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Mapeamento de sensibilidade ambiental a derramamentos de óleo na região costeira de Bertioga - SP /Cunha, Fabrício Pinheiro da. January 2009 (has links)
Orientador: Gilbero José Garcia / Banca: Paulina Setti Riedel / Banca: Décio Semensatto Junior / Obra em 2 volumes, sendo o volume 2: Mapeamento de sensibilidade ambiental a derramamento de óleo na região costeira de Bertioga - SP : atlas / Resumo: O presente trabalho realizou o mapeamento de Sensibilidade Ambiental a derramamentos de óleo da região costeira do município de Bertioga-SP. Foram mapeados os ambientes do estuário do Canal de Bertioga e do Rio Itapanhau, além da área costeira marinha compreendida entre a foz do Canal de Bertioga e a Ponta do Itaguá, na praia da Boracéia, em São Sebastião. Para tanto, foi aplicada a metodologia indicada pelo Ministério do Meio Ambiente, atualmente utilizada no Brasil. Foram mapeados e identificados em campo e na literatura três tipos de informações principais: recursos biológicos; caracterização física do meio e usos humanos dos espaços e recursos (atividades sócio-econômicas). Como produto final, os ecossistemas costeiros e marinhos presentes na linha de costa foram classificados de acordo com o índice de sensibilidade ambiental. Foi desenvolvido um banco de dados geográfico e elaborado um Atlas da região contendo as cartas de sensibilidade ambiental (Cartas SAO), sendo 03 de nível tático (1:70.000) e 11 de nível operacional (1:20.000), informações descritivas dos segmentos da linha de costa, com recursos visuais, além de uma listagem de espécies. A região costeira de Bertioga apresentou significativa heterogeneidade ambiental, em sua maior parte representados por manguezal, com alta sensibilidade ao óleo, localizada em áreas do estuário. Estes ambientes apresentam baixo hidrodinamismo, sedimentos lamosos inconsolidados, de baixa declividade, abrigando grande diversidade de fauna, resultando em grande persistência do óleo no ambiente e dificultando as ações de combate. O ambiente praial demonstrou baixa variação morfodinâmica (ângulo de declividade e granulometria) sazonal, e conseqüentemente, não houve variação sazonal na classificação no índice de sensibilidade ambiental (ISL). Foi possível identificar uma lacuna na literatura científica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This present study performed the environmental sensitivity mapping for oil spills of the coast side of Bertioga City. It has been mapped the estuary of Bertioga's Channel and Itapanhau River, besides the marine coast side between the Bertioga's Channel mouth and Ponta do Itaguá, at Boracéia beach, at São Sebastião City. To perform the present study it was applied the methodology indicated by the Ministry of the Environment, currently used in Brazil. It has been mapped and identified in field and literature three types of main information: biological resources, physical environment characterization and human land use and resources (socio-economic activities). As a final product it was developed a geographic database and an atlas of the surroundings containing ESI maps, including 03 tactical (1:70.000) and 11 operational maps (1:10.000), which show coast line descriptive information, visual resources and a list of biological species. The seashore of Bertioga City presents significant environmental diversity, the most part represented by mangrove ecosystem, with high sensitivity to oil, located at estuary. These environments present low hydrodynamism, mud sediment, low declivity, sheltering biodiversity, resulting in high oil persistence in environment difficulting actions to combat. The beach environment showed low seasonal morfodynamic variation, consequently, there was no seasonal variation at environmental sensitivity index. It was possible to identify a blank at scientific literature about biodiversity information for the studied area, despite being an exuberant environment. The study area has potential sources of pollution, as OSBAT pipeline and state highways. The building of a geographic database, directed to detailded ESI maps associated with an environmental atlas, showed to be an instrument for to guide actions in oil spills sceneries, while they are instruments... (Complete abstract click electronic access below) / Mestre
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Ion/Ion Reaction Facilitated Mass Spectrometry and Front-End Method DevelopmentNan Wang (6565601) 10 June 2019 (has links)
