Tesis sobre el tema "9-phase"
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Lowrie, Neil J. "Minor phase precipitation in 9 wt.% Cr power plant steels". Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/35027.
Texto completoRobson, Joseph Douglas. "Modelling of carbide and Laves phase precipitation in 9-12 wt% chromium steels". Thesis, University of Cambridge, 1997. https://www.repository.cam.ac.uk/handle/1810/224753.
Texto completoMathaba, Philile Nobuhle y A. Bayaga. "Errors and misconceptions related to learning algebra in the senior phase – grade 9". Thesis, University of Zululand, 2019. http://hdl.handle.net/10530/1803.
Texto completoAlgebra is a mathematical concept that explains the rules of symbol operations, equations, and inequality. Algebra is a combination of logic and language; hence common mistakes and conceptions are either attributed to logic or language problems, or both. There is also ongoing debate about the fact that learners come to class with different ideas that result in errors and misconceptions when they solve algebraic equations and expressions. Based on this debate concerning both errors and misconceptions in solving algebraic equations and expressions, the purpose of this study was to investigate the errors and misconceptions committed by learners when learning Algebra. The study answered the following research questions: What are the types and the sources of errors and misconceptions committed by Grade 9 learners in Algebra learning? How do the types and the sources of errors and misconceptions influence errors in Grade 9 learners’ cognition when learning Algebra? Which strategies work to avoid errors? What are the sources of the errors and misconceptions in Algebra? Unlike the predominant existing studies, which are urban-based, this study was based in rural schools in the King Cetshwayo District of UMlalazi and Mtunzini Municipality. The structure of the observed learning outcome (SOLO) theory was adopted to observe, examine and analyse learners’ misconceptions in rural-based secondary schools.
BERGENHOLT, TOVE y TOMMI PÖLKKÖ. "IFRS 9 Fas III : Säkringsredovisning – Förenkling eller bara förändring?" Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20805.
Texto completoBrumann, Mareen. "Serumkonzentrationen der Proteine MMP-9 und TIMP-1 bei polytraumatisierten Patienten in der frühen posstraumatischen Phase". Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-162665.
Texto completoJINGMARK, JOHANNA y CHRISTIAN LOJEK. "IFRS 9 FAS 2 : EN UNDERSÖKNING AV INTRESSENTERNAS ATTITYDER". Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20755.
Texto completoProgram: Civilekonomprogrammet
Han, Liang. "Exploring two-phase hydrothermal circulation at a seafloor pressure of 25 MPa: Application for EPR 9°50′N". Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/45440.
Texto completoMaster of Science
Simonson, Thomas. "Analyse structurale de l'onde de polarisation d'un isolant incommensurable : la thiourée : application à la phase longue période "1/9"". Paris 11, 1985. http://www.theses.fr/1985PA112146.
Texto completoBrumann, Mareen [Verfasser] y Wolf E. [Akademischer Betreuer] Mutschler. "Serumkonzentrationen der Proteine MMP-9 und TIMP-1 bei polytraumatisierten Patienten in der frühen posstraumatischen Phase / Mareen Brumann. Betreuer: Wolf E. Mutschler". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/104556124X/34.
Texto completoSalib, Matthieu. "Étude cinétique et cristallographique de la précipitation de la phase α aux joints de grains β/β dans un alliage de titane". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0042/document.
Texto completoThis work focuses on the formation and the evolution of microstructure and microtexture associated with the α phase precipitation at β/β GBs in titanium alloys. A β-metastable alloy (Ti17) has been studied, because the high temperature microstructure is frozen by a rapid quench and the untransformed parent phase remains. Numerous 2D EBSD analyses and some 3D analyses have been carried out after transformation and under various thermal and thermo-mechanical treatments (isothermal conditions and continuous cooling (CC) without and with prior deformation of the parent phase). One great originality of this study is the automated statistical approach used to characterize the microtexture from EBSD data. An algorithm has been specifically developed in order to get the variants orientation as well as different representative data characterizing the microtexture. We have identified the link between the nucleation/growth kinetics of α phase and the microtexture development, a relationship that is often neglected in the literature, where one usually associates the microtexture only to the variant selection and to the initial β texture. The occurrence of variants selection (VS) has been performed considering different VS criteria; it has been shown that VS is very active for the first grains formed. These grains have the most favorable nucleation conditions. The variant selected is the one that minimizes the deviation to the Burgers Orientation Relationship with both β grains; i.e. the one for which interfacial energy and especially the elastic energy associated to its formation are minimized. Moreover, the crystallographic conditions of α colonies formation are studied and discussed
Bachelot, Thomas. "Les essais de phase i en oncologie medicale : analyse retrospective de 154 patients inclus dans 9 etudes realisees au centre leon berard de 1986 a 1993". Lyon 1, 1994. http://www.theses.fr/1994LYO1M210.
Texto completoMgese, Nzima Meshack. "The influence of the implementation of outcomes-based education from grades R-9 on successful teaching and learning in the further education and training phase / N.M. Mgese". Thesis, North-West University, 2005. http://hdl.handle.net/10394/2445.
Texto completoMao, Youxin. "Liquid phase epitaxial growth of InAsâ†0â†.â†9â†1Sbâ†0â†.â†0â†9 and fabrication of 4.2#mu#m light emitting diodes for carbon dioxide detection". Thesis, Lancaster University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296888.
Texto completoŘezáč, Martin. "Podpůrné algoritmy pro řízení elektrických motorů". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221272.
Texto completoPan, Jinhong. "Synthesis of Fmoc-3-(N-ethyl-3-carbazolyl)-L-alanine and its incorporation into a cyclic peptide". Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0814102-133523.
Texto completoKeywords: chromophore -- N-ethyl-3-carbazolylalanine -- 9-anthrylalanine -- chiral amino acids -- cyclic peptide -- solid-phase peptide synthesis -- enzymatic resolution -- cyclization. Includes bibliographical references (p. 92-95).
Eisenbarth, Udo. "Laser cooling of fast stored ion beams to extreme phase-space densities". [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963188208.
Texto completoSun, Xiaoxi. "Effects of mifepristone on the human endometrium and the fallopian tube during the luteal phase /". Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-346-9/.
Texto completoMcKeveney, Declan y n/a. "The Solid-Phase Combinatorial Synthesis of 2,6,9- Trisubstituted Purines as Potential Adenosine A3 Receptor Antagonists". Griffith University. School of Science, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050830.120105.
Texto completoMcKeveney, Declan. "The Solid-Phase Combinatorial Synthesis of 2,6,9- Trisubstituted Purines as Potential Adenosine A3 Receptor Antagonists". Thesis, Griffith University, 2005. http://hdl.handle.net/10072/367926.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Science
Full Text
Smeltzer, Brandon. "The solubility of Triton X-114 And Tergitol 15-S-9 in high pressure carbon dioxide solutions". [Tampa, Fla] : University of South Florida, 2005. http://purl.fcla.edu/usf/dc/et/SFE0001454.
