Dissertations / Theses on the topic 'Nitric monoxide'
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1
Palm, Jörgen. "Nasal airway nitric oxide : methodological aspects and influence of inflammation /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-801-7/.
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Fiorin, Vittorio. "The interaction of nitric oxide with molecular adlayers adsorbed on Rh(111)." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368265.
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Watkins, Crystal Chanel. "Nitric oxide and carbon monoxide novel neurotransmitters in the enteric nervous system /." Available to US Hopkins community, 2003. http://wwwlib.umi.com/dissertations/dlnow/308079.
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Demoncheaux, Eric Arthur Germain. "Physico-chemical properties of nitrogen monoxide : implication for its role as a vasodilator." Thesis, Anglia Ruskin University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264045.
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Dunfield, Peter F. "Methane, nitrogen monoxide, and nitrous oxide fluxes in an organic soil." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0020/NQ36972.pdf.
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Park, Soo-Jin. "Catalytic Decomposition of Nitric Oxide and Carbon Monoxide Gases Using Nanofiber Based Filter Media." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1216931978.
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Adeyemo, Adedunni D. "Interaction of Metal Oxides with Carbon Monoxide and Nitric Oxide for Gas Sensing Applications." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1332475552.
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Crawford, Ian Stewart. "Catalytic reduction of nitric oxide by carbon monoxide or hydrogen over a Monel metal catalyst." Title page, contents and summary only, 1987. http://web4.library.adelaide.edu.au/theses/09EN/09enc899.pdf.
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Gilchrist, Ian Thomas. "The reduction of nitric oxide by carbon monoxide over excessively-exchanged copper ZSM-5 zeolite." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26388.
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Nitric oxide (NO) is a major pollutant which is produced by the combustion of fossil fuels. Current three-way catalyst (TWC) technology, used for the reduction of NO in automobile exhaust, is effective only under stoichiometric or net reducing conditions which cause incomplete use of the fuel and CO and hydrocarbon pollution. Excessively-exchanged Cu-ZSM-5 zeolite was investigated as a catalyst for the reduction of NO in net oxidizing exhaust mixtures, which would allow for greater fuel efficiency and lower NO, CO and hydrocarbon emissions.Cu-ZSM-5 powder was pelletized by extrusion and the activity for the reduction of NO by CO on the presence of O$ sb2$ was measured at temperatures of 200$ sp circ$C to 550$ sp circ$C and a space velocity of 450 hour$ sp{-1}.$ The activity of the Cu-ZSM-5 was compared to that of a TWC at 550$ sp circ$C. Under stoichiometric or net reducing conditions the conversion to N$ sb2$ over both catalysts was about 100%. Under net oxidizing conditions (when the equivalence ratio, $ lambda$, is greater than 1) the conversion decreased with increasing oxygen concentration for both catalysts, but the Cu-ZSM-5 was much more active; at $ lambda=1.3$ the conversion was 53% compared to 26%. The Cu-ZSM-5 was found to deactivate after 30 hours of use. The deactivation was accompanied by a change in the Cu-ZSM-5 structure, and a change in the chemical composition. The deactivation was not found to be a function of the composition, or of the oxidative nature of the conditioning gas used (20% O$ sb2,$ inert, or 20% CO). Regeneration of the Cu-ZSM-5 proved unsuccessful.
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Adamovich, Igor V. "Studies of nonequilibrium vibrational kinetics of carbon monoxide and nitric oxide in optical pumping experiments /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu148784730905197.
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Tengberg, Oskar. "Construction and Optimization of an Apparatus for Detection of Nitric Oxide through Faraday Modulation Spectroscopy." Thesis, Umeå universitet, Institutionen för fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-112139.
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Faraday modulation spectroscopy (FAMOS) is a technique for detection of paramagnetic molecules. By applying a magnetic field over a gaseous sample, the presence of paramagnetic species will rotate the polarization plane of light, addressing a transition in such a species. By placing a gas containing paramagnetic molecules between almost crossed polarizers and modulating the magnetic field, the intensity of the transmitted light will consequently be modulated. Since the rotation of the polarization plane of light is proportional to the concentration of species, this technique can be used for quantitative analysis of paramagnetic molecules. Since FAMOS is solely sensitive to paramagnetic molecules it is superior to many other types of laser-based detection techniques, drastically decreasing various types of noise, background signals, as well as signals from other molecules; e.g. flicker noise, etalon effects and signals from water and CO2 molecules. An experimental setup for detection of nitric oxide (NO) by FAMOS has been developed and optimized. This system is based on a quantum cascade laser emitting light at 5.331 μm, addressing the—for FAMOS—most sensitive transition in NO, Q3/2(3/2). Optimized parameters include a pressure of 60 mbar, a magnetic field of 190 G and a polarizer uncrossing angle of 0.75°. In its present configuration, this system has demonstrated a detection of NO down to 200 ppb for a detection rate of 10 measurements per second. It is very possible that the limit of detection is even lower than this number since this lowest acquirable concentration is limited by the specifications of the gas mixer. A standard deviation between subsequent measurements, of 15 s time separation, is calculated to 30 ppb. However, this is far from the expected ultimate detection limit of this system and this technique in general. One process that causes a weakening of the signal is outgassing. When measuring on an emptied system this phenomenon is greatly reduced and a standard deviation of measurements is then measured and calculated to 7.6 ppb. The detection limit is presumed to be in the very low ppb, or sub-ppb, regime and this limit should be obtainable by further optimization of the system.Gasen kvävemonoxid är en restprodukt vid förbränning av fossila bränslen, men den återfinns också i människokroppen som en signalsubstans. I stora mängder är den giftig då den interagerar med cellandningen och påverkar arvsmassan. I kombination med syre övergår den sakta till gasen kvävedioxid som i sin tur övergår till salpetersyra. Detta innebär att det är viktigt att kunna detektera denna gas i miljöer där risk för spridning kan anses vara stor. Kvävemonoxid används inom sjukvården som inhalationsgas för tidigt födda barn. Den förekommer även i ökad koncentration i utandningsluft hos människor med astma, Alzheimers eller Parkinsons sjukdom. Därmed finns det också ett intresse av att kunna mäta denna noggrant inom sjukvården, för att ge rätt dosering av gasen samt för att enklare kunna ställa korrekta diagnoser. Att mäta koncentration av kvävemonoxid görs ofta på kemiska vägar. Då detta är tidskrävande finns det anledning att utveckla nya och snabbare sätt att detektera denna gas. En effektiv teknik för att mäta kvävemonoxid är Faraday-moduleringsspektroskopi, FAMOS. Denna teknik bygger på att man med ett magnetfält, genom den så kallade Faradayeffekten, utnyttjar somliga fysikaliska egenskaper hos just kvävemonoxid, för att vidare bestämma dess mängd. FAMOS möjliggör mätningar i realtid och har en låg minsta detektionsgräns i jämförelse med andra laserbaserade tekniker. Framtidsutsikterna för denna teknik är mycket goda och möjligheterna utökas allt eftersom optisk utrustning förbättras. Denna rapport ger grunderna för FAMOS och den jämförs speciellt med en mer konventionell laserbaserad spektroskopisk teknik, våglängdsmodulering. Avhandlingen beskriver dessutom konstruktionen av ett FAMOS-system som baseras kring en kvantkaskadlaser vilken verkar med infrarött ljus på den, för kvävemonoxid, optimala energiövergången.
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Borland, Colin David Ross. "Nitric oxide and carbon monoxide in cigarette smoke in the development of cardiorespiratory disease in smokers." Thesis, University of Cambridge, 1988. https://www.repository.cam.ac.uk/handle/1810/238521.
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Shahreen, Laila. "Palladium Doped Titanium Dioxide Nanofiber Based Catalytic Support To Reduce Nitric Oxide Over Carbon Monoxide Gas." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1375362737.
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Petty, Renee Lynn. "Catalytic Decomposition of Nitric Oxide and Carbon Monoxide Gases Using Nanofiber Based Filter Media of Varying Diameters." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1279505229.
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Jasinski, Krystian. "Impact of Gaseous Nitric Oxide and Carbon Monoxide on Normal Excisional, Diabetic Excisional and Burn Wound Healing." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1256055541.
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Binti, Wan Ramli Wan Khairunnisa. "Exsolved base metal catalyst systems with anchored nanoparticles for carbon monoxide (CO) and nitric oxides (NOx) oxidation." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3875.
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Noble metals notably platinum (Pt), is a major element of heterogeneous catalysts, excel in catalysing an extensive number of important catalytic reactions in chemical and automotive industries. Since the increased use of these metals is severely limited because of their high cost and scarcity’s, there is therefore an urgent need for the search of alternative base metal catalysts that are cheaper and more widely available. This can only be practical if the main drawbacks of base metals such as the agglomeration of particles under high temperatures operational conditions and irreversible sulphur poisoning can be overcome, and their activity enhanced, such that they can directly replace Pt on a weight-to-weight basis. However, most previous studies have been restricted to low temperature reaction conditions and have not compared their activity directly to that of Pt, whether in terms of active sites or on a weight-to-weight basis. Moreover, most researchers have not investigated extensively the long-term stability of their base metal catalysts, since the longest was at most around 200 hours and at relatively low temperatures, for example at room temperature. It is proposed that long term stability can be achieved by producing uniformly distributed nano-sized socketed and strained base metal particles via the exsolution method. The main objective of this thesis is to produce exsolved base metals catalyst systems rivalling Pt on a weight-to-weight basis in two base reactions; CO and NO oxidation. NO oxidation was also chosen as our model reaction in this research since most Pt in the automotive industry are used in the lean NOx trap (LNT) or a combination of LNT and selective catalytic reduction (SCR), which demand the high conversion of NO to NO2 at low temperatures to work effectively. Initial screening experiments were performed to evaluate the potential CO oxidation activities and long-term stability at 520 °C of two different exsolved metal pellet systems namely lanthanum-doped ceria nickel titanates to exsolve nickel (Ni) metal (La0.8Ce0.1Ni0.4Ti0.6O3) and lanthanum-doped strontium iron nickel titanates to exsolve iron-nickel (FeNi) alloy (La0.5Sr0.4Fe0.1Ni0.1Ti0.6O3). Exsolved FeNi pellet system gives high and stable turnover frequencies (TOFs) of 103 s-1 at 520 °C for almost 170 hours, which confirms the potential of these stable exsolved metal systems for CO oxidation. Sixty exsolved metal powder systems with various metal formulations were produced to enable direct activity comparison to Pt on a weight-to-weight basis. Most exsolved metal systems displayed increasing CO2 production rates with increasing CO partial pressures (PCO) and reversible sulphur poisoning with exsolved CoNi powder system showing remarkable stability at 200 °C for 655 hours (one month). This exsolved CoNi system also showed enhanced activity for CO oxidation upon exposure to CO-rich environment, as a result of the restructuring of particles iv into metal oxide nanocubes anchored onto nanosockets within the support surface. The CO2 production rates of the activated exsolved CoNi powder system at 200 and 520 °C were 0.13 x 10-4 and 1.5 x 10-4 mol s-1 g-1 compared to its initial rate of around 0 (below the detected limit of 0.007 x10-4 mol s-1 g-1) and 0.8 x 10-4 mol s-1 g-1 prior to activation. These active spinel (CoNi)3O4 cubic structures were seen planted at an angle of ~55°, at the edge of an empty socket with mediocre features for CO oxidation, such as rich in Co2+ with exposed (100) planes that had only 44 cubes μm-2 compared to its initial 144 particles μm-2 particle population. Above 450 °C, the main active sites for CO oxidation were thought to be close to or at the metal-support interface of the exsolved CoNi systems. Comparable NO2 production rates to those of commercial Pt catalyst was achieved with only ± 5 % of difference at each measured point within the temperature range used (100-440 °C) over exsolved CoNi system by exploiting the effect of having two particle size ranges (10 and 30 nm). These results confirm the dual functionality of the activated exsolved CoNi system and its huge potential to be commercialised as an alternative catalyst to Pt in two oxidation reactions; CO and NO oxidation. In general, a simple procedure that induces high, long-lasting activity in a base metal catalyst, rivalling platinum for CO and NO oxidation on a weight-to-weight basis was demonstrated. The nature of this activation by tracking individual nanoparticles was successfully elucidated to link their microstructural evolution to their catalytic and kinetic behaviour. This research also illustrates new strategies for enhancing and tailoring the catalytic activity of base metal systems towards replacing platinum.
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Kandilli, Nur. "Development Of A Three Way Catalytic Converter For Elimination Of Hydrocarbons, Carbon Monoxide And Nitric Oxide In Automotive Exhaust." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612546/index.pdf.
