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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Entwicklung und Anwendung von flüssigchromatographischen Analyseverfahren zum Nachweis von Diarrhetic Shellfish Poisoning (DSP)-Toxinen

Rühl, Alexander. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2004--Jena.
72

Miniaturisierte direktgekoppelte Analysensysteme zur Strukturaufklärung von Carotinoiden und Bestimmung der Bioverfügbarkeit von markiertem Lutein

Putzbach, Karsten. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2004--Tübingen.
73

Perturbateurs endocriniens dans le milieu aquatique : développement analytique et faisabilité de traitement / Endocrine disruptors in the aquatic environment : analytical development and treatment feasibility

Ben Sghaier, Rafika 27 November 2017 (has links)
La présence des perturbateurs endocriniens dans le milieu aquatique a suscité des préoccupations croissantes en raison de leurs effets néfastes potentiels sur les écosystèmes et les humains. Celles-ci sont généralement présents à l’état de trace (ng/L), dans des matrices aqueuses complexes, telles que les eaux de surfaces ce qui rend l’analyse difficile. Dans ce travail, on a mis au point une méthode analytique pour la détermination simultanée de 13 substances perturbatrices endocriniennes (PEs) dans l’eau, dont 5 estrogènes stéroïdes, 1 progestérone, 1 androgène et 6 composées phénoliques, , par la chromatographie gazeuse couplée à la spectrométrie de masse (GC-MS). La méthode a été validée. Les limites de quantification étaient respectivement de 1 ng/L et de 5 à 50 ng/L pour les composés phénoliques et les hormones. La méthode mise au point a été appliquée pour évaluer le niveau de contamination des PEs ciblées dans de nombreux sites du Nord de la France et de la Tunisie. La majorité des composés considérés ont été détectés dans les sites d'échantillonnage. La dernière partie de ce travail est consacrée à l'étude de faisabilité d'élimination du PEs par des techniques d'adsorption sur les résidus d’une brique modifiée et la bio-rémédiation par l’algue bleu-vert (Spiruline). / The occurrence of endocrine-disrupting compounds in the aquatic environment has brought increasing concern due to their potential adverse impacts on ecosystems and humans. These compounds are generally present in complex water matrices, such as surface waters at trace levels (ng/L) making their analysis difficult. In this work, an analytical method for the simultaneous determination of 13 endocrine disrupting chemicals (EDCs), including 5 steroid estrogens, 1 progestogen, 1 androgen and 6 endocrine-disrupting phenols in water was developed using solid phase extraction (SPE), derivatization and gas chromatography-mass spectrometry (GC-MS).The method was validated by spiking the 13 EDCs to the interest matrix. The limits of quantification were 1 ng/L and 5-50 ng/L for phenolic compounds and hormones respectively. The validated method was applied to assess the contamination level of the targeted EDCs in many sites in Northern France and in Tunisia. The majority of the considered compounds were detected in the different sampling sites. The last part of this work is the feasibility study for the elimination of PE by adsorption techniques on modified brick residues and bio-remediation by blue-green algae (SPIRULINA).
74

Sledování obsahu trichothecenových mykotoxinů ve vzorcích environmentálního původu

Zvonek, Radek January 2009 (has links)
No description available.
75

Těkavé sloučeniny v meruňkovém nektaru z různě zralé suroviny

Fibikarová, Radka January 2013 (has links)
No description available.
76

Lipocortins in the central nervous system in multiple sclerosis and experimental allergic encephalomyelitis

Elderfield, Amber-Jayne January 1994 (has links)
No description available.
77

OtimizaÃÃo e ValidaÃÃo de MÃtodos Empregando LC-ESI-MS/MS e Quechers para DeterminaÃÃo de ResÃduos de AgrotÃxicos em Cajà / Optimization and Validation of Methods Employing LC-ESI-MS/MS and QuEChERS for Determination of pesticides Residues in Cashew

