Дисертації з теми "Spectrométrie de masse – Mesure"
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Guigues, Elodie. "Mesure en ligne des produits de fission gazeux par spectrométrie de masse." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4706.
Повний текст джерелаIn order to increase fuel rod performances, the basic mechanisms that promote gas (i.e. He, H2, Kr and Xe) release from irradiated nuclear fuels must be studied. In this context, the CEA fuel study department at Cadarache decided to improve its experimental facility devoted to fuel behaviour under thermal transient by modifying the existing annealing device, called MERARG-II.The first part of this dissertation adresses the fuel gas release monitoring from irradiated fuel during thermal transient. The device choice leads to a quadrupole mass filter as mass analyser according to the specification requirement, i.e. isotopic identification of Xe, Kr and masses at 4 and 2 u. It is commercialized Residual Gas Analyser, mounted in a small-volume vacuum chamber requiring adaptations to be connected to the MERARG II line. The resolution and sensitivity of the mass spectrometer have been evaluated. The calibrated device is being installed in MERARG II replica.The second part of this dissertation relates adaptation to low-mass analysis of an RF 3D ion trap operated a Fourier Transform mode. Theoretically, using this operating mode, the lower the mass, the higher the resolution. More particularly, an ion injection device and its operating mode are studied in order to gain position and velocity distributions of confinable ions. The knowledge of these initial conditions is of a great concern as they fix the signal dynamic (peak height) and the signal fluctuation, respectively. This feasibility study, using simulation, allows us to obtain the optimal values of trap operating condition for 1-6 u mass injection and confinement with high resolution
Viale, Jean-Paul. "Mesure des échanges gazeux par spectrométrie de masse en anesthésie et en réanimation." Lyon 1, 1988. http://www.theses.fr/1988LYO1H076.
Повний текст джерелаCordeau, Emmanuelle. "Mesure d'interaction récepteur-ligand par marquage au sélénium et détection en spectrométrie de masse élémentaire." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTS006/document.
Повний текст джерелаMeasuring interactions between a drug candidate and its specific target constitutes a parameter of upmost importance in drug discovery process. Because of its robustness and very high sensitivity, radio-isotopic labeling represents up to now the reference method for these pharmacological studies. However, the use of radioactivity confers several constraints about security, health hazards and environmental issues involved by radioactive waste storage. Regarding such limitations, non-radioactive technologies have been developed principally based on fluorescence detection. But the cost of such assay as well as the fact that incorporation of a bulky fluorescent block can affect the affinity for small ligand limit their use. In this context, we aim to develop a new methodology to quantify receptor-ligands interactions. Mass spectrometry (MS) presents very interesting features in terms of detection sensitivity and specificity, making this technique a challenging analytical tool to replace radioactivity and fluorescence measurements commonly used in pharmacology. Among all MS technologies, the capacity of inductively coupled plasma-mass spectrometry (ICP-MS) to provide metallic and hetero elements absolute quantification, whatever the nature of the sample medium, prompted us to investigate this technique in combination with an appropriate labeling of the molecule of interest. Selenium was selected as a good compromise between ICP-MS response and chemical tagging ability through the creation of covalent bonds using conventional organic sulfur chemistry without disturbance of the affinity toward targeted receptor. Proof of concept was illustrated on the vasopressin receptor (V1A), a GPCR involved in vasoconstriction and emotional behavior and implying peptide as native ligand. Different strategies were applied to design selenium labeled peptides relying in either conventional amino acid substitution by corresponding selenium containing residue into peptide sequence such as cysteine (Cys) replacement by selenocysteine (Sec) as well as proline (Pro) by selenazolidine (Sez), or N-terminal peptide derivatization with a selenium containing small organic entity. ICP-MS analytical methodology was carefully investigated to provide sensitive and reliable selenium signal measurement. High inorganic salts contents of pharmacological buffer along with polyatomic interferences from plasma interfering selenium detection necessitate chromatographic separation and collision reaction cell equipment before ICP-MS detection. The pharmacological protocol was also adapted to the analytical requirements, in particular quantity of cells and sample handling. Robustness of the designed competitive binding assay was evaluated through the affinity constant (Ki) measurement of several known V1A-R ligands exhibiting either high or poor affinity for the receptor. Experimental values were strongly correlated to literature data, enabling to validate the proof of concept of such methodology and to propose a suitable alternative to radioactive labeling
Beucher, Charlotte. "Production et dissolution de la silice biogène dans les systèmes marins : Mesure par spectrométrie de masse." Brest, 2003. http://www.theses.fr/2003BRES2016.
Повний текст джерелаThis PhD thesis is part of the study of the biogeochemical cycle of silicon. This study aims to quantify production and dissolution rates of biosilica (BSiO2) in coastal and open ocean (the bay of Brest and the Southern Ocean). For that, an isotopic method (30Si as a tracer), using mass spectrometry, is developed. A time series (2 years, weekly sampling) of production and dissolution rates of biosilica (BSiO2), at SOMLIT/Brest station, shows a high seasonal variability. Annually, 50% of the biosilica produced in surface waters of the bay of Brest are regenerated. During productive period, the dissolution is related to BSiO2 production and to temperature. Comparatively to studies conducted in 1981 and 1993, a change of microphytoplankton dominance is observed in the Bay of Brest. Dinoflagellates out-compete diatoms from mid-August to end of October 2001 and during August 2002. Two hypotheses are proposed to explain the shift: a bottom-up control in 2001 and a top-down control in 2002. Measurements performed in the Indian-Pacific sector of the Southern Ocean, during summer 2003, reveal a total recycling of biosilica. Dissolution rates were not related to temperature but to percentage of dead diatoms. A correlation between integrated enzymatic protease activity of total bacteria and mean specific dissolution rate is observed for stations with high BSiO2 (> 100 mmol m-2). In the Southern Ocean, the synthesis of data about biosilica recycling show that the silicic acid pump can run into 3 modes and is more efficient during spring. The existence of such periods without silica-export must be considered both, in present and past primary production reconstruction
Albrieux, Florian. "Etude conformationnelle de peptides et protéines par mesure de mobilité ionique couplée à la spectrométrie de masse." Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00594601.
