Relevant bibliographies by topics / Nitrite Stress

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Nitrite Stress'

Author: Grafiati
Published: 6 September 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Nitrite Stress.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Nitrite Stress"

1

Karwowska, Małgorzata, and Anna Kononiuk. "Nitrates/Nitrites in Food—Risk for Nitrosative Stress and Benefits." Antioxidants 9, no. 3 (March 16, 2020): 241. http://dx.doi.org/10.3390/antiox9030241.

Full text
Abstract:
In the context of impact on human health, nitrite/nitrate and related nitrogen species such as nitric oxide (NO) are a matter of increasing scientific controversy. An increase in the content of reactive nitrogen species may result in nitrosative stress—a deleterious process, which can be an important mediator of damage to cell structures, including lipids, membranes, proteins and DNA. Nitrates and nitrites are widespread in the environment and occur naturally in foods of plant origin as a part of the nitrogen cycle. Additionally, these compounds are used as additives to improve food quality and protect against microbial contamination and chemical changes. Some vegetables such as raw spinach, beets, celery and lettuce are considered to contain high concentrations of nitrates. Due to the high consumption of vegetables, they have been identified as the primary source of nitrates in the human diet. Processed meats are another source of nitrites in our diet because the meat industry uses nitrates/nitrites as additives in the meat curing process. Although the vast majority of consumed nitrates and nitrites come from natural vegetables and fruits rather than food additives, there is currently a great deal of consumer pressure for the production of meat products free of or with reduced quantities of these compounds. This is because, for years, the cancer risks of nitrates/nitrites have been considered, since they potentially convert into the nitrosamines that have carcinogenic effects. This has resulted in the development and rapid expansion of meat products processed with plant-derived nitrates as nitrite alternatives in meat products. On the other hand, recently, these two ions have been discussed as essential nutrients which allow nitric oxide production and thus help cardiovascular health. Thus, this manuscript reviews the main sources of dietary exposure to nitrates and nitrites, metabolism of nitrites/nitrates, and health concerns related to dietary nitrites/nitrates, with particular emphasis on the effect on nitrosative stress, the role of nitrites/nitrates in meat products and alternatives to these additives used in meat products.
APA, Harvard, Vancouver, ISO, and other styles
2

Rajeev, Lara, Amy Chen, Alexey E. Kazakov, Eric G. Luning, Grant M. Zane, Pavel S. Novichkov, Judy D. Wall, and Aindrila Mukhopadhyay. "Regulation of Nitrite Stress Response in Desulfovibrio vulgaris Hildenborough, a Model Sulfate-Reducing Bacterium." Journal of Bacteriology 197, no. 21 (August 17, 2015): 3400–3408. http://dx.doi.org/10.1128/jb.00319-15.

Full text
Abstract:
ABSTRACTSulfate-reducing bacteria (SRB) are sensitive to low concentrations of nitrite, and nitrite has been used to control SRB-related biofouling in oil fields.Desulfovibrio vulgarisHildenborough, a model SRB, carries a cytochromec-type nitrite reductase (nrfHA) that confers resistance to low concentrations of nitrite. The regulation of this nitrite reductase has not been directly examined to date. In this study, we show that DVU0621 (NrfR), a sigma54-dependent two-component system response regulator, is the positive regulator for this operon. NrfR activates the expression of thenrfHAoperon in response to nitrite stress. We also show thatnrfRis needed for fitness at low cell densities in the presence of nitrite because inactivation ofnrfRaffects the rate of nitrite reduction. We also predict and validate the binding sites for NrfR upstream of thenrfHAoperon using purified NrfR in gel shift assays. We discuss possible roles for NrfR in regulating nitrate reductase genes in nitrate-utilizingDesulfovibriospp.IMPORTANCEThe NrfA nitrite reductase is prevalent across several bacterial phyla and required for dissimilatory nitrite reduction. However, regulation of thenrfAgene has been studied in only a few nitrate-utilizing bacteria. Here, we show that inD. vulgaris, a bacterium that does not respire nitrate, the expression ofnrfHAis induced by NrfR upon nitrite stress. This is the first report of regulation ofnrfAby a sigma54-dependent two-component system. Our study increases our knowledge of nitrite stress responses and possibly of the regulation of nitrate reduction in SRB.
APA, Harvard, Vancouver, ISO, and other styles
3

Stojanović, Nikola M., Pavle J. Randjelović, Dragana Pavlović, Nenad I. Stojiljković, Ivan Jovanović, Dušan Sokolović, and Niko S. Radulović. "An Impact of Psychological Stress on the Interplay between Salivary Oxidative Stress and the Classic Psychological Stress-Related Parameters." Oxidative Medicine and Cellular Longevity 2021 (January 7, 2021): 1–8. http://dx.doi.org/10.1155/2021/6635310.

Full text
Abstract:
Both oxidative and psychological (mental) stress are the likely culprits for several acute and chronic health disturbances, and adequate tests mimicking that are needed. Herein, in controlled laboratory surroundings, a PEBL (Psychology Experiment Building Language) test battery was used to evoke stress-related biological responses followed by tracking changes in saliva parameters. The study objectives were to determine the impact of psychological stress on selected salivatory parameters and to assess the correlation between the determined oxidative and stress parameters. The study was conducted on 36 healthy young subjects, mainly females ( n = 24 ). Before and following the completion of a battery of four PEBL tests, subjects’ saliva samples were collected. Stress-evoking changes in total antioxidant capacity and nitrite/nitrate levels, as oxidative stress parameters, and cortisol and immunoglobulin A (IgA), as parameters of psychological stress, were established and mutually correlated by comparing the values of the evaluated parameters pre- and post-PEBL test. The results showed that there is no change in the total salivary antioxidant capacity ( p > 0.05 ); however, there was a significant increase in nitrites/nitrates levels after the PEBL test ( p = 0.007 ). On the other hand, the determined cortisol levels after the test battery were found to be statistically significantly increased ( p = 0.025 ) when compared to the values obtained before the test, while the levels of IgA were found to be statistically significantly decreased ( p < 0.001 ). The only statistically significant correlation between the changes in the studied parameters was found to be the one between cortisol and IgA levels (Spearman’s Rö = -0.4). These results suggest that the short-term stress induced by the PEBL test does evoke changes in the salivary mental stress-related parameters (an increase in cortisol and nitrite/nitrate levels, and a decrease in IgA), but not in the total antioxidant capacity. They also indicate that the constructed PEBL four-test battery might represent an adequate laboratory stress-inducing paradigm.
APA, Harvard, Vancouver, ISO, and other styles
4

Stojanović, Nikola M., Pavle J. Randjelović, Dragana Pavlović, Nenad I. Stojiljković, Ivan Jovanović, Dušan Sokolović, and Niko S. Radulović. "An Impact of Psychological Stress on the Interplay between Salivary Oxidative Stress and the Classic Psychological Stress-Related Parameters." Oxidative Medicine and Cellular Longevity 2021 (January 7, 2021): 1–8. http://dx.doi.org/10.1155/2021/6635310.

Full text
Abstract:
Both oxidative and psychological (mental) stress are the likely culprits for several acute and chronic health disturbances, and adequate tests mimicking that are needed. Herein, in controlled laboratory surroundings, a PEBL (Psychology Experiment Building Language) test battery was used to evoke stress-related biological responses followed by tracking changes in saliva parameters. The study objectives were to determine the impact of psychological stress on selected salivatory parameters and to assess the correlation between the determined oxidative and stress parameters. The study was conducted on 36 healthy young subjects, mainly females ( n = 24 ). Before and following the completion of a battery of four PEBL tests, subjects’ saliva samples were collected. Stress-evoking changes in total antioxidant capacity and nitrite/nitrate levels, as oxidative stress parameters, and cortisol and immunoglobulin A (IgA), as parameters of psychological stress, were established and mutually correlated by comparing the values of the evaluated parameters pre- and post-PEBL test. The results showed that there is no change in the total salivary antioxidant capacity ( p > 0.05 ); however, there was a significant increase in nitrites/nitrates levels after the PEBL test ( p = 0.007 ). On the other hand, the determined cortisol levels after the test battery were found to be statistically significantly increased ( p = 0.025 ) when compared to the values obtained before the test, while the levels of IgA were found to be statistically significantly decreased ( p < 0.001 ). The only statistically significant correlation between the changes in the studied parameters was found to be the one between cortisol and IgA levels (Spearman’s Rö = -0.4). These results suggest that the short-term stress induced by the PEBL test does evoke changes in the salivary mental stress-related parameters (an increase in cortisol and nitrite/nitrate levels, and a decrease in IgA), but not in the total antioxidant capacity. They also indicate that the constructed PEBL four-test battery might represent an adequate laboratory stress-inducing paradigm.
APA, Harvard, Vancouver, ISO, and other styles
5

De Luca, Chiara, Agnese Gugliandolo, Carlo Calabrò, Monica Currò, Riccardo Ientile, Desanka Raskovic, Ludmila Korkina, and Daniela Caccamo. "Role of Polymorphisms of Inducible Nitric Oxide Synthase and Endothelial Nitric Oxide Synthase in Idiopathic Environmental Intolerances." Mediators of Inflammation 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/245308.