Renata de Oliveira Silva 17 December 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O cajueiro (Anarcadium occidentale) à uma planta tÃpica da regiÃo do nordeste que responde por mais de 95% da produÃÃo nacional, sendo os estados do CearÃ, PiauÃ, Rio Grande do Norte e Bahia os principais produtores. Com o incremento de Ãreas plantadas com o cajueiro anÃo precoce, verificou-se que esta cultura era susceptÃvel ao ataque de pragas, causando prejuÃzos no desenvolvimento, produÃÃo e qualidade do fruto. Para evitar esses prejuÃzos, estudos foram realizados no sentido de controlar as pragas atravÃs do uso de agrotÃxicos. Estes compostos representam uma classe de compostos quÃmicos orgÃnicos que sÃo usados para aumentar a produtividade, no armazenamento e beneficiamento de produtos agrÃcolas. Os agrotÃxicos mesmo favorecendo a produÃÃo e conservaÃÃo de alimentos, sÃo nocivos ao homem e ao meio ambiente, e a determinaÃÃo e detecÃÃo de seus resÃduos tÃm exigido rigorosos mÃtodos de anÃlises. O avanÃo de tecnologias analÃticas sensÃveis e seletivas tem permitido a detecÃÃo destas substÃncias em nÃveis traÃos. Este trabalho descreve uma metodologia analÃtica empregando o mÃtodo de extraÃÃo QuEChERS (Quick, Easy, Cheap, Effective, Robustand Safe) e Cromatografia LÃquida acoplada à Espectrometria de Massas em sÃrie, utilizando fonte de ionizaÃÃo por eletrospray. Esta metodologia foi desenvolvida e validada para determinaÃÃo de 20 agrotÃxicos multiclasses em amostras de caju. Avaliou-se a seletividade, faixa de linearidade (6 nÃveis de concentraÃÃo), limites de detecÃÃo (LD) e quantificaÃÃo (LQ), efeito matriz, bem como a precisÃo e exatidÃo, em termos de percentual de recuperaÃÃo. Para isso, efetuou-se fortificaÃÃo dos 20 agrotÃxicos em 3 nÃveis de contraÃÃo em 10 g de caju recÃm processado. Todos agrotÃxicos estudados apresentaram boa linearidade com coeficiente de correlaÃÃo maior que 0,99. Devido à complexidade da amostra foi efetuado o estudo do efeito matriz, onde foi necessÃrio fazer a calibraÃÃo externa com superposiÃÃo na matriz. Os limites de detecÃÃo variaram entre 0,1 e 0,25Âg.L-1 e os limite de quantificaÃÃo entre 0,3 e 0,75Âg.L-1. A validaÃÃo da metodologia mostrou bons resultados de recuperaÃÃes, com taxas dentro dos limites aceitÃveis de 50% a 120%, e com RSD > 20%, estando de acordo com a faixa recomendada pela norma brasileira ABNT-NBR 14029/2005. AtravÃs do monitoramento de mÃltiplas reaÃÃes (MRM), duas transiÃÃes diferentes (Ãon precursor â Ãon produto) foram selecionadas para cada composto, uma para quantificaÃÃo e outra para confirmaÃÃo, o que aumentou a seletividade. O mÃtodo foi aplicado em amostras coletadas no comÃrcio de Fortaleza-CE e nÃo apresentaram contaminaÃÃo pelos agrotÃxicos em estudo / The cashew tree is a plant typical of the region which accounts for over 95% of national production, and the states of CearÃ, PiauÃ, Rio Grande do Norte and Bahia major producers. With the increase in areas planted with war of cashew, this culture was sensitive to pests, causing damage in the development, production and fruit quality. To avoid these losses, studies were made to control pests through the use of pesticides. These compounds represent a class of chemical compounds that are used to increase productivity, storage and processing f agricultural products. Pesticides despite favoring the production and preservation of food are harmful to humans and the environment, and the determination and detection of its residues have required rigorous analysis methods. The advancement of analytical technologies has allowed sensitive and selective detection of these substances in trace levels. This paper describes an analytical methodology employing the extraction method QuEChERS (Quick, Easy, Cheap, Effective, Robust and Safe) and Liquid Chromatography coupled to Mass Spectrometry in series, using electrospray ionization source was developed and validated for the determination of twenty multiclass pesticides in samples of cashew apple. It was evaluated the selectivity, linearity range (six concentration levels), limits of detection (LOD) and quantification (LOQ), matrix effect, as well as the precision and accuracy in terms of percentage of recovery. For this, we performed fortification of 20 pesticides in three contraction levels in 10g cashew newly processed. All pesticides studied showed good linearity with correlation coefficient greater than 0,99. Because of the complexity of the sample was performed to study the effect matrix where it was necessary to overlap with the external calibration matrix. Detection limits ranged from 0,1 to 0,25Âg.L-1 and the limit of quantification of 0,3 to 0,75Âg.L-1. The validation of the methodology showed good results of recoveries with rates within acceptable limits of 50% to 120%, and% RSD>20% which is consistent with that recommended by the Brazilian standard ABNT-NBR 14029/2005. By monitoring multiple reactions (MRM) two different transitions (precursor ion -product ion) were selected for each compound, one for quantitation and confirmation which increased the selectivity. The method was applied to samples collected in trade in Fortaleza-CE and not contaminated by pesticides under study
78

