exposure the decreased production of NO in blood was noted. In conclusion, presented results provide the information about the character of estrogen/Cr(VI) interaction in NO level in human blood. It is important knowledge for cardio protected effect e.g., hormone replacement therapy in environmental or occupational exposure to Cr(VI), chromium supplementation, also important for cancer risk evaluation.

  12. Arginase expression modulates nitric oxide production in Leishmania (Leishmania) amazonensis.

    Science.gov (United States)

    Acuña, Stephanie Maia; Aoki, Juliana Ide; Laranjeira-Silva, Maria Fernanda; Zampieri, Ricardo Andrade; Fernandes, Juliane Cristina Ribeiro; Muxel, Sandra Marcia; Floeter-Winter, Lucile Maria

    2017-01-01

    Arginase is an enzyme that converts L-arginine to urea and L-ornithine, an essential substrate for the polyamine pathway supporting Leishmania (Leishmania) amazonensis replication and its survival in the mammalian host. L-arginine is also the substrate of macrophage nitric oxide synthase 2 (NOS2) to produce nitric oxide (NO) that kills the parasite. This competition can define the fate of Leishmania infection. The transcriptomic profiling identified a family of oxidoreductases in L. (L.) amazonensis wild-type (La-WT) and L. (L.) amazonensis arginase knockout (La-arg-) promastigotes and axenic amastigotes. We highlighted the identification of an oxidoreductase that could act as nitric oxide synthase-like (NOS-like), due to the following evidences: conserved domain composition, the participation of NO production during the time course of promastigotes growth and during the axenic amastigotes differentiation, regulation dependence on arginase activity, as well as reduction of NO amount through the NOS activity inhibition. NO quantification was measured by DAF-FM labeling analysis in a flow cytometry. We described an arginase-dependent NOS-like activity in L. (L.) amazonensis and its role in the parasite growth. The increased detection of NO production in the mid-stationary and late-stationary growth phases of La-WT promastigotes could suggest that this production is an important factor to metacyclogenesis triggering. On the other hand, La-arg- showed an earlier increase in NO production compared to La-WT, suggesting that NO production can be arginase-dependent. Interestingly, La-WT and La-arg- axenic amastigotes produced higher levels of NO than those observed in promastigotes. As a conclusion, our work suggested that NOS-like is expressed in Leishmania in the stationary growth phase promastigotes and amastigotes, and could be correlated to metacyclogenesis and amastigotes growth in a dependent way to the internal pool of L-arginine and arginase activity.

  13. Daily life negative mood and exhaled nitric oxide in asthma.

    Science.gov (United States)

    Ritz, Thomas; Kullowatz, Antje; Bill, Michelle N; Rosenfield, David

    2016-07-01

    Psychosocial stress and negative affect have been linked to asthma exacerbations, but longitudinal studies demonstrating a daily life association between negative affect and airway nitric oxide are missing. The longitudinal association between negative mood fluctuations, exhaled nitric oxide, and lung function in asthma was examined. Self-assessments of the fraction of exhaled nitric oxide (FeNO), spirometry (forced expiratory volume in the first second, FEV1), negative mood, and daily activities were obtained from 20 patients with asthma for 2 months, resulting in 1108 assessments for the analyses (approximately 55 per patient). Concurrent and prospective associations between FeNO, FEV1, and negative mood were analyzed using mixed effects regression models for longitudinal data. Negative mood was positively associated with changes in FeNO during the same day, and to a stronger extent when prior day negative mood was included in the prediction. FeNO and negative mood were positively associated with same-day FEV1, with the latter relation being partially mediated by changes in FeNO. Associations between FeNO and FEV1 were stronger in younger patients, with earlier onset of asthma, or with lower asthma control. Findings were not changed when controlling for physical activity, medication, cold symptoms, air pollution, and hours spent outside. Daily life changes of negative mood in asthma are positively associated with FeNO changes and FeNO increases are associated with a mild bronchodilation. These findings indicate that psychological influences need to be considered when using FeNO as indicator of airway inflammation and guide for treatment decisions. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  15. The role of nitrite in nitric oxide homeostasis

    DEFF Research Database (Denmark)

    Jensen, Frank Bo

    2009-01-01

    Nitrite is endogenously produced as an oxidative metabolite of nitric oxide, but it also functions as a NO donor that can be activated by a number of cellular proteins under hypoxic conditions. This article discusses the physiological role of nitrite and nitrite-derived NO in blood flow regulation...... mechanisms. Nitrite reduction to NO provides cytoprotection in tissues during ischemia-reperfusion events by inhibiting mitochondrial respiration and limiting reactive oxygen species. It is argued that the study of hypoxia-tolerant lower vertebrates and diving mammals may help evaluate mechanisms and a full...

  16. Hypoxia tolerance, nitric oxide, and nitrite: Lessons from extreme animals

    DEFF Research Database (Denmark)

    Fago, Angela; B. Jensen, Frank

    2015-01-01

    survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and – in air breathing animals - redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite...... nitrite. The aim of this review is to highlight recent work illustrating the widespread roles of NO and nitrite in the tolerance to extreme oxygen deprivation, in particular in the red-eared slider turtle and crucian carp, but also in diving marine mammals. The emerging picture underscores the importance...... of NO and nitrite signaling in the adaptive response to hypoxia in vertebrate animals....

  17. Nitric Oxide Manipulation: A Therapeutic Target for Peripheral Arterial Disease?

    Directory of Open Access Journals (Sweden)

    Gareth Williams

    2012-01-01

    Full Text Available Peripheral Arterial Disease (PAD is a cause of significant morbidity and mortality in the Western world. Risk factor modification and endovascular and surgical revascularisation are the main treatment options at present. However, a significant number of patients still require major amputation. There is evidence that nitric oxide (NO and its endogenous inhibitor asymmetric dimethylarginine (ADMA play significant roles in the pathophysiology of PAD. This paper reviews experimental work implicating the ADMA-DDAH-NO pathway in PAD, focussing on both the vascular dysfunction and effects within the ischaemic muscle, and examines the potential of manipulating this pathway as a novel adjunct therapy in PAD.

  18. Reactive oxygen species and nitric oxide signaling in bystander cells.

    Science.gov (United States)

    Jella, Kishore Kumar; Moriarty, Roisin; McClean, Brendan; Byrne, Hugh J; Lyng, Fiona M

    2018-01-01

    It is now well accepted that radiation induced bystander effects can occur in cells exposed to media from irradiated cells. The aim of this study was to follow the bystander cells in real time following addition of media from irradiated cells and to determine the effect of inhibiting these signals. A human keratinocyte cell line, HaCaT cells, was irradiated (0.005, 0.05 and 0.5 Gy) with γ irradiation, conditioned medium was harvested after one hour and added to recipient bystander cells. Reactive oxygen species, nitric oxide, Glutathione levels, caspase activation, cytotoxicity and cell viability was measured after the addition of irradiated cell conditioned media to bystander cells. Reactive oxygen species and nitric oxide levels in bystander cells treated with 0.5Gy ICCM were analysed in real time using time lapse fluorescence microscopy. The levels of reactive oxygen species were also measured in real time after the addition of extracellular signal-regulated kinase and c-Jun amino-terminal kinase pathway inhibitors. ROS and glutathione levels were observed to increase after the addition of irradiated cell conditioned media (0.005, 0.05 and 0.5 Gy ICCM). Caspase activation was found to increase 4 hours after irradiated cell conditioned media treatment (0.005, 0.05 and 0.5 Gy ICCM) and this increase was observed up to 8 hours and there after a reduction in caspase activation was observed. A decrease in cell viability was observed but no major change in cytotoxicity was found in HaCaT cells after treatment with irradiated cell conditioned media (0.005, 0.05 and 0.5 Gy ICCM). This study involved the identification of key signaling molecules such as reactive oxygen species, nitric oxide, glutathione and caspases generated in bystander cells. These results suggest a clear connection between reactive oxygen species and cell survival pathways with persistent production of reactive oxygen species and nitric oxide in bystander cells following exposure to irradiated cell

  19. Redox chemistry of americium in nitric acid media

    Energy Technology Data Exchange (ETDEWEB)

    Picart, S.; Jobelin, I.; Armengol, G.; Adnet, JM

    2004-07-01

    The redox properties of the actinides are very important parameters for speciation studies and spent nuclear fuel reprocessing based on liquid-liquid extraction of actinides at different oxidation states (as in the Purex or Sesame process). They are also very useful for developing analytical tools including coulometry and redox titration. This study addressed the americium(IV)/americium(III) and americium(VI)/americium(V) redox couples, focusing on exhaustive acquisition of the thermodynamic and kinetic parameters of americium oxidation at an electrode in a complexing nitric acid medium. (authors)

  20. Redox chemistry of americium in nitric acid media

    International Nuclear Information System (INIS)

    Picart, S.; Jobelin, I.; Armengol, G.; Adnet, JM.

    2004-01-01

    The redox properties of the actinides are very important parameters for speciation studies and spent nuclear fuel reprocessing based on liquid-liquid extraction of actinides at different oxidation states (as in the Purex or Sesame process). They are also very useful for developing analytical tools including coulometry and redox titration. This study addressed the americium(IV)/americium(III) and americium(VI)/americium(V) redox couples, focusing on exhaustive acquisition of the thermodynamic and kinetic parameters of americium oxidation at an electrode in a complexing nitric acid medium. (authors)

  1. The reaction of hydrazine nitrate with nitric acid

    International Nuclear Information System (INIS)

    Kida, Takashi; Sugikawa, Susumu

    2004-03-01

    It is known that hydrazine nitrate used in nuclear fuel reprocessing plants is an unstable substance thermochemically like hydroxylamine nitrate. In order to take the basic data regarding the reaction of hydrazine nitrate with nitric acid, initiation temperatures and heats of this reaction, effect of impurity on initiation temperature and self-accelerating reaction when it holds at constant temperature for a long time were measured by the pressure vessel type reaction calorimeter etc. In this paper, the experimental data and evaluation of the safe handling of hydrazine nitrate in nuclear fuel reprocessing plants are described. (author)

  2. Nitric oxide synthase expression and enzymatic activity in multiple sclerosis

    DEFF Research Database (Denmark)

    Broholm, H; Andersen, B; Wanscher, B

    2004-01-01

    We used post-mortem magnetic resonance imaging (MRI) guidance to obtain paired biopsies from the brains of four patients with clinical definite multiple sclerosis (MS). Samples were analyzed for the immunoreactivity (IR) of the three nitric oxide (NO) synthase isoforms [inducible, neuronal......NOS expressing cells in active lesions. NOS IR expressing cells were widely distributed in plaques, in white and gray matter that appeared normal macroscopically, and on MR. Endothelial NOS (eNOS) was highly expressed in intraparenchymal vascular endothelial cells of MS patients. A control group matched for age...

  3. Nitric Oxide Generating Polymeric Coatings for Subcutaneous Glucose Sensors

    Science.gov (United States)

    2007-10-01

    primary polymer which was then aminated (2) for attachment of (Boc)3-cyclen-N-acetic acid (1). After the conjugation via EDC coupling chemistry, the Boc...dipping procedure is repeated 5 times. This is the needle-type NO sensor currently used (e.g., Figure 4 device but w/o the SePEI and alginic acid ...Cha, M. E. Meyerhoff, " Polymethacrylates with Covalently Linked Cu(II)-Cyclen Complex for the In-Situ Generation of Nitric Oxide from Nitrosothiols in

  4. Direct Reaction of Amides with Nitric Oxide To Form Diazeniumdiolates

    Science.gov (United States)

    2015-01-01

    We report the apparently unprecedented direct reaction of nitric oxide (NO) with amides to generate ions of structure R(C=O)NH–N(O)=NO–, with examples including R = Me (1a) or 3-pyridyl (1b). The sodium salts of both released NO in pH 7.4 buffer, with 37 °C half-lives of 1–3 min. As NO-releasing drug candidates, diazeniumdiolated amides would have the advantage of generating only 1 equiv of base on hydrolyzing exhaustively to NO, in contrast to their amine counterparts, which generate 2 equiv of base. PMID:25210948

  5. Role of Nitric Oxide in the Regulation of Renin and Vasopressin Secretion

    Science.gov (United States)

    Reid, Ian A.

    1994-01-01

    Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, immune, and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, and anterior pituitary gland, and evidence is accumulating that it contributes to the regulation of the secretion of renin and vasopressin, hormones that play key roles in the control of sodium and water balance. Several lines of evidence have implicated nitric oxide in the control of renin secretion. The enzyme nitric oxide synthase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa, a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro, suggesting a stimulatory role for the L-arginine/nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa, and beta adrenoceptor mechanisms that regulate renin secretion. Histochemical and immunocytochemical studies have revealed the presence of nitric oxide synthase in the supraoptic and paraventricular nuclei of the hypothalamus and in the posterior pituitary gland. Colocalization of nitric oxide synthase and vasopressin has been demonstrated in some hypothalamic neurons. Nitric oxide synthase activity in the hypothalamus and pituitary is increased by maneuvers known to stimulate vasopressin secretion, including salt loading and dehydration, Administration of L-arginine and nitric

  6. Role of inducible nitric oxide synthase-derived nitric oxide in lipopolysaccharide plus interferon-γ-induced pulmonary inflammation

    International Nuclear Information System (INIS)

    Zeidler, Patti C.; Millecchia, Lyndell M.; Castranova, Vincent

    2004-01-01

    Exposure of mice to lipopolysaccharide (LPS) plus interferon-γ (IFN-γ) increases nitric oxide (NO) production, which is proposed to play a role in the resulting pulmonary damage and inflammation. To determine the role of inducible nitric oxide synthase (iNOS)-induced NO in this lung reaction, the responses of inducible nitric oxide synthase knockout (iNOS KO) versus C57BL/6J wild-type (WT) mice to aspirated LPS + IFN-γ were compared. Male mice (8-10 weeks) were exposed to LPS (1.2 mg/kg) + IFN-γ (5000 U/mouse) or saline. At 24 or 72 h postexposure, lungs were lavaged with saline and the acellular fluid from the first bronchoalveolar lavage (BAL) was analyzed for total antioxidant capacity (TAC), lactate dehydrogenase (LDH) activity, albumin, tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein-2 (MIP-2). The cellular fraction of the total BAL was used to determine alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) counts, and AM zymosan-stimulated chemiluminescence (AM-CL). Pulmonary responses 24 h postexposure to LPS + IFN-γ were characterized by significantly decreased TAC, increased BAL AMs and PMNs, LDH, albumin, TNF-α, and MIP-2, and enhanced AM-CL to the same extent in both WT and iNOS KO mice. Responses 72 h postexposure were similar; however, significant differences were found between WT and iNOS KO mice. iNOS KO mice demonstrated a greater decline in total antioxidant capacity, greater BAL PMNs, LDH, albumin, TNF-α, and MIP-2, and an enhanced AM-CL compared to the WT. These data suggest that the role of iNOS-derived NO in the pulmonary response to LPS + IFN-γ is anti-inflammatory, and this becomes evident over time

  7. Liquid-Phase Heat-Release Rates of the Systems Hydrazine-Nitric Acid and Unsymmetrical Dimethylhydrazine-Nitric Acid

    Science.gov (United States)

    Somogyi, Dezso; Feiler, Charles E.

    1960-01-01

    The initial rates of heat release produced by the reactions of hydrazine and unsymmetrical dimethylhydrazine with nitric acid were determined in a bomb calorimeter under conditions of forced mixing. Fuel-oxidant weight ratio and injection velocity were varied. The rate of heat release apparently depended on the interfacial area between the propellants. Above a narrow range of injection velocities representing a critical amount of interfacial area, the rates reached a maximum and were almost constant with injection velocity. The maximum rate for hydrazine was about 70 percent greater than that for unsymmetrical dimethylhydrazine. The total heat released did not vary with mixture ratio over the range studied.

  8. NOx generation method from recovered nitric acid by electrolysis

    International Nuclear Information System (INIS)

    Suzuki, Y.; Shimizu, H.; Inoue, M.; Fujiso, M.; Shibuya, M.; Iwamoto, F.; Outou, Y.; Ochi, E.; Tsuyuki, T.

    1998-01-01

    An R and D has been conducted on an electrolytic NO x generation process utilizing recovered nitric acid from a PUREX reprocessing plant. The purpose of the study is to drastically reduce the amount of low-level-liquid waste(LLW). The research program phase-1, constituting mainly of electrochemical reaction mechanism study, material balance evaluation and process design study, finished in 1995. The results were presented in the previous papers). The research program phase-2 has started in 1995. The schedule is as follows: FY 1991-1994: Research program phase-1 Basic study using electrolysis equipment with 100-700 cm 2 electrodes FY 1995-1999: Research program phase-2 Process performance test by larger scale electrolysis equipment with 3.6 m 2 electrodes - pilot plant design (FY 1995) - pilot plant construction (FY 1996) - engineering data acquisition (FY 1997-1999). The process consists of many unit operations such as electrolysis, oxidation, nitric acid concentration, NO x compression and storage, NO x recovery, off-gas treatment and acid supplier. This paper outlines the pilot test plant. (author)

  9. Nitric oxide heme interactions in nitrophorin from Cimex lectularius

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, R.; Auerbach, H., E-mail: auerbach@physik.uni-kl.de [University of Kaiserslautern, Department of Physics (Germany); Berry, R. E.; Walker, F. A. [The University of Arizona, Department of Chemistry and Biochemistry (United States); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)

    2016-12-15

    The nitrophorin from the bedbug Cimex lectularius (cNP) is a nitric oxide (NO) carrying protein. Like the nitrophorins (rNPs) from the kissing bug Rhodnius prolixus, cNP forms a stable heme Fe(III)-NO complex, where the NO can be stored reversibly for a long period of time. In both cases, the NPs are found in the salivary glands of blood-sucking bugs. The insects use the nitrophorins to transport the NO to the victim’s tissues, resulting in vasodilation and reduced blood coagulation. However, the structure of cNP is significantly different to those of the rNPs from Rhodnius prolixus. Furthermore, the cNP can bind a second NO molecule to the proximal heme cysteine when present at higher concentrations. High field Mössbauer spectroscopy on {sup 57}Fe enriched cNP complexed with NO shows reduction of the heme iron and formation of a ferrous nitric oxide (Fe(II)-NO) complex. Density functional theory calculations reproduce the experimental Mössbauer parameters and confirm this observation.

  10. Alternative to Nitric Acid for Passivation of Stainless Steel Alloys

    Science.gov (United States)

    Lewis, Pattie L.; Kolody, Mark; Curran, Jerry

    2013-01-01

    Corrosion is an extensive problem that affects the Department of Defense (DoD) and National Aeronautics and Space Administration (NASA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. Consequently, it is vital to reduce corrosion costs and risks in a sustainable manner. The DoD and NASA have numerous structures and equipment that are fabricated from stainless steel. The standard practice for protection of stainless steel is a process called passivation. Typical passivation procedures call for the use of nitric acid; however, there are a number of environmental, worker safety, and operational issues associated with its use. Citric acid offers a variety of benefits including increased safety for personnel, reduced environmental impact, and reduced operational cost. DoD and NASA agreed to collaborate to validate citric acid as an acceptable passivating agent for stainless steel. This paper details our investigation of prior work developing the citric acid passivation process, development of the test plan, optimization of the process for specific stainless steel alloys, ongoing and planned testing to elucidate the process' resistance to corrosion in comparison to nitric acid, and preliminary results.

  11. Exhaled nitric oxide in diagnosis and management of respiratory diseases

    Directory of Open Access Journals (Sweden)

    Abba Abdullah

    2009-01-01

    Full Text Available The analysis of biomarkers in exhaled breath constituents has recently become of great interest in the diagnosis, treatment and monitoring of many respiratory conditions. Of particular interest is the measurement of fractional exhaled nitric oxide (FENO in breath. Its measurement is noninvasive, easy and reproducible. The technique has recently been standardized by both American Thoracic Society and European Respiratory Society. The availability of cheap, portable and reliable equipment has made the assay possible in clinics by general physicians and, in the near future, at home by patients. The concentration of exhaled nitric oxide is markedly elevated in bronchial asthma and is positively related to the degree of esinophilic inflammation. Its measurement can be used in the diagnosis of bronchial asthma and titration of dose of steroids as well as to identify steroid responsive patients in chronic obstructive pulmonary disease. In primary ciliary dyskinesia, nasal NO is diagnostically low and of considerable value in diagnosis. Among lung transplant recipients, FENO can be of great value in the early detection of infection, bronchioloitis obliterans syndrome and rejection. This review discusses the biology, factors affecting measurement, and clinical application of FENO in the diagnosis and management of respiratory diseases.

  12. Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

    Directory of Open Access Journals (Sweden)

    Kao Ming-Ching

    2011-02-01

    Full Text Available Abstract Background Hyperbaric oxygen therapy (HBOT is a known adjuvant for treating ischemia-related inner ear diseases. Controversies still exist in the role of HBOT in cochlear diseases. Few studies to date have investigated the cellular changes that occur in inner ears after HBOT. Nitric oxide, which is synthesized by nitric oxide synthase (NOS, is an important signaling molecule in cochlear physiology and pathology. Here we investigated the effects of hyperbaric oxygen on eardrum morphology, cochlear function and expression of NOS isoforms in cochlear substructures after repetitive HBOT in guinea pigs. Results Minor changes in the eardrum were observed after repetitive HBOT, which did not result in a significant hearing threshold shift by tone burst auditory brainstem responses. A differential effect of HBOT on the expression of NOS isoforms was identified. Upregulation of constitutive NOS (nNOS and eNOS was found in the substructures of the cochlea after HBOT, but inducible NOS was not found in normal or HBOT animals, as shown by immunohistochemistry. There was no obvious DNA fragmentation present in this HBOT animal model. Conclusions The present evidence indicates that the customary HBOT protocol may increase constitutive NOS expression but such upregulation did not cause cell death in the treated cochlea. The cochlear morphology and auditory function are consequently not changed through the protocol.

  13. Implications of glial nitric oxyde in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Jose Enrique eYuste

    2015-08-01

    Full Text Available Nitric oxide (NO is a pleiotropic janus-faced molecule synthesized by nitric oxide synthases (NOS which plays a critical role in a number of physiological and pathological processes in humans. The physiological roles of NO depend on its local concentrations, as well as its availability and the nature of downstream target molecules. Its double-edged sword action has been linked to neurodegenerative disorders. Excessive NO production, as the evoked by inflammatory signals, has been identified as one of the major causative reasons for the pathogenesis of several neurodegenerative diseases. Moreover, excessive NO synthesis under neuroinflammation leads to the formation of reactive nitrogen species and neuronal cell death. There is an intimate relation between microglial activation, NO and neuroinflammation in the human brain. The role of NO in neuroinflammation has been defined in animal models where this neurotransmitter can modulate the inflammatory process acting on key regulatory pathways, such as those associated with excitotoxicity processes induced by glutamate accumulation and microglial activation. Activated glia express inducible NOS and produce NO that triggers calcium mobilization from the endoplasmic reticulum, activating the release of vesicular glutamate from astroglial cells resulting in neuronal death. This change in microglia potentially contributes to the increased age-associated susceptibility and neurodegeneration. In the current review, information is provided about the role of NO, glial activation and age-related processes in the central nervous system (CNS that may be helpful in the isolation of new therapeutic targets for aging and neurodegenerative diseases.

  14. Nitric Oxide-Mediated Posttranslational Modifications: Impacts at the Synapse

    Directory of Open Access Journals (Sweden)

    Sophie A. Bradley

    2016-01-01

    Full Text Available Nitric oxide (NO is an important gasotransmitter molecule that is involved in numerous physiological processes throughout the nervous system. In addition to its involvement in physiological plasticity processes (long-term potentiation, LTP; long-term depression, LTD which can include NMDAR-mediated calcium-dependent activation of neuronal nitric oxide synthase (nNOS, new insights into physiological and pathological consequences of nitrergic signalling have recently emerged. In addition to the canonical cGMP-mediated signalling, NO is also implicated in numerous pathways involving posttranslational modifications. In this review we discuss the multiple effects of S-nitrosylation and 3-nitrotyrosination on proteins with potential modulation of function but limit the analyses to signalling involved in synaptic transmission and vesicular release. Here, crucial proteins which mediate synaptic transmission can undergo posttranslational modifications with either pre- or postsynaptic origin. During normal brain function, both pathways serve as important cellular signalling cascades that modulate a diverse array of physiological processes, including synaptic plasticity, transcriptional activity, and neuronal survival. In contrast, evidence suggests that aging and disease can induce nitrosative stress via excessive NO production. Consequently, uncontrolled S-nitrosylation/3-nitrotyrosination can occur and represent pathological features that contribute to the onset and progression of various neurodegenerative diseases, including Parkinson’s, Alzheimer’s, and Huntington’s.

  15. Use of extractive distillation to produce concentrated nitric acid

    International Nuclear Information System (INIS)

    Campbell, P.C.; Griffin, T.P.; Irwin, C.F.

    1981-04-01

    Concentrated nitric acid (> 95 wt %) is needed for the treatment of off-gases from a fuels-reprocessing plant. The production of concentrated nitric acid by means of extractive distillation in the two-pot apparatus was studied to determine the steady-state behavior of the system. Four parameters, EDP volume (V/sub EDP/) and temperature (T/sub EDP/), acid feed rate, and solvent recycle, were independently varied. The major response factors were percent recovery (CPRR) and product purity (CCP). Stage efficiencies also provided information about the system response. Correlations developed for the response parameters are: CPRR = 0.02(V/sub EDP/ - 800 cc) + 53.5; CCP = -0.87 (T/sub EDP/ - 140 0 C) + 81; eta/sub V,EDP/ = 9.1(F/sub feed/ - 11.5 cc/min) - 0.047(V/sub EDP/ - 800 cc) - 2.8(F/sub Mg(NO 3 ) 2 / - 50 cc/min) + 390; and eta/sub L,EDP/ = 1.9(T/sub EDP/ - 140 0 C) + 79. A computer simulation of the process capable of predicting steady-state conditions was developed, but it requires further work

  16. Nitric-phosphoric acid oxidation of organic waste materials

    International Nuclear Information System (INIS)

    Pierce, R.A.; Smith, J.R.

    1995-01-01

    A wet chemical oxidation technology has been developed to address issues facing defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate a heterogenous mixture of radioactive-contaminated solid waste, the technology can also remediate other hazardous waste forms. The process, unique to Savannah River, offers a valuable alternative to incineration and other high-temperature or high-pressure oxidation processes. The process uses nitric acid in phosphoric acid; phosphoric acid allows nitric acid to be retained in solution well above its normal boiling point. The reaction converts organics to carbon dioxide and water, and generates NO x vapors which can be recycled using air and water. Oxidation is complete in one to three hours. In previous studies, many organic compounds were completely oxidized, within experimental error, at atmospheric pressure below 180 degrees C; more stable compounds were decomposed at 200 degrees C and 170 kPa. Recent studies have evaluated processing parameters and potential throughputs for three primary compounds: EDTA, polyethylene, and cellulose. The study of polyvinylchloride oxidation is incomplete at this time

  17. How to protect liver graft with nitric oxide

    Institute of Scientific and Technical Information of China (English)

    Hassen Ben Abdennebi; Mohamed Amine Zaoualí; Izabel Alfany-Fernandez; Donia Tabka; Joan Roselló-Catafau

    2011-01-01

    Organ preservation and ischemia reperfusion injury associated with liver transplantation play an important role in the induction of graft injury. One of the earliest events associated with the reperfusion injury is endothelial cell dysfunction. It is generally accepted that endothelial nitric oxide synthase (e-NOS) is cell-protective by mediating vasodilatation, whereas inducible nitric oxide synthase mediates liver graft injury after transplantation. We conducted a critical review of the literature evaluating the potential applications of regulating and promoting e-NOS activity in liver preservation and transplantation, showing the most current evidence to support the concept that enhanced bioavailability of NO derived from e-NOS is detrimental to ameliorate graft liver preservation, as well as preventing subsequent graft reperfusion injury. This review deals mainly with the beneficial effects of promoting "endogenous" pathways for NO generation, via e-NOS inducer drugs in cold preservation solution, surgical strategies such as ischemic preconditioning, and alternative "exogenous" pathways that focus on the enrichment of cold storage liquid with NO donors. Finally, we also provide a basic bench-to-bed side summary of the liver physiology and cell signalling mechanisms that account for explaining the e-NOS protective effects in liver preservation and transplantation.

  18. Speciation of platinum(IV) in nitric acid solutions.

    Science.gov (United States)

    Vasilchenko, Danila; Tkachev, Sergey; Baidina, Iraida; Korenev, Sergey

    2013-09-16

    The speciation of platinum(IV) ions in nitric acid (6-15.8 M) solutions of H2[Pt(OH)6] has been studied by (195)Pt NMR and Raman spectroscopy. Series of aqua-hydroxo-nitrato complexes [Pt(L)(x)(NO3)(6-x)] (L = H2O or OH(-); x = 0, ..., 6) were found to exist in such solutions. The pair additivity model of chemical shifts and statistical theory were used to assign signals in NMR spectra to particular [Pt(L)(x)(NO3)(6-x)] species. Mononuclear hexanitratoplatinates(IV) have been isolated in solid state in substantial yield as pyridinium salt (PyH)2[Pt(NO3)6] and characterized by single-crystal X-ray diffraction. Aging of the platinum nitric acid solutions for more than 5-6 h results in oligomerization of [Pt(L)(x)(NO3)(6-x)] species and the formation of oligonuclear aqua-hydroxo-nitrato complexes with OH(-) and NO3(-) bridging ligands. Oligomeric platinum(IV) complexes with two and four nuclei were unambiguously detected by NMR on (195)Pt -enriched samples. Oligomers with even higher nuclearity were also detected. Dimeric anions [Pt2(μ-OH)2(NO3)8](2-) have been isolated as single crystals of tetramethylammonium salt and characterized by X-ray diffraction.

  19. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Beg Mohammed F S; Alzoghaibi, Mohammad A; Habib, Syed S; Abba, Abdullah A

    2009-01-01

    The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO) is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD) and compare it with the results in patients with asthma and a control population. Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naive asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54+ - 28.01 vs 22.00 + -6.69; P =0.0001) but lower than the subjects with asthma (56.54+ - 28.01 vs 84.78+ - 39.32 P 0.0285). The FENO values in COPD subjects were inversely related to the FEV 1 /FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects. (author)

  20. Requirement of argininosuccinate lyase for systemic nitric oxide production.

    Science.gov (United States)

    Erez, Ayelet; Nagamani, Sandesh C S; Shchelochkov, Oleg A; Premkumar, Muralidhar H; Campeau, Philippe M; Chen, Yuqing; Garg, Harsha K; Li, Li; Mian, Asad; Bertin, Terry K; Black, Jennifer O; Zeng, Heng; Tang, Yaoping; Reddy, Anilkumar K; Summar, Marshall; O'Brien, William E; Harrison, David G; Mitch, William E; Marini, Juan C; Aschner, Judy L; Bryan, Nathan S; Lee, Brendan

    2011-11-13

    Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases.

  1. Lack of endothelial nitric oxide synthase aggravates murine accelerated anti-glomerular basement membrane glomerulonephritis

    NARCIS (Netherlands)

    Heeringa, P; van Goor, H; Itoh-Lindstrom, Y; Maeda, N; Falk, RJ; Assmann, KJM; Kallenberg, CGM; Jennette, JC

    Nitric oxide (NO) radicals generated by endothelial nitric oxide synthase (eNOS) are involved in the regulation of vascular tone. In addition, NO radicals derived from eNOS inhibit platelet aggregation and leukocyte adhesion to the endothelium and, thus, may have anti-inflammatory effects. To study

  2. Nitric-oxide supplementation for treatment of long-term complications in argininosuccinic aciduria

    Science.gov (United States)

    Argininosuccinate lyase (ASL) is required for the synthesis and channeling of L-arginine to nitric oxide synthase (NOS) for nitric oxide (NO) production. Congenital ASL deficiency causes argininosuccinic aciduria (ASA), the second most common urea cycle disorder, and leads to deficiency of both urea...

  3. Mercury-free dissolution of aluminum-clad fuel in nitric acid

    Science.gov (United States)

    Christian, Jerry D.; Anderson, Philip A.

    1994-01-01

    A mercury-free dissolution process for aluminum involves placing the aluminum in a dissolver vessel in contact with nitric acid-fluoboric acid mixture at an elevated temperature. By maintaining a continuous flow of the acid mixture through the dissolver vessel, an effluent containing aluminum nitrate, nitric acid, fluoboric acid and other dissolved components are removed.

  4. Transportation impact analysis for the shipment of low specific activity nitric acid. Revisison 1

    Energy Technology Data Exchange (ETDEWEB)

    Green, J.R.

    1995-05-16

    This is in support of the Plutonium-Uranium Extraction (PUREX) Facility Low Specific Activity (LSA) Nitric Acid Shipment Environmental Assessment. It analyzes potential toxicological and radiological risks associated with transportation of PUREX Facility LSA Nitric Acid from the Hanford Site to Portsmouth VA, Baltimore MD, and Port Elizabeth NJ.

  5. SOIL NITROUS OXIDE, NITRIC OXIDE, AND AMMONIA EMISSIONS FROM A RECOVERING RIPARIAN ECOSYSTEM IN SOUTHERN APPALACHIA

    Science.gov (United States)

    The paper presents two years of seasonal nitric oxide, ammonia, and nitrous oxide trace gas fluxes measured in a recovering riparian zone with cattle excluded and in an adjacent riparian zone grazed by cattle. In the recovering riparian zone, average nitric oxide, ammonia, and ni...

  6. Nitric oxide mediates the stress response induced by diatom aldehydes in the sea urchin Paracentrotus lividus.

    Directory of Open Access Journals (Sweden)

    Giovanna Romano

    Full Text Available Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms.

  7. Analysis of Steam Heating of a Two-Layer TBP/N-Paraffin/Nitric Acid Mixtures

    International Nuclear Information System (INIS)

    Laurinat, J.E.; Hassan, N.M.; Rudisill, T.S.; Askew, N.M.

    1998-01-01

    This report presents an analysis of steam heating of a two-layer tri-n-butyl phosphate (TBP)/n-paraffin-nitric acid mixture.The purpose of this study is to determine if the degree of mixing provided by the steam jet or by bubbles generated by the TBP/nitric acid reaction is sufficient to prevent a runaway reaction

  8. Transportation impact analysis for the shipment of low specific activity nitric acid. Revisison 1

    International Nuclear Information System (INIS)

    Green, J.R.

    1995-01-01

    This is in support of the Plutonium-Uranium Extraction (PUREX) Facility Low Specific Activity (LSA) Nitric Acid Shipment Environmental Assessment. It analyzes potential toxicological and radiological risks associated with transportation of PUREX Facility LSA Nitric Acid from the Hanford Site to Portsmouth VA, Baltimore MD, and Port Elizabeth NJ

  9. Transportation impact analysis for the shipment of Low Specific Activity Nitric Acid

    International Nuclear Information System (INIS)

    Green, J.R.

    1994-01-01

    This document was written in support of the Plutonium-Uranium Extraction (PUREX) Facility Low Specific Activity (LSA) Nitric Acid Shipment Environmental Assessment. It analyzes the potential toxicological and radiological risks associated with the transportation of PUREX Facility LSA Nitric Acid from the Hanford Site in Washington State to three Eastern ports

  10. Increase of hepatic nitric oxide levels in a nutritional model of fatty ...

    African Journals Online (AJOL)

    GREGORY

    2010-08-30

    Aug 30, 2010 ... (MDA) and protein carbonyl (PC), and also nitric oxide (NO) in over fed broiler breeder hens, 198 hens. (30 weeks old) .... The total protein in the liver tissue was determined by a method ... Table 1. Egg production and LHS in broiler breeder hens .... trations of nitric oxide metabolites (nitrates-nitrites) in rat.

  11. Role of nitric oxide in glucose-, fructose and galactose-induced ...

    African Journals Online (AJOL)

    Previous studies have shown that the infusion of glucose, fructose and galactose resulted in significant increases in intestinal glucose uptake (IGU) and the role of nitric oxide in these responses was not known. The present study was designed to investigate the role of nitric oxide in the observed increases in IGU.

  12. Hyperbaric oxygen therapy may overcome nitric oxide blockage during cyanide intoxication

    DEFF Research Database (Denmark)

    Polzik, Peter; Hansen, Marco Bo; Olsen, Niels Vidiendal

    2017-01-01

    PURPOSE: To determine the effects of a blockade of nitric oxide (NO) synthesis on hyperbaric oxygen (HBO₂) therapy during cyanide (CN) intoxication. METHODS: 39 anesthetized female Sprague-Dawley rats were exposed to CN intoxication (5.4 mg/kg intra-arterially) with or without previous nitric oxide...

  13. Modulation of cholinergic airway reactivity and nitric oxide production by endogenous arginase activity

    NARCIS (Netherlands)

    Meurs, Herman; Hamer, M.A M; Pethe, S; Vadon-Le Goff, S; Boucher, J.-L; Zaagsma, Hans

    1 Cholinergic airway constriction is functionally antagonized by agonist-induced constitutive nitric oxide synthase (cNOS)-derived nitric oxide (NO). Since cNOS and arginase, which hydrolyzes L-arginine to L-ornithine and urea, use L-arginine as a common substrate, competition between both enzymes

  14. Sludge batch 9 follow-on actual-waste testing for the nitric-glycolic flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-03-23

    An actual-waste Sludge Batch 9 qualification run with the nitric-glycolic flowsheet (SC-18) was performed in FY16. In order to supplement the knowledge base for the nitric-glycolic flowsheet, additional testing was performed on the product slurries, condensates, and intermediate samples from run SC-18.

  15. A study on electrochemical redox behavior of nitric acid by using a glassy carbon fiber column electrode system

    International Nuclear Information System (INIS)

    Kim, K. W.; Song, K. C.; Lee, I. H.; Choi, I. K.; You, J. H.

    1999-01-01

    Electrochemical redox behaviors of nitric acid were studied by using a glassy carbon fiber column electrode system, and its reaction mechanism was analyzed in several ways. The electrochemical reaction in less than 2.0 M nitric acid was not observed, but in more than 2.0 M nitric acid, the reduction rate of nitric acid to produce nitrous acid was slow so that the nitric acid solution had to be contacted with electrode enough in order for a apparent reduction current of nitric acid to nitrous acid be to observed. The nitrous acid generated in more than 2.0 M nitric acid was rapidly and easily reduced to NOx through an autocatalytic reaction. Sulfamic acid was confirmed to be effective to destroy the nitrous acid. The sulfamic acid of at least 0.05M was necessary to remove the nitrous acid generated in 3.5 M nitric acid

  16. Recovery of Tin and Nitric Acid from Spent Solder Stripping Solutions

    International Nuclear Information System (INIS)

    Ahn, Jae-Woo; Ryu, Seong-Hyung; Kim, Tae-young

    2015-01-01

    Spent solder-stripping solutions containing tin, copper, iron, and lead in nitric acid solution, are by-products of the manufacture of printed-circuit boards. The recovery of these metals and the nitric acid, for re-use has economic and environmental benefits. In the spent solder-stripping solution, a systematic method to determine a suitable process for recovery of valuable metals and nitric acid was developed. Initially, more than 90% of the tin was successfully recovered as high-purity SnO 2 by thermal precipitation at 80 ℃ for 3 hours. About 94% of the nitric acid was regenerated effectively from the spent solutions by diffusion dialysis, after which there remained copper, iron, and lead in solution. Leakage of tin through the anion-exchange membrane was the lowest (0.026%), whereas Pb-leakage was highest (4.26%). The concentration of the regenerated nitric acid was about 5.1 N.

  17. Interfacial tension in systems involving TBP in dodecane, nitric acid, uranyl nitrate and water

    International Nuclear Information System (INIS)

    Kolarik, Z.; Pipkin, N.

    1982-08-01

    The interfacial tension was measured at 25 0 C in the systems TBP - n-dodecane/nitric acid - water and TBP - n-dodecane/nitric acid - uranyl nitrate - water. Empirical equations describing the interfacial tension as a function of the concentration of TBP in the starting organic phase and of uranium-(VI) and nitric acid in the equilibrium aqueous phase were suggested. In the absence of uranium (VI), the interfacial tension can also be correlated with the concentration of water in the equilibrium organic phase. Free TBP, hydrated or nonhydrated, and hydrated TBP solvates of nitric acid are interfacially active. Anhydrous TBP solvates of nitric acid and the TBP solvate of uranyl nitrate, which neither is hydrated, do not exhibit any visible interfacial activity. (orig.) [de

  18. Role of nitric oxide in methamphetamine neurotoxicity: protection by 7-nitroindazole, an inhibitor of neuronal nitric oxide synthase.

    Science.gov (United States)

    Di Monte, D A; Royland, J E; Jakowec, M W; Langston, J W

    1996-12-01

    The role of nitric oxide (NO.) in the neurotoxic effects of methamphetamine (METH) was evaluated using 7-nitroindazole (7-NI), a potent inhibitor of neuronal nitric oxide synthase. Treatment of mice with 7-NI (50 mg/kg) almost completely counteracted the loss of dopamine, 3,4-dihydroxyphenylacetic acid, and tyrosine hydroxylase immunoreactivity observed 5 days after four injections of 10 or 7.5 mg/kg METH. With the higher dose of METH, this protection at 5 days occurred despite the fact that combined administration of METH and 7-NI significantly increased lethality and exacerbated METH-induced dopamine release (as indicated by a greater dopamine depletion at 90 min and 1 day). Combined treatment with 4 x 10 mg/kg METH and 7-NI also slightly increased the body temperature of mice as compared with METH alone. Thus, the neuroprotective effects of 7-NI are independent from lethality, are not likely to be related to a reduction of METH-induced dopamine release, and are not due to a decrease in body temperature. These results indicate that NO. formation is an important step leading to METH neurotoxicity, and suggest that the cytotoxic properties of NO. may be directly involved in dopaminergic terminal damage.

  19. Corn silk induces nitric oxide synthase in murine macrophages.

    Science.gov (United States)

    Kim, Kyung A; Choi, Sang Kyu; Choi, Hye Seon

    2004-12-31

    Corn silk has been purified as an anticoagulant previously and the active component is a polysaccharide with a molecular mass of 135 kDa. It activates murine macrophages to induce nitric oxide synthase (NOS) and generate substantial amounts of NO in time and dose-dependent manners. It was detectable first at 15 h after stimulation by corn silk, peaked at 24 h, and undetectable by 48 h. Induction of NOS is inhibited by pyrolidine dithiocarbamate (PDTC) and genistein, an inhibitor of nuclear factor kappa B (NF-kappaB) and tyrosine kinase, respectively, indicating that iNOS stimulated by corn silk is associated with tyrosine kinase and NF-kappaB signaling pathways. IkappaB-alpha degradation was detectible at 10 min, and the level was restored at 120 min after treatment of corn silk. Corn silk induced nuclear translocation of NF-kappaB by phosphorylation and degradation of IkappaB-alpha.