Mass spectrometry is a versatile analytical tool for chemical and biomolecule identification, quantitation, and structural analysis. Tandem mass spectrometry further expands the applications of mass spectrometry, making it more than a mere detector. With tandem mass spectrometry, the mass spectrometer is capable of probing reaction mechanisms, monitoring reaction processes, and performing fast analysis on complex samples. In tandem mass spectrometry, after activation the precursor ions fragment into small fragment ions through one or more pathways, which are affected by the ion’s inherit property, the ion type, and the activation method. To obtain complementary information, one can alter the fragmentation pathway by changing the ion via ion charge manipulation and covalent modification to the ion. Gas-phase ion/ion reactions provide an easy approach to changing ion type and facile modification to the analyte ions. It has been extensively used for spectrum simplification and analyte structural studies. In this dissertation, ion/ion reaction facilitated mass spectrometry methods are studied, and explorations into the method development involving front-end mass spectrometer are discussed.<br>The first work demonstrates a special rearrangement reaction for gas-phase Schiff-base-modified peptides. Gas-phase Schiff-base modification of peptides has been applied to facilitate the primary structural characterization via tandem mass spectrometry. A major or minor fragment pathway related to the novel rearrangement reaction was observed upon in-trap collisional activation of the gas-phase Schiff-base-modified peptides. The rearrangement reaction involves the imine of the Schiff base and a nucleophile present in the polypeptide. The occurrence of the rearrangement reaction is affected by several factors, such as ion polarity, identity of the nucleophile in the peptide (e.g., side chains of lysine, histidine, and arginine), and the position of the nucleophile relative to the imine. The rearrangement reaction does not affect the amount of structural information that can be obtained by collisional activation of the Schiff-base-modified peptide, but when the rearrangement reaction is dominant, it can siphon away signal from the structurally diagnostic processes.<br>Efforts have also been put into the method development of peptide and protein aggregation detection via electrospray ionization mass spectrometry (ESI-MS). People have studied peptide and protein aggregation processes to understand the mechanism of amyloid-related diseases and to control the quality of the peptide and protein pharmaceuticals. ESI-MS is suitable for solution aggregation studies because of its compatibility with solution samples and the straightforward result of the analyte’s oligomeric state on the mass spectrum. However, peak overlap issue and nonspecific aggregation in the ESI process can obscure the result. Here, the application of proton transfer ion/ion reaction to the analyte has been found useful to reduce or eliminate the peak overlap issue. A statistical model based on Poisson statistics has been proposed to deal with the ESI-induced nonspecific aggregation in the droplet and to differentiate the solution-phase aggregation from the droplet-induced aggregation. Factors that affect the accuracy of the statistical model have been discussed with MATLAB simulations.<br>In the era of biological system studies, sample complexity is a challenge every analytical chemist has to face. The analysis of complex sample can be facilitated by the combination of separation techniques outside the mass spectrometer (such as differential mobility spectrometry (DMS)) and ion structure probing techniques inside the mass spectrometer (such as tandem mass spectrometry and gas-phase ion/ion reactions). Here the coupling method between DMS and ion/ion reaction is developed and tested with model peptide systems to demonstrate its possible application in complex sample characterization such as isomer identification.<br>
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Caracterização e determinação da atividade antifúngica in vitro de extratos obtidos de Sida tuberculata R.E. Fries (Malvaceae) / Characterization and determination of in vitro antifungal activity of Sida tuberculata. R.E. Fries (Malvaceae) extractsRosa, Hemerson Silva da 24 January 2013 (has links)