Повний текст джерелаVieira, Nelson. "Mesure de la masse atomique du noyau N=Z, 74Rb, avec le spectromètre MISTRAL." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2002. http://tel.archives-ouvertes.fr/tel-00002578.
Повний текст джерелаCarette, Michel. "Etude expérimentale d'une source ionique par capture d'électrons d'atomes excités dans des états de Rydberg : application à la spectrométrie de masse de polluants atmosphériques." Aix-Marseille 1, 1999. http://www.theses.fr/1999AIX11065.
Повний текст джерелаAmaral, Ademir de Jesus. "Application de la spectrométrie de masse d'ions secondaires dans la détection et la mesure de l'uranium dans les milieux biologiques." Paris 12, 1997. http://www.theses.fr/1997PA120055.
Повний текст джерелаViera, Nelson. "Mesure de la masse atomique du noyau N=Z 74Rb avec le spectromètre MISTRAL." Paris 6, 2002. https://tel.archives-ouvertes.fr/tel-00002578.
Повний текст джерелаRossato, Maxime. "La dilution isotopique en spectrométrie de masse MALDI-ToF pour la mesure d’interactions entre récepteurs couplés aux protéines G et ligands peptidiques." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTS007/document.
Повний текст джерелаThe SID methodology, for Stable Isotope Dilution, is a widely applied methodology for peptides and proteins analysis in mass spectrometry, usually associated with atmospheric pressure ionisation techniques. This thesis is consequently devoted to the application of SID methodology in matrix assisted laser desorption/ionisation (MALDI) mass spectrometry to quantify receptor/ligand interaction in pharmacology. Indeed, a great number of pathologies involve membrane receptors like G protein coupled receptors (GPCR) in interaction with several ligands, frequently peptides. Particularly, the V1A receptor, is related to vasoconstriction activity of the peptide hormone AVP (arginine vasopressine) and contraction of muscular cells as well as many social behaviors. This receptor was chosen as model, requiring the chemical labelling of the ligand Homo-HO-LVA (Hydroxy Linear Vasopressin Antagonist), selected for its high affinity towards the V1A receptor in order to introduce the entity on which relies the quantification in SID/MALDI. This methodology is applied through the covalent binding of HCCA (4-hydroxy-α-cyanocinnamic acid) matrix, usually encountered in peptide analysis, to obtain the modified peptide (JMV4854) through N-terminal acylation. The objective is to take advantage of the use of both HCCA tagging and HCCE (4-hydroxy-α-cinnamic methyl ester) matrix for the specific and sensitive detection of compounds down to picomolar concentrations. Importantly, quantification with SID requires a calibration protocol and a statistical validation before pharmacological assays. This consists in the measurement of JMV4854 affinity towards V1A-R through thermodynamic experiments in order to quantify the dissociation constant (Kd) and determine afterwards constants for untagged molecules by competitive binding assays. Furthermore, a second receptor model, CCKB-R (cholecystokinine B receptor), was then studied to validate the quantification methodology. Facing the renewed interest in pharmaceutic industry of kinetic experiments for dissociation constant measurement, it would be interesting to apply this new methodology to drug discovery, representing a relevant alternative to current “gold-standard” methodologies such as radioactivity and fluorescence. A second field of research has been initiated with a covalent labelling designed to enhance peptide fragmentation for electrospray-based (ESI-MS/MS) tandem mass spectrometry measurements. Preliminary studies with the synthesis of pre-formed ions like N-terminal substitution with pyridinium entities gave very promising results opening the way of other quantification strategies
Loche, Florence. "Contrôle des déchets radioactifs et couplage de mesures neutron/gamma : exploitation de la capture radiative pour corriger les effets de matrice pénalisant la mesure de la masse fissile par interrogation neutronique active." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0116.
Повний текст джерелаLn the framework of radioactive waste drums control, difficulties arise in the non-destructive measurement of fissile mass 235U, 239PU. . . ) by Active Neutron Interrogation (ANI), when dealing with matrices containing materials (CI, H. . . ) influencing the neutron flux. The idea is to use the neutron capture reaction (n,y) to determine the matrix composition to adjust the ANI calibration coefficient value. This study, dealing with 118 litres, homogeneous drums of density less than 0,4 and composed of chlorinated and/or hydrogenated materials, leads to build abacus linking the y-ray peak areas to the ANI calibration coefficient. Validation assays ofthese abacus show a very good agreement between the corrected and true fissile masses for hydrogenated matrices (max. Relative standard deviation: 23 %) and quite good for chlorinated and hydrogenated matrices (58 %). The developed correction method improves the measured values. It may be extended to 0,45 density, heterogeneous drums
Roussel, Vivien. "Mesure de la cinétique de formation du dimère de l'eau à basses températures." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S197.
Повний текст джерелаKinetics measurements of water dimer formation at low temperatures
Minaya, Ramirez Enrique. "Un nouveau piège à ions circulaire pour la spectrométrie de masse et la structure nucléaire." Phd thesis, Université Paris Sud - Paris XI, 2009. http://tel.archives-ouvertes.fr/tel-00421111.
Повний текст джерелаDemange, David. "Mesure non intrusive de l'activité de fûts de déchets tritiés par modélisation d'une fuite 3He et sa quantification par spectrométrie de masse." Besançon, 2002. http://www.theses.fr/2002BESA2016.
Повний текст джерелаBourguet, Maxime. "Développements méthodologiques en spectrométrie de masse structurale pour la caractérisation de complexes biologiques multiprotéiques." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAF013.