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In this work, slurries of powder catalysts are washcoated on 22 mm diameter
and 13 mm height cordierite monoliths. CeO2-ZrO2 (CZO) and CeO2-ZrO2-
Al2O3 (CZAO) mixed oxides are synthesized by co-precipitation and sol-gel
methods respectively, to be used as support materials of Pd and Rh metals.
Metal loaded CZO is mixed with gamma phase alumina. Powder catalysts
and their slurries are characterized by XRD, BET, ICP-MS and the monolithic
catalysts are imaged by SEM. Catalytic activities of monolithic catalysts are
tested in dynamic test system which is computerized and basically composed
of gas flow control and conditioning units, split furnace, quartz reactor, mass
spectrometer and CO analyzer. Gas mixture containing CO, C3H6, C3H8, NO,
H2, O2, CO2, SO2, H2O and N2 is used to simulate the exhaust gas of
gasoline vehicles. O2 is oscillated at 1 Hz frequency around the
stoichiometric condition. Monolithic catalyst in the reactor is heated and
cooled between 150 ºC and 600 º
C. Gas composition data from massspectrometer and CO analyzer and temperature data from thermocouple at the monolith entrance, are converted to conversion versus temperature graphs. Results of 26 activity tests are compared. Catalyst containing coimpregnated CZO support material with metals, showed the lowest loss of catalytic performance after exposure to SO2 during activity tests. Catalyst containing separately impregnated CZO support material, showed the highest resistance against thermal aging at 900 º
C and 1000 º
C, and even improved catalytic activity after aging. These catalysts showed higher resistances against the applied procedures than the commercial catalyst.
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Sanchez, Eva Shirley. "Localization and functional characterization of the nitric oxide and carbon monoxide signaling pathways in the postnatal rat hippocampal formation." Thesis, Boston University, 2012. https://hdl.handle.net/2144/32053.
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Thesis (Ph.D.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
In the rat hippocampus, nitric oxide (NO) and carbon monoxide (CO) both function as signaling molecules involved in long-term plasticity. In neurons, NO generated by the enzyme neuronal nitric oxide synthase (nNOS) and CO generated by hemeoxygenase-2 (HO-2), can activate soluble guanylyl cyclase (sGC) to produce cyclicguanosine-monophosphate (cGMP). There has not been a complete functional localization of these signaling pathways in the sub-regions and laminae of the hippocampal formation. In this work, transverse slices of ventral hippocampus (200-250 um thick) from P17-P21 Long Evans rats were used to characterize and localize the NO and CO signaling pathways in the hippocampus. Immunohistochemistry was used to characterize and localize cells containing nNOS, H0-2 and cGMP. Additionally, the NO sensitive fluorescent dye, DAF-FM, was used to localize the production of NO in response to stimulation with NMDA or AMPA. nNOS was immunolocalized in twenty-four distinct neuron types, in varicose and smooth processes, and in axons of the alveus fiber pathway. H0-2 was found in all granule cells, hilar cells and pyramidal cells. Sparse principal cells had both nNOS and H0-2, and sparse non-principal cells had H0-2 and cGMP, but no cells had both nNOS and cGMP. In response to stimulation with a NO-donor, cGMP was found in the following: dendrites and somata of three distinct basket cell types in the dentate gyrus; three distinct interneurons; axonal fibers in the perforant pathway and alveus; and in astrocytes in CA1. Simultaneous stimulation with both NO and CO produced a region specific synergistic increase in cGMP production. NMDA or AMPA stimulated cGMP was localized in the following: varicose processes in the neuropil; in varicose processes surrounding· pyramidal cells in CAl and CA3; in astrocytes in CAl; and in smooth long range processes in CA1 and the alveus. In response to stimulation with NMDA or AMPA NO-induced fluorescence was found in the principal cell layer, alveus, apical dendrites of pyramidal cells in CA1, and in occasional granule-cell somata. The results presented here indicate that NO-cGMP functions in a wide variety of hippocampal synaptic circuits and that CO interacts with NO in the modulation of cGMP levels.
2031-01-02
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Tshivhidzo, Tsumbedzo Tertius. "AtNOGC1 protein bioelectrode for the determination of stress signalling molecules - Nitric Oxide (NO), Carbon Monoxide (CO) and Calcium ion (Ca2+)." University of the Western Cape, 2018. http://hdl.handle.net/11394/6332.
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Magister Scientiae - MSc (Biotechnology)It has been estimated that the world population will reach about 10 billion by the year 2050 and in order to accommodate the increased demand of food, the world agricultural production needs to rise by 70 % in the year 2030. However, the realisation of the goal in food production is hindered by limited arable land caused by urbanisation, salinisation, desertification and environmental degradation. Furthermore, abiotic and biotic stresses affect plant growth and development, which lead to major crop losses. The long term goal of this study is to improve food security by producing genetically engineered agricultural crops that will be tolerant to diverse stresses. This research aims at developing stress tolerant crops through the determination of important signalling molecules and second messengers, such as nitric oxide (NO), carbon monoxide (CO) and calcium ion (Ca2+), which can bind to plant proteins such as AtNOGC1 in order to induce stress tolerance in plants.
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St, Denis Michael Joseph. "Products of low energy electron impact induced excited state reactions of carbon monoxide and of nitric oxide on a gold surface." Scholarly Commons, 1989. https://scholarlycommons.pacific.edu/uop_etds/2176.
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The threshold potentials were determined for the excitation energy necessary for low energy electrons to induce chemical reactions of carbon monoxide, and of nitric oxide adsorbed on a gold surface. The reactions were studied as a function of temperature (100 °C to 200 °C) and pressure (1.83 x 10-5 to 6.40 x 10-4 torr). The electron source was a thorium oxide coated iridium filament which was heated by a current between 1A and 3A to keep thermal distribution of the electrons to less than 0.4 ev. The reaction surface was a polycrystalline evaporated film prepared by subliming gold onto a stainless steel mesh support. Mass analysis was done by quadrupole mass spectrometry in a flow system.
The general results of the research is that a technique has been developed to study the products of reactions of excited state atoms or molecules on metal surfaces. The electron-impact excitation method is an alternative to photochemical and other methods.
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Liu, Jingjing [Verfasser], Wolfgang [Gutachter] Weigand, Benjamin [Gutachter] Dietzek, and Alexander [Gutachter] Schiller. "Light-induced release of nitric oxide and carbon monoxide from metal complexes / Jingjing Liu ; Gutachter: Wolfgang Weigand, Benjamin Dietzek, Alexander Schiller." Jena : Friedrich-Schiller-Universität Jena, 2019. http://d-nb.info/1205885625/34.
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Yung, Matthew Maurice. "Oxidation catalysis in environmental applications nitric oxide and carbon monoxide oxidation for the reduction of combustion emissions and purification of hydrogen streams /." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1187128442.
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Banerjee, Uddyalok. "Targeted Delivery of Gaseous Ligands (CO and NO) for the Treatment of Ischemia Reperfusion Injury." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408457273.
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Scheiblich, Hannah Christina [Verfasser]. "Nitric oxide (NO)- and carbon monoxide (CO)-mediated signal transduction in a co-culture system of microglia and human model neurons / Hannah Christina Scheiblich." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2015. http://d-nb.info/108086783X/34.
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Bartels, Nils. "Orientation-dependent energy transfer in gas-surface collisions: Scattering of vibrationally excited nitric oxide from Au(111)." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://hdl.handle.net/11858/00-1735-0000-0022-6053-9.
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Meine Doktorarbeit ist ein Beitrag zum Gebiet der Reaktionsdynamik an Oberflächen. In diesem Forschungsbereich wird daran gearbeitet, ein detailliertes mikroskopisches Verständnis von chemischen Prozessen an Oberlächen zu erzielen. Fortschritt resultierte dabei häufig aus der Zusammenarbeit von experimentell und theoretisch arbeitenden Forschern und die vorliegende Arbeit führt diese Tradition weiter. Ausgangspunkt meiner Untersuchungen war eine bemerkenswerte theoretische Vorhersage, die ich experimentell überprüft habe. Dabei habe ich mehrere neue Beobachtungen gemacht, von denen ich hoffe, dass sie zu Weiterentwicklungen in der theoretischen Chemie beitragen.
Ein aktuelles und wichtiges Thema auf das ich meine Forschung gerichtet habe, ist das Versagen der Born-Oppenheimer Näherung und die damit einhergehenden elektronisch nichtadiabatischen Energietransferprozesse an Oberflächen. Dafür habe ich das Streuverhalten von hoch schwingungsangeregtem Stickstoffmonoxid (NO) an der (111)-Oberfläche eines Goldkristalls untersucht. Dieses System war bereits vor dieser Arbeit ein bedeutendes Modellsystem für nichtadiabatische Prozesse an Oberflächen. Beim Stoß mit der Oberfläche geben die hochschwingungsangeregten NO Moleküle Schwingungsenergie an elektronische Freiheitsgrade im Metall ab. Dieser sehr effiziente Energietransfer kann nur im Rahmen eines nichtadiabatischen Effektes (Versagen der Born-Oppenheimer Näherung) erklärt werden und der aktuelle Stand der Forschung ist, dass dieser Prozess durch einen transienten Elektronentransfer (ET) von der Oberfläche zum Molekül verursacht wird.
Gemessen habe ich Schwingungs- und Rotationsverteilungen von in verschiedenen angeregten Schwingungszuständen (vi = 3, 11, und 16) präparierten NO Molekülen nach dem Stoß mit der Au(111) Oberfläche. Dabei wurden die einfallende Translationsenergie (Eitrans=0.05 - 1 eV) und die Orientierung der Moleküle systematisch variiert. Dies sollte den Einfluss dieser Parameter auf den durch ET getriebenen Energietransfer aufzeigen, sowie generell zu einem besseren Verständnis der Gesetzmäßigkeiten beitragen, nach denen Prozesse an Oberflächen ablaufen. Um die angestrebten Experimente durchführen zu können, habe ich an der Entwicklung von zwei neuen experimentellen Methoden mitgewirkt: 1) einer Methode um polare Moleküle in einem elektrischen Feld auszurichten ( "Optische Zustandsselektion mit adiabatischer Orientierung") und 2) einer Methode für die Unterdrückung von spontaner Emission beim optischen Pumpen ("Pump-Dump-Sweep").
Der Einfluss der Orientierung ist sowohl drastisch als auch komplex. Für NO in vi = 3 und 11 wird die Schwingungsrelaxation stark durch eine Ausrichtung der Moleküle mit dem N-Atom in Richtung der Oberläche gegenüber einer Ausrichtung mit dem O-Atom in Richtung der Oberfläche verstärkt. Für diese Zustände nimmt die Relaxation außerdem mit steigender einfallender Translationsenergie zu. Interessanterweise verschwinden sowohl der Einfluss der Translationsenergie, als auch der Orientierung für NO in vi = 16 und alle Moleküle relaxieren zu niedrigeren Schwingungszuständen. Die Rotationsverteilungen der gestreuten Moleküle hängen ebenfalls stark von der einfallenden Translationsenergie, Orientierung sowie dem Schwingungszustand ab und zeichnen sich durch ausgeprägte nicht-thermische Maxima ("Rotationsregenbögen") aus. Dies ist die erste Beobachtung von Rotationsregenbögen in Molekülen, die zuvor Schwingungsenergie durch einen Stoß mit einer Oberfläche verloren haben.
Die Messergebnisse weisen eine komplizierte Abhängigkeit von Orientierung, Einfallsenergie und Schwingungszustand auf. Trotzdem können die beobachteten Trends in der Schwingungsrelaxationswahrscheinlichkeit mit einem einfachen Modell verstanden werden, welches auf einer energetischen Barriere der zugrundeliegenden Elektronentransferreaktion basiert. Die Höhe dieser Barriere nimmt mit zunehmender einfallender Schwingungsenergie ab. Dies erklärt den Trend hin zu stärkerer Schwingungsrelaxation, wenn vi erhöht wird. Die Änderung der Barriere erklärt auch, warum die Schwingungsrelaxation für vi = 3 und 11 stark von der Translationsenergie beeinflusst, für vi = 16 hingegen kaum benötigt wird. Die Barrierenhöhe wird außerdem durch eine Ausrichtung der Moleküle mit dem N-Atom in Richtung der Oberfläche verringert und führt zu einem starken Anstieg der Relaxation für diese Orientierung.
Die experimentellen Daten aus dieser Arbeit ermöglichen einen sehr detaillierten Test für Methoden der theoretischen Chemie. Aktuelle Berechnungen zu dem untersuchten System basierend auf den Methoden der Elektronischen Reibung ("electronic friction") oder IESH ("independent electron surface hopping") scheitern bei der Vorhersage der erzeugten Schwingungsverteilungen und deren Abhängigkeiten von den Bedingungen des Streuexperiments. Ich hoffe, dass die neuen Daten als Grundlage für weitere theoretische Arbeiten dienen, um so noch tiefere Einblicke in dieses bedeutende Beispiel eines nichtadiabatischen Prozesses in der Oberflächendynamik zu erhalten.