  20. Reduction of nitric oxide by arc vaporized carbons (AVC)

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, S C; Chen, Y K; Green, M L.H. [The Catalysis Centre, Inorganic Chemistry Laboratory, University of Oxford, Oxford (United Kingdom)

    1996-07-04

    The reduction of nitric oxide by arc vaporized carbons (AVC) including the compound C{sub 6}0, fullerene soot and carbon nanotubes, giving dinitrogen and carbon oxides has been studied. It is found that the AVC carbons are more active towards oxidation by NO than by oxygen gas at low temperatures (300-400C). In contrast, conventional carbons such as graphite and microporous carbons are more readily oxidised by oxygen than by NO. The addition of copper salts and to a lesser extent, cobalt salts, to fullerene soot substantially promote NO reduction. The high intrinsic activity for NO reduction by AVC carbons compared to graphitic carbons is attributed to the presence of five membered carbon rings in the AVC carbons

  1. Ethylene, nitric oxide and haemoglobins in plant tolerance to flooding

    DEFF Research Database (Denmark)

    Mur, Luis A J; Gupta, Kapuganti J; Chakraborty, U

    2015-01-01

    -tolerant species Rumex palustris and the model plant Arabidopsis thaliana have been extensively exploited to reveal some key molecular events. Our groups have recently demonstrated that nitric oxide (NO) triggers the biosynthesis of ethylene during stress and that NO plays key roles in PCD and the hyponastic......As much as 12% of the world's soils may suffer excess water so that flooding is a major limiting factor on crop production in many areas. Plants attempt to deal with submergence by forming root aerenchyma to facilitate oxygen diffusion from the shoot to the root, initiating a hyponastic response....... This chapter will detail our understanding of the roles of ethylene, NO and haemoglobin in flooding stress....

  2. Investigation on the corrosion resistance of zirconium in nitric acid

    International Nuclear Information System (INIS)

    Fauvet, P.; Mur, P.

    1990-01-01

    Zirconium in nitric solutions exhibits an excellent corrosion resistance in the passive state, and a mediocre corrosion resistance in the unpassive state with risk of stress corrosion cracking. Results of the influence of some parameters (medium, potential, temperature, stress, friction, metallurgical structure and surface state) on zirconium passivation are presented. Zirconium remains passive in a large range of HNO 3 concentration (at least up to 14.4N), in the presence of oxidizing ions (Cr 4 , Ce 4 ), in a spent fuel dissolution solution. Zirconium is depassived by friction at high speed and pressure, by platinum coupling in boiling 14.4N HNO 3 with or without stress, or by imposed deformation speed under high potential. (A.B.)

  3. Exhaled nitric oxide concentration in patients after heart transplantation.

    Science.gov (United States)

    Nadziakiewicz, P; Knapik, P; Zakliczyński, M; Zembala, M; Urbańska, E; Pacholewicz, J

    2007-11-01

    Nitric oxide (NO) is present in exhaled air in humans and its level may decrease in heart diseases. In the present study we prospectively investigated how heart transplantation treated with oral immunosuppresive drugs based on ciclosporine A influences the exhaled NO concentration (exNO). The study was performed in 17 patients after heart transplantation in various time after procedure and 15 nonsmoking healthy volunteers as a control group. Patients after heart transplantation were free of clinical signs of rejection. End-tidal concentration of exNO was measured by the use of a chemiluminescence method. We found no statistically significant differences in the exNO level between patients after heart transplantation and healthy controls (6.81+/-2.70 part per billion (ppb) in the transplant group vs. 6.01+/-3.43 ppb in the control group). We conclude that heart transplantation and immunosuppresive therapy do not influence the exhaled NO concentration.

  4. Nitric oxide-related drug targets in headache

    DEFF Research Database (Denmark)

    Olesen, Jes

    2010-01-01

    -called delayed headache that fulfils criteria for migraine without aura in migraine sufferers. Blockade of nitric oxide synthases (NOS) by L-nitromonomethylarginine effectively treats attacks of migraine without aura. Similar results have been obtained for chronic the tension-type headache and cluster headache....... Inhibition of the breakdown of cyclic guanylate phosphate (cGMP) also provokes migraine in sufferers, indicating that cGMP is the effector of NO-induced migraine. Similar evidence suggests an important role of NO in the tension-type headache and cluster headache. These very strong data from human...... experimentation make it highly likely that antagonizing NO effects will be effective in the treatment of primary headaches. Nonselective NOS inhibitors are likely to have side effects whereas selective compounds are now in early clinical trials. Antagonizing the rate limiting cofactor tetrahydrobiopterin seems...

  5. Weaning of inhaled nitric oxide: is there a best strategy?

    Directory of Open Access Journals (Sweden)

    Anita M. Ware

    2015-04-01

    Full Text Available Background: Inhaled nitric oxide (iNO has been used in the treatment of pulmonary hypertension in neonates for many years. iNO was approved by the FDA in 1999 for hypoxic respiratory failure (HRF in term and near term infants, defined as > 34 weeks gestational age (GA. iNO is used for persistent pulmonary hypertension of the newborn (PPHN, secondary pulmonary hypertension caused by congenital heart disease (CHD, congenital diaphragmatic hernia (CDH, meconium aspiration syndrome (MAS, pneumonia, respiratory distress syndrome (RDS, and other pathologies. iNO has its effect locally on the pulmonary vasculature and has been studied extensively regarding its effect on morbidities such as: need for extracorporeal membrane oxygenation (ECMO, oxygen requirements, and mechanical ventilatory support. However, protocols for weaning iNO and for the duration of iNO weaning have not been studied extensively. It has been shown that an abrupt discontinuation leads to rebound pulmonary hypertension.Methods: Electronic literature search and review of published articles on the use of iNO in the neonate.Results: Electronic databases including Medline and PubMed were searched from the years 1995-2015, using the keywords "iNO", "nitric oxide", "neonate", and "weaning nitric oxide." This search revealed 2,124 articles. Articles were determined to be eligible for review if they included a specific protocol for weaning iNO, and were published in English. 16 articles with specific protocols for iNO weaning have been identified and reviewed. The studies had enrolled a total of 1,735 neonates either at term either preterm and with a mean birth weight of 3.3 kg (± 2 kg. Main diagnoses included MAS, CHD (total anomalous pulmonary venous return [TAPVR], d-transposition of the great vessels [DTGV], atrial septal defect [ASD], pulmonary atresia [PA], hypoplastic left heart syndrome [HLH], pneumonia, RDS, hyaline membrane disease (HMD, PPHN, CDH, sepsis, pulmonary hypoplasia

  6. Curcumin overcomes the inhibitory effect of nitric oxide on Leishmania.

    Science.gov (United States)

    Chan, Marion Man-Ying; Adapala, Naga Suresh; Fong, Dunne

    2005-04-01

    Upon Leishmania infection, macrophages are activated to produce nitrogen and oxygen radicals simultaneously. It is well established that the infected host cells rely on nitric oxide (NO) as the major weapon against the intracellular parasite. In India where leishmaniasis is endemic, the spice turmeric is used prolifically in food and for insect bites. Curcumin, the active principle of turmeric, is a scavenger of NO. This report shows that curcumin protects promastigotes and amastigotes of the visceral species, Leishmania donovani, and promastigotes of the cutaneous species, L. major, against the actions of S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETANONOate, which release NO, 3-morpholino-sydnonimine hydrochloride (SIN-1), which releases NO and superoxide, and peroxynitrite, which is formed from the reaction of NO with superoxide. Thus, curcumin, as an antioxidant, is capable of blocking the action of both NO and NO congeners on the Leishmania parasite.

  7. The disproportionation of Pu4+ in nitric acid solutions

    International Nuclear Information System (INIS)

    Toth, L.M.; Bell, J.T.; Friedman, H.A.

    1990-01-01

    The Pu 4+ disproportionation equilibrium in nitric acid has been examined at ≤25deg C to extend our understanding and predictive ability with regard to species distribution under these conditions. Vis/UV absorption spectrophotometry has been used in a conventional manner to determine the concentrations of the various plutonium species. Values for the overall equilibrium quotient at 5, 15, and 25deg C were determined to be 0.098, 3.46, and 58.8, respectively, at zero ionic strength. From these values, the enthalpy of the reaction was found to be +52.7 kcal (220 kJ)/mol. The excellent reproducibility of the equilibrium quotients, even while parameters such as acid, nitrate ion and plutonium concentrations were changed, lend confidence to future predictive calculations regarding this reaction. (orig.)

  8. The role of nitric oxide in the object recognition memory.

    Science.gov (United States)

    Pitsikas, Nikolaos

    2015-05-15

    The novel object recognition task (NORT) assesses recognition memory in animals. It is a non-rewarded paradigm that it is based on spontaneous exploratory behavior in rodents. This procedure is widely used for testing the effects of compounds on recognition memory. Recognition memory is a type of memory severely compromised in schizophrenic and Alzheimer's disease patients. Nitric oxide (NO) is sought to be an intra- and inter-cellular messenger in the central nervous system and its implication in learning and memory is well documented. Here I intended to critically review the role of NO-related compounds on different aspects of recognition memory. Current analysis shows that both NO donors and NO synthase (NOS) inhibitors are involved in object recognition memory and suggests that NO might be a promising target for cognition impairments. However, the potential neurotoxicity of NO would add a note of caution in this context. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Nanomaterials-based electrochemical sensors for nitric oxide

    International Nuclear Information System (INIS)

    Dang, Xueping; Hu, Hui; Wang, Shengfu; Hu, Shengshui

    2015-01-01

    Electrochemical sensing has been demonstrated to represent an efficient way to quantify nitric oxide (NO) in challenging physiological environments. A sensing interface based on nanomaterials opens up new opportunities and broader prospects for electrochemical NO sensors. This review (with 141 refs.) gives a general view of recent advances in the development of electrochemical sensors based on nanomaterials. It is subdivided into sections on (i) carbon derived nanomaterials (such as carbon nanotubes, graphenes, fullerenes), (ii) metal nanoparticles (including gold, platinum and other metallic nanoparticles); (iii) semiconductor metal oxide nanomaterials (including the oxides of titanium, aluminum, iron, and ruthenium); and finally (iv) nanocomposites (such as those formed from carbon nanomaterials with nanoparticles of gold, platinum, NiO or TiO 2 ). The various strategies are discussed, and the advances of using nanomaterials and the trends in NO sensor technology are outlooked in the final section. (author)

  10. Biological indication of nitric oxides; Zum bioindikativen Nachweis von Stickoxiden

    Energy Technology Data Exchange (ETDEWEB)

    Belotti, E.; Kaemmerer, D.; Mangold, U.; Tempes, D.; Arndt, U.

    1992-12-31

    The authors demonstrate the need for a nitrogen oxide bio-indicator and suggest to use nitrate reductase activity in exposed plant leaves to be established in vivo as the action criterium. Studies on the suitability of different plants and cultivation conditions are presented. Their results are taken to show that large-leaved plants like sunflower or tomato grown with ammonia as the only nitrogen source are best suited for bio-indication of nitric oxides. (orig.) [Deutsch] Der Beitrag zeigt die Notwendigkeit eines Bioindikators fuer Stickoxide auf und schlaegt als Wirkungskriterium die Nitratreduktase-Aktivitaet in den Blaettern exponierter Pflanzen, ermittelt mit der in-vivo-Methode, vor. Untersuchungen zur Eignung verschiedener Pflanzen und Anzuchtbedingungen werden vorgestellt. Aus ihnen ist abzuleiten, dass mit Ammonium als einziger Stickstoffquelle angezogene grossblaettrige Kulturpflanzen, etwa Sonnenblume oder Tomate, am ehesten fuer den bioindikativen Nachweis von Stickoxiden geeignet sind. (orig.)

  11. Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

    Directory of Open Access Journals (Sweden)

    Bruno P. Carreira

    2015-01-01

    Full Text Available Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO. In these conditions, NO promotes proliferation of neural stem cells (NSC in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA induced seizure mouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.

  12. Localization of Nitric Oxide in Wheat Roots by DAF Fluorescence.

    Science.gov (United States)

    Wany, Aakanksha; Gupta, Kapuganti Jagadis

    2016-01-01

    Nitric oxide is a free radical signal molecule. Various methods are available for measurement of NO. Out of all methods, fluorescent probes to localize NO is very widely used method. Diaminofluorescein in diacetate form (DAF-2DA) is most widely probe for NO measurement. This method is based on application of 4,5-diaminofluorescein diacetate (DAF-2DA) which is actively diffused into cells, once taken up by cells cytoplasmic esterases cleave the acetate groups to generate 4,5-diaminofluorescein; DAF-2. The generated DAF-2 can readily react with N2O3, which is an oxidation product of NO to generate the highly fluorescent DAF-2T (triazolofluorescein). There are various advantages and disadvantages associated with this method, but to its advantage in diffusion closely to NO producing sites, it is widely used for localization studies. Here, we describe method to make sections of the roots and localization of NO in roots subjected to hypoxic stress.

  13. Estimation of nitric oxide as an inflammatory marker in periodontitis

    Directory of Open Access Journals (Sweden)

    Menaka K

    2009-01-01

    Full Text Available Nitric oxide (NO is not only important in host defense and homeostasis but it is also regarded as harmful and has been implicated in the pathogenesis of a wide variety of inflammatory and autoimmune diseases. The presence of NO in periodontal disease may reflect the participation of an additional mediator of bone resorption responsible for disease progression. The aim of this study was to assess the level of NO in serum in chronic periodontitis, and correlate these levels with the severity of periodontal disease. Sixty subjects participated in the study and were divided into two groups. NO levels were assayed by measuring the accumulation of stable oxidative metabolite, nitrite with Griess reaction. Results showed subjects with periodontitis had significantly high nitrite in serum than healthy subjects. NO production is increased in periodontal disease, this will enable us to understand its role in disease progression and selective inhibition of NO may be of therapeutic utility in limiting the progression of periodontitis.

  14. Radiosensitization of hypoxic tumor cells in vitro by nitric oxide

    International Nuclear Information System (INIS)

    Griffin, Robert J.; Makepeace, Carol M.; Hur, Won-Joo; Song, Chang W.

    1996-01-01

    Purpose: The effects of nitric oxide (NO) on the radiosensitivity of SCK tumor cells in oxic and hypoxic environments in vitro were studied. Methods and Materials: NO was delivered to cell suspensions using the NO donors 2,2-diethyl-1-nitroso-oxyhydrazine sodium salt (DEA/NO), and a spermine/nitric oxide complex (SPER/NO), which release NO at half-lives of 2.1 min and 39 min at pH 7.4, respectively. The cells were suspended in media containing DEA/NO or SPER/NO for varying lengths of time under oxic or hypoxic conditions, irradiated, and the clonogenicity determined. Results: Both compounds markedly radiosensitized the hypoxic cells. The drug enhancement ratios (DER) for 0.1, 1.0, and 2.0 mM DEA/NO were 2.0, 2.3 and 3.0, respectively, and those for 0.1, 1.0, and 2.0 mM SPER/NO were 1.6, 2.3, and 2.8, respectively. Aerobic cells were not radiosensitized by DEA/NO or SPER/NO. When DEA/NO and SPER/NO were incubated in solution overnight to allow release of NO, they were found to have no radiosensitizing effect under hypoxic or oxic conditions indicating the sensitization by the NO donors was due to the NO molecule released from these drugs. At the higher concentrations, SPER/NO was found to be cytotoxic in aerobic conditions but not in hypoxic conditions. DEA/NO was only slightly toxic to the cells in both aerobic and hypoxic conditions. Conclusions: NO released from NO donors DEA/NO and SPER/NO is as effective as oxygen to radiosensitize hypoxic cells in vitro. Its application to the radiosensitization of hypoxic cells in solid tumors remains to be investigated

  15. Nitric oxide as a potential biomarker in inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Nesina Avdagić

    2013-02-01

    Full Text Available The aim of this study was to investigate changes in serum nitric oxide (NO concentration in inflammatory bowel diseases (IBD patients and its use as potential biomarker in differential diagnosis of ulcerative colitis (UC and Crohn's disease (CD and in disease activity assessment. In 60 patients of both genders - 30 with ulcerative colitis and 30 with Crohn's disease - and 30 controls serum nitric oxide concentration was determined by measuring nitrite concentration, a stable metabolic product of NO with oxygen. Conversion of nitrates (NO3- to nitrites (NO2- was done with elementary zinc. The nitrite concentration was determined by classic colorimetrical Griess reaction. Median serum NO concentration was statistically different (p=0,0005 between UC patients (15.25 µmol/L; 13.47 - 19.88 µmol/L, CD patients (14.54 µmol/L; 13.03 -16.32 µmol/L and healthy controls (13.29 µmol/L; 12.40 - 13.92 µmol/L. When active UC and CD patients were compared with inactive UC and CD patients respectively a significant difference in serum NO level was found (p=0.0005. With a cut-off level of 17.39 µmol/L NO had a sensitivity of 100% and a specificity of 100% in discriminating between active and inactive UC patients. With cut-off value of 14.01 µmol/L serum NO level had a sensitivity of 88% and a specificity of 69% in distinguishing between patients with active CD and inactive CD. Serum NO concentration is a minimally invasive and rapid tool for discriminating between active and inactive IBD patients and could be used as useful biomarker in monitoring of disease activity in IBD patients.

  16. Role of nitric oxide in cellular iron metabolism.

    Science.gov (United States)

    Kim, Sangwon; Ponka, Prem

    2003-03-01

    Iron regulatory proteins (IRP1 and IRP2) control the synthesis of transferrin receptors (TfR) and ferritin by binding to iron-responsive elements (IREs) which are located in the 3' untranslated region (UTR) and the 5' UTR of their respective mRNAs. Cellular iron levels affect binding of IRPs to IREs and consequently expression of TfR and ferritin. Moreover, NO*, a redox species of nitric oxide that interacts primarily with iron, can activate IRP1 RNA-binding activity resulting in an increase in TfR mRNA levels. We have shown that treatment of RAW 264.7 cells (a murine macrophage cell line) with NO+ (nitrosonium ion, which causes S-nitrosylation of thiol groups) resulted in a rapid decrease in RNA-binding of IRP2, followed by IRP2 degradation, and these changes were associated with a decrease in TfR mRNA levels. Moreover, we demonstrated that stimulation of RAW 264.7 cells with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) increased IRP1 binding activity, whereas RNA-binding of IRP2 decreased and was followed by a degradation of this protein. Furthermore, the decrease of IRP2 binding/protein levels was associated with a decrease in TfR mRNA levels in LPS/IFN-gamma-treated cells, and these changes were prevented by inhibitors of inducible nitric oxide synthase. These results suggest that NO+-mediated degradation of IRP2 plays a major role in iron metabolism during inflammation.

  17. Doxycycline reduces nitric oxide production in guinea pig inner ears.

    Science.gov (United States)

    Helling, Kai; Wodarzcyk, Karl; Brieger, Jürgen; Schmidtmann, Irene; Li, Huige; Mann, Wolf J; Heinrich, Ulf-Rüdiger

    2011-12-01

    Gentamicin application is an important therapeutic option to control vertigo spells in Ménière's disease. However, even in the case of low-dose intratympanic application, gentamicin might contribute to a pathological NO-increase leading to cochlear damage and hearing impairment. The study was performed to evaluate the nitric oxide (NO) reducing capacity of doxycycline in the inner ear after NO-induction by gentamicin. In a prospective animal study, a single dose of gentamicin (10mg/kg body weight) was injected intratympanically into male guinea pigs (n=48). The auditory brainstem responses (ABRs) were recorded prior to application and 3, 5 and 7 days afterwards. The organ of Corti and the lateral wall of 42 animals were isolated after 7 days and incubated separately for 6h in cell culture medium. Doxycycline was adjusted to organ cultures of 5 animals. Two NOS inhibitors, N(G)-Nitro-l-arginine methyl ester (l-NAME) and NG-monomethyl-l-arginine monoacetate (l-NMMA), were applied in three different concentrations to the organ cultures of 30 animals in total (5 animals per concentration). As controls, seven animals received no further substance except gentamicin. The NO-production was quantified by chemiluminescence. Additional six gentamicin-treated animals were used for immunohistochemical studies. The ABRs declined continuously from the first to the seventh day after gentamicin application. Doxycycline reduced NO-production in the lateral wall by 54% (p=.029) comparable to the effect of the applied nitric oxide inhibitors. In the organ of Corti, NO-production was reduced by about 41% showing no statistical significance in respect to great inter-animal variations. The application of doxycycline might offer a new therapeutic approach to prevent NO-induced cochlea damage through ototoxic substances. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. Triazine herbicides inhibit relaxin signaling and disrupt nitric oxide homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Si Eun; Lim, Sa Rang; Choi, Hyung-kyoon; Bae, Jeehyeon, E-mail: jeehyeon@cau.ac.kr

    2016-09-15

    Triazines are herbicides that are widely used worldwide, and we previously observed that the maternal exposure of mice to simazine (50 or 500 μg/kg) resulted in smaller ovaries and uteri of their female offspring. Here, we investigated the underlying mechanism that may account for the reproductive dysfunction induced by simazine. We found that following maternal exposure, simazine is transmitted to the offspring, as evidenced by its presence in the offspring ovaries. Analyses of the simazine-exposed offspring revealed that the expression of the relaxin hormone receptor, relaxin-family peptide receptor 1 (RXFP1), prominently decreased in their ovaries and uteri. In addition, downstream target genes of the relaxin pathway including nitric oxide (NO) synthase 2 (Nos2), Nos3, matrix metallopeptidase 9 (Mmp9), and vascular endothelial growth factor (Vegf) were downregulated in their ovaries. Moreover, AKT and extracellular signal-regulated kinases (ERK) levels and their phosphorylated active forms decreased in simazine-exposed ovaries. In vitro exposure of the human ovarian granulosa cells (KGN) and uterine endometrium cells (Hec-1A) to very low concentrations (0.001 to 1 nM) of triazines including atrazine, terbuthylazine, and propazine repressed NO production with a concurrent reduction in RXFP1, NOS2, and NOS3. The inhibitory action of triazines on NO release was dependent on RXFP1, phosphoinositol 3-kinase (PI3K)/AKT, and ERK. Radioligand-binding assay also confirmed that triazines competitively inhibited the binding of relaxin to its receptor. Therefore, the present study suggests that triazine herbicides act as endocrine disrupters by interfering with relaxin hormone signaling. Thus, further evaluation of their impact on human health is imperative. - Highlights: • Triazines downregulate critical molecules involved in the relaxin signaling pathway. • Triazines act as potent antagonists of binding of relaxin to its receptor. • Triazines disrupt nitric oxide

  19. Role of nitrous acid during the dissolution of UO2 in nitric acid

    International Nuclear Information System (INIS)

    Deigan, N.; Pandey, N.K.; Kamachi Mudali, U.; Joshi, J.B.

    2016-01-01

    Understanding the dissolution behaviour of sintered UO 2 pellet in nitric acid is very important in designing an industrial scale dissolution system for the plutonium rich fast reactor MOX fuel. In the current article we have established the role of nitrous acid on the dissolution kinetics of UO 2 pellets in nitric acid. Under the chemical conditions that prevail in a typical Purex process, NO and NO 2 gases gets generated in the process streams. These gases produce nitrous acid in nitric acid medium. In addition, during the dissolution of UO 2 in nitric acid medium, nitrous acid is further produced in-situ at the pellet solution interface. As uranium dissolves oxidatively in nitric acid medium wherein it goes from U(IV) in solid to U(VI) in liquid, presence of nitrous acid (a good oxidizing agent) accelerates the reaction rate. Hence for determining the reaction mechanism of UO 2 dissolution in nitric acid medium, knowing the nitrous acid concentration profile during the course of dissolution is important. The current work involves the measurement of nitrous acid concentration during the course of dissolution of sintered UO 2 pellets in 8M starting nitric acid concentration as a function of mixing intensity from unstirred condition to 1500 RPM

  20. Effect of Nitric Acid Concentrations on Synthesis and Stability of Maghemite Nanoparticles Suspension

    Directory of Open Access Journals (Sweden)

    Irwan Nurdin

    2014-01-01

    Full Text Available Maghemite (γ-Fe2O3 nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD, transmission electron microscopy (TEM, alternating gradient magnetometry (AGM, thermogravimetric analysis (TGA, dynamic light scattering (DLS, and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension.

  1. [Ultrasound induced the formation of nitric oxide and nitrosonium ions in water and aqueous solutions].

    Science.gov (United States)

    Stepuro, I I; Adamchuk, R I; Stepuro, V I

    2004-01-01

    Nitric oxide, nitrosonium ions, nitrites, and nitrates are formed in water saturated with air under the action of ultrasound. Nitrosonium ions react with water and hydrogen peroxide to form nitrites and nitrates in sonicated solution, correspondingly. Nitric oxide is practically completely released from sonicated water into the atmosphere and reacts with air oxygen, forming NOx compounds. The oxidation of nitric oxide in aqueous medium by hydroxyl radicals and dissolved oxygen is a minor route of the formation of nitrites and nitrates in ultrasonic field.

  2. NOpiates: Novel Dual Action Neuronal Nitric Oxide Synthase Inhibitors with μ-Opioid Agonist Activity.

    Science.gov (United States)

    Renton, Paul; Green, Brenda; Maddaford, Shawn; Rakhit, Suman; Andrews, John S

    2012-03-08

    A novel series of benzimidazole designed multiple ligands (DMLs) with activity at the neuronal nitric oxide synthase (nNOS) enzyme and the μ-opioid receptor was developed. Targeting of the structurally dissimilar heme-containing enzyme and the μ-opioid GPCR was predicated on the modulatory role of nitric oxide on μ-opioid receptor function. Structure-activity relationship studies yielded lead compound 24 with excellent nNOS inhibitory activity (IC50 = 0.44 μM), selectivity over both endothelial nitric oxide synthase (10-fold) and inducible nitric oxide synthase (125-fold), and potent μ-opioid binding affinity, K i = 5.4 nM. The functional activity as measured in the cyclic adenosine monosphospate secondary messenger assay resulted in full agonist activity (EC50 = 0.34 μM). This work represents a novel approach in the development of new analgesics for the treatment of pain.

  3. Calcium-activated potassium channels - a therapeutic target for modulating nitric oxide in cardiovascular disease?

    DEFF Research Database (Denmark)

    Dalsgaard, Thomas; Kroigaard, Christel; Simonsen, Ulf

    2010-01-01

    IMPORTANCE OF THE FIELD: Cardiovascular risk factors are often associated with endothelial dysfunction, which is also prognostic for occurrence of cardiovascular events. Endothelial dysfunction is reflected by blunted vasodilatation and reduced nitric oxide (NO) bioavailability. Endothelium...

  4. Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid ...

    African Journals Online (AJOL)

    patients after intra-articular injection of sodium hyaluronate, while the effect is insignificant in severe patients. Thus, sodium hyaluronate can effectively improve nitric oxide levels in synovial fluid, reduce ..... Modern Med Health, 2014; 1:.

  5. The effect of inhaled nitric oxide in acute respiratory distress syndrome in children and adults

    DEFF Research Database (Denmark)

    Karam, O; Gebistorf, F; Wetterslev, J

    2017-01-01

    on mortality in adults and children with acute respiratory distress syndrome. We included all randomised, controlled trials, irrespective of date of publication, blinding status, outcomes reported or language. Our primary outcome measure was all-cause mortality. We performed several subgroup and sensitivity......Acute respiratory distress syndrome is associated with high mortality and morbidity. Inhaled nitric oxide has been used to improve oxygenation but its role remains controversial. Our primary objective in this systematic review was to examine the effects of inhaled nitric oxide administration......% CI) 1.59 (1.17-2.16)) with inhaled nitric oxide. In conclusion, there is insufficient evidence to support inhaled nitric oxide in any category of critically ill patients with acute respiratory distress syndrome despite a transient improvement in oxygenation, since mortality is not reduced and it may...

  6. Dual inhibition of nitric oxide and prostaglandin E-2 production by polysubstituted 2-aminopyrimidines

    Czech Academy of Sciences Publication Activity Database

    Zídek, Z.; Kverka, Miloslav; Dusilová, Adéla; Kmoníčková, E.; Jansa, P.

    2016-01-01

    Roč. 57, July 1 (2016), s. 48-56 ISSN 1089-8603 Institutional support: RVO:61388971 Keywords : Pyrimidines * Nitric oxide * Prostaglandin E-2 Subject RIV: EE - Microbiology, Virology Impact factor: 4.181, year: 2016

  7. Feasibility of direct electrochemical recovery of fission platinoids (Ru, Rh, Pd) from nitric acid solution

    International Nuclear Information System (INIS)

    Jayakumar, M.; Venkatesan, K.A.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2010-01-01

    Electrodeposition behavior of ruthenium, rhodium and palladium from nitric acid medium at various applied potentials was studied at stainless steel electrode and the results on the recovery of these fission platinoids are reported in this paper. (author)

  8. The radiolytic formation of nitric acid in argon/air/water systems

    International Nuclear Information System (INIS)

    May, R.; Stinchcombe, D.; White, H.P.

    1992-01-01

    The extent of nitric acid formation in the γ-radiolysis of argon/air/water mixtures has been assessed. The yields of nitric acid are found to increase as water vapour pressure is increased but are lower in the presence of a discrete water phase. G values for the formation of nitric acid from argon/air mixtures based on energy absorbed in the air are increased in the presence of argon but the yields in an atmosphere of argon containing small amounts of moist air are smaller than from an atmosphere of moist air alone. The G value for nitric acid formation from pure air in the presence of a distinct water phase is 2, based on energy absorbed in the air. (author)

  9. Sensing nitric oxide with a carbon nanofiber paste electrode modified with a CTAB and nafion composite

    International Nuclear Information System (INIS)

    Zheng, Dongyun; Liu, Xiaojun; Zhu, Shanying; Cao, Huimin; Chen, Yaguang; Hu, Shengshui

    2015-01-01

    We describe an electrochemical sensor for nitric oxide that was obtained by modifying the surface of a nanofiber carbon paste microelectrode with a film composed of hexadecyl trimethylammonium bromide and nafion. The modified microelectrode displays excellent catalytic activity in the electrochemical oxidation of nitric oxide. The mechanism was studied by scanning electron microscopy and cyclic voltammetry. Under optimal conditions, the oxidation peak current at a working voltage of 0.75 V (vs. SCE) is related to the concentration of nitric oxide in the 2 nM to 0.2 mM range, and the detection limit is as low as 2 nM (at an S/N ratio of 3). The sensor was successfully applied to the determination of nitric oxide released from mouse hepatocytes. (author)

  10. Critical evaluation of pressurized microwave-assisted digestion efficiency using nitric acid oxidizing systems (M7)

    International Nuclear Information System (INIS)

    Matusiewicz, H.

    2002-01-01

    Full text: The possibilities of enhancement of a medium-pressure microwave-assisted digestion system for sample preparation in trace element analysis of biological material was investigated. Based on optimal digestion conditions for oxidizing systems with nitric acid, different digestion procedures were examined to minimize residual carbon. The substitution of nitric acid and the addition of hydrogen peroxide and ozone to nitric acid was evaluated. The residual carbon content of the digestate was determined coulometrically. Addition of hydrogen peroxide during organic oxidation reactions does not lower the resolved carbon in the solution. Ozone was tested as an additional, potentially non-contaminating, digestion/oxidation system to the nitric acid used in the sample preparation method. (author)

  11. MLS/Aura L2 Nitric Acid (HNO3) Mixing Ratio V003

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  12. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V004

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  13. MLS/Aura L2 Nitric Acid (HNO3) Mixing Ratio V002

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  14. Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid ...

    African Journals Online (AJOL)

    Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid in Osteoarthritis Patients ... Tropical Journal of Pharmaceutical Research ... and moderate phase patients after intra-articular injection of sodium hyaluronate, while the effect ...

  15. Arginase attenuates inhibitory nonadrenergic noncholinergic nerve-induced nitric oxide generation and airway smooth muscle relaxation

    NARCIS (Netherlands)

    Maarsingh, H; Tio, MA; Zaagsma, J; Meurs, H

    2005-01-01

    Background: Recent evidence suggests that endogenous arginase activity potentiates airway responsiveness to methacholine by attenuation of agonist-induced nitric oxide (NO) production, presumably by competition with epithelial constitutive NO synthase for the common substrate, L-arginine. Using

  16. Arginase strongly impairs neuronal nitric oxide-mediated airway smooth muscle relaxation in allergic asthma

    NARCIS (Netherlands)

    Maarsingh, H; Leusink, J; Bos, I Sophie T; Zaagsma, J; Meurs, H

    2006-01-01

    Background: Using guinea pig tracheal preparations, we have recently shown that endogenous arginase activity attenuates inhibitory nonadrenergic noncholinergic (iNANC) nerve-mediated airway smooth muscle relaxation by reducing nitric oxide (NO) production - due to competition with neuronal

  17. Nitric oxide mediates insect cellular immunity via phospholipase A2 activation

    Science.gov (United States)

    After infection or invasion is recognized, biochemical mediators act in signaling insect immune functions. These include biogenic amines, insect cytokines, eicosanoids and nitric oxide (NO). Treating insects or isolated hemocyte populations with different mediators often leads to similar results. Se...

  18. Nitric oxide emissions from soils amended with municipal waste biosolids

    International Nuclear Information System (INIS)

    Roelle, P.A.; Aneja, V.P.

    2002-01-01

    Land spreading nitrogen-rich municipal waste biosolids (NO 3 - -N -1 dry weight, NH 3 -N∼23,080mg Nkg -1 dry weight, Total Kjeldahl N∼41,700mg Nkg -1 dry weight) to human food and non-food chain land is a practice followed throughout the US. This practice may lead to the recovery and utilization of the nitrogen by vegetation, but it may also lead to emissions of biogenic nitric oxide (NO), which may enhance ozone pollution in the lower levels of the troposphere. Recent global estimates of biogenic NO emissions from soils are cited in the literature, which are based on field measurements of NO emissions from various agricultural and non-agricultural fields. However, biogenic emissions of NO from soils amended with biosolids are lacking. Utilizing a state-of-the-art mobile laboratory and a dynamic flow-through chamber system, in-situ concentrations of nitric oxide (NO) were measured during the spring/summer of 1999 and winter/spring of 2000 from an agricultural soil which is routinely amended with municipal waste biosolids. The average NO flux for the late spring/summer time period (10 June 1999-5 August 1999) was 69.4±34.9ngNm -2 s -1 . Biosolids were applied during September 1999 and the field site was sampled again during winter/spring 2000 (28 February 2000-9 March 2000), during which the average flux was 3.6±l.7ngNm -2 s -1 . The same field site was sampled again in late spring (2-9 June 2000) and the average flux was 64.8±41.0ng Nm -2 s -1 . An observationally based model, developed as part of this study, found that summer accounted for 60% of the yearly emission while fall, winter and spring accounted for 20%, 4% and 16% respectively. Field experiments were conducted which indicated that the application of biosolids increases the emissions of NO and that techniques to estimate biogenic NO emissions would, on a yearly average, underestimate the NO flux from this field by a factor of 26. Soil temperature and % water filled pore space (%WFPS) were observed

  19. Picosecond rotationally resolved stimulated emission pumping spectroscopy of nitric oxide

    International Nuclear Information System (INIS)

    Tanjaroon, Chakree; Reeve, Scott W.; Ford, Alan; Murry, W. Dean; Lyon, Kevin; Yount, Bret; Britton, Dan; Burns, William A.; Allen, Susan D.; Bruce Johnson, J.

    2012-01-01

    Highlights: ► Stimulated emission pumping for nitric oxide was studied using picosecond lasers. ► Weak and tightly focused pulses provide sufficient energy for population transfer. ► Selective excitation at the bandhead yields strong fluorescence depletion signals. ► We observe 19% population transfer to v″ = 2 of the X 2 Π 1/2 ground electronic state. - Abstract: Stimulated emission pumping (SEP) experiments were performed on the nitric oxide molecule in a flow cell environment using lasers with pulse widths of 17–25 ps. A lambda excitation scheme, or ‘‘pump–dump” arrangement, was employed with the pump laser tuned to the T 00 vibronic band origin (λ pump =226.35(1)nm) of the A 2 Σ + (v′ = 0, J′) ← X 2 Π 1/2 (v″ = 0, J″) and the dump laser scanned from 246–248 nm within the A 2 Σ + (v′ = 0, J′) → X 2 Π 1/2 (v″ = 2, J″) transition. The rotationally resolved SEP spectra were measured by observing the total fluorescence within the A 2 Σ + (v′ = 0, J′) → X 2 Π 1/2 (v″ = 1, J″) transition between 235 nm and 237.2 nm while scanning the dump laser wavelengths. Multiple rotational states were excited due to the broad laser bandwidth. Measurements showed that the resolved rotational structure depended on the energy and bandwidth of the applied pump and dump laser pulses. Analysis of the observed fluorescence depletion signals yielded an average percent fluorescence depletion of about 19% when λ pump =226.35(1)nm and λ dump =247.91(1)nm. This value reflects the percent transfer of the NO population from the A 2 Σ + (V′ = 0, J′) excited electronic state to the X 2 Π 1/2 (v″ = 2, J″) ground electronic state. The maximum expected depletion is 50% in the limit of dump saturation. Selective excitation of NO at the bandhead provides good spectral discrimination from the background emission and noise and unambiguously confirms the identity of the emitter.

  20. The myth of nitric oxide in central cardiovascular control by the nucleus tractus solitarii

    Directory of Open Access Journals (Sweden)

    Talman W.T.

    1997-01-01

    Full Text Available Considerable evidence suggests that nitroxidergic mechanisms in the nucleus tractus solitarii (NTS participate in cardiovascular reflex control. Much of that evidence, being based on responses to nitric oxide precursors or inhibitors of nitric oxide synthesis, has been indirect and circumstantial. We sought to directly determine cardiovascular responses to nitric oxide donors microinjected into the NTS and to determine if traditional receptor mechanisms might account for responses to certain of these donors in the central nervous system. Anesthetized adult Sprague Dawley rats that were instrumented for recording arterial pressure and heart rate were used in the physiological studies. Microinjection of nitric oxide itself into the NTS did not produce any cardiovascular responses and injection of sodium nitroprusside elicited minimal depressor responses. The S-nitrosothiols, S-nitrosoglutathione (GSNO, S-nitrosoacetylpenicillamine (SNAP, and S-nitroso-D-cysteine (D-SNC produced no significant cardiovascular responses while injection of S-nitroso-L-cysteine (L-SNC elicited brisk, dose-dependent depressor and bradycardic responses. In contrast, injection of glyceryl trinitrate elicited minimal pressor responses without associated changes in heart rate. It is unlikely that the responses to L-SNC were dependent on release of nitric oxide in that 1 the responses were not affected by injection of oxyhemoglobin or an inhibitor of nitric oxide synthesis prior to injection of L-SNC and 2 L- and D-SNC released identical amounts of nitric oxide when exposed to brain tissue homogenates. Although GSNO did not independently affect blood pressure, its injection attenuated responses to subsequent injection of L-SNC. Furthermore, radioligand binding studies suggested that in rat brain synaptosomes there is a saturable binding site for GSNO that is displaced from that site by L-SNC. The studies suggest that S-nitrosocysteine, not nitric oxide, may be an

  1. Requirement of the inducible nitric oxide synthase pathway for IL-1-induced osteoclastic bone resorption

    OpenAIRE

    van't Hof, R. J.; Armour, K. J.; Smith, L. M.; Armour, K. E.; Wei, X. Q.; Liew, F. Y.; Ralston, S. H.

    2000-01-01

    Nitric oxide has been suggested to be involved in the regulation of bone turnover, especially in pathological conditions characterized by release of bone-resorbing cytokines. The cytokine IL-1 is thought to act as a mediator of periarticular bone loss and tissue damage in inflammatory diseases such as rheumatoid arthritis. IL-1 is a potent stimulator of both osteoclastic bone resorption and expression of inducible nitric oxide synthase (iNOS) in bone cells and other cell types. In this study,...

  2. Neuronal nitric oxide synthase-deficient mice have impaired Renin release but normal blood pressure

    DEFF Research Database (Denmark)

    Sällström, Johan; Carlström, Mattias; Jensen, Boye L

    2008-01-01

    BackgroundNitric oxide deficiency is involved in the development of hypertension, but the mechanisms are currently unclear. This study was conducted to further elucidate the role of neuronal nitric oxide synthase (nNOS) in blood pressure regulation and renin release in relation to different sodiu......-116; doi:10.1038/ajh.2007.16American Journal of Hypertension (2008) 21 111-116; doi:10.1038/ajh.2007.16....

  3. Study of the zirconium passive layer in nitric medium, by the means of electrochemical impedance spectrometry

    International Nuclear Information System (INIS)

    Musy, C.

    1996-01-01

    Although zirconium exhibits a very low corrosion rate in nitric medium at 100 C, electrochemical impedance spectrometry enabled the in-situ monitoring of the zirconium oxide growth in theses conditions. The growth curve shows a very clear deceleration of the oxide growth kinetics after the first hundred hours of immersion in hot nitric medium. The initial thickness of the native oxide film is also examined

  4. Inhibition of mammalian nitric oxide synthases by agmatine, an endogenous polyamine formed by decarboxylation of arginine.

    OpenAIRE

    Galea, E; Regunathan, S; Eliopoulos, V; Feinstein, D L; Reis, D J

    1996-01-01

    Agmatine, decarboxylated arginine, is a metabolic product of mammalian cells. Considering the close structural similarity between L-arginine and agmatine, we investigated the interaction of agmatine and nitric oxide synthases (NOSs), which use L-arginine to generate nitric oxide (NO) and citrulline. Brain, macrophages and endothelial cells were respectively used as sources for NOS isoforms I, II and III. Enzyme activity was measured by the production of nitrites or L-citrulline. Agmatine was ...

  5. Nitric oxide coordinates metabolism, growth, and development via the nuclear receptor E75

    OpenAIRE

    Cáceres, Lucía; Necakov, Aleksandar S.; Schwartz, Carol; Kimber, Sandra; Roberts, Ian J.H.; Krause, Henry M.

    2011-01-01

    Nitric oxide gas acts as a short-range signaling molecule in a vast array of important physiological processes, many of which include major changes in gene expression. How these genomic responses are induced, however, is poorly understood. Here, using genetic and chemical manipulations, we show that nitric oxide is produced in the Drosophila prothoracic gland, where it acts via the nuclear receptor ecdysone-induced protein 75 (E75), reversing its ability to interfere with its heterodimer part...