Texto completoEL, HARRAD IMAD CARABATOS CONSTANTIN. "CONTRIBUTION A L'ETUDE STRUCTURALE ET SPECTROSCOPIQUE DE CERAMIQUES PEROVSKITES PLZT : (PB#1##3#X#/#2LA#X@#X#/#2)(ZR#0#,#9#5TI#0#,#0#5)O#3 (X=0,01 A 0,08) ET PZTN: PB#0#,#9#9(ZR#0#,#9#5TI#0#,#0#5)#0#,#9#7NB#0#,#0#2#5O#3 ET DE LEURS TRANSITIONS DE PHASES /". [S.l.] : [s.n.], 1994. ftp://ftp.scd.univ-metz.fr/pub/Theses/1994/El_Harrad.Imad.SMZ9419.pdf.
Texto completoROCHA, Adi Neves. "Conversor estático de 9 chaves acionando máquina hexafásica". Universidade Federal de Campina Grande, 2014. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/442.
Texto completoMade available in DSpace on 2018-04-20T22:15:13Z (GMT). No. of bitstreams: 1 ADI NEVES ROCHA - DISSERTAÇÃO PPGEE 2014..pdf: 4213060 bytes, checksum: 41dbc9ec6203a02fc678bc1c878970dc (MD5) Previous issue date: 2014-08-08
O objetivo do estudo apresentado nessa dissertação é analisar e comparar dois inversores fonte de tensão acionando uma máquina de indução hexafásica. as estruturas analisadas são: o conversor composto de seis braços possuindo dois dispositivos semicondutores por braço (12 chaves) e um conversor composto de três braços e nove dispositivos semicondutores (9 chaves). A estrutura composta por 12 chaves é a configuração padrão para acionamento de cargas hexafásicas . Analisando quanto ao aspecto da quantidade de chaves o conversor de 9 chaves apresenta uma evidente redução do número de componentes. Neste trabalho busca-se uma comparação mais fundamentada a partir da análise destas topologias com relação a outras características, tais como: (i) estrutura ou modo de conexão dos dispositivos com a descrição das limitações de cada estrutura; (ii) diferenças nas técnicas de modulação empregadas; (iii) níveis de corrente e tenção em cada um dos dispositivos que compõem a estrutura; (iv) análise do desempenho segundo a quantidade de perdas por condução e por chaveamento; (v) análise de desempenho quanto aos níveis de dispersão harmônica. Apesar da análise estar voltada para a comparação dos conversores, há uma descrição da máquina hexafásica modelada por decomposição vetorial e a aplicação de uma estratégia de controle no acionamento da máquina, utilzando a técnica de controle por fluxo rotórico.
The goal of the study presented in this thesis is to analyze and compare towo voltage source inverters driving a six-phase induction machine. The types of structures analyzed are: the converter of six legs having two semiconductor devices per leg (12 switches) and an inverter composed of three legs - (nine semiconductor devices 9 switches). The converter of 12 switches is the default configuration for driving six-phase loads. Analyzing the numbers of switches aspects, the 9 switches converter shows a clear reduction in the number of components. This paper seeks a more reasoned comparison from the analysis of these topologies with respect to other characteristics, such as: (i) structure or way of connecting devices to the description of the limitations of each structure; (ii) differences in the modulation techniques employed ; (iii) levels of current voltage in each of the devices of the structure; (iv) analysis of performance depending on the amount of conduction and switching losses; (v) performance analysis of the levels of harmonic distortion. Althought the analysis is focused on the comparison of the converters, there is a description of the six-phase machine modeled by vector decomposition and implementation of a control strategy to drive the machine using the rotor flux control technique.
Köthe, Lars Dietrich [Verfasser], Michael [Akademischer Betreuer] Nauck, Hubertus [Akademischer Betreuer] Jarry y Martin [Akademischer Betreuer] Oppermann. "Über die Bedeutung der Zugabe von humanem Serum-Albumin zu exogenen GLP-1-Infusionen am Beispiel der Antagonisierbarkeit des GLP-1 [7-36-Amid]-Einflusses auf die erste Phase der Insulin-Sekretion nach intravenöser Glukosegabe durch den GLP-1-Rezeptor-Antagonisten Exendin [9-39] bei gesunden Menschen / Lars Dietrich Köthe. Gutachter: Michael Nauck ; Hubertus Jarry ; Martin Oppermann. Betreuer: Michael Nauck". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2011. http://d-nb.info/1042385475/34.
Texto completoPereira, Marcos Aurélio Almeida. "Determinação da atividade antimicrobiana na fase vapor do óleo essencial de Hesperozygis myrtoides (St.Hil. ex Benth.) Epling". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/9/9138/tde-08092016-125335/.
Texto completoAromatic plants rich in essential oils (EO) have been used as sanitizing agents or preservatives since early civilizations. Nowadays, the increase in infectious outbreaks in hospitals and nurseries, as well as the bacterial resistance has also increased the demand for disinfectants. EO\'s are known for their antimicrobial activity, but most reports is in the liquid phase. Due to the EO high volatility, we have developed a methodology for evaluating the antimicrobial activity in the vapor phase. In this sense, we use the Hesperozygis myrtoides (St.Hil. Ex Benth.) Epling (Lamiaceae) EO, a native species occurring in southeastern Brazil. The plant was collected in Campos do Jordão (SP) and the oil had an average yield of 1.99% (m/m) and as major components pulegone (48.8%) and isomenthone (16.2%). Antimicrobial activity was compared in the liquid phase, microdilution method, with the vapor phase, modified inverted plate method. The results indicated that the vapor phase was a more potent than the liquid. Staphylococcus aureus afforded MIC 0.392 mg. L-1 for the vapor phase and 19 mg. L-1 for the liquid phase, while for Candida albicans it was 0.833 mg. L-1 for the vapor and 94.4 mg. L-1 for the liquid. However, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus brasiliensis had in both phases MIC\'s higher than 100 mg. L-1, considered then inactive. The vapor phase antimicrobial activity is more intense because the EO are free to directly bind with the microorganism without the solvent interference. Toxicity was evaluated against human breast tumor cells (MCF-7) and prostate cancer (PC-3) and with normal murine fibroblast cells (BALB/3T3) indicating a DL50 higher 2,014 mg.Kg-1, and it was considered safe. The antimicrobial activity associated with the low toxicity is a strong indication that this EO vapors can be used for environmental decontamination, even in inhabited places.
Panait, Clara. "Évolution métallurgique et résistance en fluage à 600°C et 650°C d'aciers à 9-12% Cr". Phd thesis, École Nationale Supérieure des Mines de Paris, 2010. http://pastel.archives-ouvertes.fr/pastel-00579983.
Texto completoL'intérêt des éprouvettes pré-vieillies est d'étudier l'influence de grosses phases de Laves sur la résistance au fluage. Le temps à rupture des éprouvettes pré-vieillies est quatre fois plus faible que celui des éprouvettes standard pour les mêmes niveaux de contraintes. Ceci n'est toutefois pas confirmé pour les contraintes les plus faibles.
