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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Detection of <i>in vitro</i> and <i>in vivo</i> oxidative modifications of ferritin and transferrin by mass spectrometry : hereditary hemochromatosis as a model

Ahmed, Mohamed S. 12 December 2007
Hereditary Hemochromatosis (HH) is an inherited recessive autosomal disorder characterized by accumulation of excess iron. When iron binding proteins become saturated, concentrations of free, or non-transferrin-bound iron (NTBI) rise, a condition thought to be responsible for the adverse effects associated with HH. To investigate that disturbing iron homeostasis plays a role in free radical injury in HH, protein carbonyls were found to be 1-7 times higher in patients with HH than in controls, with the greatest increases being observed in untreated HH patients with high ferritin and >90% transferrin saturation with iron. An Unpaired t test revealed a P value of 0.0278 (P< 0.05), which is considered to be statistically significant. Our data showed a significant positive correlation (linear relationship) between the level of carbonyl content and ferritin concentration in plasma samples from patients with HH. In vitro oxidation of transferrin and ferritin standards with hydrogen peroxide and excess iron, followed by immobilized trypsin digestion (Poroszyme), high-resolution LC-MS/MS analysis (Q-TOF Ultima, Waters) and MS/MS data processing (PEAKS, Bioinformatics Solution), identified several tryptic peptides containing oxidized Met,Trp and His residues. Mapping of the oxidized ferritin residues showed them to be located on the inner face of each sub-unit, the face directed toward the ferritin core where iron is normally stored. Using the same methodology, oxidized residues were subsequently detected in ferritin and transferrin isolated from plasma samples of patients severely affected with HH. Comparing of MS/MS spectra of in vitro oxidized samples that have most fragment ion peaks in common with oxidized peptide MS/MS spectra from samples of patients with HH revealed a significant correlation between the two. These data show that elevated NTBI may be involved in oxidative modification of the iron binding proteins, ferritin and transferrin, and that such modifications may play a significant role in the pathophysiology of HH.
42

Detection of <i>in vitro</i> and <i>in vivo</i> oxidative modifications of ferritin and transferrin by mass spectrometry : hereditary hemochromatosis as a model

Ahmed, Mohamed S. 12 December 2007 (has links)
Hereditary Hemochromatosis (HH) is an inherited recessive autosomal disorder characterized by accumulation of excess iron. When iron binding proteins become saturated, concentrations of free, or non-transferrin-bound iron (NTBI) rise, a condition thought to be responsible for the adverse effects associated with HH. To investigate that disturbing iron homeostasis plays a role in free radical injury in HH, protein carbonyls were found to be 1-7 times higher in patients with HH than in controls, with the greatest increases being observed in untreated HH patients with high ferritin and >90% transferrin saturation with iron. An Unpaired t test revealed a P value of 0.0278 (P< 0.05), which is considered to be statistically significant. Our data showed a significant positive correlation (linear relationship) between the level of carbonyl content and ferritin concentration in plasma samples from patients with HH. In vitro oxidation of transferrin and ferritin standards with hydrogen peroxide and excess iron, followed by immobilized trypsin digestion (Poroszyme), high-resolution LC-MS/MS analysis (Q-TOF Ultima, Waters) and MS/MS data processing (PEAKS, Bioinformatics Solution), identified several tryptic peptides containing oxidized Met,Trp and His residues. Mapping of the oxidized ferritin residues showed them to be located on the inner face of each sub-unit, the face directed toward the ferritin core where iron is normally stored. Using the same methodology, oxidized residues were subsequently detected in ferritin and transferrin isolated from plasma samples of patients severely affected with HH. Comparing of MS/MS spectra of in vitro oxidized samples that have most fragment ion peaks in common with oxidized peptide MS/MS spectra from samples of patients with HH revealed a significant correlation between the two. These data show that elevated NTBI may be involved in oxidative modification of the iron binding proteins, ferritin and transferrin, and that such modifications may play a significant role in the pathophysiology of HH.
43