  6. Removal of plutonium from nitric acid-oxalic acid solutions using anion exchange method

    International Nuclear Information System (INIS)

    Kasar, U.M.; Pawar, S.M.; Joshi, A.R.

    1999-01-01

    An anion exchange method using Amberlyst A-26 (MP) resin was developed for removal of Pu from nitric acid-oxalic acid solutions without destroying oxalate. The method consists of sorption of Pu(IV) on Amberlyst A-26, a macroporous anion exchange resin, from nitric acid-oxalic acid medium in the presence of Al(NO 3 ) 3 . Pu(IV) breakthrough capacity of Amberlyst A-26 using synthetic feed solution was determined. (author)

  7. A bibliographical review on the radiolysis of uranyl nitrate solutions in nitric acid medium

    International Nuclear Information System (INIS)

    Siri, Sandra; Mondino, Angel V.

    2004-01-01

    A bibliographical study on the effects of ionizing radiation on uranyl nitrate solutions in nitric acid medium was performed, and the state of knowledge on this subject is presented. The main experimental and theoretical results on water, nitric acid and uranium solutions radiolysis are reviewed and critically evaluated. This paper provides a collection of references as an aid to the development of practical applications, and to stimulate new research on fundamental processes in these systems. (author) [es

  8. Continuous electrochemical monitoring of nitric oxide production in murine macrophage cell line RAW 264.7

    Czech Academy of Sciences Publication Activity Database

    Pekarová, Michaela; Králová, Jana; Kubala, Lukáš; Číž, Milan; Lojek, Antonín; Gregor, Č.; Hrbáč, J.

    2009-01-01

    Roč. 394, č. 5 (2009), s. 1497-1504 ISSN 1618-2642 R&D Projects: GA AV ČR(CZ) 1QS500040507 Grant - others:GA ČR(CZ) GP524/05/P135 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : nitric oxide * macrophage s RAW 264.7 * nitric oxide sensor Subject RIV: BO - Biophysics Impact factor: 3.480, year: 2009

  9. Thermodynamics of uranium and nitric acid extraction from aqueous solution of TBP/diluent

    International Nuclear Information System (INIS)

    Souza Freitas, R.F. de.

    1982-06-01

    A thermodynamically consistent procedure for predicting distribution equilibria for uranyl nitrate and nitric acid between an aqueous solution and 30 vol % tributyl phosphate (TBP) in a hydrocarbon diluent is studied. Experimental work is developed in order to obtain equilibrium data for the system uranyl nitrate, nitric acid, water and 30 vol % TBP in n-dodecane, at 25 0 C and 40 0 C. The theoretical equilibrium data, obtained with the aid of a computer, are compared with the experimental results. (Author) [pt

  10. Comparison Between the Acute Pulmonary Vascular Effects of Oxygen with Nitric Oxide and Sildenafil

    Directory of Open Access Journals (Sweden)

    Ronald W. Day

    2015-03-01

    Full Text Available Objective. Right heart catheterization is performed in patients with pulmonary arterial hypertension to determine the severity of disease and their pulmonary vascular reactivity. The acute pulmonary vascular effect of inhaled nitric oxide is frequently used to identify patients who will respond favorably to vasodilator therapy. This study sought to determine whether the acute pulmonary vascular effects of oxygen with nitric oxide and intravenous sildenafil are similar. Methods. A retrospective, descriptive study of 13 individuals with pulmonary hypertension who underwent heart catheterization and acute vasodilator testing was performed. The hemodynamic measurements during five phases (21% to 53% oxygen, 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21% to 51% oxygen, and 21% to 51% oxygen with 0.05 mg/kg to 0.29 mg/kg intravenous sildenafil of the procedures were compared.Results. Mean pulmonary arterial pressure and pulmonary vascular resistance acutely decreased with 100% oxygen with nitric oxide, and 21% to 51% oxygen with sildenafil. Mean pulmonary arterial pressure (mm Hg, mean ± standard error of the mean was 38 ± 4 during 21% to 53% oxygen, 32 ± 3 during 100% oxygen, 29 ± 2 during 100% oxygen with nitric oxide, 37 ± 3 during 21% to 51% oxygen, and 32 ± 2 during 21% to 51% oxygen with sildenafil. There was not a significant correlation between the percent change in pulmonary vascular resistance from baseline with oxygen and nitric oxide, and from baseline with sildenafil (r2 = 0.011, p = 0.738. Conclusions. Oxygen with nitric oxide and sildenafil decreased pulmonary vascular resistance. However, the pulmonary vascular effects of oxygen and nitric oxide cannot be used to predict the acute response to sildenafil. Additional studies are needed to determine whether the acute response to sildenafil can be used to predict the long-term response to treatment with an oral phosphodiesterase V inhibitor.

  11. Studies on nitric oxide removal in simulated gas compositions under plasma-dielectric/catalytic discharges

    International Nuclear Information System (INIS)

    Rajanikanth, B.S.; Rout, Satyabrata

    2001-01-01

    Application of pulsed electrical discharges for gas cleaning is gaining prominence, mainly from the energy consideration point of view. This present paper presents recent work on applying the electrical discharge plasma technology for treating gaseous pollutants, in general, and nitric oxide, in particular, as this is one of the major contributors to air pollution. The present work focuses attention on pulsed electrical discharge technique for nitric oxide removal from simulated gas compositions and study of effect of packed dielectric pellets, with and without a coating of catalyst, on the removal process. Experiments were conducted in a cylindrical corona reactor energized by repetitive high voltage pulses. The effects of various parameters, viz. pulse voltage magnitude, pulse frequency, initial nitric oxide concentration and gas mixture composition on nitric oxide removal efficiency, are discussed. When the reactors were filled with different dielectric pellets like, barium titanate, alumina, and alumina coated with palladium catalyst, the improvement in nitric oxide removal efficiency is studied and discussed. The power dissipated in the reactor and the energy consumed per nitric oxide molecule removed was calculated. Further results and comparative study of various cases are presented in the paper

  12. Component activities in the system thorium nitrate-nitric acid-water at 25oC

    International Nuclear Information System (INIS)

    Lemire, R.J.; Brown, C.P.

    1982-01-01

    The equilibrium composition of the vapor above thorium nitrate-nitric acid-water mixtures has been studied as a function of the concentrations of thorium nitrate and nitric acid using a transpiration technique. At 25 o C, the thorium nitrate concentrations m T ranged from 0.1 to 2.5 molal and the nitric acid concentrations m N from 0.3 to 25 molal. The vapor pressure of the nitric acid was found to increase with increasing thorium nitrate concentration for a constant molality of nitric acid in aqueous solution. At constant m T , the nitric acid vapor pressure was particularly enhanced at low nitric acid concentrations. The water vapor pressures decreased regularly with increasing concentrations of both nitric acid and thorium nitrate. The experimental data were fitted to Scatchard's ion-component model, and to empirical multiparameter functions. From the fitting parameters, and available literature data for the nitric acid-water and thorium nitrate-water systems at 25 o C, expressions were calculated for the variation of water and thorium nitrate activities, as functions of the nitric acid and thorium nitrate concentrations, using the Gibbs-Duhem equation. Calculated values for the thorium nitrate activities were strongly dependent on the form of the function originally used to fit the vapor pressure data. (author)

  13. Nitric Oxide (NO) Measurements in Stomatal Guard Cells.

    Science.gov (United States)

    Agurla, Srinivas; Gayatri, Gunja; Raghavendra, Agepati S

    2016-01-01

    The quantitative measurement of nitric oxide (NO) in plant cells acquired great importance, in view of the multifaceted function and involvement of NO as a signal in various plant processes. Monitoring of NO in guard cells is quite simple because of the large size of guard cells and ease of observing the detached epidermis under microscope. Stomatal guard cells therefore provide an excellent model system to study the components of signal transduction. The levels and functions of NO in relation to stomatal closure can be monitored, with the help of an inverted fluorescence or confocal microscope. We can measure the NO in guard cells by using flouroprobes like 4,5-diamino fluorescein diacetate (DAF-2DA). This fluorescent dye, DAF-2DA, is cell permeable and after entry into the cell, the diacetate group is removed by the cellular esterases. The resulting DAF-2 form is membrane impermeable and reacts with NO to generate the highly fluorescent triazole (DAF-2T), with excitation and emission wavelengths of 488 and 530 nm, respectively. If time-course measurements are needed, the epidermis can be adhered to a cover-glass or glass slide and left in a small petri dishes. Fluorescence can then be monitored at required time intervals; with a precaution that excitation is done minimally, only when a fluorescent image is acquired. The present method description is for the epidermis of Arabidopsis thaliana and Pisum sativum and should work with most of the other dicotyledonous plants.

  14. Differential modulation of nitric oxide synthases in aging: therapeutic opportunities

    Directory of Open Access Journals (Sweden)

    Stêfany Bruno De Assis Cau

    2012-06-01

    Full Text Available Vascular aging is the term that describes the structural and functional disturbances of the vasculature with advancing aging. The molecular mechanisms of aging-associated endothelial dysfunction are complex, but reduced nitric oxide (NO bioavailability and altered vascular expression and activity of NO synthase (NOS enzymes have been implicated as major players. Impaired vascular relaxation in aging has been attributed to reduced endothelial NOS (eNOS-derived NO, while increased inducible NOS (iNOS expression seems to account for nitrosative stress and disrupted vascular homeostasis. Although eNOS is considered the main source of NO in the vascular endothelium, neuronal NOS (nNOS also contributes to endothelial cells-derived NO, a mechanism that is reduced in aging. Pharmacological modulation of NO generation and expression/activity of NOS isoforms may represent a therapeutic alternative to prevent the progression of cardiovascular diseases. Accordingly, this review will focus on drugs that modulate NO bioavailability, such as nitrite anions and NO-releasing non-steroidal anti-inflammatory drugs, hormones (dehydroepiandrosterone and estrogen, statins, resveratrol and folic acid, since they may be useful to treat/to prevent aging-associated vascular dysfunction. The impact of these therapies on life quality in elderly and longevity will be discussed.

  15. Dynamics of the water dimer + nitric oxide collision

    Energy Technology Data Exchange (ETDEWEB)

    Ree, Jong Baik [Dept. of Chemistry Education, Chonnam National University, Gwangju (Korea, Republic of); Kim, Yoo Hang [Dept. of Chemistry, Inha University, Incheon (Korea, Republic of); Shin, Hyung Kyu [Dept. of Chemistry, University of Nevada, Nevada (Korea, Republic of)

    2017-02-15

    Collision-induced intermolecular energy transfer and intramolecular vibrational redistribution in the collision of a water dimer and nitric oxide are studied by use of quasiclassical procedures. Intermolecular energy flow is shown to occur mainly through a direct-mode mechanism transferring relatively large amounts in strong collisions. About a quarter of the energy initially deposited in the dimer transfers to the ground state NO, while the rest redistributes among internal motions of the collision system. The main portion of initial energy deposited in the dimer redistributes in the stretches of the donor monomer through the 1:1 resonance followed by in the bend through the 1:2 resonance. Energy transfer from the excited NO to the ground-state dimer is equally efficient, transferring more than half the initial excitation to the donor monomer, the efficiency that is attributed to the internal modes operating as energy reservoirs. The hydrogen bond shares about 15% of the initial excitation stored in both dimer-to-NO and NO-to-dimer processes as a result of strong coupling of the hydrogen bond with the proton-donor OH bond of the monomer. A small fraction of collisions proceeds through a complex-mode mechanism and lead to NO dissociation, the dissociated O atom showing a propensity to form a new hydrogen bond.

  16. Effects of ionizing radiation on nitric oxide myoglobin

    International Nuclear Information System (INIS)

    Kamarei, A.R.; Karel, M.

    1983-01-01

    Bovine nitric oxide myoglobin (NOMb) was irradiated with 40-4000 krad of γ-radiation, and the effects on the haem studied using absorption spectroscopy and electron spin resonance (e.s.r.) spectroscopy. The results show the following behaviour: (a) The bright red colour of NOMb changes to brown upon irradiation. This is similar to changes observed in radiation sterilized, nitrite-containing meats. (b) NOMb becomes progressively denitrosylated, with met-myoglobin (metMb) as the immediate product. (c) Upon increasing doses of radiation (up to 800 krad) at O 0 C parallel to NOMb denitrosylation, metMb is gradually converted, by water radiolytic products, to other products, believed to be ferromyoglobin and ferrimyoglobin peroxide. A minor quantity of 'choleglobin-type' pigments may also be formed at the highest doses. (d) Freezing of NOMb has a substantial protective effect against radiation. (e) Native bovine NOMb behaves as a pentaco-ordinate (hfs of 3 peaks with equal intensity); the bond between iron and Nsub(epsilon) is thus dramatically stretched and weakened. (f) Using a thermal energy analyser, no NO could be detected over irradiated NOMb solution, indicating rapid reaction of NO liberated from NOMb by radiation, with radiolytic products of water. (author)

  17. Nitric oxide synthetase and Helicobacter pylori in patients undergoing appendicectomy.

    LENUS (Irish Health Repository)

    Kell, M R

    2012-02-03

    BACKGROUND: This study was designed to determine whether Helicobacter pylori forms part of the normal microenvironment of the appendix, whether it plays a role in the pathogenesis of acute appendicitis, and whether it is associated with increased expression of inducible nitric oxide synthetase (iNOS) in appendicular macrophages. METHODS: Serology for H. pylori was performed on 51 consecutive patients undergoing emergency appendicectomy. Appendix samples were tested for urease activity, cultured and stained for H. pylori, graded according to the degree of inflammatory infiltrate, and probed immunohistochemically for iNOS expression. RESULTS: The mean age of the patients was 21 (range 7-51) years. Seventeen patients (33 per cent) were seropositive for H. pylori but no evidence of H. pylori was found in any appendix specimen. However, an enhanced inflammatory cell infiltration was observed in seropositive patients (P < 0.04) and the expression of macrophage iNOS in the mucosa of normal and inflamed appendix specimens was increased (P < 0.01). CONCLUSION: H. pylori does not colonize the appendix and is unlikely to be a pathogenic stimulus for appendicitis. Priming effects on mucosal immunology downstream from the foregut may occur after infection with H. pylori.

  18. Sodium nitrite: the "cure" for nitric oxide insufficiency.

    Science.gov (United States)

    Parthasarathy, Deepa K; Bryan, Nathan S

    2012-11-01

    This process of "curing" food is a long practice that dates back thousands of years long before refrigeration or food safety regulations. Today food safety and mass manufacturing are dependent upon safe and effective means to cure and preserve foods including meats. Nitrite remains the most effective curing agent to prevent food spoilage and bacterial contamination. Despite decades of rigorous research on its safety and efficacy as a curing agent, it is still regarded by many as a toxic undesirable food additive. However, research within the biomedical science community has revealed enormous therapeutic benefits of nitrite that is currently being developed as novel therapies for conditions associated with nitric oxide (NO) insufficiency. Much of the same biochemistry that has been understood for decades in the meat industry has been rediscovered in human physiology. This review will highlight the fundamental biochemistry of nitrite in human physiology and highlight the risk benefit evaluation surrounding nitrite in food and meat products. Foods or diets enriched with nitrite can have profound positive health benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Hypertension, nitric oxide, oxidants, and dietary plant polyphenols.

    Science.gov (United States)

    Galleano, Monica; Pechanova, Olga; Fraga, Cesar G

    2010-12-01

    Fruits and vegetables are key foods whose high ingestion is associated with the improvement of numerous pathological conditions, including hypertension. Such health promoting actions have been increasingly ascribed to the antioxidant characteristics of different polyphenols in fruits and vegetables. Consequently, based on this assumption, many beverages and foods rich in polyphenols, grape, tea, cocoa, and soy products and many of their chemical constituents purified, are being studied both, as antioxidants and antihypertensive agents. This paper reviews the current evidence linking high polyphenol consumption with reductions in blood pressure. Basic chemical aspects of flavanols, flavonols, isoflavones and stilbenes, as possible responsible for the observed effects of those foods on blood pressure are included. Human interventions studies by using grapes and wine, cocoa and chocolate, black and green tea, soy products, and purified compounds ((+)-catequin, quercetin, (-)-epigallocatechin gallate) are summarized. The discussed hypothesis, strongly supported by experimental data in animals, is that by regulating nitric oxide bioavailability, polyphenols present in fruits and vegetables affect endothelial function and as a consequence, blood pressure. Even when data are not definitive and many questions remain open, the whole evidence is encouraging to start considering diets that can provide a benefit to hypertensive subjects, and those benefits will be more significant in people that do not have controlled his/her elevated blood pressure.

  20. Heterogeneous reduction of nitric oxide on synthetic coal chars

    Energy Technology Data Exchange (ETDEWEB)

    C. Pevida; A. Arenillas; F. Rubiera; J.J. Pis [Instituto Nacional del Carbon (CSIC), Oviedo (Spain)

    2005-12-01

    Model compounds, with a controlled heteroatoms content and well-defined functionalities, were used to study the release of nitrogen compounds from char combustion. In the present work, the mechanisms involved in NO-char heterogeneous reduction were studied with a synthetic coal (SC) char as carbon source. Another synthetic char (SN) without any nitrogen in its composition was also employed in these studies. Temperature programmed reduction (TPR) tests with a gas mixture of 400 ppm NO in argon and with isotopically labelled nitric oxide, {sup 15}NO (500 ppm {sup 15}NO in argon), were carried out. The gases produced were quantitatively determined by means of MS and FTIR analysers. Under the conditions of this work the main products of the NO-C reaction were found to be N{sub 2} and CO{sub 2}. The main path of reaction involves the formation of surface nitrogen compounds that afterwards react with nitrogen from the reactive gas to form N{sub 2}. It was observed that fuel-N also participates in the overall heterogeneous reduction reaction, although to a lesser extent.

  1. Nitrosation of melatonin by nitric oxide: a computational study.

    Science.gov (United States)

    Turjanski, A G; Sáenz, D A; Doctorovich, F; Estrin, D A; Rosenstein, R E

    2001-09-01

    Melatonin is being increasingly promoted as a therapeutic agent for the treatment of jet lag and insomnia, and is an efficient free radical scavenger. We have recently characterized a product for the reaction of melatonin with nitric oxide (NO), N-nitrosomelatonin. In the present work, reaction pathways with N1, C2, C4, C6 and C7 as possible targets for its reaction with NO that yield the respective nitroso derivatives have been investigated using semiempirical AM1 computational tools, both in vacuo and aqueous solution. Specifically, two different pathways were studied: a radical mechanism involving the hydrogen atom abstraction to yield a neutral radical followed by NO addition, and an ionic mechanism involving addition of nitrosonium ion to the indolic moiety. Our results show that the indolic nitrogen is the most probable site for nitrosation by the radical mechanism, whereas different targets are probable considering the ionic pathway. These results are in good agreement with previous experimental findings and provide a coherent picture for the interaction of melatonin with NO.

  2. Nitric oxide mediated bystander responses induced by microbeam targeted cells

    International Nuclear Information System (INIS)

    Shao, C.; Prise, K.M.; Folkard, M.; Michael, B.D.

    2003-01-01

    Considerable evidence has recently been accumulated in support of the existence of a 'bystander effect', which cells having received no irradiation show biological consequences from their vicinal irradiated cells. The application of microbeams is providing new insights into the radiation-induced bystander effect. The present study found that when a fraction of radioresistant human glioblastoma cells were individually targeted with a precise number of helium ions generated from the Gray Cancer Institute Charged Particle Microbeam, micronucleus (MN) induction significantly exceeded the expected value that was calculated from the number of MN observed when all of the cells were targeted assuming no bystander effect occurring. Even when only a single cell within a population was hit by one helium ion, the MN induction in the population could be increased by 16%. These results provide direct evidence of radiation-induced bystander effect. Moreover, MN was effectively induced in the unirradiated primary human fibroblasts and glioblastoma cells either co-cultured with irradiated cells or treated with the medium harvested from irradiated cells, indicating a signal molecule was produced from the irradiated cells. However, when c-PTIO, a nitric oxide (NO)-specific scavenger, was present in the medium during and after irradiation until MN analysis, the production of MN in all of the above cases was reduced to low levels. Consequently, NO plays an important role in the radiation-induced bystander effect

  3. Exhaled nitric oxide - circadian variations in healthy subjects

    Directory of Open Access Journals (Sweden)

    Antosova M

    2009-12-01

    Full Text Available Abstract Objective Exhaled nitric oxide (eNO has been suggested as a marker of airway inflammatory diseases. The level of eNO is influenced by many various factor including age, sex, menstrual cycle, exercise, food, drugs, etc. The aim of our study was to investigate a potential influence of circadian variation on eNO level in healthy subjects. Methods Measurements were performed in 44 women and 10 men, non-smokers, without respiratory tract infection in last 2 weeks. The eNO was detected at 4-hour intervals from 6 a.m. to 10 p.m. using an NIOX analyzer. We followed the ATS/ERS guidelines for eNO measurement and analysis. Results Peak of eNO levels were observed at 10 a.m. (11.1 ± 7.2 ppb, the lowest value was detected at 10 p.m. (10.0 ± 5.8 ppb. The difference was statistically significant (paired t-test, P Conclusions The daily variations in eNO, with the peak in the morning hours, could be of importance in clinical practice regarding the choice of optimal time for monitoring eNO in patients with respiratory disease.

  4. Exhaled nitric oxide in paediatric asthma and cystic fibrosis.

    Science.gov (United States)

    Lundberg, J O; Nordvall, S L; Weitzberg, E; Kollberg, H; Alving, K

    1996-01-01

    Nitric oxide (NO) is present in exhaled air of humans. This NO is mostly produced in the upper airways, whereas basal NO excretion in the lower airways is low. Children with Kartagener's syndrome have an almost total lack of NO in nasally derived air, whereas adult asthmatics have increased NO in orally exhaled air. NO excretion was measured in the nasal cavity and in orally exhaled air in 19 healthy children, in 36 age matched subjects with asthma, and in eight children with cystic fibrosis. NO levels in orally exhaled air were similar in controls and in children with cystic fibrosis, at 4.8 (SD 1.2) v 5.8 (0.8) parts per billion (ppb), but were increased in asthmatic children who were untreated or were being treated only with low doses of inhaled steroids (13.8 (2.5) ppb). Nasal NO levels were reduced by about 70% in children with cystic fibrosis compared to controls and asthmatics. Measurements of airway NO release in different parts of the airways may be useful in non-invasive diagnosis and monitoring of inflammatory airway diseases. PMID:8984919

  5. Role of nitric oxide and superoxide in Giardia lamblia killing

    Directory of Open Access Journals (Sweden)

    P.D. Fernandes

    1997-01-01

    Full Text Available Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine. Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites. This effect was inhibited (>90% by an NO synthase inhibitor (200 µM and unaffected by superoxide dismutase (SOD, 300 U/ml. Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP and sodium nitroprusside (SNP in a dose-dependent manner (LD50 300 and 50 µM, respectively. A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1, did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM. The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM. These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

  6. Nitric Oxide: A Multitasked Signaling Gas in Plants

    KAUST Repository

    Domingos, Patricia

    2014-12-01

    Nitric oxide (NO) is a gaseous reactive oxygen species (ROS) that has evolved as a signaling hormone in many physiological processes in animals. In plants it has been demonstrated to be a crucial regulator of development, acting as a signaling molecule present at each step of the plant life cycle. NO has also been implicated as a signal in biotic and abiotic responses of plants to the environment. Remarkably, despite this plethora of effects and functional relationships, the fundamental knowledge of NO production, sensing, and transduction in plants remains largely unknown or inadequately characterized. In this review we cover the current understanding of NO production, perception, and action in different physiological scenarios. We especially address the issues of enzymatic and chemical generation of NO in plants, NO sensing and downstream signaling, namely the putative cGMP and Ca2+ pathways, ion-channel activity modulation, gene expression regulation, and the interface with other ROS, which can have a profound effect on both NO accumulation and function. We also focus on the importance of NO in cell–cell communication during developmental processes and sexual reproduction, namely in pollen tube guidance and embryo sac fertilization, pathogen defense, and responses to abiotic stress.

  7. Uncoupling of Vascular Nitric Oxide Synthase Caused by Intermittent Hypoxia

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    Mohammad Badran

    2016-01-01

    Full Text Available Objective. Obstructive sleep apnea (OSA, characterized by chronic intermittent hypoxia (CIH, is often present in diabetic (DB patients. Both conditions are associated with endothelial dysfunction and cardiovascular disease. We hypothesized that diabetic endothelial dysfunction is further compromised by CIH. Methods. Adult male diabetic (BKS.Cg-Dock7m +/+ Leprdb/J (db/db mice (10 weeks old and their heterozygote littermates were subjected to CIH or intermittent air (IA for 8 weeks. Mice were separated into 4 groups: IA (intermittent air nondiabetic, IH (intermittent hypoxia nondiabetic, IADB (intermittent air diabetic, and IHDB (intermittent hypoxia diabetic groups. Endothelium-dependent and endothelium-independent relaxation and modulation by basal nitric oxide (NO were analyzed using wire myograph. Plasma 8-isoprostane, interleukin-6 (IL-6, and asymmetric dimethylarginine (ADMA were measured using ELISA. Uncoupling of eNOS was measured using dihydroethidium (DHE staining. Results. Endothelium-dependent vasodilation and basal NO production were significantly impaired in the IH and IADB group compared to IA group but was more pronounced in IHDB group. Levels of 8-isoprostane, IL-6, ADMA, and eNOS uncoupling were ≈2-fold higher in IH and IADB groups and were further increased in the IHDB group. Conclusion. Endothelial dysfunction is more pronounced in diabetic mice subjected to CIH compared to diabetic or CIH mice alone. Oxidative stress, ADMA, and eNOS uncoupling were exacerbated by CIH in diabetic mice.

  8. Studies on the solvent extraction behaviour of Pu(IV) from nitric acid, nitric-perchloric acid and hydrochloric acids, by di,2-ethylhexyl phosphoric acid (HDEHP)

    International Nuclear Information System (INIS)

    Phal, D.G.; Kannan, S.K.; Ramakrishna, V.V.

    1994-01-01

    Extraction of plutonium (IV) from aqueous nitric acid, nitric-perchloric acid and hydrochloric acids by di,2-ethylhexyl phosphoric acid, the dimeric form of which is represented as H 2 Y 2 , in different diluents (dodecane, toluene and chloroform) was investigated. The composition of the extracted Pu(IV) species were found to be Pu(NO 3 ) 2 (HY) 2 , Pu(NO 3 )(ClO 4 )(HY 2 ) 2 , PuClY(HY 2 ) 2 and PuCl 2 (HY 2 ) 2 from nitric, nitric-perchloric and hydrochloric acids respectively, the last one being pre-dominant at high aqueous acidities (i.e. 5M HCl). Synergic enhancement in the extraction of Pu(IV) from different aqueous media, by the addition of thenoyltrifluoroacetone (HTTA) to HDEHP was also investigated and was attributed to the formation and extraction of the species PuX(TTA)(HY 2 ) 2 , and Pu(TTA) 2 (HY 2 ) 2 where X=Cl - or NO 3 - . The addition of the neutral extractant TOPO to H 2 Y 2 also resulted in synergism. The possible equilibria in these systems were inferred and the corresponding equilibrium constants determined. (author). 24 refs., 10 figs., 10 tabs

  9. Pu-erh Tea Reduces Nitric Oxide Levels in Rats by Inhibiting Inducible Nitric Oxide Synthase Expression through Toll-Like Receptor 4

    Science.gov (United States)

    Xu, Yang; Wang, Guan; Li, Chunjie; Zhang, Min; Zhao, Hang; Sheng, Jun; Shi, Wei

    2012-01-01

    Pu-erh tea undergoes a unique fermentation process and contains theabrownins, polysaccharides and caffeine; although it is unclear about which component is associated with the down regulation of nitric oxide levels or how this process is mediated. To address this question we examined the effects of pu-erh tea on nitric oxide synthase (NOS) genes. Cohorts of rats were separately given four-week treatments of water as control, pu-erh tea, or the tea components: theabrownins, caffeine or polysaccharides. Five experimental groups were injected with lipopolysaccharides (LPS) to induce nitric oxide (NO) production, while the corresponding five control groups were injected with saline as a negative control. The serum and liver NO concentrations were examined and the NOS expression of both mRNA and protein was measured in liver. The results showed that the rats which were fed pu-erh tea or polysaccharides had lower levels of NO which corresponded with the down-regulation of inducible nitric oxide synthase (iNOS) expression. We further demonstrate that this effect is mediated through reduction of Toll-like receptor 4 (TLR4) signaling. Thus we find that the polysaccharide components in pu-erh tea reduce NO levels in an animal model by inhibiting the iNOS expression via signaling through TLR4. PMID:22837686

  10. Role of nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Pettorossi, V E

    2000-01-01

    In rat brainstem slices, we investigated the role of nitric oxide in long-term potentiation induced in the ventral portion of the medial vestibular nuclei by high-frequency stimulation of the primary vestibular afferents. The nitric oxide scavenger [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide ] and the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester were administered before and after induction of potentiation. Both drugs completely prevented long-term potentiation, whereas they did not impede the potentiation build-up, or affect the already established potentiation. These results demonstrate that the induction, but not the maintenance of vestibular long-term potentiation, depends on the synthesis and release into the extracellular medium of nitric oxide. In addition, we analysed the effect of the nitric oxide donor sodium nitroprusside on vestibular responses. Sodium nitroprusside induced long-term potentiation, as evidenced through the field potential enhancement and unit peak latency decrease. This potentiation was impeded by D, L-2-amino-5-phosphonopentanoic acid, and was reduced under blockade of synaptosomal platelet-activating factor receptors by ginkgolide B and group I metabotropic glutamate receptors by (R,S)-1-aminoindan-1, 5-dicarboxylic acid. When reduced, potentiation fully developed following the washout of antagonist, demonstrating an involvement of platelet-activating factor and group I metabotropic glutamate receptors in its full development. Potentiation induced by sodium nitroprusside was also associated with a decrease in the paired-pulse facilitation ratio, which persisted under ginkgolide B, indicating that nitric oxide increases glutamate release independently of platelet-activating factor-mediated presynaptic events. We suggest that nitric oxide, released after the activation of N-methyl-D-aspartate receptors, acts as a retrograde messenger leading to an enhancement of glutamate release to a

  11. Fluorescence-based detection of nitric oxide in aqueous and methanol media using a copper(II) complex.

    Science.gov (United States)

    Mondal, Biplab; Kumar, Pankaj; Ghosh, Pokhraj; Kalita, Apurba

    2011-03-14

    The quenched fluorescent intensity of a copper(II) complex, 1, of a fluorescent ligand, in degassed methanol or aqueous (buffered at pH 7.2) solution, was found to reappear on exposure to nitric oxide. Thus, it can function as a fluorescence based nitric oxide sensor. It has been found that the present complex can be used to sense nanomolar quantities of nitric oxide in both methanol and pH 7.2 buffered-water medium.

  12. DMPD: Regulation of nitric oxide synthesis and apoptosis by arginase and argininerecycling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17513437 Regulation of nitric oxide synthesis and apoptosis by arginase and arginin...tion of nitric oxide synthesis and apoptosis by arginase and argininerecycling. A...erecycling. Mori M. J Nutr. 2007 Jun;137(6 Suppl 2):1616S-1620S. (.png) (.svg) (.html) (.csml) Show Regulation of nitric oxide synthe...sis and apoptosis by arginase and argininerecycling. PubmedID 17513437 Title Regula

  13. Progress report on nitric-phosphoric acid oxidation

    International Nuclear Information System (INIS)

    Pierce, R.A.

    1994-01-01

    The purpose of this program has been to demonstrate a nitric-phosphoric acid destruction technology which can treat a heterogeneous waste stream. This technology is being developed to convert hazardous liquid and solid organics to inorganic gases and salts while simultaneously performing a surface decontamination of the noncombustible items. Pu-238 waste is an issue because it must be shipped to WIPP. However, the presence of organics and Pu-238 waste is an issue because it must be shipped to WIPP. However, the presence of organics and Pu-238 exceeds packaging requirements because of concerns of hydrogen generation. If the TRU can be separated from the organics, the allowable heat load of a container increases a factor of 25. More importantly, since the current shipping package is limited by volume and not heat loading, destroying the organic compounds and decontaminating noncombustible can potentially create a three-order magnitude decrease in the number of shipments that must be made to WIPP. The process envisioned will be configured to handle 1 million pounds (as of 12/91) of a wide range of solid TRU-contaminated waste of which 600,000 pounds is combustible. The process will oxidize the combustibles (a mixture of 14% cellulose, 3% rubber, 64% plastics, 9% absorbed oil, 4% resins and sludges, and 6% miscellaneous organics) without requiring separation from the 400,000 pounds of noncombustibles. The system is being developed to operate below 200 C at moderate pressures (0--15 psig). This report primarily discusses results obtained over the past 3 1/2 months and their impact on the feasibility of a pilot-scale system

  14. Starved Escherichia coli preserve reducing power under nitric oxide stress

    Energy Technology Data Exchange (ETDEWEB)

    Gowers, Glen-Oliver F. [Department of Molecular Biology, Princeton University, Princeton, NJ (United States); Robinson, Jonathan L. [Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ (United States); Brynildsen, Mark P., E-mail: mbrynild@princeton.edu [Department of Molecular Biology, Princeton University, Princeton, NJ (United States); Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ (United States)

    2016-07-15

    Nitric oxide (NO) detoxification enzymes, such as NO dioxygenase (NOD) and NO reductase (NOR), are important to the virulence of numerous bacteria. Pathogens use these defense systems to ward off immune-generated NO, and they do so in environments that contain additional stressors, such as reactive oxygen species, nutrient deprivation, and acid stress. NOD and NOR both use reducing equivalents to metabolically deactivate NO, which suggests that nutrient deprivation could negatively impact their functionality. To explore the relationship between NO detoxification and nutrient deprivation, we examined the ability of Escherichia coli to detoxify NO under different levels of carbon source availability in aerobic cultures. We observed failure of NO detoxification under both carbon source limitation and starvation, and those failures could have arisen from inabilities to synthesize Hmp (NOD of E. coli) and/or supply it with sufficient NADH (preferred electron donor). We found that when limited quantities of carbon source were provided, NO detoxification failed due to insufficient NADH, whereas starvation prevented Hmp synthesis, which enabled cells to maintain their NADH levels. This maintenance of NADH levels under starvation was confirmed to be dependent on the absence of Hmp. Intriguingly, these data show that under NO stress, carbon-starved E. coli are better positioned with regard to reducing power to cope with other stresses than cells that had consumed an exhaustible amount of carbon. -- Highlights: •Carbon source availability is critical to aerobic E. coli NO detoxification. •Carbon source starvation, under NO stress, preserves intracellular NADH levels. •Preservation of NADH depends on starvation-dependent inhibition of Hmp induction.

  15. Nitric oxide synthase-3 promotes embryonic development of atrioventricular valves.

    Directory of Open Access Journals (Sweden)

    Yin Liu

    Full Text Available Nitric oxide synthase-3 (NOS3 has recently been shown to promote endothelial-to-mesenchymal transition (EndMT in the developing atrioventricular (AV canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT and NOS3(-/- mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3(-/- compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3(-/- mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1(+ cells in the AV cushion were decreased in NOS3(-/- compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ, bone morphogenetic protein (BMP2 and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3(-/- compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency.

  16. Nitric oxide inhibitory substances from Curcuma mangga rhizomes

    Directory of Open Access Journals (Sweden)

    Kanidta Kaewkroek

    2009-08-01

    Full Text Available Curcuma mangga Val. & Zijp. is a member of the Zingiberaceae family commonly grown in Thailand. It is locally known as mango tumeric because of its mango-like smell when the fresh rhizomes are cut. C. mangga is a popular vegetable, the tips of the young rhizomes and shoots are consumed raw with rice. Medicinally, the rhizomes are used as a stomachic and for chest pains, fever, and general debility. It is also used in postpartum care. In the present study, we investigated the anti-inflammatory effect of the extract and compounds from C. mangga rhizomes against lipopolysaccharide (LPS-induced nitric oxide (NO production in RAW 264.7 cell line. From bioassay-guided fractionation, the chloroform fraction exhibited the most potent inhibitory activity with an IC50 value of 2.1 g/ml, followed by the hexane fraction (IC50 = 3.8 g/ml and the ethyl acetate fraction (IC50 = 23.5 g/ml, respectively. Demethoxycurcumin (1 and 3-buten-2-one, 4-[(1R, 4aR, 8aR-decahydro-5, 5, 8a-trimethyl-2-methylene-1-naphthalenyl]-, (3E-rel- (2 were isolated from the chloroform- and hexane fractions, respectively. Bisdemethoxycurcumin (3 whose structure is similar to that of 1 was also tested for NO inhibitory activity. Of the tested compounds, compound 1 exhibited the highest activity with an IC50 value of 12.1 μM, followed by 3(IC50 = 16.9 M and 2 (IC50 = 30.3 M. These results suggest that C. mangga and its compounds exert NO inhibitory activity and have a potential to be developed as a pharmaceutical preparation for treatment of inflammatory-related diseases. Moreover, this is the first report of compound 2 that was isolated from C. mangga rhizomes.

  17. Production and consumption of nitric oxide by three methanotrophic bacteria.

    Science.gov (United States)

    Ren, T; Roy, R; Knowles, R

    2000-09-01

    We studied nitrogen oxide production and consumption by methanotrophs Methylobacter luteus (group I), Methylosinus trichosporium OB3b (group II), and an isolate from a hardwood swamp soil, here identified by 16S ribosomal DNA sequencing as Methylobacter sp. strain T20 (group I). All could consume nitric oxide (nitrogen monoxide, NO), and produce small amounts of nitrous oxide (N(2)O). Only Methylobacter strain T20 produced large amounts of NO (>250 parts per million by volume [ppmv] in the headspace) at specific activities of up to 2.0 x 10(-17) mol of NO cell(-1) day(-1), mostly after a culture became O(2) limited. Production of NO by strain T20 occurred mostly in nitrate-containing medium under anaerobic or nearly anaerobic conditions, was inhibited by chlorate, tungstate, and O(2), and required CH(4). Denitrification (methanol-supported N(2)O production from nitrate in the presence of acetylene) could not be detected and thus did not appear to be involved in the production of NO. Furthermore, cd(1) and Cu nitrite reductases, NO reductase, and N(2)O reductase could not be detected by PCR amplification of the nirS, nirK, norB, and nosZ genes, respectively. M. luteus and M. trichosporium produced some NO in ammonium-containing medium under aerobic conditions, likely as a result of methanotrophic nitrification and chemical decomposition of nitrite. For Methylobacter strain T20, arginine did not stimulate NO production under aerobiosis, suggesting that NO synthase was not involved. We conclude that strain T20 causes assimilatory reduction of nitrate to nitrite, which then decomposes chemically to NO. The production of NO by methanotrophs such as Methylobacter strain T20 could be of ecological significance in habitats near aerobic-anaerobic interfaces where fluctuating O(2) and nitrate availability occur.

  18. Isothermal heat measurements of TBP-nitric acid solutions

    International Nuclear Information System (INIS)

    Smith, J.R.; Cavin, W.S.

    1994-01-01

    Net heats of reaction were measured in an isothermal calorimeter for both single phase (organic) and two phase (organic and aqueous) TBP/HNO 3 reacting solutions at temperatures above 100 C. The oxidation rate constant was determined to be 5.4E-4 min -1 at 110 C for an open ''vented'' system as compared to 1.33 E-3 min -1 in the closed system. The heat released per unit material oxidized was also reduced. The oxidation in both phases was found to be first order in nitric acid and pseudo-zero order in butylnitrate and water. The hydrolysis (esterification) rate constant determined by Nichols' (1.33E-3 min -1 ) fit the experimental data from this work well. Forced evaporation of the volatile components by the product gases from oxidation resulted in a cooling mechanism which more than balanced the heat from the oxidation reaction in the two-phased systems. Rate expressions were derived and rate constants determined for both the single and two phase systems. An approximating mathematical model was developed to fit the experimental data and to extrapolate beyond the experimental conditions. This model shows that one foot of ''reacting'' 14.3M HNO 3 aqueous phase solution at 121 C will transport sufficient water to the organic phase to replace evaporative losses, maintaining endothermicity, for organic layers up to 12.2 + 6.0 feet deep. If the pressure in a reacting system is allowed to increase due to insufficient venting the temperature of the organic phase would increase in temperature to reach a new equilibrium. The rate of oxidation would increase not only due to the increase in temperature but also from the increased concentration of dissolved HNO 3 reduction products. Another important factor is that the cooling system described in this work becomes less effective as the total pressure increases. These factors probably contributed to the explosion at Tomsk

  19. Mitochondria recycle nitrite back to the bioregulator nitric monoxide

    International Nuclear Information System (INIS)

    Nohl, H.; Staniek, K.; Sobhian, B.; Bahrami, S.; Redl, H.; Kozlov, A.V.