Full text
Abstract:
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 (CCTTT)nas 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 (CCTTT)11allele represents a genetic determinant for FM/CFS, and the (CCTTT)16allele discriminates MCS from SMCS patients. Instead, the (CCTTT)8allele 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 (CCTTT)npolymorphism may be useful for differential diagnosis of various IEI.
APA, Harvard, Vancouver, ISO, and other styles
6

Förster, Moritz, Christopher Nelke, Saskia Räuber, Hans Lassmann, Tobias Ruck, Maria Pia Sormani, Alessio Signori, et al. "Nitrosative Stress Molecules in Multiple Sclerosis: A Meta-Analysis." Biomedicines 9, no. 12 (December 14, 2021): 1899. http://dx.doi.org/10.3390/biomedicines9121899.

Full text
Abstract:
Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system of unknown etiology. As it is still a diagnosis of exclusion, there is an urgent need for biomarkers supporting its diagnosis. Increasing evidence suggests that nitrosative stress may play a pivotal role in the pathogenesis of MS. However, previous reports supporting the role of nitrosative stress molecules as disease biomarkers are inconsistent overall. We therefore systematically analyzed the existing literature to compare the serum and cerebrospinal fluid (CSF) levels of nitrite/nitrate in MS patients with those in patients with noninflammatory other neurological diseases (NIOND) and healthy controls (HC), respectively. We searched the PubMed database and included original articles investigating nitrite/nitrate levels in MS patients and NIOND patients or HC based on predefined selection criteria. Effect sizes were estimated by the standardized mean difference using a random effects model. Our results suggest that MS is associated with higher nitrite/nitrate levels within the CSF compared with patients with NIOND (SMD of 1.51; 95% CI: 0.72, 2.30; p = 0.0008). Likewise, nitrite/nitrate in the CSF of MS patients trends towards increased levels compared with those of HC but does not reach statistical significance (SMD of 3.35; 95% CI: −0.48, 7.19; p = 0.07). Measurement of nitrite/nitrate in the CSF might be a valuable tool facilitating the differentiation of MS and NIOND. Further studies with more homogeneous study criteria are needed to corroborate this hypothesis.
APA, Harvard, Vancouver, ISO, and other styles
7

Gruber, H.-J., C. Bernecker, A. Lechner, S. Weiss, M. Wallner-Blazek, A. Meinitzer, G. Höbarth, et al. "Increased nitric oxide stress is associated with migraine." Cephalalgia 30, no. 4 (September 1, 2009): 486–92. http://dx.doi.org/10.1111/j.1468-2982.2009.01964.x.

Full text
Abstract:
Nitric oxide (NO) has been implicated in migraine attacks, but the role of NO in migraine remains unclear. We here hypothesize that increased NO in the headache-free period is associated with migraine. One hundred and thirty probands participated in this study. Various parameters of the NO pathway, such as nitrate, nitrite, arginine, citrulline, nitrosylated proteins, asymmetric dimethylarginine, symmetrical dimethylarginine, expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase and two polymorphisms of eNOS were investigated. We found significant increased nitrate and decreased nitrite levels in migraineurs in the headache-free period. Nitrate and nitrite levels showed a significant inverse correlation. Logistic regression revealed an odds ratio of 3.6 for migraine. Other parameters of the NO pathway were neither altered in migraineurs nor correlated with nitrate. We show here that migraine patients suffer under sustained increased nitrosative stress in the headache-free period, which is associated with a 3.6-fold higher risk for migraine.
APA, Harvard, Vancouver, ISO, and other styles
8

Kern, Melanie, Christine Winkler, and Jörg Simon. "Respiratory nitrogen metabolism and nitrosative stress defence in ϵ-proteobacteria: the role of NssR-type transcription regulators." Biochemical Society Transactions 39, no. 1 (January 19, 2011): 299–302. http://dx.doi.org/10.1042/bst0390299.

Full text
Abstract:
ϵ-Proteobacteria form a globally ubiquitous group of ecologically significant organisms and comprise a diverse range of host-associated and free-living species. To grow by anaerobic respiration, many ϵ-proteobacteria reduce nitrate to nitrite followed by either nitrite ammonification or denitrification. Using the ammonifying model organisms Wolinella succinogenes and Campylobacter jejuni, the electron transport chains of nitrate respiration, respiratory nitrite ammonification and even N2O (nitrous oxide) respiration have been characterized in recent years, but knowledge on nitrosative stress defence, nitrogen compound-sensing and corresponding signal transduction pathways is limited. The potentially dominant role of NssR (nitrosative stress-sensing regulator)-type transcription regulators in ϵ-proteobacterial nitrogen metabolism is discussed.
APA, Harvard, Vancouver, ISO, and other styles
9

Sun, Dong, An Huang, Ellen H. Yan, Zhiping Wu, Changdong Yan, Pawel M. Kaminski, Tim D. Oury, Michael S. Wolin, and Gabor Kaley. "Reduced release of nitric oxide to shear stress in mesenteric arteries of aged rats." American Journal of Physiology-Heart and Circulatory Physiology 286, no. 6 (June 2004): H2249—H2256. http://dx.doi.org/10.1152/ajpheart.00854.2003.

Full text
Abstract:
We hypothesized that aging is characterized by a reduced release of nitric oxide (NO) in response to shear stress in resistance vessels. Mesenteric arterioles and arteries of young (6 mo) and aged (24 mo) male Fischer 344 rats were isolated and cannulated. Shear stress (15 dyn/cm2)-induced dilation was significantly reduced and shear stress (1, 5, 10, and 15 dyn/cm2)-induced increases in perfusate nitrite were significantly smaller at all shear stress levels in vessels of aged rats. Inhibition of NO synthesis abolished shear stress-induced release of nitrite. Furthermore, shear stress (15 dyn/cm2)-induced release of nitrate was significantly higher and total nitrite (nitrite plus nitrate) was significantly lower in vessels of aged rats. Tiron or SOD significantly increased nitrite released from vessels of aged rats, but this was still significantly less than that in young rats. Superoxide production was increased and the activity of SOD was decreased in vessels of aged rats. There were no differences in endothelial NO synthase (eNOS) protein and basal activity or in Cu/Zn-SOD and Mn-SOD proteins in vessels of the two groups, but extracellular SOD was significantly reduced in vessels of aged rats. Maximal release of NO induced by shear stress plus ACh (10−5 M) was comparable in the two groups, but phospho-eNOS in response to shear stress (15 dyn/cm2) was significantly reduced in vessels of aged rats. These data suggest that an increased production of superoxide, a reduced activity of SOD, and an impaired shear stress-induced activation of eNOS are the causes of the decreased shear stress-induced release of NO in vessels of aged rats.
APA, Harvard, Vancouver, ISO, and other styles
10

Liu, Jianfeng, Jiao Yin, Yanshuang Li, Dingjin Li, Jiaxuan Wu, Chengxian Wang, Changmei Wang, Fang Yin, Bin Yang, and Wudi Zhang. "High nitrite–nitrogen stress intensity drives nitrite anaerobic oxidation to nitrate and inhibits methanogenesis." Science of The Total Environment 832 (August 2022): 155109. http://dx.doi.org/10.1016/j.scitotenv.2022.155109.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Nitrite Stress"

1

Okeremi, Akinyemi. "The effect of nitrite on pitting and stress corrosion cracking of corrosion resistant alloys (CRA) under oil field conditions." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/the-effect-of-nitrite-on-pitting-and-stress-corrosion-cracking-of-corrosion-resistant-alloys-cra-under-oil-field-conditions(aced05b8-f8b0-40de-bbc5-990474d87794).html.