Deux essais de fluage ont été réalisés sur des éprouvettes pré-fatiguées à 550°C pour étudier l'effet de l'état de la matrice sur la résistance au fluage. Un temps à rupture deux fois plus faible a été observé à 600°C sur une éprouvette pré-fatiguée comparée à une éprouvette standard pour le même niveau de contrainte. Cet effet n'a pas été observé à 650°C pour les contraintes faibles.
Des éprouvettes entaillées ont été également utilisées pour étudier l'influence du taux de triaxialité des contraintes sur le développement de l'endommagement par fluage. Pour des temps de fluage comparables, l'endommagement est plus développé dans une éprouvette entaillée que dans une éprouvette lisse.
Un modèle mécanique qui prend en compte l'évolution métallurgique de l'acier a été développé pour estimer la résistance au fluage " à long terme " de l'acier Grade 92 à 600°C et 650°C. Le modèle prend également en compte le taux de triaxialité des contraintes. A ce titre, il peut être utilisé pour estimer la durée de vie des composants en service ou pour analyser les composants avec une géométrie complexe qui serait plus sensible au développement de l'endommagement par fluage, du fait d'une triaxialité des contraintes plus élevée.
Renault, Alexandra-Evelyne. "Propriétés piézoélectriques géantes dans les monocristaux PZN-x%PT (x=4,5 et 9) : relation conditions de polarisation-structures en domaines". Châtenay-Malabry, Ecole centrale de Paris, 2001. http://www.theses.fr/2002ECAP0876.
Texto completoReiserer, Andreas [Verfasser], Gerhard Akademischer Betreuer] Rempe y Rudolf [Akademischer Betreuer] [Gross. "A controlled phase gate between a single atom and an optical photon / Andreas Anton Reiserer. Gutachter: Rudolf Gross ; Gerhard Rempe. Betreuer: Gerhard Rempe". München : Universitätsbibliothek der TU München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:91-diss-20140327-1192216-0-9.
Texto completoSilveira, Gabriela de Oliveira. "Avaliação da exposição de crianças a substâncias psicoativas durante a lactação através da análise toxicológica em leite materno". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-12082016-091919/.
Texto completoMaternal breastfeeding is related with nutritional, immunological, affective, economic, and social benefits. Most licit and illicit substances consumed by the nursing mother might be excreted in breast milk, which may cause potential harmful effects to the breastfed infant at short and long terms. Although the knowledge about the psychoactive substances during lactation is increasing, there is still few information on the levels in which these substances are excreted in breast milk and many questions about the possible effects of these substances in the infant during the nursing period still remain unanswered. Breast milk is an unconventional matrix that can be used to assess infant exposure to drugs, and its main advantage is its easy and non-invasive collection. However, the extraction of substances from breast milk is an analytical challenge because of its high protein and fat content and changing composition during the postpartum period. In this study, miniaturized analytical techniques will be carried out to determine psychoactive substances such as cocaine, cocaethylene, norcocaine, tetrahydrocannabinol, cannabinol, and cannabidiol in milk samples by using gas chromatography-mass spectrometry (GC-MS). Liquid-phase microextraction (LPME) was applied to cocaine analytes and solid-phase microextraction (SPME) was applied to cannabinoids. After the development and validation, the methods were applied in milk samples collected from municipal hospital Dr. Arthur Ribeiro de Saboya (n=109). These techniques have proved to be suitable for analyte extraction and detection. Cocaine excretion in breast milk has been confirmed given that one sample was positive to cocaine in moderate amounts (138 ng/mL), as well as, two samples could be confirmed positive to tetrahydrocannabinol at 20 ng/mL and 31 ng/mL.
Novaes, Letícia Célia de Lencastre. "Extração de bromelina dos resíduos de abacaxi (Ananas comosus) por sistemas de duas fases aquosas e sua aplicação em hidrogel polimérico". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-17012014-133545/.
Texto completoBromelain is a collective name for the proteolytic enzymes found in the stem, fruit and leaves of pineapple (Ananas comosus Merr.). Bromelain possesses anti-inflammatory properties, debridement, among others. For bromelain production one should preferably use the waste materials, whereas pineapple fruit products have commercial application. This study aimed to extract bromelain from pineapple peels using aqueous two-phase system (ATPS), and its application in polymeric hydrogels. Stability studies of commercial bromelain were performed, which found greater stability at pH 5.0 with minor loss of relative activity at all temperatures studied. The study of bromelain extraction in ATPS composed by polyethylene glycol (PEG) and poly acrylic acid (PAA) (with assistance of variance analysis of parameters such as yield, purification factor and partition coefficient) showed yield 335% and purification factor of 25.8. The PEG-based hydrogels studied presented flexibility, low elasticity and swelling ratio higher than 1000%. Hydrogel containing bromelain, loading by embedding (solvent sorption) method, yielded the highest enzyme release, as well as the highest activity (80% bromelain released over 24 h and 278 ± 89 U / mL).
Rangel-Yagui, Carlota de Oliveira. "Sistemas micelares de duas fases aquosas aplicados à purificação de enzimas". Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/9/9134/tde-03072008-135902/.
Texto completoThe partitioning of the hydrophilic enzymes glucose-6-phosphate dehydrogenase (G6PD) and urokinase (UK) in two-phase aqueous micellar systems was investigated, both experimentally and theoretically. Initially, the partitioning of G6PD in two-phase aqueous micellar system composed of the nonionic surfactant C10E4 (n-decyl tetra(ethylene oxide) was studied. It was observed a partitioning behavior governed primarily by repulsive, steric, excluded-volume interactions, which drove the enzyme preferentially to the bottom, micelle-poor phase, resulting in KG6PD values smaller than one. The cationic surfactants CnTAB ((alkyltrimethylammonium bromide, n = 8, 10, and 12) were mixed wíth the nonionic surfactant C10E4 to form two-phase aqueous mixed (nonionic/cationic) micellar systems. The measured G6PD partition coefficients in the C10E4/CnTAB/buffer systems were at least 2.5 times larger than those in the corresponding C10E4/buffer system, clearly demonstrating that the net negatively charged G6PD was attracted electrostatically to the top, mixed micelle-rich phase, containing a greater number of positively-charged C10E4/CnTAB mixed micelles. Overall, the two-phase aqueous mixed (C10E4/C10TAB) micellar system yielded the highest KG6PD = 7.7, with a G6PD yield in the top phase of 71%. The addition of affinity ligands (enzyme inhibitors) to the two-phase C10E4 /buffer systems was studied for UK and G6PD purification. No significant differences in the UK partitioning behavior was observed in the presence or not of the ligand p-aminobenzamidine, since the ligand was found to partition evenly between the two phases of the system. Partition coefficient values of about 0.70 were obtained in both cases. For the G6PD, the partition coefficient was found to be slightly higher in the presence of either cibacron blue or procion red as affinity ligand, however still smaller than one. Therefore, the use of competitive inhibitors free in solution as affinity ligands for UK and G6PD purification in two-phase C10E4 /buffer systems did not provide significant differences in the enzymes partitioning behaviors. Finally, a two-step purification process, combining a two-phase aqueous nonionic (C10E4) micelar system, followed by a two-phase aqueous mixed (C10E4/C10TAB) micellar system, was employed for the purification of G6PD present in a Saccharomyces cerevisiae cell homogenate. It was obtained a G6PD final yield of 59%, and a purification factor of 1,3.