Ein unabhängiges Thema, welches in der vorliegenden Arbeit zusätzlich behandelt wird, ist die Erzeugung eines Molekularstrahls hoch schwingungsangeregter CO Moleküle. Dafür habe ich eine Methode entwickelt, die "Pump-pump-perturb and dump" genannt wird und auf dem optischen Pumpen in erster Näherung dipolverbotener elektronischer Übergänge beruht. Ich demonstriere die erfolgreiche Implementierung der Methode in dem bestehenden Versuchsufbau.
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Thompson, Bruce Thomas. "Fourier transform infrared spectroscopic measurement of carbon monoxide and nitric oxide in sidestream cigarette smoke in real time using a hollow waveguide gas cell and nonimaging optics." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06232004-172923/unrestricted/thompson%5Fbruce%5Ft%5F200407%5Fphd.pdf.
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Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2005. Directed by Boris Mizaikoff.Hunt, William, Committee Member ; Weck, Marcus, Committee Member ; Mizaikoff, Boris, Committee Chair ; Janata, Jiri, Committee Member ; Orlando, Thomas, Committee Member. Includes bibliographical references.
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Lima, Juliana Bezerra Medeiros de. "Participação das vias intracelulares moduladas pelo monóxido de carbono na regulação do equilíbrio hidroeletrolítico." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/17/17134/tde-07022019-140504/.
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O monóxido de carbono (CO) tem um importante papel na fisiologia animal incluindo plasticidade sináptica, processos de memória e aprendizagem, inflamação e liberação de neuropeptídios hipotalâmicos. Recentemente tem sido demonstrado que a liberação de vasopressina (AVP) e ocitocina (OT) em resposta a alterações no balanço hidromineral pode ser modulada por esse neuromodulador gasoso, contudo, os mecanismos pelos quais essa modulação ocorre ainda não foram elucidados. Nesse sentido, nós mapeamos possíveis alvos intracelulares do CO pelos quais esse gás poderia afetar as respostas neuroendócrinas tais como as propriedades passivas de membrana de neurônios magnocelulares do núcleo supraóptico (SON), via de sinalização da p38 MAPK, sistema óxido nítrico (NO)/óxido nítrico sintase (NOS), participação de astrócitos hipotalâmicos e a resposta antioxidante à diferentes condições de hidratação: euhidratação, 24 e 48 horas de privação hídrica. Nós observamos que a inibição da formação central de CO reduziu o aumento das concentrações plasmáticas de AVP e OT induzido pela privação hídrica, bem como inibiu a atividade NOS nos grupos hidratado e desidratado por 48 horas (PH 48); enquanto a razãoe p-p38 MAPK/p38 MAPK ratio foi aumentada pela doação central de CO em todas as condições de hidratação analisadas. Além do mais, nós demonstramos a expressão de HO-1, p38 MAPK e p-p38 MAPK em astrócitos hipotalâmicos. Em relação à resposta antioxidade, observamos que camundongos silenciados para Nrf2 no SON tem a resposta à desidratação prejudicada. Esses dados indicam o papel do CO como uma molécula neuromodulatória nas respostas neuroendócrinas à desidratação onde pode exercer sua função via resposta antioxidante em tempo mais curto de restrição hídrica e via sistema do NO em tempo mais prolongadoCarbon monoxide plays important roles in animal physiology including synaptic plasticity, learning and memory processes, inflammation and hypothalamic neuropeptide release. Recently it has been demonstrated that the AVP and OT release in response to changes in hydromineral balance can be modulated by this gaseous neuromodulator; however, the mechanisms by which this modulation occurs need to be elucidated. In order to answer this questioning, we evaluated the CO effect on neuroendocrine responses, SON magnocellular neurons passive membrane properties, p38 MAPK signaling, NO/NOS system and astrocytes participation in rats during control or 24/48 WD conditions. We observed that CO formation inhibition reduced the water deprivation-induced increase in plasma AVP and OT concentration and NOS activity in basal and 48 WD groups; while p-p38 MAPK/p38 MAPK ratio was increased by central CO donation in both euhydrated and dehydrated conditions. Furthermore, we demonstrated HO-1, p38 MAPK and p-p38 MAPK expression in MBH astrocytes. These data indicate the CO role as neuromodulatory molecule in neuroendocrine responses to dehydration where it might play its biological functions through p38 MAPK phosphorylation and NOS activity in a water restriction longer period
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Swaminathan, Sneha. "Metal Oxide Nanofibers as Filters, Catalyst and Catalyst Support Structures." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1279564885.
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Hervera, Abad Arnau. "Role of gaseous neurotransmitters in the effects and expression of opioid and cannabinoid receptors during neuropathic pain." Doctoral thesis, Universitat Autònoma de Barcelona, 2012. http://hdl.handle.net/10803/117583.
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El dolor neuropàtic es causat per una lesió o malaltia del sistema nerviós somatosensiorial, i es caracteritza per la presencia d'alodínia e hiperalgèsia. Actualment el seu tractament es basa en la teràpia amb opioids, però són necessàries altes dosis per alleujar el símptomes, les quals van acompanyades de nombrosos efectes secundaris. Aleshores es necessari investigar noves dianes així com nous mecanismes per tal de millorar els tractaments amb opioids a fi d’evitar l’administració de dosis altes i els efectes no desitjats. En aquest estudi hem investigat el paper que juguen dos dels principals neurotransmissors gasosos, l'òxid nítric (NO) i el monòxid de carboni (CO) en el desenvolupament del dolor neuropàtic, així com dels seus efectes en les teràpies mediades per receptors opioids mu (MOR) i delta (DOR), i cannabinoids tipus 2 (CB2). D'aquesta manera, utilitzant la constricció crònica del nervi ciàtic com a model de dolor neuropàtic hem demostrat que: I) la via de senyalització perifèrica de l'NO-sGC-PKG, activada per NOS1 i NOS2, juga un paper essencial en el desenvolupament i l’expressió dels principals símptomes del dolor neuropàtic, II) els efectes antinociceptius perifèrics, però no sistèmics, dels agonistes MOR durant el dolor neuropàtic, es produeixen per activació de la via de senyalització de HO1/NOS1/NOS2-sGC-PKG-K+ATP, i que l'NO, sintetitzat per NOS1 i NOS2, esta implicat en la disminuïda expressió del MOR, III) els efectes antinociceptius perifèrics dels agonistes dels receptors DOR i CB2 durant el dolor neuropàtic es poden incrementar a través de l' inhibició de la via de senyalització de NOS1/NOS2-sGC-PKG. A més, l'NO sintetitzat per NOS1, es un dels responsables de la disminuïda i augmentada expressió perifèrica dels receptors DOR i CB2 respectivament durant el dolor neuropàtic, IV) la inhibició de la via de senyalització de NO-sGC-PKG-JNK evita l'aparició de tolerància als efectes antialodínics perifèrics produïts per la morfina durant el dolor neuropàtic, V) el CO, sintetitzat per HO1, inhibeix la simptomatologia del dolor neuropàtic mitjançant l'atenuació de la sobrepressió de NOS1 i NOS2 així com de l'activació microglial produïdes per la lesió nerviosa, i finalment VI) el tractament amb CO, administrat exògenament o sintetitzat endògenament per HO1, potencia els efectes antinociceptius perifèrics dels agonistes MOR, a través d'una sobrepressió perifèrica dels seus receptors i inhibint l'activació microglial. En resum, tant NO com CO tenen un paper essencial durant l’expressió del dolor neuropàtic, i tots dos son capaços de modular els efectes i l'expressió dels receptors MOR, DOR i CB2 durant el dolor neuropàtic, no obstant, mentre que els agonistes MOR produeix els seus efectes antinociceptius perifèrics a través de l'activació de la via de senyalització de HO1/NOS-sGC-PKG-K+ATP, els agonistes DOR i CB2 no utilitzen aquesta via per produir els seus efectes. Finalment, malgrat en aquest estudi es mostren diferents possibilitats d’augmentar l’acció antinociceptiva local produïda per opioids i cannabinoids i evitar el desenvolupament de tolerància durant el dolor neuropàtic, la investigació dels mecanismes d’acció d’aquests fàrmacs es indispensable per millorar la seva acció terapèutica durant el dolor neuropàtic.Neuropathic pain is caused by a lesion or disease of the somatosensory nervous system, and is characterized by the presence of allodynia and hyperalgesia. Nowadays, its treatment is based upon opioids, but high doses are necessary to alleviate symptoms and they have several undesirable side effects. Therefore, it is important to investigate new targets and mechanisms to improve the current opioid treatments in order to reduce dosage and avoid side effects. In this study, we investigated the role played by the two main gaseous neurotransmitters, nitric oxide (NO) and carbon monoxide (CO) in the development of neuropathic pain, as well as their effects in the mu (MOR) and delta (DOR) opioid, and cannabinoid 2 (CB2) receptors mediated therapies. Indeed, by using the chronic constriction of the sciatic nerve, as a mouse model of neuropathic pain, we demonstrated that: I) the peripheral NO-sGC-PKG signaling pathway, triggered by NOS1 and NOS2, plays a key role in the development and expression of the main symptoms of neuropathic pain, II) the peripheral, but not systemic, antinociceptive effects of MOR agonists during neuropathic pain are produced through the activation of the HO1/NOS1/NOS2-sGC-PKG-K+ATP signaling pathway, and the NO, synthesized by NOS1 and NOS2, is implicated in the peripheral down regulation of MOR, III) the peripheral antinociceptive effects of DOR and CB2 receptor agonists during neuropathic pain can be increased by the inactivation of the NOS1/NOS2-sGC-PKG signaling pathway. Moreover the NO, synthesized by NOS1, is implicated in the peripheral down- and up-regulation of DOR and CB2 receptor during neuropathic pain, IV) the inhibition of the NO-sGC-PKG-JNK signaling pathway avoids the development of tolerance to the local antiallodynic effects produced by morphine during neuropathic pain, V) CO, synthesized by HO1, inhibits neuropathic pain by the attenuation of NOS1/NOS2 overexpression and microglial activation induced by nerve injury, and VI) the treatment with CO, exogenously deliberated or endogenously synthesized by HO1, enhances the peripheral antinociceptive effects of MOR agonists by up-regulating the peripheral expression of MOR and inhibiting the microglial activation. In summary, both NO and CO systems have an essential role in the expression of neuropathic pain and both modulate the effects and expression of MOR, DOR and CB2 receptors after sciatic nerve injury, but while MOR elicits its peripheral antinociceptive effects through the activation of the HO1/NOS-sGC-PKG-K+ATP signaling pathway, DOR or CB2 receptor do not use this pathway to produce their effects. Finally, although this study shows different strategies to increase the local antinociceptive effects produced by opioids and cannabinoids and avoid the development of tolerance during neuropathic pain, the investigation of new mechanisms of action of these drugs is essential to improve their therapeutic actions in neuropathic pain.