Full text
Abstract:
The need to inject treated seawater to enhance reservoir pressure and secondary oil recovery is increasing in the oil field, so also is the reservoir souring potential caused by the activities of Sulphate Reducing Bacteria (SRB) generating H2S in the reservoir. The total cost of SRB mediated corrosion in the United States alone is estimated to be 1-2 billion US dollars per year. In the last few years, a number of potential souring mitigation and prevention tools have been studied. These include: sulphate-reduction using membranes, biocide injection and nitrate injection. Out of all the various methods used for the mitigation and prevention of reservoir souring, the use of nitrate injection in conjunction with waterflood projects is becoming more popular because of its economic benefits and least environmental impact. However, nitrate injection is still widely considered as an emergent technology because there are still many unknowns. One of the major unknowns, of great concern is the susceptibility of subsea hardware components to nitrite, which is a by-product of nitrate anti-souring treatment. Any detrimental effect can compromise the technical integrity of subsea installations. The objective of this research is to study the corrosion susceptibility of CRA (13Cr- Martensitic, 22Cr, and 25Cr super duplex stainless steel) to pitting and stress corrosion cracking in the presence of nitrite. Research hitherto, has investigated corrosion susceptibility of carbon steel to nitrite and found out that nitrite causes pitting in carbon steel. This research work built on previous studies and extensively investigated the effect of nitrite on CRA materials in terms of pitting and stress corrosion cracking. Using electrochemistry techniques in conjunction with C-ring test and slow strain rate test, with variables such as temperature, and nitrite concentration all under anaerobic conditions. Metallographic examination and further evaluation using scanning electron microscopy confirmed pitting and intergranular stress corrosion cracking of 13Cr-L80 and 25Cr due to presence of nitrite.Test data confirmed that sodium nitrite is an anodic inhibitor; it shifts the corrosion potentials to more noble potential and also shifts the anodic curve to lower current, given a net reduction in corrosion rate. A critical concentration of 400ppm is required for inhibition to be effective on 13Cr-L80 and 25Cr. However, below the critical concentration, nitrite significantly increases the corrosion rate. The experimental data generated from this research work provides very valuable information that will tremendously assist the materials selection process for subsea and subsurface hardware components and also serve as a guide in the corrosion management process in existing systems.
APA, Harvard, Vancouver, ISO, and other styles
2

SCULCO, FRANCESCA. "Effetti dello stress ossidativo sulla tolleranza ai nitroderivati." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/784.

Full text
Abstract:
Nel secolo scorso, la nitroglicerina è stato il farmaco più comunemente usato come agente antiischemico ed antianginoso. La sua continua somministrazione, però, ne fa svanire piuttosto rapidamente l’efficacia terapeutica. L’attivazione neuroormonale dei segnali vasocostrittori e l’espansione del volume intravascolare costituiscono le iniziali risposte contro-regolatorie (pseudotelleranza), mentre il trattamento a lungo termine induce cambiamenti vascolari intrinseci, come per esempio la perdita delle risposte nitrovasodilatatorie (tolleranza vascolare). Tutto ciò è causato da un’incrementata produzione di anione superossido e da una ipersensibilità verso vasocostrittori secondari per una tonica attivazione della PKC. Come fonti di anione superossido sono state proposte la NADPH ossidasi e la eNOS disaccoppiata. Il superossido ed il nitrossido vascolare formano rapidamente perossinitrito, che aumenta la tolleranza promuovendo il disaccoppiamento della eNOS e l’inibizione della guanilato ciclasi solubile e della prostaciclina. Questo concetto di stress ossidtivo può spiegare perché gli scavangers dei radicali e le sostanze che riducono indirettamente lo stress ossidativo, sono capaci di attenuare la tolleranza e la disfunzione endoteliale. Un lavoro recente ha definito un nuovo meccanismo di tolleranza basato sull’inibizione dell’ALDH-2, l’enzima deputato alla bioconversione enzimatica del GTN in NO, ed ha identificato i mitocondri come una fonte addizionale di specie reattive dell’ossigeno (ROS). Le specie reattive indotte dal GTN inibiscono la 6 bioattivazione della nitroglicerina medinte l’ossidazione tiolica dell’ALDH-2. Sia l’increnmento dello stress ossidativo che l’alterazione della bioconversione del GTN in NO, possono fornire un nuovo concetto di tolleranza ai nitrati nonché di cross-tolerance. Nel presente lavoro abbiamo documentato che la somministrazione a lungo termine di IS-5-MN in vitro ed in vivo induce tolleranza al GTN (definita cross-tolerance). Si sono altresì studiati gli effetti di CPT, ENA e NAC sulle risposte in vivo al GTN dopo trattamento cronico dei ratti con IS-5-MN e sono stati paragonati gli effetti di CPT, ENA o glutatione con quelli della NAC sugli effetti antipiastrinici del GTN in assenza o in presenza di TSMCs e TECs e sulla produzione di perossinitrito da GTN in un Krebs buffer. Per finire, sono stati valutate le risposte emodinamiche al GTN in ratti tolleranti e non, in presenza ed in assenza di co-trattamento con MnTBAP (1, 20 mg/kg/die, i.p.). Il presente studio, nel tentativo di chiarire i meccanismi molecolari che sottendono alla tolleranza ai nitrati, ha incentrato l’attenzione sul ruolo, che in tale fenomeno hanno, enzimi essenziali, quali la SOD e l’ALDH-2, i quali risultano, rispettivamente, down-regulated ed inattivata dal fenomeno della tolleranza. Il MnTBAP, un SOD-mimic di ultima generazione, si è rivelato in grado di inibire lo sviluppo di tolleranza ai nitrati organici in maniera dose-dipendente, ripristinando l’effetto del GTN sulla pressione sanguigna e sull’ggregazione piastrinica, riducendo la formazione di perossinitrito, come dimostrato dallo staining della nitrotirosina ed antagonizzando l’inibizione dell’ALDH-2 indotta dallo stress ossidativo. La formazione di perossinitrito gioca un ruolo 7 cruciale durante lo sviluppo di tolleranza ai nitroderivati in quanto riduce la biodisponibilità di NO. Quindi, quanto riportato nel nostro studio potrebbe aprire una nuova frontiera nel management delle malattie cardiovascolari, consentendo l’uso a lungo termine dei nitrati organici, senza che si sviluppi tolleranza.
During the last century, nitroglycerin has been the most commonly used antiischemic and antianginal agent. Unfortunately, after continuous application, its therapeutic efficacy rapidly vanishes. Neurohormonal activation of vasoconstrictor signals and intravascular volume expansion constitute early counter-regulatory responses (pseudotolerance), whereas long-term treatment induces intrinsic vascular changes, eg, a loss of nitrovasodilatorresponsiveness (vascular tolerance). This is caused by increased vascular superoxide production and a supersensitivity to vasoconstrictors secondary to a tonic activation of protein kinase C. NADPH oxidase(s) and uncoupled endothelial nitric oxide synthase have been proposed as superoxide sources. Superoxide and vascular NO rapidly form peroxynitrite, which aggravates tolerance by promoting NO synthase uncoupling and inhibition of soluble guanylyl cyclase and prostacyclin synthase. This oxidative stress concept may explain why radical scavengers and substances, which reduce oxidative stress indirectly, are able to relieve tolerance and endothelial dysfunction. Recent work has defined a new tolerance mechanism, ie, an inhibition of mitochondrial aldehyde dehydrogenase, the enzyme that accomplishes bioactivation of nitroglycerin, and has identified mitochondria as an additional source of reactive oxygen species. Nitroglycerin-induced reactive oxygen species inhibit the bioactivation of nitroglycerin by thiol oxidation of aldehyde dehydrogenase. Both mechanisms, increased oxidative 3 stress and impaired bioactivation of nitroglycerin, can be joined to provide a new concept for nitroglycerin tolerance and crosstolerance. In this work we have demonstrate that long-term administration of isosorbide-5-mononitrate in vitro ed in vivo induces tolerance to GTN (this is the so-called cross-tolerance). Here we have studied the effects of CPT, NAC or ENA on the in vivo responses to GTN after long-term treatment of rats with IS-5-MN. In addition, we have compared the effects of CPT, ENA or glutathione to those of NAC on the anti-platelet effects of GTN in the absence or presence of tolerant cultured SMCs or ECs and on production from GTN in Krebs buffer. Finally, we have valuated the haemodynamic responses to glyceryl trinitrate in non-tolerant rats and in tolerant rats with or without pharmacological co- treatment with MnTBAP (1-20 mg/kg, i.p.). The present study was designed to elucidate the mechanisms of nitrate tolerance by assessing the function of essential enzymes implicated in this phenomenon. We demonstrated that SOD and ALDH-2 are downregulated and inactivated, respectly, during nitrate-tolerance. MnTBAP, a new generation antioxidant, is able to inhibit the development of tolerance to organic nitrates in a dose dependent fashion restoring the GTN effect on blood pressure and on platelets aggregation and reducing the peroxynitrite formation as evaluated by the inhibition of the nitrotyrosine staining and antagonizing the ALDH-2 inhibition oxidative stress-induced. Peroxynitrite formation play a crucial role during the development of tolerance to organic nitrates most likely via reduction of nitric oxide bioavalaibility. The broader implications 4 of these findings may open a new frontier in the clinical management of cardiovascular disease, in particular allowing the use of long-term organic nitrates treatment without development of tolerance.
APA, Harvard, Vancouver, ISO, and other styles
3

Choi, Sukwon. "Stress metrology and thermometry of AlGaN/GaN HEMTs using optical methods." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49108.