Polakiewicz, Bronislaw. "Aplicação da catálise de trasnferência de fase na avaliação de rotas alternativas para obtenção industrial da dicicloverina caramifeno e amiodarona". Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-24102007-144408/.
Texto completoThe phase transfer catalysis application replacing one or more steps in the drug synthesis, can be of advantage in the technologycal approach. Applied to the synthesis of important drugs such as diciclomine, caramiphen,and amiodarone, the phase transfer catalysis resulted in a very advantageous method in the first two drugs. The diciclomine and the caramiphen, gets their obtention routes from raw materiaIs wi th good resul ts and low coasts, when compared wi th the drugs presently purchassed in foreign countries. It is clear that the phase transfer catalysis, can be applied succesfully in the manufacturing of these and other drugs, in conjuction with known techniques with good results.
Flores, Roxana Lili Roque. "Caracterização do estado sólido de ganciclovir". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-16112017-173605/.
Texto completoThis presented work aims to study the solid state of ganciclovir (GCV) and its different polymorphic forms. GCV is an antiviral drug useful in the treatment of cytomegalovirus (CMV) infections. Although it is a widely-used drug, few studies have been conducted on its solid state. Currently, GCV is known to have four crystalline forms, two anhydrous (Form I and II) and two hydrates (III and IV). In this investigation, we report a successful preparation of GCV Form I and its crystallographic structure, which was found during the crystallization of the drug, in which nine crystallization tests (GCV-1, GCV-A, GCV-B, GCV- D, GCV-E, GCV-F, GCV-G and GCV-H) were performed and the resulting materials were characterized by X-ray diffractometry (XRD), thermal analysis (DTA/TG) and Hot Stage Microscopy. Of all the crystallizations performed, four solid forms were obtained, denoted as Form I (GCV-1, GCV-B and GCV- H), Form III (GCV-C, GCV-D, GCV-F and GCV-G), Form IV (GCV-A) and Form V (GCV-E). The latter is being described for the first time in the literature and indicates the presence of another hydrated form of GCV. Forms I, III and IV corresponded to the anhydrous form and the two hydrated forms of the drug, respectively. In addition, it was evident by both the slurry conversion and the thermal analysis methods that the GCV-1 crystallized (Form I) was indeed the most stable amongst the materials obtained. This gave rise to GCV Form I monocrystal, anhydrous crystalline structure of the drug. The compound was characterized by monocrystal X-ray crystallography. The structural analysis showed that Form I of the drug crystallized in the monoclinic system space group P21/c is composed of four molecules of GCV in its asymmetric unit. Each molecule is linked intermolecularly by hydrogen bonds, which give rise to the formation of infinite chains arranged in a way that form a three-dimensional structure.
Paula, Daniela Mendes Louzada de. "Análise toxicológica de antidepressivos em sangue total por cromatografia em fase gasosa com detector de nitrogênio e fósforo". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-10042007-150259/.
Texto completoA gas chromatographic method was developed to determine antidepressants most prescribed in Brazil and their metabolites (amitriptyline, imipramine, clomipramine, desmethylclomipramine, desipramine, nortriptyline, fluoxetine, norfluoxetine, and sertralina) in whole blood, using solid phase extraction and gas chromatography with nitrogen-phosphorus detection. The solid-phase extraction (SPE) with abselutTM NEXUS was applied in an innovative manner. The extraction procedure consists of the dilution of 0.5mL of whole blood in buffer (pH 9.5), application of the sample in the cartridge, washing with buffer (pH 9.5) and elution of the analytes with dichloromethane/isopropanol (17/3, v/v). The limit of detection (LOD) and quantification (LLOQ) were from 0.1mg/L to 0.4mg/L and from 0.4mg/L to 1.6mg/L, respectively. Etidocaine was used as internal standard. The method was precise, specific and linear in the studied concentration (range from LLOQ to 12mg/L). The average recovery of all analytes was 65,5%. Forensic and clinical emergency samples were submitted to the validated method.
Molino, João Vitor Dutra. "Extração de adenovírus em sistemas micelares de duas fases aquosas". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-08032013-170422/.
Texto completoBiotechnological processes depend significantly on separation and purification techniques used to maintain cost-effective industrial-scale production of biotechnological products for commercial, industrial and therapeutic uses. The application of the aqueous two-phase micelar system (ATPMS) is proposed as an alternative for purification, since it allows the separation and analysis of biomolecules /bioparticles, often without loses of activity or their properties. This allows to perform a selective partition that enables high yields. This work aims to study the use of this methodology in the extraction and purification of adenovirus in micelle aqueous two-phase formed by TritonX-114/Viral suspension. All assays were performed in 5 g systems following a full factorial design (23) with four central points. The studied factors were extraction temperature, pH of the viral suspension and concentration of the surfactant. Systems containing masses of 3g, 10g and 40g were evaluated. Extraction procedure effects over integrity and infectivity of adenovirus were also evaluated. Some of the parameters evaluated in the viral recovery process were viral potency (RPv) and recovery of viral specific potency (RPvø). These two parameters measure the inactivation of Adenovirus by the extraction process and both showed improvement when compared with the viral suspension for some of the systems studied (i.e RPv: 341% and RPvø 1466%). These results show that ATPMS selectively partition the infectious viral particles. According to the results of the experimental design is possible to increase, even further, these results controlling the surfactant concentration, viral suspension pH and temperature of extraction.
Lima, Camila Bento de. "Efeitos da administração aguda e prolongada de diazepam sobre parâmetros imunológicos de ratos". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-22042009-170435/.