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SimÃo, Antonio Felipe Leite. "Efeito inibitÃrio do prÃ-condicionamento isquÃmico a distÃncia sobre a migraÃÃo de neutrÃfilos: Mecanismos e mediadores." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5004.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoIntroduÃÃo:O prÃ-condicionamento isquÃmico (PCI) vem sendo considerado como um potente mecanismo endÃgeno capaz de inibir a resposta inflamatÃria. A migraÃÃo de neutrÃfilos (mn) à um evento central no desenvolvimento da reaÃÃo inflamatÃria. Nosso grupo tem demonstrado que o PCI inibe a mn em modelos experimentais, entretanto os mecanismos e mediadores envolvidos ainda nÃo sÃo conhecidos.Objetivo:Estudar a participaÃÃo dos mediadores Ãxido nÃtrico e MonÃxido de carbono, proteÃnas de adesÃo (ICAM-1 e β2-integrina) e da expressÃo de CXCR2 no efeito inibitÃrio do PCI a distÃncia sobre a mn. MÃtodos:O modelo de PCI a distÃncia foi realizado com um torniquete no membro posterior direito de camundongos durante 10 minutos seguidos de 30 de reperfusÃo. ParticipaÃÃo do NO e CO foi investigada atravÃs de inibidores de iNOS (1400 W, 3 mg/kg ou Aminoguanidina (Amg), 50 mg/kg) e HO-1 (ZnPPIX, 10 mg/kg) como prÃ-tratamento de 30 min. Posteriormente, induziu-se peritonite comCarragenina(Cg) (500 mg /cav). Quatro horas apÃs, a cavidade peritoneal (cp) era lavada e leucÃcitos eram contados. ApÃs aquele mesmo procedimento, os animais foram submetidos a microscopia intravital (miv) para avaliar os efeitos do NO e CO nas vÃnulas mesentÃricas de 3 ordem.NeutrÃfilos de animais prÃ-condicionados e prÃ-tratados ou nÃo, foram utilizados para o ensaio de quimiotaxiain vitro, usandocomo estÃmulo a quimiocina KC(30ng/ml). AexpressÃo de CXCR2 e GRK2 dos neutrÃfilos foi determinada por citometria de fluxo e imunofluorescÃncia, respectivamente.AsparticipaÃÃes de ICAM-1/CD54 e β2-integrina/CD11b foram investigadas em camundongos nocautes para os genes dessas molÃculas. A mn nesses animais foi avaliada segundo protocolo jà descrito pelo lavado peritonela.Na investigaÃÃo do papel do NO e CO na modulaÃÃo da proteÃna de adesÃo celular (β2-integrina), utilizou-se inibidores da iNOS (1400W, 3 mg/kg ou Amg, 50 mg/kg, sc), HO-1 (ZnPPIX, 10 mg/kg, sc) eGuanilato Ciclase (ODQ (5 Âmol/kg, ip)) em prÃ-tratamento de 30 min antes do PCI. ApÃs peritonite, o sangue foi colhido e a expressÃo de CD11bem neutrÃfilos foi determinada por citometria de fluxo. Para anÃlise estatÃstica, utilizou-se ANOVA/Bonferroni. P<0,05 foi aceito. Resultados:Os inibidores de CO e NO preveniram o efeito inibitÃrio do PCIsobre a mn (p <0,05). AlÃm disso, os neutrÃfilos de animais prÃ-condicionados apresentaram reduÃÃo de quimiotaxia (p <0,05),achado que se correlacionou com a diminuiÃÃo da expressÃode CXCR2 na membrana dos neutrÃfilos (p <0,05) e comaumento da expressÃo de GRK2. NÃo houve alteraÃÃo da quimiotaxia, nem da expressÃo de GRK2 quando os neutrÃfilos foram obtidos a partir de animais prÃ-condicionados e prÃ-tratados com inibidores de de CO, NO e GCs. Os animais prÃ-condicionados apresentaram reduÃÃo nos neutrÃfilos circulantes e da aderÃnciana miv, as quais foram prevenidas pelo prÃ-tratamento com os inibidores (p <0,05). O efeito inibitÃrio do PCI persistiu em animais nocautes para β2-integrina, o que nÃo se observou nos animais nocautes para ICAM-1. AlÃm disso, os neutrÃfilos de animais prÃ-condicionados apresentaram reduÃÃo significativa na expressÃo de CD11b, que foi prevenida nos animais prÃ-tratados com os inibidores de iNOS, HO-1 e GCs.ConclusÃes: Os resultados sugerem que o NO e CO atuam no efeito inibitÃrio do PCI via iNOS e HO-1 em sitio distante, modulando ICAM-1, β2-integrina e CXCR2 via GRK2.
Introduction: Ischemic preconditioning (IPC) has been considered as a potent endogenous mechanism capable of inhibiting the inflammatory response. The migration of neutrophils (mn) is a central event in the development of inflammation. Our group has demonstrated that PCI inhibits mn in experimental models, however the mechanisms and mediators involved are not yet known. Aim: To study the involvement of mediators nitric oxide and carbon monoxide, adhesion proteins (ICAM-1 and β2-integrin) and expression of CXCR2 in the inhibitory effect of PCI on the distance min. Methods: The model of distance PCI was performed with a tourniquet in the right hind limb of mice for 10 minutes followed by 30 reperfusion. Involvement of NO and CO was investigated using inhibitors of iNOS (1400 W, 3 mg/kg or aminoguanidine (Amg), 50 mg/kg) and HO-1 (ZnPPIX, 10 mg/kg) as pretreatment 30 min. Later, peritonitis was induced by carrageenan (Cg) (500 mg/cav). Four hours later the peritoneal cavity (pc) was washed and leukocytes were counted. After that same procedure, the animals were subjected to intravital microscopy (IVM) to evaluate the effects of NO and CO in the mesenteric venules of 3rd order. Neutrophils from animals preconditioned and pre-treated or untreated, were used for testing chemotaxis in vitro, using the stimulus to chemokine KC (30ng/ml). The expression of GRK2 and CXCR2 in neutrophils was determined by flow cytometry and immunohistochemistry, respectively. The stakes and ICAM-1/CD54 β2-integrina/CD11b been investigated in knockout mice for genes of these molecules. The mn in these animals was evaluated according to protocol previously described by washed peritonela. In the investigation of the role of NO and CO in the modulation of cell adhesion protein (β2-integrin), we used iNOS inhibitor (1400W, 3 mg/kg or Amg, 50 mg/kg, sc), HO-1 (ZnPPIX, 10 mg/kg, sc) and guanylate cyclase (ODQ (5 Âmol/kg, ip)) in pre-treatment 30 min before PCI. After peritonitis, blood was collected and the expression of CD11b on neutrophils was determined by flow cytometry. For statistical analysis, we used ANOVA/Bonferroni. P<0,05 was accepted. Results: The CO and NO inhibitors prevented the inhibitory effect of PCI on mn (P<0,05). Moreover, neutrophils from animals preconditioned showed reduced chemotaxis (p<0,05), a finding that correlated with decreased expression of CXCR2 in the membrane of neutrophils (p<0,05) and increased expression of GRK2. There was no change in chemotaxis or the expression of GRK2 when neutrophils were obtained from animals pre-conditioned and pretreated with inhibitors of CO, NO and sGC. Preconditioned animals showed a reduction in circulating neutrophils and the grip on IVM, which were prevented by pretreatment with inhibitors (P<0,05). The inhibitory effect of PCI was shown in knockout animals for β2-integrin, which was not observed in the knockout animals to ICAM-1. Moreover, neutrophils from animals preconditioned showed a significant reduction in the expression of CD11b, which was prevented in animals pretreated with inhibitors of iNOS, HO-1 and GCs. Conclusions: The results suggest that NO and CO act in the inhibitory effect of PCI via iNOS and HO-1 in place apart by modulating ICAM-1, β2-integrin and CXCR2 via GRK2.
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Caillau, Philippe. "Modélisation et simulation de la combustion turbulente par une approche probabiliste eulérienne lagrangienne." Rouen, 1994. http://www.theses.fr/1994ROUES080.
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L'objet de cette thèse concerne la modélisation des écoulements réactifs turbulents. L'objectif visé consiste à développer un modèle susceptible de prédire la formation des polluants comme le monoxyde d'azote NO ou le monoxyde de carbone CO dans des foyers tridimensionnels complexes. Pour y parvenir, on fait appel à une approche probabiliste eulérienne lagrangienne (PEUL) où le champ de vitesse est calculé à l'aide des équations eulériennes de bilan moyennées et le champ de composition et de température par une méthode dite à transport de PDF (probability density function) lagrangienne. La modélisation des termes inconnus de dispersion turbulente et de mélange aux petites échelles est détaillée. Des mécanismes réduits et un mécanisme détaillé d'oxydation du combustible (qui est ici le méthane, CH4) ainsi que le mécanisme de formation du NO thermique sont introduits et testés. On présente les résultats obtenus avec le modèle PEUL dans trois configurations expérimentales. Les comparaisons calcul-expérience démontrent la capacité du modèle à prédire la formation du NO thermique et (partiellement) du prompt NO, du CO dans des configurations bi- et tridimensionnelles ainsi qu'à représenter correctement un régime d'extinction locale de la flamme.
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Silva, Camila Fontes Neves da. "Investigação comparativa da liberação controlada de CO e NO por carboxilatos trinucleares de rutênio contendo ligantes pi-receptor e sigma-doador." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-23052015-113643/.
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Neste trabalho foram realizadas as sínteses e caracterizações dos precursores (1) [Ru3O(CH3COO)6(CH3OH)3]CH3COO, (2) [Ru3O(CH3COO)6(CO)(CH3OH)2] (3) [Ru3O(CH3COO)6(4-acpy)2(H2O)]PF6, (4) [Ru3O(CH3COO)6(4-tbpy)2(H2O)]PF6 e dos complexos inéditos (5) [Ru3O(CH3COO)6(4-acpy)2(CO)], (6) [Ru3O(CH3COO)6(4-tbpy)2(CO)], (7) [Ru3O(CH3COO)6(4-acpy)2(NO)]PF6, (8) [Ru3O(CH3COO)6(4-tbpy)2(NO)]PF6. Os complexos foram caracterizados por espectroscopia na região do UV-Vis e do infravermelho, espectroscopia de ressonância magnética nuclear (RMN), voltametria cíclica e análise elementar. Por meio dos resultados obtidos nas técnicas de caracterização, foi possível confirmar a estrutura proposta inicialmente para os complexos e também para os precursores. Além disso, também foi possível observar a influência dos ligantes, -receptor e -doador na estrutura dos mesmos. Por meio da técnica de espectroscopia de infravermelho analisou-se principalmente estiramentos dos ligantes CO nos complexos 5 e 6 e do NO nos complexos 7 e 8. Nos estudos de RMN observou-se as características diamagnéticas dos complexos 5 e 6, e no caso dos complexos 7 e 8 foi possível confirmar que há uma forte interação entre o elétron desemparelhado na unidade [Ru3O]+ e do ligante NO0. Os ensaios eletroquímicos de voltametria cíclica mostraram a influência dos ligantes CO e NO na comunicação eletrônica da unidade [Ru3O].Os complexos com ligantes CO e NO foram irradiados com laser em 377 nm e 660 nm em soluções de acetonitrila e tampão fosfato pH 7,4. Estas irradiações foram acompanhadas por espectroscopia na região do UV-visível. No caso dos complexos 5 e 6, o aumento da banda na região de 900 nm indicou a formação do complexo, [Ru3O(CH3COO)6(L)2(S)], após a liberação do ligante monóxido de carbono (CO). A liberação de CO ocorreu predominantemente com irradiação em 377 nm na região do ultravioleta em pH fisiológico (solução aquosa de tampão fosfato, pH=7,4) e também em solução de acetonitrila. Para os complexos com ligantes NO, o perfil espectral obtido após fotólise indicou a formação de um complexo oxidado sem a coordenação do NO, [Ru3O(CH3COO)6(L)2(S)]+.In this study it was performed the synthesis and characterization of the precursors (1) [Ru3O(CH3COO)6(CH3OH)3]CH3COO, (2) [Ru3O(CH3COO)6(CO)(CH3OH)2] (3) [Ru3O(CH3COO)6(4-acpy)2(H2O)]PF6 (4) [Ru3O(CH3COO)6(4-tbpy)2(H2O)]PF6 and the unpublished complexes (5) [Ru3O(CH3COO)6(4-acpy)2(CO)] (6) [Ru3O(CH3COO)6(4-tbpy)2(CO)] (7) [Ru3O(CH3COO)6(4-acpy)2(NO)]PF6 (8) [Ru3O(CH3COO)6(4-tbpy)2(NO)]PF6. The complexes were characterized by UV-Vis and infrared spectroscopy, nuclear magnetic resonance (NMR), cyclic voltametry, and elemental analysis. By means of the results obtained from the characterization, it was possible to confirm the initially proposed structure for both complexes and precursors. Furthermore, it was also possible to observe the influence of ligands, - receptor and the -donor in the structure of the complexes. By infrared spectroscopy it was verified primarily stretches of the CO and NO ligands in complexes 5,6 and 7,8 respectively. In NMR it was observed the diamagnetic character of complexes 5 and 6, and in the case of complexes 7 and 8 it was confirmed that there is a strong interaction between the unpaired electron in the [Ru3O]+ unit and the NO0 ligand. The cyclic voltammograms showed the influence of the CO and NO ligands on the electronic communication of the [Ru3O] unit. Complexes with ligands CO and NO were irradiated with laser at 377 nm and 660 nm in solutions of acetonitrile and phosphate buffer pH 7.4. The photolysis were accompanied by spectroscopy in the UV-visible region. In the case of complexes 5 and 6, the increase of the band in the region of 900 nm indicated the formation of the complex, [Ru3O(CH3COO)6(L)2(S)]+ produced after release of carbon monoxide (CO). The release of CO occurs predominantly with irradiation at 377 nm in the ultraviolet region at physiological pH (aqueous phosphate buffer solution, pH = 7.4) and in acetonitrile solution. For complexes with NO ligands, the spectral profile obtained after photolysis indicated the formation of an oxidized complex without coordination of NO, the [Ru3O(CH3COO)6(L)2(S)] + molecule.
