Spelling suggestions: "subject:"micellar"" "subject:"bicellar""
21 |
Efeitos das suplementações de caseína e da sua associação com as proteínas do soro do leite sobre a via de sinalização da mTOR em músculos esqueléticos de ratos /January 2019 (has links)
Resumo: Objetivo: O objetivo do estudo foi comparar os efeitos de uma dose-única de caseína micelar (MCa) com a ingestão de caseína micelar associada à proteína do soro do leite (whey protein) (1:1) sobre a resposta aminoacidêmica e a via de sinalização do alvo da rapamicina (mTOR) em músculos esqueléticos de ratos durante a fase de inatividade (período de luz ambiente). Métodos: Após 10h de jejum durante a fase ativa, os ratos foram alimentados com MCa ou PB (5,6g proteína por kg de massa corporal) por gavagem e a água foi usada como veículo (grupo controle, PLA). Em 30 e 450 min após a suplementação das proteínas, os animais foram sacrificados e as amostras de sangue e do músculo gastrocnêmio foram coletadas para análises bioquímicas. Resultados: Os níveis plasmáticos dos aminoácidos de cadeia ramificada (BCAA) aumentaram após as suplementações de MCa (3 vezes) e PB (3,2 vezes). Ainda mais relevante, os níveis estimulatórios da fosforilação da mTOR e do seu alvo downstream p70S6K foram maiores 30 min após MCa (2,6 e 2,9 vezes, respectivamente) e PB (2,8 e 3,8 vezes, respectivamente) quando comparado com PLA. As concentrações plasmáticas de leucina forma correlacionadas com a ativação da mTOR (r = 0,60; p < 0,05) e p70S6K (r = 0,77; p < 0,05) em 30 min. Não existiu diferença para as concentrações plasmáticas de BCAA e a via de sinalização da mTOR em 450 min. Conclusão: Nós concluímos que a suplementação de MCa e PB resultaram em um efeito anabólico semelhante no músculo esquelético ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objective: The aim of the study was to compare the effects of single-dose supplementation of a protein blend (PB) composed of micellar casein and whey protein (1:1) with isolated micellar casein (MCa) on aminoacidemic response and the mammalian target of the rapamycin (mTOR) signaling pathway 30 and 450 min after the beginning of the inactive phase in Wistar rats. Methods: After 10h of fasting during the active phase, rats were fed with MCa or PB (5.6g protein per kg of body mass) by gavage and water was used as the vehicle (PLA, placebo group). At 30 and 450 min after protein supplementation, the animals were euthanized and blood and gastrocnemius muscle samples were collected for biochemical and immunoblot analysis. Results: Plasma BCAA levels increased after MCa (3-fold) and PB (3.2-fold) supplementations. More importantly, the stimulatory phosphorylation levels of mTOR and its downstream target ribosomal protein S6 kinase (p70S6K) were higher 30 min after MCa (2.6 and 2.9-fold, respectively) and PB (2.8 and 3.8-fold, respectively) when compared with PLA. Plasma leucine levels were correlated with activation of mTOR (r = 0.60, p < 0.05) and p70S6K (r = 0.77; p < 0.05) at 30 min. There were no differences for plasma amino acids levels and the mTOR signaling pathway at 450 min. Conclusions: MCa and PB supplementations resulted in a similar anabolic milieu in rat skeletal muscle by inducing a transient increase in BCAA plasma levels and activation of the mTOR/p70S6K axis. / Mestre
|
22 |
Utility of Cationic and Anionic Chiral Surfactants in Capillary Electrophoresis (CE) and CE Coupled to Mass Spectrometry (CE-MS)Wang, Bin 27 January 2009 (has links)
The research presented in this thesis involves the application of chiral cationic and anionic surfactants for simultaneous enantioseparation of structurally similar compounds in capillary electrophoresis (CE) and CE coupled to mass spectrometry (CE-MS). The first chapter briefly introduces the fundamentals of CE and CE-MS, emphasizing the micellar electrokinetic chromatography (MEKC) and MEKC-MS techniques, as well as ionic liquids (ILs) and affinity CE (ACE). In chapter 2, a mixture of five racemic profen (PROF) drugs are simultaneously separated with the combined use of 2,3,6-tri-O-methyl-β-cyclodextrin (TM-β-CD) and IL-type surfactant, N-undecenoxycarbonyl-L-leucinol bromide (L-UCLB). Enantioseparations of these PROFs are optimized using a standard recipe containing 35.00 mM TM-β-CD, 5.00 mM sodium acetate at pH 5.0, and varying the concentration as well as chain length of the IL surfactants. The batch-to-batch reproducibility of L-UCLB is found to be acceptable in terms of enantiomeric resolution, and migration time. A competitive inhibition mechanism is proposed to investigate the ternary interactions among TM-β-CD, ILs, and PROFs. The apparent binding constant of TM-β-CD to L-UCLB is estimated by nonlinear and linear plotting methods. The binding constants