Subunit Disassembly of Human Hemoglobin and the Site-specific Roles of Its Cysteine Residues

Kan, Heng-I 28 July 2012 (has links)
Hemoglobin plays an important role in transporting oxygen in human beings and other mammals. Hemoglobin is a tetrameric protein composed of two alpha and two beta subunits. The £\ and £] subunits are both necessary and the stoichiometric ratio of the two dislike subunits is critical for hemoglobin to perform its oxygen-carrying function properly. To better understand the coupling between the £\ and £] subunits and the subunit disassembly pathway, p-hydroxymercuri-benzoate (PMB) has been used to react with the cysteine residues in hemoglobin. The hemoglobin tetramer becomes unstable and disassembles into £\ and £] subunits when the cysteine sites are perturbed upon reacting with PMB. There are three kinds of cysteine residues, £]93, £\104 and £]112, in human hemoglobin. The reactivity of different cysteine residues with PMB and their reaction sequence have been studied via the Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The resonance Raman spectroscopy has been used to investigate the structural changes of hemoglobin accompanying the PMB-modification under the oxygenated and deoxygenated conditions. At last, a hemoglobin subunit disassembly mechanism is proposed and the site-specific roles of cysteine residues in human hemoglobin are discussed in detail.
44

Qualitativer und quantitativer Nachweis von Bestandteilen der extrazellulären Matrix des Knorpels mittels MALDI-TOF MS