Повний текст джерелаThis PhD thesis focuses on developing methods in structural mass spectrometry (MS) to characterize complex protein systems, given their size and their heterogeneity, frequently inaccessible by classical biophysic approaches. In this context, methodological developments have particularly focused on the characterization of protein complexes involved in ribosomes biogenesis and transcriptional regulation. These fundamental cellular processes are related to numerous diseases such as cancers and genetic diseases. Thus native MS, crosslink, and hydrogen/deuterium exchange coupled to MS (HDX-MS) allowed gaining insights about the stoechiometry, spatial proximities and conformational dynamics of studied systems. Among these approaches, HDX-MS enables a comparative approach based on deuterium incorporation measurements giving information about the conformational dynamics of labeled proteins in various experimental conditions. Finally, the combination of structural approaches enables to deeply characterize complex protein systems, highlighting the advantages of an integrative approach in this context
Devoto, Pierre. "Conception et réalisation d'un spectromètre de masse à temps de vol spatialisable de type "réflectron" électronique et tête de mesure." Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00090727.
Повний текст джерелаLe travail réalisé au cours de cette thèse porte en premier lieu sur l'électronique de la chaîne de mesure qui a été conçue dans un souci de modularité. Un spectromètre de masse complet de type « réflectron » a ensuite été conçu, simulé puis développé. Le prototype construit, qui utilise l'électronique développée, a été soumis à des flux d'ions de masses et d'énergies différentes dans les chambres à vide du CESR. Ses performances mesurées valident les principes mis en œuvre et démontrent qu'un spectromètre de masse identique peut être embarqué avec profit sur satellite, tant dans le cadre de missions planétaires que solaires.
Chauveau, Pierre. "Design, simulations and test of a Time-of-Flight spectrometer for mass measurement of exotic beams from SPIRAL1/SPIRAL2 and gamma-ray spectroscopy of nuclei close to 100Sn." Caen, 2016. http://hal.in2p3.fr/tel-01469429.
Повний текст джерелаThe new generation of nuclear facilities calls for new technological developments to produce, accelerate, manipulate and analyse exotic nuclei. The main topic of this thesis work was the simulation, design and test of a Multi-Reflection Time-of-Flight Mass spectrometer (MR-ToF-MS) for fast mass separation and fast mass measurement of radioactive ions in the installations S3 and DESIR at SPIRAL2. Such a device could separate isobaric nuclei and provide SPIRAL2 with high purity beams. Also, its mass measurement capabilities would help to determine binding energies of exotic and superheavy nuclei with a high precision. This apparatus has been simulated with the SIMION 8. 1 software and designed accordingly. First offline tests have been performed with a stable ion source at LPC Caen. In addition a low-aberration electrostatic deflector has been simulated and designed to operate with this MR-ToF-MS without spoiling its performances. This work also describes the analysis and results of the first online tests of a FEBIAD-type ion source intended to provide SPIRAL1 and SPIRAL2 radioactive beams of competitive intensities. Finally, we describe the analysis of a nuclear physics experiment, including the calibration of the different detectors and the gamma-spectroscopy of nuclei in the vicinity of the doubly magic 100Sn
Dobson, Gareth. "Amélioration de la précision des mesures de rapport m/z d'ions en spectrométrie de masse par piégeage d'ions." Paris 6, 2004. http://www.theses.fr/2004PA066093.
Повний текст джерелаJubeaux, Guilaume. "Développement de la mesure de la vitellogénine chez les invertébrés & utilisation de marqueurs de la perturbation endocrinienne chez le crustacé amphipode gammarus fossarum." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10111/document.
Повний текст джерелаAmong pollutants, endocrine disruptors (ED) are in central scientific preoccupation because of the risks of these compounds to the environment, in particular for aquatic ecosystems. The availability and impact study of ED on aquatic vertebrates, in particular fishes, was the subject of many projects and papers. These studies led to the development of diagnostic tools, such as vitellogenin (Vg) induction in male organisms, inhibition of ovarian and testicular growth, delayed sexual maturity, presence of intersex individuals and abnormal concentrations of steroid hormones. However, little attention was paid to invertebrates which account for more than 95% of animal species and play an essential role in functioning and health of aquatic ecosystems. Therefore, the result is a lack of specific tools for endocrine disruption assessment in these species. In this context, the proposed work focuses first on the interest and relevance of mass spectrometry (LC-MS/MS) to develop and to transfer among species a method for measuring Vg in invertebrates species, including crustaceans, molluscs and insects. Then, this work has focused on a model amphipod crustacean (Gammarus fossarum) and aims were (1) to develop the Vg biomarker, through the validation of its functional role in reproduction (vitellogenesis, embryogenesis and inter-sex differences), its sensitivity towards model compounds and to its use in field monitoring, using caged organisms and (2) develop a biotest in the female to assess the ED risk of chemical compounds and aquatic systems, by studying and measuring individual markers
Thomen, Aurélien. "Développement instrumental de la mesure de l'hydrogène, du carbone et de l'azote à la nanosims : applications à l'origine des volatils en cosmochimie." Paris, Muséum national d'histoire naturelle, 2012. http://www.theses.fr/2012MNHN0025.
Повний текст джерелаThis thesis is focused on the measurements of isotopic and elementary compositions of hydrogen and nitrogen in the Insoluble Organic Matter (IOM) isolated from the carbonaceous chondrites and Wild 2 materials collected by the Stardust mission. Analysis were performed by means of secondary ions mass spectrometry (SIMS). In this thesis, an effort was done to quantify the N/C ratio in the IOM. The precision on the N/C ratio is improved by collecting secondary ions with similar physical parameters, in that case molecular ions C−2 and CN−. The IOM in carbonaceous chondrites shows that isotopic anomalies in hydrogen and nitrogen are spatially correlated for the most of them. For the non -correlated anomalies, enrichments in D and 15N are decoupled. Apart from isotopic ratios, no classification of these isotopic anomalies can be done on the basis of their elementary H/C and N/C ratios. The isotopic fractionation of the hydrogen is not systematically correlated with the nitrogen isotopic fractionation. The measured Wild 2 cometary grains have chondritic carbon and nitrogen isotopic compositions. Two peculiar grains bearing isotopic anomalies were observed, probably condensed in stellar envelopes of novae stars. One of these grains is composed of organic matter as shown by its spectrocopic signature
Chouiali, Ahlem. "Comparaison de deux méthodes de mesure de la vitamine D en post chirurgie bariatrique malabsorptive de type dérivation bilio-pancréatique." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/11786.