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Previous issue date: 2013-01-24 / Sida tuberculata (Malvaceae), conhecida popularmente como “guanxuma”, é uma espécie vegetal de porte herbáceo, bem representada na região sul do Brasil. Na cultura popular é utilizada para tratamento de diversas enfermidades, em especial àquelas relacionadas ao diabetes e ao colesterol elevado. Para algumas espécies, existem relatos de eventual potencial antimicrobiano. Considerando a ausência de estudos sobre esta planta, o presente trabalho investigou a composição química dos extratos brutos de S. tuberculata e avaliou seu potencial antifúngico in vitro. Após a coleta e identificação, o material vegetal foi submetido aos processos de secagem e trituração. Submeteu-se a extração a frio por percolação, utilizando-se como solvente solução hidroetanólica a 40% para folhas e 70% para raízes. Para fins de comparação foram feitas extrações aquosas por infusão. Na sequência, foram determinados os teores de fenólicos totais e flavonóides totais. Posteriormente, as amostras foram analisadas através de método por CLAE-UV, com seleção das condições cromatográficas de melhor eficiência de separação. Sendo estas estabelecidas, efetuou-se análise por LC-MS em modo ESI positivo. Para os ensaios da atividade antifúngica foram utilizados os protocolos de microdiluição em ágar para determinação da concentração inibitória mínima (CIM) e concentração fungicida mínima (CFM). Também foi aplicada a metodologia para avaliação do potencial de remoção de biofilme em Cateter Venoso Central (CVC). Os resultados obtidos demonstraram um maior teor de fenólicos e flavonóides totais nos extratos das folhas. As análises por LC-UV-MS permitiram a identificação e proposição de cinco compostos, entre ecdisteróides, flavonóides e alcalóides. Nos ensaios de atividade antifúngica os extratos aquosos apresentaram atividade contra linhagens de Candida krusei, com valores de CIM variando entre 3.9 - 62.5 μg/ml para folhas e 1.95 - 31.25 μg/ml para raízes. No teste de remoção de biofilme, os extratos aquosos das folhas demonstraram um maior potencial de remoção. Os dados de composição química obtidos, nas variantes de diferentes partes da planta, bem como a atividade antimicrobiana detectada, geram expectativas quanto a novos estudos de exploração do potencial biológico de S. tuberculata. / Sida tuberculata (Malvaceae), popularly known as "guanxuma", is an herbaceous plant species present in southern Brazil. In popular culture, it is used for the treatment of several diseases, such as those related to diabetes and high cholesterol level. For some species of Sida, there are also reports about the antimicrobial potential. Considering the lack of studies at this species, this study proposed an investigation about the chemical composition of Sida tuberculata extracts and their in vitro antifungal activity. After collection and identification, the plant material was submitted to dryness and powdered. Then, it was submitted to extraction by percolation using hydroethanolic solution at 40% and 70% as solvent, to leaves and roots respectively. For comparison, aqueous extracts were obtained by infusion. The total phenolic and flavonoid contents of extracts were determined. The samples were also evaluated by HPLC-UV, testing the chromatographic conditions that promote the better separation efficiency. After, for the identification procedure, the analysis by LC-ESI-MS in positive mode was conducted using previously established conditions. For the antifungal activity assay, the agar microdilution protocols were used for determination of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). In addition, the extracts were tested for potential biofilm removal in Central Venous Catheter (CVC). The results demonstrated a higher concentration of total phenolic and flavonoids compounds in the leaves extracts. LC-MS analysis allowed the identification of five components, between ecdysteroids, flavonoids and alkaloids. In the assay of antifungal activity, the aqueous extract had activity against Candida krusei strains, with the MIC values varying between 3.9 - 62.5 μg/ml for leaves and 1.95 - 31.25 μg/ml for roots. In the CVC biofilm removal testing, the aqueous leaves extracts presented a greater potential. The chemical composition data obtained in this work, considering the different parts of plant, as well as the antimicrobial activity detected, bring perspectives of exploring this species concerning its biological potential.