Full text
Abstract:
The development of state-of-the-art AlGaN/GaN high electron mobility transistors (HEMTs) has shown much promise for advancing future RF and microwave communication systems. These revolutionary devices demonstrate great potential and superior performance and many commercial companies have demonstrated excellent reliability results based on multiple temperature accelerated stress testing. However, a physical understanding of the various reliability limiting mechanisms is lacking and the role and relative contribution of the various intrinsic material factors, such as physical stress and strain has not been clearly explained in the literature. Part of issues that impact device reliability are the mechanical stresses induced in the devices as well as the self-heating that also limit device performance. Thus, quantification of stress and temperature in AlGaN/GaN HEMTs is of great importance. To address some of the needs for metrology to quantify stress in AlGaN/GaN HEMTs, micro-Raman spectroscopy and micro-photoluminescence (micro-PL) were utilized to quantify the residual stress in these devices. Through the use of micro-Raman and micro-PL optical characterization methods, mapping of the vertical and lateral stress distributions in the device channels was performed. Results show that stress can be influenced by the substrate material as well as patterned structures including metal electrodes and passivation layers. Previously developed and reported micro-Raman thermometry methods require an extensive calibration process for each device investigated. To improve the implementation of micro-Raman thermometry, a method was developed which offers both experimental simplicity and high accuracy in temperature results utilizing a universal calibration method that can be applied to a broad range of GaN based devices. This eliminates the need for performing calibration on different devices. By utilizing this technique, it was revealed that under identical power dissipation levels, the bias conditions (combination of Vgs and Vds) alter the heat generation profile across the conductive channel and thus influence the degree of device peak temperature. The role of stress in the degradation of AlGaN/GaN HEMTs was also explored. A combined analysis using micro-Raman spectroscopy, coupled electro-thermo-mechanical simulation, and electrical step stress tests was conducted to investigate the link between performance degradation and the evolution of total stress in devices. It was found that in addition to stresses arising from the inverse piezoelectric effect, the substrate induced residual stress and the operational themo-elastic stress in the AlGaN layer play a major role in determining the onset of mechanically driven device degradation. Overall, these experiments were the first to suggest that a critical level of stress may exist at which point device degradation will start to occur. The optical characterization methods developed in this study show the ability to reveal unprecedented relationships between temperature/stress and device performance/reliability. They can be used as effective tools for facilitating improvement of the reliability of future AlGaN/GaN HEMTs.
APA, Harvard, Vancouver, ISO, and other styles
4

Herrman, Kyle S. "Mechanisms controlling nitrogen removal in agricultural headwater streams." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1181667344.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lízalová, Martina. "Aplikace vybraných metod k analýze oxidačního stresu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-233302.

Full text
Abstract:
Chronic pancreatitis (CP) is a heterogeneous disease defined as chronic inflammatory changes of the pancreatic tissue caused by variety of aetiologies. Oxidative stress accompanying the inflammatory processes has been suggested as an important factor contributing to CP development. The aim of this study was to determine levels of lipid peroxidation products malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), together with nitrites, the total antioxidant capacity, cytokines, biochemical and haematological parameters in the plasma of patients with CP and control subjects. Levels of MDA and 4-HNE were analyzed using high-performance liquid chromatography. The total antioxidant capacity of plasma against peroxyl radicals was evaluated using chemiluminescence determination. Nitrites were determined using Griess reaction. Cytokines - TNF-alfa; TNF RI; PDGF-AB; TGF-beta, together with myeloperoxidase and hyaluronan were determined using ELISA Kits. Biochemical and haematological parameters were measured by standard methods.
APA, Harvard, Vancouver, ISO, and other styles
6

Silva, Petterson Costa Conceição. "Papel da glutamina na regulação do influxo de nitrato em raízes de feijão-caupí expostas à salinidade." reponame:Repositório Institucional da UFC, 2015. http://www.repositorio.ufc.br/handle/riufc/19323.

Full text
Abstract:
SILVA, Petterson Costa Conceição. Papel da glutamina na regulação do influxo de nitrato em raízes de feijão-caupí expostas à salinidade. 2015. 91 f. Dissertação (Mestrado em solos e nutrição de plantas)-Universidade Federal do Ceará, Fortaleza, 2015.
Submitted by Vitor Campos (vitband@gmail.com) on 2016-08-31T21:37:40Z No. of bitstreams: 1 2015_dissertacao_pccsilva.pdf: 2241402 bytes, checksum: 90dfc5f9012e295047f9193c64411616 (MD5)
Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-08-31T22:51:31Z (GMT) No. of bitstreams: 1 2015_dissertacao_pccsilva.pdf: 2241402 bytes, checksum: 90dfc5f9012e295047f9193c64411616 (MD5)
Made available in DSpace on 2016-08-31T22:51:31Z (GMT). No. of bitstreams: 1 2015_dissertacao_pccsilva.pdf: 2241402 bytes, checksum: 90dfc5f9012e295047f9193c64411616 (MD5) Previous issue date: 2015
There are many studies showing that the salinity may directly affect the nitrate uptake, from their osmotic effect, nature of the salt and its ionic composition. However, little is known about the mechanisms related to the salt ability to inhibit the nitrate acquisition indirectly. This study was carried with aim to induce inhibition of NO3- influx in cowpea roots of indirect form triggered by a negative feedback mechanism, caused by the increase in the pool of free amino acids in the tissue, induced by salt stress.For this, were done three isolated studies and continuous.The exogenous glutamine application promoted an increase in the free amino acids content.The presence of glutamine decreased significantly the nitrate acquisition.The free ammonium can also be listed as a key-compound in the role of nitrate influx regulation, since use of the MSX (Methionine sulfoximine) promoted the increase of NH4+ content and also reduced nitrate influx, but, in a lesser degree when compared to treatment with AZA (Azaserine). Salt stress caused a reduction in NO3- influx by decrease in the growth of plants induced by salt. The data indicated which this reduction in the influx is triggered by increase of amino acids content, mainly the glutamine, that is main likely compound to act as signal in the N-feedback regulation.
Existem muitos estudos mostrando que a salinidade pode afetar a absorção de nitrato de forma direta, a partir do seu efeito osmótico, da natureza do sal e de sua composição iônica. Entretanto, pouco se sabe sobre os mecanismos relacionados com a capacidade do sal em inibir a aquisição de nitrato de forma indireta. O presente estudo teve como objetivo induzir a inibição do influxo de NO3- em raízes de feijão-caupí de forma indireta desencadeada por um mecanismo de feedback negativo, provocado pelo aumento no pool de aminoácidos livres no tecido, induzido por estresse salino. Para isso, foram realizados três estudos isolados e contínuos. A aplicação de glutamina exógena promoveu um aumento no conteúdo de aminoácidos livres. A presença de glutamina reduziu significativamente a aquisição de nitrato. O amônio livre também pode ser listado como um composto-chave no papel da regulação do influxo de nitrato, pois a utilização do MSO (Metionina sulfoximina) promoveu o aumento do conteúdo de NH4+ e também reduziu o influxo de nitrato, porém em menor grau quando comparado ao o tratamento com AZA (Azaserina). O estresse salino causou uma redução no influxo de NO3-, pela diminuição no crescimento das plantas induzida pelo sal. Adicionalmente, estes dados indicaram que esta redução no influxo está ligada ao aumento do teor de aminoácidos, principalmente a glutamina, que é o principal componente para atuar como sinal na regulação por N-feedback.
APA, Harvard, Vancouver, ISO, and other styles
7

Masson, Isabelle. "Détermination des propriétés mécaniques en fluage a haute température et étude des microstructures de déformation de céramiques a base de nitrure d'aluminium." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL136N.

Full text
Abstract:
En vue d'applications en sidérurgie dans les nouveaux procédés de coulée continue de bandes minces, plusieurs céramiques à base de nitrure d'aluminium (AlN fritte (SAlN), AlN presse a chaud (HPAlN) et composites al#2o#3-AlN) ont été déformées en compression uniaxiale soit sous contrainte constante (150-250 MPa) soit à vitesse de déformation imposée (5. 10##6s##1) à des températures variant de 1200 à 1650c puis caractérisées en microscopie électronique à balayage, en microscopie électronique à transmission et par analyse EDX. En fluage a charge constante, la vitesse de déformation est proportionnelle à la contrainte appliquée à la puissance 1,5 et varie exponentiellement avec la temperature, l'énergie d'activation apparente ayant une valeur moyenne de 650 kj. Mol##1 (la valeur maximale de la vitesse de déformation atteinte pour HPAlN déformé à 1650c sous 250 MPa étant de 4. 10##6s##1). A vitesse imposée, les courbes contrainte-déformation passent par une contrainte maximale qui croit quand la température diminue (la valeur maximale obtenue pour HPAlN déformé à 1550c étant de 670 MPa) puis décroissent. Après essai, la présence de nombreuses cavités aux joints de grains et aux points triples montre que la déformation est surtout intergranulaire. Les grains se déforment aussi plastiquement par mouvement de dislocations situées majoritairement dans le plan de base et de vecteur de burgers 1/3<1120>. Nous avons également observé plusieurs preuves de la montée de ces dislocations et de glissement dévié dans des plans prismatiques ou pyramidaux favorisée par l'absence de dissociation
APA, Harvard, Vancouver, ISO, and other styles
8

Nguyen, Chi Tam. "Identification et caractérisation d'un canal chlorure, AtCLCg, impliqué dans la réponse au stress salin chez Arabidopsis thaliana." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00856592.