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黃大偉 and Tai-wai Wong. "Laser spectroscopy of sulphur monoxide and titanium nitride." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31210612.
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Wong, Tai-wai. "Laser spectroscopy of sulphur monoxide and titanium nitride /." [Hong Kong] : University of Hong Kong, 1992. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13205043.
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Jackson, Andrew B. Templeton J. L. "Nitrile reduction and carbon monoxide replacement in tungstenII bisacetylacetonate complexes." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1895.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.Title from electronic title page (viewed Dec. 11, 2008). "...in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.
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Monteparo, Christopher Nicholas. "Gallium nitride sensors for hydrogen/nitrogen and hydrogen/carbon monoxide gas mixtures." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0002838.
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Carusio, Nunzia. "Role of nitric oxide in the protection of myosin light chain kinase 210 delection against vascular inflammation induced by endotoxins." Strasbourg 1, 2006. http://www.theses.fr/2006STR13232.
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Tiev, Kiet Phong. "Rôle du monoxyde d'azote dans la physiopathologie des atteintes pulmonaires de la sclérodermie systémique." Thesis, Paris Est, 2008. http://www.theses.fr/2008PEST0081.
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La pneumopathie interstitielle (PI) est devenue la principale cause de décès de la sclérodermie systémique (ScS). Au cours de PI, l’activation immunitaire déclenche une forte production du monoxyde d’azote (NO) et l’augmentation de la concentration de NO dans l’air expiré des patients atteints de ScS avec PI suggère que cette méthode pourrait détecter précocement l’alvéolite, afin de traiter à temps la PI pour éviter son évolution vers la fibrose pulmonaire. En utilisant le modèle à deux compartiments séparant le NO alvéolaire (CANO) du NO bronchique, nous avons montré que la CANO est : (1) augmentée chez les patients atteints de ScS comparativement aux volontaires sains; (2) associée à l’alvéolite et (3) corrélée à la sévérité de la PI. De plus, une valeur de CANO = 10,8 ppb permettait d’affirmer la présence de la PI et une valeur = 3,8 ppb, d’écarter l’existence d’une PI avec une valeur prédictive= 95%. Le modèle bi-compartimenté néglige la distribution arborisée des voies aériennes et la diffusion axiale du NO, que prend en compte le nouveau « modèle de la trompette ». Les résultats de CANO des 2 méthodes sont comparables (rho=0,98, p<0.001). Enfin, La capacité des sérums à induire la prolifération des fibroblastes pulmonaires et sa conversion en myofibroblaste est augmentée chez les patients atteints de ScS avec une CANO > 5ppb par rapport à celle des patients atteints de ScS qui ont une CANO = 5 ppb et à celle des volontaires sains. Nos résultats suggèrent une relation possible entre l’inflammation alvéolaire et la fibrose pulmonaire au cours de la ScSInterstitial lung disease (ILD) has become the main cause of death in systemic sclerosis (SSc). In ILD, immune activation leads to strong nitric oxide (NO) output by inducible NO synthase. Increased the whole fractional rate of NO in exhaled air has been reported in SSc patients with ILD and suggested that exhaled NO can be an accurate none-invasive marker of early alveolar inflammation in order to initiate in time treatment. The two compartment-model method partitioned exhaled NO into alveolar concentration (CANO) and conducting airway flux, We hypothesized that overproduction of NO in the lung eventually leads to ILD in SSc. We have found that CANO is significantly increased in SSc patients as compared with healthy controls. We have also demonstrated that high levels of CANO were related to alveolitis and the severity of ILD in SSc. Moreover, we have found that ILD could be ruled in (positive predictive value > 95%) when CANO = 10.8 ppb, and ruled out when CANO values = 3.8 ppb (negative predictive value > 95%). The two-compartment model neglected the trumpet shape of airway tree and the axial diffusion of NO that the advanced “trumpet model” takes account. We have found that CANO levels assessed by the two models were comparable (rho=0,98, p<0.001). Finally, we have found that the serum ability to induce lung fibroblast proliferation and myofibroblast transition was increased in SSc patients with high levels of CANO (>5ppb) as compared to SSc patients with low levels of CANO (=5ppb) and healthy controls. Our findings suggest a possible link between alveolar inflammation, and lung fibrosis in SSc. 1624 caractères avec espace
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Cam, Yvan. "Rôle du monoxyde d'azote dans la symbiose entre Sinorhizobium meliloti et Medicago truncatula." Toulouse 3, 2012. http://www.theses.fr/2012TOU30355.
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Le monoxyde d'azote (NO) est une molécule gazeuse connue pour participer à de nombreux processus biologiques allant du développement aux réponses aux stress biotiques ou abiotiques chez tous les organismes vivants. Au cours des interactions hôte-pathogène, le NO est utilisé par l'hôte en tant que moyen de défense pour bloquer une éventuelle infection, ce à quoi les pathogènes se sont adaptés en mettant en place des systèmes de réponses au NO et de dégradation du NO. Au cours d'interactions symbiotiques de type mutualiste, du NO a également été mis en évidence et joue un rôle dans la mise en place de l'interaction via une action sur les deux partenaires. Dans la symbiose fixatrice d'azote entre la légumineuse Medicago truncatula et l'alpha-proteobactérie Sinorhizobium meliloti, du NO a été détecté durant toutes les phases de l'interaction. Au cours de cette thèse, nous nous sommes intéressés à déterminer le rôle du NO et de la réponse bactérienne associée sur la symbiose M. Truncatula/ S. Meliloti. Nous avons pu montrer que la bactérie en développe une réponse au NO via deux régulateurs, le système à deux composants FixLJ et le régulateur spécifique du NO, NnrR. Au cours de cette réponse, nous avons montré que la bactérie exprime une flavohémoglobine, Hmp, capable de dégrader le NO. In planta, nous avons détecté du NO dans les crosses de berger des poils absorbants et au niveau des parois des cordons d'infections. Par l'utilisation de mutants nuls ou surexprimant cette flavohémoglobine et par des traitements pharmacologiques, nous avons fait varier le niveau de NO dans les nodules et suivi le phénotype symbiotique résultant. Ainsi, nous avons montré que le NO est nécessaire à la mise en place de la symbiose. Au cours des étapes tardives, nous avons montré que le NO déclenche la sénescence des nodules et que les bactéries via la flavohémoglobine participent de façon importante au contrôle du niveau de NO dans les nodules et donc au contrôle de la sénescence nodulaireNitric oxide (NO) is a little gaseous molecule known to participate in many biological processes from development to responses to biotic and abiotic stress in all living organisms. During host-pathogens interactions, NO is used by the host as a defense mechanism to prevent a possible infection. Pathogens adapt themselves to it by developing response and degradation systems to NO. During symbiotic interactions, NO has also been detected and it has been shown that it plays a role in the establishment of the interaction through an action on both partners. In the nitrogen fixing symbiosis between the legume Medicago truncatula and the ?-proteobacteria Sinorhizobium meliloti, NO has been detected during each step of the interaction. In this thesis, we've been interested in finding the role of NO and of the associated bacterial response on the M. Truncatula/ S. Meliloti symbiosis. We've shown that bacteria develop a response to NO through two regulators, the two components system FixLJ and the NO specific regulator NnrR. During this response, we've demonstrated that bacteria express a flavohemoglobin, Hmp, able to degrade NO. In planta, we've detected NO in shepherd crosses of root hairs and on infection thread membrane. By using null or overexpressing mutants of Hmp and by pharmacological treatments, we modified the NO level in nodules and follow the resulting symbiotic phenotype. Thus, we've shown that NO is needed to establish the symbiosis. During the late steps of the symbiosis, we've also demonstrated that NO triggers the nodule senescence and that bacteria through the flavohemoglobin are largely involved in the NO level control in nodules and consequently in the control of nodule senescence
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Stys, Agnieska. "Role of iron regulatory proteins in the regulation of iron metabolism by nitric oxide." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA11T056.
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Les Iron Regulatory Proteins 1 (IRP1/2) sont des protéines cytosoliques qui contrôlent l’homéostasie du fer chez les mammifères. Elles régulent la concentration de fer intracellulaire au niveau post-transcriptionnel, en interagissant spécifiquement avec des motifs appelés iron responsive élément (IREs). Ces motifs sont localisés dans les régions non traduites des ARNm codant notamment pour la ferritine (Ft), la ferroportine (Fpn) et le récepteur de la transferrine (TfR1). L’IRP1 est une protéine bifonctionnelle, majoritairement exprimée sous une forme contenant un centre [4Fe-4S] qui présente une activité aconitase. Les deux activités de l’IRP1 (aconitase/trans-régulateur) s’excluent mutuellement par la présence ou non du centre Fe-S. L’IRP2 est exprimée constitutivement sous une forme liant les IREs. Le monoxyde d’azote (NO), une importante molécule de signalisation impliquée dans les défenses immunitaires, cible le centre Fe-S de l’IRP1 et permet la conversion de l’IRP1 de sa forme aconitase vers sa forme liant les séquences IREs. Il a également été rapporté que l’IRP2 détecterait NO, cependant la fonction intrinsèque de l’IRP1 et de l’IRP2 dans le contrôle du métabolisme du fer intracellulaire en réponse à NO reste à ce jour non élucidée. Dans cette étude, nous avons identifié le régulateur principal du métabolisme du fer intracellulaire en réponse à NO, en utilisant des modèles de souris déficients pour les gènes IRP1 et/ou IRP2 et testé la contribution de la tension en oxygène dans cette régulation. Ainsi, nous avons exposé des macrophages primaires issus de la moelle osseuse de souris Irp1-/-, Irp2-/- et de souris Irp1-/- Irp2-/- de la lignée macrophagique à une source de NO, sous différentes tensions en oxygène. Les activités IRPs, l’expression des gènes Ft, Fpn et TfR1 ainsi que l’activité d’une protéine à centre Fe-S (l’aconitase mitochondriale) ont été mesurées après fractionnement cellulaire. Nous avons montré qu’en normoxie, la conversion de l’aconitase cytosolique en apo-IRP1 par NO est entièrement responsable de la régulation post-transcriptionnelle des ferritines (L-Ft et H-Ft), de la Fpn et du TfR1. En augmentant le transport du fer intracellulaire et en diminuant le stockage et l’export, l’activation de l’IRP1 par NO servirait à maintenir des taux de fer intracellulaire suffisants pour alimenter la biogenèse des centres Fe-S après l’arrêt des flux de NO. En effet, nous observons une restauration efficace de l’activité de l’aconitase mitochondriale dans les macrophages de souris sauvage alors qu’elle est bloquée dans les macrophages de souris Irp1-/-. De plus, l’IRP1 activée par NO, permet également de diminuer les taux de L- et H-Ft, anormalement élevée dans les macrophages de souris Irp2-/-. Nous montrons que le NO endogène active l’IRP1 sous sa forme trans-régulatrice alors qu’il tend à diminuer l’activité de l’IRP2. Néanmoins, l’IRP1 reste le régulateur principal des ferritines en conditions de normoxie. En condition hypoxique, les deux IRPs semble coopérer pour inhiber la traduction des ferritines car dans les macrophages Irp1-/-exposés à NO, l’IRP2 stabilisée est suffisante pour inhiber la traduction de la L- et H-Ft et ceci malgré l’activation transcriptionnelle des gènes de la L- et H-Ft. Concernant la régulation du TfR1 par NO et en hypoxie, TfR1 est principalement régulé par une voie transcriptionnelle dominant largement la voie post-transcriptionnelle impliquant l’IRP1. Le facteur de transcription HIF-1 alpha pourrait être le régulateur critique dans cette régulation. En conclusion, nous montrons dans cette étude, comment le regulon IRP participe à la régulation du métabolisme du fer intracellulaire en réponse à NO et son étroite connexion avec la concentration en oxygène. Nos résultats soulignent l’importance d’explorer davantage le rôle de l’IRP1 dans des situations inflammatoires in vivo, où les tissus peuvent être exposé à un microenvironnement non hypoxiqueIron Regulatory Protein 1 (IRP1) and 2 (IRP2) are two cytosolic regulators of mammalian cellular iron homeostasis. IRPs post-transcriptionally modulate expression of iron-related genes by binding to specific sequences, called Iron Regulatory Elements (IREs), located in the untranslated regions (UTR) of mRNAs. Either of the two IRPs inhibits translation when bound to the single 5’UTR IRE in the mRNA encoding proteins of iron export (ferroportin - Fpn) and storage (ferritin - Ft) or prevents mRNA degradationwhen bound to the multiple IREs within the 3’UTR of the mRNA encoding the transferrinreceptor 1 (TfR1) - iron uptake molecule. The IRE-binding activity of both IRPs respondsto cellular iron levels, albeit via distinct mechanisms. IRP1 is a bifunctional protein, whichmostly exists in its non IRE-binding, [4Fe-4S] aconitase form and can be regulated by apost-translational incorporation or removal of the Fe-S cluster. In contrast to IRP1, IRP2 isnot able to ligate an Fe-S cluster, and its IRE-binding activity is determined by the rate ofits proteasomal degradation. Although both IRP1 and IRP2 can regulate cellular ironhomeostasis, only mice lacking IRP2 were shown to display iron mismanagement in mosttissues. This could be explained by the fact that IRP1 exists mostly in its non IRE−binding,aconitase form under physiological oxygen conditions (3-6%). Interestingly, nitric oxide(NO), an important signalling molecule involved in immune defence, targets the Fe-Scluster of IRP1 in both normoxia and hypoxia, and converts IRP1 from aconitase to anIRE-binding form. It has also been reported that IRP2 could sense NO, but the intrinsicfunction of IRP1 and IRP2 in NO−mediated regulation of cellular iron metabolism hasremained a matter of controversy. In this study, we took advantage of mouse models ofIRP deficiency to define the respective role of IRP1 and IRP2 in the regulation of cellulariron metabolism by NO and assess the contribution of oxygen tension on the regulation.Therefore, we exposed bone marrow-derived macrophages (BMMs) from Irp1-/-, Irp2-/- andmacrophage specific double knockout mosaic mice (Irp1/2-/-) to exogenous andendogenous NO under different oxygen conditions (21% O2 for normoxia and 3-5% forhypoxia experiments) and measured IRPs activities, iron-related genes expression andactivity of Fe-S cluster protein – mitochondrial aconitase. We showed that in normoxia, thegenerated apo-form of IRP1 by NO was entirely responsible for the post-transcriptionalregulation of TfR1, H-Ft, L-Ft and Fpn. Moreover, by increasing iron uptake and reducingiron sequestration and export, NO−dependent IRP1 activation served to maintainadequate levels of intracellular iron in order to fuel the Fe−S biosynthetic pathway, asdemonstrated by the efficient restoration of the mitochondrial Fe−S aconitase, which wasprevented under IRP1 deficiency. Furthermore, activated IRP1 was potent enough todown-regulate the abnormally increased L-Ft and H-Ft protein levels in Irp2-/-macrophages. Endogenous NO activated IRP1 IRE-binding activity and tended todecrease IRP2 IRE-binding activity. Nevertheless, IRP1 was the predominant regulator offerritin in those conditions. In hypoxia, in Irp1+/+ and Irp2+/+ macrophages exposed to NO,both stabilized IRP2 and NO-activated IRP1 seemed to cooperate to inhibit ferritinsynthesis. However, in Irp1-/- cells, IRP2 stabilized in hypoxia was sufficient to inhibit LandH-Ft synthesis despite the concomitant increase of corresponding mRNAs.Interestingly, TfR1 was shown to be predominantly regulated at the transcriptional level byNO in hypoxia, in which HIF-1 alpha may be the critical regulator. In conclusion, we revealin this study how the IRP regulon participates in the regulation of cellular iron metabolismin response to NO and its intimate interplay with the oxygen pathway. The findingsunderlie the importance to further explore the role of IRP1 in inflammation in vivo, in nonhypoxictissue microenvironments
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Amrouni, Donia. "Monoxyde d'azote (NO) et trypanosomose africaine expérimentale chez le rat." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10129.