Texto completoBenzodiazepines (BZD) are widely used for the treatment of anxiety. They enhance GABA-ergic neurotransmission through binding on specific BDZ recognition sites, within the GABAA receptor-ion channel complex, where they allosterically modulate its activity. However, recents studies showed that BZD also act on peripheral benzodiazepine receptor sites (PBR). Evidence for a direct immunomodulatory action for BZD emerged from studies that demonstrated the presence of PBR on immune/inflammatory cells. The present experiment was designed to analyze the effects of diazepam on rat immune parameters and to develop a method to detect diazepam on rat plasma through a liquid-phase microextraction technique (LPME). The effects of both acute and long-term (21 days) diazepam (1 and 10 mg/kg/day) administrations were evaluated. Results showed that diazepam (1 mg/kg) treatment did not change the immune parameters analyzed; however, long-term diazepam treatment decreased erytrocytes, hemoglobin and hematocrit values. Both diazepam (10mg/kg) acute and long-term treatments decreased the number of apoptotic cells and, consequently, enhanced the percentage of viable cells; they also increased the percentage of Thelper and Tcitotoxic cells; decreased the percentage of B cells and increased the corticosterone serum levels. Long-term diazepam (10 mg/kg) treatment enhanced reticulocytes and segmented cells in the peripheric blood; however, only acute diazepam (10mg/kg) treatment increased the number of segmented cells on spleen. The low dose of diazepam used (1 mg/kg) was unable to induce tolerance, differently of that found after the high dose of diazepam (10 mg/kg). This latter treatment indicated the development of functional tolerance, at least for diazepam effects on corticosterone serum levels. These results suggested that low doses of diazepam (< 1 mg/kg) were not able to change the immune parameters analyzed; however, high doses of diazepam (> 10 mg/kg) changed many of these immune parameters. It is possible that the observed effects were related to the number of PBR receptor sites present on immune cells and/or to the levels of serum diazepam after the treatments used. The analytical method provided to be linear in the interest range (dynamic range from 25 to 2000 ng/mL) for diazepam and its main metabolite, desmethyldiazepam. The limits of detection and quantification were 20 and 25 ng/mL, respectively, and the parameters analyzed provided to be satisfactory. Finally, the method developed utilizing the liquid-phase microextraction technique showed to be practical, with low costs and thus presenting potential to be used previously to the extraction procedures, i.e., prior to the injection into the gas-chromatography apparatus.
Plamarit, Komnino. "Optochimie de phases solides sol-gel. Chimiluminescence du 10-méthylacridinium-9-carboxylate de phényle. Spectroscopie de transmission appliquée à l'étude des propriétés de films minces". Doctoral thesis, Universite Libre de Bruxelles, 2000. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211789.
Texto completoSingh, Anil Kumar. "Separação enantiomérica de fármacos em medicamentos por cromatografia líquida com fase estacionária quiral". Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-01072008-162603/.
Texto completoThe majority of the therapeutic agents, frequently prescribed, are formulated and commercialized as racemic mixture, even so for some of them, it has been demonstrated that the pharmacological and/or toxic effect are confined only to one of the enantiomer. Besides, it is well known that the enantiomers can present different pharmacokinetic and pharmacodynamic profiles. In the present work we selected drugs belonging to two classes of clínical importance. These pharmaceuticals are widely prescribed in clinical practice such as, the beta-blockers (atenolol, metoprolol, pindoloI, betaxolol and nadolol) and the non-steroid anti-inflammatorydrugs (ibuprofen and flurbiprofen). Several references could be found in scientific literature that describes the use of high performance liquid chromatography with chiral stationary phase (HPLC-CSP) in pharmacological studies, seldom in the quantitative determination of enantiomers in pharmaceutical formulations. It is well known that the HPLC-CSP methods offer distinct advantages over classical techniques of isomeric separation and analysis, especially for the enantiomeric separation. The direct enantiomeric separation of atenolol metoprolol nadolol and betaxolol were obtained using CSP Chiralcel OD®.The enantiomers of pindolol were separate utilizing CSP α-Burke 2® and those of ibuprofen and the flurbiprofen with CSP Whelk-O 1®. In this work are presented efficient and sensitive methods for stereospecific determination of atenolol (AT), metoprolol (MT) and flurbiprofen (FLU) in pharmaceutical formulations. The stereoselective determination of atenolol and metoprolol in pharmaceuticals was performed through validated chromatographic method. The validation of liquid chromatographic methods was done utilizing a cellulose tris- 3,5-dimethylphenyl carbamate, Chiralcel OD®, (250x4.6 mm, 10µm)as CSP. The samples were analyzed at room temperature with injection volume of 20µL and UV detection was made at 276nm. In case of atenolol, the mobile phase was constituted of hexane:ethanol:diethylamine:acetic acid (60:40:0.2:0.2 v/v), with a flow rate of 1.0 mL/min. Separate standard curve for R-AT and S-AT showed good linearity over a concentration range from 50-130 µg/mL, with coefficient of correlation of 0.9991 and 0.998, respectively. The coefficient of variation and average recovery for R-AT in the samples A, B, C, and D were 1.15% and 101.06%; 0.74% and 99.25%; 1.05% and 102.57%; 0.84% and 101.57% respectively. The coefficient of variation and average recovery for S-AT in samples A, B, C and D were 1.33% and 98.87%; 0.99% and 100.76%; 1.17% and 101.69%; 1.26% and 100.39%, respectively. In case of metoprolol, the mobile phase was constituted of hexane:ethanol:diethylamine:acetic acid (40:60:0.2:0.2 v/v), with a flow rate of 0.8 m L/min. Separate standard curve for R-MT and S-MT showed good linearity over a concentration range fIom 30-110 µg/mL, with coefficient of correlation of 0.9988 and 0.9990, respectively. The coefficient of variation and average recovery for R-MT in sample analyzed was 0.86% and 98.62% and for S-MT was 1.40% and 99.39%, respectively. A high performance liquid chromatographic method is developed and validated for enantiomeric separation and quantitative determination of FLU in pharmaceutical preparation. A WheIk-O 1® column (250x4.6 mm, 5µm)was used as chiral stationary phase (CSP). The mobile phase was constituted of hexane:ethanol:acetic acid (95:05:0.2 v/v/v), at a flow rate of 0.9 rnL/min and UV detection at 246nm. All experiments were done at ambient temperature. The S-FLU standard curve showed linearity over a concentration range from 2-18µg/mL, (R2 = 0.9993). The coefficient of variation and average recovery of R-FLU were 0.16% and 100.13% and for S-FLU were 0.14% and 100.4%; respectively. The proposed methods permits quantitative separation of AT, MT and FLU enantiomers in pharmaceutical formulations studied with precision and accuracy. The proposed validated methods can be used in the enantiomeric quality controI of referred pharmaceutical drugs.
Prestes, Paula Souza. "Tomografia por coerência óptica (OCT), reologia, análise térmica e tamanho de partículas aplicados na caracterização de sistemas emulsionados de orientação de uso cosmético". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-08032013-163451/.