Повний текст джерелаAbstract : Introduction: The prevalence of hypovitaminosis D may reach 90 % in patients after BPD despite supplementation with mega doses of vitamin D. Although LC-MS/MS is the gold standard for vitamin D measurements, it is not routinely use in clinical practice. Our hypothesis is that methods of assays currently used in laboratories of Medical Biochemistry for evaluation of serum 25-hydroxyvitamin D may not recognize equimolarly the two forms of 25-OH-D (D2 and D3) thus overestimating the prevalence of vitamin D deficiency supplemented with D2 and exposing patients to the risk of toxicity. Objective: Our objective was to compare the ECLIA from Roche versus the LC-MS/MS method for quantitation of serum 25-hydroxy-vitamin D in patients who have undergone bariatric surgery. Design and methods: Cross-sectional and correlational study was performed on three different groups for the 25-OH-D levels quantitated by both methods. The control group of apparently healthy subjects (n=48) was randomly selected in a clinical chemistry laboratory. Test groups were patients who had undergone bilio-pancreatic diversion (BPD) and were supplemented either with vitamin D2 (n=30) or with vitamin D3 (n=44). Patients were recruited during their follow-up visit to the obesity clinics at the CHUS and at the IUCPQ. The number of samples per group was established according to the Clinical and Laboratory Standard Institute recommendation protocol (EPO9-A2-IR). The study comparing methods (linear regression, Deming and Bland-Altman bias) was performed using the Analyse-it software program considering p < 0.05 as statistically significant. Results: The agreement of LC-MS/MS with the Roche method was acceptable in the apparently healthy subjects group and in the post-BPD D3-supplemented group with an average bias of -1.7% and -9.2%, respectively. However, this agreement was unacceptable in the post-BPD D2-supplemented group with an average bias of -45.3%. The LC-MS/MS enabled us to detect four patients (13%) who had excess vitamin D or intoxication with vitamin D for which it was necessary to stop the supplementation with vitamin D in the D2 -supplemented group. Conclusion: Despite the apparent good agreement between the Roche method and LCMS/MS in the healthy subjects group and in the post-DBP D3-supplemented patient group, a considerable bias seems to exist, particularly in the presence of D2. Results showed that the routine method underestimated total vitamin D ad 95.7% in patients post BPD supplemented with D2. The LC-MS/MS method is therefore the most accurate method to follow the vitamin D2-supplemented bariatric population. This study could generalize the results to all types of bariatric surgeries and other patients such as renal impairment. The study could also update the recommendations of the postbariatric surgery monitoring, and suggest making changes to the clinical practices so as to optimize the choices of vitamin D supplements (D2 vs D3) depending on the assay method available. It could also guide laboratories in choosing methods depending on dosage of clients served.
Regulus, Peggy. "Détection, caractérisation et mesure d'un nouveau dommage radio-induit de l'ADN isolé cellulaire." Phd thesis, Université Joseph Fourier (Grenoble), 2006. http://tel.archives-ouvertes.fr/tel-00134380.
Повний текст джерелаLamrini, El-Uahhabi Rachid. "Étude d'un modèle cellulaire et de deux modèles acellulaires de production d'espèces oxygénées réactives : intérêt de la mesure du rapport isotopique 13C-12C par chromatographie en phase gazeuse couplée à la spectrométrie de masse isotopique." Lyon 1, 1996. http://www.theses.fr/1996LYO1T186.
Повний текст джерелаMonsanglant, Céline. "Mesures de masses de haute précision avec MISTRAL au voisinage de ^32_12Mg_20." Phd thesis, Université Paris Sud - Paris XI, 2000. http://tel.archives-ouvertes.fr/tel-00002383.
Повний текст джерелаStrubel, Grégory. "Reconstruction de profils moléculaires : modélisation et inversion d'une chaîne de mesure protéomique." Phd thesis, Grenoble INPG, 2008. http://tel.archives-ouvertes.fr/tel-00361919.
Повний текст джерелаBousoumah, Radia. "Le challenge de l’analyse multi-résidus de perturbateurs endocriniens à activité estrogénique dans les fluides et tissus biologiques humains : Choix de stratégies de préparation des échantillons et de mesure par spectrométrie de masse." Electronic Thesis or Diss., Paris, AgroParisTech, 2015. http://www.theses.fr/2015AGPT0028.
Повний текст джерелаFor over twenty years, the issue of endocrine disruptors (EDs) mobilizes the scientific community and public authorities because of the negative effects, actual or suspected, of these compounds on human health. In particular, the generation of internal exposure data (impregnation) in some subpopulations, which are recognized or assumed as being sensitive (pregnant women, fetuses, infants), is both a priority and a demanding field associated with a certain rarity. Considering their structural diversity and with regards to their physicochemical properties, the simultaneous analysis of a large panel of EDs remains a real analytical challenge. In this context, the objective of this work was to develop a multi-residue method for the simultaneous isolation and measurement of estrogenic endocrine disruptors (13 EDs in total). Firstly, an analysis method using liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) after chemical derivatisation by dansyl chloride was developed. Secondly, a molecularly imprinted polymer (MIP with phenolic imprint) was implemented for the simultaneous extraction of the targeted EDs from aqueous medium and biological matrices of increasing complexity (urine, serum, breast milk). The strategy developed on MIP was applied, after validation, to a set of samples (maternal serum, cord serum and urine of newborns). Finally, a column support grafted with estrogen receptor α (ERα column) was applied for the simultaneous isolation of the targeted compounds from an aqueous medium
Bail, Adeline. "Mesures de rendements isobariques et isotopiques des produits de fission lourds sur le spectromètre de masse LOHENGRIN." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2009. http://tel.archives-ouvertes.fr/tel-00410261.