Sintese e reatividade de complexos de iridio(I) / Synthesis and reactivity of complexes of iridium(I)

Paula, Vanderlei Inacio de 05 August 2018 (has links)
Orientadores: Regina Buffon, Regina Mara Silva Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T04:42:43Z (GMT). No. of bitstreams: 1 Paula_VanderleiInaciode_M.pdf: 3879101 bytes, checksum: f5ec10f585405c9d2de0c5df2a99eb1b (MD5) Previous issue date: 2004 / Mestrado / Quimica Inorganica / Mestre em Química
79

Avaliação pré-clínica do perfil farmacocinético do protótipo antitumoral lLQFM030 em ratos por LC-MS/MS / Pre-clinical evaluation of pharmacokinetic profile of antitumoral LQFM030 prototype in rats by LC-MS/MS

Zoghaib, Iury Valentim Jorge 18 October 2013 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-29T14:34:23Z No. of bitstreams: 2 Dissertação - Iury Valentim Jorge Zoghaib - 2013.pdf: 1607539 bytes, checksum: d92b3313edee2773935cb667be5b908d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-30T10:48:45Z (GMT) No. of bitstreams: 2 Dissertação - Iury Valentim Jorge Zoghaib - 2013.pdf: 1607539 bytes, checksum: d92b3313edee2773935cb667be5b908d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-30T10:48:45Z (GMT). No. of bitstreams: 2 Dissertação - Iury Valentim Jorge Zoghaib - 2013.pdf: 1607539 bytes, checksum: d92b3313edee2773935cb667be5b908d (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-10-18 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The LQFM030 was obtained by molecular simplification of nutlins (inhibitors of p53-MDM2 interaction) and, having demonstrated excellent antineoplastic activity in vitro (cytotoxicity against K-562 cell line with IC50 = 23 M) and in vivo against Ehrlich ascitic tumor with increased survival in treated animals developed the pharmacokinetic study of p.o. in rats. It was used for LC-MS/MS analytical method (Applied Biosystems MDS Sciex API 3200) previously validated together. O LQFM030 was administered to 3 rats (mean weight 186g) in predetermined dose of 100 mg/kg by gavage. After administration, samples were collected from 1.0 mL of blood by cannulation of the left jugular vein with heparinized syringe, the intervals 0-8 h. The blood samples were identified and centrifuged to obtain plasma which was frozen at -20°C until analysis. The kinetic parameters were calculated in the software WinNonlin 5.0 (Pharsight™). Results (mean ± SD) half-life (t1/2) 3.61 ± 0.68 h, total clearance (CLT) 36.49 ± 2.23 mL/min/kg, volume of distribution (Vd) 11,40 ± 1.58 L/kg. The LQFM030 had low value of t1/2, Vd high and high value of CLT. These values allow us to understand that the prototype study demonstrated a good safety profile of tissue distribution and/or has been extensively eliminated. When compared with the kinetic parameters obtained in other studies, it was observed difference in results is justified by the high interspecies variability, mainly in basal metabolic rate and body weight, once the route of administration, orally and intraperitoneally, are kinetically similar. / O LQFM030 foi obtido por simplificação molecular dos nutlins (inibidores da interação MDM2-p53) e, tendo demonstrado excelente atividade antineoplásica in vitro (citotoxicidade contra a linhagem celular K-562 com IC50 = 23 M) e in vivo contra tumor ascítico de Ehrlich, com aumento de sobrevida em animais tratados, desenvolveu-se o estudo do perfil farmacocinético, p.o., em ratos. Empregou-se método analítico em LC-MS/MS (Applied Biosystems MDS Sciex API 3200) previamente validado em colaboração. O LQFM030 foi administrado a 3 ratos (peso médio de 186g), em dose preestabelecida de 100 mg/kg, por gavagem. Após a administração, foram coletadas amostras de 1,0 mL de sangue, por canulação da veia jugular esquerda, com seringa heparinizada, nos intervalos de tempo de 0 a 8 h. As amostras sanguíneas foram identificadas e centrifugadas para obtenção do plasma, que foi congelado a -20ºC até o momento da análise. Os parâmetros cinéticos foram calculados no software Winnonlin 5.0 (Pharsight™). Resultados (média ± DP): meia-vida (t1/2) 3,61 ± 0,68 h; clearance total (CLT) 36,49 ± 2,23 mL/min/kg; volume de distribuição (Vd) 11,40 ± 1,58 L/kg. O LQFM030 apresentou baixo valor de t1/2, elevado Vd e elevado valor de CLT. Estes valores permitem entender que o protótipo estudado demonstrou um bom perfil de distribuição tecidual e/ou foi extensivamente eliminado. Quando comparados com parâmetros cinéticos obtidos em outros estudos, observou-se diferença nos resultados, justificada pela elevada variabilidade interespécies, principalmente na taxa de metabolismo basal e peso corporal, uma vez que as vias de administração, oral e intraperitoneal, são cineticamente semelhantes.
80

Nimodipine determination in human plasma by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS-MS). / DeterminaÃÃo de nimodipino em plasma humano atravÃs de cromatografia lÃquida de alta eficiÃncia acoplada à espectrometria de massa (LC-MS-MS)