of one representative PROF (e.g., fenoprofen) to TM-β-CD and to L-UCLB are estimated by a secondary plotting approach. The R- and S-fenoprofen having different binding constant values, resulting in the enantioseparation due to the synergistic effect of TM-β-CD and L-UCLB. The R- and S-configurations of barbiturates display differences in potency and biological activity. In Chapter 3, a multivariate MEKC-ESI-MS approach for the simultaneous analysis of the racemic mixture of three barbiturates is presented. The chiral selector employed is the polymeric surfactant polysodium N-undecenoxycarbonyl-L-isoleucinate. The central composite design is used to optimize the chiral resolution, decrease the total analysis time, and improve the ESI-MS signal-to-noise ratio for these barbiturates. In preliminary experiments, the ranges of the factors investigated in the multivariate approaches are determined. Then the multivariate optimizations are conducted to determine the best overall chiral resolution with shortest possible run times for barbiturates. The limit of detection of ESI-MS is several folds higher compared to the UV detection. The predicted optimum results are in good agreement with the experimental data.
|
23 |
Chiral Analysis Using Capillary Electrophoresis Coupled to Mass Spectrometry: Development of Novel Modes and Applications Using Molecular Micelles and Surfactant-Bound Monolithic ColumnsHe, Jun 13 December 2011 (has links)
Micellar electrokinetic chromatography (MEKC) and capillary electrochromatography (CEC) are two of the major capillary electrophoresis (CE) modes that have been interfaced to mass spectrometry (MS) for sensitive and selective analysis of chiral compounds. This research combines these two modes and expands their applications in chiral CE analysis. Chapter 1 is a review of amino acid based molecular micelles used in MEKC-MS for enantioselective analysis over the past five years. In this chapter, a typical MEKC-MS experiment setup as well as detailed standard operating procedure in synthesis of molecular micelles and running a typical MEKC-MS experiment using the molecular micelles is discussed. Chapter 2 described a multivariate MEKC-MS optimization for the simultaneous analysis of two negatively charged model chiral compounds in negative ion mode with molecular micelles. In this chapter, a central composite design (CCD) is used to first construct a series of experiments to optimize all the important MEKC-MS parameters. Next, response surface methodology (RSM) was used to analyze the interactions between the factors, picking up the best separation and detection conditions, predicting the result of the chiral separation/MS detection, and finally running the actual experiment and comparing the chromatographic results with the predicted parameters. Chapter 3 demonstrates a similar multivariate MEKC-MS optimization for analysis of a positively charged model chiral compound in a positive ion mode. The same CCD and RSM methods were used to optimize the separations and MS sensitivity. Chapter 4 describes a chiral analysis of four neutral benzoin derivatives (hydrobenzoin, benzoin, benzoin methyl ether, and benzoin ethyl ether) using MEKC coupled to atmospheric pressure photo-ionization mass spectrometry (APPI-MS). The same multivariate experimental design strategy was used to optimize the MEKC as well as APPI-MS parameters. Simultaneous chiral separation of all four benzoin derivatives was achieved with high detection sensitivity compared to UV-detection. Chapter 5 introduces a novel one-pot synthesis scheme for an acryloyl-terminated, carbamate-linked surfactant-bound monolith with leucine head group and different chain lengths. The method promises to open up the discovery of new amino acid based polymeric monoliths for chiral separations and enhanced chemoselectivity for simultaneous chiral separations and enhanced detection in CEC and CEC-MS. In Chapter 6, five amide-linked surfactant-bound monoliths with different chain lengths and head groups (leucine, valine, and phenylalanine) were synthesized and characterized. Enantioseparation of several test compounds was achieved by CEC using the monolithic columns. One of the chiral surfactant, sodium 11-acrylamidoundecanoyl-L-leucinate (SAAUL), was polymerized in aqueous solution under 60Co radiation to form molecular micelle poly-SAAUL. MEKC experiments were carried out with the poly-SAAUL molecular micelle to separate ten cationic chiral compounds. The result was compared with the CEC separation using the AAUL monolithic column. This study is the first comparison of chiral CEC and MEKC with the same surfactant monomer, which has the capability of forming both chiral stationary phase for CEC and chiral pseudophase for MEKC.