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Approche expérimentale par ESI/ITMS et théorique des affinités cationiques (Na+) d'acides aminés, de bases nucléiques et de nucléosidesRochut, Sophie 10 September 2004 (has links) (PDF)
Cette thèse consiste en l'étude de la réactivité en phase gazeuse d'acides aminés, de bases nucléiques et de nucléosides modifiés et non modifiés vis à vis du cation sodium. Les affinités cationiques ont été déterminées expérimentalement par couplage ESI/ITMS et théoriquement, par calculs ab initio d'énergie. La méthode expérimentale permet de déterminer les valeurs des affinités cationiques des biomolécules en étudiant la décomposition des dimères cationisés formés en phase gazeuse selon la méthode de Cooks. Les calculs ab initio permettent de déterminer les affinités cationiques et les structures des complexes formés en phase gazeuse. Après avoir montré que l'utilisation de la théorie de la fonctionnelle de la densité (DFT) avec la fonctionnelle B3P86 était bien adaptée à notre problématique, l'excellente corrélation obtenue entre les résultats expérimentaux et théoriques a permis de déterminer les sites privilégiés de cationisation et donc les structures cationisées des acides aminés, des bases nucléiques et des nucléosides modifiés et non modifiés en phase gazeuse.
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Palladium(II)-Catalyzed Coupling ReactionsLindh, Jonas January 2010 (has links)
Sustainable chemical processes are becoming increasingly important in all fields of synthetic chemistry. Catalysis can play an important role in developing environmentally benign chemical processes, and transition metals have an important role to play in the area of green chemistry. In particular, palladium(II) catalysis includes many key features for successful green chemistry methods, as demonstrated by a number of eco-friendly oxidation reactions catalyzed by palladium(II). The aim of the work presented in this thesis was to develop novel and greener palladium(II)-catalyzed coupling reactions. In striving to achieve this aim, the first open-vessel, room-temperature palladium(II)-catalyzed oxidative Heck reaction, using oxygen from the air as the reoxidant of palladium, was developed. In a further investigation of the palladium(II)-catalyzed oxidative Heck reaction, base-free conditions for the transformation were identified and suitable conditions for microwave-assisted oxidative Heck reactions were established. A convenient and low-cost palladium(II)-catalyzed method for the synthesis of styrene derivatives, by coupling arylboranes with vinyl acetate, was developed. The reaction mechanism was studied using ESI-MS, which enabled the detection of cationic palladium intermediates in ongoing productive reactions, and a plausible catalytic cycle was proposed. In an attempt to make the oxidative Heck and the styrene synthesis reactions more attractive from an industrial point of view, conditions for continuous flow synthesis were identified. The results were generally good and rapid synthesis of the desired products was obtained. The first palladium(II)-catalyzed C–P bond-forming Hirao-type reaction, employing arylboranes instead of the commonly used aryl halides, was developed. An ESI-MS study was performed, and a plausible catalytic pathway was suggested. Finally, a novel method for synthesizing aryl ketones from benzoic acids and nitriles, via palladium(II)-catalyzed decarboxylation of the benzoic acids, was established. Further, the reaction mechanism was studied by ESI-MS and a plausible catalytic route presented.
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Studies of non-covalent interactions using nano-electrospray ionization mass spectrometrySundqvist, Gustav January 2004 (has links)
No description available.
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Mass Spectrometry with Electrospray Ionization from an Adjustable GapEk, Patrik January 2008 (has links)
<p><b>In this thesis the fabrication and analytical evaluation of two new electrospray emitters utilized for mass spectrometry analysis is presented. The emitters are based on a new concept, where the spray orifice can be varied in size. The thesis is based on two papers.</b></p><p>All present-day nanoelectrospray emitters have fixed dimensions. The range of the applicable flow rate for such an emitter is therefore rather limited and exchange of emitters may be necessary from one experiment to another. Optimization of the signal of the analyte ions is also limited to adjustments of the applied voltage or the distance between the emitter and the mass spectrometer inlet. Furthermore, clogging can occur in emitters with fixed dimensions of narrow orifice sizes. In this thesis, electrospray emitters with a variable size of the spray orifice are proposed. An open gap between two thin substrates is filled with sample solution via a liquid bridge from a capillary. Electrospray is generated at the end point of the gap, which can be varied in width.