    2000-01-01

    Nitric monoxide (NO) exerts a great variety of physiological functions. L-Arginine supplies amino groups which are transformed to NO in various NO-synthase-active isoenzyme complexes. NO-synthesis is stimulated under various conditions increasing the tissue of stable NO-metabolites. The major oxidation product found is nitrite. Elevated nitrite levels were reported to exist in a variety of diseases including HIV, reperfusion injury and hypovolemic shock. Denitrifying bacteria such as Paracoccus denitrificans have a membrane bound set of cytochromes (cyt cd 1 , cyt bc) which were shown to be involved in nitrite reduction activities. Mammalian mitochondria have similar cytochromes which form part of the respiratory chain. Like in bacteria quinols are used as reductants of these types of cytochromes. The observation of one-e - divergence from this redox-couple to external dioxygen made us to study whether this site of the respiratory chain may also recycle nitrite back to its bioactive form NO. Thus, the aim of the present study was therefore to confirm the existence of a reductive pathway which reestablishes the existence of the bioregulator NO from its main metabolite NO 2 - . Our results show that respiring mitochondria readily reduce added nitrite to NO which was made visible by nitrosylation of deoxyhemoglobin. The adduct gives characteristic triplet-ESR-signals. Using inhibitors of the respiratory chain for chemical sequestration of respiratory segments we were able to identify the site where nitrite is reduced. The results confirm the ubiquinone/cyt bc 1 couple as the reductant site where nitrite is recycled. The high affinity of NO to the heme-iron of cytochrome oxidase will result in an impairment of mitochondrial energy-production. ''Nitrite tolerance'' of angina pectoris patients using NO-donors may be explained in that way. (author)

  20. Regulation of adrenomedullin and nitric oxide production by periodontal bacteria.

    Science.gov (United States)

    Hussain, Q A; McKay, I J; Gonzales-Marin, C; Allaker, R P

    2015-10-01

    In periodontitis the host response to bacterial challenge includes activity of the multifunctional molecules adrenomedullin (AM) and nitric oxide (NO). The aim of this study was to investigate the role of periodontal bacteria in regulating the production of these molecules from cultured cells. Regulation of AM and NO production from oral keratinocytes when challenged with culture supernatants from Aggregatibacter actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Veillonella atypica, Streptococcus salivarius and Candida albicans was examined. AM and NO were measured in cell culture supernatants using an enzyme-linked immunosorbent assay and the nitrate/nitrite (NO metabolites) Griess assay respectively. Cellular production of AM and inducible NO synthase was also analysed in target cells by immunofluorescence and Western blot analysis. The inter-relationship of AM and NO production were further investigated with macrophages. A. actinomycetemcomitans and C. rectus induced maximal levels of both AM and NO after 6 and 48 h respectively from oral keratinocytes. AM production in macrophages was upregulated in response to the NO donor S-nitrosoglutathione and partially blocked by the inducible NO synthase inhibitor, N(ω) -Nitro-l-arginine methyl ester hydrochloride. Likewise, NO production was increased upon exposure to AM, while the AM receptor antagonist AM 22-52 reduced the release of NO. Pathogens associated with aggressive periodontitis, A. actinomycetemcomitans and C. rectus, were more effective than those associated with chronic periodontitis, P. gingivalis and Prev. intermedia, and commensals, S. salivarius and V. atypica, as regards the upregulation of AM and NO production from oral keratinocytes. Interaction between these molecules was also demonstrated with macrophages. Understanding the coordinated regulation of AM and NO production in response to periodontal bacteria may identify

  1. Determination of free nitric acid in uranyl nitrate solution

    International Nuclear Information System (INIS)

    Mayankutty, P.C.; Ravi, S.; Nadkarni, M.N.

    1981-01-01

    Potentiometric titration of uranyl nitrate solution with sodium hydroxide exhibits two peaks. The first peak characterises the following reaction, UO 2 (C 2 O 4 )+NaOH Na[UO 2 (C 2 O 4 )(OH)]. This reaction, indicating the partial hydrolysis of uranyl oxalate complex, appears to be complete at pH9. If the titration is carried out to this end-point pH, the total alkali consumed can be equated to the sum of uranium content and the free acidity present in the sample volume. Based on this, a method was standardised to determine the free acidity in uranyl nitrate solution. The sample, taken in a solution of potassium oxalate previously adjusted to pH9, is titrated to this pH with standard sodium hydroxide. The free acidity in the sample can be computed by subtracting the alkali reacted with uranium from the total alkali consumed. Analyses of several synthetic samples containing uranium and nitric acid in a wide range of combinations indicate that the free acidity can be accurately determined by this method, if uranium concentration in the sample is known. The results are compared to those obtained by two other widely used methods, viz., (i) titration of pH7 in the presence of neutral potassium oxalate to suppress hydrolysis and (ii) separation of hydrolyzable ions on a cationic resin and alkali titration of the free acid released. The advantages of and the precision obtained with the present method over the above two methods are discussed. (author)

  2. The Antibiofilm efficacy of nitric oxide on soft contact lenses.

    Science.gov (United States)

    Kim, Dong Ju; Park, Joo-Hee; Kim, Marth; Park, Choul Yong

    2017-11-21

    To investigate the antibiofilm efficacy of nitric oxide (NO) on soft contact lenses. Nitrite (NO precursor) release from various concentrations (0-1000 μM) of sodium nitrite (NaNO 2, NO donor) was measured by Griess Assay. Cell viability assay was performed using human corneal epithelial cell under various concentration (0-1000 μM) of NaNO 2 . Biofilm formation on soft contact lenses was achieved by adding Staphylococcus aureus or Pseudomonas aeruginosa to the culture media. Various concentrations of NaNO 2 (0-1000 μM) were added to the culture media, each containing soft contact lens. After incubation in NaNO 2 containing culture media for 1, 3, or 7 days, each contact lens was transferred to a fresh, bacteria-free media without NaNO 2 . The bacteria in the biofilm were dispersed in the culture media for planktonic growth. After reculturing the lenses in the fresh media for 24 h, optical density (OD) of media was measured at 600 nm and colony forming unit (CFU) was counted by spreading media on tryptic soy agar plate for additional 18 h. Nitrite release from NaNO 2 showed dose-dependent suppressive effect on biofilm formation. Most nitrite release from NaNO 2 tended to occur within 30 min. The viability of human corneal epithelial cells was well maintained at tested NaNO 2 concentrations. The bacterial CFU and OD showed dose-dependent decrease in the NaNO 2 treated samples on days 1, 3 and 7 for both Staphylococcus aureus and Pseudomonas aeruginosa. NO successfully inhibited the biofilm formation by Staphylococcus aureus or Pseudomonas aeruginosa on soft contact lenses in dose-dependent manner.

  3. Picosecond rotationally resolved stimulated emission pumping spectroscopy of nitric oxide

    Science.gov (United States)

    Tanjaroon, Chakree; Reeve, Scott W.; Ford, Alan; Murry, W. Dean; Lyon, Kevin; Yount, Bret; Britton, Dan; Burns, William A.; Allen, Susan D.; Bruce Johnson, J.

    2012-01-01

    Stimulated emission pumping (SEP) experiments were performed on the nitric oxide molecule in a flow cell environment using lasers with pulse widths of 17-25 ps. A lambda excitation scheme, or ''pump-dump" arrangement, was employed with the pump laser tuned to the T 00 vibronic band origin ( λ=226.35(1)nm) of the A2Σ+( v' = 0, J') ← X2Π1/2( v″ = 0, J″) and the dump laser scanned from 246-248 nm within the A2Σ+( v' = 0, J') → X2Π1/2( v″ = 2, J″) transition. The rotationally resolved SEP spectra were measured by observing the total fluorescence within the A2Σ+( v' = 0, J') → X2Π1/2( v″ = 1, J″) transition between 235 nm and 237.2 nm while scanning the dump laser wavelengths. Multiple rotational states were excited due to the broad laser bandwidth. Measurements showed that the resolved rotational structure depended on the energy and bandwidth of the applied pump and dump laser pulses. Analysis of the observed fluorescence depletion signals yielded an average percent fluorescence depletion of about 19% when λ=226.35(1)nm and λ=247.91(1)nm. This value reflects the percent transfer of the NO population from the A2Σ+( V' = 0, J') excited electronic state to the X2Π1/2( v″ = 2, J″) ground electronic state. The maximum expected depletion is 50% in the limit of dump saturation. Selective excitation of NO at the bandhead provides good spectral discrimination from the background emission and noise and unambiguously confirms the identity of the emitter.

  4. Intestinal nitric oxide synthase activity changes during experimental colon obstruction.

    Science.gov (United States)

    Palásthy, Zsolt; Kaszaki, József; Lázár, György; Nagy, Sándor; Boros, Mihály

    2006-08-01

    The experiments in this study were designed to follow the time course of nitric oxide (NO) synthesis in the large bowel during acute mechanical ileus. Occlusion of the mid-transverse colon was maintained for 420 min in anesthetized dogs. Strain-gauge transducers were used to analyze motility changes on the hepatic and lienal flexures, respectively. Constitutive NO synthase (cNOS) and inducible NOS (iNOS) activities were determined in tissue biopsies, and plasma nitrite/nitrate (NOx) level was measured in the portal blood. Following completion of the baseline studies, the animals were treated with either 7-nitroindazole (7-NI, selective neuronal NOS inhibitor), or N-nitro-L-arginine (NNA, non-selective NOS inhibitor). In the sham-operated group the cNOS activities differed significantly in the oral and aboral tissue samples (oral: 102.9; versus aboral: 62.1 fmol/mg protein/min). The obstruction elicited a significant increase in portal NOx and elevated tissue inducible NO synthase (iNOS) activity. NNA treatment decreased the motility index in both intestinal segments for 60 min, but 120 min later the motility index was significantly elevated (2.5-fold increase in the oral part, and 1.8-fold enhancement in the aboral segment, respectively). Treatment with 7-NI decreased the cNOS activity in the oral and aboral parts by approximately 40% and 70%, respectively, and suppressed the motility increase in the aboral colon segment. The motility of the colon was either significantly increased or decreased, depending on the type and selectivity of the NOS inhibitor compounds applied. NO of neuronal origin is a transmitter that stimulates peristaltic activity; but an increased iNOS/nNOS ratio significantly moderates the obstruction-induced motility increase.

  5. Impact of scaling on the nitric-glycolic acid flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-02-01

    Savannah River Remediation (SRR) is considering using glycolic acid as a replacement for formic acid in Sludge Receipt and Adjustment Tank (SRAT) processing in the Defense Waste Processing Facility (DWPF). Catalytic decomposition of formic acid is responsible for the generation of hydrogen, a potentially flammable gas, during processing. To prevent the formation of a flammable mixture in the offgas, an air purge is used to dilute the hydrogen concentration below the 60% of the Composite Lower Flammability Limit (CLFL). The offgas is continuously monitored for hydrogen using Gas Chromatographs (GCs). Since formic acid is much more volatile and toxic than glycolic acid, a formic acid spill would lead to the release of much larger quantities to the environment. Switching from formic acid to glycolic acid is expected to eliminate the hydrogen flammability hazard leading to lower air purges, thus downgrading of Safety Significant GCs to Process Support GCs, and minimizing the consequence of a glycolic acid tank leak in DWPF. Overall this leads to a reduction in process operation costs and an increase in safety margin. Experiments were completed at three different scales to demonstrate that the nitric-glycolic acid flowsheet scales from the 4-L lab scale to the 22-L bench scale and 220-L engineering scale. Ten process demonstrations of the sludge-only flowsheet for SRAT and Slurry Mix Evaporator (SME) cycles were performed using Sludge Batch 8 (SB8)-Tank 40 simulant. No Actinide Removal Process (ARP) product or strip effluent was added during the runs. Six experiments were completed at the 4-L scale, two experiments were completed at the 22-L scale, and two experiments were completed at the 220-L scale. Experiments completed at the 4-L scale (100 and 110% acid stoichiometry) were repeated at the 22-L and 220-L scale for scale comparisons.

  6. Nitric Oxide-Induced Polycystic Ovaries in The Wistar Rat

    Directory of Open Access Journals (Sweden)

    Fatemeh Hassani

    2012-01-01

    Full Text Available Background: Nitric oxide (NO involves in polycystic ovary syndrome (PCOS, a causeof infertility in women during the reproductive age. The PCOS is now categorized as aninflammatory phenomenon. The aim of this study was to evaluate the role of NO, a proinflammatoryagent, in this syndrome at histological and biochemical levels.Materials and Methods: In this experimental study, animals were female Wistar rats(weighing 200-250 g kept under standard conditions. L-Arginine (50-200 mg/kg, a precursorof NO, was injected intra-peritoneally (i.p. through a period ranging from 9 to14 days/once a day. The rats' estrous cycle was studied using Papanicolaou test; those showing phaseof Diestrous were grouped into experimental and control groups. The control group solelyreceived saline (1 ml/kg, i.p. throughout all experiments. To evaluate the inflammatory effectof NO, the rats were treated an anti-inflammatory agent, naloxone hydrochloride (0.4 mg/kg,i.p., prior to L-arginine. At the end of the treatment period all animals’ ovaries were assessedfor histopathological and histochemical investigations. Also, activation of NO synthase (NOSin the experiments was studied using NADPH-diaphorase technique.Results: The ovaries of rats treated with L-arginine showed polycystic characteristics incontrast to those collected from control or naloxone pretreated groups, based on image analysis.A difference in enzyme activation was also shown in the sections that belonged to thegroups that received L-arginine when compared with the pre-naloxone and control groups.Conclusion: Based on these results, we believe that NO may play a major role in thepathophysiology of PCOS.

  7. Nitric Oxide in Plants: The Roles of Ascorbate and Hemoglobin

    Science.gov (United States)

    Wang, Xiaoguang; Hargrove, Mark S.

    2013-01-01

    Ascorbic acid and hemoglobins have been linked to nitric oxide metabolism in plants. It has been hypothesized that ascorbic acid directly reduces plant hemoglobin in support of NO scavenging, producing nitrate and monodehydroascorbate. In this scenario, monodehydroascorbate reductase uses NADH to reduce monodehydroascorbate back to ascorbate to sustain the cycle. To test this hypothesis, rates of rice nonsymbiotic hemoglobin reduction by ascorbate were measured directly, in the presence and absence of purified rice monodehydroascorbate reductase and NADH. Solution NO scavenging was also measured methodically in the presence and absence of rice nonsymbiotic hemoglobin and monodehydroascorbate reductase, under hypoxic and normoxic conditions, in an effort to gauge the likelihood of these proteins affecting NO metabolism in plant tissues. Our results indicate that ascorbic acid slowly reduces rice nonsymbiotic hemoglobin at a rate identical to myoglobin reduction. The product of the reaction is monodehydroascorbate, which can be efficiently reduced back to ascorbate in the presence of monodehydroascorbate reductase and NADH. However, our NO scavenging results suggest that the direct reduction of plant hemoglobin by ascorbic acid is unlikely to serve as a significant factor in NO metabolism, even in the presence of monodehydroascorbate reductase. Finally, the possibility that the direct reaction of nitrite/nitrous acid and ascorbic acid produces NO was measured at various pH values mimicking hypoxic plant cells. Our results suggest that this reaction is a likely source of NO as the plant cell pH drops below 7, and as nitrite concentrations rise to mM levels during hypoxia. PMID:24376554

  8. Intracellular conversion of environmental nitrate and nitrite to nitric oxide with resulting developmental toxicity to the crustacean Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Bethany R Hannas

    2010-08-01

    Full Text Available Nitrate and nitrite (jointly referred to herein as NO(x are ubiquitous environmental contaminants to which aquatic organisms are at particularly high risk of exposure. We tested the hypothesis that NO(x undergo intracellular conversion to the potent signaling molecule nitric oxide resulting in the disruption of endocrine-regulated processes.These experiments were performed with insect cells (Drosophila S2 and whole organisms Daphnia magna. We first evaluated the ability of cells to convert nitrate (NO(3(- and nitrite (NO(2(- to nitric oxide using amperometric real-time nitric oxide detection. Both NO(3(- and NO(2(- were converted to nitric oxide in a substrate concentration-dependent manner. Further, nitric oxide trapping and fluorescent visualization studies revealed that perinatal daphnids readily convert NO(2(- to nitric oxide. Next, daphnids were continuously exposed to concentrations of the nitric oxide-donor sodium nitroprusside (positive control and to concentrations of NO(3(- and NO(2(-. All three compounds interfered with normal embryo development and reduced daphnid fecundity. Developmental abnormalities were characteristic of those elicited by compounds that interfere with ecdysteroid signaling. However, no compelling evidence was generated to indicate that nitric oxide reduced ecdysteroid titers.Results demonstrate that nitrite elicits developmental and reproductive toxicity at environmentally relevant concentrations due likely to its intracellular conversion to nitric oxide.

  9. Laboratory studies of 2H evaporator scale dissolution in dilute nitric acid

    International Nuclear Information System (INIS)

    Oji, L.

    2014-01-01

    The rate of 2H evaporator scale solids dissolution in dilute nitric acid has been experimentally evaluated under laboratory conditions in the SRNL shielded cells. The 2H scale sample used for the dissolution study came from the bottom of the evaporator cone section and the wall section of the evaporator cone. The accumulation rate of aluminum and silicon, assumed to be the two principal elemental constituents of the 2H evaporator scale aluminosilicate mineral, were monitored in solution. Aluminum and silicon concentration changes, with heating time at a constant oven temperature of 90 deg C, were used to ascertain the extent of dissolution of the 2H evaporator scale mineral. The 2H evaporator scale solids, assumed to be composed of mostly aluminosilicate mineral, readily dissolves in 1.5 and 1.25 M dilute nitric acid solutions yielding principal elemental components of aluminum and silicon in solution. The 2H scale dissolution rate constant, based on aluminum accumulation in 1.5 and 1.25 M dilute nitric acid solution are, respectively, 9.21E-04 ± 6.39E-04 min -1 and 1.07E-03 ± 7.51E-05 min -1 . Silicon accumulation rate in solution does track the aluminum accumulation profile during the first few minutes of scale dissolution. It however diverges towards the end of the scale dissolution. This divergence therefore means the aluminum-to-silicon ratio in the first phase of the scale dissolution (non-steady state conditions) is different from the ratio towards the end of the scale dissolution. Possible causes of this change in silicon accumulation in solution as the scale dissolution progresses may include silicon precipitation from solution or the 2H evaporator scale is a heterogeneous mixture of aluminosilicate minerals with several impurities. The average half-life for the decomposition of the 2H evaporator scale mineral in 1.5 M nitric acid is 12.5 hours, while the half-life for the decomposition of the 2H evaporator scale in 1.25 M nitric acid is 10.8 hours

  10. Modelling of nitric and nitrous acid chemistry for solvent extraction purposes

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, H.; McLachlan, F. [National Nuclear Laboratory, Building D5, Culham Science Centre, Abingdon, Oxfordshire, OX14 3DB (United Kingdom); MacDonald-Taylor, J. [National Nuclear Laboratory, 5th Floor, Chadwick House, Warrington Road, Birchwood Park, Warrington, WA3 6AE (United Kingdom); Orr, R.; Woodhead, D. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom)

    2016-07-01

    Nitric acid plays an integral role in the reprocessing of irradiated fuel. It is well known that nitric acid degrades; its often yellow hue signifies the presence of decomposition products. The decomposition of nitric acid is accelerated by temperature and radiolysis; therefore it is an important consideration in the reprocessing of nuclear fuels. Thermal and radiolytic reactions of nitric acid result in the formation of redox active nitrogen species, of which nitrous acid is of particular concern, largely due to its redox reactions with plutonium and neptunium. Such reactions are important to understand as plutonium and neptunium can exist in a number of oxidation states; the oxidation state has a direct effect on the species extractability. The effect of nitrous acid is exacerbated as it catalyzes its own production and its reactions with actinides are typically autocatalytic; thus even micromolar quantities can have a large effect. A full understanding of solvent extraction requires us to understand actinide valence states which in turn require us to understand what nitrogen species are present and their concentrations. As a first step in the overall objective of enhancing process models, the kinetic data for nitric acid decomposition reactions has been investigated in order to produce an initial dynamic model of decomposition under aqueous conditions. The identification of a set of kinetic reactions suitable for modelling has been the primary focus of this work. A model of nitric acid thermal decomposition will help develop a better understanding of nitric acid decomposition chemistry and enable better prediction of the oxidation states of species in solution. It is intended to later extend the model to include radiolytic reactions and then further to incorporate an organic phase in order to have a model which covers all decomposition routes for nitric acid within a nuclear fuel reprocessing scheme. The model will be used as a sub model for process models

  11. Role of Polymorphisms of Inducible Nitric Oxide Synthase and Endothelial Nitric Oxide Synthase in Idiopathic Environmental Intolerances

    Directory of Open Access Journals (Sweden)

    Chiara De Luca

    2015-01-01

    Full Text Available Oxidative stress and inflammation play a pathogenetic role in idiopathic environmental intolerances (IEI, namely, multiple chemical sensitivity (MCS, fibromyalgia (FM, and chronic fatigue syndrome (CFS. Given the reported association of nitric oxide synthase (NOS gene polymorphisms with inflammatory disorders, we aimed to investigate the distribution of NOS2A −2.5 kb (CCTTTn as well as Ser608Leu and NOS3 −786T>C variants and their correlation with nitrite/nitrate levels, in a study cohort including 170 MCS, 108 suspected MCS (SMCS, 89 FM/CFS, and 196 healthy subjects. Patients and controls had similar distributions of NOS2A Ser608Leu and NOS3 −786T>C polymorphisms. Interestingly, the NOS3 −786TT genotype was associated with increased nitrite/nitrate levels only in IEI patients. We also found that the NOS2A −2.5 kb (CCTTT11 allele represents a genetic determinant for FM/CFS, and the (CCTTT16 allele discriminates MCS from SMCS patients. Instead, the (CCTTT8 allele reduces by three-, six-, and tenfold, respectively, the risk for MCS, SMCS, and FM/CFS. Moreover, a short number of (CCTTT repeats is associated with higher concentrations of nitrites/nitrates. Here, we first demonstrate that NOS3 −786T>C variant affects nitrite/nitrate levels in IEI patients and that screening for NOS2A −2.5 kb (CCTTTn polymorphism may be useful for differential diagnosis of various IEI.

  12. The Semireduced Mechanism for Nitric Oxide Reduction by Non-Heme Diiron Complexes: Modeling Flavodiiron Nitric Oxide Reductases.

    Science.gov (United States)

    White, Corey J; Speelman, Amy L; Kupper, Claudia; Demeshko, Serhiy; Meyer, Franc; Shanahan, James P; Alp, E Ercan; Hu, Michael; Zhao, Jiyong; Lehnert, Nicolai

    2018-02-21

    Flavodiiron nitric oxide reductases (FNORs) are a subclass of flavodiiron proteins (FDPs) capable of preferential binding and subsequent reduction of NO to N 2 O. FNORs are found in certain pathogenic bacteria, equipping them with resistance to nitrosative stress, generated as a part of the immune defense in humans, and allowing them to proliferate. Here, we report the spectroscopic characterization and detailed reactivity studies of the diiron dinitrosyl model complex [Fe 2 (BPMP)(OPr)(NO) 2 ](OTf) 2 for the FNOR active site that is capable of reducing NO to N 2 O [Zheng et al., J. Am. Chem. Soc. 2013, 135, 4902-4905]. Using UV-vis spectroscopy, cyclic voltammetry, and spectro-electrochemistry, we show that one reductive equivalent is in fact sufficient for the quantitative generation of N 2 O, following a semireduced reaction mechanism. This reaction is very efficient and produces N 2 O with a first-order rate constant k > 10 2 s -1 . Further isotope labeling studies confirm an intramolecular N-N coupling mechanism, consistent with the rapid time scale of the reduction and a very low barrier for N-N bond formation. Accordingly, the reaction proceeds at -80 °C, allowing for the direct observation of the mixed-valent product of the reaction. At higher temperatures, the initial reaction product is unstable and decays, ultimately generating the diferrous complex [Fe 2 (BPMP)(OPr) 2 ](OTf) and an unidentified ferric product. These results combined offer deep insight into the mechanism of NO reduction by the relevant model complex [Fe 2 (BPMP)(OPr)(NO) 2 ] 2+ and provide direct evidence that the semireduced mechanism would constitute a highly efficient pathway to accomplish NO reduction to N 2 O in FNORs and in synthetic catalysts.

  13. Trigeminocardiac reflex by mandibular extension on rat pial microcirculation: role of nitric oxide.

    Directory of Open Access Journals (Sweden)

    Dominga Lapi

    Full Text Available In the present study we have extended our previous findings about the effects of 10 minutes of passive mandibular extension in anesthetized Wistar rats. By prolonging the observation time to 3 hours, we showed that 10 minutes mandibular extension caused a significant reduction of the mean arterial blood pressure and heart rate respect to baseline values, which persisted up to 160 minutes after mandibular extension. These effects were accompanied by a characteristic biphasic response of pial arterioles: during mandibular extension, pial arterioles constricted and after mandibular extension dilated for the whole observation period. Interestingly, the administration of the opioid receptor antagonist naloxone abolished the vasoconstriction observed during mandibular extension, while the administration of Nω-Nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, abolished the vasodilation observed after mandibular extension. Either drug did not affect the reduction of mean arterial blood pressure and heart rate induced by mandibular extension. By qRT-PCR, we also showed that neuronal nitric oxide synthase gene expression was significantly increased compared with baseline conditions during and after mandibular extension and endothelial nitric oxide synthase gene expression markedly increased at 2 hours after mandibular extension. Finally, western blotting detected a significant increase in neuronal and endothelial nitric oxide synthase protein expression. In conclusion mandibular extension caused complex effects on pial microcirculation involving opioid receptor activation and nitric oxide release by both neurons and endothelial vascular cells at different times.

  14. Characterization of condensed phase nitric acid particles formed in the gas phase

    Institute of Scientific and Technical Information of China (English)

    Long Jia; Yongfu Xu

    2011-01-01

    The formation of nitric acid hydrates has been observed in a chamber during the dark reaction of NO2 with O3 in the presence of air.The size of condensed phase nitric acid was measured to be 40-100 nm and 20-65 nm at relative humidity (RH) ≤ 5% and RH = 67% under our experimental conditions, respectively.The nitric acid particles were collected on the glass fiber membrane and their chemical compositions were analyzed by infrared spectrum.The main components of nitric acid hydrates in particles are HNO3·3H2O and NO3-·xH2O (x≥ 4) at low RH, whereas at high RH HNO3·H2O, HNO3·2H2O, HNO3·3H2O and NO3-·xH2O (x≥ 4) all exist in the condensed phase.At high RH HNO3·xH2O (x ≤ 3) collected on the glass fiber membrane is greatly increased, while NO3-·xH2O (x ≥4) decreased, compared with low RH.To the best of our knowledge, this is the first time to report that condensed phase nitric acid can be generated in the gas phase at room temperature.

  15. Nitric oxide and TGF-β1 inhibit HNF-4α function in HEPG2 cells

    International Nuclear Information System (INIS)

    Lucas, Susana de; Lopez-Alcorocho, Juan Manuel; Bartolome, Javier; Carreno, Vicente

    2004-01-01

    This study analyzes if the profibrogenic factors nitric oxide and transforming growth factor-β1 (TGF-β1) affect hepatocyte nuclear factor-4α (HNF-4α) function. For this purpose, HepG2 cells were treated with TGF-β1 or with a nitric oxide donor to determine mRNA levels of coagulation factor VII and HNF-4α. Treatment effect on factor VII gene promoter was assessed by chloramphenicol acetyl-transferase assays in cells transfected with the pFVII-CAT plasmid. HNF-4α binding and protein levels were determined by gel shift assays and Western blot. TGF-β1 and nitric oxide downregulated factor VII mRNA levels by inhibiting its gene promoter activity. This inhibition is caused by a decrease in the DNA binding of HNF-4α. TGF-β1 induces degradation of HNF-4α in the proteasome while nitric oxide provokes nitrosylation of cysteine residues in this factor. TGF-β1 and nitric oxide inhibit HNF-4α activity. These findings may explain the loss of liver functions that occurs during fibrosis progression

  16. Nitric oxide levels in the anterior chamber of vitrectomized eyes with silicon oil

    Directory of Open Access Journals (Sweden)

    Paulo Escarião

    2013-10-01

    Full Text Available PURPOSE: To investigate the nitric oxide levels in the anterior chamber of eyes who underwent pars plana vitrectomy (PPV with silicone oil. METHODS: Patients who underwent PPV with silicon oil injection, from february 2005 to august 2007, were selected. Nine patients (nine eyes participated in the study (five women and four men. Nitric oxide concentration was quantified after the aspiration of aqueous humor samples during the procedure of silicon oil removal. Data such as: oil emulsification; presence of oil in the anterior chamber; intraocular pressure and time with silicone oil were evaluated. Values of p <0.05 were considered to be statistically significant. RESULTS: A positive correlation between nitric oxide concentration and time with silicon oil in the vitreous cavity (r=0.799 was observed. The nitric oxide concentration was significantly higher (p=0.02 in patients with silicon oil more than 24 months (0.90µmol/ml ± 0.59, n=3 in the vitreous cavity comparing to patients with less than 24 months (0.19µmol/ml ± 0.10, n=6. CONCLUSION: A positive correlation linking silicone oil time in the vitreous cavity with the nitric oxide concentration in the anterior chamber was observed.

  17. Caffeinated nitric oxide-releasing lozenge improves cycling time trial performance.

    Science.gov (United States)

    Lee, J; Kim, H T; Solares, G J; Kim, K; Ding, Z; Ivy, J L

    2015-02-01

    Boosting nitric oxide production during exercise by various means has been found to improve exercise performance. We investigated the effects of a nitric oxide releasing lozenge with added caffeine (70 mg) on oxygen consumption during steady-state exercise and cycling time trial performance using a double-blinded randomized, crossover experimental design. 15 moderately trained cyclists (7 females and 8 males) were randomly assigned to ingest the caffeinated nitric oxide lozenge or placebo 5 min before exercise. Oxygen consumption and blood lactate were assessed at rest and at 50%, 65% and 75% maximal oxygen consumption. Exercise performance was assessed by time to complete a simulated 20.15 km cycling time-trial course. No significant treatment effects for oxygen consumption or blood lactate at rest or during steady-state exercise were observed. However, time-trial performance was improved by 2.1% (p<0.01) when participants consumed the nitric oxide lozenge (2,424±69 s) compared to placebo (2,476±78 s) and without a significant difference in rating of perceived exertion. These results suggest that acute supplementation with a caffeinated nitric oxide releasing lozenge may be a practical and effective means of improving aerobic exercise performance. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Characteristics and mechanism of explosive reactions of Purex solvents with Nitric Acid at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Teijiro [Radiation Application Development Association, Tokai, Ibaraki (Japan); Takada, Junichi; Koike, Tadao; Tsukamoto, Michio; Watanabe, Koji [Department of Fuel Cycle Safety Research, Nuclear Safety Research Center, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Ida, Masaaki [JGC PLANTECH CO., LTD (Japan); Nakagiri, Naotaka [JGC Corp., Tokyo (Japan); Nishio, Gunji [Research Organization for Information Science and Technology, Tokai, Ibaraki (Japan)

    2000-03-01

    This investigation was undertaken to make clear the energetic properties and mechanism of explosive decomposition of Purex solvent systems (TBP/n-Dodecane/HNO{sub 3}) by Nitric Acid at elevated temperatures using a calorimetric technique (DSC, ARC) and a chromatographic technique (GC, GC/MS). The measurement of exothermic events of solvent-HNO{sub 3} reactions using DSC with a stainless steel sealed cell showed distinct two peaks with maxima at around 170 and 320degC, respectively. The peak at around 170degC was mainly attributed to the reactions of dealkylation products (n-butyl nitrate) of TBP and the solvent with nitric acid, and the peak at around 320degC was attributed to the exothermic decomposition of nitrated dodecanes formed in the foregoing exothermic reaction of dodecane with nitric acid. By using the data obtained in ARC experiments, activation energies of 123.2 and 152.5 kJ/mol were determined for the exothermic reaction of TBP with nitric acid and for the exothermic pyrolysis of n-butyl nitrate, respectively. Some possible pathways were considered for the explosive decomposition of TBP by nitric acid at elevated temperatures. (author)

  19. Thermodynamic and kinetic modelling of the reduction of concentrated nitric acid

    International Nuclear Information System (INIS)

    Sicsic, David

    2011-01-01

    This research thesis aimed at determining and quantifying the different stages of the reduction mechanism in the case of concentrated nitric acid. After having reported the results of a bibliographical study on the chemical and electrochemical behaviour of concentrated nitric media (generalities, chemical equilibriums, NOx reactivity, electrochemical reduction of nitric acid), the author reports the development and discusses the results of a thermodynamic simulation of a nitric environment at 25 C. This allowed the main species to be identified in the liquid and gaseous phases of nitric acid solutions. The author reports an experimental electrochemical investigation coupled with analytic techniques (infrared and UV-visible spectroscopy) and shows that the reduction process depends on the cathodic overvoltage, and identifies three potential areas. A kinetic modelling of the stationary state and of the impedance is then developed in order to better determine, discuss and quantify the reduction process. The application of this kinetic model to the preliminary results of an electrochemical study performed on 304 L steel is then discussed [fr

  20. Increasing the Fungicidal Action of Amphotericin B by Inhibiting the Nitric Oxide-Dependent Tolerance Pathway

    Directory of Open Access Journals (Sweden)

    Kim Vriens

    2017-01-01

    Full Text Available Amphotericin B (AmB induces oxidative and nitrosative stresses, characterized by production of reactive oxygen and nitrogen species, in fungi. Yet, how these toxic species contribute to AmB-induced fungal cell death is unclear. We investigated the role of superoxide and nitric oxide radicals in AmB’s fungicidal activity in Saccharomyces cerevisiae, using a digital microfluidic platform, which enabled monitoring individual cells at a spatiotemporal resolution, and plating assays. The nitric oxide synthase inhibitor L-NAME was used to interfere with nitric oxide radical production. L-NAME increased and accelerated AmB-induced accumulation of superoxide radicals, membrane permeabilization, and loss of proliferative capacity in S. cerevisiae. In contrast, the nitric oxide donor S-nitrosoglutathione inhibited AmB’s action. Hence, superoxide radicals were important for AmB’s fungicidal action, whereas nitric oxide radicals mediated tolerance towards AmB. Finally, also the human pathogens Candida albicans and Candida glabrata were more susceptible to AmB in the presence of L-NAME, pointing to the potential of AmB-L-NAME combination therapy to treat fungal infections.

  1. Modeling of the Nitric Oxide Transport in the Human Lungs.

    Science.gov (United States)

    Karamaoun, Cyril; Van Muylem, Alain; Haut, Benoît

    2016-01-01

    In the human lungs, nitric oxide (NO) acts as a bronchodilatator, by relaxing the bronchial smooth muscles and is closely linked to the inflammatory status of the lungs, owing to its antimicrobial activity. Furthermore, the molar fraction of NO in the exhaled air has been shown to be higher for asthmatic patients than for healthy patients. Multiple models have been developed in order to characterize the NO dynamics in the lungs, owing to their complex structure. Indeed, direct measurements in the lungs are difficult and, therefore, these models are valuable tools to interpret experimental data. In this work, a new model of the NO transport in the human lungs is proposed. It belongs to the family of the morphological models and is based on the morphometric model of Weibel (1963). When compared to models published previously, its main new features are the layered representation of the wall of the airways and the possibility to simulate the influence of bronchoconstriction (BC) and of the presence of mucus on the NO transport in lungs. The model is based on a geometrical description of the lungs, at rest and during a respiratory cycle, coupled with transport equations, written in the layers composing an airway wall and in the lumen of the airways. First, it is checked that the model is able to reproduce experimental information available in the literature. Second, the model is used to discuss some features of the NO transport in healthy and unhealthy lungs. The simulation results are analyzed, especially when BC has occurred in the lungs. For instance, it is shown that BC can have a significant influence on the NO transport in the tissues composing an airway wall. It is also shown that the relation between BC and the molar fraction of NO in the exhaled air is complex. Indeed, BC might lead to an increase or to a decrease of this molar fraction, depending on the extent of the BC and on the possible presence of mucus. This should be confirmed experimentally and might

  2. Mars’ seasonal mesospheric transport seen through nitric oxide nightglow

    Science.gov (United States)

    Milby, Zachariah; Stiepen, Arnaud; Jain, Sonal; Schneider, Nicholas M.; Deighan, Justin; Gonzalez-Galindo, Francisco; Gerard, Jean-Claude; Stevens, Michael H.; Bougher, Stephen W.; Evans, J. Scott; Stewart, A. Ian; Chaffin, Michael; Crismani, Matteo; McClintock, William E.; Clarke, John T.; Holsclaw, Greg; Montmessin, Franck; Lefevre, Franck; Forget, Francois; Lo, Daniel Y.; Hubert, Benoît; Jakosky, Bruce

    2017-10-01

    We analyze the ultraviolet nightglow in the atmosphere of Mars through nitric oxide (NO) δ and γ band emissions as observed by the Imaging UltraViolet Spectrograph (IUVS) instrument onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft when it is at apoapse and periapse.In the dayside thermosphere of Mars, solar extreme-ultraviolet radiation dissociates CO2 and N2 molecules. O(3P) and N(4S) atoms are carried from the dayside to the nightside by the day-night hemispheric transport process, where they descend through the nightside mesosphere and can radiatively recombine to form NO(C2Π). The excited molecules rapidly relax by emitting photons in the UV δ and γ bands. These emissions are indicators of the N and O atom fluxes from the dayside to Mars’ nightside and the descending circulation pattern from the nightside thermosphere to the mesosphere (e.g. Bertaux et al., 2005 ; Bougher et al., 1990 ; Cox et al., 2008 ; Gagné et al., 2013 ; Gérard et al., 2008 ; Stiepen et al., 2015, 2017).Observations of these emissions are gathered from a large dataset spanning different seasonal conditions.We present discussion on the variability in the brightness and altitude of the emission with season, geographical position (longitude), and local time, along with possible interpretation by local and global changes in the mesosphere dynamics. We show the possible impact of atmospheric waves forcing longitudinal variability and data-to-model comparisons indicating a wave-3 structure in Mars’ nightside mesosphere. Quantitative comparison with calculations of the Laboratoire de Météorologie Dynamique-Mars Global Climate Model (LMD-MGCM) suggests the model reproduces both the global trend of NO nightglow emission and its seasonal variation. However, it also indicates large discrepancies, with the emission up to a factor 50 times fainter in the model, suggesting that the predicted transport is too efficient toward the night winter pole in the thermosphere by

  3. ExoMol line list - XXI. Nitric Oxide (NO)

    Science.gov (United States)

    Wong, Andy; Yurchenko, Sergei N.; Bernath, Peter; Müller, Holger S. P.; McConkey, Stephanie; Tennyson, Jonathan

    2017-09-01

    Line lists for the X 2Π electronic ground state for the parent isotopologue of nitric oxide (14N16O) and five other major isotopologues (14N17O, 14N18O, 15N16O, 15N17O and 15N18O) are presented. The line lists are constructed using empirical energy levels (and line positions) and high-level ab initio intensities. The energy levels were obtained using a combination of two approaches, from an effective Hamiltonian and from solving the rovibronic Schrödinger equation variationally. The effective Hamiltonian model was obtained through a fit to the experimental line positions of NO available in the literature for all six isotopologues using the programs spfit and spcat. The variational model was built through a least squares fit of the ab initio potential and spin-orbit curves to the experimentally derived energies and experimental line positions of the main isotopologue only using the duo program. The ab initio potential energy, spin-orbit and dipole moment curves (PEC, SOC and DMC) are computed using high-level ab initio methods and the marvel method is used to obtain energies of NO from experimental transition frequencies. The line lists are constructed for each isotopologue based on the use of the most accurate energy levels and the ab initio DMC. Each line list covers a wavenumber range from 0 to 40 000 cm-1 with approximately 22 000 rovibronic states and 2.3-2.6 million transitions extending to Jmax = 184.5 and vmax = 51. Partition functions are also calculated up to a temperature of 5000 K. The calculated absorption line intensities at 296 K using these line lists show excellent agreement with those included in the HITRAN and HITEMP data bases. The computed NO line lists are the most comprehensive to date, covering a wider wavenumber and temperature range compared to both the HITRAN and HITEMP data bases. These line lists are also more accurate than those used in HITEMP. The full line lists are available from the CDS http://cdsarc.u-strasbg.fr and ExoMol www

  4. Antibacterial activity of nitric oxide releasing silver nanoparticles

    Science.gov (United States)

    Seabra, Amedea B.; Manosalva, Nixson; de Araujo Lima, Bruna; Pelegrino, Milena T.; Brocchi, Marcelo; Rubilar, Olga; Duran, Nelson

    2017-06-01

    Silver nanoparticles (AgNPs) are well known potent antimicrobial agents. Similarly, the free radical nitric oxide (NO) has important antibacterial activity, and due to its instability, the combination of NO and nanomaterials has been applied in several biomedical applications. The aim of this work was to synthesize, characterize and evaluate the antibacterial activity of a new NO-releasing AgNPs. Herein, AgNPs were synthesized by the reduction of silver ions (Ag+) by catechin, a natural polyphenol and potent antioxidant agent, derived from green tea extract. Catechin acts as a reducing agent and as a capping molecule on the surface of AgNPs, minimizing particle agglomeration. The as-synthesized nanoparticles were characterized by different techniques. The results showed the formation of AgNPs with average hydrodynamic size of 44 nm, polydispersity index of 0.21, and zeta potential of -35.9 mV. X-ray diffraction and Fourier transform infrared spectroscopy revealed the presence of the AgNP core and cathecin as capping agent. The low molecular weight mercaptosuccinic acid (MSA), which contain free thiol group, was added on the surface of catechin-AgNPs, leading to the formation of MSA-catechin-AgNPs (the NO precursor nanoparticle). Free thiol groups of MSA-catechin-AgNPs were nitrosated leading to the formation of S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), the NO donor. The amount of 342 ± 16 µmol of NO was released per gram of S-nitroso-MSA-catechin-AgNPs. The antibacterial activities of catechin-AgNPs, MSA-catechin-AgNPs, and S-nitroso-MSA-catechin-AgNPs were evaluated towards different resistant bacterial strains. The results demonstrated an enhanced antibacterial activity of the NO-releasing AgNP. For instance, the minimal inhibitory concentration values for Pseudomonas aeruginosa (ATCC 27853) incubated with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 62, 125 and 3 µg/mL, respectively. While in the case of

  5. Nitric oxide levels of aqueous humor after photorefractive keratectomy.

    Science.gov (United States)

    Adiguzel, U; Bilgihan, K; Ozdek, S C; Sancak, B; Hasanreisoglu, B

    2004-01-01

    To measure the nitric oxide (NO) levels of aqueous humor in rabbits after photorefractive keratectomy (PRK) and to evaluate the alterations of NO levels according to the PRK surgery steps, ablation depth, and time. Fifty eyes of 25 New Zealand white rabbits were included in the study. One eye was later randomly excluded from the study in order to equalize the number of eyes in groups. Eyes were divided into seven groups, each comprising seven eyes: unwounded control (Group 1), epithelial scrape (Group 2; aqueous humor samples taken at the 4th hour), superficial PRK (Group 3; samples taken at the 4th hour), deep PRK (Group 4; samples taken at the 4th hour), epithelial scrape (Group 5; samples taken at the 24th hour), superficial PRK (Group 6; samples taken at the 24th hour), and deep PRK (Group 7; samples taken at the 24th hour). The corneal epithelium was mechanically removed in surgical groups. The authors performed superficial corneal ablation (59 microm) in Groups 3 and 6 and deep corneal ablation (99 microm) in Groups 4 and 7. Aqueous humor samples were taken at the 4th hour (Groups 2-4) or 24th hour (Groups 5-7) after corneal surgeries. NO measurements were performed indirectly by using the Griess reaction with a spectrophotometer. Aqueous humor NO levels 4 hours after corneal surgery were statistically significantly lower than the control group (p0.05). At the 24th hour, the deep PRK group had significantly lower NO levels than both the control group and Groups 5 and 6 (p0.05) but remained stable at lower levels in deep PRK groups (p<0.05). Corneal surgery caused low NO levels in aqueous humor 4 hours after surgery. However, 24 hours after surgery, NO levels normalized following epithelial scrape and superficial PRK and were stable at lower levels in the deep PRK group. Complications of deep PRK application are possibly induced by low NO existence in the aqueous humor.