Full text
Abstract:
Dans les cellules végétales, les canaux et les transporteurs anioniques sont essentiels pour les fonctions clés telles que la nutrition, l'homéostasie ionique et la tolérance aux stress biotiques ou abiotiques. Chez Arabidopsis thaliana, les membres de la famille CLC (pour ChLoride Channel), situés sur le tonoplaste, sont requis pour l'homéostasie du nitrate (AtCLCa et AtCLCb) ou impliqués dans la tolérance au sel (AtCLCc).Dans mon travail de thèse, j'ai identifié et caractérisé un canal chlorure, AtCLCg, chez A. thaliana. L'étude de la protéine fusion AtCLCg::GFP a révélé que cette protéine est localisée sur le tonoplaste. Deux lignés mutants indépendants d'insertion ADN-T, atclcg ont été sélectionnés. Les études physiologiques sur ces deux lignés ont démontré qu'AtCLCg joue un rôle dans le passage de chlorure mais pas dans l'homéostasie du nitrate au travers du tonoplaste. En effet, aucune différence de contenu en nitrate (NO3-) racinaire et foliaire n'a été observée entre le sauvage et les mutants dans nos conditions. Par contre, les plantes mutantes présentent un phénotype par rapport au sauvage lorsqu'elles se développent sur milieu de croissance contenant 75 mM NaCl: (i) une diminution de 20% de la masse fraîche ; (ii) une diminution de 16% de la longueur de racines primaires et une réduction de 19% du nombre de racines secondaires ; (iii) une sur-accumulation de 21% et 26% de chlorure et sulfate foliaire, respectivement. Ces phénotypes sont abolis chez les lignés complétées avec 35S::AtCLCg. De plus, les mutants atclcg présentent un phénotype similaire à la présence de 75 mM KCl, mais aucune différence n'est détectée en réponse à 140 mM mannitol. Ce résultat suggère que le phénotype d'hypersensibilité des mutants atclcg dépend du chlorure et non du l'effet osmotique du stress salin.Sachant qu'AtCLCg et AtCLCc partagent un haut degré d'homologie, environ 75% d'identité au niveau des protéines, et que les deux sont impliquées dans la réponse au stress salin de la plante, nous avons généré le double mutant atclcc/atclcg. L'analyse phénotypique a montré que le double mutant ne présente pas un phénotype additif sur milieu de stress 75 mM NaCl. En parallèle, l'analyse de l'expression des gènes a montré qu'AtCLCg est réprimé dans le fond mutant atclcc, et inversement. Par ailleurs, l'analyse de l'expression de gène rapporteur démontre que PAtCLCg::GUS est fortement exprimé dans les cellules du mésophylle alors qu'une forte expression de PAtCLCc::GUS dans les cellules de garde et le pollen est observé. Ainsi, l'ensemble de ces résultats montrent que ces deux protéines AtCLCc et AtCLCg sont impliquées dans la réponse au stress salin de la plante, mais elles n'ont pas de fonction redondante.
APA, Harvard, Vancouver, ISO, and other styles
9

Ke, Jiaxin. "Stress engineering with silicon nitride stressors for Ge-on-Si lasers." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62116.

Full text
Abstract:
Silicon compatible lasers are in great need for applications such as on-chip and short-reach optical interconnects. Although InAs/GaAs quantum dot lasers monolithically grown on Si have been realized and are well-performed, due to material contamination issues, it is time and cost intensive for those III-V materials to enter mainstream Si processing facilities. Germanium(Ge)-on-Silicon(Si) laser is promising as a solution to solve the Si-compatible laser problem as it is compatible with Si processing. So far, the main problems in Ge lasers are that they have a high threshold current density and low efficiency. Laser structure designs with top and side silicon nitride stressors were proposed in this work and shown to be effective in reducing the threshold current (Ith) and improving the wall-plug efficiency (ηwp) of Ge-on-Si lasers. Side stressors turned out to be a more efficient way to increase ηwp than using the top and side stressors together. With the side stressors and geometry optimizations, a maximum ηwp of 34.8% and an Ith of 36 mA (Jth of 27 kA/cm²) were achieved with a defect limited carrier lifetime (𝜏𝑝,𝑛) of 1 ns. With 𝜏𝑝,𝑛 being 10 𝑛𝑠 , an Ith of 4 mA (Jth of 3 kA/cm²) and a ηwp of 43.8% were achieved. These are tremendous improvements from cases without any stressors. Compared to other stress introduction methods, such design is much more suitable for Ge laser structure implementation. These results provide a strong support to the Ge-on-Si laser technology and create an effective way to improve the Ge laser performance.
Applied Science, Faculty of
Materials Engineering, Department of
Graduate
APA, Harvard, Vancouver, ISO, and other styles
10

Paterson, Stuart. "Studies of dietary nitrate induced nitrosative stress in the upper gastrointestinal tract." Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/394/.

Full text
Abstract:
The incidence of neoplasia at the gastroesophageal junction has increased markedly over the past 20 years, but the mutagen responsible for this remains unknown. Human saliva contains substantial quantities of nitrite and is the main source of nitrite entering the stomach. It is derived from the enterosalivary recirculation of dietary nitrate and its reduction by buccal bacteria. Carcinogenic N-nitrosocompounds may be formed from the nitrite in swallowed saliva by bacterially-catalysed nitrosation in the achlorhydric stomach or acid-catalysed nitrosation in the healthy acid secreting stomach. Protection against luminal acid-catalysed nitrosation is provided by the ascorbic acid content of human gastric juice which reduces nitrite to nitric oxide (NO). A high luminal concentration of NO generated from salivary nitrite has been shown at the gastroesophageal junction. A bench top model has been developed to explore the chemistry occurring in an aqueous phase, representing the lumen at the gastroesophageal junction, after the addition of nitrite. Within this model an adjacent lipid phase has been created. The lipid phase represents the adjacent mucosa to the lumen or the dietary fat shown to sit within the fundus of the stomach. In this two-phase model, addition of physiological concentrations of nitrite to an acidic aqueous phase in the absence of ascorbic acid generated nitrosative stress within the aqueous phase. The addition of physiological concentrations of ascorbic acid to the aqueous phase prevents nitrosative stress within the aqueous phase but in so doing generates nitrosative stress within the lipid phase. This can be explained by the ascorbic acid converting the salivary nitrite to NO which diffuses into the lipid phase and there reacts with O2 to form the nitrosating species N2O3. The bench top model has been developed further to include the lipid antioxidants, α-tocopherol, β-carotene and BHT. All three of these antioxidants are effective in inhibiting nitrosative stress within the lipid phase. The concentration of α-tocopherol required to inhibit nitrosation is less than would be expected from the reaction equation. A possible explanation for this is that ascorbic acid recycles the active antioxidant α-tocopherol from its reduced form. Further studies to support recycling of α-tocopherol by ascorbic acid are presented within this thesis. The design of a model used in vivo to assess for nitrosative stress is discussed. The model consisted of a hydrophobic silastic tubing containing a secondary amine at a neutral pH. The hydrophobic membrane that the tubing is composed of allowed the passage of gaseous NO. Human studies in healthy volunteers were performed using the silastic tubing. The data presented shows that after a nitrate rich drink there is significantly more nitrosative stress within the upper gastrointestinal tract and this is particularly the case in the first part of the stomach where salivary nitrite meets acidic gastric juice containing ascorbic acid. Finally, the studies explore directly measuring nitrosative stress in biopsy samples from humans and rats. As nitrite has been shown previously to be a marker of nitrosative stress in bench top models biopsy samples were assessed for nitrite and nitrate concentrations. Methods for assessing nitrite and nitrate concentrations within biopsy samples from the upper gastrointestinal tract are discussed, as nitrite and nitrate have not been analysed from this region previously. Thereafter, upper gastrointestinal biopsy samples from healthy human subjects were analysed after a control drink and a drink rich in nitrate. The studies presented show that biopsy nitrate and nitrite was higher in samples taken from the proximal stomach as compared to the oesophagus and distal stomach. This suggests that there is more nitrosative stress in the biopsies from the same area as where NO is generated after a nitrate meal. Together the data presented supports a novel mechanism for N-nitrosation in the upper gastrointestinal tract of a healthy subject. The N-nitrosation is maximal where swallowed salivary nitrite from dietary nitrate meets acidic gastric juice containing the aqueous antioxidant ascorbic acid.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Nitrite Stress"