Schibur, Stephanie 27 February 2014 (has links) (PDF)
Eine traumatische Läsion am artikulären Knorpel stellt eine noch ungelöste Herausforderung für den behandelnden Arzt dar. Bei den betroffenen Patienten handelt es sich häufig um junge, sportlich aktive Menschen im Arbeitsprozess {Hjelle et al. 2002}, bei denen eine längerfristige Belastungs- und Bewegungseinschränkung oder sogar eine Verminderung der Erwerbsfähigkeit zwingend vermieden werden muss. Jedoch existiert für den traumatischen Gelenkknorpelschaden derzeit noch keine Therapie mit sehr gutem, funktionellem Langzeitergebnis {Richter 2005}. Die konservativen Therapieformen haben immer eine narbige Ausheilung zur Folge. Aber auch mit der chirurgischen Basisversorgung, bestehend aus Debridement und Lavage des betroffenen Gelenks, kann keine Ausheilung erreicht werden. Regenerierende Verfahren, die auf der Grundlage der Penetration des subchondralen Knochens basieren, sollen durch das Einspülen von körpereigenen Stammzellen in den Defekt eine autologe Regeneration induzieren. Langzeitstudien zeigen, dass trotz der oft erreichten, guten funktionellen Ergebnisse histomorphologisch keine Wiederherstellung von intaktem, hyalinem Gelenkknorpel erreicht werden kann {Gaissmaier et al. 2003, Bernholt/Höher 2003}. Vielversprechende neue Therapiekonzepte liefert derzeit das „Tissue Engineering“ am Gelenkknorpel. Vor allem die Autologe Chondrozytentransplantation (ACT) eröffnet vollkommen neue Behandlungsstrategien. Bei der ACT werden arthroskopisch patienteneigene Chondrozyten gewonnen, die in dreidimensionale Gele eingesät und in Zellkultur gebracht werden. Durch verschiedene Stimulationstechniken werden die Zellen zur Proliferation und Produktion von Extrazellulärer Matrix (ECM), insbesondere Kollagen und Proteoglykan, angeregt. Nach drei bis sechs Wochen Kultivierung erfolgt die Implantation in den aufbereiteten Knorpeldefekt des Patienten. Aktuelle Studien konnten zeigen, dass das Transplantat mittelfristig ohne Narbenbildung in den bestehenden Gelenkknorpel einwächst und so die Inkongruenz des Gelenks, welche präarthrotisch wirkt, aufhebt {Brittberg et al. 1996, Peterson et al. 2000, Horas et al. 2000}. Um dieses neuartige Verfahren schnell im klinischen Alltag zu etablieren, bedarf es ausgereifter analytischer Methoden, die eine Qualitätsprüfung des biotechnologisch hergestellten Knorpels ermöglichen. MALDI-TOF MS (matrix-assisted laser desorption and ionization time-of-flight mass spectrometry) ist eine schnelle und sehr sensitive Methode, um die molaren Massen von Stoffen genau zu bestimmen und komplex zusammengesetzte Proben zu analysieren. Ziel dieser Arbeit war es, MALDI-TOF Massenspektrometrie als Analyseverfahren zu nutzen, um die Zusammensetzung des natürlichen Knorpels zu bestimmen und die hier gewonnenen Erkenntnisse auf biotechnologisch hergestellten Knorpel anzuwenden. Somit war die Überprüfung der Anwendbarkeit dieser massenspektrometrischen Untersuchungsmethode auf das komplexe biologische System Knorpel die erste Fragestellung in dieser Arbeit. Es erfolgte daher zunächst die Anpassung und Optimierung der Präparations- und Messmethoden mit dem Ziel, standardisierte Protokolle festzulegen, welche zu reproduzierbaren Spektren führen. Es schloss sich die Analyse der kommerziell verfügbaren Hauptbestandteile der ECM - Proteoglykane und Kollagene – mittels MADI-TOF MS an. Hierzu wurden Chondroitinsulfat und Kollagen verschiedener Typen enzymatisch verdaut und analysiert. So konnten Referenzspektren erstellt werden, welche die Grundlage für die Analyse des wesentlich komplexeren Systems des natürlichen Knorpels bildeten. Durch den Einsatz von Trypsin zur Hydrolyse nach thermischer Denaturierung des Kollagens wurde die Differenzierung zwischen den verschiedenen Kollagentypen ermöglicht. Es schlossen sich Studien zur Quantifizierung der enzymatischen Verdauungsprodukte der ECM an, welche das Ziel verfolgten, neben der stofflichen Zusammensetzung Aussagen zu den relativen Anteilen der einzelnen Bestandteile zu erlauben. Nachdem die grundsätzliche Eignung der Methode gezeigt werden konnte, diente der zweite Teil der hier dargelegten Forschungsarbeit der Beantwortung der Frage, ob die Erkenntnisse, welche bei der Analyse der Einzelbestandteile gewonnen wurden, auf natürliches Knorpelgewebe anwendbar sind. Der artikuläre Schweineknorpel ähnelt im Aufbau und den biomechanischen Eigenschaften dem menschlichen Knorpel. Da er zudem noch günstig und in adäquaten Mengen zur Verfügung gestellt werden kann, wurde der Gelenkknorpel des Schweins als Modellgewebe für die Anwendbarkeit der Methode auf natürlichen Knorpel genutzt. Ziel war es, die Hauptbestandteile der ECM einwandfrei zu identifizieren, Untersuchungen zur Quantifizierung anzustellen und Unterschiede zwischen den Knorpeltypen verschiedener Spezies nachzuweisen. Im letzten Abschnitt dieser Arbeit erfolgte die Analyse von biotechnologisch hergestelltem Knorpel und somit die Anwendung der bisher erworbenen, vor allem einem theoretisch-wissenschaftlichem Interesse folgenden Erkenntnisse auf eine praktisch-klinische Fragestellung nach der tatsächlichen Beschaffenheit des zu transplantierenden Konstrukts. Dazu wurden Konstrukte, welche zum einem aus dreidimensionalen Agarosegele bestückt mit Chondrozyten, zum anderen aus Kollagengel mit eingesäten Stammzellen oder Chondrozyten bestanden, untersucht. Dieser Schritt erfolgte in Zusammenarbeit mit dem Biotechnologisch-Biomedizinischen Zentrum Leipzig. Ziel war es, die bis dahin etablierten Probenpräparations- und Messbedingungen auf den künstlichen Knorpel anzuwenden und mit Referenzspektren von Bestandteilen der ECM sowie des natürlichen Schweineknorpels zu vergleichen. Durch die Analyse des Materials zu verschiedenen Kultivierungszeitpunkten sollte eine Aussage über die Qualität und die Menge der de novo synthetisierten ECM erreicht werden. Mit dieser Arbeit wurde die Grundlage geschaffen, die MALDI-TOF MS als geeignetes analytisches Verfahren zur Bestimmung der Konstruktqualität einzuführen. Perspektivisch sollte es so möglich sein, die Qualität der Konstrukte, welche für die Autologe Chondrozytentransplantation bestimmt sind, zu bewerten und zu überwachen.
45