|
24 |
Studies of micellar electrokinetic chromatography as an analytical technique in pharmaceutical analysis : an industrial perspective /Stubberud, Karin, January 2002 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 5 uppsatser.
|
25 |
Propriedades analíticas de materiais a base de sílica e óxido de titânio modificados /Pipi, Angelo Ricardo Fávaro. January 2010 (has links)
Orientador: Devaney Ribeiro do Carmo / Banca: Newton Luiz Dias Filho / Banca: Marcelo Firmino de Oliveira / Resumo: O presente trabalho apresenta a preparação e caracterização de uma sílica micelar template modificada com Ti(IV), e posterior reação em H3PO4. O produto formado, chamado de SMT-2, foi caracterizado por espectroscopia na região do infravermelho (FTIR), difração de Raios X (DRX), análise de área superficial e porosidade. Este material não adsorveu metais e sim compostos fenotiazínicos. Uma caracterização dos compostos fenotiazínicos nas cavidades da SMT-2 foi realizada empregando técnicas de FTIR, termogravimetria e voltametrica cíclica. O voltamograma cíclico do eletrodo de pasta de grafite modificado apresentou dois pares redox com potencial padrão (E0'), onde E0' = (Epa+Epc)/2, 0,09 V para o pico I e 0,42 V para o pico II (v=50 mV s-1; solução tampão Britton-robinson; pH 2) versus Ag/AgCl que foi atribuído ao monômero e dímero do azul de orto toluidina nas cavidades da SMT-2, estes resultados foram análogos ao azul de metileno e azure A. Em uma segunda etapa, preparou-se óxido de titânio seguindo uma nova metodologia de síntese. Por analogia a SMT-2, o material preparado foi modificado com H3PO4, que foi descrito como TiP, e contrariamente ao SMT-2, o material apresentou capacidade de adsorver íons metálicos (Co2+, Cu2+, Ni2+). Após a caracterização do TiP pelas técnicas supracitadas, efetuaram-se os estudos de adsorção de íons de Co2+, Cu2+ e Ni2+ em meio aquoso, etanol/água (42%) e etanol (99%) onde se determinou para estes metais os respectivos tempos de equilíbrio de sorção. Após a determinação do tempo de equilíbrio para a adsorção dos íons metálicos em cada sistema, determinou-se a capacidade específica de sorção (NfMax) através de isotermas de sorção. Para o Co2+, os valores de Nf foram: em meio aquoso (4,95 x 10-4 mol g-1), etanol/água 42% (6,09 x 10-4 mol g-1) e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work presents the preparation of a micellar template silica modified with Ti (IV), and subsequent reaction with H3PO4. The product formed, called SMT-2, was characterized by spectroscopy in infrared region (FTIR), X-ray diffraction (XRD), surface area analysis and porosity. This material did not adsorbed metals but adsorbed phenothiazine compounds. A characterization of phenothiazine compounds in the wells of SMT-2 was performed using techniques of FTIR, thermogravimetric analysis and cyclic voltammetry. The cyclic voltammogram of modified graphite paste electrode showed two redox couples with standard potential (E0'), where E0' = (Epa + Epc) / 2, 0.09 to peak I and 0.42 to peak II ( v = 50 mV s-1 BR solution, pH 2) vs. Ag / AgCl which was assigned to the monomer and dimer of ortho toluidine blue into the wells of SMT-2, these results were similar to methylene blue and azure A. In a second step, prepared titanium oxide following a new methodology for synthesis. By analogy of SMT-2, the prepared material was modified with H3PO4, which was abbreviated as TiP, contrary to the SMT-2, the material shows the ability to adsorb metal ions (Co2+, Cu2+, Ni2+). After characterizing the TiP by the techniques described above, were conducted studies of ion adsorption of Co2+, Cu2+ and Ni2+ in water, ethanol/water (42%) and ethanol (99%) which was determined for these metals their equilibrium times sorption. After determining the equilibrium time for adsorption of metal ions in each system, we determined the specific sorption capacity (NfMax) through sorption isotherms. For the Co2+, the values of Nf were in water (4.95 x 10-4 mol g-1), ethanol/water 42% (6.09 x 10-4 mol g-1) and ethanol 99% (3.00 x 10-4 mol g-1), with concentrations of Co2 + ions ranging from 9.03 to 18.63 x 10-4 mol L-1. As for the Cu2 + these values were: in water... (Summary complete electronic access click below) / Mestre