1

Dillow, Jonathan J. A. Estimates of the loads of nitrite + nitrate in the flow of Bassett Creek to the Maryland Coastal Bays adjacent to Assateague Island National Seashore, water years 2003-2004. Reston, Va: U.S. Dept. of Interior, U.S. Geological Survey, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

E, Groseclose Lance, and United States. National Aeronautics and Space Administration., eds. Flexural stress rupture and creep of commercial silicon nitrides. [Washington, DC: National Aeronautics and Space Administration, 1991.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Jorgensen, Eric E. Ecosystem stress from chronic exposure to low levels of nitrate. Cincinnati, Ohio: National Risk Management Research Laboratory, 2005.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Khan, M. Nasir, Mohammad Mobin, Firoz Mohammad, and Francisco J. Corpas, eds. Nitric Oxide Action in Abiotic Stress Responses in Plants. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-17804-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lamattina, Lorenzo, and Joseph C. Polacco, eds. Nitric Oxide in Plant Growth, Development and Stress Physiology. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/11563280.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Khan, M. Nasir, Mohammad Mobin, Firoz Mohammad, and Francisco J. Corpas, eds. Nitric Oxide in Plants: Metabolism and Role in Stress Physiology. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06710-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Packer, Lester, and Enrique Cadenas. Nitric oxide: Oxidative and nitrosative stress in redox regulation of cell signaling. San Diego, Calif: Elsevier/Academic Press, 2008.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Abdul-Aziz, Ali. Design evaluation using finite element analysis of cooled silicon nitride plates for a turbine blade application. [Cleveland, Ohio]: National Aeronautics and Space Administration, Glenn Research Center, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Abdul-Aziz, Ali. Design evaluation using finite element analysis of cooled silicon nitride plates for a turbine blade application. [Cleveland, Ohio]: National Aeronautics and Space Administration, Glenn Research Center, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

M, Matata Bashir, and Elahi Maqsood M, eds. Oxidative stress: Clinical and biomedical implications. New York: Nova Biomedical Books, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Nitrite Stress"

1

Lewis, Janina P., and Benjamin R. Belvin. "What is it About NO That You don't Understand? The Role of Heme and HcpR inPorphyromonas Gingivalis's Response to Nitrate (NO3), Nitrite (NO2), and Nitric Oxide (NO)." In Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria, 976–88. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119004813.ch95.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Yadav, Divyansh, and Seema Nara. "Nanozymes for Neurodegenerative Diseases." In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 77–95. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_9.

Full text
Abstract:
AbstractNeurodegenerative diseases are incurable diseases that get worse as time passes. These diseases are very heterogeneous in nature but have common characteristics like abnormal deposition of protein, glycation, inflammation in particular areas of the brain, and progressive neuronal loss due to oxidative stress. Among these, oxidative stress alone causes a high level of degeneration of neurons. To reduce oxidative stress, natural antioxidants are used but they have some drawbacks like instability, high cost and low reusability. To overcome this, nanozymes are introduced and we have emphasized on major nanozymes whose antioxidant capability has been proven which are gold nanozymes, fullerene, nanoceria, and quantum dots. Gold nanoparticles and their conjugates with other molecules can mimic the enzymatic activity of superoxide dismutase and catalase which decrease the amount of hydrogen peroxide and superoxide radicals in cells. Gold Nanozyme treatment reduces the oxidative stress, nitrite, and sulfhydryl levels in the brain and also rectifies the superoxide dismutase, glutathione, and catalase activity levels. Fullerenols has shown superoxide dismutase activity which was 268 times more effective than mannitol and 37 times more effective than Vitamin E for lipid radicals. Nanoceria has the ability to mimic Superoxide Dismutase as well as catalase activity, can also detoxify peroxynitrite. Quantum dots (QDs) like Graphene Oxide QDs can scavenge the reactive oxygen species and also show indirect activity which alleviates the pathogenesis of the disease. Thus, a nanozyme can be used as an efficient nanomedicine if it is tailored to possess high catalytic activity while eliminating all complications.
APA, Harvard, Vancouver, ISO, and other styles
3

Hasanuzzaman, Mirza, Kamrun Nahar, Jubayer-Al-Mahmud, Parvaiz Ahmad, and Masayuki Fujita. "Nitric oxide." In Water Stress and Crop Plants, 628–48. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781119054450.ch36.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Saito, K., and R. G. Cutler. "Nitrone spin-traps release nitric oxide reaction with reactive oxygen species: Possible mechanism of biological activity." In Oxidative Stress and Aging, 379–86. Basel: Birkhäuser Basel, 1995. http://dx.doi.org/10.1007/978-3-0348-7337-6_35.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Sheokand, Sunita, and Anita Kumari. "Nitric Oxide and Abiotic Stress-Induced Oxidative Stress." In Nitric Oxide Action in Abiotic Stress Responses in Plants, 43–63. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-17804-2_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Shiotani, A., K. Okada, Y. Mantani, M. Iguchi, H. Magari, H. Tamai, S. Kitauchi, and M. Ichinose. "Nitric Oxide in the Gastric Lumen." In Oxidative Stress and Digestive Diseases, 136–46. Basel: KARGER, 2001. http://dx.doi.org/10.1159/000062736.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Wink, D. A., K. M. Miranda, M. G. Espey, J. B. Mitchell, M. B. Grisham, J. Fukuto, and M. Feelisch. "The Chemical Biology of Nitric Oxide. Balancing Nitric Oxide with Oxidative and Nitrosative Stress." In Nitric Oxide, 7–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-57077-3_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Yokoi, I., K. Inada, H. Habu, H. Kabuto, A. Mori, H. Ohyama, K. Iwaya, S. Koyama, Y. Nishijima, and K. Nishijima. "Age-related changes in nitric oxide content and nitric oxide synthase activity in senescence-accelerated mouse (SAMP8) brain." In Oxidative Stress and Aging, 387–91. Basel: Birkhäuser Basel, 1995. http://dx.doi.org/10.1007/978-3-0348-7337-6_36.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Chakraborti, Ayanabha, Kavita Gulati, and Arunabha Ray. "Sex Differences in Stress and Stress Related Neuropsychiatric Disorders: Focus on Nitric Oxide." In Nitric Oxide: From Research to Therapeutics, 279–95. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-24778-1_14.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Richter, Christoph, and Renato Laffranchi. "Nitric Oxide Signaling Through Mitochondrial Calcium Release." In Oxidative Stress and Signal Transduction, 52–76. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5981-8_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Nitrite Stress"

1

Seablom, Craig M., Lauren M. Frasier, Kathleen L. Falkner, and Anthony P. Pietropaoli. "Oxidative Stress Impairs Blood Nitrite Metabolism In Vitro." In American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California. American Thoracic Society, 2012. http://dx.doi.org/10.1164/ajrccm-conference.2012.185.1_meetingabstracts.a4958.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Lam, Poh-Sang, Craig S. Stripling, Donald L. Fisher, and James B. Elder. "Potential for Stress Corrosion Cracking of A537 Carbon Steel Nuclear Waste Tanks Containing Highly Caustic Solutions." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25117.

Full text
Abstract:
The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 × 30.38 × 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 °C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 °C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The absence of evidence of stress corrosion cracking and general corrosion in the laboratory-scaled specimens indicate that this type of nuclear waste tank is not susceptible to highly caustic solutions up to 12 M hydroxide at 125 °C when sufficient nitrite inhibitor is present.
APA, Harvard, Vancouver, ISO, and other styles
3

Sorger, S. C. "Effects of PECVD hardware configuration on mechanical stress and stoichiometry of silicon nitride films." In STRESS-INDUCED PHENOMENA IN METALLIZATION: Seventh International Workshop on Stress-Induced Phenomena in Metallization. AIP, 2004. http://dx.doi.org/10.1063/1.1845855.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Sun, S. C. "Performance of MOCVD transition metal nitrides as diffusion barriers for Cu metallization." In STRESS INDUCED PHENOMENA IN METALLIZATION. ASCE, 1998. http://dx.doi.org/10.1063/1.54666.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Choi, Sung R. "Foreign Object Damage in Gas-Turbine Grade Silicon Nitrides by Silicon Nitride Ball Projectiles." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59031.

Full text
Abstract:
Foreign object damage (FOD) behavior of two gas-turbine grade silicon nitrides (AS800 and SN282) was determined with a considerable sample size at ambient temperature using impact velocities ranging from 50 to 225 m/s by 1.59-mm diameter silicon nitride ball projectiles. The degree of impact damage as well as of post-impact strength degradation increased with increasing impact velocity, and was greater in SN282 than in AS800 silicon nitride. The critical impact velocity in which target specimens fractured catastrophically was remarkably low: about 200 and 130 m/s, respectively, for AS800 and SN282. The difference in the critical impact velocity and impact damage between the two target silicon nitrides was attributed to the fracture toughness of the target materials. The FOD by silicon nitride projectiles was significantly greater than that by steel ball projectiles. Prediction of impact force was made based on a yield model and compared with the conventional Hertzian contact-stress model.
APA, Harvard, Vancouver, ISO, and other styles
6

Akhtar, Syed Sohail, Abba Abdulhamid Abubakar, and Abul Fazal M. Arif. "Prediction of Transformation-Induced Residual Stresses During Gas Nitriding of H13 Steels Using Phase Field Approach." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37945.