Повний текст джерелаDrut, Amandine. "La mesure de l’homocystéinémie plasmatique chez le chat : validité de la méthode de chromatographie liquide haute performance couplée à la spectrométrie de masse en tandem, déterminants biologiques, intervalle de référence et application aux maladies rénales chroniques." Thesis, Nantes, Ecole nationale vétérinaire, 2019. http://www.theses.fr/2019ONIR131F.
Повний текст джерелаIn human medicine, plasma plasma homocysteine concentration is a biomarker used for early diagnosis of cobalamin or folate deficiencies, and cardiovascular risk assessment in some medical conditions such as chronic kidney failure. ln veterinary medicine, several studies are beginning to address the status of homocysteine in diseased animals. The first objective of our study was to define the biological determinants and the reference interval of plasma homocysteine concentration in healthy adult cats, after having verified the concentration validity of the high-performance liquid chromatography - tandem mass spectrometry method. Our work confirmed the suitability of this technique for the measurement of homocysteine in feline plasma. The study of plasma homocysteine concentrations in healthy cats provided a particularly wide reference interval, showing high inter-individual variability that we were not able to explain by epidemiological determinants. We described an influence of the dietary protein content and plasma creatinine concentration. A strong metabolic signature was identified in a group of animals with elevated plasma homocysteine concentrations, suggesting alterations in the homocysteine metabolism in some healthy cats. The second aim of our work was to compare plasma homocysteine concentrations between a population of cats with stable chronic kidney disease and the previously established population of healthy individuals. This study of a small number of cats with chronic kidney disease did not show any differences from the reference population
Gandolfi, Frédéric. "Évaluation des techniques de micro-extraction/préconcentration et d’échantillonnage passif comme outils de mesure de la contamination du milieu aquatique par des composés organo-halogénés hydrophobes émergents." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4387.
Повний текст джерелаIn order to achieve good water quality for 2015, the water framework directives (WFD 2000/60/EC and 2013/39/EU) force European countries to monitor the quality of their aquatic environment. For this purpose, all water bodies shall be monitored for all the 33 priority substances listed in annex X of WFD (annex X, decision No 2455/2001/EC) and for which environmental quality standards (EQS) were fixed (Directive 2013/39 / EU). Among these substances, we found the short chain chlorinated paraffins (SCCPs) and the polybrominated diphenyl ethers (PBDEs) belonging to the class of emergent halogenated micro-pollutants. From an analytical point of view, the analysis of SCCPs and PBDEs in water is still a major challenge, either in terms of sampling or sensitivity.In respect of WFD, this thesis work has, among other things, aimed to develop a method to analyze SCCPs in water by using SPME coupled with GC/ECNI-MS. The limit of quantification below 0.2 µg.L-1 and its degree of automation makes this method a tool of choice to ensure the monitoring of the aquatic environment as required by the WFD. In addition to the traditional approach, a laboratory system for passive sampler calibration was also developed and validated to calibrate MESCO for PAHs analysis. Moreover, our participation in an inter-laboratory study, has served to test the applicability of MESCO and SR for the analysis of PBDEs in a waste water treatment plant. Finally the deployment of LDPE, SR and MESCO in Berre lagoon has yielded some encouraging results about applicability of these passive samplers to analyze SCCPs and PBDE in water
Habchi, Baninia. "Mise en évidence des perturbations métaboliques liées à l’exposition aux toxiques présents dans l’environnement ou l’aliment par spectrométrie de masse à ultra haute résolution FTMS combinée avec des outils chimiométriques." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLA032.
Повний текст джерелаPublic health monitoring involves evaluation of population exposure to environmental toxicants which can have an impact on their health. To do this, robust and high-throughput approaches are required to perform large scale analyses. Global approaches such as metabolomics which aim to reveal metabolic changes due to environmental stress or diseases seem to be the most appropriate approach. This multidisciplinary approach requires powerful analytical techniques such as mass spectrometry (MS) associated with statistical and chemometric data processing. It allows to detect general metabolic disruptions induced by a given physiological or pathological conditions. The studied samples can be injected either directly by the DIMS technique (direct introduction mass spectrometry) or following a chromatographic separation using GC/MS or LC/MS (gas or liquid chromatography / mass spectrometry). The DIMS approach leads to a significant reduction in analysis time, down to only a few minutes (usually less than 3 min). Additionally, in combination with Fourier transform mass spectrometers (DIFTMS), it provides very high mass resolving power and accurate mass measurements, as well as a wide dynamic range resulting in improved efficiency. Nevertheless, the DI-FTMS approach generates complex data containing several thousands of peaks. Processing such large data sets requires the development of dedicated chemometric and statistical tools to detect exposure biomarkers. Therefore, the objective of my work was to develop a rapid, highthroughput workflow, including the development of chemometric tools, in order to highlight metabolomic perturbations induced by exposure to toxicants. The first part of this work concerns the study of farmers professionally exposed to two pesticides. The DIMS approach was performed on an Orbitrap instrument and a new chemometric tool called Independent Component - Discriminant Analysis (IC-DA) was developed for supervised analysis of the DIMS data. The developed methodology was then applied to a larger number of samples corresponding to five types of exposure. In this later study, two analytical approaches DIMS and LC/MS were examined in order to validate the DIMS approach as well as the developed chemometric data analysis tool. In a second part of this work, the DIMS approach was applied to an instrument of higher performances, the FT-ICR (Fourier transform-ion cyclotron resonance) equipped with a dynamically harmonized cell in order to improve the quality of the DIMS data. A first study explored the effects of exposure of rats to different concentrations of pesticides. In a second step, the procedure was applied to a large number of samples (of approximately 500 individuals) to test the robustness of the approach. All this work demonstrated the feasibility and effectiveness of our high-throughput metabolomic approach combining the direct introduction (DIMS), the very high resolution detection and the chemometric tools. This approach could be very promising to perform large scale metabolic phenotyping such as in epidemiological studies
Duca, Dumitru. "Physico-chemical characterization of size-selected internal combustion engine nanoparticles and original method for measuring adsorption energies on carbonaceous surfaces by laser mass spectrometry." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1R019.