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Grâce à un modèle expérimental de la trypanosomose humaine Africaine (THA ou maladie du sommeil), le rat infecté par Trypanosoma brucei brucei, nous avons examiné l’implication du monoxyde d’azote (NO) dans le développement de cette pathologie. Des variations opposées de la concentration de ce composé ont été observées chez les animaux infectés, au niveau des compartiments périphérique et central : le NO diminue au niveau du sang et augmente au niveau cérébral. Ces changements sont dépendants de la NO-synthase inductible (iNOS). Au niveau périphérique, la diminution du NO qui survient favorise l’installation du parasite car la pression trypanocide de ce composé est diminuée. Dans cette situation, la L-arginine, le substrat à la base de la synthèse du NO, est utilisée pour la synthèse de polyamines, des composés nécessaires à la croissance du parasite. Ces mécanismes sont très probablement déclenchés par le trypanosome via ses facteurs solubles. Au niveau cérébral, la synthèse du NO est aussi soumise à des régulations qui impliquent l’arginase et la NG, NG-diméthylarginine diméthylaminohydrolase (DDAH). Tandis que l’activité de l’arginase demeure constante, celle de la DDAH augmente au cours de l’infection en accord avec les données des western-blot et des amino-acides. Cette augmentation, qui dépend essentiellement de l’isoforme DDAH-2, conduit à une augmentation du NO cérébral dont les propriétés sont trypanocides. Ces changements, contraires à ceux observés en périphérie, sont défavorables à la survie du trypanosome au niveau du cerveau. Ils pourraient constituer une protection supplémentaire contre l’entrée des trypanosomes dans cet organeBy way of an experimental model of human African trypanosomiasis (HAT or sleeping sickness), the rat infected by Trypanosoma brucei brucei, we examined the involvement of nitric oxide (NO) in the development of this pathology. In the infected animals, opposite variations in NO concentration were observedeither at peripheral or brain compartments: NO decreases in blood but increases in brain. These changes are dependent on the activity of the inducible NO-synthase (iNOS). In periphery, the decrease observed in NO concentration favors the parasite entrance because the trypanocidal pressure exerted by NO is decreased. In such a situation, L-arginine, the substrate conducing to the synthesis of NO, is employed for the synthesis of polyamines, a category of compounds necessary for the parasite growth. It is likely that above mechanisms might be triggered by parasites. In brain, NO synthesis is submitted to additive complex regulatory processes implying arginase and NG, NG-dimethylarginine dimethylaminohydrolase (DDAH). While the arginase activity remains constant, that of DDAH increases throughout the infection process in keeping with western-blot and amino acids data. This increase, depending mainly on DDAH-2 isoform, lasts in a brain NO increase which enhance the trypanocidal pressure. Above changes, opposite to those observed in periphery, are not favorable to the parasite survival in brain. They might constitute an additive protection against the parasite entry in this organ
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Parent, Marianne. "Formulations in situ de donneurs de monoxyde d'azote." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0127/document.
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Les systèmes in situ sont des liquides à base de polymère et de solvant organique pharmaceutiquement acceptable, contenant le principe actif. Après injection sous-cutanée, lors du contact avec les fluides corporels, le polymère précipite sous forme d'implant (ISI) ou de microparticules (ISM) qui se dégradent progressivement en libérant le principe actif. Dans ce travail, des ISI et des ISM réalisés à partir d'un copolymère d'acide lactique et glycolique ont été développés pour la libération prolongée de S-nitrosothiols (RSNO), des donneurs de monoxyde d'azote. L'influence du type de formulation, du solvant, de l'hydrophobie du principe actif et de l'environnement (in vitro ou in vivo) sur la solidification, la dégradation de la matrice polymérique et sur la libération du RSNO ont été étudiés. Les expériences in vivo ont prouvé la prolongation par la formulation de l'effet des RSNO sur la pression artérielle chez le rat (jusque 42 h). Néanmoins, le temps de dégradation des formulations est supérieur à 1 mois et doit donc être optimisé pour une application de longue durée. Le potentiel de ces formulations dans un modèle d'infarctus a été évalué. La faisabilité d'une injection directe dans le myocarde infarci a été démontrée. D'après les premiers résultats, ces implants chargés en RSNO permettraient d'améliorer la perfusion du coeur. Enfin, la porosité de ces systèmes augmente durant leur dégradation, ce qui rend la matrice susceptible de recruter et d'héberger des cellules. In vitro, des ISI ont permis l'adhésion et la prolifération de cellules musculaires. Ces formulations adaptées aux RSNO pourraient constituer un outil thérapeutique dans le cadre des maladies ischémiquesIn situ forming injectable systems are liquids based of a polymer and a pharmaceutically acceptable organic solvent, to which drug is added. After subcutaneous injection, contact with aqueous body fluids triggers polymer precipitation as implant (ISI) or microparticles (ISM). This matrix degrades then slowly while releasing the drug. In this work, ISI and ISM made of a copolymer of lactic and glycolic acid were developed for sustained release of S-nitrosothiols (RSNO), prodrugs of nitric oxide. Influence of formulation type, solvent, drug hydrophobicity and environment (in vitro vs in vivo) on polymeric matrix solidification, degradation and on RSNO release was studied. In vivo experiments proved that formulation extend (until 42 h) RSNO effect on arterial pressure of rats. However, matrix life-span is higher than 1 month, thus need optimization in view of an application requiring a long lasting release. Evaluation of these formulations has begun in a model of cardiac infarction. First, the feasibility of a direct injection into the infarct area has been established. Second, first results seem to indicate that these implants loaded with RSNO could enhance heart perfusion. Finally, porosity of these systems increases during their degradation, allowing cell recruitment and colonization of resulting matrix. An in vitro study conducted on implants with porosity artificially increased showed adhesion and proliferation of muscular cells seeded onto the systems. As a result, in situ formulations are suitable drug delivery systems for S-nitrosothiols, and represent a potential therapeutic tool, in particular in the field of ischemic diseases
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Ras, Geoffrey. "Production de monoxyde d’azote par les staphylocoques à coagulase négative : implication de l’oxyde nitrique synthase de staphylococcus xylosus." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC029/document.
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Les staphylocoques à coagulase négative (SCN) sont des bactéries fréquemment isolées de viandes et de produits carnés. Parmi les SCN, seules les deux espèces S. xylosus et S. carnosus sont utilisées comme ferments dans les produits carnés. Dans ces produits, il est d’usage d’ajouter du nitrate/nitrite pour le développement de la couleur typique des salaisons. Les staphylocoques participent au développement et à la stabilité de la couleur en réduisant le nitrate en nitrite via leur activité nitrate réductase. Le nitrite est chimiquement réduit en monoxyde d’azote (NO), qui se lie au fer de l’hème de la myoglobine pour former la nitrosomyoglobine, un pigment rouge et stable. Le contexte actuel vise à réduire l’utilisation du nitrate/nitrite afin de limiter le risque de formation de composés N-nitrosés tels que les nitrosamines. Il a été montré que les bactéries pouvaient synthétiser du NO à partir d’une oxyde nitrique synthase (NOS). Le gène nos a été identifié dans une collection de souches de SCN isolées de viande. La séquence protéique de la NOS est fortement conservée entre les espèces. Pour mettre en évidence la production de NO, un test basé sur la conversion de metmyoglobine en pigments rouges, l’oxymyoglobine et la nitrosomyoglobine, a été utilisé. Le nitrosohème contenu dans la nitrosomyoglobine a été extrait. La formation du nitrosohème, chez un mutant de délétion du gène nos de la souche S. xylosus C2a, est fortement réduite en condition limitée en oxygène et abolie en condition aérobie. De plus, la NOS de S. xylosus C2a est impliquée dans la réponse à un stress oxydant. Afin de déterminer le potentiel de production de NO de souches de S. xylosus et d’autres espèces de SCN, leur capacité à former de la nitrosomyoglobine a été évaluée. Cette formation est espèce- et souche-dépendante. Les souches de S. xylosus ont un potentiel de production de NO plus élevé que les souches des autres espèces. Ce test a également révélé que certaines souches de SCN sont capables de former de l’oxymyoglobine à partir de la metmyoglobine.Cette étude a permis de mettre en évidence l’implication de la NOS dans la production de NO chez S. xylosus et la capacité de formation de nitrosomyoglobine chez d’autres souches de SCN isolées de viandeCoagulase Negative Staphylococci (CNS) are usually isolated from meat and meat products. In meat products, S. xylosus and S. carnosus are the only CNS species used as meat starter cultures. In these products, nitrate and nitrite are used as additives where they contribute to the development of the typical red coloration. Staphylococci contribute to the development and stability of colour through their nitrate reductase activity that reduces nitrate to nitrite. Nitrite is chemically reduced to nitric oxide (NO) which is able to bind the ferrous-heme iron to form the stable bright red nitrosomyoglobin pigment. However, the safety regarding the use of these additives on meat products has been questioned as nitrite is able to form N-nitroso compounds such as nitrosamines. Some bacteria are able to synthesize NO by nitric oxide synthase (NOS). The nos gene was identified in a collection of CNS isolated from meat. The NOS sequence is well conserved between species. NO production has been investigated based on the formation of red myoglobin derivatives from metmyoglobin such as oxymyoglobin and nitrosomyoglobin. Subsequently, the nitrosoheme was extracted from nitrosomyoglobin. Nitrosoheme formation was reduced under limited oxygenated condition while it was abolished under aerobic condition in a S. xylosus C2a nos deleted mutant. Moreover, NOS is involved in oxidative stress resistance in S. xylosus C2a. In order to determine the potential of NO production among other strains of S. xylosus and other CNS species, their potential to form nitrosomyoglobin was evaluated. Nitrosomyoglobin formation is strain- and species-dependent. This assay has also revealed that several CNS strains are able to form oxymyoglobin from metmyoglobin.This study has demonstrated NOS-dependent NO production in S. xylosus and the ability of CNS isolated from meat to form nitrosomyoglobin
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Olekhnovitch, Romain. "The antimicrobial activity of nitric oxide at the site of Leishmania infection." Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC152.