</p><p>In Paper I, electrospray emitters fabricated in polyethylene terephthalate have been evaluated. Triangular tips are manually cut from the polymer film. The tips are mounted to form a gap between the edges of the tips. The gap wall surfaces are subjected to a hydrophilic surface treatment to increase the wetting of the gap walls.</p><p>In Paper II, silicon electrospray chips with high precision are fabricated and evaluated. A thin beam, elevated from the bulk silicon chip is fabricated by means of deep reactive ion etching. The top surfaces of the beams of two chips act as a sample conduit when mounted in the electrospray setup. An anisotropic etching step with KOH of the intersecting <100> crystal planes results in a very sharp spray point. The emitters were given a hydrophobic surface treatment except for the hydrophilic gap walls.</p><p>For both emitter designs, the gap width has been adjusted during the experiments without any interruption of the electrospray. For a continuously applied peptide mixture, a shift towards higher charge states and increased signal to noise ratios could be observed when decreasing the gap width. The limit of detection has been investigated and the silicon chips have been interfaced with capillary electrophoresis.</p>
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Synthese und Charakterisierung peripher funktionalisierter Carbosiloxan- und Carbosilandendrimere / Synthesis and Characterization of peripherally functionalized Carbosiloxane and Carbosilane DendrimersBuschbeck, Roy 19 April 2005 (has links) (PDF)
In der vorliegenden Arbeit wird die Synthese und die Charakterisierung von Carbosiloxandendrimeren der 1. 3. Generation, welche periphere Me2SiH, MeSiH2 bzw. SiH3 Gruppen besitzen, vorgestellt. Ausgehend von diesen Verbindungen konnte am Beispiel eines mit einer Dimethylvinylsilyl-Einheit funktionalisierten Titanocendichlorides gezeigt werden, dass sich durch die Hydrosilylierungsreaktion metallorganische Bausteine an SiH-funktionalisierte Carbosiloxandendrimere anbinden lassen.
Einen weiteren Schwerpunkt dieser Arbeit bildeten Carbosilandendrimere. Eine neue Variante der Darstellung dieser Moleküle durch die konvergente Synthesemethode mit Hilfe von kettenverlängernden, 1 zu 2 bzw. 1 zu 3 verzweigten Bausteinen konnte partiell erfolgreich durchgeführt werden. Die Anbindung von cyclischen (12-Krone-4, 15-Krone-5, 18-Krone-6, Sila-8-Krone-3, Sila-11-Krone-4) und acyclischen (Triethylenglycolmonomethylether) Polyethern an dendritische Carbosilane der 1. und 2. Generation wird ebenfalls beschrieben. Hierzu wurden Carbosilandendrimere mit peripheren SiH-Einheiten durch Hydrosilylierung mit den entsprechenden allyl- bzw. vinylfunktionalisierten Ethern zur Reaktion gebracht. Die auf diesem Weg erhaltenen Dendrimere mit endständigen cyclischen bzw. linearen Polyethern wurden mit Alkalimetallionen (Li+, Na+, K+) umgesetzt und die entstandenen Komplexe massenspektrometrisch untersucht.
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The effect of sulforaphane on oxidative stress and biotransformation in HepaRG cells / A. Crous.Crous, Ané January 2013 (has links)
Sulforaphane is an isothiocyanate found in high concentrations in cruciferous vegetables like broccoli. Sulforaphane has received much attention due to the evidence that it inhibits phase I carcinogen-bioactivating enzymes and/or induces phase II antioxidant enzymes as well as metallothioneins (MTs) (Perocco et al., 2006; Clarke et al., 2008; Yeh & Yen, 2009). Since MTs and antioxidant enzymes are involved in the scavenging of reactive oxygen species (ROS), the question was raised whether sulforaphane can provide protection against increased oxidative stress and if sulforaphane exposure of a human hepatocellular carcinoma cell line, like HepaRG cells, will have a negative impact on phase I and II biotransformation in these cells. Oxidative stress was exogenously induced in HepaRG cells with tert- Butyl hydroperoxide (t-BHP). Phase I and phase II biotransformation pathways were assessed with caffeine, paracetamol, aspirin, sodium benzoate, and paraaminobenzoic acid, respectively, as probe substances. Through the use of a liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) assay, the biotransformation of caffeine in phase I and the formation of paracetamol, aspirin, sodium benzoate and para-aminobenzoic acid conjugates in phase II were investigated. This involved elucidating the time it took for the whole probe to be completely biotransformed during phase I biotransformation and the unique conjugates formed during phase II biotransformation in HepaRG cells.