Texto completoThe physical, physicochemical and chemical attributes of the emulsified systems are influenced by the characteristics of their internal phase droplets, such as: concentration, size and morphology. Thus, the aims involved the physical and physicochemical characterization of emulsions obtained from the stearyl alcohol condensed with 21 mols ethylene oxide (EO) (steareth-21) and oleyl alcohol with 20 mols EO (oleth-20), as well as, the introduction of the optical coherence tomography (OCT) as the analytical technique tool to the determination of the particle size and morphological characterization of the emulsified systems. Three formulations were prepared, differing at the surfactant used, being the emulsified system SE-1 composed by 8.0% (p/p) of oleth-20, the SE-2 by 4.0% (p/p) of oleth-20 and 4.0% (p/p) steareth-21; and the SE-3 by 8.0% (p/p) steareth-21. The preliminary stability was evaluated, such as the ph value and the rheological and thermogravimetric profiles. The presence of the crystalline gel phase was determined from microscopy with polarized light and the droplet size through regular optical microscopy, laser diffraction and OCT. The samples did not present signs of instability throughout the centrifugation and thermal stress tests. The ph value was considered compatible to human skin (4.6 to 5.8). Systems represent the non-Newtonian pseudoplastic rheological behaviour. The SE-1 presented inferior apparent viscosity (223.53 mPa.s) and the hysteresis area (2238.38 Pa/s) statistically equal to SE-2 (2911.19 Pa/s); the SE-2 presented an average value of apparent viscosity (332.20 mPa.s) and, the SE-3, superior values to both parameters (636.40 mPa.s and 4248.97 Pa/s). The oscillating tests verified the elastic character predomination to the three systems. Throughout the thermogravimetry, the profile of the three samples was similar, independent from the kind and concentration of the non-ionic surfactant. The presence of the crystalline gel phase was identified at the three systems, being apparently more pronounced to the SE-2. Either at the microscopic analysis as well as at the laser diffraction were obtained an average size of the particles minor than 6.0 µm. According to OCT results, the particles below 6.0 µm were not possible to be identified and the major particles were suggested be the internal phase of the systems, however new studies should be performed.
Silva, Marcela de Siqueira Cardoso. "Estudo da partição do ácido clavulânico empregando sistemas micelares de duas fases aquosas com adição de sal ou polímero". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/9/9138/tde-16052013-093913/.
Texto completoClavulanic acid (CA) corresponds to a potent β-lactamase inhibitor that is used in association with β-lactamic antibiotics. The industrial purification of CA usually involves liquid-liquid extraction processes employing organic solvents followed by several chromatographic steps. Therefore, new purification alternatives such as aqueous two-phase micellar systems (ATPS) are of great interest. These systems can provide selectivity in biomolecule partitioning according to hydrophobicity and other molecular properties. Within this context, the main goal of this study was to investigate CA partitioning in aqueous two-phase micellar (nonionic) systems, with and without the addition of (NH4)2SO4 or dextrane sulfate (Dx-S). Stability studies performed with CA indicated that the drug is more stable at pH 6.5 and lower temperatures (5 - 20 ºC). In addition, it was demonstrated that Dx-S addition led to a lower loss of CA stability in comparisson to (NH4)2SO4, with residual values ≥ 90% at 35 °C. The drug was found to be very stable in the presence of the surfactants Triton X-114 and Triton X-100, with residual values around 100%. Regarding CA partitioning in the ATPMS, the drug partitioned preferentially to the micelle-poor phase, irrespective of the surfactante employed and of the presence of (NH4)2SO4,with partition coefficient (KAC) ~ 0.7 and yield in the poor phase (Yclavd) ~ 75%. Nonetheless, the addition of Dx-S in concentrations (≥ 8.0% p/p) resulted in a discrete increase in KAC, with values around 1 - 1.5. Therefore, the results obtained in this work demostrated that the addition of (NH4)2SO4 or Dx-S to ATPMS did not significantly influenced CA partitioning to the micelle-rich phase and, in this context, the systems investigated could be considered more eficiente for CA recovery in the micelle-poor phase, as a previous extraction step of a biotechnological process.
Porto, Tatiana Souza. ""Extração da pró-toxina épsilon e de uma protease a partir de ´Clostridium perfringens´ em sistemas de duas fases aquosas utilizando PEG/citrato"". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-26102004-092107/.
Texto completoThe purpose of this work is to obtain best conditions of recovery and purification of proteins (epsilon prototoxin and a protease) produced by Clostridium perfringens through the use of the liquid-liquid extraction by aqueous two-phases systems (ATPS). The application of these systems is proposed as alternative for protein purification, because it allows the separation and analysis of biological particles. This technique is advisable process purification applied to large scale since it provides a selective partition with high yields, and good cost-benefit ratio. The binodal curves were constructed and used to determine the system composition based on polyethylene glicol and citrate concentrations. The binodal curves were built by using PEG 400, 550, 1000, 1500, 3350 and 8000 g/mol at different pH values (6.0; 6.5; 7.0; 7.5 and 8.0). The curves were, initially, built in the presence of water and, later, with clarified fermented broth. The differences in the curve profiles (water versus broth) helped to explain the phase separation behaviour. The stability, as a function of pH and temperature, of the epsilon prototoxin was evaluated before the extraction, while the stability of the protease was evaluated before and after the extraction. An experimental design ('2pot.8-3') was used to evaluate the influence of the following variables on epsilon prototoxin extraction: concentration and molar mass of PEG, citrate concentration and NaCl concentrations, pH, dilution factor of the extract, temperature and total mass of the system. However, the partition of the protease was studied through the use of the three full different experimental designs (two of the type '2pot.4', and one of the type '2pot.3') that evaluated the influence of the following variables: concentration and molar mass of PEG, citrate concentration and pH. Three parameter responses were obtained: purification factor; coefficient partition; and recovery yield of the enzyme. The results were satisfactory: partition coefficient = 0.57, purification factor = 4.2; yield = 131%. The extraction conditions which provided the best results were: molar mass of PEG 10000 (g/mol); concentration of PEG of 22% (w/w); concentration of citrate of 8% (w/w); and pH 8.5. The protease was stable (during 48h), even after the extraction, in the temperatures of 5°C and 25°C, and at pH values of from 6.0 to 9.0.
Buzby, Scott Edward. "The effect of doping titanium dioxide nanoparticles on phase transformation, photocatalytic activity and anti-bacterial properties". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 120 p, 2008. http://proquest.umi.com/pqdweb?did=1459918071&sid=9&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Texto completoKrenkel, Martin [Verfasser], Tim [Akademischer Betreuer] Salditt y Detlev [Akademischer Betreuer] Schild. "Cone-beam x-ray phase-contrast tomography for the observation of single cells in whole organs / Martin Krenkel. Betreuer: Tim Salditt. Gutachter: Tim Salditt ; Detlev Schild". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://nbn-resolving.de/urn:nbn:de:gbv:7-11858/00-1735-0000-0023-9684-C-9.
Texto completoBairros, André Valle de. "Desenvolvimento de métodos analíticos para a identificação de drogas facilitadoras de crime em amostras de urina". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-15012015-142703/.