DemÃtrius Fernandes do Nascimento 19 January 2005 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A rapid, specific and highly sensitive liquid chromatography-tandem mass spectrometry method was developed to determine nimodipine in human plasma using dibucaine as the internal standard (IS) is described. The analyte (m/z 418,6 > 342,6) and IS (m/z 344,2 > 271,0) were extracted from plasma samples by liquid-liquid extraction using hexane-ethyl acetate (1:1v/v). Chromatography was performed on a Varian Polaris C18 analytical column (3 micrometer, 50 x 2,0 mm) and pre-column SecurityguardTM C18 (4,0 x 3,0 mm). The phase mobile consisted of Acetonitrile-Ammonium acetate 0.02 ml/L (80:20v/v). The method had a chromatographic run time of 4.5 min and linear calibration curve over the range 0.1- 40 ng/mL (r2 > 0.9938). The limit of quantification (LQ) was 0.1 ng/mL. The intra-day precision for the limit quantification was 0.00% (batch 01), 5.71% (batch 02) and 5.27% (batch 03); for the quality controls low (QCL), middle (QCM) and high (QCH) the results were respectively 8.57, 0.81 and 1.37%. The inter-day precision for LQ and QCL, QCM and QCH were respectively: 7% and 5.46, 4.12 and 3.37%. The intra-day accuracy for LQ was 110, 96 and 104%; for QCL, QCM and QCH the results were100.67, 109.09 and 109.72% respectively. The results of the inter-day accuracy for LQ, QCL, QCM and QCH were respectively and 110.0, 96.0, 104.0% for the limit of quantification and 8.57, 0.81, 1.37% and 100.67, 109.09, 109.72% respectively: 103% e 102.89, 106.60, 109.69%. This validated method was successfully applied for the pharmacokinetic profiles of nimodipine tablets administered to 24 healthy volunteerâs participant of bioavailability comparative study. Geometric mean of Test formulation/Refernce formulation individual percent ratio was 104,56% for AUC0-48h and 55,73% for Cmax. The 90% for the confidence intervals (CI) were 94,80-115,32% e 44,73-69,42%, respectively. The values of half-life and Cmax for test formulation and reference formulation were 27,83;32,78h and 9,48;18,76ng/mL, respectively. The values of Tmax were 2,34;0,98h for the formulations test and reference respectively. Since the 90% CI for Cmax and AUC0-48h, were within the 80-125% interval proposed by the âFood and Drug Administrationâ and ANVISA, it was concluded that the two formulations of nimodipine 30mg tablets were not bioequivalent, according to the rate of absorption