Využití biologicky aktivních látek z rostlin pro prodloužení úchovy vybrané kořenové zeleniny / The application of plant-derived biologically active substances for shelf-life improvement of root vegetable

Krondlová, Marie January 2017 (has links)
High level of agricultural products processing and especially better storage of products currently represent one of the hottest topics. At the same time, there is a lot of effort to grow crops without chemical substances. Root vegetables, which are consumed a lot, are prone to many harmful and damaging influences. There are several risk factors, including a long vegetation period. This creates an opportunity to use natural substances, in particular essential oils. Their effects are used in various different fields because they are safe for the environment as well as for the human health and the area of food commodities treatment. This study focuses on antibacterial activity testing of several essential oils: satureja, cinnamon, clove, thyme and oregano. Carrot, garden parsley and celery were chosen as representatives of root vegetables. The antibacterial activity was measured by the broth microdilution method. Even though the vegetables were inoculated with pathogenic bacteria, putrefaction did not develop in the specific places. Therefore an isolate from the parsley and the celery was then used to identify several other microorganisms by the MALDI TOF mass spectrometry. Consequently, the minimum inhibitory concentration of essential oils was again tested against these bacteria in in vitro conditions. There was a demonstrable positive result: the most frequent minimum inhibitory concentration of the cinnamon essential oil was 0.128 mg/ml. At this level the essential oil inhibited eight out of the seventeen tested microorganisms. The other tested essential oils showed some inhibition activity at least against one bacterium in in vitro conditions.
46

iMALDI as a tool to improve patient stratification for targeted cancer therapies

Popp, Robert 24 December 2018 (has links)
The PI3K/AKT/mTOR signaling pathway is commonly dysregulated in cancer. The goal of this thesis project was to assess the hypothesis of a strong correlation between PI3K/AKT/mTOR pathway activity and the response to targeted therapies, by using a protein quantitation technique called immuno-matrix assisted laser desorption/ionization (iMALDI). The use of iMALDI as a clinical tool was demonstrated by automating an established iMALDI assay for quantifying plasma renin activity. The results from the automated method gave high correlation coefficients of ≥0.98 with a clinical LC-MS/MS method and could be performed significantly faster than with manual sample preparation. The 7.5-fold faster analysis compared to LC-MS/MS, reduction in human error, and higher throughput, demonstrated the suitability of this assay for clinical use. The automated iMALDI platform was then adapted for use with cancer cell lines and tissue analysis, targeting the kinases AKT1 and AKT2 as surrogate proteins for signaling pathway activity. Using minute amounts (10 µg/capture), AKT1 and AKT2 expression and phosphorylation stoichiometry (PS) were successfully quantified via their C-terminal tryptic peptides, which encompassed key phosphorylation sites. After assay optimization, the assays were analytically validated for linear range, accuracy, and interferences. In addition, PS cut-off values based on measurement errors were established for confident PS quantitation. The functionality of the assay was demonstrated with cell lines, and flash-frozen and FFPE tissue lysates, with, on average, lower AKT1/AKT2 measurements obtained from FFPE samples. The developed assays were sensitive and precise enough to detect differences between matched normal and adjacent tumor tissues. To answer the hypothesis, patient-derived xenograft (PDX) mouse-model tumors treated with Herceptin, Everolimus, a combination of both (E+H), or with no treatment, were assessed for molecular patterns linked to tumor response. One mouse from the E+H group showed a partial response, with elevated total and phosphorylated AKT1/AKT2. Unfortunately, overlapping values between treatment groups were obtained in this study, and the large within-group spread and the low number of biological replicates made it difficult to confirm a definite correlation between PI3K/AKT/mTOR pathway activity and response to treatment. A follow-up study with additional protein targets, a larger number of samples, and serial biopsies will be required to determine if there is, in fact, a correlation between PI3K/AKT/mTOR pathway activity and response to treatment. / Graduate / 2019-10-05
47