Texto completoDrug-facilitated crime (DFC) are a series of chemicals that allow the sexual act and/or theft with little or no resistance from the victim. Benzodiazepines, gamma-hydroxybutyrate (GHB) and ketamine and ethanol are considered classic DFC, however other substances were also used as the DFC. Due to the different classes of DFC and the need for sensitive methods, the determination of these substances is a challenge to forensic toxicologists. The purpose of this study was to develop analytical methods for determination of the main target analytes of DFC for benzodiazepines, ketamine and GHB in urine samples. This biological matrix is considered a non-invasive sample and shows a larger window of detection than blood. Sample preparation was assessed using liquid phase microextraction (LPME) and liquid-liquid extraction (LLE). The LPME is a drug extraction technique that uses less organic solvents, greater practicality and possibility of obtaining high recovery values. The analytes were determined by gas chromatography - mass spectrometry (GC-MS). The validated LPME technique for benzodiazepines and their metabolites required a combination of solvents and double derivatization to achieve the required sensitivity, while the ketamine, norketamine and dehydronorketamine method used essential oil of eucalyptus as solvent, characterizing a green chemistry approach with high sensitivity. The extraction of GHB was effective by LLE with a reduced amount of solvent and the analysis time without loss in sensitivity. In general, the methods developed in this work using GC-MS are sensitive and reliable for all analytes reported and LPME technique showed to be an efficient sample preparation, versatile and low cost. These conditions allow LPME implementation in any laboratory of toxicological analysis and it can be applied in situations of DFC or any other kind of analysis.
Marques, Daniela de Araujo Viana. "Produção e extração de ácido clavulânico de Streptomyces spp. por fermentação extrativa utilizando sistemas de duas fases aquosas". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-22032010-111244/.
Texto completoClavulanic acid (CA) is a potent inhibitor of β-lactamases used in the medical field. Alternative methods, economic and simple purification are of great interest. This PhD project aims to produce and extract clavulanic acid of Streptomyces spp. By extractive fermentation using aqueous two-phase system (ATPS) - Polyethylene glycol (PEG)/phosphate salts. The best producer of clavulanic acid among seven strains of Streptomyces spp was selected. The influence of five factors in the cultivation of the best producer in flasks (pH, temperature, agitation velocity, concentrations of nitrogen and carbon sources) using statistical experimental design was evaluated. Defined the best cultivation conditions, the production and extraction of clavulanic acid by extractive fermentation using ATPS in flasks and in a batch system using a bioreactor was analyzed. In batch system using a bioreactor were also carried out the thermodynamic study of the fermentation process in optimum conditions determined in previous steps and also determined the volumetric mass transfer coefficient (kLa) comparing the fermentation systems in simple culture medium (SF) and in a extractive fermentation using aqueous two-phase system (ATPS) PEG/phosphate salts (SEF) medium with and without microbial growth. A strain of Streptomyces spp. selected as the best producer of AC was DAUFPE 3060, which showed the highest production of this inhibitor, 494 mg/L at 48h, in flasks under the conditions of pH 6.0, 32 °C, 150 rpm, 5 g/L of glycerol and 20 g/L of soybean flour. After the optimization step, the most significant variables in the study selection, temperature and concentration of soybean flour, were studied. The optimal values were 32 °C and 40 g/L of temperature and soybean flour concentration, respectively, with production of 629 mg/L of CA after 48h of cultivation. The thermodynamic study confirmed that 32 °C is the maximum temperature production of CA, after this value, starts gradually, the degradation of CA. In the study of volumetric mass transfer coefficient, kLa, without microbial growth, showed higher values of kLa for the SF, because the high viscosity of the PEG used in the SFE. The PEG molar mas and agitation velocity were the variables that most influenced the extraction of CA in flasks using a SFE, with similar behavior in a bioreactor. Finally, the study of oxygen transfer rate in SFE using ATPS with microbial growth was evaluated to optimize the production and extraction of CA. The results showed that there is an ideal range of agitation and aeration to prevent cell disruption and increase the CA recovery.
Oliveira, Carolina Dizioli Rodrigues de. "Determinação de canabinóides em cabelo por microextração em fase sólida por Headspace e análise por espectrometria de massa associada à cromatografia em fase gasosa". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-21082007-160740/.
Texto completoA method was to develop to detect cannabinoids (cannabidiol, cannabinol and delta-9-tetrahydrocannabinol) in hair. A 10 mg of hair sample was descontaminated by dichloromethane followed by alkalin digestion, headspace solid-phase microextraction technique (HS-SPME) and analyzed by gas chromatography-mass spectrometry (CG/MS). The detection and quantitation limits were 0,07 and 0,12ng/mg respectively for all studied cannabinoids. The method proved to be simple, fast, precise and linear at the range of 0,12 to 12ng/mg (r2 > 0,98). Eight hair samples of Cannabis user were collected from patients at admittance from a dependence clinic by clinical staff. The method showed efficient in samples of users who use the drug at least 10 fold a week.
Santos, Valéria de Carvalho. "Extração líquido-líquido de ácido clavulânico empregando sistemas micelares mistos de duas fases aquosas". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/9/9134/tde-30032009-181850/.
Texto completoClavulanic acid is a potent inhibitor of β-lactamases that is used as a therapeutic in conjunction with amoxicillin. Its industrial process of production involves bacterial growing in a batch process, while its purification is carried out mainly by process of liquid-liquid extraction with organic solvents and chromatographic steps. Thus, alternative methods like the purification employing two-phase aqueous micellar systems, which offer both hydrophobic and hydrophilic environments to solute species and allow selectivity in partitioning depending on the hydrophobicity of biomolecules, are of great concern. This work studied the feasibility of using two-phase aqueous mixed (nonionic/anionic) micellar systems formed by nonionic surfactant Triton X-114 and anionic surfactant AOT to extract clavulanic acid from broths fermented by Streptomyces clavuligerus in batch process. The stability of clavulanic acid at different values of pH, salts and their concentration, temperature and in the presence of different surfactants was investigated so as to limit the areas to be submitted to further studies. The cloud-point of the systems Triton X-114/Buffer and Triton X-114/AOT/Buffer was also determined under different conditions, and studies were performed on partitioning the biomolecule between the phases and the time needed to balance of the system. From these initial investigations the following levels of the variables were defined: concentration of AOT (0.50, 0.75, and 1.00 mM), Triton X-114 (1, 3 and 5% w/w), NaCl (0, 0.05 and 0.10 M) and temperature (24, 26 and 28°C), whose influences on the partition coefficient (KCA) and yield in the top phase (nCA) were investigated using factorial design. Statistical analysis and the mathematical model derived from the results allowed obtaining KCA≈ 1.65 e nCA≈ 71.58%. However, the statistical analysis using the response nCA indicated experimental conditions devoid of any physico-chemical meaning. In serial experiments performed with Triton X-114 3% w/w, Mcllvaine buffer at 6.5 pH and gradual addition of AOT, an increase in the concentration of anionic surfactant led to higher KCA and mass balance (BMCA≈ 85%). Thus, is possible conclude that the two-phase aqueous mixed micellar system provides low loss and partition to dilute phase, which is an advantage because it implies less problems in a subsequent step of purification.
Marin, Ana Verónica Flores. "\"Verificação da janela de detcção do etilglicuronídeo urinário entre usuários crônicos e bebedores sociais de etanol por cromatografia em fase gasosa acoplada à espectrometria de massas\"". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-01092006-100951/.