  6. Cellular targets of nitric oxide in the hippocampus.

    Directory of Open Access Journals (Sweden)

    Katalin Bartus

    Full Text Available In the hippocampus, as in many other CNS areas, nitric oxide (NO participates in synaptic plasticity, manifested as changes in pre- and/or postsynaptic function. While it is known that these changes are brought about by cGMP following activation of guanylyl cyclase-coupled NO receptors attempts to locate cGMP by immunocytochemistry in hippocampal slices in response to NO have failed to detect the cGMP elevation where expected, i.e. in the pyramidal neurones. Instead, astrocytes, unidentified varicose fibres and GABA-ergic nerve terminals are reported to be the prominent NO targets, raising the possibility that NO acts indirectly via other cells. We have re-investigated the distribution of cGMP generated in response to endogenous and exogenous NO in hippocampal slices using immunohistochemistry and new conditions designed to optimise cGMP accumulation and, hence, its detectability. The conditions included use of tissue from the developing rat hippocampus, a potent inhibitor of phosphodiesterase-2, and an allosteric enhancer of the NO-receptive guanylyl cyclase. Under these conditions, cGMP was formed in response to endogenous NO and was found in a population of pyramidal cell somata in area CA3 and subiculum as well as in structures described previously. The additional presence of exogenous NO resulted in hippocampal cGMP reaching the highest level recorded for brain tissue (1700 pmol/mg protein and in cGMP immunolabelling throughout the pyramidal cell layer. Populations of axons and interneurones were also stained. According with these results, immunohistochemistry for the common NO receptor β1-subunit indicated widespread expression. A similar staining pattern for the α1-subunit with an antibody used previously in the hippocampus and elsewhere, however, proved to be artefactual. The results indicate that the targets of NO in the hippocampus are more varied and extensive than previous evidence had suggested and, in particular, that the

  7. Crack propagation behavior of Ti-5Ta alloy in boiling nitric acid solution

    International Nuclear Information System (INIS)

    Motooka, Takafumi; Kiuchi, Kiyoshi

    1999-05-01

    The crack propagation behavior of Ti-5Ta alloy both in boiling nitric acid solution and in air at room temperature has been investigated. The crack growth rate of Ti-5Ta alloy was measured as a function of the stress intensity factor range. After the tests, the fracture surface morphology was observed by a scanning electron microscope and the crystallographic orientation was examined by X-ray diffraction analysis. Difference in the crack growth behavior was not observed in both environments. The crack growth rate in boiling nitric acid solution was similar to that in air at room temperature. Moreover, the crystallographic orientation of Ti-5Ta alloy had little effect on the fatigue behavior, because this alloy does not have the susceptibility to SCC in nitric acid solution. (author)

  8. Observation of gaseous nitric acid production at a high-energy proton accelerator facility

    CERN Document Server

    Kanda, Y; Nakajima, H

    2005-01-01

    High-energy protons and neutrons produce a variety of radionuclides as well as noxious and oxidative gases, such as ozone and nitric acid, in the air mainly through the nuclear spallation of atmospheric elements. Samples were collected from the surfaces of magnets, walls, and floors in the neutrino beamline tunnel and the target station of the KEK 12-GeV proton synchrotron facility by wiping surfaces with filter paper. Considerably good correlations were found between the amounts of nitrate and tritium and between those of nitrate and /sup 7/Be. This finding gives evidence that at high-energy proton facilities, nitric acid is produced in the radiolysis of air in beam- loss regions. Also, the nitric acid on the surfaces was found to be desorbed and tended to be more uniform throughout the tunnel due to air circulation. The magnitude of diminishing from the surfaces was in the order of tritium>nitrate>/sup 7/Be1).

  9. Progesterone modulates the LPS-induced nitric oxide production by a progesterone-receptor independent mechanism.

    Science.gov (United States)

    Wolfson, Manuel Luis; Schander, Julieta Aylen; Bariani, María Victoria; Correa, Fernando; Franchi, Ana María

    2015-12-15

    Genital tract infections caused by Gram-negative bacteria induce miscarriage and are one of the most common complications of human pregnancy. LPS administration to 7-day pregnant mice induces embryo resorption after 24h, with nitric oxide playing a fundamental role in this process. We have previously shown that progesterone exerts protective effects on the embryo by modulating the inflammatory reaction triggered by LPS. Here we sought to investigate whether the in vivo administration of progesterone modulated the LPS-induced nitric oxide production from peripheral blood mononuclear cells from pregnant and non-pregnant mice. We found that progesterone downregulated LPS-induced nitric oxide production by a progesterone receptor-independent mechanism. Moreover, our results suggest a possible participation of glucocorticoid receptors in at least some of the anti-inflammatory effects of progesterone. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Study of Nitric Oxide production by murine peritoneal macrophages induced by Brucella Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Kavoosi G

    2001-07-01

    Full Text Available Brueclla is a gram negative bacteria that causes Brucellosis. Lipopolysaccharide (LPS ", the pathogenic agent of Brucella is composed of O-chain, core oligosaccharide and lipid A. in addition, the structural and biological properties of different LPS extracted from different strains are not identical. The first defense system against LPS is nonspecific immunity that causes macrophage activation. Activated macrophages produce oxygen and nitrogen radicals that enhance the protection against intracellular pathogens.In this experiment LPS was extracted by hot phenol- water procedure and the effect of various LPSs on nitric oxide prodution by peritoneal mouse macrophages was examined.Our results demonstrated that the effect of LPS on nitric oxide production is concentration-dependent we observed the maximum response in concentration of 10-20 microgram per milliliter. Also our results demonstrate that LPS extracted from vaccine Brucella abortus (S 19 had a highe effect on nitric oxide production than the LPS from other strains

  11. Spectrophotometric determination of uranium and plutonium in nitric acid solutions at their co-presence

    International Nuclear Information System (INIS)

    Levakov, B.I.; Mishenev, V.B.; Nezgovorov, N.Yu.; Ryazanova, G.K.; Timofeev, G.A.

    1986-01-01

    The method of spectrophotometric determination of uranium (6) and plutonium (4) in nitric acid solutions is described. Uranium is determined by light absorption of the complex with arsenazo 3 in 0.05 mol/l nitric acid at λ=654 nm, plutonium - by light absorption of the complex with xylenol orange in 0.1 mol/l nitric acid at λ=540 nm. To disguise plutonium, tetravalent and certain trivalent elements DTPA is introduced into photometered solution for uranium determination. The relative root-mean square deviation of determination results does not exceed 0.03 in uranium concenration ranges 0.5-5 μg/ml, of plutonium -1-3 μg/ml

  12. Investigations on the oxidation of nitric acid plutonium solutions with ozone

    International Nuclear Information System (INIS)

    Boehm, M.

    1983-01-01

    The reaction of ozone with nitric acid Pu solutions was studied as a function of reaction time, acid concentration and Pu concentration. Strong nitric acid Pu solutions are important in nuclear fuel element production and reprocessing. The Pu must be converted into hexavalent Pu before precipitation from the homogeneous solution together with uranium-IV, ammonia and CO 2 in the form of ammonium uranyl/plutonyl carbonate (AUPuC). Formation of a solid phase during ozonation was observed for the first time. The proneness to solidification increases with incrasing plutonium concentrations and with decreasing acid concentrations. If the formation of a solid phase during ozonation of nitric acid Pu solutions cannot be prevented, the PU-IV oxidation process described is unsuitable for industrial purposes as Pu solutions in industrial processes have much higher concentrations than the solutions used in the present investigation. (orig./EF) [de

  13. Disposition and transportation of surplus radioactive low specific activity nitric acid. Volume 1, Environmental Assessment

    International Nuclear Information System (INIS)

    1995-05-01

    DOE is deactivating the PUREX plant at Hanford; this will involve the disposition of about 692,000 liters (183,000 gallons) of surplus nitric acid contaminated with low levels of U and other radionuclides. The nitric acid, designated as low specific activity, is stored in 4 storage tanks at PUREX. Five principal alternatives were evaluated: transfer for reuse (sale to BNF plc), no action, continued storage in Hanford upgraded or new facility, consolidation of DOE surplus acid, and processing the LSA nitric acid as waste. The transfer to BNF plc is the preferred alternative. From the analysis, it is concluded that the proposed disposition and transportation of the acid does not constitute a major federal action significantly affecting the quality of the human environment within the meaning of NEPA; therefore an environmental impact statement is not required

  14. Placebo neural systems: nitric oxide, morphine and the dopamine brain reward and motivation circuitries.

    Science.gov (United States)

    Fricchione, Gregory; Stefano, George B

    2005-05-01

    Evidence suggests that the placebo response is related to the tonic effects of constitutive nitric oxide in neural, vascular and immune tissues. Constitutive nitric oxide levels play a role in the modulation of dopamine outflow in the nigrostriatal movement and the mesolimbic and mesocortical reward and motivation circuitries. Endogenous morphine, which stimulates constitutive nitric oxide, may be an important signal molecule working at mu receptors on gamma aminobutyric acid B interneurons to disinhibit nigral and tegmental dopamine output. We surmise that placebo induced belief will activate the prefrontal cortex with downstream stimulatory effects on these dopamine systems as well as on periaqueductal grey opioid output neurons. Placebo responses in Parkinson's disease, depression and pain disorder may result. In addition, mesolimbic/mesocortical control of the stress response systems may provide a way for the placebo response to benefit other medical conditions.

  15. Nitric oxide signaling pathways involved in the inhibition of spontaneous activity in the guinea pig prostate.

    Science.gov (United States)

    Dey, Anupa; Lang, Richard J; Exintaris, Betty

    2012-06-01

    We investigated nitric oxide mediated inhibition of spontaneous activity recorded in young and aging guinea pig prostates. Conventional intracellular microelectrode and tension recording techniques were used. The nitric oxide donor sodium nitroprusside (10 μM) abolished spontaneous contractions and slow wave activity in 5 young and 5 aging prostates. Upon adding the nitric oxide synthase inhibitor L-NAME (10 μM) the frequency of spontaneous contractile and electrical activity was significantly increased in each age group. This increase was significantly larger in 4 to 8 preparations of younger vs aging prostates (about 40% to 50% vs about 10% to 20%, 2-way ANOVA pguinea pig prostates (Student paired t test pproduction. This may further explain the increase in prostatic smooth muscle tone observed in age related prostate specific conditions, such as benign prostatic hyperplasia. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  16. Nitric oxide scavenging by hemoglobin or nitric oxide synthase inhibition by N-Nitro-L-arginine induces cortical spreading ischemia when K+0+ is increased in the subarachnoid space

    DEFF Research Database (Denmark)

    Dreier, J.P.; Körner, K.; Ebert, Nathalie

    1998-01-01

    Cerebral blood flow, nitric oxide, potassium, spreading depression, vasospasm, migraine, migrainous stroke, mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS)......Cerebral blood flow, nitric oxide, potassium, spreading depression, vasospasm, migraine, migrainous stroke, mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS)...

  17. Association of Endothelial Nitric Oxide Synthase Gene Polymorphisms With Acute Rejection in Liver Transplant Recipients.

    Science.gov (United States)

    Azarpira, Negar; Namazi, Soha; Malahi, Sayan; Kazemi, Kourosh

    2016-06-01

    Polymorphisms of the endothelial nitric oxide synthase gene have been associated with altered endothelial nitric oxide synthase activity. The purpose of this study was to investigate the relation between endothelial nitric oxide synthase -786T/C and 894G/T polymorphism and their haplotypes on the occurrence of acute rejection episodes in liver transplant recipients. We conducted a case control study in which 100 liver transplant recipients and 100 healthy controls were recruited from Shiraz Transplant Center. The patients used triple therapy including tacrolimus, mycophenolate mofetil, and prednisolone for immunosuppression maintenance. DNA was extracted from peripheral blood and endothelial nitric oxide synthase polymorphisms were determined by polymerase chain reaction and restriction fragment length polymorphism. Patients included 60 men and 40 women (mean age, 32.35 ± 10.2 y). There was a significant association of endothelial nitric oxide synthase 894G/T and acute rejection episode. The GT* gen-otype and acute rejection episodes had a significant association (odds ratio, 2.42; 95% confidence interval, 0.97-6.15; P = .03). The GG and GT* genotype and T* allele frequency were significantly different between patients and control subjects (P = .001). Haplotype TT* was higher in recipients than control subjects (odds ratio, 2.17; 95% confidence interval, 1.12-4.25; P = .01). Haplotype TG was higher in the control group (odds ratio, 0.62; 95% confidence interval, 0.40-0.96; P = .02). Our results suggest a relation between different endothelial nitric oxide synthase geno-types and risk of acute rejection episodes. However, further study is necessary to determine genetic susceptibility for transplant patients.

  18. Reactivity of tributyl phosphate degradation products with nitric acid: Relevance to the Tomsk-7 accident

    International Nuclear Information System (INIS)

    Barney, G.S.; Cooper, T.D.

    1995-01-01

    The reaction of a degraded tributyl phosphate (TBP) solvent with nitric acid is thought to have caused the chemical explosion at the Tomsk-7 reprocessing plant at Tomsk, Russia in 1993. The estimated temperature of the organic layer was not high eneough to cause significant reaction of nitric acid with TBP or hydrocarbon diluent compounds. A more reactive organic compound was likely present in the organic layer that reacted with sufficient heat generation to raise the temperature to the point where an autocatalytic oxidation of the organic solvent was initiated. Two of the most likely reactive compounds that are present in degraded TBP solvents are n-butanol and n-butyl nitrate. The reactions of these compounds with nitric acid are the subject of this study. The objective of laboratory-scale tests was to identify chemical reactions that occur when n-butanol and n-butyl nitrate contact heated nitric acid solutions. Reaction products were identified and quantitified, the temperatures at which these reactions occur and heats of reaction were measured, and reaction variables (temperature, nitric acid concentration, organic concentration, and reaction time) were evaluated. Data showed that n-butyl nitrate is less reactive than n-butanol. An essentially complete oxidation reaction of n-butanol at 110-120 C produced four major reaction products. Mass spectrometry identified the major inorganic oxidation products for both n-butanol and n-butyl nitrate as nitric oxide and carbon dioxide. Calculated heats of reaction for n-butanol and n-butyl nitrate to form propionic acid, a major reaction product, are -1860 cal/g n-butanol and -953 cal/g n-butyl nitrate. These heats of reaction are significant and could have raised the temperature of the organic layer in the Tomsk-7 tank to the point where autocatalytic oxidation of other organic compounds present resulted in an explosion

  19. Iron(II) porphyrins induced conversion of nitrite into nitric oxide: A computational study.

    Science.gov (United States)

    Zhang, Ting Ting; Liu, Yong Dong; Zhong, Ru Gang

    2015-09-01

    Nitrite reduction to nitric oxide by heme proteins was reported as a protective mechanism to hypoxic injury in mammalian physiology. In this study, the pathways of nitrite reduction to nitric oxide mediated by iron(II) porphyrin (P) complexes, which were generally recognized as models for heme proteins, were investigated by using density functional theory (DFT). In view of two type isomers of combination of nitrite and Fe(II)(P), N-nitro- and O-nitrito-Fe(II)-porphyrin complexes, and two binding sites of proton to the different O atoms of nitrite moiety, four main pathways for the conversion of nitrite into nitric oxide mediated by iron(II) porphyrins were proposed. The results indicate that the pathway of N-bound Fe(II)(P)(NO2) isomer into Fe(III)(P)(NO) and water is similar to that of O-bound isomer into nitric oxide and Fe(III)(P)(OH) in both thermodynamical and dynamical aspects. Based on the initial computational studies of five-coordinate nitrite complexes, the conversion of nitrite into NO mediated by Fe(II)(P)(L) complexes with 14 kinds of proximal ligands was also investigated. Generally, the same conclusion that the pathways of N-bound isomers are similar to those of O-bound isomer was obtained for iron(II) porphyrin with ligands. Different effects of ligands on the reduction reactions were also found. It is notable that the negative proximal ligands can improve reactive abilities of N-nitro-iron(II) porphyrins in the conversion of nitrite into nitric oxide compared to neutral ligands. The findings will be helpful to expand our understanding of the mechanism of nitrite reduction to nitric oxide by iron(II) porphyrins. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

    International Nuclear Information System (INIS)

    Liu Jing; Gupta, Ramesh C.; Goad, John T.; Karanth, Subramanya; Pope, Carey

    2007-01-01

    Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with no significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation

  1. Nitric acid leaching of radium and other significant radionuclides from uranium ores and tailings

    International Nuclear Information System (INIS)

    Ryon, A.D.; Hurst, F.J.; Seeley, F.G.

    1977-08-01

    Nitric acid leaching of representative uranium ores and mill tailings from the western U.S. mining districts removes up to 98% of the 226 Ra and 230 Th, yielding a residue containing 17 to 60 pCi of radium per gram. At best, this is an order of magnitude greater than that in surrounding soils, but about the same level as a standard proposed for building materials in the United Kingdom. Data are also presented on the water penetration and leaching of tailings, the solubility of BaSO 4 , and radon emanation coefficients of ores, tailings, and nitric acid-leached residues

  2. The pitting resistance of AISI 316 stainless steel passivated in diluted nitric acid

    International Nuclear Information System (INIS)

    Barbosa, M.A.

    1983-01-01

    The pitting resistance of AISI 316 stainless steel after passivation in diluted nitric acid was studied in comparison with that of non-passivated specimens. The passivation treatment increased the pitting potential but decreased the resistance to crevice corrosion under open circuit conditions in aerated sea water. Immersion in the nitric acid solution was found to remove the sulphide inclusions from the metal surface, thus eliminating the most susceptible sites for attack. In the absence of sulphide particles pitting nucleated at aluminium-rich oxides. (author)

  3. OPTIMAL CONTROL OF AUTOCLAVE START MODE IN THE PRODUCTION OF NITRIC ACID

    OpenAIRE

    Ладієва, Леся Ростиславівна; Ширма, А. В.

    2015-01-01

    The algorithm of optimal control of autoclave start mode in the production of nitric acid is proposed. By optimality criterion is selected minimum time-autoclave at preset mode with the restriction on the concentration of nitric acid. End time start mode is entered on the terminal part of the cost function. The method of penalties and a gradient procedure is used to solve the problem. The applied algorithm is allowed to bring an autoclave at a given technological regime.Keywords: production o...

  4. The effect of energetic electron precipitation on the nitric oxide density in the lower thermosphere

    International Nuclear Information System (INIS)

    Saetre, Camilla

    2006-12-01

    The objective of this thesis has been the study of the chemical effects of the electron precipitation in the upper atmosphere, and mainly the increase of thermospheric nitric oxide (NO). NO plays an important role in the temperature balance for the mesosphere and thermosphere.In this project auroral electron precipitation data, derived from the Polar Ionospheric X-ray Imaging Experiment (PIXIE) and the Ultraviolet Imager (UVI) on board the Polar satellite, have been used together with NO density measurements from the Student Nitric Oxide Explorer (SNOE)

  5. [Studies on the oxidation reaction of octanol-2 with nitric acid by infrared spectroscopy].

    Science.gov (United States)

    Zhang, G; Zhao, G; Wang, Y; Zhang, Q; Zhang, S; Lu, F

    1998-04-01

    In this paper, the reaction process of oxidation of octanol-2 with nitric acid has been studied by IR spectroscopy. It is found that the main components of non-sapoifiable matter are different in different oxidation degrees. The relation between oxidation products and the amount of nitric acid are investigated,the reaction mechanism has also been studied. Experimental results show that the oxidation process of octanol-2 is as follows: first, octanol-2 is oxidated to octanone-2, or to nitrate, nitrite and nitrile copmpounds, then these compounds are reoxidated to caproic acid in the meantime some by-products, such as valeric, enanthic acids are also found in oxidated products.

  6. Corrosion resistance of nickel alloys with chromium and silicon to the red fuming nitric acid

    International Nuclear Information System (INIS)

    Gurvich, L.Ya.; Zhirnov, A.D.

    1994-01-01

    Corrosion and electrochemical behaviour of binary Ni-Cr, Ni-Si nickel and ternary Ni-Cr-Si alloys in the red fuming nitric acid (RFNA) (8-% of HNO 3 +20% of N 2 O 4 ) is studied. It is shown that nickel alloying with chromium improves its corrosion resistance to the red fuming nitric acid. Nickel alloying with silicon in quantities of up to 5 % reduces, and up to 10%-increases abruptly the corrosion resistance with subsequent decrease of the latter after the further increase of concentration. Ni-15% of Cr alloy alloying with silicon increases monotonously the corrosion resistance. 10 refs., 7 figs., 3 tabs

  7. The extraction of rhodium from aqueous nitric acid by dinonylnaphthalene sulphonic acid

    International Nuclear Information System (INIS)

    Patel, N.M.; Miles, J.H.; Thornback, J.R.

    1987-01-01

    The extraction of rhodium from aqueous nitric acid using dinonylnaphthalene sulphonic acid has been investigated. The extraction occurs readily from 0.1 M to 1.0 M nitric acid and, since the rhodium is extracted as {Rh(H 2 O) 6 } 3+ into the inverted micelles of the organic solution, equilibration times are less than 5 minutes. Extraction is enhanced by addition of nitrite ion to form {Rh(H 2 O) 5 NO 2 } 2+ as the extracted species. (author)

  8. Evaporation and NARS Nitric Acid Mass Balance Summary: 2000--2005

    International Nuclear Information System (INIS)

    Kreutzberg, B.D.; Ames, R.L.; Hansel, K.M.

    2005-01-01

    A compilation of the historical nitric acid processing data for the evaporation and nitric acid recycle system (NARS) in TA-55 has provided general acid mass balance trends, as well as the location of missing information in both the evaporation system and NARS data logs. The data were accumulated during the calendar years 2000 to 2005. After making a number of processing assumptions, the empirical system information was used to create an interactive spreadsheet that predicts, with moderate accuracy, some of the various stream variables for the combined evaporation and acid recycle processes. Empirical data and interactive calculations were compared to an Aspen Plus(trademark) simulation of the process

  9. In vitro inducible nitric oxide synthesis inhibitory active constituents from Fraxinus rhynchophylla.

    Science.gov (United States)

    Kim, N Y; Pae, H O; Ko, Y S; Yoo, J C; Choi, B M; Jun, C D; Chung, H T; Inagaki, M; Higuchi, R; Kim, Y C

    1999-10-01

    Bioassay-guided fractionation of an H2O extract of the barks of Fraxinus rhynchophylla has furnished two inducible nitric oxide synthase (iNOS) inhibitory compounds, ferulaldehyde (1) and scopoletin (3) together with a coumarin, fraxidin (2). Compounds 1 and 3 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner by murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibition of NO synthesis of 1 was reflected in the decreased amount of iNOS protein, as determined by Western blotting.

  10. Stabilization and Solidification of Nitric Acid Effluent Waste at Y-12

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dileep [Argonne National Lab. (ANL), Argonne, IL (United States); Lorenzo-Martin, Cinta [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-16

    Consolidated Nuclear Security, LLC (CNS) at the Y-12 plant is investigating approaches for the treatment (stabilization and solidification) of a nitric acid waste effluent that contains uranium. Because the pH of the waste stream is 1-2, it is a difficult waste stream to treat and stabilize by a standard cement-based process. Alternative waste forms are being considered. In this regard, Ceramicrete technology, developed at Argonne National Laboratory, is being explored as an option to solidify and stabilize the nitric acid effluent wastes.

  11. Nitric oxide coordinates metabolism, growth, and development via the nuclear receptor E75.

    Science.gov (United States)

    Cáceres, Lucía; Necakov, Aleksandar S; Schwartz, Carol; Kimber, Sandra; Roberts, Ian J H; Krause, Henry M

    2011-07-15

    Nitric oxide gas acts as a short-range signaling molecule in a vast array of important physiological processes, many of which include major changes in gene expression. How these genomic responses are induced, however, is poorly understood. Here, using genetic and chemical manipulations, we show that nitric oxide is produced in the Drosophila prothoracic gland, where it acts via the nuclear receptor ecdysone-induced protein 75 (E75), reversing its ability to interfere with its heterodimer partner, Drosophila hormone receptor 3 (DHR3). Manipulation of these interactions leads to gross alterations in feeding behavior, fat deposition, and developmental timing. These neuroendocrine interactions and consequences appear to be conserved in vertebrates.

  12. Inducible nitric oxide synthase (iNOS) in tumor biology: the two sides of the same coin

    NARCIS (Netherlands)

    Lechner, Matthias; Lirk, Philipp; Rieder, Josef

    2005-01-01

    Inducible nitric oxide synthase (iNOS) is one of three key enzymes generating nitric oxide (NO) from the amino acid l-arginine. iNOS-derived NO plays an important role in numerous physiological (e.g. blood pressure regulation, wound repair and host defence mechanisms) and pathophysiological

  13. Reaction of nitrous acid with U(IV) and nitric acid in 30% TBP-kerosene solution

    International Nuclear Information System (INIS)

    Xu Xiangrong; Hu Jingxin; Huang Huaian; Qiu Xiaoxi

    1990-01-01

    Reaction of nitrous acid with U(IV) and nitric acid in 30% TBP-kerosene solution is investigated, the rate equations of oxidation of U(IV) by nitrous acid and that of nitrous acid reacting with nitric acid are obtained

  14. Neuronal Nitric-Oxide Synthase Deficiency Impairs the Long-Term Memory of Olfactory Fear Learning and Increases Odor Generalization

    Science.gov (United States)

    Pavesi, Eloisa; Heldt, Scott A.; Fletcher, Max L.

    2013-01-01

    Experience-induced changes associated with odor learning are mediated by a number of signaling molecules, including nitric oxide (NO), which is predominantly synthesized by neuronal nitric oxide synthase (nNOS) in the brain. In the current study, we investigated the role of nNOS in the acquisition and retention of conditioned olfactory fear. Mice…

  15. Nitric oxide synthase in the gill of Atlantic salmon: colocalization with and inhibition of Na+,K+-ATPase

    DEFF Research Database (Denmark)

    Ebbesson, Lars O E; Tipsmark, Christian K; Holmqvist, Bo

    2005-01-01

    We investigated the relationship between nitric oxide (NO) and Na(+),K(+)-ATPase (NKA) in the gill of anadromous Atlantic salmon. Cells containing NO-producing enzymes were revealed by means of nitric oxide synthase (NOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphor...

  16. Altered contractile response due to increased beta3-adrenoceptor stimulation in diabetic cardiomyopathy: the role of nitric oxide synthase 1-derived nitric oxide.

    Science.gov (United States)

    Amour, Julien; Loyer, Xavier; Le Guen, Morgan; Mabrouk, Nejma; David, Jean-Stéphane; Camors, Emmanuel; Carusio, Nunzia; Vivien, Benoît; Andriantsitohaina, Ramaroson; Heymes, Christophe; Riou, Bruno

    2007-09-01

    In the diabetic heart, the positive inotropic response to beta-adrenoceptor stimulation is altered and beta1 and beta2 adrenoceptors are down-regulated, whereas beta3 adrenoceptor is up-regulated. In heart failure, beta3-adrenoceptor stimulation induces a negative inotropic effect that results from endothelial nitric oxide synthase (NOS3)-derived nitric oxide production. The objective of our study was to investigate the role of beta3-adrenoceptor in diabetic cardiomyopathy. beta-Adrenergic responses were investigated in vivo (dobutamine echocardiography) and in vitro (left ventricular papillary muscle) in healthy and streptozotocin-induced diabetic rats. The effect of beta3-adrenoceptor inhibition on the inotropic response was studied in vitro. Immunoblots and NOS activities were performed in heart homogenates (electron paramagnetic resonance) and isolated cardiomyocytes. Data are mean percentage of baseline +/- SD. The impaired positive inotropic effect was confirmed in diabetes both in vivo (121 +/- 15% vs. 160 +/- 16%; P < 0.05) and in vitro (112 +/- 5% vs. 179 +/- 15%; P < 0.05). In healthy rat, the positive inotropic effect was not significantly modified in presence of beta3-adrenoceptor antagonist (174 +/- 20%), nonselective NOS inhibitor (N -nitro-l-arginine methylester [l-NAME]; 183 +/- 19%), or selective NOS1 inhibitor (vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine [l-VNIO]; 172 +/- 13%). In diabetes, in parallel with the increase in beta3-adrenoceptor protein expression, the positive inotropic effect was partially restored by beta3-adrenoceptor antagonist (137 +/- 8%; P < 0.05), l-NAME (133 +/- 11%; P < 0.05), or l-VNIO (130 +/- 13%; P < 0.05). Nitric oxide was exclusively produced by NOS1 within diabetic cardiomyocytes. NOS2 and NOS3 proteins were undetectable. beta3-Adrenoceptor is involved in altered positive inotropic response to beta-adrenoceptor stimulation in diabetic cardiomyopathy. This effect is mediated by NOS1-derived nitric oxide in diabetic

  17. Glufosinate ammonium stimulates nitric oxide production through N-methyl D-aspartate receptors in rat cerebellum.

    Science.gov (United States)

    Nakaki, T; Mishima, A; Suzuki, E; Shintani, F; Fujii, T

    2000-09-01

    Glufosinate ammonium, a structural analogue of glutamate, is an active herbicidal ingredient. The neuronal activities of this compound were investigated by use of a microdialysis system that allowed us to measure nitric oxide production in the rat cerebellum in vivo. Kainate (0.3-30 nmol/10 microliter), N-methyl-D-aspartate (NMDA) (3-300 nmol/10 microliter) and glufosinate ammonium (30-3000 nmol/10 microliter), which were administered through the microdialysis probe at a rate of 1 microliter/min for 10 min, stimulated nitric oxide production. The glufosinate ammonium-elicited increase in nitric oxide production was suppressed by an inhibitor of nitric oxide synthase and was antagonized by NMDA receptor antagonists, but not by a kainate/(+/-)-alphaamino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist. These results suggest that glufosinate ammonium stimulates nitric oxide production through NMDA receptors.

  18. Nitric oxide as a mediator of gastrointestinal mucosal injury?—Say it ain't so

    Directory of Open Access Journals (Sweden)

    Paul Kubes

    1995-01-01

    Full Text Available Nitric oxide has been suggested as a contributor to tissue injury in various experimental models of gastrointestinal inflammation. However, there is overwhelming evidence that nitric oxide is one of the most important mediators of mucosal defence, influencing such factors as mucus secretion, mucosal blood flow, ulcer repair and the activity of a variety of mucosal immunocytes. Nitric oxide has the capacity to down-regulate inflammatory responses in the gastrointestinal tract, to scavenge various free radical species and to protect the mucosa from injury induced by topical irritants. Moreover, questions can be raised regarding the evidence purported to support a role for nitric oxide in producing tissue injury. In this review, we provide an overview of the evidence supporting a role for nitric oxide in protecting the gastrointestinal tract from injury.

  19. Carboxyhemoglobin formation secondary to nitric oxide therapy in the setting of interstitial lung disease and pulmonary hypertension.

    Science.gov (United States)

    Ruisi, Phillip; Ruisi, Michael

    2011-01-01

    Carbon monoxide (CO) has been widely recognized as an exogenous poison, although endogenous mechanisms for its formation involve heme-oxygenase (HO) isoforms, more specifically HO-1, in the setting of oxidative stress such as acute respiratory distress syndrome, sepsis, trauma, and nitric oxide use have been studied. In patients with refractory hypoxemia, inhaled nitric oxide (iNO) therapy is used to selectively vasodilate the pulmonary vasculature and improve ventilation-perfusion match. Inhaled nitric oxide is rapidly inactivated on binding to hemoglobin in the formation of nitrosyl- and methemoglobin in the pulmonary vasculature. Hence, inhaled nitric oxide has minimal systemic dissemination. Several experimental design studies involving lab rats have demonstrated increased levels of carboxyhemoglobin and exhaled CO as a result of nitric oxide HO-1 induction.

  20. Argon Shrouded Plasma Spraying of Tantalum over Titanium for Corrosion Protection in Fluorinated Nitric Acid Media

    Science.gov (United States)

    Vetrivendan, E.; Jayaraj, J.; Ningshen, S.; Mallika, C.; Kamachi Mudali, U.

    2018-02-01

    Argon shrouded plasma spraying (ASPS) was used to deposit a Ta coating on commercially pure Ti (CP-Ti) under inert argon, for dissolver vessel application in the aqueous spent fuels reprocessing plant with high plutonium content. Oxidation during plasma spraying was minimized by shrouding argon system. Porosity and oxide content were controlled by optimizing the spraying parameters, to obtain a uniform and dense Ta coating. The Ta particle temperature and velocity were optimized by judiciously controlling the spray parameters, using a spray diagnostic charge-coupled device camera. The corrosion resistance of the Ta coatings developed by ASPS was investigated by electrochemical studies in 11.5 M HNO3 and 11.5 M HNO3 + 0.05 M NaF. Similarly, the durability of the ASPS Ta coating/substrate was evaluated as per ASTM A262 Practice-C test in boiling nitric acid and fluorinated nitric acid for 240 h. The ASPS Ta coating exhibited higher corrosion resistance than the CP-Ti substrate, as evident from electrochemical studies, and low corrosion rate with excellent coating stability in boiling nitric, and fluorinated nitric acid. The results of the present study revealed that tantalum coating by ASPS is a promising strategy for improving the corrosion resistance in the highly corrosive reprocessing environment.

  1. Nitric oxide synthase expression and apoptotic cell death in brains of AIDS and AIDS dementia patients

    NARCIS (Netherlands)

    Vincent, V. A.; de Groot, C. J.; Lucassen, P. J.; Portegies, P.; Troost, D.; Tilders, F. J.; van Dam, A. M.

    1999-01-01

    To determine the occurrence and cellular localization of inducible nitric oxide synthase (iNOS), NOS activity and its association with cell death in brains of AIDS and AIDS dementia complex (ADC) patients. Post-mortem cerebral cortex tissue of eight AIDS patients, eight ADC patients and eight

  2. Sesquiterpene lactone trilobolide activates production of interferon-γ and nitric oxide

    Czech Academy of Sciences Publication Activity Database

    Kmoníčková, Eva; Harmatha, Juraj; Vokáč, Karel; Kostecká, Petra; Farghali, H.; Zídek, Zdeněk

    2010-01-01

    Roč. 81, č. 8 (2010), s. 1213-1219 ISSN 0367-326X R&D Projects: GA ČR GA305/07/0061 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40550506 Keywords : trilobolide * nitric oxide * sesquiterpene lactones Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 1.899, year: 2010

  3. Efficacy and residue analysis of nitric oxide fumigation of strawberries for control of Drosophila suzukii

    Science.gov (United States)

    Nitric oxide (NO) has been demonstrated as an effective fumigant against various insect pests on postharvest products under ultralow oxygen (ULO) conditions. NO showed efficacy against all life stages of insect pests with varied fumigation time and temperature, and had feasible cost-effectiveness to...

  4. Testing a Conceptual Model of Soil Emissions of Nitrous and Nitric Oxides

    Science.gov (United States)

    Eric A. Davidson; Michael Keller; Heather E. Erickson; Verchot NO-VALUE; Edzo Veldkamp

    2000-01-01

    Nitrous and nitric oxides are often studied separately by atmospheric chemists because they play such different roles in the atmosphere. N2O is a stable greenhouse gas in the lower atmosphere (the troposphere; Ramanathan et al. 1985), but it participates in photochemical reactions in the upper atmosphere (the stratosphere) that destroy ozone (Crutzen 1970). In contrast...

  5. Chemiluminescence from the reaction of Ba 3D with nitric oxide

    International Nuclear Information System (INIS)

    Johnson, S.A.; Solarz, R.W.; Dubrin, J.W.; Brotzmann, R.

    1977-01-01

    The reaction of laser excited Ba*( 3 D) states with nitric oxide is presented. BaO product is not detected, although the channel is thermodynamically open, and instead chemiluminescence is observed. Experiments which suggest that radiative recombination, Ba + NO → BaNO* → BaNO, is the observed reaction channel will also be presented

  6. Acute and chronic effects of dinner with alcoholic beverages on nitric oxide metabolites in healthy men

    NARCIS (Netherlands)

    Sierksma, A.; Gaag, M.S. van der; Grobbee, D.E.; Hendriks, H.F.J.

    2003-01-01

    1. The present study investigated the acute and chronic effect of dinner with alcoholic beverages on serum nitric oxide (NO) metabolites, namely nitrate and nitrite (NOx), in 11 healthy, non-smoking middle-aged men. 2. In a randomized, diet-controlled, cross-over trial, subjects consumed dinner with

  7. The effect of nitric oxide releasing cream on healing pressure ulcers

    Directory of Open Access Journals (Sweden)

    Vahid Saidkhani

    2016-01-01

    Full Text Available Background: Pressure ulcer is one of the main concerns of nurses in medical centers around the world, which, if untreated, causes irreparable problems for patients. In recent years, nitric oxide (NO has been proposed as an effective method for wound healing. This study was conducted to determine the effect of nitric oxide on pressure ulcer healing. Materials and Methods: In this clinical trial, 58 patients with pressure ulcer at hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences were homogenized and later divided randomly into two groups of treatment (nitric oxide cream; n = 29 and control (placebo cream; n = 29. In this research, the data collection tool was the Pressure Ulcer Scale for Healing (PUSH. At the outset of the study (before using the cream, the patients' ulcers were examined weekly in terms of size, amount of exudates, and tissue type using the PUSH tool for 3 weeks. By integrating these three factors, wound healing was determined. Data were analyzed using SPSS. Results: Although no significant difference was found in terms of the mean of score size, the amount of exudates, and the tissue type between the two groups, the mean of total score (healing between the two groups was statistically significant (P = 0.04. Conclusions: Nitric oxide cream seems to accelerate wound healing. Therefore, considering its easy availability and cost-effectiveness, it can be used for treating pressure ulcers in the future.

  8. Bronchoconstriction induced by citric acid inhalation in guinea pigs: role of tachykinins, bradykinin, and nitric oxide

    NARCIS (Netherlands)

    Ricciardolo, F. L.; Rado, V.; Fabbri, L. M.; Sterk, P. J.; Di Maria, G. U.; Geppetti, P.

    1999-01-01

    Gastroesophageal acid reflux into the airways can trigger asthma attacks. Indeed, citric acid inhalation causes bronchoconstriction in guinea pigs, but the mechanism of this effect has not been fully clarified. We investigated the role of tachykinins, bradykinin, and nitric oxide (NO) on the citric

  9. Kinetic analysis of nitric oxide reduction using biogas as reburning fuel

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... Emission of nitric oxide (NO) from coal combustion continues to be a significant ... mass has been focused as a renewable fuel without CO2 addition, and researches ..... Giles DE, Som S, Aggarwal SK (2006). NOx emission ...

  10. Influence of nitric acid concentration on the characteristics of active carbons obtained from a mineral coal

    Energy Technology Data Exchange (ETDEWEB)

    Khelifi, A.; Temdrara, L.; Addoun, A. [Laboratoire d' Etude Physicochimique des Materiaux et Application a l' Environnement, Faculte de Chimie, USTHB, BP. 32 El Alia, Bab Ezzouar 16111, Algiers (Algeria); Almazan-Almazan, M.C.; Perez-Mendoza, M.; Domingo-Garcia, M.; Lopez-Garzon, F.J [Departamento de Quimica Inorganica, Facultad de Ciencias, 18071 Granada (Spain); Lopez-Domingo, F.J. [Departamento de CCIA, ETS de Ingenieria Informatica y Telecomunicacion, Granada, 18071 (Spain)

    2010-10-15

    This paper deals with the effect of the concentration of nitric acid solutions on the properties of activated carbons obtained by the oxidation of a parent activated carbon. For this purpose a mineral coal from Algeria has been used as raw material to prepare the parent active carbon AC. This was further treated with nitric acid solutions. The analysis of the samples includes the chemical and textural characterization. The former was carried out by selective titrations and FTIR spectroscopy. The latter, by nitrogen and carbon dioxide adsorption at 77 and 273 K, respectively, and by adsorption of organic probes (benzene, dichloromethane, cyclohexane and 2,2-dimethyl butane) at 303 K. The nitrogen adsorption isotherms have been analysed by using the BET equation, {alpha}{sub s}-method and molecular simulation. The Dubinin-Radushkevich approach has been applied to the carbon dioxide and vapours adsorption data. The results show that the treatment with 2 N nitric acid solution is very appropriate because it introduces a large amount of oxygen containing groups with a small change of the textural characteristics of the parent AC. More concentrated nitric acid solutions change in large extent the textural properties although they also introduce large amount of chemical groups. (author)

  11. Lithium-Vanadium bronzes as model catalysts for the selective reduction of nitric oxide

    NARCIS (Netherlands)

    Bosch, H.; Bongers, Annemie; Enoch, Gert; Snel, Ruud; Ross, Julian R.H.

    1989-01-01

    The effect of alkali metals on the selective reduction of nitric oxide with ammonia has been studied on bulk iron oxide and bulk vanadium oxide. The influence of additions of LiOH, NaOH and KOH on the activity was screened by pulse experiments carried out in the absence of gaseous oxygen; FTIR

  12. In vivo measurement of nitric oxide production in porcine gut, liver and muscle during hyperdynamic endotoxaemia

    NARCIS (Netherlands)

    Bruins, Maaike J.; Lamers, Wouter H.; Meijer, Alfred J.; Soeters, Peter B.; Deutz, Nicolaas E. P.

    2002-01-01

    1. During prolonged endotoxaemia, an increase in arginine catabolism may result in limiting substrate availability for nitric oxide (NO) production. These effects were quantitated in a chronically instrumented porcine endotoxaemia model. 2. Ten days prior to the beginning of the experiments, pigs

  13. Dual inhibition of nitric oxide and prostaglandin E2 production by polysubstituted 2-aminopyrimidines

    Czech Academy of Sciences Publication Activity Database

    Zídek, Zdeněk; Kverka, Miloslav; Dusilová, Adéla; Kmoníčková, Eva; Jansa, Petr

    2016-01-01

    Roč. 57, jul (2016), s. 48-56 ISSN 1089-8603 R&D Projects: GA ČR(CZ) GAP303/12/0172 Institutional support: RVO:68378041 ; RVO:61388963 Keywords : pyrimidines * nitric oxide * prostaglandin E-2 Subject RIV: FR - Pharmacology ; Medidal Chemistry; CC - Organic Chemistry (UOCHB-X) Impact factor: 4.181, year: 2016

  14. S-nitrosylation mediates nitric oxide -auxin crosstalk in auxin signaling and polar auxin transport

    Science.gov (United States)

    Nitric oxide (NO) and auxin phytohormone cross talk has been implicated in plant development and growth. Addition and removal of NO moieties to cysteine residues of proteins, is termed S-nitrosylation and de-nitrosylation, respectively and functions as an on/off switch of protein activity. This dyna...