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La production d'oxyde nitrique (NO) par l'enzyme iNOS (inducible NO synthase) est impliquée dans le contrôle de nombreuses infections causées par des pathogènes intracellulaires. Cependant, la nature des signaux nécessaires à l'induction d'iNOS in vivo et les mécanismes responsables de son activité antimicrobienne restent à définir. En particulier, plusieurs études suggèrent que le NO exerce son activité de manière intrinsèque : l'induction d'iNOS par les cellules infectées leur permettrait donc de contrôler individuellement leur charge microbienne. Alternativement, la capacité du NO à diffuser à travers les membranes cellulaires pourrait bien jouer un rôle déterminant dans le contrôle de ces infections à pathogènes intracellulaires. Les contributions respectives de ces deux modes d'action dans le contrôle de l'infection restent inconnues. Dans cette thèse, nous démontrons dans le cadre de l'infection par Leishmania major que iNOS est rapidement induite en réponse à l'IFNy et le TNF par les phagocytes mononucléés recrutés au site d'infection mais ne confère aucune capacité intrinsèque à contrôler les parasites. Au contraire, nous démontrons que la diffusion du NO permet de tuer les parasites aussi bien dans les cellules exprimant iNOS que dans les cellules à proximité et que la production collective de NO par de nombreux phagocytes et nécessaire pour atteindre une activité antimicrobienne efficace. Finalement, en s'appuyant sur une méthode innovante impliquant une protéine photoconvertible, nous démontrons que ce milieu riche en NO limite le métabolisme et ainsi la prolifération du parasite in vivo, permettant ainsi de contrôler efficacement l'infection par LeishmaniaThe production of nitric oxide (NO) by the inducible NO synthase (iNOS) plays a critical role in the control of many infections with intracellular pathogens. However, the signais mediating iNOS induction in vivo and the precise mechanisms underlying its antimicrobial activity at the site of infection remain unclear. In particular, several studies have promoted the idea that NO production in infected cells may enable them to individually control their pathogen burden. Alternatively, the ability of NO to diffuse efficiently across cell membranes may be critical for the control of infection with intracellular pathogens. Whether pathogen control primarily depends on cell-intrinsic or cell-extrinsic activity of NO is unknown. In this thesis, we demonstrate that during Leishmania major infection, iNOS is rapidly induced in recruited mononuclear phagocytes in response to IFNy and TNF. We show that this rapid iNOS induction does not confer any cell-intrinsic ability to lower parasite content. Ln fact, we demonstrate that the diffusion of NO promotes equally effective parasite killing in producing and bystander cells and that the collective production of NO by numerous phagocytes is necessary to exert an effective antimicrobial activity. Altogether, we prOpose that in contrast to a cell-autonomous control of intracellular pathogens, this cooperative mechanism generates an antimicrobial milieu that provides the basis for pathogen containment at the tissue level. Finally, using a new method based on a photoconvertible protein, we demonstrate that this NO-rich microenvironment controls Leishmania infection in part by dampening parasite metabolism and subsequent proliferation in vivo
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Nguyen, Nhi Ha. "Synthèse de nano-déclencheurs photo-activables pour le contrôle spatio-temporel de la formation de NO." Thesis, Cachan, Ecole normale supérieure, 2015. http://www.theses.fr/2015DENS0020.
Full textAbstract:
Le monoxyde d’azote (NO), dont le rôle biologique a été découvert à la fin du 20ème siècle, est impliqué dans la régulation de nombreux processus à l’échelle de la cellule et de l’organisme. Sa biosynthèse est réalisée par les enzymes NO synthases (NOS), et met en jeu la liaison de NADPH à leur domaine réductase suivie d’une série de transfert d’électrons vers leur domaine oxygénase, où la formation de NO se produit par oxydation de la L-arginine. En s’inspirant de mimes photo-activables de NADPH précédemment décrits dans la littérature, appelés nano-déclencheurs (NT, de l’anglais nanotriggers), induisant la production de NO par illumination, nous avons conçu et synthétisé de nouvelles générations de composés potentiellement capables d’initier l’activité catalytique de NOS sous irradiation. Ils comportent une unité de reconnaissance de NOS dérivée de l’adénosine et une unité chromophorique de type diaminophényl butadiène, liées entre elles par un groupement triazole. Ces structures modulables, facilement assemblées par chimie « click » ont permis la préparation d’une librairie de nano-déclencheurs, dont les propriétés photophysiques et la stabilité dans des conditions physiologiques ont été évaluées. Ces nouvelles générations de composés offrent des perspectives intéressantes pour le contrôle de processus biologiques par la lumièreNitric oxide (NO), whose biological role has been discovered in the late 20th century, is involved in the regulation of many processes in cell and organism. Its biosynthesis is carried out by enzymes named nitric oxide synthases (NOS) and involves NADPH binding to their reductase domain followed by a series of electron transfers to their oxygenase domain, where the formation of NO takes place by oxidation of L-arginine. Inspired by photoactivatable NADPH mimics called nano-triggers (NT), previously described in the literature, able to produce NO upon illumination, we designed and synthesized new generations of compounds potentially capable of initiating the catalytic activity of NOS under irradiation. They contain a recognition unit for NOS derived from adenosine and a diaminophenyl butadiene chromophoric moiety, linked together by a triazole group. These modular structures, easily assembled by "click" chemistry allowed the preparation of a library of nano-triggers, whose photophysical properties and stability under physiological conditions were evaluated. These new generations of compounds offer interesting perspectives for the control of biological processes by light
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Simeni, Simeni Marien. "Quantum cascade laser absorption studies of nitric oxide production by nanosecond pulsed discharges in air and in combustible mixtures." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2015. http://www.theses.fr/2015ECAP0033/document.
Full textAbstract:
Les plasmas d’air à pression atmosphérique ont de nombreuses applications. Nous pouvons par exemple citer les applications biomédicales, le traitement des matériaux, la bio-décontamination environnementale et la combustion assistée par plasma. La polyvalence des décharges plasma résulte de leur capacité à produire des densités élevées d’espèces actives, sans toutefois chauffer substantiellement le gaz. Les décharges nanosecondes répétitivement pulsées (NRP) ont particulièrement reçu une grande attention en raison de leur capacité à produire des densités électroniques élevées, qui conduisent à la création de fortes densités d’espèces actives telles que l’oxygène atomique (O). Par ailleurs, des mesures de spectroscopie d’émission ont montré que des états excités du monoxyde d’azote (NO) sont produits par les décharges NRP opérant dans l’air ou dans des mélanges combustibles. Bien que les décharges NRP aient déjà fait l’objet de plusieurs investigations, les mécanismes cinétiques conduisant à la production de NO sont toujours incertains. C’est la motivation première des travaux menés dans le cadre de cette thèse. En outre, les décharges NRP se sont avérées produire une grande quantité d’oxygène d’atomique, espèce de grande importance pour la combustion assistée par plasma. Il a été en particulier démontré que grâce à la production élevée d’espèces actives, les décharges NRP peuvent stabiliser efficacement des flammes pauvres, à pression atmosphérique. Cependant la production de NO par les décharges NRP et les flammes stabilisées à l’aide des décharges NRP reste à étudier. Cela constitue le second objectif de cette thèse. Les mesures in-situ de densités absolues de NO dans les décharges plasmas et/ou en combustion sont très difficiles. Les techniques de fluorescence telle que la fluorescence induite par laser (LIF) nécessitent de complexes méthodes de calibration. Ces techniques requièrent également la connaissance des taux de quenching des états excités (en particulier à pression atmosphérique). Or ces taux de quenching sont très fortement dépendants de la température, de la nature des espèces en présence et de leur densité, et peuvent donc énormément différer entre un plasma opérant dans l’air et en combustion. D’autres techniques telles que l’utilisation des sondes à chimiluminescence sont tout aussi sujettes aux problèmes de calibration et de quenching des états excités tandis que les mesures ex-situ à l’aide d’analyseurs à gaz réalisant de l’absorption dans l’UV et l’IR peuvent conduire à des erreurs, surtout lorsqu’il s’agit de mesurer des radicaux. Dans cette étude, nous avons développé la spectroscopie d’absorption par laser à cascade quantique (QCLAS), pour des mesures in-situ de densités de NO dans l’air et en combustion. Cette technique permet de surmonter les difficultés des autres méthodes par utilisation d’une spectroscopie rotationnelle-vibrationnelle de haute résolution spectrale (10-3 cm-1). La QCLAS a les avantages d’être spectralement sélective, d’avoir une grande sensibilité et de ne pas nécessiter de calibration. Deux dispositifs expérimentaux ont été développés pour mesurer des densités de NO et des températures (1) dans une décharge NRP dans l’air, avec une résolution spatiale de 300-µm, et (2) en aval de la décharge NRP opérant dans l’air et dans des flammes méthane/air assistée par plasma, par utilisation d’une cellule multi-passages. [...]Atmospheric pressure plasmas have numerous potential applications. These applications include for instance biomedicine, material processing, environmental biodecontamination and plasma-assisted combustion. The versatility of plasma discharges results from their ability to produce high quantities of active species without increasing the temperature of the gas appreciably. Nanosecond Repetitively Pulsed discharges (NRP) have received great attention owing to their capacity to generate high electron densities, which lead to the creation of a high density of active species such as atomic oxygen. Optical Emission Spectroscopy (OES) showed that excited nitric oxide (NO) was released by NRP discharges in air or in air/fuel mixtures.Although NRP discharges have already been the object of several investigations, the kinetic mechanisms of NO production by NRP discharges at atmospheric pressure remain somewhat unclear. This is one of the motivations for the investigations conducted in this thesis. In addition, NRP discharges were found to produce large amounts of atomic oxygen, which is of great interest for applications such as plasma-assisted combustion. It was shown in particular that thanks to this high production of active species, NRP discharges can effectively stabilize lean flames at atmospheric pressure. However, the production of NO in NRP discharges and in plasma-stabilized flames remains to be investigated. This is the second purpose of this thesis.Absolute and in-situ NO density measurements in atmospheric pressure plasma or/and flame environments are very challenging. Fluorescence-based techniques such as Laser Induced Fluorescence (LIF) require complex calibration methods. These techniques also require the knowledge of the quenching rates of the excited states (particularly at atmospheric pressure), which strongly depend on the temperature, density and nature of the species and can be very different for plasma or/and flame environments. Other techniques, such as chemiluminescence probe sampling also have quenching and calibration issues, and ex-situ UV and IR absorption-based gas analyzers can lead to errors, in particular for radicals.In this study, we developed Quantum Cascade Laser Absorption Spectroscopy (QCLAS) for in-situ nitric oxide absolute density measurements in open-air and in combustion environments. This technique overcomes the difficulties of the previous ones by using high-resolution (10-3 cm-1) rotational-vibrational absorption spectroscopy. This technique presents the advantages of high spectral selectivity, no calibration requirement, and high sensitivity. Two experimental setups were developed to measure NO densities and temperature, (1) within a NRP discharge in air, with 300-µm spatial resolution, and (2) downstream of NRP discharges in air and in plasma-assisted methane/air flames, using multi pass cell. [...]
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Kerckx, Yannick. "Modeling nitric oxide production and transport in the human lung." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210324.
Full textAbstract:
Le travail présenté ici porte sur l’étude de la production et du transport du monoxyde d’azote (NO) dans le poumon humain. Le NO est une molécule dont l’implication dans des processus physiologiques n’a été mis en évidence qu’en 1987. Depuis, il a été démontré que le NO joue de nombreux rôles dans le corps humain. Le NO est un gaz labile (instable) dans les conditions physiologiques, il diffuse très facilement au travers des parois et il a une grande affinité pour l’hémoglobine. La production du NO est liée à 3 isoformes différentes de la protéine appelées synthases du NO ou NO synthases.\
Doctorat en sciences, Spécialisation physique
info:eu-repo/semantics/nonPublished
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Arnal, Jean-François. "Inhibition chronique de la synthèse de monoxyde d'azote chez le rat." Paris 5, 1994. http://www.theses.fr/1994PA05CD11.