Texto completoThe detection range of the ethylglicuronide (EtG) seems to vary in accordance to the intensity of ethanol consumption. Thus, the objective of the present work was to develop and validate a method using extraction in solid phase and GCMS for the determination of urinary EtG, in order to verify its detection window in a group of social drinkers and chronic ethanol users. The limits of detection and quantification were 0,2 and 0.1 mg/L, respectively. The method showed to be linear in the interval of 0,2 to 100,0 mg/L (r2>0,99), and presented good accuracy and precision. The urinary EtG detection range in samples of five volunteers after controlled ingestion of 0,5 g/kg of ethanol varied between 24 to 35 hours. Urine samples were also collected from 14 patients from a recovery clinic. The results showed that the majority of them probably consumed ethanol, which compromised the interpretation of the results. In the cases where the urinary concentration of EtG decayed with time, the detection window varied from 72 to 120 hours. The method showed to be useful to monitor the ethanol abstinence during treatment of alcoholic patients or the consumption of only one ethanol low dose.
Santos, Marcelo Filonzi dos. "Redistribuição postmortem de antidepressivos e seus produtos de biotransformação em tecidos biológicos humanos". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-09022015-092617/.
Texto completoAntidepressants belong to an important class of drugs investigated in forensic toxicology. In cases of samples from corpses, the interval between death and obtaining the biological specimens can provide the postmortem redistribution of these drugs. Aiming to elucidate this phenomenon, analytical methods were developed and applied using whole blood (WB), vitreous humor (VH) and liver. For samples of WB and HV, the extraction method chosen and validated was the three-phase liquid phase microextraction (LPME). Hollow fibers consist of polypropylene, with a length of 8 cm each were treated with dodecane organic solvent (organic phase) resulting in a membrane with selective permeability. Into the lumen of these fibers was added formic acid 0.1 mol/ L (acceptor phase). In the vial containing 3.5 mL of NaOH 0.1 mol / L (donor phase) was spiked 0.5 ml of biological fluids (WB or VH). Subsequently, the samples were injected in GC-MS without derivatization reactions. The study of the ST included antidepressants amitriptyline (AMI), nortriptyline (NTR), imipramine (IMI), desipramine (DES), clomipramine (CLO), desmethylclomipramine (DMC), fluoxetine (FLU) and norfluoxetine (NFL). The quantification limits for these substances were below the therapeutic levels (20 ng / ml). The mean coefficients of variation and separate intradays were respectively 9.7 and 9.8%. The calibration curves showed linearity between concentrations of 20 to 1200 ng / mL. The validation of the integrity of the dilution parameter assured measurement higher than the limit shown in the calibration curve quantities. The method was applied to seven real postmortem samples and in one case a significant difference (300%) between the measured values in the peripheral and central ST was observed. The tricyclic antidepressants AMI, NTR, IMI and DES were evaluated in VH and the matrix effect was detected in the last two analytes. The method was optimized and validated using saline spiked AMI and NTR. The limit of detection (5 ng/ml) was obtained by reducing the voltage of the ion source of the mass spectrometer 50 eV. Coefficients of variation were below 15%. The procedures were validated in six real samples of HV. The relationship found between the values obtained in the peripheral ST and HV was approximately 0.1. Accelerated solvent extraction (ASE) and subsequently the solid phase extraction (SPE) were the techniques of separation of analytes liver matrix. At the end of the cited extractions, antidepressants were analyzed in GC-MS. To this solid tissue, further studies are needed, because the values found in the analytical tests were not in accordance with the guidelines used in the validation of the methods.
Porto, Tatiana Souza. "Extração da ascorbato oxidase de Cucurbita maxima por processo descontínuo e contínuo em coluna de discos rotativos perfurados utilizando sistemas de duas fases aquosas". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-25062008-102745/.
Texto completoThe partition and purification of ascorbate oxidase from pumpkin (Cucurbita maxima) by liquid-liquid extraction in aqueous two-phase system (ATPS) by discontinuous and continuous process, using perforated rotating disc contactor (PRDC) was studied. Experimental designs were used to choose the significant variables for discontinuous process, and polyethylene glycol (PEG) molar mass and concentration, citrate concentration, pH, NaCl concentration, dilution factor and total mass of the system, were the variables studied. The better results (partition coefficient 1.72, recovery 90.8% and purification factor 3.12) were obtained with following conditions: PEG molar mass of 20000 g/mol, pH 6.0, PEG concentration of 25% (w/w) and citrate concentration of 10% (w/w). In the pH 6.0 and temperature of 35?C the ascorbate oxidase showed their high activity values and the enzyme was stable in the pH range of 5.0 to 9.0 during 36 hours and temperatures up to 40?C for 1 hour. Experiments were also conducted to estimate the main kinetic and thermodynamic properties of ascorbate oxidase activity and stability, and this study revealed the interesting stability of this enzyme. The PRDC showed a good performance for extracting in continuous mode using aqueous two-phase systems. The best operating condition was selected in this study for the extraction of ascorbate oxidase in the PRDC, and it was obtained with PEG molar mass of 20000 g/mol, PEG concentration of 20% (w/w) and citrate concentration of 10% (w/w), the disc rotational speed of 80 rpm and dispersed phase flowrate of 2 mL/min. The results in mean values were: partition coefficient 3.36, recovery 152%, purification factor 2.31, mass transfer coefficient 0.045, separation efficiency 43.7% and Hold up 0.33. The experimental data showed the potential application of aqueous two-phase systems PEG/citrate to purification ascorbate oxidase using perforated rotating disc contactor.
Presutti, Thais Rodrigues. "Aplicação da cromatografia a gás associada à espectrometria de massas em tandem no diagnóstico da deficiência de 3β-hidroxidesidrogenase". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-10052017-152745/.
Texto completoPregnenolone (PREG) and 17α-hydroxypregnenolone (17OHPREG) are two steroid precursors produced by the adrenal gland. The quantification of these compounds is essential for the evaluation of 3-β-hidroxidesidrogenase enzyme activity, which promotes the conversion of PREG in 17OHPREG. The 3-β:-hidroxidesidrogenase deficiency is a rare but severe type of adrenal hyperplasia that causes serious defects in steroid synthesis. Chromatographic methods coupled to mass spectrometry overcame immunoassays limitations such as reduced specificity, and have been widely used for steroids quantification. Recent years have been marked by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) hegemony due to the speed and possibility to analyze directly several analytes. However, in the case of type 3-hydroxy-5-ene steroids, which have low affinity for protons and, therefore, low ionization efficiency, many steps are required for conversion to detectable products. Notwithstanding, gas chromatography coupled to mass spectrometry (GC-MS) has some favorable features for steroid analysis such as unbeatable chromatographic efficiency. In addition, the incorporation of tandem mass spectrometry (GC-MS/MS) makes it as selective as LC-MS/MS. In this study, a new method for simultaneous extraction and derivatization of PREG and 17OHPREG from serum was developed. This procedure makes sample preparation for GC-MS/MS as simples as those described for LC-MS/MS. The detection method based on negative mode chemical ionization achieved the sensitivity required for the diagnosis of 3-β-hidroxidesidrogenase defficiency using only 250 µL of sample.