|
26 |
Propriedades analíticas de materiais a base de sílica e óxido de titânio modificadosPipi, Angelo Ricardo Fávaro [UNESP] 08 April 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:25:32Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-04-08Bitstream added on 2014-06-13T19:53:24Z : No. of bitstreams: 1
pipi_arf_me_ilha.pdf: 5601014 bytes, checksum: e6e8165f62f904c9ebc3d807bad047c8 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho apresenta a preparação e caracterização de uma sílica micelar template modificada com Ti(IV), e posterior reação em H3PO4. O produto formado, chamado de SMT-2, foi caracterizado por espectroscopia na região do infravermelho (FTIR), difração de Raios X (DRX), análise de área superficial e porosidade. Este material não adsorveu metais e sim compostos fenotiazínicos. Uma caracterização dos compostos fenotiazínicos nas cavidades da SMT-2 foi realizada empregando técnicas de FTIR, termogravimetria e voltametrica cíclica. O voltamograma cíclico do eletrodo de pasta de grafite modificado apresentou dois pares redox com potencial padrão (E0’), onde E0’ = (Epa+Epc)/2, 0,09 V para o pico I e 0,42 V para o pico II (v=50 mV s-1; solução tampão Britton-robinson; pH 2) versus Ag/AgCl que foi atribuído ao monômero e dímero do azul de orto toluidina nas cavidades da SMT-2, estes resultados foram análogos ao azul de metileno e azure A. Em uma segunda etapa, preparou-se óxido de titânio seguindo uma nova metodologia de síntese. Por analogia a SMT-2, o material preparado foi modificado com H3PO4, que foi descrito como TiP, e contrariamente ao SMT-2, o material apresentou capacidade de adsorver íons metálicos (Co2+, Cu2+, Ni2+). Após a caracterização do TiP pelas técnicas supracitadas, efetuaram-se os estudos de adsorção de íons de Co2+, Cu2+ e Ni2+ em meio aquoso, etanol/água (42%) e etanol (99%) onde se determinou para estes metais os respectivos tempos de equilíbrio de sorção. Após a determinação do tempo de equilíbrio para a adsorção dos íons metálicos em cada sistema, determinou-se a capacidade específica de sorção (NfMax) através de isotermas de sorção. Para o Co2+, os valores de Nf foram: em meio aquoso (4,95 x 10-4 mol g-1), etanol/água 42% (6,09 x 10-4 mol g-1) e... / This work presents the preparation of a micellar template silica modified with Ti (IV), and subsequent reaction with H3PO4. The product formed, called SMT-2, was characterized by spectroscopy in infrared region (FTIR), X-ray diffraction (XRD), surface area analysis and porosity. This material did not adsorbed metals but adsorbed phenothiazine compounds. A characterization of phenothiazine compounds in the wells of SMT-2 was performed using techniques of FTIR, thermogravimetric analysis and cyclic voltammetry. The cyclic voltammogram of modified graphite paste electrode showed two redox couples with standard potential (E0'), where E0' = (Epa + Epc) / 2, 0.09 to peak I and 0.42 to peak II ( v = 50 mV s-1 BR solution, pH 2) vs. Ag / AgCl which was assigned to the monomer and dimer of ortho toluidine blue into the wells of SMT-2, these results were similar to methylene blue and azure A. In a second step, prepared titanium oxide following a new methodology for synthesis. By analogy of SMT-2, the prepared material was modified with H3PO4, which was abbreviated as TiP, contrary to the SMT-2, the material shows the ability to adsorb metal ions (Co2+, Cu2+, Ni2+). After characterizing the TiP by the techniques described above, were conducted studies of ion adsorption of Co2+, Cu2+ and Ni2+ in water, ethanol/water (42%) and ethanol (99%) which was determined for these metals their equilibrium times sorption. After determining the equilibrium time for adsorption of metal ions in each system, we determined the specific sorption capacity (NfMax) through sorption isotherms. For the Co2+, the values of Nf were in water (4.95 x 10-4 mol g-1), ethanol/water 42% (6.09 x 10-4 mol g-1) and ethanol 99% (3.00 x 10-4 mol g-1), with concentrations of Co2 + ions ranging from 9.03 to 18.63 x 10-4 mol L-1. As for the Cu2 + these values were: in water... (Summary complete electronic access click below)