Estudo proteômico do desenvolvimento folicular de vacas zebuinas não gestantes / Estudo proteômico do desenvolvimento folicular de vacas zebuinas não gestantes

Lourenço, Tarcísio Torre [UNESP] 30 March 2016 (has links)
Submitted by TARCISIO TORRE LOURENÇO null (tarcisiolourenco16@yahoo.com.br) on 2016-12-09T13:14:54Z No. of bitstreams: 1 Dissertação Tarcísio com a ficha.pdf: 10339060 bytes, checksum: 23f48d3539cc446a8efd713c0a0b082d (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-12-13T10:58:12Z (GMT) No. of bitstreams: 1 lourenco_tt_me_bot.pdf: 10339060 bytes, checksum: 23f48d3539cc446a8efd713c0a0b082d (MD5) / Made available in DSpace on 2016-12-13T10:58:12Z (GMT). No. of bitstreams: 1 lourenco_tt_me_bot.pdf: 10339060 bytes, checksum: 23f48d3539cc446a8efd713c0a0b082d (MD5) Previous issue date: 2016-03-30 / O ciclo estral da vaca é composto por 2-3 ondas de crescimento folicular, no qual vários folículos são recrutados e iniciam um novo crescimento. Durante o período denominado desvio folicular, um folículo se torna dominante e os outros entram em atresia. Este processo envolve um mecanismo ainda não completamente compreendido, incluindo proteínas específico, como já estabelecido pela expressão gênica. O objetivo do presente estudo foi caracterizar as proteínas do fluído folicular a fim de identificar macromoléculas relacionadas ao desenvolvimento dos folículos de vacas zebuínas nã-gestantes. Foram colhidos os ovários de 25 vacas mestiças não-gestantes em um abatedouro. A presença do corpo lúteo foi anotada para cada ovário. O líquido folicular foi colhido utilizando-se a imersão do ovário em meio líquido e ultrassonografia. De acordo com a mensuração do diâmetro folicular, foram formados 3grupos, folículos pequenos (≤6,5mm, n=25), médios (>6,5mm a ≤9mm, n=9) e grandes (>9,0mm, n=11). Após 2 centrifugações (600xg/10 minutos e 15.000xg/30 minutos, 4ºC) o sobrenadante foi separado e utilizado para determinação da concentração de proteína total (método de Bradford). A eletroforese foi conduzida sob condições desnaturantes e redutoras, em gel de separação de poliacrilamidaà 12%. A concentração de progesterona e estradiol do líquido folicular foi determinada a fim de identificar os folículos saudáveis. As proteínas diferenciais identificadas pela eletroforese foram submetidas à espectrometria de massas e a ontologia gênica foi investigada nos bancos de dados disponíveis. Foram encontradas 45 bandas proteicas em 45 amostras de líquido folicular. A média da concentração ± desvio padrão da progesterona foi de 129,91 ± 186,43, considerando todos os folículos. Os resultados mostram que houve uma expressão diferenciada de proteínas nas diferentes categorias de folículos. / The estrous cycle of the cow consists of 2-3 follicular waves, in which several follicles are recruited and initiate growth. During the period called follicular deviation, one follicle becomes dominant and the other come into atresia.This process involves mechanisms not yet fully understood, including specific proteins as already determined by gene expression. As a result, the objective of this study was to characterize the proteins of the follicular fluid to identify macromolecules related to the development of follicles from Zebu cow. The ovaries of nonpregnant cows 25 were harvested. The presence of luteum body was noted for each ovary. Follicular fluid was collected using ultrasound. According to the measurement of follicular diameter was 3 separate groups, small follicles (≤6,5mm, n = 28), medium (> 6.5mm to ≤9mm, n = 7) and large (> 9,0mm, n = 11). After 2 centrifugations (600xg / 10 minutes, 15.000xg / 30 minutes, 4 ° C) the supernatant was separated and used for determination of total protein concentration (Bradford method). Electrophoresis was conducted under denaturing and reducing conditions on polyacrylamide separating gel at 12%. The concentration of progesterone and follicular fluid estradiol was determined to identify healthy follicles. The differential proteins identified by electrophoresis will be submitted for MALDI TOF MS / MS approach and gene ontology will be investigated in the databases available. They found 45 protein bands in electrophoresis in 45 follicular fluid samples. The mean ± standard deviation of progesterone concentration was 129.91 ± 186.43 considering all follicles. The results show that there was a differential expression of proteins in different categories of follicles.
48