Повний текст джерелаEmission of carbonaceous aerosols by combustion-powered ground transport vehicles has a major impact on both global climate and human health. Intensive research efforts are dedicated to the development of robust procedures able to reliably measure particles as small as 10 nm in real-driving conditions, as current European Union regulations are limited to 23 nm. Within the H2020 PEMS4Nano project, we performed detailed physico-chemical characterization of size-selected particulate matter emitted by a gasoline direct injection engine. This included chemical characterization performed with mass spectrometry as well as structural/morphology data obtained with electron and atomic force microscopy together with Tip-Enhanced Raman Spectroscopy. In addition, to gain insight into the interaction between the carbonaceous surface and adsorbed compounds, a novel laser-based method for determining the adsorption energy of chemical species on carbonaceous surfaces was developed
Messedi, Mounir. "Automatisation d'un spectromètre de masse : application à l'analyse des gaz résiduels d'une capsule contenant une puce AsGa." Rouen, 1986. http://www.theses.fr/1986ROUES049.
Повний текст джерелаSlimani, Kahina. "Produits biocides désinfectants dans les produits laitiers : méthodes quantitatives d'analyse des résidus et étude de l'impact des procédés de transformation du lait sur l'apparition de produits néoformés selon des approches d'analyse ciblée et non ciblée par spectrométrie de masse." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B011/document.
Повний текст джерелаThe thesis work focuses on the presence of disinfectants biocides in dairy products and on the impact of milk processing on the possible appearance of process-induced food contaminants related to the exposition of milk with biocides. Disinfectants biocides are chemicals daily used in the dairy industry in cleaning-disinfection (CD) processes of food contact surfaces. Quaternary ammoniums as benzalkonium chloride (BACs) and dialkyldimethylammonium chloride (DDACs), and the Aminopropyldodecylpropane diamine are the most widely used disinfectants in dairy industry. These biocides can lead residues on the surfaces of food contact materials therefore present a health risk for the consumer. With aim of measuring consumers exposure, two reliable analytical methods have been developed for the analysis of these substances in dairy products involving liquid chromatography hyphenated with tandem mass spectrometry. Raw cow's milk, whole milk powder, hard pressed and processed cheeses were selected as representing the diversity of dairy products. The evaluation of the performances of each of the methods was carried out by the global approach based on the accuracy profile. For most of compounds and matrices studied, analytical methods were validated within the range of 5 to 150 μg/kg. To answer to the questioning of the impact of milk processes on biocides disinfectants residues, the evolution of compounds contents and their fate in the various matrices resulting from the milk were studied. For this, two proof-of-concept studies implementing global chemical fingerprint comparisons, acquired by High Resolution Mass Spectrometry, of processed cheese and hard pressed cheese (contaminated vs control) samples were carried out. These studies allowed to detect 4 discriminant ions linked to the presence of biocides in processed cheese. Their identification remains to be done. Whole this work is related for food safety purposes. The first part was linked to elaborate targeted analytical methods for biocides residues in milk and milk products thus allowing the measurement of biocides residues on food. These measurements are necessary for the risk analysis linked to these residues. The second part is in relation with the question of the behavior of biocides residues within milk processing presenting the strategy, the results we could obtain and the perspective for future works
Latappy, Hubert. "Étude des COV issus de la dégradation thermique et oxydative des matériaux polymères." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01059771.
Повний текст джерелаVrancken, Patrick. "Characterization of T2L2 (Time Transfer by Laser Link) on the Jason 2 ocean altimetry satellite and Micrometric laser ranging." Phd thesis, Université de Nice Sophia-Antipolis, 2008. http://tel.archives-ouvertes.fr/tel-00367703.
Повний текст джерелаLa première partie de ce travail traite la caractérisation intégrale de l'instrument spatial T2L2, incluant la calibration et l'évaluation de sa performance en métrologie de temps/fréquence. Ces tests furent menée à l'aide d'un banc de test de haute complexité, développé à l'Observatoire de la Côte d'Azur.
Par ailleurs, le document décrit un bilan des performances du schéma intégrale T2L2, incluant l'instrument spatial ainsi que le segment sol et autres contributeurs ; par conséquent on démontre la performance finale de tout le transfert de temps: Avec une stabilité de quelques picosecondes en intégrant pendant un passage du satellite, T2L2 permettra de comparer les horloges les plus avancés, incluant les fontaines atomiques. L'exactitude absolue d'un transfert de temps fut déterminé à moins que 50 ps en configuration vue commune.
La deuxième partie du document présent est orientée autour l'extension de la technologie de télémétrie laser et T2L2 à la mesure absolue et de très haute résolution de distances en espace.
Cet objectif devra être atteint en utilisant un laser de peigne de fréquences en combinant la mesure de temps de vol avec une mesure interférométrique.
Le document décrit un pas important vers la faisabilité de cet approche, la mesure de distances en datation à très haute cadence et en mesure de phase, ce qui devrait permettre de franchir le seuil de la longueur d'onde.
Hubert, Amélie. "Déséquilibres des séries de l'uranium dans les aquifères : quantification des mécanismes de transport de l'uranium et de ses descendants : cas de l'aquifère de la craie (Champagne, France)." Paris, Institut de physique du globe, 2005. http://www.theses.fr/2005GLOB0012.
Повний текст джерелаKennel, Claire. "Mesures expérimentales et modélisation de la formation des oxydes d'azote dans les flammes d'hydrocarbures dopées à l'amoniac." Rouen, 1989. http://www.theses.fr/1989ROUES001.