  15. Nitric oxide production and monoamine oxidase activity in cancer patients during interferon-a therapy

    NARCIS (Netherlands)

    D. Fekkes (Durk); A.R. van Gool (Arthur); M. Bannink (Marjolein); S. Sleijfer (Stefan); W.H.J. Kruit (Wim); B. van der Holt (Bronno); A.M.M. Eggermont (Alexander); M.W. Hengeveld (Michiel); G. Stoter (Gerrit)

    2009-01-01

    textabstractAbstract Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-alpha (IFN-alpha). Animal studies showed that IFN-alpha administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases

  16. Simultaneous Measurement of Nitrous Acid,Nitric Acid, and Nitrogen Dioxide by Means \

    Czech Academy of Sciences Publication Activity Database

    Vichi, F.; Mašková, Ludmila; Frattoni, M.; Imperiali, A.; Smolík, Jiří

    2016-01-01

    Roč. 4, FEB 22 (2016), s. 4 ISSN 2050-7445. [International Conference on Indoor Air Quality in Heritage and Historic Environments /11./. Prague, 13.04.2014-16.04.2014] Institutional support: RVO:67985858 Keywords : diffusive sampling * nitrous acid * nitric acid Subject RIV: CF - Physical ; Theoretical Chemistry

  17. Serum uric acid levels and leukocyte nitric oxide production in multiple sclerosis patients outside relapses

    NARCIS (Netherlands)

    Mostert, JP; Ramsaransing, GSM; Heerserna, DJ; Heerings, M; Wilczak, N; De Keyser, J

    2005-01-01

    Background: A number of studies found that patients with multiple sclerosis (MS) have low serum levels of uric acid. It is unclear whether this represents a primary deficit or secondary effect. Uric acid is a scavenger of peroxynitrite, which is the product of nitric oxide (NO) and superoxide.

  18. Nitric oxide metabolites in gnotobiotic piglets orally infected with Salmonella enterica serovar Typhimurium

    Czech Academy of Sciences Publication Activity Database

    Trebichavský, Ilja; Zídek, Zdeněk; Franková, Daniela; Zahradníčková, Marie; Šplíchal, Igor

    2001-01-01

    Roč. 46, č. 4 (2001), s. 353-358 ISSN 0015-5632 R&D Projects: GA ČR GA524/01/0917 Institutional research plan: CEZ:AV0Z5020903 Keywords : nitric oxide metabolites Subject RIV: EC - Immunology Impact factor: 0.776, year: 2001

  19. Exhaled nitric oxide in spray painters exposed to isocyanates : Effect modification by atopy and smoking

    NARCIS (Netherlands)

    Jonaid, Badri Sadat; Pronk, Anjoeka; Doekes, Gert; Heederik, Dick

    2014-01-01

    Background: Isocyanate asthma is one of the most frequently identified forms of occupational asthma in industrialised countries. The underlying mechanisms have not been clarified. There is only limited information about the relationship between exhaled nitric oxide (eNO) and occupational exposure to

  20. Exhaled nitric oxide in spray painters exposed to isocyanates: Effect modification by atopy and smoking

    NARCIS (Netherlands)

    Jonaid, B.S.; Pronk, A.; Doekes, G.; Heederik, D.

    2014-01-01

    Background: Isocyanate asthma is one of the most frequently identified forms of occupational asthma in industrialised countries. The underlying mechanisms have not been clarified. There is only limited information about the relationship between exhaled nitric oxide (eNO) and occupational exposure to

  1. Antimicrobial Activity of Nitric Oxide-Releasing Ti-6Al-4V Metal Oxide

    Science.gov (United States)

    Reger, Nina A.; Meng, Wilson S.; Gawalt, Ellen S.

    2017-01-01

    Titanium and titanium alloy materials are commonly used in joint replacements, due to the high strength of the materials. Pathogenic microorganisms can easily adhere to the surface of the metal implant, leading to an increased potential for implant failure. The surface of a titanium-aluminum-vanadium (Ti-6Al-4V) metal oxide implant material was functionalized to deliver an small antibacterial molecule, nitric oxide. S-nitroso-penicillamine, a S-nitrosothiol nitric oxide donor, was covalently immobilized on the metal oxide surface using self-assembled monolayers. Infrared spectroscopy was used to confirm the attachment of the S-nitrosothiol donor to the Ti-Al-4V surface. Attachment of S-nitroso-penicillamine resulted in a nitric oxide (NO) release of 89.6 ± 4.8 nmol/cm2 under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli and Staphylococcus epidermidis growth by 41.5 ± 1.2% and 25.3 ± 0.6%, respectively. Combining the S-nitrosothiol releasing Ti-6Al-4V with tetracycline, a commonly-prescribed antibiotic, increased the effectiveness of the antibiotic by 35.4 ± 1.3%, which allows for lower doses of antibiotics to be used. A synergistic effect of ampicillin with S-nitroso-penicillamine-modified Ti-6Al-4V against S. epidermidis was not observed. The functionalized Ti-6Al-4V surface was not cytotoxic to mouse fibroblasts. PMID:28635681

  2. Nitric Oxide Binds to and Modulates the Activity of a Pollen Specific Arabidopsis Diacylglycerol Kinase

    KAUST Repository

    Wong, Aloysius Tze

    2014-01-01

    Nitric oxide (NO) is an important signaling molecule in plants. In the pollen of Arabidopsis thaliana, NO causes re-orientation of the growing tube and this response is mediated by 3′,5′-cyclic guanosine monophosphate (cGMP). However, in plants, NO

  3. Caveolin versus calmodulin. Counterbalancing allosteric modulators of endothelial nitric oxide synthase.

    Science.gov (United States)

    Michel, J B; Feron, O; Sase, K; Prabhakar, P; Michel, T

    1997-10-10

    Nitric oxide is synthesized in diverse mammalian tissues by a family of calmodulin-dependent nitric oxide synthases. The endothelial isoform of nitric oxide synthase (eNOS) is targeted to the specialized signal-transducing membrane domains termed plasmalemmal caveolae. Caveolin, the principal structural protein in caveolae, interacts with eNOS and leads to enzyme inhibition in a reversible process modulated by Ca2+-calmodulin (Michel, J. B., Feron, O., Sacks, D., and Michel, T. (1997) J. Biol. Chem. 272, 15583-15586). Caveolin also interacts with other structurally distinct signaling proteins via a specific region identified within the caveolin sequence (amino acids 82-101) that appears to subserve the role of a "scaffolding domain." We now report that the co-immunoprecipitation of eNOS with caveolin is completely and specifically blocked by an oligopeptide corresponding to the caveolin scaffolding domain. Peptides corresponding to this domain markedly inhibit nitric oxide synthase activity in endothelial membranes and interact directly with the enzyme to inhibit activity of purified recombinant eNOS expressed in Escherichia coli. The inhibition of purified eNOS by the caveolin scaffolding domain peptide is competitive and completely reversed by Ca2+-calmodulin. These studies establish that caveolin, via its scaffolding domain, directly forms an inhibitory complex with eNOS and suggest that caveolin inhibits eNOS by abrogating the enzyme's activation by calmodulin.

  4. Continuous determination of nitric oxide and nitrogen dioxide in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Yanagisawa, S; Yamate, N; Mitsuzawa, S; Mori, M

    1966-10-01

    Continuous determinations of nitric oxide and nitrogen dioxide in that atmospheric air by the use of a modified Saltzman reagent is described. Measurement was made intermittently, once every 30 min., by an automatic continuous analyzer equipped with a single-path colorimeter. The response of the analyzer was obtained as an average of the concentration of nitrogen oxides over a period of 25 min. Two bubblers were used for absorbing nitrogen oxides into the modified Saltzman reagent, whose transmittance was measured for the determination. One bubbler was designed to absorb nitrogen dioxide, and the other, nitric oxide plus nitrogen dioxide after the oxidation of the nitric oxide by permanganate. The oxidizing efficiency of the permanganate was 96-100%. The acetic acid in the Saltzman reagent was replaced with n-propyl alcohol in the modified Saltzman reagent; the spontaneous coloration and corrosive quality of the reagent was decreased by this substitution. The concentration of nitric oxide was obtained from the difference between the two responses of the analyzer, while the concentration of nitrogen dioxide could be read directly from the indication of the recorder. The transmittance ratio method was applied to the measurements, accurate determinations were possible, even at high blank values. Therefore, the reagent was used repeatedly by cycling it on the basis of measuring the difference in the coloration of the reagent before and after the absorption of nitrogen oxides. The analyzer could be used for a long period without changing the reagent.

  5. Inhaled nitric oxide for acute respiratory distress syndrome (ARDS) in children and adults

    DEFF Research Database (Denmark)

    Gebistorf, Fabienne; Karam, Oliver; Wetterslev, Jørn

    2016-01-01

    BACKGROUND: Acute hypoxaemic respiratory failure (AHRF) and mostly acute respiratory distress syndrome (ARDS) are critical conditions. AHRF results from several systemic conditions and is associated with high mortality and morbidity in individuals of all ages. Inhaled nitric oxide (INO) has been...

  6. of endothelial nitric oxide synthase gene and serum level of vascular ...

    African Journals Online (AJOL)

    uwerhiavwe

    Davignon and Ganz, 2004). NO is synthe- sized via a reaction that includes the conversion of L- arginine to L-citruline catalyzed by endothelial nitric oxide synthase (eNOS), which is one of the three isoforms of the enzyme (Mayer and Hemmens, 1997) ...

  7. Nitric oxide in a diesel engine : laser-based detection and interpretation

    NARCIS (Netherlands)

    Stoffels, G.G.M.

    1999-01-01

    Nitric oxide (NO) is one of the most polluting components in the exhaust gases of a diesel engines. Therefore, knowledge of the time and place where it is produced during the combustion process is of interest to find a way to reduce diesel engine emissions. Non-intrusive optical diagnostics, based

  8. Intercellular calcium signaling and nitric oxide feedback during constriction of rabbit renal afferent arterioles

    DEFF Research Database (Denmark)

    Uhrenholt, Torben Rene; Schjerning, J; Vanhoutte, Paul M. G.

    2007-01-01

    Vasoconstriction and increase in the intracellular calcium concentration ([Ca(2+)](i)) of vascular smooth muscle cells may cause an increase of endothelial cell [Ca(2+)](i), which, in turn, augments nitric oxide (NO) production and inhibits smooth muscle cell contraction. This hypothesis was test...

  9. Manipulation of nitric oxide in an animal model of acute liver injury ...

    African Journals Online (AJOL)

    We evaluated the impact of altering nitric oxide release on acute liver injury, the associated gut injury and bacterial translocation, at different time intervals. Methods: An acute rat liver injury model induced by D-galactosamine was used. Sprague Dawley rats were divided into four main groups: normal control, acute liver ...

  10. TWOPOT: a computer model of the two-pot extractive distillation concept for nitric acid

    International Nuclear Information System (INIS)

    Jubin, R.T.; Holland, W.D.; Counce, R.M.; Beckwith, D.R.

    1985-05-01

    A mathematical model, TWOPOT, of the ''two-pot'' extractive distillation concept for nitric acid concentration has been developed. Prediction from a computer simulation using this model shows excellent agreement with the experimental data. This model is recommended for use in the design of large-scale, similar-purpose equipment. 9 refs., 15 figs., 2 tabs

  11. Novel Insights into the Electrochemical Detection of Nitric Oxide in Biological Systems

    Czech Academy of Sciences Publication Activity Database

    Pekarová, Michaela; Lojek, Antonín; Hrbáč, J.; Kuchta, R.; Kadlec, J.; Kubala, Lukáš

    2014-01-01

    Roč. 60, č. 1 (2014), s. 8-12 ISSN 0015-5500 R&D Projects: GA MŠk(CZ) EE2.3.30.0030; GA ČR(CZ) GP13-40882P Institutional support: RVO:68081707 Keywords : nitric oxide * electrochemical detector * biological systems Subject RIV: BO - Biophysics Impact factor: 1.000, year: 2014

  12. Variations in exhaled nitric oxide concentration after three types of dives

    NARCIS (Netherlands)

    van Ooij, Pieter-Jan; Houtkooper, Antoinette; van Hulst, Rob

    2010-01-01

    An increase in exhaled nitric oxide concentration (FENO) occurs during an exacerbation of chronic obstructive lung disease or other inflammatory processes of the airway. Raised FENO levels are also observed during normobaric, mild hyperoxic exposures, whereas after hyperbaric hyperoxic exposure the

  13. Brightening of the global cloud field by nitric acid and the associated radiative forcing

    Directory of Open Access Journals (Sweden)

    R. Makkonen

    2012-08-01

    Full Text Available Clouds cool Earth's climate by reflecting 20% of the incoming solar energy, while also trapping part of the outgoing radiation. The effect of human activities on clouds is poorly understood, but the present-day anthropogenic cooling via changes of cloud albedo and lifetime could be of the same order as warming from anthropogenic addition in CO2. Soluble trace gases can increase water condensation to particles, possibly leading to activation of smaller aerosols and more numerous cloud droplets. We have studied the effect of nitric acid on the aerosol indirect effect with the global aerosol-climate model ECHAM5.5-HAM2. Including the nitric acid effect in the model increases cloud droplet number concentrations globally by 7%. The nitric acid contribution to the present-day cloud albedo effect was found to be −0.32 W m−2 and to the total indirect effect −0.46 W m−2. The contribution to the cloud albedo effect is shown to increase to −0.37 W m−2 by the year 2100, if considering only the reductions in available cloud condensation nuclei. Overall, the effect of nitric acid can play a large part in aerosol cooling during the following decades with decreasing SO2 emissions and increasing NOx and greenhouse gases.

  14. Nitric oxide formation in H2/CO syngas non-premixed jet flames

    NARCIS (Netherlands)

    Ranga Dinesh, K.K.J.; Richardson, E.S.; van Oijen, J.A.; Luo, K.H.; Jiang, X.

    2015-01-01

    Direct numerical simulations (DNS) of high hydrogen content (HHC) syngas nonpremixed jet flames have been carried out to study the nitric oxide (NO) formation. The detailed chemistry employed is the GRI 3.0 updated with the influence of the NCN radical chemistry using flamelet generated manifolds

  15. White Paper on Potential Hazards Associated with Contaminated Cheesecloth Exposed to Nitric Acid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hypes, Philip A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-20

    This white paper addresses the potential hazards associated with waste cheesecloth that has been exposed to nitric acid solutions. This issue was highlighted by the cleanup of a 100 ml leak of aqueous nitric acid solution containing Heat Source (HS) plutonium on 21 June 2016. Nitration of cellulosic material is a well-understood process due to industrial/military applications of the resulting material. Within the Department of Energy complex, nitric acids have been used extensively, as have cellulosic wipes. If cellulosic materials are nitrated, the cellulosic material can become ignitable and in extreme cases, reactive. We have chemistry knowledge and operating experience to support the conclusion that all current wastes are safe and compliant. There are technical questions worthy of further experimental evaluation. An extent of condition evaluation has been conducted back to 2004. During this time period there have been interruptions in the authorization to use cellulosic wipes in PF-4. Limited use has been authorized since 2007 (for purposes other than spill cleanup), so our extent of condition includes the entire current span of use. Our evaluation shows that there is no indication that process spills involving high molarity nitric acid were cleaned up with cheesecloth since 2007. The materials generated in the 21 June leak will be managed in a safe manner compliant with all applicable requirements.

  16. Chemical kinetic models for combustion of hydrocarbons and formation of nitric oxide

    Science.gov (United States)

    Jachimowski, C. J.; Wilson, C. H.

    1980-01-01

    The formation of nitrogen oxides NOx during combustion of methane, propane, and a jet fuel, JP-4, was investigated in a jet stirred combustor. The results of the experiments were interpreted using reaction models in which the nitric oxide (NO) forming reactions were coupled to the appropriate hydrocarbon combustion reaction mechanisms. Comparison between the experimental data and the model predictions reveals that the CH + N2 reaction process has a significant effect on NO formation especially in stoichiometric and fuel rich mixtures. Reaction models were assembled that predicted nitric oxide levels that were in reasonable agreement with the jet stirred combustor data and with data obtained from a high pressure (5.9 atm (0.6 MPa)), prevaporized, premixed, flame tube type combustor. The results also suggested that the behavior of hydrocarbon mixtures, like JP-4, may not be significantly different from that of pure hydrocarbons. Application of the propane combustion and nitric oxide formation model to the analysis of NOx emission data reported for various aircraft gas turbines showed the contribution of the various nitric oxide forming processes to the total NOx formed.

  17. Foliar loading and metabolic assimilation of dry deposited nitric acid air pollutants by trees

    Science.gov (United States)

    Pamela E. Padgett; Hillary Cook; Andrzej Bytnerowicz; Robert L. Heath

    2009-01-01

    Dry deposition of nitric acid vapor (HNO(3)) is a major contributor to eutrophication of natural ecosystems. Although soil fertilization by nitrogen deposition is considered to be the primary pathway for changes in plant nutrient status and shifts in ecological structure, the aerial portion of plants offer many times the surface area in which to...

  18. Decrease in emissions of nitric oxides during burning of Kuznetsk hard coal

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Gedike, I.A.; Lobov, G.V.

    1983-01-01

    Results are presented of introducing and studying the plan for gradual combustion of Kuznetsk hard coals on a BKZ-210-140 F type boiler. Supply of 16-18% theoretically necessary air through the nozzle of the tertiary injection made it possible to reduce 1.5-fold the emissions of nitric oxides without reducing the economy of the furnace process.

  19. Comparison of nitric oxide binding to different pure and mixed protoporphyrin IX monolayers

    NARCIS (Netherlands)

    Knoben, W.; Crego-Calama, M.; Brongersma, S.H.

    2012-01-01

    The nitric oxide (NO) binding properties of monolayers of four different protoporphyrins IX adsorbed on aluminum oxide surfaces have been investigated. XPS and AFM results are consistent with the presence of a monolayer of porphyrins, bound to the surface by their carboxylic acid groups and with the

  20. Influence of zirconium ion concentration in model extraction systems TBP - diluents - Zr+4 - nitric acid

    International Nuclear Information System (INIS)

    Rogoz, F.; Tlalka, M.

    1987-07-01

    In systems containing TBP, MBP, DBP and 1-butanol stable emulsions and precipitates are formed which separation is difficult in certain domain of concentration in zirconium ions. MPB and DBP increase stability of primary emulsion in kerosen and carbon tetrachloride but for different concentrations of nitric acid. Addition of 1-butanol decreases slightly the stability of primary emulsion [fr

  1. Corrosion behavior of ODS steels with several chromium contents in hot nitric acid solutions

    Science.gov (United States)

    Tanno, Takashi; Takeuchi, Masayuki; Ohtsuka, Satoshi; Kaito, Takeji

    2017-10-01

    Oxide dispersion strengthened (ODS) steel cladding tubes have been developed for fast reactors. Tempered martensitic ODS steels with 9 and 11 wt% of chromium (9Cr-, 11Cr-ODS steel) are the candidate material in research being carried out at JAEA. In this work, fundamental immersion tests and electrochemical tests of 9 to 12Cr-ODS steels were systematically conducted in various nitric acid solutions at 95 °C. The corrosion rate decreased exponentially with effective solute chromium concentration (Creff) and nitric acid concentration. Addition of vanadium (V) and ruthenium (Ru) also decreased the corrosion rate. The combination of low Creff and dilute nitric acid could not avoid the active mass dissolution during active domain at the beginning of immersion, and the corrosion rate was high. Higher Creff decreased the partial anodic current during the active domain and assisted the passivation of the surface of the steel. Concentrated nitric acid and addition of Ru and V increased partial cathodic current and shifted the corrosion potential to noble side. These effects should have prevented the active mass dissolution and decreased the corrosion rate.

  2. A method for nitric oxide radical scavenging properties of sulfur containing compounds.

    NARCIS (Netherlands)

    Vriesman, M.F.; Haenen, G.R.M.M.; Westerveld, G.J.; Paquay, J.B.G.; Voss, H.P.; Bast, A.

    1997-01-01

    A new method for the quantification of the nitric oxide (NO) scavenging activity of compounds in aqueous solutions is described using an amperometric NO sensor. After correction for the spontaneous degradation of NO, second-order rate kinetics of the scavenging reaction are observed.

  3. The effect of nitric oxide releasing cream on healing pressure ulcers

    Science.gov (United States)

    Saidkhani, Vahid; Asadizaker, Marziyeh; Khodayar, Mohammad Javad; Latifi, Sayed Mahmoud

    2016-01-01

    Background: Pressure ulcer is one of the main concerns of nurses in medical centers around the world, which, if untreated, causes irreparable problems for patients. In recent years, nitric oxide (NO) has been proposed as an effective method for wound healing. This study was conducted to determine the effect of nitric oxide on pressure ulcer healing. Materials and Methods: In this clinical trial, 58 patients with pressure ulcer at hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences were homogenized and later divided randomly into two groups of treatment (nitric oxide cream; n = 29) and control (placebo cream; n = 29). In this research, the data collection tool was the Pressure Ulcer Scale for Healing (PUSH). At the outset of the study (before using the cream), the patients' ulcers were examined weekly in terms of size, amount of exudates, and tissue type using the PUSH tool for 3 weeks. By integrating these three factors, wound healing was determined. Data were analyzed using SPSS. Results: Although no significant difference was found in terms of the mean of score size, the amount of exudates, and the tissue type between the two groups, the mean of total score (healing) between the two groups was statistically significant (P = 0.04). Conclusions: Nitric oxide cream seems to accelerate wound healing. Therefore, considering its easy availability and cost-effectiveness, it can be used for treating pressure ulcers in the future. PMID:27186212

  4. Adsorption of zirconium from nitric acid solutions on hydrated tin dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Tret' yakov, S Ya; Sharygin, L M; Egorov, Yu V

    1977-01-01

    Adsorption of zirconium from nitric acid solutions has been studied with the use of the labeled atom method on hydrated tin dioxide depending on the sorbate concentration, pH and prehistory of the solution. It has been found that adsorption behavior of zirconium essentially depends on its state in the solution.

  5. Formation of nitric oxide in an industrial burner measured by 2-D laser induced fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, A; Bombach, R; Kaeppeli, B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    We have performed two-dimensional Laser Induced Fluorescence (2-D LIF) measurements of nitric oxide and hydroxyl radical distributions in an industrial burner at atmospheric pressure. The relative 2-D LIF data of NO were set to an absolute scale by calibration with probe sampling combined with gas analysis. (author) 3 figs., 7 refs.

  6. Physiological responses of lichens to factorial fumigations with nitric acid and ozone

    Science.gov (United States)

    J. Riddell; P.E. Padgett; T. Nash

    2012-01-01

    This paper addresses the effects of gaseous nitric acid (HNO3) and ozone (O3), two important air pollutants, on six lichen species with different morphological, ecological, and biological characteristics. The treatment chambers were set up in a factorial design consisting of control chambers, chambers fumigated with HNO

  7. L-arginine increases nitric oxide and attenuates pressor and heart ...

    African Journals Online (AJOL)

    olayemitoyin

    heart rate responses to change in posture in sickle cell anemia subjects. 1 .... the standing position and measurements made immediately. Arterial ... pressure was the difference between systolic and diastolic ... Table 3. Effect of L-Arginine Supplementation on Blood Pressure Parameters, Plasma L-Arginine and Nitric Oxide.

  8. Quantitative laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine

    NARCIS (Netherlands)

    Verbiezen, K.; Klein-Douwel, R. J. H.; van Viet, A. P.; Donkerbroek, A. J.; Meerts, W. L.; Dam, N. J.; ter Meulen, J. J.

    2007-01-01

    We present quantitative, in-cylinder, UV-laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine. Processing of the raw fluorescence signals includes a detailed correction, based on additional measurements, for the effect of laser beam and fluorescence attenuation, and

  9. Nitric Oxide and Interlukin-6 Levels in Intellectual Disability Adults with Epilepsy

    Science.gov (United States)

    Carmeli, Eli; Beiker, Reut; Morad, Mohammed

    2009-01-01

    Nitric oxide (NO) and interlukin-6 (IL-6) are highly reactive mediators that have been shown to play different roles in a variety of different biological process. The role of NO and IL-6 in the neuropathogenesis of brain seizures is still questionable. In order to evaluate the role of NO and IL-6 in neurological disorders such as seizures, we…

  10. Medicinal chemistry and anti-inflammatory activity of nitric oxide-releasing NSAI drugs.

    Science.gov (United States)

    Koç And, Esra; Küçükgüzel, S Güniz

    2009-05-01

    Nitric Oxide, which acts as a non-specific cytotoxic mediator and a biological messenger on immunological competence, has been gaining significantly increasing importance. As an alternative to conventional NSAIDs having significant side effects, pharmacologically improved and therapeutically enhanced NO releasing non-steroidal anti-inflammatory drugs with less side effects are being planned to produce.

  11. Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

    Science.gov (United States)

    Stamler, J S; Jaraki, O; Osborne, J; Simon, D I; Keaney, J; Vita, J; Singel, D; Valeri, C R; Loscalzo, J

    1992-01-01

    We have recently shown that nitric oxide or authentic endothelium-derived relaxing factor generated in a biologic system reacts in the presence of specific protein thiols to form S-nitrosoprotein derivatives that have endothelium-derived relaxing factor-like properties. The single free cysteine of serum albumin, Cys-34, is particularly reactive toward nitrogen oxides (most likely nitrosonium ion) under physiologic conditions, primarily because of its anomalously low pK; given its abundance in plasma, where it accounts for approximately 0.5 mM thiol, we hypothesized that this plasma protein serves as a reservoir for nitric oxide produced by the endothelial cell. To test this hypothesis, we developed a methodology, which involves UV photolytic cleavage of the S--NO bond before reaction with ozone for chemiluminescence detection, with which to measure free nitric oxide, S-nitrosothiols, and S-nitrosoproteins in biologic systems. We found that human plasma contains approximately 7 microM S-nitrosothiols, of which 96% are S-nitrosoproteins, 82% of which is accounted for by S-nitroso-serum albumin. By contrast, plasma levels of free nitric oxide are only in the 3-nM range. In rabbits, plasma S-nitrosothiols are present at approximately 1 microM; 60 min after administration of NG-monomethyl-L-arginine at 50 mg/ml, a selective and potent inhibitor of nitric oxide synthetases, S-nitrosothiols decreased by approximately 40% (greater than 95% of which were accounted for by S-nitrosoproteins, and approximately 80% of which was S-nitroso-serum albumin); this decrease was accompanied by a concomitant increase in mean arterial blood pressure of 22%. These data suggest that naturally produced nitric oxide circulates in plasma primarily complexed in S-nitrosothiol species, principal among which is S-nitroso-serum albumin. This abundant, relatively long-lived adduct likely serves as a reservoir with which plasma levels of highly reactive, short-lived free nitric oxide can be

  12. The Consistency of Isotopologues of Ambient Atmospheric Nitric Acid in Passively Collected Samples

    Science.gov (United States)

    Bell, M. D.; Sickman, J. O.; Bytnerowicz, A.; Padgett, P.; Allen, E. B.

    2012-12-01

    Anthropogenic sources of nitrogen oxides have previously been shown to have distinctive isotopic signatures of oxygen and nitrogen. Nylon filters are currently used in passive sampling arrays to measure ambient atmospheric nitric acid concentrations and estimate deposition rates. This experiment measured the ability of nylon filters to consistently collect isotopologues of atmospheric nitric acid in the same ratios as they are present in the atmosphere. Samplers were deployed in continuous stirred tank reactors (CSTR) and at field sites across a nitrogen deposition gradient in Southern California. Filters were exposed over a four week period with individual filters being subjected to 1-4 week exposure times. Extracted nitric acid were measured for δ18O and δ15N ratios and compared for consistency based on length of exposure and amount of HNO3 collected. Filters within the CSTRs collected HNO3 at a consistent rate in both high and low concentration chambers. After two weeks of exposure, the mean δ18O values were within 0.5‰ of the δ18O of the source HNO3 solution. The mean of all weekly exposures were within 0.5‰ of the δ15N of the source solution, but after three weeks, the mean δ15N of adsorbed HNO3 was within 0.2‰. As the length of the exposure increased, the variability of measured delta values decreased for both elements. The field samplers collected HNO3 consistent with previously measured values along a deposition gradient. The mean δ18O at high deposition sites was 52.2‰ compared to 35.7‰ at the low deposition sites. Mean δ15N values were similar at all sites across the deposition gradient. Due to precipitation events occurring during the exposure period, the δ15N and δ18O of nitric acid were highly variable at all field sites. At single sites, changes in δ15N and δ18O were negatively correlated, consistent with two-sourcing mixing dynamics, but the slope of the regressions differed between high and low deposition sites. Anthropogenic

  13. Study of precipitation behaviour of Mo and Zr in nitric acid solution

    International Nuclear Information System (INIS)

    Lin Cansheng; Wang Xiaoying; Zhang Chonghai

    1992-01-01

    The precipitation behaviour of Mo and Zr which depends on the concentrations of Mo, Zr, nitric acid and temperature is studied. Precipitation, post-precipitation and ultracentrifugation experiments are made at 100 deg C, 80 deg C, 60 deg C, 40 deg C and room temperatures in the range of 0.6-6.0 mol/1 nitric acid. The experimental feeds are made up of molybdenum labelled with 99 Mo, zirconium labelled with 95 Zr and nitric acid solution. The feed is allowed to stand at constant temperature for some time for the observation of precipitation behaviour. The filtered precipitate and ultracentrifuged liquid is to be measured with HP (Ge)-multichannel analyser in order to determine the content of Mo, Zr and their mole ration in the precipitate and to find out whether there is colloid in the liquid. The results show that the mixed solution of Mo and Zr can produce precipitate and post-precipitate in nitric acid. If the filtrated liquid is allowed to stand for some time, precipitate can be produced again, until the concentration of Mo and Zr in the feed is too low to form precipitate, such as 2.5 x 10 -3 mol/1. If the concentration of nitric acid is less than 4.0 mol/1, the precipitation is produced easily and more precipitate is formed. Precipitation is slower in solutions which are more than 4.0 mol/1 in HNO 3 . The mole-ratio of Mo to Zr in the precipitate is 2 to 1 and it is not dependent on that ratio in the system

  14. Nitric Acid Revamp and Upgrading of the Alarm & Protection Safety System at Petrokemija, Croatia

    Directory of Open Access Journals (Sweden)

    Hoško, I.

    2012-04-01

    Full Text Available Every industrial production, particularly chemical processing, demands special attention in conducting the technological process with regard to the security requirements. For this reason, production processes should be continuously monitored by means of control and alarm safety instrumented systems. In the production of nitric acid at Petrokemija d. d., the original alarm safety system was designed as a combination of an electrical relay safety system and transistorized alarm module system. In order to increase safety requirements and modernize the technological process of nitric acid production, revamping and upgrading of the existing alarm safety system was initiated with a new microprocessor system. The newly derived alarm safety system, Simatic PCS 7, links the function of "classically" distributed control (DCS and logical systems in a common hardware and software platform with integrated engineering tools and operator interface to meet the minimum safety standards with safety integrity level 2 (SIL2 up to level 3 (SIL3, according to IEC 61508 and IEC 61511. This professional paper demonstrates the methodology of upgrading the logic of the alarm safety system in the production of nitric acid in the form of a logical diagram, which was the basis for a further step in its design and construction. Based on the mentioned logical diagram and defined security requirements, the project was implemented in three phases: analysis and testing, installation of the safety equipment and system, and commissioning. Developed also was a verification system of all safety conditions, which could be applied to other facilities for production of nitric acid. With the revamped and upgraded interlock alarm safety system, a new and improved safety boundary in the production of nitric acid was set, which created the foundation for further improvement of the production process in terms of improved analysis.

  15. Metagenomic analysis of nitrate-reducing bacteria in the oral cavity: implications for nitric oxide homeostasis.

    Science.gov (United States)

    Hyde, Embriette R; Andrade, Fernando; Vaksman, Zalman; Parthasarathy, Kavitha; Jiang, Hong; Parthasarathy, Deepa K; Torregrossa, Ashley C; Tribble, Gena; Kaplan, Heidi B; Petrosino, Joseph F; Bryan, Nathan S

    2014-01-01

    The microbiota of the human lower intestinal tract helps maintain healthy host physiology, for example through nutrient acquisition and bile acid recycling, but specific positive contributions of the oral microbiota to host health are not well established. Nitric oxide (NO) homeostasis is crucial to mammalian physiology. The recently described entero-salivary nitrate-nitrite-nitric oxide pathway has been shown to provide bioactive NO from dietary nitrate sources. Interestingly, this pathway is dependent upon oral nitrate-reducing bacteria, since humans lack this enzyme activity. This pathway appears to represent a newly recognized symbiosis between oral nitrate-reducing bacteria and their human hosts in which the bacteria provide nitrite and nitric oxide from nitrate reduction. Here we measure the nitrate-reducing capacity of tongue-scraping samples from six healthy human volunteers, and analyze metagenomes of the bacterial communities to identify bacteria contributing to nitrate reduction. We identified 14 candidate species, seven of which were not previously believed to contribute to nitrate reduction. We cultivated isolates of four candidate species in single- and mixed-species biofilms, revealing that they have substantial nitrate- and nitrite-reduction capabilities. Colonization by specific oral bacteria may thus contribute to host NO homeostasis by providing nitrite and nitric oxide. Conversely, the lack of specific nitrate-reducing communities may disrupt the nitrate-nitrite-nitric oxide pathway and lead to a state of NO insufficiency. These findings may also provide mechanistic evidence for the oral systemic link. Our results provide a possible new therapeutic target and paradigm for NO restoration in humans by specific oral bacteria.

  16. Serum ferritin, serum nitric oxide, and cognitive function in pediatric thalassemia major

    Directory of Open Access Journals (Sweden)

    Septiana Nur Qurbani

    2017-06-01

    Full Text Available Background Hemolysis and repeated blood transfusions in children with thalassemia major cause iron overload in various organs, including the brain, and may lead to neurodegeneration. Hemolysis also causes decreased levels of nitric oxide, which serves as a volume transmitter and slow dynamic modulation, leading to cognitive impairment. Objective To assess for correlations between serum ferritin as well as nitric oxide levels and cognitive function in children with thalassemia major.  Methods This analytical study with cross-sectional design on 40 hemosiderotic thalassemia major patients aged 6−14 years, was done at the Thalassemia Clinic in Dr. Hasan Sadikin Hospital, Bandung, West Java, from May to June 2015. Serum ferritin measurements were performed by an electrochemiluminescence immunoassay; serum nitric oxide was assayed by a colorimetric procedure based on Griess reaction; and cognitive function was assessed by the Wechsler Intelligence Scale for Children test. Statistical analysis was done using Spearman’s Rank correlation, with a significance value of 0.05. Results Abnormal values in verbal, performance, and full scale IQ were found in 35%, 57.5% and 57.5%, respectively. Serum nitric oxide level was significantly correlated with performance IQ (P=0.022, but not with verbal IQ (P=0.359 or full scale IQ (P=0.164. There were also no significant correlations between serum ferritin level and full scale, verbal, or performance IQ (P=0.377, 0.460, and 0.822, respectively. Conclusion Lower serum nitric oxide level is significantly correlated to lower cognitive function, specifically in the performance IQ category. However, serum ferritin level has no clear correlation with cognitive function.

  17. Metagenomic analysis of nitrate-reducing bacteria in the oral cavity: implications for nitric oxide homeostasis.

    Directory of Open Access Journals (Sweden)

    Embriette R Hyde

    Full Text Available The microbiota of the human lower intestinal tract helps maintain healthy host physiology, for example through nutrient acquisition and bile acid recycling, but specific positive contributions of the oral microbiota to host health are not well established. Nitric oxide (NO homeostasis is crucial to mammalian physiology. The recently described entero-salivary nitrate-nitrite-nitric oxide pathway has been shown to provide bioactive NO from dietary nitrate sources. Interestingly, this pathway is dependent upon oral nitrate-reducing bacteria, since humans lack this enzyme activity. This pathway appears to represent a newly recognized symbiosis between oral nitrate-reducing bacteria and their human hosts in which the bacteria provide nitrite and nitric oxide from nitrate reduction. Here we measure the nitrate-reducing capacity of tongue-scraping samples from six healthy human volunteers, and analyze metagenomes of the bacterial communities to identify bacteria contributing to nitrate reduction. We identified 14 candidate species, seven of which were not previously believed to contribute to nitrate reduction. We cultivated isolates of four candidate species in single- and mixed-species biofilms, revealing that they have substantial nitrate- and nitrite-reduction capabilities. Colonization by specific oral bacteria may thus contribute to host NO homeostasis by providing nitrite and nitric oxide. Conversely, the lack of specific nitrate-reducing communities may disrupt the nitrate-nitrite-nitric oxide pathway and lead to a state of NO insufficiency. These findings may also provide mechanistic evidence for the oral systemic link. Our results provide a possible new therapeutic target and paradigm for NO restoration in humans by specific oral bacteria.

  18. Nitric Oxide and ERK mediates regulation of cellular processes by Ecdysterone

    Energy Technology Data Exchange (ETDEWEB)

    Omanakuttan, Athira; Bose, Chinchu; Pandurangan, Nanjan; Kumar, Geetha B.; Banerji, Asoke; Nair, Bipin G., E-mail: bipin@amrita.edu

    2016-08-15

    The complex process of wound healing is a major problem associated with diabetes, venous or arterial disease, old age and infection. A wide range of pharmacological effects including anabolic, anti-diabetic and hepato-protective activities have been attributed to Ecdysterone. In earlier studies, Ecdysterone has been shown to modulate eNOS and iNOS expression in diabetic animals and activate osteogenic differentiation through the Extracellular-signal-Regulated Kinase (ERK) pathway in periodontal ligament stem cells. However, in the wound healing process, Ecdysterone has only been shown to enhance granulation tissue formation in rabbits. There have been no studies to date, which elucidate the molecular mechanism underlying the complex cellular process involved in wound healing. The present study, demonstrates a novel interaction between the phytosteroid Ecdysterone and Nitric Oxide Synthase (NOS), in an Epidermal Growth Factor Receptor (EGFR)-dependent manner, thereby promoting cell proliferation, cell spreading and cell migration. These observations were further supported by the 4-amino-5-methylamino- 2′ ,7′ -difluorofluorescein diacetate (DAF FM) fluorescence assay which indicated that Ecdysterone activates NOS resulting in increased Nitric Oxide (NO) production. Additionally, studies with inhibitors of both the EGFR and ERK, demonstrated that Ecdysterone activates NOS through modulation of EGFR and ERK. These results clearly demonstrate, for the first time, that Ecdysterone enhances Nitric Oxide production and modulates complex cellular processes by activating ERK1/2 through the EGF pathway. - Highlights: • Ecdysterone significantly enhances cell migration in a dose dependent manner. • Ecdysterone augments cell spreading during the initial phase of cell migration through actin cytoskeletal rearrangement. • Ecdysterone enhances cell proliferation in a nitric oxide dependent manner. • Ecdysterone enhances nitric oxide production via activation of EGFR

  19. Nitric Oxide and ERK mediates regulation of cellular processes by Ecdysterone

    International Nuclear Information System (INIS)

    Omanakuttan, Athira; Bose, Chinchu; Pandurangan, Nanjan; Kumar, Geetha B.; Banerji, Asoke; Nair, Bipin G.

    2016-01-01

    The complex process of wound healing is a major problem associated with diabetes, venous or arterial disease, old age and infection. A wide range of pharmacological effects including anabolic, anti-diabetic and hepato-protective activities have been attributed to Ecdysterone. In earlier studies, Ecdysterone has been shown to modulate eNOS and iNOS expression in diabetic animals and activate osteogenic differentiation through the Extracellular-signal-Regulated Kinase (ERK) pathway in periodontal ligament stem cells. However, in the wound healing process, Ecdysterone has only been shown to enhance granulation tissue formation in rabbits. There have been no studies to date, which elucidate the molecular mechanism underlying the complex cellular process involved in wound healing. The present study, demonstrates a novel interaction between the phytosteroid Ecdysterone and Nitric Oxide Synthase (NOS), in an Epidermal Growth Factor Receptor (EGFR)-dependent manner, thereby promoting cell proliferation, cell spreading and cell migration. These observations were further supported by the 4-amino-5-methylamino- 2′ ,7′ -difluorofluorescein diacetate (DAF FM) fluorescence assay which indicated that Ecdysterone activates NOS resulting in increased Nitric Oxide (NO) production. Additionally, studies with inhibitors of both the EGFR and ERK, demonstrated that Ecdysterone activates NOS through modulation of EGFR and ERK. These results clearly demonstrate, for the first time, that Ecdysterone enhances Nitric Oxide production and modulates complex cellular processes by activating ERK1/2 through the EGF pathway. - Highlights: • Ecdysterone significantly enhances cell migration in a dose dependent manner. • Ecdysterone augments cell spreading during the initial phase of cell migration through actin cytoskeletal rearrangement. • Ecdysterone enhances cell proliferation in a nitric oxide dependent manner. • Ecdysterone enhances nitric oxide production via activation of EGFR

  20. Nitrosation and Nitration of Fulvic Acid, Peat and Coal with Nitric Acid.

    Directory of Open Access Journals (Sweden)

    Kevin A Thorn

    Full Text Available Nitrohumic acids, produced from base extraction of coals and peats oxidized with nitric acid, have received considerable attention as soil ammendments in agriculture. The nitration chemistry however is incompletely understood. Moreover, there is a need to understand the reaction of nitric acid with natural organic matter (NOM in general, in the context of a variety of environmental and biogeochemical processes. Suwannee River NOM, Suwannee River fulvic acid, and Pahokee Peat fulvic acid were treated with 15N-labeled nitric acid at concentrations ranging from 15% to 22% and analyzed by liquid and solid state 15N NMR spectroscopy. Bulk Pahokee peat and Illinois #6 coal were also treated with nitric acid, at 29% and 40% respectively, and analyzed by solid state 15N NMR spectroscopy. In addition to nitro groups from nitration of aromatic carbon, the 15N NMR spectra of all five samples exhibited peaks attributable to nitrosation reactions. These include nitrosophenol peaks in the peat fulvic acid and Suwannee River samples, from nitrosation of phenolic rings, and N-nitroso groups in the peat samples, from nitrosation of secondary amides or amines, the latter consistent with the peat samples having the highest naturally abundant nitrogen contents. Peaks attributable to Beckmann and secondary reactions of the initially formed oximes were present in all spectra, including primary amide, secondary amide, lactam, and nitrile nitrogens. The degree of secondary reaction product formation resulting from nitrosation reactions appeared to correlate inversely with the 13C aromaticities of the samples. The nitrosation reactions are most plausibly effected by nitrous acid formed from the reduction of nitric acid by oxidizable substrates in the NOM and coal samples.