Aplicação de tecnicas avançadas de espectrometria de massas em ciencias de alimentos e perfumaria / Advanced mass spectrometry techniques applied in food analysis and perfume characterization

Marques, Lygia de Azevedo 28 July 2006 (has links)
Orientador: Marcos Nogueira Eberlin / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T11:19:58Z (GMT). No. of bitstreams: 1 Marques_LygiadeAzevedo_M.pdf: 2432568 bytes, checksum: 7bf6003b0fa0df13e1ba0f91d7ebf00b (MD5) Previous issue date: 2006 / Resumo: Neste trabalho aplicamos técnicas avançadas de espectrometria de massas, (MALDI-TOF e ESI-MS) na análise de micotoxinas em alimentos e na tipificação e verificação de fraudes em perfumes. Aplicamos a técnica MALDI-TOF em análises de micotoxinas, e esta mostrou excelente desempenho nas análises de aflatoxinas e ocratoxina e vantagem sobre a técnica de escolha atual, o método ELISA. Esta vantagem é principalmente maior especificidade através de maior exatidão em medidas de massas e, portanto, maior confiabilidade. O Planejamento de experimento foi uma ferramenta valiosa para obtenção das melhores condições e estudo dos parâmetros de interferência. O limite de detecção encontrado para a técnica foi da ordem de 25 pg para aflatoxinas e de 1 ng para ocratoxina, com perspectiva de melhoria através de aumento da massa amostral em estudos futuros para adaptação da metodologia de extração na matriz de interesse à técnica MALDI-TOF. A técnica ESI-MS foi utilizada para a tipificação e detecção de perfumes proporcionando, através da análise de componentes principais (PCA), a diferenciação com segurança entre perfumes originais, falsos e inspirados, utilizando como indicadores componentes polares não majoritários característicos de cada categoria avaliada. Este estudo abre caminho para que esta técnica seja utilizada na avaliação de perfumes que estão sob suspeita de falsificação com auxilio de uma biblioteca de "fingerprint" de perfumes por ESI-MS. O emprego da técnica de MALDI-TOF também é uma opção vantajosa para o monitoramento da qualidade de grãos quanto a presença de toxinas indesejáveis, bem como ameaças de bioterrorismo. / Abstract: In this work we applied advanced mass spectrometry techniques (MALDI-TOF and ESI-MS) to micotoxin analysis in food and for the typification and detection of counterfeit perfumes. MALDI-TOF was applied to micotoxin analysis, which showed excellent performance for the analysis of aflatoxins and ochratoxin with advantage over the current technique of choice, the ELISA method. This advantage is mainly its greater specifity due the exactness of the measurements, therefore with higher reliability. The surface analysis was a valuable tool to attain the best conditions and study the interference of several parameters. The detection limit found for the technique was 25 pg for aflatoxins and 1 ng for ochratoxins, with perspective of improvement through increase of the sample mass in future studies for adaptation of the methodology of extration in the matrix of interest for the MALDI-TOF technique. The ESI-MS technique was used for typification and detection of counterfeit perfumes, providing, through principal component analysis (PCA), the characterization of original, counterfeit and inspired perfumes, using as minoritarian polar compounds as diagnostic ions of each perfume category evaluated. We envisage that the method can be used to establish a ESI-MS fingerprinting library of perfumes for comparison with those from samples under investigation, and that such a library could be updated constantly by the addition of ESI-MS of new perfumes even before they are commercially released. MALDI-TOF technique is also an advantageous option for the monitoring of crop quality relating to the presence of undesirable toxins, as well as bioterrorism threats by micotoxin poisoning. / Mestrado / Quimica Analitica / Mestre em Química
49