|
27 |
\"Estudo dos extratos dos frutos de Sapindus saponaria enriquecidos em saponinas e outros glicosídeos e sua aplicação em eletroforese capilar\" / \"Study of Sapindus saponaria fruit?s extracts rich on saponins and other glycosides and their application in capillary electrophoresis\"Sheila Barreto Guterres 20 January 2006 (has links)
Os frutos de S. saponaria, espécie bastante abundante em São Carlos e outras regiões do Brasil são ricos em glicosídeos anfifílicos, ou seja, compostos por uma parte polar e outra apolar. Devido a esta peculiaridade tendem a formar espuma mostrando propriedades químicas semelhantes às dos tensoativos. Alguns destes glicosídeos pertencem à classe das saponinas e são constituídos por uma aglicona de estrutura carbônica a qual está ligada a uma ou duas cadeias de açúcar. O interesse pelas propriedades tensoativas deste glicosídeos motivou o estudo destas substâncias para uso em eletroforese capilar. Os frutos foram extraídos com metanol e fracionados em coluna cromatográfica preparativa utilizando sephadex LH-20 como fase estacionária. Após a eluição, as frações foram analisadas por espectrometria de massas e estudadas por eletroforese capilar. A eletroforese capilar de zona mostrou-se uma técnica viável para o estudo das frações obtidas. Embora um grau de pureza elevado não tenha sido alcançado, a fração B foi utilizada como aditivo para tampão em cromatografia eletrocinética micelar (MEKC) e uma interação diferenciada foi observada do nitrobenzeno com o tampão aditivado em relação ao tampão com SDS puro. / Sapindus saponaria is a very abundant species in São Carlos and others regions of Brazil. Fruits of S. saponaria have a high content of glycosides which possess well-defined regions of hydrophobic and hydrophilic feature denominated amphiphilic molecule. Thus, this can form a foam showing chemical proprieties equals to surfactants. Some glycosides belong to class of saponins and are composed of carbonic structure designates aglycone, which is linked in one or two sugar chains. The purpose of the present study was the use of glycosides due to their surfactants properties in further applications of capillary electrophoresis. The extraction of crude fruits was carried out with methanol and this extract was fractionated in Sephadex LH-20. The fractions were analyzed for mass spectrometry and studied in capillary electrophoresis (CE). This is a feasible technique for the study of fractions obtained. Although a high degree of purity was not reached, the fraction B were used as additive for the electrolyte background in MEKC. The nitrobenzene showed different interaction with micellar system in the electrolyte background with fraction B.
|
28 |
Změny obsahu vybraných fenolických látek při zpracování léčivých rostlin / The content changes of selected phenolic compounds during processing of medicinal plantsGROŠAFTOVÁ, Blanka January 2007 (has links)
This work was aimed to the problem of change of the content of selected phenolic substances during treatment and storage of medical plants. Flavonoids represent small, but very important group of phenolic compounds. The biggest attention was paid to quercetin and rutine.Content of phenolic substances was determined by method of micellar electrokinetic capillary chromatography (MECC) in case of 6 medicinal plants usually used in traditional and modern medicine.