  1. Nitric Oxide Synthase and Cyclooxygenase Pathways: A Complex Interplay in Cellular Signaling.

    Science.gov (United States)

    Sorokin, Andrey

    2016-01-01

    The cellular reaction to external challenges is a tightly regulated process consisting of integrated processes mediated by a variety of signaling molecules, generated as a result of modulation of corresponding biosynthetic systems. Both, nitric oxide synthase (NOS) and cyclooxygenase (COX) systems, consist of constitutive forms (NOS1, NOS3 and COX-1), which are mostly involved in housekeeping tasks, and inducible forms (NOS2 and COX-2), which shape the cellular response to stress and variety of bioactive agents. The complex interplay between NOS and COX pathways can be observed at least at three levels. Firstly, products of NOS and Cox systems can mediate the regulation and the expression of inducible forms (NOS2 and COX-2) in response of similar and dissimilar stimulus. Secondly, the reciprocal modulation of cyclooxygenase activity by nitric oxide and NOS activity by prostaglandins at the posttranslational level has been shown to occur. Mechanisms by which nitric oxide can modulate prostaglandin synthesis include direct S-nitrosylation of COX and inactivation of prostaglandin I synthase by peroxynitrite, product of superoxide reaction with nitric oxide. Prostaglandins, conversely, can promote an increased association of dynein light chain (DLC) (also known as protein inhibitor of neuronal nitric oxide synthase) with NOS1, thereby reducing its activity. The third level of interplay is provided by intracellular crosstalk of signaling pathways stimulated by products of NOS and COX which contributes significantly to the complexity of cellular signaling. Since modulation of COX and NOS pathways was shown to be principally involved in a variety of pathological conditions, the dissection of their complex relationship is needed for better understanding of possible therapeutic strategies. This review focuses on implications of interplay between NOS and COX for cellular function and signal integration.

  2. Mechanism of vasoconstriction induced by chronic inhibition of nitric oxide in rats.

    Science.gov (United States)

    Bank, N; Aynedjian, H S; Khan, G A

    1994-09-01

    Either acute or chronic inhibition of nitric oxide synthesis by L-arginine analogues results in increases in mean arterial pressure and reductions in renal blood flow. The role of endogenous vasoconstrictors in mediating these effects is not entirely clear. In the present study, nitric oxide was inhibited in male Sprague-Dawley rats by oral administration of nitro-L-arginine for 3 weeks. At the end of this time, mean arterial pressure was 30 to 40 mm Hg higher than in normal controls, renal blood flow and glomerular filtration rate were 25% to 30% lower, and renal vascular resistance was markedly increased. Intravenous infusion of receptor antagonists for angiotensin II, thromboxane, epinephrine, and endothelin-1 had no significant effect on the hypertension. Inhibition of prostaglandin synthesis and furosemide-induced diuresis in the presence of angiotensin blockade also had no effect on blood pressure. Renal vascular resistance was also unaffected by these interventions, except that saralasin did reduce renal resistance in both control and nitric oxide-inhibited groups. However, the absolute level of renal vascular resistance remained higher in the latter group. Calcium channel blockade partially corrected blood pressure and renal resistance, but the levels remained significantly higher than in control animals. The findings are consistent with the view that the increase in vascular smooth muscle tone caused by inhibition of nitric oxide synthesis cannot be accounted for by overexpression of common endogenous vasoconstrictors. Rather, the generalized increase in vascular smooth muscle tone appears to be due to a direct effect of reduced nitric oxide availability, which may lead to an increase in intracellular calcium concentration or sensitivity.

  3. Thermodynamics and kinetics of thermal decomposition of dibutylalkyl and dipentylalkyl phosphonate-nitric acid systems

    International Nuclear Information System (INIS)

    Chandran, K.; Brahmananda, C.V.S.; Anthonysamy, S.; Srinivasan, T.G.; Ganesan, V.

    2013-01-01

    Tributyl phosphate (TBP) is used in the reprocessing industry for the separation of uranium and plutonium from the spent nuclear fuels by PUREX process. A variety of dialkylalky/phosphonates were synthesised and their extraction behaviour on actinides was studied in this laboratory. The superior extraction characteristics of phosphonates make them useful for several metal recovery applications in the nuclear fuel cycle. However, higher solubility of phosphonates in aqueous phase as compared to TBP, introduces higher chances of the formation of thermally active 'red oil' like substances during the evaporation of aqueous streams. Thermal stability of neat and nitric acid solvated homologues of four dibutylalkyl phosphonates namely, dibutylpropyl phosphonate (DBPrP), dibutylbutyl phosphonate (DBBP), dibutylpentyl phosphonate (DBPP), dibutylhexyl phosphonate (DBHeP), and two dipentylalkyl phosphonates viz. dipentylbutyl phosphonate (DPBP), dipentylhexyl phosphonate (DPHeP) were studied. Experiments were conducted using an adiabatic calorimeter in heat-wait-search mode. Various stoichiometry of nitric acid-solvated DBalP and DPalP were prepared by equilibrating the respective organic with 4-15.6 M nitric acid followed by separation. Neat DBalP and DPalP are stable up to the temperature of ∼ 555 K while their acid-solvates decomposed in the temperature range 380-403 K. The results also indicated that the presence of nitric acid accelerated the decomposition of phosphonates. Decomposition of these acid solvated phosphonates is found to be exothermic and follows first order kinetics. The onset temperature, adiabatic temperature rise, pressure rise, decomposition enthalpy and activation energy were found to strongly depend on the nitric acid content of the acid-solvates. The studies also indicate that dibutylalkyl and dipentylalkyl phosphonates are also prone to form 'red oil' like substances under extreme conditions and can lead to run-away reactions

  4. Experience with inhaled nitric oxide therapy in hypoxic respiratory failure of the newborn.

    Science.gov (United States)

    Sehgal, Arvind; Callander, Ian; Stack, Jacqueline; Momsen, Tracey; Sterling-Levis, Katy

    2005-01-01

    Respiratory diseases are the commonest cause of morbidity and mortality in newborns. Inhaled nitric oxide (iNO) has been shown to be effective in the management of persistent pulmonory hypertension of newborn (PPHN). To retrospectively analyse data to determine the effectiveness of inhaled nitric oxide (iNO) in the management of newborns with PPHN in terms of survival and changes in oxygenation status. Neo-natal data since inception of iNO therapy at the unit (past six years) was reviewed. Pertinent demographic and clinical information was collected from medical records of newborns that received inhaled nitric oxide therapy during their stay. Details of underlying illnesses, other therapeutic modalities, arterial blood gas, ventilatory and nitric oxide parameters were assessed and analysed to ascertain efficacy of iNO. A total of 36 babies (gestational age ranging from 24-41 weeks) received iNO during this period; two were excluded from final analysis. Overall survival rate was 80 percent. There was a statistically significant increase in systemic oxygenation (PaO2) from 41.1 +/- 2.1 mmHg to 128.5 +/- 13.2 mmHg and a decline in oxygenation index (OI) from 49.4 +/- 5.9 to 17.3 +/- 2.5, when assessed after four hours (P < 0.001). Mean duration of iNO therapy was 63 +/- 7.3 hours and the maximum methaemoglobin levels were noted to be 2.1 percent. Inhaled nitric oxide appears to be an effective rescue therapy for the management of PPHN associated with hypoxic respiratory failure. It is safe and well tolerated with no evidence of clinical or biochemical side effects.

  5. The production of nitric oxide in EL4 lymphoma cells overexpressing growth hormone.

    Science.gov (United States)

    Arnold, Robyn E; Weigent, Douglas A

    2003-01-01

    Growth hormone (GH) is produced by immunocompetent cells and has been implicated in the regulation of a multiplicity of functions in the immune system involved in growth and activation. However, the actions of endogenous or lymphocyte GH and its contribution to immune reactivity when compared with those of serum or exogenous GH are still unclear. In the present study, we overexpressed lymphocyte GH in EL4 lymphoma cells, which lack the GH receptor (GHR), to determine the role of endogenous GH in nitric oxide (NO) production and response to genotoxic stress. Western blot analysis demonstrated that the levels of GH increased approximately 40% in cells overexpressing GH (GHo) when compared with cells with vector alone. The results also show a substantial increase in NO production in cells overexpressing GH that could be blocked by N(G)-monomethyl-L-arginine (L-NMMA), an L-arginine analogue that competitively inhibits all three isoforms of nitric oxide synthase (NOS). No evidence was obtained to support an increase in peroxynitrite in cells overexpressing GH. Overexpression of GH increased NOS activity, inducible nitric oxide synthase (iNOS) promoter activity, and iNOS protein expression, whereas endothelial nitric oxide synthase and neuronal nitric oxide synthase protein levels were essentially unchanged. In addition, cells overexpressing GH showed increased arginine transport ability and intracellular arginase activity when compared with control cells. GH overexpression appeared to protect cells from the toxic effects of the DNA alkylating agent methyl methanesulfonate. This possibility was suggested by maintenance of the mitochondrial transmembrane potential in cells overexpressing GH when compared with control cells that could be blocked by L-NMMA. Taken together, the data support the notion that lymphocyte GH, independently of the GH receptor, may play a key role in the survival of lymphocytes exposed to stressful stimuli via the production of NO.

  6. Determination of small amounts of nitric acid in the presence of large amounts of uranium (VI) and extraction of nitric acid into TBP solutions highly loaded with uranyl nitrate

    International Nuclear Information System (INIS)

    Kolarik, Z.; Schuler, R.

    1982-10-01

    A new method for the determination of small amounts of nitric acid in the presence of large amounts of uranium(VI) was elaborated. The method is based on the precipitation of uranium(VI) as iodate and subsequent alkalimetric titration of the acid in the supernatant. The extraction of nitric acid and uranium(VI) with 30% TBP in dodecane was studied at high loading of the organic phase with uranyl nitrate and at 25, 40 and 60 0 C. The results are compared with available published data on the extraction of nitric acid under similar conditions. (orig.) [de

  7. Stimulation of nitric oxide synthesis by the aqueous extract of Panax ginseng root in RAW 264.7 cells.

    Science.gov (United States)

    Friedl, R; Moeslinger, T; Kopp, B; Spieckermann, P G

    2001-12-01

    1. In this study, we investigated the effect of Panax ginseng root aqueous extracts upon inducible nitric oxide synthesis in RAW 264.7 cells. Panax ginseng root extract has been used in the Asian world for centuries as a traditional herb to enhance physical strength and resistance and is becoming more and more popular in Europe and North America. 2. Incubation of murine macrophages (RAW 264.7 cells) with increasing amounts of aqueous extracts of Panax ginseng (0.05 - 0.8 microg microl(-1)) showed a dose dependent stimulation of inducible nitric oxide synthesis. 3. Polysaccharides isolated from Panax ginseng showed strong stimulation of inducible nitric oxide synthesis, whereas a triterpene-enriched fraction from an aqueous extract of Panax ginseng did not show any stimulation. 4. Inducible nitric oxide synthase protein expression was enhanced in a dose dependent manner as revealed by immunoblotting when cells were incubated with increasing amounts of Panax ginseng extract. This was associated with an incline in inducible nitric oxide synthase mRNA-levels as determined by semiquantitative polymerase chain reaction and electromobility shift assay studies indicated enhanced nuclear factor-kappaB DNA binding activity. 5. As nitric oxide plays an important role in immune function, Panax ginseng treatment could modulate several aspects of host defense mechanisms due to stimulation of the inducible nitric oxide synthase.

  8. Effect of selective inhibition of renal inducible nitric oxide synthase on renal blood flow and function in experimental hyperdynamic sepsis.

    Science.gov (United States)

    Ishikawa, Ken; Calzavacca, Paolo; Bellomo, Rinaldo; Bailey, Michael; May, Clive N

    2012-08-01

    Nitric oxide plays an important role in the control of renal blood flow and renal function. In sepsis, increased levels of inducible nitric oxide synthase produce excessive nitric oxide, which may contribute to the development of acute kidney injury. We, therefore, examined the effects of intrarenal infusion of selective inducible nitric oxide synthase inhibitors in a large animal model of hyperdynamic sepsis in which acute kidney injury occurs in the presence of increased renal blood flow. Prospective crossover randomized controlled interventional studies. University-affiliated research institute. Twelve unilaterally nephrectomized Merino ewes. Infusion of a selective (1400W) and a partially selective inducible nitric oxide synthase inhibitor (aminoguanidine) into the renal artery for 2 hrs after the induction of sepsis, and comparison with a nonselective inhibitor (Nω-nitro-L-arginine methyl ester). In sheep with nonhypotensive hyperdynamic sepsis, creatinine clearance halved (32 to 16 mL/min, ratio [95% confidence interval] 0.51 [0.28-0.92]) despite increased renal blood flow (241 to 343 mL/min, difference [95% confidence interval] 102 [78-126]). Infusion of 1400W did not change renal blood flow, urine output, or creatinine clearance, whereas infusion of Nω-nitro-L-arginine methyl ester and a high dose of aminoguanidine normalized renal blood flow, but did not alter creatinine clearance. In hyperdynamic sepsis, intrarenal infusion of a highly selective inducible nitric oxide synthase inhibitor did not reduce the elevated renal blood flow or improve renal function. In contrast, renal blood flow was reduced by infusion of a nonselective NOS inhibitor or a high dose of a partially selective inducible nitric oxide synthase inhibitor. The renal vasodilatation in septic acute kidney injury may be due to nitric oxide derived from the endothelial and neural isoforms of nitric oxide synthase, but their blockade did not restore renal function.

  9. Corrosion mechanism of Z3 CN18.10 stainless steel in the presence of nitric acid condensates

    International Nuclear Information System (INIS)

    Balbaud, Fanny

    1998-01-01

    In installations handling concentrated boiling nitric acid, a severe intergranular corrosion can sometimes occur in condensation zones constituted of non-sensitized Z3 CN 18.10 stainless steel. Corrosion tests in reactors and in a specific loop, CIRCE, allowed to specify the conditions of occurrence of this type of corrosion and showed the similitude with the corrosion in non-renewed liquid nitric acid: the specific parameters linked to the condensate phase are the high ratio metallic surface area to volume of condensate and the low renewing rate which induce a concentration of oxidation products of the metal and of reduction products of nitric acid. The initiation of the intergranular corrosion is attributed to the increase in the reduction rate of nitric acid by an autocatalytic mechanism which was demonstrated by electrochemical measurements on platinum and on stainless steel. The reduction mechanism involves a charge transfer step where nitrous acid, the electro-active species, is reduced into nitrogen monoxide and a chemical regeneration reaction of nitrous acid. The thermodynamic study led to a representation of the chemical and electrochemical properties of nitric acid. This study allowed also to determine the Gibbs free energy of formation of nitrous acid in solution in concentrated nitric acid at 100 deg. C. The diagram, constructed in coordinates log(P O 2 ) / [-log(P HNO 3 )] or E eXperimental / [-log(P HNO 3 )], shows that the final reduction product of nitric acid depends on the concentration of nitric acid: at 100 deg. C, NO is obtained for concentrations lower than 8 mol.L -1 and NO 2 is obtained for higher concentrations. All these results allowed to propose a corrosion mechanism of Z3 CN 18.10 stainless steel in the presence of nitric acid condensates. [fr

  10. Study of plutonium IV elution from macromolecular anion exchange resin by 0.5 M nitric acid

    International Nuclear Information System (INIS)

    Nadkarni, M.N.; Mayankutty, P.C.; Pillai, N.S.; Shinde, S.S.

    1976-01-01

    Preliminary studies indicated that macroreticular resins possess more or less the same capacities and absorption characteristics for thorium, uranium and plutonium from nitric acid solutions as the conventional resins. Detailed studies were, then, conducted. It was found that Pu(IV) can be loaded on the macroreticular anion exchange resin, Amberlyst A-26 from 7.2 M nitric acid in much the same way as Dowex 1x4. It was also observed that the elution of Pu(IV) from Amberlyst A-26 by 0.5 M nitric acid is much more rapid and quantitative than from Dowex 1x4. (author)

  11. Involvement of beta 3-adrenoceptor in altered beta-adrenergic response in senescent heart: role of nitric oxide synthase 1-derived nitric oxide.

    Science.gov (United States)

    Birenbaum, Aurélie; Tesse, Angela; Loyer, Xavier; Michelet, Pierre; Andriantsitohaina, Ramaroson; Heymes, Christophe; Riou, Bruno; Amour, Julien

    2008-12-01

    In senescent heart, beta-adrenergic response is altered in parallel with beta1- and beta2-adrenoceptor down-regulation. A negative inotropic effect of beta3-adrenoceptor could be involved. In this study, the authors tested the hypothesis that beta3-adrenoceptor plays a role in beta-adrenergic dysfunction in senescent heart. beta-Adrenergic responses were investigated in vivo (echocardiography-dobutamine, electron paramagnetic resonance) and in vitro (isolated left ventricular papillary muscle, electron paramagnetic resonance) in young adult (3-month-old) and senescent (24-month-old) rats. Nitric oxide synthase (NOS) immunolabeling (confocal microscopy), nitric oxide production (electron paramagnetic resonance) and beta-adrenoceptor Western blots were performed in vitro. Data are mean percentages of baseline +/- SD. An impaired positive inotropic effect (isoproterenol) was confirmed in senescent hearts in vivo (117 +/- 23 vs. 162 +/- 16%; P < 0.05) and in vitro (127 +/- 10 vs. 179 +/- 15%; P < 0.05). In the young adult group, the positive inotropic effect was not significantly modified by the nonselective NOS inhibitor N-nitro-L-arginine methylester (L-NAME; 183 +/- 19%), the selective NOS1 inhibitor vinyl-L-N-5(1-imino-3-butenyl)-L-ornithine (L-VNIO; 172 +/- 13%), or the selective NOS2 inhibitor 1400W (183 +/- 19%). In the senescent group, in parallel with beta3-adrenoceptor up-regulation and increased nitric oxide production, the positive inotropic effect was partially restored by L-NAME (151 +/- 8%; P < 0.05) and L-VNIO (149 +/- 7%; P < 0.05) but not by 1400W (132 +/- 11%; not significant). The positive inotropic effect induced by dibutyryl-cyclic adenosine monophosphate was decreased in the senescent group with the specific beta3-adrenoceptor agonist BRL 37344 (167 +/- 10 vs. 142 +/- 10%; P < 0.05). NOS1 and NOS2 were significantly up-regulated in the senescent rat. In senescent cardiomyopathy, beta3-adrenoceptor overexpression plays an important role in the

  12. Nitric Oxide - Its Importance in Swallowing, Inflammatory Bowel Disease and Cirrhotic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    ABR Thomson

    2001-01-01

    Full Text Available Nitric oxide is a neurotransmitter found in the central and peripheral nervous systems. Nitric oxide synthase (NOS is localized in the central nervous system, including the nucleus of the solitary tract, nucleus ambiguus and dorsal motor nucleus of the vagus. These are regions that are implicated in the central control of swallowing and esophageal motility. In rats and rabbits, NOS has been shown to be present in the nucleus subcentralis of the nucleus of the solitary tract, and is thought to be responsible for the central programming of the striated muscle component of esophageal peristalsis. Beyak and co-workers from the University of Toronto, Toronto, Ontario provided evidence that the L-arginine-nitric oxide pathway is implicated in the central control of swallowing and esophageal motility. They studied oropharyngeal swallowing as well as esophageal peristalsis, and determined the functional role of brain stem nitric oxide by examining the effects of blockade of central nervous system NOS on swallowing, and on primary and secondary peristalsis. Administering NOS inhibitors intravenously or intracerebroventricularly into the fourth ventricle produced a number of oropharyngeal swallows and induced primary peristalsis in the smooth muscle portion of the esophageal body. NOS reduced the number of oropharyngeal swallows and the incidence of primary peristalsis in both smooth and striated muscle, and reduced the amplitude of peristalsis and smooth muscle contraction. This suggests that nitric oxide is a functional neurotransmitter in the central pattern generator responsible for swallowing and the central control of esophageal peristalsis. Peripherally administered NOS inhibitor can access structures within the blood-brain barrier to affect neuronal activity and physiological function. The central pattern generated for swallowing and esophageal peristalsis is suggested to be a serial network of linked neurons within the nucleus of the solitary

  13. Investigation of the direct and indirect electrochemical oxidation of hydrazine in nitric acid medium on platinum

    International Nuclear Information System (INIS)

    Cames, B.

    1997-01-01

    In nuclear fuel processing by the PUREX process, the purification of plutonium in nitric acid medium requires the oxidation of Pu(III) to Pu(IV), and of hydrazinium nitrate to nitrogen. The study helped to characterize the electrochemical behavior of the oxidation of hydrazinium nitrate and the reduction of nitric acid to nitrous acid, a compound which can chemically oxidize hydrazinium nitrate and Pu(III). Electro-analytical studies on polycrystalline platinum showed that hydrazine is oxidized in two potential zones, which depend on the surface texture of the platinum anode. Electrolysis in separate compartments, carried out in medium-acid media (2 and 4 mo/l) in the potential zone where these processes take place, showed that, at 0.9 V/ECS, the hydrazine oxidation reactions involved are: a four-electron process (75 %) with nitrogen formation and a one-electron process (25 %) with formation of nitrogen and ammonium ion. By contrast, electrolysis carried out at 0.65 V/ECS (with reactivation of the electrode at - 0.2 V/ECS to remove the poison from the platinum) allowed the selective oxidation of hydrazine to nitrogen by the four-electron reaction. Nitric acid can only be reduced to nitrous acid in the absence of hydrazine. For medium-acid media (≤ 6 mol/l), this reaction takes place at potentials below - 0.2 V/ECS. However, the production rate of nitrous acid (partial order 0 with respect to nitric acid) is very low compared with the values obtained for strongly-acid media (6 to 10 mol/l) at the potential of - 0.1 V/ECS. Note that, in concentrated nitric medium, the selectivity of the reduction reaction is 47 to 85 % for nitrous acid, depending on the nitric acid concentration (6 to 10 mol/l) and the potential imposed (- 0.1 ≤ E ≤ 0.6 V/ECS). A kinetic study helped to determine the hydrazine oxidation rates as a function of the operating conditions. In all cases, the reaction rate is of partial order 0 with respect to hydrazine. These studies accordingly

  14. Modeling the solar cycle change in nitric oxide in the thermosphere and upper mesosphere

    International Nuclear Information System (INIS)

    Fuller-Rowell, T.J.

    1993-01-01

    Measurements from the Solar Mesosphere Explorer (SME) satellite have shown that low-latitude nitric oxide densities at 110 km decrease by about a factor of 8 from January 1982 to April 1985. This time period corresponds to the descending phase of the last solar cycle where the monthly smoothed sunspot number decreased from more than 150 to less than 25. In addition, nitric oxide was observed to vary by a factor of 2 over a solar rotation, during high solar activity. A one-dimensional, globally averaged model of the thermosphere and upper mesosphere has been used to study the height distribution of nitric oxide (NO) and its response to changes in the solar extreme ultraviolet radiation (EUV) through the solar cycle and over a solar rotation. The primary source of nitric oxide is the reaction of excited atomic nitrogen, N( 2 D), with molecular oxygen. The atomic nitrogen is created by a number of ion-neutral reactions and by direct dissociation of molecular nitrogen by photons and photoelectrons. The occurrence of the peak nitric oxide density at or below 115 km is a direct consequence of ionization and dissociation of molecular nitrogen by photoelectrons, which are produced by the solar flux below 30.0 nm (XUV). Nitric oxide is shown to vary over the solar cycle by a factor of 7 at low latitudes in the lower thermosphere E region, due to the estimated change in the solar EUV flux, in good agreement with the SME satellite observations. The NO density is shown to be strongly dependent on the temperature profile in the lower thermosphere and accounts for the difference between the current model and previous work. Wavelengths less than 1.8 nm have little impact on the NO profile. A factor of 3 change in solar flux below 5.0 nm at high solar activity produced a factor of 2 change in the peak NO density, consistent with SME observations over a solar rotation; this change also lowered the peak to 100 km, consistent with rocket data. 52 refs., 10 figs., 5 tabs

  15. Nitric Oxide: The Wonder Molecule -R-ES-O-N-A-N--CE--I-A-p-r-il-2 ...

    Indian Academy of Sciences (India)

    Sciences and Biology at ... cancer and diabetes mellitus to coronary artery disease. (heart attack) and hypertension. Nitric oxide (NO), an inorganic molecule formed by vascular ... cell types from which they were first cloned: neuronal NOS.

  16. Mechanism of the extraction of nitric acid and water by organic solutions of tertiary alkyl-amines

    International Nuclear Information System (INIS)

    Gourisse, D.

    1966-06-01

    The micellar aggregation of tri-alkyl-ammonium nitrates in low polarity organic solvents has been verified by viscosity, conductivity and sedimentation velocity measurements. The aggregation depends upon the polarity of solvent, the length of the alkyl radicals and the organic concentration of the various constituents (tri-alkyl-ammonium nitrate, tri-alkyl-amine, nitric acid, water). The amine salification law has been established and the excess nitric acid and water solubilities in the organic solutions have been measured. Nitric acid and water are slightly more soluble in micellar organic solutions than in molecular organic solutions. A description of excess nitric acid containing tri-alkyl-ammonium nitrate solutions is proposed. (author) [fr

  17. GOZCARDS Source Data for Nitric Acid Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOZCARDS Source Data for Nitric Acid Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozSmlpHNO3) contains zonal means and related...

  18. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V003 (ML2HNO3) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  19. MLS/Aura Level 2 Nitric Acid (HNO3) Mixing Ratio V004 (ML2HNO3) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HNO3 is the EOS Aura Microwave Limb Sounder (MLS) standard product for nitric acid derived from radiances measured by the 240 GHz radiometer at and below 10 hPa,...

  20. GOZCARDS Merged Data for Nitric Acid Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOZCARDS Merged Data for Nitric Acid Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpHNO3) contains zonal means and related...

  1. Investigating nitric oxide signalling involvement in the antidepressant action of ketamine

    DEFF Research Database (Denmark)

    Liebenberg, Nico; Müller, Heidi Kaastrup; Elfving, Betina

    2012-01-01

    Stress-induced excessive glutamate transmission at N-methyl-D-aspartate receptors (NMDA-R’s) may underlie a primary mechanism in the physiology that leads to depression, and ketamine, an NMDA-R antagonist, has been shown to rapidly relieve depression in humans. A number of downstream mechanisms...... have been suggested to mediate the antidepressant action of ketamine, including the activation of extracellular-signal-regulated kinases 1/2 (ERK1/2), protein kinase B (or Akt) and the mammalian target of rapamycin (mTOR). However, the mechanism(s) that are affected immediately downstream of NMDA......-R’s remain unclear. Neuronal nitric oxide synthase (nNOS) is directly coupled to and activated by NMDA-R’s, and the uncoupling of the nNOS-NMDA-R complex prevents NMDA-R-mediated excitotoxicity. Therefore, we investigated whether the antidepressant mechanism of ketamine involves the inhibition of nitric...

  2. Evaluation of the Magnesium Hydroxide Treatment Process for Stabilizing PFP Plutonium/Nitric Acid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Mark A.; Schmidt, Andrew J.; Delegard, Calvin H.; Silvers, Kurt L.; Baker, Aaron B.; Gano, Susan R.; Thornton, Brenda M.

    2000-09-28

    This document summarizes an evaluation of the magnesium hydroxide [Mg(OH)2] process to be used at the Hanford Plutonium Finishing Plant (PFP) for stabilizing plutonium/nitric acid solutions to meet the goal of stabilizing the plutonium in an oxide form suitable for storage under DOE-STD-3013-99. During the treatment process, nitric acid solutions bearing plutonium nitrate are neutralized with Mg(OH)2 in an air sparge reactor. The resulting slurry, containing plutonium hydroxide, is filtered and calcined. The process evaluation included a literature review and extensive laboratory- and bench-scale testing. The testing was conducted using cerium as a surrogate for plutonium to identify and quantify the effects of key processing variables on processing time (primarily neutralization and filtration time) and calcined product properties.

  3. Calcium mobilization in HeLa cells induced by nitric oxide.

    Science.gov (United States)

    Huang, Yimei; Zheng, Liqin; Yang, Hongqin; Chen, Jiangxu; Wang, Yuhua; Li, Hui; Xie, Shusen

    2014-01-01

    Nitric oxide (NO) has been proposed to be involved in tumor growth and metastasis. However, the mechanism by which nitric oxide modulates cancer cell growth and metastasis on cellular and molecular level is still not fully understood. This work utilized confocal microscopy and fluorescence microplate reader to investigate the effects of exogenous NO on the mobilization of calcium, which is one of the regulators of cell migration, in HeLa cells. The results show that NO elevates calcium in concentration-dependent manner in HeLa cells. And the elevation of calcium induced by NO is due to calcium influx and calcium release from intracellular calcium stores. Moreover, calcium release from intracellular stores is dominant. Furthermore, calcium release from mitochondria is one of the modulation pathways of NO. These findings would contribute to recognizing the significance of NO in cancer cell proliferation and metastasis. © Wiley Periodicals, Inc.

  4. The influence of nitric oxide and mercury chloride on leaf mesophyll structure under natural drought conditions

    Directory of Open Access Journals (Sweden)

    Mykola M. Musiyenko

    2012-03-01

    Full Text Available It is established that under natural drought conditions starch was accumulated in the central part of chloroplasts of mesophyll cells and chloroplasts were localized on the periphery of cells at plasmalemma. After treatment wheat plants by nitric oxide donor the decreasing of starch deposits number and close contacts between chloroplasts were indicated, elongated nucleus was localized in the centre of cells. After treatment wheat plant by mercury chloride chloroplasts in the cells lost their oval shape and contacts, increased eventually deposition of starch, indicating the acceleration of aging tissues. Thus, nitric oxide in drought conditions reduced the destructive effect of drought on mesophyll cells, and mercury chloride caused deformation of the membrane cell.

  5. Gastroprotective Effect of Geopropolis from Melipona scutellaris Is Dependent on Production of Nitric Oxide and Prostaglandin

    Directory of Open Access Journals (Sweden)

    Jerônimo Aparecido Ribeiro-Junior

    2015-01-01

    Full Text Available The aim of this study was to evaluate the gastroprotective activity of ethanolic extract of geopropolis (EEGP from Melipona scutellaris and to investigate the possible mechanisms of action. The gastroprotective activity of the EEGP was evaluated using model ulcer induced by ethanol. To elucidate the possible mechanisms of action, we investigated the involvement of the nonprotein sulfhydryl (NP-SH groups, nitric oxide and prostaglandins. In addition, the antisecretory activity of EEGP was also evaluated by pylorus ligated model. The EEGP orally administrated (300 mg/kg reduced the ulcerative lesions induced by the ethanol (P0.05. These results support the alternative medicine use of geopropolis as gastroprotective and the activities observed show to be related to nitric oxide and prostaglandins production.

  6. Kinetic study of dilute nitric acid treatment of corn stover at relatively high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, R.; Lu, X.; Liu, Y.; Wang, X.; Zhang, S. [Tianjin University, School of Environmental Science and Technology, Tianjin (China)

    2011-03-15

    Corn stover was hydrolyzed using dilute nitric acid at 150 C. Several concentrations of HNO{sub 3} (0.2, 0.4 and 0.6 wt-%) and reaction times (0-60 min) were evaluated. The kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, arabinose, acetic acid, and furfural in the hydrolysates were determined. The hydrolysates obtained from corn stover can be used to produce methane by an anaerobic fermentation process. Thus, the hydrolysis process of corn stover using dilute nitric acid can be conceived as the first stage of an integrated strategy for corn stover utilization. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Nitric oxide-sphingolipid interplays in plant signalling: a new enigma from the Sphinx?

    Directory of Open Access Journals (Sweden)

    Isabelle eGuillas

    2013-09-01

    Full Text Available Nitric oxide (NO emerged as one of the major signalling molecules operating during plant development and plant responses to its environment. Beyond the identification of the direct molecular targets of NO, a series of studies considered its interplay with other actors of signal transduction and the integration of nitric oxide into complex signalling networks. Beside the close relationships between NO and calcium or phosphatidic acid signalling pathways that are now well-established, recent reports paved the way for interplays between NO and sphingolipids. This mini-review summarises our current knowledge of the influence NO and sphingolipids might exert on each other in plant physiology. Based on comparisons with examples from the animal field, it further indicates that, although sphingolipid-NO interplays are common features in signalling networks of eukaryotic cells, the underlying mechanisms and molecular targets significantly differ.

  8. Flotation-nitric acid leach procedure for increasing uranium recovery from a refractory ore

    International Nuclear Information System (INIS)

    Carnahan, T.G.; Lei, K.P.V.

    1979-01-01

    The Bureau of Mines investigated a flotation-nitric acid leach procedure as part of the goal to maximize minerals and metals recovered from primary and secondary domestic resources. Studies were conducted on an ore that contained carbon-bearing and sulfide mineralization that rendered a portion of the ore refractory (resistant) to conventional leaching technology. The procedure investigated for treating the ore consisted of the following: (1) separation by flotation of the carbonaceous and sulfidic components from the ore, (2) leaching the flotation concentrate with nitric acid at 100 0 to 110 0 C, (3) leaching the flotation tailings with sulfuric acid, and (4) processing the combined leached slurries in a conventional manner to recover yellow cake. In step 2, HNO 3 is converted to gaseous products from which it is regenerated by reacting these products with air and water for further leaching. An overall uranium extraction of 96% was achieved by this procedure

  9. Evaporation of iodine from nitric acid with the aid of peroxide

    International Nuclear Information System (INIS)

    Cathers, G.I.; Shipman, C.J.

    1975-01-01

    Traces of radioactive iodine with a concentration of 5 x 10 -4 M or less that remained in nitric acid solution after reprocessing of nuclear fuels can, without great apparatus effort, be distilled off as hydrogen iodide by continuous addition of hydrogen peroxide to the solution boiling at about 105 0 C to 1,15 0 C, and then be separated as elementary iodine. Starting from a 4 to 6 molecular nitric acid solution, the H 2 O 2 -concentration amounts to 0.012 percentage by weight and is kept at this level during the entire distillation process. The iodine concentration is also profitably kept at the level of the starting solution by adding non-radioactive iodine, since an isotopec exchange of radioactive iodine bound in organic impurities is advanced in that way. (UWI) [de

  10. Gastroprotective Effect of Geopropolis from Melipona scutellaris Is Dependent on Production of Nitric Oxide and Prostaglandin.

    Science.gov (United States)

    Ribeiro-Junior, Jerônimo Aparecido; Franchin, Marcelo; Cavallini, Miriam Elias; Denny, Carina; de Alencar, Severino Matias; Ikegaki, Masaharu; Rosalen, Pedro Luiz

    2015-01-01

    The aim of this study was to evaluate the gastroprotective activity of ethanolic extract of geopropolis (EEGP) from Melipona scutellaris and to investigate the possible mechanisms of action. The gastroprotective activity of the EEGP was evaluated using model ulcer induced by ethanol. To elucidate the possible mechanisms of action, we investigated the involvement of the nonprotein sulfhydryl (NP-SH) groups, nitric oxide and prostaglandins. In addition, the antisecretory activity of EEGP was also evaluated by pylorus ligated model. The EEGP orally administrated (300 mg/kg) reduced the ulcerative lesions induced by the ethanol (P 0.05). These results support the alternative medicine use of geopropolis as gastroprotective and the activities observed show to be related to nitric oxide and prostaglandins production.

  11. Nitric oxide in plants: an assessment of the current state of knowledge

    DEFF Research Database (Denmark)

    Mur, Luis A J; Mandon, Julien; Persijn, Stefan

    2013-01-01

    Background and aims After a series of seminal works during the last decade of the 20th century nitric oxide (NO) is now firmly placed in the pantheon of plant signals. NO acts in plant-microbe interactions, responses to abiotic stress, stomatal regulation and a range of developmental processes...... of NO production from DEANO (diethylamine nitric oxide), S-nitrosoglutathione (GSNO) and sodium nitroprusside (SNP) following infiltration of tobacco leaves which could aid workers in their experiments. Further, based on current data it is difficult to define a bespoke plant NO signalling pathway, but rather....... By considering the recent advances in plant NO biology, this review will highlight certain key aspects that require further attention. Scope and conclusions The following questions will be considered. Whilst cytosolic nitrate reductase is an important source of NO, the contributions of other mechanisms...

  12. Inhibition of the adrenomedullin/nitric oxide signaling pathway in early diabetic retinopathy.

    Science.gov (United States)

    Blom, Jan J; Giove, Thomas J; Favazza, Tara L; Akula, James D; Eldred, William D

    2011-06-01

    The nitric oxide (NO) signaling pathway is integrally involved in visual processing and changes in the NO pathway are measurable in eyes of diabetic patients. The small peptide adrenomedullin (ADM) can activate a signaling pathway to increase the enzyme activity of neuronal nitric oxide synthase (nNOS). ADM levels are elevated in eyes of diabetic patients and therefore, ADM may play a role in the pathology of diabetic retinopathy. The goal of this research was to test the effects of inhibiting the ADM/NO signaling pathway in early diabetic retinopathy. Inhibition of this pathway decreased NO production in high-glucose retinal cultures. Treating diabetic mice with the PKC β inhibitor ruboxistaurin for 5 weeks lowered ADM mRNA levels and ADM-like immunoreactivity and preserved retinal function as assessed by electroretinography. The results of this study indicate that inhibiting the ADM/NO signaling pathway prevents neuronal pathology and functional losses in early diabetic retinopathy.

  13. Mid-Ir Cavity Ring-Down Spectrometer for Biological Trace Nitric Oxide Detection

    Science.gov (United States)

    Kan, Vincent; Ragab, Ahemd; Stsiapura, Vitali; Lehmann, Kevin K.; Gaston, Benjamin M.

    2011-06-01

    S-nitrosothiols have received much attention in biochemistry and medicine as donors of nitrosonium ion (NO^+) and nitric oxide (NO) - physiologically active molecules involved in vasodilation and signal transduction. Determination of S-nitrosothiols content in cells and tissues is of great importance for fundamental research and medical applications. We will report on our ongoing development of a instrument to measure trace levels of nitric oxide gas (NO), released from S-nitrosothiols after exposure to UV light (340 nm) or reaction with L-Cysteine+CuCl mixture. The instrument uses the method of cavity ring-down spectroscopy, probing rotationally resolved lines in the vibrational fundamental transition near 5.2 μm. The laser source is a continuous-wave, room temperature external cavity quantum cascade laser. An acousto-optic modulator is used to abruptly turn off the optical power incident on the cavity when the laser and cavity pass through resonance.

  14. Expression of inducible nitric oxide synthase in trigeminal ganglion cells during culture

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Zhou, MingFang; Zinck, Tina Jovanovic

    2005-01-01

    RNA and protein could be detected. The data suggest that iNOS expression may be a molecular mechanism mediating the adaptive response of trigeminal ganglia cells to the serum free stressful stimulus the culture environment provides. It may act as a cellular signalling molecule that is expressed after cell......Nitric oxide (NO) is an important signalling molecule that has been suggested to be a key molecule for induction and maintenance of migraine attacks based on clinical studies, animal experimental studies and the expression of nitric oxide synthase (NOS) immunoreactivity within the trigeminovascular......, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. In trigeminal ganglia cells not subjected to culture, endothelial (e) and neuronal (n) but not inducible (i) NOS mRNA and protein were detected. Culture of rat neurones resulted in a rapid axonal outgrowth of NOS positive...

  15. [Potential protective role of nitric oxide and Hsp70 linked to functional foods in the atherosclerosis].

    Science.gov (United States)

    Camargo, Alejandra B; Manucha, Walter

    Atherosclerosis, one of the main pathologic entities considered epidemic and a worldwide public health problem, is currently under constant review as regards its basic determining mechanisms and therapeutic possibilities. In this regard, all patients afflicted with the disease exhibit mitochondrial dysfunction, oxidative stress and inflammation. Interestingly, nitric oxide - a known vasoactive messenger gas - has been closely related to the inflammatory, oxidative and mitochondrial dysfunctional process that characterizes atherosclerosis. In addition, it has recently been demonstrated that alterations in the bioavailability of nitric oxide would induce the expression of heat shock proteins. This agrees with the use of functional foods as a strategy to prevent both vascular aging and the development of atherosclerosis. Finally, a greater knowledge regarding the mechanisms implied in the development of atherosclerosis will enable proposing new and possible hygiene, health and therapeutic interventions. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Extractive distillation of nitric acid using the two-pot concept

    International Nuclear Information System (INIS)

    Counce, R.M.; Groenier, W.S.; Holland, W.D.; Jubin, R.T.; North, E.D.; Thompson, L.E. Jr.; Hebble, T.L.

    1982-12-01

    Experiments have confirmed the validity of a novel design for a nitric acid concentration system for use in shielded nuclear fuel reprocessing plants. Current plans for producing the scrub solution for the IODOX process require the concentration and recycle of low strength ( 3 ) 2 as the solvent and features two pots: an extractive distillation pot in which a concentrated acid product is obtained by contacting the acid feed with the solvent and a solvent recovery pot in which the solvent is dehydrated and recovered for recycle. In these experiments, a concentrated product of 89 wt % nitric acid was produced from azeotropic feed. The available vapor-liquid equilibria data for the Mg(NO 3 ) 2 -HNO 3 -H 2 O system has been empirically correlated, and a design methodology has been developed for the two-pot extractive distillation process

  17. Nitric acid treated multi-walled carbon nanotubes optimized by Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin, Shahidah Arina; Hashim, Uda; Halim, Nur Hamidah Abdul [Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Derman, Mohd Nazree, E-mail: nazree@unimap.edu.my; Tahir, Muhammad Faheem Mohd [Centre of Excellence Geopolymer & Green Technology (CEGeoGTech), School of Material Engineering, Universiti Malaysia Perlis, 01000, Kangar, Perlis (Malaysia); Kashif, Muhammad [Faculty of Engineering, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak (Malaysia); Adam, Tijjani [Faculty of Engineering Technology, Universiti Malaysia Perlis, 02100, Padang Besar, Perlis (Malaysia)

    2016-07-19

    Electron transfer rate (ETR) of CNTs can be enhanced by increasing the amounts of COOH groups to their wall and opened tips. With the aim to achieve the highest production amount of COOH, Taguchi robust design has been used for the first time to optimize the surface modification of MWCNTs by nitric acid oxidation. Three main oxidation parameters which are concentration of acid, treatment temperature and treatment time have been selected as the control factors that will be optimized. The amounts of COOH produced are measured by using FTIR spectroscopy through the absorbance intensity. From the analysis, we found that acid concentration and treatment time had the most important influence on the production of COOH. Meanwhile, the treatment temperature will only give intermediate effect. The optimum amount of COOH can be achieved with the treatment by 8.0 M concentration of nitric acid at 120 °C for 2 hour.