Etude de la qualité du piégeage des matières organiques par la matrice cimentaire vis-à-vis de la lixiviation / Study of the trapping quality of organic materials by the cementing matrix during leaching process

Guerandel, Cyril 23 November 2009 (has links)
Dans le cadre de la qualité environnementale des matériaux, il est essentiel d'apporter la preuve que les matériaux à base de ciments adjuvantés ne relarguent pas ou peu de matières organiques lors de leur contact avec l'eau constituant une solution lixiviante. Les additifs organiques, tels que les agents de mouture et les superplastifiants, constituent deux classes d'adjuvants organiques utilisés de manière systématique dans la fabrication ou la formulation des matériaux cimentaires, notamment quand ils sont en contact avec l'eau potable (conduites et châteaux d'eau). Pour évaluer le piégeage de ces composés organiques par une pâte de ciment CEM I, cinq montages de lixiviation dynamique CTG-LEACHCRETE ont été mis en place et adaptés pour l'étude de pâtes de ciment formulées avec des adjuvants organiques. La seconde partie de ce travail a pour objectif de mettre au point des techniques analytiques sensibles pour la détection de traces des constituants du superplastifiant et de l'agent de mouture directement dans les produits de la lixiviation de pâtes de ciment (les lixiviats) grâce aux techniques de spectrométrie de masse MALDI-TOF et Py-THM-MS. Enfin, l'application du protocole global de "lixiviation dynamique couplée à la spectrométrie de masse" nous permet d'apprécier la présence des composés organiques suite à des essais de lixiviation de pâtes de ciment formulées avec de l'agent de mouture et du superplastifiant. Cette démarche nous a permis d'obtenir de nombreux résultats donnant des informations sur les mécanismes de piégeage des différents additifs organiques par une pâte de ciment / Evidence that materials used by the industry are not damageable for the environment has become a major issue. In cement industry, organic admixtures such as grinding aids or superplasticizers ar widely used. In particular, they constitute cementitious materials in concrete contacting water like in water pipes and water tower. It is therefore essential to test whether these organic coumpounds are enventually dissolved into water by leaching. In this aim, five different dynamic leaching tests were developed and applied to a CEM I cement paste formulated with organic admixtures. In paralell, highly sensitive analytical methods based on MALDI-TOF and Py-THM-MS mass spectrometry techniques were designed in order to detect traces of leached superplasticizers or grinding aids. The dynamic leaching tests coupled to mass spectrometry allowed us to detect the presence of organic compounds in the leachate, and to better understand the mechanisms involved in the trapping of additives into a cement paste
50

Comparative evaluation of the extraction and analysis of urinary phospholipids and lysophospholipids using MALDI-TOF/MS / MALDI-TOF/MSを用いた尿中リン脂質およびリゾリン脂質の抽出法および分析法に関する比較検討

Li, Xin 26 July 2021 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第23410号 / 医博第4755号 / 新制||医||1052(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 村川 泰裕, 教授 長尾 美紀, 教授 柳田 素子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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