Full text
Abstract:
Gas nitriding is a common surface treatment practice to improve the wear resistance of AISI H13 hot extrusion die cavities. However, due to the presence of complex and sharp features of die cavities, it has been observed that non-uniform nitride layer develops in these regions. Moreover, the formation of compound layer in the surface vicinity of nitrided surfaces leads to the development of transformation-induced stresses. The present work presents the application of the phase field method in predicting the evolution of the nitride layers and associated residual stresses during the gas nitriding of AISI H13 tool steels. Nitriding process is modeled and simulated in line with experimental set-up which uses automated two-stage controlled nitriding process. Some representative samples having commonly used geometric features are manufactured and nitrided for validation purpose. Both experimental and numerical results are found in close agreement in terms of nitrogen concentration and corresponding micro-hardness profiles. The results show that high stresses are induced at the surface due to formation of the nitride layers and these stresses are found to be higher at the sharp corners. In view of the current results, some process and design strategies are suggested for improved and more effective nitriding treatment of hot extrusion dies used in the industry.
APA, Harvard, Vancouver, ISO, and other styles
7

Dvorak, Nathan A., Kunook Chung, Kobie Mueller, and Pei-Cheng Ku. "Mapping tensorial shear stress with light-emitting GaN nanopillars." In Gallium Nitride Materials and Devices XVI, edited by Hadis Morkoç, Hiroshi Fujioka, and Ulrich T. Schwarz. SPIE, 2021. http://dx.doi.org/10.1117/12.2577640.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Lee, Seok-Hee, Samantha Lee, John C. Bravman, Paul A. Flinn, and Thomas N. Marieb. "Stress-induced and electromigration voiding in nitride passivated Al interconnects." In The fifth international workshop on stress induced phenomena in metallization. AIP, 1999. http://dx.doi.org/10.1063/1.59906.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Zhu, Congyong, Mo Wu, Cemil Kayis, Fan Zhang, Xing Li, Romualdo Ferreyra, Vitaliy Avrutin, Umit Ozgur, and Hadis Morkoc. "Degradation mechanism of InAlN/GaN based HFETs under high electric field stress." In Gallium Nitride Materials and Devices VII. SPIE, 2012. http://dx.doi.org/10.1117/12.903983.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Greene, Rawley B., and Jamie J. Kruzic. "Fatigue Behavior, Bridging Stresses, and Fatigue Reliability in Silicon Nitride Ceramics." In ASME 2011 International Manufacturing Science and Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/msec2011-50056.

Full text
Abstract:
Silicon nitride ceramics doped with rare-earth oxides exhibit excellent hardness, toughness, and strength at elevated temperatures making them attractive materials for replacing cemented carbides in a variety of manufacturing applications such as cutting and rolling tools. One recent example is the application of rolling of high strength alloy wires from steels and nickel-based super-alloys where cemented carbide rolls suffer wear and thermal fatigue cracking, leading to a degradation of wire quality. [1] Furthermore, it has been shown that under moderate loading silicon nitride rolls can give >10 times longer life and improved wire surface quality. [1] However, it has also been shown that the rolls can suffer fatigue failure at higher loadings, for example when rolling wires with high deformation resistance such as the super alloy wire Nicrofer S7020. [1–2] Accordingly the aim of this study is the develop a design tool for predicting the fatigue failure of silicon nitride ceramics. The silicon nitrides with favorable mechanical properties have microstructures with elongated β-phase grains and a glassy intergranular film. The weak film encourages intergranular fracture allowing the formation of grain bridges across the crack wake which helps to reduce the stress intensity felt at the crack tip, Ktip. [3]
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Nitrite Stress"

1

Anast, Kurt Roy. Engineering Options Assessment Report. Nitrate Salt Waste Stream Processing. Office of Scientific and Technical Information (OSTI), November 2015. http://dx.doi.org/10.2172/1226136.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Anast, Kurt Roy. Engineering Options Assessment Report: Nitrate Salt Waste Stream Processing. Office of Scientific and Technical Information (OSTI), November 2015. http://dx.doi.org/10.2172/1226899.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Dudley, Lynn M., Uri Shani, and Moshe Shenker. Modeling Plant Response to Deficit Irrigation with Saline Water: Separating the Effects of Water and Salt Stress in the Root Uptake Function. United States Department of Agriculture, March 2003. http://dx.doi.org/10.32747/2003.7586468.bard.

Full text
Abstract:
Standard salinity management theory, derived from blending thermodynamic and semi- empirical considerations leads to an erroneous perception regarding compensative interaction among salinity stress factors. The current approach treats matric and osmotic components of soil water potential separately and then combines their effects to compute overall response. With deficit water a severe yield decrease is expected under high salinity, yet little or no reduction is predicted for excess irrigation, irrespective of salinity level. Similarly, considerations of competition between chloride and nitrate ions have lead to compensation hypothesis and to application of excess nitrate under saline conditions. The premise of compensative interaction of growth factors behind present practices (that an increase in water application alleviates salinity stress) may result in collateral environmental damage. Over-irrigation resulting in salinization and elevated ground water threatens productivity on a global scale. Other repercussions include excessive application of nitrate to compensate for salinity, unwillingness to practice deficit irrigation with saline water, and under-utilization of marginal water. The objectives for the project were as follows: 1) To develop a database for model parameterization and validation by studying yield and transpiration response to water availability, excessive salinity and salt composition. 2) To modify the root sink terms of an existing mechanism-based model(s) of water flow, transpiration, crop yield, salt transport, and salt chemistry. 3) To develop conceptual and quantitative models of ion uptake that considers the soil solution concentration and composition. 4) To develop a conceptual and quantitative models of effects of NaCl and boron accumulation on yield and transpiration. 5) To add a user interface to the water flow, transpiration, crop yield, salt transport, chemistry model to make it easy for others to use. We conducted experiments in field plots and lysimeters to study biomass production and transpiration of com (Zeamays cv. Jubilee), melon (Cucumismelo subsp. melo cv. Galia), tomato (Lycopersiconesculentum Mill. cv. 5656), onion (Alliumcepa L. cv. HA 944), and date palms (Phoenix Dactylifera L. cv. Medjool) under salinity combined with water or with nitrate (growth promoters) or with boron (growth inhibitor). All factors ranged from levels not limiting to plant function to severe inhibition. For cases of combined salinity with water stress, or excess boron, we observed neither additive nor compensative effects on plant yield and transpiration. In fact, yield and transpiration at each combination of the various factors were primarily controlled by one of them, the most limiting factor to plant activity. We proposed a crop production model of the form Yr = min{gi(xi), where Yr = Yi ym-1 is relative yield,Ym is the maximum yield obtained in each experiment, Xi is an environmental factor, gi is a piecewise-linear response function, Yi is yield of a particular treatment. We selected a piecewise-linear approach because it highlights the irrigation level where the response to one factor ceases and a second factor begins. The production functions generate response "envelopes" containing possible yields with diagonal lines represent response to Xi alone and the lines parallel to the X-axis represent response to salinity alone. A multiplicative model was also derived approximating the limiting behaviour for incorporation in a hydrochemical model. The multiplicative model was selected because the response function was required to be continuous. The hydrochemical model was a better predictor of field-measured water content and salt profiles than models based on an additive and compensative model of crop response to salinity and water stress.
APA, Harvard, Vancouver, ISO, and other styles
4

Smith, W. H., and G. Purdy. Chromium in aqueous nitrate plutonium process streams: Corrosion of 316 stainless steel and chromium speciation. Office of Scientific and Technical Information (OSTI), August 1994. http://dx.doi.org/10.2172/10171982.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Desiderati, Christopher. Carli Creek Regional Water Quality Project: Assessing Water Quality Improvement at an Urban Stormwater Constructed Wetland. Portland State University, 2022. http://dx.doi.org/10.15760/mem.78.