|
29 |
Métodos eletroforéticos e cromatográficos aplicados para a determinação simultânea de fármacos hipolipidêmicos em medicamentos / Electrophoretic and chromatographic methods apllied for the simultaneous determination of hypolipidemic drugs in medicines.Antonio Marcos Callejo de Souza 15 April 2015 (has links)
A ezetimiba e a sinvastatina são fármacos hipolipidêmicos. A ezetimiba pertence à nova classe das 2 - azetidinona, inibidores e bloqueadores do colesterol intestinal. A sinvastatina pertence à classe dos inibidores competitivos da hidroxi-3-metilglutarilcoenzima A redutase (HMG-CoA), que é a última etapa regulada na síntese do colesterol. O objetivo do trabalho foi desenvolver e validar métodos por cromatografia liquida de alta eficiência (HPLC) e eletroforese capilar (CE), rápidos, seletivos e confiáveis para determinação dos hipolipidêmicos em formulações farmacêuticas. A separação cromatográfica foi realizada usando coluna Nano separation technologies (NST) Cianopropril (CN) (150 mmx 4,6 mm, com partícula 3,5 µm), e eluição isocrático usando água purificada: acetonitrila (48:52, v/v); vazão 0,8 mL/min e volume de injeção de 20 µL. A temperatura da coluna foi de 35 ºC e a detecção foi realizada com detector na região do UV em 238 nm. O método por cromatografia eletrocinética micelar (MEKC) foi desenvolvido utilizando capilar de sílica fundida 30 cm (comprimento efetivo) x 50 µm d.i. e eletrólito constituído de tetraborato de sódio (TBS) 20 mmol L-1: dodecil sulfato de sódio (SDS) 30 mmol L-1, pH 9,0 ajustado com 10% ácido fosfórico: acetonitrila 12% v/v. O tempo de injeção foi de 3 segundos com pressão hidrodinâmica de 20 mbar, voltagem aplicada de 30 kV e detecção no UV em 238 nm. Os métodos analíticos foram validados de acordo com os requerimentos vigentes da ANVISA, ICH e Farmacopéia Americana. Portanto, os métodos propostos demonstraram ser lineares, precisos, exatos e adequados para quantificação simultânea da ezetimiba e sinvastatina em formas farmacêuticas sólidas. / Ezetimibe and simvastatin are hipolipidemic drugs. Ezetimibe belongs to a new class of 2 - azetidione, inhibitors and blockers of intestinal chrolesterol. Simvastatin belongs a class of competitive inhibitors of 3-hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, which is the last regulated step in the cholesterol synthesis. The aim of this project was to develop and validate fast, selective and reliable chromatographic and electrophoretic methods, to determine hypolipidemic drugs in pharmaceutical formulations. The chromatographic separation was carried out on a Nano separation technologies (NST) Cyanpropyl (CN) (150 mm x 4,6 mm, 3,5 µm), isocratic elution using purified water: acetonitrila (48:52 v/v), the flow rate was 0,8 mL/min and the injection volume was 20 µL. The column temperature was kept at 35 ºC and detection wavelength was set at 238 mn. The micellar electrokinetic chromatographic method was developed using a fused silica capillary column 30 cm (effective length) x 50 µm i.d, the electrolyte was constituted of 20 mmol L-1 tetraborate buffer solution: 30 mmol L-1 sodium dodecyl sulphate (SDS), pH 9.0 adjusted with 10% phosphoric acid: 12 % v/v acetonitrile. The injection time was 3 s at 20 mbar, the applied voltage was 30 kV and detection was set at 238 nm. The both methods were developed and validated according to ANVISA, ICH and US Pharmacopeia guidelines. Therefore, the proposed methods proved to be linear, precise, accurate and suitable for simultaneous quantitation of ezetimibe and simvastatin in solid pharmaceutical formulations.
|
30 |
Solubilization Of Oils Into Micellar Solutions : A CFD StudyBhaumik, Soubhik Kumar 10 1900 (has links) (PDF)
No description available.
|
Page generated in 0.0967 seconds