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Afin d'évaluer l'importance de la voie L-arginine-monoxyde d'azote (NO) dans l'homéostasie circulatoire, nous avons étudié les conséquences du blocage chronique de la NO synthase à l'aide d'un antagoniste de l'arginine (NG-nitro-L-arginine methyl ester, L-NAME) chez le rat Wistar normotendu. L'administration de L-NAME entraîne une hypertension artérielle d'un niveau manométrique comparable à celui des autres modèles d'hypertension artérielle. L'hypertension artérielle induite par la L-NAME se caractérise par une absence d'hypertrophie ventriculaire gauche pendant les premières semaines, l'apparition d'intenses lésions de néphroangiosclérose s'accompagnant d'une activation du système rénine angiotensive, et enfin l'existence d'infarctus de la moelle épinière. L'administration de L-NAME pendant 4 mois entraîne la mort de tous les animaux. L'activité de la NO synthase paraît normale chez le rat spontanément hypertendu. Par contre, nous avons observé deux situations au cours desquelles l'activité de la NO synthase est modifiée de façon chronique. La prolifération des cellules endothéliales en culture entraîne une augmentation de l'expression du gène de la NO synthase ainsi que celle de son activité. Les taux circulants de glutamine inhibent l'activité de la NO synthase, cette inhibition pouvant être réservée par de fortes concentrations d'arginine.
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Prevot, Marianne. "Étude de la respiration "nitrate-NO" dans l'interaction symbiotique entre Medicago truncatula et Sinorhizobium meliloti : à la recherche d'un transporteur de nitrite mitochondrial." Nice, 2012. http://www.theses.fr/2012NICE4099.
Full textAbstract:
Les symbioses entre les légumineuses et les bactéries fixatrices d’azote (rhizobium) représentent un enjeu majeur pour la réduction des intrants azotés en agriculture. La réduction de l'azote moléculaire (N2) en ammonium (NH4+) par la nitrogénase bactérienne, puis son assimilation par la cellule végétale constituent la fonction centrale des nodosités symbiotiques. Ce processus, très coûteux en énergie, présente le paradoxe de se produire dans un organe très appauvri en oxygène, ce qui conduit à fortement réduire la respiration mitochondriale, principale source d'ATP. La question se posait donc de savoir par quels mécanismes l'ATP nécessaire au fonctionnement cellulaire est régénéré au sein de la nodosité. Sur la base d'observations récentes faites dans les racines en hypoxie, nous avons posé l'hypothèse selon laquelle, dans la nodosité fixatrice d'azote, une partie de l'ATP est régénérée par le biais d'une respiration cyclique (respiration nitrate-NO) en quatre étapes: 1) le nitrate (NO3-) est réduit en nitrite (NO2-) dans le cytosol par la nitrate réductase (NR); 2) le NO2- est transporté du cytosol dans la mitochondrie par l'intermédiaire d'un (ou plusieurs) transporteur(s); 3) le NO2- est réduit en oxyde nitrique (NO) par les électrons de la chaîne respiratoire (permettant ainsi le fonctionnement de la respiration et la régénération de l'ATP); et 4) le NO diffuse librement vers le cytosol où il est oxydé en NO3- par la leghémoglobine (Lb). Au cours de ce travail de thèse, mené sur le modèle Medicago truncatula-Sinorhizobium meliloti, nous avons d'abord montré que les nitrate réductases et les chaînes de transfert d'électron des deux partenaires, végétal et bactérien, sont impliquées dans la production de NO dans les nodosités fonctionnelles. Nous avons également montré que l'activité nitrate réductase est nécessaire au maintien d'un état énergétique élevé permettant la fixation de l'azote. Dans un second temps, nous avons entrepris de caractériser le transport du nitrite chez des mitochondries purifiées de racines. L’objectif était ensuite d’identifier un ou plusieurs candidats pour le transport du nitrite dans les mitochondries. Pour cela, sur la base d'homologies de séquence avec des transporteurs déjà identifiés et de séquences d'adressage putatives, une recherche in silico des protéines prédites de M. Truncatula a été conduite. Cette analyse a permit de sélectionner 6 candidats avec une localisation possible aux mitochondries. L’analyse par spectrométrie de masse des protéines présentes sur les membranes des mitochondries a révélé 3 autres candidats. L'expression des 9 candidats retenus a été caractérisée en situation de normoxie et d’hypoxie dans les racines et les nodosités. Cela a permis de mettre en évidence deux profils intéressants. Enfin, l'étude de l’adressage subcellulaire et l’expression tissulaire au cours du développement de la nodosité ont été débutés pour certains des candidats retenus sur leur profil d’expression et ceux obtenus par spectrométrie de masseSymbiosis between legume plants and nitrogen-fixing bacteria (rhizobium) constitute a major issue to reduce nitrogen fertilization in crops. Central function of nodules is the enzymatic reduction of atmospheric nitrogen (N2) into ammoniac (NH4+) by the bacterial nitrogenise, and the subsequent assimilation in the plant cell. This highly energy-consuming process is a paradox as occurring in hypoxied tissue where mitochondrial respiration -the main ATP source- is strongly reduced. The question rose how the ATP required for cellular functioning is generated into nodules. Based on recent observations on hypoxied roots, we rose the hypothesis that, in nodules, ATP is formed trough a cyclic respiration -called nitrate-NO respiration- that consists in four steps: 1) nitrate reductase (NR) reduces nitrate (NO3-) into nitrite (NO2-) in the cytosol ; 2) NO2- is transported from cytosol into mitochondria using transporter(s) protein(s) ; 3) electrons of mitochondrial transfer chain reduces NO2- into nitric oxide (NO), thus allowing respiration functioning and ATP formation ; and 4) NO freely diffuses from mitochondria to cytosol to be oxidized back into NO3- through leghemoglobine (Lb) action. During this thesis, we showed, using Medicago truncatula-Sinorhizobium meliloti system as a model, that NRs and electron transfer chains from both plant and bacterial partners were involved in NO production of functioning nodules. NR activity was also showed to be crucial to maintain high energetic status required for nitrogen fixation. The second aim was to characterized nitrite transport across purified root mitochondria. Then, mitochondrial nitrite transporter candidate(s) were investigated. An in silico strategy searching for predicted proteins in M. Truncatula genome, potentially localized to mitochondria, that shared homologous sequences with known transporters was conducted. 6 candidates were chosen at the end of this analysis. Membrane mitochondria proteins were identified using mass spectrometry (MS) analysis, revealing 3 new candidates. The expression profile in normoxied and hypoxied roots and nodules was characterized for the 9 candidates retained. Two of them showed particularly promising patterns. Finally, sub-cellular localization and tissular expression during nodule development were analyzed for some candidates that shared interesting expression patterns
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Bruni, Antonio de Castro. "Critérios para identificação de veículos leves do ciclo Otto com elevadas emissões, utilizando dispositivo de sensoriamento remoto." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-19042018-120404/.
Full textAbstract:
Ocorrem anualmente aproximadamente 600.000 mortes de crianças com até cinco anos, no mundo. Pneumonia é a principal causa e mais de 50 por cento destas mortes são atribuídas à poluição do ar. Ela ainda é responsável pelo aumento do risco de infecções respiratórias, asma, condições neonatais adversas e anomalias congênitas. A poluição do ar também afeta o desenvolvimento cognitivo de crianças e induz o desenvolvimento de doenças crônicas na idade adulta. Entre 70 e 80 por cento da poluição do ar em nações em desenvolvimento são de origem veicular. Objetivando definir critérios baseados em medições com sensoriamento remoto para identificação de veículos automotores leves do ciclo Otto com elevadas emissões de monóxido de carbono, hidrocarbonetos ou óxido nítrico, foram utilizados os dados secundários gerados pela Remote Sensing do Brasil Ltda dos quais foram selecionados 179.142 veículos em uso da frota circulante da cidade de São Paulo com medições completas dos índices de emissão dos poluentes monóxido de carbono (CO), hidrocarbonetos (HC) e óxido nítrico (NO) e ainda velocidade e aceleração do veículo quando da medição e inclinação da pista no local escolhido para as medições. Foram ajustados modelos estatísticos da classe Generalised Additive Models for Location, Scale and Shape (GAMLSS) visando testar a influência do Tipo de Combustível, da Potência Específica do Veículo (VSP) e das Fases do Programa de Controle da Poluição do Ar por Veículos Automotores (Proconve) sobre as emissões de CO, HC e NO, medidos usando o Remote Sensing Device (RSD). As emissões foram então conceitualmente subdivididas em dois grupos: veículos com emissões normais e com emissões anormais, isso para os diversos poluentes em veículos das Fases L3, L4 e L5 que são as fases de interesse para o gerenciamento da qualidade do ar. Variáveis latentes foram definidas para indicarem as distribuições dos veículos em relação a esses grupos e Fases. O algoritmo Expectation-Maximization (EM) foi empregado para identificação dos parâmetros das distribuições. Para determinação dos valores associados aos veículos com elevadas emissões de determinado poluente e fase do Proconve, foi empregado o percentil 98 por cento da distribuição ajustada para os veículos dos grupos com emissões normais. Assim sendo, o Erro de Tipo I foi fixado em 2 por cento sendo que esse percentual foi estabelecido considerando o Erro de Tipo II, de apontar o veículo como tendo emissão normal quando na realidade trata-se de um high emitter. Através desta abordagem foram determinados os valores indicativos de veículos com elevadas emissões segundo o poluente e a Fase do Proconve. Os resultados apontaram decréscimo nas emissões de CO e de HC segundo as Fases do Proconve. Para o NO, o comportamento das emissões não acompanhou as reduções impostas pelas Fases do Proconve. Foi constatado que os veículos de 2005 a 2009, movidos exclusivamente a gasool, foram os que apresentaram as maiores emissões de NO. Diversos possíveis fatores causadores deste comportamento diferenciado do NO foram discutidos neste trabalho. Os dados de qualidade do ar detectaram aumento significativo nas concentrações ambientais de Óxidos de Nitrogênio (NOx) em 2007, quando foi monitorado este parâmetro no período de inverno, o que pode indicar a influência dos high emitters, mas necessita de estudos mais aprofundados para confirmação da causa deste comportamento.Approximately 600,000 deaths occur worldwide annually for children up to five years of age. Pneumonia is the leading cause and more than 50 per cent of these deaths are attributed to air pollution. It is still responsible for increased risk of respiratory infections, asthma, adverse neonatal conditions and congenital anomalies. Air pollution also affects the cognitive development of children and induces future development of chronic diseases in adulthood. In order to define criteria based on remote sensing measurements to identify Otto cycle light duty vehicles (LDV) with high emissions of carbon monoxide, hydrocarbons or nitric oxide it was used secondary data produced by Remote Sensing do Brasil Ltda, from which 179,142 inuse vehicles were selected, that belongs to the city of São Paulos current fleet. All those vehicles had complete measurements of emission of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO), and also speed and acceleration of the vehicle during measurements, and slope of the track at the place chosen for the measurements. Statistical models of the Generalized Additive Models for Location, Scale and Shape (GAMLSS) class were adjusted to test the influence of fuel type, Vehicle Specific Power (VSP) and of the Brazilian Vehicle Emission Control Program [Proconve] phases on CO, HC and NO emissions, measured using Remote Sensing Device (RSD). The emissions were then conceptually subdivided into two groups: vehicles with normal and abnormal emission, for the various pollutants in vehicles of L3, L4 and L5 phases of Proconve, which were of interest for the air quality management. Latent variables were defined to indicate the distribution of vehicles in relation to those groups and phases. The algorithm Expectation Maximization (EM) was employed to identify all parameters of the distributions. We use the 98 per cent percentiles of the statistical distribution set, for vehicles of groups with normal emissions to determine the limit values for vehicles with high emissions of pollutants and Proconve Phase. Therefore, the Type I Error was set at 2 per cent and this percentage was established considering the Type II Error to point the vehicle as having normal emission when in fact it is a high emitter. Through this approach, the indicative values of vehicles with high emissions according to the pollutant and the Proconve Phase were determined. Results of emissions measured with the RSD technique indicated a decrease in CO and HC emissions according to the Proconve Phase. For the NO, the emissions behavior did not follow the reductions imposed by the Proconve Phases. It was found that newer vehicles year model from 2005 to 2009 exclusively gasohol-powered vehicles, were the ones that presented the highest NO emissions. Several possible causative factors of this differential behavior of NO were discussed in this study. A significant increase in the environmental concentrations of Nitrogen Oxides (NOx) was detected in 2007, when this parameter was monitored in the winter period. This may indicate the influence of the high emitter vehicles, but it requires a more in-depth cause-effect study for confirmation of this behavior.