  18. Nitric acid treated multi-walled carbon nanotubes optimized by Taguchi method

    International Nuclear Information System (INIS)

    Shamsuddin, Shahidah Arina; Hashim, Uda; Halim, Nur Hamidah Abdul; Derman, Mohd Nazree; Tahir, Muhammad Faheem Mohd; Kashif, Muhammad; Adam, Tijjani

    2016-01-01

    Electron transfer rate (ETR) of CNTs can be enhanced by increasing the amounts of COOH groups to their wall and opened tips. With the aim to achieve the highest production amount of COOH, Taguchi robust design has been used for the first time to optimize the surface modification of MWCNTs by nitric acid oxidation. Three main oxidation parameters which are concentration of acid, treatment temperature and treatment time have been selected as the control factors that will be optimized. The amounts of COOH produced are measured by using FTIR spectroscopy through the absorbance intensity. From the analysis, we found that acid concentration and treatment time had the most important influence on the production of COOH. Meanwhile, the treatment temperature will only give intermediate effect. The optimum amount of COOH can be achieved with the treatment by 8.0 M concentration of nitric acid at 120 °C for 2 hour.

  19. Pseudomacrocyclic effect in extraction processes of metal salts by polyethers from nitric acid solutions

    International Nuclear Information System (INIS)

    Yakshin, V.V.; Vilkova, O.M.; Kotlyar, S.A.; Kamalov, G.L.

    1997-01-01

    Comparison of macrocyclic (ME) and pseudmacrocyclic effects (PME), originating by conduct of the metal salt extraction processes (Cs, Sr, In, Zr, Cd, etc) from nitric acid solutions through linear and cyclic polyethers, containing 5 or 6 atoms of ether oxygen and having close molecular masses (290-360), is carried out. It is shown that ordinary ethers practically do not extract the studied metals from nitric acid solutions. By transfer from linear polyethers to their macrocyclic analogs the ME impact is expressed clearly enough: the separation coefficient value grows by tens and hundred times. At the some time the PME role in the extraction processes of metal nitrates through crown-ethers with alkyl and groups is expressed less clearly

  20. [Techniques and complementary techniques. Complementary treatments: nitric oxide, prone positioning and surfactant].

    Science.gov (United States)

    Martos Sánchez, I; Vázquez Martínez, J L; Otheo de Tejada, E; Ros, P

    2003-11-01

    The management of hypoxic respiratory failure is based on oxygen delivery and ventilatory support with lung-protective ventilation strategies. Better understanding of acute lung injury have led to new therapeutic approaches that can modify the outcome of these patients. These adjunctive oxygenation strategies include inhaled nitric oxide and surfactant delivery, and the use of prone positioning. Nitric oxide is a selective pulmonary vasodilator that when inhaled, improves oxygenation in clinical situations such as persistent pulmonary hypertension of the newborn, pulmonary hypertension associated with congenital heart disease, and acute respiratory distress syndrome (ARDS). When applied early in ARDS, prone positioning improves distribution of ventilation and reduces the intrapulmonary shunt. The surfactant has dramatically decreased mortality caused by hyaline membrane disease in premature newborns, although the results have been less successful in ARDS. Greater experience is required to determine whether the combination of these treatments will improve the prognosis of these patients.

  1. Involvement of the nitric oxide in melatonin-mediated protection against injury.

    Science.gov (United States)

    Fan, Wenguo; He, Yifan; Guan, Xiaoyan; Gu, Wenzhen; Wu, Zhi; Zhu, Xiao; Huang, Fang; He, Hongwen

    2018-05-01

    Melatonin is a hormone mainly synthesized by the pineal gland in vertebrates and known well as an endogenous regulator of circadian and seasonal rhythms. It has been demonstrated that melatonin is involved in many physiological and pathophysiological processes showing antioxidant, anti-apoptotic and anti-inflammatory properties. Nitric oxide (NO) is a free radical gas in the biological system, which is produced by nitric oxide synthase (NOS) family. NO acts as a biological mediator and plays important roles in different systems in humans. The NO/NOS system exerts a broad spectrum of signaling functions. Accumulating evidence has clearly revealed that melatonin regulates NO/NOS system through multiple mechanisms that may influence physiological and pathophysiological processes. This article reviews the latest evidence for the effects of melatonin on NO/NOS regulation in different organs and disease conditions, the potential cellular mechanisms by which melatonin is involved in organ protection are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Easy synthesis of graphene sheets from alfalfa plants by treatment of nitric acid

    International Nuclear Information System (INIS)

    Qu, Jiao; Luo, Chunqiu; Zhang, Qian; Cong, Qiao; Yuan, Xing

    2013-01-01

    Highlights: ► An easy method for synthesis of graphene sheets using alfalfa plants was introduced. ► An novelty formation mechanism of graphene sheets using alfalfa plants was proposed. ► This method exploits a new carbon source and provides a novel idea to synthesize graphene sheets. -- Abstract: This letter focuses on synthesis of graphene sheets from alfalfa plants by treatment of nitric acid. The transmission electron microscopy image (TEM) demonstrates that the graphene sheets are agglomerated and overlapped, the energy dispersive spectrum (EDS) indicates that the products are pure, and the Raman spectrum shows the graphene sheets are well graphitized. In addition, the formation mechanism of the graphene sheets from alfalfa plants by treatment nitric acid is discussed. These findings inspire the search for a new strategy for synthesis of graphene sheets from renewable natural products, and the lower cost of this new process and carbon source may facilitate industrial production

  3. Easy synthesis of graphene sheets from alfalfa plants by treatment of nitric acid

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jiao, E-mail: qujiao@bhu.edu.cn [School of Chemistry and Chemical Engineering, Bohai University, Jinzhou 121013 (China); School of Urban and Environmental Sciences, Northeast Normal University, Changchun 130024 (China); Luo, Chunqiu, E-mail: fplj_lcq@163.com [School of Chemistry and Chemical Engineering, Bohai University, Jinzhou 121013 (China); Zhang, Qian; Cong, Qiao [School of Chemistry and Chemical Engineering, Bohai University, Jinzhou 121013 (China); Yuan, Xing [School of Urban and Environmental Sciences, Northeast Normal University, Changchun 130024 (China)

    2013-04-01

    Highlights: ► An easy method for synthesis of graphene sheets using alfalfa plants was introduced. ► An novelty formation mechanism of graphene sheets using alfalfa plants was proposed. ► This method exploits a new carbon source and provides a novel idea to synthesize graphene sheets. -- Abstract: This letter focuses on synthesis of graphene sheets from alfalfa plants by treatment of nitric acid. The transmission electron microscopy image (TEM) demonstrates that the graphene sheets are agglomerated and overlapped, the energy dispersive spectrum (EDS) indicates that the products are pure, and the Raman spectrum shows the graphene sheets are well graphitized. In addition, the formation mechanism of the graphene sheets from alfalfa plants by treatment nitric acid is discussed. These findings inspire the search for a new strategy for synthesis of graphene sheets from renewable natural products, and the lower cost of this new process and carbon source may facilitate industrial production.

  4. Inducible nitric oxide synthase catalyzes ethanol oxidation to α-hydroxyethyl radical and acetaldehyde

    International Nuclear Information System (INIS)

    Porasuphatana, Supatra; Weaver, John; Rosen, Gerald M.

    2006-01-01

    The physiologic function of nitric oxide synthases, independent of the isozyme, is well established, metabolizing L-arginine to L-citrulline and nitric oxide (NO). This enzyme can also transfer electrons to O 2 , affording superoxide (O 2 · - ) and hydrogen peroxide (H 2 O 2 ). We have demonstrated that NOS1, in the presence of L-arginine, can biotransform ethanol (EtOH) to α-hydroxyethyl radical (CH 3 ·CHOH). We now report that a competent NOS2 with L-arginine can, like NOS1, oxidize EtOH to CH 3 ·CHOH. Once this free radical is formed, it is metabolized to acetaldehyde as shown by LC-ESI-MS/MS and HPLC analysis. These observations suggest that NOS2 can behave similarly to cytochrome P-450 in the catalysis of acetaldehyde formation from ethanol via the generation of α-hydroxyethyl radical when L-arginine is present

  5. Passive Sampler for Measurements of Atmospheric Nitric Acid Vapor (HNO3 Concentrations

    Directory of Open Access Journals (Sweden)

    Andrzej Bytnerowicz

    2001-01-01

    Full Text Available Nitric acid (HNO3 vapor is an important nitrogenous air pollutant responsible for increasing saturation of forests with nitrogen and direct injury to plants. The USDA Forest Service and University of California researchers have developed a simple and inexpensive passive sampler for monitoring air concentrations of HNO3. Nitric acid is selectively absorbed on 47-mm Nylasorb nylon filters with no interference from particulate NO3-. Concentrations determined with the passive samplers closely corresponded with those measured with the co-located honeycomb annular denuder systems. The PVC protective caps of standardized dimensions protect nylon filters from rain and wind and allow for reliable measurements of ambient HNO3 concentrations. The described samplers have been successfully used in Sequoia National Park, the San Bernardino Mountains, and on Mammoth Mountain in California.

  6. Disposition of PUREX contaminated nitric acid the role of stakeholder involvement

    International Nuclear Information System (INIS)

    Jasen, W.G.; Duncan, R.A.

    1996-01-01

    What does the United States space shuttle and the Hanford PUREX facility's contaminated nitric acid have in common. Both are reusable. The PUREX Transition Project has achieved success and, minimized project expenses and waste generation by looking at excess chemicals not as waste but as reusable substitutes for commercially available raw materials. This philosophy has helped PUREX personnel to reuse or recycle more than 2.5 million pounds of excess chemicals, a portion of which is the slightly contaminated nitric acid. After extensive public review, the first shipment of contaminated acid was made in May 1995. Removal of the acid was completed on November 6, 1995 when the fiftieth shipment left the Hanford site. This activity, which avoided dispositioning the contaminated acid as a waste, generated significantly more public input and concern than was expected. One of the lessons learned from this process is to not underestimate public perceptions regarding the reuse of contaminated materials

  7. Ribavirin in Cancer Immunotherapies: Controlling Nitric Oxide Augments Cytotoxic Lymphocyte Function

    Directory of Open Access Journals (Sweden)

    Richard E. Kast

    2003-01-01

    Full Text Available Either ribavirin (RBV or cyclophosphamide (CY can shift an immune response from Th2 toward a Thi cytokine profile. CY is used in this role in various current cancer immunotherapy attempts but with mixed success. More potent and reliable immunoadjuvants and Th1 response biasing methods are needed. RBV is used today mainly to augment interferon-alpha treatment of hepatitis C. RBV shifts an immune response from Th2 toward Th1 more effectively than CY and may be a safe and useful adjuvant for current cancer immunotherapeutic efforts. RBV is thought to act by inhibition of tetrahydrobiopterin synthesis. Tetrahydrobiopterin is an essential cofactor for all known isoforms of nitric oxide synthase. Lowered nitric oxide favors Th1 development as high levels favor Th2 weighting.

  8. Hydrogen generation in SRAT with nitric acid and late washing flowsheets

    International Nuclear Information System (INIS)

    Hsu, C.W.

    1992-01-01

    Recently, SRTC recommended two process changes: (1) a final wash of the tetraphenylborate precipitate feed slurry and (2) the use of nitric acid to neutralize the sludge in the SRAT. The first change produced an aqueous hydrolysis product (PHA) with higher formic acid/formate and copper concentration, and reduced the nitrate content in the PHA by an order of magnitude. The second change is to substitute part of formic acid added to the SRAT with nitric acid, and therefore may reduce the hydrogen generated in the SRAT as well as provide nitrate as an oxidant to balance the redox state of the melter feed. The purpose of this report is to determine the pertinent variables that could affect the hydrogen generation rate with these process changes

  9. Nitric oxide and HSV vaginal infection in BALB/c mice

    International Nuclear Information System (INIS)

    Benencia, Fabian; Gamba, Gisela; Cavalieri, Hernan; Courreges, Maria Cecilia; Benedetti, Ruben; Villamil, Soledad Maria; Massouh, Ernesto Jorge

    2003-01-01

    Here we study the role of nitric oxide in the vaginal infection of Balb/c mice with herpes simplex virus type 2. Inducible nitric oxide synthase (iNOS) mRNA was detected by RT-PCR in vaginal tissue and inguinal lymph nodes early postinfection. iNOS was also found to be activated in cells recovered from vaginal washings of infected animals. Animals treated with aminoguanidine (AG), an iNOS inhibitor, showed a dose-dependent increase in vaginal pathology after viral infection compared to controls. Viral titers in vaginal washings and vaginas were higher in AG-treated mice. Treated animals presented higher PMN counts in vaginal washings compared to controls. Histopathology studies revealed a profound inflammatory exudate in vaginal tissue of treated animals. Finally, RT-PCR analysis showed increased expression of the chemokines MIP-2 and RANTES in vaginal tissue and inguinal lymph nodes of these animals

  10. Inhaled Nitric Oxide for the Prevention of Impaired Arterial Oxygenation during Myocardial Revascularization with Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    I. A. Kozlov

    2011-01-01

    Full Text Available Objective: to study the efficacy of inhaled nitric oxide used intraoperatively to prevent lung oxygenating dysfunction in patients with coronary heart disease after myocardial revascularization under extracorporeal circulation (EC. Subjects and methods. Thirty-two patients aged 55.0±2.0 years were examined. The inclusion criteria were the standard course of surgical intervention (the absence of hemorrhage, acute cardiovascular insufficiency, perioperative myocardial infarction, etc., a pulmonary artery wedge pressure of less than 15 – mm Hg throughout the study, and the baseline arterial partial oxygen tension/inspired mixture oxygen fraction (PaO2/FiO2 ratio of at least 350 mm Hg. There was a control group (n=21; Group 1 that used no special measures to prevent and/or to correct lung oxygenating dysfunction and Group 2 (n=11 that received inhaled nitric oxide. Ihe administration of inhaled nitric oxide at a concentration of 10 ppm was initiated after water anesthesia, stopped during EC, and resumed in the postperfusion period. Results. At the end, PaO2/FiO2 and intrapulmonary shunt fraction did not differ between the groups (p>0.05. Before EC, the patients receiving inhaled nitric oxide had a lower intrapulmonary blood shunting (8.9±0.7 and 11.7±1.0%; p<0.05. There were no intergroup differences in the values of PaO2/FiO2 at this stage. In the earliest postperfusion period, PaO2/FiO2 was higher in Group 2 than that in Group 1. At the end of operations, Groups 1 and 2 had a PaO2/FiO2 of 336.0±16.8 and 409.0±24.3 mm Hg, respectively (p<0.05 and an intrapulmonary shunt fraction of 14.5±1.0 and 10.4±1.0% (p<0.05. At the end of surgery, the rate of a reduction in PaO2/FiO2 to the level below 350 mm Hg was 52.4±11.1% in Group 1 and 18.2±11.6% in Group 2 (p<0.05. Six hours after surgery, PaO2/FiO2 values less than 300 mm Hg were diagnosed in 61.9±10.5% of Group 1 patients and in 27.3±13.4% of Group 2 ones (p<0.05. Conclusion. The

  11. Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase.

    Science.gov (United States)

    Xiao, Ran; Li, Shan; Cao, Qian; Wang, Xiuling; Yan, Qiujin; Tu, Xiaoning; Zhu, Ying; Zhu, Fan

    2017-06-01

    Human endogenous retrovirus W env (HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis (MS). These diseases are accompanied by immunological reactions in the central nervous system (CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter-nitric oxide (NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase (hiNOS) and enhanced the promoter activity of hiNOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.

  12. Role of heat shock protein 90 and endothelial nitric oxide synthase during early anesthetic and ischemic preconditioning.

    Science.gov (United States)

    Amour, Julien; Brzezinska, Anna K; Weihrauch, Dorothee; Billstrom, Amie R; Zielonka, Jacek; Krolikowski, John G; Bienengraeber, Martin W; Warltier, David C; Pratt, Philip F; Kersten, Judy R

    2009-02-01

    Nitric oxide is known to be essential for early anesthetic preconditioning (APC) and ischemic preconditioning (IPC) of myocardium. Heat shock protein 90 (Hsp90) regulates endothelial nitric oxide synthase (eNOS) activity. In this study, the authors tested the hypothesis that Hsp90-eNOS interactions modulate APC and IPC. Myocardial infarct size was measured in rabbits after coronary occlusion and reperfusion in the absence or presence of preconditioning within 30 min of isoflurane (APC) or 5 min of coronary artery occlusion (IPC), and with or without pretreatment with geldanamycin or radicicol, two chemically distinct Hsp90 inhibitors, or N-nitro-L-arginine methyl ester, a nonspecific nitric oxide synthase NOS inhibitor. Isoflurane-dependent nitric oxide production was measured (ozone chemiluminescence) in human coronary artery endothelial cells or mouse cardiomyocytes, in the absence or presence of Hsp90 inhibitors or N-nitro-L-arginine methyl ester. Interactions between Hsp90 and eNOS, and eNOS activation, were assessed with immunoprecipitation, immunoblotting, and confocal microscopy. APC and IPC decreased infarct size (by 50% and 59%, respectively), and this action was abolished by Hsp90 inhibitors. N-nitro-L-arginine methyl ester blocked APC but not IPC. Isoflurane increased nitric oxide production in human coronary artery endothelial cells concomitantly with an increase in Hsp90-eNOS interaction (immunoprecipitation, immunoblotting, and immunohistochemistry). Pretreatment with Hsp90 inhibitors abolished isoflurane-dependent nitric oxide production and decreased Hsp90-eNOS interactions. Isoflurane did not increase nitric oxide production in mouse cardiomyocytes, and eNOS was below the level of detection. The results indicate that Hsp90 plays a critical role in mediating APC and IPC through protein-protein interactions, and suggest that endothelial cells are important contributors to nitric oxide-mediated signaling during APC.

  13. Hyperglycemia adversely modulates endothelial nitric oxide synthase during anesthetic preconditioning through tetrahydrobiopterin- and heat shock protein 90-mediated mechanisms.

    Science.gov (United States)

    Amour, Julien; Brzezinska, Anna K; Jager, Zachary; Sullivan, Corbin; Weihrauch, Dorothee; Du, Jianhai; Vladic, Nikolina; Shi, Yang; Warltier, David C; Pratt, Phillip F; Kersten, Judy R

    2010-03-01

    Endothelial nitric oxide synthase activity is regulated by (6R-)5,6,7,8-tetrahydrobiopterin (BH4) and heat shock protein 90. The authors tested the hypothesis that hyperglycemia abolishes anesthetic preconditioning (APC) through BH4- and heat shock protein 90-dependent pathways. Myocardial infarct size was measured in rabbits in the absence or presence of APC (30 min of isoflurane), with or without hyperglycemia, and in the presence or absence of the BH4 precursor sepiapterin. Isoflurane-dependent nitric oxide production was measured (ozone chemiluminescence) in human coronary artery endothelial cells cultured in normal (5.5 mm) or high (20 mm) glucose conditions, with or without sepiapterin (10 or 100 microm). APC decreased myocardial infarct size compared with control experiments (26 +/- 6% vs. 46 +/- 3%, respectively; P < 0.05), and this action was blocked by hyperglycemia (43 +/- 4%). Sepiapterin alone had no effect on infarct size (46 +/- 3%) but restored APC during hyperglycemia (21 +/- 3%). The beneficial actions of sepiapterin to restore APC were blocked by the nitric oxide synthase inhibitor N (G)-nitro-L-arginine methyl ester (47 +/- 2%) and the BH4 synthesis inhibitor N-acetylserotonin (46 +/- 3%). Isoflurane increased nitric oxide production to 177 +/- 13% of baseline, and this action was attenuated by high glucose concentrations (125 +/- 6%). Isoflurane increased, whereas high glucose attenuated intracellular BH4/7,8-dihydrobiopterin (BH2) (high performance liquid chromatography), heat shock protein 90-endothelial nitric oxide synthase colocalization (confocal microscopy) and endothelial nitric oxide synthase activation (immunoblotting). Sepiapterin increased BH4/BH2 and dose-dependently restored nitric oxide production during hyperglycemic conditions (149 +/- 12% and 175 +/- 9%; 10 and 100 microm, respectively). The results indicate that tetrahydrobiopterin and heat shock protein 90-regulated endothelial nitric oxide synthase activity play a central

  14. 4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit. The dependence of nitric acid decomposition of calcined boric raw material for extraction of boron oxide on temperature (20-100 deg C) and process duration (15-60 minutes) was defined. It was defined that at temperature increasing the extraction rate of boron oxide increases from 20.8 to 78.6%.

  15. Synthesis of N-(Methoxycarbonylthienylmethylthioureas and Evaluation of Their Interaction with Inducible and Neuronal Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    Michael D. Threadgill

    2010-04-01

    Full Text Available Two isomeric N-(methoxycarbonylthienylmethylthioureas were synthesised by a sequence of radical bromination of methylthiophenecarboxylic esters, substitution with trifluoroacetamide anion, deprotection, formation of the corresponding isothiocyanates and addition of ammonia. The interaction of these new thiophene-based thioureas with inducible and neuronal nitric oxide synthase was evaluauted. These novel thienylmethylthioureas stimulated the activity of inducible Nitric Oxide Synthase (iNOS.

  16. NITRIC OXIDE ACTIVITY OF NEUTROPHIL IN BLOOD AND CEREBROSPINAL FLUID OF THE CHILDREN WITH BACTERIAL AND VIRAL MENINGITIS

    Directory of Open Access Journals (Sweden)

    V. P. Molochniy

    2014-01-01

    Full Text Available The article presents the results of study of nitric oxide activity of neutrophil leucocytic and freeradical processes in blood and cerebrospinal fluid of the children with bacterial and viral meningitison the acute period diseases. The peculiarities or activity of freeradical processes and nitric oxide of cerebrospinal fluid with bacterial meningitis in acute period diseases and activities of studies of ferments with the health children. 

  17. Enhancement of fracture healing in the rat, modulated by compounds that stimulate inducible nitric oxide synthase

    OpenAIRE

    Rajfer, R. A.; Kilic, A.; Neviaser, A. S.; Schulte, L. M.; Hlaing, S. M.; Landeros, J.; Ferrini, M. G.; Ebramzadeh, E.; Park, S-H.

    2017-01-01

    Objectives We investigated the effects on fracture healing of two up-regulators of inducible nitric oxide synthase (iNOS) in a rat model of an open femoral osteotomy: tadalafil, a phosphodiesterase inhibitor, and the recently reported nutraceutical, COMB-4 (consisting of L-citrulline, Paullinia cupana, ginger and muira puama), given orally for either 14 or 42 days. Materials and Methods Unilateral femoral osteotomies were created in 58 male rats and fixed with an intramedullary compression na...

  18. Nitric-phosphoric acid oxidation of solid and liquid organic materials

    International Nuclear Information System (INIS)

    Pierce, R.A.; Smith, J.R.; Poprik, D.C.

    1995-01-01

    Nitric-phosphoric acid oxidation has been developed specifically to address issues that face the Savannah River Site, other defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate SRS solid, Pu-contaminated job-control waste, the technology has also exhibited potential for remediating hazardous and mixed-hazardous waste forms. The process is unique to Savannah River and offers a valuable alternative to other oxidation processes that require extreme temperatures and/or elevated pressures. To address the broad categories of waste, many different organic compounds which represent a cross-section of the waste that must be treated have been successfully oxidized. Materials that have been quantitatively oxidized at atmospheric pressure below 180 degrees C include neoprene, cellulose, EDTA, tributylphosphate, and nitromethane. More stable compounds such as benzoic acid, polyethylene, oils, and resins have been completely decomposed below 200 degrees C and 10 psig. The process uses dilute nitric acid in a concentrated phosphoric acid media as the main oxidant for the organic compounds. Phosphoric acid allow nitric acid to be retained in solution well above its normal boiling point. The reaction forms NOx vapors which can be reoxidized and recycled using air and water. The addition of 0.001M Pd(II) reduces CO generation to near 1% of the released carbon gases. The advantages of this process are that it is straightforward, uses relatively inexpensive reagents, operates at relatively low temperature and pressure, and produces final solutions which are compatible with stainless steel equipment. For organic wastes, all carbon, hydrogen, and nitrogen are converted to gaseous products. If interfaced with an acid recovery system which converts NOx back to nitric acid, the net oxidizer would be oxygen from air

  19. Gamma radiolytic stability of CyMe4BTBP and effect of nitric acid

    Czech Academy of Sciences Publication Activity Database

    Schmidt, H.; Wilden, A.; Modolo, G.; Švehla, Jaroslav; Grüner, Bohumír; Ekberg, C.

    Roč. 60, č. 4 ( 2015 ), s. 879-884 ISSN 0029-5922 R&D Projects: GA MŠk(CZ) 7G13003 EU Projects: European Commission(XE) 323282 - SACSESS Institutional support: RVO:61388980 Keywords : CyMe4BTBP * Protective effect * Gamma radiolysis * Liquid-liquid extraction * Nitric acid Subject RIV: CA - Inorganic Chemistry Impact factor: 0.546, year: 2015

  20. The investigation of antimony extraction with tributyl phosphate from nitric acid solutions

    International Nuclear Information System (INIS)

    Lakaev, V.S.; Smelov, V.S.

    1988-01-01

    Experimental data on trivalent antimony extraction with tributyl phosphate from nitric acid solutions containing (3.2-4.3)x10 -6 mol/l of antimony-125 isotope are presented. Possible mechanism of antimony (3) extraction is determined and the concentration constant for this process is calculated. Effect of temperature on the extraction of trivalent antimony is estimated. The values of enthalpy, free enthalpy and entropy are determined

  1. Exhaled Nitric Oxide is Decreased by Exposure to the Hyperbaric Oxygen Therapy Environment

    Directory of Open Access Journals (Sweden)

    Zudin A. Puthucheary

    2006-01-01

    or 40% oxygen, 1 ATA. In an in vitro study, nitrate/nitrite release decreased after 90 minutes HBOT in airway epithelial (A549 cells. Conclusion. HBO exposure causes a fall in eNO. Inducible nitric oxide synthase (iNOS may cause elevated eNO in patients secondary to inflammation, and inhibition of iNOS may be the mechanism of the reduction of eNO seen with HBOT.

  2. The role of nitric oxide during embryonic epidermis development of Xenopus laevis

    Czech Academy of Sciences Publication Activity Database

    Tománková, Silvie; Abaffy, Pavel; Šindelka, Radek

    2017-01-01

    Roč. 6, č. 6 (2017), s. 862-871 ISSN 2046-6390 R&D Projects: GA AV ČR LK21305; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Development * Nitric oxide * Epidermis * Xenopus laevis Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Developmental biology Impact factor: 2.095, year: 2016

  3. Anti-Biofilm Efficacy of Nitric Oxide-Releasing Silica Nanoparticles

    OpenAIRE

    Hetrick, Evan M.; Shin, Jae Ho; Paul, Heather S.; Schoenfisch, Mark H.

    2009-01-01

    The ability of nitric oxide (NO)-releasing silica nanoparticles to kill biofilm-based microbial cells is reported. Biofilms of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans were formed in vitro and exposed to NO-releasing silica nanoparticles. Replicative viability experiments revealed that ≥ 99% of cells from each type of biofilm were killed via NO release, with the greatest efficacy (≥ 99.999% killing) against gram-negative...

  4. Plant hemoglobins: Important players at the crossroads between oxygen and nitric oxide

    DEFF Research Database (Denmark)

    Gupta, Kapuganti J; Hebelstrup, Kim; Mur, Luis A J

    2011-01-01

    Plant hemoglobins constitute a diverse group of hemeproteins and evolutionarily belong to three different classes. Class 1 hemoglobins possess an extremely high affinity to oxygen and their main function consists in scavenging of nitric oxide (NO) at very low oxygen levels. Class 2 hemoglobins have...... at high O2 concentrations. Depending on their physical properties, hemoglobins belong either to hexacoordinate non-symbiotic or pentacoordinate symbiotic groups. Plant hemoglobins are plausible targets for improving resistance to multiple stresses....

  5. Nitric oxide increases myocardial efficiency in the hypoxia-tolerant turtle Trachemys scripta

    DEFF Research Database (Denmark)

    Misfeldt, Mikkel; Fago, Angela; Gesser, Hans

    2009-01-01

    Nitric oxide (NO) may influence cardiac mechanical performance relative to O2 consumption by depressing respiration rate and by affecting the excitation-contraction coupling. Such effects of NO should be particularly important during hypoxia in species such as the hypoxia-tolerant turtle Trachemys....... This effect was particularly pronounced under O2 deficiency and may therefore contribute towards preserving cardiac function and to the overall excellent hypoxic tolerance of the turtle...

  6. The role of nitric oxide in the maintenance of vasoactive balance

    Czech Academy of Sciences Publication Activity Database

    Pecháňová, Olga; Šimko, F.

    2007-01-01

    Roč. 56, Suppl.2 (2007), S7-S16 ISSN 0862-8408 Grant - others:VEGA(SK) 2/6148/26; VEGA(SK) 1/3429/06; APPV(SK) 0596-06 Institutional research plan: CEZ:AV0Z50110509 Keywords : nitric oxide * vasorelaxation and vasoconstriction factors * hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.505, year: 2007

  7. Inhibition by sodium nitroprusside of the expression of inducible nitric oxide synthase in rat neutrophils.

    OpenAIRE

    Mariotto, S; Cuzzolin, L; Adami, A; Del Soldato, P; Suzuki, H; Benoni, G

    1995-01-01

    A well-known nitric oxide (NO)-releasing compound, sodium nitroprusside (SNP), decreases in a dose-dependent manner NO synthase (NOS) activity induced in rat neutrophils by treatment with lipopolysaccharide (LPS). This inhibitory action of SNP seems not to be due to its direct effect on the enzyme activity. The strong nitrosonium ion (NO+) character of SNP could be responsible for its inhibition of NOS induction in neutrophils.

  8. Inhibition by sodium nitroprusside of the expression of inducible nitric oxide synthase in rat neutrophils.

    Science.gov (United States)

    Mariotto, S; Cuzzolin, L; Adami, A; Del Soldato, P; Suzuki, H; Benoni, G

    1995-01-01

    A well-known nitric oxide (NO)-releasing compound, sodium nitroprusside (SNP), decreases in a dose-dependent manner NO synthase (NOS) activity induced in rat neutrophils by treatment with lipopolysaccharide (LPS). This inhibitory action of SNP seems not to be due to its direct effect on the enzyme activity. The strong nitrosonium ion (NO+) character of SNP could be responsible for its inhibition of NOS induction in neutrophils. PMID:7542530

  9. Nitric Oxide Synthesis Is Reduced in Subjects With Type 2 Diabetes and Nephropathy

    OpenAIRE

    Tessari, Paolo; Cecchet, Diego; Cosma, Alessandra; Vettore, Monica; Coracina, Anna; Millioni, Renato; Iori, Elisabetta; Puricelli, Lucia; Avogaro, Angelo; Vedovato, Monica

    2010-01-01

    OBJECTIVE Nitric oxide (NO) is a key metabolic and vascular regulator. Its production is stimulated by insulin. A reduced urinary excretion of NO products (NOx) is frequently found in type 2 diabetes, particularly in association with nephropathy. However, whether the decreased NOx excretion in type 2 diabetes is caused by a defective NOx production from arginine in response to hyperinsulinemia has never been studied. RESEARCH DESIGN AND METHODS We measured NOx fractional (FSR) and absolute (A...

  10. Evidence for a link between atmospheric thermonuclear detonations and nitric acid

    International Nuclear Information System (INIS)

    Holdsworth, G.

    1986-01-01

    Data are presented for an ice core, which show that during the era of intense atmospheric thermonuclear weapons testing, a significant part of the nitrate content in the snow was modulated by the intensity of the nuclear detonations. The fixation of nitrogen by nuclear fireballs leads to NOsub(x) gases in the atmosphere and ultimately to nitric acid in precipitation. At certain concentrations, these gases and the associated aerosols may perturb the climate. (author)

  11. Nitric oxide nanoparticles: Pre-clinical utility as a therapeutic for intramuscular abscesses

    OpenAIRE

    Schairer, David O.; Martinez, Luis R.; Blecher, Karin; Chouake, Jason S.; Nacharaju, Parimala; Gialanella, Philip; Friedman, Joel M.; Nosanchuk, Joshua D.; Friedman, Adam J.

    2012-01-01

    Nitric oxide (NO) is a critical component of host defense against invading pathogens; however, its therapeutic utility is limited due to a lack of practical delivery systems. Recently, a NO-releasing nanoparticulate platform (NO-np) was shown to have in vitro broad-spectrum antimicrobial activity and in vivo pre-clinical efficacy in a dermal abscess model. To extend these findings, both topical (TP) and intralesional (IL) NO-np administration was evaluated in a MRSA intramuscular murine absce...

  12. Melatonin effect on hypertension and nitric oxide balance in the heart and aorta

    Czech Academy of Sciences Publication Activity Database

    Pecháňová, Olga; Paulis, L.; Zicha, Josef; Kuneš, Jaroslav; Šimko, F.

    2006-01-01

    Roč. 24, č. S6 (2006), s. 395-395 ISSN 0263-6352. [Scientific Meeting of the International Society of Hypertension /21./. 15.10.2006-19.10.2006, Fukuoka] Grant - others:VEGA(SK) 2/6148/26 Institutional research plan: CEZ:AV0Z50110509 Keywords : melatonin * nitric oxide balance * hypertension * SHR and WKY rat * heart and aorta Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  13. Effect of a nitric oxide donor (glyceryl trinitrate) on nociceptive thresholds in man

    DEFF Research Database (Denmark)

    Thomsen, L L; Brennum, J; Iversen, Helle Klingenberg

    1996-01-01

    Several animal studies suggest that nitric oxide (NO) plays a role in central and peripheral modulation of nociception. Glyceryl trinitrate (GTN) exerts its physiological actions via donation of NO. The purpose of the present study was to examine the effect of this NO donor on nociceptive...... central facilitation of nociception by NO. However, we regard convergence of nociceptive input from pericranial myofascial tissue and from cephalic blood vessels dilated by NO as a more likely explanation of our findings....

  14. The role of nitric oxide radicals in removal of hyper-radiosensitivity by priming irradiation

    International Nuclear Information System (INIS)

    Edin, Nina Jeppesen; Sandvik, Joe Alexander; Pettersen, Erik Olai; Vollan, Hilde Synnove; Reger, Katharina; Görlach, Agnes

    2013-01-01

    In this study, a mechanism in which low-dose hyper-radiosensitivity (HRS) is permanently removed, induced by low-dose-rate (LDR) (0.2 - 0.3 Gy/h for 1 h) but not by high-dose-rate priming (0.3 Gy at 40 Gy/h) was investigated. One HRS-negative cell line (NHIK 3025) and two HRS-positive cell lines (T-47D, T98G) were used. The effects of different pretreatments on HRS were investigated using the colony assay. Cell-based ELISA was used to measure nitric oxide synthase (NOS) levels, and microarray analysis to compare gene expression in primed and unprimed cells. The data show how permanent removal of HRS, previously found to be induced by LDR priming irradiation, can also be induced by addition of nitric oxide (NO)-donor DEANO combined with either high-dose-rate priming or exposure to prolonged cycling hypoxia followed by reoxygenation, a treatment not involving radiation. The removal of HRS appears not to involve DNA damage induced during priming irradiation as it was also induced by LDR irradiation of cell-conditioned medium without cells present. The permanent removal of HRS in LDR-primed cells was reversed by treatment with inducible nitric oxide synthase (iNOS) inhibitor 1400W. Furthermore, 1400W could also induce HRS in an HRS-negative cell line. The data suggest that LDR irradiation for 1 h, but not 15 min, activates iNOS, and also that sustained iNOS activation is necessary for the permanent removal of HRS by LDR priming. The data indicate that nitric oxide production is involved in the regulatory processes determining cellular responses to low-dose-rate irradiation. (author)

  15. Edge-carboxylated graphene nanoflakes from nitric acid oxidised arc-discharge material

    OpenAIRE

    NICOLOSI, VALERIA

    2010-01-01

    PUBLISHED Graphene nanoflakes (GNFs) with average diameters of 30 nm have been prepared by a single-step oxidation procedure using single-wall carbon nanotube arc-discharge material and nitric acid. The GNFs are predominately single sheets containing a small number of internal defects. The edges are decorated with primarily carboxylic acid groups which allow facile chemical functionalisation and cross-linking of the fragments using multivalent cations

  16. Tolerance and withdrawal to anticonvulsant action of clonazepam: role of nitric oxide.

    Science.gov (United States)

    Gupta, N; Bhargava, V K; Pandhi, P

    2000-05-01

    The use of clonazepam in the long-term treatment of epilepsy is greatly inhibited by its capacity to induce tolerance and dependence. A means of preventing or minimizing the tolerance and dependence inducing properties is required. Here the role of nitric oxide in preventing the development of tolerance and withdrawal hyperexcitability was studied. In Wistar rats, clonazepam at a dose of 0.25 mg/kg i.p. twice daily produced tolerance to its anticonvulsant action in 28 days. After sudden cessation of therapy it produced hyperexcitability. Tolerance was shown by a decrease in seizure threshold to near control value while withdrawal hyperexcitability was evidenced by a significant decrease in seizure threshold below the control value. L-Arginine (a donor of nitric oxide) and N omega-nitro-L-arginine (an inhibitor of nitric oxide synthase) were given in doses of 150 mg/kg and 8 mg/kg, respectively on day 1, 3, 7, 14, 21 and 28 with clonazepam. Withdrawal hyperexcitability was seen on day 1, 2 and 4 after cessation of drug therapy. Electroshock was used as a model of epilepsy and seizure thresholds were determined by an up and down method of Kimball et al. L-Arginine was found to inhibit the development tolerance as well as withdrawal hyperexcitability when administered with clonazepam while N omega-L-arginine did not prevent either the development of tolerance or withdrawal hyperexcitability in the electroshock model. In the PTZ model, however, L-arginine had no effect on the anticonvulsant action and withdrawal hyperexcitability while inhibition of nitric oxide synthesis prevented withdrawal hyperexcitability in PTZ-induced seizures.

  17. Effect of Genistein on reproductive parameter and serum nitric oxide levels in morphine-treated mice

    Directory of Open Access Journals (Sweden)

    Cyrus Jalili

    2016-02-01

    Full Text Available Background: The predominant phytoestrogen in soy and derived products is the isoflavone Genistein. Genistein has antioxidant properties. Morphine is a main psychoactive chemical in opium that can increase the generation of free radicals and therefore it could adversely affects the spermatogenesis. Objective: The main goal was to investigate whether the Genistein could protect morphine adverse effects on sperm cells viability, count, motility, and testis histology and testosterone hormone and nitric oxide in blood serum. Materials and Methods: In this study, various doses of Genistein (0, 1, 2, and 3 mg/kg and Genistein plus morphine (0, 1, 2, and 3 mg/kg were administered interaperitoneally to 48 male mice for 30 consequent days. These mice were randomly assigned to 8 groups (n=6 and sperm parameters (sperm cells viability, count, motility and morphology, testis weight and histology, testosterone hormone (ELISA method, FSH and LH hormones (immunoradiometry and serum nitric oxide (griess assay were analyzed and compared. Results: The results indicated that morphine administration significantly decreased testosterone (0.03 ng/mg LH and FSH level, histological parameters, count, viability (55.3%, morphology and motility of sperm cells (1%, testis weight (0.08 gr and increase nitric oxide compared to saline group (p=0.00. However, administration of Genistein and Genistein plus morphine significantly boosted motility, morphology, count, viability of sperm cells, seminiferous tubules diameter, germinal thickness, testosterone, LH and FSH while decrease nitric oxide level in all groups compared to morphine group (p<0.025. Conclusion: It seems that Genistein administration could increase the quality of spermatozoa and prevent morphine- induced adverse effects on sperm parameters.

  18. Role of nitric oxide in pheromone-mediated intraspecific communication in mice.

    Science.gov (United States)

    Agustín-Pavón, Carmen; Martínez-Ricós, Joana; Martínez-García, Fernando; Lanuza, Enrique

    2009-12-07

    Nitric oxide is known to take part in the control of sexual and agonistic behaviours. This is usually attributed to its role in neural transmission in the hypothalamus and other structures of the limbic system. However, socio-sexual behaviours in rodents are mainly directed by chemical signals detected by the vomeronasal system, and nitric oxide is abundant in key structures along the vomeronasal pathway. Thus, here we check whether pharmacological treatments interfering with nitrergic transmission could affect socio-sexual behaviour by impairing the processing of chemical signals. Treatment with an inhibitor of nitric oxide synthesis (Nomega-Nitro-l-arginine methyl ester hydrochloride, L-NAME, 100mg/kg) blocks the innate preference displayed by female mice for sexual pheromones contained in male-soiled bedding, with a lower dose of the drug (50mg/kg) having no effect. Animals treated with the high dose of L-NAME show no reduction of olfactory discrimination of male urine in a habituation-dishabituation test, thus suggesting that the effect of the drug on the preference for male pheromones is not due to an inability to detect male urine. Alternatively, it may result from an alteration in processing the reinforcing value of pheromones as sexual signals. These results add a new piece of evidence to our understanding of the neurochemistry of intraspecific chemical communication in rodents, and suggest that the role of nitric oxide in socio-sexual behaviours should be re-evaluated taking into account the involvement of this neuromodulator in the processing of chemical signals.

  19. Association of indoor air pollution with rhinitis symptoms, atopy and nitric oxide levels in exhaled air

    DEFF Research Database (Denmark)

    Hersoug, Lars-Georg; Husemoen, Lise Lotte N; Thomsen, Simon Francis

    2010-01-01

    Exposure to particulate matter (PM) outdoors can induce airway inflammation and exacerbation of asthma in adults. However, there is limited knowledge about the effects of exposure to indoor PM. The aim of this study was to investigate the association of exposure to indoor sources of PM...... with rhinitis symptoms, atopy and nitric oxide in exhaled air (FeNO) as a measure of airway inflammation....

  20. Actual waste demonstration of the nitric-glycolic flowsheet for sludge batch 9 qualification

    Energy Technology Data Exchange (ETDEWEB)

    Newell, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martino, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reboul, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Johnson, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-03-09

    For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch is processable. Based on the results of this actual-waste qualification and previous simulant studies, SRNL recommends implementation of the nitric-glycolic acid flowsheet in DWPF. Other recommendations resulting from this demonstration are reported in section 5.0.