Повний текст джерелаSuarez, Stéphanie. "Microbiologie clinique et spectrométrie de masse." Phd thesis, Université René Descartes - Paris V, 2013. http://tel.archives-ouvertes.fr/tel-00920410.
Повний текст джерелаJankowski, Krzysztof. "Spectrométrie de masse des acides nucléiques." Paris 11, 1985. http://www.theses.fr/1985PA112257.
Повний текст джерелаThe nucleic acids and the oligonucleotides have been studied by using different mass spectrometric techniques. Through the revue and three chapters of particular interest (fragmentation mechanisms under normal and slowed down pyrolysis conditions, some biochemical applications and finally the oligonucleotide sequence studies using FAB ionization) we present these studies
Gilles, Isabelle. "Spectrométrie de masse et réactivité chimique." Montpellier 2, 1995. http://www.theses.fr/1995MON20080.
Повний текст джерелаJeanne, dit Fouque Kevin. "Différenciation de topoisomères peptidiques par spectrométrie de masse à mobilité ionique et spectrométrie de masse en tandem." Rouen, 2016. http://www.theses.fr/2016ROUES020.
Повний текст джерелаLasso peptides are ribosomally synthesized and post-translationnally modified peptides produced by bacteria, sharing a mechanically interlocked topology that is essential for their biological activity. This PhD work focused on the structural characterization of lasso peptides and differentiation between their branched-cyclic topoisomers using ion mobility – mass spectrometry (IM-MS) and tandem mass spectrometry (MS/MS). IM-MS studies led to the development of a method based on the use of a supercharging reagent, highlighting an additional charge state of multiply protonated species, for which the lasso and branched-cyclic topologies were clearly differentiated and separated in mixture. To assess the developed method, this strategy was also applied to other types of constrained (macrocyclic, disulfide bonds) and unconstrained (linear) structures. IRMPD spectroscopy studies allowed to characterize the changes in the hydrogen bond network, associated with the unfolding of the gas phase conformation, as a function of the charge state of multiply protonated species. The spectroscopic data could thus be correlated with the ion mobility data. IM-MS provides an overview of the conformation through a collision cross section measure (CCS), while IRMPD spectroscopy allows to probe intramolecular interactions through the hydrogen bonds. The structural characterization of lasso and branched-cyclic peptides was also carried out using MS/MS of triply protonated species. These experiments enabled us to establish general rules of fragmentation evidencing lasso topologies in collision induced dissociation (CID) and electron transfer dissociation (ETD)
Heuillet, Maud. "Développement de méthodes de référence pour les biomarqueurs du bilan lipidique : application au contrôle qualité en biologie clinique." Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOS057/document.
Повний текст джерелаReliable measurements in medical biology are essential for early screening and appropriate follow-up of patients. Ensuring metrological traceability of clinical measurements to higher order reference methods or certified reference materials enables to obtain comparable results over time and between different laboratories that could use different methods to quantify the same biomarker.In this study, reference methods were developed and validated for lipid profile biomarkers (total cholesterol, triglycerides, HDL-C, and LDL-C). Their value added in proficiency testing schemes was demonstrated against consensus mean. They were also used to characterize a certified reference material (CRM) that may be used both as quality control and/or calibrator of field methods. The CRM was shown to be commutable for most field methods and lipid profile biomarkers, which proved it was suitable to assess trueness. Results of our multicenter study showed that field methods tend to underestimate triglycerides (particularly at low concentrations) and overestimate total cholesterol and LDL-C (especially around the clinical threshold), resulting in false positives and significant patient misclassifications. An approach of non-commutanility correction was also presented to allow trueness assessment with non-commutable samples. In conclusion, this work highlights the importance of using reference methods and also commutable CRM to rigorously assess accuracy of field methods used in clinical laboratories
Renoud, Julie. "Etude expérimentale des interactions du vent solaire avec la molécule prébiotique d'hydantoine (C3N2O2H4)." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30225.
Повний текст джерелаThis thesis presents the study of the interaction of solar wind components with the hydantoin molecule C3N2O2H4, thought to have played a role in the appearance of life on Earth. This prebiotic molecule was detected in several meteorite samples and is thus potentially present in cometary outgasing, where it interacs with solar wind composed of electrons and energetic ions. The physico-chemistry of hydantoin in interaction with 100 eV electrons, which are one of the major components of solar wind, was studied with the new experimental apparatus SWEET (Stellar Wind and Electrons interactions on astrophysical molecules - Experiment and Theory), which was set-up during this thesis in the LCAR (Laboratoire Collisions Agrégats Réactivité), within the Ion Matter Interaction team. This is a crossed-beam apparatus which enables the investigation of unique collisions between one neutral isolated molecule and one electron or ion. The coincident use of several spectrometries techniques (spectrometry of emitted and scattered electrons and ionic spectrometry by velocity map imaging and time of flight) enables the identification of ionic produced fragments, the characterisation of the fragmentation dynamics, the measurement of the energetic threshold for dissociation pathways, and the probe of molecular excited states. The results obtained on SWEET were extended to the study of the interaction of hydantoin with multi-charged minority ions of solar wind (He2+ at 8 keV and O6+ at 30 keV), studied during a measurement campaign on the COLIMACON set-up at the GANIL (Grand Accélérateur National d'Ions Lourds, Caen, France). Experimental results were completed by a quantum chemistry approach (DFT B3LYP/6-311++G(d,p)) to calculate the energy and geometry of the molecular systems as well as the dissociation potential barriers. As important results, the interaction between hydantoin and the solar wind components shows that the molecule easily fragments when multiply charged (q>+3) and the cycle opens when doubly charged, implying a high reactivity interesting within the framework of early Earth chemistry. The energetic thresholds for the major cation and dication fragmentations were measured and a theoretical reaction scheme was proposed, in accordance with the experimental measurments. The first results of the SWEET apparatus pave the way to quantitative measurements such as the absolute cross section of the observed relaxation processes, to complete the characterisation of the specific hydantoin - solar wind interaction
Domalain, Virginie. "Différenciation de stéréoisomères par couplage, spectrométrie de masse et spectrométrie de mobilité ionique." Rouen, 2014. http://www.theses.fr/2014ROUES023.
Повний текст джерелаThis PhD work deals with analysis of stereoisomers, which present very close collision cross section difference (DeltaCCS ≤ Å2), by the coupling of ion mobility spectrometry and mass spectrometry (IM-MS). A study of diastereoisomers M which are functionalized entities found in a lot of natural products, rise to an efficient strategy based on cationisation (with alkali cations X and transition metals (X)II) and formation of multimers [3M+X]+ and [3M+(X)II-H]+ allowing the differentiation and the separation of stereoisomers, particularly enantiomers of amino acids and diastereomers with a major biological interest. It has been highlighted that the cationisation allows a significant increase of the stereoisomers differenciation. Then, we have shown that the nature of asymmetric center substituents plays an important role on the ion mobility separation
Tirsoaga, Alina. "Analyse structurale d'endotoxines bactériennes par spectrométrie de masse." Paris 11, 2007. http://www.theses.fr/2007PA112002.
Повний текст джерелаEndotoxins are lipopolysaccharides (LPS) made up of a lipid - (called lipid A) and a sugar - chain, both characteristic of each bacterial species. We developed methods of structure analysis and a purification method representing an important improvement for studies of structure/activity relationships. The first one is a micro analytical method that can be applied to milligram quantities of bacteria. With it, one can obtain spectra of the lipid A in one day, instead of a week as for previous techniques. The second one leads to the determination of the structure and the positions of the fatty acids with a little amount of lipid A. This technology was applied to Citrobacter, an Enterobacterium causing nosocomial diseases. A LPS purification method gave highly purified samples suitable for biological tests. This method will give preparation having identical activities in different laboratories. We also have established the existence of new constituents on the lipid A of B. Bronchiseptica, from which the whooping cough originated. The presence of a glucosamine on the phosphate group(s) was demonstrated and its effect on the biological activities will be of high impact particularly on the activity of anti-bacterial peptides, as glucosamines neutralise the lipid A structure responsible for the endotoxic activities of LPS
Causse, Jean Etienne. "Spectrométrie de masse de quatre séries de phosphonates." Montpellier 2, 1991. http://www.theses.fr/1991MON20231.
Повний текст джерелаVanbellingen, Quentin. "Imagerie de substances naturelles par spectrométrie de masse." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS172/document.
Повний текст джерелаThis thesis was devoted to the improvement of mass spectrometry imaging methods, and to their use for in situ analysis of natural substances. The first part of this thesis has been dedicated to the development of a new acquisition mode in TOF-SIMS imaging able to acquire images with a high spatial resolution of 400 nm while keeping a good mass resolution. For that, a delayed extraction of the secondary ions has been characterized and optimized. Then, a second part has been dedicated to the study of heartwood production in a tropical species named Dicorynia guianensis. This species is one of the most exploited in French Guiana for its heartwood which exhibits a good durability. Metabolic changes are shown by sub-micrometric resolution ion images recorded in and around the transition zone, where the heartwood formation occurs. Then, TOF-SIMS and MALDI-TOF have both been used to analyse the surface of a bacterial competition. Species have been isolated from a Japanese conifer (Cephalotaxus harringtonia), from which the stains are an endophitic fungi (Paraconiothyrium variabile) and a pathogenic bacteria of the conifer (Bacillus subtilis). The results have shown that the fungus is able to hydrolyze surfactines produced by the bacteria during the competition. Furthermore, both the MALDI-TOF and the TOF-SIMS mass spectrometry imaging are methods of choice to study in vitro models of what could happen in vivo
Bruneleau, Natacha. "Le dispositif PIRENEA dans l'étude des interactions gaz/grain dans la chimie interstellaire : mise en place d'une procédure expérimentale." Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00262417.
Повний текст джерелаCe travail de thèse s'inscrit dans ce cadre et vise à explorer expérimentalement les interactions gaz/grain sur des nanograins de type molécules polycycliques aromatiques hydrogénées (PAH) à différentes températures. Il utilise le dispositif expérimental PIRENEA (Piège à Ions pour la Recherche et l'Étude de Nouvelles Espèces Astrochimiques) qui présente l'originalité de coupler les performances d'un instrument de spectrométrie de masse à résonance cyclotronique ionique à transformée de Fourier (FTICR-MS) avec un environnement cryogénique. Grâce à ce dispositif, le PAH peut être isolé de son environnement comme dans l'espace interstellaire et ses propriétés peuvent être étudiées à l'aide d'une interface photophysique (lampe UV-visible) et d'une interface chimique pour l'injection de gaz.
Notre étude concerne la réactivité de C24H11+ (cation du coronène déshydrogéné) avec la molécule H2O à basses températures entre 35 K et 300 K. Dans un premier temps, nous montrerons comment la densité de molécules d'H2O dans la cellule ICR peut être quantifiée à toutes ces températures par mesure traditionnelle de la pression et par mesure de l'amortissement du mouvement cyclotronique des ions. Ces résultats nous ont permis de tracer l'évolution du taux de réaction de C24H11+ + H2O avec la température du piège. Aucune dépendance avec la température n'a été mise en évidence. Nous confronterons et discuterons les résultats obtenus avec des calculs ab-initio.
Collard-Simard, Gabriel. "Caractérisation du récepteur de l'insuline par spectrométrie de masse." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25309/25309.pdf.
Повний текст джерелаDufresne-Martin, Geneviève. "Développement d'outils proteomiques basés sur la spectrométrie de masse." Mémoire, Université de Sherbrooke, 2004. http://savoirs.usherbrooke.ca/handle/11143/3365.
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