The optimal t-BHP concentration and exposure time in HepaRG cells were standardized with a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. LC-ESI-MS/MS assays to monitor phase I and phase II biotransformation were optimized and validated. The optimal sulforaphane concentration and exposure time in HepaRG cells were standardized with a MTT assay. To evaluate the possible protective effect of sulforaphane against oxidative stress, HepaRG cells were pre-incubated with sulforaphane followed by the induction of oxidative stress with t-BHP and the quantification of the amount of viable cells with a MTT assay. To investigate the effect of sulforaphane on phase I and phase II biotransformation pathways, HepaRG cells were first pre-incubated with sulforaphane followed by the addition of a specific probe substance and the assessment of the biotransformation of the probe with a LC-ESI-MS/MS assay.
The results partially supported the hypothesis of the study that sulforaphane will protect HepaRG cells against oxidative stress without negatively influencing phase I and phase II biotransformation. The results indicated that sulforaphane provided partial protection against t-BHP induced oxidative stress and had no effect on phase II paracetamol biotransformation in HepaRG cells. / Thesis, MSc (Biochemistry), North-West University, Potchefstroom Campus, 2013.
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The effect of sulforaphane on oxidative stress and biotransformation in HepaRG cells / A. Crous.Crous, Ané January 2013 (has links)
Sulforaphane is an isothiocyanate found in high concentrations in cruciferous vegetables like broccoli. Sulforaphane has received much attention due to the evidence that it inhibits phase I carcinogen-bioactivating enzymes and/or induces phase II antioxidant enzymes as well as metallothioneins (MTs) (Perocco et al., 2006; Clarke et al., 2008; Yeh & Yen, 2009). Since MTs and antioxidant enzymes are involved in the scavenging of reactive oxygen species (ROS), the question was raised whether sulforaphane can provide protection against increased oxidative stress and if sulforaphane exposure of a human hepatocellular carcinoma cell line, like HepaRG cells, will have a negative impact on phase I and II biotransformation in these cells. Oxidative stress was exogenously induced in HepaRG cells with tert- Butyl hydroperoxide (t-BHP). Phase I and phase II biotransformation pathways were assessed with caffeine, paracetamol, aspirin, sodium benzoate, and paraaminobenzoic acid, respectively, as probe substances. Through the use of a liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) assay, the biotransformation of caffeine in phase I and the formation of paracetamol, aspirin, sodium benzoate and para-aminobenzoic acid conjugates in phase II were investigated. This involved elucidating the time it took for the whole probe to be completely biotransformed during phase I biotransformation and the unique conjugates formed during phase II biotransformation in HepaRG cells.
The optimal t-BHP concentration and exposure time in HepaRG cells were standardized with a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. LC-ESI-MS/MS assays to monitor phase I and phase II biotransformation were optimized and validated. The optimal sulforaphane concentration and exposure time in HepaRG cells were standardized with a MTT assay. To evaluate the possible protective effect of sulforaphane against oxidative stress, HepaRG cells were pre-incubated with sulforaphane followed by the induction of oxidative stress with t-BHP and the quantification of the amount of viable cells with a MTT assay. To investigate the effect of sulforaphane on phase I and phase II biotransformation pathways, HepaRG cells were first pre-incubated with sulforaphane followed by the addition of a specific probe substance and the assessment of the biotransformation of the probe with a LC-ESI-MS/MS assay.
The results partially supported the hypothesis of the study that sulforaphane will protect HepaRG cells against oxidative stress without negatively influencing phase I and phase II biotransformation. The results indicated that sulforaphane provided partial protection against t-BHP induced oxidative stress and had no effect on phase II paracetamol biotransformation in HepaRG cells. / Thesis, MSc (Biochemistry), North-West University, Potchefstroom Campus, 2013.
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