after single dose administration. / Um mÃtodo rÃpido, sensÃvel e especÃfico de Cromatografia LÃquida de Alta EficiÃncia acoplada à Espectrometria de Massa (LC-MS-MS) foi desenvolvido para determinar nimodipino (analito) em plasma humano usando dibucaÃna como padrÃo interno (PI). O analito (m/z 418,6 > 342,6) e o PI (m/z 344,2 > 271,0) foram extraÃdos de amostras de plasma atravÃs de extraÃÃo lÃquido-lÃquido utilizando hexano-acetato de etila (1:1v/v). As corridas cromatogrÃficas foram executadas utilizando-se uma coluna analÃtica Varian Polaris C18 (3 micrÃmetros, 50 x 2,0 mm) e uma prÃ-coluna SecurityguardTM C18 (4,0 x 3,0 mm). A fase mÃvel consistiu de acetonitrila-soluÃÃo de acetato de amÃnio 0,02 mol/L (80:20v/v). O mÃtodo teve um tempo total de corrida de 4,5 min e uma curva de calibraÃÃo linear que variou de 0,1-40 ng/mL. O limite de quantificaÃÃo de 0,1 ng/mL. A precisÃo intra-ensaio para o limite de quantificaÃÃo (LQ) foi 0,00% (lote 01), 5,71% (lote 02) e 5,27% (lote 03); para os controles de qualidade baixo (CQB), mÃdio (CQM) e alto (CQA) os resultados foram respectivamente: 8,57, 0,81 e 1,37%. A precisÃo interensaio para o LQ e os CQB, CQM e CQA foram respectivamente de: 7% e 5,46, 4,12 e 3,37%. A exatidÃo intra-ensaio para o LQ foi 110, 96 e 104%; para CQB, CQM e CQA os resultados foram 100,67, 109,09 e 109,72% respectivamente. Os resultados da exatidÃo interensaio para o LQ, CQB, CQM e CQA foram respectivamente de: 103% e 102,89, 106,6, 109,69%. Este mÃtodo foi aplicado para a avaliaÃÃo do perfil farmacocinÃtico do nimodipino administrado em 24 voluntÃrios sadios participantes de um estudo de biodisponibilidade comparativa. A mÃdia geomÃtrica da FormulaÃÃo teste/FormulaÃÃo referÃncia para as porcentagens individuais foi 104,56% para ASC0-48h e 55,73% para Cmax. Os intervalos obtidos a partir do intervalo de confianÃa (IC) de 90% foram 94,80-115,32% e 44,73-69,42% respectivamente. Os valores de meia-vida e Cmax para as formulaÃÃes teste e referÃncia foram de 27,83;32,78h e 9,48;18,76ng/mL, respectivamente. Os valores de Tmax foram de 2,34;0,98h para as formulaÃÃes teste e referÃncia, respectivamente. Considerando o IC de 90% para Cmax e ASC0-48h dentro da variaÃÃo de 80-125% proposto pelo Food and Drug Administration e ANVISA, as duas formulaÃÃes de nimodipino 30mg nÃo sÃo bioequivalentes quanto à taxa de absorÃÃo (Cmax) apÃs uma Ãnica administraÃÃo.

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