Full text
Abstract:
Stormwater management is an ongoing challenge in the United States and the world at-large. As state and municipal agencies grapple with conflicting interests like encouraging land development, complying with permits to control stormwater discharges, “urban stream syndrome” effects, and charges to steward natural resources for the long-term, some agencies may turn to constructed wetlands (CWs) as aesthetically pleasing and functional natural analogs for attenuating pollution delivered by stormwater runoff to rivers and streams. Constructed wetlands retain pollutants via common physical, physicochemical, and biological principles such as settling, adsorption, or plant and algae uptake. The efficacy of constructed wetlands for pollutant attenuation varies depending on many factors such as flow rate, pollutant loading, maintenance practices, and design features. In 2018, the culmination of efforts by Clackamas Water Environment Services and others led to the opening of the Carli Creek Water Quality Project, a 15-acre constructed wetland adjacent to Carli Creek, a small, 3500-ft tributary of the Clackamas River in Clackamas County, OR. The combined creek and constructed wetland drain an industrialized, 438-acre, impervious catchment. The wetland consists of a linear series of a detention pond and three bioretention treatment cells, contributing a combined 1.8 acres of treatment area (a 1:243 ratio with the catchment) and 3.3 acre-feet of total runoff storage. In this study, raw pollutant concentrations in runoff were evaluated against International Stormwater BMP database benchmarks and Oregon Water Quality Criteria. Concentration and mass-based reductions were calculated for 10 specific pollutants and compared to daily precipitation totals from a nearby precipitation station. Mass-based reductions were generally higher for all pollutants, largely due to runoff volume reduction on the treatment terrace. Concentration-based reductions were highly variable, and suggested export of certain pollutants (e.g., ammonia), even when reporting on a mass-basis. Mass load reductions on the terrace for total dissolved solids, nitrate+nitrite, dissolved lead, and dissolved copper were 43.3 ± 10%, 41.9 ± 10%, 36.6 ± 13%, and 43.2 ± 16%, respectively. E. coli saw log-reductions ranging from -1.3 — 3.0 on the terrace, and -1.0 — 1.8 in the creek. Oregon Water Quality Criteria were consistently met at the two in-stream sites on Carli Creek for E. coli with one exception, and for dissolved cadmium, lead, zinc, and copper (with one exception for copper). However, dissolved total solids at the downstream Carli Creek site was above the Willamette River guidance value 100 mg/L roughly 71% of the time. The precipitation record during the study was useful for explaining certain pollutant reductions, as several mechanisms are driven by physical processes, however it was not definitive. The historic rain/snow/ice event in mid-February 2021 appeared to impact mass-based reductions for all metals. Qualitatively, precipitation seemed to have the largest effect on nutrient dynamics, specifically ammonia-nitrogen. Determining exact mechanisms of pollutant removals was outside the scope of this study. An improved flow record, more targeted storm sampling, or more comprehensive nutrient profiles could aid in answering important questions on dominant mechanisms of this new constructed wetland. This study is useful in establishing a framework and baseline for understanding this one-of-a-kind regional stormwater treatment project and pursuing further questions in the future.
APA, Harvard, Vancouver, ISO, and other styles
6

Locy, Robert D., Hillel Fromm, Joe H. Cherry, and Narendra K. Singh. Regulation of Arabidopsis Glutamate Decarboxylase in Response to Heat Stress: Modulation of Enzyme Activity and Gene Expression. United States Department of Agriculture, January 2001. http://dx.doi.org/10.32747/2001.7575288.bard.

Full text
Abstract:
Most plants accumulate the nonprotein amino acid, g-aminobutyric acid (GABA), in response to heat stress. GABA is made from glutamate in a reaction catalyzed by glutamate decarboxylase (GAD), an enzyme that has been shown by the Israeli PI to be a calmodulin (CaM) binding protein whose activity is regulated in vitro by calcium and CaM. In Arabidopsis there are at least 5 GAD genes, two isoforms of GAD, GAD1 and GAD2, are known to be expressed, both of which appear to be calmodulin-binding proteins. The role of GABA accumulation in stress tolerance remains unclear, and thus the objectives of the proposed work are intended to clarify the possible roles of GABA in stress tolerance by studying the factors which regulate the activity of GAD in vivo. Our intent was to demonstrate the factors that mediate the expression of GAD activity by analyzing the promoters of the GAD1 and GAD2 genes, to determine the role of stress induced calcium signaling in the regulation of GAD activity, to investigate the role of phosphorylation of the CaM-binding domain in the regulation of GAD activity, and to investigate whether ABA signaling could be involved in GAD regulation via the following set of original Project Objectives: 1. Construction of chimeric GAD1 and GAD2 promoter/reporter gene fusions and their utilization for determining cell-specific expression of GAD genes in Arabidopsis. 2. Utilizing transgenic plants harboring chimeric GAD1 promoter-luciferase constructs for isolating mutants in genes controlling GAD1 gene activation in response to heat shock. 3. Assess the role of Ca2+/CaM in the regulation of GAD activity in vivo in Arabidopsis. 4. Study the possible phosphorylation of GAD as a means of regulation of GAD activity. 5. Utilize ABA mutants of Arabidopsis to assess the involvement of this phytohormone in GAD activation by stress stimuli. The major conclusions of Objective 1 was that GAD1 was strongly expressed in the elongating region of the root, while GAD2 was mainly expressed along the phloem in both roots and shoots. In addition, GAD activity was found not to be transcriptionally regulated in response to heat stress. Subsequently, The Israeli side obtained a GAD1 knockout mutation, and in light of the objective 1 results it was determined that characterization of this knockout mutation would contribute more to the project than the proposed Objective 2. The major conclusion of Objective 3 is that heat-stress-induced changes in GAD activity can be explained by heat-stress-induced changes in cytosolic calcium levels. No evidence that GAD activity was transcriptionally or translationally regulated or that protein phosphorylation was involved in GAD regulation (objective 4) was obtained. Previously published data by others showing that in wheat roots ABA regulated GABA accumulation proved not to be the case in Arabidopsis (Objective 5). Consequently, we put the remaining effort in the project into the selection of mutants related to temperature adaptation and GABA utilization and attempting to characterize events resulting from GABA accumulation. A set of 3 heat sensitive mutants that appear to have GABA related mutations have been isolated and partially characterized, and a study linking GABA accumulation to growth stimulation and altered nitrate assimilation were conducted. By providing a better understanding of how GAD activity was and was not regulated in vivo, we have ruled out the use of certain genes for genetically engineering thermotolerance, and suggested other areas of endeavor related to the thrust of the project that may be more likely approaches to genetically engineering thermotolerance.
APA, Harvard, Vancouver, ISO, and other styles
7

Pokrzywinski, Kaytee, Cliff Morgan, Scott Bourne, Molly Reif, Kenneth Matheson, and Shea Hammond. A novel laboratory method for the detection and identification of cyanobacteria using hyperspectral imaging : hyperspectral imaging for cyanobacteria detection. Engineer Research and Development Center (U.S.), June 2021. http://dx.doi.org/10.21079/11681/40966.

Full text
Abstract:
To assist US Army Corps of Engineers resource managers in monitoring for cyanobacteria bloom events, a laboratory method using hyperspectral imaging has been developed. This method enables the rapid detection of cyanobacteria in large volumes and has the potential to be transitioned to aerial platforms for field deployment. Prior to field data collection, validation of the technology in the laboratory using monocultures was needed. This report describes the development of the detection method using hyperspectral imaging and the stability/reliability of these signatures for identification purposes. Hyperspectral signatures of different cyanobacteria were compared to evaluate spectral deviations between genera to assess the feasibility of using this imaging method in the field. Algorithms were then developed to spectrally deconvolute mixtures of cyanobacteria to determine relative abundances of each species. Last, laboratory cultures of Microcystis aeruginosa and Anabaena sp. were subjected to varying macro (nitrate and phosphate) and micro-nutrient (iron and magnesium) stressors to establish the stability of signatures within each species. Based on the findings, hyperspectral imaging can be a valuable tool for the detection and monitoring of cyanobacteria. However, it should be used with caution and only during stages of active growth for accurate identification and limited interference owing to stress.
APA, Harvard, Vancouver, ISO, and other styles
8

Anast, Kurt Roy, and David John Funk. Summary Report of Laboratory Testing to Establish the Effectiveness of Proposed Treatment Methods for Unremediated and Remediated Nitrate Salt Waste Streams. Office of Scientific and Technical Information (OSTI), May 2016. http://dx.doi.org/10.2172/1253508.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Anast, Kurt Roy, David John Funk, and Kenneth Marshall Hargis. Summary Report of Comprehensive Laboratory Testing to Establish the Effectiveness of Proposed Treatment Methods for Unremediated and Remediated Nitrate Salt Waste Streams. Office of Scientific and Technical Information (OSTI), October 2017. http://dx.doi.org/10.2172/1394998.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Mulholland, P. J., J. L. Tank, D. M. Sanzone, J. R. Webster, W. Wollheim, B. J. Peterson, and J. L. Meyer. Ammonium and nitrate uptake lengths in a small forested stream determined by {sup 15}N tracer and short-term nutrient enrichment experiments. Office of Scientific and Technical Information (OSTI), November 1998. http://dx.doi.org/10.2172/290966.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Nitrite Stress' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography